539 research outputs found

    To boil an egg: substrate binding affects critical stability in thermal unfolding of proteins

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    Thermal unfolding of proteins is used extensively in screening of drug candidates because molecular interactions with ligands and substrates affect strongly protein stability, transition temperature, and cooperativity. We use synchrotron radiation circular dichroism to monitor the thermal evolution of secondary structure in proteins as they approach the melting point and the impact of substrate on their thermal behavior. Using Landau free energy expansion, we quantify transition strength and proximity to a critical point through the relative separation τ+ between the transition temperature Tm and the spinodal T+, obtained from the equation of state. The weakest transition was observed in lysozyme with τ+ = −0.0167 followed by holo albumin with τ+ = −0.0208 with the strongest transition in monomeric apo albumin τ+ = − 0.0242. A structural transition at 45 °C in apo albumin leads to a noncooperative melt with τ+ = −0.00532 and amyloidogenic increase in beta content

    A genetic fingerprint of Amphipoda from Icelandic waters – the baseline for further biodiversity and biogeography studies

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    Source at https://doi.org/10.3897/zookeys.731.19931.Amphipods constitute an abundant part of Icelandic deep-sea zoobenthos yet knowledge of the diversity of this fauna, particularly at the molecular level, is scarce. The present work aims to use molecular methods to investigate genetic variation of the Amphipoda sampled during two IceAGE collecting expeditions. The mitochondrial cytochrome oxidase subunit 1 (COI) of 167 individuals originally assigned to 75 morphospecies was analysed. These targeted morhospecies were readily identifiable by experts using light microscopy and representative of families where there is current ongoing taxonomic research. The study resulted in 81 Barcode Identity Numbers (BINs) (of which >90% were published for the first time), while Automatic Barcode Gap Discovery revealed the existence of 78 to 83 Molecular Operational Taxonomic Units (MOTUs). Six nominal species (Rhachotropis helleri, Arrhis phyllonyx, Deflexilodes tenuirostratus, Paroediceros propinquus, Metopa boeckii, Astyra abyssi) appeared to have a molecular variation higher than the 0.03 threshold of both p-distance and K2P usually used for amphipod species delineation. Conversely, two Oedicerotidae regarded as separate morphospecies clustered together with divergences in the order of intraspecific variation. The incongruence between the BINs associated with presently identified species and the publicly available data of the same taxa was observed in case of Paramphithoe hystrix and Amphilochus manudens. The findings from this research project highlight the necessity of supporting molecular studies with thorough morphology species analyses

    The malleability of stigmatizing attitudes: Combining imagined social contact with implicit attitude feedback

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    © 2016, Copyright © Taylor & Francis Group, LLC. Research is reported that examines whether imagined social contact combined with implicit attitude feedback may be an effective intervention for inducing changes in attitudes toward mental ill health. The Implicit Relational Assessment Procedure (IRAP) captured participants’ implicit attitudes toward individuals with a mental illness and provided a measure of attitude bias. Forty-eight participants (17 male, 95.8% White British) were randomly assigned to one of four experimental conditions: (1) Imagined social contact with implicit attitude feedback, (2) imagined social contact without feedback, (3) control with feedback, and (4) control without feedback. This resulted in a data set detailing 12,288 implicit responses, with each participant completing 256 IRAP trials. Participants then completed an attitude change assessment 24 hours later. Results revealed that imagined social contact was successful in changing implicit attitudes, with the addition of implicit attitude feedback further strengthening participants’ positive attitudes toward mental ill health. Explicit attitudes remained unaffected. These findings are the first to highlight the practical importance of combining imagined social contact with implicit attitude feedback to improve attitudes toward out-groups who are stigmatized

    Konsensusprotokoll zur Standardisierung von Entnahme und Biobanking des Liquor cerebrospinalis

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    Die Erforschung von Biomarkern in Körperflüssigkeiten bei neurodegenerativen und neuroinflammatorischen Erkrankungen blickt auf eine langjährige Geschichte zurück. Dennoch werden nur wenige Liquor cerebrospinalis (Liquor)-Biomarker in der klinischen Praxis verwendet. Einer der problematischen Faktoren in der Liquorbiomarker-Forschung ist die eingeschränkte Aussagekraft von Studien aufgrund einer nicht ausreichend großer Anzahl von Proben, die in Studien von einzelnen Zentren akquiriert werden können. Deshalb ist die Kooperation zwischen mehreren Zentren erforderlich, um große Biobanken von definierten Proben zu etablieren. Standardisierte Protokolle für Biobanking sind unumgänglich, um die durch die größere Anzahl von Liquorproben gewonnene statistische Aussagekraft sicherzustellen und nicht durch mangelhafte Präanalytik einzuschränken. Hier wird ein Konsensusbericht über Leitlinien zu Liquorentnahme und Biobanking durch das BioMS-eu Netzwerk für Liquorbiomarker-Forschung in Multipler Sklerose präsentiert. Schwerpunkte des Berichts sind Liquorentnahme, präanalytische Faktoren und klinische sowie sonstige Informationen. Biobanking-Protokolle sind für Liquor-Biobanken im Rahmen der Erforschung jeder neurologischen Krankheit anwendba

    Obstacles to researching the researchers: A case study of the ethical challenges of undertaking methodological research investigating the reporting of randomised controlled trials

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    <p>Abstract</p> <p>Background</p> <p>Recent cohort studies of randomised controlled trials have provided evidence of within-study selective reporting bias; where statistically significant outcomes are more likely to be more completely reported compared to non-significant outcomes. Bias resulting from selective reporting can impact on meta-analyses, influencing the conclusions of systematic reviews, and in turn, evidence based clinical practice guidelines.</p> <p>In 2006 we received funding to investigate if there was evidence of within-study selective reporting in a cohort of RCTs submitted to New Zealand Regional Ethics Committees in 1998/99. This research involved accessing ethics applications, their amendments and annual reports, and comparing these with corresponding publications. We did not plan to obtain informed consent from trialists to view their ethics applications for practical and scientific reasons.</p> <p>In November 2006 we sought ethical approval to undertake the research from our institutional ethics committee. The Committee declined our application on the grounds that we were not obtaining informed consent from the trialists to view their ethics application. This initiated a seventeen month process to obtain ethical approval. This publication outlines what we planned to do, the issues we encountered, discusses the legal and ethical issues, and presents some potential solutions.</p> <p>Discussion and conclusion</p> <p>Methodological research such as this has the potential for public benefit and there is little or no harm for the participants (trialists) in undertaking it. Further, in New Zealand, there is freedom of information legislation, which in this circumstance, unambiguously provided rights of access and use of the information in the ethics applications. The decision of our institutional ethics committee defeated this right and did not recognise the nature of this observational research.</p> <p>Methodological research, such as this, can be used to develop processes to improve quality in research reporting. Recognition of the potential benefit of this research in the broader research community, and those who sit on ethics committees, is perhaps needed. In addition, changes to the ethical review process which involve separation between those who review proposals to undertake methodological research using ethics applications, and those with responsibility for reviewing ethics applications for trials, should be considered. Finally, we contend that the research community could benefit from quality improvement approaches used in allied sectors.</p

    SCOT: a comparison of cost-effectiveness from a large randomised phase III trial of two durations of adjuvant Oxaliplatin combination chemotherapy for colorectal cancer.

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    BACKGROUND: The Short Course Oncology Therapy (SCOT) study is an international, multicentre, non-inferiority randomised controlled trial assessing the efficacy, toxicity, and cost-effectiveness of 3 months (3 M) versus the usually given 6 months (6 M) of adjuvant chemotherapy in colorectal cancer. METHODS: In total, 6088 patients with fully resected high-risk stage II or stage III colorectal cancer were randomised and followed up for 3-8 years. The within-trial cost-effectiveness analysis from a UK health-care perspective is presented using the resource use data, quality of life (EQ-5D-3L), time on treatment (ToT), disease-free survival after treatment (DFS) and overall survival (OS) data. Quality-adjusted partitioned survival analysis and Kaplan-Meier Sample Average Estimator estimated QALYs and costs. Probabilistic sensitivity and subgroup analysis was undertaken. RESULTS: The 3 M arm is less costly (-£4881; 95% CI: -£6269; -£3492) and entails (non-significant) QALY gains (0.08; 95% CI: -0.086; 0.230) due to a better significant quality of life. The net monetary benefit was significantly higher in 3 M under a wide range of monetary values of a QALY. The subgroup analysis found similar results for patients in the CAPOX regimen. However, for the FOLFOX regimen, 3 M had lower QALYs than 6 M (not statistically significant). CONCLUSIONS: Overall, 3 M dominates 6 M with no significant detrimental impact on QALYs. The results provide the economic case that a 3 M treatment strategy should be considered a new standard of care

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Consensus Guidelines for CSF and Blood Biobanking for CNS Biomarker Studies

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    There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in cerebrospinal fluid (CSF) are being used in clinical practice. Anti-aquaporin-4 antibodies in serum are currently useful for the diagnosis of neuromyelitis optica (NMO), but we could expect novel CSF biomarkers that help define prognosis and response to treatment for this disease. One of the most critical factors in biomarker research is the inadequate powering of studies performed by single centers. Collaboration between investigators is needed to establish large biobanks of well-defined samples. A key issue in collaboration is to establish standardized protocols for biobanking to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by pre-analytical factors. Here, consensus guidelines for CSF collection and biobanking are presented, based on the guidelines that have been published by the BioMS-eu network for CSF biomarker research. We focussed on CSF collection procedures, pre-analytical factors and high quality clinical and paraclinical information. Importantly, the biobanking protocols are applicable for CSF biobanks for research targeting any neurological disease
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