3,304 research outputs found

    CSF protein biomarkers predicting longitudinal reduction of CSF β-amyloid42 in cognitively healthy elders.

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    β-amyloid (Aβ) plaque accumulation is a hallmark of Alzheimer's disease (AD). It is believed to start many years prior to symptoms and is reflected by reduced cerebrospinal fluid (CSF) levels of the peptide Aβ1-42 (Aβ42). Here we tested the hypothesis that baseline levels of CSF proteins involved in microglia activity, synaptic function and Aβ metabolism predict the development of Aβ plaques, assessed by longitudinal CSF Aβ42 decrease in cognitively healthy people. Forty-six healthy people with three to four serial CSF samples were included (mean follow-up 3 years, range 2-4 years). There was an overall reduction in Aβ42 from a mean concentration of 211-195 pg ml(-1) after 4 years. Linear mixed-effects models using longitudinal Aβ42 as the response variable, and baseline proteins as explanatory variables (n=69 proteins potentially relevant for Aβ metabolism, microglia or synaptic/neuronal function), identified 10 proteins with significant effects on longitudinal Aβ42. The most significant proteins were angiotensin-converting enzyme (ACE, P=0.009), Chromogranin A (CgA, P=0.009) and Axl receptor tyrosine kinase (AXL, P=0.009). Receiver-operating characteristic analysis identified 11 proteins with significant effects on longitudinal Aβ42 (largely overlapping with the proteins identified by linear mixed-effects models). Several proteins (including ACE, CgA and AXL) were associated with Aβ42 reduction only in subjects with normal baseline Aβ42, and not in subjects with reduced baseline Aβ42. We conclude that baseline CSF proteins related to Aβ metabolism, microglia activity or synapses predict longitudinal Aβ42 reduction in cognitively healthy elders. The finding that some proteins only predict Aβ42 reduction in subjects with normal baseline Aβ42 suggest that they predict future development of the brain Aβ pathology at the earliest stages of AD, prior to widespread development of Aβ plaques

    Nutrition Strategies for Triathlon

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    Contemporary sports nutrition guidelines recommend that each athlete develop a personalised, periodised and practical approach to eating that allows him or her to train hard, recover and adapt optimally, stay free of illness and injury and compete at their best at peak races. Competitive triathletes undertake a heavy training programme to prepare for three different sports while undertaking races varying in duration from 20 min to 10 h. The everyday diet should be adequate in energy availability, provide CHO in varying amounts and timing around workouts according to the benefits of training with low or high CHO availability and spread high-quality protein over the day to maximise the adaptive response to each session. Race nutrition requires a targeted and well-practised plan that maintains fuel and hydration goals over the duration of the specific event, according to the opportunities provided by the race and other challenges, such as a hot environment. Supplements and sports foods can make a small contribution to a sports nutrition plan, when medical supplements are used under supervision to prevent/treat nutrient deficiencies (e.g. iron or vitamin D) or when sports foods provide a convenient source of nutrients when it is impractical to eat whole foods. Finally, a few evidence-based performance supplements may contribute to optimal race performance when used according to best practice protocols to suit the triathlete’s goals and individual responsiveness

    Broadening public participation in systematic reviews : a case example involving young people in two configurative reviews

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    Background: Arguments supporting the involvement of users in research have even more weight when involving the public in systematic reviews of research. We aimed to explore the potential for public involvement in systematic reviews of observational and qualitative studies. Methods: Two consultative workshops were carried out with a group of young people (YP) aged 12–17 years to examine two ongoing reviews about obesity: one about children's views and one on the link between obesity and educational attainment. YP were invited to comment on the credibility of themes, to propose elements of interventions, to suggest links between educational attainment and obesity and to comment on their plausibility. Results: Researchers had more confidence in review findings, after checking that themes identified as important by YP were emphasised appropriately. Researchers were able to use factors linking obesity and attainment identified as important by YP to identify limitations in the scope of extant research. Conclusion: Consultative workshops helped researchers draw on the perspectives of YP when interpreting and reflecting upon two systematic reviews. Involving users in judging synthesis credibility and identifying concepts was easier than involving them in interpreting findings. Involvement activities for reviews should be designed with review stage, purpose and group in mind

    A Multistage Stochastic Programming Approach to the Dynamic and Stochastic VRPTW - Extended version

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    We consider a dynamic vehicle routing problem with time windows and stochastic customers (DS-VRPTW), such that customers may request for services as vehicles have already started their tours. To solve this problem, the goal is to provide a decision rule for choosing, at each time step, the next action to perform in light of known requests and probabilistic knowledge on requests likelihood. We introduce a new decision rule, called Global Stochastic Assessment (GSA) rule for the DS-VRPTW, and we compare it with existing decision rules, such as MSA. In particular, we show that GSA fully integrates nonanticipativity constraints so that it leads to better decisions in our stochastic context. We describe a new heuristic approach for efficiently approximating our GSA rule. We introduce a new waiting strategy. Experiments on dynamic and stochastic benchmarks, which include instances of different degrees of dynamism, show that not only our approach is competitive with state-of-the-art methods, but also enables to compute meaningful offline solutions to fully dynamic problems where absolutely no a priori customer request is provided.Comment: Extended version of the same-name study submitted for publication in conference CPAIOR201

    Cerebrospinal fluid markers including trefoil factor 3 are associated with neurodegeneration in amyloid-positive individuals.

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    We aimed to identify cerebrospinal fluid (CSF) biomarkers associated with neurodegeneration in individuals with and without CSF evidence of Alzheimer pathology. We investigated 287 Alzheimer's Disease Neuroimaging Initiative (ADNI) subjects (age=74.9±6.9; 22/48/30% with Alzheimer's disease/mild cognitive impairment/controls) with CSF multiplex analyte data and serial volumetric MRI. We calculated brain and hippocampal atrophy rates, ventricular expansion and Mini Mental State Examination decline. We used false discovery rate corrected regression analyses to assess associations between CSF variables and atrophy rates in individuals with and without amyloid pathology, adjusting in stages for tau, baseline volume, p-tau, age, sex, ApoE4 status and diagnosis. Analytes showing statistically significant independent relationships were entered into reverse stepwise analyses. Adjusting for tau, baseline volume, p-tau, age, sex and ApoE4, 4/83 analytes were significantly independently associated with brain atrophy rate, 1/83 with ventricular expansion and 2/83 with hippocampal atrophy. The strongest CSF predictor for the three atrophy measures was low trefoil factor 3 (TFF3). High cystatin C (CysC) was associated with higher whole brain atrophy and hippocampal atrophy rates. Lower levels of vascular endothelial growth factor and chromogranin A (CrA) were associated with higher whole brain atrophy. In exploratory reverse stepwise analyses, lower TFF3 was associated with higher rates of whole brain, hippocampal atrophy and ventricular expansion. Lower levels of CrA were associated with higher whole brain atrophy rate. The relationship between low TFF3 and increased hippocampal atrophy rate remained after adjustment for diagnosis. We identified a series of CSF markers that are independently associated with rate of neurodegeneration in amyloid-positive individuals. TFF3, a substrate for NOTCH processing may be an important biomarker of neurodegeneration across the Alzheimer spectrum

    Towards Subject and Diagnostic Identifiability in the Alzheimer’s Disease Spectrum Based on Functional Connectomes

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    Alzheimer’s disease (AD) is the only major cause of mortality in the world without an effective disease modifying treatment. Evidence supporting the so called “disconnection hypothesis” suggests that functional connectivity biomarkers may have clinical potential for early detection of AD. However, known issues with low test-retest reliability and signal to noise in functional connectivity may prevent accuracy and subsequent predictive capacity. We validate the utility of a novel principal component based diagnostic identifiability framework to increase separation in functional connectivity across the Alzheimer’s spectrum by identifying and reconstructing FC using only AD sensitive components or connectivity modes. We show that this framework (1) increases test-retest correspondence and (2) allows for better separation, in functional connectivity, of diagnostic groups both at the whole brain and individual resting state network level. Finally, we evaluate a posteriori the association between connectivity mode weights with longitudinal neurocognitive outcomes

    Vegetation and the importance of insecticide-treated target siting for control of Glossina fuscipes fuscipes

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    Control of tsetse flies using insecticide-treated targets is often hampered by vegetation re-growth and encroachment which obscures a target and renders it less effective. Potentially this is of particular concern for the newly developed small targets (0.25 high Ă— 0.5 m wide) which show promise for cost-efficient control of Palpalis group tsetse flies. Consequently the performance of a small target was investigated for Glossina fuscipes fuscipes in Kenya, when the target was obscured following the placement of vegetation to simulate various degrees of natural bush encroachment. Catches decreased significantly only when the target was obscured by more than 80%. Even if a small target is underneath a very low overhanging bush (0.5 m above ground), the numbers of G. f. fuscipes decreased by only about 30% compared to a target in the open. We show that the efficiency of the small targets, even in small (1 m diameter) clearings, is largely uncompromised by vegetation re-growth because G. f. fuscipes readily enter between and under vegetation. The essential characteristic is that there should be some openings between vegetation. This implies that for this important vector of HAT, and possibly other Palpalis group flies, a smaller initial clearance zone around targets can be made and longer interval between site maintenance visits is possible both of which will result in cost savings for large scale operations. We also investigated and discuss other site features e.g. large solid objects and position in relation to the water's edge in terms of the efficacy of the small targets

    Cerebrospinal fluid biomarker panel of synaptic dysfunction in Alzheimer's disease and other neurodegenerative disorders

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    Introduction: Synaptic degeneration is a key part of the pathophysiology of neurodegenerative diseases, and biomarkers reflecting the pathological alterations are greatly needed. Method: Seventeen synaptic proteins were quantified in a pathology-confirmed cerebrospinal fluid cohort of patients with Alzheimer's disease (AD; n = 63), frontotemporal lobar degeneration (FTLD; n = 53), and Lewy body spectrum of disorders (LBD; n = 21), as well as healthy controls (HC; n = 48). Results: Comparisons revealed four distinct patterns: markers decreased across all neurodegenerative conditions compared to HC (the neuronal pentraxins), markers increased across all neurodegenerative conditions (14-3-3 zeta/delta), markers selectively increased in AD compared to other neurodegenerative conditions (neurogranin and beta-synuclein), and markers selectively decreased in LBD and FTLD compared to HC and AD (AP2B1 and syntaxin-1B). Discussion: Several of the synaptic proteins may serve as biomarkers for synaptic dysfunction in AD, LBD, and FTLD. Additionally, differential patterns of synaptic protein alterations seem to be present across neurodegenerative diseases. Highlights: A panel of synaptic proteins were quantified in the cerebrospinal fluid using mass spectrometry. We compared Alzheimer's disease, frontotemporal degeneration, and Lewy body spectrum of disorders. Pathology was confirmed by autopsy or familial mutations. We discovered synaptic biomarkers for synaptic degeneration and cognitive decline. We found differential patterns of synaptic proteins across neurodegenerative diseases

    Awareness and utilization of HIV testing and prevention services among female sex workers in Dnipro, Ukraine: implications for prevention program strengthening from the dynamics study

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    INTRODUCTION: Approximately 240,000 people live with HIV in Ukraine, concentrated among key populations, including sex workers. Non-governmental organizations (NGOs) play an important role in the funding and delivery of HIV testing and prevention services in Ukraine. These services are set within the context of national healthcare reforms as well as ongoing armed conflict. This study seeks to describe and understand the usage of HIV testing and prevention services among sex workers in the eastern Ukrainian city of Dnipro. METHODS: A cross-sectional bio-behavioral survey was administered in September 2017-March 2018 among 560 sex workers working in Dnipro. Descriptive analyses of survey data are presented alongside multivariable logistic regression models identifying factors associated with NGO awareness and HIV testing in the past 12 months; adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) are reported. RESULTS: Sixty-two percent of respondents were aware of NGOs offering HIV services. Sixty-eight percent had tested for HIV in the past 12 months, and 51% of those who reported the location of their most recent test were tested at an NGO. Those with 5-9 years in sex work had greater odds of being aware of NGOs (AOR = 5.5, 95%CI: 3.2-9.7) and testing for HIV (AOR = 3.4, 95%CI: 2.0-6.0) compared to those new to the profession. Contact with outreach workers was strongly associated with increased odds of testing (AOR = 13.0, 95%CI: 7.0-24.0). Sex workers in "offices" (brothel-like venues) reported higher odds of testing than all other workplaces, while those in entertainment venues (AOR = 0.3, 95%CI: 0.2-0.5) and public places (AOR = 0.2, 95%CI: 0.1-0.3) reported lower rates. Receiving prevention services, such as free condoms, was associated with increased testing (AOR = 16.9, 95%CI: 9.7-29.3). DISCUSSION: NGOs in Dnipro, Ukraine play an important role in HIV testing and prevention for women involved in sex work. However, focused efforts should be placed on supporting access to these services for women that are newer to sex work, and those working in entertainment venues or public places. Outreach workers appear to support access to HIV prevention information and supplies and facilitate linkages to HIV testing for sex workers
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