Brain serotonin and dopamine modulators, perceptual responses and endurance performance during exercise in the heat following creatine supplementation

Background:The present experiment examined the responses of peripheral modulators and indices of brain serotonin (5-HT) and dopamine (DA) function and their association with perception of effort during prolonged exercise in the heat after creatine (Cr) supplementation. Methods:Twenty one endurance-trained males performed, in a double-blind fashion, two constant-load exercise tests to exhaustion at 63 ± 5% V O2 max in the heat (ambient temperature: 30.3 ± 0.5°C, relative humidity: 70 ± 2%) before and after 7 days of Cr (20 g·d-1 Cr + 140 g·d-1 glucose polymer) or placebo (Plc) (160 g·d-1 glucose polymer) supplementation.Results:3-way interaction has shown that Cr supplementation reduced rectal temperature, heart rate, ratings of perceived leg fatigue (P < 0.05), plasma free-tryptophan (Trp) (P < 0.01) and free-Trp:tyrosine ratio (P < 0.01) but did not influence the ratio of free-Trp:large neutral amino acids or contribute in improving endurance performance (Plc group, n = 10: 50.4 ± 8.4 min vs. 51.2 ± 8.0 min, P > 0.05; Cr group, n = 11: 47.0 ± 4.7 min vs. 49.7 ± 7.5 min, P > 0.05). However, after dividing the participants into "responders" and "non-responders" to Cr, based on their intramuscular Cr uptake, performance was higher in the "responders" relative to "non-responders" group (51.7 ± 7.4 min vs.47.3 ± 4.9 min, p < 0.05).Conclusion:although Cr influenced key modulators of brain 5-HT and DA function and reduced various thermophysiological parameters which all may have contributed to the reduced effort perception during exercise in the heat, performance was improved only in the "responders" to Cr supplementation. The present results may also suggest the demanding of the pre-experimental identification of the participants into "responders" and "non-responders" to Cr supplementation before performing the main experimentation. Otherwise, the possibility of the type II error may be enhance

EXAMINING THE RELATIONSHIP BETWEEN PARENTING PRACTICES AND CHILDREN’S CHARACTERISTICS

The present research examined the relationship between parenting practices and children's characteristics. Specifically, the study focused on the children's characteristics, such as age, gender, birth order, and family structure, which influence parenting practices and have an impact on children's family relations, school performance, social competence, and children's self-esteem. The sample consisted of 336 Greek-speaking parents who had children age six up to twelve years old. Most of the participating parents were mothers (77%), with an average age of 35,7 +5,18. A large majority of the participants (75%) were a part of two parents-family, and 25% were a one parent-family. Parents answered four self-report questionnaires: Α Personal Information Form (PIF) was used to collect information about family and children's characteristics, the Parental Acceptance-Rejection Questionnaire (PARQ-mother and father version), the Parental Authority Styles (PAQ) Questionnaire and the Children's Family Relations, School Performance, Social Competence, and Self-Esteem Questionnaire. Research results showed that children's characteristics (gender, age, and birth order) are significantly related to parents' parenting styles. Furthermore, the family structure (one or two parents - family) was statistically significant in parenting practices. As a result, parenting practices affected children's family relations, social competence, school performance, and self-esteem. Article visualizations

EXAMINING THE RELATIONSHIP BETWEEN DISTANCE LEARNING PROCESSES AND UNIVERSITY STUDENTS’ ANXIETY IN TIMES OF COVID19

Governments worldwide have implemented strict physical and social distancing measures to prevent contamination from the COVID-19 pandemic and flatten the epidemic curve. Recent findings show that university students have experienced increased anxiety and moderate-to-severe stress because of confinement measures (quarantine) (Husky et al., 2020; Islam et al., 2020). In Cyprus, universities switched to distance learning in mid-March 2020. The present research examined the social and academic challenges that university students are experiencing during the lockdown measures to contain the spread of the COVID-19 virus. We focused on assessing the students' stress levels while they were trying to adjust to distance learning and while, at the same time, balancing their jobs with their studies. We considered whether they lived with or separated from their family and friends during that time. Our study is a quantitative study with a sample of 80 students from Cyprus and Greece who attended a private university in Cyprus until November 2020. We collected our data using Beck's Anxiety Inventory and a self-report e-questionnaire, which we created especially for the purposes of our study. The instrument was generated using the Google Form, and shared through social media platforms. We analysed data with the chi-square test application to detect correlations between working and non-working students and students who lived with or away from their family network during the lockdown regarding their stress levels and their adaptability to distance-learning. Results indicated statistically significant positive correlations between employment, distance learning, students' anxiety and stress levels. Article visualizations

From tumour perfusion to drug delivery and clinical translation of in silico cancer models

In silico cancer models have demonstrated great potential as a tool to improve drug design, optimise the delivery of drugs to target sites in the host tissue and, hence, improve therapeutic efficacy and patient outcome. However, there are significant barriers to the successful translation of in silico technology from bench to bedside. More precisely, the specification of unknown model parameters, the necessity for models to adequately reflect in vivo conditions, and the limited amount of pertinent validation data to evaluate models' accuracy and assess their reliability, pose major obstacles in the path towards their clinical translation. This review aims to capture the state-of-the-art in in silico cancer modelling of vascularised solid tumour growth, and identify the important advances and barriers to success of these models in clinical oncology. Particular emphasis has been put on continuum-based models of cancer since they - amongst the class of mechanistic spatio-temporal modelling approaches - are well-established in simulating transport phenomena and the biomechanics of tissues, and have demonstrated potential for clinical translation. Three important avenues in in silico modelling are considered in this contribution: first, since systemic therapy is a major cancer treatment approach, we start with an overview of the tumour perfusion and angiogenesis in silico models. Next, we present the state-of-the-art in silico work encompassing the delivery of chemotherapeutic agents to cancer nanomedicines through the bloodstream, and then review continuum-based modelling approaches that demonstrate great promise for successful clinical translation. We conclude with a discussion of what we view to be the key challenges and opportunities for in silico modelling in personalised and precision medicine

The role of putative brain serotonergic and dopaminergic modulators in central fatigue during exercise in health and disease

The primary purpose of the present experiments was to elucidate the role of putative brain serotonergic and dopaminergic modulators and indices (markers) in 'central fatigue' during exercise in health and disease, with a concurrent examination of metabolic, cardiovascular and perceptual responses. In experiments (EXPs) 1 and 2, the subjects underwent three main exercise trials. The first, following a pre-exercise high CHO meal (Control trial) and the remaining two after a pre-exercise high fat meal with (FC trial) and without (F trial) caffeine. The use of fat meals was employed to elevate circulating plasma free fatty acids (FFA) levels in an attempt to produce i) a similar muscle metabolic adjustment, and, ii) a parallel displacement of plasma Trp from albumin by plasma FFA and therefore similar brain serotonin (5-HT) manipulation in both F and FC trials. Differences on brain 5-HT and dopamine (DA) modulators and indices, exercise performance and perceptual (RPE), metabolic and cardiovascular responses could be examined by ingestion of caffeine. Thus, caffeine would differentiate between peripheral and central aspects affecting exercise fatigue and therefore the mechanism(s) associated with central fatigue could be evaluated. Modulators and indices of brain 5-HT and DA functions (i.e. plasma free and total tryptophan (Trp), tyrosine (Tyr), large neutral amino acids (LNAA), Trp:LNAA ratio, free-[Trp];[Tyr] ratio, Trp:Tyr ratio, and prolactin) and exercise performance were not different between the trials but RPE was reduced and metabolic/cardiovascular responses increased during exercise with caffeine. The aim of EXP 3 was to examine the effects of a creatine (Cr) supplementation on putative modulators and indices of brain 5-HT and DA function and on thermal stress during prolonged exercise in the heat. The Cr was used as a 'vehicle' to increase hydration and/or reduce thermal stress-induced increase in brain 5-HT function. Cr reduced thermoregulatory (e.g. sweat rate, rectal temperature and heart rate) and perceptual responses, plasma free-[Trp] (P = 0.001) and free-[Trp]:[Tyr] ratio (P = 0.001) and enhanced endurance performance in subjects classified as 'responders' to Cr. The aim of the fourth EXP was to elucidate the role of putative modulators (Trp, LNAA, Tyr) of central fatigue in CFS, to evaluate the association between these modulators with perceptual and metabolic responses in CFS patients and to compare their results to those of matched sedentary controls. Taken together, the results across studies imply that putative modulators of brain serotonergic and dopaminergic systems (and therefore brain 5-HT and DA function) play a key role in pre exercise central motivation and also in central fatigue process of well-trained humans during exercise in the heat (EXP 3) and in the exacerbated RPE, exercise intolerance and pathogenesis of CFS (EXP 4). However, under physiological conditions this central neural drive of fatigue associated with metabolic up-regulation of brain 5-HT does not affect exercise performance of well- trained humans (EXPs 1,2). The exact mechanism(s) therefore for the attenuation of RPE with caffeine is unlikely to be a brain 5-HT-mediated but most likely a DA- mediated effect. (Abstract shortened by ProQuest.)

School Scoliosis Screening: The Influence of Dominant Limbs and Gender

This study aimed to examine whether (a) there is an association of the dominant hand (DH) and leg (DL) with the side of the primary angle of trunk rotation (ATR A) and (b) there are any differences between boys and girls in the degree of the angle of trunk rotation (ATR) and the dominant hand and leg. One thousand sixty-five (age: 14 ± 3 years; height: 162 ± 13 cm; weight: 56 ± 18.7 kg; BMI: 21.18 ± 5.07) secondary school children participated in this study. Of the participants, 52.5% (n = 559) were male students (age: 14 ± 2 years; height: 166 ± 16 cm; weight: 58.7 ± 22.6 kg; BMI: 21.41 ± 5.61), and 47.5% (n = 506) were female students (age: 14 ± 3 years; height: 159.5 ± 8.5 cm; weight: 53.9 ± 14.8 kg; BMI: 21.03 ± 4.38). The ATR was measured with a scoliometer. Boys were taller and heavier (p = 0.001) and had more left DLs (p = 0.039) than girls. Girls were biologically more mature (p = 0.002), also having higher measurements for the ATR A (p = 0.004) and secondary angle of trunk rotation (ATR B) (p = 0.023) degrees compared to boys. In the general sample, only in boys, there was a significant association between the DH (p = 0.012) and DL (p = 0.001) with the ATR A side. Also, within the scoliotic group, only in boys, there was a significant association between the DH (p = 0.048) and DL (p = 0.024) with the ATR A. In conclusion, girls had higher measurements for the ATR than boys, but cross laterality was found only in boys. The results suggest different progression patterns of ATR between genders during their growth. Future research should focus on examining other possible progression mechanisms

The effects of moderate alterations in adrenergic activity on acute appetite regulation in obese women: a randomised crossover trial

Background: Previous evidence has demonstrated that serum leptin is correlated with appetite in combination with, but not without, modest exercise. Aim: The present experiments investigated the effects of exogenous adrenaline and α/β adrenoceptor blockade in combination with moderate exercise on serum leptin concentrations, appetite/satiety sensations and subsequent food intake in obese women. Methods: A total of 10 obese women ((mean ± SEM), age: 50 (1.9) years, body mass index 36 (4.1) kg/m2, waist 104.8 (4.1) cm) participated in two separate, double-blind randomised experimental trials. Experiment 1: moderate exercise after α/β adrenergic blocker (labetalol, 100 mg orally) versus moderate exercise plus placebo; experiment 2: adrenaline infusion for 20 minutes versus saline infusion. Appetite/satiety and biochemistry were measured at baseline, pre- and immediately post-intervention, then 1 hour post-intervention (i.e., before dinner). Food intake was assessed via ad libitum buffet-style dinner. Results: No differences were found in appetite/satiety, subsequent food intake or serum leptin in any of the studies (experiment 1 or experiment 2). In experiment 1, blood glucose was higher (p < 0.01) and plasma free fatty acids lower (p = 0.04) versus placebo. In experiment 2, plasma free fatty acids (p < 0.05) increased after adrenaline versus saline infusion. Conclusions: Neither inhibition of exercise-induced adrenergic activity by combined α/β adrenergic blockade nor moderate increases in adrenergic activity induced by intravenous adrenaline infusion affected acute appetite regulation