Internet addiction among Greek university students: Demographic associations with the phenomenon, using the Greek version of young's Internet addiction rest

Internet addiction (IA) is a new disorder described in 1996 by the psychologist Kimberly Young. The aim of this paper is to estimate the percentage of IA among Greek university students. Results of a sample survey among 1876 Greek university students, 18-27 years old, are presented. The questionnaire consisted of eight questions from Young's Diagnostic Test for Internet Addiction (YDTIA) as well as an inventory including demographic factors and questions about academic performance, computer and Internet use. YDTIA had a good reliability and diagnostic accuracy, tested with Cronbach's alpha (0.71) and sensitivity analysis. Results show that the percentage of IA (5-8 YDTIA criteria) is 11.6%, while problematic Internet users were (3-8 YDTIA criteria) 34.7%. Men were more likely to be addicted to the Internet than women, and Internet addicted students were associated with poorer academic performance. Multiple logistic regression showed that significant predictors of IA included increased hours of daily Internet use, increased hours visiting chat rooms, sex pages and blogs, male gender, divorced status, poor grades, and accessing the Internet outside of the home. The results of this study will allow health officials to recognise students who are Internet addicted or on the verge of becoming addicted and stress risk factors indicating a need for intervention in order to prevent the appearance of IA

The radiation problem from a vertical short dipole antenna above flat and lossy ground. Novel formulation in the spectral domain with closed form analytical solution in the high frequency regime

In this paper we consider the problem of radiation from a vertical short Hertzian dipole above flat lossy ground, which represents the well known in the literature Sommerfeld radiation problem. The problem is formulated in a novel spectral domain approach, and by inverse three dimensional Fourier transformation the expressions for the received electric and magnetic field in the physical space are derived as one dimensional integrals over the radial component of wavevector, in cylindrical coordinates. Subsequent use of the Stationary Phase Method in the high frequency regime yields closed form analytical solutions for the received EM field vectors, which coincide with the corresponding reflected EM field originating from the image point. In this way, we conclude that the so called in the literature space wave, i.e. line of sight plus reflected EM field, represents the total solution of the Sommerfeld problem in the high frequency regime, in which case the surface wave can be ignored. Finally, numerical results in the high frequency regime are presented in this paper, in comparison with corresponding numerical results based on Norton solution of the problem, i.e. space and surface waves

Structural empowerment is a strong predictor of organizational commitment in nurses: A systematic review and meta-analysis

AIMS: The aim of this systematic review and meta-analysis is to explore the relationship between structural empowerment and organizational commitment and to examine a theoretical model under which empowerment could potentially affect organizational performance. DESIGN: PRISMA guidelines for systematic reviews and meta-analyses were used and quality assessment of articles was performed. DATA SOURCES: Electronic database searches were conducted in Google Scholar, PubMed/Medline, CINAHL, Scopus, and EMBASE from January 1950–1 January 2019, which resulted in 204 retrieved studies, published between 1994–2018. REVIEW METHODS: A random effects model was used to produce a pooled estimate of effect sizes (correlation coefficient, Cronbach's alpha), with analysis of heterogeneity and publication bias. A meta-analytic structural equation model of the constructs analysed was also performed. RESULTS: The final review included 22 studies. The meta-analytic means of structural empowerment, organizational commitment, job satisfaction, and psychological empowerment alpha reliabilities were 0.87, 0.84, 0.85, and 0.87, respectively. Heterogeneity but no publication bias was present in these outcomes. Structural empowerment was strongly correlated with organizational commitment (r = 0.43). The meta-analytic correlation coefficients of organizational commitment with psychological empowerment and job satisfaction were 0.53 and 0.47, respectively. Structural empowerment was correlated with job satisfaction and psychological empowerment with correlation coefficients of 0.57 and 0.44, respectively. Finally, job satisfaction was correlated with psychological empowerment with a correlation coefficient of 0.53. A meta-analytic structural equation model was tested with good fit which predicted performance (commitment and job satisfaction) from empowerment (structural and psychological). CONCLUSION: Structural empowerment is strongly correlated to organizational commitment and with psychological empowerment, they increase organizational performance. Organizations should attempt to make structural empowerment as widespread as possible to create an effective workplace culture. IMPACT: Structural empowerment in nurses is important to help deliver an effective workplace culture where nurses can be committed and have reduced intention-to-leave. Structural empowerment was strongly correlated with organizational commitment. Organizational commitment was significantly correlated with psychological empowerment and job satisfaction. Structural empowerment was correlated with job satisfaction and psychological empowerment as well. A meta-analytic structural equation model with good fit predicted performance. These results will affect nursing researchers and practitioners. Results indicate a need for organizational restructuring that promotes empowerment and formation of theoretical models that connect empowerment to performance

Fatiguing high-intensity intermittent exercise depresses maximal Na⁺-K⁺-ATPase activity in human skeletal muscle assessed using a novel NADH-coupled assay

The Na+-K+-ATPase is a critical regulator of ion homeostasis during contraction, buffering interstitial K+ accumulation, which is linked to muscle fatigue during intense exercise. Within this context, we adopted a recently reported methodology to examine exercise-induced alterations in maximal Na+-K+-ATPase activity. Eighteen trained healthy young males completed a repeated high-intensity cycling protocol consisting of three periods (EX1-EX3) of intermittent exercise. Each period comprised 10 × 45-s cycling at ~ 105% Wmax and a repeated sprint test. Muscle biopsies were sampled at baseline and after EX3 for determination of maximal in vitro Na+-K+-ATPase activity. Blood was drawn after each period and in association with a 2-min cycling test at a standardized high intensity (~ 90% Wmax) performed before and after the session to assess plasma K+ accumulation. Further, a 5-h recovery period with the ingestion of carbohydrate or placebo supplementation was implemented to explore potential effects of carbohydrate availability before sampling a final biopsy and repeating all tests. A ~ 12% reduction in maximal Na+-K+-ATPase activity was demonstrated following EX3 compared to baseline (25.2 ± 3.9 vs. 22.4 ± 4.8 μmol·min−1·g−1 protein, P = 0.039), which was sustained at the recovery time point (~ 15% decrease compared to baseline to 21.6 ± 5.9 μmol·min−1·g−1 protein, P = 0.008). No significant effect of carbohydrate supplementation was observed on maximal Na+-K+-ATPase activity after recovery (P = 0.078). In conclusion, we demonstrate an exercise-induced depression of maximal Na+-K+-ATPase activity following high-intensity intermittent exercise, which was sustained during a 5-h recovery period and unrelated to carbohydrate availability under the present experimental conditions. This was shown using a novel NADH coupled assay and confirms previous findings using other methodological approaches.</p

Dyadic adjustment, family coping, body image, quality of life and psychological morbidity in patients with psoriasis and their partners

Background Psoriasis is an incurable and chronic disease that includes unpredictable periods of remission and relapse requiring long-term therapy. Purpose This paper focuses on the relationship among family coping, psychological morbidity, body image, dyadic adjustment and quality of life in psoriatic patients and their partners. Method One hundred and one patients with psoriasis and 78 partners comprised the sample. They were regular users of the Dermatology Service of a Central Northern hospital in Portugal and a private dermatology clinic. Patients with psoriasis were assessed on anxiety, depression, body image, quality of life, dyadic adjustment and family coping. Partners were assessed on the same measures except body image and quality of life. Results A positive relationship among dyadic adjustment, psychological morbidity and family coping in patients and their partners was found. Also, patients with lower levels of quality of life had partners with higher levels of depressive and anxious symptoms. Better dyadic adjustment predicted family coping in the psoriatic patient. High levels of dyadic adjustment in patients and low partners’ trait anxiety predicted better dyadic adjustment in partners. Conclusion The results highlight the importance of incorporating family variables in psychological interventions in psoriasis’ care, particularly family coping and dyadic adjustment as well as the need for psychological intervention to focus both on patients and partners

Clinical Studies of Nonpharmacological Methods to Minimize Salivary Gland Damage after Radioiodine Therapy of Differentiated Thyroid Carcinoma: Systematic Review

Purpose. To systematically review clinical studies examining the effectiveness of nonpharmacological methods to prevent/minimize salivary gland damage due to radioiodine treatment of differentiated thyroid carcinoma (DTC). Methods. Reports on relevant trials were identified by searching the PubMed, CINHAL, Cochrane, and Scopus electronic databases covering the period 01/2000-10/2015. Inclusion/exclusion criteria were prespecified. Search yielded eight studies that were reviewed by four of the present authors. Results. Nonpharmacological methods used in trials may reduce salivary gland damage induced by radioiodine. Sialogogues such as lemon candy, vitamin E, lemon juice, and lemon slice reduced such damage significantly (p < 0.0001, p < 0.05, p < 0.10, and p < 0.05, resp.). Parotid gland massage also reduced the salivary damage significantly (p < 0.001). Additionally, vitamin C had some limited effect (p = 0.37), whereas no effect was present in the case of chewing gum(p = 0.99). Conclusion. The review showed that, among nonpharmacological interventions, sialogogues and parotid gland massage had the greatest impact on reducing salivary damage induced by radioiodine therapy of DTC. However, the studies retrieved were limited in number, sample size, strength of evidence, and generalizability. More randomized controlled trials of these methods with multicenter scope and larger sample sizes will provide more systematic and reliable results allowing more definitive conclusions

A deep learning enabler for non-intrusive reduced order modeling of fluid flows

In this paper, we introduce a modular deep neural network (DNN) framework for data-driven reduced order modeling of dynamical systems relevant to fluid flows. We propose various deep neural network architectures which numerically predict evolution of dynamical systems by learning from either using discrete state or slope information of the system. Our approach has been demonstrated using both residual formula and backward difference scheme formulas. However, it can be easily generalized into many different numerical schemes as well. We give a demonstration of our framework for three examples: (i) Kraichnan-Orszag system, an illustrative coupled nonlinear ordinary differential equations, (ii) Lorenz system exhibiting chaotic behavior, and (iii) a non-intrusive model order reduction framework for the two-dimensional Boussinesq equations with a differentially heated cavity flow setup at various Rayleigh numbers. Using only snapshots of state variables at discrete time instances, our data-driven approach can be considered truly non-intrusive, since any prior information about the underlying governing equations is not required for generating the reduced order model. Our \textit{a posteriori} analysis shows that the proposed data-driven approach is remarkably accurate, and can be used as a robust predictive tool for non-intrusive model order reduction of complex fluid flows.Comment: 36 pages, 21 figure