Understanding the sex ratio in India: A simulation approach

The highly masculine sex ratio in India has increased substantially in the twentieth century, in contrast to most other countries in the world. Competing arguments alternatively posit under-enumeration, highly masculine sex ratios at birth, or excess female mortality throughout the life course as the factors underlying the level of the overall sex ratio; these arguments have not been resolved. Based on population projections that simulate population dynamics, our findings show that small differences in mortality at young ages, persisting over a long period, as well as a sex ratio at birth of 106 males per 100 females, result in a highly masculine population sex ratio.     

Welfare,work, and changes in mothers’ living arrangements in low-income families

Data from a two-wave survey of low-income families in Boston, Chicago, and San Antonio are used to replicate recent reports of a modest increase in the number of low-income children living in two-adult families and to analyze the increase. We find that most of the increase occurred through the addition of a man other than the biological father to the household and that more of it occurred through cohabitation than through marriage. Moreover, across the two waves, cohabiting and marital unions were highly unstable. We review research on stepfamilies and on instability in childrens living arrangements, and we conclude that the kinds of two-adult families being formed in these low-income central-city neighborhoods may not benefit children as much as policy-makers hope. In addition, we investigate the associations between marital and cohabiting transitions, on the one hand, and transitions into and out of Temporary Assistance to Needy Families (TANF) receipt, employment, and Earned Income Tax Credit (EITC) usage between the two waves on the other. We find that marital transitions are related to TANF and employment transitions but that cohabiting transitions are not. We suggest that low-income mothers may view marriage as more of an economic partnership than cohabitation and may expect more of an economic contribution from a husband than from a cohabiting partner.     

Family Context and Spanish‐Language Use: A Study of Latino Children in the United States*

Objective. This article seeks to explain why Latino children maintain some knowledge of their native language even though past research has consistently supported the view that non‐English‐language use rarely lasts past the third generation. I argue that family context, in addition to assimilation characteristics, plays an important role in determining their language situation. Method. I use both logistic regression and tobit regression, as well as data from the 1988 National Education Longitudinal Study, to examine the use and proficiency of Spanish among Latino children. Results. The results demonstrate that language and family context strongly influence Spanish usage and proficiency for Latino children, regardless of generational status. Conclusions. These findings reveal a relationship between assimilation, family, and language that can have important implications for the future academic and economic success of Latino children.     

The Choice Revolution: Privatization of Swedish Welfare Services in the 1990s

During the 1990s, the Swedish welfare state was declared by some to be in a “crisis”, due to both financial strain and loss of political support. Others have argued that the spending cuts and reforms undertaken during this period did slow down the previous increase in social spending, but left the system basically intact. The main argument put forward in this article is that the Swedish welfare state has been and is still undergoing a transforming process whereby it risks losing one of its main characteristics, namely the belief in and institutional support for social egalitarianism. During the 1990s, the public welfare service sector opened up to competing private actors. As a result, the share of private provision grew, both within the health‐care and primary education systems as well as within social service provision. This resulted in a socially segregating dynamic, prompted by the introduction of “consumer choice”. As will be shown in the article, the gradual privatization and market‐orientation of the welfare services undermine previous Swedish notions of a “people's home”, where uniform, high‐quality services are provided by the state to all citizens, regardless of income, social background or cultural orientation.     

Residuals for log-Burr XII regression models in survival analysis

In this paper, we compare three residuals to assess departures from the error assumptions as well as to detect outlying observations in log-Burr XII regression models with censored observations. These residuals can also be used for the log-logistic regression model, which is a special case of the log-Burr XII regression model. For different parameter settings, sample sizes and censoring percentages, various simulation studies are performed and the empirical distribution of each residual is displayed and compared with the standard normal distribution. These studies suggest that the residual analysis usually performed in normal linear regression models can be straightforwardly extended to the modified martingale-type residual in log-Burr XII regression models with censored data.     

Task analysis of healthcare delivery: A case study

Human error and medical error are highly known as contributors to patient safety [Institute of Medicine (IOM), November 1999. To err is human: building a safer health system. Available at: http://www.nap.edu/openbook/0309068371/html/11.html (accessed 05.03.07); Institute of Medicine (IOM), March 2001. Crossing the quality chasm: a new health system for the 21st century. Available at: http://www.nap.edu/openbook/0309072808/html (accessed 05.03.07); Joint Commission on Accreditation of Healthcare Organizations (JCAHO), 2007. Failure mode, effect, and criticality analysis (FMECA) worksheet. Available at: http://www.jcaho.org (accessed 24.06.07)]. A study was performed to identify the process flow affiliated with elder patients transitioning through different continuums of emergency and non-emergency care. This research is part of a larger research effort to develop and implement a web-based healthcare system that enables hospitals and nursing homes to share patient information resulting in increased knowledge of a patient's medical history, decreased errors and enhanced patient safety. Future research efforts for this study are also presented.     

Residents’ preferred policy actions for shrinking cities

Cities facing a continued and prolonged process of population decline require innovative urban regeneration policies complementary to growth-oriented policies. Losing inhabitants involves a decrease in economic activity and social capital. Therefore citizens’ participation in defining policies to cope with population decline is being increasingly advocated. This research focused on four shrinking cities of Portugal to capture residents’ knowledge about the strengths and weaknesses of their city of residence as well as the policies and actions they prioritized for dealing with the population decline. The responses from 701 questionnaires show that economic revival policies as well as safety and accessibility policies were preferred. To put these policies into action, the recovery of industrial activity, the creation of business incubators, an improvement in law enforcement, and public lighting were ranked as top priorities. Rank-ordered logistic regression models were used to understand which variables influenced the residents’ rankings. We found that the evaluation of the city's characteristics impact the ranking of the policies and actions. Hence, residents show a high level of coherence when engaging in a discussion at the level of policy-making. Therefore, the findings support residents’ involvement in decision-making processes regarding urban regeneration in shrinking cities.     

Neuropathology in Alzheimer's disease: awaking from a hundred-year-old dream

For one hundred years after Alois Alzheimer's first report of Alzheimer's disease (AD) in 1906, the pathological hallmarks of the disease, senile plaques and neurofibrillary tangles (NFTs), have been attractive targets for researchers. Therefore, not surprisingly, efforts to understand disease mechanisms have concentrated on the cell biology of amyloid-beta (Abeta) deposition as senile plaques or on the phosphorylation and aggregation of tau as NFTs. However, it now appears that this focus on pathology as a central contributor to disease may be misguided. Indeed, neurons associated with Abeta and NFTs in AD brain show a decrease in oxidative damage relative to those in vulnerable but morphologically intact areas of the brain, suggesting that neurodegenerative lesions are compensatory phenomena, and thus manifestations of cellular adaptation. That Abeta and tau accumulations indicate an age-related physiological reaction to chronic stress calls into question the rationale of current therapeutic efforts targeted toward lesion removal. Moreover, if this concept holds true for pathology in other neurodegenerative diseases, we may need to restructure our thinking and undergo a paradigm shift before substantial progress can be made in therapeutic intervention.     

On estimation and influence diagnostics for log-Birnbaum–Saunders Student-t regression models: Full Bayesian analysis

The purpose of this paper is to develop a Bayesian approach for log-Birnbaum–Saunders Student-t regression models under right-censored survival data. Markov chain Monte Carlo (MCMC) methods are used to develop a Bayesian procedure for the considered model. In order to attenuate the influence of the outlying observations on the parameter estimates, we present in this paper Birnbaum–Saunders models in which a Student-t distribution is assumed to explain the cumulative damage. Also, some discussions on the model selection to compare the fitted models are given and case deletion influence diagnostics are developed for the joint posterior distribution based on the Kullback–Leibler divergence. The developed procedures are illustrated with a real data set.     

Sample size estimation for non-inferiority trials of time-to-event data

We consider the problem of sample size calculation for non-inferiority based on the hazard ratio in time-to-event trials where overall study duration is fixed and subject enrollment is staggered with variable follow-up. An adaptation of previously developed formulae for the superiority framework is presented that specifically allows for effect reversal under the non-inferiority setting, and its consequent effect on variance. Empirical performance is assessed through a small simulation study, and an example based on an ongoing trial is presented. The formulae are straightforward to program and may prove a useful tool in planning trials of this type.