20 results on '"David GM"'
Search Results
2. Contributors
- Author
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Barr, Alistair RS, primary, Bernard, William V, additional, Doherty, Thomas J, additional, Edwards, G Barrie, additional, Epstein, Kira L, additional, Frank, Nicholas, additional, Frazer, Grant S, additional, Hart, Kelsey A, additional, Head, Marcus J, additional, Hughes, Kristopher, additional, Jeffcott, Leo B, additional, Labens, Raphael, additional, Lane, J Geoffrey, additional, Love, Sandy, additional, Mair, Tim S, additional, Mudge, Margaret C, additional, Nout, Yvette S, additional, Pascoe, Robert, additional, Pinto, Carlos, additional, Pollock, Patrick J., additional, Rush, Bonnie R, additional, Schramme, Michael CA, additional, Schumacher, Jim, additional, Schumacher, John, additional, Schwarzwald, Colin C, additional, Sellon, Debra C, additional, Sinclair, Charlotte, additional, Smith, Roger KW, additional, Spano, Joseph S, additional, Sutton, David GM, additional, Toribio, Ramiro E, additional, Valverde, Alexander, additional, Vogelnest, Linda J, additional, Weaver, Martin P, additional, and Weller, Renate, additional
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- 2012
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3. Contributors
- Author
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Alistair RS Barr, William V Bernard, Thomas J Doherty, G Barrie Edwards, Kira L Epstein, Nicholas Frank, Grant S Frazer, Kelsey A Hart, Marcus J Head, Kristopher Hughes, Leo B Jeffcott, Raphael Labens, J Geoffrey Lane, Sandy Love, Tim S Mair, Margaret C Mudge, Yvette S Nout, Robert Pascoe, Carlos Pinto, Patrick J. Pollock, Bonnie R Rush, Michael CA Schramme, Jim Schumacher, John Schumacher, Colin C Schwarzwald, Debra C Sellon, Charlotte Sinclair, Roger KW Smith, Joseph S Spano, David GM Sutton, Ramiro E Toribio, Alexander Valverde, Linda J Vogelnest, Martin P Weaver, and Renate Weller
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- 2012
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4. Arrhythmogenic right ventricular cardiomyopathy secondary to adipose infiltration as a cause of episodic collapse in a horse
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Raftery, Alexandra G., primary, Garcia, Nuria C., additional, Thompson, Hal, additional, and Sutton, David GM, additional
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- 2015
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5. Phylogenetic analysis of the complete mitochondrial genome of the orange-winged sulphur butterfly Dercas nina Mell 1913 (Insecta: Lepidoptera: Pieridae: Coliadinae).
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Agcaoili AM, Ameena N, Andres D, Caners R, Chahal MK, Croitor NJ, David GM, Enns KL, Fedorova O, Garber HA, Gregoire SD, Ilnisky TE, Jiang A, Kozak A, Ladha F, Martin A, McAuley MA, McEachern LR, McNeill C, Nanayakkara SD, Nguyen NTV, Park G, Peters DK, Poitras MN, Potts J, Prajapati DV, Prefontaine CD, Rajapaksha RV, Singhal P, Souriyavong C, Stoker C, Talabis KR, Tan Y, Tang JL, Tkach KW, Tohms AJ, Tramley CG, Treftlin J, Ukani D, Vallelly EA, Wiens PV, Yee C, Yu K, and Marcus JM
- Abstract
Dercas nina Mell 1913 (Pieridae) is a little-studied butterfly species endemic to China that flies primarily in the forest canopy. Genome skimming by Illumina sequencing allowed assembly of 146,702 reads for complete 1471.3-fold mean coverage of the circular 15,264 bp mitogenome from D. nina consisting of 82.1% AT nucleotides. A gene order typical of butterflies was recovered consisting of 13 protein-coding genes, 22 tRNAs, two rRNAs, and a predicted control region. The Dercas nina COX1 open reading frame begins with atypical start codon CGA. Six protein-coding genes ( COX1 , COX2 , ND2 , ND3 , ND4 , ND5 ) with single-nucleotide (T) stop codons, and two protein-coding genes ( ATP6 , ATP8 ) with two-nucleotide (TA) stop codons encoded in the DNA were inferred to be completed by adenine nucleotides from the Poly-A tail of the mRNA. Bayesian's phylogenetic reconstruction places the D. nina and D. lycorias mitogenomes as sister clades. Dercas mitogenomes were sister to those from genus Colias in the monophyletic subfamily Coliadinae. The mitogenome phylogeny is consistent with previous molecular phylogenetic hypotheses based on other markers, but differs somewhat from a morphology-based hypothesis that suggested that Dercas was more closely related to genus Gonepteryx . This may falsify the hypothesis or may instead reflect mitochondrial-nuclear phylogenetic discordance., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)
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- 2024
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6. Bone regeneration by a bone substitute biomaterial containing hydroxyapatite, chitosan, xanthan and graphene oxide supplemented with conditioned medium from mesenchymal stem cells.
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Rocha DN, López DG, Ferreira JR, Silva MH, Filgueiras IA, Alves BF, Almeida BM, Kotaka T, Buss LF, Teixeira ML, Mariano ÉD, Cationi MH, Bosco I, Nascimento M, Canal R, Neves JG, Aloise AC, Martinez EF, Holliday LS, and Pelegrine AA
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- Animals, Rats, Culture Media, Conditioned, Male, Biocompatible Materials pharmacology, Bone Regeneration drug effects, Chitosan pharmacology, Graphite, Mesenchymal Stem Cells drug effects, Durapatite, Bone Substitutes pharmacology, Rats, Wistar, Polysaccharides, Bacterial pharmacology
- Abstract
This study analyzed a recently developed bone substitute biomaterial made of chitosan-xanthanhydroxyapatite-graphene oxide (CXHAG). The CXHAG particles underwent in vitro structural and morphological characterization, and in vivo testing with or without osteogenic conditioned medium from mesenchymal stem cells. Aim: The aim of this study was to determine whether the CXHAG novel biomaterial, supplemented with conditioned medium from mesenchymal stem cells, could be useful for bone regeneration. Materials and Method: For the in vitro study, cells were incubated with 20mg of CXHAG granules for 24 hours and a MTT assay was performed to tests for cytotoxicity. For the in vivo study, critical size calvarial bone defects were created in twenty-five rats. One animal had the defect unfilled (Control Group-CG) and was euthanized after 42 days. Twelve rats received the CXHAG particles (Group 1-G1) and the other twelve received the CXHAG particles supplemented with the conditioned medium (Group 2-G2). All G1/G2 grafts were covered with a CXHAG membrane. G1/G2 animals were euthanized after 14 days (T1) or 42 days (T2). The specimens were processed and histologically evaluated. Results: SEM analysis of the CXHAG particles showed granules of 300-400μm, with a rough irregular surface. They were not cytotoxic to dental pulp stem cells in vitro. The CG specimen showed loose immature connective tissue and no bone formation at the center of the defect. G1 and G2 presented remnant biomaterial particles at both time points, but only G2 had bone formation at the enter of the defect. Conclusions: The conditioned medium had a positive effect on bone regeneration in rat calvarial critical size defects when associated with the novel bone substitute biomaterial., Competing Interests: The authors declare no conflicts of interest concerning the publication of this article, (SAIO.)
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- 2024
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7. Multiple stressors affecting microbial decomposer and litter decomposition in restored urban streams: Assessing effects of salinization, increased temperature, and reduced flow velocity in a field mesocosm experiment.
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David GM, Pimentel IM, Rehsen PM, Vermiert AM, Leese F, and Gessner MO
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- Biodegradation, Environmental, Ecosystem, Plant Leaves, Alnus, Temperature, Environmental Monitoring, Rivers chemistry, Rivers microbiology, Salinity
- Abstract
A multitude of anthropogenic stressors impact biological communities and ecosystem processes in urban streams. Prominent among them are salinization, increased temperature, and altered flow regimes, all of which can affect microbial decomposer communities and litter decomposition, a fundamental ecosystem process in streams. Impairments caused by these stressors individually or in combination and recovery of communities and ecosystem processes after release from these stressors are not well understood. To improve our understanding of multiple stressors impacts we performed an outdoor stream mesocosm experiment with 64 experimental units to assess the response of microbial litter decomposers and decomposition. The three stressors we applied in a full-factorial design were increased salinity (NaCl addition, 0.53 mS cm
-1 above ambient), elevated temperature (3.5 °C above ambient), and reduced flow velocity (3.5 vs 14.2 cm s-1 ). After two weeks of stressor exposure (first sampling) and two subsequent weeks of recovery (second sampling), we determined leaf-associated microbial respiration, fungal biomass, and the sporulation activity and community composition of aquatic hyphomycetes in addition to decomposition rates of black alder (Alnus glutinosa) leaves confined in fine-mesh litter bags. Microbial colonization of the litter was accompanied by significant mass loss in all mesocosms. However, there was little indication that mass loss, microbial respiration, fungal biomass, sporulation rate or community composition of aquatic hyphomycetes was strongly affected by either single stressors or their interactions. Two exceptions were temperature effects on sporulation and decomposition rate. Similarly, no notable differences among mesocosms were observed after the recovery phase. These results suggest that microbial decomposers and leaf litter decomposition are either barely impaired by exposure to the tested stressors at the levels applied in our experiment, or that communities in restored urban streams are well adapted to cope with these stressor levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
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8. Differential associations of five riverine organism groups with multiple stressors.
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Kaijser W, Lorenz AW, Brauer VS, Burfeid-Castellanos A, David GM, Nuy JK, Baikova D, Beszteri B, Gillmann SM, Kiesel J, Mayombo NAS, Peters K, Rettig K, Rolauffs P, Haase P, and Hering D
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- Animals, Fungi, Diatoms physiology, Invertebrates physiology, Fishes, Bacteria classification, Water Pollutants, Chemical analysis, Rivers microbiology, Environmental Monitoring, Biodiversity
- Abstract
The decline of river and stream biodiversity results from multiple simultaneous occuring stressors, yet few studies explore responses explore responses across various taxonomic groups at the same locations. In this study, we address this shortcoming by using a coherent data set to study the association of nine commonly occurring stressors (five chemical, one morphological and three hydraulic) with five taxonomic groups (bacteria, fungi, diatoms, macro-invertebrates and fish). According to studies on single taxonomic groups, we hypothesise that gradients of chemical stressors structure community composition of all taxonomic groups, while gradients of hydraulic and morphological stressors are mainly related to larger organisms such as benthic macro-invertebrates and fish. Organisms were sampled over two years at 20 sites in two catchments: a recently restored urban lowland catchment (Boye) and a moderately disturbed rural mountainous catchment (Kinzig). Dissimilarity matrices were computed for each taxonomic group within a catchment. Taxonomic dissimilarities between sites were linked to stressor dissimilarities using multivariable Generalized Linear Mixed Models. Stressor gradients were longer in the Boye, but did in contrast to the Kinzig not cover low stress intensities. Accordingly, responses of the taxonomic groups were stronger in the Kinzig catchment than in the recently restored Boye catchment. The discrepancy between catchments underlines that associations to stressors strongly depend on which part of the stressor gradient is covered in a catchment. All taxonomic groups were related to conductivity. Bacteria, fungi and macro-invertebrates change with dissolved oxygen, and bacteria and fungi with total nitrogen. Morphological and hydraulic stressors had minor correlations with bacteria, fungi and diatoms, while macro-invertebrates were strongly related to fine sediment and discharge, and fish to high flow peaks. The results partly support our hypotheses about the differential associations of the different taxonomic groups with the stressors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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9. Assessing the response of an urban stream ecosystem to salinization under different flow regimes.
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Madge Pimentel I, Baikova D, Buchner D, Burfeid Castellanos A, David GM, Deep A, Doliwa A, Hadžiomerović U, Mayombo NAS, Prati S, Spyra MA, Vermiert AM, Beisser D, Dunthorn M, Piggott JJ, Sures B, Tiegs SD, Leese F, and Beermann AJ
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- Animals, Invertebrates physiology, Fresh Water, Sodium Chloride, Ecosystem, Rivers
- Abstract
Urban streams are exposed to a variety of anthropogenic stressors. Freshwater salinization is a key stressor in these ecosystems that is predicted to be further exacerbated by climate change, which causes simultaneous changes in flow parameters, potentially resulting in non-additive effects on aquatic ecosystems. However, the effects of salinization and flow velocity on urban streams are still poorly understood as multiple-stressor experiments are often conducted at pristine rather than urban sites. Therefore, we conducted a mesocosm experiment at the Boye River, a recently restored stream located in a highly urbanized area in Western Germany, and applied recurrent pulses of salinity along a gradient (NaCl, 9 h daily of +0 to +2.5 mS/cm) in combination with normal and reduced current velocities (20 cm/s vs. 10 cm/s). Using a comprehensive assessment across multiple organism groups (macroinvertebrates, eukaryotic algae, fungi, parasites) and ecosystem functions (primary production, organic-matter decomposition), we show that flow velocity reduction has a pervasive impact, causing community shifts for almost all assessed organism groups (except fungi) and inhibiting organic-matter decomposition. Salinization affected only dynamic components of community assembly by enhancing invertebrate emigration via drift and reducing fungal reproduction. We caution that the comparatively small impact of salt in our study can be due to legacy effects from past salt pollution by coal mining activities >30 years ago. Nevertheless, our results suggest that urban stream management should prioritize the continuity of a minimum discharge to maintain ecosystem integrity. Our study exemplifies a holistic approach for the assessment of multiple-stressor impacts on streams, which is needed to inform the establishment of a salinity threshold above which mitigation actions must be taken., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
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10. The effect of limited healthcare access on poor outcomes among hospitalized COVID-19 patients in Honduras: A single center cohort study.
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Alas-Pineda C, Aguilar-Andino D, Vallecillo Munguia FA, Padilla David GM, Umaña AN, Romero Reyes L, Cárcamo A, Osorio AL, Zuniga-Moya J, Montalvan-Sanchez E, Atchley TJ, Laskay NMB, Estevez-Ordonez D, Garner O, and Norwood DA
- Abstract
Background: The COVID-19 pandemic has had a severe impact on the Latin American subcontinent, particularly in areas with limited hospital resources and a restricted Intensive Care Unit (ICU) capacity. This study aimed to provide a comprehensive description of the clinical characteristics, outcomes, and factors associated with survival of COVID-19 hospitalized patients in Honduras., Research Question: What were the characteristics and outcomes of COVID-19 patients in a large referral center in Honduras?, Study Design and Methods: This study employed a retrospective cohort design conducted in a single center in San Pedro Sula, Honduras, between October 2020 to March 2021. All hospitalized cases of confirmed COVID-19 during this timeframe were included in the analysis. Univariable and multivariable survival analysis were performed using Kaplan-Meier curves and Cox proportional hazards model aiming to identify factors associated with decreased 30 day in-hospital survival, using a priori-selected factors., Results: A total of 929 confirmed cases were identified in this cohort, with males accounting for 55.4 % of cases. The case fatality rate among the hospitalized patients was found to be 50.1 % corresponding to 466 deaths. Patients with comorbidities such as hypertension, diabetes, obesity, chronic kidney disease, chronic obstructive pulmonary disease and cardiovascular disease had a higher likelihood of mortality. Additionally, non-survivors had a significantly longer time from illness onset to hospital admission compared to survivors (8.2 days vs 4.7 days). Among the cohort, 306 patients (32.9 %) met criteria for ICU admission. However, due to limited capacity, only 60 patients (19·6 %) were admitted to the ICU. Importantly, patients that were unable to receive level-appropriate care had lower likelihood of survival compared to those who received level-appropriate care (hazard ratio: 1.84)., Interpretation: This study represents, the largest investigation of in-hospital COVID-19 cases in Honduras and Central America. The findings highlight a substantial case fatality rate among hospitalized patients. In this study, patients who couldn't receive level-appropriate care (ICU admission) had a significantly lower likelihood of survival when compared to those who did. These results underscore the significant impact of healthcare access during the pandemic, particularly in low- and middle-income countries., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)
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- 2024
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11. Tweak/Fn14 system is involved in rhabdomyolysis-induced acute kidney injury.
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Guerrero-Hue M, Vallejo-Mudarra M, García-Caballero C, Córdoba-David GM, Palomino-Antolín A, Herencia C, Vendrell-Casana B, Rubio-Navarro A, Egido J, Blanco-Colio LM, and Moreno JA
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- Animals, Mice, Cytokine TWEAK metabolism, Fibrosis, Inflammation, Tumor Necrosis Factors metabolism, TWEAK Receptor metabolism, Acute Kidney Injury metabolism, Renal Insufficiency, Chronic, Rhabdomyolysis complications
- Abstract
Background: Rhabdomyolysis is a severe clinical syndrome associated to acute kidney injury (AKI) and chronic kidney disease (CKD). TWEAK/Fn14 signaling axis regulates renal inflammation and tubular cell death. However, the functional role of TWEAK/Fn14 in rhabdomyolysis remains unknown., Methods: Rhabdomyolysis was induced in wild-type, TWEAK- and Fn14-deficient mice or mice treated with TWEAK blocking antibody. Renal injury, inflammation, fibrosis and cell death were assessed. Additionally, we performed in vivo and in vitro studies to explore the possible signalling pathways involved in Fn14 regulation., Findings: Fn14 renal expression was increased in mice with rhabdomyolysis, correlating with decline of renal function. Mechanistically, myoglobin (Mb) induced Fn14 expression via ERK and p38 pathway, whereas Nrf2 activation diminished Mb-mediated Fn14 upregulation in cultured renal cells. TWEAK or Fn14 genetic depletion ameliorated rhabdomyolysis-associated loss of renal function, histological damage, tubular cell death, inflammation, and expression of both tubular and endothelial injury markers. Deficiency of TWEAK or Fn14 also decreased long-term renal inflammation and fibrosis in mice with rhabdomyolysis. Finally, pharmacological treatment with a blocking TWEAK antibody diminished the expression of acute renal injury markers and cell death and lessened residual kidney fibrosis and chronic inflammation in rhabdomyolysis., Interpretation: TWEAK/Fn14 axis participates in the pathogenesis of rhabdomyolysis-AKI and subsequent AKI-CKD transition. Blockade of this signaling pathway may represent a promising therapeutic strategy for reducing rhabdomyolysis-mediated renal injury., Funding: Spanish Ministry of Science and Innovation, ISCIII and Junta de Andalucía., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
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- 2023
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12. New therapies in non-small cell lung cancer with EGFR exon 20 insertion mutations.
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David GM, Maria Del Pilar BC, and Cristina MR
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- Humans, Mutagenesis, Insertional, Protein Kinase Inhibitors therapeutic use, Mutation, ErbB Receptors genetics, Exons genetics, Carcinoma, Non-Small-Cell Lung drug therapy, Carcinoma, Non-Small-Cell Lung genetics, Carcinoma, Non-Small-Cell Lung pathology, Lung Neoplasms drug therapy, Lung Neoplasms genetics, Lung Neoplasms pathology
- Abstract
Objective: Patients with non-small cell lung cancer (NSCLC) and epidermal growth factor receptor (EGFR) exon 20 insertion mutations have a poor prognosis and few therapeutic alternatives. We conducted a review of scientific evidence about therapies in NSCLC with EGFR exon 20 insertion mutations., Data Sources: A systematic review in PubMed® database was performed up to November 19, 2022. Clinical trials (CTs) about treatments of patients diagnosed with advanced or metastatic NSCLC harbouring EGFR exon 20 insertions who had previously received platinum-based chemotherapy were selected. CTs with a sample size of less than 10 patients were discarded. Efficacy results were used to determine the most interesting drugs. Subsequently, a more exhaustive analysis of the design of the CTs and safety of the most interesting schemes was conducted. Comparisons were attempted to develop., Data Summary: A total of 40 records were found in the systematic search. Twelve selected CTs included the following therapies: poziotinib, osimertinib, pertuzumab-trastuzumab-docetaxel scheme, mobocertinib, amivantamab, erlotinib-onalespib regimen, luminespib, ado-trastuzumab emtansine and dacomitinib. Mobocertinib, amivantamab and poziotinib were determined as the most interesting treatments according to efficacy data. Gastrointestinal and dermatological adverse reactions were relevant in these regimens. All CTs presented a non-randomised design. No reliable comparisons could be developed., Conclusions: The efficacy of mobocertinib, amivantamab and poziotinib in NSCLC with EGFR exon 20 insertion mutations is promising. However, therapies were assessed in single-arm CTs with low-quality evidence. Comparative studies with more extensive patient follow-up, larger sample size and better design are needed to reliably quantify the effect of these drugs.
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- 2023
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13. Author Correction: Predicting potential global and future distributions of the African armyworm (Spodoptera exempta) using species distribution models.
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Gómez-Undiano I, Musavi F, Mushobozi WL, David GM, Day R, Early R, and Wilson K
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- 2022
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14. Predicting potential global and future distributions of the African armyworm (Spodoptera exempta) using species distribution models.
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Gómez-Undiano I, Musavi F, Mushobozi WL, David GM, Day R, Early R, and Wilson K
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- Animals, Crops, Agricultural, Introduced Species, Larva, Spodoptera, Tanzania, Moths
- Abstract
Invasive species have historically been a problem derived from global trade and transport. To aid in the control and management of these species, species distribution models (SDMs) have been used to help predict possible areas of expansion. Our focal organism, the African Armyworm (AAW), has historically been known as an important pest species in Africa, occurring at high larval densities and causing outbreaks that can cause enormous economic damage to staple crops. The goal of this study is to map the AAW's present and potential distribution in three future scenarios for the region, and the potential global distribution if the species were to invade other territories, using 40 years of data on more than 700 larval outbreak reports from Kenya and Tanzania. The present distribution in East Africa coincides with its previously known distribution, as well as other areas of grassland and cropland, which are the host plants for this species. The different future climatic scenarios show broadly similar potential distributions in East Africa to the present day. The predicted global distribution shows areas where the AAW has already been reported, but also shows many potential areas in the Americas where, if transported, environmental conditions are suitable for AAW to thrive and where it could become an invasive species., (© 2022. The Author(s).)
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- 2022
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15. Small freshwater ecosystems with dissimilar microbial communities exhibit similar temporal patterns.
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David GM, López-García P, Moreira D, Alric B, Deschamps P, Bertolino P, Restoux G, Rochelle-Newall E, Thébault E, Simon M, and Jardillier L
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- Archaea genetics, Biodiversity, France, Fresh Water, Phylogeny, RNA, Ribosomal, 16S genetics, Ecosystem, Microbiota genetics
- Abstract
Despite small freshwater ecosystems being biodiversity reservoirs and contributing significantly to greenhouse fluxes, their microbial communities remain largely understudied. Yet, microorganisms intervene in biogeochemical cycling and impact water quality. Because of their small size, these ecosystems are in principle more sensitive to disturbances, seasonal variation and pluri-annual climate change. However, how microbial community composition varies over space and time, and whether archaeal, bacterial and microbial eukaryote communities behave similarly remain unanswered. Here, we aim to unravel the composition and intra/interannual temporal dynamic patterns for archaea, bacteria and microbial eukaryotes in a set of small freshwater ecosystems. We monitored archaeal and bacterial community composition during 24 consecutive months in four ponds and one brook from northwestern France by 16S rRNA gene amplicon sequencing (microbial eukaryotes were previously investigated for the same systems). Unexpectedly for oxic environments, bacterial Candidate Phyla Radiation (CPR) were highly diverse and locally abundant. Our results suggest that microbial community structure is mainly driven by environmental conditions acting over space (ecosystems) and time (seasons). A low proportion of operational taxonomic units (OTUs) (<1%) was shared by the five ecosystems despite their geographical proximity (2-9 km away), making microbial communities almost unique in each ecosystem and highlighting the strong selective influence of local environmental conditions. Marked and similar seasonality patterns were observed for archaea, bacteria and microbial eukaryotes in all ecosystems despite strong turnovers of rare OTUs. Over the 2-year survey, microbial community composition varied despite relatively stable environmental parameters. This suggests that biotic associations play an important role in interannual community assembly., (© 2021 John Wiley & Sons Ltd.)
- Published
- 2021
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16. Environmental drivers of plankton protist communities along latitudinal and vertical gradients in the oldest and deepest freshwater lake.
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David GM, Moreira D, Reboul G, Annenkova NV, Galindo LJ, Bertolino P, López-Archilla AI, Jardillier L, and López-García P
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- Lakes, Oceans and Seas, Dinoflagellida, Microbiota, Plankton genetics
- Abstract
Identifying which abiotic and biotic factors determine microbial community assembly is crucial to understand ecological processes and predict how communities will respond to environmental change. While global surveys aim at addressing this question in the world's oceans, equivalent studies in large freshwater systems are virtually lacking. Being the oldest, deepest and most voluminous freshwater lake on Earth, Lake Baikal offers a unique opportunity to test the effect of horizontal versus vertical gradients in community structure. Here, we characterized the structure of planktonic microbial eukaryotic communities (0.2-30 μm cell size) along a North-South latitudinal gradient (~600 km) from samples collected in coastal and pelagic waters and from surface to the deepest zones (5-1400 m) using an 18S rRNA gene metabarcoding approach. Our results show complex and diverse protist communities dominated by alveolates (ciliates and dinoflagellates), ochrophytes and holomycotan lineages, with cryptophytes, haptophytes, katablepharids and telonemids in moderate abundance and many low-frequency lineages, including several typical marine members, such as diplonemids, syndinians and radiolarians. Depth had a strong significant effect on protist community stratification. By contrast, the effect of the latitudinal gradient was marginal and no significant difference was observed between coastal and surface open water communities. Co-occurrence network analyses showed that epipelagic communities were significantly more interconnected than communities from the dark water column and suggest specific biotic interactions between autotrophic, heterotrophic and parasitic lineages that influence protist community structure. Since climate change is rapidly affecting Siberia and Lake Baikal, our comprehensive protist survey constitutes a useful reference to monitor ongoing community shifts., (© 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.)
- Published
- 2021
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17. A minimalist macroparasite diversity in the round goby of the Upper Rhine reduced to an exotic acanthocephalan lineage.
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David GM, Staentzel C, Schlumberger O, Perrot-Minnot MJ, Beisel JN, and Hardion L
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- Animals, Biodiversity, DNA Barcoding, Taxonomic, Electron Transport Complex IV genetics, Europe, Eastern epidemiology, France epidemiology, Haplotypes, High-Throughput Nucleotide Sequencing, Introduced Species, Phylogeny, Acanthocephala genetics, Genetic Variation, Helminthiasis, Animal epidemiology, Perciformes parasitology, Rivers parasitology
- Abstract
The round goby, Neogobius melanostomus, is a Ponto-Caspian fish considered as an invasive species in a wide range of aquatic ecosystems. To understand the role that parasites may play in its successful invasion across Western Europe, we investigated the parasitic diversity of the round goby along its invasion corridor, from the Danube to the Upper Rhine rivers, using data from literature and a molecular barcoding approach, respectively. Among 1666 parasites extracted from 179 gobies of the Upper Rhine, all of the 248 parasites barcoded on the c oxidase subunit I gene were identified as Pomphorhynchus laevis. This lack of macroparasite diversity was interpreted as a loss of parasites along its invasion corridor without spillback compensation. The genetic diversity of P. laevis was represented by 33 haplotypes corresponding to a haplotype diversity of 0·65 ± 0·032, but a weak nucleotide diversity of 0·0018 ± 0·00015. Eight of these haplotypes were found in 88·4% of the 248 parasites. These haplotypes belong to a single lineage so far restricted to the Danube, Vistula and Volga rivers (Eastern Europe). This result underlines the exotic status of this Ponto-Caspian lineage in the Upper Rhine, putatively disseminated by the round goby along its invasion corridor.
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- 2018
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18. Investigation of an outbreak of acute respiratory disease in côte d'ivoire in april 2007.
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Ekaza E, Kadjo HA, Coulibaly D, Koutouan GG, Coulibaly-N'golo GM, Kouakou B, Talla Nzussouo N, Olsen SJ, Ekra DK, Akoua-Koffi CG, Gilbernair EA, and Bretin-Dosso MC
- Abstract
Background: This study aim was to investigate an outbreak of human cases of unexplained influenza-like illness and fatal acute respiratory infection (ARI), with simultaneous poultry illness and high mortality raising concerns of possible influenza A (H5N1), virus in Cote d'Ivoire in February and March 2007., Materials and Methods: To investigate the outbreak, we conducted active surveillance in the community and reviewed health registries. Persons meeting the case definition were asked to provide nasopharyngeal specimens. On the basis of clinical and epidemiological information, specimens were tested using conventional RT-PCR for the M gene of the influenza viruses and hemagglutinin H5 of avian influenza A (H5N1), virus; negative samples were tested for other respiratory viruses. Specimens from healthy animals were also collected., Results: Between October 2006, and February 2007, 104 suspected cases of Acute Respiratory Disease that included; 31 deaths recorded. We collected and tested 73 nasopharyngeal specimens; of which, 2, were positive for human Coronavirus OC43 and 1 for influenza C virus. No pathogens were identified in animal specimens., Conclusions: The investigation quickly ruled out influenza A (H5N1), virus as the cause and found laboratory-confirmed cases of influenza C virus and human Coronavirus OC 43 for the first time in both Côte d'Ivoire and in a Sub-Saharan African country. However we were not able to show that these viruses caused the outbreak. Monitoring of influenza viruses must be a priority but other respiratory viruses and non-viral causes may be of interest too.
- Published
- 2014
19. Multilocus VNTR analysis of Mycobacterium ulcerans strains isolated in Côte d'Ivoire.
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Coulibaly-N'Golo GM, Ekaza E, Coulibaly B, Aka N, N'guessan RK, Thiberge JM, Caro V, Brisse S, and Bretin-Dosso M
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- Cote d'Ivoire, Genotype, Humans, Mycobacterium ulcerans genetics, Polymorphism, Genetic, Bacterial Typing Techniques, Buruli Ulcer microbiology, Minisatellite Repeats, Molecular Typing, Mycobacterium ulcerans classification, Mycobacterium ulcerans isolation & purification
- Abstract
Introduction: Buruli ulcer, caused by Mycobacterium ulcerans, is endemic in more than 30 countries worldwide, with Côte d'Ivoire being among the most affected countries., Methodology: We used seven variable number of tandem repeats (VNTR) markers and analyzed 114 samples from 11 Ivorian localities consisting of 33 bacterial strains and 81 clinical samples. Complete data sets at loci 1, 6, 9 and 33 were obtained for 18 of these strains (n = 15) and samples (n = 3) collected in each of the localities., Results: All the strains had allelic profile [3113], corresponding to the previously described Atlantic Africa genotype., Conclusion: Sequencing of PCR products at all loci showed no variation in sequence or repeat number, underlining the genetic monomorphism of M. ulcerans in Côte d'Ivoire.
- Published
- 2011
- Full Text
- View/download PDF
20. Darier's disease with cystic changes in the bones.
- Author
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Thambiah AS, Rao US, Annamalai R, and David GM
- Subjects
- Adult, Darier Disease diagnosis, Diagnosis, Differential, Humans, Male, Bone Cysts etiology, Bone and Bones pathology, Darier Disease complications
- Published
- 1966
- Full Text
- View/download PDF
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