Likelihood Ratio Tests for Multiply Imputed Datasets: Introducing milrtest

Through the use of user-written programs, primarily mim (Carlin, Galati, and Royston, 2008), Stata users can analyze multiply imputed (MI) datasets. Among other capabilities, mim allows the user to estimate a range of regression models and to perform a multi-parameter hypothesis tests after model estimation using a Wald test. The program presented here allows the user to perform likelihood ratio tests on models using multiply imputed datasets after mim. This provides an additional means of testing nested models after estimation using MI data. The process used to perform the likelihood ratio tests is described in Meng and Rubin (1992). The test statistic is calculated based on two sets of likelihood ratio tests. The first involves calculating the likelihood ratio for the null versus alternative hypothesis in each of the m imputed datasets. The second involves calculating the likelihood for the null and alternative hypotheses in each of the m datasets, constraining the parameters to be the estimates based on combining coefficient estimates from the m datasets (i.e. the average of the parameter estimates across the m imputed datasets). The current version allows testing for a limited number of regression commands (i.e. regression, logit, and ologit), but subsequent versions may include compatibility with additional commands.

Adolescent sexual orientation and parent-child relationship quality

The literature on gay, lesbian, and bisexual (GLB) young people commonly assumes that GLB adolescents have difficult relationships with their parents, due to their parents\u27 difficulty accepting their sexual orientation. However, research tends to show that the family experiences of GLB individuals are diverse. The current research compared the family experiences of GLB and non-GLB college students, specifically, levels of conflict with parents during the respondent\u27s last year of high school, parent-child relationship quality, and physical and psychological assaults by parents during the same time frame, as well as perceived social support from parents at the time of the survey. Levels of depressive symptoms in GLB and non-GLB respondents were also compared. The possibility that parent-adolescent conflict mediated the relationship between sexual orientation, and relationship quality, perceived social support, or depression was also examined. No relationship was found between respondent\u27s sexual orientation and any of the dependent variables, nor did any of the results suggest significant mediation. The lack of significant differences between GLB respondents and non-GLB respondents in this study suggests that the family experiences of GLB young people are not necessarily a great deal worse than those of their non-GLB counterparts. These findings are consistent with recent scholarship on adolescents with same sex attractions (including those who identify as gay, lesbian, or bisexual), which tend to emphasize the diversity of identities and experiences of young people with same-sex attractions. Implications for future research, particularly the need for more realistic models of sexual orientation are discussed

Using Regular Expressions for Data Management in Stata

Regular expressions make a number of data management operations involving string variables much easier. They do this by allowing the user to search for (and copy or replace) complex patterns of characters within a string. Examples of when regular expression are useful include extracting zip codes from addresses, reformatting dates if they were entered in an inconsistent manner, and removing excess spaces from string expressions. This presentation will give the user a basic introduction to the use of regular expressions, and the Stata functions related to regular expressions, as well as examples of applications where regular expressions can be used to streamline data management.

An Unusual Antagonistic Pleiotropy in the Penna Model for Biological Ageing

We combine the Penna Model for biological aging, which is based on the mutation-accumulation theory, with a sort of antagonistic pleiotropy. We show that depending on how the pleiotropy is introduced, it is possible to reproduce both the humans mortality, which increases exponentially with age, and fruitfly mortality, which decelerates at old ages, allowing the appearance of arbitrarily old Methuselah's.Comment: 8 pages, 3 figures, to appear in Physica

Time evolution of the Partridge-Barton Model

The time evolution of the Partridge-Barton model in the presence of the pleiotropic constraint and deleterious somatic mutations is exactly solved for arbitrary fecundity in the context of a matricial formalism. Analytical expressions for the time dependence of the mean survival probabilities are derived. Using the fact that the asymptotic behavior for large time $t$ is controlled by the largest matrix eigenvalue, we obtain the steady state values for the mean survival probabilities and the Malthusian growth exponent. The mean age of the population exhibits a $t^{-1}$ power law decayment. Some Monte Carlo simulations were also performed and they corroborated our theoretical results.Comment: 10 pages, Latex, 1 postscript figure, published in Phys. Rev. E 61, 5664 (2000

O sociocultural e o intercultural no Livro Didático Édito A1 Méthode de français.

Ce travail a comme objet d’étude réfléchir sur le contenu socioculturel proposé par les auteurs de la Méthode de Français Édito A1, adoptée actuellement à l’Université Fédérale de Paraíba, auprès des étudiants en “Licenciatura”, mention FLE. Nous avons comme objectif identifier le thème ‘intercuturel’ dans les sept premières unités de cette Méthode, bien qu’il ne soit pas inscrit dans les rubriques concernées. Notre étude s’appuie notamment sur des auteurs de la Didactique des Langues Étrangères tels Rosalina Chianca, Maddalena de Carlo, Sandra Medeiros, parmi d’autres. Nous adoptons des procédures méthodologiques de caractère qualitatif et explolatoire ainsi que bibliographique. Lors de l’analyse, nous signalons le rôle de l’enseignant en tant que médiateur entre les cultures de contact, la maternelle et celle d’autrui. Après la description et l’ analyse des unités cibles, sur les thèmes et exercices proposés, nous essayons de faire des suggestions d’exercices qui, à notre avis, pourraient pousser l’apprenant à l’appréhension et à la découverte de la façon d’agir dans une autre langue-culture et, aussi, à la (re)découverte de sa propre culture, dans une analyse contrastive entre sa culture d’origine et la culture de l’‘autre’. Ce Mémoire est présenté en deux chapitres; dans le premier nous abordons les bases théoriques sur lesquelles nous nous appuyons et définissons les termes culture, identité, entre autres. Dans le deuxième, nous situons tout d’abord la Méthode employée, considérée comme un document pédagogique fabriqué, pour ensuite passer à l’analyse de notre corpus. Nous présentons enfin les résultats de la recherche réalisée et les considérations finales.Este trabalho tem por objeto de estudo refletir sobre o conteúdo sociocultural proposto pelos autores do Livro Didático Édito A1, Méthode de français (2016), utilizado no curso de Letras, com habilitação em língua francesa, na Universidade Federal da Paraíba. Nosso objetivo com essa pesquisa é identificar o tema intercultural possível de ser trabalhado nas sete primeiras unidades do Manual, apesar deste não estar explicitado no referido livro. Nosso estudo se apoia em teóricos da Didática das Línguas Estrangeiras, como Rosalina Chianca (2007), Maddalena de Carlo (1998), Sandra Medeiros (2017) e outros. Adotamos uma metodologia de caráter qualitativo exploratório e de cunho bibliográfico. Na análise, apontamos o papel do professor como mediador entre as culturas em contato, a materna e a do outro. Após a descrição e a análise dessas unidades sobre o tema e exercícios propostos no Livro Didático, fizemos sugestões de exercícios que, a nosso ver, levariam o aprendente à compreensão do agir em outra língua-cultura e à (re)descoberta de sua própria cultura, dentro de uma análise contrastiva entre a sua cultura de origem e a cultura do ‘outro’. Este Trabalho de Conclusão de Curso divide-se em dois capítulos; no primeiro, apresentamos a fundamentação teórica referente ao Intercultural e definimos os termos relativos à cultura, identidade, entre outros. No segundo, desenvolvemos a metodologia utilizada, precedendo à análise das lições objeto da pesquisa; abordamos sobre documentos pedagógicos, documentos autênticos, fabricados e didatizados, sobre o Livro Didático, descrevendo as unidades e apresentando o resultado da pesquisa realizada com apoio na fundamentação teórica. Por fim, expomos o resultado da pesquisa realizada e as nossas considerações finais

The Heumann-Hotzel model for aging revisited

Since its proposition in 1995, the Heumann-Hotzel model has remained as an obscure model of biological aging. The main arguments used against it were its apparent inability to describe populations with many age intervals and its failure to prevent a population extinction when only deleterious mutations are present. We find that with a simple and minor change in the model these difficulties can be surmounted. Our numerical simulations show a plethora of interesting features: the catastrophic senescence, the Gompertz law and that postponing the reproduction increases the survival probability, as has already been experimentally confirmed for the Drosophila fly.Comment: 11 pages, 5 figures, to be published in Phys. Rev.

Typologies of substance use and illegal behaviors: A comparison of emerging adults with histories of foster care and the general population

This study used latent class analysis (LCA) to explore whether patterns of substance use and illegal behaviors among emerging adults, 18 to 28 years old, differ depending on whether they have a prior history in foster care. The study sample, consisting of 316 respondents who had previously been in foster care and 14,301 respondents without a foster care history, was drawn from the third wave of the National Longitudinal Study of Adolescent Health. A multiple-group LCA compared former foster youth to their peers in the general population. The following four classes were identified: illegal behaviors, substance use, illegal behaviors with problematic substance use and normative behaviors. Most of the differences between the groups were not statistically significant. However, within the illegal behavior class former foster youth were less likely to have bought, sold, or held stolen goods; injured someone in a fight so that she or he needed medical attention; to have sold drugs; and to have been drunk at school or work. Additionally, in the illegal behaviors with problematic substance use class emerging adults in the general population were more likely to have used cocaine. Within the normative behaviors class, former foster youth were more likely to be current smokers, and to have injured someone in a fight so that he or she required medical attention. Within the substance use class, emerging adults from the general population were more likely to have taken place in a fight where one group fought another. Additional statistically significant, but very small differences were also identified

Humanization and reception in hospital emergency: conditioning factors under the look of nurses

Objective: to identify factors those facilitate and make difficult the practice of hosting in a humane way in an adult emergency department (PSA). Method: a descriptive and an exploratory study with qualitative approach. Data were collected using a structured questionnaire and a semistructured interview with the PSA nurses of a state hospital. Results: the analysis of the questionnaire data allowed profiling the nurses: 86% are women with an average age of 38 years old. There was identified that the physical structure and insufficient human resources are among the main factors those make difficult the practice of welcoming. Already as facilities it could identify the willingness of professionals and risk rating. Conclusion: it is necessary to pay greater attention on the part of the state authorities towards the health institution where this research was developed

Teaching Environmental Management Competencies Online: Towards “Authentic” Collaboration?

Environmental Management (EM) is taught in many Higher Education Institutions in the UK. Most this provision is studied full-time on campuses by younger adults preparing themselves for subsequent employment, but not necessarily as environmental managers, and this experience can be very different from the complexities of real-life situations. This formal academic teaching or initial professional development in EM is supported and enhanced by training and continuing professional development from the major EM Institutes in the UK orientated to a set of technical and transferable skills or competencies expected of professional practitioners. In both cases there can be a tendency to focus on the more tractable, technical aspects of EM which are important, but may prove insufficient for EM in practice. What is also necessary, although often excluded, is an appreciation of, and capacity to deal with, the messiness and unpredictability of real world EM situations involving many different actors and stakeholders with multiple perspectives and operating to various agendas. Building on the work of Reeves, Herrington and Oliver (2002), we argue that EM modules need to include the opportunity to work towards the practice of authentic activities with group collaboration as a key pursuit. This paper reports on a qualitative study of our experiences with a selected sample taken from two on-line undergraduate EM modules for second and third year students (referred to respectively as Modules A and B) at the Open University, UK where online collaboration was a key component. Our tentative findings indicate that on-line collaboration is difficult to ensure as a uniform experience and that lack of uniformity reduces its value as an authentic experience. Whilst it can provide useful additional skills for EM practitioners the experience is uneven in the student body and often requires more time and support to engage with than originally planned