81 research outputs found

    Mitochondrial and nuclear genetic analyses of the tropical black-lip rock oyster (Saccostrea echinata) reveals population subdivision and informs sustainable aquaculture development

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    The black-lip rock oyster (Saccostrea echinata) has considerable potential for aquaculture throughout the tropics. Previous attempts to farm S. echinata failed due to an insufficient supply of wild spat; however, the prospect of hatchery-based aquaculture has stimulated renewed interest, and small-scale farming is underway across northern Australia and in New Caledonia. The absence of knowledge surrounding the population genetic structure of this species has raised concerns about the genetic impacts of this emerging aquaculture industry. This study is the first to examine population genetics of S. echinata and employs both mitochondrial cytochrome c oxidase subunit I gene (COI) and single nucleotide polymorphism (SNP) markers

    Loneliness as a predictor of suicidal ideation and behaviour: a systematic review and meta-analysis of prospective studies

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    Background: Suicide and suicidal behaviour are global health concerns with complex aetiologies. Given the recent research and policy focus on loneliness, this systematic review aimed to determine the extent to which loneliness predicts suicidal ideation and/or behaviour (SIB) over time. Methods: A keyword search of five major databases (CINHAL, Medline, PsychArticles, PsychInfo and Web of Knowledge) was conducted. Papers for inclusion were limited to those using a prospective longitudinal design, written in English and which measured loneliness at baseline and SIB at a later time-point. Results: After duplicates were removed, 947 original potential papers were identified, with 22 studies meeting the review criteria. Meta-analysis revealed loneliness was a significant predictor of both suicidal ideation and behaviour and there was evidence that depression acted as a mediator. Furthermore, studies which consisted of predominantly female participants were more likely to report a significant relationship, as were studies where participants were aged 16-20 or >55 years at baseline. Limitations: There was considerable variability in measures, samples and methodologies used across the studies. Middle-aged adults were under-represented, as were individuals from minority ethnic backgrounds. All studies were conducted in countries where self-reliance and independence (i.e. individualism) are the cultural norm. Conclusions: Loneliness predicts later SIB in select populations. However, due to the heterogeneity of the studies further research is needed to draw more robust conclusions. Suicide death also needs to be included as an outcome measure. A focus on more collectivist countries is also required

    Loneliness and Social Internet Use: Pathways to Reconnection in a Digital World?

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    With the rise of online social networking, social relationships are increasingly developed and maintained in a digital domain. Drawing conclusions about the impact of the digital world on loneliness is difficult because there are contradictory findings, and cross-sectional studies dominate the literature, making causation difficult to establish. In this review, we present our theoretical model and propose that there is a bidirectional and dynamic relationship between loneliness and social Internet use. When the Internet is used as a way station on the route to enhancing existing relationships and forging new social connections, it is a useful tool for reducing loneliness. But when social technologies are used to escape the social world and withdraw from the “social pain” of interaction, feelings of loneliness are increased. We propose that loneliness is also a determinant of how people interact with the digital world. Lonely people express a preference for using the Internet for social interaction and are more likely to use the Internet in a way that displaces time spent in offline social activities. This suggests that lonely people may need support with their social Internet use so that they employ it in a way that enhances existing friendships and/or to forge new ones

    Reciprocal relationships between trajectories of depressive symptoms and screen media use during adolescence

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    Adolescents are constantly connected with each other and the digital landscape through a myriad of screen media devices. Unprecedented access to the wider world and hence a variety of activities, particularly since the introduction of mobile technology, has given rise to questions regarding the impact of this changing media environment on the mental health of young people. Depressive symptoms are one of the most common disabling health issues in adolescence and although research has examined associations between screen use and symptoms of depression, longitudinal investigations are rare and fewer still consider trajectories of change in symptoms. Given the plethora of devices and normalisation of their use, understanding potential longitudinal associations with mental health is crucial. A sample of 1,749 (47% female) adolescents (10-17 years) participated in six waves of data collection over two years. Symptoms of depression, time spent on screens, and on separate screen activities (social networking, gaming, web browsing, TV/passive) were self-reported. Latent growth curve modelling revealed three trajectories of depressive symptoms (Low-Stable, High-Decreasing, and Low-Increasing) and there were important differences across these groups on screen use. Some small, positive associations were evident between depressive symptoms and later screen use, and between screen use and later depressive symptoms. However, a Random Intercept Cross Lagged Panel Model revealed no consistent support for a longitudinal association. The study highlights the importance of considering differential trajectories of depressive symptoms and specific forms of screen activity to understand these relationships

    Loneliness and social media: A qualitative investigation of young people's motivations for use and perceptions of social networking sites

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    The democratisation of Internet access has incrementally changed every domain of activity and has created new business and economic models. From answering work emails to learning a new language, shopping, booking medical appointments or managing one’s finances, almost everything is attainable at the click of a button. The added implications of the rapid rise of social networking websites (SNSs), such as Facebook, Twitter, Instagram or Snapchat, have further contributed to changing the way we communicate and build new friendships. Indeed most of our social relationships are now being ‘increasingly developed and maintained online’ (Nowland, Necka & Cacioppo, 2017: 1). Ostensibly, despite improved Internet access and enhanced social connectedness, modern societies are struggling to combat loneliness. It is reported to affect people of all ages, especially young adults (16-24 and 25-34 years old) who are avid Internet and social media users (see Office for National Statistics, 2018)
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