298 research outputs found

    Cross-genus amplification and characterisation of microsatellite loci in the large-eared free tailed bat, Otomops (Chiroptera: Molossidae) from Africa and Madagascar

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    Primers developed for the Brazilian free-tailed bat, Tadarida brasiliensis, were successfully used to cross-amplify microsatellite loci in two Afro-tropical Otomops species. Seventy one (71) bats from two species were genotyped for two dinucleotide and four tetranucleotide loci, yielding 1 to 15 alleles per locus. For the combined sample, the observed and expected heterozygosities ranged from 0.125 to 1.000 and 0.125 to 0.919, respectively. The polymorphism information content (PIC) values were 0.295 to 0.905 (mean 0.687) for Otomops martiensseni and 0.110 to 0.797 (mean 0.442) for Otomops madagascariensis. Five O. martiensseni loci deviated significantly from Hardy-Weinberg equilibrium. These six loci provide genetic markers that will be useful in investigating the population genetic structure of Afro-Arabian O. martiensseni and Malagasy O. madagascariensis, with potential application to Asian species of Otomops and possibly other genera within the Molossidae.Keywords: Bats, Otomops, Chiroptera, microsatellites, Molossidae, cross-genus amplificationAfrican Journal of Biotechnology Vol. 12(27), pp. 4233-423

    Cross-genus amplification and characterisation of microsatellite loci in the little free tailed bat, Chaerephon pumilus s. l. (Molossidae) from South Eastern Africa

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    Microsatellite loci for Chaerephon pumilus sensu lato from south eastern Africa were cross-amplified using primers developed for the Mexican free-tailed bat, Tadarida brasiliensis. Two dinucleotide and four tetranucleotide loci were recovered and genotyped for 74 bats, yielding 9 to 15 alleles per locus. The observed and expected heterozygosities were 0.06 to 0.84 and 0.54 to 0.81 respectively, and the PIC values ranged from 0.51 to 0.80, indicative of considerable variability within the sample. There was no evidence of linkage disequilibrium among pairs of loci, or of deviation from Hardy-Weinberg equilibrium. These six loci were informative in studies of population genetic structure of C. pumilus sensu lato.Keywords: Bats, Chaerephon pumilus, Chiroptera, microsatellites, Molossidae, cross-genus amplificationAfrican Journal of Biotechnology Vol. 12(21), pp. 3143-314

    Suppression of interdiffusion in GaAs/AlGaAs quantum-well structure capped with dielectric films by deposition of gallium oxide

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    In this work, different dielectric caps were deposited on the GaAs/AlGaAs quantum well(QW) structures followed by rapid thermal annealing to generate different degrees of interdiffusion. Deposition of a layer of GaxOy on top of these dielectric caps resulted in significant suppression of interdiffusion. In these samples, it was found that although the deposition of GaxOy and subsequent annealing caused additional injection of Ga into the SiO₂ layer, Ga atoms were still able to outdiffuse from the GaAsQW structure during annealing, to generate excess Ga vacancies. The suppression of interdiffusion with the presence of Ga vacancies was explained by the thermal stress effect which suppressed Ga vacancydiffusion during annealing. It suggests that GaxOy may therefore be used as a mask material in conjunction with other dielectric capping layers in order to control and selectively achieve impurity-free vacancy disordering.J. Wong-Leung, P. N. K. Deenapanray, and H. H. Tan acknowledge the fellowships awarded by the Australian Research Council

    Genetic monitoring detects an overlooked cryptic species and reveals the diversity and distribution of three invasive Rattus congeners in South Africa

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    Background: South Africa's long and extensive trade activity has ensured ample opportunities for exotic species introduction. Whereas the rich biodiversity of endemic southern African fauna has been the focus of many studies, invasive vertebrates are generally overlooked despite potential impacts on biodiversity, health and agriculture. Genetic monitoring of commensal rodents in South Africa which uncovered the presence of Rattus tanezumi, a South-East Asian endemic not previously known to occur in Africa, provided the impetus for expanded studies on all invasive Rattus species present. Results: To this end, intensified sampling at 28 South African localities and at one site in Swaziland, identified 149 Rattus specimens. Cytochrome b gene sequencing revealed the presence of two R. tanezumi, seven R. rattus and five R. norvegicus haplotypes in south Africa. Phylogenetic results were consistent with a single, recent R. tanezumi introduction and indicated that R. norvegicus and R. rattus probably became established following at least two and three independent introductions, respectively. Intra- and inter-specific diversity was highest in informal human settlements, with all three species occurring at a single metropolitan township site. Rattus norvegicus and R. rattus each occurred sympatrically with R. tanezumi at one and five sites, respectively. Karyotyping of selected R. rattus and R. tanezumi individuals identified diploid numbers consistent with those reported previously for these cryptic species. Ordination of bioclimatic variables and MaxEnt ecological niche modelling confirmed that the bioclimatic niche occupied by R. tanezumi in south Africa was distinct from that occupied in its naturalised range in south-east Asia suggesting that factors other than climate may influence the distribution of this species. Conclusions: This study has highlighted the value of genetic typing for detecting cryptic invasive species, providing historical insights into introductions and for directing future sampling. The apparent ease with which a cryptic species can become established signals the need for broader implementation of genetic monitoring programmes. In addition to providing baseline data and potentially identifying high-risk introduction routes, the predictive power of ecological niche modelling is enhanced when species records are genetically verified

    Bibliometric analysis of authorship trends and collaboration dynamics over the past three decades of BONE's publication history

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    The existence of a gender gap in academia has been a hotly debated topic over the past several decades. It has been argued that due to the gender gap, it is more difficult for women to obtain higher positions. Manuscripts serve as an important measurement of one's accomplishments within a particular field of academia. Here, we analyzed, over the past 3 decades, authorship and other trends in manuscripts published in BONE, one of the premier journals in the field of bone and mineral metabolism. For this study, one complete year of manuscripts was evaluated (e.g. 1985, 1995, 2005, 2015) for each decade. A bibliometric analysis was then performed of authorship trends for those manuscripts. Analyzed fields included: average number of authors per manuscript, numerical position of the corresponding author, number of institutions collaborating on each manuscript, number of countries involved with each manuscript, number of references, and number of citations per manuscript. Each of these fields increased significantly over the 30-year time frame (p < 10− 6). The gender of both the first and corresponding authors was identified and analyzed over time and by region. There was a significant increase in the percentage of female first authors from 23.4% in 1985 to 47.8% in 2015 (p = 0.001). The percentage of female corresponding authors also increased from 21.2% in 1985 to 35.4% in 2015 although it was not significant (p = 0.07). With such a substantial emphasis being placed on publishing in academic medicine, it is crucial to comprehend the changes in publishing characteristics over time and geographical region. These findings highlight authorship trends in BONE over time as well as by region. Importantly, these findings also highlight where challenges still exist

    Search algorithms as a framework for the optimization of drug combinations

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    Combination therapies are often needed for effective clinical outcomes in the management of complex diseases, but presently they are generally based on empirical clinical experience. Here we suggest a novel application of search algorithms, originally developed for digital communication, modified to optimize combinations of therapeutic interventions. In biological experiments measuring the restoration of the decline with age in heart function and exercise capacity in Drosophila melanogaster, we found that search algorithms correctly identified optimal combinations of four drugs with only one third of the tests performed in a fully factorial search. In experiments identifying combinations of three doses of up to six drugs for selective killing of human cancer cells, search algorithms resulted in a highly significant enrichment of selective combinations compared with random searches. In simulations using a network model of cell death, we found that the search algorithms identified the optimal combinations of 6-9 interventions in 80-90% of tests, compared with 15-30% for an equivalent random search. These findings suggest that modified search algorithms from information theory have the potential to enhance the discovery of novel therapeutic drug combinations. This report also helps to frame a biomedical problem that will benefit from an interdisciplinary effort and suggests a general strategy for its solution.Comment: 36 pages, 10 figures, revised versio

    Completeness of Reporting in Diet- and Nutrition-Related Randomized Controlled Trials and Systematic Reviews With Meta-Analysis:Protocol for 2 Independent Meta-Research Studies

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    Background: Journal articles describing randomized controlled trials (RCTs) and systematic reviews with meta-analysis of RCTs are not optimally reported and often miss crucial details. This poor reporting makes assessing these studies’ risk of bias or reproducing their results difficult. However, the reporting quality of diet- and nutrition-related RCTs and meta-analyses has not been explored. Objective: We aimed to assess the reporting completeness and identify the main reporting limitations of diet- and nutrition-related RCTs and meta-analyses of RCTs, estimate the frequency of reproducible research practices among these RCTs, and estimate the frequency of distorted presentation or spin among these meta-analyses. Methods: Two independent meta-research studies will be conducted using articles published in PubMed-indexed journals. The first will include a sample of diet- and nutrition-related RCTs; the second will include a sample of systematic reviews with meta-analysis of diet- and nutrition-related RCTs. A validated search strategy will be used to identify RCTs of nutritional interventions and an adapted strategy to identify meta-analyses in PubMed. We will search for RCTs and meta-analyses indexed in 1 calendar year and randomly select 100 RCTs (June 2021 to June 2022) and 100 meta-analyses (July 2021 to July 2022). Two reviewers will independently screen the titles and abstracts of records yielded by the searches, then read the full texts to confirm their eligibility. The general features of these published RCTs and meta-analyses will be extracted into a research electronic data capture database (REDCap; Vanderbilt University). The completeness of reporting of each RCT will be assessed using the items in the CONSORT (Consolidated Standards of Reporting Trials), its extensions, and the TIDieR (Template for Intervention Description and Replication) statements. Information about practices that promote research transparency and reproducibility, such as the publication of protocols and statistical analysis plans will be collected. There will be an assessment of the completeness of reporting of each meta-analysis using the items in the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and collection of information about spin in the abstracts and full-texts. The results will be presented as descriptive statistics in diagrams or tables. These 2 meta-research studies are registered in the Open Science Framework. Results: The literature search for the first meta-research retrieved 20,030 records and 2182 were potentially eligible. The literature search for the second meta-research retrieved 10,918 records and 850 were potentially eligible. Among them, random samples of 100 RCTs and 100 meta-analyses were selected for data extraction. Data extraction is currently in progress, and completion is expected by the beginning of 2023. Conclusions: Our meta-research studies will summarize the main limitation on reporting completeness of nutrition- or diet-related RCTs and meta-analyses and provide comprehensive information regarding the particularities in the reporting of intervention studies in the nutrition field

    Completeness of reporting in diet- and nutrition-related randomized controlled trials and systematic reviews with meta-analysis: protocol for 2 independent meta-research studies

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    Background: Journal articles describing randomized controlled trials (RCTs) and systematic reviews with meta-analysis of RCTs are not optimally reported and often miss crucial details. This poor reporting makes assessing these studies’ risk of bias or reproducing their results difficult. However, the reporting quality of diet- and nutrition-related RCTs and meta-analyses has not been explored. Objective: We aimed to assess the reporting completeness and identify the main reporting limitations of diet- and nutrition-related RCTs and meta-analyses of RCTs, estimate the frequency of reproducible research practices among these RCTs, and estimate the frequency of distorted presentation or spin among these meta-analyses. Methods: Two independent meta-research studies will be conducted using articles published in PubMed-indexed journals. The first will include a sample of diet- and nutrition-related RCTs; the second will include a sample of systematic reviews with meta-analysis of diet- and nutrition-related RCTs. A validated search strategy will be used to identify RCTs of nutritional interventions and an adapted strategy to identify meta-analyses in PubMed. We will search for RCTs and meta-analyses indexed in 1 calendar year and randomly select 100 RCTs (June 2021 to June 2022) and 100 meta-analyses (July 2021 to July 2022). Two reviewers will independently screen the titles and abstracts of records yielded by the searches, then read the full texts to confirm their eligibility. The general features of these published RCTs and meta-analyses will be extracted into a research electronic data capture database (REDCap; Vanderbilt University). The completeness of reporting of each RCT will be assessed using the items in the CONSORT (Consolidated Standards of Reporting Trials), its extensions, and the TIDieR (Template for Intervention Description and Replication) statements. Information about practices that promote research transparency and reproducibility, such as the publication of protocols and statistical analysis plans will be collected. There will be an assessment of the completeness of reporting of each meta-analysis using the items in the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and collection of information about spin in the abstracts and full-texts. The results will be presented as descriptive statistics in diagrams or tables. These 2 meta-research studies are registered in the Open Science Framework. Results: The literature search for the first meta-research retrieved 20,030 records and 2182 were potentially eligible. The literature search for the second meta-research retrieved 10,918 records and 850 were potentially eligible. Among them, random samples of 100 RCTs and 100 meta-analyses were selected for data extraction. Data extraction is currently in progress, and completion is expected by the beginning of 2023. Conclusions: Our meta-research studies will summarize the main limitation on reporting completeness of nutrition- or diet-related RCTs and meta-analyses and provide comprehensive information regarding the particularities in the reporting of intervention studies in the nutrition field. International Registered Report Identifier (IRRID): DERR1-10.2196/4353

    Protocol for a meta-research study of protocols for diet or nutrition-related trials published in indexed journals:general aspects of study design, rationale and reporting limitations

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    INTRODUCTION: The Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) reporting guideline establishes a minimum set of items to be reported in any randomised controlled trial (RCT) protocol. The Template for Intervention Description and Replication (TIDieR) reporting guideline was developed to improve the reporting of interventions in RCT protocols and results papers. Reporting completeness in protocols of diet or nutrition-related RCTs has not been systematically investigated. We aim to identify published protocols of diet or nutrition-related RCTs, assess their reporting completeness and identify the main reporting limitations remaining in this field. METHODS AND ANALYSIS: We will conduct a meta-research study of RCT protocols published in journals indexed in at least one of six selected databases between 2012 and 2022. We have run a search in PubMed, Embase, CINAHL, Web of Science, PsycINFO and Global Health using a search strategy designed to identify protocols of diet or nutrition-related RCTs. Two reviewers will independently screen the titles and abstracts of records yielded by the search in Rayyan. The full texts will then be read to confirm protocol eligibility. We will collect general study features (publication information, types of participants, interventions, comparators, outcomes and study design) of all eligible published protocols in this contemporary sample. We will assess reporting completeness in a randomly selected sample of them and identify their main reporting limitations. We will compare this subsample with the items in the SPIRIT and TIDieR statements. For all data collection, we will use data extraction forms in REDCap. This protocol is registered on the Open Science Framework (DOI: 10.17605/OSF.IO/YWEVS). ETHICS AND DISSEMINATION: This study will undertake a secondary analysis of published data and does not require ethical approval. The results will be disseminated through journals and conferences targeting stakeholders involved in nutrition research
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