Large deformation of spherical vesicle studied by perturbation theory and Surface evolver

With tangent angle perturbation approach the axial symmetry deformation of a spherical vesicle in large under the pressure changes is studied by the elasticity theory of Helfrich spontaneous curvature model.Three main results in axial symmetry shape: biconcave shape, peanut shape, and one type of myelin are obtained. These axial symmetry morphology deformations are in agreement with those observed in lipsome experiments by dark-field light microscopy [Hotani, J. Mol. Biol. 178, (1984) 113] and in the red blood cell with two thin filaments (myelin) observed in living state (see, Bessis, Living Blood Cells and Their Ultrastructure, Springer-Verlag, 1973). Furthermore, the biconcave shape and peanut shape can be simulated with the help of a powerful software, Surface Evolver [Brakke, Exp. Math. 1, 141 (1992) 141], in which the spontaneous curvature can be easy taken into account.Comment: 16 pages, 6 EPS figures and 2 PS figure

The structure relaxation of carbon nanotube

A simple macroscopic continuum elasticity theory (CET) is used to calculate the structure relaxation of single-wall carbon nanotube (SWNT), an analytic formula is obtained. We also expand an atomic scale three-parameter empirical model [ T. Lenosky {\emph et al.} Nature 355, 333(1992)] in order to correctly describe the bond-length change effects. The structure relaxation of SWNT expected by the model is good in agreement with our CET results, and very well consistent with the previous calculation from a first principles local density function approximation. Using the expanded Lenosky model, we calculate the strain energy of bending tube. The obtained results are good in agreement with the previous theoretical expectation. It shows the model may be a good simple replacement of some more sophisticated methods on determining carbon networks deformations.Comment: 9 pages, 4 eps figure

Self-reported Rates of Abuse, Neglect, and Bullying Experienced by Transgender and Gender-Nonbinary Adolescents in China

open access articleImportance This is the first comprehensive national study reporting the rates of abuse, neglect, and bullying from family and classmates or teachers among Chinese transgender and gender-nonbinary adolescents and identifying risk factors associated with poor mental health in this population. Objective To assess the rates of abuse, neglect, and bullying and their association with poor mental health among Chinese transgender and gender nonbinary adolescents. Design, Setting, and Participants This national survey study used an online self-selecting survey conducted between January 1, 2017, and September 29, 2017, in China. Eligibility criteria included reporting being aged 12 to 18 years and being transgender or gender nonbinary. Data analysis was performed from March 25 to 28, 2019. Main Outcomes and Measures The main outcome was self-reported poor mental health, including depressive symptoms, anxiety symptoms, and suicidal ideation. Depressive symptoms were measured using the Center for Epidemiological Studies Depression 9-item scale. Anxiety symptoms were measured using the 7-item General Anxiety Disorder scale. Suicidal ideation was measured using standardized questions adapted from previous Chinese studies. Abuse, neglect, and bullying were measured using specifically designed questions. Results Of 564 responses collected, 385 respondents (mean [SD] age, 16.7 [1.2] years) met inclusion criteria, including 109 (28.3%) transgender adolescent boys, 167 (43.4%) transgender adolescent girls, and 109 (28.3%) gender-nonbinary adolescents. Among 319 respondents who reported that their parents were aware of their gender identity, 296 (92.8%) reported having experienced parental abuse or neglect. Among the full cohort, 295 respondents (76.6%) reported having experienced abuse or bullying owing to being transgender or gender nonbinary in school from classmates or teachers. There were 173 respondents (44.9%) with Center for Epidemiological Studies Depression 9-item scale scores indicating they were at risk of major depressive disorder, and 148 respondents (38.4%) had 7-item General Anxiety Disorder scale scores indicating they were at risk of an anxiety disorder. In univariate analysis, reporting experiences of bullying from a classmate or teacher was significantly associated with suicidal ideation (odds ratio, 1.68 [95% CI, 1.04-2.70]; P = .03), but the association was no longer statistically significant after controlling for level of educational attainment, aversion to assigned sex, and depressed mood at the onset of puberty (odds ratio, 1.63 [95% CI, 0.97-2.73]; P = .06). Conclusions and Relevance In this survey study, transgender and gender-nonbinary adolescents in China reported high rates of abuse, neglect, and bullying at home and in school and high rates of symptoms associated with poor mental health. This study highlights the importance of reducing home- and school-based abuse, neglect, and bullying of transgender and gender-nonbinary adolescents in China to improve mental health outcomes; however, broader change in the social environment may be required to address the prejudice and stigma aimed at gender minorities

The relationship between childhood trauma and Internet gaming disorder among college students: A structural equation model

open access journalBackground The aim of this study was to investigate the mechanisms of Internet gaming disorder (IGD) and the associated interaction effects of childhood trauma, depression and anxiety in college students. Methods Participants were enrolled full-time as freshmen at a University in the Hunan province, China. All participants reported their socio-demographic characteristics and undertook a standardized assessment on childhood trauma, anxiety, depression and IGD. The effect of childhood trauma on university students' internet gaming behaviour mediated by anxiety and depression was analysed using structural equation modelling (SEM) using R 3.6.1. Results In total, 922 freshmen participated in the study, with an approximately even male-to-female ratio. A mediation model with anxiety and depression as the mediators between childhood trauma and internet gaming behaviour allowing anxiety and depression to be correlated was tested using SEM. The SEM analysis revealed that a standardised total effect of childhood trauma on Internet gaming was 0.18, (Z = 5.60, 95% CI [0.02, 0.05], P < 0.001), with the direct effects of childhood trauma on Internet gaming being 0.11 (Z = 3.41, 95% CI [0.01, 0.03], P = 0.001), and the indirect effects being 0.02 (Z = 2.32, 95% CI [0.00, 0.01], P = 0.020) in the pathway of childhood trauma-depression-internet gaming; and 0.05 (Z = 3.67, 95% CI [0.00, 0.02], P < 0.001) in the pathway of childhood trauma-anxiety-Internet gaming. In addition, the two mediators anxiety and depression were significantly correlated (r = 0.50, Z = 13.54, 95% CI [3.50, 5.05], P < 0.001). Conclusions The study revealed that childhood trauma had a significant impact on adolescents' Internet gaming behaviours among college students. Anxiety and depression both significantly mediated the relationship between childhood trauma and internet gaming and augmented its negative influence. Discussion of the need to understand the subtypes of childhood traumatic experience in relationship to addictive behaviours is included

Внедрение зарплатного проекта с использованием банковских пластиковых карточек в ОАО «Белинвестбанк»

Материалы VI Междунар. межвуз. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 4–5 мая 2006 г

Impulse Measurement Methods for Space Micro-Propulsion Systems

Space micro-propulsion systems are increasingly considered an attractive option for station-keeping and drag-makeup purposes for the mass- and power-limited satellites due to their critical factors of simple design, small volume, and high specific impulse. These systems typically generate low-range thrust from nN to mN, and their impulses are less than mNs, making it difficult for conventional sensors to detect them directly. Consequently, the design of a special thrust stand is often necessary to measure these micro-propulsion systems. This chapter outlines recommended practices for the operation and calibration of three conventional measurement methods, along with the introduction of an impulse measurement stand developed at the National University of Defense Technology. The chapter presents the fundamentals, calibration method, and experimental results of the stand operation, while also analyzing error sources. Finally, the chapter discusses the demand and direction of micro-impulse measurement development

Frequency Resource Sharing and Allocation Scheme Based on Coalition Formation Game in Hybrid D2D-Cellular Network

A distributed cooperation scheme on frequency resource sharing is proposed to improve the quality of service (QoS) in device-to-device (D2D) communications underlaying cellular networks. Specifically, we formulate the resource allocation problem as a coalition formation game with transferable utility, in which all users have the incentive to cooperate with some others and form a competitive group to maximize the probability of obtaining their favorite spectrum resources. Taking the cost for coalition formation into account, such as the path loss for data sharing, we prove that the core of the proposed game is empty, which shows the impossibility of grand coalition. Hence, we propose a distributed merge-and-split based coalition formation algorithm based on a new defined Max-Coalition order to effectively solve the coalition game. Compared with the exhaustive search, our algorithm has much lower computer complexity. In addition, we prove that stability and convergence of the proposed algorithm using the concept of a defection function. Finally, the simulation results show that the proposed scheme achieves a suboptimal performance in terms of network sum rate compared with the centralized optimal resource allocation scheme obtained via exhaustive search

A qualitative study of how self-harm starts and continues among Chinese adolescents

Background It is essential to investigate the experiences behind why adolescents start and continue to self-harm in order to develop targeted treatment and prevent future self-harming behaviours. Aims The aims of this study are to understand the motivations for initiating and repeating nonfatal self-harm, the different methods used between first-time and repeated self-harm and the reasons that adolescents do not seek help from health services. Methods Adolescents with repeated nonfatal self-harm experiences were recruited to participate in individual, semi-structured qualitative interviews. The interviews were analysed with interpretative phenomenological analysis. Results We found that nonfatal self-harm among adolescents occurred comparatively early and was often triggered by specific reasons. However, the subsequent nonfatal self-harm could be causeless, with repeated self-harm becoming a maladaptive coping strategy to handle daily pressure and negative emotions. The choice of tools used was related to the ease of accessibility, the life-threatening risk and the size of the scars. Adolescents often concealed their scars on purpose, which made early identification insufficient. Peer influence, such as online chat groups encouraging self-harm by discussing and sharing self-harm pictures, could also lead to increased self-harm. The results also included participants’ opinions on how to stop nonfatal self-harm and their dissatisfaction with the current healthcare services. Conclusions The current study provides important implications both for early identification and interventions for adolescents who engage in repeated nonfatal self-harm, and for individualising treatment planning that benefits them. It is also worthwhile to further investigate how peer influence and social media may affect self-harm in adolescents