Curve Model Research Articles

Developmental patterns of athletic performance and physical fitness in youth baseball players: A longitudinal analysis

ABSTRACT This study aimed to evaluate developmental patterns in athletic performance during youth and determine their association with changes in physical fitness. The testing included three athletic performance (i.e. ball speed in pitching, swing velocity in batting, 30-metre sprint time) and two physical fitness tests (i.e. medicine ball [MB] back throw and modified star excursion balance test [SEBT]). Data from 235 players (557 measurements) aged 6 to 14 were eligible for a longitudinal evaluation. The statistical analysis was based on the latent growth curve models of the athletic performance development process and the random-effect panel data multivariate regression analysis for ball speed, swing velocity, and 30-metre sprint time. The 30-metre sprint time showed a small curvature but an accelerated increase around 12‒13 years old. However, the ball speed, swing velocity, and modified SEBT demonstrated a slower or less accelerated change in the developmental pattern starting around 12‒13 years old. Multivariate longitudinal analysis revealed that developmental change in athletic performance was positively associated with age and MB back throw. Our findings highlight the developmental patterns of athletic performance associated with baseball exhibiting stagnation as well as acceleration, which may help develop effective age-appropriate strategies for improving performance in youth baseball players.

An asymmetrical reinforcing spiral? Disentangling the longitudinal dynamics of media use and mainstream media trust

Abstract While numerous studies have documented an association between mainstream media trust and mainstream media use, only little is known about potential causal mechanisms underlying the association. We theorize that selective exposure, social influence, and the reinforcing spirals model offer three possible mechanisms that may underlie the association. These possibilities were studied using random intercept cross-lagged panel models and latent curve models on a four-wave panel data set (n = 3,540). For mainstream media, the results show an asymmetrical reinforcing spiral, in which the effect of mainstream media trust on use can be considered as one of yielding maintenance, while the impact of media use on mainstream media trust to a limited degree is in line with the notion of a spiral gradually (though inconsistently) increasing trust over time. We also find that use of right-wing alternative media consistently and sometimes robustly leads to decreasing mainstream media trust.

Changes in Language Learners’ Affect: A Complex Dynamic Systems Theory Perspective

AbstractThis study investigated changes in motivation, self‐efficacy beliefs, and a range of emotions, including enjoyment, hope, pride, curiosity, anxiety, boredom, apathy, confusion, and shame, from a complex dynamic systems theory (CDST) perspective over a 2‐year period in the Hungarian English as a Foreign Language (EFL) context. Using the same questionnaire, we collected data four times throughout 4 semesters from 101 participants studying English in two Hungarian high schools. For data analysis, we used latent growth curve modeling (LGCM) to detect the group‐level changes in learners’ motivation, self‐efficacy, and emotions. We also employed dynamic cluster analysis to identify trends in learners’ trajectories regarding these variables. In our panel data, linear models described the data well concerning the ought‐to second language (L2) self, language learning experience, boredom, apathy, and confusion, and for enjoyment, curiosity, anxiety, and shame, nonlinear models had the best fit. We could also identify trajectories depicting attractor states and learner paths that featured influences of perturbations.

Burnt out and still single: Susceptibility to dating app burnout over time

Despite the ubiquity of dating apps, there is little longitudinal research examining the mental health and well-being of dating app users. To fill this void, this study takes a social compensation approach to exploring dating app users’ burnout experiences (i.e., emotional exhaustion, inefficacy, and depersonalization) over time. Four hundred ninety-three active single dating app users were surveyed over four waves across 12 weeks, with a final sample of 190. Multilevel growth curve models showed that dating app users experienced increased emotional exhaustion and inefficacy over time. Furthermore, depression, anxiety, and loneliness predicted more emotional exhaustion and inefficacy, while problematic dating app use predicted more emotional exhaustion and less inefficacy. The results suggest that dating apps may exacerbate existing difficulties with relationship initiation among vulnerable users by increasing their risk of burnout. Dating app burnout is a potential intervention target to improve users’ dating success.

Gender Differences in Co-developmental Trajectories of Internalizing and Externalizing Problems: A 7-Year Longitudinal Study from Ages 3 to 12.

The co-occurrence of externalizing and internalizing problems is acknowledged, but gender differences remain unclear. The present study examines gender differences in the longitudinal relationships between conduct and emotional problems throughout childhood. The sample, drawn from the ELISA project, included 2368 children (48.1% girls; ages 3-12). Latent growth curve models were employed to analyze the trajectories of parent-reported conduct problems and emotional symptoms separately, while parallel process latent growth curve models were utilized to compare joint trajectories. The decrease in conduct problems was consistent for girls, but not for boys. High initial emotional symptoms predicted a slower increase in emotional symptoms over time for girls. Parental positivity was a protective factor for conduct problems in girls. Grandiose-deceitful traits were more related to conduct problems in girls, while callous-unemotional traits were related to emotional symptoms in boys. This study highlights the importance of considering gender in childhood conduct and emotional problems.

Clinical Effects of Asynchronous Provider-Guided Practice Sessions During Blended Care Therapy for Anxiety and Depression: Pragmatic Retrospective Cohort Study.

Blended care therapy models are intended to increase the efficiency and effectiveness of evidence-based psychotherapy by combining synchronous and asynchronous components of care. This retrospective cohort study evaluated the clinical effects of synchronous video therapy sessions and asynchronous guided practice session elements on anxiety and depression in a blended care therapy program, with a novel focus on asynchronous provider feedback messages. Participants were adults (N=33,492) with clinical symptoms of anxiety (Generalized Anxiety Disorder 7-item scale [GAD-7] score of ≥8) and depression (Patient Health Questionnaire 9-item scale [PHQ-9] score of ≥10) at intake. Symptom trajectories were evaluated via individual growth curve models. Time-varying covariates evaluated effects of synchronous video session attendance and the presence or absence of each asynchronous guided practice session element occurring within 7 days and 8-14 days prior to each clinical outcome assessment. Guided practice session elements included client digital lesson completion, client digital exercise completion, and feedback messages sent by providers. Approximately 86.6% (29,012/33,492) of clients met criteria for clinical improvement by end of care (median 6, IQR 4-8 synchronous sessions). Synchronous video session attendance and client digital lesson completion in the past 7 days and in the past 8-14 days were each uniquely and significantly associated with lower GAD-7 scores (video session effects: bsession7=-0.82, bsession8-14=-0.58, P values<.001; digital lesson effects: blesson7=-0.18, blesson8-14=-0.26, P values <.001) and PHQ-9 scores (video session effects: bsession7=-0.89, bsession8-14=-0.67, P values <.001; digital lesson effects: blesson7=-0.12, blesson8-14=-0.30, P values <.001). Client digital exercise completion in the past 8-14 days was significantly associated with lower GAD-7 scores (bexercise8-14=-0.10; P<.001) but exercise completion in the 7 days prior to clinical outcome assessment was not (bexercise7=0.00; P=.89). Exercise completion in the past 7 days was significantly associated with lower PHQ-9 scores (bexercise7=-0.16; P<.001) but exercise completion in the past 8-14 days was not (bexercise8-14=-0.05; P=.09). Provider feedback messaging in the past 7 days and in the past 8-14 days was significantly associated with lower GAD-7 and PHQ-9 scores, respectively (GAD-7: bfeedback7=-0.12, P<.001; bfeedback8-14=-0.07, P=.004; PHQ-9: bfeedback7=-0.15, P<.001; bfeedback8-14=-0.08, P=.01). Provider feedback between synchronous therapy sessions provided significant benefit for symptom reduction, beyond the effects of client digital engagement and synchronous video sessions. When guided practice sessions are well integrated into care, blended care therapy provides meaningful improvements upon the traditional, synchronous session-only therapy model. Provider guidance and feedback for clients between synchronous sessions support more efficient and effective mental health care overall.

Model of time-distance curve of electromagnetic waves diffracted on a local feature in the georadar study of permafrost zone rock layers

In GPR (georadar) studies, one of the most popular procedures for determining electromagnetic waves propagation velocity in a rock mass is the selection of theoretical hyperbolic time-distance curves and subsequent comparison with the time-distance curve obtained from a GPR measurement. This procedure is based on the model of homogeneous medium, but nowadays the subject of GPR study is often inhomogeneous media, such as horizontally layered media characteristic of loose permafrost zone sediments. The paper presents the findings of studying the formation of hyperbolic time-distance curves of georadar impulses in a horizontally layered medium without taking into account the dispersion and absorption of electromagnetic waves. On the basis of geometrical optics laws, formulas were derived to calculate the shape of the hyperbolic lineup of georadar impulses reflected from a local feature in a multilayer frozen rock mass. On the example of a permafrost zone rock mass containing a layer of unfrozen rocks, the effect of the thicknesses of rock layers and their relative dielectric permittivity on the apparent dielectric permittivity resulting from the calculation of the theoretical hyperbolic time-distance curve was shown. The conditions under which it is impossible to determine the presence of a layer of unfrozen rocks from a hyperbolic time-distance curve are also presented. The established regularities were tested on synthetic georadar radargrams calculated in the gprMax software program. The findings of the theoretical studies were confirmed by the comparison with the results of the analysis of the georadar measurements computer simulation data in the gprMax system (the relative error was less than 0.5%).

Growth curve models for weight among infants: a scoping review protocol

Growth curve models for weight among infants: a scoping review protocol

Personality trait similarity in recently cohabiting couples: Partner choice, convergence, or selective breakup?

Romantic partners tend to be more similar in self-reported personality traits than would be expected by chance. This similarity can be due to the choice of a similar partner, partners becoming more similar to each other over time, or dissimilar couples breaking up. To examine whether these processes (choice, convergence, or breakup) explain personality trait similarities in couples, we followed a sample of 1,180 German couples (N = 2,360 individuals; age range = 17-82 years old) from right after moving in together (ranging from 0 to 4 years after) up to 16 years thereafter. Using bivariate latent growth curve models, we found that couples were already similar in openness, conscientiousness, extraversion, and agreeableness in the first years of moving in together. Although couples showed correlated change in conscientiousness, this did not increase similarity. Response surface analyses showed that separation risk was generally unrelated to dissimilarity. Furthermore, romantic partners did not become more dissimilar in the years before separation. Taken together, these results suggest that personality similarity in cohabiting couples is fully driven by choosing a similar partner. We discuss the implications of these findings for theory and research on personality similarity in romantic relationships. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Inverse Open Circuit Voltage Curve Model for LiCoO2 Battery at Different Temperatures

Lithium-ion batteries are widely used in a variety of applications. For effective battery management, accurate estimation of the state of charge (SOC) is essential. One of the most commonly employed methods for SOC estimation relies on the open circuit voltage (OCV) curve with respect to SOC. However, inverting the OCV-SOC function is not always straightforward. This paper proposes a novel analytical function that directly models the inverse OCV-SOC function, providing a more efficient and reliable method for SOC estimation. Moreover, the dependency of the proposed function on battery temperature is also being investigated, allowing for a wider application of the method under different OCV measuring conditions.

The Decline in Mastery Goal Orientation and Person-Environment Fit and the Preventive Effect of Classroom Community: Examining Transitions Using Latent Growth Curve Modelling

&lt;p style="text-align:justify"&gt;Students’ mastery goal orientation tends to decline over the course of compulsory school, especially after the transition to lower secondary school. According to stage-environment fit theory, secondary school is less accommodating to students' needs, interests, and abilities than primary school. In consequence, the perceived person-environment fit declines as well. It is assumed that a strong sense of classroom community in primary school can counteract a potential decline in both of these important individual aspects. Using data from the Swiss longitudinal research project WiSel (“Wirkungen der Selektion”; “Effects of Tracking”), we conducted a latent growth curve model (LGCM) to examine the correlation between the development of students' mastery goal orientation and the development of their person-environment fit during the transition from primary school to lower secondary school. Perceived classroom community was assumed to benefit from these developments. The results show that both mastery goal orientation and person-environment fit decrease during the transition to lower secondary school. A strong sense of classroom community in fifth grade leads to a smaller decline in both constructs. Implications for educational practice are discussed.&lt;/p&gt;

Exploring the Nexus between Greenhouse Emissions, Environmental Degradation and Green Energy in Europe: A Critique of the Environmental Kuznets Curve

This study examines the intricate relationship between economic growth and European environmental degradation via the Environmental Kuznets Curve (EKC). Our results contest the traditional inverted U-shape model of the Environmental Kuznets Curve, indicating that the theory may not be consistently applicable across European countries. Utilizing CS-ARDL and MMQR modelling, we reveal substantial regional disparities. Western European nations demonstrate a typical Environmental Kuznets Curve (EKC) pattern in the short term, characterized by an initial increase in emissions alongside GDP development, followed by a subsequent fall. Conversely, Eastern and Balkan nations exhibit a U-shaped connection, described by an early decline in emissions followed by a subsequent increase as their development levels increase. The influence of renewable energy differs, as it decreases emissions in the short term in Western Europe. However, its long-term impacts are variable, especially when contrasted with its more pronounced effect on emissions in Eastern and Balkan countries. Furthermore, trade openness intensifies environmental degradation in the short-term across all regions, although its long-term impact diminishes, particularly concerning greenhouse gases (GHG). The relationship between renewable energy and trade openness is substantial for the short-term reduction of carbon dioxide emissions, but this effect declines with time. The results indicate that a uniform environmental policy throughout Europe may lack efficacy. Customized strategies to expedite the transition in Western Europe and more specific interventions in Eastern Europe are essential to harmonize economic progress with environmental sustainability. Future research should examine the determinants of the diminishing long-term effects of renewable energy and the interplay between trade and environmental policies.

Quality of Life Effects of Renal Artery Stenting Versus Medical Therapy for Atherosclerotic Renal-Artery Stenosis: Results from the Randomized CORAL Trial.

Renal-artery stenosis can be associated with difficult to control hypertension, although renal-artery stenting has not been shown to improve clinical outcomes. Alternative antihypertensive medications could potentially result in quality of life benefits with renal-artery stenting. We performed a pre-specified quality of life sub-study of the CORAL trial-multicenter, randomized, open-label trial of renal-artery stenting versus medical therapy in patients with atherosclerotic renal-artery stenosis. Longitudinal growth curve models were used to compare the Physical Symptoms Distress Index (PSDI), SF-36, and EQ-5D scores over time between treatment groups. We also sought to validate the approach of assessing quality of life in hypertension studies. Among 906 patients (mean age 69.2±9.1years, 49.7% men), symptom frequency and distress due to side effects from antihypertensive medications changed minimally over time, with no significant differences between treatment groups. There were also no clinically significant differences between treatment groups for the SF-36 and its subscales or the EQ-5D. In internal validation of the quality of life measures, the PSDI correlated well with number/type of antihypertensive medications, and generic health status measures correlated with late clinical events. In a large, multicenter, randomized clinical trial, we found no significant benefit of routine renal-artery stenting over medical management for the treatment of atherosclerotic renal-artery stenosis in terms of disease-specific or generic quality of life measures. As these quality of life measures are important to patients and are associated with medication compliance, future studies of antihypertensive treatments should consider including these quality of life measures as secondary outcomes. Trial registration: ClinicalTrials.gov: NCT00081731.

Optimizing sheep growth curves using a meta-heuristic algorithm.

Sheep were among the first animals domesticated by humans, and to this day, small ruminants are primarily raised for their meat, milk, and wool. This study evaluated the goodness of fit for growth curve models using observed age and weight data from crossbred lambs of various breeds based on the mean values between paired breeds. We employed a hybrid metaheuristic algorithm, combining a simulated annealing (SA) algorithm and a genetic algorithm (GA) called SAGAC, to determine the optimal parameter values for growth models, ensuring the best alignment between simulated and observed curves. The goodness of fit and model accuracy was assessed using the coefficient of determination (R2), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE). Errors were measured by comparing the criteria differences between simulated and observed data. Thirty crossbreed combinations were simulated, considering the average weight. Analysis of the observed and simulated growth curves indicated that specific crossbreeding scenarios produced promising results. This simulation approach is believed to assist geneticists in predicting potential crossbreeding outcomes, thereby saving time and financial resources in field research.

Bidirectional association between frailty and quality of life within English longitudinal study of aging.

The relationship between quality of life (QoL) and frailty has previously been investigated cross-sectionally and longitudinally as unidirectional where QoL depends upon frailty and where frailty depends on QoL. Here a bidirectional relationship is examined. This work uses a latent curve model with structured residuals to address the bidirectional association between QoL and frailty in older English people considering within-person and group levels. The study measures frailty using a functional frailty measure and quality of life using CASP-12. The sample size is 17,529. There is a strong relationship between QoL (Quality of Life) and frailty, which is almost linear and inversely proportional over time. Although the cross-lagged coefficients from QoL to frailty and vice versa showed statistical significance, the impact was found to be minimal. The time between assessments (which are two years apart) and/or the few observations available per individual may have impacted the effect of this relationship. When accounting for gender, age, net wealth, and multimorbidity, some variations in the results were observed at the group level but not at the within-person level. The study provides empirical evidence that supports a bidirectional association between QoL and frailty in older individuals who reside at home. These results offer valuable insights for healthcare providers, as participants did not exhibit an advanced need for health services. Additionally, involving participants in evaluating and assessing these services enhances their effectiveness and overall benefit.

Green Hydrogen Synthesis from Human Urine as Sustainable Bioenergy Resources

With the earths cry for help as pollution rate increases, researchers are faced with a common task of tackling pollution resulting from dependence on fossil fuel as well as delivering sustainable energy. Renewable energy resources such as solar, wind, hydro to mention a few are currently finding applications within the world energy mix but some limitations which range from meteorology of locations to expected maximum energy output attainable. Hydrogen, the most abundant element in the world stand chance of abating this problem. However conventional method of its producing, poses severe treat to the atmospheric environment with the release of oxides of carbon hence, referred as blue hydrogen. Contrarily, green hydrogen from human urine stands a more sustainable and environmentally friendly energy resource. This study was aimed to empirically model the synthesis of green hydrogen from urea in human urine by an electrolytic process. The synthesized hydrogen was characterized on physiochemical properties of conductivity, turbidity, pH, specific gravity and colour, while the precursor urine characterized on gender, exposure duration and storage temperature. The synthesis process was modelled using Microsoft excel solver for the overall cell energy or polarization curve model, the Faraday’s efficiency model and gas purity model at electrolyte concentrations of 25 wt./wt., 30 wt./wt. and 35 wt./wt. of potassium oxide (buffer} to urea over a five-temperature interval range of 45 to 85 oC. Findings revealed that the gas produced was 99.88% hydrogen at the cathode. Also, hydrogen produced increased with increase in electrolyte concentration and moderate temperature with optimal conditions at 35 w/w electrolyte concentration and 65 oC. However, the minimum cell voltage was 2.06 V at 85 oC and 35 w/w electrolyte concentration. With an exception of the Faraday’s efficiency model at 30 wt./wt. electrolyte concentration across the system’s operating temperature range yielding an R2 value of 0.711, all the models yielded coefficient of determination values in the range of 0.96 and 0.99, indicating good fit for the alkaline urine electrolysis for green hydrogen synthesis from human urine.

Emotional intelligence development predicts novice teachers’ professional identity, teaching enthusiasm, and teacher-student relationships: the mediation of positive teacher emotions

ABSTRACT Teacher development involves the dynamic interplay between emotional intelligence and emotions. While previous research links these factors with their professional identity, teaching enthusiasm, and teacher-student relationships, the development characteristics of emotional intelligence and emotions remain unexplored in relation to these outcomes. In a two-year study with 357 novice teachers, emotional intelligence and emotions were tracked thrice. Data on professional identity, enthusiasm, and teacher-student relationships were collected at the final assessment. Latent growth curve modelling results revealed that only positive emotions, not negative ones, mediate the connection. Specifically, the initial level of positive emotions mediated the link between the initial level of emotional intelligence and teaching enthusiasm, professional identity, and teacher-student relationships. The growth rate of positive emotions notably mediated the relationship between emotional intelligence and professional identity, teaching enthusiasm, and teacher-student relationships. These findings offer new insights into the development of teachers’ emotional intelligence, emotions, and professional growth.

Predicting the volumetric heat capacity of freezing soils using the soil freezing characteristic curve

The heat capacity during the freezing process is a vital hydrothermal parameter. It is difficult to experimentally measure the heat capacity of freezing soils. Therefore, in this study, we proposed a new method to estimate the volumetric heat capacity based on the combination of the weighted arithmetic mean model for volumetric heat capacity and soil freezing characteristic curve (SFCC) estimation model. Five specific heat capacity models for solid particle and six SFCC estimation models were introduced. It can be concluded that the six SFCC-based volumetric heat capacity models with specific heat capacity of solid particle = 0.725 MJMg-1K−1 exhibited the best performance. Among the six SFCC-based volumetric heat capacity models, the Kong et al-based volumetric heat capacity model has the best performance in predicting the volumetric heat capacity. The predicted SFCC-based volumetric heat capacity model is easy to use and can be applied to mimic the variation of volumetric heat capacity with subzero temperature.

Base joint hysteresis model for reinforced concrete assembly columns with post-pouring area

In response to the problem of uncontrollable grouting quality of traditional grouting sleeves in the connection between prefabricated components, a column base joint with post pouring area connected by grouting sleeves (PCGS) is proposed. Both the sleeve and post pouring area could cause differences in hysteresis characteristics between prefabricated and cast-in-place components. In order to investigate the hysteresis model of PCGS column base joint, the cyclic load tests and finite element parametric analysis of PCGS column base joint were conducted. The theoretical calculation method for load and displacement of PCGS column base joint at yield, peak, and ultimate characteristic points was established based on equivalent rectangular stress and plastic hinge length in joint area. The average ratios of theoretical calculations to test results for load and displacement at the above three characteristic points are 0.997, 0.983, and 0.983, and 1.020, 1.041, and 0.970, respectively, indicating that the theoretical calculation method can accurately predict the strength and deformation of PCGS column base joint. The dimensionless skeleton curve model with double broken lines in the elastic and strengthening stages, and exponential function in descending stage has been established based on the test and simulated results. The degradation behavior of unloading stiffness and bearing capacity was quantitatively described using the regression fitting method, and the hysteresis rule was defined. The established hysteresis model can effectively reflect the strength and stiffness degradation under cyclic loading, which can provide guidance for the elastic-plastic seismic response analysis of PCGS column base joint.

The influence of hope and optimism on trajectories of COVID-19 stress, health anxiety, and wellbeing during the COVID-19 pandemic.

The COVID-19 pandemic posed a threat to public health and psychological functioning, with early studies documenting higher rates of psychopathology within the United States and globally. Hope and optimism promote adjustment and are associated with positive physical and mental health outcomes. Thus, individual differences in hope and optimism may also foster resilience during a global health crisis. The current study examined how hope and optimism influenced longitudinal health-focused distress and wellbeing during the pandemic. Data were collected from 788 American adults across three periods during Spring-Summer 2020 using MTurk. Latent growth curve modeling examined whether hope and optimism predicted COVID stress, health anxiety, and wellbeing trajectories. COVID stress and health anxiety decreased after the onset of the pandemic, whereas wellbeing was stable. Individually, hope and optimism predicted lower initial COVID stress and health anxiety, along with greater initial wellbeing. When examining the combined influence of hope and optimism, optimism was more strongly related to health-focused distress, though both were strong predictors of wellbeing. These findings indicate that Americans were resilient and positive expectancies, particularly optimism, predicted better initial adjustment to the early phases of the pandemic. Thus, positive expectancies appear to be protective during a global health crisis.