Finding a Length-Constrained Maximum-Density Path in a Tree

Let T = (V,E,w) be an undirected and weighted tree with node set V and edge set E, where w(e) is an edge weight function for e E. The density of a path, say e₁, e₂,..., e_k, is defined as ^k_{i = 1} w(e_i)/k. The length of a path is the number of its edges. Given a tree with n edges and a lower bound L where 1 L n, this paper presents two efficient algorithms for finding a maximum-density path of length at least L in O(nL) time. One of them is further modified to solve some special cases such as full m-ary trees in O(n) time.     

Religious Involvement and Physical Functioning among Older Mexican Americans

BACKGROUND AND PURPOSE: Examine the association between attendance at religious services and incidence of ADL disability over a period of seven years among older Mexican Americans 65 years and older. METHODS: Using data from the Hispanic Established Population for the Epidemiological Study of the Elderly (H-EPESE), logistic generalized estimation equation (GEE) models were used to analyze the contribution of attendance at religious services to the differences in incidence of ADL disability over seven years, controlling for demographics, medical conditions, and physical mobility. RESULTS: Frequent attendees at religious services had 30% lower odds of developing ADL disability over seven years compared to the non-regular attendance group. The odds were reduced to 23%, but remained significant when physical and mental health were controlled. CONCLUSIONS: In this older Mexican American population, regular attendees at religious services were less likely to develop ADL disability over a period of seven years compared to those who attended services less often.     

The multiple sequence sets: problem and heuristic algorithms

“Sequence set” is a mathematical model used in many applications such as biological sequences analysis and text processing. However, “single” sequence set model is not appropriate for the rapidly increasing problem size. For example, very large genome sequences should be separated and processed chunk by chunk. For these applications, the underlying mathematical model is “Multiple Sequence Sets” (MSS). To process multiple sequence sets, sequences are distributed to different sets and then sequences on each set are processed in parallel. Deriving effective algorithm for MSS processing is challenging.     

College Students Define Binge Drinking and Estimate Its Prevalence: Results of a National Survey

Abstract

Data from the 1999 College Alcohol Study were used to examine how students define the term binge drinking, to determine how much binge drinking the students think exists on their campuses, and to analyze how students' estimates compare with aggregated self-reports of student drinking. The findings indicate that the median of the students' definitions of binge drinking is 6 drinks in a row for men and 5 for women, 1 drink higher than the definition used by researchers. Students' definitions of binge drinking vary with their own drinking levels, suggesting that dissenting views of the research definition may represent voices of the heaviest drinkers. At the median, students estimated that 35% of all students were binge drinkers. Half (47%) of the students underestimated the binge drinking rate at their school, 29% over-estimated it, and 13% were accurate. Although programs designed to reduce the frequency or prevalence of binge drinking by emphasizing healthier norms would be most useful in addressing binge drinkers who overestimate drinking norms, this group includes only 13% of college students.     

College Binge Drinking in the 1990s: A Continuing Problem Results of the Harvard School of Public Health 1999 College Alcohol Study

Abstract

In 1999, the Harvard School of Public Health College Alcohol Study resurveyed colleges that participated in the 1993 and 1997 surveys. Responses to mail questionnaires from more than 14 000 students at 119 nationally representative 4-year colleges in 39 states were compared with responses received in 1997 and 1993. Two of 5 students (44%) were binge drinkers in 1999, the same rate as in 1993. However, both abstention and frequent binge-drinking rates increased significantly. In 1999, 19% were abstainers, and 23% were frequent binge drinkers. As before, binge drinkers, and particularly frequent binge drinkers, were more likely than other students to experience alcohol-related problems. At colleges with high binge-drinking rates, students who did not binge drink continued to be at higher risk of encountering the secondhand effects of others' heavy drinking. The continuing high level of binge drinking is discussed in the context of the heightened attention and increased actions at colleges. Although it may take more time for interventions to take effect, the actions college health providers have undertaken thus far may not be a sufficient response.     

Sister–Sister Incest: Data from an Anonymous Computerized Survey

Retrospective data were entered anonymously by 1,521 adult women using a computer-assisted self-interview. Thirty-one participants were victims of sister–sister incest, 40 were victims of brother–sister incest, 19 were victims of father–daughter incest, 8 were victims of sexual abuse by an adult female (including one mother), and 232 were victims of sexual abuse by an adult male other than their father before reaching 18 years of age. The rest (1,203) served as controls. The victims of sister–sister incest had significantly more problematic outcomes than controls on many measures as adults. Victims of sister–sister incest were more depressed and more likely than controls to be distant from the perpetrator-sister and to have traded sex for money, experienced an unplanned pregnancy, engaged in four different types of masturbation, and engaged in 13 different same-sex behaviors. Our findings were consistent with other reports of early eroticization and persistent hypereroticization of incest victims.     

多元线性模型共同均值矩阵参数的线性估计的可容许性特征

讨论了一般多元线性模型共同均值矩阵参数的线性组合函数SXO的线性估计在一切估计类中的A－可容许性问题，并得到了它的充要条件。