1,985 research outputs found

    Parsimony and Model-Based Analyses of Indels in Avian Nuclear Genes Reveal Congruent and Incongruent Phylogenetic Signals

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    Insertion/deletion (indel) mutations, which are represented by gaps in multiple sequence alignments, have been used to examine phylogenetic hypotheses for some time. However, most analyses combine gap data with the nucleotide sequences in which they are embedded, probably because most phylogenetic datasets include few gap characters. Here, we report analyses of 12,030 gap characters from an alignment of avian nuclear genes using maximum parsimony (MP) and a simple maximum likelihood (ML) framework. Both trees were similar, and they exhibited almost all of the strongly supported relationships in the nucleotide tree, although neither gap tree supported many relationships that have proven difficult to recover in previous studies. Moreover, independent lines of evidence typically corroborated the nucleotide topology instead of the gap topology when they disagreed, although the number of conflicting nodes with high bootstrap support was limited. Filtering to remove short indels did not substantially reduce homoplasy or reduce conflict. Combined analyses of nucleotides and gaps resulted in the nucleotide topology, but with increased support, suggesting that gap data may prove most useful when analyzed in combination with nucleotide substitutions

    Crotalus atrox venom preconditioning increases plasma fibrinogen and reduces perioperative hemorrhage in a rat model of surgical brain injury.

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    Perioperative bleeding is a potentially devastating complication in neurosurgical patients, and plasma fibrinogen concentration has been identified as a potential modifiable risk factor for perioperative bleeding. The aim of this study was to evaluate preconditioning with Crotalus atrox venom (Cv-PC) as potential preventive therapy for reducing perioperative hemorrhage in the rodent model of surgical brain injury (SBI). C. atrox venom contains snake venom metalloproteinases that cleave fibrinogen into fibrin split products without inducing clotting. Separately, fibrinogen split products induce fibrinogen production, thereby elevating plasma fibrinogen levels. Thus, the hypothesis was that preconditioning with C. atrox venom will produce fibrinogen spilt products, thereby upregulating fibrinogen levels, ultimately improving perioperative hemostasis during SBI. We observed that Cv-PC SBI animals had significantly reduced intraoperative hemorrhage and postoperative hematoma volumes compared to those of vehicle preconditioned SBI animals. Cv-PC animals were also found to have higher levels of plasma fibrinogen at the time of surgery, with unchanged prothrombin time. Cv-PC studies with fractions of C. atrox venom suggest that snake venom metalloproteinases are largely responsible for the improved hemostasis by Cv-PC. Our findings indicate that Cv-PC increases plasma fibrinogen levels and may provide a promising therapy for reducing perioperative hemorrhage in elective surgeries

    Evolution of changes in the computed tomography scans of the brain of a patient with left middle cerebral artery infarction: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Stroke is a common and important condition in medicine. Effective early management of acute stroke can reduce morbidity and mortality.</p> <p>Case presentation</p> <p>A 63-year-old man presented to the Accident and Emergency department with a history of collapse and progressive right-sided weakness. Clinically this was a cerebrovascular accident affecting the left hemisphere of the brain causing right hemiplegia. Computed tomography scans, performed 3 days apart, showed the evolution of infarction in the brain caused by the thrombus in the left middle cerebral artery. This is one of the early signs for stroke seen on computed tomography imaging and it is called the hyperdense middle cerebral artery sign.</p> <p>Conclusion</p> <p>Patients admitted with a stroke, undergo CT brain within 24 hours. The scan usually takes place at admission into the hospital and is done to rule out a bleed or a space occupying lesion within the brain. A normal CT brain does not confirm a stroke has not taken place. When scanned early, the changes seen on the CT due to an infarction from a thrombus may not have taken place yet. This paper highlights the early changes that can be seen on the CT brain following a stroke caused by infarction due to a thrombus in the middle cerebral artery.</p

    Development and Validation of the Behavioral Tendencies Questionnaire

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    At a fundamental level, taxonomy of behavior and behavioral tendencies can be described in terms of approach, avoid, or equivocate (i.e., neither approach nor avoid). While there are numerous theories of personality, temperament, and character, few seem to take advantage of parsimonious taxonomy. The present study sought to implement this taxonomy by creating a questionnaire based on a categorization of behavioral temperaments/tendencies first identified in Buddhist accounts over fifteen hundred years ago. Items were developed using historical and contemporary texts of the behavioral temperaments, described as “Greedy/Faithful”, “Aversive/Discerning”, and “Deluded/Speculative”. To both maintain this categorical typology and benefit from the advantageous properties of forced-choice response format (e.g., reduction of response biases), binary pairwise preferences for items were modeled using Latent Class Analysis (LCA). One sample (n1 = 394) was used to estimate the item parameters, and the second sample (n2 = 504) was used to classify the participants using the established parameters and cross-validate the classification against multiple other measures. The cross-validated measure exhibited good nomothetic span (construct-consistent relationships with related measures) that seemed to corroborate the ideas present in the original Buddhist source documents. The final 13-block questionnaire created from the best performing items (the Behavioral Tendencies Questionnaire or BTQ) is a psychometrically valid questionnaire that is historically consistent, based in behavioral tendencies, and promises practical and clinical utility particularly in settings that teach and study meditation practices such as Mindfulness Based Stress Reduction (MBSR)

    The promoter from SlREO, a highly-expressed, root-specific Solanum lycopersicum gene, directs expression to cortex of mature roots

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    Root-specific promoters are valuable tools for targeting transgene expression, but many of those already described have limitations to their general applicability. We present the expression characteristics of SlREO, a novel gene isolated from tomato (Solanum lycopersicum L.). This gene was highly expressed in roots but had a very low level of expression in aerial plant organs. A 2.4-kb region representing the SlREO promoter sequence was cloned upstream of the uidA GUS reporter gene and shown to direct expression in the root cortex. In mature, glasshouse-grown plants this strict root specificity was maintained. Furthermore, promoter activity was unaffected by dehydration or wounding stress but was somewhat suppressed by exposure to NaCl, salicylic acid and jasmonic acid. The predicted protein sequence of SlREO contains a domain found in enzymes of the 2-oxoglutarate and Fe(II)-dependent dioxygenase superfamily. The novel SlREO promoter has properties ideal for applications requiring strong and specific gene expression in the bulk of tomato root tissue growing in soil, and is also likely to be useful in other Solanaceous crop

    Cardiac surgery and percutaneous intervention in pregnant women with heart disease

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    In pregnant women with heart disease, complications can arise due to the haemodynamic burden of pregnancy and to hypercoagulation. Most problems can be managed medically, but sometimes cardiac surgery or percutaneous intervention is unavoidable. Cardiac surgery has similar maternal mortality to that outside pregnancy, but foetal mortality and morbidity are considerable. Measures to reduce the risk by adaptation of the management of cardiopulmonary bypass are described. When gestational age is > 28 weeks, pre-surgery delivery of the foetus should be considered. Percutaneous intervention exposes the foetus to radiation. The radiation dose for common cardiac procedures, however, does not result in detectable harmful foetal effects

    Origin and segregation of the human germline

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    Acknowledgements This work was supported by the Wellcome Investigator Awards in Science (2094)75/Z/17/Z (to MA Surani), the Wellcome Investigator Awards in Science 096738/Z/11/Z (to MA Surani), the BBSRC research grant G103986 (to MA Surani), the Croucher Postdoctoral Research Fellowship (to WWC Tang), the Wellcome 4-Yr PhD Programme in Stem Cell Biology & Medicine (2038)31/Z/16/Z (to A Castillo-Venzor) and the Cambridge Commonwealth European and International Trust (to A Castillo-Venzor), the Isaac Newton Trust (to WWC Tang), the Butterfield Awards of Great Britain Sasakawa Foundation (to T Kobayashi and MA Surani), and the Astellas Foundation for Research on Metabolic Disorders (to T Kobayashi). The marmoset embryo research is generously supported by the Wellcome Trust (WT RG89228, WT RG9242), the Centre for Trophoblast Research, the Isaac Newton Trust, and JSPS KAKENHI 15H02360, 19H05759. TE Boroviak was supported by a Wellcome Sir Henry Dale Fellowship. JC Marioni acknowledges core support from EMBL and from Cancer Research UK (C9545/A29580), which supports MD Morgan. We would like to thank Roger Barker and Xiaoling He for providing human embryonic tissues and Charles Bradshaw for bioinformatics support. We also thank The Weizmann Institute of Science for the WIS2 human PSC line and the Genomics Core Facility of CRUK Cambridge Institute for sequencing services. We thank members of the Surani laboratory for insightful comments and critical reading of the manuscript.Peer reviewedPublisher PD

    Seasonal changes in patterns of gene expression in avian song control brain regions.

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Photoperiod and hormonal cues drive dramatic seasonal changes in structure and function of the avian song control system. Little is known, however, about the patterns of gene expression associated with seasonal changes. Here we address this issue by altering the hormonal and photoperiodic conditions in seasonally-breeding Gambel's white-crowned sparrows and extracting RNA from the telencephalic song control nuclei HVC and RA across multiple time points that capture different stages of growth and regression. We chose HVC and RA because while both nuclei change in volume across seasons, the cellular mechanisms underlying these changes differ. We thus hypothesized that different genes would be expressed between HVC and RA. We tested this by using the extracted RNA to perform a cDNA microarray hybridization developed by the SoNG initiative. We then validated these results using qRT-PCR. We found that 363 genes varied by more than 1.5 fold (>log(2) 0.585) in expression in HVC and/or RA. Supporting our hypothesis, only 59 of these 363 genes were found to vary in both nuclei, while 132 gene expression changes were HVC specific and 172 were RA specific. We then assigned many of these genes to functional categories relevant to the different mechanisms underlying seasonal change in HVC and RA, including neurogenesis, apoptosis, cell growth, dendrite arborization and axonal growth, angiogenesis, endocrinology, growth factors, and electrophysiology. This revealed categorical differences in the kinds of genes regulated in HVC and RA. These results show that different molecular programs underlie seasonal changes in HVC and RA, and that gene expression is time specific across different reproductive conditions. Our results provide insights into the complex molecular pathways that underlie adult neural plasticity
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