1,207 research outputs found
The Voluntary Adjustment of Railroad Obligations
Automatic memory management techniques eliminate many programming errors that are both hard to find and to correct. However, these techniques are not yet used in embedded systems with hard realtime applications. The reason is that current methods for automatic memory management have a number of drawbacks. The two major ones are: (1) not being able to always guarantee short real-time deadlines and (2) using large amounts of extra memory. Memory is usually a scarce resource in embedded applications. In this paper we present a new technique, Real-Time Reference Counting (RTRC) that overcomes the current problems and makes automatic memory management attractive also for hard real-time applications. The main contribution of RTRC is that often all memory can be used to store live objects. This should be compared to a memory overhead of about 500% for garbage collectors based on copying techniques and about 50% for garbage collectors based on mark-and-sweep techniques
Artificial Intelligence
Contains research objectives and reports on five research projects.Computation Center, M.I.T
Anaemia in schoolchildren in eight countries in Africa and Asia
Objective: To report on the haemoglobin concentrations and prevalence of anaemia in schoolchildren in eight countries in Africa and Asia.
Design: Blood samples were collected during surveys of the health of schoolchildren as a part of programmes to develop school-based health services.
Setting: Rural schools in Ghana, Indonesia, Kenya, Malawi, Mali, Mozambique, Tanzania and Vietnam.
Subjects: Nearly 14 000 children enrolled in basic education in three age ranges (7-11 years, 12-14 years and >/= 15 years) which reflect the new UNICEF/WHO
thresholds to define anaemia.
Results: Anaemia was found to be a severe public health problem (defined as >40% anaemic) in five African countries for children aged 7-11 years and in four of the same countries for children aged 12-14 years. Anaemia was not a public health problem in the children studied in the two Asian countries. More boys than girls were anaemic, and children who enrolled late in school were more likely to be
anaemic than children who enrolled closer to the correct age. The implications of the four new thresholds defining anaemia for school-age children are examined.
Conclusions: Anaemia is a significant problem in schoolchildren in sub-Saharan Africa. School-based health services which provide treatments for simple conditions
that cause blood loss, such as worms, followed by multiple micronutrient supplements including iron, have the potential to provide relief from a large burden of anaemia
Rare Variant Analysis of Human and Rodent Obesity Genes in Individuals with Severe Childhood Obesity
Obesity is a genetically heterogeneous disorder. Using targeted and whole-exome sequencing, we studied 32 human and 87 rodent obesity genes in 2,548 severely obese children and 1,117 controls. We identified 52 variants contributing to obesity in 2% of cases including multiple novel variants in GNAS, which were sometimes found with accelerated growth rather than short stature as described previously. Nominally significant associations were found for rare functional variants in BBS1, BBS9, GNAS, MKKS, CLOCK and ANGPTL6. The p.S284X variant in ANGPTL6 drives the association signal (rs201622589, MAF∼0.1%, odds ratio = 10.13, p-value = 0.042) and results in complete loss of secretion in cells. Further analysis including additional case-control studies and population controls (N = 260,642) did not support association of this variant with obesity (odds ratio = 2.34, p-value = 2.59 × 10 -3 ), highlighting the challenges of testing rare variant associations and the need for very large sample sizes. Further validation in cohorts with severe obesity and engineering the variants in model organisms will be needed to explore whether human variants in ANGPTL6 and other genes that lead to obesity when deleted in mice, do contribute to obesity. Such studies may yield druggable targets for weight loss therapies
Distorted policy transfer? South Korea’s adaptation of UK social enterprise policy
This study draws upon communicative processes in policy transfer to consider the ways in which policy may be adapted to context or distorted. The theoretical framework is used to investigate exactly what the South Korean government borrowed from UK social enterprise policy. Despite claims that the UK was the source of both the general policy direction and the particular regulatory device, the Korean government did not learn about the specific contexts of the British policy, nor attempt two-way communication with domestic stakeholders. Rather, the UK policy was interpreted in accordance with the Korean government’s own ideas about how to utilize social enterprise. Historical legacies of top-down decision-making played an important role in this process, as did the state’s role as a regulator which mobilizes the private sector to achieve policy goals. The consequences have been negative for those organizations refused social enterprise status under the Ministry of Labor’s strict approval system, as well as for the original target population: the socially disadvantaged and vulnerable. It is suggested that the model advanced may help to illuminate the reasons why some borrowed policies differ considerably from the originals, and the use of policy transfer as a means of legitimizatio
Need for Alloparental Care and Attitudes Toward Homosexuals in 58 Countries: Implications for the Kin Selection Hypothesis
Homosexuality is an evolutionary puzzle. Many theories attempt to explain how a trait undermining individual reproduction can be maintained, but experimental testing of their predictions remains scarce. The kin selection hypothesis (KSH) is an important theoretical framework to account for the evolution of human homosexuality, postulating that its direct cost to reproduction can be offset by inclusive fitness gains through alloparental assistance to kin. Consistent evidence in support of the KSH has only been garnered from research on Samoan fa’afafine (i.e. feminine, same-sex attracted males), whereas research in numerous industrialized societies has repeatedly failed to secure empirical support for the theory. Here, we propose an alternative test of the KSH by investigating how need for alloparental care influences women’s attitudes toward homosexuality (AtH). AtH would influence the likelihood of women receiving alloparental care from homosexual kin. We applied logistic regression analysis to a large dataset (17,295 women in 58 countries) derived from the World Values Survey. As predicted by the KSH, women who are potentially most in need of alloparental support exhibit significantly more positive attitudes toward homosexuals. For single mothers who expressed parental care concerns, each additional child mothered was associated with an increase of 1.24 in their odds of exhibiting positive attitudes toward homosexuals. Our study is the first to provide circumstantial evidence in support of the KSH on a global scale
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