774 research outputs found

    A Meta-Analysis of the Effectiveness of High, Medium, and Low Voltage Electrical Stimulation on the Meat Quality of Small Ruminants

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    The current study is a meta-analysis of the effects of electrical stimulation (ES, n = 28 papers) with different voltages combined with different ageing periods (0–3, 4–7, and 8–14 days) on the meat quality of small ruminants. A comprehensive search for published studies on meat quality of small ruminants investigating the application of low, medium, and high voltage electrical stimulation, was performed using Google Scholar, ScienceDirect, PubMed, and Scopus databases. Forest plots, funnel plots, and other statistical tools and tests were used in the study to analyze the results. Electrical stimulation significantly reduced ultimate pH (p < 0.001), Warner–Bratzler shear force (WBSF) (p < 0.001), cooking loss (p < 0.05), and purge loss (p < 0.001). In addition, sarcomere length (p < 0.01), myofibrillar-fragmentation index (MFI) (p < 0.001), and color (L*, a*, b*) (p < 0.001) showed higher values in meat subjected to ES as compared with the control group. In conclusion, the meta-analysis revealed statistical proof of beneficial effects of ES on meat quality of small ruminants in terms of ultimate pH, tenderness, enhanced proteolysis, and higher colorimetric values

    Functional Analysis of Missense Mutations in Kv8.2 Causing Cone Dystrophy with Supernormal Rod Electroretinogram

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    Mutations in KCNV2 have been proposed as the molecular basis for cone dystrophy with supernormal rod electroretinogram. KCNV2 codes for the modulatory voltage-gated potassium channel α-subunit, Kv8.2, which is incapable of forming functional channels on its own. Functional heteromeric channels are however formed with Kv2.1 in heterologous expression systems, with both α-subunit genes expressed in rod and cone photoreceptors. Of the 30 mutations identified in the KCNV2 gene, we have selected three missense mutations localized in the potassium channel pore and two missense mutations localized in the tetramerization domain for analysis. We characterized the differences between homomeric Kv2.1 and heteromeric Kv2.1/Kv8.2 channels and investigated the influence of the selected mutations on the function of heteromeric channels. We found that two pore mutations (W467G and G478R) led to the formation of nonconducting heteromeric Kv2.1/Kv8.2 channels, whereas the mutations localized in the tetramerization domain prevented heteromer generation and resulted in the formation of homomeric Kv2.1 channels only. Consequently, our study suggests the existence of two distinct molecular mechanisms involved in the disease pathology

    GP coding behaviour for non-specific clinical presentations: a pilot study.

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    Clinical coding is an integral part of primary care. Disease incidence studies based on primary care electronic health records (EHRs) rely on the accuracy of these codes. Current code validation methods are not appropriate for non-specific conditions and provide limited information about GPs' decision-making behaviour around coding. Qualitative methods could offer insight into decision-making behaviour around coding of patients with non-specific conditions. To investigate the decision-making behaviour of GPs when applying Read codes to non-specific clinical presentations, using Lyme disease as a case example. A pilot study was undertaken, involving masked semi-structured interviews of eight GPs in the North West of England. Semi-structured interviews were carried out based on 11 clinical cases representative of Lyme disease presentations. Discrete answers were described descriptively. Interview transcripts were analysed using a thematic approach. Themes underpinning GPs' coding behaviour included: GP personal and professional experience; clinical evidence; diagnostic uncertainty; professional integrity and defensive practice; and patient-sourced health information and beliefs. GPs placed Lyme disease on their differential diagnosis list for five cases; in only two cases would GPs select a Lyme disease related Read code. GPs were reluctant to code with specific diagnostic Read codes when they were presented with patients with vague or unfamiliar symptomology. This masked questionnaire methodology offers a new approach to validate incidence figures, based on Read codes of non-specific conditions. The reluctance to code poses many problems for primary care EHRs research. Further research is needed to understand what drives GPs' coding behaviour

    Transactivation of EGFR by LPS induces COX-2 expression in enterocytes

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    Necrotizing enterocolitis (NEC) is the leading cause of gastrointestinal morbidity and mortality in preterm infants. NEC is characterized by an exaggerated inflammatory response to bacterial flora leading to bowel necrosis. Bacterial lipopolysaccharide (LPS) mediates inflammation through TLR4 activation and is a key molecule in the pathogenesis of NEC. However, LPS also induces cyclooxygenase-2 (COX-2), which promotes intestinal barrier restitution through stimulation of intestinal cell survival, proliferation, and migration. Epidermal growth factor receptor (EGFR) activation prevents experimental NEC and may play a critical role in LPS-stimulated COX-2 production. We hypothesized that EGFR is required for LPS induction of COX-2 expression. Our data show that inhibiting EGFR kinase activity blocks LPS-induced COX-2 expression in small intestinal epithelial cells. LPS induction of COX-2 requires Src-family kinase signaling while LPS transactivation of EGFR requires matrix metalloprotease (MMP) activity. EGFR tyrosine kinase inhibitors block LPS stimulation of mitogen-activated protein kinase ERK, suggesting an important role of the MAPK/ERK pathway in EGFR-mediated COX-2 expression. LPS stimulates proliferation of IEC-6 cells, but this stimulation is inhibited with either the EGFR kinase inhibitor AG1478, or the selective COX-2 inhibitor Celecoxib. Taken together, these data show that EGFR plays an important role in LPS-induction of COX-2 expression in enterocytes, which may be one mechanism for EGF in inhibition of NEC

    IL-1ÎČ Is Upregulated in the Diabetic Retina and Retinal Vessels: Cell-Specific Effect of High Glucose and IL-1ÎČ Autostimulation

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    Many molecular and cellular abnormalities detected in the diabetic retina support a role for IL-1ÎČ-driven neuroinflammation in the pathogenesis of diabetic retinopathy. IL-1ÎČ is well known for its role in the induction and, through autostimulation, amplification of neuroinflammation. Upregulation of IL-1ÎČ has been consistently detected in the diabetic retina; however, the mechanisms and cellular source of IL-1ÎČ overexpression are poorly understood. The aim of this study was to investigate the effect of high glucose and IL-1ÎČ itself on IL-1ÎČ expression in microglial, macroglial (astrocytes and MĂŒller cells) and retinal vascular endothelial cells; and to study the effect of diabetes on the expression of IL-1ÎČ in isolated retinal vessels and on the temporal pattern of IL-1ÎČ upregulation and glial reactivity in the retina of streptozotocin-diabetic rats. IL-1ÎČ was quantified by RealTime RT-PCR and ELISA, glial fibrillar acidic protein, α2-macroglobulin, and ceruloplasmin by immunoblotting. We found that high glucose induced a 3-fold increase of IL-1ÎČ expression in retinal endothelial cells but not in macroglia and microglia. IL-1ÎČ induced its own synthesis in endothelial and macroglial cells but not in microglia. In retinal endothelial cells, the high glucose-induced IL-1ÎČ overexpression was prevented by calphostin C, a protein kinase C inhibitor. The retinal vessels of diabetic rats showed increased IL-1ÎČ expression as compared to non-diabetic rats. Retinal expression of IL-1ÎČ increased early after the induction of diabetes, continued to increase with progression of the disease, and was temporally associated with upregulation of markers of glial activation. These findings point to hyperglycemia as the trigger and to the endothelium as the origin of the initial retinal upregulation of IL-1ÎČ in diabetes; and to IL-1ÎČ itself, via autostimulation in endothelial and macroglial cells, as the mechanism of sustained IL-1ÎČ overexpression. Interrupting the vicious circle triggered by IL-1ÎČ autostimulation could limit the progression of diabetic retinopathy

    The Evolution of Compact Binary Star Systems

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    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

    Asteroseismology and Interferometry

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    Asteroseismology provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Recent developments, including the first systematic studies of solar-like pulsators, have boosted the impact of this field of research within Astrophysics and have led to a significant increase in the size of the research community. In the present paper we start by reviewing the basic observational and theoretical properties of classical and solar-like pulsators and present results from some of the most recent and outstanding studies of these stars. We centre our review on those classes of pulsators for which interferometric studies are expected to provide a significant input. We discuss current limitations to asteroseismic studies, including difficulties in mode identification and in the accurate determination of global parameters of pulsating stars, and, after a brief review of those aspects of interferometry that are most relevant in this context, anticipate how interferometric observations may contribute to overcome these limitations. Moreover, we present results of recent pilot studies of pulsating stars involving both asteroseismic and interferometric constraints and look into the future, summarizing ongoing efforts concerning the development of future instruments and satellite missions which are expected to have an impact in this field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume 14, Issue 3-4, pp. 217-36

    Identifying work related injuries: comparison of methods for interrogating text fields

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    Background: Work-related injuries in Australia are estimated to cost around $57.5 billion annually, however there are currently insufficient surveillance data available to support an evidence-based public health response. Emergency departments (ED) in Australia are a potential source of information on work-related injuries though most ED’s do not have an ‘Activity Code’ to identify work-related cases with information about the presenting problem recorded in a short free text field. This study compared methods for interrogating text fields for identifying work-related injuries presenting at emergency departments to inform approaches to surveillance of work-related injury.---------- Methods: Three approaches were used to interrogate an injury description text field to classify cases as work-related: keyword search, index search, and content analytic text mining. Sensitivity and specificity were examined by comparing cases flagged by each approach to cases coded with an Activity code during triage. Methods to improve the sensitivity and/or specificity of each approach were explored by adjusting the classification techniques within each broad approach.---------- Results: The basic keyword search detected 58% of cases (Specificity 0.99), an index search detected 62% of cases (Specificity 0.87), and the content analytic text mining (using adjusted probabilities) approach detected 77% of cases (Specificity 0.95).---------- Conclusions The findings of this study provide strong support for continued development of text searching methods to obtain information from routine emergency department data, to improve the capacity for comprehensive injury surveillance
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