7,154 research outputs found

    How the Devil Ray Got Its Horns: The Evolution and Development of Cephalic Lobes in Myliobatid Stingrays (Batoidea: Myliobatidae)

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    Manta rays and their relatives of the family Myliobatidae have pectoral fins that have been modified for underwater flight, as well as a pair of fleshy projections at the anterior of the body called cephalic lobes, which are specialized for feeding. As a unique trait with a dedicated function, cephalic lobes offer an excellent opportunity to elucidate the processes by which diverse body plans and features evolve. To shed light on the morphological development and genetic underpinnings of cephalic lobes, we examined paired fin development in cownose rays, which represent the sister taxon to manta rays in the genus Mobula. We find that cephalic lobes develop as anterior pectoral fin domains and lack independent posterior patterning by 5\u27 HoxD genes and Shh, indicating that cephalic lobes are not independent appendages but rather are modified pectoral fin domains. In addition, by leveraging interspecies comparative transcriptomics and domain-specific RNA-sequencing, we identify shared expression of anterior patterning genes, including Alx1, Alx4, Pax9, Hoxa13, Hoxa2, and Hoxd4, in the pectoral fins of cownose ray (Rhinoptera bonasus) and little skate (Leucoraja erinacea), providing evidence supporting homology between the cephalic lobes of myliobatids and the anterior pectoral fins of skates. We also suggest candidate genes that may be involved in development of myliobatid-specific features, including Omd, which is likely associated with development of thick anterior pectoral fin radials of myliobatids, and Dkk1, which may inhibit tissue outgrowth at the posterior boundary of the developing cephalic lobes. Finally, we observe that cephalic lobes share a surprising number of developmental similarities with another paired fin modification: the claspers of male cartilaginous fishes, including enrichment of Hand2, Hoxa13, and androgen receptor. These results suggest that cephalic lobes may have evolved by co-opting developmental pathways that specify novel domains in paired fins. Taken together, these data on morphological development and comparative gene expression patterns illustrate how distinct body plans and seemingly novel features can arise via subtle changes to existing developmental pathways

    A Bayesian method for evaluating and discovering disease loci associations

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    Background: A genome-wide association study (GWAS) typically involves examining representative SNPs in individuals from some population. A GWAS data set can concern a million SNPs and may soon concern billions. Researchers investigate the association of each SNP individually with a disease, and it is becoming increasingly commonplace to also analyze multi-SNP associations. Techniques for handling so many hypotheses include the Bonferroni correction and recently developed Bayesian methods. These methods can encounter problems. Most importantly, they are not applicable to a complex multi-locus hypothesis which has several competing hypotheses rather than only a null hypothesis. A method that computes the posterior probability of complex hypotheses is a pressing need. Methodology/Findings: We introduce the Bayesian network posterior probability (BNPP) method which addresses the difficulties. The method represents the relationship between a disease and SNPs using a directed acyclic graph (DAG) model, and computes the likelihood of such models using a Bayesian network scoring criterion. The posterior probability of a hypothesis is computed based on the likelihoods of all competing hypotheses. The BNPP can not only be used to evaluate a hypothesis that has previously been discovered or suspected, but also to discover new disease loci associations. The results of experiments using simulated and real data sets are presented. Our results concerning simulated data sets indicate that the BNPP exhibits both better evaluation and discovery performance than does a p-value based method. For the real data sets, previous findings in the literature are confirmed and additional findings are found. Conclusions/Significance: We conclude that the BNPP resolves a pressing problem by providing a way to compute the posterior probability of complex multi-locus hypotheses. A researcher can use the BNPP to determine the expected utility of investigating a hypothesis further. Furthermore, we conclude that the BNPP is a promising method for discovering disease loci associations. © 2011 Jiang et al

    A coherent middle Pliocene magnetostratigraphy, Wanganui Basin, New Zealand

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    We document magnetostratigraphies for three river sections (Turakina, Rangitikei, Wanganui) in Wanganui Basin and interpret them as corresponding to the Upper Gilbert, the Gauss and lower Matuyama Chrons of the Geomagnetic Polarity Timescale, in agreement with foraminiferal biostratigraphic datums. The Gauss-Gilbert transition (3.58 Ma) is located in both the Turakina and Wanganui River sections, while the Gauss-Matuyama transition (2.58 Ma) is located in all three sections, as are the lower and upper boundaries of the Mammoth (3.33–3.22 Ma) and Kaena (3.11–3.04 Ma) Subchrons. Our interpretations are based in part on the re-analysis of existing datasets and in part on the acquisition and analysis of new data, particularly for the Wanganui River section. The palaeomagnetic dates of these six horizons provide the only numerical age control for a thick (up to 2000 m) mudstone succession (Tangahoe Mudstone) that accumulated chiefly in upper bathyal and outer neritic palaeoenvironments. In the Wanganui River section the mean sediment accumulation rate is estimated to have been about 1.8 m/k.y., in the Turakina section it was about 1.5 m/k.y., and in the Rangitikei section, the mean rate from the beginning of the Mammoth Subchron to the Hautawa Shellbed was about 1.1 m/k.y. The high rates may be associated with the progradation of slope clinoforms northward through the basin. This new palaeomagnetic timescale allows revised correlations to be made between cyclothems in the Rangitikei River section and the global Oxygen Isotope Stages (OIS) as represented in Ocean Drilling Program (ODP) Site 846. The 16 depositional sequences between the end of the Mammoth Subchron and the Gauss-Matuyama Boundary are correlated with OIS MG2 to 100. The cyclothems average 39 k.y. in duration in our age model, which is close to the 41 k.y. duration of the orbital obliquity cycles. We support the arguments advanced recently in defence of the need for local New Zealand stages as a means of classifying New Zealand sedimentary successions, and strongly oppose the proposal to move stage boundaries to selected geomagnetic polarity transitions. The primary magnetisation of New Zealand mudstone is frequently overprinted with secondary components of diagenetic origin, and hence it is often difficult to obtain reliable magnetostratigraphic records. We suggest specific approaches, analytical methods, and criteria to help ensure robustness and coherency in the palaeomagnetic identification of chron boundaries in typical New Zealand Cenozoic mudstone successions

    Multicentre RCT and economic evaluation of a psychological intervention together with a leaflet to reduce risk behaviour amongst men who have sex with men (MSM) prescribed post-exposure prophylaxis for HIV following sexual exposure (PEPSE): A protocol

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    Background: Post-exposure prophylaxis (PEP) following sexual exposure to HIV has been recommended as a method of preventing HIV infection in the UK. Men who have sex with men (MSM) are the group most affected by HIV in the UK and their sexual risk taking behaviour is reported to be increasing. One-to-one behavioural interventions, such as motivational interviewing (MI) have been recommended to reduce HIV in high risk groups. The Information, Motivation and Behavioral skills (IMB) model has been shown to provide a good basis for understanding and predicting HIV-relevant health behaviour and health behaviour change, however the IMB has yet to be applied to PEP after risky sexual exposure. The primary aim of this trial is to examine the impact of MI augmented with information provision and behavioural skills building (informed by the IMB Model), over and above usual care, on risky sexual behaviour in MSM prescribed PEP after potential sexual exposure. A secondary aim of this research is to examine the impact of the intervention on adherence to PEP. This study will also provide estimates of the cost-effectiveness of the intervention. Methods: A manualised parallel group randomised controlled trial with economic evaluation will be conducted. The primary outcome is the proportion of risky sexual practices. Secondary outcomes include: i) Levels of adherence to PEP treatment; ii) Number of subsequent courses of PEP; iii) Levels of motivation to avoid risky sexual behaviours; iv) Levels of HIV risk-reduction information/knowledge; v) Levels of risk reduction behavioural skills; vi) Diagnosis of anal gonorrhoea, Chlamydia and/or HIV. 250 participants will be asked to self-complete a questionnaire at four time points during the study (at 0,3,6,12 months). The intervention will consist of a two-session, fixed duration, telephone administered augmented MI intervention based on the IMB model. A newly developed treatment manual will guide the selection of persuasive communication strategies as appropriate for each participant and will be based on underlying change mechanisms specified by the IMB theoretical framework. Information provision and skills building will also be included in the intervention package through the use of information leaflets and tailored action plans. Fidelity of intervention delivery will be assessed. Discussion: The results from this NIHR funded study will identify whether it is appropriate and cost-effective to intervene using one-to-one telephone calls with MSM seeking PEP. If the intervention is effective, further work will be needed on training staff to deliver the intervention competently

    Protecting eyewitness evidence: Examining the efficacy of a self-administered interview tool

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    Given the crucial role of eyewitness evidence, statements should be obtained as soon as possible after an incident. This is not always achieved due to demands on police resources. Two studies trace the development of a new tool, the Self-Administered Interview (SAI), designed to elicit a comprehensive initial statement. In Study 1, SAI participants reported more correct details than participants who provided a free recall account, and performed at the same level as participants given a Cognitive Interview. In Study 2, participants viewed a simulated crime and half recorded their statement using the SAI. After a delay of 1 week, all participants completed a free recall test. SAI participants recalled more correct details in the delayed recall task than control participants

    Molecular Genetics of T Cell Development

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    T cell development is guided by a complex set of transcription factors that act recursively, in different combinations, at each of the developmental choice points from T-lineage specification to peripheral T cell specialization. This review describes the modes of action of the major T-lineage-defining transcription factors and the signal pathways that activate them during intrathymic differentiation from pluripotent precursors. Roles of Notch and its effector RBPSuh (CSL), GATA-3, E2A/HEB and Id proteins, c-Myb, TCF-1, and members of the Runx, Ets, and Ikaros families are critical. Less known transcription factors that are newly recognized as being required for T cell development at particular checkpoints are also described. The transcriptional regulation of T cell development is contrasted with that of B cell development, in terms of their different degrees of overlap with the stem-cell program and the different roles of key transcription factors in gene regulatory networks leading to lineage commitment

    NAIL COSMETICS

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66131/1/j.1365-4362.1992.tb01368.x.pd

    Illuminating Choices for Library Prep: A Comparison of Library Preparation Methods for Whole Genome Sequencing of Cryptococcus neoformans Using Illumina HiSeq.

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    The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use

    Switching the World's Salt Supply—Learning from Iodization to Achieve Potassium Enrichment

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    Sodium is an essential dietary component, but excess sodium intake can lead to high blood pressure and an increased risk of cardiovascular disease. Many national and international bodies, including the World Health Organization, have advocated for population-wide sodium reduction interventions. Most have been unsuccessful due to inadequate sodium reduction by food industry and difficulties in persuading consumers to add less salt to food. Recent research highlights potassium-enriched salt as a new, feasible, acceptable, and scalable approach to reducing the harms caused by excess sodium and inadequate potassium consumption. Modeling shows that a global switch from regular salt to potassium-enriched salt has the potential to avert millions of strokes, heart attacks, and premature deaths worldwide each year. There will be many challenges in switching the world's salt supply to potassium-enriched salt, but the success of universal salt iodization shows that making a global change to the manufacture and use of salt is a tractable proposition. This in-depth review of universal salt iodization identified the importance of a multisectoral effort with strong global leadership, the support of multilateral organizations, engagement with the salt industry, empowered incountry teams, strong participation of national governments, understanding the salt supply chain, and a strategic advocacy and communication plan. Key challenges to the implementation of the iodization program were costs to government, industry, and consumers, industry concerns about consumer acceptability, variance in the size and capabilities of salt producers, inconsistent quality control, ineffective regulation, and trade-related regulatory issues. Many of the opportunities and challenges to universal salt iodization will likely also be applicable to switching the global salt supply to iodized and potassium-enriched salt

    Unusual exanthema combined with cerebral vasculitis in pneumococcal meningitis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Bacterial meningitis is a complex, rapidly progressive disease in which neurological injury is caused in part by the causative organism and in part by the host's own inflammatory responses.</p> <p>Case presentation</p> <p>We present the case of a two-year-old Greek girl with pneumococcal meningitis and an atypical curvilinear-like skin eruption, chronologically associated with cerebral vasculitis. A diffusion-weighted MRI scan showed lesions with restricted diffusion, reflecting local areas of immunologically mediated necrotizing vasculitis.</p> <p>Conclusions</p> <p>Atypical presentations of bacterial meningitis may occur, and they can be accompanied by serious unexpected complications.</p
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