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Waves
Kinds of Waves Terms modified by Waves Selected AbstractsA novel function of WAVE in lamellipodia: WAVE1 is required for stabilization of lamellipodial protrusions during cell spreadingGENES TO CELLS, Issue 5 2005Daisuke Yamazaki When a cell spreads and moves, reorganization of the actin cytoskeleton pushes the cell membrane, and the resulting membrane protrusions create new points of contact with the substrate and generate the locomotive force. Membrane extension and adhesion to a substrate must be tightly coordinated for effective cell movement, but little is known about the mechanisms underlying these processes. WAVEs are critical regulators of Rac-induced actin reorganization. WAVE2 is essential for formation of lamellipodial structures at the cell periphery stimulated by growth factors, but it is thought that WAVE1 is dispensable for such processes in mouse embryonic fibroblasts (MEFs). Here we show a novel function of WAVE in lamellipodial protrusions during cell spreading. During spreading on fibronectin (FN), MEFs with knockouts (KOs) of WAVE1 and WAVE2 showed different membrane dynamics, suggesting that these molecules have distinct roles in lamellipodium formation. Formation of lamellipodial structures on FN was inhibited in WAVE2 KO MEFs. In contrast, WAVE1 is not essential for extension of lamellipodial protrusions but is required for stabilization of such structures. WAVE1-deficiency decreased the density of actin filaments and increased the speed of membrane extension, causing deformation of focal complex at the tip of spreading edges. Thus, at the tip of the lamellipodial protrusion, WAVE2 generates the membrane protrusive structures containing actin filaments, and modification by WAVE1 stabilizes these structures through cell-substrate adhesion. Coordination of WAVE1 and WAVE2 activities appears to be necessary for formation of proper actin structures in stable lamellipodia. [source] THE GLOBAL BANK MERGER WAVE: IMPLICATIONS FOR DEVELOPING COUNTRIESTHE DEVELOPING ECONOMIES, Issue 4 2002GARY A. DYMSKI This paper reconsiders causes and implications of the global bank merger wave, especially for developing economies. Previous studies of the global bank mergers,that is, mergers between banks from different nations,had assumed that these combinations are efficiency-driven, and that the U.S. case defines the paradigm for all other nations' banking systems. This paper argues that the U.S. experience is unique, not paradigmatic, and that bank mergers are not efficiency-driven; instead, this merger wave has arisen because of macrostructural circumstances and because of shifts over time in banks' strategic motives. This paper argues that large, offshore banks often engage in cross-border mergers because they want to provide financial services to households and firms that have reached minimal threshold wealth levels. For developing economies, this suggests that cross-border acquisitions of local banks by offshore banks will have mixed effects; and it cannot be assumed that the net social impact is positive. [source] THE AURICULAR WAVE (P) OF THE ELECTROCARDIOGRAMANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2001CLINICAL OBSERVATIONS WITH ESPECIAL REFERENCE TO PULMONIC AND MITRAL STENOSES No abstract is available for this article. [source] TRANSIENT STRESS WAVES IN STUDY OF COCONUT PHYSICAL PROPERTIESEXPERIMENTAL TECHNIQUES, Issue 1 2010J. Trnka First page of article [source] ON AXISYMMETRIC TRAVELING WAVES AND RADIAL SOLUTIONS OF SEMI-LINEAR ELLIPTIC EQUATIONSNATURAL RESOURCE MODELING, Issue 3 2000THOMAS P. WITELSKI ABSTRACT. Combining analytical techniques from perturbation methods and dynamical systems theory, we present an elementaryapproach to the detailed construction of axisymmetric diffusive interfaces in semi-linear elliptic equations. Solutions of the resulting non-autonomous radial differential equations can be expressed in terms of a slowlyvarying phase plane system. Special analytical results for the phase plane system are used to produce closed-form solutions for the asymptotic forms of the curved front solutions. These axisym-metric solutions are fundamental examples of more general curved fronts that arise in a wide variety of scientific fields, and we extensivelydiscuss a number of them, with a particular emphasis on connections to geometric models for the motion of interfaces. Related classical results for traveling waves in one-dimensional problems are also reviewed briefly. Manyof the results contained in this article are known, and in presenting known results, it is intended that this article be expositoryin nature, providing elementarydemonstrations of some of the central dynamical phenomena and mathematical techniques. It is hoped that the article serves as one possible avenue of entree to the literature on radiallysymmetric solutions of semilinear elliptic problems, especiallyto those articles in which more advanced mathematical theoryis developed. [source] A novel function of WAVE in lamellipodia: WAVE1 is required for stabilization of lamellipodial protrusions during cell spreadingGENES TO CELLS, Issue 5 2005Daisuke Yamazaki When a cell spreads and moves, reorganization of the actin cytoskeleton pushes the cell membrane, and the resulting membrane protrusions create new points of contact with the substrate and generate the locomotive force. Membrane extension and adhesion to a substrate must be tightly coordinated for effective cell movement, but little is known about the mechanisms underlying these processes. WAVEs are critical regulators of Rac-induced actin reorganization. WAVE2 is essential for formation of lamellipodial structures at the cell periphery stimulated by growth factors, but it is thought that WAVE1 is dispensable for such processes in mouse embryonic fibroblasts (MEFs). Here we show a novel function of WAVE in lamellipodial protrusions during cell spreading. During spreading on fibronectin (FN), MEFs with knockouts (KOs) of WAVE1 and WAVE2 showed different membrane dynamics, suggesting that these molecules have distinct roles in lamellipodium formation. Formation of lamellipodial structures on FN was inhibited in WAVE2 KO MEFs. In contrast, WAVE1 is not essential for extension of lamellipodial protrusions but is required for stabilization of such structures. WAVE1-deficiency decreased the density of actin filaments and increased the speed of membrane extension, causing deformation of focal complex at the tip of spreading edges. Thus, at the tip of the lamellipodial protrusion, WAVE2 generates the membrane protrusive structures containing actin filaments, and modification by WAVE1 stabilizes these structures through cell-substrate adhesion. Coordination of WAVE1 and WAVE2 activities appears to be necessary for formation of proper actin structures in stable lamellipodia. [source] Emergent properties from organisms to ecosystems: towards a realistic approachBIOLOGICAL REVIEWS, Issue 3 2005Jean-François Ponge ABSTRACT More realistic approaches are needed to understand the complexity of ecological systems. Emergent properties of real systems can be used as a basis for a new, neither reductionist nor holistic, approach. Three systems, termed here BUBBLEs, WAVEs and CRYSTALS, have been identified as exhibiting emergent properties. They are non-hierarchical assemblages of individual components, with amplification and connectedness being two main principles that govern their build-up, maintenance and mutual relationships. Examples from various fields of biological and ecological science are referred to, ranging from individual organisms to landscapes. [source] Lighting and Occlusion in a Wave-Based FrameworkCOMPUTER GRAPHICS FORUM, Issue 2 2008Remo Ziegler Abstract We present novel methods to enhance Computer Generated Holography (CGH) by introducing a complex-valued wave-based occlusion handling method. This offers a very intuitive and efficient interface to introduce optical elements featuring physically-based light interaction exhibiting depth-of-field, diffraction, and glare effects. Fur-thermore, an efficient and flexible evaluation of lit objects on a full-parallax hologram leads to more convincing images. Previous illumination methods for CGH are not able to change the illumination settings of rendered holo-grams. In this paper we propose a novel method for real-time lighting of rendered holograms in order to change the appearance of a previously captured holographic scene. These functionalities are features of a bigger wave-based rendering framework which can be combined with 2D framebuffer graphics. We present an algorithm which uses graphics hardware to accelerate the rendering. [source] Longitudinal Dust Lattice Shock Wave in a Strongly Coupled Complex Dusty PlasmaCONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2008S. Ghosh Abstract The effect of hydrodynamical damping that arises due to the irreversible processes within the system have been studied on 1D nonlinear longitudinal dust lattice wave (LDLW) in homogeneous strongly coupled complex (dusty) plasma. Analytical investigation shows that the nonlinear wave is governed by Korteweg-de Vries Burgers' equation. This hydrodynamical damping induced dissipative effect is responsible for the Burgers' term that causes the generation of shock wave in dusty plasma crystal. Numerical investigation on the basis of the glow-discharge plasma parameters reveal that LDLW exhibits both oscillatory and monotonic shock. The shock is compressive in nature and its strength decreases (increases) with the increase of the shielding parameter , (characteristic length L). The effects of dust-neutral collision are also discussed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The relationship between anxiety disorders and suicide attempts: findings from the National Epidemiologic Survey on Alcohol and Related ConditionsDEPRESSION AND ANXIETY, Issue 9 2010Josh Nepon M.D. Abstract Background: Previous work has suggested that anxiety disorders are associated with suicide attempts. However, many studies have been limited by lack of accounting for factors that could influence this relationship, notably personality disorders. This study aims to examine the relationship between anxiety disorders and suicide attempts, accounting for important comorbidities, in a large nationally representative sample. Methods: Data came from the National Epidemiologic Survey on Alcohol and Related Conditions Wave 2. Face-to-face interviews were conducted with 34,653 adults between 2004 and 2005 in the United States. The relationship between suicide attempts and anxiety disorders (panic disorder, agoraphobia, social phobia, specific phobia, generalized anxiety disorder, posttraumatic stress disorder (PTSD)) was explored using multivariate regression models controlling for sociodemographics, Axis I and Axis II disorders. Results: Among individuals reporting a lifetime history of suicide attempt, over 70% had an anxiety disorder. Even after adjusting for sociodemographic factors, Axis I and Axis II disorders, the presence of an anxiety disorder was significantly associated with having made a suicide attempt (AOR=1.70, 95% confidence interval (CI): 1.40,2.08). Panic disorder (AOR=1.31, 95% CI: 1.06,1.61) and PTSD (AOR=1.81, 95% CI: 1.45,2.26) were independently associated with suicide attempts in multivariate models. Comorbidity of personality disorders with panic disorder (AOR=5.76, 95% CI: 4.58,7.25) and with PTSD (AOR=6.90, 95% CI: 5.41,8.79) demonstrated much stronger associations with suicide attempts over either disorder alone. Conclusion: Anxiety disorders, especially panic disorder and PTSD, are independently associated with suicide attempts. Clinicians need to assess suicidal behavior among patients presenting with anxiety problems. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source] Political parties, electoral systems and democracy: A cross-national analysisEUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 2 2005AMANDA L. HOFFMAN Models are used to explore whether the number of political parties increases a country's democracy score on the POLITY IV measure of democracy, and whether countries with proportional representation electoral systems have higher democracy scores than those without. Multiple regression analysis reveals that countries with proportional electoral systems have higher democracy scores. Countries involved in the Third Wave of democracy may find the choice of an electoral system among the most important issues in structuring a democratic government. [source] Facing the Age Wave and Economic Policy: Fixing Public Pension Systems with Healthcare in the Wings,FISCAL STUDIES, Issue 1 2005David A. Wise Abstract There are two overriding problems faced by ageing societies. One is the financing of public pension (social security in US terms) programmes. The other is paying for healthcare. This paper considers the healthcare issue briefly, emphasising that the issue arises primarily because of advances in medical technology. Better medical technology will improve healthcare in the future, but more advanced technologies also cost more. The focus of the rest of the paper is on the public pension problem. The emphasis is on the early retirement incentives inherent in the provisions of most public pension programmes around the world, the reduction in the labour force participation of older people caused by these incentives, and the large fiscal implication of the inducement of older people to leave the labour force. These results are based on the Gruber,Wise ongoing international social security comparison project. [source] Wave and sediment dynamics along a shallow subtidal sandy beach inhabited by modern stromatolitesGEOBIOLOGY, Issue 1 2008J. E. ECKMAN ABSTRACT To help define the habitat of modern marine stromatolites, wave-dominated flow and sediment transport were studied in the shallow subtidal region (1,2 m depth) along the slightly concave, windward face of Highborne Cay, Exuma, Bahamas , the only face of the cay that includes a population of stromatolites concentrated near the region of highest curvature of the beach. Wave energy impacting this island's most exposed beach was driven by local wind forcing which increases largely in response to the passage of atmospheric disturbances that typically affect the region for periods of a few days. Although some wave energy is almost always noted (maximum horizontal orbital speeds at the bottom are rarely <10 cm s,1), wave conditions remain comparatively calm until local winds increase above speeds of ,3,4 m s,1 at which point maximum wave speeds rapidly increase to 50,80 cm s,1. Stromatolites, which are largely restricted to the shoreward side of a shallow platform reef, are sheltered by the reef beyond which wave speeds are one to four times higher (depending on tidal stage). Moreover, stromatolite populations are predominantly found along a region of this wave-exposed beach that experiences comparatively reduced wave energy because of the curved morphology of the island's face. Maximum wave speeds are 1.4 to 2 times higher along more northern sections of the beach just beyond the locus of stromatolite populations. A quantitative model of sediment transport was developed that accurately predicted accumulation of suspended sediment in sediment traps deployed in the shallow subtidal zone along this beach. This model, coupled with in situ wave records, indicates that gross rates of suspended sediment deposition should be two to three times higher northward of the main stromatolite populations. Regions of the beach containing stromatolites nevertheless should experience significant rates of gross suspended sediment deposition averaging 7,10 g cm,2 day,1 (,4,6 cm day,1). Results suggest that one axis of the habitat of modern marine stromatolites may be defined by a comparatively narrow range of flow energy and sediment transport conditions. [source] Studies in Urban Ecology: the First Wave of Biological Invasion by Pistacia chinensis in Armidale, New South Wales, AustraliaGEOGRAPHICAL RESEARCH, Issue 3 2000J. M. B. Smith Biological invasions by deliberately introduced organisms seriously compromise the integrity of ecosystems, but their early stages have seldom been documented, especially in urban contexts. Since the 1940s, the small Asian tree Pistacia chinensis has been widely planted in streets and gardens in Armidale, New South Wales, Australia, where it makes a major contribution to the autumn colours that are exploited to promote the city. Numerous wild plants are now becoming established in and near Armidale. This ongoing biological invasion may have been accelerated by the large size of the initial (planted) population, and by the presence of efficient avian seed dispersers. It is now at the stage of the first wild generation reaching reproductive maturity. While it is probably still possible to halt the invasion, various human factors appear to make this an unlikely prospect. [source] The Effects of Health Sector Market Factors and Vulnerable Group Membership on Access to Alcohol, Drug, and Mental Health CareHEALTH SERVICES RESEARCH, Issue 3p1 2007Susan E. Stockdale Objective. This study adapts Andersen's Behavioral Model to determine if health sector market conditions affect vulnerable subgroups' use of alcohol, drug, and mental health services (ADM) differently than the general population, focusing specifically on community-level predisposing and enabling characteristics. Data Sources. Wave 2 data (2000,2001) from the Health Care for Communities study, supplemented with cases from wave 1 (1997,1998), were merged with area characteristics taken from Census, Area Resource File (ARF), and other data sources. Study Design. The study used four-level hierarchical logistic regression to examine access to ADM care from any provider and specialty ADM access. Interactions between community-level predisposing and enabling vulnerability characteristics with individual race/ethnicity, age, income category, and insurance type were explored. Principal Findings. Nonwhites, the poor, uninsured, and elderly had lower likelihoods of service use, but interactions between race/ethnicity, income, age and insurance status with community-level vulnerability factors were not statistically significant for any service use. For ADM specialty care, those with Medicare, Medicaid, private fully managed, and private partially managed insurance, the likelihood of utilization was higher in areas with higher HMO penetration. However, for those with other insurance or no insurance plan, the likelihood of utilization was lower in areas with higher HMO penetration. Conclusions. Community-level enabling factors explain part of the effect of disadvantaged status but, with the exception of the effect of HMO penetration on the relationship between insurance and specialty care use, do not modify any of the residual individual-level effects of disadvantage. Interventions targeting both structural and individual levels may be necessary to address the problem of health disparities. More research with longitudinal data is necessary to sort out the causal direction of social context and ADM access outcomes, and whether policy interventions to change health sector market conditions can shift ADM treatment utilization. [source] Exact integration of polynomial,exponential products with application to wave-based numerical methodsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 3 2009G. Gabard Abstract Wave-based numerical methods often require to integrate products of polynomials and exponentials. With quadrature methods, this task can be particularly expensive at high frequencies as large numbers of integration points are required. This paper presents a set of closed-form solutions for the integrals of polynomial,exponential products in two and three dimensions. These results apply to arbitrary polygons in two dimensions, and for arbitrary polygonal surfaces or polyhedral volumes in three dimensions. Quadrature methods are therefore not required for this class of integrals that can be evaluated quickly and exactly. Copyright © 2008 John Wiley & Sons, Ltd. [source] A comparison of early family life events amongst monozygotic twin women with lifetime anorexia nervosa, bulimia nervosa, or major depressionINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 8 2007Tracey D Wade PhD Abstract Objectives: To investigate the differential profile of early family life events associated with lifetime anorexia nervosa (AN), bulimia nervosa (BN), and major depression (MD). Method: Only data from the monozygotic twins (n = 622) were examined from a community sample of female twins who had participated in three waves of data collection. Eating disorder and MD diagnoses were ascertained from the Eating Disorder Examination at Wave 3 and interview at Wave 2 respectively. Early family events were ascertained from self-report measures at Waves 1 and 3. Two case control designs were used, including a comparison of women: (1) who had lifetime AN, BN, MD, and controls, and (2) twin pairs discordant for either AN, BN, or MD (where the unaffected cotwin formed the control group). Results: Across the two types of designs, compared to controls, both AN and BN were associated with more comments from the family about weight and shape when growing up. AN was uniquely associated with higher levels of paternal protection while BN was associated with higher levels of parental expectations. Conclusion: While some overlap among early life events was indicated, especially related to parental conflict and criticism, there was evidence to support some degree of nonoverlap among life events associated with AN, BN, and MD. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007 [source] Prevalence and patterns of executive impairment in community dwelling Mexican Americans: results from the Hispanic EPESE StudyINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 10 2004Donald R. Royall Abstract Introduction Little is known about the prevalence of impaired executive control function (ECF) in community dwelling elderly or minority populations. We have determined the prevalence of cognitive impairment and impaired ECF in a community dwelling Mexican American elderly population, and their associations with functional status. Subjects Subjects were 1165 Mexican Americans age 65 and over who were administered CLOX as part of the third wave of the Hispanic Established Population for Epidemiological Study (HEPESE) conducted from 1998 to 1999. Methods ECF was measured by an executive clock-drawing task (CDT) (i.e. CLOX1). Non-executive cognitive function was assessed by the Mini-Mental State Examination (MMSE) and a non-executive CDT (CLOX2). CLOX scores were combined to estimate the prevalence of global CLOX failure (i.e. ,Type 1' cognitive impairment) vs isolated CLOX1 failure (i.e. Type 2 cognitive impairment). Results 59.3% of subjects failed CLOX1. 31.1% failed both CLOX1 and CLOX2 (Type 1 cognitive impairment). 33.3% failed CLOX1 only (Type 2 cognitive impairment). 35.6% passed both measures [no cognitive impairment (NCI)]. Many subjects with CLOX1 impairment at Wave 3 had normal MMSE scores. This was more likely to occur in the context of Type 2 cognitive impairment. Both CLOX defined cognitive impairment groups were associated with functional impairment. Conclusions A large percentage of community dwelling Mexican American elderly suffer cognitive impairment that can be demonstrated through a CDT. Isolated executive impairments appear to be most common. The ability of a CDT to demonstrate ECF impairments potentially offers a rapid, culturally unbiased and cost-effective means of assessing this domain. In contrast, the MMSE is relatively insensitive to ECF assessed by CLOX1. Copyright © 2004 John Wiley & Sons, Ltd. [source] Selective non-response to clinical assessment in the longitudinal study of aging: implications for estimating population levels of cognitive function and dementiaINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2002Kaarin J. Anstey Abstract Objective To identify the cognitive outcome of interviewed participants who did not progress to partake in clinical assessments in a longitudinal aging study. Design A retrospective study was conducted on participants who were interviewed but who did not complete the clinical assessment (including an extended cognitive assessment) at either Wave 1 or both Wave 1 and Wave 3 of the Australian Longitudinal Study of Ageing. A total of 1947 participants aged 70 and older commenced the study, 246 participants without clinical data at either or both Waves 1 and 3 were identified for the sub-sample followed-up retrospectively. The Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) was administered to informants and medical records were reviewed. Results Participants who did not complete the clinical assessment at Wave 3 reported poorer health and had poorer cognitive function at Wave 1 independent of age and gender. Rates of possible dementia or cognitive decline were higher in the group who did not undertake the clinical assessment compared with both those who did the clinical assessment and with population data. Conclusion Selective non-response to clinical assessment in a longitudinal aging study is associated with higher risk of cognitive decline and probable dementia. Longitudinal aging studies may underestimate rates of dementia and population levels of cognitive decline. Copyright © 2002 John Wiley & Sons, Ltd. [source] The cognitive decline scale of the psychogeriatric assessment scales (PAS): longitudinal data on its validityINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 3 2001A.F. Jorm Abstract Objective The Cognitive Decline scale of the Psychogeriatric Assessment Scales (PAS), uses informant data to assess retrospectively change from earlier in life. Data from a 7,8-year longitudinal study were used to assess the validity of this scale against changes in cognitive performance and mortality. Design and measures PAS data were collected on three occasions, with gaps of 3.6 and 4.1 years between the waves. The Cognitive Decline score at Wave 3 was validated retrospectively against actual change on a brief test of current cognitive status (the PAS Cognitive Impairment scale) over the three waves, while the Cognitive Decline score at Wave 1 was assessed for predictive validity against future mortality and cognitive change. Setting A community survey in the Australian cities of Canberra and Queanbeyan. Participants Participants were aged 70+ at the beginning of the study. The sample size varied from 729 to 279, depending on the number of waves involved. Results Participants with scores of 4+ on the Cognitive Decline scale at Wave 3 showed substantial deterioration over the previous 7,8 years. Scores of 4+ at Wave 1 predicted mortality and further cognitive deterioration. Conclusions The Cognitive Decline scale allows a valid retrospective assessment of change and has predictive validity for subsequent cognitive deterioration and increased mortality. Copyright © 2001 John Wiley & Sons, Ltd. [source] An 8-Year Prospective Study of the Relationship Between Cognitive Performance and Falling in Very Old AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2006Kaarin J. Anstey PhD OBJECTIVES: To determine whether cognitive performance, as distinct from cognitive impairment, predicts falling during an 8-year follow-up in a community-based sample of very old adults and to evaluate how cognitive change is associated with falling. DESIGN: Prospective cohort study including three waves of data collected in 1992, 1994, and 2000. SETTING: Population based, with the baseline sample drawn from the electoral roll. PARTICIPANTS: Inclusion criteria were completion of at least three cognitive tests at baseline and completion of the falls questionnaire at Wave 6 (N=539). MEASUREMENTS: Assessments of health and medical conditions, visual acuity, cognitive function, functional reach, semitandem stand, and grip strength were conducted in 1992 (baseline), 1994, and 2000. Self-report information on falls in the previous 12 months was obtained on each of these occasions. Marginal models using generalized estimating equations were used to assess the association between baseline cognitive performance and falling over 8 years, adjusting for sociodemographic, health, and sensorimotor variables. Random effects models were used to assess the relationship between change in cognitive performance and change in fall rate and fall risk over 8 years. RESULTS: Mini-Mental State Examination and verbal reasoning at baseline predicted rate of falling over an 8-year period. Within individuals, declines in verbal ability, processing speed, and immediate memory were associated with increases in rates of falling and fall risk. CONCLUSION: Cognitive performance is associated with falling over 8 years in very old adults and should be assessed in clinical practice when evaluating short- and long-term fall risk. [source] Contrasting effects of the extent of sea-ice on the breeding performance of an Antarctic top predator, the Snow Petrel Pagodroma niveaJOURNAL OF AVIAN BIOLOGY, Issue 4 2001Christophe Barbraud Recent studies have shown that the Antarctic Circumpolar Wave and the related sea-ice cover around the Antarctic continent may have a profound effect on the lower trophic levels of the marine environment. In particular, extensive sea-ice cover enhances the survival of krill. However, the effects of sea-ice cover on top predators remain poorly understood. Using time series from 1973 to 1999, we examine the influence of regional sea-ice extent on a number of indices of breeding performance of an avian predator, the Snow Petrel, in Antarctica. The percentage of breeding pairs was highly variable and there were fewer birds breeding when sea-ice cover was extensive during July. By contrast, overall breeding success and fledgling body condition were improved during years with extensive sea-ice cover during the preceding November and July,September. These results indicate that the same sea-ice conditions may have different effects on the breeding performance of a species. The overall increase in winter sea-ice extent during the last decade appears to have resulted in an overall improvement of the quality of fledglings produced, and thus probably of future recruitment. [source] Clinical Characteristics of Patients With Spontaneous or Inducible Ventricular Fibrillation Without Apparent Heart Disease Presenting with J Wave and ST Segment Elevation in Inferior LeadsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2000MASAHTKO TAKAGI M.D., Ph.D. Ventricular Fibrillation with J Wave in Inferior Leads. Introduction: The clinical characteristics of three patients with spontaneous or inducible ventricular fibrillation (VF) without apparent heart disease, who presented with J wave and ST segment elevation in inferior leads, are described. Methods and Results: All patients were male and experienced syncope. Their symptoms occurred at night or early in the morning. Holter ECG revealed infrequent premature ventricular complexes. Injection with disopyramide 2 mg/kg augmented ST segment elevation. Conclusion: These characteristics were very similar to those of patients with Brugada syndrome. These three patients with these specific features might have a variant of Brugada syndrome. [source] Intimate partner violence relationship dissolution among couples with children: the counterintuitive role of "Law and Order" neighborhoodsJOURNAL OF COMMUNITY PSYCHOLOGY, Issue 4 2010Clifton R. Emery This study examined the relationship between intimate partner violence (IPV) relationship dissolution and neighborhood concentrated disadvantage, ethnic heterogeneity, residential instability, collective efficacy, and legal cynicism. Data from the Project on Human Development in Chicago Neighborhoods (PHDCN) Longitudinal survey were used to identify 658 cases of IPV in Wave 1. A generalized boosting model (GBM) was used to determine the best proximal predictors of relationship dissolution from the longitudinal data. Controlling for these predictors, logistic regression of neighborhood characteristics from the PHDCN community survey was used to predict IPV relationship dissolution in Wave 2. Counterintuitively, the authors find that neighborhoods high in legal cynicism have a greater likelihood of IPV relationship dissolution, controlling for other variables in the logistic regression model. However, analyses did not find that IPV relationship dissolution was related to neighborhood concentrated disadvantage, ethnic heterogeneity, residential instability, and collective efficacy. © 2010 Wiley Periodicals, Inc. [source] Evaluation of the Personal Dental Services (Wave 1) for Lambeth, Southwark and Lewisham Primary Care Trusts , Part 1: Retrospective analyses of registration data and access issuesJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2005Helen Best BDS MDS PhD Abstract Aim/objective, The purpose of the study was to undertake analyses of registration data for the personal dental services (PDS) of Lambeth, Southwark and Lewisham primary care trusts and relate the analyses to the PDS goal ,of ,increasing ,uptake ,of ,dental services. Method, Secondary analyses of registration statistics provided by the Dental Practice Board were undertaken for both 1 years pre-PDS (October 1997 to September 1998) and post-PDS (October 1998 to March 2003) periods. Three sets of analyses were undertaken to consider different aspects of changing registrations: (1) Absolute numbers of patients registered at each time interval; (2) Rates of change in numbers of patients registered for the entire period after the introduction of PDS; and (3) Rates of change in numbers of patients registered ,for ,the ,most recent 3 years of available data. Results, There was a significant increase in the numbers of children registered under capitation, post-PDS as compared to the pre-PDS level (all ages and both genders combined). Post-PDS, the rate of increase for the children was approximately one additional child per practice per month (0.96, 95% CI 0.41,1.52). Similarly there was a significant trend for increasing adults registrations over time of about two and a half adults per practice per month (2.42, 95% CI 0.90,3.95). There was no evidence of a change in registrations for children or adults in total over the most recent period of 3 years. Conclusions, The analysis of the absolute numbers of registered patients each month indicated that the PDS practices had more children registered than before the implementation of the PDS scheme, but not adults. Overall post-implementation there was a trend for increasing registrations in both children and adults, but the most recent data indicated a plateau effect. Further consideration of facilitators to achieve PDS goals of improved uptake of services is required, particularly as they relate to local contexts. [source] Evaluation of the Personal Dental Services (Wave 1) for Lambeth, Southwark and Lewisham Primary Care Trusts , Part 2: Retrospective analyses of treatment and other dental record dataJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2005Helen Best BDS MDS PhD Abstract Aim/Objective, The purpose of the study was to undertake analyses of treatment data for the Personal Dental Services (PDS) of Lambeth, Southwark and Lewisham Primary Care Trusts and relate the analyses to the PDS goals of supporting practitioners deliver appropriate quality dental care and ensuring that appropriate quality safety net services are available for all residents. Method, Analyses of treatment data provided by the Dental Practice Board were undertaken for the post-PDS period (February 1999,March 2003, based on data availability). Analyses of the clinic notes for 1500 patients were also undertaken for the 1 year pre-PDS period (October 1997,September 1998) and post-introduction of the PDS (October 1998,June 2003). Two sets of analyses were undertaken to evaluate trends in treatment claims for the Dental Practice Board data, absolute numbers of each type of treatment claimed each month and change in numbers of types of treatments claimed over time. The clinic notes were used to undertake post-PDS, pre-PDS comparisons of the number of treatment items and grouped treatment item categories undertaken and the number of courses and percentages of private treatment items provided. The following sociodemographic characteristics of the patients were also analysed, age, gender, exemption ,status ,and ,attendance ,status. Results, Overall it was identified that the percentage reduction in the number of treatment items undertaken was 13% (95% CI ,19%, ,7%), post- as compared to the pre-PDS introduction period. On an annual basis it was identified that the percentage reduction in the number of treatment items undertaken per year per patient post-PDS was 4% (95% CI ,6%, ,2%). There were significant variations in the impact of the PDS on the number of treatment items undertaken for different types of patients. A limited number of treatment types changed significantly post- as compared to pre-PDS. The proportion of exempt patients treated did not increase ,post-PDS. Conclusions, It is possible that a less, invasive style of dental treatment was provided during the course of the PDS, however, there was only limited evidence to indicate that dentists practice style changed based on types of treatment categories provided. The PDS provided a limited safety net service for local residents. In setting program goals the nature of quality dental practice requires definition and evaluation should be undertaken on a prospective basis. [source] Stepfamily Formation: Implications for Adolescent Ties to Mothers, Nonresident Fathers, and StepfathersJOURNAL OF MARRIAGE AND FAMILY, Issue 4 2009Valarie King This study examines how the entrance of a stepfather influences adolescent ties to mothers and nonresident fathers and how prior ties to each biological parent influence the development of stepfather-stepchild ties. Data come from 1,753 adolescents in the National Longitudinal Study of Adolescent Health who lived with a single mother in Wave 1 who remained single, cohabited, or married by Wave 2, approximately 1 year later. Stepfamily formation had little consequence for adolescent-nonresident father ties. Adolescent-mother closeness, however, declined when cohabiting, but not married, stepfathers entered the household. Close ties to married stepfathers were more likely to develop when adolescents were closer to their mothers before stepfather entry. Prior ties to nonresident fathers were unrelated to stepfather-stepchild ties. [source] Cumulative Environmental Risk and Youth Problem BehaviorJOURNAL OF MARRIAGE AND FAMILY, Issue 3 2004Jean M. Gerard Using data from Wave 1 (n = 5,070) and Wave 2 (n = 4,404) of the National Longitudinal Study of Adolescent Health, we examined the relationship between cumulative risk exposure and youth problem behavior. Cross-sectional analyses revealed a positive, linear association between cumulative risk and problem behaviors. The association between cumulative risk and externalizing problems was stronger for White youth than for Black youth. The association between cumulative risk and internalizing problems was stronger for girls than for boys, and stronger for White youth than for Black and Hispanic youth. Cumulative risk predicted change over time in internalizing problems. Findings support the theoretical notion that adolescents experience diminished psychological comfort when risk factors are present across several social domains. [source] Prospective Follow-Up of Empirically Derived Alcohol Dependence Subtypes in Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC): Recovery Status, Alcohol Use Disorders and Diagnostic Criteria, Alcohol Consumption Behavior, Health Status, and Treatment SeekingALCOHOLISM, Issue 6 2010Howard B. Moss Background:, We have previously reported on an empirical classification of Alcohol Dependence (AD) individuals into subtypes using nationally representative general population data from the 2001 to 2002 Wave 1 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and latent class analysis. Our results suggested a typology of 5 separate clusters based upon age of onset of AD, multigenerational familial AD, rates of antisocial personality disorder (ASPD), endorsement of specific AD and Alcohol Abuse (AA) criteria, and the presence of comorbid mood, anxiety, and substance use disorders (SUD). In this report, we focus on the clinical follow-up of these cluster members in Wave 2 of the NESARC (2004 to 2005). Methods:, The mean interval between NESARC Wave 1 and NESARC Wave 2 interviews was 36.6 (SD = 2.6) months. For these analyses, we utilized a Wave 2 NESARC sample that was comprised of a total of 1,172 individuals who were initially ascertained as having past-year AD at NESARC Wave 1 and initially subtyped into one of 5 groupings using latent class analysis. We identified these subtypes as: (i) Young Adult, characterized by very early age of onset, minimal family history, and low rates of psychiatric and SUD comorbidity; (ii) Functional, characterized by older age of onset, higher psychosocial functioning, minimal family history, and low rates of psychiatric and SUD comorbidity; (iii) Intermediate Familial, characterized by older age of onset, significant familial AD, and elevated comorbid rates of mood disorders SUD; (iv) Young Antisocial, characterized by early age of onset and elevated rates of ASPD, significant familial AD, and elevated rates of comorbid mood disorders and SUD; (v) Chronic Severe, characterized by later onset, elevated rates of ASPD, significant familial AD, and elevated rates of comorbid mood disorders and SUD. In this report, we examine Wave 2 recovery status, health status, alcohol consumption behavior, and treatment episodes based upon these subtypes. Results:, Significantly fewer of the Young Adult and Functional subtypes continued to meet full DSM-IV AD criteria in Wave 2 than did the Intermediate Familial, the Young Antisocial, and the Chronic Severe subtypes. However, we did not find that treatment seeking for alcohol problems increased over Wave 1 reports. In Wave 2, Young Antisocial and Chronic Severe subtypes had highest rates of past-year treatment seeking. In terms of health status, the Intermediate Familial, the Young Antisocial, and the Chronic Severe subtypes had significantly worse mental health scores than the Young Adult and Functional subtypes. For physical health status, the Functional, Intermediate Familial, Young Antisocial, and the Chronic Severe subtypes had significantly worse scores than the Young Adult subtype. In terms of alcohol consumption behavior, the Young Adult, Functional, and Young Antisocial subtypes significantly reduced their risk drinking days between Wave 1 and Wave 2, whereas the Intermediate Familial and the Chronic Severe subtypes did not. Discussion:, The results suggest that the empirical AD typology predicts differential clinical outcomes 3 years later. Persistence of full AD, treatment seeking, and worse mental health status were associated most strongly with those subtypes manifesting the greatest degree of psychiatric comorbidity. Reductions in alcohol consumption behavior and good physical health status were seen among the 2 younger subtypes. Overall, the least prevalent subtype, the Chronic Severe, showed the greatest stability in the manifestations of AD, despite having the highest rate of treatment seeking. [source] A Rasch Model Analysis of Alcohol Consumption and Problems Across Adolescence and Young AdulthoodALCOHOLISM, Issue 4 2009Christopher W. Kahler Background:, Recent investigations using item response modeling have begun to conceptualize alcohol consumption, problems, and dependence as representing points along a single continuum of alcohol involvement. Such a conceptualization may be of particular benefit to measurement of alcohol involvement in adolescents, but investigations to date have been limited to adult samples and may not generalize to adolescents due to age-related developmental differences. Methods:, This study used Rasch model analyses to examine the properties of indices of alcohol consumption and problems among 6,353 adolescents, aged 12 to 18 years, in Wave 1 of the Add Health survey. A particular focus was on whether the functioning of items changed when these adolescents were re-interviewed in Wave 3 when they were 18 to 24 years of age. Results:, Rasch model analyses supported the unidimensionality and additive properties of the items in the Wave 1 data. Comparisons of Wave 1 and Wave 3 data indicated differential item functioning in most of the items such that items related to alcohol consumption were more severe during adolescence, whereas items related to alcohol problems were more severe in young adulthood. Conclusions:, A valid index of alcohol involvement in adolescents can be constructed combining indices of alcohol consumption and alcohol problems. Such an index covers a range of severity and functions similarly across sex and race/ethnicity. A similar index can be constructed in young adulthood. However, the interpretation of scores must be attentive to developmental differences. In particular, for adolescents, indices of alcohol consumption are relatively closer in severity to indices of alcohol problems than they are among young adults. Thus, alcohol problems are more likely among adolescents than young adults given a similar level of drinking. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||