Changes In Dependent Variables Research Articles

Body image concern and demographic characteristics as predictors of anxiety in adolescent girls.

Adolescence is a critical and sensitive period of growth, marked by significant physical and psychological changes. During this time, adolescents often experience increased anxiety and concerns about their body image. Thisstudy aims to examine body image concern and demographic characteristics as predictors of anxiety in adolescent girls. This cross-sectional study included 381 female students aged 12-13 from Babol city. The participants were selected based on predefined inclusion criteria. Multi-stage sampling method was employed, and the samples were selected from six middle schools. The data collection tools consisted of a demographic information questionnaire, Littleton's body image concern scale, and Zung's anxiety scale. The mean score for body image concern was 16.59±44.82, while the mean score for anxiety was 10.53±37.31. When investigating the relationship between body image concern and anxiety, a significant and positive correlation between these two variables was observed during regression analysis (p<0.001). Both univariate and multivariate regression analyses indicated that for every one-unit increase in students' body image concern score, theiroverall anxiety score increased by an average of 0.34 units in both models (B: 0.34, 95 % CI: 0.29-0.39) (p<0.001). Additionally, in univariate regression analyses students whoreceived puberty information from sources other thantheir mother exhibited 2.68 units higher anxiety levels, which was statistically significant (B: 2.68, 95 % CI: 0.38-4.98) (p<0.001) and, concerning the preferred source of information, students who favored a non-mother source experienced 3.91 units increase in their anxiety score (B:3.91, 95 % CI: 1.74-6.08) (p<0.001). The results of multivariate regression analysis showed that with the presence of all independent variables in the model, 30 % of the dependent variable changes can be predicted (explained) (R 2 =0.302). The findings indicated a positive association between body image concerns and anxiety among students. Moreover, students who relied on sources other than their mother for obtaining information about puberty displayed higher levels of anxiety. Consequently, it is imperative to implement preventive and supportive programs targeting adolescents as well as empowering mothers to effectively deal with these issues.

Evolving higher-order synergies reveals a trade-off between stability and information-integration capacity in complex systems.

There has recently been an explosion of interest in how "higher-order" structures emerge in complex systems comprised of many interacting elements (often called "synergistic" information). This "emergent" organization has been found in a variety of natural and artificial systems, although at present, the field lacks a unified understanding of what the consequences of higher-order synergies and redundancies are for systems under study. Typical research treats the presence (or absence) of synergistic information as a dependent variable and report changes in the level of synergy in response to some change in the system. Here, we attempt to flip the script: rather than treating higher-order information as a dependent variable, we use evolutionary optimization to evolve boolean networks with significant higher-order redundancies, synergies, or statistical complexity. We then analyze these evolved populations of networks using established tools for characterizing discrete dynamics: the number of attractors, the average transient length, and the Derrida coefficient. We also assess the capacity of the systems to integrate information. We find that high-synergy systems are unstable and chaotic, but with a high capacity to integrate information. In contrast, evolved redundant systems are extremely stable, but have negligible capacity to integrate information. Finally, the complex systems that balance integration and segregation (known as Tononi-Sporns-Edelman complexity) show features of both chaosticity and stability, with a greater capacity to integrate information than the redundant systems while being more stable than the random and synergistic systems. We conclude that there may be a fundamental trade-off between the robustness of a system's dynamics and its capacity to integrate information (which inherently requires flexibility and sensitivity) and that certain kinds of complexity naturally balance this trade-off.

Pengaruh Struktur Modal, Ukuran Perusahaan Dan Umur Perusahaan Terhadap Nilai Perusahaan: Survey Pada Sektor Makanan dan Minuman Yang Terdaftar di Bursa Efek Indonesia Tahun 2015-2019

This study aims to determine the effect of capital structure, firm size and firm age on firm value in food and beverage companies listed on the Indonesia Stock Exchange. This type of research is quantitative research. The sample used was 19 companies from a population of 26 food and beverage companies listed on the Indonesian stock exchange in 2015-2019. This study uses secondary data, the data analysis method used is the panel data regression analysis method. The results showed that simultaneously capital structure, firm size and firm age had an effect on firm value. Then, partially capital structure and firm age have a significant negative effect on firm value. On the other hand, firm size has no significant negative effect on firm value. The amount of the Adjusted R Square (R2) is 0.692658 or 69.26%, which means that the ability of the independent variable to explain the variation in the dependent variable change is 69.26%, while the rest is 0.30% (100% - 69.26%) is influenced by other factors outside the research variables. The results of this study are expected to be taken into consideration by companies when they want to increase company value.

The role of interoception in reducing trauma-associated distress: a feasibility study

ABSTRACT Background: Altered interoception plays an important role in chronic stress and posttraumatic stress disorder. The aim of this study was to evaluate the feasibility of a Trauma Sensitive Yoga (TSY) intervention for improving emotional distress and psychological discomfort in women living under circumstances of social and gender vulnerability. We assessed the effect of the treatment on the interoceptive mechanisms, and whether the psychological improvements were mediated by the changes in these mechanisms. Methods: The study involved a sample of 62 women who attended public community centres dedicated to supporting women victims of gender-based violence or who were socially and economically disadvantaged because of their gender. Participants underwent a six-week TSY programme. We evaluated dropout rate, adherence, and intervention satisfaction. We measured emotional distress, psychological discomfort, interoceptive mechanisms, and two nonequivalent dependent variables to enhance internal validity. We compared pre–post differences using paired samples t-test and a structural equation model (SEM) analysis was performed to compare the changes in the outcomes with the changes in the nonequivalent dependent variables. Mediation models were adjusted to evaluate the role of changes in interoception on outcome changes. Results: Fourteen (23%) women dropped out, mainly after the first intervention session. Intervention adherence (mean attendance 5.3 over 6 sessions) and acceptability were high (mean satisfaction 3.4 over 4). We observed post-intervention improvements in anxiety, depression, psychological discomfort, body responsiveness, and interoceptive awareness. The changes in the outcomes were larger than the changes in the nonequivalent dependent variables. Additionally, we found that the changes in body responsiveness partially mediated the change in anxiety and psychological discomfort but not in depression. Conclusions: TSY could be an interesting therapeutic approach for women experiencing chronic posttraumatic stress symptomatology. Our findings underscore the role of interoceptive mechanisms in traumatic stress and emphasize the importance of addressing these aspects.

Effect of a Follow-up Program Involving an Early Intervention and Self-help Group on Parenting Stress, Depression, and Parenting Efficacy for Mothers of Premature Infants

Purpose: This study is intended to investigate the impact of an early intervention and follow-up program involving self-help groups on maternal parenting stress, depression, and parenting efficacy in families with premature infants.Methods: The study included 30 mothers in the experimental group and 29 in the control group, all of whom had premature infants in the neonatal intensive care unit. Changes in dependent variables before and after the followup program were analyzed using paired t-tests with mean and standard deviation, and variables that differed in presurvey scores were analyzed using analysis of covariance with covariates.Results: Parenting stress decreased in the experimental group that participated in the follow-up program, while it increased in the control group. Depression decreased by 3.44 points in the intervention group and 1.76 points in the control group. Parenting efficacy increased by 3.03 points in the experimental group and decreased by 1.03 points in the control group after the program.Conclusion: This study highlights the significance of offering family-centered early interventions within existing hospitals or institutions, rather than relying solely on home visits, to promptly address the early developmental issues of premature infants, share information, and provide emotional support through regular self-help meetings.

Correlation Between of Gadget Use to Sleep Patterns and Social Interaction in Students During COVID-19 Pandemic

Introduction: The change in learning methods online during COVID-19 pandemic has an impact duration of gadget use. Cause health problems such as sleep patterns and changes social interaction patterns students. Study aims to determine relationship between gadget use with sleep patterns and social interaction among nursing students at Airlangga University during the COVID-19 pandemic. Methods: This research was conducted from 21-23 January 2022 using a correlational descriptive design with a cross-sectional approach. Population of nursing students the regular class of 2020 and B23 Airlangga University with large sample of 164 respondents using simple random sampling technique. Independent variable use of gadgets and the dependent variable changes in sleep patterns and social interactions. Instruments used SAS (Smartphone Addiction Scale), PSQI (Pittsburgh Sleep Quality Index), SIAS (Social Interaction Anxiety Scale). Data were collected by questionnaire and analyzed using spearman's rho test with significance level of &lt;0.05. Result : Based on the results study, there was significant relationship between gadget use and sleep patterns (p = 0.037, r = -0.163) and social interaction with results (p = 0.002, r = -236). Conclusion: Excessive use of gadgets without good time management makes students experience social dysfunction, become apathetic and less sensitive to surrounding environment. This means higher use of gadgets, lower level of sleep patterns and social interaction. It is hoped research will become source of information well as reference for providing health education and counseling regarding use of gadgets.

Bringing safety analytics to the online shopper: evaluating designs for augmenting point-of-sale interfaces with safety information

PurposeThe widespread adoption of online purchasing has prompted increasing concerns about product safety, and regulators are beginning to hold e-commerce sites accountable for dangerous product defects. For online consumers, understanding the many inherent safety risks among the extensive array of products they browse is a formidable task. The authors attempt to address this problem via a client-side software artifact that warns shoppers about potential product safety hazards at the point of sale.Design/methodology/approachIn this study, the authors built four candidate designs and assessed their effectiveness by means of a large randomized controlled experiment (n = 466). The authors define effectiveness as significant changes in dependent variables associated with health behaviors and technology adoption.FindingsThe authors find that all of the designs score high on adoption likelihood, that designs incorporating highlighting and scoring are better at increasing safety knowledge and that simpler designs are better at enhancing safety awareness.Originality/valueThese findings will inform the design of safety information dissemination systems and open new areas of safety awareness enhancement research. More generally, the authors introduce a novel method of testing text visualization variations and their impact on behavioral decisions.

The predictive role of personality traits and demographic features on post-traumatic stress disorder in a sample of COVID-19 hospitalized patients

BackgroundHospitalized COVID-19 patients suffer from psychological and psychiatric disorders such as post-traumatic stress disorder, depression, and anxiety. Because there was no comprehensive study on psychological factors in hospitalized COVID-19 patients in Iran, we investigated the predictive role of personality traits and demographic features on post-traumatic stress disorder in COVID-19 hospitalized patients.ResultsIn this research method first, 160 patients selected randomly and completed relevant questionnaires, which are prepared online. We examined the multivariate linear regression between the mentioned variables. The results showed that the independent variables are able to predict changes in post-traumatic stress disorder (P < 0.001). The percentage of explanation of changes in dependent variables was equal to 0.77, 0.65, 0.71, and 0.68, respectively.ConclusionPeople’s personality traits play a key role in facing and responding to stressful environmental events for instance COVID-19 pandemic, and as a result, some personality traits such as conscientiousness protect people from stress even though, neuroticism personality trait cause instability and make people more stresses, identifying these traits and treating them is.

Sex and Body Mass Index differences after one-year follow-up of an eating disorders risk factors universal prevention intervention in university students in Mexico City

Introduction. Interventions based on cognitive dissonance theory are the most effective for preventing eating disorders. Objective. To identify the changes at one year follow-up of a universal prevention intervention in disordered eating behaviors (DEB), thin-ideal internalization (TII), and drive for muscularity (DM). Method. A pre-experimental, pretest-posttest study was conducted on 602 university student subjects (76.1% women and 23.9% men) with an average age of 20.74 years at a public (30.6%) and a private university (69.4%) in Mexico City. A Split Plot ANOVA was performed with the intrasubject variable equal to each measurement (pretest, posttest, and follow-up), as well as the sex and body mass index (BMI) intersubject variables to analyze whether there was a significant interaction between these variables and the changes in dependent variables, as well as the changes through each measurement by group. Results. In the intrasubject analyses, statistically significant differences were found for DEB through the various measurements, without taking the interactions into account. Statistically significant interactions were observed between each measurement and BMI, and between each measurement and sex and BMI for the DM variable. Discussion and conclusion. Since a reduction of TII in women and DM in men was achieved, together with a decrease in DEB in women, the workshop can be said to have fully achieved its objectives for women and partly so for men.

A Study of Critical Thinking Ability in Relation to Learning Styles of EFL Learners

This study aims to fill the gap by exploring critical thinking ability in relation to the key learning styles for language learning: field independence, left-brain dominance, ambiguity tolerance, reflectivity/impulsivity, and visual, auditory, and kinesthetic. To do this, students performed the critical thinking process according to the specific syllabus, and the questionnaires for WGCTT (Watson-Glaser Critical Thinking Test) and LSA (LSA) were distributed. The data were collected from 127 EFL students to identify their learning styles and critical thinking ability. In this study, while analyzing the questionnaire of the WGCTT and LSA, hierarchical regression analysis was conducted to verify the influence of independent variables on changes in dependent variables. According to the results, some components of critical thinking ability were positively related to left-brain dominance, ambiguity tolerance, and reflectivity, while others were negatively associated with some elements of critical thinking ability. The positive relationship between critical thinking and learning styles could imply that some learning style patterns could change with adopting the critical thinking ability in the L2 performance.

The Effect of Mediterranean Diet on Body Composition, Inflammatory Factors, and Nutritional Status in Patients with Cachexia Induced by Colorectal Cancer: A Randomized Clinical Trial.

Along with high calorie and high protein diet, a new comprehensive dietary approach is needed to control cachexia caused by cancer and its related outcomes. This study was done to evaluate the effect of a Mediterranean diet on body composition, nutritional status, and inflammatory markers among cancer cachexia patients. In this randomized clinical trial, 46 patients with colorectal cancer-induced cachexia were included. After randomization, 23 patients were allocated to the intervention group (Mediterranean diet) and 23 to the control group (nutritional counseling for weight gain and prevention of weight loss in cancer patients). The primary outcome including muscle health, nutritional status, and inflammatory markers along with secondary outcomes such as quality of life, and serum proteins were evaluated at the start and the eighth week of the study. Statistical analysis was performed according to the intention-to-treat concept. To compare changes in dependent variables between the 2 groups, analysis of covariance (ANCOVA) was performed. After adjustment for the baseline values, age, sex, and supplements use, in the Mediterranean diet group mean of weight (P < .001), lean body mass (P = .001), fat mass (P = .002), and muscle strength (P < .001) were significantly increased compared to the control group. Regarding inflammatory markers, the mean serum level of tumor necrosis factor-alpha (TNF-α) (P < .001), high sensitive-C-reactive protein (hs-CRP) (P = .01) and Interleukin 6 (IL-6) (P < .001) were significantly improved in the Mediterranean diet group. Moreover, in the Mediterranean diet group, the score for global health status (P = .02) and physical performance score (P < .001) were significantly increased. It appears that the implementation of the Mediterranean diet might be a strategy to improve nutritional status, quality of life, inflammatory markers, and body composition in patients with colorectal cancer cachexia. Iranian Registry of Clinical Trials (www.irct.ir); ID: IRCT20211027052884N1.

THE EFFECTS OF A SUMMER PROGRAM ON PHYSICAL FITNESS AND HEALTH OUTCOMES IN CHILDREN

https://youtu.be/uCkCVkd6kSY BACKGROUND High rates of adolescent obesity and its associated co-morbidities have been attributed to a lack of physical activity and unhealthy nutrition habits. This is especially apparent during the summer months, when adolescents are out of school and do not have the structure of the academic year and its planned extracurricular activities. The Translational Health in Nutrition and Kinesiology (THINK) program is a nutrition and exercise science curriculum that is interfaced with social emotional learning (SEL) to enhance to personal health and lifestyle behaviors in middle school youth. The purpose of this study is to determine whether the THINK program could improve physical fitness, nutrition habits, and SEL in a 6-week summer program across a 3 year period. METHODS/DESIGN Participants from the South Miami community were enrolled in the THINK (n =108, 58 males, 50 females, 12.03 +.56 years). The assessments of physical fitness included: cardiorespiratory fitness (CRF) using the Pacer test, flexibility using the Sit &amp; Reach test, power using the Vertical Jump test, agility using the Shuttle Run, and muscular endurance using the Curl-up test. Body composition was analyzed using the Inbody 520 and SEL was measured using the Positive Youth Inventory. Food habits were measured using the Adolescent Food Habits Checklist. Means and standard error values were evaluated for all dependent variables. Paired sample t-tests (SPSS version 27) were performed to determine changes in dependent variables over time. RESULTS Significant improvements in CFF (p&amp;lt;.001), power (p&amp;lt;.006), flexibility (p&amp;lt;.001), agility (p&amp;lt;.001), muscular endurance (p&amp;lt;.001), lean body mass (p&amp;lt;.001) Food Habits (p&amp;lt;.001), and SEL (p=.038) were found. CONCLUSION An integrative and physically active summer program can result in improvements in physical fitness, nutrition habits, and SEL in as little as 6-weeks. The emphasis on physical activities in combination with nutrition, science and SEL in programs such the THINK program may serve as novel approach for improving physical fitness and lifestyle behaviors in middle school adolescents during the summer months. Future studies should include control groups to determine whether these changes occur independent of typical maturation and developmental processes in youth.

ESTILO DE VIDA Y FACTORES DE RIESGO CARDIOVASCULAR EN ESTUDIANTES UNIVERSITARIOS

Introduction: The beginning of university studies is associated with changes in lifestyle that could create predisposition to the appearance of cardiovascular risk factors. Objective: The purpose of this study was to examine the association between two-year changes in the lifestyle and incident elevated Blood Pressure (BP) and central obesity in university students. Materials and Methods: First-year medical students were evaluated in 2017 and 2019. Waist circumference and BP were assessed. A Lifestyle Score (HOLS) was applied that included Body Mass Index, plus four behavioral factors: smoking, alcohol use, fruit/vegetable consumption, and physical activity. Multivariate logistic regression was used with BP and waist circumference in 2019 as dependent variable and HOLS change between 2017 and 2019 as the primary predictor. Results: The prevalence of borderline BP was higher in men than in women in 2017 and unchanged in 2019. The proportion of students with abdominal obesity did not change. In 2017, in both sexes, excess weight, low consumption of fruits and vegetables and little physical activity were highlighted. This determined a low HOLS score (6.2). After two years a decrease in the score was observed in both sexes. A two-year decrease in HOLS was associated with significantly greater odds of incident central obesity as compared to stable HOLS. No associations were observed between variations in HOLS and BP. Conclusion: The applied score is a tool to evaluate the lifestyle of the students. A decrease in HOLS was associated with an increased risk of central obesity. Key words: Lifestyle; blood pressure; central obesity; student.

The effect of “moderately restricted carbohydrate” diet on gut microbiota composition and metabolic parameters in women with metabolic syndrome: a study protocol for a randomized controlled trial

BackgroundMetabolic syndrome (MetS) is a group of risk factors that increase the risk of death and a variety of chronic diseases. Recent studies have indicated that the imbalance of gut microbiota might contribute to development and progression of metabolic syndrome. Carbohydrate restriction in the diet has been proven to be one of the most effective methods in the management of metabolic syndrome, even in the absence of weight loss. However, no study has examined the effects of a carbohydrate-restricted diet on gut microbiota composition in metabolic syndrome patients. Thus, we will examine the effects of a “moderately restricted carbohydrate (MRC)” diet on gut microbiota, insulin resistance, and components of MetS among Iranian women. In addition, the stability of changes in dependent variables, including gut microbiota, will also be assessed.MethodsThis is a parallel randomized clinical trial in which 70 overweight or obese women aged 20–50 years with MetS will be randomly assigned to receive either MRC diet (42–45% carbohydrate, 35–40% fats) or a normal weight loss (NWL) diet (52–55% carbohydrate, 25–30% fats) for 3 months. Protein accounted for 15–17% of total energy in both diets. The quantity of gut microbiota including Firmicutes, Bacteroidetes, Bifidobacteria, Lactobacillus, Clostridium, Prevotella, Bacteroidetes, and Akkermansia muciniphila, as well as anthropometric, blood pressure, and metabolic parameters will be measured at study baseline and the end of trail. At the end of this phase, all participants will be placed on a weight maintenance diet for an additional 6 months. After following up study subjects in this duration, all dependent variables will be examined again to assess their stability over this period.DiscussionTo the best of our knowledge, this is the first randomized controlled trial investigating the effects of a moderately restricted carbohydrate diet on gut microbiota composition and several metabolic parameters during the weight loss and maintenance phases in women with MetS.Trial registrationIranian Registry of Clinical Trials (www.irct.ir, IRCT20210307050621N1). Registered on May 31, 2021.

Gender differences in social environmental changes associated with smoking: a cross-sectional study from Chinese internal migrants

ObjectivesTo identify clues for women’s tobacco control, this study analyses the gender differences in social environmental changes associated with smoking and the interaction between the environment and individuals’ social integration.Design,...

Alterations in Essential Fatty Acids, Immunoglobulins (IgA, IgG, and IgM), and Enteric Methane Emission in Primiparous Sows Fed Hemp Seed Oil and Their Offspring Response.

This study shows the effects of dietary hemp seed oil on the milk composition, blood immunoglobulins (Ig), and enteric methane (E-CH4) production of primiparous sows, and their offspring's response at three time points. A bifactorial experiment was conducted for 21 days (d) on 18 primiparous sows (195 ± 3 days old). The sows were fed two diets: (i) a control diet (SO) based on soybean oil (1.6%), with an 18.82 n-6:n-3 polyunsaturated fatty acids (PUFA) ratio; (ii) an experimental diet (HO) based on hemp seed oil (1.6%), with a 9.14 n-6:n-3 PUFA ratio. The milk contained an elevated level of linoleic acids (LA), n-3 FA, and especially alpha-linolenic acids (ALA), while the n-6:n-3 ratio declined using hemp oil. The Ig concentration was higher in colostrum than in milk. In the first few hours, the IgG in the plasma of piglets was more than double that of maternal plasma IgG (+2.39 times). A period effect (p &lt; 0.0001) for IgG concentration in the plasma of piglets was recorded (40% at 10 d, respectively 73% lower at 21 d than 12 h after parturition). However, the sow diet did not affect Ig (p &gt; 0.05). The frequency of diarrhoea declined after about 7 d. The value of the rate of diarrhoea was 6.2% lower in the PHO group. We found a 4.5% decline in E-CH4 in the HO group. Applying multiple linear regression, feed intake, n-6:n-3 ratio, ALA, and lean meat were potential indicators in estimating E-CH4. In conclusion, sow dietary hemp seed oil increased lean meat %, milk EFA, and milk IgM. Significant changes in the other dependent variables of interest (body weight, plasma Igs in sows and offspring, E-CH4 production) were not recorded. There was reduced diarrhoea which shows that EFA could play a therapeutic role in the incidence of diarrhoea and in lowering of E-CH4 emission in sows and progeny. All dependent variables were significantly altered at different time points, except for fat concentration in milk and sow plasma IgG.

Pilot study of an online intervention for young people with a first psychotic episode: Thinkapp

IntroductionOnline interventions can be a complement to maintain the long-term effectiveness of psychosocial interventions in First Episode Psychosis (FEP) that have already demonstrated their efficacy in the short and medium term (Calvo et al., 2015).ObjectivesTo test the effectiveness of a mobile app–based intervention (Thinkapp) to improve quality of life, functioning and symptomatology, and reduce days of admission and hospitalizations, in young people with FEP.MethodsFourteen patients with FEP, aged 14–30, recruited from Gregorio Marañón Hospital, Ramón y Cajal Hospital and AMAFE Foundation in Madrid (Spain) received treatment as usual plus a psychoeducational intervention through a mobile app. Changes in dependent variables over the course of the intervention were assessed by means of a battery of clinical tests at baseline, 3-month and 6-month follow-up using a Wilcoxon test.ResultsOf the fourteen patients included, 7 patients completed the 6-month follow-up and 8 completed the 3-month follow-up. There were significant differences in days of admission (p = 0.042) between baseline and 6-month follow-up. No significant results were observed in other clinical variables.ConclusionsThe study provides preliminary data potentially related to the reduction of days of admissions.DisclosureNo significant relationships.

Improving the Output Quality of Official Statistics Based on Machine Learning Algorithms

Abstract National statistical institutes currently investigate how to improve the output quality of official statistics based on machine learning algorithms. A key issue is concept drift, that is, when the joint distribution of independent variables and a dependent (categorical) variable changes over time. Under concept drift, a statistical model requires regular updating to prevent it from becoming biased. However, updating a model asks for additional data, which are not always available. An alternative is to reduce the bias by means of bias correction methods. In the article, we focus on estimating the proportion (base rate) of a category of interest and we compare two popular bias correction methods: the misclassification estimator and the calibration estimator. For prior probability shift (a specific type of concept drift), we investigate the two methods analytically as well as numerically. Our analytical results are expressions for the bias and variance of both methods. As numerical result, we present a decision boundary for the relative performance of the two methods. Our results provide a better understanding of the effect of prior probability shift on output quality. Consequently, we may recommend a novel approach on how to use machine learning algorithms in the context of official statistics.

The Effect of a Heavy Resisted Sled-Pull Mesocycle on Sprint Performance in Junior Australian Football Players.

Edwards, T, Piggott, B, Banyard, HG, Haff, GG, and Joyce, C. The effect of a heavy resisted sled-pull mesocycle on sprint performance in junior Australian football players. J Strength Cond Res 37(2): 388-393, 2023-This study assessed the effect of heavy resisted sled-pull training on sprint times and force, velocity, and power characteristics in junior Australian football players. Twenty-six athletes completed a 6-week resisted sled-pull training intervention which included 10 training sessions and 1-week taper. Instantaneous velocity during 2 maximal 30 m sprints was recorded 1 week before and 1 week after the intervention with a radar gun. Velocity-time data were used to derive sprint performance and force, velocity, and power characteristics. A paired t -test assessed the within-group differences between preintervention and postintervention testing. Statistical significance was accepted at p ≤ 0.05. Hedges' g effect sizes (ESs) were used to determine the magnitude of change in dependent variables. Maximum velocity (ES = 1.33) and sprint times at all distances (ES range 0.80-1.41) significantly improved after heavy resisted sled-pull training. This was reflected in sprint force, velocity, and power characteristics with significant improvements in relative theoretical force (ES = 0.63), theoretical velocity (ES = 0.99), relative maximum power (ES = 1.04), and ratio of horizontal to vertical force (ES = 0.99). Despite the multifactorial nature of training and competing physical demands associated with preseason training, these findings imply that a short, resisted sled-pull training mesocycle may improve sprint performance and underlying force, velocity, and power characteristics in junior athletes.

Regularising Transformations for Complex Differential Equations with Movable Algebraic Singularities

In a 1979 paper, Okamoto introduced the space of initial values for the six Painlevé equations and their associated Hamiltonian systems, showing that these define regular initial value problems at every point of an augmented phase space, a rational surface with certain exceptional divisors removed. We show that the construction of the space of initial values remains meaningful for certain classes of second-order complex differential equations, and more generally, Hamiltonian systems, where all movable singularities of all their solutions are algebraic poles (by some authors denoted the quasi-Painlevé property), which is a generalisation of the Painlevé property. The difference here is that the initial value problems obtained in the extended phase space become regular only after an additional change of dependent and independent variables. Constructing the analogue of space of initial values for these equations in this way also serves as an algorithm to single out, from a given class of equations or system of equations, those equations which are free from movable logarithmic branch points.