110 research outputs found

    The Impact of Crown Conch on Intertidal Oyster Populations in Mosquito Lagoon

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    Commercial oyster harvesters in Florida have long complained that the Florida crown conch Melongena coronais in competition with them for harvestable-sized eastern oysters (Crassostrea virginica). Harvesters also suggest that crown conch, rather than overharvesting, has led to a large decline in oyster populations. To determine the role of M. corona on oysters in Mosquito Lagoon, we must first better understand the biology and ecology of M. corona., and to comprehend crown conch biology in Mosquito Lagoon along the east coast of central Florida, we conducted a three-part experiment in Canaveral National Seashore (northern Mosquito Lagoon). Specifically, we designed a field feeding trial to determine prey oyster size preference. To this end, we executed surveys of oyster reefs to gauge the population density of M. corona in Mosquito Lagoon and tracked conch movements in intervals to determine locomotive capabilities. Our results indicate M. corona: 1) was uncommon in Mosquito Lagoon, with the exception of hotspots, 2) did not selectively forage based on tested oyster shell lengths, and 3) moved a mean of 63.5 meters in 24 hours. Based on our abundance data, we estimate that there are 5137 M. corona across 2802 oyster reefs in Mosquito Lagoon (mean: 0.01 conch/m2, with 0.75 conch/m2 in hotspots). More common were thin stripe hermit crabs (Clibanarius vittatus) occupying shells that once housed M. corona. Therefore, it is not likely that M. corona has played a significant role in oyster population declines in Canaveral National Seashore

    How open science helps researchers succeed

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    Open access, open data, open source, and other open scholarship practices are growing in popularity and necessity. However, widespread adoption of these practices has not yet been achieved. One reason is that researchers are uncertain about how sharing their work will affect their careers. We review literature demonstrating that open research is associated with increases in citations, media attention, potential collaborators, job opportunities, and funding opportunities. These findings are evidence that open research practices bring significant benefits to researchers relative to more traditional closed practices

    Serum neurofilament dynamics predicts neurodegeneration and clinical progression in presymptomatic Alzheimer's disease

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    Neurofilament light chain (NfL) is a promising fluid biomarker of disease progression for various cerebral proteopathies. Here we leverage the unique characteristics of the Dominantly Inherited Alzheimer Network and ultrasensitive immunoassay technology to demonstrate that NfL levels in the cerebrospinal fluid (n = 187) and serum (n = 405) are correlated with one another and are elevated at the presymptomatic stages of familial Alzheimer's disease. Longitudinal, within-person analysis of serum NfL dynamics (n = 196) confirmed this elevation and further revealed that the rate of change of serum NfL could discriminate mutation carriers from non-mutation carriers almost a decade earlier than cross-sectional absolute NfL levels (that is, 16.2 versus 6.8 years before the estimated symptom onset). Serum NfL rate of change peaked in participants converting from the presymptomatic to the symptomatic stage and was associated with cortical thinning assessed by magnetic resonance imaging, but less so with amyloid-β deposition or glucose metabolism (assessed by positron emission tomography). Serum NfL was predictive for both the rate of cortical thinning and cognitive changes assessed by the Mini-Mental State Examination and Logical Memory test. Thus, NfL dynamics in serum predict disease progression and brain neurodegeneration at the early presymptomatic stages of familial Alzheimer's disease, which supports its potential utility as a clinically useful biomarker

    Developing effective policy strategies to retain health workers in rural Bangladesh: a policy analysis

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    This article was published in Human Resources for Health [ © 2015 Rawal et al.; licensee BioMed Central] and the definite version is available at: https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-015-0030-6Introduction: Retention of human resources for health (HRH), particularly physicians and nurses in rural and remote areas, is a major problem in Bangladesh. We reviewed relevant policies and provisions in relation to HRH aiming to develop appropriate rural retention strategies in Bangladesh. Methods: We conducted a document review, thorough search and review of relevant literature published from 1971 through May 2013, key informant interviews with policy elites (health policy makers, managers, researchers, etc.), and a roundtable discussion with key stakeholders and policy makers. We used the World Health Organization's (WHO's) guidelines as an analytical matrix to examine the rural retention policies under 4 domains, i) educational, ii) regulatory, iii) financial, and iv) professional and personal development, and 16 sub-domains. Results: Over the past four decades, Bangladesh has developed and implemented a number of health-related policies and provisions concerning retention of HRH. The district quota system in admissions is in practice to improve geographical representation of the students. Students of special background including children of freedom fighters and tribal population have allocated quotas. In private medical and nursing schools, at least 5% of seats are allocated for scholarships. Medical education has a provision for clinical rotation in rural health facilities. Further, in the public sector, every newly recruited medical doctor must serve at least 2 years at the upazila level. To encourage serving in hard-to-reach areas, particularly in three Hill Tract districts of Chittagong division, the government provides an additional 33% of the basic salary, but not exceeding US$ 38 per month. This amount is not attractive enough, and such provision is absent for those working in other rural areas. Although the government has career development and promotion plans for doctors and nurses, these plans are often not clearly specified and not implemented effectively. Conclusion: The government is committed to address the rural retention problem as shown through the formulation and implementation of related policies and strategies. However, Bangladesh needs more effective policies and provisions designed specifically for attraction, deployment, and retention of HRH in rural areas, and the execution of these policies and provisions must be monitored and evaluated effectivelyPublishe

    Extensive Evolutionary Changes in Regulatory Element Activity during Human Origins Are Associated with Altered Gene Expression and Positive Selection

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    Understanding the molecular basis for phenotypic differences between humans and other primates remains an outstanding challenge. Mutations in non-coding regulatory DNA that alter gene expression have been hypothesized as a key driver of these phenotypic differences. This has been supported by differential gene expression analyses in general, but not by the identification of specific regulatory elements responsible for changes in transcription and phenotype. To identify the genetic source of regulatory differences, we mapped DNaseI hypersensitive (DHS) sites, which mark all types of active gene regulatory elements, genome-wide in the same cell type isolated from human, chimpanzee, and macaque. Most DHS sites were conserved among all three species, as expected based on their central role in regulating transcription. However, we found evidence that several hundred DHS sites were gained or lost on the lineages leading to modern human and chimpanzee. Species-specific DHS site gains are enriched near differentially expressed genes, are positively correlated with increased transcription, show evidence of branch-specific positive selection, and overlap with active chromatin marks. Species-specific sequence differences in transcription factor motifs found within these DHS sites are linked with species-specific changes in chromatin accessibility. Together, these indicate that the regulatory elements identified here are genetic contributors to transcriptional and phenotypic differences among primate species

    “Working the System”—British American Tobacco's Influence on the European Union Treaty and Its Implications for Policy: An Analysis of Internal Tobacco Industry Documents

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    Katherine Smith and colleagues investigate the ways in which British American Tobacco influenced the European Union Treaty so that new EU policies advance the interests of major corporations, including those that produce products damaging to health

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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