Using the EM algorithm for Bayesian variable selection in logistic regression models with related covariates

We develop a Bayesian variable selection method for logistic regression models that can simultaneously accommodate qualitative covariates and interaction terms under various heredity constraints. We use expectation-maximization variable selection (EMVS) with a deterministic annealing variant as the platform for our method, due to its proven flexibility and efficiency. We propose a variance adjustment of the priors for the coefficients of qualitative covariates, which controls false-positive rates, and a flexible parameterization for interaction terms, which accommodates user-specified heredity constraints. This method can handle all pairwise interaction terms as well as a subset of specific interactions. Using simulation, we show that this method selects associated covariates better than the grouped LASSO and the LASSO with heredity constraints in various exploratory research scenarios encountered in epidemiological studies. We apply our method to identify genetic and non-genetic risk factors associated with smoking experimentation in a cohort of Mexican-heritage adolescents.     

The Undisciplined Youth and a Moral Panic in Independent India,Circa 1947-1964

The undisciplined youth is one figure that is key to understanding the 1950s and 1960s in India. Politicians, officials, academics, youth leaders, and journalists developed and spread a discourse that imagined the collective behaviour of Indian youths as falling well below adult expectations of them in independent India. The imagery of the youth lacking in discipline was tied up with cycles of student unrest and the idea that the methods of protest used during the pre-independence period had wrongly continued into the post-independence period, but this discursive formation was often extended to include all Indian youths and it became translated into a long-term anxiety about the future of the newly established nation-state. These tropes about the undisciplined Indian youth became a symbol of the country's unresolved future. Unless the crisis of youth could be remedied, the narrative went, then the potentiality of Indian independence and its first generation of citizens could never be realised. This discourse took on a novel and distinctive shape during the initial years following Indian independence in 1947, it crystallised during the early 1950s, and there was a continued build-up of public concern that lasted throughout the 1960s.     

A network epidemic model for online community commissioning data

A statistical model assuming a preferential attachment network, which is generated by adding nodes sequentially according to a few simple rules, usually describes real-life networks better than a model assuming, for example, a Bernoulli random graph, in which any two nodes have the same probability of being connected, does. Therefore, to study the propagation of “infection” across a social network, we propose a network epidemic model by combining a stochastic epidemic model and a preferential attachment model. A simulation study based on the subsequent Markov Chain Monte Carlo algorithm reveals an identifiability issue with the model parameters. Finally, the network epidemic model is applied to a set of online commissioning data.     

Condom use,frequency of sex,and number of partners: Multidimensional characterization of adolescent sexual risk‐taking

Sexual health research often relies on single risk indicators. However, multi‐variable composites may better capture the underlying construct of risk‐taking. Latent Profile Analysis identified subgroups based on condom use consistency, partner numbers, and sex frequency among 605 adolescents. Three profiles were identified for each of grades 8 to 10 (Condom Users, Few Partners, and Risk‐Takers) and 4 in grades 11 and 12 (Condom Users, One Partner, Two Partners, and Risk‐Takers). Inconsistent condom use groups reported more non‐condom (and often less effective) birth control use and STD and pregnancy histories. Females had greater representation in the Few Partners, One Partners, and Two Partners groups, which also contained increasing proportions of participants in each subsequent year. Males had greater representation in the Risk‐Takers group. A profile approach to measurement has methodological advantages, can add to substantive knowledge, and can inform content, timing, and targets of sexual health interventions.     

How much culture is enough? Inuit teachers’ perceptions on the state of Inuit culture in Nunavik classrooms

This paper highlights findings of a survey conducted with the Kativik School Board, Canada, to gain insight into the perceptions of Inuit teachers concerning how Inuit culture is taught in the classroom. While findings indicate that teachers are integrating Inuit culture to varying degrees, roughly half of respondents suggest that not enough Inuit culture is being taught. Responses additionally suggest that attempts to articulate culture in schools should consider teachers’ access to cultural knowledge, the creation of effective learning spaces, and the inclusion of community Elders.     

Value of park reserves to migrating and breeding landbirds in an urban important bird area

Increasing urban development threatens not only breeding habitat for migratory landbirds but also critical stopover habitat. The purpose of this study was to investigate the relationship between landbird community composition and land cover in and surrounding urban park reserves in the Mississippi River Twin Cities Important Bird Area (IBA) in order to evaluate this area’s value during both spring migration and summer breeding seasons. This IBA includes a mosaic of residential, commercial, and park reserve land running along the Mississippi River between Minneapolis and Hastings, Minnesota. Using citizen-science data collected at 8 park reserve sites in the IBA between 2007 and 2010, we calculated species richness, diversity, and evenness for the migrating and breeding landbird community at each site and categorized species into three conservation statuses (species of greatest conservation need, native and exotic) and four migratory behavior classes (permanent residents, short-distance migrants, resident neotropical migrants, and en-route neotropical migrants). We used AIC to rank multiple regression models to evaluate how these groupings vary across sites in comparison to the land cover in and surrounding each site. We found that most measures of both the spring migration and breeding communities were negatively related to increased impervious cover. Exotic species and permanent residents were less affected by surrounding land use, while breeding season resident and transitory neotropical migrants were greatly affected. Patterns of landbird richness and density suggest that removing impervious cover within lower quality sites can improve habitat supporting migrating birds.     

Transforming the social order: The role of the university in social change

The contemporary multicultural and secular university in the United States is experiencing an array of value transitions as well as ideological contradictions. The present dilemmas and challenges confronting the academy appear to emanate from the preoccupation with new schools of explanation and interpretation and from arbitrarily defined appropriate speech. In the social sciences and in the humanities, value neutrality and traditional constructs are viewed as strategies for concealing and promoting anachronistic standards of conduct. Faculty interviewed express concern and skepticism about the direction and future of the American university in a postindustrial and a postmodernistic era. Many perceive the university as not assuming a leading role in constructive social change. This results from its absorption with political symbols and selectively perceived meanings of varied cultural interests. Some faculty sense a major transformation in the way the university and its culture are produced and arranged. The social sciences and humanities have the potential for coping with the current paradoxes.This paper is a revision of the presidential address delivered in Boston at the 1993 annual meeting of the Eastern Sociological Society.     

Moment closure based parameter inference of stochastic kinetic models

Parameter inference for stochastic kinetic models is a topic that spans many disciplines. Although it is possible to carry out exact inference using partial observations of a stochastic process, it is often computationally impractical. In this paper we use the moment closure approximation of the underlying stochastic process as a fast approximation of the likelihood. We show that this approximation is fast and accurate, even when the population numbers are small.