On an exponential power sum

Using combinatorial techniques, we derive a recurrence identity that expresses an exponential power sum with negative powers in terms of another exponential power sum with positive powers. Consequently, we propose a formula for the power sum of first $k$ natural numbers when the power is odd

Facebook Social Use and Anxiety: A Replication Attempt

The relationship between social media use and mental health remains under scrutiny by researchers, policy makers, and the general public. Recently, researchers have addressed whether Facebook use is beneficial to people with high social anxiety. The findings from such studies are mixed, partly due to differences in how variables are operationalised. A study by McCord et al (McCord, B., Rodebaugh, T. L., & Levinson, C. A., 2014. Facebook: Social uses and anxiety.  Computers in Human Behavior, 34, 23-27) suggested that the inclusion of a new variable, Facebook-centric social anxiety, helps explain the complex relationship between general social anxiety and frequency of usage of socially-interactive Facebook features. We undertook two studies (N=202 and N=542; majority British and non-student participants) with the aim of replicating McCord et al (2014), using the original measures (general social anxiety, Facebook-centric social anxiety, and frequency of usage of socially-interactive Facebook features). Replicating the original study, we found a significant positive association between general social anxiety and Facebook-centric social anxiety. However, unlike the original study, we did not find evidence that general social anxiety and Facebook-centric social anxiety interacted to predict frequency of usage of socially-interactive Facebook features. We discuss the implications for future research on social Facebook use

Is Marital Quality Related to Physical Activity Across the Life Course for Men and Women?

Objectives: Although physical activity is linked to multiple health outcomes, a majority of Americans do not meet physical activity guidelines, often with precipitous declines among older adults. Marital quality is a less-explored, but important, factor that may influence physical activity, as spouses often influence each other’s health behaviors. Methods: We use nationally representative panel data to investigate whether positive and negative dimensions of marital quality influence physical activity, and whether age and gender moderate these relationships. Results: We find that both marital support and strain are related to higher odds of more frequent active exercise and walking, pointing to the complex influence of marital quality. Marital support became increasingly important to higher levels of walking frequency as men aged. Discussion: This study provides new information on the ways in which both positive and negative dimensions of marital quality may contribute to trajectories of physical activity across the life course

Sharing and Preserving Computational Analyses for Posterity with encapsulator

Open data and open-source software may be part of the solution to science's "reproducibility crisis", but they are insufficient to guarantee reproducibility. Requiring minimal end-user expertise, encapsulator creates a "time capsule" with reproducible code in a self-contained computational environment. encapsulator provides end-users with a fully-featured desktop environment for reproducible research.Comment: 11 pages, 6 figure

IN VITRO ANTIBACTERIAL PROFILE OF ALSTONIA VENENATA R. BR-A COMPARATIVE STUDY

Objective: To investigate the antibacterial efficacy of leaves, stem-bark, root-bark, flowers and fruits of Alstonia venenata R. Br. Methods: The antimicrobial efficacy of butanol and methanol solvent extracts was evaluated by agar well diffusion against selected pathogenic bacterial strains. Gram negative strains like Pseudomonas aerugenosa, Proteus vulgaris, Escherichia coli, Klebsiella pneumoniae, Slamonella enteric typhimurium, Salmonella typhi, Salmonella paratyphi A, Shigella spp. were tested. Gram positive strains tested were Micrococcus luteus and Staphylococcus aureus. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using macro broth dilution method against clinical isolate of Staphylococcus aureus. Streptomycin 0.125 mg/ml was used as positive control and Dimethyl sulfoxide (DMSO) as the solvent control. Results: Butanol and methanol extracts of all the plant parts are highly effective against Gram positive strains and show moderate inhibition against Gram negative strains. Stem-bark and root-bark butanol were the most effective fractions followed by fruit, flower and leaf extracts. The inhibition zones of Micrococcus luteus and Staphylococcus aureus were 24-26 mm and 18-20 mm respectively. The observed zone size was equal to or greater than the positive control used. The MIC value for stem-bark butanol and root-bark butanol were 0.98 mg/ml and the MBC values were 7.8 mg/ml and 3.9 mg/ml respectively. For fruit, flower and leaf butanol the MIC values were 15.6, 31.25 and 125 mg. Conclusion: The extracts were highly active against Gram positive strains than Gram negative strains. The butanol extracts were the most active fraction followed by the methanol extracts. Highest activity was observed for root-bark and stem-bark followed by fruit, flower and leaf extracts

A Longitudinal Examination of the Impact of Major Life Events on Physical Activity

Background: Despite promotion of physical activity guidelines, less than one third of U.S. adults are sufficiently active and an even larger number of older adults fail to meet guidelines. To address this major public health issue, it is essential to broadly consider determinants of physical activity. Aims: This study explores how physical activity behavior is impacted by the experience of major life events and considers the stress experienced due to these events across the life course. Methods: Nationally representative panel data from the American’s Changing Lives survey (1986-2012) was used to analyze a growth model with age-based trajectories to examine the relationship between major life events and physical activity overall and separately by gender and race. Results: In the overall sample, retiring was associated with greater physical activity at baseline. As respondents aged, entering into retirement was associated with decreased physical activity, while a parent or friend dying were associated with greater physical activity. Differences by gender and race were also seen over time. Conclusions: Results show that when considering physical activity trajectories, experiencing these major life events is not always detrimental, and in some cases may be beneficial. Considering these impacts is important in planning effective health promotion interventions to increase and promote maintenance of physical activity, while paying attention to specific differences by gender and race

IN VITRO ANTIBACTERIAL PROFILE OF ALSTONIA VENENATA R. BR- A COMPARATIVE STUDY

Objective: To investigate the antibacterial efficacy of leaves, stem-bark, root- bark, flowers and fruits of Alstonia venenata R. Br. Methods: The antimicrobial efficacy of butanol and methanol solvent extracts was evaluated by agar well diffusion against selected pathogenic bacterial strains. Gram negative strains like Pseudomonas aerugenosa, Proteus vulgaris, Escherichia coli, Klebsiella pneumoniae, Slamonella enteric typhimurium, Salmonella typhi, Salmonella paratyphi A, Shigella spp. were tested. Gram positive strains tested were Micrococcus luteus and Staphylococcus aureus. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using macro broth dilution method against clinical isolate of Staphylococcus aureus. Streptomycin 0.125mg/ml was used as positive control and Dimethyl sulfoxide (DMSO) as solvent control. Results: Butanol and methanol extracts of all the plant parts are highly effective against Gram positive strains and show moderate inhibition against Gram negative strains. Stem-bark and root-bark butanol were the most effective fractions followed by fruit, flower and leaf extracts. The inhibition zones of Micrococcus luteus and Staphylococcus aureus were 24-26 mm and 18-20 mm respectively. The observed zone size was equal to or greater than the positive control used. The MIC value for stem-bark butanol and root-bark butanol were 0.98 mg/ml and the MBC values were 7.8 mg/ml and 3.9 mg/ml respectively. For fruit, flower and leaf butanol the MIC values were 15.6, 31.25 and 125mg. Conclusion: The extracts were highly active against Gram positive strains than Gram negative strains. The butanol extracts were the most active fraction followed by the methanol extracts. Highest activity was observed for root-bark and stem-bark followed by fruit, flower and leaf extracts

The Role of Government in Corporate Governance

Numerous corporate scandals in the past several years have fueled widespread debate over proposals for government action. The central challenge for government is how to restore corporate integrity and market confidence without overreacting and stifling the dynamism that underlies a strong economy. To examine this challenge, the Center for Business and Government\u27s Regulatory Policy Program organized a conference in May 2004 on The Role of Government in Corporate Governance. The conference brought together government officials, business leaders, and academic researchers to discuss three fundamental public policy issues raised by recent corporate abuses. First, who should regulate corporate management - government agencies or self-regulatory organizations? Second, how should regulatory commands be designed, either as detailed rules or broad principles? Finally, how should regulations be enforced? This report synthesizes the conference dialogue organized around these three questions and explores conditions under which different configurations of regulatory institutions, standards, and enforcement practices can further both corporate integrity and productivity