Comparing latent distributions

We consider the problem of comparingm latent population distributions when the observed values are scores on a test battery with binary items. The latent densities are assumed to be normal densities, and we consider a test for equality of the means as well as a test equality of the variances. In addition, we consider a longitudinal model, where the test battery has been applied to the same individuals at different points in time. This model allows for correlations between the latent variable at different time points, and methods are discussed for estimating the correlation coefficient.This work was supported in part by a grant from the Danish Social Science Research Council.     

Exploring a Source of Uneven Score Equity across the Test Score Range

Score equity assessment (SEA) refers to an examination of population invariance of equating across two or more subpopulations of test examinees. Previous SEA studies have shown that score equity may be present for examinees scoring at particular test score ranges but absent for examinees scoring at other score ranges. No studies to date have performed research for the purpose of understanding why score equity can be inconsistent across the score range of some tests. The purpose of this study is to explore a source of uneven subpopulation score equity across the score range of a test. It is hypothesized that the difficulty of anchor items displaying differential item functioning (DIF) is directly related to the score location at which issues of score inequity are observed. The simulation study supports the hypothesis that the difficulty of DIF items has a systematic impact on the uneven nature of conditional score equity.     

多巴胺系统基因对注意网络的调控作用

多巴胺是脑内重要的神经递质之一,与注意活动紧密相关。本文选取作用于突触前膜、间隙和后膜的多巴胺系统基因——多巴胺转运蛋白基因、儿茶酚氧化甲基转移酶基因和多巴胺受体基因,整合影像遗传学研究,探讨多巴胺基因对注意网络的调控。元分析发现背侧和腹侧注意网络的主要脑区均有较大的基因调控效应,且腹侧网络的效应值显著大于背侧网络,表明多巴胺系统基因在全脑范围内调控注意网络,且对腹侧网络的调控作用更强于背侧网络。     

Genetic Studies of Autism: From the 1970s into the Millennium

Reviewers in the 1960s and early 1970s were skeptical about any substantial role for genetic factors in the etiology of autism. A realization that the 2% rate of autism in siblings (as estimated at that time) was far above the general population base rate, and that this suggested a possible high genetic liability, led to the first small-scale twin study of autism. The replicated evidence from both twin and family studies undertaken in the 1970s and 1980s indicated both strong genetic influences and the likelihood that they applied to a phenotype that was much broader than the traditional diagnostic category of autism. Medical and chromosomal findings also indicated genetic heterogeneity. Advances in molecular genetics led to genome-wide scans of affected relative pair samples with a positive log of the odds to base 10 score for a location on chromosome 7. The major remaining research challenges and the likely clinical benefits that should derive from genetic research are considered in relation to both current knowledge and that anticipated to emerge from research over the next decade.     

医学遗传服务与遗传学研究的伦理问题

遗传工程的分子技术于本世纪７０年代问世。这一技术的创新使人类与医学遗传学突飞猛进,由此导致遗传医学的飞速发展。与此同步,医学伦理学兴起,临床医学遗传服务与遗传学研究的伦理问题日益成为人文科学关注的核心。世界卫生组织（ＷＨＯ）于１９９７年发布的《医学遗传学与遗传服务伦理问题的建议国际准则》。探讨我国医学伦理学发展的策略和面临的挑战,祈盼适合我国国情的中华医学遗传服务与遗传学研究的伦理准则早日问世。     

Schizophrenia Epigenesis?

I begin by examining how genetics drivesschizophrenia research, and raise both familiar andrelatively novel criticisms of the evidence putativelysupporting the genetic basis of schizophrenia. Inparticular, I call attention to a set of concernsabout the effects of placentation on concordance ratesof schizophrenia in monozygotic twins, which furtherweakens the case for schizophrenia's so-called stronggenetic component. I then underscore two criticalpoints. First, I emphasize the importance of takingseriously considerations about the complexity of bothontogenesis and the development of hereditarydiseases. The recognition of developmentalconstraints and supports is crucial, for attention todevelopment exposes the naivete of too many models ofgene action in the aetiology of disease. Secondly, Iattend to those schizophreniologists who ignoremethodological criticisms and thus presume a geneticbasis for schizophrenia, and then seek the schizophrenic genotype lacking an adequatephenotype. In response I attempt to demonstrate thenecessity of a sustained effort at characterizing thephenotype of schizophrenia as an enabling conditionfor the whole enterprise of psychiatric genetics – andfor psychiatry itself. Without the organism-levelphenotype, research at the level of genes will remainunproductive – assuming of course that research at thegenetic level is appropriate at all.     

Midwives’ Approach to Genetic Diseases and Genetic Counseling in Denizli, Turkey

The purpose of this study was to evaluate Denizli midwives’ self-reported knowledge of genetic diseases and genetic counseling. Data was collected on forms that obtained information about midwives approaches to basic genetics, genetic disorders, and genetic counseling (response rate = 70.1%). The highest response rate of midwives describing themselves as “knowledgeable” about basic genetic information was for mitosis and meiosis with 4.8%, about genetic disorders was for phenylketonuria with 61.1%, and about genetic counseling was for recommending ultrasonography during pregnancy with 98.1%. The source for basic genetics information for 56.4% of participants was in their school level classes. None of the midwives felt that they had sufficient knowledge about genetic counseling or screening and 76.4% would like to attend an educational course. Even though the midwives have recognized their knowledge deficit they occasionally give genetic counseling. As a result of this study a genetics course is planned for midwives so they can actively participate in the prevention and early diagnosis of genetic diseases.     

Ethnic variations in the initial phase of mental health treatment: a study of Sami and non-Sami clients and therapists in northern Norway

Several studies indicate that mental health and mental health service vary with ethnicity. Ethnically linked social differences affect these results. We examined the multiethnic population in northern Norway where social inequalities between the Sami and the non-Sami population are not prominent. Clients (N=347) and therapists (N=32) in outpatient treatments reported demographics, ethnicity and the therapeutic alliance. Clients also reported pretreatment psychosocial status, service utilization and the type of help requested. Therapist recorded clinical and diagnostic assessments and treatment plans. The Sami and non-Sami client groups were similar in demographics and pretreatment psychosocial characteristics. However, the therapists prescribed more sessions and more socially focused interventions when clients were Sami. Verbal therapy was more often used by the non-Sami therapists. Alliance ratings were positively correlated only between Sami therapists and their clients, and Sami therapists rated the largest initial clinical improvement. Clinics located in the high Sami density areas offered their clients more therapy sessions, than in clinics in the high non-Sami density areas. Ethnic similarity between client and therapist were associated with more frequent use of medication and less frequent use of verbal therapy.