685 research outputs found

    Lipid Content and Condition in an Estuarine Teleost

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    The value of lipid content as a measure of the feeding level of fish compared with condition factor was assessed using two populations of juvenile Rhabdosargus holubi, one from the closed West Kleinemond estuary and the other from the open Kowie estuary. Results from feeding experiments conducted in the laboratory showed that total lipid level could be related to feeding level, and was not affected by temperature although food intake at 15°C was half that at 2°C. Condition factor was affected by temperature. R. holubi from the West Kleinemond estuary showed a seasonal variation in lipid content (6,4% in summer, 0,75 % in winter) but those from the Kowie estuary showed little or no variation (1-2 %). It is suggested that the difference in the fat content of the fish between the two estuaries in summer was related to the lipid content of the food, which was much less in the Kowie estuary. The condition factor of West Kleinemond fish declined in winter while that of Kowie fish remained stable. It is considered that condition factor is a more sensitive index of the actual feeding level of fish than the lipid content since the latter may be affected by the lipid content of the food

    Improved image-based deformation measurement for geotechnical applications

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    This paper describes and benchmarks a new implementation of image-based deformation measurement for geotechnical applications. The updated approach combines a range of advances in image analysis algorithms and techniques best suited to geotechnical applications. Performance benchmarking of the new approach has used a series of artificial images subjected to prescribed spatially varying displacement fields. An improvement by at least a factor of 10 in measurement precision is achieved relative to the most commonly used particle image velocimetry (PIV) approach for all deformation modes, including rigid-body displacements, rotations, and strains (compressive and shear). Lastly, an example analysis of a centrifuge model test is used to demonstrate the capabilities of the new approach. The strain field generated by penetration of a flat footing and an entrapped sand plug into an underlying clay layer is computed and compared for both the current and updated algorithms. This analysis demonstrates that the enhanced measurement precision improves the clarity of the interpretation. </jats:p

    Spaceflight Activates Autophagy Programs and the Proteasome in Mouse Liver

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    Increased oxidative stress is an unavoidable consequence of exposure to the space environment. Our previous studies showed that mice exposed to space for 13.5 days had decreased glutathione levels, suggesting impairments in oxidative defense. Here we performed unbiased, unsupervised and integrated multi-'omic analysis of metabolomic and transcriptomic datasets from mice flown aboard the Space Shuttle Atlantis. Enrichment analyses of metabolite and gene sets showed significant changes in osmolyte concentrations and pathways related to glycerophospholipid and sphingolipid metabolism, likely consequences of relative dehydration of the spaceflight mice. However, we also found increased enrichment of aminoacyl-tRNA biosynthesis and purine metabolic pathways, concomitant with enrichment of genes associated with autophagy and the ubiquitin-proteasome. When taken together with a down-regulation in NRF2-mediated signaling, our analyses suggest that decreased hepatic oxidative defense may lead to aberrant tRNA post-translational processing, induction of degradation programs and senescence-associated mitochondrial dysfunction in response to the spaceflight environment.

    Does Prior Acromioplasty Increase the Incidence of Acromial Fracture Following Reverse Total Shoulder Arthroplasty? A Retrospective Matched Cohort Analysis

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    Introduction: Reverse total shoulder arthroplasty (RTSA) is an effective treatment option for multiple shoulder pathologies. Arthroscopic acromioplasty is a treatment for subacromial impingement. RTSA can place excess stress on the acromion. No studies have evaluated outcomes following RTSA among patients with prior acromioplasty. The purpose of this study was to report outcomes in patients following RTSA who have had a prior acromioplasty. The authors hypothesized patients with prior acromioplasty who undergo RTSA will have significant improvements in clinical outcomes with no increased risk of acromial fracture. Methods: Patients from a single institution who underwent RTSA with a history of acromioplasty from 2009 to 2017 with two-year follow up were identified. Clinical outcome scores were obtained using ASES, SST, VAS, and SANE surveys. X-rays and charts will be reviewed to determine if patients sustained anacromion fracture following RTSA. Patients will be matched to a cohort of patients who underwent RTSA without a prior acromioplasty.These groups will be compared to determine any differences in clinical outcome scores or number of postoperative acromial fractures. Results: 45 patients were included.Average outcomes scores were: ASES:70.7%, SST: 62.1%, VAS: 2.4, and a SANE: 60.6%. On average, active external rotation improved from 33.1° to 37.1° and forward elevation improved from 92.2° to 136.1°. Discussion: While data collection in the matched cohort remains ongoing to compare the outcomes of RTSA with prior acromioplasty to the outcomes of RTSA alone, initial data suggests history of acromioplasty does not negatively impact RTSA outcomes

    Endothelial MAPKs Direct ICAM-1 Signaling to Divergent Inflammatory Functions.

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    Lymphocyte transendothelial migration (TEM) is critically dependent on intraendothelial signaling triggered by adhesion to ICAM-1. Here we show that endothelial MAPKs ERK, p38, and JNK mediate diapedesis-related and diapedesis-unrelated functions of ICAM-1 in cerebral and dermal microvascular endothelial cells (MVECs). All three MAPKs were activated by ICAM-1 engagement, either through lymphocyte adhesion or Ab-mediated clustering. MAPKs were involved in ICAM-1-dependent expression of TNF-α in cerebral and dermal MVECs, and CXCL8, CCL3, CCL4, VCAM-1, and cyclooxygenase 2 (COX-2) in cerebral MVECs. Endothelial JNK and to a much lesser degree p38 were the principal MAPKs involved in facilitating diapedesis of CD4(+) lymphocytes across both types of MVECs, whereas ERK was additionally required for TEM across dermal MVECs. JNK activity was critical for ICAM-1-induced F-actin rearrangements. Furthermore, activation of endothelial ICAM-1/JNK led to phosphorylation of paxillin, its association with VE-cadherin, and internalization of the latter. Importantly ICAM-1-induced phosphorylation of paxillin was required for lymphocyte TEM and converged functionally with VE-cadherin phosphorylation. Taken together we conclude that during lymphocyte TEM, ICAM-1 signaling diverges into pathways regulating lymphocyte diapedesis, and other pathways modulating gene expression thereby contributing to the long-term inflammatory response of the endothelium

    Optimisation of absorption efficiency for varying dielectric spherical nanoparticles

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    Abstract-In this paper we compare the optical absorption for nanospheres made from a range of transition and alkali metals from Li (A=3) to Au (A=79). Numerical solutions to Mie theory were used to calculate the absorption efficiency, Q abs , for nanospheres varying in radii between 5 nm and 100 nm in vacuum. We show that, although gold is the most commonly used nanoparticle material, its absorption efficiency at the plasmon resonance is not as strong as materials such as the alkali metals. Of all the materials tried, potassium spheres with a radius of 21 nm have an optimum absorption efficiency of 14.7. In addition we also show that, unlike gold, the wavelength of the plasmon peak in other materials is sensitive to the sphere radius. In potassium the peak position shifts by 100 nm for spheres ranging from 5 nm to 65 nm, the shift is less than 10 nm for gold spheres

    Preventing PTSD, depression and associated health problems in student paramedics: Protocol for PREVENT-PTSD, a randomised controlled trial of supported online cognitive training for resilience versus alternative online training and standard practice

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    This the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Introduction: Emergency workers dedicate their lives to promoting public health and safety, yet suffer higher rates of post-traumatic stress disorder (PTSD) and major depression (MD) compared with the general population. They also suffer an associated increased risk for physical health problems, which may be linked to specific immunological and endocrine markers or changes in relevant markers. Poor physical and mental health is costly to organisations, the National Health Service and society. Existing interventions aimed at reducing risk of mental ill health in this population are not very successful. More effective preventative interventions are urgently needed. We first conducted a large-scale prospective study of newly recruited student paramedics, identifying two cognitive factors (rumination and resilience appraisals) that predicted episodes of PTSD and MD over a 2-year period. We then developed internet-delivered cognitive training for resilience (iCT-R), a supported online intervention, to modify cognitive predictors. This protocol is for a randomised controlled trial to evaluate the efficacy of the resilience intervention. Methods and analysis: 570 student paramedics will be recruited from participating universities. They will be randomly allocated to iCT-R or to supported online training of an alternative, widely available intervention or to training-as-usual. Follow-up will occur after the intervention/standard practice period and at 6, 12 and 24 months. Primary outcomes include rates of PTSD and MD and subsydnromal PTSD and MD, measured by the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, fifth edition, the Patient-Health Questionnaire-9 and the Post-traumatic Stress Disorder Checklist for Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Secondary outcomes include measures of resilience, rumination, anxiety, psychological distress, well-being, salivary cortisol, plasma levels of C-reactive protein, smoking and alcohol use, weight gain, sleep problems, health-related quality of life, health resource utilisation and productivity. Ethics and dissemination: The Medical Sciences Inter-Divisional Research Ethics Committee at the University of Oxford granted approval, reference: R44116/RE001. The results will be published in a peer-reviewed journal. Access to raw data and participant information will be available only to members of the research team. Trial registration number ISRCTN16493616; Pre-results.Wellcome TrustMQ: Transforming Mental HealthNIHR: National Institute for Health Researc
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