Associations between Physical Activity and Mental Health in Iranian Adolescents during the COVID-19 Pandemic: An Accelerometer-Based Study.

Using self-reported questionnaires, several studies found that social isolation during the COVID-19 pandemic has significantly changed the level of physical activity (PA) in children and adolescents. Since the objectivity of self-reported PA is limited in several ways, we used modern accelerometers in this study to assess the PA levels of male and female adolescents during the pandemic-related lockdown. Moreover, the association of PA with mental health of the adolescents were analyzed. A total of 136 students (76 girls, mean age of 16.28 ± 0.97 years) from various schools in Iran wore the accelerometer (ActiGraph GT3X-BT) for seven consecutive days. Mental health was measured through the Depression, Anxiety, Stress Scale-21 of Lovibond and Lovibond (1995). Descriptive statistics and independent t-tests were used to analyze the PA levels of male and female students, and linear regressions were computed to examine whether PA predicts mental health status. On average, the daily time spent in moderate-to-vigorous PA (MVPA) was 18.47 min, which is clearly below the WHO guideline of at least 60 min of MVPA per day. Only 4% of adolescents showed MVPA for more than 30 min per day. Male students were significantly more active than their female peers (p = 0.015). As expected, MVPA was negatively associated with mental health issues such as depression, anxiety, and stress. However, the majority of adolescents reported symptoms of mild-to-moderate mental health disorders. These results emphasize the need for targeted strategies and offerings geared to young people's needs and preferences to promote an adequate level of PA and good mental health during and after the ongoing pandemic.

MoVi: A large multi-purpose human motion and video dataset.

Large high-quality datasets of human body shape and kinematics lay the foundation for modelling and simulation approaches in computer vision, computer graphics, and biomechanics. Creating datasets that combine naturalistic recordings with high-accuracy data about ground truth body shape and pose is challenging because different motion recording systems are either optimized for one or the other. We address this issue in our dataset by using different hardware systems to record partially overlapping information and synchronized data that lend themselves to transfer learning. This multimodal dataset contains 9 hours of optical motion capture data, 17 hours of video data from 4 different points of view recorded by stationary and hand-held cameras, and 6.6 hours of inertial measurement units data recorded from 60 female and 30 male actors performing a collection of 21 everyday actions and sports movements. The processed motion capture data is also available as realistic 3D human meshes. We anticipate use of this dataset for research on human pose estimation, action recognition, motion modelling, gait analysis, and body shape reconstruction.

Histone deacetylases in virus-associated cancers.

Oncogenic viruses are one of the most important causes of cancer worldwide. The pathogens contribute to the establishment of human malignancies by affecting various cellular events. Epigenetic mechanisms, such as histone modification methylation/demethylation, are one of the most critical events manipulated by oncogenic viruses to drive tumorigenesis. Histone modifications are mediated by histone acetylation and deacetylation, regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. Dysregulation of HDACs activity affects viral tumorigenesis in several ways, such as manipulating tumor suppressor and viral gene expression. The present review aims to describe the vital interactions between both cancer-caused/associated viruses and the HDAC machinery, particularly by focusing on those viruses involved in gastrointestinal tumors, as some of the most common viral-mediated cancers.

Association between human papillomavirus infection and prostate cancer: A global systematic review and meta-analysis.

Although an increasing number of studies have been conducted to evaluate the association between human papillomavirus (HPV) infections and distribution of HPV types worldwide with the risk of prostate cancer (PC), the results remain inadequate. Hence, we investigated the association between HPV infection and PC risk using a meta-analysis. Relevant studies from January 1990 to December 2016 were searched in PubMed, Web of sciences, and Scopus databases. Pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were calculated to find the association between the prevalence of HPV and prostate cancer risk. To do so, data from 24 studies with 5546 prostate cancer cases were pooled in order to evaluate the heterogeneity of chief parameters including study region, specimen type, HPV DNA source, detection technique, publication calendar period, and Gleason score. All statistical analyses were performed using STATA 11 and MedCalc 13. A significant positive association was found between HPV infection and PC risk (OR = 1.281; P = 0.026). The genotype 16 was more frequently found in patients with PC which significantly increased the cancer risk (OR = 1.60; P < 0.001). Age 65 and older could significantly escalate PC risk (OR = 3.564; P < 0.001). Our results clearly favor the potential pathogenetic link between HPV infection and increased risk of PC affirming that HPV infections could play a part in the risk of PC.

Motivational effects of enhancing expectancies and autonomy for motor learning: An examination of the OPTIMAL theory.

The OPTIMAL theory proposes that enhancing expectancies and autonomy facilitate motor performance and learning (Wulf & Lewthwaite). Present study with two experiments aimed to examine this proposition by using a modified dart throwing as motor task. In both experiments, motor learning (i.e., retention test) was enhanced by practice conditions, which enhance expectancies for future performance and support learners' autonomy. Moreover, they led to significantly superior self-efficacy scores during all acquisition phase, retention, and transfer tests. Findings of the present study provided support for propositions of the OPTIMAL theory. Results are discussed in terms of motivational aspects of enhancing expectancies and autonomy and their role on facilitating motor learning.

Percepción de competencia física en escolares de España e Irán. Un estudio cultural / Perception of physical competence in schoolchildren in Spain and Iran. A cultural study

La percepción de competencia física (PCF) es un constructo psicológico que puede estar influenciado por factores culturales. Objetivo: analizar la PCF en una muestra de escolares españoles e iraníes. Método: en el estudio participaron 910 escolares, con edades entre 10 y 12 años, pertenecientes a Castilla la Mancha (España) y Golestan (Irán). El instrumento utilizado para medir este constructo fue la Percepción de la competencia en Educación Física, y se aplicó la prueba U-Mann Whitney. Resultados: los varones y las mujeres de España obtuvieron valores superiores en los factores de experiencia personal (p< .05) y compañeros (p<.05). A nivel global, solo los varones españoles presentaron una mayor PCF que sus homólogos iraníes (p<.05). Estos resultados muestran diferencias interculturales en la PCF a favor de los escolares españoles. Conclusión: conocer la PCF permite adecuar el desarrollo de las clases de Educación Física con el fin de influir en la intención de ser físicamente activo y un mayor ajuste psicológico del escolar.

The perception of physical competence (PPC) is a psychological construct that may be influenced by cultural factors. The objective was to analyze the PPC in a sample of Spanish and Iranian schoolchildren. 910 schoolchildren (ages 10-12 years) belonging to Castilla la Mancha (Spain) and Golestan (Iran) participated in the study. The instrument used to measure this construct is the perception of the competence in Physical Education. The U-Mann Whitney test has shown that men and women in Spain obtain higher values in personal experience factors (p <.05) and partners (p <.05). At a global level, Spanish schoolchildren present a higher perception of physical competence than their Iranian counterparts (p <.05). These results show intercultural differences in the PPC in favor of Spanish schoolchildren. Knowing the perception of physical competence allows adapting the development of Physical Education classes in order to influence the intention to be physically active and a greater psychological adjustment of the school.

A percepção de concorrência física (PCF) é um conceito psicológico que pode estar influenciado por fatores culturais. Objetivo: analisar a PCF em uma mostra de escolares espanhóis e iranianos. Método: no estudo participaram no estudo 910 escolares, com (idades entre 10 e- 12 anos,) pertencentes a Castilla a Mancha (Espanha) e Golestan (Irão). Instrumento utilizado para medir este conceito foi é a percepção da concorrência em Educação Física, e aplicou-se a prova Ou-Mann Whitney. Resultados: os varões e as mulheres de Espanha obtiveram valores superiores nos fatores de experiência pessoal (p< .05) e colegas (p<.05) A nível global, só os varões espanhóis apresentaram uma maior percepção de concorrência física que seus homólogos iranianos (p<.05) Estes resultados mostram diferenças interculturais na PCF a favor de os escolares espanhóis. Conclusão: conhecer a percepção de concorrência física permite adequar o desenvolvimento das classes de Educação Física com o fim de influir na intenção de ser fisicamente ativo e um maior ajuste psicológico do escoar.

Presenting a new method to improve the detection of micro-seismic events.

Seismic events such as earthquakes are one of the most important issues in the field of geology. Meanwhile, less attention has been paid to micro-seismic events, despite the high number of earthquakes. Earthquakes, regardless of their size, affect human life; therefore, their detection and management is considered an important issue. For this purpose, experts developed seismic arrays as a system of linked seismometers. These systems equipped with sensors and seismographs are able to receive a range of waves from the earth, which are then sent to the central seismic station for analysis. So far, many tools and methods have been devised to analyze seismic data. However, the dominant method in most seismic mechanisms is trigger function, based on STA/LTA (short-time-average through long-time-average trigger). These mechanisms have considerable threshold in terms of earthquake range, so many micro-events are ignored as noise. Generally, in this field of geology, computer science techniques have been used to detect and classify these events. Statistical methods such as kurtosis, variance, and skewness can be applied to understand the changes in the signal curves of geophones in a seismic event, thereby helping in the initial detection of fuzzy features. According to the last 3 years' reports of global data mining agencies such as Rexer, KDnugget, and Gartner, Rapid Miner is one of the most popular tools for data mining in recent years. Furthermore, these institutions considered artificial neural networks, especially multilayer perceptron (MLP) and base radial function (RBF), to be among the most successful algorithms for detection and classification of stream data. In this research, the recorded data from several seismic experiments has been classified by a hybrid model. Hence, the present study was aimed to enhance the authenticity of data based on the application of effective variables. This was undertaken through use of a fuzzy method and an integrated neural network algorithm, involving MLP perceptron and radial network of RBF in the form of a collective learning system, in order to identify seismic events on a small scale. Based on the results, in comparison to basic methods, the proposed method significantly improved using the actual error and root-mean-square error (RMSE) criteria.

Throwing Skills.

Traditionally, motor learning scientists have evaluated the process of learning a new motor skill by considering the skill as a whole. Yet, motor skills comprise various phases, and in the motor learning literature, it is not clear whether new learners show similar or different learning across various phases. We provide exploratory data on learning movement phases by novices, using baseball pitching as the learning task. Eight participants (four male, four female, M age = 23.7 years, SD = 2.4) performed five trials each in the pretest followed by three blocks of 10 trials each in the acquisition phase. Finally, two retention tests of five trials were conducted by each participant 10 minutes and seven days after the last acquisition block, respectively. Intra- and interlimb coordination of upper and lower body segments were measured as dependent variables. We found significant differences between the stride phase and the other phases at pretest, during the acquisition phase, and on both retention tests across all kinematic variables. Participants experienced more trouble coordinating the stride phase than the other phases of pitching, perhaps because the stride phase is the only phase in which the participants had to move their upper and lower body parts simultaneously. We discuss implications for motor learning generally.

A Three-Dimensional Movement Analysis of the Spike in Fistball.

Due to its relevancy to point scoring, the spike is considered as one of the most important skills in fistball. Biomechanical analyses of this sport are very rare. In the present study, we performed a three-dimensional kinematic analysis of the fistball spike, which helps to specify performance parameters on a descriptive level. Recorded by four synchronized cameras (120 Hz) and linked to the motion capture software Simi Motion® 5.0, three female fistball players of the second German league (24⁻26 years, 1.63⁻1.69 m) performed several spikes under standardized conditions. Results show that the segment velocities of the arm reached their maximum successively from proximal to distal, following the principle of temporal coordination of single impulses. The wrist shows maximum speed when the fist hits the ball. The elbow joint angle performs a rapid transition from a strong flexion to a (almost) full extension; however, the extension is completed after the moment of ball impact. In contrast, the shoulder joint angle increases almost linearly until the fistball contact and decreases afterward. The findings can be used to optimize the training of the spike.

Effect of Different pH Values on the Compressive Strength of Calcium-Enriched Mixture Cement.

INTRODUCTION: The aim of this study was to evaluate the compressive strength of calcium-enriched mixture (CEM) cement in contact with acidic, neutral and alkaline pH values. METHODS AND MATERIALS: The cement was mixed according to the manufacturer's instructions, it was then condensed into fourteen split molds with five 4×6 mm holes. The specimens were randomly divided into 7 groups (n=10) and were then exposed to environments with pH values of 4.4, 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4 in an incubator at 37(°) C for 4 days. After removing the samples from the molds, cement pellets were compressed in a universal testing machine. The exact forces required for breaking of the samples were recorded. The data were analyzed with the Kruskal-Wallis and Dunn tests for individual and pairwise comparisons, respectively. The level of significance was set at 0.05. RESULTS: The greatest (48.59±10.36) and the lowest (9.67±3.16) mean compressive strength values were observed after exposure to pH value of 9.4 and 7.4, respectively. Alkaline environment significantly increased the compressive strength of CEM cement compared to the control group. There was no significant difference between the pH values of 9.4 and 10.4 but significant differences were found between pH values of 9.4, 8.4 and 7.4. The acidic environment showed better results than the neutral environment, although the difference was not significant for the pH value of 6.4. Alkaline pH also showed significantly better results than acidic and neutral pH. CONCLUSION: The compressive strength of CEM cement improved in the presence of acidic and alkaline environments but alkaline environment showed the best results.