Consequences of HIV for children: avoidable or inevitable?

The HIV/AIDS epidemic has many serious consequences for children. These consequences are, however, rarely inevitable. Families can provide a protective barrier that deflects blows, or minimises their impact and a supportive nurturing environment that can help children recover from harm. If strong enough, and with sufficient access to quality services and support from communities, families can reduce the impacts of HIV/AIDS on children to negligible levels in most areas of impact. It is apparent that the impacts felt by children are not simply unfortunate, inevitable consequences of this epidemic. A strong and supported family with good access to quality services can deflect almost all of the impact. It is as a result of an interaction of the context of poverty, which weakens families, and a failure to adequately respond, that impacts are felt by children

Second-generation bio-based plastics are becoming a reality - Non-renewable energy and greenhouse gas (GHG) balance of succinic acid-based plastic end products made from lignocellulosic biomass:NREU and GHG balance of succinic acid-based PBS products made from lignocellulosic biomass

Bio-based and bio-degradable plastics such as polybutylene succinate (PBS) have the potential to become sustainable alternatives to petrochemical-based plastics. Polybutylene succinate can be produced from bio-based succinic acid and 1,4-butanediol using first-generation (1G) or second-generation (2G) sugars. A cradle-to-grave environmental assessment was performed for PBS products in Europe to investigate the non-renewable energy use (NREU) and greenhouse gas (GHG) impacts. The products investigated are single-use trays and agricultural film, with incineration, industrial composting and degradation on agricultural land as end-of-life scenarios. Both end products manufactured from fully bio-based PBS and from partly bio-based PBS (made from bio-based succinic acid and fossil fuel-based 1,4 butanediol) were analysed. We examine corn (1G) as well as corn stover, wheat straw, miscanthus and hardwood as 2G feedstocks. For the cradle-to-grave system, 1G fully bio-based PBS plastic products were found to have environmental impacts comparable with their petrochemical incumbents, while 2G fully bio-based PBS plastic products allow to reduce NREU and GHG by around one third under the condition of avoidance of concentration of sugars and energy integration of the pretreatment process with monomer production. Without energy integration and with concentration of sugars (i.e., separate production), the impacts of 2G fully bio-based PBS products are approximately 15–20% lower than those of 1G fully bio-based PBS products. The environmental analysis of PBS products supports the value proposition related to PBS products while also pointing out areas requiring further research and development

Distillation of photon entanglement using a plasmonic metamaterial

Plasmonics is a rapidly emerging platform for quantum state engineering with the potential for building ultra-compact and hybrid optoelectronic devices. Recent experiments have shown that despite the presence of decoherence and loss, photon statistics and entanglement can be preserved in single plasmonic systems. This preserving ability should carry over to plasmonic metamaterials, whose properties are the result of many individual plasmonic systems acting collectively, and can be used to engineer optical states of light. Here, we report an experimental demonstration of quantum state filtering, also known as entanglement distillation, using a metamaterial. We show that the metamaterial can be used to distill highly entangled states from less entangled states. As the metamaterial can be integrated with other optical components this work opens up the intriguing possibility of incorporating plasmonic metamaterials in on-chip quantum state engineering tasks

Le sida en Afrique : recherches en sciences de l'homme et de la société

Cet article présente les grands principes méthodologiques d'une étude portant sur le devenir socio-économique de familles touchées par le sida dans trois pays en développement (Burundi, Haïti et Côte d'Ivoire), et les problèmes éthiques posés par sa réalisation. Les évolutions des conditions de vie des ménages et de leur structure familiale, notamment en cas de décès du malade, sont analysées à la lumière des résultats de l'enquête menée en Côte d'Ivoire. Une attention particulière est portée sur les changements dans les conditions de vie des femmes, particulièrement affectées par l'instabilité matrimoniale, et aux bouleversements subis par les enfants, notamment en cas de décès des parents. (Résumé d'auteur

Quantum entanglement distillation using an optical metamaterial

We perform an entanglement distillation protocol on pure and mixed states using optical metamaterials composed of gold nano-antennas and measure the density matrices by quantum-state tomography. The fidelity is improved from 0.85 to 0.97. © OSA 2015

HIV/AIDS and Food and Nutrition Security: Interactions and Response

Today, there is an urgent need for a broader understanding of the integral role that food and nutrition security can and should play in better matching the scale, breadth, and interconnectedness of HIV/AIDS' causes and impacts. According to several studies, inequalities of several sorts including gender, mobility, orphanhood, malnutrition and maternal nutritional status are central to the HIV risk that people face. Different actors need tools and processes to turn their growing knowledge into appropriate responses. One such tool is the HIV/AIDS lens developed by Loevinsohn and Gillespie in the context of the emerging, Regional Network on HIV/AIDS, Rural Livelihoods and Food Security (RENEWAL) initiative. The lens is designed to support evidence-based reflection on how a particular situation or particular policy may increase or reduce the risks people face either of contracting HIV or of suffering severe consequences from AIDS-linked illness and death. Thus, the lens helps clarify options for response

A review of the applicability of existing tree and forest characteristics prediction models to forest inventory in Vietnam and Nepal

Forest inventories provide vital and up-to-date information for use in basic decision making on the ma¬nagement and conservation of forest resources. Data collected in forest inventories are stored and pro¬cessed in databases which can be updated by conducting additional measurements or by applying pre¬dictive models for imputing missing values of tree and forest stand-level variables. The inventory results can thereafter be calculated based on sample units, i.e. sample plots or forest stands within them, after which the forest inventory variables can be aggregated using different stratification units. For strategic decision-making, however, the future development of forest resources needs to be predicted. For this purpose, growth and yield simulators comprising tree and stand-level growth models are utilised to ob¬tain prediction results for alternative scenarios based on inventory information, i.e. sample-based field data. In large-scale forest inventories, only easily assessable characteristics are measured for all tallied trees, whereas height characteristics and other variables, which are difficult to measure accurately, are collected from a sub-sample only. In order to generalise the variables measured from sample trees to also cover tally trees, generalization techniques need to be applied. The ongoing national-level forest as¬sessments conducted in Nepal and Vietnam require efficient calculation procedures for reporting inven¬tory results and quantifying the availability and location of forest resources. The aim of this review was to assess the availability of the existing models for the prediction of tree and forest characteristics and their applicability to large-scale forest inventory in Nepal and Vietnam. Through comparisons made bet¬ween country- and species-specific models and prediction systems and through an assessment based on modelling literature, recommendations are also given for further developing the model-based prediction systems used in the ongoing national forest inventories of Nepal and Vietnam. The existing model sets can be used to estimate conventional stand volume characteristics for the inventoried areas. However, according to the new reporting requirements set for the current National Forest Inventory (NFI) of Viet¬nam and the Forest Resource Assessment (FRA) of Nepal, it is recommended that their model bases, which are currently under upgrading, be updated and improved in the future

In vacuum permanent magnet wiggler optimized for the production of hard x rays

A new concept of wiggler has been designed and realized at SOLEIL to produce high energy photons in low/intermediate electron storage rings. Instead of using the superconducting technology which requires new equipment and instrumentation, heavy maintenance, and additional running costs, we have proposed to build a compact in-vacuum small gap short period wiggler that operates rather at moderate field than at high field. The wiggler composed of 38 periods of 50 mm produces 2.1 T at a gap of 5.5 mm. The moderate value of the magnetic field enables one to limit the effects on the beam dynamics and to avoid excessive power and magnetic forces. In this purpose, the narrow magnetic system has been equipped with a counterforce device made of nonmagnetic springs. The roll-off resulting from the small size of poles has been compensated in situ by permanent magnet magic fingers. This paper reports the phases of design, construction, magnetic measurements, and on-beam tests of the in-vacuum wiggler WSV50