The etiology of low back pain in military helicopter aviators: prevention and treatment

Low back pain (LPB) is a major health problem among military rotary-wing aircrews worldwide. In order to define the etiology and propose remedies to LBP in helicopter aviators a review and critique of the literature was conducted. In-flight sitting posture and vibration generated by the aircraft were identified as high risk factors for LBP. Consequently, researchers recommended ergonomic modifications to the crew stations. The efficacy of these technical interventions has not been proven. As well, these design changes are not financially practical. Following an in depth kinesiological analysis of the physical demands of this type of flying, and preliminary experimentation, an alternative aeromedical approach focusing on the aircrew rather than the craft is presented. The authors propose a set of flight-specific exercises that might effectively deal with this problem. A thorough testing of this approach is envisioned.     

Interfering with longevity

Several recent studies have highlighted how RNA interference has advanced aging-related research in Caenorhabditis elegans. Two new genome-wide RNAi-based screens together identified more than 100 new candidate longevity genes. RNAi has also greatly facilitated the functional validation of several large-scale gene expression profiling studies. Furthermore, RNAi is flexible and can be administered at different times throughout life; this feature has been exploited to analyze the temporal requirement of genes in life-span determination.     

“Parents and Children Talk: English Language Proficiency within Immigrant Families”

This paper extends the analysis of the acquisition of destination language proficiency among immigrants by explicitly incorporating interactions among family members—mother, father and children. Single equation, bivariate, and four-equation (multivariate) probit analyses are employed. Immigrant English language skills are greater the younger the age at migration, the longer the duration of residence, the higher the level of education, and for immigrants not from Asia. Large positive correlations in the unmeasured determinants of proficiency exist between spouses, between siblings, and between parents and children, although the latter relationship is stronger for the mother. The findings imply that learning takes place within the household.     

Multilevel Mixed Linear Models for Survival Data

For the analysis of correlated survival data mixed linear models are useful alternatives to frailty models. By their use the survival times can be directly modelled, so that the interpretation of the fixed and random effects is straightforward. However, because of intractable integration involved with the use of marginal likelihood the class of models in use has been severely restricted. Such a difficulty can be avoided by using hierarchical-likelihood, which provides a statistically efficient and fast fitting algorithm for multilevel models. The proposed method is illustrated using the chronic granulomatous disease data. A simulation study is carried out to evaluate the performance.     

Elder mistreatment in urban India: a community based study

This study examined the extent and correlates of elder mistreatment among 400 community dwelling older adults aged 65 and above in Chennai, India. The prevalence rate of mistreatment was 14%. Chronic verbal abuse was the most common followed by financial abuse and the rate of physical abuse and neglect was similar. Among the mistreated, exactly half of them had experienced more than one type of mistreatment (multifaceted-mistreatment). With the exception of financial abuse, a significantly greater number of women experienced verbal and physical abuse as well as neglect compared to men. Adult children, daughters-in-law, spouses, and sons-in-law were the prominent perpetrators. The mistreated older adults were more depressed and less satisfied with life than those who were not mistreated. Logistic regression analysis revealed gender, social support, and subjective rating of physical health as significant factors associated with abuse.     

A Standardized Normal-Laplace Mixture Distribution Fitted to Symmetric Implied Volatility Smiles

This article proposes to use a standardized version of the normal-Laplace mixture distribution for the modeling of tail-fatness in an asset return distribution and for the fitting of volatility smiles implied by option prices. Despite the fact that only two free parameters are used, the proposed distribution allows arbitrarily high kurtosis and uses one shape parameter to adjust the density function within three standard deviations for any specified kurtosis. For an asset price model based on this distribution, the closed-form formulas for European option prices are derived, and subsequently the volatility smiles can be easily obtained. A regression analysis is conducted to show that the kurtosis, which is commonly used as an index of tail-fatness, is unable to explain the smiles satisfactorily under the proposed model, because the additional shape parameter also significantly accounts for the deviations revealed in smiles. The effectiveness of the proposed parsimonious model is demonstrated in the practical examples where the model is fitted to the volatility smiles implied by the NASDAQ market traded foreign exchange options.     

Stability and Change in an Urban Homeless Population

Few studies have produced the over-time observational data needed to draw valid conclusions about changes in urban homeless populations during the 1980s. One place for which such data exist is Nashville, Tennessee. An ongoing series of enumerations lends little support to Nashvillians' perception that the number of homeless in their city is growing rapidly. Enumeration results also (1) contradict expectations regarding the rise of "new homeless" groups and (2) show two types of spatial redistribution--from indoor to outdoor and core to peripheral locations--to be under way. The applicability of the enumeration methodology to other communities is discussed, as are the discrepancies between purported and measured demographic changes in homelessness.     

Empirical Analysis of Fiscal Soundness and Public Social Expenditure: A Lesson for the Future Direction of the Korean Welfare State

The aim of this paper is to investigate the relations between fiscal soundness and public social expenditure in advanced welfare states so as to reconsider the conventional wisdom that welfare expenditure aggravates national finances. Through this, I propose the clues of building the sustainable Korean welfare state. I focus on the interdependent relationship between fiscal soundness and public social expenditure based on fiscal sociology. Considering this interaction, I form two sets of simultaneous equations models and employ a special statistical method, three‐stage least squares (3SLS). The results regarding the causal relationship between fiscal soundness and public social spending indicate that, if public welfare spending is increased, fiscal health is damaged. However, as many comparative social policy researchers have pointed out, outcomes of welfare states differ from country to country according to the composition of public welfare spending. Specifically, some welfare states with priority given to social services such as vocational training or childcare services have maintained the stability of public finance. By extension, we can say that public social expenditures have a positive influence on fiscal soundness based on the composition of social expenditures. Finally, it is possible to create financially sustainable welfare states.