9,817 research outputs found
Predicting ecosystem shifts requires new approaches that integrate the effects of climate change across entire systems.
Most studies that forecast the ecological consequences of climate change target a single species and a single life stage. Depending on climatic impacts on other life stages and on interacting species, however, the results from simple experiments may not translate into accurate predictions of future ecological change. Research needs to move beyond simple experimental studies and environmental envelope projections for single species towards identifying where ecosystem change is likely to occur and the drivers for this change. For this to happen, we advocate research directions that (i) identify the critical species within the target ecosystem, and the life stage(s) most susceptible to changing conditions and (ii) the key interactions between these species and components of their broader ecosystem. A combined approach using macroecology, experimentally derived data and modelling that incorporates energy budgets in life cycle models may identify critical abiotic conditions that disproportionately alter important ecological processes under forecasted climates
Food security, nutrition and health of food bank attendees in an English city: A cross-sectional study
Food banks in contemporary Britain are feeding record numbers of people. Little is known about attendees’ level of food insecurity, background diet quality or health. We surveyed 112 food bank attendees. Over 50% had experienced food shortage with hunger on a weekly basis or more often. Obesity and mental health problems were prevalent in women. Diet quality was poor, with energy, protein, fibre, iron and calcium intakes inadequate, while saturated fat and sugars intake were disproportionate. Women had poorer diet quality than men. Such patterns may lead to ill health
Cluster randomised trials in the medical literature: two bibliometric surveys
Background: Several reviews of published cluster randomised trials have reported that about half did not take clustering into account in the analysis, which was thus incorrect and potentially misleading. In this paper I ask whether cluster randomised trials are increasing in both number and quality of reporting. Methods: Computer search for papers on cluster randomised trials since 1980, hand search of trial reports published in selected volumes of the British Medical Journal over 20 years. Results: There has been a large increase in the numbers of methodological papers and of trial reports using the term 'cluster random' in recent years, with about equal numbers of each type of paper. The British Medical Journal contained more such reports than any other journal. In this journal there was a corresponding increase over time in the number of trials where subjects were randomised in clusters. In 2003 all reports showed awareness of the need to allow for clustering in the analysis. In 1993 and before clustering was ignored in most such trials. Conclusion: Cluster trials are becoming more frequent and reporting is of higher quality. Perhaps statistician pressure works
"Boring formal methods" or "Sherlock Holmes deduction methods"?
This paper provides an overview of common challenges in teaching of logic and
formal methods to Computer Science and IT students. We discuss our experiences
from the course IN3050: Applied Logic in Engineering, introduced as a "logic
for everybody" elective course at at TU Munich, Germany, to engage pupils
studying Computer Science, IT and engineering subjects on Bachelor and Master
levels. Our goal was to overcome the bias that logic and formal methods are not
only very complicated but also very boring to study and to apply. In this
paper, we present the core structure of the course, provide examples of
exercises and evaluate the course based on the students' surveys.Comment: Preprint. Accepted to the Software Technologies: Applications and
Foundations (STAF 2016). Final version published by Springer International
Publishing AG. arXiv admin note: substantial text overlap with
arXiv:1602.0517
Combined tissue and fluid proteomics with Tandem Mass Tags to identify low-abundance protein biomarkers of disease in peripheral body fluid: An Alzheimer's Disease case study
RATIONALE:
Ideal biomarkers are present in readily accessible samples including plasma and cerebrospinal fluid (CSF), and are directly derived from diseased tissue, therefore likely to be of relatively low abundance. Traditional unbiased proteomic approaches for biomarker discovery have struggled to detect low-abundance markers due to the high dynamic range of proteins, the predominance of hyper-abundant proteins, and the use of data-dependent acquisition mass spectrometry (MS). To overcome these limitations and improve biomarker discovery in peripheral fluids, we have developed TMTcalibrator™; a novel MS workflow combining isobarically labelled diseased tissue digests in parallel with an appropriate set of labelled body fluids to increase the chance of identifying low-abundance, tissue-derived biomarkers.
METHODS:
A disease relevant cell line was labelled with TMT® in a range of concentrations generating a multi-point calibration curve. Peripheral biofluid samples were labelled with the remaining tags and quantitative analysis was performed using an Orbitrap Fusion Tribrid mass spectrometer with a Top10 CID-HCD MS3 synchronous precursor selection (SPS) method. SPS allowed direct analysis of non-depleted, unfractionated CSF samples with complete profiling of six individual samples requiring only 15 hours of MS time, equivalent to 1.5 h per sample.
RESULTS:
Using the TMTcalibrator™ workflow allowed the identification of several markers of microglia activation that are differentially quantified in the CSF of patients with Alzheimer's disease (AD). We report peptides from 41 proteins that have not previously been detected in the CSF, that appear to be regulated by at least 60% in AD.
CONCLUSIONS:
This study has demonstrated the benefits of the new TMTcalibrator™ workflow and the results suggest this is a suitable and efficient method of detecting low-abundance peptides within biological fluids. The use of TMTcalibrator™ in further biomarker discovery studies should be considered to overcome some of the limitations commonly associated with more conventional approaches
Micro-fading spectrometry: investigating the wavelength specificity of fading
A modified microfading spectrometer incorporating a linear variable filter is used to investigate the wavelength dependence of fading of traditional watercolour pigments, dosimeters and fading standards at a higher spectral resolution and/or sampling than had previously been attempted. While the wavelength dependence of photochemical damage was largely found to correlate well with the absorption spectra of each material, exceptions were found in the case of Prussian blue and Prussian green pigments (the latter includes Prussian blue), for which an anti-correlation between the spectral colour change and the absorption spectrum was found
Sequential Extensions of Causal and Evidential Decision Theory
Moving beyond the dualistic view in AI where agent and environment are
separated incurs new challenges for decision making, as calculation of expected
utility is no longer straightforward. The non-dualistic decision theory
literature is split between causal decision theory and evidential decision
theory. We extend these decision algorithms to the sequential setting where the
agent alternates between taking actions and observing their consequences. We
find that evidential decision theory has two natural extensions while causal
decision theory only has one.Comment: ADT 201
Dietary patterns of university students in the UK: A cross-sectional study
© 2018 The Author(s). Background: University represents a key transition into adulthood for many adolescents but there are associated concerns about health and behaviours. One important aspect relates to diet and there is emerging evidence that university students may consume poor quality diets, with potential implications for body weight and long-term health. This research aimed to characterise dietary patterns of university students in the UK and their sociodemographic and lifestyle antecedents. Methods: An online, cross-sectional survey was undertaken with a convenience sample of 1448 university students from five UK universities (King's College London, Universities of St Andrews, Southampton and Sheffield, and Ulster University). The survey comprised a validated food frequency questionnaire alongside lifestyle and sociodemographic questions. Dietary patterns were generated from food frequency intake data using principal components analysis. Nutrient intakes were estimated to characterise the nutrient profile of each dietary pattern. Associations with sociodemographic variables were assessed through general linear modelling. Results: Dietary analyses revealed four major dietary patterns: 'vegetarian'; 'snacking'; 'health-conscious'; and 'convenience, red meat & alcohol'. The 'health-conscious' pattern had the most favourable micronutrient profile. Students' gender, age, year of study, geographical location and cooking ability were associated with differences in pattern behaviour. Female students favoured the 'vegetarian' pattern, whilst male students preferred the 'convenience, red meat & alcohol' pattern. Less healthful dietary patterns were positively associated with lifestyle risk factors such as smoking, low physical activity and take-away consumption. The health-conscious pattern had greatest nutrient density. The 'convenience, red meat & alcohol' pattern was associated with higher weekly food spending; this pattern was also identified most consistently across universities. Students reporting greater cooking ability tended towards the 'vegetarian' and 'health-conscious' patterns. Conclusions: Food intake varied amongst university students. A substantial proportion of students followed health-promoting diets, which had good nutrient profiles obviating a need for dietary intervention. However, some students consumed poor diets, incurred greater food costs and practised unfavourable lifestyle behaviours, which may have long-term health effects. University policy to improve students' diets should incorporate efforts to promote student engagement in cooking and food preparation, and increased availability of low cost healthier food items
Neuromuscular Blockade with Rocuronium Bromide Increases the Tolerance of Acute Normovolemic Anemia in Anesthetized Pigs
Background: The patient's individual anemia tolerance is pivotal when blood transfusions become necessary, but are not feasible for some reason. To date, the effects of neuromuscular blockade (NMB) on anemia tolerance have not been investigated. Methods: 14 anesthetized and mechanically ventilated pigs were randomly assigned to the Roc group (3.78 mg/kg rocuronium bromide followed by continuous infusion of 1 mg/kg/min, n = 7) or to the Sal group (administration of the corresponding volume of normal saline, n = 7). Subsequently, acute normovolemic anemia was induced by simultaneous exchange of whole blood for a 6% hydroxyethyl starch solution (130/0.4) until a sudden decrease of total body O-2 consumption (VO2) indicated a critical limitation of O-2 transport capacity. The Hb concentration quantified at this time point (Hb(crit)) was the primary end-point of the protocol. Secondary endpoints were parameters of hemodynamics, O-2 transport and tissue oxygenation. Results: Hb(crit) was significantly lower in the Roc group (2.4 +/- 0.5 vs. 3.2 +/- 0.7 g/dl) reflecting increased anemia tolerance. NMB with rocuronium bromide reduced skeletal muscular VO2 and total body O-2 extraction rate. As the cardiac index increased simultaneously, total body VO2 only decreased marginally in the Roc group (change of VO2 relative to baseline -1.7 +/- 0.8 vs. 3.2 +/- 1.9% in the Sal group, p < 0.05). Conclusion: Deep NMB with rocuronium bromide increases the tolerance of acute normovolemic anemia. The underlying mechanism most likely involves a reduction of skeletal muscular VO2. During acellular treatment of an acute blood loss, NMB might play an adjuvant role in situations where profound stages of normovolemic anemia have to be tolerated (e.g. bridging an unexpected blood loss until blood products become available for transfusion). Copyright (C) 2011 S. Karger AG, Base
Dark Matter from Minimal Flavor Violation
We consider theories of flavored dark matter, in which the dark matter
particle is part of a multiplet transforming nontrivially under the flavor
group of the Standard Model in a manner consistent with the principle of
Minimal Flavor Violation (MFV). MFV automatically leads to the stability of the
lightest state for a large number of flavor multiplets. If neutral, this
particle is an excellent dark matter candidate. Furthermore, MFV implies
specific patterns of mass splittings among the flavors of dark matter and
governs the structure of the couplings between dark matter and ordinary
particles, leading to a rich and predictive cosmology and phenomenology. We
present an illustrative phenomenological study of an effective theory of a
flavor SU(3)_Q triplet, gauge singlet scalar.Comment: 10 pages, 2 figures; v2: references added, minor changes to collider
analysis, conclusions unchange
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