Numerous Challenges (numerous + challenge)

Distribution by Scientific Domains


Selected Abstracts


Job completion prediction using case-based reasoning for Grid computing environments

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2007
Lilian Noronha Nassif
Abstract One of the main focuses of Grid computing is solving resource-sharing problems in multi-institutional virtual organizations. In such heterogeneous and distributed environments, selecting the best resource to run a job is a complex task. The solutions currently employed still present numerous challenges and one of them is how to let users know when a job will finish. Consequently, reserve in advance remains unavailable. This article presents a new approach, which makes predictions for job execution time in Grid by applying the case-based reasoning paradigm. The work includes the development of a new case retrieval algorithm involving relevance sequence and similarity degree calculations. The prediction model is part of a multi-agent system that selects the best resource of a computational Grid to run a job. Agents representing candidate resources for job execution make predictions in a distributed and parallel manner. The technique presented here can be used in Grid environments at operation time to assist users with batch job submissions. Experimental results validate the prediction accuracy of the proposed mechanisms, and the performance of our case retrieval algorithm. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Conservation Biology in Asia: the Major Policy Challenges

CONSERVATION BIOLOGY, Issue 4 2009
JEFFREY A. McNEELY
Asia; bosques; comercio de vida silvestres; conflicto humano-animal; economía Abstract:,With about half the world's human population and booming economies, Asia faces numerous challenges to its biodiversity. The Asia Section of the Society for Conservation Biology has identified some key policy issues in which significant progress can be made. These include developing new sources of funding for forest conservation; identifying potential impacts of energy alternatives on the conservation of biodiversity; curbing the trade in endangered species of plants and animals; a special focus on the conservation of mountain biodiversity; enhancing relevant research; ensuring that conservation biology contributes to major international conventions and funding mechanisms; using conservation biology to build a better understanding of zoonotic diseases; more effectively addressing human,animal conflicts; enhancing community-based conservation; and using conservation biology to help address the pervasive water-deficit problems in much of Asia. These challenges can be met through improved regional cooperation among the relevant stakeholders. Resumen:,Con aproximadamente la mitad de la población humana y economías prósperas, Asia enfrenta numerosos retos para su biodiversidad. La sección Asia de la Sociedad para la Biología de la Conservación ha identificado algunos temas políticos claves en los que se puede hacer un progreso significativo. Estos incluyen el desarrollo de nuevas fuentes de financiamiento para la conservación de bosques; la identificación de impactos potenciales de las energías alternativas sobre la conservación de la biodiversidad; reducción del comercio de especies de animales y plantas en peligro; un enfoque especial en la conservación de la biodiversidad montana; promoción de investigación relevante; garantía de que la biología de la conservación contribuye a convenios internacionales y mecanismos de financiamiento; utilización de la biología de la conservación para lograr un mejor entendimiento de enfermedades zoonóticas; mejor atención a los conflictos humanos-animales; reforzamiento de la conservación basada en comunidades y utilización de la biología de la conservación para atender los problemas de déficit de agua en gran parte de Asia. Estos retos se pueden atender mediante una mejor cooperación regional entre los principales actores. [source]


The clinical aspects of newborn screening: Importance of newborn screening follow-up

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2006
Philip M. James
Abstract The aim of newborn screening is to identify presymptomatic healthy infants that will develop significant metabolic or endocrine derangements if left undiagnosed and untreated. The goal of ultimately reducing or eliminating irreversible sequelae is reached by maximizing test sensitivity of the primary newborn screening that measures specific analytes by a number of methodologies. Differentiation of true from false negatives is accomplished by the test specificity. This review discusses disorders for which, in general, there are available therapies and that are detected by routine and expanded newborn screening. Recommendations are presented for evaluation by a primary care physician, with confirmation by a metabolic or endocrinology specialist. Disorders are organized in tabular format by class of pathway or analyte, with attention to typical clinical presentations, confirmatory biochemical and molecular tests, and therapies. There are numerous challenges in clinical follow-up, including diagnosis and appropriate understanding of the consequences of the disorders. The data required to meet these challenges can be acquired only by large scale longitudinal comprehensive studies of outcome in children identified by newborn screening. Only with such data can newborn screening fully serve families. © 2006 Wiley-Liss, Inc. MRDD Research Reviews 2006;12:246,254. [source]


A modular access gateway for managing intermittent connectivity in vehicular communications

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 2 2006
Jörg Ott
The Drive-thru Internet architecture allows exploiting intermittent connectivity by temporarily connecting to IEEE 802.11 WLAN access points at the roadside from moving vehicles. This poses numerous challenges to a mobile user's equipment: extreme networking characteristics such as short periods of connectivity, unpredictable disconnection times, and vastly varying transmission characteristics. Heterogeneous WLAN hotspot installations may also require different authentication mechanisms and credentials. We have designed a mobile access gateway to deal with these issues on behalf of a user (group) in a moving vehicle and provide usable connectivity for applications without requiring manual operation. The gateway maximises the use of short connectivity periods by detecting network access providing signalling functions for local application processes. It also allows using dedicated radio equipment to prolong connectivity periods. Finally, in selected multi-user scenarios, further performance improvements are conceivable by sharing (non-confidential) information across users and applications. Copyright © 2005 AEIT. [source]


Boundary Perturbation Methods for Water Waves

GAMM - MITTEILUNGEN, Issue 1 2007
David P. Nicholls
Abstract The most successful equations for the modeling of ocean wave phenomena are the free,surface Euler equations. Their solutions accurately approximate a wide range of physical problems from open,ocean transport of pollutants, to the forces exerted upon oil platforms by rogue waves, to shoaling and breaking of waves in nearshore regions. These equations provide numerous challenges for theoreticians and practitioners alike as they couple the difficulties of a free boundary problem with the subtle balancing of nonlinearity and dispersion in the absence of dissipation. In this paper we give an overview of, what we term, "Boundary Perturbation" methods for the analysis and numerical simulation of this "water wave problem". Due to our own research interests this review is focused upon the numerical simulation of traveling water waves, however, the extensive literature on the initial value problem and additional theoretical developments are also briefly discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Summary of contributions to GAW Group 15: family-based samples are useful in identifying common polymorphisms associated with complex traits

GENETIC EPIDEMIOLOGY, Issue S1 2009
Stacey Knight
Abstract Traditionally, family-based samples have been used for genetic analyses of single-gene traits caused by rare but highly penetrant risk variants. The utility of family-based genetic data for analyzing common complex traits is unclear and contains numerous challenges. To assess the utility as well as to address these challenges, members of Genetic Analysis Workshop 16 Group 15 analyzed Framingham Heart Study data using family-based designs ranging from parent,offspring trios to large pedigrees. We investigated different methods including traditional linkage tests, family-based association tests, and population-based tests that correct for relatedness between subjects, and tests to detect parent-of-origin effects. The analyses presented an assortment of positive findings. One contribution found increased power to detect epistatic effects through linkage using ascertainment of sibships based on extreme quantitative values or presence of disease associated with the quantitative value. Another contribution found four single-nucleotide polymorphisms (SNPs) showing a maternal effect, two SNPs with an imprinting effect, and one SNP having both effects on a binary high blood pressure trait. Finally, three contributions illustrated the advantage of using population-based methods to detect association to complex binary or quantitative traits. Our findings highlight the contribution of family-based samples to the genetic dissection of complex traits. Genet. Epidemiol. 33 (Suppl. 1):S99,S104, 2009. © 2009 Wiley-Liss, Inc. [source]


Engaging the professional: organising call centre agents in India

INDUSTRIAL RELATIONS JOURNAL, Issue 3 2009
Ernesto Noronha
ABSTRACT The extremely challenging external environment poses numerous challenges to union formation among call centre agents in India. Complicating matters is the acquired professional identity of call centre agents. In this scenario, the union organising call centre employees envisaged that partnership with employers was the only possibility acceptable to call centre agents, employer organisations and society at large, enabling them to regain some acceptability and credibility for the heretofore tainted Indian trade union movement. [source]


Korean mothers' psychosocial adjustment to their children's cancer

JOURNAL OF ADVANCED NURSING, Issue 5 2003
Hae-Ra Han PhD RN
Background., During the course of adjustment to their child's illness and medical treatment, parents of children with cancer may experience numerous challenges and difficulties. Although parental adjustment has been a research topic for many years, little research has been conducted among families in different cultures and countries. Aim., To identify factors that influence maternal psychosocial adjustment to childhood cancer using a new cultural group: Korean. Methods., A sample of 200 Korean mothers of children with cancer was included in the study. Guided by the double ABCX model of family adjustment and adaptation, a series of variables (i.e. maternal stress, coping, social support and selected illness-related and demographic questions) were examined for their relationships with maternal psychosocial adjustment to childhood cancer. Results., Using a hierarchical multiple regression, we found perceived level of stress, coping, social support, and time since diagnosis to be significant correlates of maternal psychosocial adjustment. Stress accounted for most (50%) of the total variance explained (56%) in maternal adjustment. Conclusion., The results suggest that the stress-coping framework may be appropriate in explaining maternal responses to childhood cancer across cultures. [source]


Mass spectrometry in newborn and metabolic screening: historical perspective and future directions

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2009
Donald H. Chace
Abstract The growth of mass spectrometry (MS) in clinical chemistry has primarily occurred in two areas: the traditional clinical chemistry areas of toxicology and therapeutic drug monitoring and more recent, human genetics and metabolism, specifically inherited disorders of intermediary metabolism and newborn screening. Capillary gas chromatography and electrospray tandem MS are the two most common applications used to detect metabolic disease in screening, diagnostics and disease monitoring of treated patients. A few drops of blood from several million newborn infants are screened annually throughout the world making this the largest application of MS in medicine. Understanding the technique, how it grew from a few dozen samples per week in the early 1990s to increasing daily volume today will provide important information for new tests that either expand newborn screening or screening in other areas of metabolism and endocrinology. There are numerous challenges to the further expansion of MS in clinical chemistry but also many new opportunities in closely related applications. The model of newborn screening and MS in medicine may be useful in developing other applications that go beyond newborns and inherited metabolic disease. As MS continues to expand in clinical chemistry, it is clear that two features will drive its success. These features are excellent selectivity and multiple analyte or profile analysis; features recognized in the 1950s and remain true today. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Faith-Based Programs for Reentry Courts: A Summary of Issues and Recommendations

JUVENILE AND FAMILY COURT JOURNAL, Issue 4 2004
DENISE C. HERZ
ABSTRACT In 2002, the Bush Administration directed the Department of Justice to include faith-based organizations in its distribution of funds earmarked for programs targeting the prevention and treatment of juvenile delinquency and substance abuse. Among the initiatives most likely to be affected by this new policy are reentry court programs that endeavor to reintegrate juvenile delinquents into their communities by placing them within local neighborhood-based programs. However, reentry court personnel and leaders of faith-based organizations are likely to encounter numerous challenges as they try to establish appropriate programming. In this article, we discuss the current understanding of First Amendment jurisprudence governing the federal funding of faith-based organizations and summarize key issues identified by a National Council of Juvenile and Family Court Judges' workgroup on faith-based programming that are necessary for including faith-based organizations within a reentry court's continuum of care. We also discuss several concerns that reentry court personnel and faith-based organizations should consider as they seek to maximize the impact of their programs. [source]


Diversity Within the Virtual Classroom

NEW DIRECTIONS FOR INSTITUTIONAL RESEARCH, Issue 118 2003
Kevin Kinser
The dynamic nature of virtual classrooms presents numerous challenges to assessment and interpretation. This chapter provides an overview of these challenges and sets forth general measures to guide research. [source]


Children with learning disabilities

PEDIATRIC ANESTHESIA, Issue 3 2008
SIMON P. COURTMAN
Summary Children with learning disabilities can present numerous challenges in the acute hospital setting. This review article examines the causes and presentations of learning disability, and considers some of the management strategies employed when these children present for surgery. [source]


Regulatory hurdles for transgenic biofuel crops

BIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 4 2009
David Lee
Abstract Policy-makers have described the many potential benefits that biofuels can provide, but there are numerous challenges in realizing this potential. The technical hurdles to producing biofuels economically and on a scale to replace a significant fraction of petroleum-based transportation fuels have been well described, along with the potential environmental concerns. The use of biotechnology can potentially address many of these technical challenges and environmental concerns, but brings significant regulatory obstacles that have not been discussed extensively in the scientific community. This review will give an overview of some of the approaches being developed to produce transgenic biofuel feedstocks, particularly cellulosic ethanol, and the regulatory process in the United States that oversees the introduction of new transgenic plants. We hope to illustrate that the level of regulation for transgenic organisms is not proportional to their potential risk to human health or to the environment, and that while revisions to the regulatory system in the USA are currently under consideration, further modifications are necessary to reflect the risk level of transgenic crops and realize their benefits. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source]


Improved synthesis of 5-hydroxylysine (Hyl) derivatives,

CHEMICAL BIOLOGY & DRUG DESIGN, Issue 2 2005
M. Cudic
Abstract:, The synthesis of 5-hydroxylysine (Hyl) derivatives for incorporation by solid-phase methodologies presents numerous challenges. Hyl readily undergoes intramolecular lactone formation, and protected intermediates often have poor solubilities. The goals of this work were twofold: first, develop a convenient method for the synthesis of O -protected Fmoc-Hyl; secondly, evaluate the efficiency of methods for the synthesis of O -glycosylated Fmoc-Hyl. The 5- O - tert -butyldimethylsilyl (TBDMS) fluoren-9-ylmethoxycarbonyl-Hyl (Fmoc-Hyl) derivative was conveniently prepared by the addition of tert -butyldimethylsilyl trifluoromethanesulfonate to copper-complexed Hyl[, - tert -butyloxycarbonyl (Boc)]. The complex was decomposed with Na+ Chelex resin and the Fmoc group added to the , -amino group. Fmoc-Hyl(, -Boc, O -TBDMS) was obtained in 67% overall yield and successfully used for the solid-phase syntheses of 3 Hyl-containing peptides. The preparation of Fmoc-Hyl[, -Boc, O -(2,3,4,6-tetra- O -acetyl- , - d -galactopyranosyl)] was compared for the thioglycoside, trichloroacetimidate and Koenigs,Knorr methods. The most efficient approach was found to be Koenigs,Knorr under inverse conditions, where Fmoc-Hyl(, -Boc)-OBzl and peracetylated galactosyl bromide were added to silver trifluoromethanesulfonate in 1,2-dichloroethane, resulting in a 45% isolated yield. Side-reactions that occurred during previously described preparations of glycosylated Hyl derivatives, such as lactone formation, loss of side-chain protecting groups, orthoester formation, or production of anomeric mixtures, were avoided here. Research on the enzymology of Lys hydroxylation and subsequent glycosylation, as well as the role of glycosylated Hyl in receptor recognition, will be greatly aided by the convenient and efficient synthetic methods developed here. [source]