922 research outputs found
Health-related costs in a sample of premenopausal non-diabetic overweight or obese females in Antwerp region : a cost-of-illness analysis
Background: People with overweight or obesity are at increased risk for disease later in life which cause important health costs. The aim of this study was to estimate the health status and the corresponding costs in a sample of females with overweight or obesity which were participating in a Randomized Controlled Trial (RCT) exploring the effect of lifestyle habits changes on ectopic adipose tissue.
Methods: Sixty-two non-diabetic premenopausal females without major comorbidities of overweight and obesity were recruited among patients visiting endocrinologists at the obesity clinic of the University Hospital of Antwerp and the University of Antwerp. A RCT-embedded cost-of-illness approach with societal perspective, based on self-reported questionnaires and cost diaries (3 months recall) was applied to estimate the prevalence of different comorbidities and the related direct and indirect costs in this sample of overweight or obese females. The European Quality-of-Life-5D questionnaire was used to define the health state and the corresponding utility index of the participants.
Results: The average direct health costs and health utilities observed in this sample were comparable with the general Flemish female population. This may partially be explained by the strict inclusion criteria of the RCT (i.e. overweight or obesity without diabetes type 2 or cardiovascular diseases). However, 15% of the participants had five or more comorbidities resulting in higher average costs and lower average health utility as compared to the general population, only 3 participants were diagnozed with the metabolic syndrome. In this subsample productivity was low due to high average absenteeism, yielding important total costs for the society.
Conclusion: Secondary prevention to avoid health deterioration in overweight or obese females without major comorbidies is needed to contain health care costs.
Trial registration: ClinicalTrials.gov: NCT02831621, approval of the ethics committee of the University Hospital of Antwerp (number: 14/17/205 -ref: 7543075363)
Effect of substrate conditions on the plasma beam deposition of amorphous hydrogenated carbon
A study on the effect of substrate conditions was performed for the plasma beam deposition of amorphous hydrogenated carbon ( a -C:H) from an expanding thermal argon/acetylene plasma on glass and crystalline silicon. A new substrate holder was designed, which allows the control of the substrate temperature independent of the plasma settings with an accuracy of 2 K. This is obtained via a combination of a good control of the holder’s yoke temperature and the injection of helium gas between thermally ill connected parts of the substrate holder system. It is demonstrated that the substrate temperature influences both the a -C:H material quality and the deposition rate. The deposition rate and substrate temperature are presented as the two parameters which determine the material quality. In situ studies prove that the deposition process is constant in time and that thermally activated etching processes are unlikely to contribute significantly during deposition. Preliminary experiments with an additional substrate bias reveal that an energetic ion bombardment of the growingfilm surface does not influence the deposition process. A tentative deposition model is proposed based on the creation and destruction of active sites, which depend on the particle fluxes towards the substrate and the substrate temperature. This model allows the qualitative explanation of the observed deposition results
Hysteresis and bi-stability by an interplay of calcium oscillations and action potential firing
Many cell types exhibit oscillatory activity, such as repetitive action
potential firing due to the Hodgkin-Huxley dynamics of ion channels in the cell
membrane or reveal intracellular inositol triphosphate (IP) mediated
calcium oscillations (CaOs) by calcium-induced calcium release channels
(IP-receptor) in the membrane of the endoplasmic reticulum (ER). The
dynamics of the excitable membrane and that of the IP-mediated CaOs have
been the subject of many studies. However, the interaction between the
excitable cell membrane and IP-mediated CaOs, which are coupled by
cytosolic calcium which affects the dynamics of both, has not been studied.
This study for the first time applied stability analysis to investigate the
dynamic behavior of a model, which includes both an excitable membrane and an
intracellular IP-mediated calcium oscillator. Taking the IP
concentration as a control parameter, the model exhibits a novel rich spectrum
of stable and unstable states with hysteresis. The four stable states of the
model correspond in detail to previously reported growth-state dependent states
of the membrane potential of normal rat kidney fibroblasts in cell culture. The
hysteresis is most pronounced for experimentally observed parameter values of
the model, suggesting a functional importance of hysteresis. This study shows
that the four growth-dependent cell states may not reflect the behavior of
cells that have differentiated into different cell types with different
properties, but simply reflect four different states of a single cell type,
that is characterized by a single model.Comment: 29 pages, 6 figure
IRAS\,11472-0800: an extremely depleted pulsating binary post-AGB star
We focus here on one particular and poorly studied object, IRAS11472-0800. It
is a highly evolved post-Asymptotic Giant Branch (post-AGB) star of spectral
type F, with a large infrared excess produced by thermal emission of
circumstellar dust. We deploy a multi-wavelength study which includes the
analyses of optical and IR spectra as well as a variability study based on
photometric and spectroscopic time-series. The spectral energy distribution
(SED) properties as well as the highly processed silicate N-band emission show
that the dust in IRAS11472-0800 is likely trapped in a stable disc. The
energetics of the SED and the colour variability show that our viewing angle is
close to edge-on and that the optical flux is dominated by scattered light.
With photospheric abundances of [Fe/H] = -2.7 and [Sc/H]=-4.2, we discovered
that IRAS11472-0800 is one of the most chemically-depleted objects known to
date. Moreover, IRAS11472-0800 is a pulsating star with a period of 31.16 days
and a peak-to-peak amplitude of 0.6 mag in V. The radial velocity variability
is strongly influenced by the pulsations, but the significant cycle-to-cycle
variability is systematic on a longer time scale, which we interpret as
evidence for binary motion. We conclude that IRAS11472-0800 is a pulsating
binary star surrounded by a circumbinary disc. The line-of-sight towards the
object lies close the the orbital plane making that the optical light is
dominated by scattered light. IRAS11472-0800 is one of the most
chemically-depleted objects known so far and links the dusty RV\,Tauri stars to
the non-pulsating class of strongly depleted objects.Comment: 12 pages, 14 figures Accepted for publication in A&A Main Journa
Landbouw en drinkwaterwinning kunnen goed samengaan
In het project ‘Boeren voor Drinkwater’ werken melkveehouders sinds 2010 samen met onder andere de provincie Overijssel en drinkwaterbedrijf Vitens aan het verminderen van de milieubelasting op het grondwater in de meest kwetsbare zandgebieden. Hoewel nog niet overal de doelstelling voor nitraatuitspoeling gehaald wordt, is bij de deelnemers al een aanzienlijke vermindering bereikt. Het project laat zien dat een efficiëntere mineralenkringloop leidt tot minder milieubelasting en hand in hand gaat met een verbeterd economisch rendement. Om de drinkwaterwinning veilig te stellen is het echter nodig de mineralenbenutting in (vrijwel) het gehele intrekgebied te optimaliseren
Topological defects and shape of aromatic self-assembled vesicles
We show that the stacking of flat aromatic molecules on a curved surface
results in topological defects. We consider, as an example, spherical vesicles,
self-assembled from molecules with 5- and 6-thiophene cores. We predict that
the symmetry of the molecules influences the number of topological defects and
the resulting equilibrium shape.Comment: accepted as a Letter in the J. Phys. Chem.
Intrinsic Detectivity Limits of Organic Near-Infrared Photodetectors
Organic photodetectors (OPDs) with a performance comparable to that of conventional inorganic ones have recently been demonstrated for the visible regime. However, near-infrared photodetection has proven to be challenging and, to date, the true potential of organic semiconductors in this spectral range (800–2500 nm) remains largely unexplored. In this work, it is shown that the main factor limiting the specific detectivity (D*) is non-radiative recombination, which is also known to be the main contributor to open-circuit voltage losses. The relation between open-circuit voltage, dark current, and noise current is demonstrated using four bulk-heterojunction devices based on narrow-gap donor polymers. Their maximum achievable D* is calculated alongside a large set of devices to demonstrate an intrinsic upper limit of D* as a function of the optical gap. It is concluded that OPDs have the potential to be a useful technology up to 2000 nm, given that high external quantum efficiencies can be maintained at these low photon energies
Quantum simplicial geometry in the group field theory formalism: reconsidering the Barrett-Crane model
A dual formulation of group field theories, obtained by a Fourier transform
mapping functions on a group to functions on its Lie algebra, has been proposed
recently. In the case of the Ooguri model for SO(4) BF theory, the variables of
the dual field variables are thus so(4) bivectors, which have a direct
interpretation as the discrete B variables. Here we study a modification of the
model by means of a constraint operator implementing the simplicity of the
bivectors, in such a way that projected fields describe metric tetrahedra. This
involves a extension of the usual GFT framework, where boundary operators are
labelled by projected spin network states. By construction, the Feynman
amplitudes are simplicial path integrals for constrained BF theory. We show
that the spin foam formulation of these amplitudes corresponds to a variant of
the Barrett-Crane model for quantum gravity. We then re-examin the arguments
against the Barrett-Crane model(s), in light of our construction.Comment: revtex, 24 page
Deformed General Relativity and Torsion
We argue that the natural framework for embedding the ideas of deformed, or
doubly, special relativity (DSR) into a curved spacetime is a generalisation of
Einstein-Cartan theory, considered by Stelle and West. Instead of interpreting
the noncommuting "spacetime coordinates" of the Snyder algebra as endowing
spacetime with a fundamentally noncommutative structure, we are led to consider
a connection with torsion in this framework. This may lead to the usual
ambiguities in minimal coupling. We note that observable violations of charge
conservation induced by torsion should happen on a time scale of 10^3 s, which
seems to rule out these modifications as a serious theory. Our considerations
show, however, that the noncommutativity of translations in the Snyder algebra
need not correspond to noncommutative spacetime in the usual sense.Comment: 20 pages, 1 figure, revtex; expanded sections 3 and 4 for clarity,
moved material to appendix B, corrected a few minor error
Estimating the Magnitude of Genetic Factors by Calculating the Genetic Relative Risk of Stroke in First-Ever Lacunar Stroke Patients
BACKGROUND: Positive family history of stroke is an independent risk factor for lacunar stroke. However, the magnitude of familial aggregation of a certain disease is better evaluated by the genetic relative risk. This is calculated by dividing the prevalence of specific disease in family members of patients by the prevalence of this disease in the general population. In a cohort of lacunar stroke patients, who were subtyped clinically and radiologically, we determined the genetic relative risk of stroke. METHODS: By questionnaire and additional interview, we obtained a complete first-degree family history of stroke. The prevalence of stroke in first-degree relatives of these lacunar stroke patients was compared to the self-reported prevalence of stroke in a Dutch community based cohort of elderly volunteers. Secondly, the influence of proband characteristics and family composition on parental and sibling history of stroke were evaluated. PRINCIPAL FINDINGS: We collected data of 1066 first-degree relatives of 195 lacunar stroke patients. Strokes occurred in 13.5% of first-degree relatives. The genetic relative risk was 2.94 (95%CI 2.45-3.53) for overall first-degree relatives, 4.52 (95%CI 3.61-5.65) for patients' parents and 2.10 (95%CI 1.63-2.69) for patients' siblings. Age of proband and proband status for hypertension influenced the chance of having a parent with a history of stroke whereas the likelihood of having a concordant sibling increased with sibship size. CONCLUSIONS: We found an increased genetic relative risk of stroke in first-degree relatives of patients with lacunar stroke. Our data warrant further genomic research in this well-defined high risk population for stroke
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