A DIRICHLET PROCESS MIXTURE OF HIDDEN MARKOV MODELS FOR PROTEIN STRUCTURE PREDICTION

By providing new insights into the distribution of a protein's torsion angles, recent statistical models for this data have pointed the way to more efficient methods for protein structure prediction. Most current approaches have concentrated on bivariate models at a single sequence position. There is, however, considerable value in simultaneously modeling angle pairs at multiple sequence positions in a protein. One area of application for such models is in structure prediction for the highly variable loop and turn regions. Such modeling is difficult due to the fact that the number of known protein structures available to estimate these torsion angle distributions is typically small. Furthermore, the data is "sparse" in that not all proteins have angle pairs at each sequence position. We propose a new semiparametric model for the joint distributions of angle pairs at multiple sequence positions. Our model accommodates sparse data by leveraging known information about the behavior of protein secondary structure. We demonstrate our technique by predicting the torsion angles in a loop from the globin fold family. Our results show that a template-based approach can now be successfully extended to modeling the notoriously difficult loop and turn regions.     

Psychological Distress and Size of Place: The Epidemiology of Rural Economic Stress

Abstract Size-of-place differences in the distribution of psychological distress are examined. Residents in communities of less than 2,500 population are predicted to have higher levels of distress than persons living in farm, rural nonfarm, and larger places. A research instrument was designed to measure economic stress, personal resources, and psychological distress in a survey of adult householders in a midwestern state. Results support the interpretation that long-term demographic and social trends had a negative impact upon the psychological well-being of residents in rural communities. Residents of these rural communities have higher levels of distress than persons living on farms or in towns of up to 9,999 population. Levels of psychological distress are not significantly different between persons living in rural communities and those in small cities or urban centers.     

Trends in return migration to the south

Demography - The rate of return migration to the South rose by nearly 19 percent between the late 1950’s and the late 1960’s and was an important factor in changing the South’s...     

Gender-related differences in physical performance among seniors

This study examined gender differences in balance, gait, and muscle performance in seniors and identified gender-specific factors contributing to physical performance. Forty (20 men, 20 women) healthy, community-dwelling seniors (74.5 +/- 5.3 years) participated. Limits of stability, gait speed, lower limb flexor and extensor isokinetic concentric peak torques, self-reported activity level, and balance confidence were measured. No gender differences were detected in gait speed, limits of stability when normalized to height, activity level, or balance confidence (p = .188). Women were weaker than men (p = .007), even after controlling for weight and body-mass index, suggesting that other gender-related factors contribute to strength. Gender accounted for 18-46% of the variance in strength and served as a modifier of the relationship between activity level and strength in some muscle groups. The primary factors relating to gender-specific strength was activity level in men and body weight in women.     

Leader motive profiles in eight types of organizations

McClelland (1975) introduced the leadership motive pattern (LMP), a motivational configuration found to contribute to leader performance in traditional bureaucratic organizations. Using McClelland's general theory of motivation and Miner's work on organizational sociology, we refine McClelland's original leadership motive pattern, develop leader motive profiles for eight classical and new types of organizations, and advance eight testable propositions for empirical verification. We conclude with implications for future research and practice.     

Adult resilience among maltreated children: A prospective investigation of main effect and mediating models

Studies examining resilience to child maltreatment reveal that maltreatment victims can achieve adaptive functioning in several areas of development; however, few of these individuals persistently demonstrate resilience across multiple domains. The majority of these investigations define adjustment with a limited number of outcomes measured proximal in time to the maltreatment experience. In contrast, this study measured adjustment across a diverse set of domains during early adulthood (ages 16–24), a number of years after the occurrence of childhood maltreatment (ages 0–11).     

A rising tide: Measuring the economic effects of broadband use across California

This research estimates the economic effects of broadband use across 39 California counties between 2001 and 2006. Broadband usage data are obtained from household surveys that identify how individuals access the Internet: through dial-up or broadband, where broadband is defined as Internet access through cable modem or digital subscriber line (DSL). The surveys were conducted in California counties twice each year from 2001 to 2006. Estimates from panel regression analysis demonstrate that increased broadband use within California has had a positive and significant effect on growth in employment and total payroll.