84 research outputs found
Consistency of Minority and Socioeconomic Status as Predictors of Health
This paper examines the relative consistency of economic and racial status as predictors of the individualās physical and emotional health. The focus of the study is the covariates of (1) limited activity resulting from poor physical and (2) limited activity resulting from poor emotional health. Using data from the 2003 Behavioral Risk Factor Surveillance System survey, the study was developed in two phases. In the first, logistic regression analysis was used to examine two binary variables that identified respondents who reported at least one day of limited activity that resulted from poor physical and then poor emotional or mental health. Limited to those who reported at least one day of limited activity, the second stage of the study examined variability in the number of days of limited activity that resulted from 1) poor physical health and; 2) poor mental or emotional health. After controlling for chronic conditions, risk factors, access to care and the demographic attributes of the individual, the results indicate that the economically disadvantaged consistently reported poor health while wealthier members of the study group reported good health. The coefficients derived for membership in minority groups, defined as African Americans, Native Americans and Latinos, were inconsistent and, in general, insignificant (P\u3c.05)
LINE-1 Hypomethylation in a Choline-Deficiency-Induced Liver Cancer in Rats: Dependence on Feeding Period
Chronic feeding of methyl-donor (methionine, choline, folic acid, and vitamin B12) deficient diet induces hepatocellular carcinoma formation in rats. Previous studies have shown that promoter CpG islands in various cancer-related genes are aberrantly methylated in this model. Moreover, the global genome in methyl-donor-deficient diet fed rats contains a lesser amount of 5-methylcytosine than control livers. It is speculated that more than 90% of all 5-methylcytosines lie within the CpG islands of the transposons, including the long/short interspersed nucleotide elements (LINE and SINE). It is considered that the 5-methylcytosines in LINE-1 limit the ability of retrotransposons to be activated and transcribed; therefore, the extent of hypomethylation of LINE-1 could be a surrogate marker for aberrant methylation in other tumor-related genes as well as genome instability. Additionally, LINE-1 methylation status has been shown to be a good indicator of genome-wide methylation. In this study, we determined cytosine methylation status in the LINE-1 repetitive sequences of rats fed a choline-deficient (CD) diet for various durations and compared these with rats fed a choline-sufficient (CS) diet. The methylation status of LINE-1 was assessed by the combined bisulfite restriction analysis (COBRA) method, where the amount of bisulfite-modified and RsaI-cleaved DNA was quantified using gel electrophoresis. Progressive hypomethylation was observed in LINE-1 of CD livers as a function of feeding time; that is, the amount of cytosine in total cytosine (methylated and unmethylated) increased from 11.1% (1 week) to 19.3% (56 weeks), whereas in the control CS livers, it increased from 9.2% to 12.9%. Hypomethylation in tumor tissues was slightly higher (6%) than the nontumorous surrounding tissue. The present result also indicates that age is a factor influencing the extent of cytosine methylation
A time-dependent perturbative analysis for a quantum particle in a cloud chamber
We consider a simple model of a cloud chamber consisting of a test particle
(the alpha-particle) interacting with two other particles (the atoms of the
vapour) subject to attractive potentials centered in . At time zero the alpha-particle is described by an outgoing
spherical wave centered in the origin and the atoms are in their ground state.
We show that, under suitable assumptions on the physical parameters of the
system and up to second order in perturbation theory, the probability that both
atoms are ionized is negligible unless lies on the line joining the
origin with . The work is a fully time-dependent version of the original
analysis proposed by Mott in 1929.Comment: 23 page
Wittgenstein's Thought Experiments and Relativity Theory
In this paper, I discuss the similarity between Wittgensteinās use of thought experiments and Relativity Theory. I begin with introducing Wittgensteinās idea of āthought experimentsā and a tentative classification of different kinds of thought experiments in Wittgensteinās work. Then, after presenting a short recap of some remarks on the analogy between Wittgensteinās point of view and Einsteinās, I suggest three analogies between the status of Wittgensteinās mental experiments and Relativity theory: the topics of time dilation, the search for invariants, and the role of measuring tools in Special Relativity. This last point will help to better define Wittgensteinās idea of description as the core of his philosophical enterprise
Human Rights in the Context of Environmental Conservation on the US-Mexico Border
At Cabeza Priesta National Wildlife Refuge, a wilderness area on the US-Mexico border in Arizona, conflicting policies permit the provision of supplementary water for wildlife but not for undocumented immigrants passing through the area. Federal refuge environmental policy prioritizes active management of endangered and threatened species. Vast systems of water resources have been developed to support wildlife conservation in this extremely hot and dry environment. At the same time, humanitarian groups are not allowed to supply water to undocumented border crossers in the park. Human border-crossers must utilize non-potable wildlife water guzzlers for survival and face risk of illness or death by dehydration. This article analyzes human rights via an ethnographic lens. From this perspective, water policy at the wildlife refuge brings into question the value of human life in a border conservation context, especially for those entering the site illegally
The Forgotten Half of Food System Reform: Using Food and Agricultural Law to Foster Healthy Food Production
A method for determining the total storage requirements in a high-rise automated warehouse
M.S.Kailash M. Bafn
BELLOWS DESIGN EQUATIONS SUPPORTED BY LIMIT ANALYSIS
ABSTRACT Limit analysis can be used to design metal bellows for pressure capacity. The objective of limit analysis is to prevent gross plastic deformation with an appropriate design margin. The primary advantage of limit analysis over other methods is that it can find the max. allowable limit load for the structure as a whole and not just for the individual parts. In the case of bellows, an allowable limit pressure can be found which assures a specified margin on plastic collapse. In this paper, a parametric FEA study is performed on a series of twodimensional axisymmetric models of un-reinforced U-shaped bellows with wide ranging dimensions. The non-linear analysis gives the max. allowable limit pressure for each bellows based on limit analysis and a closed form equation is confirmed to accurately describe the FEA results. Combined with existing equations for column instability and external buckling, limiting design pressure equations are presented for bellows design. LIMIT ANALYSIS Limit analysis is used to find the maximum load a structure made of ideally plastic material can carry. The deformations of an ideally plastic structure increase without bound at this load, which is termed the collapse load. The analysis can be performed using a closed form equation or finite element analysis (FEA). With FEA, a computer model of the structure is created with appropriate boundary conditions. The model is then exposed to stepwise loading. Component stresses are calculated at each load step. A yield criterion is selected which specifies the state of multiaxial stress corresponding to the onset of plastic flow. The yield criterion can be represented geometrically by a fixed limit surface in the principal stresses space. Commonly used limit surfaces are Tresca and von Mises. The stresses at every point in the structure must lie in or on the limit surface. Since limit analysis is normally based on a yield criterion, it is only applicable for materials operating at temperatures below the creep range
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