4,314 research outputs found
The reliability of single-error protected computer memories
The lifetimes of computer memories which are protected with single-error-correcting-double-error-detecting (SEC-DED) codes are studies. The authors assume that there are five possible types of memory chip failure (single-cell, row, column, row-column and whole chip), and, after making a simplifying assumption (the Poisson assumption), have substantiated that experimentally. A simple closed-form expression is derived for the system reliability function. Using this formula and chip reliability data taken from published tables, it is possible to compute the mean time to failure for realistic memory systems
Strengths and Difficulties Questionnaire scores and mental health in looked after children.
British local authorities are required to monitor the mental health of looked after children using mean Strengths and Difficulties Questionnaire (SDQ) scores from parents or carers. This assumes that differences in mean SDQ scores reflect genuine differences in child mental health in this group, something we examined using nationally representative surveys (n = 1391, age 5-16). We found that the SDQ was a genuinely dimensional measure of mental health in these children and provided accurate estimates of disorder prevalence
Explaining the socio-economic gradient in child outcomes: the intergenerational transmission of cognitive skills
Papers in this volume and elsewhere consistently find a strong relationship between children's cognitive abilities and their parents' socio-economic position (SEP). Most studies seeking to explain the paths through which SEP affects cognitive skills suffer from a potentially serious omitted variables problem, as they are unable to account for an important determinant of children's cognitive abilities, namely parental cognitive ability. A range of econometric strategies have been employed to overcome this issue, but in this paper, we adopt the very simple (but rarely available) route of using data that includes a range of typically unobserved characteristics, such as parental cognitive ability and social skills. In line with previous work on the intergenerational transmission of cognitive skills, we find that parental cognitive ability is a significant predictor of children's cognitive ability; moreover, it explains one sixth of the socio-economic gap in those skills, even after controlling for a rich set of demographic, attitudinal and behavioural factors. Despite the importance of parental cognitive ability in explaining children's cognitive ability, however, the addition of such typically unobserved characteristics does not alter our impression of the relative importance of other factors in explaining the socio-economic gap in cognitive skills. This is reassuring for studies that are unable to control for parental cognitive ability.
Phased burst error-correcting array codes
Various aspects of single-phased burst-error-correcting array codes are explored. These codes are composed of two-dimensional arrays with row and column parities with a diagonally cyclic readout order; they are capable of correcting a single burst error along one diagonal. Optimal codeword sizes are found to have dimensions n1Ă—n2 such that n2 is the smallest prime number larger than n1. These codes are capable of reaching the Singleton bound. A new type of error, approximate errors, is defined; in q-ary applications, these errors cause data to be slightly corrupted and therefore still close to the true data level. Phased burst array codes can be tailored to correct these codes with even higher rates than befor
Expression and modulation of the UGT1A family of phase II metabolism genes via liganded vitamin D receptor
Abandoning presumptive antimalarial treatment for febrile children aged less than five years--a case of running before we can walk?
Current guidelines recommend that all fever episodes in African children be treated presumptively with antimalarial drugs. But declining malarial transmission in parts of sub-Saharan Africa, declining proportions of fevers due to malaria, and the availability of rapid diagnostic tests mean it may be time for this policy to change. This debate examines whether enough evidence exists to support abandoning presumptive treatment and whether African health systems have the capacity to support a shift toward laboratory-confirmed rather than presumptive diagnosis and treatment of malaria in children under five
Development of methods for use of antibiotics to control fireblight (Erwinia amylovora)
Digitized 2007 AES.Includes bibliographical references (pages 15-16)
The Impact of a Mindful State on Ego-Salience and Self-Control
Convergent findings among several distinct lines of research have revealed that mindfulness, an open and receptive form of present-centered awareness, is positively associated with numerous indices of well-being. Much of this research has focused on dispositional mindfulness, the frequency with which one enters into mindful states over time. However, state mindfulness, the degree to which one is mindful at a specific point in time, has been left relatively unexplored. Current theories suggest that many beneficial effects attributable to mindfulness are due to changes in the way one relates to thoughts about the self. In this study we hypothesized that a heightened mindful state would reduce the salience of self-relevant concepts. Further, we hypothesized that this difference in cognitions would alter how people deal with self-threatening information and lead to advantages in one\u27s ability to exert volitional control over subsequent behaviors. To test these hypotheses, all participants were told that we were measuring their personality traits to make predictions about their sociability. After completing an initial battery of self-report measures, half of the participants underwent a 15-minute state mindfulness induction, while the other half received instructions to let their mind wander. Immediately afterward, a lexical decision task was administered which was designed to assess the salience of previously rated self-descriptive words. Each participant was then given a report that contained negative feedback about the future of his or her social life. Finally, participants completed a dichotic listening task designed to assess self-regulatory ability and a self-report measure sensitive to state affect. Our analyses indicated that the mindfulness induction significantly reduced the salience of self-relevant cognitions and that the degree of this change significantly predicted improvements in self-control. Additionally, we found evidence that mindful people responded to self-threatening information in a more ada
Gene Transfer in Crop Improvement - An Introduction and Overview
The application of recombinant DNA technology to plant breeding promises important applications in agriculture and advances in many plant science disciplines. Gene transfer at the molecular level can be routinely accomplished in an increasing number of plant species. For many of the world\u27s important crops, new methods or refinements of proven methods will be needed and are being developed. Experience with gene regulation in transgenic plants is accumulating in many laboratories around the world. The action of any particular gene cannot be predicted precisely without reference to the genetic background in which it acts, but, qualitatively speaking, the cis-acting elements located near and within coding sequences of genes appear co play a dominant role in governing gene expression. This result means that chimeric genes can be constructed and expressed with at least qualitatively predictable results. Several agriculturally interesting traits have been engineered and are undergoing field trials. These traits include several different herbicide resistances, modified fruit characteristics, viral disease resistance, and insect tolerance in rapeseed, tobacco, tomato, potato, alfalfa and cotton. Much work is underway to provide a better understanding of plant metabolism and development with a view to engineering ocher traits. These traits include the composition of storage lipids, regulation of fruit development, and disease resistance. The new tools for genetic manipulation of crop plants provide important opportunities for improving crop performance and the economic and environmental performance of agriculture
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