A Critical Review of Centrality Measures in Social Networks

Social networks are currently gaining increasing impact in the light of the ongoing growth of web-based services like facebook.com. One major challenge for the economically successful implementation of selected management activities such as viral marketing is the identification of key persons with an outstanding structural position within the network. For this purpose, social network analysis provides a lot of measures for quantifying a member’s interconnectedness within social networks. In this context, our paper shows the state of the art with regard to centrality measures for social networks. Due to strongly differing results with respect to the quality of different centrality measures, this paper also aims at illustrating the tremendous importance of a reflected utilization of existing centrality measures. For this purpose, the paper analyzes five centrality measures commonly discussed in literature on the basis of three simple requirements for the behavior of centrality measures

Storing data on RFID tags: A standards-based approach

Online social networks are gaining increasing economic importance in light of the rising number of members. The numerous recent acquisitions priced at enormous amounts illustrate this development. Therefore, the growing relevance of online social networks in science as well as in practise revealed the need for adequate valuation models, which take into account the networks’ specific characteristics. Thus, this article develops an economic model for valuation of online social networks. The model allows the evaluation of whether the purchase prices on the market, which recently amounted to millions, are justifiable. Finally, the practical application of the model is illustrated by an example of the major European online social network XING.com

Sex-specific impact of major depressive disorder on 12-year change in glycaemic status: Results from a nationwide cohort study of adults without diabetes in Germany

Aims: There is evidence for an increased type 2 diabetes (T2D) risk associated with depression, but its role for diabetes prevention remains unclear. This study aimed to add insight by investigating the impact of major depressive disorder (MDD) on prospective glycaemic changes. Methods: The study was based on a cohort of n = 1,766 adults without diabe- tes (776 men, 990 women; 18– 65 years of age) who participated in the mental health supplement of the German National Health Interview and Examination Survey (GNHIES98-MHS, 1997–1999) and in a follow-up survey (DEGS1, 2008– 2011). Glycaemic status was defined as normoglycaemia [HbA1c < 39 mmol/ mol (<5.7%)], prediabetes [39 ≤ HbA1c < 48 mmol/mol (5.7–6.4%)] and diabetes [HbA1c ≥ 48 mmol/mol (≥ 6.5%), diagnosed diabetes, or antidiabetic medication], and glycaemic changes categorized as ‘remission’, ‘stability’ and ‘progres- sion’. Baseline MDD was assessed via a modified German version of the WHO Composite International Diagnostic Interview. Multivariable logistic regressions were applied to analyse the association of MDD with glycaemic changes and in- cident T2D, adjusting for socio-demographics, lifestyle conditions, chronic dis- eases, antidepressant use and mental health care. Results: MDD prevalence was 21.4% for women and 8.9% for men. Among women, MDD was associated with a lower chance for remission (RRR 0.43; 95% CI 0.23, 0.82). Among men, MDD was not significantly related to glycaemic changes. MDD had no significant effect on incident T2D (men: OR 1.58; 0.55, 4.52; women: OR 0.76; 0.37, 1.58). Conclusions: Findings of the current study highlight the role of depression in T2D prevention, particularly among women.Peer Reviewe

Associations between dietary patterns and biomarkers of nutrient status and cardiovascular risk factors among adolescents in Germany: results of the German Health Interview and Examination Survey for Children and Adolescents in Germany (KiGGS)

Background: The aim of this study is to analyse prevailing dietary patterns among German adolescents and their associations with biomarkers of nutrient status and cardiovascular risk factors. Methods: Analyses were based on data from the nationwide, representative Health Interview and Examination Survey for Children and Adolescents in Germany, conducted between 2003 and 2006 (KiGGS baseline). Dietary habits of 12 to 17 year olds (2646 boys and 2551 girls) were determined using 34 food groups assessed with a food frequency questionnaire. Principal component analysis was applied to determine the major dietary patterns. The associations between dietary patterns and biomarkers were analysed using linear regression analyses. Results: We identified three major dietary patterns among boys and two among girls. Higher scores of the ‘healthy’ patterns (fruits, salad vegetables, wholemeal bread) were associated with higher levels of serum folate and lower levels of homocysteine among both sexes and higher levels of serum vitamin B12 among girls. Conversely, higher scores of the ‘western’ pattern among boys (salty snacks, burger, French fries) were associated with a lower ferritin level and lower diastolic blood pressure. The ‘traditional’ pattern among boys (white bread, processed meat, meat) was associated with a lower folate level and the ‘western and traditional’ pattern among girls (salty snacks, burger, French fries) with lower folate and higher homocysteine levels. No associations between dietary patterns and blood lipids, HbA1c and uric acid were found. The mean age of boys with higher scores in the ‘western’ pattern was higher, whereas the mean age of girls with higher scores in the ‘western and traditional’ dietary patterns was lower. Conclusions: Adolescents with higher scores in the ‘healthy’ dietary patterns had a better nutrient profile. Therefore, healthy dietary patterns should be promoted early in life, with a special focus on the sex differences

Are depressive symptoms associated with quality of care in diabetes? Findings from a nationwide populationbased study

Introduction We investigated whether the presence of depressive symptoms among adults with diagnosed diabetes is associated with adverse quality of diabetes care. Research design and methods The study population was drawn from the German national health survey ‘German Health Update’ 2014/2015-European Health Interview Survey and included 1712 participants aged ≥18 years with self-reported diabetes during the past 12 months. Depressive symptoms in the past 2weeks were assessed by the eight-item depression module of the Patient Health Questionnaire (PHQ-8), with PHQ-8 sum score values ≥10 indicating current depressive symptoms. We selected 12 care indicators in diabetes based on selfreported information on care processes and outcomes. Associations of depressive symptoms with those indicators were examined in multivariable logistic regression models with stepwise adjustments. Results Overall, 15.6% of adults with diagnosed diabetes reported depressive symptoms, which were higher in women than in men (18.7% vs 12.9%). Adjusted for age, sex, education, social support, health-related behaviors, and diabetes duration, adults with depressive symptoms were more likely to report acute hypoglycemia (OR 1.81, 95%CI 1.13 to 2.88) or hyperglycemia (OR 2.10, 95% CI 1.30 to 3.37) in the past 12 months, long-term diabetes complications (OR 2.30, 95% CI 1.55 to 3.39) as well as currently having a diet plan (OR 2.14, 95%CI 1.39 to 3.29) than adults without depressive symptoms. Significant associations between depressive symptoms and other care indicators were not observed. Conclusions The present population-based study of adults with diagnosed diabetes indicates an association between depressive symptoms and adverse diabetesspecific care with respect to outcome but largely not to process indicators. Our findings underline the need for intensified care for persons with diabetes and depressive symptoms. Future research needs to identify underlying mechanisms with a focus on the inter-relationship between diabetes, depression and diabetes-related distress.Peer Reviewe

Enfrentamento da COVID-19 e as possibilidades para promover a saúde: diálogos com professores

 Objetivo: compreender a vivência de professores do ensino fundamental no enfrentamento da COVID-19, desvelando as suas possibilidades para promover sua própria saúde nesse contexto pandêmico. Método: estudo qualitativo, tipo ação participante, com guia metodológico do Itinerário de Pesquisa de Paulo Freire, que integra três etapas: Investigação Temática; Codificação e Descodificação; Desvelamento Crítico. Participaram do Círculo de Cultura 14 professoras do ensino fundamental, atuantes em escolas particulares e públicas de diferentes estados brasileiros. Resultados: a análise resultou dois temas geradores: 1) Desafios no enfrentamento da COVID-19; 2) Possibilidades para promover saúde de professores em tempos de COVID-19. Conclusão: os desafios do ensino remoto para o enfrentamento da COVID-19 envolvem sobrecarga, estresse, ansiedade, medos, preocupações, insegurança e saudade da escola. Como possibilidades para promover a saúde, as professoras buscam apoio familiar, organizando tempo para cuidar de si e aliviar a ansiedade por meio de leitura de livros, filmes e prática de exercícios.Objetivo: compreender a vivência do enfrentamento da COVID-19 e as possibilidades para promover a saúde, na percepção dos professores do ensino fundamental. Método: estudo qualitativo, tipo ação participante, tendo como guia metodológico o Itinerário de Pesquisa de Paulo Freire, que integra três etapas: Investigação Temática; Codificação e Descodificação; Desvelamento Crítico. Participaram do Círculo de Cultura 14 professoras do ensino fundamental, atuantes em escolas particulares e públicas de diferentes estados brasileiros. Resultados: dialogaram sobre dois temas geradores: 1) Desafios no enfrentamento da COVID-19; 2) Possibilidades para promover saúde em tempos de COVID-19. Conclusão: a situação pandêmica repercutiu na necessidade de os professores trabalharem em casa, gerando intenso trabalho, estresse, ansiedade, medos, preocupações, insegurança, saudades da escola e dos estudantes.  Para promover saúde, as professoras buscam apoio da família, organizando tempo para cuidar de si e aliviar a ansiedade por meio de leitura de livros, filmes e prática de exercícios físicos

A randomized trial on effectiveness of artemether-lumefantrine versus artesunate plus amodiaquine for unsupervised treatment of uncomplicated Plasmodium falciparum malaria in Ghanaian children

<p>Abstract</p> <p>Background</p> <p>Numerous trials have demonstrated high efficacy and safety of artemisinin-based combination therapy (ACT) under supervised treatment. In contrast, effectiveness studies comparing different types of ACT applied unsupervised are scarce. The aim of this study was to compare effectiveness, tolerability and acceptance of artesunate plus amodiaquine (ASAQ) against that of artemether-lumefantrine (AL) in Ghanaian children with uncomplicated <it>Plasmodium falciparum </it>malaria.</p> <p>Methods</p> <p>A randomized open-label trial was conducted at two district hospitals in the Ashanti region, Ghana, an area of intense malaria transmission. A total of 246 children under five years of age were randomly assigned to either ASAQ (Arsucam^®) or AL (Coartem^®). Study participants received their first weight-adjusted dose under supervision. After the parent/guardian was advised of times and mode of administration the respective three-day treatment course was completed unobserved at home. Follow-up visits were performed on days 3, 7, 14 and 28 to evaluate clinical and parasitological outcomes, adverse events, and haematological recovery. Length polymorphisms of variable regions of <it>msp1 </it>and <it>msp2 </it>were determined to differentiate recrudescences from reinfections. Acceptance levels of both treatment regimens were assessed by means of standardized interviews.</p> <p>Results</p> <p>Adequate clinical and parasitological responses after AL and ASAQ treatment were similar (88.3% and 91.7%, respectively). Interestingly, more late clinical failures until day 28 occurred in AL-treated children than in those who received ASAQ (17.5% and 7.3%, respectively; Hazard Ratio 2.41, 95% CI 1.00–5.79, p < 0.05).</p> <p>Haematological recovery and drug tolerability were not found to be significantly different in both study arms. The acceptance of treatment with ASAQ was higher than that with AL (rank-scores 10.6 and 10.3, respectively; p < 0.05).</p> <p>Conclusion</p> <p>Unobserved AL and ASAQ treatment showed high adequate clinical and parasitological responses, though AL was inferior in preventing late clinical failures.</p

which marker is best for prediction? Pooled analysis of four German population-based cohort studies and comparison with a nationwide cohort study

Objective To compare the association between different anthropometric measurements and incident type 2 diabetes mellitus (T2DM) and to assess their predictive ability in different regions of Germany. Methods Data of 10 258 participants from 4 prospective population-based cohorts were pooled to assess the association of body weight, body mass index (BMI), waist circumference (WC), waist-to-hip-ratio (WHR) and waist-to-height-ratio (WHtR) with incident T2DM by calculating HRs of the crude, adjusted and standardised markers, as well as providing receiver operator characteristic (ROC) curves. Differences between HRs and ROCs for the different anthropometric markers were calculated to compare their predictive ability. In addition, data of 3105 participants from the nationwide survey were analysed separately using the same methods to provide a nationally representative comparison. Results Strong associations were found for each anthropometric marker and incidence of T2DM. Among the standardised anthropometric measures, we found the strongest effect on incident T2DM for WC and WHtR in the pooled sample (HR for 1 SD difference in WC 1.97, 95% CI 1.75 to 2.22, HR for WHtR 1.93, 95% CI 1.71 to 2.17 in women) and in female DEGS participants (HR for WC 2.24, 95% CI 1.91 to 2.63, HR for WHtR 2.10, 95% CI 1.81 to 2.44), whereas the strongest association in men was found for WHR among DEGS participants (HR 2.29, 95% CI 1.89 to 2.78). ROC analysis showed WHtR to be the strongest predictor for incident T2DM. Differences in HR and ROCs between the different markers confirmed WC and WHtR to be the best predictors of incident T2DM. Findings were consistent across study regions and age groups (<65 vs ≥65 years). Conclusions We found stronger associations between anthropometric markers that reflect abdominal obesity (ie, WC and WHtR) and incident T2DM than for BMI and weight. The use of these measurements in risk prediction should be encouraged