Alkaptonuria, a metabolic disorder characterized by a triad of homogentisic aciduria, arthritis and ochronosis is one of the first conditions in the charter of group of inborn errors of metabolism proposed to have Mendelian recessive inheritance. It is due to the deficiency of the enzyme homogentisic acid oxidase which catalyzes the conversion of homogentisic acid to maleylacetoacetic acid in the catabolism of tyrosine. Homogentisic acid thus accumulates in cells and body fluids and its oxidized polymers bind to collagen, leading to progressive deposition of grey to bluish black pigment resulting in degenerative changes in cartilage, intervertebral disc and other connective tissues, leading to arthritis which is the only disabling effect in an affected older individual. However the diagnosis can be made in neonates when blackish stain is noticed in an unwashed diaper. Alkaptonuria is treated symptomatically, surgical intervention necessitates in advanced stages, treatment with ascorbic acid (Vitamin C) and dietary restrictions of food containing phenylalanine and tyrosine have proved to be successful in alleviating the symptoms. 相似文献
This study extends recent coach stress research by evaluating how coaches perceive their stress experiences to affect athletes, and the broader coach–athlete relationship. A total of 12 coaches working across a range of team sports at the elite level took part in semi-structured interviews to investigate the 3 study aims: how they perceive athletes to detect signals of coach stress; how they perceive their stress experiences to affect athletes; and, how effective they perceive themselves to be when experiencing stress. Following content analysis, data suggested that coaches perceived athletes able to detect when they were experiencing stress typically via communication, behavioural, and stylistic cues. Although coaches perceived their stress to have some positive effects on athletes, the overwhelming effects were negative and affected “performance and development”, “psychological and emotional”, and “behavioural and interaction” factors. Coaches also perceived themselves to be less effective when stressed, and this was reflected in their perceptions of competence, self-awareness, and coaching quality. An impactful finding is that coaches are aware of how a range of stress responses are expressed by themselves, and to how they affect athletes, and their coaching quality. Altogether, findings support the emerging view that coach stress affects their own, and athlete performance. 相似文献
Carnitine is an essential co‐factor in the catabolism of fats as an energy source. The primary purpose of this study was to investigate the effect of running a marathon on the metabolism of carnitine by endurance‐trained athletes, and to evaluate the effect of carnitine administration on the performance of such exercise. The effects of marathon running on mitochondrial enzymes and cellular anti‐oxidants were also examined to assess whether the expression of these activities is altered by exercise. Subjects were 10 experienced male marathon runners aged between 19 and 25 years. Running a marathon caused a fall in the plasma content of unesterified carnitine (37%) and an increase in the level of acetylcarnitine present (288%). Loading of the athletes with L‐carnitine for 10 days before running a marathon abolished the exercise‐induced fall in plasma‐free carnitine (P<0.05) whilst amplifying the production of acetylcarnitine (P<0.05). Carnitine loading of the athletes studied made no detectable improvement in performance of the marathon (P > 0.05). Cytochrome oxidase, succinate cytochrome C reductase and Superoxide dismutase activities present in skeletal muscle were unaltered by marathon running. However, such exercise caused a large increase in the tissue content of oxidized glutathione (189%) at the expense of reduced glutathione (–18%). 相似文献
Abstract Reaction time of the batter in Softball is important because of short pitching distance and the speed of the pitcher. Nine pitchers were tested for speed and had an average velocity of 59.95 mph and a mean reaction time of .215 sec. was found for 258 students tested. With these averages, the ball would be 29.33 ft. from home plate before 116 of these students began their swing and in 41 cases the ball would be less than 20 ft from the plate. Pitchers with greater velocity would decrease the success of the batter if the reaction time remains the same. 相似文献
Abstract Nine males (age 24.7 ± 2.1 years, height 175.3 ± 5.5 cm, body mass 80.8 ± 7.2 kg, power clean 1-RM 97.1 ± 6.36 kg, squat 1-RM = 138.3 ± 20.9 kg) participated in this study. On day 1, the participants performed a one-repetition maximum (1-RM) in the power clean and the squat. On days 2, 3, and 4, participants performed the power clean, squat or jump squat. Loading for the power clean ranged from 30% to 90% of the participant's power clean 1-RM and loading for the squat and jump squat ranged from 0% to 90% of the participant's squat 1-RM, all at 10% increments. Peak force, velocity, and power were calculated for the bar, body, and system (bar + body) for all power clean, squat, and jump squat trials. Results indicate that peak power for the bar, body, and system is differentially affected by load and movement pattern. When using the power clean, squat or jump squat for training, the optimal load in each exercise may vary. Throwing athletes or weightlifters may be most concerned with bar power, but jumpers or sprinters may be more concerned with body or system power. Thus, the exercise type and load vary according to the desired stimulus. 相似文献
Prostate Specific Antigen (PSA) has emerged as the most applicable and important tumor marker for carcinoma prostate. In the present study PSA was determined in serum of healthy subjects, patients of benign prostate hypertrophy (BPH) and Carcinoma Prostate (Ca−P) to evaluate its diagnostic efficiency in day to day management of prostate cancer patients and in differentiating patients of early prostate cancer from those with BPH. Receiver operating characteristic curve (ROC) revealed 2 ng/ml and 10 ng/ml cut off serum PSA level for BPH and untreated carcinoma prostate patients (Ca−P). An extremely significant increase (P<0.0001) was observed in mean PSA concentration in BPH patients and adenocarcinoma prostate patients when compared to healthy males. Clinical relevance of PSA was highlighted by a case study of cancer patient prior to any therapy till death. 相似文献
Purpose: This study discusses the process of co-constructing a prototype pedagogical model for working with youth from socially vulnerable backgrounds.
Participants and settings: This six-month activist research project was conducted in a soccer program in a socially vulnerable area of Brazil in 2013. The study included 17 youths, 4 coaches, a pedagogic coordinator and a social worker. An expert in student-centered pedagogy and inquiry-based activism assisted as a debriefer helping in the progressive data analysis and the planning of the work sessions.
Data collection/analysis: Multiple sources of data were collected, including 38 field journal/observation and audio records of: 18 youth work sessions, 16 coaches’ work sessions, 3 combined coaches and youth work sessions, and 37 meetings between the researcher and the expert.
Findings: The process of co-construction of this prototype pedagogical model was divided into three phases. The first phase involved the youth and coaches identifying barriers to sport opportunities in their community. In the second phase, the youth, coaches and researchers imagined alternative possibilities to the barriers identified. In the final phase, we worked collaboratively to create realistic opportunities for the youth to begin to negotiate some of the barriers they identified. In this phase, the coaches and youth designed an action plan to implement (involving a Leadership Program) aimed at addressing the youths’ needs in the sport program. Five critical elements of a prototype pedagogical model were co-created through the first two processes and four learning aspirations emerged in the last phase of the project.
Implications: We suggest an activist approach of co-creating a pedagogical model of sport for working with youth from socially vulnerable backgrounds is beneficial. That is, creating opportunities for youth to learn to name, critique and negotiate barriers to their engagement in sport in order to create empowering possibilities. 相似文献