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Showing papers by "University of Western Ontario published in 2003"


Journal ArticleDOI
TL;DR: A bibliographical review on reconfigurable fault-tolerant control systems (FTCS) is presented, with emphasis on the reconfiguring/restructurable controller design techniques.

2,455 citations


Journal ArticleDOI
TL;DR: In this article, the authors review the use of thermal remote sensing in the study of urban climates, focusing primarily on the urban heat island effect and progress made towards answering the methodological questions posed by Roth et al.

2,013 citations


Journal ArticleDOI
TL;DR: The link between sarc Openia and disability among elderly men and women highlights the need for continued research into the development of the most effective interventions to prevent or at least partially reverse sarcopenia, including the role of resistance exercise and other novel pharmacological and nutritional interventions.
Abstract: Aging is associated with progressive loss of neuromuscular function that often leads to progressive disability and loss of independence. The term sarcopenia is now commonly used to describe the loss of skeletal muscle mass and strength that occurs in concert with biological aging. By the seventh and eighth decade of life, maximal voluntary contractile strength is decreased, on average, by 20-40% for both men and women in proximal and distal muscles. Although age-associated decreases in strength per unit muscle mass, or muscle quality, may play a role, the majority of strength loss can be accounted for by decreased muscle mass. Multiple factors lead to the development of sarcopenia and the associated impact on function. Loss of skeletal muscle fibers secondary to decreased numbers of motoneurons appears to be a major contributing influence, but other factors, including decreased physical activity, altered hormonal status, decreased total caloric and protein intake, inflammatory mediators, and factors leading to altered protein synthesis, must also be considered. The prevalence of sarcopenia, which may be as high as 30% for those ≥60 yr, will increase as the percentage of the very old continues to grow in our populations. The link between sarcopenia and disability among elderly men and women highlights the need for continued research into the development of the most effective interventions to prevent or at least partially reverse sarcopenia, including the role of resistance exercise and other novel pharmacological and nutritional interventions.

1,692 citations


Journal ArticleDOI
TL;DR: The Humor Styles Questionnaire (HSQ) as mentioned in this paper assesses four dimensions relating to individual differences in uses of humor: relatively benign uses of humour to enhance the self (Self-enhancing), use of humor to enhance relationships at the expense of self (Aggressive), and self-defeating.

1,512 citations


Journal ArticleDOI
20 Mar 2003-Nature
TL;DR: It is found that surface momentum flux levels off as the wind speeds increase above hurricane force, contrary to surface flux parameterizations that are currently used in a variety of modelling applications, including hurricane risk assessment and prediction of storm motion, intensity, waves and storm surges.
Abstract: The transfer of momentum between the atmosphere and the ocean is described in terms of the variation of wind speed with height and a drag coefficient that increases with sea surface roughness and wind speed. But direct measurements have only been available for weak winds; momentum transfer under extreme wind conditions has therefore been extrapolated from these field measurements. Global Positioning System sondes have been used since 1997 to measure the profiles of the strong winds in the marine boundary layer associated with tropical cyclones. Here we present an analysis of these data, which show a logarithmic increase in mean wind speed with height in the lowest 200 m, maximum wind speed at 500 m and a gradual weakening up to a height of 3 km. By determining surface stress, roughness length and neutral stability drag coefficient, we find that surface momentum flux levels off as the wind speeds increase above hurricane force. This behaviour is contrary to surface flux parameterizations that are currently used in a variety of modelling applications, including hurricane risk assessment and prediction of storm motion, intensity, waves and storm surges.

1,314 citations


Journal ArticleDOI
TL;DR: It is reported that NOD1 mediates selective recognition of bacteria through detection of iE-DAP-containing peptidoglycan derived primarily from Gram-negative bacteria.
Abstract: Nucleotide-binding oligomerization domain protein 1 (NOD1) belongs to a family that includes multiple members with NOD and leucine-rich repeats in vertebrates and plants. NOD1 has been suggested to have a role in innate immune responses, but the mechanism involved remains unknown. Here we report that NOD1 mediates the recognition of peptidoglycan derived primarily from Gram-negative bacteria. Biochemical and functional analyses using highly purified and synthetic compounds indicate that the core structure recognized by NOD1 is a dipeptide, γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP). Murine macrophages deficient in NOD1 did not secrete cytokines in response to synthetic iE-DAP and did not prime the lipopolysaccharide response. Thus, NOD1 mediates selective recognition of bacteria through detection of iE-DAP-containing peptidoglycan. *Note: In the version of this article initially published online, one author's first name and last name were reversed. The correct author name should be Su Qiu. This mistake has been corrected for the HTML and print versions of the article.

1,267 citations


Journal ArticleDOI
TL;DR: A new de novo sequencing software package, PEAKS, is described, to extract amino acid sequence information without the use of databases, using a new model and a new algorithm to efficiently compute the best peptide sequences whose fragment ions can best interpret the peaks in the MS/MS spectrum.
Abstract: A number of different approaches have been described to identify proteins from tandem mass spectrometry (MS/MS) data. The most common approaches rely on the available databases to match experimental MS/MS data. These methods suffer from several drawbacks and cannot be used for the identification of proteins from unknown genomes. In this communication, we describe a new de novo sequencing software package, PEAKS, to extract amino acid sequence information without the use of databases. PEAKS uses a new model and a new algorithm to efficiently compute the best peptide sequences whose fragment ions can best interpret the peaks in the MS/MS spectrum. The output of the software gives amino acid sequences with confidence scores for the entire sequences, as well as an additional novel positional scoring scheme for portions of the sequences. The performance of PEAKS is compared with Lutefisk, a well-known de novo sequencing software, using quadrupole-time-of-flight (Q-TOF) data obtained for several tryptic peptides from standard proteins.

1,239 citations


Journal ArticleDOI
TL;DR: A mechanistic basis of the observation that CK2 is essential for viability may reside in part in this ability to protect cellular proteins from caspase action, which may contribute to its ability to participate in transformation and tumorigenesis.
Abstract: Protein kinase CK2 (9casein kinase II9) has traditionally been classified as a messenger-independent protein serine/threonine kinase that is typically found in tetrameric complexes consisting of two catalytic (α and/or α′) subunits and two regulatory β subunits. Accumulated biochemical and genetic evidence indicates that CK2 has a vast array of candidate physiological targets and participates in a complex series of cellular functions, including the maintenance of cell viability. This review summarizes current knowledge of the structural and enzymic features of CK2, and discusses advances that challenge traditional views of this enzyme. For example, the recent demonstrations that individual CK2 subunits exist outside tetrameric complexes and that CK2 displays dual-specificity kinase activity raises new prospects for the precise elucidation of its regulation and cellular functions. This review also discusses a number of the mechanisms that contribute to the regulation of CK2 in cells, and will highlight emerging insights into the role of CK2 in cellular decisions of life and death. In this latter respect, recent evidence suggests that CK2 can exert an anti-apoptotic role by protecting regulatory proteins from caspase-mediated degradation. The mechanistic basis of the observation that CK2 is essential for viability may reside in part in this ability to protect cellular proteins from caspase action. Furthermore, this anti-apoptotic function of CK2 may contribute to its ability to participate in transformation and tumorigenesis.

1,181 citations


Posted Content
TL;DR: In this paper, the authors considered the relationship between the stocks and flows of learning across levels in an overall organizational learning system and found that there is a positive relationship between stocks of learning at all levels and business performance.
Abstract: This paper considers the relationship between the stocks and flows of learning across levels in an overall organizational learning system. A survey instrument based on the Strategic Learning Assessment Map (SLAM) was administered to 15 individuals representing senior-, middle- and non-management levels from each of 32 organizations, resulting in a total sample of 480 respondents. This research supports the premise that there is a positive relationship between the stocks of learning at all levels and business performance. Furthermore, the proposition that the misalignment of stocks and flows in an overall organizational learning system is negatively associated with business performance is also supported.

1,085 citations


Journal ArticleDOI
TL;DR: Future research needs are identified, including the need for large-scale longitudinal data and theoretically guided approaches that take into account relevant contextual factors.
Abstract: A wide range of children's developmental outcomes are compromised by exposure to domestic violence, including social, emotional, behavioral, cognitive, and general health functioning. However, there are relatively few empirical studies with adequate control of confounding variables and a sound theoretical basis. We identified 41 studies that provided relevant and adequate data for inclusion in a meta-analysis. Forty of these studies indicated that children's exposure to domestic violence was related to emotional and behavioral problems, translating to a small overall effect (Zr = .28). Age, sex, and type of outcome were not significant moderators, most likely due to considerable heterogeneity within each of these groups. Co-occurrence of child abuse increased the level of emotional and behavioral problems above and beyond exposure alone, based on 4 available studies. Future research needs are identified, including the need for large-scale longitudinal data and theoretically guided approaches that take into account relevant contextual factors.

961 citations


Journal Article
TL;DR: It is suggested that class prediction models, based on defined molecular profiles, classify diagnostically challenging malignant gliomas in a manner that better correlates with clinical outcome than does standard pathology.
Abstract: In modern clinical neuro-oncology, histopathological diagnosis affects therapeutic decisions and prognostic estimation more than any other variable. Among high-grade gliomas, histologically classic glioblastomas and anaplastic oligodendrogliomas follow markedly different clinical courses. Unfortunately, many malignant gliomas are diagnostically challenging; these nonclassic lesions are difficult to classify by histological features, generating considerable interobserver variability and limited diagnostic reproducibility. The resulting tentative pathological diagnoses create significant clinical confusion. We investigated whether gene expression profiling, coupled with class prediction methodology, could be used to classify high-grade gliomas in a manner more objective, explicit, and consistent than standard pathology. Microarray analysis was used to determine the expression of ∼12,000 genes in a set of 50 gliomas, 28 glioblastomas and 22 anaplastic oligodendrogliomas. Supervised learning approaches were used to build a two-class prediction model based on a subset of 14 glioblastomas and 7 anaplastic oligodendrogliomas with classic histology. A 20-feature k -nearest neighbor model correctly classified 18 of the 21 classic cases in leave-one-out cross-validation when compared with pathological diagnoses. This model was then used to predict the classification of clinically common, histologically nonclassic samples. When tumors were classified according to pathology, the survival of patients with nonclassic glioblastoma and nonclassic anaplastic oligodendroglioma was not significantly different ( P = 0.19). However, class distinctions according to the model were significantly associated with survival outcome ( P = 0.05). This class prediction model was capable of classifying high-grade, nonclassic glial tumors objectively and reproducibly. Moreover, the model provided a more accurate predictor of prognosis in these nonclassic lesions than did pathological classification. These data suggest that class prediction models, based on defined molecular profiles, classify diagnostically challenging malignant gliomas in a manner that better correlates with clinical outcome than does standard pathology.

Journal ArticleDOI
TL;DR: In this article, the shareholders' wealth affects of supply chain glitches are estimated by computing the abnormal stock returns around the date when information about information about glitches is publicly announced, and the results are based on a sample of 519 glitches announcements made during 1989-2000.

Journal ArticleDOI
TL;DR: There is mounting evidence that selected probiotic strains can provide health benefits to their human hosts, and accepted standards and guidelines proposed by the Food and Agriculture Organization of the United Nations and the World Health Organization represent a key step in ensuring that reliable products with suitable, informative health claims become available.
Abstract: Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host There is now mounting evidence that selected probiotic strains can provide health benefits to their human hosts Numerous clinical trials show that certain strains can improve the outcome of intestinal infections by reducing the duration of diarrhea Further investigations have shown benefits in reducing the recurrence of urogenital infections in women, while promising studies in cancer and allergies require research into the mechanisms of activity for particular strains and better-designed trials At present, only a small percentage of physicians either know of probiotics or understand their potential applicability to patient care Thus, probiotics are not yet part of the clinical arsenal for prevention and treatment of disease or maintenance of health The establishment of accepted standards and guidelines, proposed by the Food and Agriculture Organization of the United Nations and the World Health Organization, represents a key step in ensuring that reliable products with suitable, informative health claims become available Based upon the evidence to date, future advances with single- and multiple-strain therapies are on the horizon for the management of a number of debilitating and even fatal conditions

Journal ArticleDOI
TL;DR: In this article, a comparative study of the export performance of U.S. and Canadian small and medium-sized exporters is presented, where a parsimonious model is developed drawing on the resource-based theory of the firm, with three sets of resources, namely firm size, enterprise and technological intensity.
Abstract: This paper presents a comparative study of the export performance of U.S. and Canadian small and medium-sized exporters. A parsimonious model is developed drawing on the resource-based theory of the firm, with three sets of resources, namely firm size, enterprise, and technological intensity. These key resources are good predictors of the export strategy of a firm. Export strategy is modeled as degree of internationalization, and its effect on the overall firm performance is studied using firm-level performance measures. LISREL's multiple group analysis feature is used in the analysis to test the model. The results confirm the validity of the model across the two data sets.

Journal ArticleDOI
TL;DR: The method permits real‐time clinical acquisition and display of whole brain T1 and T2 maps for the first time and represents the most efficient of those examined.
Abstract: A novel, fully 3D, high-resolution T(1) and T(2) relaxation time mapping method is presented. The method is based on steady-state imaging with T(1) and T(2) information derived from either spoiling or fully refocusing the transverse magnetization following each excitation pulse. T(1) is extracted from a pair of spoiled gradient recalled echo (SPGR) images acquired at optimized flip angles. This T(1) information is combined with two refocused steady-state free precession (SSFP) images to determine T(2). T(1) and T(2) accuracy was evaluated against inversion recovery (IR) and spin-echo (SE) results, respectively. Error within the T(1) and T(2) maps, determined from both phantom and in vivo measurements, is approximately 7% for T(1) between 300 and 2000 ms and 7% for T(2) between 30 and 150 ms. The efficiency of the method, defined as the signal-to-noise ratio (SNR) of the final map per voxel volume per square root scan time, was evaluated against alternative mapping methods. With an efficiency of three times that of multipoint IR and three times that of multiecho SE, our combined approach represents the most efficient of those examined. Acquisition time for a whole brain T(1) map (25 x 25 x 10 cm) is less than 8 min with 1 mm(3) isotropic voxels. An additional 7 min is required for an identically sized T(2) map and postprocessing time is less than 1 min on a 1 GHz PIII PC. The method therefore permits real-time clinical acquisition and display of whole brain T(1) and T(2) maps for the first time.

Journal ArticleDOI
TL;DR: It is demonstrated that the conversion of arginine to citrulline at the peptide side-chain position interacting with the shared epitope significantly increases peptide-MHC affinity and leads to the activation CD4+ T cells in DR4-IE tg mice.
Abstract: Rheumatoid arthritis (RA) is genetically associated with MHC class II molecules that contain the shared epitope. These MHC molecules may participate in disease pathogenesis by selectively binding arthritogenic peptides for presentation to autoreactive CD4(+) T cells. The nature of the arthritogenic Ag is not known, but recent work has identified posttranslationally modified proteins containing citrulline (deiminated arginine) as specific targets of the IgG Ab response in RA patients. To understand how citrulline might evoke an autoimmune reaction, we have studied T cell responses to citrulline-containing peptides in HLA-DRB1*0401 transgenic (DR4-IE tg) mice. In this study, we demonstrate that the conversion of arginine to citrulline at the peptide side-chain position interacting with the shared epitope significantly increases peptide-MHC affinity and leads to the activation CD4(+) T cells in DR4-IE tg mice. These results reveal how DRB1 alleles with the shared epitope could initiate an autoimmune response to citrullinated self-Ags in RA patients.

Journal ArticleDOI
01 Apr 2003-Stroke
TL;DR: Intense therapy over a short amount of time can improve outcomes of speech and language therapy for stroke patients with aphasia.
Abstract: Background— It has been speculated that the conflicting results demonstrated across poststroke aphasia therapy studies might be related to differences in intensity of therapy provided across studies. The aim of this study is to investigate the relationship between intensity of aphasia therapy and aphasia recovery. Methods— A MEDLINE literature search was conducted to retrieve clinical trials investigating aphasia therapy after stroke. Changes in mean scores from each study were recorded. Intensity of therapy was recorded in terms of length of therapy, hours of therapy provided per week, and total hours of therapy provided. Pearson correlation was used to assess the relationship between changes in mean scores of outcome measures and intensity of therapy. Results— Studies that demonstrated a significant treatment effect provided 8.8 hours of therapy per week for 11.2 weeks versus the negative studies that only provided ≈2 hours per week for 22.9 weeks. On average, positive studies provided a total of 98.4 h...

Journal ArticleDOI
TL;DR: In this paper, the 4I framework of organizational learning is used to examine the phenomenon of strategic renewal at Canada Post Corporation (CPC) and illustrates the underlying processes that form the tension between exploration and exploitation, demonstrating why strategic renewal is so challenging.
Abstract: This paper attempts to fill an important gap in the integration of strategy and organizational learning through empirical research that examines the process of strategic renewal using a comprehensive framework of organizational learning. The 4I framework of organizational learning is used to examine the phenomenon of strategic renewal at Canada Post Corporation (CPC). The study illustrates the underlying processes that form the tension between exploration and exploitation, demonstrating why strategic renewal is so challenging. Furthermore, it challenges assumptions about organizational learning, suggesting that we need to demystify organizational learning by removing the halo that surrounds it. Copyright © 2003 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: The capacity of transplanted bone marrow–derived stem cells to initiate endogenous pancreatic tissue regeneration represents a previously unrecognized means by which these cells can contribute to the restoration of organ function.
Abstract: We show that transplantation of adult bone marrow-derived cells expressing c-kit reduces hyperglycemia in mice with streptozotocin-induced pancreatic damage. Although quantitative analysis of the pancreas revealed a low frequency of donor insulin-positive cells, these cells were not present at the onset of blood glucose reduction. Instead, the majority of transplanted cells were localized to ductal and islet structures, and their presence was accompanied by a proliferation of recipient pancreatic cells that resulted in insulin production. The capacity of transplanted bone marrow-derived stem cells to initiate endogenous pancreatic tissue regeneration represents a previously unrecognized means by which these cells can contribute to the restoration of organ function.

Journal ArticleDOI
TL;DR: The analyses of data collected from 899 young men and women of African American and non-Hispanic white ancestry suggest that status differences in exposure to stress vary considerably by the measure of stress that is employed, and that women are more exposed to recent life events than men, males report more major events and discrimination stress than females.
Abstract: Life events checklists have been the predominant method for estimating variations in stress exposure. It is unknown, however, whether such inventories are equally meaningful for estimating differences in exposure between men and women, African Americans and whites, and those in lower and higher socioeconomic categories. In this paper, we employ a wider range of measures of stress--recent life events, chronic stressors, lifetime major events, and discrimination stress--to examine the extent to which these dimensions collectively yield conclusions about status variations in stress exposure that are similar to or different from estimates based only on a life events checklist. Our analyses of data collected from 899 young men and women of African American and non-Hispanic white ancestry suggest that status differences in exposure to stress vary considerably by the measure of stress that is employed. Although women are more exposed to recent life events than men, males report more major events and discrimination stress than females. Our results also reveal that life event measures tend to substantially under-estimate differences between African Americans and non-Hispanic whites in exposure to stress. A similar pattern also holds for socioeconomic status. When stress is more comprehensively estimated, level of exposure profoundly affects ethnic differences in depressive symptomatology, accounting for almost half of the difference by socioeconomic status but contributing little to the explanation of the gender difference in distress. The implications of these findings for the debate over the relative mental health significance of exposure and vulnerability to stress are discussed.

Journal ArticleDOI
TL;DR: Functional magnetic resonance imaging results suggest that dorsal areas, including AIP, but not ventral areas such as LOC, play a fundamental role in computing object properties during grasping.
Abstract: Although both reaching and grasping require transporting the hand to the object location, only grasping also requires processing of object shape, size and orientation to preshape the hand. Behavioural and neuropsychological evidence suggests that the object processing required for grasping relies on different neural substrates from those mediating object recognition. Specifically, whereas object recognition is believed to rely on structures in the ventral (occipitotemporal) stream, object grasping appears to rely on structures in the dorsal (occipitoparietal) stream. We used functional magnetic resonance imaging (fMRI) to determine whether grasping (compared to reaching) produced activation in dorsal areas, ventral areas, or both. We found greater activity for grasping than reaching in several regions, including anterior intraparietal (AIP) cortex. We also performed a standard object perception localizer (comparing intact vs. scrambled 2D object images) in the same subjects to identify the lateral occipital complex (LOC), a ventral stream area believed to play a critical role in object recognition. Although LOC was activated by the objects presented on both grasping and reaching trials, there was no greater activity for grasping compared to reaching. These results suggest that dorsal areas, including AIP, but not ventral areas such as LOC, play a fundamental role in computing object properties during grasping.

Journal Article
TL;DR: In this paper, a translocation involving a single gene family, consisting of EWS and related genes, has been identified in five different sarcomas, and its chimeric protein products could prove similarly amenable to inhibitors.
Abstract: Sarcomas--like leukemias, which are also mesodermal malignancies--carry biological significance disproportionate to their clinical frequency. Identification of mutations and translocations associated with these tumors has illuminated aberrant signaling pathways that cause these diseases, determine their behavior, and are therapeutic targets. Activated receptor-associated tyrosine kinase c-kit, mutated in most gastrointestinal stromal tumors, has proven a clinically effective target for enzyme inhibition. A translocation involving a single gene family, consisting of EWS and related genes, has been identified in five different sarcomas, and its chimeric protein products could prove similarly amenable to inhibitors. Resolution of the histopathological complexity is being aided by data from molecular and chromosomal characterization. Improvements in imaging, definition of prognostic factors, and surgical and radiotherapeutic treatment have resulted in improved local control. Continued progress will depend on further adapting the rapidly evolving technologies of genomics and proteomics. It will also depend upon accurate histopathological diagnosis based on validated reagents and consistent methodologies applied to adequate tissue samples derived from patients with complete clinical data. Finally, multicenter, coordinated trials, such as those that occurred with assessment of imatinib mesylate in metastatic gastrointestinal stromal tumors, will assure the most rapid reductions in morbidity and mortality.

Journal ArticleDOI
TL;DR: Because of their anti-inflammatory nature, many of these poxvirus proteins hold promise as potential therapeutic agents for acute or chronic inflammatory conditions.
Abstract: Large DNA viruses defend against hostile assault executed by the host immune system by producing an array of gene products that systematically sabotage key components of the inflammatory response. Poxviruses target many of the primary mediators of innate immunity including interferons, tumor necrosis factors, interleukins, complement, and chemokines. Poxviruses also manipulate a variety of intracellular signal transduction pathways such as the apoptotic response. Many of the poxvirus genes that disrupt these pathways have been hijacked directly from the host immune system, while others have demonstrated no clear resemblance to any known host genes. Nonetheless, the immunological targets and the diversity of strategies used by poxviruses to disrupt these host pathways have provided important insights into diverse aspects of immunology, virology, and inflammation. Furthermore, because of their anti-inflammatory nature, many of these poxvirus proteins hold promise as potential therapeutic agents for acute or chronic inflammatory conditions.

ReportDOI
TL;DR: The authors examined the theoretical foundations of the Mincer model and examined the empirical support for it using data from Decennial Censuses and Current Population Surveys and found that the results from later decades are inconsistent with it.
Abstract: The Mincer earnings function is the cornerstone of a large literature in empirical economics. This paper discusses the theoretical foundations of the Mincer model and examines the empirical support for it using data from Decennial Censuses and Current Population Surveys. While data from 1940 and 1950 Censuses provide some support for Mincer's model, data from later decades are inconsistent with it. We examine the importance of relaxing functional form assumptions in estimating internal rates of return to schooling and of accounting for taxes, tuition, nonlinearity in schooling, and nonseparability between schooling and work experience. Inferences about trends in rates of return to high school and college obtained from our more general model differ substantially from inferences drawn from estimates based on a Mincer earnings regression. Important differences also arise between cohort-based and cross-sectional estimates of the rate of return to schooling. In the recent period of rapid technological progress, widely used cross-sectional applications of the Mincer model produce dramatically biased estimates of cohort returns to schooling. We also examine the implications of accounting for uncertainty and agent expectation formation. Even when the static framework of Mincer is maintained, accounting for uncertainty substantially affects the return estimates. Considering the sequential resolution of uncertainty over time in a dynamic setting gives rise to option values, which fundamentally changes the analysis of schooling decisions. In the presence of sequential resolution of uncertainty and option values, the internal rate of return - a cornerstone of classical human capital theory - is not a useful guide to policy analysis.

Journal ArticleDOI
TL;DR: The goal of this study was to test for a possible relationship between cocontraction and movement accuracy in multi-joint limb movements and observed an inverse relationship between target size and cocontracted activity: as target size was reduced, cocontractions activity increased.
Abstract: Cocontraction (the simultaneous activation of antagonist muscles around a joint) provides the nervous system with a way to adapt the mechanical properties of the limb to changing task requirements—...


Journal ArticleDOI
TL;DR: A conceptual model of 11 environmental, family, and child factors that are thought to influence children's participation in recreation and leisure activities is presented, outlining the existing evidence for the influence of these factors on one another and on children'sparticipation.
Abstract: Participation in everyday activities is considered to be a vital part of children's development, which is related to their quality of life and future life outcomes. Research studies indicate that children with disabilities are at risk for lower participation in ordinary activities at home and in the community. This article presents a conceptual model of 11 environmental, family, and child factors that are thought to influence children's participation in recreation and leisure activities. The article outlines the existing evidence for the influence of these factors on one another and on children's participation. The review encompasses four bodies of literature: the participation of children or adults with disabilities, the risk and resilience of children facing adversity, the determinants of leisure and recreation activities, and the factors influencing physical activity and exercise. The proposed model is expected to be a useful tool for guiding future research studies and for developing policies and programs for children with disabilities and their families.

Journal ArticleDOI
TL;DR: In this article, seven trends regarding the categories that tend to be impaired/preserved in category-specific semantic deficits were identified and the authors hypothesized that these trends arise despite the multiple sources of variation in patient testing because numerous factors that structure semantic memory probabilistically converge to make some categories of knowledge more susceptible to damage than others.
Abstract: Seven trends regarding the categories that tend to be impaired/preserved in category-specific semantic deficits were identified. The authors hypothesized that these trends arise despite the multiple sources of variation in patient testing because numerous factors that structure semantic memory probabilistically converge to make some categories of knowledge more susceptible to damage than others. Analysis of semantic feature norms and corpus data for 541 concepts revealed that differences in the distribution of knowledge types across categories are sufficient to explain 6 of the trends and are necessary to explain loss of knowledge about nonliving things. Feature informativeness, concept confusability, visual complexity, familiarity, and name frequency contributed to this patterning and provide insight into why knowledge about living things is most often impaired.

Journal ArticleDOI
TL;DR: In this article, the authors traced the development of natural environmental issues in two organizations in real time over a period of a year and identified the factors that influenced the scope, scale, and speed of organizational response to issues.
Abstract: In this research, we traced the development of natural environmental issues in two organizations in real time over the period of a year. Participant observations, discussions with organizational members, and corporate documents yielded insights used to develop a model describing issue flows in both organizations. With this model, we identified the factors that influenced the scope, scale, and speed of organizational response to issues. Our methods provided insights into why issues generated organizational responses and also why they did not.Two factors appeared to be critical in explaining organizational responses to issues: individual concerns and organizational values. Individual concerns gave rise to an issue champion or seller. An issue consistent with organizational values was perceived as strategic. These werenecessary conditions; without either condition, the issue would not be resolved. It is argued further that individual discretion and excess resource slack will moderate the relationship between these direct effects and the scope, scale, and speed of organizational response. The framework that emerged from the data is conveyed through a set of four propositions.

Journal ArticleDOI
05 Feb 2003-JAMA
TL;DR: Much has been learned in recent years about the epidemiology of violence against women, yet information about evidence-based approaches in the primary care setting for preventing intimate partner violence is seriously lacking.
Abstract: ContextIntimate partner violence is prevalent and is associated with significant impairment, yet it remains unclear which interventions, if any, reduce rates of abuse and reabuse.ObjectiveTo systematically review, from the perspective of primary health care, the available evidence on interventions aimed at preventing abuse or reabuse of women.Data SourcesMEDLINE, PsycINFO, CINAHL, HealthStar, and Sociological Abstracts were searched from the database start dates to March 2001 using database-specific key words such as domestic violence, spouse abuse, partner abuse, shelters, and battered women. References of key articles were hand searched. The search was updated in December 2002.Study SelectionBoth authors reviewed all titles and abstracts using established inclusion/exclusion criteria. Twenty-two articles met the inclusion criteria for critical appraisal.Data ExtractionFollowing the evidence-based methods of the Canadian Task Force on Preventive Health Care, both authors independently reviewed the 22 included studies using an established hierarchy of study designs and criteria for rating internal validity. Quality ratings of individual studies—good, fair, or poor—were determined based on a set of operational parameters specific to each design category developed with the US Preventive Services Task Force.Data SynthesisScreening instruments exist that can identify women who are experiencing intimate partner violence. No study has examined, in a comparative design, the effectiveness of screening when the end point is improved outcomes for women (as opposed to identification of abuse). No high-quality evidence exists to evaluate the effectiveness of shelter stays to reduce violence. Among women who have spent at least 1 night in a shelter, there is fair evidence that those who received a specific program of advocacy and counseling services reported a decreased rate of reabuse and an improved quality of life. The benefits of several other intervention strategies in treating both women and men are unclear, primarily because of a lack of suitably designed research measuring appropriate outcomes. In most cases, the potential harms of interventions are not assessed within the studies reviewed.ConclusionsMuch has been learned in recent years about the epidemiology of violence against women, yet information about evidence-based approaches in the primary care setting for preventing intimate partner violence is seriously lacking. The evaluation of interventions to improve the health and well-being of abused women remains a key research priority.