Psychological interventions to prevent HIV infection are urgently needed: New priorities for behavioral research in the second decade of AIDS.

Behavior change remains the only means for primary prevention of HIV disease. Psychology should take a leading role in efforts to curtail the epidemic, but has not contributed to HIV prevention at a level proportionate to the urgency of the crisis. The authors propose an updated agenda for behavioral research on AIDS-HIV prevention implementing accelerated community trials of promising behavior change models, conducting trials of community-level interventions on a large scale and focused on populations most vulnerable to HIV infections, establishing partnerships between HIV research and community service organizations, integrating efforts from across psychology disciplines to advance and refine HIV prevention interventions, and mobilizing interdisciplinary HIV prevention resources and communication mechanisms to rapidly translate research findings to community and public policy arenas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences between completers and early dropouts from 2 HIV intervention trials: a health belief approach to understanding prevention program attrition

OBJECTIVES: The purpose of this study was to identify factors predicting program attrition among participants in human immunodeficiency virus (HIV) risk reduction trials. METHODS: Participants were gay/bisexual men and severely mentally ill adults recruited to take part in HIV risk reduction small-group interventions. Program completers were compared with participants who were assessed at baseline but then failed to attend any sessions. The health belief model provided a framework for selection of possible predictors of program attrition. RESULTS: Younger age was associated with early dropout in both samples. Other predictors among gay/bisexual men included involvement in an exclusive sexual relationship, minority ethnicity, injection drug use, and higher perceived severity of AIDS. Severely mentally ill dropouts were less knowledgeable about safer sex methods and more likely to hold positive outcome expectancies for condom use. CONCLUSIONS: Evaluation of intervention effectiveness among vulnerable population segments is threatened if there is selective attrition. Better methods are needed to attract and maintain participation in HIV prevention programs. Alternatively, wider application of "intention to treat" analysis of intervention outcomes is recommended to minimize selection bias due to program dropout.     

Advanced methods for container stacking

In this paper, we study stacking policies for containers at an automated container terminal. It is motivated by the increasing pressure on terminal performance put forward by the increase in the size of container ships. We consider several variants of category stacking, where containers can be exchanged during the loading process. The categories facilitate both stacking and online optimization of stowage. We also consider workload variations for the stacking cranes.     

An Evolutionary Model of Price Competition Among Spatially Distributed Firms

Various studies have shown the emergence of cooperative behavior in evolutionary models with repeated local interaction among spatially distributed agents. We investigate to what extent these findings generalize to evolutionary models of price competition among spatially distributed firms. We consider both one- and two-dimensional models, and we vary the amount of information firms have about competitors in their neighborhood. Our computer simulations show that the emergence of cooperative behavior depends strongly on the amount of information available to firms. Firms tend to behave most cooperatively if they have only a very limited amount of information about their competitors. We provide an intuitive explanation for this phenomenon. Our simulations further indicate that three other factors in our models, namely the accuracy of firms’ information, the probability of experimentation, and the spatial distribution of consumers, have little effect on the emergence of cooperative behavior.     

Preparation,morphology, and deformation behavior of polyoxypropylene-co-nylon 6 thermoplastic elastomers

Segmented block copolymers consisting of nylon 6 and polyoxypropylene blocks were prepared and characterized. Pronounced phase separation in the solid phase was deduced from differential calorimetry and from small-angle X-ray scattering, as well as from dynamic mechanical measurements. The morphology (from X-ray diffraction) and anisotropy in mechanical properties strongly suggest phase separation in the melt (which is optically clear). Elastomerlike properties are described and discussed.     

The role of European forests in the global carbon cycle-A review

The first part of this paper presents an overview of national forest carbon balance studies that have been carried out in Europe. Based on these national assessments, an estimate is made of the present role of European forests in the global carbon cycle. Differences in the methodologies applied are discussed. At present, 15 European countries have assessed a national forest and/or forest sector carbon balance. Together, these studies cover 104 million ha and present the average situation in the mid-1980s. Most of the studies have used a static methodology to convert forest inventory data into carbon. Extrapolating those studies to the total forest area of Europe (149 million ha) (excluding the FSU), yields a whole tree carbon sink of 101.3 Tg C y⁻¹ (9.5% of the European emissions) and a whole tree carbon stock of 7929 Tg C. Although in general the applied methodologies are comparable, they differ considerably in the way net fluxes are assessed and in the applied conversion coefficients. The role of forest fires in the European forest C balance might be larger than generally expected. A disadvantage of the static methodologies used is that they often regard only the forest ecosystem part of the carbon cycle which may result in misleading results concerning the role of the total forest sector; another disadvantage is that results are only valid for the year(s) on which the data are based. The second part of the paper discusses a methodology that could be applied to all national forests and forest sectors yielding more consistent results. The possibilities of using a large-scale forestry scenario model for a study on the present and future European forest sector carbon balance are presented.     

Implications of HIV treatment advances for behavioral research on AIDS: Protease inhibitors and new challenges in HIV secondary prevention.

Protease inhibitor combination therapies can reduce HIV viral load, improve immune system functioning, and decrease mortality from AIDS. These medical developments raise a host of critical new issues for behavioral research on HIV/AIDS. This article reviews developments in HIV combination therapy regimens and behavioral factors involved in these regimens and focuses on four key behavioral research areas: (a) the development of interventions to promote treatment adherence, (b) psychological coping with HIV/AIDS in the context of new treatments for the disease, (c) the possible influence of treatment on continued risk behavior, and (d) behavioral research in HIV prevention and care policy areas. Advances in HIV medical care have created important new opportunities for health psychologists to contribute to the well-being of persons with HIV/AIDS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cell Fuelling and Metabolic Energy Conservation in Synthetic Cells

We are aiming for a blue print for synthesizing (moderately complex) subcellular systems from molecular components and ultimately for constructing life. However, without comprehensive instructions and design principles, we rely on simple reaction routes to operate the essential functions of life. The first forms of synthetic life will not make every building block for polymers de novo according to complex pathways, rather they will be fed with amino acids, fatty acids and nucleotides. Controlled energy supply is crucial for any synthetic cell, no matter how complex. Herein, we describe the simplest pathways for the efficient generation of ATP and electrochemical ion gradients. We have estimated the demand for ATP by polymer synthesis and maintenance processes in small cell-like systems, and we describe circuits to control the need for ATP. We also present fluorescence-based sensors for pH, ionic strength, excluded volume, ATP/ADP, and viscosity, which allow the major physicochemical conditions inside cells to be monitored and tuned.     

A Defined and Flexible Pocket Explains Aryl Substrate Promiscuity of the Cahuitamycin Starter Unit–Activating Enzyme CahJ

Cahuitamycins are biofilm inhibitors assembled by a convergent nonribosomal peptide synthetase pathway. Previous genetic analysis indicated that a discrete enzyme, CahJ, serves as a gatekeeper for cahuitamycin structural diversification. Here, the CahJ protein was probed structurally and functionally to guide the formation of new analogues by mutasynthetic studies. This analysis enabled the in vivo production of a new cahuitamycin congener through targeted precursor incorporation.