826 research outputs found
Test of Information Theory on the Boltzmann Equation
We examine information theory using the steady-state Boltzmann equation. In a
nonequilibrium steady-state system under steady heat conduction, the
thermodynamic quantities from information theory are calculated and compared
with those from the steady-state Boltzmann equation. We have found that
information theory is inconsistent with the steady-state Boltzmann equation.Comment: 12 page
Some thoughts about nonequilibrium temperature
The main objective of this paper is to show that, within the present
framework of the kinetic theoretical approach to irreversible thermodynamics,
there is no evidence that provides a basis to modify the ordinary Fourier
equation relating the heat flux in a non-equilibrium steady state to the
gradient of the local equilibrium temperature. This fact is supported, among
other arguments, through the kinetic foundations of generalized hydrodynamics.
Some attempts have been recently proposed asserting that, in the presence of
non-linearities of the state variables, such a temperature should be replaced
by the non-equilibrium temperature as defined in Extended Irreversible
Thermodynamics. In the approximations used for such a temperature there is so
far no evidence that sustains this proposal.Comment: 13 pages, TeX, no figures, to appear in Mol. Phy
Diet Soda Intake and Risk of Incident Metabolic Syndrome and Type 2 Diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA)*
Stereo imaging is an important area of image and video processing, with exploding progress in the last decades. An open issue in this field is the understanding of the conditions under which the straightforward application of a given image processing operator to both the left and right image of a stereo pair preserves the stereoscopic perception. In this paper, we explore this problem with application to artistic imaging and we prove that, unlike other methods, artistic operators based on edge preserving smoothing have this desirable property. We also present a novel multiresolution artistic operator, purposely designed for stereo images, which enhances the perception of three-dimensionality by means of a depth driven local scale control.
Information theory in the study of anisotropic radiation
Information theory is used to perform a thermodynamic study of non
equilibrium anisotropic radiation. We limit our analysis to a second-order
truncation of the moments, obtaining a distribution function which leads to a
natural closure of the hierarchy of radiative transfer equations in the
so-called variable Eddington factor scheme. Some Eddington factors appearing in
the literature can be recovered as particular cases of our two-parameter
Eddington factor. We focus our attention in the study of the thermodynamic
properties of such systems and relate it to recent nonequilibrium thermodynamic
theories. Finally we comment the possibility of introducing a nonequilibrium
chemical potential for photons.Comment: 1 eps figure upon request by e-mail, to appear in Journal of Physics
Gene expression in intestinal mucosal biopsy specimens obtained from dogs with chronic enteropathy
ObjectiveâTo characterize mucosal gene expression in dogs with chronic enteropathy (CE). Animalsâ18 dogs with CE and 6 healthy control dogs.
ProceduresâSmall intestinal mucosal biopsy specimens were endoscopically obtained from dogs. Disease severity in dogs with CE was determined via inflammatory bowel index scores and histologic grading of biopsy specimens. Total RNA was extracted from biopsy specimens and microchip array analysis (approx 43,000 probe sets) and quantitative reverse transcriptase PCR assays were performed.
Resultsâ1,875 genes were differentially expressed between dogs with CE and healthy control dogs; 1,582 (85%) genes were downregulated in dogs with CE, including neurotensin, fatty acidâbinding protein 6, fatty acid synthase, aldehyde dehydrogenase 1 family member B1, metallothionein, and claudin 8, whereas few genes were upregulated in dogs with CE, including genes encoding products involved in extracellular matrix degradation (matrix metallopeptidases 1, 3, and 13), inflammation (tumor necrosis factor, interleukin-8, peroxisome proliferatorâactivated receptor Îł, and S100 calcium-binding protein G), iron transport (solute carrier family 40 member 1), and immunity (CD96 and carcinoembryonic antigenârelated cell adhesion molecule [CEACAM] 18). Dogs with CE and protein-losing enteropathy had the greatest number of differentially expressed genes. Results of quantitative reverse transcriptase PCR assay for select genes were similar to those for microchip array analysis.
Conclusions and Clinical RelevanceâExpression of genes encoding products regulating mucosal inflammation was altered in dogs with CE and varied with disease severity.
Impact for Human MedicineâMolecular pathogenesis of CE in dogs may be similar to that in humans with inflammatory bowel disease
Gene expression in intestinal mucosal biopsy specimens obtained from dogs with chronic enteropathy
ObjectiveâTo characterize mucosal gene expression in dogs with chronic enteropathy (CE). Animalsâ18 dogs with CE and 6 healthy control dogs.
ProceduresâSmall intestinal mucosal biopsy specimens were endoscopically obtained from dogs. Disease severity in dogs with CE was determined via inflammatory bowel index scores and histologic grading of biopsy specimens. Total RNA was extracted from biopsy specimens and microchip array analysis (approx 43,000 probe sets) and quantitative reverse transcriptase PCR assays were performed.
Resultsâ1,875 genes were differentially expressed between dogs with CE and healthy control dogs; 1,582 (85%) genes were downregulated in dogs with CE, including neurotensin, fatty acidâbinding protein 6, fatty acid synthase, aldehyde dehydrogenase 1 family member B1, metallothionein, and claudin 8, whereas few genes were upregulated in dogs with CE, including genes encoding products involved in extracellular matrix degradation (matrix metallopeptidases 1, 3, and 13), inflammation (tumor necrosis factor, interleukin-8, peroxisome proliferatorâactivated receptor Îł, and S100 calcium-binding protein G), iron transport (solute carrier family 40 member 1), and immunity (CD96 and carcinoembryonic antigenârelated cell adhesion molecule [CEACAM] 18). Dogs with CE and protein-losing enteropathy had the greatest number of differentially expressed genes. Results of quantitative reverse transcriptase PCR assay for select genes were similar to those for microchip array analysis.
Conclusions and Clinical RelevanceâExpression of genes encoding products regulating mucosal inflammation was altered in dogs with CE and varied with disease severity.
Impact for Human MedicineâMolecular pathogenesis of CE in dogs may be similar to that in humans with inflammatory bowel disease
âA Faustian bargain?â Public voices on forensic DNA technologies and the National DNA Database
This article draws on the idea of the âforensic imaginaryâ (Williams 2010) to explore UK public perspectives on the place, role and significance of forensic DNA technologies, both independent of and in relation to other genetic applications. Using correspondentsâ replies to the Spring 2006 Mass Observation Directive âGenes, Genetics and Cloningâ, the analysis focuses on continuities and tensions in their discursive repertoires. The argument examines (a) the ways in which knowledge is made sense of in these accounts, and (b) the discrepancy between an appreciation of the benefits of using DNA identification techniques in police work and a more critical attitude towards a wider national DNA database. The conclusion reflects on the need for a wider scope in research on public understandings of science, which looks beyond targeted consultations and specific publics, and provides more textured data to document collective views on the development and governance of forensic DNA technologies
Beings in their own right? Exploring Children and young people's sibling and twin relationships in the Minority World
This paper examines the contributions that the sociological study of sibship and twinship in the Minority World can make to childhood studies. It argues that, in providing one forum within which to explore children and young people's social relationships, we can add to our understanding of children and young people's interdependence and develop a more nuanced understanding of agency. As emergent subjects, children, young people and adults are in a process of âbecomingâ. However, this does not mean that they can âbecomeâ anything they choose to. The notion of negotiated interdependence (Punch 2002) is useful in helping us to grasp the contingent nature of children and young people's agency
Metabolomics and Incident Hypertension Among Blacks: The Atherosclerosis Risk in Communities Study
Development of hypertension is influenced by genes, environmental effects and their interactions, and the human metabolome is a measurable manifestation of gene-environment interaction. We explored the metabolomic antecedents of developing incident hypertension in a sample of African Americans, a population with a high prevalence of hypertension and its comorbidities. We examined 896 (565 females, aged 45â64 years) African American normotensives from the Atherosclerosis Risk in Communities (ARIC) Study, whose metabolome was measured in serum collected at the baseline examination and analyzed by high throughput methods. The analyses presented here focus on 204 stably measured metabolites over a period of 4â6 weeks. Weibull parametric models considering interval censored data were used to assess the hazard ratio for incident hypertension. We used a modified Bonferroni correction accounting for the correlations among metabolites to define a threshold for statistical significance (p<3.9Ă10â4). During 10-years of follow-up, 38% of baseline normotensives developed hypertension (N=344). With adjustment for traditional risk factors and estimated glomerular filtration rate, each +1-standard deviation difference in baseline 4-hydroxyhippurate, a product of gut microbial fermentation, was associated with 17% higher risk of hypertension (p=2.5Ă10â4), which remained significant after adjusting for both baseline systolic and diastolic blood pressure (p=3.8Ă10â4). After principal component analyses, a sex steroids pattern was significantly associated with risk of incident hypertension (highest versus lowest quintile hazard ratio, 1.72; 95% CI, 1.05 to 2.82; p for trend=0.03), and stratified analyses suggested that this association was consistent in both genders. Metabolomic analyses identify novel pathways in the etiology of hypertension
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