谈家庭教育中父教缺失对青少年行为的影响及对策——以顺德区某农村中学一名初中生为例

父教缺失是当今社会相当普遍的现象，本文通过对顺德区某农村中学一名父母离异并随母生活的初中生进行个案研究，发现父教缺失的青少年更容易产生自我否定感，容易在同伴交往中缺乏自信，从而导致孤僻的心理。本文针对个案研究的结果，结合学校实际，提出了一些建议。

Sedentary behavior and physical activity predicting depressive symptoms in adolescents beyond attributes of health-related physical fitness

Background： Sedentary behavior （SB）, physical activity （PA）, and attributes of physical fitness have been shown to be related to depressive symptoms in adolescents. The purpose of the present study was to investigate whether SB and fitness-producing activity predicted depression in active adolescents over and above gender and fitness attributes. Methods： Participants were 249 adolescents （age： 12.85 ± 0.89 years, mean ± SD） from 3 public middle schools who wore Actical accelerometers to assess their SB and PA. Participants also completed the FITNESSGRAM health-related fitness assessment and a brief depression questionnaire. A 3-step hierarchical regression analysis was conducted with gender and fitness attributes （i.e., body mass index （BMI）, maximal volume oxygen uptake （VO2max）, curlups, and pushups）, moderate- and vigorous-intensity activity, and SB entered in respective steps. Results： Regression analysis indicated activity variables （i.e., moderate- and vigorous-intensity activity） significantly predicted depression （△R^2= 0.12, p 〈 0.01） beyond gender and fitness attributes. Overall, gender, fitness attributes, activity variables, SB explained 31% of the variance in depression. Structure coefficients revealed VO2max （rs= -0.77）, moderate-intensity activity （rs= -0.67）, vigorous-intensity activity （rs = -0.81）, and SB （rs = 0.57） were substantially correlated with the criterion variable; thus, they were the strongest predictors of depression. Conclusion： The findings of the current study indicated SB and PA were both significant predictors of depression; however, sufficient fitness-producing activity and adequate cardiorespiratory fitness may nullify the negative influence of SB on depressive symptoms in active adolescents.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.

Study on Major Issues Conceming the Implementation of the Online Game Shutdown System --With an Emphasis on Examples of Korea

This study is conducted on the special provision of the Korean government to prevent youths＇ addiction to online games. Judging that the youths＇ addiction to online games is serious, the Korea government made a legal provision to control the phenomena of youths＇ online game addiction. At that time, there were lots of conflicting opinions in the course of implementation of the related governmental act. The purpose of this study is investigating what conflicting opinions there were in the course of the legislation and also the fundamental cause of the opinion confliction and the countermeasures thereby. Especially, it is noteworthy that two departments of the government had different legal approaches toward the issue. Thus, this study will present an affordable suggestion for other countries which have youths＇ online game addiction problems.

Physical activity,sedentary behaviors,physical fitness,and their relation to health outcomes in youth with type 1 and type 2 diabetes:A review of the epidemiologic literature

Diabetes is a leading chronic disease of childhood and adolescence. In addition to the well-known auto-immune, insulin-dependent diabetes mellitus （type 1 diabetes （T 1D））, the past two decades have witnessed the emergence of type 2 diabetes （T2D） in children and adolescents, which previously was only seen in middle-aged or older adults. One of the key components of diabetes management is physical activity （PA）. The beneficial effects of increased PA and decreased sedentary behavior are extremely important in youth with diabetes because of the markedly increased long-term risk of cardiovascular disease in this population compared to persons without diabetes. This review aims to comprehensively summarize the epidemiologic, observational research published and listed in PubMed between 1970 and 2012 on PA and sedentary behaviors, as well as physical fitness in children and adolescents with T1D and T2D. Additionally, we describe briefly the state of knowledge on perceived barriers of PA in persons with diabetes, with a focus on hypoglycemia. Finally, we provide an overview of the epidemiological literature pertaining to health benefits of increased PA in youth with TID and T2D and briefly discuss the topic of exercise-related hypoglycemia, Copyright ~ 2012, Shanghai University of Sport. Production and hosting by Elsevier B.V. All rights reserved.

Effects of photoperiod on daily activity rhythm of juvenile sea cucumber, Apostichopus japonicus (Selenka)

In nature, Apostichopus japonicus exhibits a behavioral characteristic of emerging at night and sheltering during the day. Hence, it was commonly believed that longer and darker light conditions are better for a population of A. japonicus. In aquaculture situations therefore, animals have commonly been cultured without lighting, especially during juvenile-hatching culture. However, how the length of darkness each day affects .4.japonicus and what the mechanism is of behavioral response of A. japonicus to different photoperiods remain unclear, and are specifically addressed in this study. We applied nine photoperiod treatments （light：dark （LD） cycles at 0：24, 3：21, 6：18, 9：15, 12：12, 15：9, 18：6, 21：3, and 24：0 under 500Ix） to 60 individuals （29.73±0.23 g） per treatment （with 3 replicates）. The enviroramental conditions were set as： water temperature = 16.9±0.3℃, dissolved oxygen〉6.0 rag/L, ammonia〈0.3 mg/L, pH=7.8-8.2, and salinity=30-32. Under experimental conditions of continuous darkness as well as continuous light, cyclic nocturnal activity patterns of A. japonicus （viz. the animals emerged and fed at night and sheltered during the day） were observed. However, they spent more and less time, respectively, moving and feeding under continuous darkness and continuous light, than those under a natural light cycle. Under photoperiods with 6-12 h of light, the animals showed one sheltering behavior transition and two emerging behavior transitions. These behavior transitions appeared to be governed by some internal physiological factors and induced by daily light variation. The behavior of the animals was significantly affected by different photoperiods, and the distribution rate （DR） of the animals emerging at ＂daytime＂ increased with lengthening ＂light time＂ （except for the LD 3：21 cycle）. We also found that there was no significant difference in mean DR per day under LD cycles of 6：18, 9：15, 15：9, and 12：12. Mean DRs per day were significantly lower for these photoperiods, than for those under LD cycles of 0：24 and 3：21, and significantly higher than for those under LD cycles of 18：6, 21：3 and 24：0. These results imply that 6-15 h light per day were the similar photoperiods to natural sunlight. From the viewpoint of activity and feeding behaviors, these might be the optimal photoperiods for rearing A. japonicus.

Parental perceptions of the effects of exercise on behavior in children and adolescents with ADHD

Background： Anecdotally, parents often report that children with attention deficit hyperactivity disorder （ADHD） who engage in regular physical activity （PA） experience positive behavioral changes. The purpose of this study was to examine this anecdotal relationship to provide preliminary evidence relevant to the potential benefits of PA on ADHD symptoms. Methods： Parents （n = 68） of children diagnosed with ADHD completed an lnternet survey assessing perceptions of how PA influences their child＇s symptoms. Results： A significantly greater percentage of parents reported that regular PA positively impacted symptoms. However, there were no uniform effects for all types of ADHD symptoms. The results indicate that there may be more positive benefits for symptoms of inattention and hyperactivity than for those of impulsivity. Conclusion： This is the first study to empirically document parents＇ perceptions of how PA influences ADHD and suggests that PA can be a viable strategy for reducing symptoms. PA may have greater benefits for specific symptoms of ADHD, providing critical information for developing PA interventions for children and adolescents.

Alarm cue induces an antipredator morphological defense in juvenile Nicaragua cichlids Hypsophrys nicaraguensis

Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficient to also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphological plasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed to alarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensis to test if the perception of predation risk from alarm cue （conspecific skin extract） alone induces an increased relative body depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecific alarm cue increased their relative body depth nearly double the amount of those exposed to distilled water （control） and zebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks （12 and 14） of cue exposure when the fish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions between the three treatments. Our results show that 1） the Nicaragua cichlid has an innate response to conspecific alarm cue which is not a generalized response to an injured fish, and 2） this innate recognition ultimately results in developing a deeper body at a stage of the life history where predation risk is high [Current Zoology 56 （1）： 36-42, 2010].

Effects of salinity on survival,feeding behavior and growth of the juvenile swimming crab,Portunus trituberculatus(Miers,1876)

Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fed 2 or 3 times at the salinity 20 and 30,each lasted for about 25 minutes,for a total feeding time of 73.2±22.65 minutes per day. At these salinities,there were significantly higher in the frequency of feeding and in total feeding time than those at lower salinities of 5 and 10. All crab juveniles moulted when reared at a salinity of 20 during the 5 days duration of the experiment,which is significantly higher than those at other salinities. All juveniles survived at salinity 20,and the survivorship was not significantly different from that at 30,but was signif icantly higher than those at other salinities. The crab juveniles reared at a salinity of 20 had the highest value of food ration of 0.190 8±0.011 3 g/g BW,average body weight gain of 0.796±0.128 g,gain rate of 87%–96%,and food conversion ratio of 1.20±0.09. There was no significant difference in the values found between 20 and 30 but these values were significantly lower than that at the other salinities( P> 0.05). Highest activities of digestive enzymes(Amylase,Protease,Lipase) and lowest activities of protective enzymes(SOD,PO,CAT) were also obtained on crab juveniles reared at salinity of 20.

Strategies for Dealing with Gang Activity in Urban Communities

As disturbing as youth and gun violence is, it is not hard to reduce the mortality rate because it is preventable. The information provided in this research will help to get policies waiting to be reviewed by legislators, and any new proposal that reaches the appropriate legislative chamber, reviewed without obstacles and will help to prevent youth violence. Upon completion of this research, the study shows that rates of youth violence have decreased based on programs implemented at the state government level with a stronger juvenile justice system holding offenders accountable to ensure public safety and reduce youth violence and victimization. The study shows that community and school involvement with law enforcement and government agencies are some of the strategies needed to help reduce gun violence and rebuild communities.

The Relationship Between Exposure to Televised Violence and Malaysian Adolescents＇ Aggressive Behaviours＂ A Structural Equation Modelling Analysis

Previous studies on the relationship between exPosure to televised violence and viewers＇ aggressive behaviours have produced mixed results. Some studies have found significant effect sizes while others have found low and non-significant effect sizes. Television effects scholars have postulated that these mixed results are caused by the inconsistencies of research methodology employed and the inability to control major mediating variables in the studies. The present study is designed with the objectives to overcome these shortcomings. The respondents for this study were 514 students aged between 13 and 18 from 10 schools in the State of Perak, Malaysia. Exploratory data analyses provided evidence that the employed instruments achieved sound psychometric properties. Hypotheses testing suggested that exposure to the Contents of Television Violence （TVCN） did not have a direct relationship with adolescents＇ aggressive behaviours; instead, Contextual Features of Television Violence （TVCX） totally mediated this relationship. Some other mediating variables then mediated totally and some mediated partially the relationship between TVCX and adolescents＇ aggressive behaviours. To conclude, this study provides valuable information for parents, the television industry, and the policy makers in recognizing pro-violent and anti-violent features of television violence programmes for Malaysian school-going adolescents. It also provides a new perspective for future studies of television violence in Malaysia.