Assembly and Maturation of a T = 4 Quasi-Equivalent Virus Is Guided by Electrostatic and Mechanical Forces

Nudaurelia capensis ω virus (NωV) is a eukaryotic RNA virus that is well suited for the study of virus maturation. The virus initially assembles at pH 7.6 into a marginally stable 480-Å procapsid formed by 240 copies of a single type of protein subunit. During maturation, which occurs during apoptosis at pH 5.0, electrostatic forces guide subunit trajectories into a robust 410-Å virion that is buttressed by subunit associated molecular switches. We discuss the competing factors in the virus capsid of requiring near-reversible interactions during initial assembly to avoid kinetic traps, while requiring robust stability to survive in the extra-cellular environment. In addition, viruses have a variety of mechanisms to deliver the genome, which must remain off while still inside the infected cell, yet turn on under the proper conditions of infection. We conclude that maturation is the process that provides a solution to these conflicting requirements through a program that is encoded in the procapsid and that leads to stability and infectivity.     

Parental influence on academic achievement among the primary school students in Trinidad

The present study examined the level of parental influence on academic achievement in primary school students who prepare for the National-level test at standard five (grade 6), Secondary Entrance Examinations in Trinidad. A sample of 128 students studying standard five from primary schools was randomly selected. The data were analysed using SPSS. The findings of the study revealed that regardless of parental educational status, all parents try to influence their children to study well. The results showed that there was a positive influence on academic achievement in students. The findings of the study were discussed and implications for future research have been proposed. The study highlighted several recommendations to mitigate the effects of academic anxiety and suggested some measures to be taken by the parents, teachers, peers and social workers to successfully navigate this phase of life marked by transition and search for identity.     

Extracurricular School-Based Social Change Communication Program Associated with Reduced HIV Infection Among Young Women in South Africa

ABSTRACT

Background: Young women in South Africa are at high risk for HIV, particularly after they leave school. There are few studies examining the long-term impact of school-based public health interventions aimed at protecting young women from HIV. We undertook a long-term evaluation of an extracurricular, school-based HIV prevention program, that leveraged off a mass media television series in South Africa.

Methods: We recruited 403 women aged 18–28 years. One hundred and seventy were members of Soul Buddyz Clubs (SBCs) between 2004 and 2008 and 233 were matched controls from the same communities as the ex-Buddyz. Face-to-face interviews were conducted and HIV testing undertaken. Analysis was restricted to 320 women who had ever had sex (136 ex-Buddyz and 184 controls). Multivariate analysis in Stata v14 was conducted.

Findings: 16.4% of women tested HIV positive. Ex-Buddyz were more likely to be HIV negative than controls (AOR 2.92, 95% CI 1.26–6.77, p = 0.013). Ex-Buddyz were more likely to have only had one sexual partner in the past year (AOR 2.14, 95% CI 1.17–3.89, p = 0.013) and 1.7 times more likely to have used a condom at first sex (95% CI 0.99–2.92, p = 0.053).

Interpretation: Participation in an SBC is associated with a decrease in young women’s HIV risk and suggests an impact on some key risky sexual behaviors. School-based prevention programs that leverage off of other media platforms demonstrate a positive outcome on health status.     

Day-to-Day Variation in Food Intake and Energy Expenditure in Healthy Women: The Dietitian II Study

Because day-to-day food intake varies, we tested the hypothesis that ad libitum food intake and energy expenditure show corrective responses over periods of 1 to 10 days in healthy young women. Food intake and accelerometry measurements were collected daily for 17 days in 15 young women. Total daily energy expenditure (TDEE) using doubly labeled water was also measured. The daily deviations in macronutrient and energy intake and energy expenditure from the average values were compared with the deviations observed over succeeding intervals to estimate the corrective responses. The intraindividual coefficients of variation for energy intake averaged ±25%, ranging from 16% to 34%. TDEE had a coefficient of variation of 8.3%, and accelerometry had a coefficient of variation of 8.4% (range=4.6% to 16.4%). Energy expenditure by accelerometry (2,087±191 kcal/day) was not significantly different from TDEE (2,128±177 kcal/day), but reported daily energy intake was 20.4% lower (1,693±276 kcal/day). There were significant corrective responses in energy from fat and total energy intake. This occurred from Days 3 to 6, with a peak at Day 5 that disappeared when data were randomized within each subject. Human beings show corrective responses to deviations from average energy and macronutrient intakes with a lag time of 3 to 6 days, but not 1 to 2 days. These corrective responses are likely to play a role in bringing about weight stability.