560 research outputs found
Field lab: analysis of quantitative investment strategies constructing a multi-factor investment strategy optimized sector momentum
In the combined part a multi-factor investment strategy is constructed out of four different
enhanced single factor strategies using an optimization to maximize the Sharpe ratio of the
combined portfolio. In the individual part an optimized sector momentum strategy is
constructed that consists of a combination of a long and a market-neutral long/short strategy
utilizing a simple regime-switching process with the goal to minimize momentum crashes and
achieve robust returns in all market states
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Early preterm nutrition and the urinary metabolome in young adult life: follow-up of a randomised controlled trial
Objective We aimed to test the hypothesis that early diet
programmes the metabolic profile of young adults born
preterm.
Design We analysed banked urine samples obtained at
a 20-year follow-up visit from adults that had participated
as neonates in controlled trials involving randomisation
within 48 hours of birth to feeds of preterm formula (PTF),
banked breast milk (BBM) or term formula (TF) for 1month
postnatally.
Main outcome measures We performed proton
nuclear magnetic resonance spectroscopy, analysing
spectra by dietary group and sex. Orthogonal projections to
latent structure discriminant analyses was used to model
class differences and identify metabolites contributing to
the differences between groups. Additionally, spectra were
correlated with birth weight, gestational age and weight z
score at 2weeks of age.
Results Of the original number of 926 trial participants,
urine samples were available from 197 (21%) healthy
young adults (42% men) born preterm (mean 30.7±2.8
weeks) and randomised to BBM (n=55; 28 men), TF (n=48;
14 men) and PTF (n=93; 40 men). We found no significant
differences in urinary spectra between dietary groups
including when stratified by sex. Correlation analysis
revealed a weak association between metabolic profile
and gestational age that was lost on controlling for ethanol
excretion.
Conclusions We found no evidence that dietary
exposures in the neonatal period influence the metabolic
phenotype in young adult life
Reportage: Gallery Walk
Buchbesprechung "Team of Teams" von Stanley McChristal.Im Rahmen eines Change-Management-Seminars beschäftigten sich Studierende des 2. Semesters im Masterstudiengangs Kommunikation und Management mit dem Buch ‚Team of Teams‘ von Stanley McChristal. Der ehemalige General der US-Army beschreibt darin, wie Führung auch in Extremsituationen gemeistert werden kann. Zum Abschluss des Seminars gestalteten die Studierenden Poster zu den Schlüsselbegriffen 'Leading like a gardener', 'Team of Teams', 'Empowered Execution', 'Adaptability' und 'Shared Concsiousness', die Stanleys Konzept prägen. Ziel dieser Handlungskonzepte ist es, dass Organisationen ihre Anpassungsfähigkeit in einer komplexen Welt verbessern können
Metabonomics and Intensive Care
This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2016. Other selected articles can be found online at http://www.biomedcentral.com/collections/annualupdate2016. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901
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Metabolic phenotyping for understanding the gut microbiome and host metabolic interplay
There is growing interest in the role of the gut microbiome in human health and disease. This unique complex ecosystem has been implicated in a number of health conditions including intestinal disorders, inflammatory skin diseases and metabolic syndrome. However, there is still much to learn regarding its capacity to affect host health. Many gut microbiome research studies focus on compositional analysis to better understand the causal relationships between microbial communities and disease phenotypes. Yet microbial diversity and complexity is such, that community structure alone does not provide full understanding of microbial function.
Metabolic phenotyping is an exciting field in systems biology that provides information on metabolic outputs taking place in the system at a given moment in time. These readouts provide information relating to by-products of endogenous metabolic pathways, exogenous signals arising from diet, drugs and other lifestyle and environmental stimuli, as well as products of microbe-host co-metabolism. Thus, better understanding of the gut microbiome and host metabolic interplay can be gleaned by using such analytical approaches.
In this Review, we describe research findings focussed on gut microbiota-host interactions, for functional insight into the impact of microbiome composition on host health. We evaluate different analytical approaches for capturing metabolic activity, and discuss analytical methodological advancements that have made a contribution to the field. This information will aid in developing novel approaches to improve host health in the future, and therapeutic modulation of the microbiome may soon augment conventional clinical strategies
Feature selection in the reconstruction of complex network representations of spectral data
Complex networks have been extensively used in the last decade to characterize and analyze complex systems, and they have been recently proposed as a novel instrument for the analysis of spectra extracted from biological samples. Yet, the high number of measurements composing spectra, and the consequent high computational cost, make a direct network analysis unfeasible. We here present a comparative analysis of three customary feature selection algorithms, including the binning of spectral data and the use of information theory metrics. Such algorithms are compared by assessing the score obtained in a classification task, where healthy subjects and people suffering from different types of cancers should be discriminated. Results indicate that a feature selection strategy based on Mutual Information outperforms the more classical data binning, while allowing a reduction of the dimensionality of the data set in two orders of magnitud
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Combined transcriptomic-(1)H NMR metabonomic study reveals yhat monoethylhexyl phthalate stimulates adipogenesis and glyceroneogenesis in human adipocytes
Adipose tissue is a major storage site for lipophilic environmental contaminants. The environmental metabolic disruptor hypothesis postulates that some pollutants can promote obesity or metabolic disorders by activating nuclear receptors involved in the control of energetic homeostasis. In this context, monoethylhexyl phthalate (MEHP) is of particular concern since it was shown to activate the peroxisome proliferator-activated receptor γ (PPARγ) in 3T3-L1 murine preadipocytes. In the present work, we used an untargeted, combined transcriptomic-(1)H NMR-based metabonomic approach to describe the overall effect of MEHP on primary cultures of human subcutaneous adipocytes differentiated in vitro. MEHP stimulated rapidly and selectively the expression of genes involved in glyceroneogenesis, enhanced the expression of the cytosolic phosphoenolpyruvate carboxykinase, and reduced fatty acid release. These results demonstrate that MEHP increased glyceroneogenesis and fatty acid reesterification in human adipocytes. A longer treatment with MEHP induced the expression of genes involved in triglycerides uptake, synthesis, and storage; decreased intracellular lactate, glutamine, and other amino acids; increased aspartate and NAD, and resulted in a global increase in triglycerides. Altogether, these results indicate that MEHP promoted the differentiation of human preadipocytes to adipocytes. These mechanisms might contribute to the suspected obesogenic effect of MEHP
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Early intervention with Bifidobacterium lactis NCC2818 modulates the host-microbe interface independent of the sustained changes induced by the neonatal environment
Inflammatory and metabolic diseases can originate during early-life and have been correlated with shifts in intestinal microbial ecology. Here we demonstrate that minor environmental fluctuations during the early neonatal period had sustained effects on the developing porcine microbiota and host-microbe interface. These inter-replicate effects appear to originate during the first day of life, and are likely to reflect very early microbiota acquisition from the environment. We statistically link early systemic inflammation with later local increases in inflammatory cytokine (IL-17) production, which could have important enteric health implications. Immunity, intestinal barrier function, host metabolism and host-microbiota co-metabolism were further modified by Bifidobacterium lactis NCC2818 supplementation, although composition of the in situ microbiota remained unchanged. Finally, our robust model identified novel, strong correlations between urinary metabolites (eg malonate, phenylacetylglycine, alanine) and mucosal immunoglobulin (IgM) and cytokine (IL-10, IL-4) production, thus providing the possibility of the development of urinary ‘dipstick’ tests to assess non-accessible mucosal immune development and identify early precursors (biomarkers) of disease. These results have important implications for infants exposed to neonatal factors including caesarean delivery, antibiotic therapy and delayed discharge from hospital environments, which may predispose to the development of inflammatory and metabolic diseases in later life
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Investigating mechanisms underpinning the detrimental impact of a high-fat diet in the developing and adult hypermuscular myostatin null mouse
Background: Obese adults are prone to develop metabolic and cardiovascular diseases. Furthermore, over-weight expectant mothers give birth to large babies who also have increased likelihood of developing metabolic and cardiovascular diseases. Fundamental advancements to better understand the pathophysiology of obesity are critical in the development of anti-obesity therapies not only for this but also future generations. Skeletal muscle plays a major role in fat metabolism and much work has focused in promoting this activity in order to control the development of obesity. Research has evaluated myostatin inhibition as a strategy to prevent the development of obesity and concluded in some cases that it offers a protective mechanism against a high-fat diet.
Results: We hypothesised that myostatin inhibition should protect not only the mother but also its developing foetus from the detrimental effects of a high-fat diet. Unexpectedly, we found muscle development was attenuated in the foetus of myostatin null mice raised on a high-fat diet. We therefore re-examined the effect of the high-fat diet on adults and found myostatin null mice were more susceptible to diet-induced obesity through a mechanism involving impairment of inter-organ fat utilization.
Conclusions: Loss of myostatin alters fatty acid uptake and oxidation in skeletal muscle and liver. We show that abnormally high metabolic activity of fat in myostatin null mice is decreased by a high-fat diet resulting in excessive adipose deposition and lipotoxicity. Collectively, our genetic loss-of-function studies offer an explanation of the lean phenotype displayed by a host of animals lacking myostatin signalling.
Keywords: Muscle, Obesity, High-fat diet, Metabolism, Myostati
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Dominant components of the Thoroughbred metabolome characterised by 1H‐NMR spectroscopy: a metabolite atlas of common biofluids
Summary
Reasons for performing study: Metabonomics is emerging as a powerful tool for disease screening and investigating mammalian metabolism. This study aims to create a metabolic framework by producing a preliminary reference guide for the normal equine metabolic milieu.
Objectives: To metabolically profile plasma, urine and faecal water from healthy racehorses using high resolution 1H-NMR spectroscopy and to provide a list of dominant metabolites present in each biofluid for the benefit of future research in this area.
Study design: This study was performed using seven Thoroughbreds in race training at a single time-point. Urine and faecal samples were collected non-invasively and plasma was obtained from samples taken for routine clinical chemistry purposes.
Methods: Biofluids were analysed using 1H-NMR spectroscopy. Metabolite assignment was achieved via a range of 1D and 2D experiments.
Results: A total of 102 metabolites were assigned across the three biological matrices. A core metabonome of 14 metabolites was ubiquitous across all biofluids. All biological matrices provided a unique window on different aspects of systematic metabolism. Urine was the most populated metabolite matrix with 65 identified metabolites, 39 of which were unique to this biological compartment. A number of these were related to gut microbial host co-metabolism. Faecal samples were the most metabolically variable between animals; acetate was responsible for the majority (28%) of this variation. Short chain fatty acids were the predominant features identified within this biofluid by 1H-NMR spectroscopy.
Conclusions: Metabonomics provides a platform for investigating complex and dynamic interactions between the host and its consortium of gut microbes and has the potential to uncover markers for health and disease in a variety of biofluids. Inherent variation in faecal extracts along with the relative abundance of microbial-mammalian metabolites in urine and invasive nature of plasma sampling, infers that urine is the most appropriate biofluid for the purposes of metabonomic analysis
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