Triploid induction in the South African abalone, Haliotis midae

Bibliography: leaves 72-80.An investigation was undertaken to determine whether triploidy could be induced and improve the growth rate of the South African abalone, Haliotis midae. From the polar body counts at 17 °C the release times of polar body 1 and 2 were found to be at 12 - 15 min. post insemination (pi.) and 33-36 min. pi. respectively. Cytochalasin B (CB) (0.5mg. 1-¹ seawater) and elevated temperature (30 °C) were used as stresses to induce triploidy. CB induced 48.4% polar body 1 and 70.9 % polar body 2 triploid larvae at 20 hrs pi. At 120 hrs pi. induction rates were 55.5% and 62.4% respectively. Temperature induction was more successful, producing 92.9% polar body 1 and 86.4% polar body 2 triploid larvae at 20 hrs pi. This success was still evident at 120 hrs pi, where 71.1 % polar body 1 and 62.5% polar body 2 triploid larvae were produced. In the CB induction, where polar body 1 was retained, there was a pronounced production of tetraploid larvae (34. 2%). It appeared that CB affected the ova's resistance to polyspermy, which was found to be dependent on both CB concentration and the amount of excess sperm present. At 0.4 mg 1-¹ CB in seawater, 86.5% triploids and 0% tetraploids were produced. However, on the addition of sperm, 25.4% triploids and 69% tetraploids resulted. CB (0.5 mg 1-¹ ) in seawater produced 42.6%> tetraploids which, after the addition of sperm, increased even further to 50. l % pentaploids. Larval survival was found to be low overall with only 17% and 22% of control (diploid) animals surviving the rearing period, in the temperature and CB treatments respectively. The survival rates of the polar body 2 treatment were 11 % and 15% whilst those of the polar body 1 treatment were 7% and 11 %. Although these percentages indicated a difference in survival rates between the CB and temperature inductions, the actual numbers of larvae surviving were the same. The polar body 1 triploid larval survival was significantly less than both control and polar body 2 triploid animals

Exercise and Glycemic Control: Focus on Redox Homeostasis and Redox-Sensitive Protein Signaling

Physical inactivity, excess energy consumption, and obesity are associated with elevated systemic oxidative stress and the sustained activation of redox-sensitive stress-activated protein kinase (SAPK) and mitogen-activated protein kinase signaling pathways. Sustained SAPK activation leads to aberrant insulin signaling, impaired glycemic control, and the development and progression of cardiometabolic disease. Paradoxically, acute exercise transiently increases oxidative stress and SAPK signaling, yet postexercise glycemic control and skeletal muscle function are enhanced. Furthermore, regular exercise leads to the upregulation of antioxidant defense, which likely assists in the mitigation of chronic oxidative stress-associated disease. In this review, we explore the complex spatiotemporal interplay between exercise, oxidative stress, and glycemic control, and highlight exercise-induced reactive oxygen species and redox-sensitive protein signaling as important regulators of glucose homeostasis

Mental Health and Physical Activity in Women with Polycystic Ovary Syndrome: A Brief Review

This review was designed to consider the available literature concerning mental health and physical activity in women with polycystic ovary syndrome (PCOS). A systematic approach was taken and two electronic databases (PubMed and EBSCO Research articles published between 1970 and 2013) were searched in 2013 to inform a narrative review. Inclusion criteria encompassed requirements for the research to involve a physical activity intervention and assessment of mental health outcomes in women with PCOS. Seven articles considered mental health outcomes and physical activity interventions for women with PCOS. The results demonstrated positive outcomes following physical activity intervention for health-related quality of life, depression, and anxiety. Only one paper reported the independent effects of physical activity on mental health. All other interventions included multi-factor lifestyle interventions or did not establish a control group. Physical activity is likely to be beneficial to the mental health of women with PCOS; however, more research is required to establish the nature of the relationship between physical activity and mental health outcomes

Overview of a new eHealth intervention to promote healthy eating and exercise in pregnancy: initial user responses and acceptability

Purpose: The purpose of this project was to develop and evaluate an eHealth intervention to promote healthy lifestyle for pregnant women. The setting was a low socio-economic and multi-ethnic area in Melbourne, Australia. Methods: This paper briefly describes the development of the eHealth intervention, which was aimed at a low level of literacy, and the evaluation of the intervention by pregnant women. A basic descriptive survey was undertaken to evaluate user friendliness, usefulness and acceptability of the intervention. Results: The intervention was developed by a team of experts and forty pregnant women participated in the evaluation. Results indicated that participants found the intervention informative, useful and easy to navigate. They also identified some minor areas for improvement which will be addressed prior to proceeding to a formal controlled evaluation. Conclusion: Results from this evaluation are encouraging and suggest that women found the intervention convenient, trustworthy and engaging. Most enjoyed navigating the website information. As such, it is likely to prove a useful support for delivering dietary and exercise information to pregnant women in the local low socioeconomic area. Further formal evaluation will test the efficacy of the website in improving diet and exercise outcomes during pregnancy

Endurance Training Intensity Does Not Mediate Interference to Maximal Lower-Body Strength Gain during Short-Term Concurrent Training

We determined the effect of concurrent training incorporating either high-intensity interval training (HIT) or moderate-intensity continuous training (MICT) on maximal strength, counter-movement jump (CMJ) performance, and body composition adaptations, compared with single-mode resistance training (RT). Twenty-three recreationally-active males (mean ± SD: age, 29.6 ± 5.5 y; [Formula: see text], 44 ± 11 mL kg(-1)·min(-1)) underwent 8 weeks (3 sessions·wk(-1)) of either: (1) HIT combined with RT (HIT+RT group, n = 8), (2) work-matched MICT combined with RT (MICT+RT group, n = 7), or (3) RT performed alone (RT group, n = 8). Measures of aerobic capacity, maximal (1-RM) strength, CMJ performance and body composition (DXA) were obtained before (PRE), mid-way (MID), and after (POST) training. Maximal (one-repetition maximum [1-RM]) leg press strength was improved from PRE to POST for RT (mean change ± 90% confidence interval; 38.5 ± 8.5%; effect size [ES] ± 90% confidence interval; 1.26 ± 0.24; P < 0.001), HIT+RT (28.7 ± 5.3%; ES, 1.17 ± 0.19; P < 0.001), and MICT+RT (27.5 ± 4.6%, ES, 0.81 ± 0.12; P < 0.001); however, the magnitude of this change was greater for RT vs. both HIT+RT (7.4 ± 8.7%; ES, 0.40 ± 0.40) and MICT+RT (8.2 ± 9.9%; ES, 0.60 ± 0.45). There were no substantial between-group differences in 1-RM bench press strength gain. RT induced greater changes in peak CMJ force vs. HIT+RT (6.8 ± 4.5%; ES, 0.41 ± 0.28) and MICT+RT (9.9 ± 11.2%; ES, 0.54 ± 0.65), and greater improvements in maximal CMJ rate of force development (RFD) vs. HIT+RT (24.1 ± 26.1%; ES, 0.72 ± 0.88). Lower-body lean mass was similarly increased for RT (4.1 ± 2.0%; ES; 0.33 ± 0.16; P = 0.023) and MICT+RT (3.6 ± 2.4%; ES; 0.45 ± 0.30; P = 0.052); however, this change was attenuated for HIT+RT (1.8 ± 1.6%; ES; 0.13 ± 0.12; P = 0.069). We conclude that concurrent training incorporating either HIT or work-matched MICT similarly attenuates improvements in maximal lower-body strength and indices of CMJ performance compared with RT performed alone. This suggests endurance training intensity is not a critical mediator of interference to maximal strength gain during short-term concurrent training

Barriers and Facilitators to the Implementation of Evidence-Based Lifestyle Management in Polycystic Ovary Syndrome: A Narrative Review

Polycystic ovary syndrome (PCOS) is a complex condition that involves metabolic, psychological and reproductive complications. Insulin resistance underlies much of the pathophysiology and symptomatology of the condition and contributes to long term complications including cardiovascular disease and diabetes. Women with PCOS are at increased risk of obesity which further compounds metabolic, reproductive and psychological risks. Lifestyle interventions including diet, exercise and behavioural management have been shown to improve PCOS presentations across the reproductive, metabolic and psychological spectrum and are recommended as first line treatment for any presentation of PCOS in women with excess weight by the International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome 2018. However, there is a paucity of research on the implementation lifestyle management in women with PCOS by healthcare providers. Limited existing evidence indicates lifestyle management is not consistently provided and not meeting the needs of the patients. In this review, barriers and facilitators to the implementation of evidence-based lifestyle management in reference to PCOS are discussed in the context of a federally-funded health system. This review highlights the need for targeted research on the knowledge and practice of PCOS healthcare providers to best inform implementation strategies for the translation of the PCOS guidelines on lifestyle management in PCOS

Exercise interventions for mental disorders in young people: a scoping review

Aims This scoping review determines the breadth and outcomes of controlled trials testing the effect of physical activity/exercise interventions across mental health outcomes in young people with a mental disorder.Methods The literature search was conducted using the open-access ‘Evidence Finder’, a comprehensive youth mental health-specific database that is systematically populated from MEDLINE, Embase, PsycINFO and Cochrane CENTRAL databases.Results Sixteen publications were identified after meeting the following eligibility criteria: (1) participants were young people (mean age 12–25.9 years) with a mental disorder diagnosed by a trained clinician or by reaching a predefined cut score on a symptom measure, (2) interventions were exercise, (3) designs were randomised or non-randomised controlled trials, (4) outcomes were mental health related. Eight studies included young people with depression, three included people with psychosis/schizophrenia, three included people with eating disorders and two included people with anxiety. The available evidence suggests that moderate-to-vigorous-intensity exercise may be beneficial, particularly for reducing depression. The available evidence for other intervention intensities, and for other mental disorders, is mixed.Conclusions Overall, the evidence regarding the impact of exercise interventions on a range of mental health outcomes in clinical populations of young people with various mental disorders looks promising but requires further development. Findings from this scoping review can inform the development of future exercise interventions in the youth mental health field

Physical activity and exercise in youth mental health promotion: A scoping review

Background/Aim: This scoping review examined the breadth and outcomes of controlled trials testing the effect of physical activity and exercise interventions across all mental health outcomes for mental health promotion and indicated prevention studies in young people. Methods: The literature search was conducted using 'Evidence Finder'. Results: Thirty publications were included. Available evidence suggested that interventions of varying intensity may lead to a reduction in depression symptoms and that moderate-to-vigorous-intensity and light-intensity interventions may reduce anxiety symptoms. Effects of physical activity/exercise interventions on additional mental health outcomes were also shown; however, the number of studies was small, indicating a limited evidence base. Robust research regarding the effects of physical activity/exercise on mental health promotion and as an indicated prevention strategy in young people is lacking. Conclusion: The available evidence suggests that physical activity/exercise is a promising mental health promotion and early intervention strategy and warrants further investigation

Acute high-intensity interval exercise-induced redox signaling is associated with enhanced insulin sensitivity in obese middle-aged men

Background: Obesity and aging are associated with increased oxidative stress, activation of stress and mitogen activated protein kinases (SAPK), and the development of insulin resistance and metabolic disease. In contrast, acute exercise also increases oxidative stress and SAPK signaling, yet is reported to enhance insulin sensitivity and reduce the risk of metabolic disease. This study explored this paradox by investigating the effect of a single session of high-intensity interval-exercise (HIIE) on redox status, muscle SAPK and insulin protein signaling in eleven middle-aged obese men. Methods: Participants completed a 2 h hyperinsulinaemic-euglycaemic clamp at rest, and 60 min after HIIE (4 × 4 mins at 95% HRpeak; 2 min recovery periods), separated by 1–3 weeks. Results: Irrespective of exercise-induced changes to redox status, insulin stimulation both at rest and after HIIE similarly increased plasma superoxide dismutase activity, plasma catalase activity, and skeletal muscle 4-HNE; and significantly decreased plasma TBARS and hydrogen peroxide. The SAPK signaling pathways of p38 MAPK, NF-κB p65, and JNK, and the distal insulin signaling protein AS160Ser588, were activated with insulin stimulation at rest and to a greater extent with insulin stimulation after a prior bout of HIIE. Higher insulin sensitivity after HIIE was associated with higher insulin-stimulated SOD activity, JNK, p38 MAPK and NF-κB phosphorylation (r = 0.63, r = 0.71, r = 0.72, r = 0.71; p < 0.05, respectively). Conclusion: These findings support a role for redox homeostasis and SAPK signaling in insulin-stimulated glucose uptake which may contribute to the enhancement of insulin sensitivity in obese men 3 h after HIIE

Exercise and glycemic control: focus on redox homeostasis and redox-sensitive protein signaling

Physical inactivity, excess energy consumption, and obesity are associated with elevated systemic oxidative stress and the sustained activation of redox-sensitive stress-activated protein kinase (SAPK) and mitogen-activated protein kinase signaling pathways. Sustained SAPK activation leads to aberrant insulin signaling, impaired glycemic control, and the development and progression of cardiometabolic disease. Paradoxically, acute exercise transiently increases oxidative stress and SAPK signaling, yet postexercise glycemic control and skeletal muscle function are enhanced. Furthermore, regular exercise leads to the upregulation of antioxidant defense, which likely assists in the mitigation of chronic oxidative stress-associated disease. In this review, we explore the complex spatiotemporal interplay between exercise, oxidative stress, and glycemic control, and highlight exercise-induced reactive oxygen species and redox-sensitive protein signaling as important regulators of glucose homeostasis.<br /