Folding model study of the elastic α+α\alpha + \alpha scattering at low energies

The folding model analysis of the elastic $\alpha + \alpha$ scattering at the incident energies below the reaction threshold of 34.7 MeV (in the lab system) has been done using the well-tested density dependent versions of the M3Y interaction and realistic choices for the $^4$He density. Because the absorption is negligible at the energies below the reaction threshold, we were able to probe the $\alpha + \alpha$ optical potential at low energies quite unambiguously and found that the $\alpha + \alpha$ overlap density used to construct the density dependence of the M3Y interaction is strongly distorted by the Pauli blocking. This result gives possible explanation of a long-standing inconsistency of the double-folding model in its study of the elastic $\alpha + \alpha$ and $\alpha$-nucleus scattering at low energies using the same realistic density dependent M3Y interaction

Vietnam research situation analysis on orphans and other vulnerable children

This item is archived in the repository for materials published for the USAID supported Orphans and Vulnerable Children Comprehensive Action Research Project (OVC-CARE) at the Boston University Center for Global Health and Development.Addressing the needs of orphans and vulnerable children (OVC) and mitigating negative outcomes of the growing OVC population worldwide is a high priority for national governments and international stakeholders across the globe who recognize this as an issue with social, economic, and human rights dimensions. Assembling the relevant available data on OVC in one place, and acknowledging the gaps that still exist in our knowledge, will assist policy makers and program implementers to make evidence-based decisions about how best to direct funding and program activities and maximize positive outcomes for children and their caretakers. This Research Situation Analysis, Vietnam Country Brief presents a program-focused summary of available information on: • The number of orphans and vulnerable children in Vietnam. • Current policies, programs and interventions designed and implemented to assist them. • Gaps in these policies, programs and interventions. • OVC research conducted between 2004 -2008. • Gaps in the OVC evidence base. The Brief analyzes the available data for critical gaps in the national response and our understanding about whether current interventions are fulfilling the needs and improving the lives of vulnerable children. The report then recommends actions required to increase the knowledge base for improving the effectiveness and impact of OVC programs.The USAID | Project SEARCH, Orphans and Vulnerable Children Comprehensive Action Research (OVC-CARE) Task Order, is funded by the U.S. Agency for International Development under Contract No. GHH-I-00-07-00023-00, beginning August 1, 2008. OVC-CARE Task Order is implemented by Boston University. The opinions expressed herein are those of the authors and do not necessarily reflect the views of the funding agency

DEWATS dissemination in Vietnam: achievements and lessons learnt

The speedy economic development and rapid growth of population and urbanization in Vietnam have created great pressure on the environment by its manufacturing process and human activities. Thus, it is necessary to protect the environment through policies and appropriate technology for the sustainable development of the country. The DEcentralized WAstewater Treatment Solutions (DEWATS) dissemination in Vietnam is one of the measures contributing to address this issue

Ecophysiological responses of four boreal tree species to soil nitrogen supply

The ecophysiological responses of four boreal tree species, trembling aspen (Populus tremuloides Michx.), black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss), and jack pine (Pinus banksiana Lamb.) were examined at six different levels (from 25 to 775 ppm) of soil nitrogen (N). At the 50th and 100th day of treatment, two-year-old conifer seedlings and six-month-old trembling aspen seedlings were measured for gas exchange, foliar N concentration, growth and biomass allocation traits. The gas exchange and resource use efficiency responses varied with species. The additional N input had no significant effect on photosynthesis (see document) and positive effect on transpiration (E, mmol/m2/s), and beyond 175 ppm N treatment it produced negative effect on whole seedling photosynthetic capacity (see document) in trembling aspen. A, E and At in conifers responded negatively to N treatment, except for a brief positive response from 25 to 125 ppm N in jack pine. PSII revealed relevant relationship with A but only for jack pine and white spruce. We found explicit positive response of foliar N concentration and negative response of PNUE to increasing soil N availability. However, the trends of PWUE between species varied across six N treatments and possibly due to luxury consumption. The PWUE was positively correlated with soil N supply in only white spruce and was negatively correlated in other species. The sufficient soil N availability for optimum gas exchange and nutritional status were at 75 ppm N for black spruce and at 125 for the other three species. Overall, the growth response of aspen to N was more pronounced than that of conifers due to its fast growing nature. Significant growth response of aspen occurred between the 75 to 175 ppm N treatments. Substantial growth reduction occurred when aspen seedlings were induced to excessively high soil N concentrations (375 and 775 ppm), specifically due to the vulnerability of these seedlings to pest damages. This is also related to the significant increase in foliar N concentration at these N treatments. Greatest growth was achieved at 25 ppm N addition rate in black spruce and jack pine, and most notables at 125 ppm N in white spruce. However, these N levels are not conclusive when optimum soil N concentration(s) for gas exchange parameters, particularly for At, in these seedlings are taken into consideration. Nonetheless, at highest soil N supply (375 and 775 ppm), the growth of conifer seedlings was not as adversely affected as that of aspen seedlings. Our results also proved strong significance of N availability on biomass allocation between root and shoot components and height growth in all species. Root production was significantly suppressed as soil N availability increased in the conifers. The opposite was found in aspen. In conifers, the proportions of total seedling biomass allocated to roots (or the root-toshoot ratio, R/S), at all N treatments, were highest in white spruce, followed by black spruce then jack pine. The R/S ratio in aspen was comparable with, but followed an opposite pattern to, white spruce. The stem and foliage productions in all studied species showed negligible positive response to increasing soil N treatments. However, with the exception of aspen, the order of the species allocating highest to lowest portions of its total biomass to the foliage followed the exact opposite pattern as that of root allocation percentage. Aspen showed lesser biomass allocation to the foliage than conifers. However, it allocated highest percentages of total seedling biomass to the stem, at all N treatments, followed in sequential order by black spruce, white spruce and jack pine. When all ecophysiological parameters are considered, our results indicated that low soil N availability, such as that at 25 ppm, does not adversely affect the boreal seedling growth and survival as much as it does at excessively high soil N availability (e.g., 375 and 775 ppm). Within the sufficient N regimes (i.e., 75 - 175 ppm), the most suitable soil N concentration for black spruce is at 75 ppm and at 125 ppm for other species

A Simple Linear Time Algorithm for Computing a 1-Median on Cactus Graphs

We address the problem of finding a 1-median on a cactus graph. The problem has already been solved in linear time by the algorithms of Burkard and Krarup (1998), and Lan and Wang (2000). These algorithms are complicated and need efforts. Hence, we develop in this paper a simpler algorithm. First, we construct a condition for a cycle that contains a 1-median or for a vertex that is indeed a 1-median of the cactus. Based on this condition, we localize the search for deriving a 1-median on the underlying cactus. Complexity analysis shows that the approach runs in linear time

Innovative in silico approaches to address avian flu using grid technology

The recent years have seen the emergence of diseases which have spread very quickly all around the world either through human travels like SARS or animal migration like avian flu. Among the biggest challenges raised by infectious emerging diseases, one is related to the constant mutation of the viruses which turns them into continuously moving targets for drug and vaccine discovery. Another challenge is related to the early detection and surveillance of the diseases as new cases can appear just anywhere due to the globalization of exchanges and the circulation of people and animals around the earth, as recently demonstrated by the avian flu epidemics. For 3 years now, a collaboration of teams in Europe and Asia has been exploring some innovative in silico approaches to better tackle avian flu taking advantage of the very large computing resources available on international grid infrastructures. Grids were used to study the impact of mutations on the effectiveness of existing drugs against H5N1 and to find potentially new leads active on mutated strains. Grids allow also the integration of distributed data in a completely secured way. The paper presents how we are currently exploring how to integrate the existing data sources towards a global surveillance network for molecular epidemiology.Comment: 7 pages, submitted to Infectious Disorders - Drug Target

Self expression versus the environment: Attitudes in conflict

Abstract Purpose - This paper aims to present the findings of a survey into attitudes towards the environment and the pro-environmental behaviours of young adults in Vietnam. Design/Methodology/Approach - An online survey was administered to university students in Vietnam's two most populous cities, Ha Noi and Ho Chi Minh City (N 391). Findings - The results suggest that environmental considerations are not taken into account in young Vietnamese adults' purchase intentions. This is more evident in expressive purchases, but also, to some degree, in utilitarian purchases. Practical implications - For the marketers of environmentally friendly products, this represents at least two key challenges: first, to try to shift the attitudes of young adult consumers towards thinking of environmental friendliness as an attractive characteristic and status-filled activity for potential expressive purchases. Second, making environmentally friendly alternatives of expressive goods more visible and more widely available in Vietnam. Social implications - Non-government organisations and governments seeking to protect the environment need to consider this unique dynamic in social marketing campaigns to increase the desirability of pro-environmental product choices and other pro-environmental behaviours. Originality/value - This paper examines pro-environmental behaviours and intentions of young adults in Vietnam for the first time. The paper establishes that self-expression is more important than the environment, and it is also evident that these young consumers are still vulnerable to perceived social pressure when it comes to expressing themselves