5,502 research outputs found
The strategic impact of META-NET on the regional, national and international level
This article provides an overview of the dissemination work carried out in META-NET from 2010 until early 2014; we describe its impact on the regional, national and international level, mainly with regard to politics and the situation of funding for LT topics. This paper documents the initiative’s work throughout Europe in order to boost progress and innovation in our field.Postprint (published version
Estimating uncertainty of alcohol-attributable fractions for infectious and chronic diseases
Background: Alcohol is a major risk factor for burden of disease and injuries globally. This paper presents a systematic method to compute the 95% confidence intervals of alcohol-attributable fractions (AAFs) with exposure and risk relations stemming from different sources.Methods: The computation was based on previous work done on modelling drinking prevalence using the gamma distribution and the inherent properties of this distribution. The Monte Carlo approach was applied to derive the variance for each AAF by generating random sets of all the parameters. A large number of random samples were thus created for each AAF to estimate variances. The derivation of the distributions of the different parameters is presented as well as sensitivity analyses which give an estimation of the number of samples required to determine the variance with predetermined precision, and to determine which parameter had the most impact on the variance of the AAFs.Results: The analysis of the five Asian regions showed that 150 000 samples gave a sufficiently accurate estimation of the 95% confidence intervals for each disease. The relative risk functions accounted for most of the variance in the majority of cases.Conclusions: Within reasonable computation time, the method yielded very accurate values for variances of AAFs
Bid participates in genotoxic drug-induced apoptosis of HeLa cells and is essential for death receptor ligands' apoptotic and synergistic effects
Background: The BH3-only protein Bid is an important component of death receptor-mediated caspase activation. Bid is cleaved by caspase-8 or -10 into t-Bid, which translocates to mitochondria and triggers the release of caspase-activating factors. Bid has also been reported to be cleaved by other proteases. Methodology/Principal Findings: To test the hypothesis that Bid is a central mediator of stress-induced apoptosis, we investigated the effects of a small molecule Bid inhibitor on stress-induced apoptosis, and generated HeLa cells deficient for Bid. Stable knockdown of bid lead to a pronounced resistance to Fas/CD95- and TRAIL-induced caspase activation and apoptosis, and significantly increased clonogenic survival. While Bid-deficient cells were equally sensitive to ER stress-induced apoptosis, they showed moderate, but significantly reduced levels of apoptosis, as well as increased clonogenic survival in response to the genotoxic drugs Etoposide, Oxaliplatin, and Doxorubicin. Similar effects were observed using the Bid inhibitor BI6C9. Interestingly, Bid-deficient cells were dramatically protected from apoptosis when subtoxic concentrations of ER stressors, Etoposide or Oxaliplatin were combined with subtoxic TRAIL concentrations. Conclusions/Significance: Our data demonstrate that Bid is central for death receptor-induced cell death and participates in anti-cancer drug-induced apoptosis in human cervical cancer HeLa cells. They also show that the synergistic effects of TRAIL in combination with either ER stressors or genotoxic anti-cancer drugs are nearly exclusively mediated via an increased activation of Bid-induced apoptosis signalling
Low Mach Number Modeling of Type Ia Supernovae
We introduce a low Mach number equation set for the large-scale numerical
simulation of carbon-oxygen white dwarfs experiencing a thermonuclear
deflagration. Since most of the interesting physics in a Type Ia supernova
transpires at Mach numbers from 0.01 to 0.1, such an approach enables both a
considerable increase in accuracy and savings in computer time compared with
frequently used compressible codes. Our equation set is derived from the fully
compressible equations using low Mach number asymptotics, but without any
restriction on the size of perturbations in density or temperature. Comparisons
with simulations that use the fully compressible equations validate the low
Mach number model in regimes where both are applicable. Comparisons to
simulations based on the more traditional anelastic approximation also
demonstrate the agreement of these models in the regime for which the anelastic
approximation is valid. For low Mach number flows with potentially finite
amplitude variations in density and temperature, the low Mach number model
overcomes the limitations of each of the more traditional models and can serve
as the basis for an accurate and efficient simulation tool.Comment: Accepted for publication in the Astrophysical Journal 31 pages, 5
figures (some figures degraded in quality to conserve space
Systematics of heavy-ion fusion hindrance at extreme sub-barrier energies
The recent discovery of hindrance in heavy-ion induced fusion reactions at
extreme sub-barrier energies represents a challenge for theoretical models.
Previously, it has been shown that in medium-heavy systems, the onset of fusion
hindrance depends strongly on the "stiffness" of the nuclei in the entrance
channel. In this work, we explore its dependence on the total mass and the
-value of the fusing systems and find that the fusion hindrance depends in a
systematic way on the entrance channel properties over a wide range of systems.Comment: Submitted to Phys. Rev. Lett., 5 pages, 3 figure
Quantification of p38/synaptophysin in highly purified adrenal medullary chromaffin vesicles
p38/synaptophysin is a membrane protein present
in clear (synaptic) vesicles of neurons and endocrine
ceHs [1-4]. From the amino acid sequence
deduced from cDNAs encoding p38/synaptophysin,
a model with several membrane spanning
polypeptide segments and a carboxy-terminal
protein domain exposed to the cytoplasmic surface
has been constructed [5-7].
The function of p38/synaptophysin is not
known. It has been suggested to form a transmembrane
channel for ions, or to interact with
cytoplasmic factors via its cytoplasmic domain [7].
Since synaptophysin binds Ca2
+, it may also play
a role in the release of neurotransmitters stored in
clear (synaptic) vesicles [3].
Recently it has been reported [8] that p38/synaptophysin
also occurs in hormone containing large
dense core vesicles. This would imply that
p38/synaptophysin could fulfill similar functions
as described above in chromaffin and other
secretory ceHs containing large dense core vesicles.
In dear (synaptic) vesicles p38/synaptophysin constitutes
7.51Jfo of the vesicle membrane proteins [I].
The amount of p38/synaptophysin in large dense
core vesides is not known. Here we report on the
quantification of p38/synaptophysin in highly
purified chromaffin secretory veside
Mortality risk and mental disorders: longitudinal results from the Upper Bavarian Study
The object of the study was the assessment of the mortality risk for persons with a mental disorder in an unselected representative community sample assessed longitudinally. Subjects from a rural area in Upper Bavaria (Germany) participated in semi-structured interviews conducted by research physicians in the 1970s (first assessment) and death-certificate diagnoses were obtained after an interval up to 13 years later. The sample consisted of 1668 community residents aged 15 years and over. Cox regression estimates resulted in an odds ratio of 1·35 (confidence interval 1·01 to 1·81) for persons with a mental disorder classified as marked to very severe. The odds ratio increased with increasing severity of mental illness from 1·04 for mild disorders, 1·30 for marked disorders, to 1·64 for severe or very severe disorders. The relative risk (odds ratio) for persons with a mental disorder only and no somatic disorder was 1·22, for persons with only a somatic disorder 2·00, and for those with both a mental and a somatic disorder 2·13. The presence of somatic illness was responsible for most of the excess mortality. Somatic disorders associated with excess mortality in mental disorders were diseases of the nervous system or sensory organs, diseases of the circulatory system, diseases of the gastrointestinal tract, and diseases of the skeleton, muscles and connective tissue (ICD-8). Thus, while mental illness alone had a limited effect on excess mortality, comorbidity with certain somatic disorders had a significant effec
Linear approaches to intramolecular Förster Resonance Energy Transfer probe measurements for quantitative modeling
Numerous unimolecular, genetically-encoded Forster Resonance Energy Transfer (FRET) probes for monitoring biochemical activities in live cells have been developed over the past decade. As these probes allow for collection of high frequency, spatially resolved data on signaling events in live cells and tissues, they are an attractive technology for obtaining data to develop quantitative, mathematical models of spatiotemporal signaling dynamics. However, to be useful for such purposes the observed FRET from such probes should be related to a biological quantity of interest through a defined mathematical relationship, which is straightforward when this relationship is linear, and can be difficult otherwise. First, we show that only in rare circumstances is the observed FRET linearly proportional to a biochemical activity. Therefore in most cases FRET measurements should only be compared either to explicitly modeled probes or to concentrations of products of the biochemical activity, but not to activities themselves. Importantly, we find that FRET measured by standard intensity-based, ratiometric methods is inherently non-linear with respect to the fraction of probes undergoing FRET. Alternatively, we find that quantifying FRET either via (1) fluorescence lifetime imaging (FLIM) or (2) ratiometric methods where the donor emission intensity is divided by the directly-excited acceptor emission intensity (denoted R<sub>alt</sub>) is linear with respect to the fraction of probes undergoing FRET. This linearity property allows one to calculate the fraction of active probes based on the FRET measurement. Thus, our results suggest that either FLIM or ratiometric methods based on R<sub>alt</sub> are the preferred techniques for obtaining quantitative data from FRET probe experiments for mathematical modeling purpose
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