24,371 results on '"Physical Sciences"'
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2. Isotopic compositions of ground ice in near-surface permafrost in relation to vegetation and microtopography at the Taiga–Tundra boundary in the Indigirka River lowlands, northeastern Siberia.
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Takano, Shinya, Sugimoto, Atsuko, Tei, Shunsuke, Liang, Maochang, Shingubara, Ryo, Morozumi, Tomoki, and Maximov, Trofim C.
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TUNDRAS , *COMPOSITION of water , *ICE , *PERMAFROST , *ISOTOPIC fractionation , *WATERFRONTS , *FROST heaving , *SNOW cover - Abstract
The warming trend in the Arctic region is expected to cause drastic changes including permafrost degradation and vegetation shifts. We investigated the spatial distribution of ice content and stable isotopic compositions of water in near-surface permafrost down to a depth of 1 m in the Indigirka River lowlands of northeastern Siberia to examine how the permafrost conditions control vegetation and microtopography in the Taiga–Tundra boundary ecosystem. The gravimetric water content (GWC) in the frozen soil layer was significantly higher at microtopographically high elevations with growing larch trees (i.e., tree mounds) than at low elevations with wetland vegetation (i.e., wet areas). The observed ground ice (ice-rich layer) with a high GWC in the tree mounds suggests that the relatively elevated microtopography of the land surface, which was formed by frost heave, strongly affects the survival of larch trees. The isotopic composition of the ground ice indicated that equilibrium isotopic fractionation occurred during ice segregation at the tree mounds, which implies that the ice formed with sufficient time for the migration of unfrozen soil water to the freezing front. In contrast, the isotopic data for the wet areas indicated that rapid freezing occurred under relatively non-equilibrium conditions, implying that there was insufficient time for ice segregation to occur. The freezing rate of the tree mounds was slower than that of the wet areas due to the difference of such as soil moisture and snow cover depends on vegetation and microtopography. These results indicate that future changes in snow cover, soil moisture, and organic layer, which control underground thermal conductivity, will have significant impacts on the freezing environment of the ground ice at the Taiga–Tundra boundary in northeastern Siberia. Such changes in the freezing environment will then affect vegetation due to changes in the microtopography of the ground surface. [ABSTRACT FROM AUTHOR]
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- 2019
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3. 3D analysis of human islet amyloid polypeptide crystalline structures in Drosophila melanogaster.
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Xie, Ling, Gu, Xiaohong, Okamoto, Kenta, Westermark, Gunilla T., and Leifer, Klaus
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AMYLIN , *DROSOPHILA melanogaster , *CRYSTAL structure , *AMYLOID beta-protein , *VAN der Waals forces , *TRANSMISSION electron microscopy , *UNIT cell - Abstract
Expression of the Alzheimer's disease associated polypeptide Aβ42 and the human polypeptide hormon islet amyloid polypeptide (hIAPP) and the prohormone precursor (hproIAPP) in neurons of Drosophila melanogaster leads to the formation of protein aggregates in the fat body tissue surrounding the brain. We determined the structure of these membrane-encircled protein aggregates using transmission electron microscopy (TEM) and observed the dissolution of protein aggregates after starvation. Electron tomography (ET) as an extension of transmission electron microscopy revealed that these aggregates were comprised of granular subunits having a diameter of 20 nm aligned into highly ordered structures in all three dimensions. The three dimensional (3D) lattice of hIAPP granules were constructed of two unit cells, a body centered tetragonal (BCT) and a triclinic unit cell. A 5-fold twinned structure was observed consisting of the cyclic twinning of the BCT and triclinic unit cells. The interaction between the two nearest hIAPP granules in both unit cells is not only governed by the van der Waals forces and the dipole-dipole interaction but potentially also by filament-like structures that can connect the nearest neighbors. Hence, our 3D structural analysis provides novel insight into the aggregation process of hIAPP in the fat body tissue of Drosophila melanogaster. [ABSTRACT FROM AUTHOR]
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- 2019
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4. Mechanical effects of MitraClip on leaflet stress and myocardial strain in functional mitral regurgitation – A finite element modeling study.
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Zhang, Yue, Wang, Vicky Y., Morgan, Ashley E., Kim, Jiwon, Handschumacher, Mark D., Moskowitz, Chaya S., Levine, Robert A., Ge, Liang, Guccione, Julius M., Weinsaft, Jonathan W., and Ratcliffe, Mark B.
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MITRAL valve , *MITRAL valve insufficiency , *PAMPHLETS , *RADIAL stresses , *CORONARY disease , *PSYCHOLOGICAL stress - Abstract
Purpose: MitraClip is the sole percutaneous device approved for functional mitral regurgitation (MR; FMR) but MR recurs in over one third of patients. As device-induced mechanical effects are a potential cause for MR recurrence, we tested the hypothesis that MitraClip increases leaflet stress and procedure-related strain in sub-valvular left ventricular (LV) myocardium in FMR associated with coronary disease (FMR-CAD). Methods: Simulations were performed using finite element models of the LV + mitral valve based on MRI of 5 sheep with FMR-CAD. Models were modified to have a 20% increase in LV volume (↑LV_VOLUME) and MitraClip was simulated with contracting beam elements (virtual sutures) placed between nodes in the center edge of the anterior (AL) and posterior (PL) mitral leaflets. Effects of MitraClip on leaflet stress in the peri-MitraClip region of AL and PL, septo-lateral annular diameter (SLAD), and procedure-related radial strain (Err) in the sub-valvular myocardium were calculated. Results: MitraClip increased peri-MitraClip leaflet stress at end-diastole (ED) by 22.3±7.1 kPa (p<0.0001) in AL and 14.8±1.2 kPa (p<0.0001) in PL. MitraClip decreased SLAD by 6.1±2.2 mm (p<0.0001) and increased Err in the sub-valvular lateral LV myocardium at ED by 0.09±0.04 (p<0.0001)). Furthermore, MitraClip in ↑LV_VOLUME was associated with persistent effects at ED but also at end-systole where peri-MitraClip leaflet stress was increased in AL by 31.9±14.4 kPa (p = 0.0268) and in PL by 22.5±23.7 kPa (p = 0.0101). Conclusions: MitraClip for FMR-CAD increases mitral leaflet stress and radial strain in LV sub-valvular myocardium. Mechanical effects of MitraClip are augmented by LV enlargement. [ABSTRACT FROM AUTHOR]
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- 2019
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5. Chitotetraose activates the fungal-dependent endosymbiotic signaling pathway in actinorhizal plant species.
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Chabaud, Mireille, Fournier, Joëlle, Brichet, Lukas, Abdou-Pavy, Iltaf, Imanishi, Leandro, Brottier, Laurent, Pirolles, Elodie, Hocher, Valérie, Franche, Claudine, Bogusz, Didier, Wall, Luis G., Svistoonoff, Sergio, Gherbi, Hassen, and Barker, David G.
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PLANT species , *VESICULAR-arbuscular mycorrhizas , *TRANSGENIC organisms , *BOTANY , *HOST plants , *SYMBIODINIUM - Abstract
Mutualistic plant-microbe associations are widespread in natural ecosystems and have made major contributions throughout the evolutionary history of terrestrial plants. Amongst the most remarkable of these are the so-called root endosymbioses, resulting from the intracellular colonization of host tissues by either arbuscular mycorrhizal (AM) fungi or nitrogen-fixing bacteria that both provide key nutrients to the host in exchange for energy-rich photosynthates. Actinorhizal host plants, members of the Eurosid 1 clade, are able to associate with both AM fungi and nitrogen-fixing actinomycetes known as Frankia. Currently, little is known about the molecular signaling that allows these plants to recognize their fungal and bacterial partners. In this article, we describe the use of an in vivo Ca2+ reporter to identify symbiotic signaling responses to AM fungi in roots of both Casuarina glauca and Discaria trinervis, actinorhizal species with contrasting modes of Frankia colonization. This approach has revealed that, for both actinorhizal hosts, the short-chain chitin oligomer chitotetraose is able to mimic AM fungal exudates in activating the conserved symbiosis signaling pathway (CSSP) in epidermal root cells targeted by AM fungi. These results mirror findings in other AM host plants including legumes and the monocot rice. In addition, we show that chitotetraose is a more efficient elicitor of CSSP activation compared to AM fungal lipo-chitooligosaccharides. These findings reinforce the likely role of short-chain chitin oligomers during the initial stages of the AM association, and are discussed in relation to both our current knowledge about molecular signaling during Frankia recognition as well as the different microsymbiont root colonization mechanisms employed by actinorhizal hosts. [ABSTRACT FROM AUTHOR]
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- 2019
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6. Assessing precision and requirements of three methods to estimate roe deer density.
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Marcon, Andrea, Battocchio, Daniele, Apollonio, Marco, and Grignolio, Stefano
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ROE deer , *DEER populations , *POPULATION density , *DENSITY - Abstract
Roe deer (Capreolus capreolus) is the most abundant cervid in Europe and, as such, has a considerable impact over several human activities. Accurate roe deer population size estimates are useful to ensure their proper management. We tested 3 methods for estimating roe deer abundance (drive counts, pellet-group counts, and camera trapping) during two consecutive years (2012 and 2013) in the Apennines (Italy) in order to assess their precision and applicability. During the study period, population density estimates were: drive counts 21.89±12.74 roe deer/km2 and pellet-group counts 18.74±2.31 roe deer/km2 in 2012; drive counts 19.32±11.12 roe deer/km2 and camera trapping 29.05±7.48 roe deer/km2 in 2013. Precision of the density estimates differed widely among the 3 methods, with coefficients of variation ranging from 12% (pellet-group counts) to 58% (drive counts). Drive counts represented the most demanding method on account of the higher number of operators involved. Pellet-group counts yielded the most precise results and required a smaller number of operators, though the sampling effort was considerable. When compared to the other two methods, camera trapping resulted in an intermediate level of precision and required the lowest sampling effort. We also discussed field protocols of each method, considering that volunteers, rather than technicians, will more likely be appointed for these tasks in the near future. For this reason, we strongly suggest that for each method managers of population density monitoring projects take into account ease of use as well as the quality of the results obtained and the resources required. [ABSTRACT FROM AUTHOR]
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- 2019
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7. ECMO with vasopressor use during early endotoxic shock: Can it improve circulatory support and regional microcirculatory blood flow?
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Mu, Thornton S., Becker, Amy M., Clark, Aaron J., Batts, Sherreen G., Murata, Lee-Ann M., and Uyehara, Catherine F. T.
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SEPTIC shock , *BLOOD pressure , *BLOOD flow , *EXTRACORPOREAL membrane oxygenation , *OXYGEN consumption - Abstract
Introduction: While extracorporeal membrane oxygenation (ECMO) is effective in preventing further hypoxemia and maintains blood flow in endotoxin-induced shock, ECMO alone does not reverse the hypotension. In this study, we tested whether concurrent vasopressor use with ECMO would provide increased circulatory support and blood flow, and characterized regional blood flow distribution to vital organs. Methods: Endotoxic shock was induced in piglets to achieve a 30% decrease in mean arterial pressure (MAP). Measurements of untreated pigs were compared to pigs treated with ECMO alone or ECMO and vasopressors. Results: ECMO provided cardiac support during vasodilatory endotoxic shock and improved oxygen delivery, but vasopressor therapy was required to return MAP to normotensive levels. Increased blood pressure with vasopressors did not alter oxygen consumption or extraction compared to ECMO alone. Regional microcirculatory blood flow (RBF) to the brain, kidney, and liver were maintained or increased during ECMO with and without vasopressors. Conclusion: ECMO support and concurrent vasopressor use improve regional blood flow and oxygen delivery even in the absence of full blood pressure restoration. Vasopressor-induced selective distribution of blood flow to vital organs is retained when vasopressors are administered with ECMO. [ABSTRACT FROM AUTHOR]
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- 2019
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8. Nitrogen nutrition is a key modulator of the sugar and organic acid content in citrus fruit.
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Liao, Ling, Dong, Tiantian, Qiu, Xia, Rong, Yi, Wang, Zhihui, and Zhu, Jin
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CITRUS fruits , *CITRUS , *ORGANIC acids , *NUTRITION , *MANDARIN orange , *SUGARS , *CITRIC acid - Abstract
'Huangguogan' (Citrus reticulata × C. sinensis) is a new cultivar of mandarin citrus in China, and the research on fertilization of 'Huangguogan' is very limited. In this study, the effect of N fertilization on 'Huangguogan' fruit quality was determined at ripening. Sugars (sucrose, fructose, and glucose), organic acids (pyruvic, oxalic, citric acid, etc.), and vitamin components were measured at six stages of fruit development, and eight enzymes related to the glycolytic and Krebs cycle were assessed. The 1.81 kg N y-1 treatment group showed the highest total soluble solids concentration and total soluble solids/titratable acidity ratio but the lowest titratable acidity (acid content) at ripening, while the N1 treatment (0 kg N y-1) showed the opposite trend. Sucrose and citric acid accumulated to the largest extent during fruit development. Sucrose and ascorbic acid content increased (8.46 to 50.97 mg g-1 and 8.16 to 27.39 mg g-1, respectively), while citric acid content decreased (90.81 to 0.02 mg g-1). Aconitase was the key enzyme responsible for the observed changes in citric acid. The N concentrations in ripening fruit ranged from 2.25% to 4.15%. Curve estimation and principal component analysis revealed that fruit N was positively correlated with the sugars and vitamin components and negatively correlated with the organic acids. The accumulation of these metabolites seemed closely related to the dynamic changes in fruit N concentration at the five N levels tested. In conclusion, we suggest that the 1.81 kg N y-1 treatment represents the most suitable N fertilizer treatment for 'Huangguogan' citrus fruit. [ABSTRACT FROM AUTHOR]
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- 2019
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9. Comparison of transcriptomes of an orthotospovirus vector and non-vector thrips species.
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Shrestha, Anita, Champagne, Donald E., Culbreath, Albert K., Abney, Mark R., and Srinivasan, Rajagopalbabu
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TOMATO spotted wilt virus disease , *CELL receptors , *PLANT viruses , *VIRUS diseases , *TOMATO diseases & pests , *TRANSCRIPTOMES , *THRIPS - Abstract
Thrips transmit one of the most devastating plant viruses worldwide–tomato spotted wilt tospovirus (TSWV). Tomato spotted wilt tospovirus is a type species in the genus Orthotospovirus and family Tospoviridae. Although there are more than 7,000 thrips species, only nine thrips species are known to transmit TSWV. In this study, we investigated the molecular factors that could affect thrips ability to transmit TSWV. We assembled transcriptomes of a vector, Frankliniella fusca [Hinds], and a non-vector, Frankliniella tritici [Fitch], and performed qualitative comparisons of contigs associated with virus reception, virus infection, and innate immunity. Annotations of F. fusca and F. tritici contigs revealed slight differences across biological process and molecular functional groups. Comparison of virus cell surface receptors revealed that homologs of integrin were present in both species. However, homologs of another receptor, heperan sulfate, were present in F. fusca alone. Contigs associated with virus replication were identified in both species, but a contig involved in inhibition of virus replication (radical s-adenosylmethionine) was only present in the non-vector, F. tritici. Additionally, some differences in immune signaling pathways were identified between vector and non-vector thrips. Detailed investigations are necessary to functionally characterize these differences between vector and non-vector thrips and assess their relevance in orthotospovirus transmission. [ABSTRACT FROM AUTHOR]
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- 2019
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10. Genome-wide investigation of superoxide dismutase (SOD) gene family and their regulatory miRNAs reveal the involvement in abiotic stress and hormone response in tea plant (Camellia sinensis).
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Zhou, Chengzhe, Zhu, Chen, Fu, Haifeng, Li, Xiaozhen, Chen, Lan, Lin, Yuling, Lai, Zhongxiong, and Guo, Yuqiong
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REGULATOR genes , *GENE families , *ABIOTIC stress , *TEA , *SUPEROXIDE dismutase , *MICRORNA , *PHYSIOLOGICAL effects of cold temperatures , *JASMONATE - Abstract
Superoxide dismutases (SODs), as a family of metalloenzymes related to the removal of reactive oxygen species (ROS), have not previously been investigated at genome-wide level in tea plant. In this study, 10 CsSOD genes were identified in tea plant genome, including 7 Cu/Zn-SODs (CSDs), 2 Fe-SODs (FSDs) and one Mn-SOD (MSD), and phylogenetically classified in three subgroups, respectively. Physico-chemical characteristic, conserved motifs and potential protein interaction analyses about CsSOD proteins were carried out. Exon-intron structures and codon usage bias about CsSOD genes were also examined. Exon-intron structures analysis revealed that different CsSOD genes contained various number of introns. On the basis of the prediction of regulatory miRNAs of CsSODs, a modification 5' RNA ligase-mediated (RLM)-RACE was performed and validated that csn-miR398a-3p-1 directly cleaves CsCSD4. By prediction of cis-acting elements, the expression patterns of 10 CsSOD genes and their regulatory miRNAs were detected under cold, drought, exogenous methyl jasmonate (MeJA) and gibberellin (GA3) treatments. The results showed that most of CsSODs except for CsFSD2 were induced under cold stress and CsCSDs may play primary roles under drought stress; exogenous GA3 and MeJA could also stimulated/inhibited distinct CsSODs at different stages. In addition, we found that csn-miR398a-3p-1 negatively regulated the expression of CsCSD4 may be a crucial regulatory mechanism under cold stress. This study provides a certain basis for the studies about stress resistance in tea plants, even provide insight into comprehending the classification, evolution, diverse functions and influencing factors of expression patterns for CsSOD genes. [ABSTRACT FROM AUTHOR]
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- 2019
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11. Increased aggression and reduced aversive learning in honey bees exposed to extremely low frequency electromagnetic fields.
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Shepherd, Sebastian, Hollands, Georgina, Godley, Victoria C., Sharkh, Suleiman M., Jackson, Chris W., and Newland, Philip L.
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HONEYBEES , *ELECTROMAGNETIC fields , *POLLINATORS , *POLLINATION by bees , *ANIMAL aggression , *BEEHIVES - Abstract
Honey bees, Apis mellifera, are a globally significant pollinator species and are currently in decline, with losses attributed to an array of interacting environmental stressors. Extremely low frequency electromagnetic fields (ELF EMFs) are a lesser-known abiotic environmental factor that are emitted from a variety of anthropogenic sources, including power lines, and have recently been shown to have a significant impact on the cognitive abilities and behaviour of honey bees. Here we have investigated the effects of field-realistic levels of ELF EMFs on aversive learning and aggression levels, which are critical factors for bees to maintain colony strength. Bees were exposed for 17 h to 100 μT or 1000 μT ELF EMFs, or a sham control. A sting extension response (SER) assay was conducted to determine the effects of ELF EMFs on aversive learning, while an intruder assay was conducted to determine the effects of ELF EMFs on aggression levels. Exposure to both 100 μT and 1000 μT ELF EMF reduced aversive learning performance by over 20%. Exposure to 100 μT ELF EMFs also increased aggression scores by 60%, in response to intruder bees from foreign hives. These results indicate that short-term exposure to ELF EMFs, at levels that could be encountered in bee hives placed under power lines, reduced aversive learning and increased aggression levels. These behavioural changes could have wider ecological implications in terms of the ability of bees to interact with, and respond appropriately to, threats and negative environmental stimuli. [ABSTRACT FROM AUTHOR]
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- 2019
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12. Spread of domestic animals across Neolithic western Anatolia: New stable isotope evidence from Uğurlu Höyük, the island of Gökçeada, Turkey.
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Pilaar Birch, Suzanne E., Atici, Levent, and Erdoğu, Burçin
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STABLE isotopes , *DENTAL enamel , *ISLANDS , *EARTH sciences , *PARTICLE physics , *DOMESTIC animals - Abstract
The origins of agriculture in Southwest Asia over 10,000 years ago and its subsequent spread into Europe during the Neolithic have been the focus of much archaeological research over the past several decades. Increasingly more sophisticated analytical techniques have allowed for better understanding of the complex interactions that occurred amongst humans, animals, and their environments during this transition. The Aegean Islands are critically situated where Anatolia and the mainland Greece meet, making the region pivotal for understanding the movement of the Neolithic into Europe. Located on the largest Turkish Aegean island of Gökçeada, the site of Uğurlu Höyük dates to the early Neolithic and has been the subject of ongoing excavations and research integrating a rigorous dating program with comprehensive zooarchaeological research. This paper focuses on the combination of bone collagen and tooth enamel stable isotope data with existing archaeological data to develop a fine-resolution picture of the spread of the Neolithic, particularly the importation and management of domestic fauna on Gökçeada, with broader relevance for understanding Aegean-Anatolian interactions. The stable isotope values from the fauna at Uğurlu have been used for both diachronic intrasite analyses and intersite comparisons between contemporaneous mainland sites. Integrating stable isotope and zooarchaeological datasets makes Uğurlu one of the first island sites to provide a comprehensive understanding of the geographic origin of Neolithic livestock populations and the timing of their spread from Anatolia into Europe during the process of Neolithization. [ABSTRACT FROM AUTHOR]
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- 2019
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13. Safety and efficacy of artesunate-amodiaquine combined with either methylene blue or primaquine in children with falciparum malaria in Burkina Faso: A randomized controlled trial.
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Mendes Jorge, Margarida, Ouermi, Lucienne, Meissner, Peter, Compaoré, Guillaume, Coulibaly, Boubacar, Nebie, Eric, Krisam, Johannes, Klose, Christina, Kieser, Meinhard, Jahn, Albrecht, Lu, Guangyu, D'Alessandro, Umberto, Sié, Ali, Mockenhaupt, Frank Peter, and Müller, Olaf
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METHYLENE blue , *ANTIMALARIALS , *RANDOMIZED controlled trials , *MALARIA , *PRIMAQUINE - Abstract
Artemisinin resistance is threatening global efforts for malaria control and elimination. Primaquine (PQ) and methylene blue (MB) are gametocytocidal drugs that can be combined with artemisinin-based combination therapy (ACT) to reduce malaria transmission, including resistant strains. Children (6–59 months) with uncomplicated falciparum malaria in Burkina Faso were treated with artesunate-amodiaquine (AS-AQ) and randomized to MB (15 mg/kg/day for 3 days) or PQ (0.25 mg/kg at day 2) with the aim to show non-inferiority of the MB regimen with regard to haematological recovery at day 7 (primary endpoint). MB-AS-AQ could not be shown to be non-inferior to PQ-AS-AQ (mean Hb difference between treatment groups on day 7 was -0.352, 95% CI -0.832–0.128, p = 0.0767), however, haemoglobin recovery following treatment was alike in the two study arms (day 7: mean 0.2±1.4 g/dl vs. 0.5±0.9 g/dl, p = 0.446). Occurrence of adverse events was similar in both groups, except for vomiting, which was more frequent in the MB than in the PQ arm (20/50 vs 7/50, p = 0.003). Adequate clinical and parasitological response was above 95% in both groups, but significantly more asexual parasites were cleared in the MB arm compared to the PQ arm already on day 1 (48/50, 96%, vs 40/50, 80%, p = 0.014). Moreover, P. falciparum gametocyte prevalence and density were lower in the MB arm than in the PQ arm, which reached statistical significance on day 2 (prevalence: 2/50, 4%, vs 15/49, 31%, p<0.001; density: 9.6 vs 41.1/μl, p = 0.024). However, it should be considered that PQ was given only on day 2. MB-ACT appears to be an interesting alternative to PQ-ACT for the treatment of falciparum malaria. While there is a need to further improve MB formulations, MB-ACT may already be considered useful to reduce falciparum malaria transmission intensity, to increase treatment efficacy, and to reduce the risk for resistance development and spread. Trial registration: ClinicalTrials.gov . [ABSTRACT FROM AUTHOR]
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- 2019
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14. Intrabladder pressure as predictor of intra-abdominal pressure in horses.
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de Paula, Vanessa B., Canola, Paulo A., Rivera, Gabriela G., Z. Filho, Dárcio, Amaral, Gabriel P. D., Ferraz, Guilherme C., Ferraudo, Antônio S., and Canola, Júlio C.
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INTRA-abdominal pressure , *POSTURE , *PUBIC symphysis , *HORSES , *REGRESSION analysis , *AGRICULTURAL colleges , *BLADDER - Abstract
Objectives: To investigate effects of postural changes and bladder distention on intrabladder pressure whilst estimating intra-abdominal pressure in horses. Design: Two-year cohort study. Patients admitted for elective surgical procedures unrelated to gastrointestinal or genitourinary tract. Setting: School of Agricultural and Veterinarian Sciences, Jaboticabal, SP, Brazil. Animals: 20 adult horses, 11 males (stallions and geldings) and 9 females; between 3.5 and 12 years, weighing 350 to 500 kg. Interventions: Intra-abdominal pressure was directly-recorded through abdominocentesis at the ventral midline with a fluid-filled system. Intrabladder pressure was obtained from a bladder catheter with the fluid-filled system zeroed at the level of the tuber ischia with patients in dorsal recumbency or pubic symphysis if in lateral recumbency. Measurements and main results: Body position directly influenced intra-abdominal pressure. In dorsal recumbency, intra-abdominal pressure differed (p < 0.05) from intrabladder pressure at end-inspiration and end-expiration regardless of whether the bladder was empty or distended. There was no correlation nor association between the two pressures in this body position. In lateral recumbency a difference (p <0.05) between intra-abdominal pressure and intrabladder pressure was recorded at end-inspiration with the bladder distended with 25 ml, and at end-expiration for distension volumes of 25 ml and 50 ml. There was a strong correlation between both pressures for left and right lateral recumbency, regardless of the distension volume. Ordinary least product (OLP) regression analysis showed no fixed or proportional bias between both pressures for distension volume of 50 ml, at both end-inspiration and end-expiration. Conclusions: Indirect assessment of equine intra-abdominal pressure cannot be made in dorsal recumbency. For that purpose, patients should be in left lateral recumbency with the bladder distended with 50 ml. Values can be recorded at end-inspiration or end-expiration. Restriction: Occlusion of the catheter tip by the bladder wall when minimally distended. [ABSTRACT FROM AUTHOR]
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- 2019
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15. Genetic modification and yield risk: A stochastic dominance analysis of corn in the USA.
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Nolan, Elizabeth and Santos, Paulo
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STOCHASTIC dominance , *STOCHASTIC analysis , *CORN yields , *CORN stover , *SOIL science , *PHYSICAL sciences ,CORN analysis - Abstract
Production risk has been ignored in most of the analysis of GM technology, which has mostly focused on its effects on mean yield. We use stochastic dominance to quantify the effect of GM traits on the entire distribution of yields in corn in the USA under a wide range of growing conditions. Although no GM hybrid outperforms conventional hybrids under all growing conditions, we present evidence that most GM hybrids can be considered as improvements of the yield distribution. [ABSTRACT FROM AUTHOR]
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- 2019
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16. Positive effect of an electrolyzed reduced water on gut permeability, fecal microbiota and liver in an animal model of Parkinson's disease.
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Bordoni, Laura, Gabbianelli, Rosita, Fedeli, Donatella, Fiorini, Dennis, Bergheim, Ina, Jin, Cheng Jun, Marinelli, Lisa, Di Stefano, Antonio, and Nasuti, Cinzia
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PARKINSON'S disease , *WATER electrolysis , *FECAL contamination , *ANIMAL models in research , *PERMEABILITY , *INFLAMMATORY bowel diseases , *INTESTINES - Abstract
There is growing awareness within the scientific community of the strong connection between the inflammation in the intestine and the pathogenesis of Parkinson's disease (PD). In previous studies we developed a PD animal model exposing pup rats to permethrin (PERM) pesticide. Here, we intended to explore whether in our animal model there were changes in gut permeability, fecal microbiota and hepatic injury. Moreover, we tested if the co-treatment with an electrolyzed reduced (ERW) was effective to protect against alterations induced by PERM. Rats (from postnatal day 6 to 21) were gavaged daily with PERM, PERM+ERW or vehicle and gut, liver and feces were analyzed in 2-months-old rats. Increased gut permeability, measured by FITC-dextran assay, was detected in PERM group compared to control and PERM+ERW groups. In duodenum and ileum, concentration of occludin was higher in control group than those measured in PERM group, whereas only in duodenum ZO-1 was higher in control than those measured in PERM and PERM+ERW groups. Number of inflammatory focis and neutrophils as well as iNOS protein levels were higher in livers of PERM-treated rats than in those of PERM+ERW and control rats. Fecal microbiota analysis revealed that Lachnospira was less abundant and Defluviitaleaceae more abundant in the PERM group, whereas the co-treatment with ERW was protective against PERM treatment since the abundances in Lachnospira and Defluviitaleaceae were similar to those in the control group. Higher abundances of butyrate- producing bacteria such as Blautia, U.m. of Lachnospiraceae family, U.m. of Ruminococcaceae family, Papillibacter, Roseburia, Intestinimonas, Shuttleworthia together with higher butyric acid levels were detected in PERM+ERW group compared to the other groups. In conclusion, the PD animal model showed increased intestinal permeability together with hepatic inflammation correlated with altered gut microbiota. The positive effects of ERW co-treatment observed in gut, liver and brain of rats were linked to changes on gut microbiota. [ABSTRACT FROM AUTHOR]
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- 2019
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17. Metabolomic analysis of the occurrence of bitter fruits on grafted oriental melon plants.
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Zhang, Shuangshuang, Nie, Lanchun, Zhao, Wensheng, Cui, Qiang, Wang, Jiahao, Duan, Yaqian, and Ge, Chang
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ROOTSTOCKS , *LIQUID chromatography-mass spectrometry , *MELONS , *FRUIT , *GRAFTING (Horticulture) , *PLANT physiology - Abstract
Grafting has been widely applied to melon (Cucumis melo L.) production to alleviate obstacles of continuous cropping and control soil-borne diseases. However, grafting often leads to a decline of fruit quality. For example, sometimes bitter fruits are produced on grafted plants. However, the underlying physiological mechanism still remains unclear. This study investigated the effects of different rootstocks on the taste of fruits of the Balengcui, an oriental melon cultivar, during summer production. The results showed that all grafted plants with Cucurbita maxima Duch. rootstocks produced bitter fruits, while non-grafted plants and plants grafted onto muskmelon rootstocks produced no bitter fruits. Liquid chromatography–mass spectrometry and metabonomic analysis were performed to investigate the mechanism underlying the occurrence of bitter fruits. Metabolite comparisons of fruits from plants grafted onto Ribenxuesong rootstocks both with non-grafted plants and plants grafted onto muskmelon rootstocks showed that 17 metabolites including phospholipids, cucurbitacins and flavonoids, exhibited changes. The three Cucurbitacins, Cucurbitacin O, Cucurbitacin C, and Cucurbitacin S, increased dramatically. The 10 phospholipids PS(18:1(9Z)/18:2(9Z,12Z)), PS(P-18:0/15:0), PA(18:1(11Z)/18:1(11Z)), PE(16:0/18:0), PS(O-16:0/17:2(9Z,12Z)), PI(16:0/18:2(9Z,12Z)), PA(15:0/22:6(4Z,7Z,10Z,13Z,16Z,19Z)), PS(P-16:0/17:2(9Z,12Z)), PS(22:0/22:1(11Z)), and PA(17:1(9Z)/0:0)) were significantly decreased, while two PA (16:0/18:2 (9Z, 12Z) and 16:0/18:1 (11Z)), two flavonoids (pelargonidin 3-(6''-malonylglucoside)-5-glucoside and malvidin 3-rutinoside) significantly increased in fruits of plants grafted onto Cucurbita maxima Duch. rootstocks. These metabolites were involved in the glycerophospholipid metabolic pathway, the mevalonate pathway, and the phenylpropanoid pathway. In summary, these results showed that the bitter fruits of grafted Balengcui were caused by Cucurbita maxima Duch. rootstocks. Phospholipids, cucurbitacins, and flavonoids were the key contributors for the occurrence of bitter fruits in Balengcui melon after grafting onto Cucurbita maxima Duch. rootstocks. [ABSTRACT FROM AUTHOR]
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- 2019
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18. Analysis of gene co-expression networks of phosphate starvation and aluminium toxicity responses in Populus spp.
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Cardoso, Thiago Bergamo, Pinto, Renan Terassi, and Paiva, Luciano Vilela
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ACID soils , *PLANT adaptation , *POPLARS , *ALUMINUM phosphate , *STARVATION , *GENE regulatory networks - Abstract
The adaptation of crops to acid soils is needed for the maintenance of food security in a sustainable way, as decreasing fertilizers use and mechanical interventions in the soil would favor the reduction of agricultural practices' environmental impact. Phosphate deficiency and the presence of reactive aluminum affect vital processes to the plant in this soil, mostly water and nutrient absorption. From this, the understanding of the molecular response to these stresses can foster strategies for genetic improvement, so the aim was to broadly analyze the transcriptional variations in Poupulus spp. in response to these abiotic stresses, as a plant model for woody crops. A co-expression network was constructed among 3,180 genes differentially expressed in aluminum-stressed plants with 34,988 connections. Of this total, 344 genes presented two-fold transcriptional variation and the group of genes associated with those regulated after 246 hours of stress had higher number of connections per gene, with some already characterized genes related to this stress as main hubs. Another co-expression network was made up of 8,380 connections between 550 genes regulated by aluminum stress and phosphate deficiency, in which 380 genes had similar profile in both stresses and only eight with transcriptional variation higher than 20%. All the transcriptomic data are presented here with functional enrichment and homology comparisons with already characterized genes in another species that are related to the explored stresses, in order to provide a broad analysis of the co-opted responses for both the stresses as well as some specificity. This approach improves our understanding regarding the plants adaptation to acid soils and may contribute to strategies of crop genetic improvement for this condition that is widely present in regions of high agricultural activity. [ABSTRACT FROM AUTHOR]
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- 2019
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19. Is summer food intake a limiting factor for boreal browsers? Diet, temperature, and reproduction as drivers of consumption in female moose.
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Shively, Rachel D., Crouse, John A., Thompson, Dan P., and Barboza, Perry S.
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INGESTION , *MOOSE , *REPRODUCTION , *ANIMAL feeds , *GROWING season - Abstract
Food intake may limit the ability of browsing mammals to gain body mass during the growing season when the leaves and stems of woody plants are most abundant. Moose are highly productive browsers with high demands for energy and nutrients, particularly during lactation. Using an indigestible marker, we estimated dry matter intake of free ranging adult female moose with and without calves over three growing seasons. During the same period, we analyzed forage quality. Intakes were highest in late spring (280 ± 19 g·kg-0.75·d-1) when forage quality peaked; however, intakes declined by 39% throughout the summer as temperatures increased and as acid detergent fiber content of browse increased. Digestibility of dry matter declined over summer from 71% to 57% among browse. Intakes were similar for moose with and without calves. Heat loads may impair the ability of moose to consume sufficient energy and nutrients. Warming and habitat change can adversely affect browser populations when poor forage qualities and low dry matter intakes combine to suppress digestible intakes of energy and nutrients. [ABSTRACT FROM AUTHOR]
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- 2019
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20. Whole genome resequencing of watermelons to identify single nucleotide polymorphisms related to flesh color and lycopene content.
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Subburaj, Saminathan, Lee, Kayoun, Jeon, Yongsam, Tu, Luhua, Son, Gilwoo, Choi, SuBok, Lim, Yong-Pyo, McGregor, Cecilia, and Lee, Geung-Joo
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WATERMELONS , *SINGLE nucleotide polymorphisms , *FOOD crops , *BOTANY , *LYCOPENE , *COMPUTATIONAL biology - Abstract
Cultivated watermelon (Citrullus lanatus) is one of the most important food crops in the Cucurbitaceae family. Diversification after domestication has led cultivated watermelons to exhibit diverse fruit flesh colors, including red, yellow, and orange. Recently, there has been increased interest in red-fleshed watermelons because they contain the antioxidant cis-isomeric lycopene. We performed whole genome resequencing (WGRS) of 24 watermelons with different flesh colors to identify single-nucleotide polymorphisms (SNPs) related to high lycopene content. The resequencing data revealed 203,894–279,412 SNPs from read mapping between inbred lines and the 97103 reference genome. In total, 295,065 filtered SNPs were identified, which had an average polymorphism information content of 0.297. Most of these SNPs were intergenic (90.1%) and possessed a transversion (Tv) rate of 31.64%. Overall, 2,369 SNPs were chosen at 0.5 Mb physical intervals to analyze genetic diversity across the 24 inbred lines. A neighbor-joining dendrogram and principal coordinate analysis (PCA) based on the 2,369 SNPs revealed that the 24 inbred lines could be grouped into high and low lycopene-type watermelons. In addition, we analyzed SNPs that could discriminate high lycopene content, red-fleshed watermelon from low lycopene, yellow or orange watermelon inbred lines. For validation, 19 SNPs (designated as WMHL1–19) were chosen randomly, and cleavage amplified polymorphic sequence (CAPS) markers were designed. Genotyping of the above 24 lines and 12 additional commercial cultivars using WMHL1–19 CAPS markers resulted in match rates of over 0.92 for most validated markers in correlation with the flesh color phenotypes. Our results provide valuable genomic information regarding the high lycopene content phenotype of red-fleshed cultivated watermelons, and the identified SNPs will be useful for the development of molecular markers in the marker-assisted breeding of watermelons with high lycopene content. [ABSTRACT FROM AUTHOR]
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- 2019
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21. The dialogue between protozoa and bacteria in a microfluidic device.
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Gaines, Anna, Ludovice, Miranda, Xu, Jie, Zanghi, Marc, Meinersmann, Richard J., Berrang, Mark, Daley, Wayne, and Britton, Doug
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MICROFLUIDIC devices , *PROTOZOA , *VOLATILE organic compounds , *BACTERIAL cells , *SMALL molecules , *MEMBRANE separation - Abstract
In nature, protozoa play a major role in controlling bacterial populations. This paper proposes a microfluidic device for the study of protozoa behaviors change due to their chemotactic response in the presence of bacterial cells. A three-channel microfluidic device was designed using a nitrocellulose membrane into which channels were cut using a laser cutter. The membrane was sandwiched between two glass slides; a Euglena suspension was then allowed to flow through the central channel. The two side channels were filled with either, 0.1% peptone as a negative control, or a Listeria suspension respectively. The membrane design prevented direct interaction but allowed Euglena cells to detect Listeria cells as secretions diffused through the nitrocellulose membrane. A significant number of Euglena cells migrated toward the chambers near the bacterial cells, indicating a positive chemotactic response of Euglena toward chemical cues released from Listeria cells. Filtrates collected from Listeria suspension with a series of molecular weight cutoffs (3k, 10k and 100k) were examined in Euglena chemotaxis tests. Euglena cells were attracted to all filtrates collected from the membrane filtration with different molecular weight cutoffs, suggesting small molecules from Listeria might be the chemical cues to attract protozoa. Headspace volatile organic compounds (VOC) released from Listeria were collected, spiked to 0.1% peptone and tested as the chemotactic effectors. It was discovered that the Euglena cells responded quickly to Listeria VOCs including decanal, 3,5- dimethylbenzaldehyde, ethyl acetate, indicating bacterial VOCs were used by Euglena to track the location of bacteria. [ABSTRACT FROM AUTHOR]
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- 2019
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22. Successful development of methodology for detection of hapten-specific contact hypersensitivity (CHS) memory in swine.
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Putz, E. J., Putz, A. M., Boettcher, A., Charley, S., Sauer, M., Palmer, M., Phillips, R., Hostetter, J., Loving, C. L., Cunnick, J. E., and Tuggle, C. K.
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CONTACT dermatitis , *SWINE , *T cells , *OTITIS , *MEMORY , *LEUCOCYTES - Abstract
Hapten contact hypersensitivity (CHS) elicits a well-documented inflammation response that can be used to illustrate training of immune cells through hapten-specific CHS memory. The education of hapten-specific memory T cells has been well-established, recent research in mice has expanded the “adaptive” characteristic of a memory response from solely a function of the adaptive immune system, to innate cells as well. To test whether similar responses are seen in a non-rodent model, we used hapten-specific CHS to measure the ear inflammation response of outbred pigs to dinitrofluorobenzene (DNFB), oxazolone (OXA), or vehicle controls. We adapted mouse innate memory literature protocols to the domestic pig model. Animals were challenged up to 32 days post initial sensitization exposure to the hapten, and specific ear swelling responses to this challenge were significant for 7, 21, and 32 days post-sensitization. We established hapten-specific CHS memory exists in a non-rodent model. We also developed a successful protocol for demonstrating these CHS responses in a porcine system. [ABSTRACT FROM AUTHOR]
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- 2019
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23. Autism candidate gene DIP2A regulates spine morphogenesis via acetylation of cortactin.
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Ma, Jun, Zhang, Lu-Qing, He, Zi-Xuan, He, Xiao-Xiao, Wang, Ya-Jun, Jian, You-Li, Wang, Xin, Zhang, Bin-Bin, Su, Ce, Lu, Jun, Huang, Bai-Qu, Zhang, Yu, Wang, Gui-Yun, Guo, Wei-Xiang, Qiu, De-Lai, Mei, Lin, Xiong, Wen-Cheng, Zheng, Yao-Wu, and Zhu, Xiao-Juan
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PYRAMIDAL neurons , *NEURAL circuitry , *ACETYLATION , *AUTISM spectrum disorders , *NEUROLOGICAL disorders , *MORPHOGENESIS , *DENDRITIC spines - Abstract
Dendritic spine development is crucial for the establishment of excitatory synaptic connectivity and functional neural circuits. Alterations in spine morphology and density have been associated with multiple neurological disorders. Autism candidate gene disconnected-interacting protein homolog 2 A (DIP2A) is known to be involved in acetylated coenzyme A (Ac-CoA) synthesis and is primarily expressed in the brain regions with abundant pyramidal neurons. However, the role of DIP2A in the brain remains largely unknown. In this study, we found that deletion of Dip2a in mice induced defects in spine morphogenesis along with thin postsynaptic density (PSD), and reduced synaptic transmission of pyramidal neurons. We further identified that DIP2A interacted with cortactin, an activity-dependent spine remodeling protein. The binding activity of DIP2A-PXXP motifs (P, proline; X, any residue) with the cortactin-Src homology 3 (SH3) domain was critical for maintaining the level of acetylated cortactin. Furthermore, Dip2a knockout (KO) mice exhibited autism-like behaviors, including excessive repetitive behaviors and defects in social novelty. Importantly, acetylation mimetic cortactin restored the impaired synaptic transmission and ameliorated repetitive behaviors in these mice. Altogether, our findings establish an initial link between DIP2A gene variations in autism spectrum disorder (ASD) and highlight the contribution of synaptic protein acetylation to synaptic processing. [ABSTRACT FROM AUTHOR]
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- 2019
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24. Shaping of a three-dimensional carnivorous trap through modulation of a planar growth mechanism.
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Lee, Karen J. I., Bushell, Claire, Koide, Yohei, Fozard, John A., Piao, Chunlan, Yu, Man, Newman, Jacob, Whitewoods, Christopher, Avondo, Jerome, Kennaway, Richard, Marée, Athanasius F. M., Cui, Minlong, and Coen, Enrico
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CELL morphology , *LEAF development , *BOTANY , *CELL size , *DEVELOPMENTAL biology , *CELL sheets (Biology) - Abstract
Leaves display a remarkable range of forms, from flat sheets with simple outlines to cup-shaped traps. Although much progress has been made in understanding the mechanisms of planar leaf development, it is unclear whether similar or distinctive mechanisms underlie shape transformations during development of more complex curved forms. Here, we use 3D imaging and cellular and clonal analysis, combined with computational modelling, to analyse the development of cup-shaped traps of the carnivorous plant Utricularia gibba. We show that the transformation from a near-spherical form at early developmental stages to an oblate spheroid with a straightened ventral midline in the mature form can be accounted for by spatial variations in rates and orientations of growth. Different hypotheses regarding spatiotemporal control predict distinct patterns of cell shape and size, which were tested experimentally by quantifying cellular and clonal anisotropy. We propose that orientations of growth are specified by a proximodistal polarity field, similar to that hypothesised to account for Arabidopsis leaf development, except that in Utricularia, the field propagates through a highly curved tissue sheet. Independent evidence for the polarity field is provided by the orientation of glandular hairs on the inner surface of the trap. Taken together, our results show that morphogenesis of complex 3D leaf shapes can be accounted for by similar mechanisms to those for planar leaves, suggesting that simple modulations of a common growth framework underlie the shaping of a diverse range of morphologies. [ABSTRACT FROM AUTHOR]
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- 2019
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25. Spliceosomal Prp8 intein at the crossroads of protein and RNA splicing.
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Green, Cathleen M., Li, Zhong, Smith, Aaron D., Novikova, Olga, Bacot-Davis, Valjean R., Gao, Fengshan, Hu, Saiyang, Banavali, Nilesh K., Thiele, Dennis J., Li, Hongmin, and Belfort, Marlene
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RNA splicing , *SPLICEOSOMES , *PROTEINS , *CRYPTOCOCCUS neoformans , *AMINO acid sequence , *SULFUR amino acids - Abstract
The spliceosome is a large ribonucleoprotein complex that removes introns from pre-mRNAs. At its functional core lies the essential pre-mRNA processing factor 8 (Prp8) protein. Across diverse eukaryotes, this protein cofactor of RNA catalysis harbors a self-splicing element called an intein. Inteins in Prp8 are extremely pervasive and are found at 7 different sites in various species. Here, we focus on the Prp8 intein from Cryptococcus neoformans (Cne), a human fungal pathogen. We solved the crystal structure of this intein, revealing structural homology among protein splicing sequences in eukaryotes, including the Hedgehog C terminus. Working with the Cne Prp8 intein in a reporter assay, we find that the biologically relevant divalent metals copper and zinc inhibit intein splicing, albeit by 2 different mechanisms. Copper likely stimulates reversible modifications on a catalytically important cysteine, whereas zinc binds at the terminal asparagine and the same critical cysteine. Importantly, we also show that copper treatment inhibits Prp8 protein splicing in Cne. Lastly, an intein-containing Prp8 precursor model is presented, suggesting that metal-induced protein-splicing inhibition would disturb function of both Prp8 and the spliceosome. These results indicate that Prp8 protein splicing can be modulated, with potential functional implications for the spliceosome. [ABSTRACT FROM AUTHOR]
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- 2019
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26. NF1-cAMP signaling dissociates cell type–specific contributions of striatal medium spiny neurons to reward valuation and motor control.
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Sutton, Laurie P., Muntean, Brian S., Ostrovskaya, Olga, Zucca, Stefano, Dao, Maria, Orlandi, Cesare, Song, Chenghui, Xie, Keqiang, and Martemyanov, Kirill A.
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DOPAMINERGIC neurons , *DOPAMINE receptors , *MOTOR learning , *NEURONS , *CYTOLOGY , *GENETIC models , *PHYSICAL sciences - Abstract
The striatum plays a fundamental role in motor learning and reward-related behaviors that are synergistically shaped by populations of D1 dopamine receptor (D1R)- and D2 dopamine receptor (D2R)-expressing medium spiny neurons (MSNs). How various neurotransmitter inputs converging on common intracellular pathways are parsed out to regulate distinct behavioral outcomes in a neuron-specific manner is poorly understood. Here, we reveal that distinct contributions of D1R-MSNs and D2R-MSNs towards reward and motor behaviors are delineated by the multifaceted signaling protein neurofibromin 1 (NF1). Using genetic mouse models, we show that NF1 in D1R-MSN modulates opioid reward, whereas loss of NF1 in D2R-MSNs delays motor learning by impeding the formation and consolidation of repetitive motor sequences. We found that motor learning deficits upon NF1 loss were associated with the disruption in dopamine signaling to cAMP in D2R-MSN. Restoration of cAMP levels pharmacologically or chemogenetically rescued the motor learning deficits seen upon NF1 loss in D2R-MSN. Our findings illustrate that multiplex signaling capabilities of MSNs are deployed at the level of intracellular pathways to achieve cell-specific control over behavioral outcomes. [ABSTRACT FROM AUTHOR]
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- 2019
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27. Bacillus subtilis PgcA moonlights as a phosphoglucosamine mutase in support of peptidoglycan synthesis.
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Patel, Vaidehi, Black, Katherine A., Rhee, Kyu Y., and Helmann, John D.
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BACILLUS subtilis , *ORGANIC chemistry , *MATERIALS science , *PHYSICAL sciences , *NUCLEIC acids - Abstract
Phosphohexomutase superfamily enzymes catalyze the reversible intramolecular transfer of a phosphoryl moiety on hexose sugars. Bacillus subtilis phosphoglucomutase PgcA catalyzes the reversible interconversion of glucose 6-phosphate (Glc-6-P) and glucose 1-phosphate (Glc-1-P), a precursor of UDP-glucose (UDP-Glc). B. subtilis phosphoglucosamine mutase (GlmM) is a member of the same enzyme superfamily that converts glucosamine 6-phosphate (GlcN-6-P) to glucosamine 1-phosphate (GlcN-1-P), a precursor of the amino sugar moiety of peptidoglycan. Here, we present evidence that B. subtilis PgcA possesses activity as a phosphoglucosamine mutase that contributes to peptidoglycan biosynthesis. This activity was made genetically apparent by the synthetic lethality of pgcA with glmR, a positive regulator of amino sugar biosynthesis, which can be specifically suppressed by overproduction of GlmM. A gain-of-function mutation in a substrate binding loop (PgcA G47S) increases this secondary activity and suppresses a glmR mutant. Our results demonstrate that bacterial phosphoglucomutases may possess secondary phosphoglucosamine mutase activity, and that this dual activity may provide some level of functional redundancy for the essential peptidoglycan biosynthesis pathway. [ABSTRACT FROM AUTHOR]
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- 2019
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28. NusG prevents transcriptional invasion of H-NS-silenced genes.
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Bossi, Lionello, Ratel, Mathilde, Laurent, Camille, Kerboriou, Patricia, Camilli, Andrew, Eveno, Eric, Boudvillain, Marc, and Figueroa-Bossi, Nara
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RHO factor , *BACTERIAL RNA , *GENE silencing , *CHIMERIC proteins , *BACTERIAL proteins , *RNA polymerases - Abstract
Evolutionarily conserved NusG protein enhances bacterial RNA polymerase processivity but can also promote transcription termination by binding to, and stimulating the activity of, Rho factor. Rho terminates transcription upon anchoring to cytidine-rich motifs, the so-called Rho utilization sites (Rut) in nascent RNA. Both NusG and Rho have been implicated in the silencing of horizontally-acquired A/T-rich DNA by nucleoid structuring protein H-NS. However, the relative roles of the two proteins in H-NS-mediated gene silencing remain incompletely defined. In the present study, a Salmonella strain carrying the nusG gene under the control of an arabinose-inducible repressor was used to assess the genome-wide response to NusG depletion. Results from two complementary approaches, i) screening lacZ protein fusions generated by random transposition and ii) transcriptomic analysis, converged to show that loss of NusG causes massive upregulation of Salmonella pathogenicity islands (SPIs) and other H-NS-silenced loci. A similar, although not identical, SPI-upregulated profile was observed in a strain with a mutation in the rho gene, Rho K130Q. Surprisingly, Rho mutation Y80C, which affects Rho’s primary RNA binding domain, had either no effect or made H-NS-mediated silencing of SPIs even tighter. Thus, while corroborating the notion that bound H-NS can trigger Rho-dependent transcription termination in vivo, these data suggest that H-NS-elicited termination occurs entirely through a NusG-dependent pathway and is less dependent on Rut site binding by Rho. We provide evidence that through Rho recruitment, and possibly through other still unidentified mechanisms, NusG prevents pervasive transcripts from elongating into H-NS-silenced regions. Failure to perform this function causes the feedforward activation of the entire Salmonella virulence program. These findings provide further insight into NusG/Rho contribution in H-NS-mediated gene silencing and underscore the importance of this contribution for the proper functioning of a global regulatory response in growing bacteria. The complete set of transcriptomic data is freely available for viewing through a user-friendly genome browser interface. [ABSTRACT FROM AUTHOR]
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- 2019
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29. A rapid, low pH, nutrient stress, assay to determine the bactericidal activity of compounds against non-replicating Mycobacterium tuberculosis.
- Author
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Early, Julie V., Mullen, Steven, and Parish, Tanya
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MYCOBACTERIUM tuberculosis , *MYCOBACTERIA , *CITRATES , *MONENSIN , *ELECTROMAGNETIC radiation , *PHYSICAL sciences , *LUMINESCENCE - Abstract
There is an urgent need for new anti-tubercular agents which can lead to a shortened treatment time by targeting persistent or non-replicating bacilli. In order to assess compound activity against non-replicating Mycobacterium tuberculosis, we developed a method to detect the bactericidal activity of novel compounds within 7 days. Our method uses incubation at low pH in order to induce a non-replicating state. We used a strain of M. tuberculosis expressing luciferase; we first confirmed the linear relationship between luminescence and viable bacteria (determined by colony forming units) under our assay conditions. We optimized the assay parameters in 96-well plates in order to achieve a reproducible assay. Our final assay used M. tuberculosis in phosphate-citrate buffer, pH 4.5 exposed to compounds for 7 days; viable bacteria were determined by luminescence. We recorded the minimum bactericidal concentration at pH 4.5 (MBC4.5) representing >2 logs of kill. We confirmed the utility of the assay with control compounds. The ionophores monensin, niclosamide, and carbonyl cyanide 3-chlorophenylhydrazone and the anti-tubercular drugs pretomanid and rifampicin were active, while several other drugs such as isoniazid, ethambutol, and linezolid were not. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
30. A novel short-term high-lactose culture approach combined with a matrix-assisted laser desorption ionization-time of flight mass spectrometry assay for differentiating Escherichia coli and Shigella species using artificial neural networks.
- Author
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Ling, Jin, Wang, Hong, Li, Gaomin, Feng, Zhen, Song, Yufei, Wang, Peng, Shao, Hong, Zhou, Hu, and Chen, Gang
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MATRIX-assisted laser desorption-ionization , *ARTIFICIAL neural networks , *ESCHERICHIA coli , *MASS spectrometry , *SHIGELLA , *RECEIVER operating characteristic curves - Abstract
Background: Escherichia coli is currently unable to be reliably differentiated from Shigella species by routine matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. In the present study, a reliable and rapid identification method was established for Escherichia coli and Shigella species based on a short-term high-lactose culture using MALDI-TOF MS and artificial neural networks (ANN). Materials and methods: The Escherichia coli and Shigella species colonies, treated with (Condition 1)/without (Condition 2) a short-term culture with an in-house developed high-lactose fluid medium, were prepared for MALDI-TOF MS assays. The MS spectra were acquired in linear positive mode, with a mass range from 2000 to 12000 Da and were then compared to discover new biomarkers for identification. Finally, MS spectra data sets 1 and 2, extracted from the two conditions, were used for ANN training to investigate the benefit on bacterial classification produced by the new biomarkers. Results: Twenty-seven characteristic MS peaks from the Escherichia coli and Shigella species were summarized. Seven unreported MS peaks, with m/z 2330.745, m/z 2341.299, m/z 2371.581, m/z 2401.038, m/z 3794.851, m/z 3824.839 and m/z 3852.548, were discovered in only the spectra from the E. coli strains after a short-term high-lactose culture and were identified as belonging to acid shock protein. The prediction accuracies of the ANN models, based on data set 1 and 2, were 97.71±0.16% and 74.39±0.34% (n = 5), with an extremely remarkable difference (p < 0.001), and the areas under the curve of the receiver operating characteristic curve were 0.72 and 0.99, respectively. Conclusions: In summary, adding a short-term high-lactose culture approach before the analysis enabled a reliable and easy differentiation of Escherichia coli from the Shigella species using MALDI-TOF MS and ANN. [ABSTRACT FROM AUTHOR]
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- 2019
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31. Time scale of resilience loss: Implications for managing critical transitions in water quality.
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Batt, Ryan D., Eason, Tarsha, and Garmestani, Ahjond
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WATER quality , *TIME series analysis , *CHLOROPHYLL spectra , *ECOLOGICAL resilience , *PHYSICAL sciences , *ALGAL blooms , *MICROCYSTIS - Abstract
Regime shifts involving critical transitions are a type of rapid ecological change that are difficult to predict, but may be preceded by decreases in resilience. Time series statistics like lag-1 autocorrelation may be useful for anticipating resilience declines; however, more study is needed to determine whether the dynamics of autocorrelation depend on the resolution of the time series being analyzed, i.e., whether they are time-scale dependent. Here, we examined timeseries simulated from a lake eutrophication model and gathered from field measurements. The field study involved collecting high frequency chlorophyll fluorescence data from an unmanipulated reference lake and a second lake undergoing experimental fertilization to induce a critical transition in the form of an algal bloom. As part of the experiment, the fertilization was halted in response to detected early warnings of the algal bloom identified by increased autocorrelation. We tested these datasets for time-scale dependence in the dynamics of lag-1 autocorrelation and found that in both the simulation and field experiment, the dynamics of autocorrelation were similar across time scales. In the simulated time series, autocorrelation increased exponentially approaching algal bloom development, and in the field experiment, the difference in autocorrelation between the manipulated and reference lakes increased sharply. These results suggest that, as an early warning indicator, autocorrelation may be robust to the time scale of the analysis. Given that a time scale can be shortened by increasing sampling frequency, or lengthened by aggregating data during analysis, these results have important implications for management as they demonstrate the potential for detecting early warning signals over a wide range of monitoring frequencies and without requiring analysts to make situation-specific decisions regarding aggregation. Such an outcome provides promise that data collection procedures, especially by automated sensors, may be used to monitor and manage ecosystem resilience without the need for strict attention to time scale. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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32. Transepithelial transport of P-glycoprotein substrate by the Malpighian tubules of the desert locust.
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Rossi, Marta, De Battisti, Davide, and Niven, Jeremy Edward
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DESERT locust , *P-glycoprotein , *RHODAMINE B , *SECONDARY metabolism , *LIQUID chromatography-mass spectrometry , *METABOLITES , *ATP-binding cassette transporters , *DESERT ecology - Abstract
Extrusion of xenobiotics is essential for allowing animals to remove toxic substances present in their diet or generated as a biproduct of their metabolism. By transporting a wide range of potentially noxious substrates, active transporters of the ABC transporter family play an important role in xenobiotic extrusion. One such class of transporters are the multidrug resistance P-glycoprotein transporters. Here, we investigated P-glycoprotein transport in the Malpighian tubules of the desert locust (Schistocerca gregaria), a species whose diet includes plants that contain toxic secondary metabolites. To this end, we studied transporter physiology using a modified Ramsay assay in which ex vivo Malpighian tubules are incubated in different solutions containing the P-glycoprotein substrate dye rhodamine B in combination with different concentrations of the P-glycoprotein inhibitor verapamil. To determine the quantity of the P-glycoprotein substrate extruded we developed a simple and cheap method as an alternative to liquid chromatography–mass spectrometry, radiolabelled alkaloids or confocal microscopy. Our evidence shows that: (i) the Malpighian tubules contain a P-glycoprotein; (ii) tubule surface area is positively correlated with the tubule fluid secretion rate; and (iii) as the fluid secretion rate increases so too does the net extrusion of rhodamine B. We were able to quantify precisely the relationships between the fluid secretion, surface area, and net extrusion. We interpret these results in the context of the life history and foraging ecology of desert locusts. We argue that P-glycoproteins contribute to the removal of xenobiotic substances from the haemolymph, thereby enabling gregarious desert locusts to maintain toxicity through the ingestion of toxic plants without suffering the deleterious effects themselves. [ABSTRACT FROM AUTHOR]
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- 2019
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33. Phage resistance at the cost of virulence: Listeria monocytogenes serovar 4b requires galactosylated teichoic acids for InlB-mediated invasion.
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Sumrall, Eric T., Shen, Yang, Keller, Anja P., Rismondo, Jeanine, Pavlou, Maria, Eugster, Marcel R., Boulos, Samy, Disson, Olivier, Thouvenot, Pierre, Kilcher, Samuel, Wollscheid, Bernd, Cabanes, Didier, Lecuit, Marc, Gründling, Angelika, and Loessner, Martin J.
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LISTERIA monocytogenes , *BACTERIOPHAGES , *LIPOTEICHOIC acid , *CELL receptors , *INTRACELLULAR pathogens , *CELL surface antigens - Abstract
The intracellular pathogen Listeria monocytogenes is distinguished by its ability to invade and replicate within mammalian cells. Remarkably, of the 15 serovars within the genus, strains belonging to serovar 4b cause the majority of listeriosis clinical cases and outbreaks. The Listeria O-antigens are defined by subtle structural differences amongst the peptidoglycan-associated wall-teichoic acids (WTAs), and their specific glycosylation patterns. Here, we outline the genetic determinants required for WTA decoration in serovar 4b L. monocytogenes, and demonstrate the exact nature of the 4b-specific antigen. We show that challenge by bacteriophages selects for surviving clones that feature mutations in genes involved in teichoic acid glycosylation, leading to a loss of galactose from both wall teichoic acid and lipoteichoic acid molecules, and a switch from serovar 4b to 4d. Surprisingly, loss of this galactose decoration not only prevents phage adsorption, but leads to a complete loss of surface-associated Internalin B (InlB),the inability to form actin tails, and a virulence attenuation in vivo. We show that InlB specifically recognizes and attaches to galactosylated teichoic acid polymers, and is secreted upon loss of this modification, leading to a drastically reduced cellular invasiveness. Consequently, these phage-insensitive bacteria are unable to interact with cMet and gC1q-R host cell receptors, which normally trigger cellular uptake upon interaction with InlB. Collectively, we provide detailed mechanistic insight into the dual role of a surface antigen crucial for both phage adsorption and cellular invasiveness, demonstrating a trade-off between phage resistance and virulence in this opportunistic pathogen. [ABSTRACT FROM AUTHOR]
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- 2019
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34. Manipulating mtDNA in vivo reprograms metabolism via novel response mechanisms.
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Bahhir, Diana, Yalgin, Cagri, Ots, Liina, Järvinen, Sampsa, George, Jack, Naudí, Alba, Krama, Tatjana, Krams, Indrikis, Tamm, Mairi, Andjelković, Ana, Dufour, Eric, González de Cózar, Jose M., Gerards, Mike, Parhiala, Mikael, Pamplona, Reinald, Jacobs, Howard T., and Jõers, Priit
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MITOCHONDRIAL DNA , *METABOLISM , *PYRUVATE dehydrogenase kinase , *ORGANIC chemistry , *DEVELOPMENTAL biology , *PHYSICAL sciences , *ENDONUCLEASES - Abstract
Mitochondria have been increasingly recognized as a central regulatory nexus for multiple metabolic pathways, in addition to ATP production via oxidative phosphorylation (OXPHOS). Here we show that inducing mitochondrial DNA (mtDNA) stress in Drosophila using a mitochondrially-targeted Type I restriction endonuclease (mtEcoBI) results in unexpected metabolic reprogramming in adult flies, distinct from effects on OXPHOS. Carbohydrate utilization was repressed, with catabolism shifted towards lipid oxidation, accompanied by elevated serine synthesis. Cleavage and translocation, the two modes of mtEcoBI action, repressed carbohydrate rmetabolism via two different mechanisms. DNA cleavage activity induced a type II diabetes-like phenotype involving deactivation of Akt kinase and inhibition of pyruvate dehydrogenase, whilst translocation decreased post-translational protein acetylation by cytonuclear depletion of acetyl-CoA (AcCoA). The associated decease in the concentrations of ketogenic amino acids also produced downstream effects on physiology and behavior, attributable to decreased neurotransmitter levels. We thus provide evidence for novel signaling pathways connecting mtDNA to metabolism, distinct from its role in supporting OXPHOS. [ABSTRACT FROM AUTHOR]
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- 2019
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35. Spatiotemporal cytoskeleton organizations determine morphogenesis of multicellular trichomes in tomato.
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Chang, Jiang, Xu, Zhijing, Li, Meng, Yang, Meina, Qin, Haiyang, Yang, Jie, and Wu, Shuang
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TRICHOMES , *TOMATOES , *BOTANY , *CONTRACTILE proteins , *CYTOLOGY , *CYTOSKELETON , *MICROTUBULES - Abstract
Plant trichomes originate from epidermal cell, forming protective structure from abiotic and biotic stresses. Different from the unicellular trichome in Arabidopsis, tomato trichomes are multicellular structure and can be classified into seven different types based on cell number, shape and the presence of glandular cells. Despite the importance of tomato trichomes in insect resistance, our understanding of the tomato trichome morphogenesis remains elusive. In this study, we quantitatively analyzed morphological traits of trichomes in tomato and further performed live imaging of cytoskeletons in stably transformed lines with actin and microtubule markers. At different developmental stages, two types of cytoskeletons exhibited distinct patterns in different trichome cells, ranging from transverse, spiral to longitudinal. This gradual transition of actin filament angle from basal to top cells could correlate with the spatial expansion mode in different cells. Further genetic screen for aberrant trichome morphology led to the discovery of a number of independent mutations in SCAR/WAVE and ARP2/3 complex, which resulted in actin bundling and distorted trichomes. Disruption of microtubules caused isotropic expansion while abolished actin filaments entirely inhibited axial extension of trichomes, indicating that microtubules and actin filaments may control distinct aspects of trichome cell expansion. Our results shed light on the roles of cytoskeletons in the formation of multicellular structure of tomato trichomes. [ABSTRACT FROM AUTHOR]
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- 2019
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36. A systematic review and evaluation of Zika virus forecasting and prediction research during a public health emergency of international concern.
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Kobres, Pei-Ying, Chretien, Jean-Paul, Johansson, Michael A., Morgan, Jeffrey J., Whung, Pai-Yei, Mukundan, Harshini, Del Valle, Sara Y., Forshey, Brett M., Quandelacy, Talia M., Biggerstaff, Matthew, Viboud, Cecile, and Pollett, Simon
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PUBLIC health research , *ZIKA virus , *META-analysis , *WORLD health , *PANDEMICS - Abstract
Introduction: Epidemic forecasting and prediction tools have the potential to provide actionable information in the midst of emerging epidemics. While numerous predictive studies were published during the 2016–2017 Zika Virus (ZIKV) pandemic, it remains unknown how timely, reproducible, and actionable the information produced by these studies was. Methods: To improve the functional use of mathematical modeling in support of future infectious disease outbreaks, we conducted a systematic review of all ZIKV prediction studies published during the recent ZIKV pandemic using the PRISMA guidelines. Using MEDLINE, EMBASE, and grey literature review, we identified studies that forecasted, predicted, or simulated ecological or epidemiological phenomena related to the Zika pandemic that were published as of March 01, 2017. Eligible studies underwent evaluation of objectives, data sources, methods, timeliness, reproducibility, accessibility, and clarity by independent reviewers. Results: 2034 studies were identified, of which n = 73 met the eligibility criteria. Spatial spread, R0 (basic reproductive number), and epidemic dynamics were most commonly predicted, with few studies predicting Guillain-Barré Syndrome burden (4%), sexual transmission risk (4%), and intervention impact (4%). Most studies specifically examined populations in the Americas (52%), with few African-specific studies (4%). Case count (67%), vector (41%), and demographic data (37%) were the most common data sources. Real-time internet data and pathogen genomic information were used in 7% and 0% of studies, respectively, and social science and behavioral data were typically absent in modeling efforts. Deterministic models were favored over stochastic approaches. Forty percent of studies made model data entirely available, 29% provided all relevant model code, 43% presented uncertainty in all predictions, and 54% provided sufficient methodological detail to allow complete reproducibility. Fifty-one percent of predictions were published after the epidemic peak in the Americas. While the use of preprints improved the accessibility of ZIKV predictions by a median of 119 days sooner than journal publication dates, they were used in only 30% of studies. Conclusions: Many ZIKV predictions were published during the 2016–2017 pandemic. The accessibility, reproducibility, timeliness, and incorporation of uncertainty in these published predictions varied and indicates there is substantial room for improvement. To enhance the utility of analytical tools for outbreak response it is essential to improve the sharing of model data, code, and preprints for future outbreaks, epidemics, and pandemics. [ABSTRACT FROM AUTHOR]
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- 2019
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37. Inactivation of chronic wasting disease prions using sodium hypochlorite.
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Williams, Katie, Hughson, Andrew G., Chesebro, Bruce, and Race, Brent
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CHRONIC wasting disease , *PRION diseases , *BOVINE spongiform encephalopathy , *SODIUM hypochlorite , *CREUTZFELDT-Jakob disease , *CHEMICAL processes - Abstract
Chronic wasting disease (CWD) is a fatal prion disease that can infect deer, elk and moose. CWD has now been detected in 26 states of the USA, 3 Canadian provinces, South Korea, Norway, Sweden and Finland. CWD continues to spread from endemic areas, and new foci of infections are frequently detected. As increasing numbers of cervids become infected, the likelihood for human exposure increases. To date, no cases of CWD infection in humans have been confirmed, but experience with the BSE zoonosis in the United Kingdom suggests exposure to CWD should be minimized. Specifically, hunters, meat processors and others in contact with tissues from potentially CWD-infected cervids need a practical method to decontaminate knives, saws and other equipment. Prions are notoriously difficult to inactivate, and most effective methods require chemicals or sterilization processes that are either dangerous, caustic, expensive or not readily available. Although corrosive, sodium hypochlorite (bleach) is widely available and affordable and has been shown to inactivate prion agents including those that cause scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease. In the current study, we confirm that bleach is an effective disinfectant for CWD prions and establish minimum times and bleach concentrations to eliminate prion seeding activity from stainless steel and infected brain homogenate solutions. We found that a five-minute treatment with a 40% dilution of household bleach was effective at inactivating CWD seeding activity from stainless-steel wires and CWD-infected brain homogenates. However, bleach was not able to inactivate CWD seeding activity from solid tissues in our studies. [ABSTRACT FROM AUTHOR]
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- 2019
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38. Development of a fixed list of terms for the Qualitative Behavioural Assessment of shelter dogs.
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Arena, Laura, Wemelsfelder, Franҫoise, Messori, Stefano, Ferri, Nicola, and Barnard, Shanis
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PRINCIPAL components analysis , *VIDEO excerpts , *ANIMAL behavior , *INTER-observer reliability , *HAWTHORNE effect - Abstract
The shelter environment may have a severe impact on the dogs’ quality of life, and there is thus a need to develop valid tools to assess their welfare. These tools should be sensitive not only to the animals’ physical health but also to their mental health, including the assessment of positive and negative emotions. Qualitative Behaviour Assessment (QBA) is a ‘whole animal’ measure that captures the expressive quality of an animal’s demeanour, using descriptive terms such as ‘relaxed’, ‘anxious’, and ‘playful’. In this study, for the first time, we developed and tested a fixed-list of qualitative QBA terms for application to kennelled dogs. A list of 20 QBA terms was developed based on literature search and an expert opinion survey. Inter-observer reliability was investigated by asking 11 observers to use these terms to score 13 video clips of kennelled dogs. Principal Component Analysis (PCA) was used to extract four main dimensions explaining 70.9% of the total variation between clips. PC1 characterised curious/playful/excitable/sociable demeanour, PC2 ranged from comfortable/relaxed to anxious/nervous/stressed expression, PC3 described fearful demeanour, and PC4 characterised bored/depressed demeanour. Observers’ agreement on the ranking of video clips on these four expressive dimensions was good (Kendall’s W: 0.60–0.80). ANOVA showed a significant effect of observer on mean clip score on all PCs (p<0.05), due to few observers scoring differently from the rest of the group. Results indicate the potential of the proposed list of QBA terms for sheltered dogs to serve, in alignment with other measures, as a non-invasive assessment tool. However, the observer effect on mean PC scores points towards the need for adequate observer training, particularly in live scoring conditions. The QBA scoring tool can be integrated with existing welfare assessment protocols for shelter dogs and strengthen the power of those protocols to evaluate the animals’ experience in shelters. [ABSTRACT FROM AUTHOR]
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- 2019
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39. Kinetic characteristics of propofol-induced inhibition of electron-transfer chain and fatty acid oxidation in human and rodent skeletal and cardiac muscles.
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Urban, Tomáš, Waldauf, Petr, Krajčová, Adéla, Jiroutková, Kateřina, Halačová, Milada, Džupa, Valér, Janoušek, Libor, Pokorná, Eva, and Duška, František
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FATTY acid oxidation , *PROPOFOL infusion syndrome , *SKELETAL muscle , *MYOCARDIUM , *VASTUS lateralis , *ULTRAVIOLET spectrophotometry , *RODENTS , *CHARGE exchange - Abstract
Introduction: Propofol causes a profound inhibition of fatty acid oxidation and reduces spare electron transfer chain capacity in a range of human and rodent cells and tissues–a feature that might be related to the pathogenesis of Propofol Infusion Syndrome. We aimed to explore the mechanism of propofol-induced alteration of bioenergetic pathways by describing its kinetic characteristics. Methods: We obtained samples of skeletal and cardiac muscle from Wistar rat (n = 3) and human subjects: vastus lateralis from hip surgery patients (n = 11) and myocardium from brain-dead organ donors (n = 10). We assessed mitochondrial functional indices using standard SUIT protocol and high resolution respirometry in fresh tissue homogenates with or without short-term exposure to a range of propofol concentration (2.5–100 μg/ml). After finding concentrations of propofol causing partial inhibition of a particular pathways, we used that concentration to construct kinetic curves by plotting oxygen flux against substrate concentration during its stepwise titration in the presence or absence of propofol. By spectrophotometry we also measured the influence of the same propofol concentrations on the activity of isolated respiratory complexes. Results: We found that human muscle and cardiac tissues are more sensitive to propofol-mediated inhibition of bioenergetic pathways than rat’s tissue. In human homogenates, palmitoyl carnitine-driven respiration was inhibited at much lower concentrations of propofol than that required for a reduction of electron transfer chain capacity, suggesting FAO inhibition mechanism different from downstream limitation or carnitine-palmitoyl transferase-1 inhibition. Inhibition of Complex I was characterised by more marked reduction of Vmax, in keeping with non-competitive nature of the inhibition and the pattern was similar to the inhibition of Complex II or electron transfer chain capacity. There was neither inhibition of Complex IV nor increased leak through inner mitochondrial membrane with up to 100 μg/ml of propofol. If measured in isolation by spectrophotometry, propofol 10 μg/ml did not affect the activity of any respiratory complexes. Conclusion: In human skeletal and heart muscle homogenates, propofol in concentrations that are achieved in propofol-anaesthetized patients, causes a direct inhibition of fatty acid oxidation, in addition to inhibiting flux of electrons through inner mitochondrial membrane. The inhibition is more marked in human as compared to rodent tissues. [ABSTRACT FROM AUTHOR]
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- 2019
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40. Incidence and predictors of retreatment in chronic hepatitis B patients after discontinuation of entecavir or tenofovir treatment.
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Ma, Te-Ling, Hu, Tsung-Hui, Hung, Chao-Hung, Wang, Jing-Houng, Lu, Sheng-Nan, and Chen, Chien-Hung
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CHRONIC hepatitis B , *HEPATITIS associated antigen , *HEPATITIS A - Abstract
Background: This study investigated the incidence and predictors of retreatment after discontinuation of either entecavir (ETV) or tenofovir disoproxil fumarate (TDF) treatment in Taiwan. Methods: A total of 535 non-cirrhotic chronic hepatitis B (CHB) patients undergoing either ETV (n = 358) or TDF (n = 177) treatment were enrolled. Patients were followed for at least 12 months after stopping ETV or TDF treatment. Most patients (86.3%) fulfilled the retreatment criteria of Taiwan's National Health Plan. Results: The 5-year cumulative rates of clinical relapse and retreatment were 52.1% and 47%, respectively, in 160 hepatitis B e antigen (HBeAg)-positive patients, and were 62% and 54.8%, respectively, in 375 HBeAg-negative patients. The median duration from the end of treatment until clinical relapse and retreatment was 40 and 57 weeks, respectively, for all patients. Multivariate Cox regression analysis revealed that discontinuing TDF treatment, old age, male gender, and higher baseline HBsAg levels were independent factors of retreatment in HBeAg-positive patients; old age, HBV genotype B, and higher baseline and end-of-treatment HBsAg levels were independent factors in HBeAg-negative patients. A total of 18.8% of retreated patients satisfied the retreatment criteria of hepatic decompensation according to Taiwan's National Health Plan. Of the 64 patients who had clinical relapse without retreatment, 17 achieved sustained virological remission and 26 did not experience clinical relapse until their last visit after clinical relapse. Four patients developed HBsAg loss. Conclusions: The 5-year retreatment rate was about 50% in HBeAg-positive and HBeAg-negative patients. Discontinuing TDF treatment was an independent factor of retreatment in HBeAg-positive patients. [ABSTRACT FROM AUTHOR]
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- 2019
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41. Histopathological investigation of complex gill disease in sea farmed Atlantic salmon.
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Gjessing, Mona C., Steinum, Terje, Olsen, Anne Berit, Lie, Kai Inge, Tavornpanich, Saraya, Colquhoun, Duncan J., and Gjevre, Anne-Gerd
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ATLANTIC salmon , *MARICULTURE , *SALMON farming , *ANATOMY , *GILLS , *MUCUS , *PHAGOCYTOSIS - Abstract
Various agents including Ca. Piscichlamydia salmonis, Ca. Branchiomonas cysticola, Desmozoon lepeophtherii, Paramoeba perurans and salmon gill poxvirus may be associated with complex gill disease in Atlantic salmon. Co-infections involving two or more of these agents are common and histopathological interpretation of lesions is therefore challenging. In this study, we developed a semi-quantitative scoring system for examination of histopathological gill lesions in sea-farmed Atlantic salmon suffering from gill disease. Following qPCR analysis of gills sampled for Ca. P. salmonis, Ca. B. cysticola, D. lepeophtherii and P. perurans from 22 geographically spread outbreaks, five cases representing different infectious loads and combinations of agents were chosen for histopathological scoring. Twenty-eight histological features were evaluated and potential associations between individual pathological changes and the occurrence of individual agents studied. The inter-observer agreement in interpretation of histological parameters between the three pathologists involved, was calculated to validate robustness of the scoring scheme. Seventeen histological parameters met the criteria for inter-observer agreement analysis and were included in the calculation. The three most frequent findings were identification of subepithelial leukocytes, epithelial cell hyperplasia and mucus cell hyperplasia. While few findings could be specifically related to particular agents, necrosis in hyperplastic lesions, pustules and necrosis of subepithelial cells appeared to be associated with the presence of Ca. B. cysticola. Further, lesion profiles clearly support the previously identified association between P. perurans and pathological changes associated with AGD. Very few pathological changes were observed in the single case in which Ca. P. salmonis was the dominating agent. Some lesions were only very rarely observed e.g. chloride cell necrosis, epithelial cell apoptosis, lamellar deposition of melanin and haemophagocytosis. The scoring scheme developed and applied was robust and sensitive. A less extensive scheme for routine diagnostic use is proposed. [ABSTRACT FROM AUTHOR]
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- 2019
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42. Botulinum toxin A injection into the entopeduncular nucleus improves dynamic locomotory parameters in hemiparkinsonian rats.
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Tsang, Adrianna R., Rajakumar, Nagalingam, and Jog, Mandar S.
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BOTULINUM A toxins , *BOTULINUM toxin , *DEEP brain stimulation , *LOCOMOTOR control , *GLOBUS pallidus , *PARKINSON'S disease - Abstract
Parkinson’s disease is associated with hyperactivity of the subthalamic nucleus (STN), contributing to motor and gait disturbances. Although deep brain stimulation of the STN alleviates certain motor dysfunction, its specific effect on gait abnormalities remains controversial. This study investigated the long-term changes in locomotion following direct infusions of botulinum toxin-A into the globus pallidus internal segment (GPi) to suppress the flow of information from the STN to the GPi in a hemiparkinsonian rat model. Static and dynamic gait parameters were quantified using a CatWalk apparatus. Interestingly, botulinum toxin-A at 0.5 ng significantly reduced only the dynamic gait parameters of hemiparkinsonian rats at 1 week and 1 month post-infusion, while static gait parameters did not change. This study offers new insights into the complexity of basal ganglia in locomotor control and shows the potential of central infusion of botulinum toxin-A as a novel intervention in the study of experimental hemiparkinson’s disease. [ABSTRACT FROM AUTHOR]
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- 2019
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43. L-3,3’,5-triiodothyronine and pregnenolone sulfate inhibit Torpedo nicotinic acetylcholine receptors.
- Author
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Moffett, Steven X., Klein, Eric A., Brannigan, Grace, and Martin, Joseph V.
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NICOTINIC acetylcholine receptors , *LIGAND-gated ion channels , *MUSCARINIC acetylcholine receptors , *CHOLINERGIC receptors , *BINDING sites , *SULFATES , *THYROID hormones - Abstract
The nicotinic acetylcholine receptor (nAChR) is an excitatory pentameric ligand-gated ion channel (pLGIC), homologous to the inhibitory γ-aminobutyric acid (GABA) type A receptor targeted by pharmaceuticals and endogenous sedatives. Activation of the GABAA receptor by the neurosteroid allopregnanolone can be inhibited competitively by thyroid hormone (L-3,3’,5-triiodothyronine, or T3), but modulation of nAChR by T3 or neurosteroids has not been investigated. Here we show that allopregnanolone inhibits the nAChR from Torpedo californica at micromolar concentrations, as do T3 and the anionic neurosteroid pregnenolone sulfate (PS). We test for the role of protein and ligand charge in mediated receptor inhibition by varying pH in a narrow range around physiological pH. We find that both T3 and PS become less potent with increasing pH, with remarkably similar trends in IC50 when T3 is neutral at pH < 7.3. After deprotonation of T3 (but no additional deprotonation of PS) at pH 7.3, T3 loses potency more slowly with increasing pH than PS. We interpret this result as indicating the negative charge is not required for inhibition but does increase activity. Finally, we show that both T3 and PS affect nAChR channel desensitization, which may implicate a binding site homologous to one that was recently indicated for accelerated desensitization of the GABAA receptor by PS. [ABSTRACT FROM AUTHOR]
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- 2019
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44. Genetic relationships between the RACK1 homolog cpc-2 and heterotrimeric G protein subunit genes in Neurospora crassa.
- Author
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Garud, Amruta, Carrillo, Alexander J., Collier, Logan A., Ghosh, Arit, Kim, James D., Lopez-Lopez, Berenise, Ouyang, Shouqiang, and Borkovich, Katherine A.
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NEUROSPORA crassa , *G proteins , *EPISTASIS (Genetics) , *SCAFFOLD proteins , *CHIMERIC proteins , *HOMOLOGY (Biology) , *PROTEIN fractionation - Abstract
eceptor for ctivated inase-1 (RACK1) is a multifunctional eukaryotic scaffolding protein with a seven WD repeat structure. Among their many cellular roles, RACK1 homologs have been shown to serve as alternative Gβ subunits during heterotrimeric G protein signaling in many systems. We investigated genetic interactions between the RACK1 homolog cpc-2, the previously characterized Gβ subunit gnb-1 and other G protein signaling components in the multicellular filamentous fungus Neurospora crassa. Results from cell fractionation studies and from fluorescent microscopy of a strain expressing a CPC-2-GFP fusion protein revealed that CPC-2 is a cytoplasmic protein. Genetic epistasis experiments between cpc-2, the three Gα genes (gna-1, gna-2 and gna-3) and gnb-1 demonstrated that cpc-2 is epistatic to gna-2 with regards to basal hyphae growth rate and aerial hyphae height, while deletion of cpc-2 mitigates the increased macroconidiation on solid medium observed in Δgnb-1 mutants. Δcpc-2 mutants inappropriately produce conidiophores during growth in submerged culture and mutational activation of gna-3 alleviates this defect. Δcpc-2 mutants are female-sterile and fertility could not be restored by mutational activation of any of the three Gα genes. With the exception of macroconidiation on solid medium, double mutants lacking cpc-2 and gnb-1 exhibited more severe defects for all phenotypic traits, supporting a largely synergistic relationship between GNB-1 and CPC-2 in N. crassa. [ABSTRACT FROM AUTHOR]
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- 2019
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45. Model-based QTL detection is sensitive to slight modifications in model formulation.
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Barrasso, Caterina, Memah, Mohamed-Mahmoud, Génard, Michel, and Quilot-Turion, Bénédicte
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CROP growth , *CROP yields , *GOODNESS-of-fit tests , *GLOBAL optimization , *ABIOTIC stress - Abstract
Classical crop models have been developed to predict crop yield and quality, and they are based on physiological and environmental inputs. After molecular discoveries, models should integrate genetic variation to allow predictions that are more genotype-dependent. An interesting approach, Quantitative Trait Locus (QTL)-based ecophysiological modeling, has shown promising results for the design of ideotypes that are adapted to biotic and abiotic stresses, but there are still limitations to attaining a fully integrated model. The aim of this case study is to clarify the impact of choosing different model equations (closely related and with different numbers of parameters) and optimization methods on the detection of QTLs controlling the parameters of crop growth. Different growth equations were parameterized based on a genetic population by following different approaches. The correlations between parameters were analyzed, and two different strategies were adopted to address the correlation issue. QTL analysis was performed on the optimized values of the parameters of the growth equations and on the observed dry mass (DM) data to validate the QTLs detected. Overall, models and strategies resulted in different QTLs being detected. Similar LOD profiles but with peaks of different heights were observed, some of which were significant, resulting in different numbers of QTLs. In some cases, peaks had slightly different positions or were absent. Even closely related growth models led to the detection of different QTLs. The goodness of fit and complexity of the growth models were found to be insufficient to select the best model. Calculating parameters independently of observed data may not be a good strategy, whereas setting parameters independent of the genotype is recommended. Given the large-scale global optimization problem and the strong correlations between parameters, the two algorithms tested showed poor performance. Currently, the lack of effective algorithms is the main obstacle to answering the question posed. The authors therefore suggest testing different model formulations and comparing the QTLs detected before choosing the best formulation to use in an ecophysiological modeling approach based on QTLs. [ABSTRACT FROM AUTHOR]
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- 2019
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46. Is latent tuberculosis infection challenging in Iranian health care workers? A systematic review and meta-analysis.
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YektaKooshali, Mohammad Hossein, Movahedzadeh, Farahnaz, Foumani, Ali Alavi, Sabati, Hoda, and Jafari, Alireza
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MEDICAL subject headings , *MEDICAL care , *LATENT variables , *META-analysis , *PERSIAN language , *SEARCH engines - Abstract
Background: The high chances of getting latent tuberculosis infection (LTBI) among health care workers (HCWs) will an enormous problem in low and upper-middle-income countries. Method: Search strategies were done through both national and international databases include SID, Barakat knowledge network system, Irandoc, Magiran, Iranian national library, web of science, Scopus, PubMed/MEDLINE, OVID, EMBASE, the Cochrane library, and Google Scholar search engine. The Persian and the English languages were used as the filter in national and international databases, respectively. Medical Subject Headings (MeSH) terms was used to controlling comprehensive vocabulary. The search terms were conducted without time limitation till January 01, 2019. Results: The prevalence of LTBI in Iranian’s HCWs, based on the PPD test was 27.13% [CI95%: 18.64–37.7]. The highest prevalence of LTBI in Iranian’s HCWs were estimated 41.4% [CI95%: 25.4–59.5] in the north, and 33.8% [CI95%: 21.1–49.3] in the west. The lowest prevalence of LTBI was evaluated 18.2% [CI95%: 3.4–58.2] in the south of Iran. The prevalence of LTBI in Iranian’s HCWs who had work-experience more than 20 years old were estimated 20.49% [CI95%: 11–34.97]. In the PPD test, the prevalence of LTBI in Iranian’s HCWs who had received the Bacille Calmette–Guérin (BCG) was estimated 15% [CI95%: 3.6–47.73]. While, in the QFT, the prevalence of LTBI in Iranian’s HCWs in non-vaccinated was estimated 25.71% [CI95%: 13.96–42.49]. Conclusions: This meta-analysis shows the highest prevalence of LTBI in Iranian’s HCWs in the north and the west probably due to neighboring countries like Azerbaijan and Iraq, respectively. It seems that Iranian’s HCWs have not received the necessary training to prevent of TB. We also found that BCG was not able to protect Iranian’s HCWs from TB infections, completely. [ABSTRACT FROM AUTHOR]
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- 2019
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47. Soil erosion and corn yield in a cultivated catchment of the Chinese Mollisol region.
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Yang, Weige, Zhang, Xiaocun, Gong, Wei, Ye, Yuanyuan, and Yang, Yongsheng
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CORN yields , *SOIL erosion , *CORN , *AGRICULTURAL productivity , *SOIL conservation , *CROP yields - Abstract
Evaluation of soil redistribution rates and influence on crop yield in agricultural catchments is very important information, which can provide a scientific basis for arrangement of soil and water conservation measures and sustainable crop production. In recent decades, the soil erosion has greatly aggravated in the Mollisol region of Northeast China due to unreasonable land management, which in turn has reduced crop yield. The objectives of this study were to investigate the spatial distribution of soil redistribution and the relationship between crop yield and soil redistribute at a catchment of the Chinese Mollisol region. A total of 176 soil samples were collected based on a 200 m by 200 m grid and 4 yr of corn (Zea mays L.) yields were measured. The 137Cs trace technique and Zhang Xinbao’s mass balance model indicated that the soil redistribution rates ranged from −7122.25 to 5471.70 t km−2 yr−1 and averaged −830.10 t km−2 yr−1. Soil erosion dominated in the research area. The corn yields for four years ranged from 43.24 to 136.19 kg km−2 and averaged 90.42 kg km−2. The spatial distribution of soil redistribution rates and corn yield showed a similar ribbon and plaque characteristics at the catchment. An equation between corn yield and soil redistribution rates was fitted and showed that there was a significant negative correlation between corn yield and soil erosion rates, while there was no relationship between the corn yield and soil deposition rates. Therefore, effective soil and water conservation measures are urgently needed to increase crop yield and realize sustainable land-use management. [ABSTRACT FROM AUTHOR]
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- 2019
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48. An elevated glycemic gap predicts adverse outcomes in diabetic patients with necrotizing fasciitis.
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Chen, Po-Chuan, Tsai, Shih-Hung, Wang, Jen-Chun, Tzeng, Yuan-Sheng, Wang, Yung-Chih, Chu, Chi-Ming, Chu, Shi-Jye, and Liao, Wen-I
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INTENSIVE care units , *TRAUMA centers , *NECROTIZING fasciitis , *APACHE (Disease classification system) - Abstract
Background: Diabetes is the most common comorbidity of necrotizing fasciitis (NF), but the effect of stress-induced hyperglycemia (SIH) on diabetic patients with NF has never been investigated. The aim of this study was to assess whether SIH, as determined by the glycemic gap between admission glucose levels and A1C-derived average glucose levels, predicts adverse outcomes in diabetic patients hospitalized with NF. Methods: We retrospectively reviewed the glycemic gap and clinical outcomes in 252 diabetic patients hospitalized due to NF from 2011 to 2018 in a single medical center in Taiwan. A receiver operating characteristic (ROC) curve was used to analyze the optimal cutoff values for predicting adverse outcomes. Univariate and multivariate logistic regression analyses were employed to identify significant predictors of adverse outcomes. Results: In total, 194 diabetic NF patients were enrolled. Compared with patients without adverse outcomes, patients with adverse outcomes had significantly higher glycemic gaps, Acute Physiology and Chronic Health Evaluation (APACHE) II scores and C-reactive protein (CRP) levels; lower albumin and hemoglobin levels; greater incidence of limb loss; and longer hospital and intensive care unit stays. The glycemic gap positively correlates with the laboratory risk indicator for NF scores, APACHE II scores and CRP levels. A glycemic gap of 146 mg/dL was the optimal cutoff value for predicting adverse outcomes using the ROC curve. Compared with patients with glycemic gaps ≤146 mg/dL, those with glycemic gaps >146 mg/dL had higher APACHE II scores and incidence rates of adverse outcomes, especially bacteremia and acute kidney injury. Multivariate analysis revealed that a glycemic gap >146 mg/dL and APACHE II score >15 were independent predictors of adverse outcomes, while the presence of hyperglycemia at admission was not. Conclusions: An elevated glycemic gap was significantly independently associated with adverse outcomes in diabetic NF patients. Further prospective studies are warranted to validate the role of the glycemic gap in NF patients with diabetes. [ABSTRACT FROM AUTHOR]
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- 2019
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- View/download PDF
49. Variation in pickleweed root-associated microbial communities at different locations of a saline solid waste management unit contaminated with petroleum hydrocarbons.
- Author
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Khan, Abdur Rahim, Reichmann, L. G., Ibal, J. C., Shin, J. H., Liu, Y., Collins, H., LePage, B., and Terry, N.
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SOLID waste management , *MICROBIAL communities , *POLYCYCLIC aromatic hydrocarbons , *PETROLEUM , *HYDROCARBONS , *PETROLEUM chemicals , *FUNGAL communities , *MICROBIAL enzymes - Abstract
The main purpose of this study was to explore the potential influences of pickleweed vegetation on the abundance, diversity and metabolic activities of microbial communities in four distinct areas of a petroleum-contaminated solid waste management unit (SWMU) located in Contra Costa County, northern California. The four areas sampled include two central areas, one of which is central vegetated (CV) and one unvegetated (UV), and two peripheral vegetated areas, one of which is located to the west side of the SWMU (V-West) and one located to the east side (V-East). Measurements were made of total petroleum hydrocarbons (TPH), polyaromatic hydrocarbons (PAH), soil physicochemical properties, and various aspects of microbial communities including metabolic activities, microbial abundances (PLFAs), diversity and composition based on amplicon sequencing. The peripheral V-East and V-West sites had 10-times lower electrical conductivity (EC) than that of the CV and UV sites. The high salinity levels of the CV and UV sites were associated with significant reductions in bacterial and fungal abundances (PLFA) when compared to V-East but not when compared to V-West. TPH levels of CV and UV were not significantly different from those of V-West but were substantially lower than V-East TPH (19,311 mg/kg of dry soil), the high value of which may have been associated with a pipeline that ran through the area. Microbial activities (in terms of soil respiration and the activities of three soil enzymes, i.e., urease, lipase, and phosphatase) were greatest in the vegetated sites compared to the UV site. The prokaryotic community was not diverse as revealed by the Shannon index with no significant variation among the four groups of samples. However, the fungal community of the peripheral sites, V-East and V-West had significantly higher OTU richness and Shannon index. Structure of prokaryotic communities inhabiting the rhizosphere of pickleweed plants at the three sites differed significantly and were also different from those found in the UV region of the central site according to pairwise, global PERMANOVA and ANOSIM analyses. The differences in OTU-based rhizosphere-associated bacterial and fungal communities’ composition were explained mainly by the changes in soil EC and pH. The results suggest that saline TPH-contaminated areas that are vegetated with pickleweed are likely to have increased abundances, diversity and metabolic activities in the rhizosphere compared to unvegetated areas, even in the presence of high salinity. [ABSTRACT FROM AUTHOR]
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- 2019
- Full Text
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50. Movement and habitat selection of the western spadefoot (Spea hammondii) in southern California.
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Baumberger, Katherine L., Eitzel, M. V., Kirby, Matthew E., and Horn, Michael H.
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HABITAT selection , *LOAM soils , *NATURAL history , *URBAN planning , *RADIO transmitters & transmission , *WILDLIFE conservation , *TUNDRAS - Abstract
Agricultural activity, urban development and habitat alteration have caused the disappearance of the western spadefoot (Spea hammondii) from 80% of its geographic range in southern California. Despite the western spadefoot’s continuing decline, little research has been conducted on its natural history. The home range of adult spadefoots is unknown, and their use of upland habitat is poorly understood. Both factors are important for the long-term conservation of the species because adult spadefoots spend the majority of their lives away from breeding pools in self-excavated burrows. Between January 2012 and January 2013, we surgically implanted radio transmitters in 15 spadefoots at two locations and recorded their movements and habitat use. The mean distance moved between burrow locations was 18 m (SD ± 24.1 m, range1–204 m). The mean distance of burrows from the breeding pools was 40 m (SD ± 37.42 m, range 1–262 m). Rain was a significant predictor of spadefoot movement, with more rain predicting higher probability of movement and larger distances moved. At remote sensing scale (1 m) spadefoots selected grassland habitat for their burrow locations. At the microsite scale (< 1 m) spadefoots strongly selected duff over grass or shrub cover. Spadefoots burrowed in friable, sandy/loam soil with significantly less clay than random pseudoabsence points. This research enhances our understanding of a little-studied species and will contribute to the development of effective management plans for the western spadefoot. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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