Oxidative Stress and Skin Cancer: An Overview

Skin is the largest body organ that serves as an important environmental interface providing a protective envelope that is crucial for homeostasis. On the other hand, it is a major target for toxic insult by a broad spectrum of physical and chemical agents that are capable of altering its structure and function. There are a large number of dietary contaminants and drugs can manifest their toxicity in skin. These environmental toxicants or their metabolites are inherent oxidants and/or directly or indirectly drive the production of a variety of reactive oxidants also known as reactive oxygen species. These are short-lived entities that are continuously generated at low levels during the course of normal aerobic metabolism. These are believed to activate proliferative and cell survival signaling that can alter apoptotic pathways that may be involved in the pathogenesis of a number of skin disorders. The skin possesses an array of antioxidant defense mechanisms that interact with toxicants to obviate their deleterious effect. The “antioxidant power” of a food is an expression of its capability both to defend the human organism from the action of the free radicals and to prevent degenerative disorders. Plants like olive trees have their own built-in protection against the oxidative damage of the sun, and these built-in protectors function as cell protectors in our own body. Although many antioxidants have shown substantive efficacy in cell culture systems and in animal models of oxidant injury, unequivocal confirmation of their beneficial effects in human populations has proven elusive.     

Match running performance and skill execution improves with age but not the number of disposals in young Australian footballers

This study investigated age-related differences in maturity, physical and functional characteristics and playing performance in youth Australian Football (AF). Young male players (n = 156) were recruited from 12 teams across 6 age groups (U10–U15) of a recreational AF club. All players were tested for body size, maturity and fitness. Player performance was assessed during a match in which disposals (kicks and handballs) and their effectiveness were coded from a video recording and match running performance measured using Global Positioning System. Significant main effects (P < 0.01) for age group were observed for age, years to peak height velocity, body mass, height, 20 m sprint, maximal speed over 20 m, vertical jump, 20 m multistage shuttle run, match distance, high-speed running distance, peak speed, number of effective disposals and percentage of effective disposals. Age-related differences in fitness characteristics (speed, lower body power and endurance) appeared to transfer to match running performance. The frequency in which players disposed of the football did not differ between age groups, however the effectiveness of each disposal (i.e., % effective disposals) improved with age. Match statistics, particularly those that evaluate skill execution outcome (i.e., effectiveness), are useful to assess performance and to track player development over time. Differences between age groups, and probably variability within age groups, are strongly associated with chronological age and maturity.     

Examining focus,duration, and classroom impact of literacy and mathematics professional development

Over $18 billion is spent annually on professional development for in-service teachers. This study examined the focus, duration, and impact of professional development activities in which elementary (students ages 5–11) and middle school (students ages 11–14) teachers participated. Ninety-eight teacher-participants completed an online survey about their professional development experiences. In the analysis of literacy survey items and mathematics survey items, there were similarities in focus areas that received greater participation and areas that received less. There were also noticeable differences in frequency of participation in literacy and mathematics professional development. Comparisons between literacy and mathematics professional development indicated that more teachers reported participating in literacy experiences. This included workshops as well as ongoing support through planning meetings and mentorship. Overall, the consensus from teachers was that professional development was effective and has a beneficial impact on their classroom. Researchers share implications for the design and research of future professional development programs.     

Child abuse and neglect: Preventable causes of mental retardation

Retrospective case study analysis was done to determine the number of persons retarded due to child abuse and neglect. Analysis was made of 436 cases of mental retardation diagnosed between 1957 and 1973 by a multiprofessional team in Anchorage, Alaska. Independent analysis was made by the two authors using predetermined criteria of maltreatment and reliability of data. Sixty-five of 436 (14.9) cases had evidence of abuse and neglect prior to identification of their retardation. Higher rates of abuse and neglect were found among native Alaskans (Aleuts, Eskimos, and Indians) than Caucasians. Higher rates of abuse and neglect were found among females than males of the mentally retarded population.Paucity of reported studies of abuse and neglect as causes of mental retardation is discussed. It is concluded that abuse and neglect are preventable, but underappreciated, causes of mental retardation.     

Crawling versus Walking Infants' Perception of Affordances for Locomotion over Sloping Surfaces

14-month-old toddlers vs. 8.5-month-old crawling infants were encouraged to ascend and descend a sloping walkway (10°, 20°, 30°, and 40°). Infants in both locomotor groups overestimated their ability to ascend slopes. However, on descending trials where falling was more aversive, most toddlers switched from walking to sliding positions for safe descent, but crawlers plunged down headfirst and many fell at each increment. Toddlers touched and hesitated most before descending 10° and 20° slopes, and they explored alternative means for descent by testing out different sliding positions before leaving the starting platform. In contrast, crawlers touched and hesitated most before descending 30° and 40° slopes, and they never explored alternative sliding positions. In addition, we analyzed measures of locomotor skill and experience in relation to children's ability to perceive affordances. Findings indicate that children must learn to perceive affordances for locomotion over slopes and that learning may begin by fine-tuning of exploratory activity.     

Achievement Motivation Goals in Relation to Academic Performance in Traditional and Nontraditional College Students

This study extended Dweck's model of achievement motivation to the collegiate level, and it is the first to apply this model to nontraditional students. We examined the relationship between goal orientations and academic performance in 262 undergraduate students grouped by nontraditional vs. traditional status. Although both groups rated themselves higher on learning goals than on performance goals, non-traditional students endorsed learning goals even more strongly than their traditional peers. Goal orientations were a better predictor of academic success than student status. Consistent with Dweck's model, a learning goal orientation was positively related to successful academic performance for both groups. The relationship between performance goals and academic success was less straightforward, but students who rated both goal orientations as relatively weak had the lowest cumulative GPAs. Traditional and nontraditional students differed on variables that were inversely related to academic performance. Less successful traditional students endorsed irrational beliefs (a possible index of learned helplessness), while less successful nontraditional students worked more hours at a paid job.     

Assessing children's perceptions of prosocial and antisocial peer behaviour

The aims of this study were to administer an assessment measure that would identify prosocial children, bullies and their victims, and to examine the underlying structure of children's perceptions of peer social behaviour in these three groups. Three versions (peer nomination, self and teacher rating) of a newly developed child social behaviour questionnaire (CSBQ) were completed by children (aged 9/10 years, n=321) and their teachers in 14 Scottish primary schools. The CSBQ is distinguished from other extant measures by its joint focus on both prosocial and antisocial child behaviours, and by its use of concrete and empirically derived items. In conjunction with sociometric data, which was also elicited from the children, the CSBQ yielded scores on 12 behavioural dimensions. Based upon the peer nomination data, a set of rigorous criteria, capable of reliably identifying children in the three groups, was developed to take account of varying peer nomination practices within and between schools. Factor analysis of the 12 measures yielded four factors (two antisocial factors, a prosocial factor and a victim factor) which accounted for 71% of the variance, and which offer further insight into the organisation of children's perceptions of social behaviour. Gender differences in peer nomination patterns and comparisons between the different informant groups are discussed in relation to previous work.     

Extracting Data Off the Internet

This article shows how to use Microsoft Excel to get data from the Internet into a statistically usable form.