Both Virus and Host Components Are Important for the Manifestation of a Nef- Phenotype in HIV-1 and HIV-2

AbstractWhile it has been demonstrated that the Nef protein of simian immunodeficiency virus is obligatory for the establishment of high viral loads and the development of simian AIDS in rhesus macaques, demonstrating a critical role for the human immunodeficiency virus (HIV) Nef protein in tissue culture has been elusive. Data have been contradictory as to whether Nef has a negative or positive influence on in vitro virus replication. In an attempt to define a role for Nef during virus propagation in tissue culture and to obtain virus-host systems that could distinguish between the Nef mutant and wildtype viruses, we have introduced mutations into the nef genes of infectious molecular clones of three HIV-1 strains and two isolates of the HIV-2ROD strain and have investigated the capacity of viruses derived from them to infect a number of CD4-positive T-cell lines and peripheral blood mononuclear cells (PBMC). Mutating the nef gene of all viruses had a modest negative effect on virus production in activated PBMC. In some T-cell lines with some viruses, the effects were severe, and little or no Nef mutant virus could be detected. In other cell lines, the result of mutating the nef gene either had no effect or had a slight negative effect on the replication kinetics. Therefore, whether the consequences of loss of Nef activity can be demonstrated in vitro depends on both the particular virus and the host cell used, suggesting that Nef is exerting its activity on some cellular pathway. In addition, we describe the construction and properties of hitherto unreported infectious molecular clones of the ROD strain of HIV-2

Personal, social, and environmental factors associated with lifejacket wear in adults and children: A systematic literature review

Objective: Drowning claims 7% of the global burden of injury-related deaths. Lifejackets are routinely recommended as a drowning prevention strategy; however, a review of related factors regarding lifejacket wear has not previously been investigated. Methods: This systematic review examined literature published from inception to December 2016 in English and German languages. The personal, social, and environmental factors associated with lifejacket wear among adults and children were investigated, a quantitative evaluation of the results undertaken, and gaps in the literature identified. Results: Twenty studies, with sample sizes of studies ranging between 20 and 482,331, were identified. Fifty-five percent were cross-sectional studies. All studies were scored IV or V on the Australian National Health and Medical Research Council (NHMRC) grading system indicating mostly descriptive and cross-sectional levels of evidence. Factors associated with increased wear included age (mostly children), gender (mostly female), boat type (non-motorised), boat size (small boats), role modelling (children influenced by adult lifejacket wear), and activity (water-skiing, fishing). Factors not associated or inconsistent with lifejacket wear included education, household income, ethnicity, boating ability, confidence in lifejackets, waterway type, and weather and water conditions. Factors associated with reduced lifejacket wear included adults, males, discomfort, cost and accessibility, consumption of alcohol, and swimming ability. Three studies evaluated the impact of interventions. Conclusion: This review identified factors associated with both increased and decreased lifejacket wear. Future research should address the motivational factors associated with individuals’ decisions to wear or not wear lifejackets. This, combined with further research on the evaluation of interventions designed to increase lifejacket wear, will enhance the evidence base to support future drowning prevention interventions

Anomalous Behavior of Ru for Catalytic Oxidation: A Theoretical Study of the Catalytic Reaction CO + 1/2 O_2 --> CO_2

Recent experiments revealed an anomalous dependence of carbon monoxide oxidation at Ru(0001) on oxygen pressure and a particularly high reaction rate. Below we report density functional theory calculations of the energetics and reaction pathways of the speculated mechanism. We will show that the exceptionally high rate is actuated by a weakly but nevertheless well bound (1x1) oxygen adsorbate layer. Furthermore it is found that reactions via scattering of gas-phase CO at the oxygen covered surface may play an important role. Our analysis reveals, however, that reactions via adsorbed CO molecules (the so-called Langmuir-Hinshelwood mechanism) dominate.Comment: 5 pages, 4 figures, Phys. Rev. Letters, Feb. 1997, in prin

Drivers’ experiences during floods: Investigating the psychological influences underpinning decisions to avoid driving through floodwater

A major risk factor for many flood-related drownings is driving through floodwater. We aimed to understand Australian drivers’ experiences and beliefs with respect to avoid driving through floodwater using the theory of planned behaviour as a framework. Study 1 (N = 23) used a qualitative design to gain an in-depth understanding of individuals’ experiences with driving through floodwater. Study 2 (N = 157) used a survey-based design to identify the factors related to this behaviour including knowledge, beliefs, and social-cognitive factors. In Study 1, drivers identified a range of advantages (e.g., didn't damage car), disadvantages (e.g., inconvenient, but not so terrible), barriers (e.g., urgency to reach destination), and facilitators (e.g., making plans and using existing plans) to avoiding driving through floodwater. Normative factors were also important influences on drivers’ decisions including normative expectancy, approval of significant others, and a moral obligation for the safety of others. In Study 2, participants were able to recall information about driving through floodwater (e.g., dangerous/risky) and its meaning (e.g., body of water over road). A range of experiences were described for avoiding driving through floodwater (e.g., took an alternative route). Across the studies, a range of behavioural, normative, and control beliefs were elicited. Finally, sex (women more likely), attitude, subjective norm, and perceived behavioural control significantly predicted intentions to avoid driving through floodwater, with the model explaining 55% of the variance. These findings can inform intervention targets and development of prevention strategies for effective behaviour change, saving lives otherwise lost to Australian waterways in flood