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 individual’s 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)

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 $a_1, a_2 \in \mathbb{R}^3$. 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 $a_2$ lies on the line joining the origin with $a_1$. The work is a fully time-dependent version of the original analysis proposed by Mott in 1929.Comment: 23 page

The use of hospital and physician services under a national health insurance program: an examination of the Canada Health Survey

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A qualitative assessment of the medicare prospective payment system

This paper employs commonly accepted criteria to evaluate the potential outcomes of the Medicare pricing mechanism. The analysis suggests that the recent revisions in the Medicare payment system have less potential to contain increases in total hospital costs than those embodied in all-payer systems. In addition, this paper also suggests that the pricing mechanism will jeopardize the financial viability of many hospitals while exacerbating inequities that emanate from differential pricing policies. Finally, when viewed from the perspective of insured beneficiaries, it is reasonable to expect that the payment mechanism will reduce not only access to inpatient care but also the use of service once admitted.

Genetic Relationships Deduced from emm and Multilocus Sequence Typing of Invasive Streptococcus dysgalactiae subsp. equisimilis and S. canis Recovered from Isolates Collected in the United States ▿

Beta-hemolytic group C and G streptococci cause a considerable invasive disease burden and sometimes cause disease outbreaks. Little is known about the critical epidemiologic parameter of genetic relatedness between isolates. We determined the emm types of 334 Streptococcus dysgalactiae subsp. equisimilis isolates, and attempted emm typing of 5 Streptococcus canis isolates from a recent population-based surveillance for invasive isolates. Thirty-four emm types were observed, including one from S. canis. We formulated multilocus sequence typing (MLST) primers with six of the seven loci corresponding to the Streptococcus pyogenes MLST scheme. We performed MLST with 65 of the 334 surveillance isolates (61 S. dysgalactiae subsp. equisimilis isolates, 4 S. canis isolates) to represent each emm type identified, including 2 to 3 isolates for each of the 25 redundantly represented emm types. Forty-one MLST sequence types (STs) were observed. Isolates within 16 redundantly represented S. dysgalactiae subsp. equisimilis emm types shared identical or nearly identical STs, demonstrating concordance between the emm type and genetic relatedness. However, seven STs were each represented by two to four different emm types, and 7 of the 10 S. dysgalactiae subsp. equisimilis eBURST groups represented up to six different emm types. Thus, S. dysgalactiae subsp. equisimilis isolates were similar to S. pyogenes isolates, in that strains of the same emm type were often highly related, but they differed from S. pyogenes, in that S. dysgalactiae subsp. equisimilis strains with identical or closely similar STs often exhibited multiple unrelated emm types. The phylogenetic relationships between S. dysgalactiae subsp. equisimilis and S. pyogenes alleles revealed a history of interspecies recombination, with either species often serving as genetic donors. The four S. canis isolates shared highly homologous alleles but were unrelated clones without evidence of past recombination with S. dysgalactiae subsp. equisimilis or S. pyogenes