Method for X and Y Spermatozoa Separation

A method for separating male and female determining spermatozoa includes the initial step of exposing freshly ejaculated spermatozoa in a substantially protein free diluent to an excess concentration of a monoclonal antibody directed against H-Y antigen that binds substantially exclusively with male determining spermatozoa. The method continues with the suspending of the exposed spermatozoa together with a conjugate of (1) an immunoglobulin G antibody that binds substantially exclusively to the monoclonal antibody and (2) an immunoabsorbant substrate in a substantially protein free diluent. This forms a conjugate/spermatozoa preparation. The method concludes with the recovering of the separated male and female determining spermatozoa

The association between bullying‐victimisation and sleep disturbances in adolescence: Evidence from a twin study

Bullying‐victimisation has been associated with sleep disturbances. This study investigated the degree to which subtypes of bullying‐victimisation in adolescence are linked with sleep disturbances. Genetic and environmental contributions underlying bullying‐victimisation and sleep disturbances were investigated. Participants (3,242–5,076 pairs) from a longitudinal community twin study reported on their bullying‐victimisation at the age of 14 years, and sleep quality and insomnia symptoms at age 16. Regression analyses were used, accounting for the role of individual and family factors. Structural equation twin model fitting was conducted. Bullying‐victimisation was modestly associated with sleep quality and insomnia symptoms (r = 0.22–0.23) and a similar strength of associations was found across bullying‐victimisation subtypes (r = 0.11–0.22). Bullying‐victimisation, sleep quality and insomnia symptoms were predominantly influenced by genes (25–59%) and non‐shared environments (40–62%). The association between bullying‐victimisation and sleep quality was explained by genetic and non‐shared environmental influences. For insomnia symptoms and sleep quality, the association with bullying‐victimisation was in part explained by a genetic overlap. Associations between bullying‐victimisation and sleep disturbances are not limited to specific aspects of bullying‐victimisation but appear to exist for all subtypes. These findings stimulate research questions regarding the mechanisms underlying these links. For example, could certain heritable traits, such as temperament, increase vulnerability to experiencing sleep disturbances and being bullied? Research on bullying and sleep should aim to take the role of genetic predisposition into account, while also noting that it is not the only causal influence. Understanding more about these pathways could strengthen the development of techniques to prevent these difficulties from occurring

The Genesis 12–19 (G1219) Study: A Twin and Sibling Study of Gene–Environment Interplay and Adolescent Development in the UK

The Genesis 12–19 (G1219) Study is an ongoing longitudinal study of a sample of UK twin pairs, non-twin sibling pairs, and their parents. G1219 was initially designed to examine the role of gene–environment interplay in adolescent depression. However, since then data have continued to be collected from both parents and their offspring into young adulthood. This has allowed for longitudinal analyses of depression and has enabled researchers to investigate multiple phenotypes and to ask questions about intermediate mechanisms. The study has primarily focused on emotional development, particularly depression and anxiety, which have been assessed at multiple levels of analysis (symptoms, cognitions, and relevant environmental experiences). G1219 has also included assessment of a broader range of psychological phenotypes ranging from antisocial behaviors and substance use to sleep difficulties, in addition to multiple aspects of the environment. DNA has also been collected. The first wave of data collection began in the year 1999 and the fifth wave of data collection will be complete before the end of 2012. In this article, we describe the sample, data collection, and measures used. We also summarize some of the key findings to date

Sub-types of insomnia in adolescents: insights from a quantitative/ molecular twin study

Background: Insomnia with short sleep duration has been postulated as more severe than that accompanied by normal/long sleep length. While the short duration subtype is considered to have greater genetic influence than the other subtype, no studies have addressed this question. This study aimed to compare these subtypes in terms of: 1) the heritability of insomnia symptoms; 2) polygenic scores (PGS) for insomnia symptoms and sleep duration; 3) the associations between insomnia symptoms and a wide variety of traits/disorders. Methods: The sample comprised 4,000 pairs of twins aged 16 from the Twins Early Development Study. Twin models were fitted to estimate the heritability of insomnia in both groups. PGS were calculated for self-reported insomnia and sleep duration and compared among participants with short and normal/long sleep duration. Results: Heritability was not significantly different in the short sleep duration group (A=0.13 [95%CI=0.01, 0.32]) and the normal/long sleep duration group (A=0.35 [95%CI=0.29, 0.40]). Shared environmental factors accounted for a substantial proportion of the variance in the short sleep duration group (C=0.19 [95%CI= 0.05, 0.32]) but not in the normal/long sleep duration group (C=0.00 [95%CI=0.00, 0.04]). PGS did not differ significantly between groups although results were in the direction expected by the theory. Our results also showed that insomnia with short (as compared to normal/long) sleep duration had a stronger association with anxiety and depression (p<.05) - although not once adjusting for multiple testing. Conclusions: We found mixed results in relation to the expected differences between the insomnia subtypes in adolescents. Future research needs to further establish cut-offs for ‘short’ sleep at different developmental stages and employ objective measures of sleep

The Sri Lankan twin registry biobank: South Asia's first twin biobank

Introduction: Biobanks are a valuable resource for creating advancements in science through cutting-edge omics research. Twin research methods allow us to understand the degree to which genetics and environmental factors contribute to health outcomes. Methods: The Sri Lankan Twin Registry biobank (SLTR-b) was established in 2015 as part of Colombo Twin and Singleton Follow-up Study. Venous blood and urine were collected from twins and comparative sample of singletons for clinical investigations and biobanking. Results: The SLTR-b currently houses 3369 DNA and serum samples. Biobank specimens are linked to longitudinal questionnaire data, clinical investigations, anthropometric measurements, and other data. Discussion: The SLTR-b aims to address gaps in health and genetics research. It will provide opportunities for academic collaborations, local and international, and capacity building of future research leaders in twin and omics research. This paper provides a cohort profile of the SLTR-b and its linked data, and an overview of the strategies used for biobanking

The Colombo Twin and Singleton Follow-up Study: a population based twin study of psychiatric disorders and metabolic syndrome in Sri Lanka

BACKGROUND: The disease burden related to mental disorders and metabolic syndrome is growing in low-and middle-income countries (LMIC). The Colombo Twin and Singleton Study (COTASS) is a population-based sample of twins and singletons in Colombo, Sri Lanka. Here we present prevalence estimates for metabolic syndrome (metS) and mental disorders from a follow-up (COTASS-2) of the original study (COTASS-1), which was a mental health survey. METHODS: In COTASS-2, participants completed structured interviews, anthropometric measures and provided fasting blood and urine samples. Depressive disorder, depressive symptoms, anxiety symptoms, post-traumatic stress disorder (PTSD) and hazardous alcohol use were ascertained with structured psychiatric screens (Composite International Diagnostic Interview (CIDI), Beck Depression Inventory (BDI-II), Generalised Anxiety Disorder Questionnaire (GAD-7), PTSD Checklist - Civilian Version (PCL-C), and Alcohol Use Disorders Identification Test (AUDIT)). We defined metS according to the International Diabetes Federation (IDF) criteria and the revised National Cholesterol Education Programme Adult Treatment Panel (NCEP ATP III) criteria. We estimated the prevalence of psychiatric disorders and metS and metS components, and associations with gender, education and age. RESULTS: Two thousand nine hundred thirty-four twins and 1035 singletons were followed up from COTASS-1 (83.4 and 61.8% participation rate, respectively). Prevalence estimates for depressive disorder (CIDI), depressive symptoms (BDI ≥ 16), anxiety symptoms (GAD-7 ≥ 10) and PTSD (PCL-C DSM criteria) were 3.8, 5.9, 3.6, and 4.5% respectively for twins and 3.9, 9.8, 5.1 and 5.4% for singletons. 28.1 and 30.9% of male twins and singletons respectively reported hazardous alcohol use. Approximately one third met the metS criteria (IDF: 27.4% twins, 44.6% singletons; NCEP ATP III: 30.6% twins, 48.6% singletons). The most prevalent components were central obesity (59.2% twins, 71.2% singletons) and raised fasting blood glucose or diabetes (38.2% twins, 56.7% singletons). CONCLUSION: MetS was highly prevalent in twins, and especially high in singletons, whereas the prevalence of mental disorders was low, but consistent with local estimates. The high levels of raised fasting plasma glucose and central obesity were particularly concerning, and warrant national diabetes prevention programmes

Association between stressful life events and psychotic experiences in adolescence: evidence for gene-environment correlations

- Background: Stressful life events (SLEs) are associated with psychotic experiences (PEs). SLEs might act as an environmental risk factor, but may also share a genetic propensity with PEs. - Aims: Estimate the extent to which genetic and environmental factors influence the relationship between SLEs and PEs. - Method: Self and parent-reports from a community-based twin sample (4,830 16-year-old pairs) were analysed using structural equation model-fitting. - Results: SLEs correlated with positive PEs (r = .12-.14, all p<. 001). Modest heritability was shown for PEs (25-57%) and dependent SLEs (32%). Genetic influences explained the majority of the modest covariation between dependent SLEs and paranoia and cognitive disorganisation (bivariate heritabilities = 74-86%). The relationship between SLEs and hallucinations and grandiosity was explained by both genetic and common environmental effects. - Conclusion: Further to dependent SLEs being an environmental risk factor, individuals may have an underlying genetic propensity increasing their risk of dependent SLEs and positive PEs

Mobility assemblages and lines of flight in women’s narratives of forced displacement

In this paper I take the notion of the mobility assemblage as a theoretical lens through which I consider entanglements between refugee and migrant women on the move, intense experiences of gendered labour, and affective encounters in crossing borders and following lines of flight. The analysis revolves around the life-story of a young refugee woman, who recounts her experiences of travelling to Greece. What emerges from her narrative is a whirl of lines of flight that deterritorialize her from patriarchal regimes, harsh border practices, labour exploitation and the pain of separation on a plane of remaking her present and re-imagining her future