109 results on '"Michel, K."'
Search Results
2. Gaia search for stellar companions of TESS Objects of Interest IV.
- Author
-
Mugrauer, M., Rück, J., and Michel, K.‐U.
- Subjects
MAIN sequence (Astronomy) ,ASTROMETRY ,MULTIPLICITY (Mathematics) - Abstract
We present the latest results of our ongoing multiplicity study of (Community) TESS Objects of Interest, using astrometric and photometric data from the ESA‐Gaia mission to detect stellar companions of these stars and characterize their properties. A total of 134 binary, 6 hierarchical triple, and two quadruple star systems are identified among 1106 targets whose multiplicity is investigated in the course of our survey, located at distances closer than about 500 pc around the Sun. The detected companions and targets are at the same distance and have a common proper motion, as expected for components of gravitationally bound stellar systems, as demonstrated by their accurate Gaia DR3 astrometry. The companions have masses from about 0.11 to 2 M⊙$$ {M}_{\odot } $$ and are most abundant in the mass range between 0.2 and 0.5 M⊙$$ {M}_{\odot } $$. The companions have projected separations from the targets between about 50 and 9700 au. Their frequency is the highest and constant from about 300 up to 750 au, decreasing at larger projected separations. In addition to main sequence stars, four white dwarf companions are detected in this study, whose true nature is revealed by their photometric properties. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Comparing Field, Probabilistic, and 2D Numerical Approaches to Assess Gravel Mobility in a Gravel‐Bed River.
- Author
-
Arnaud, F., Paquier, A., Vázquez‐Tarrío, D., Camenen, B., Le Coz, J., Michel, K., Naudet, G., Pella, H., and Piégay, H.
- Subjects
GRAVEL ,DISTRIBUTION (Probability theory) ,SEDIMENT transport ,PARTICLE tracks (Nuclear physics) ,BED load ,PROBABILISTIC number theory - Abstract
Sediment transport is a key process that affects the morphology and ecological habitat diversity of rivers. As part of a gravel augmentation program to mitigate sediment deficit below a dam, gravel mobility in the Ain River in Eastern France was investigated by tracking of a large amount (n = 1,063) of PIT‐tagged gravels in the field, conducting a probabilistic approach based on published tracer studies, and performing two‐dimensional (2D) numerical modeling of flow and bedload transport. This comparative study highlights the strengths, weaknesses, and complementary aspects of the three approaches to the understanding of river gravel mobility. Thanks to recent technological improvements, PIT‐tagged gravels provide an increasingly reliable and accurate representation of bedload movement in the field, although it remains limited in spatio‐temporal resolution. Based on an exponential distribution, the probabilistic approach correctly reproduces the average trend in travel distances by the different classes of particles over hydrological periods, including one or several significant floods. Furthermore, the 2D numerical modeling accounts for the variability of local hydrodynamic conditions and can simulate realistic displacement distributions for the different classes of particles with high spatio‐temporal resolution. Numerical modeling is a very encouraging approach, which makes our study original because it is the first time that the estimation of mean travel distances, the application of an exponential distribution, and the comparison with a hydrodynamic model are combined. A more effective modeling strategy involves incorporating a probabilistic transport model in the 2D numerical model to reproduce the observed scatter of the individual particle trajectories. Key Points: PIT‐tagged gravels are used to track gravel mobility in the restored Ain RiverThe results of field tracer surveys are compared with probabilistic and two‐dimensional numerical modelingThe three approaches are found to be meaningful and complementary [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Raman spectroscopy system for real‐time diagnosis of clinically significant prostate cancer tissue.
- Author
-
van Breugel, Suse J., Low, Irene, Christie, Mary L., Pokorny, Morgan R., Nagarajan, Ramya, Holtkamp, Hannah U., Srinivasa, Komal, Amirapu, Satya, Nieuwoudt, Michel K., Simpson, M. Cather, Zargar‐Shoshtari, Kamran, and Aguergaray, Claude
- Abstract
Prostate cancer (PCa) is a significant healthcare problem worldwide. Current diagnosis and treatment methods are limited by a lack of precise in vivo tissue analysis methods. Real‐time cancer identification and grading could dramatically improve current protocols. Here, we report the testing of a thin optical probe using Raman spectroscopy (RS) and classification methods to detect and grade PCa accurately in real‐time. We present the first clinical trial on fresh ex vivo biopsy cores from an 84 patient cohort. Findings from 2395 spectra measured on 599 biopsy cores show high accuracy for diagnosing and grading PCa. We can detect clinically significant PCa from benign and clinically insignificant PCa with 90% sensitivity and 80.2% specificity. We also demonstrate the ability to differentiate cancer grades with 90% sensitivity and specificity ≥82.8%. This work demonstrates the utility of RS for real‐time PCa detection and grading during routine transrectal biopsy appointments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. A rare case of drug sensitive adult‐onset temporal lobe epilepsy due to a focal cortical dysplasia revealed by ictal coughing: First report in sub‐Saharan Africa.
- Author
-
Chokote, Eric‐Samuel, Ngarka, Leonard, Takoeta, Emmanuel Oben, Kengni, Hermann Nestor Tsague, Nfor, Leonard N., Mengnjo, Michel K., Mendo, Edwige Laure, Djeutcheu, Fabrice, Yepnjio, Faustin N., Tatah, Godwin Y., Mbassi, Hubert Désiré Awa, and Njamnshi, Alfred K.
- Subjects
FOCAL cortical dysplasia ,TEMPORAL lobe epilepsy ,COUGH ,PARTIAL epilepsy ,EPILEPSY ,MAGNETIC resonance imaging ,LOSS of consciousness - Abstract
This case suggests that clinicians should consider seizures as a differential diagnosis of paroxystic cough with loss of consciousness. Focal cortical dysplasia should equally be screened for with magnetic resonance imaging (MRI) scans even in adults with epilepsy in sub‐Saharan Africa. This case suggests that clinicians should consider seizures as a differential diagnosis of paroxystic cough with loss of consciousness. Focal cortical dysplasia should equally be screened for with Magnetic Resonance Imaging (MRI) scans even in adults with epilepsy in sub‐Saharan Africa. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Morphological assessment of GABA and glutamate inputs to GnRH neurons in intact female mice using expansion microscopy.
- Author
-
Yeo, Shel‐Hwa, Herde, Michel K., and Herbison, Allan E.
- Subjects
- *
EXPANSION microscopy , *GLUTAMATE receptors , *DENDRITES , *NEURONS , *GLUTAMATE transporters , *GABA transporters , *GABA - Abstract
The roles GABAergic and glutamatergic inputs in regulating the activity of the gonadotrophin‐releasing hormone (GnRH) neurons at the time of the preovulatory surge remain unclear. We used expansion microscopy to compare the density of GABAergic and glutamatergic synapses on the GnRH neuron cell body and proximal dendrite in dioestrous and pro‐oestrous female mice. An evaluation of all synapses immunoreactive for synaptophysin revealed that the highest density of inputs to rostral preoptic area GnRH neurons occurred within the first 45 µm of the primary dendrite (approximately 0.19 synapses µm‐1) with relatively few synapses on the GnRH neuron soma or beyond 45 µm of the dendrite (0.05‐0.08 synapses µm‐1). Triple immunofluorescence labelling demonstrated a predominance of glutamatergic signalling with twice as many vesicular glutamate transporter 2 synapses detected compared to vesicular GABA transporter. Co‐labelling with the GABAA receptor scaffold protein gephyrin and the glutamate receptor postsynaptic density marker Homer1 confirmed these observations, as well as the different spatial distribution of GABA and glutamate inputs along the dendrite. Quantitative assessments revealed no differences in synaptophysin, GABA or glutamate synapses at the proximal dendrite and soma of GnRH neurons between dioestrous and pro‐oestrous mice. Taken together, these studies demonstrate that the GnRH neuron receives twice as many glutamatergic synapses compared to GABAergic synapses and that these inputs preferentially target the first 45 µm of the GnRH neuron proximal dendrite. These inputs appear to be structurally stable before the onset of pro‐oestrous GnRH surge. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
7. Optimal allocation of law enforcement patrol effort to mitigate poaching activities.
- Author
-
Moore, Jennifer F., Udell, Bradley J., Martin, Julien, Turikunkiko, Ezechiel, and Masozera, Michel K.
- Subjects
POACHING ,LAW enforcement ,INTEGER programming ,DECISION making ,MATHEMATICAL optimization ,LINEAR programming - Abstract
Poaching is a global problem causing the decline of species worldwide. Optimizing the efficiency of ranger patrols to deter poaching activity at the lowest possible cost is crucial for protecting species with limited resources. We applied decision analysis and spatial optimization algorithms to allocate efforts of ranger patrols throughout a national park. Our objective was to mitigate poaching activity at or below management risk targets for the lowest monetary cost. We examined this trade‐off by constructing a Pareto efficiency frontier using integer linear programming. We used data from a ranger‐based monitoring program in Nyungwe National Park, Rwanda. Our measure of poaching risk is based on dynamic occupancy models that account for imperfect detection of poaching activities. We found that in order to achieve a 5% reduction in poaching risk, 622 ranger patrol events (each corresponding to patrolling 1‐km2 sites) were needed within a year at a cost of US$49,760. In order to attain a 60% reduction in poaching risk, 15,560 patrol events were needed at a cost of US$1,244,800. We evaluated the trade‐off between patrol cost and poaching risk based on our model by constructing a Pareto efficiency frontier and park managers found the solution for a 50% risk reduction to be a practical trade‐off based on funding constraints (comparable to recent years) and the diminishing returns between risk mitigation and cost. This expected reduction in risk required 8,558 patrol events per year at a cost of US$684,640. Our results suggest that optimal solutions could increase efficiency compared to the actual effort allocations from 2006 to 2016 in Nyungwe National Park (e.g., risk reductions of ~30% under recent budgets compared to ~50% reduction in risk under the optimal strategy). The modeling framework in this study took into account imperfect detection of poaching risk as well as the directional and conditional nature of ranger patrol events given the spatial adjacency relationships of neighboring sites and access points. Our analyses can help to improve the efficiency of ranger patrols, and the modeling framework can be broadly applied to other spatial conservation planning problems with conditional, multilevel, site selection. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
8. The Cascade Reactions of Indigo with Propargyl Substrates for Heterocyclic and Photophysical Diversity.
- Author
-
McCosker, Patrick M., Butler, Nicholas M., Shakoori, Alireza, Volland, Michel K., Perry, Matthew J., Mullen, Jesse W., Willis, Anthony C., Clark, Timothy, Bremner, John B., Guldi, Dirk M., and Keller, Paul A.
- Subjects
DENSITY functional theory ,PERMUTATION groups ,EXCITED states ,SPACE exploration ,ELECTROPHILES - Abstract
The synthesis of structurally diverse heterocycles for chemical space exploration was achieved via the cascade reactions of indigo with propargylic electrophiles. New pyrazinodiindolodione, naphthyridinedione, azepinodiindolone, oxazinoindolone and pyrrolodione products were prepared in one pot reactions by varying the leaving group (‐Cl, ‐Br, ‐OMs, ‐OTs) or propargyl terminal functionality (‐H, ‐Me, ‐Ph, ‐Ar). Mechanistic and density functional theory studies revealed that the unsaturated propargyl moiety can behave as an electrophile when aromatic terminal substitutions are made, and therefore competes with leaving group substitution for new outcomes. Selected products from the cascade reactions were investigated for their absorption and fluorescence properties, including transient absorption spectroscopy. This revealed polarity dependent excited state relaxation pathways, fluorescence, and triplet formation, thus highlighting these reactions as a means to access diverse functional materials rapidly. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
9. Effects of the herbal preparation STW 5‐II on in vitro muscle activity in the guinea pig stomach.
- Author
-
Schemann, Michael, Landmann, Martina, Kelber, O., Ammar, Ramy M., Krueger, Dagmar, and Michel, K.
- Subjects
GUINEA pigs ,GASTROINTESTINAL motility ,MUSCLES ,STOMACH ,MUSCLE tone ,PYLORUS - Abstract
Background: STW 5 is a combination of nine medicinal herbal extracts and used to treat functional gastrointestinal disorders including functional dyspepsia. It has a region‐specific effect by relaxing the proximal and contracting the distal stomach. The research combination STW 5‐II (Iberogast® Advance) lacks three herbal extracts but seems clinically as effective as STW 5. However, the action of STW 5‐II on gastric motility is unknown. Methods: In vitro circular and longitudinal muscle tone and contractility were recorded from guinea pig gastric fundus and antrum with isometric force transducers. Key Results: STW 5‐II decreased concentration‐dependently (64‐512 µg/ml) the tone of circular and longitudinal muscle strips from the fundus. In contrast, STW 5‐II increased concentration‐dependently contraction amplitude in antral circular and longitudinal muscle. The effects were region‐dependent but comparable in the two muscle layers. Application of 512 µg STW 5 or STW 5‐II revealed comparable effects in the fundus and antrum circular and longitudinal muscle strips. Conclusions and Interferences: STW 5‐II had a region‐specific effect and relaxed the proximal stomach but increased the contractility in the antrum. It was as effective as STW 5 which may explain its comparable clinical effects in treating functional dyspepsia. Impaired accommodation may be normalized through relaxation of the fundus, while the motility‐promoting effects leading to an increase in antral motility may activate the gastric pump. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
10. Comparison of ground‐based and UAV a‐UHF artificial tracer mobility monitoring methods on a braided river.
- Author
-
Cassel, M., Piégay, H., Fantino, G., Lejot, J., Bultingaire, L., Michel, K., and Perret, F.
- Subjects
BRAIDED rivers ,SCIENTIFIC community ,WATERSHEDS ,WATER depth ,RADIO frequency ,FREIGHT trucking - Abstract
Radio frequency identification (RFID) technologies, which allow wireless detection of individual buried or immersed tracers, represent a step forward in sediment tracking, especially passive integrated transponders (PIT tags) that have been widely used. Despite their widespread adoption in the scientific community, they typically have low efficiency when deployed in river systems with active bedload transport or deep wet channels, attributed to their technical specifications. A recent evaluation of active ultra‐high frequency transponders (a‐UHF tags) assessed their larger detection range and provided a methodology for their geopositioning. In this study, we test five different survey methods (one including an unmanned aerial vehicle [UAV]) in a sediment tracking study, and compare them in terms of recovery rate, field effort, geopositioning error, and efficiency. We then tested the method on a larger reach following a Q5 flood and performed cross‐comparisons between active and passive RFIDs. The results confirmed that the a‐UHF RFID technology allowed rapid (1.5 h ha−1) survey of a large area (<34 ha) of emerged bars and shallow water channels with recovery of a high percentage of tracers (72%) that had travelled large distances (mean ≈ 1000 m; max ≈ 3400 m). Moreover, the tracers were identified with low geopositioning error (mean ≈ 7.1 m, ≤1% of their travel distance). We also showed that a UAV‐based survey was fast (0.38 h ha−1), efficient (recovery rate = 84%), and low error (mean ≈ 4.2 m). Thus, a‐UHF RFID technology permits the development of a variety of survey methods, depending on the study objectives and the human and financial resources available. This allows field efforts to be optimized by determining an appropriate balance between the high equipment cost of a‐UHF tracers and the resulting reduced survey costs. © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. Cover Picture: Astron. Nachr. 09/2023.
- Author
-
Mugrauer, M., Rück, J., and Michel, K.‐U.
- Subjects
MAIN sequence (Astronomy) - Abstract
The non-detection in the IR image reveals that TOI 4301 B must be a white dwarf rather than a main sequence star. Discovery of a white dwarf companion of TESS Object of Interest TOI 4301 A seen at the center of all images. The co-moving white dwarf companion TOI 4301 B is imaged with the UK Schmidt Telescope (UKST) in filters GG 395 (Blue) and RG 610 (Red), respectively. [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
12. Shifting through the forest: home range, movement patterns, and diet of the eastern chimpanzee (Pan troglodytes schweinfurthii) in Nyungwe National Park, Rwanda.
- Author
-
Moore, Jennifer F., Mulindahabi, Felix, Gatorano, Gratien, Niyigaba, Protais, Ndikubwimana, Innocent, Cipolletta, Chloé, and Masozera, Michel K.
- Subjects
PAN troglodytes schweinfurthii ,ENDANGERED species ,NATIONAL parks & reserves ,CHIMPANZEES ,WILDLIFE conservation - Abstract
Abstract: Populations of the endangered eastern chimpanzee (Pan troglodytes schweinfurthii) are declining throughout their range. Although Nyungwe National Park (NNP) harbors the largest remaining eastern chimpanzee population in Rwanda, we know little about their space use and dietary patterns. We studied home range, movement, and diet of two communities of chimpanzees in NNP using daily tracking data (6:00 am to 6:00 pm) collected from 2000 to 2015. One community, Mayebe, resided in the forest center, and the other community, Cyamudongo, inhabited a forest fragment located about 10 km from the main forest. Home range estimated with the 95% kernel density estimation (KDE) method was 21 km
2 for the Mayebe community and 4 km2 for the Cyamudongo community. Chimpanzee home range sizes were smaller during the dry versus wet season and varied monthly throughout the year. The Mayebe community had an average hourly step length of 75 ± SE 5 m with a daily movement range of 987 ± SE 71 m, while the Cyamudongo community had a shorter hourly step length of 52 ± SE 3 m with a daily movement range of 651 ± SE 71 m. Both chimpanzee communities fed primarily on Ficus spp. Other important dietary items included fruits of Symphonia globulifera, Syzygium guineense, and Chrysophyllum gorungosanum for the Mayebe community and Trilepisium madagascariense for the Cyamudongo community. Food choice varied monthly and seasonally for each chimpanzee community. Our study provides the first estimates of home range size and movement parameters for chimpanzees in Rwanda and documents their food habits and seasonal variations therein. We also identified the 50% core home range for each chimpanzee community and suggest this area as the focus of management actions. These results could help park management reduce threats to chimpanzees and other sympatric species by improving the efficiency of ranger patrols. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
13. High prevalence and functional effects of serum antineuronal antibodies in patients with gastrointestinal disorders.
- Author
-
Lütt, A., Michel, K., Krüger, D., Volz, M. S., Nassir, M., Schulz, E., Poralla, L., Tangermann, P., Bojarski, C., Höltje, M., Teegen, B., Stöcker, W., Schemann, M., Siegmund, B., and Prüss, H.
- Subjects
- *
DISEASE prevalence , *NEUROPLASTICITY , *IMMUNOGLOBULINS , *ANGIOTENSIN converting enzyme - Abstract
Abstract: Background: Antineuronal antibodies can be associated with both gastrointestinal (GI) and brain disorders. For example, antibodies against the potassium channel subunit dipeptidyl‐peptidase‐like protein‐6 (DPPX) bind to neurons in the central nervous system (CNS) and myenteric plexus and cause encephalitis, commonly preceded by severe unspecific GI symptoms. We therefore investigated the prevalence of antineuronal antibodies indicative of treatable autoimmune CNS etiologies in GI patients. Methods: Serum samples of 107 patients (Crohn's disease n = 42, ulcerative colitis n = 16, irritable bowel syndrome n = 13, others n = 36) and 44 healthy controls were screened for anti‐DPPX and further antineuronal antibodies using immunofluorescence on rat brain and intestine and cell‐based assays. Functional effects of high‐titer reactive sera were assessed in organ bath and Ussing chamber experiments and compared to non‐reactive patient sera. Key Results: Twenty‐one of 107 patients (19.6%) had antibodies against the enteric nervous system, and 22 (20.6%) had anti‐CNS antibodies, thus significantly exceeding frequencies in healthy controls (4.5% each). Screening on cell‐based assays excluded established antienteric antibodies. Antibody‐positive sera were not associated with motility effects in organ bath experiments. However, they induced significant, tetrodotoxin (TTX)‐insensitive secretion in Ussing chambers compared to antibody‐negative sera. Conclusions & Inferences: Antineuronal antibodies were significantly more frequent in GI patients and associated with functional effects on bowel secretion. Future studies will determine whether such antibodies indicate patients who might benefit from additional antibody‐directed therapies. However, well‐characterized encephalitis‐related autoantibodies such as against DPPX were not detected, underlining their rarity in routine cohorts. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
14. Are ranger patrols effective in reducing poaching-related threats within protected areas?
- Author
-
Moore, Jennifer F., Mulindahabi, Felix, Masozera, Michel K., Nichols, James D., Hines, James E., Turikunkiko, Ezechiel, and Oli, Madan K.
- Subjects
PROTECTED area management ,POACHING ,FOREST rangers ,WILDLIFE conservation ,BIOLOGICAL extinction - Abstract
Poaching is one of the greatest threats to wildlife conservation world-wide. However, the spatial and temporal patterns of poaching activities within protected areas, and the effectiveness of ranger patrols and ranger posts in mitigating these threats, are relatively unknown., We used 10 years (2006-2015) of ranger-based monitoring data and dynamic multi-season occupancy models to quantify poaching-related threats, to examine factors influencing the spatio-temporal dynamics of these threats and to test the efficiency of management actions to combat poaching in Nyungwe National Park (NNP), Rwanda., The probability of occurrence of poaching-related threats was highest at lower elevations (1,801-2,200 m), especially in areas that were close to roads and tourist trails; conversely, occurrence probability was lowest at high elevation sites (2,601-3,000 m), and near the park boundary and ranger posts. The number of ranger patrols substantially increased the probability that poaching-related threats disappear at a site if threats were originally present (i.e. probability of extinction of threats). Without ranger visits, the annual probability of extinction of poaching-related threats was an estimated 7%; this probability would increase to 20% and 57% with 20 and 50 ranger visits per year, respectively., Our results suggest that poaching-related threats can be effectively reduced in NNP by adding ranger posts in areas where they do not currently exist, and by increasing the number of patrols to sites where the probability of poaching activities is high., Synthesis and applications. Our application of dynamic occupancy models to predict the probability of presence of poaching-related threats is novel, and explicitly considers imperfect detection of illegal activities. Based on the modelled relationships, we identify areas that are most vulnerable to poaching, and offer insights regarding how ranger patrols can be optimally deployed to reduce poaching-related threats and other illegal activites, while taking into account potential sampling biases. We show that poaching can be effectively reduced by increasing ranger patrols to areas under high risk of poaching activities, and by adding ranger patrols near these sites. These findings are broadly applicable to national parks and protected areas experiencing a high degree of poaching and other illegal activities. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
15. Subcellular reorganization and altered phosphorylation of the astrocytic gap junction protein connexin43 in human and experimental temporal lobe epilepsy.
- Author
-
Deshpande, Tushar, Li, Tingsong, Herde, Michel K., Becker, Albert, Vatter, Hartmut, Schwarz, Martin K., Henneberger, Christian, Steinhäuser, Christian, and Bedner, Peter
- Published
- 2017
- Full Text
- View/download PDF
16. Tryptase potentiates enteric nerve activation by histamine and serotonin: Relevance for the effects of mucosal biopsy supernatants from irritable bowel syndrome patients.
- Author
-
Ostertag, D., Annahazi, A., Krueger, D., Michel, K., Demir, I. E., Ceyhan, G. O., Zeller, F., and Schemann, M.
- Subjects
TRYPTASE ,HISTIDINE ,BIOGENIC amines ,HISTAMINE ,CLINICAL pathology - Abstract
Background We previously showed that mucosal biopsy supernatants from irritable bowel syndrome patients activated neurons despite low concentrations of tryptase, histamine, and serotonin which individually would not cause spike discharge. We studied the potentiating responses between these mediators on excitability of enteric neurons. Methods Calcium-imaging was performed using the calcium-sensitive dye Fluo-4 AM in human submucous plexus preparations from 45 individuals. Histamine, serotonin, and tryptase were applied alone and in combinations to evaluate nerve activation which was assessed by analyzing increase in intracellular Ca
2+ ([Ca2+ ]i ), the proportion of responding neurons and the product of both defined as Ca-neuroindex ( NI). Protease activated receptor ( PAR) 2 activating peptide, PAR2 antagonist and the serine protease-inhibitor FUT-175 were used to particularly investigate the role of proteases. Key Results Histamine or serotonin (1 μmol/L each) evoked only few small responses (median NI [25%/75%]: 0 [0/148]; 85 [0/705] respectively). Their combined application evoked statistically similar responses (216 [21/651]). Addition of the PAR2 activator tryptase induced a significantly higher Ca- NI (1401 [867/4075]) compared to individual application of tryptase or to coapplied histamine and serotonin. This synergistic potentiation was neither mimicked by PAR2 activating peptide nor reversed by the PAR2 antagonist GB83, but abolished by FUT-175. Conclusions & Inferences We observed synergistic potentiation between histamine, serotonin, and tryptase in enteric neurons, which is mediated by proteolytic activity rather than PAR2 activation. This explained neuronal activation by a cocktail of these mediators despite their low concentrations and despite a relatively small PAR2-mediated response in human submucous neurons. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
17. Many de novo donor-specific antibodies recognize β2-microglobulin-free, but not intact HLA heterodimers.
- Author
-
Michel, K., Santella, R., Steers, J., Sahajpal, A., Downey, F. X., Thohan, V., and Oaks, M.
- Subjects
- *
MICROGLOBULINS , *IMMUNOGLOBULINS , *TRANSPLANTATION of organs, tissues, etc. , *HLA histocompatibility antigens , *IMMUNOASSAY - Abstract
Solid-phase single antigen bead ( SAB) assays are standard of care for detection and identification of donor-specific antibody ( DSA) in patients who receive solid organ transplantation ( SOT). While several studies have documented the reproducibility and sensitivity of SAB testing for DSA, there are little data available concerning its specificity. This study describes the identification of antibodies to β2-microglobulin-free human leukocyte antigen (β2-m- fHLA) heavy chains on SAB arrays and provides a reassessment of the clinical relevance of DSA testing by this platform. Post-transplant sera from 55 patients who were positive for de novo donor-specific antibodies on a SAB solid-phase immunoassay were tested under denaturing conditions in order to identify antibodies reactive with β2-m- fHLA or native HLA ( nHLA). Antibodies to β2-m- fHLA were present in nearly half of patients being monitored in the post-transplant period. The frequency of antibodies to β2-m- fHLA was similar among DSA and HLA antigens that were irrelevant to the transplant (non- DSA). Among the seven patients with clinical or pathologic antibody-mediated rejection (AMR), none had antibodies to β2-m- fHLA exclusively; thus, the clinical relevance of β2-m- fHLA is unclear. Our data suggests that SAB testing produces false positive reactions due to the presence of β2-m- fHLA and these can lead to inappropriate assignment of unacceptable antigens during transplant listing and possibly inaccurate identification of DSA in the post-transplant period. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
18. Theory of thermal expansion in 2D crystals.
- Author
-
Michel, K. H., Costamagna, S., and Peeters, F. M.
- Subjects
- *
THERMAL expansion , *THERMAL properties of crystals , *ELASTICITY , *ANHARMONIC motion , *NANOTECHNOLOGY , *GRAPHENE - Abstract
The thermal expansion [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
19. Construction of a robust and sensitive arginine biosensor through ancestral protein reconstruction.
- Author
-
Whitfield, Jason H., Zhang, William H., Herde, Michel K., Clifton, Ben E., Radziejewski, Johanna, Janovjak, Harald, Henneberger, Christian, and Jackson, Colin J.
- Abstract
Biosensors for signaling molecules allow the study of physiological processes by bringing together the fields of protein engineering, fluorescence imaging, and cell biology. Construction of genetically encoded biosensors generally relies on the availability of a binding 'core' that is both specific and stable, which can then be combined with fluorescent molecules to create a sensor. However, binding proteins with the desired properties are often not available in nature and substantial improvement to sensors can be required, particularly with regard to their durability. Ancestral protein reconstruction is a powerful protein-engineering tool able to generate highly stable and functional proteins. In this work, we sought to establish the utility of ancestral protein reconstruction to biosensor development, beginning with the construction of an l-arginine biosensor. l-arginine, as the immediate precursor to nitric oxide, is an important molecule in many physiological contexts including brain function. Using a combination of ancestral reconstruction and circular permutation, we constructed a Förster resonance energy transfer (FRET) biosensor for l-arginine (cpFLIPR). cpFLIPR displays high sensitivity and specificity, with a K
d of ∼14 µ M and a maximal dynamic range of 35%. Importantly, cpFLIPR was highly robust, enabling accurate l-arginine measurement at physiological temperatures. We established that cpFLIPR is compatible with two-photon excitation fluorescence microscopy and report l-arginine concentrations in brain tissue. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
20. Inducing RNA interference in the arbovirus vector, Culicoides sonorensis.
- Author
-
Mills, M. K., Nayduch, D., and Michel, K.
- Subjects
ARBOVIRUS diseases ,RNA interference ,CULICOIDES ,CERATOPOGONIDAE ,COMMUNICABLE diseases in animals ,VIRAL genomes - Abstract
Biting midges in the genus Culicoides are important vectors of arboviral diseases, including epizootic haemorrhagic disease, bluetongue and most likely Schmallenberg, which cause significant economic burdens worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the difficulty of consistent culturing of certain species and the absence of molecular techniques such as RNA interference ( RNAi). Here, we report the establishment of RNAi as a research tool for the adult midge, Culicoides sonorensis. Based on previous research and transcriptome analysis, which revealed putative small interfering RNA pathway member orthologues, we hypothesized that adult C. sonorensis midges have the molecular machinery needed to perform RNA silencing. Injection of control double-stranded RNA targeting green fluorescent protein ( ds GFP), into the haemocoel of 2-3-day-old adult female midges resulted in survival curves that support virus transmission. dsRNA injection targeting the newly identified C. sonorensis inhibitor of apoptosis protein 1 ( CsIAP1) orthologue resulted in a 40% decrease of transcript levels and 73% shorter median survivals as compared with ds GFP-injected controls. These results reveal the conserved function of IAP1. Importantly, they also demonstrate the feasibility of RNAi by dsRNA injection in adult midges, which will greatly facilitate studies of the underlying mechanisms of vector competence in C. sonorensis. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
21. Soil types will alter the response of arable agroecosystems to future rainfall patterns.
- Author
-
Tataw, J. Tabi, Hall, R., Ziss, E., Schwarz, T., von Hohberg und Buchwald, C., Formayer, H., Hösch, J., Baumgarten, A., Berthold, H., Michel, K., and Zaller, J.G.
- Subjects
SOIL classification ,ARABLE land ,RAINFALL ,VEGETATION & climate ,ECOSYSTEM management ,LYSIMETER ,PEA varieties - Abstract
Climate change scenarios for central Europe predict fewer but heavier rains during the vegetation period without substantial changes in the total amount of annual rainfall. To investigate the impact of rainfall patterns derived from regionalised IPCC scenarios on agroecosystems in Austria, we conducted an experiment using 3 m
2 lysimeters where prognosticated (progn.) rainfall patterns were compared with long-term current rainfall patterns on three agriculturally important soil types (sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem). Lysimeters were cultivated with field peas ( Pisum sativum) according to good farming practice. Prognosticated rainfall patterns decreased crop cover, net primary production ( NPP) and crop yields, but increased root production and tended to decrease mycorrhization. Soil types affected the NPP, crop density and yields, weed biomass and composition, as well as the root production with lowest values commonly found in sandy soils, while other soil types showed almost similar effects. Significant interactions between rainfall patterns and soil types were observed for the harvest index (ratio crop yield versus straw), yield per crop plant, weed density and weed community composition. Abundance of the insect pest pea moth ( Cydia nigricana) tended to be higher under progn. rainfall, but was unaffected by soil types. These results show that (a) future rainfall patterns will substantially affect various agroecosystem processes and crop production in the studied region, and (b) the influence of different soil types in altering ecosystem responses to climate change should be considered when attempting to scale-up experimental results derived at the plot level to the landscape level. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
22. Effect of hyoscine butylbromide (Buscopan®) on cholinergic pathways in the human intestine.
- Author
-
Krueger, D., Michel, K., Allam, S., Weiser, T., Demir, I. E., Ceyhan, G. O., Zeller, F., and Schemann, M.
- Subjects
- *
INTESTINAL disease treatment , *ANTISPASMODICS , *PARASYMPATHOLYTIC agents , *VISCERAL pain , *ENTERIC nervous system , *GASTROINTESTINAL motility disorders , *THERAPEUTICS - Abstract
Background Hyoscine butylbromide ( HBB, Buscopan®) is clinically used to treat intestinal cramps and visceral pain. Various studies, mainly on animal tissues, suggested that its antimuscarinic action is responsible for its spasmolytic effect. However, functional in vitro studies with human tissue have not been performed so far. Methods We wanted to provide a comprehensive study on the mode of action of HBB in human intestinal samples and investigated HBB (1 nmol L−1-10 μmol L−1) effects on muscle activity with isometric force transducers and calcium imaging, on epithelial secretion with Ussing chamber technique and on enteric neurons using fast neuroimaging. Key Results Hyoscine butylbromide concentration dependently reduced muscle contractions, calcium mobilization, and epithelial secretion induced by the muscarinic agonist bethanechol with IC50 values of 429, 121, and 224 nmol L−1, respectively. Forskolin-induced secretion was not altered by HBB. Cholinergic muscarinic muscle and epithelial responses evoked by electrical nerve stimulation were inhibited by 1-10 μmol L−1 HBB. Moreover, HBB significantly reduced the bethanechol-induced action potential discharge in enteric neurons. Interestingly, we observed that high concentrations of HBB (10 μmol L−1) moderately decreased nicotinic receptor-mediated secretion, motility, and nerve activity. Conclusions & Inferences The results demonstrated the strong antimuscarinic action of HBB whereas the nicotinic antagonism at higher concentrations plays at most a moderate modulatory role. The muscle relaxing effect of HBB and its inhibition of muscarinic nerve activation likely explain its clinical use as an antispasmodic drug. Our results further highlight a so far unknown antisecretory action of HBB which warrants further clinical studies on its use in secretory disorders. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
23. Rigid-plane phonons in layered crystals.
- Author
-
Michel, K. H. and Verberck, B.
- Abstract
The determination of the layer number ${\cal N}$ in nanoscale thin layered crystals is a challenging problem of technological relevance. In addition to innovative experimental techniques, a thorough knowledge of the underlying lattice dynamics is required. Starting from phenomenological atomic interaction potentials we have carried out an analytical study of the low-frequency optical phonon dispersions in layered crystals. At the gamma point of the two-dimensional Brillouin zone the optical phonon frequencies correspond to rigid-plane shearing and compression modes. We have investigated graphene multilayers (GML) and hexagonal boron-nitride multilayers (BNML). The frequencies show a characteristic dependence on ${\cal N}$. The results which are represented in the form of fan diagrams are very similar for both materials. Due to charge neutrality within layers Coulomb forces play no role, only van der Waals forces between nearest neighbor layers are relevant. The theoretical results agree with recent low-frequency Raman results on rigid-layer modes [Tan et al., Nature Mater. 11, 294 (2012)] in GML and double-resonant Raman scattering data on rigid-layer compression modes [Herziger et al., Phys. Rev. B 85, 235447 (2012)] in GML. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
24. Fast calcium and voltage-sensitive dye imaging in enteric neurones reveal calcium peaks associated with single action potential discharge.
- Author
-
Michel, K., Michaelis, M., Mazzuoli, G., Mueller, K., Vanden Berghe, P., and Schemann, M.
- Subjects
- *
ACTION potentials , *ELECTROPHYSIOLOGY , *CALCIUM , *NEURONS , *CALCIUM channels , *SODIUM channels - Abstract
Non-technical summary Imaging of slow, long-lasting changes in intracellular Ca2+ levels ([Ca2+]i) is a common method to assess neuronal activity. We found that fast [Ca2+]i imaging (≥200 Hz sampling rate) may be a new option to record fast neuronal events including spike discharge and fast synaptic transmission in enteric neurones. These [Ca2+]i peaks required opening of voltage-gated sodium and calcium channels as well as Ca2+ release from intracellular stores. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
25. Impact of land use on the hydraulic properties of the topsoil in a small French catchment.
- Author
-
Gonzalez-Sosa, E., Braud, I., Dehotin, J., Lassabatëre, L., Angulo-Jaramillo, R., Lagouy, M., Branger, F., Jacqueminet, C., Kermadi, S., and Michel, K.
- Subjects
LAND use & the environment ,SPATIAL variation ,GROUNDWATER flow ,WATER seepage ,SOIL permeability ,SOIL porosity ,SOIL density - Abstract
The article discusses the study on the spatial variability of soil hydraulic properties in a catchment in France to analyze land use effects to soil. It states that single ring infiltration tests and tension-disk infiltration were conducted and processed using the Beerkan Estimation of Soil Transfer (BEST). It says that the increase in hydraulic conductivity is due to macroporosity effect which is linked to land use management. Results show that land use affects dry bulk density and porosity.
- Published
- 2010
- Full Text
- View/download PDF
26. Theoretical phonon dispersions in monolayers and multilayers of hexagonal boron-nitride.
- Author
-
Michel, K. H. and Verberck, B.
- Published
- 2009
- Full Text
- View/download PDF
27. The multi-herbal drug STW 5 (Iberogast®) has prosecretory action in the human intestine.
- Author
-
KRUEGER, D., GRUBER, L., BUHNER, S., ZELLER, F., LANGER, R., SEIDL, S., MICHEL, K., and SCHEMANN, M.
- Subjects
CHLORIDES ,CYSTIC fibrosis ,ENTERIC nervous system ,INTESTINES ,INDIGESTION ,IRRITABLE colon ,MUCOUS membranes - Abstract
There is growing evidence that STW 5 (Iberogast
® , fixed combination of hydroethanolic herbal extracts), besides being effective in functional dyspepsia, also improves symptoms in irritable bowel syndrome (IBS). Clinical data indicate that modulation of mucosal secretion is a promising approach to treat intestinal disorders associated with IBS. We therefore explored the effect of STW 5 on secretion in the human intestine and the mechanisms by which it acts. The Ussing chamber technique was used to measure mucosal secretion in human intestinal mucosa/submucosa preparations and in human epithelial cell line T84. In addition, we recorded STW 5 effects on human enteric neurons with voltage sensitive dye imaging. In human tissue and T84 cells STW 5 induced a dose-dependent increase in ion secretion that was significantly reduced by the Na–K–Cl cotransporter blocker bumetanide, the adenylate cyclase inhibitor MDL-12 330, the non-specific and selective cystic fibrosis transmembrane conductance regulator (CFTR) inhibitors glibenclamide and CFTRinh -172, respectively, and the blocker of calcium dependent Cl− channels (ClCa) SITS (4-acetamido-4-isothiocyanatostilbene-2,2-disulphonic acid). It was unaffected by amiloride, a blocker of epithelial Na+ channels. In human tissue, the nerve blocker tetrodotoxin significantly suppressed the STW 5 response. STW 5 evoked an increased spike discharge in 51% of human submucous neurons. Results suggest that STW 5 is a secretogogue in the human intestine by direct epithelial actions and through activation of enteric neurons. The prosecretory effect is due to increased epithelial Cl− fluxes via CFTR and Ca-dependent ClCa channels. STW 5 may be a novel option to treat secretory disorders associated with IBS and constipation. [ABSTRACT FROM AUTHOR]- Published
- 2009
- Full Text
- View/download PDF
28. Theory of the elastic constants of graphite and graphene.
- Author
-
Michel, K. H. and Verberck, B.
- Published
- 2008
- Full Text
- View/download PDF
29. Anisotropic packing of C70 molecules in carbon nanotubes.
- Author
-
Verberck, B. and Michel, K. H.
- Published
- 2007
- Full Text
- View/download PDF
30. Syringolin A, a new plant elicitor from the phytopathogenic bacterium Pseudomonas syringae pv. syringae, inhibits the proliferation of neuroblastoma and ovarian cancer cells and induces apoptosis.
- Author
-
Coleman, C. S., Rocetes, J. P., Park, D. J., Wallick, C. J., Warn-Cramer, B. J., Michel, K., Dudler, R., and Bachmann, A. S.
- Subjects
PSEUDOMONAS syringae ,NEUROBLASTOMA ,CANCER cells ,APOPTOSIS ,CANCER treatment ,PHYTOPATHOGENIC bacteria - Abstract
Syringolin A is a new plant elicitor produced by the plant pathogen Pseudomonas syringae pv. syringae. The goal of this study was to investigate whether syringolin A exhibits anti-proliferative properties in cancer cells. The treatment of human neuroblastoma (NB) cells (SK-N-SH and LAN-1) and human ovarian cancer cells (SKOV3) with syringolin A (0–100 µm) inhibited cell proliferation in a dose-dependent manner. The IC
50 (50% inhibition) for each cell line ranged between 20 µm and 25 µm. In SK-N-SH cells, the treatment with 20 µm syringolin A led to a rapid (24 h) increase of the apoptosis-associated tumour suppressor protein p53. In addition, we found that the treatment of SK-N-SH cells caused severe morphological changes after 48 h such as rounding of cells and loss of adherence, both conditions observed during apoptosis. The induction of apoptosis by syringolin A was confirmed by both poly (ADP-ribose) polymerase (PARP) cleavage and annexin V assay. Taken together, we show for the first time that the natural product syringolin A exhibits anti-proliferative activity and induces apoptosis. Syringolin A and structurally modified syringolin A derivatives may serve as new lead compounds for the development of novel anticancer drugs. [ABSTRACT FROM AUTHOR]- Published
- 2006
- Full Text
- View/download PDF
31. Modelling cation transport and pH buffering during unsaturated flow through intact subsoils.
- Author
-
Ludwig, B., Beese, F., and Michel, K.
- Subjects
CATIONS ,HYDROGEN-ion concentration ,SUBSOILS ,SOIL chemistry ,IRRIGATION ,PRECIPITATION (Chemistry) - Abstract
Prediction of cation transport during unsaturated flow through soils is complex, and chemical models are necessary for the purpose. Our objectives were to determine whether the reactions considered in the model PHREEQC2 were appropriate to predict cation transport in soils when small amounts of CaCl
2 or acid are added and to investigate the usefulness of different parameterization approaches. Undisturbed columns of three subsoils were irrigated for 2 years with 4 mm day−1 at 8°C. The experiments were (A) irrigation with 1 m m and 5 m m CaCl2 and (B) irrigation with 1 m m HCl. The model PHREEQC2 was used to calculate one-dimensional transport, inorganic complexation, dissolution or precipitation of Al(OH)3 , AlOHSO4 and CaCO3 and multiple cation exchange. We compared three models: one with no adjustable parameters, a second with optimized solubilities within a reported range, pCO2 and cation exchange capacity (CEC), and a third which also included an optimization of the exchange coefficients. The first was of little use to predict cation transport in soils. The second was appropriate for one of the soils, but an optimization of the exchange coefficients was required for an accurate description and prediction of cation transport for the others. The CEC accessible for seepage water varied between 50% and 100% of the total CEC. Our results indicate that for a reliable assessment of cation transport in soils during unsaturated flow, calibration experiments are required. The parameter optimization program PEST in combination with PHREEQC2 gave a better understanding of cation transport in undisturbed soil. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
- View/download PDF
32. Human mast cell mediator cocktail excites neurons in human and guinea-pig enteric nervous system.
- Author
-
Schemann, M., Michel, K., Ceregrzyn, M., Zeller, F., Seidl, S., and Bischoff, S. C.
- Subjects
- *
NERVOUS system , *NEURONS , *INTESTINES , *MAST cells , *NEUROIMMUNOLOGY - Abstract
Neuroimmune interactions are an integral part of gut physiology and involved in the pathogenesis of inflammatory and functional bowel disorders. Mast cells and their mediators are important conveyors in the communication from the innate enteric immune system to the enteric nervous system (ENS). However, it is not known whether a mediator cocktail released from activated human mast cells affects neural activity in the ENS. We used the Multi-Site Optical Recording Technique to image single cell activity in guinea-pig and human ENS after application of a mast cell mediator cocktail (MCMC) that was released from isolated human intestinal mucosa mast cells stimulated by IgE-receptor cross-linking. Local application of MCMC onto individual ganglia evoked an excitatory response consisting of action potential discharge. This excitatory response occurred in 31%, 38% or 11% neurons of guinea-pig submucous plexus, human submucous plexus, or guinea-pig myenteric plexus, respectively. Compound action potentials from nerve fibres or fast excitatory synaptic inputs were not affected by MCMC. This study demonstrates immunoneural signalling in the human gut and revealed for the first time that an MCMC released from stimulated human intestinal mast cells induces excitatory actions in the human and guinea-pig ENS. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
33. Neurotransmitter coding of enteric neurones in the submucous plexus is changed in non-inflamed rectum of patients with Crohn's disease.
- Author
-
Schneider, J., Jehle, E. C., Starlinger, M. J., Neunlist, M., Michel, K., Hoppe, S., and Schemann, M.
- Subjects
NEURONS ,CROHN'S disease ,GASTROINTESTINAL mucosa - Abstract
Knowledge of the neurochemicaI coding of submucosal neurones in the human gut is important to assess neuronal changes under pathological conditions. We therefore investigated transmitter colocalization patterns in rectal submucosal neurones in normal tissue (n = 11) and in noninflamed tissue of Crohn's disease (CD) patients (n=17). Neuronespecific enolase (NSE), choline acetyltransferase (CHAT), vasoactive intestinal polypeptide (VIP), substance P (SP), nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) were detected immunohistochemically in whole-mount preparations from rectal biopsies. The neuronal marker NSE revealed no differences in the number of cells per ganglion (controls 5.0; CD 5.1). Four cell populations with distinct neurochemical codes were identified. The sizes of the populations ChAT/VIP (58% vs. 55%), ChAT/SP (8% vs. 8%), and CHAT/- (22% vs. 22%) were similar in control and CD. The population VIP/was significantly increased in CD (12% vs. 2% in controls). Unlike in controls, all NOS neurones colocalized ChAT in CD. Thickened CGRP-fibres occurred in CD. We identified neurochemically distinct populations in the human submucous plexus. The increase in the VIP/-population, extensive colocalization of ChAT and NOS and hypertrophied CGRP fibres indicated adaptive changes in the enteric nervous system in noninflamed rectum of CD patients. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
34. Hermes-mediated germ-line transformation of the Mediterranean fruit fly Ceratitis capitata.
- Author
-
Michel, K., Stamenova, A., Pinkerton, A. C., Franz, G., Robinson, A. S., Gariou-Papalexiou, A., Zacharopoulou, A., O'Brochta, D. A., and Atkinson, P. W.
- Subjects
- *
MEDITERRANEAN fruit-fly , *TRANSPOSONS , *GENETIC transformation , *NUCLEOTIDE sequence , *MOLECULAR genetics - Abstract
AbstractWe report the use of the Hermes transposable element for germ-line transformation of the Mediterranean fruit fly, Ceratitis capitata. Hermes was able to genetically transform this insect at an estimated frequency between 0.6 and 1.1%, which is comparable to the transformation frequencies obtained for this species when using other transposable elements. Hermes integrates into the medfly genome by a cut-and-paste mechanism and the sequences integrated into the genome are delimited by the terminal nucleotides of the Hermes inverted terminal repeats. Integration resulted in the generation of 8 bp target site duplications, the sequences of which conformed to the target site duplications generated by hAT element transposition in insects. The Hermes element is one additional genetic tool that can be deployed in manipulating and characterizing the medfly genome. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
35. Green fluorescent protein as a genetic marker in transgenic Aedes aegypti.
- Author
-
Pinkerton, A. C., Michel, K., O’Brochta, D. A., and Atkinson, P. W.
- Subjects
- *
AEDES aegypti , *GREEN fluorescent protein , *GENE expression , *TRANSPOSONS , *GENETICS - Abstract
AbstractWe report here the use of the enhanced green fluorescent protein (EGFP) from the jellyfish, Aequorea victoria, as a genetic marker for the genetic transformation of mosquitoes. The EGFP gene, under the control of the actin5C promoter of Drosophila melanogaster was inserted into the Hermes transposable element. Preblastoderm embryos of a wild-type strain of the yellow fever mosquito, Aedes aegypti, were microinjected with this plasmid, together with a helper plasmid containing the Hermes transposase placed under the control of the D. melanogaster hsp70 promoter. Somatic EGFP expression was observed during early instars in approximately one-half of all G0 individuals. Two G1 individuals arising from a G0 female displayed high levels of EGFP gene expression during all stages of development. EGFP was transmitted in a Mendelian fashion to the G2 and G3 generations and molecular analysis confirmed the presence of the Hermes[actin5C:EGFP] gene in these insects. These results clearly demonstrate that EGFP can be used as an effective genetic marker in wild-type Ae. aegypti and most likely in other mosquito species as well. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
36. Attempted suicide and major public holidays in Europe: findings from the WHO/EURO Multicentre Study on Parasuicide.
- Author
-
Jessen, G., Jensen, B. F., Arensman, E., Bib-Brahe, U., Crepet, P., Leo, D. De, Hawton, K., Haring, C., Hjelmeland, H., Michel, K., Ostamo, A., Salander-Renberg, E., Schmidtke, A., Temesvary, B., and Wasserman, D.
- Published
- 1999
- Full Text
- View/download PDF
37. Effect of a Lignan-Enriched Extract of Schisandra Chinensis on Aflatoxin B1 and Cadmium Chloride-Induced Hepatotoxicity in Rats.
- Author
-
Ip, Sin Po, Mak, Duncan H. F., Li, Pui Chun, Poon, Michel K. T., and Ko, Kam Ming
- Abstract
Treatment of rats with a lignan-enriched extract of the fruit of Schisandra chinensis could enhance hepatic antioxidant/detoxification system, as indicated by increases in hepatic reduced glutathione (GSH) level as well as hepatic glutathione reductase and glutathione S-transferase activities. The hepatoprotective action was evident after aflatoxin β
1 or cadmium chloride (Cd) challenge. Schisandra chinensis pretreatment protected against aflatoxin B1 or Cd-induced hepatocellular damage in rats. However, pretreating rats with α-tocopherol acetate (vitamin E) did not protect against hepatic damage induced by both toxins. Results from the present as well as our previous studies demonstrate that the hepatoprotection afforded by Schisandra chiensis pretreatment is not hepatotoxin specific. Schisandra chinensis seems to be more effective than vitamin E in protecting against aflatoxin B1 and Cd toxicity. The mechanism of hepatoprotection afforded by Schisandra chinensis pretreatment may involve facilitation of both antioxidant and detoxification processes in the liver. [ABSTRACT FROM AUTHOR]- Published
- 1996
- Full Text
- View/download PDF
38. Placement of a low-profile duodenostomy and jejunostomy device in five dogs.
- Author
-
Swann, H. M., Sweet, D. C., Holt, D. E., and Michel, K.
- Published
- 1998
- Full Text
- View/download PDF
39. A repetition-prediction study of European parasuicide populations: a summary of the first report from Part II of the WHO/EURO Multicentre Study on Parasuicide in co-operation with the EC Concerted Action on Attempted Suicide.
- Author
-
Bille-Brahe, U., Kerkhof, A., Leo, D., Schmidtke, A., Crepet, P., Lönnqvist, J., Michel, K., Salander-Renberg, E., Stiles, T. C., Wasserman, D., Aagaard, B., Egebo, H., and Jensen, B.
- Published
- 1997
- Full Text
- View/download PDF
40. Contacts of suicide attempters with GPs prior to the event: a comparison between Stockholm and Bern.
- Author
-
Michel, K., Runeson, B., Valach, L., and Wasserman, D.
- Published
- 1997
- Full Text
- View/download PDF
41. Magnetic interactions in NiSO4.
- Author
-
Scheerlinck, D., Peetroons, C., Speybrouck, P., Hautecler, S., and Michel, K.
- Published
- 1975
- Full Text
- View/download PDF
42. Attempted suicide in Europe: rates, trend.S and sociodemographic characteristics of suicide attempters during the period 1989-1992. Results of the WHO/EURO Multicentre Study on Parasuicide.
- Author
-
Schmidtke, A., Bille-Brahe, U., Deleo, D., Kerkhof, A., Bjerke, T., Crepef, P., Haring, C., Hawton, K., Lönnqvist, J., Michel, K., Pommereau, X., Querejeta, ., Phillipe, I., Salander-Renberg, E., Temesváry, B., Wasserman, D., Fricke, S., Weinacker, B., and Sampaio-Faria, J. G.
- Published
- 1996
- Full Text
- View/download PDF
43. A comparison of the drugs taken in fatal and nonfatal self-poisoning.
- Author
-
Michel, K., Waeber, V., Valach, L., Arestegui, G., and Spuhler, T.
- Published
- 1994
- Full Text
- View/download PDF
44. Parasiticide in Europe: the WHO/EURO multicentre study on parasuicide. I. Introduction and preliminary analysis for 1989.
- Author
-
Platt, S., Bille-Brahe, U., Kerkhof, A., Schmidtke, A., Bjerke, T., Crepet, P., Leo, D. De, Haring, C., Lonnqvist, J., Michel, K., Philippe, A., Pommereau, X., Querejeta, I., Salander-Renberg, E., Temesvary, B., Wasserman, D., and Faria, J. Sampaio
- Published
- 1992
- Full Text
- View/download PDF
45. Bestrahlung von 2-Morpholinomethyl-phenol in Isopropanol 5. Mitt.: Zur Photochemie der 2-Aminomethyl-phenole.
- Author
-
Roth, H. J. and Michel, K.
- Published
- 1971
- Full Text
- View/download PDF
46. Bestrahlung von 2-Morpholinomethyl-phenol in Äthanol Mitt.: Zur Photochemie der 2-Aminomethyl-phenole.
- Author
-
Roth, H. J. and Michel, K.
- Published
- 1971
- Full Text
- View/download PDF
47. Bestrahlung von 1-Piperidinomethyl-naphthol-(2) in Tetrahydrofuran Mitt.: Zur Photochemie der 2-Aminomethyl-phenole.
- Author
-
Roth, H. J. and Michel, K.
- Published
- 1971
- Full Text
- View/download PDF
48. Bestrahlung von 2-Morpholinomethyl-phenol in Dioxan. Mitt.: Zur Photochemie der 2-Aminomethyl-phenole.
- Author
-
Roth, H. J. and Michel, K.
- Published
- 1971
- Full Text
- View/download PDF
49. Bestrahlung von 2-Morpholinomethyl-phenol in Tetrahydrofuran Mitt.: Zur Photochemie der 2-Aminomethyl-phenole.
- Author
-
Roth, H. J. and Michel, K.
- Published
- 1971
- Full Text
- View/download PDF
50. Über Isoxazolidin-3,5-dione.
- Author
-
Michel, K., Gerlach-Gerber, H., Vogel, Ch., and Matter, M.
- Published
- 1965
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.