Home About us Contact
|
Home About us Contact | ||
|
|
||
Heterogeneous Groups (heterogeneous + groups)
Selected AbstractsMultiple causality in developmental disorders: methodological implications from computational modellingDEVELOPMENTAL SCIENCE, Issue 5 2003Michael S.C. Thomas When developmental disorders are defined on the basis of behavioural impairments alone, there is a risk that individuals with different underlying cognitive deficits will be grouped together on the basis that they happen to share a certain impairment. This phenomenon is labelled multiple causality. In contrast, a developmental disorder generated by a single underlying cognitive deficit may nevertheless show variable patterns of impairments due to individual differences. Connectionist computational models of development are used to investigate whether there may be ways to distinguish disorder groups with a single underlying cause (homogeneous disorder groups) from disorder groups with multiple underlying causes (heterogeneous disorder groups) on the basis of behavioural measures alone. A heuristic is proposed to assess the underlying causal homogeneity of the disorder group based on the variability of different behavioural measures from the target domain. Heterogeneous disorder groups are likely to show smaller variability on the measure used to define the disorder than on subsequent behavioural measures, while homogeneous groups should show approximately equivalent variability. Homogeneous disorder groups should show reductions in the variability of behavioural measures over time, while heterogeneous groups may not. It is demonstrated how these predictions arise from computational assumptions, and their use is illustrated with reference to behavioural data on naming skills from two developmental disorder groups, Williams syndrome and children with Word Finding Difficulties. [source] Who is that (wo)man in the street?EUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 4 2001From the normalisation of protest to the normalisation of the protester The time has long since passed that protests and demonstrations were regarded as the possible beginning of violent revolutionary ferment. Venting dissatisfaction or making demands in the streets has become commonplace in our ,demonstration,democracy'. In this article we examine whether this normalisation of street protest also means that more heterogeneous groups of people take to the streets. Have citizens become potentially peaceful protesters or is protest politics still the domain of union militants, progressive intellectuals, and committed students? In answering these questions we will use the three research methods most commonly used for studying collective action: population surveys, protest event,analysis and interviews with protesters at demonstrations. [source] Practices of global capital: gaps, cracks and ironies in transnational call centres in IndiaGLOBAL NETWORKS, Issue 4 2004Kiran Mirchandani Recent theorists have focused on how capitalism is continually under construction, and how heterogeneous groups of workers play active roles in relation to transnational corporate processes. Accordingly, I trace three practices that constitute transnational call centre work ,scripting, synchronicity and locational masking , and examine how Indian workers negotiate these practices. I argue that the transnationalization of voice-to-voice service work provides the opportunity for Indian workers to construct ,Americans' and situate their own jobs within global labour markets. Drawing on interviews with call centre workers, managers and trainers in India, I explore the ways in which analyses of the practices of globalization provides an insight on workers' attempts to enhance their quality of life vis-à-vis transnational capitalism. [source] IBDfinder and SNPsetter: Tools for pedigree-independent identification of autozygous regions in individuals with recessive inherited disease,HUMAN MUTATION, Issue 6 2009Ian M. Carr Abstract Autozygosity mapping of recessive genes can be performed on a small number of affected individuals from consanguineous pedigrees. With the advent of microarray SNP analysis, acquiring genotype data has become extremely simple and quick, in comparison to gene mapping with microsatellite markers. However, the subsequent data analysis required to identify autozygous regions can still be a significant obstacle. For rapid gene identification, it may be desirable to integrate information from heterogeneous groups of affected individuals, both familial and isolated, under various assumptions of ancestry and locus heterogeneity, that are not amenable to formal linkage analysis. Unfortunately, there are few computer programs aimed specifically at facilitating this type of data sifting. Here, we demonstrate two new programs that facilitate the identification of autozygous regions within a heterogeneous SNP dataset derived from familial and sporadic affected individuals. Hum Mutat 30:1,8, 2009. © 2009 Wiley-Liss, Inc. [source] Perceived cultural distance and acculturation among exchange students in RussiaJOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 3 2009Irina Suanet Abstract The relations of perceived cultural distance, personality, acculturation orientations and outcomes were studied among exchange students (N,=,187) in Russia who came from various countries in Asia, sub-Saharan Africa, Latin America and the former Soviet Union. The hypothesis was supported that a larger perceived cultural distance between mainstream and immigrant culture is associated with less psychological (homesickness and stress) and sociocultural (behaviour with Russian students and behaviour with co-nationals) adjustment. The statistical relations between perceived cultural distance, personality and sociocultural adjustment were much stronger for host domain behaviour than for home domain behaviour. Adjustment was higher for participants with more cultural empathy, openmindedness and flexibility. Adjustment showed statistically stronger associations with cultural distance than with acculturation orientations. It is concluded that cultural distance may be more salient than acculturation orientations in studies of heterogeneous groups of immigrants. Copyright © 2008 John Wiley & Sons, Ltd. [source] Involvement with peers: comparisons between young children with and without Down's syndromeJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 5 2002M. J. Guralnick Abstract Background It has been well established that heterogeneous groups of young children with mild intellectual disability are at considerable risk of becoming socially isolated from their peers in school, home and community settings. Method Matched groups of young children with and without Down's syndrome (DS) were compared in terms of the children's involvement with peers, maternal arranging and monitoring of peer play, and maternal beliefs about inclusion. Results Despite aetiology-specific expectations for children with DS, no differences were found for a variety of measures of peer involvement focusing on the frequency of contacts and the characteristics of children's peer social networks. Maternal arranging of activities with peers was similarly related to peer involvement for both groups of children. Higher ratings of the benefits of inclusion were obtained from mothers of children with DS, but these maternal beliefs were unrelated to maternal arranging or peer involvement. Conclusions Parental adaptations to the aetiology-specific behavioural patterns of children and the general influence of children's experiences within a developmental framework are discussed in the context of interpreting aetiology-specific findings. [source] MRI and cognitive impairment in Parkinson's disease,MOVEMENT DISORDERS, Issue S2 2009Naroa Ibarretxe-Bilbao PhD Abstract Patients with Parkinson's disease (PD) may present impairment in cognitive functions even at early stages of the disease. When compared with the general population, their risk of dementia is five to six times higher. Recent investigations using structural MRI have shown that dementia in PD is related to cortical structural changes and that specific cognitive dysfunctions can be attributed to atrophy in specific structures. We review the structural MRI studies carried out in PD using either a manual region of interest (ROI) approach or voxel-based morphometry (VBM). ROI studies have shown that hippocampal volume is decreased in patients with PD with and without dementia; in addition, hippocampal atrophy correlated with deficits in verbal memory. VBM studies have demonstrated that dementia in PD involves structural changes in limbic areas and widespread cortical atrophy. Findings in nondemented patients with PD are less conclusive, possibly because cognitively heterogeneous groups of patients have been studied. Patients with PD with cognitive impairment and/or visual hallucinations present greater brain atrophy than patients without these characteristics. These findings suggest that cortical atrophy is related to cognitive dysfunction in PD and precedes the development of dementia. Structural MRI might therefore provide an early marker for dementia in PD. © 2009 Movement Disorder Society [source] Unobserved Heterogeneity in Models of Competing Mortgage Termination RisksREAL ESTATE ECONOMICS, Issue 2 2006John M. Clapp This article extends unobserved heterogeneity to the multinomial logit (MNL) model framework in the context of mortgages terminated by refinance, move or default. It tests for the importance of unobserved heterogeneity when borrower characteristics such as income, age and credit score are included to capture lender-observed heterogeneity. It does this by comparing the proportional hazard model to MNL with and without mass-point estimates of unobserved heterogeneous groups of borrowers. The mass-point mixed hazard (MMH) model yields larger and more significant coefficients for several important variables in the move model, whereas the MNL model without unobserved heterogeneity performs well with the refinance estimates. The MMH clearly dominates the alternative models in sample and out of sample. However, it is sometimes difficult to obtain convergence for the models estimated jointly with mass points. [source] Trials and tribulations associated with angina and traditional therapeutic approachesCLINICAL CARDIOLOGY, Issue S1 2007Prakash C. Deedwania M.D. Abstract Ischemic heart disease is the foremost cause of death in the United States and the developed countries. Stable angina is the initial manifestation of ischemic heart disease in one half of the patients and becomes a recurrent symptom in survivors of myocardial infarction (MI) and other forms of acute coronary syndromes (ACS). There are multiple therapeutic modalities currently available for treatment of anginal symptoms in patients with stable CAD. These include anti-anginal drugs and myocardial revascularization procedures such as coronary artery bypass graft surgery (CABGS), percutaneous transluminal coronary angioplasty (PTCA) and percutaneous coronary intervention (PCI). Anti-anginal drug therapy is based on treatment with nitrates, beta blockers, and calcium channel blockers. A newly approved antianginal drug, ranolazine, is undergoing phase III evaluation. Not infrequently, combination therapy is often necessary for adequate symptom control in some patients with stable angina. Howerever, there has not been a systematic evaluation of individual or combination antianginal grug therapy on hard clinical end points in patients with stable angina. Most revascularization trials that have evaluated treatment with CABGS, PTCA, or PCI in patients with chronic CAD and stable angina have not shown significant improvement in survival or decreased incidence of non-fatal MI compared to medical treatment. In the CABGS trials, various post-hoc analyses have identified several smaller subgroups at high-risk in whom CABGS might improve clinical outcomes. However, there are conflicting findings in different reports and these findings are futher compromised due to the heterogeneous groups of patients in these trials. Moreover, no prospective randomized controlled trial (RCT) has confirmed an advantage of CABGS, compared to medical treatment, in reduction of hard clinical outcomes in any of the high-risk subgroups. Based on the available data, it appears reasonable to conclude that for most patients (except perhaps in those with presence of left main disease > 50% stenosis) there is no apparent survival benefit of CABGS compared to medical therapy in stable CAD patients with angina. Although these trial have reported better symptom control associated with the revascularization intervention in most patients, this has not been adequately compared using modern medical therapies. Available data from recent studies also suggest treatment with an angiotensin converting enzyme inhibitor (ACEI), a statin and a regular exercise regimen in patients with stable CAD and angina pectoris. Copyright © 2007 Wiley Periodicals, Inc. [source] | ||||||||||||||||