1,720,966 research outputs found
Family functioning and problematic usage of the internet in youth: a cross-sectional investigation
No full textBackground: problematic usage of the internet (PUI) refers to maladaptive use of the Internet linked to functional impairment as a growing concern in many countries. Youths are often considered more vulnerable to PUI than other age groups. The relationship between PUI and family dynamics is likely bidirectional and complex, warranting further research. Using a cross-sectional study design, we aimed to determine the rate of PUI and the association between PUI and family functioning in a South African sample between the ages of 18 and 30 years.Methods: South African youths were recruited via email and social media. Respondents completed an online survey as part of a cross-sectional study to assess the extent and the types of activities for which they use the internet, as well as the quality of their family relationships and functioning, employing standardised questionnaires (including the IAT-10) and the General Functioning Scale of the Family Assessment Device (GF-FAD). The sample included 814 participants (65% female; aged 21 years; SD 3 years).Results: 15.5% of our sample presented with PUI. There was a significant, moderate positive correlation between totals on the IAT-10 and GF-FAD (r = 0.33, p < .001). An independent samples t-test found that individuals with self-reported PUI (GF-FAD: M = 2.57, SD = 0.51) had significantly poorer quality family functioning than individuals without PUI (GF-FAD: M = 2.13, SD = 0.61; t (812) = -7.52, p < .001; Cohen's d = -0.73, 95% CI [-0.92, -0.54]). Correlations were found between increased time spent on various online activities, including pornography (r = 0.20, p < 0.001), cyberbullying (r = 0.17, p < 0.001), social networking (r = 0.11, p = 0.003), and streaming media (r = 0.11, p = 0.003), and poorer quality family functioning.Conclusion: PUI is common in South African youth. Presence of PUI and increased PUI severity were associated with worse family functioning in this sample. We recommend using family-based approaches in promoting a healthy family environment, and in the prevention of PUI and mitigation of its effects, with the goal of striking a balance between the benefits of the internet and its potential role in compromising aspects of family relationships.</p
Vascular health assessment with flow-mediated dilatation and retinal image analysis : a pilot study in an adult population from Cape Town
No full textAbstract: Aim: Flow-mediated dilatation (FMD) and retinal vascular analysis (RVA) may assist in predicting cardiovascular disease (CVD) but are poorly characterised in South Africa. We recorded baseline FMD and retinal vascular widths in healthy participants, and investigated associations with cardiovascular risk factors. Methods: Endothelial function (measured with FMD), microvascular structure (evaluated via fundus image analysis) and major CVD risk factors were assessed in 66 participants from Cape Town. Results: Median FMD% was 9.6%, with higher values in females. Mean retinal arteriolar and venular widths were similar to 156 and similar to 250 mu m, respectively. FMD was not associated with CVD risk factors. Hypertension was associated with narrower retinal arterioles and venules. Conclusions: We report novel baseline FMD data in healthy South African adults from the Western Cape, and show that retinal microvascular calibres are associated with blood pressure. Our baseline FMD and RVA data could serve as a reference for future studies in South Africa
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Vascular endothelial dysfunction in the wake of HIV and ART
No full textMounting evidence points to increased rates of cardiovascular disease (CVD) among people living with HIV/AIDS (PLWHA). Endothelial dysfunction (loss of endothelium-dependent vascular relaxation in response to provasodilatory stimuli) constitutes an early pathophysiological event in atherogenesis and CVD. Both HIV-1 infection and antiretroviral therapy (ART) are implicated in the development of endothelial dysfunction; however, conclusions are frequently drawn from associations shown in epidemiological studies. In this narrative review of mainly in vitro and animal studies, we report on the current understanding of how various HIV-1 proteins, HIV-1-induced proinflammatory cytokines and common antiretroviral drugs directly impact vascular endothelial cells. Proposed cellular mechanisms underlying the switch to a dysfunctional state are discussed, including oxidative stress, impaired expression and regulation of endothelial nitric oxide (NO) synthase (eNOS) and increased expression of vascular adhesion molecules. From the literature, it appears that increased reactive oxygen species (ROS) production, linked to decreased NO bioavailability and ensuing endothelial dysfunction, may be proposed as a putative final common pathway afflicting the vascular endothelium in PLWHA. The HIV-1-proteins Tat, Gp120 and Nef in particular, the proinflammatory cytokine, TNF-α, and the antiretroviral drugs Efavirenz and Lopinavir, most commonly postulated to be primary causal agents of endothelial dysfunction, are also discussed. We conclude that, despite existing evidence from basic research papers, a significant gap remains in terms of the exact underlying cellular mechanisms involved in HIV-1 and ART induced endothelial dysfunction. Bridging this gap could help pave the way for future strategies to prevent and treat early cardiovascular changes in PLWHA.sponsorship: This work was supported by the National Research Foundation of South Africa; the Department of Science and Technology, South Africa; Early Research Career Funding (Stellenbosch University) and the Harry Crossley Foundation (Stellenbosch University). (National Research Foundation of South Africa, Department of Science and Technology, South Africa, Early Research Career Funding (Stellenbosch University), Harry Crossley Foundation (Stellenbosch University))status: Publishe
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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