Strain-induced topological phase transition in phosphorene and phosphorene nanoribbons

Using the tight-binding (TB) approximation with inclusion of the spin-orbit interaction, we predict a topological phase transition in the electronic band structure of phosphorene in the presence of axial strains. We derive a low-energy TB Hamiltonian that includes the spin-orbit interaction for bulk phosphorene. Applying a compressive biaxial in-plane strain and perpendicular tensile strain in ranges where the structure is still stable leads to a topological phase transition. We also examine the influence of strain on zigzag phosphorene nanoribbons (zPNRs) and the formation of the corresponding protected edge states when the system is in the topological phase. For zPNRs up to a width of 100 nm the energy gap is at least three orders of magnitude larger than the thermal energy at room temperature.Comment: 10 pages, 6 figure

Distribution of Maximal Luminosity of Galaxies in the Sloan Digital Sky Survey

Extreme value statistics (EVS) is applied to the distribution of galaxy luminosities in the Sloan Digital Sky Survey (SDSS). We analyze the DR8 Main Galaxy Sample (MGS), as well as the Luminous Red Galaxies (LRG). Maximal luminosities are sampled from batches consisting of elongated pencil beams in the radial direction of sight. For the MGS, results suggest a small and positive tail index $\xi$, effectively ruling out the possibility of having a finite maximum cutoff luminosity, and implying that the luminosity distribution function may decay as a power law at the high luminosity end. Assuming, however, $\xi=0$, a non-parametric comparison of the maximal luminosities with the Fisher-Tippett-Gumbel distribution (limit distribution for variables distributed by the Schechter fit) indicates a good agreement provided uncertainties arising both from the finite batch size and from the batch size distribution are accounted for. For a volume limited sample of LRGs, results show that they can be described as being the extremes of a luminosity distribution with an exponentially decaying tail, provided the uncertainties related to batch-size distribution are taken care of

Community-based physical activity interventions among women: A systematic review

Objective: Review and assess the effectiveness of community-based physical activity interventions among women aged 18-65 years. Design: Systematic review Methods: To find relevant articles, the researcher selected reports published in English between 1 January 2000 and 31 March 2013. Systematic search was to find controlled-trial studies that were conducted to uncover the effect of community-based interventions to promote physical activity among women 18-65 years of age, in which physical activity was reported as one of the measured outcomes. The methodological quality assessment was performed using a critical appraisal sheet. Also, the levels of evidence were assessed for the types of interventions. Results: The literature search identified nine articles. Four of the studies were randomised and the others studies had high methodological quality. There was no evidence, on the basis of effectiveness, for social cognitive theory-based interventions and inconclusive evidence of effectiveness for the rest of interventions. Conclusions: There is insufficient evidence to assess the effectiveness of community-based interventions for enhancing physical activity among women. There is a need for high-quality randomised clinical trials with adequate statistical power to determine whether multicomponent and community-based intervention programmes increase physical activity among women, as well as to determine what type of interventions have a more effective and sustainable impact on women's physical activity. © 2015, BMJ. All rights reserved

Study of secondary school teachers and students experiences in use of technology: phenomenological study

The main purpose of this study is to investigate high school teachers’ and students’ experience in using technology. The quality and phenomenology method has been applied in this study. The statistic population includes all high school teachers and students in Behbahan city. Therefore, based on purposive sampling method, semi-structured interviews have been done with 8 teachers and 6 students in Behbahan with regard to the use of technology. To ensure the reliability of research data, continuous study method and comparison of the data, summarizing and classifying the information was used without causing any damage to data. The data were analyzed by Smith´s suggested method. In using technology three main themes gained including the effective use of technology, barriers in using technology, factors influencing the use of technology. Three major themes were extracted from the findings that can depict teachers and students’ experiences in the use of technology. The finding revealed that teachers and students are faced with many problems in using technology. The most important issues include; (a) ignoring computer training books (b) pass the entrance examination (c) teachers’ interest and (d) type of course

Deep learning for the rapid automatic quantification and characterization of rotator cuff muscle degeneration from shoulder CT datasets.

This study aimed at developing a convolutional neural network (CNN) able to automatically quantify and characterize the level of degeneration of rotator cuff (RC) muscles from shoulder CT images including muscle atrophy and fatty infiltration. One hundred three shoulder CT scans from 95 patients with primary glenohumeral osteoarthritis undergoing anatomical total shoulder arthroplasty were retrospectively retrieved. Three independent radiologists manually segmented the premorbid boundaries of all four RC muscles on standardized sagittal-oblique CT sections. This premorbid muscle segmentation was further automatically predicted using a CNN. Automatically predicted premorbid segmentations were then used to quantify the ratio of muscle atrophy, fatty infiltration, secondary bone formation, and overall muscle degeneration. These muscle parameters were compared with measures obtained manually by human raters. Average Dice similarity coefficients for muscle segmentations obtained automatically with the CNN (88% ± 9%) and manually by human raters (89% ± 6%) were comparable. No significant differences were observed for the subscapularis, supraspinatus, and teres minor muscles (p > 0.120), whereas Dice coefficients of the automatic segmentation were significantly higher for the infraspinatus (p < 0.012). The automatic approach was able to provide good-very good estimates of muscle atrophy (R <sup>2</sup> = 0.87), fatty infiltration (R <sup>2</sup> = 0.91), and overall muscle degeneration (R <sup>2</sup> = 0.91). However, CNN-derived segmentations showed a higher variability in quantifying secondary bone formation (R <sup>2</sup> = 0.61) than human raters (R <sup>2</sup> = 0.87). Deep learning provides a rapid and reliable automatic quantification of RC muscle atrophy, fatty infiltration, and overall muscle degeneration directly from preoperative shoulder CT scans of osteoarthritic patients, with an accuracy comparable with that of human raters. • Deep learning can not only segment RC muscles currently available in CT images but also learn their pre-existing locations and shapes from invariant anatomical structures visible on CT sections. • Our automatic method is able to provide a rapid and reliable quantification of RC muscle atrophy and fatty infiltration from conventional shoulder CT scans. • The accuracy of our automatic quantitative technique is comparable with that of human raters

Preventing HIV transmission among Iranian prisoners: Initial support for providing education on the benefits of harm reduction practices

<p>Abstract</p> <p>Background</p> <p>Harm reduction is a health-centred approach that seeks to reduce the health and social harms associated with high-risk behaviors, such as illicit drug use. The objective of this study is to determine the association between the beliefs of a group of adult, male prisoners in Iran about the transmission of HIV and their high-risk practices while in prison.</p> <p>Methods</p> <p>A cross-sectional study was conducted in 2004. The study population was a random selection of 100 men incarcerated at Rajaei-Shahr prison. The data were collected through a self-administered questionnaire. Focus group discussions were held at the prison to guide the design of the questionnaire. The relationship between components of the Health Belief Model (HBM) and prisoners' risky HIV-related behaviors was examined.</p> <p>Results</p> <p>Calculating Pearson's correlation coefficient, a significant, positive association was found between the benefit component of the HBM and prisoners <it>not </it>engaging in HIV high-risk behaviors.</p> <p>Conclusion</p> <p>Educational harm reduction initiatives that promote the effectiveness of strategies designed to reduce the risk of HIV transmission may decrease prisoners' high-risk behaviors. This finding provides initial support for the Iran prison system's current offering of HIV/AIDS harm reduction programming and suggests the need to offer increased education about the effectiveness of HIV prevention practices.</p

Diet and cancer prevention: Dietary compounds, dietary MicroRNAs, and dietary exosomes

Cancer is one of main health public problems worldwide. Several factors are involved in beginning and development of cancer. Genetic and internal/external environmental factors can be as important agents that effect on emerging and development of several cancers. Diet and nutrition may be as one of important factors in prevention or treatment of various cancers. A large number studies indicated that suitable dietary patterns may help to cancer prevention or could inhibit development of tumor in cancer patients. Moreover, a large numbers studies indicated that a variety of dietary compounds such as curcumin, green tea, folat, selenium, and soy isoflavones show a wide range anti-cancer properties. It has been showed that these compounds via targeting a sequence of cellular and molecular pathways could be used as suitable options for cancer chemoprevention and cancer therapy. Recently, dietary microRNAs and exosomes have been emerged as attractive players in cancer prevention and cancer therapy. These molecules could change behavior of cancer cells via targeting various cellular and molecular pathways involved in cancer pathogenesis. Hence, the utilization of dietary compounds which are associated with powerful molecules such as microRNAs and exosomes and put them in dietary patterns could contribute to prevention or treatment of various cancers. Here, we summarized various studies that assessed effect of dietary patterns on cancer prevention shortly. Moreover, we highlighted the utilization of dietary compounds, dietary microRNAs, and dietary exosomes and their cellular and molecular pathways in cancer chemoprevention. © 2017 Wiley Periodicals, Inc

Distribution of Maximal Luminosity of Galaxies in the Sloan Digital Sky Survey

Extreme value statistics (EVS) is applied to the pixelized distribution of galaxy luminosities in the Sloan Digital Sky Survey (SDSS). We analyze the DR8 Main Galaxy Sample (MGS) as well as the Luminous Red Galaxy Sample (LRGS). A non-parametric comparison of the EVS of the luminosities with the Fisher-Tippett-Gumbel distribution (limit distribution for independent variables distributed by the Press-Schechter law) indicates a good agreement provided uncertainties arising both from the finite size of the samples and from the sample size distribution are accounted for. This effectively rules out the possibility of having a finite maximum cutoff luminosit

Distribution of Maximal Luminosity of Galaxies in the Sloan Digital Sky Survey

Extreme value statistics (EVS) is applied to the pixelized distribution of galaxy luminosities in the Sloan Digital Sky Survey (SDSS). We analyze the DR8 Main Galaxy Sample (MGS) as well as the Luminous Red Galaxy Sample (LRGS). A non-parametric comparison of the EVS of the luminosities with the Fisher-Tippett-Gumbel distribution (limit distribution for independent variables distributed by the Press-Schechter law) indicates a good agreement provided uncertainties arising both from the finite size of the samples and from the sample size distribution are accounted for. This effectively rules out the possibility of having a finite maximum cutoff luminosit

Objective allergy markers and risk of cancer mortality and hospitalization in a large population-based cohort

PURPOSE: There are indications that a history of allergy may offer some protection against cancer. We studied the relation of three objectively determined allergy markers with cancer mortality and hospitalization risk. METHODS: Associations between three allergy markers (number of peripheral blood eosinophil counts, skin test positivity, and serum total IgE) with mortality and hospitalization from any type and four common types of cancer (lung, colorectal, prostate, and breast cancer) were assessed in the Vlagtwedde-Vlaardingen cohort (1965-1990), with follow-up of mortality until 31 December 2008. Hospitalization data were available since 1 January 1995. RESULTS: There were no significant associations between objective allergy markers and cancer mortality or hospitalization. We found several associations in specific subgroups. A higher number of eosinophils was associated with a decreased risk of colorectal cancer mortality in ever smokers HR (95 % CI) = 0.61 (0.45-0.83) and in males 0.59 (0.42-0.83); however, no overall association was observed 0.84 (0.64-1.09). Skin test positivity was associated with a decreased risk of any cancer mortality only among females 0.59 (0.38-0.91) and showed no overall association 0.83 (0.67-1.04). Serum total IgE levels were associated with an increased risk of lung cancer mortality among females 4.64 (1.04-20.70), but with a decreased risk of cancer hospitalization in ever smokers 0.77 (0.61-0.97) and males 0.72 (0.55-0.93); however, no overall associations were observed [mortality 0.99 (0.79-1.25), and hospitalization 0.86 (0.71-1.04)]. CONCLUSIONS: We found no associations between objective allergy markers and cancer in the total population. However, skin test positivity and a high number of eosinophils were associated with a reduced risk to die of cancer in specific subgroups. Hence, it seems important to study specific subgroups defined by gender and smoking habits in order to identify allergy markers of predictive value for cancer mortality