Puerto Rican injection drug users: Prevention implications in Massachusetts and Puerto Rico

This study examines whether place of residence is a factor associated with reporting a positive HIV/AIDS, Hepatitis C (HCV), or Sexually Transmitted Disease (STD) status in a sample of 400 injection drug users (IDUs) residing on the Island of Puerto Rico (N=139) and in western Massachusetts (N=261). Logistic regression models revealed that IDUs residing in western Massachusetts were 66% less likely to be HIV positive compared to IDUs residing in Puerto Rico (p<.000) while IDUs residing in western Massachusetts were about 67% less likely to have a positive STD status than those residing in Puerto Rico (p<.000). Place of residence was not significantly associated with HCV status. Results indicate the need to develop prevention programs tailored to the unique socio-cultural context of Puerto Rican IDUs residing on the Island of Puerto Rico whose circumstances differ from those in the mainland US. To reduce drug use, HIV/AIDS, HCV, and STDs among Puerto Ricans in both locales, the Capacity Enhancement Model is proposed in order to develop more effective prevention programs.     

Measurement of attitudes toward bisexual men and women among South African university students: the validation of an instrument

Research was conducted investigating university students' prejudicial attitudes toward bisexual men and women in South Africa. The combined male and female Attitudes Regarding Bisexuality Scale (ARBS) showed unacceptable internal consistency reliabilities, especially for the Black-African participants. An expert focus group was convened in order to elaborate on and clarify the low reliability coefficients. The ARBS was then adapted for the South African population and resulted in two separate instruments designed to measure attitudes regarding bisexual men and bisexual women separately. Five hundred eighty seven university students completed these scales. The results indicated that the attitudes of heterosexual, homosexual, and asexual students toward bisexual men and women are more negative than the attitudes of bisexual students.     

Employing the Components of the Human Development Index to Drive Resources to Educational Policies

A new form of composition of the indicators employed to generate the United Nations Human Development Index (HDI) is presented here. This form of composition is based on the assumption that random errors affect the measurement of each indicator. This assumption allows for replacing the vector of evaluations according to each indicator by vectors of probabilities of being the best or the worst according to such attribute. The probabilistic composition of such probabilities of preference according to each indicator into probabilities of being the best or the worst according to all of them generates indices that may unveil, on one hand, performances to be followed and, on the other hand, extreme conditions that an additive composition would hide. Differences between the results of application of the diverse forms of composition are examined in the case of the HDI and in the case of the districts version of the HDI employed to compare Brazilian municipalities. It is verified that the smallest correlation between the education enrolment rate and the other indicators in the Brazilian case enlarges such differences.     

Stepping stones for the unemployed: the effect of temporary jobs on the duration until (regular) work

Transitions from unemployment into temporary work are often succeeded by a transition from temporary into regular work. This paper investigates whether temporary work increases the transition rate to regular work. We use longitudinal survey data of individuals to estimate a multi-state duration model, applying the ‘timing of events’ approach. The data contain multiple spells in labour market states at the individual level. We analyse results using novel graphical representations, which unambiguously show that temporary jobs shorten the unemployment duration, although they do not increase the fraction of unemployed workers having regular work within a few years after entry into unemployment.     

Religion, politics, and support for same-sex marriage in the United States, 1988-2008

We examine how religious and political factors structure support for same-sex marriage in the United States over the last two decades. Using data from the General Social Surveys, we show that respondents who identify more strongly with the Republican Party, sectarian denominations, and those who subscribe to biblical fundamentalism and political conservatism are substantially more opposed to same-sex marriage than are other Americans. Heterogeneous ordinal logistic regression models show that these religious and political factors have become more important over the last two decades. Cohorts born after 1945 became substantially more supportive of marriage rights between 1988 and 2008, but shifts in support for marriage rights were less sizeable for persons affiliated with sectarian denominations, religious fundamentalists, Republicans, and political conservatives. Estimates from structural equation models show that religious factors influence political conservatism and Republican identification, yet both religious and political factors have significant and substantial independent direct effects on support for same-sex marriage.     

Conditional quantile estimation with auxiliary information for left-truncated and dependent data

In this paper, the empirical likelihood method is used to define a new estimator of conditional quantile in the presence of auxiliary information for the left-truncation model. The asymptotic normality of the estimator is established when the data exhibit some kind of dependence. It is assumed that the lifetime observations with multivariate covariates form a stationary α‐mixing sequence. The result shows that the asymptotic variance of the proposed estimator is not larger than that of standard kernel estimator. Finite sample behavior of the estimator is investigated via simulations too.     

Stochastic Templates for Aquaculture Images and a Parallel Pattern Detector

A general statistical approach is presented for the identification of objects in digital images, motivated by an application in aquaculture involving underwater images of fish. Using Procrustes analysis, a point distribution model is fitted on a set of training images and used as a prior distribution for the shape of a deformable template. The likelihood of a proposed template is calculated in terms of the response from a feature detector along the boundary of the template. The posterior distribution of template variables is examined by using Markov chain Monte Carlo analysis. A key challenge in the aquaculture application is the variable nature of edges arising from the surface curvature of fish and the low contrast between the foreground and background. Conventional gradient-based edge detection proves inadequate, but a parallel pattern detector copes much better. Results are presented for a fully automated analysis of the database. The strengths and weaknesses of this approach are discussed and future developments are outlined.     

On an extension of the von Mises distribution due to Batschelet

This paper considers the three-parameter family of symmetric unimodal circular distributions proposed by Batschelet in [1 Batschelet, E. 1981. Circular Statistics in Biology, London: Academic Press.  [Google Scholar]], an extension of the von Mises distribution containing distributional forms ranging from the highly leptokurtic to the very platykurtic. The family's fundamental properties are given, and likelihood-based techniques described which can be used to perform estimation and hypothesis testing. Analyses are presented of two data sets which illustrate how the family and three of its most direct competitors can be applied in the search for parsimonious models for circular data.     

Comparison of normal probability plots and dot plots in judging the significance of effects in two level factorial designs

In this article, we present a study carried out to compare the effectiveness of the normal probability plot (NPP) and a simple dot plot in assessing the significance of the effects in experimental designs with factors at two levels (2 ^k?p designs). Several groups of students who had just completed a course that covered factorial designs were asked to identify the significant effects in a total of 32 situations, 16 of which were represented using NPPs and the other 16 using dot plots. Although the 32 scenarios were said to be different, there were really only 16 different situations, each of which was represented using the two methods to be compared. A simple graphical analysis shows no evidence that there is a difference between the two procedures. However, in designs with 16 runs there are some cases where NPP seems to give slightly better results.