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BACKGROUND: Adopting a person-centered approach to coping potentially allows researchers to explore the multifaceted nature of the construct. However, this increasingly adopted approach also has limitations. Namely, employing cluster or latent profile analysis to investigate coping through a person-centered lens often brings a lack of generalizability and subjectivity in interpreting the generated profiles. As such, this study aimed to explore the impact of varied methodology in person-centered investigations of coping profiles. METHODS: 682 university students' (M = 21.3 years old, SD = 3.5) responses to the COPE Inventory were analyzed across item, subscale, and higher-order category levels using cluster and latent profile analysis to produce 6 finalized models for cross-method comparison. RESULTS: Throughout 19 analyses, approach coping, avoidance coping, low coping, and help-seeking profiles were consistently identified, alluding to the potential of universal coping trends. However, membership overlap across COPE structures and methodology was largely inconsistent, with individual participants classified into theoretically distinct profiles based on the methodology employed. CONCLUSION: While evidence suggests latent profile analysis provides a more rigorous approach, the significant impact of minor methodological variations urges a reevaluation of person-centered approaches and incorporation of multi-construct data to enhance the understanding of coping profiles.
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Dominance analysis (DA) is a very useful tool for ordering independent variables in a regression model based on their relative importance in explaining variance in the dependent variable. This approach, which was originally described by Budescu, has recently been extended to use with structural equation models examining relationships among latent variables. Research demonstrated that this approach yields accurate results for latent variable models involving normally distributed indicator variables and correctly specified models. The purpose of the current simulation study was to compare the use of this DA approach to a method based on observed regression DA and DA when the latent variable model is estimated using two-stage least squares for latent variable models with categorical indicators and/or model misspecification. Results indicated that the DA approach for latent variable models can provide accurate ordering of the variables and correct hypothesis selection when indicators are categorical and models are misspecified. A discussion of implications from this study is provided.
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The efficacy of the NASA SPRINT exercise countermeasures program for quadriceps (vastus lateralis) and triceps surae (soleus) skeletal muscle health was investigated during 70 days of simulated microgravity. Individuals completed 6° head-down-tilt bedrest (BR, n = 9), bedrest with resistance and aerobic exercise (BRE, n = 9), or bedrest with resistance and aerobic exercise and low-dose testosterone (BRE + T, n = 8). All groups were periodically tested for muscle (n = 9 times) and aerobic (n = 4 times) power during bedrest. In BR, surprisingly, the typical bedrest-induced decrements in vastus lateralis myofiber size and power were either blunted (myosin heavy chain, MHC I) or eliminated (MHC IIa), along with no change (P > 0.05) in %MHC distribution and blunted quadriceps atrophy. In BRE, MHC I (vastus lateralis and soleus) and IIa (vastus lateralis) contractile performance was maintained (P > 0.05) or increased (P < 0.05). Vastus lateralis hybrid fiber percentage was reduced (P < 0.05) and energy metabolism enzymes and capillarization were generally maintained (P > 0.05), while not all of these positive responses were observed in the soleus. Exercise offsets 100% of quadriceps and approximately two-thirds of soleus whole muscle mass loss. Testosterone (BRE + T) did not provide any benefit over exercise alone for either muscle and for some myocellular parameters appeared detrimental. In summary, the periodic testing likely provided a partial exercise countermeasure for the quadriceps in the bedrest group, which is a novel finding given the extremely low exercise dose. The SPRINT exercise program appears to be viable for the quadriceps; however, refinement is needed to completely protect triceps surae myocellular and whole muscle health for astronauts on long-duration spaceflights.NEW & NOTEWORTHY This study provides unique exercise countermeasures development information for astronauts on long-duration spaceflights. The NASA SPRINT program was protective for quadriceps myocellular and whole muscle health, whereas the triceps surae (soleus) was only partially protected as has been shown with other programs. The bedrest control group data may provide beneficial information for overall exercise dose and targeting fast-twitch muscle fibers. Other unique approaches for the triceps surae are needed to supplement existing exercise programs.
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Exercício Físico , Músculo Esquelético , Cadeias Pesadas de Miosina , Músculo Quadríceps , Simulação de Ausência de Peso , Humanos , Masculino , Músculo Quadríceps/fisiologia , Músculo Quadríceps/metabolismo , Simulação de Ausência de Peso/métodos , Adulto , Exercício Físico/fisiologia , Cadeias Pesadas de Miosina/metabolismo , Músculo Esquelético/fisiologia , Músculo Esquelético/metabolismo , United States National Aeronautics and Space Administration , Estados Unidos , Repouso em Cama/efeitos adversos , Testosterona/metabolismo , Testosterona/sangue , Voo Espacial/métodos , Atrofia Muscular/prevenção & controle , Atrofia Muscular/fisiopatologia , Treinamento Resistido/métodos , Ausência de Peso/efeitos adversos , Força Muscular/fisiologiaRESUMO
Psychometricians have devoted much research and attention to categorical item responses, leading to the development and widespread use of item response theory for the estimation of model parameters and identification of items that do not perform in the same way for examinees from different population subgroups (e.g., differential item functioning [DIF]). With the increasing use of computer-based measurement, use of items with a continuous response modality is becoming more common. Models for use with these items have been developed and refined in recent years, but less attention has been devoted to investigating DIF for these continuous response models (CRMs). Therefore, the purpose of this simulation study was to compare the performance of three potential methods for assessing DIF for CRMs, including regression, the MIMIC model, and factor invariance testing. Study results revealed that the MIMIC model provided a combination of Type I error control and relatively high power for detecting DIF. Implications of these findings are discussed.
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This study seeks to compare fixed and mixed effects models for the purposes of predictive classification in the presence of multilevel data. The first part of the study utilizes a Monte Carlo simulation to compare fixed and mixed effects logistic regression and random forests. An applied examination of the prediction of student retention in the public-use U.S. PISA data set was considered to verify the simulation findings. Results of this study indicate fixed effects models performed comparably with mixed effects models across both the simulation and PISA examinations. Results broadly suggest that researchers should be cognizant of the type of predictors and data structure being used, as these factors carried more weight than did the model type.
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Aspirin is one of the most commonly consumed cyclooxygenase (COX)-inhibitors and anti-inflammatory drugs and has been shown to block COX-produced regulators of inflammation and aging skeletal muscle size. We used propensity score matching to compare skeletal muscle characteristics of individuals from the Health ABC study that did not consume aspirin or any other COX-inhibiting drugs (non-consumers, n = 497, 74 ± 3 year, 168 ± 9 cm, 75.1 ± 13.8 kg, 33.1 ± 7.4% body fat, 37% women, 34% black) to those that consumed aspirin daily (and not any other COX-inhibiting drugs) and for at least 1 year (aspirin consumers, n = 515, 74 ± 3 year, 168 ± 9 cm, 76.2 ± 13.6 kg, 33.8 ± 7.1% body fat, 39% women, 30% black, average aspirin consumption: 6 year). Subjects were matched (p > 0.05) based on age, height, weight, % body fat, sex, and race (propensity scores: 0.33 ± 0.09 vs. 0.33 ± 0.09, p > 0.05). There was no difference between non-consumers and aspirin consumers for computed tomography-determined muscle size of the quadriceps (103.5 ± 0.9 vs. 104.9 ± 0.8 cm2 , p > 0.05) or hamstrings (54.6 ± 0.5 vs. 54.9 ± 0.5 cm2 , p > 0.05), or quadriceps muscle strength (111.1 ± 2.0 vs. 111.7 ± 2.0 Nm, p > 0.05). However, muscle attenuation (i.e., density) was higher in the aspirin consumers in the quadriceps (40.9 ± 0.3 vs. 44.4 ± 0.3 Hounsfield unit [HU], p < 0.05) and hamstrings (27.7 ± 0.4 vs. 33.2 ± 0.4 HU, p < 0.05). These cross sectional data suggest that chronic aspirin consumption does not influence age-related skeletal muscle atrophy, but does influence skeletal muscle composition in septuagenarians. Prospective longitudinal investigations remain necessary to better understand the influence of chronic COX regulation on aging skeletal muscle health.
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Aspirina , Músculo Esquelético , Humanos , Feminino , Masculino , Aspirina/farmacologia , Estudos Transversais , Estudos Prospectivos , Músculo Esquelético/fisiologia , Envelhecimento/fisiologia , Inibidores de Ciclo-Oxigenase/farmacologiaRESUMO
Social science research is heavily dependent on the use of standardized assessments of a variety of phenomena, such as mood, executive functioning, and cognitive ability. An important assumption when using these instruments is that they perform similarly for all members of the population. When this assumption is violated, the validity evidence of the scores is called into question. The standard approach for assessing the factorial invariance of the measures across subgroups within the population involves multiple groups confirmatory factor analysis (MGCFA). CFA models typically, but not always, assume that once the latent structure of the model is accounted for, the residual terms for the observed indicators are uncorrelated (local independence). Commonly, correlated residuals are introduced after a baseline model shows inadequate fit and inspection of modification indices ensues to remedy fit. An alternative procedure for fitting latent variable models that may be useful when local independence does not hold is based on network models. In particular, the residual network model (RNM) offers promise with respect to fitting latent variable models in the absence of local independence via an alternative search procedure. This simulation study compared the performances of MGCFA and RNM for measurement invariance assessment when local independence is violated, and residual covariances are themselves not invariant. Results revealed that RNM had better Type I error control and higher power compared to MGCFA when local independence was absent. Implications of the results for statistical practice are discussed.
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There is some evidence that the age-associated change in skeletal muscle mass is muscle specific, yet the number of specific muscles that have been studied to form our understanding in this area is limited. In addition, few aging investigations have examined multiple muscles in the same individuals. This longitudinal investigation compared changes in skeletal muscle size via computed tomography of the quadriceps (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius), hamstrings (biceps femoris short and long heads, semitendinosus, and semimembranosus), psoas, rectus abdominis, lateral abdominals (obliques and transversus abdominis), and paraspinal muscles (erector spinae and multifidi) of older individuals from the Health, Aging, and Body Composition (Health ABC) study at baseline and 5.0 ± 0.1 years later (n = 469, 73 ± 3 yr and 78 ± 3 yr, 49% women, 33% black). Skeletal muscle size decreased (P < 0.05) in quadriceps (-3.3%), hamstrings (-5.9%), psoas (-0.4%), and rectus abdominis (-7.0%). The hamstrings and rectus abdominis atrophied approximately twice as much as the quadriceps (P < 0.05), whereas the quadriceps atrophied substantially more than the psoas (P < 0.05). The lateral abdominals (+5.9%) and paraspinals (+4.3%) hypertrophied (P < 0.05) to a similar degree (P > 0.05) over the 5 years. These data suggest that older individuals experience skeletal muscle atrophy and hypertrophy in a muscle group-specific fashion in the eighth decade, a critical time period in the aging process. A broader understanding of muscle group-specific skeletal muscle aging is needed to better guide exercise programs and other interventions that mitigate decrements in physical function with aging.NEW & NOTEWORTHY These longitudinal analyses of six muscle groups in septuagenarians provide novel information on the muscle group-specific aging process. Although the quadriceps, hamstrings, psoas, and rectus abdominis atrophied with different magnitudes, the lateral abdominals and paraspinals hypertrophied over the 5 years. These findings contribute to a better understanding of the skeletal muscle aging process and highlight the need to complete studies in this area with a muscle-specific focus.
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Músculo Esquelético , Músculo Quadríceps , Humanos , Feminino , Masculino , Estudos Longitudinais , Músculo Esquelético/fisiologia , Músculo Quadríceps/fisiologia , Atrofia Muscular , Envelhecimento , HipertrofiaRESUMO
BACKGROUND: Active commuting is inversely related with cardiovascular disease (CVD) risk factors yet associations with CVD prevalence in the US population are unknown. METHODS: Aggregate data from national surveys conducted in 2017 provided state-level percentages of adults who have/had coronary heart disease, myocardial infarction, and stroke, and who actively commuted to work. Associations between active commuting and CVD prevalence rates were assessed using Pearson correlations and generalized additive models controlling for covariates. RESULTS: Significant correlations were observed between active commuting and all CVD rates (r range = -.31 to -.47; P < .05). The generalized additive model analyses for active commuting (walking, cycling, or public transport) in all adults found no relationships with CVD rates; however, a significant curvilinear association was observed for stroke within men. The generalized additive model curves when examining commuting via walking or cycling in all adults demonstrated nuanced, generally negative linear or curvilinear associations between coronary heart disease, myocardial infarction, and stroke. CONCLUSION: Significant negative correlations were observed between active commuting and prevalence rates of coronary heart disease, myocardial infarction, and stroke. Controlling for covariates influenced these associations and highlights the need for future research to explore the potential of active commuting modes to reduce CVD in the United States.
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Doenças Cardiovasculares , Infarto do Miocárdio , Acidente Vascular Cerebral , Adulto , Ciclismo , Doenças Cardiovasculares/epidemiologia , Exercício Físico , Humanos , Masculino , Infarto do Miocárdio/epidemiologia , Meios de Transporte , Estados Unidos/epidemiologia , CaminhadaRESUMO
Oftentimes in many fields of the social and natural sciences, data are obtained within a nested structure (e.g., students within schools). To effectively analyze data with such a structure, multilevel models are frequently employed. The present study utilizes a Monte Carlo simulation to compare several novel multilevel classification algorithms across several varied data conditions for the purpose of prediction. Among these models, the panel neural network and Bayesian generalized mixed effects model (multilevel Bayes) consistently yielded the highest prediction accuracy in test data across nearly all data conditions.
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Social scientists are frequently interested in identifying latent subgroups within the population, based on a set of observed variables. One of the more common tools for this purpose is latent class analysis (LCA), which models a scenario involving k finite and mutually exclusive classes within the population. An alternative approach to this problem is presented by the grade of membership (GoM) model, in which individuals are assumed to have partial membership in multiple population subgroups. In this respect, it differs from the hard groupings associated with LCA. The current Monte Carlo simulation study extended on prior work on the GoM by investigating its ability to recover underlying subgroups in the population for a variety of sample sizes, latent group size ratios, and differing group response profiles. In addition, this study compared the performance of GoM with that of LCA. Results demonstrated that when the underlying process conforms to the GoM model form, the GoM approach yielded more accurate classification results than did LCA. In addition, it was found that the GoM modeling paradigm yielded accurate results for samples as small as 200, even when latent subgroups were very unequal in size. Implications for practice were discussed.
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PURPOSE: PCNL requires a lithotrite to efficiently break stones, and some devices include active suction to remove the fragments. We set out to determine the efficacy and safety of the Swiss LithoClast® Trilogy, in a prospective European multicentre evaluation and compared it to published stone clearance rates for Trilogy based on surface area (68.9 mm2/min) and using the 3D calculated stone volume (526.7 mm3/min). METHODS: Ten European centres participated in this prospective non-randomized study of Trilogy for PCNL. Objective measures of stone clearance rate, device malfunction, complications and stone-free rates were assessed. Each surgeon subjectively evaluated ergonomic and device effectiveness, on a 1-10 scale (10 = extremely ergonomic/effective) and compared to their usual lithotrite on a 1-10 scale (10 = extremely effective). RESULTS: One hundred and fifty seven PCNLs using Trilogy were included (53% male, 47% female; mean age 55 years, range 13-84 years). Mean stone clearance rate was 65.55 mm2/min or 945 mm3/min based on calculated 3D volume. Stone-free rate on fluoroscopy screening at the end of the procedure was 83%. Feedback for suction effectiveness was 9.0 with 9.1 for combination and 9.0 for overall effectiveness compared to lithotrite used previously. Ergonomic score was 8.1, the least satisfactory element. Complications included 13 (8.2%) Clavien-Dindo Grade II and 2 (1.3%) Grade III. Probe breakage was seen in 9 (5.7%), none required using a different lithotrite. CONCLUSIONS: We have demonstrated that Trilogy is highly effective at stone removal. From a user perspective, the device was perceived by surgeons to be highly effective overall and compared to the most commonly used previous lithotrite, with an excellent safety profile.
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Cálculos Renais/cirurgia , Nefrolitotomia Percutânea/instrumentação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto JovemRESUMO
Several structural equation modeling estimation methods have recently been developed to alleviate problems associated with model misspecification. Two of the more popular such approaches are 2-stage least squares and regularization methods. Prior work examining the performance of these estimators has generally focused on problems with adequately sized samples and relatively large factor loadings. In contrast, relatively little research has been conducted comparing these estimation techniques with small samples and weak loadings, though both conditions are not uncommon in the multivariate modeling. The current simulation study focused on comparing these relatively new structural estimation methods for misspecified models (e.g., misspecified interactions and cross-loadings) with small samples and relatively weak factor loadings. Results indicated that regularized 2-stage least squares estimation performed better compared to the regularized structural equation modeling framework for small samples and with weak factor loadings. Implications and guidelines for applied researchers are presented.
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Modelos Estatísticos , Simulação por Computador , Análise de Classes Latentes , Análise dos Mínimos Quadrados , Funções VerossimilhançaRESUMO
Student motivational profiles and self-regulated learning strategies are significant influences on overall academic success in university settings. Test anxiety has been repeatedly linked to maladaptive learning strategies and ineffective motivational frameworks. However, the results in the field have been inconsistent with respect to the precise interactions among these variables. This study employed anonymous responses from a group of volunteer students in a mid-sized Midwestern United States university, serving a primarily Caucasian and female population with an average age of 20 years. Adopting a curvilinear analytic design, this study attempted to examine the relationships among these common domains of inquiry into student thriving. The results of this study provide insights examining under which conditions cognitive test anxiety is most likely to be heightened or diminished. The results demonstrated that levels of test anxiety were greatest when (a) learners adopted primarily extrinsic or primarily intrinsic goal orientations, (b) academic tasks where the outcome was uncertain, (c) learners adopted passive learning strategies, and (d) learning strategies were more personally involved (as opposed to externalized study behaviors). Our results add to the field by identifying curvilinear models provide greater utility in identifying the relationships among these critical emotional and cognitive factors in academic settings. Furthermore, we advocate for employing identification and intervention strategies that recognize individually specific profiles of interactions among test anxiety, motivation, and self-regulation to promote more optimal success in supporting learners in university settings.
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Background Repeated assessment of cardiorespiratory fitness (CRF) improves mortality risk predictions in apparently healthy adults. Accordingly, the American Heart Association suggests routine clinical assessment of CRF using, at a minimum, nonexercise prediction equations. However, the accuracy of nonexercise prediction equations over time is unknown. Therefore, we compared the ability of nonexercise prediction equations to detect changes in directly measured CRF. Methods and Results The sample included 987 apparently healthy adults from the BALL ST (Ball State Adult Fitness Longitudinal Lifestyle Study) cohort (33% women; average age, 43.1±10.4 years) who completed 2 cardiopulmonary exercise tests ≥3 months apart (3.2±5.4 years of follow-up). The change in estimated CRF (eCRF) from 27 distinct nonexercise prediction equations was compared with the change in directly measured CRF. Analysis included Pearson product moment correlations, SEE values, intraclass correlation coefficient values, Cohen's κ coefficients, γ coefficients, and the Benjamini-Hochberg procedure to compare eCRF with directly measured CRF. The change in eCRF from 26 of 27 equations was significantly associated to the change in directly measured CRF (P<0.001), with intraclass correlation coefficient values ranging from 0.06 to 0.63. For 16 of the 27 equations, the change in eCRF was significantly different from the change in directly measured CRF. The median percentage of participants correctly classified as having increased, decreased, or no change in CRF was 56% (range, 39%-61%). Conclusions Variability was observed in the accuracy between nonexercise prediction equations and the ability of equations to detect changes in CRF. Considering the appreciable error that prediction equations had with detecting even directional changes in CRF, these results suggest eCRF may have limited clinical utility.
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Algoritmos , Aptidão Cardiorrespiratória , Teste de Esforço , Modelos Teóricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Nível de Saúde , Voluntários Saudáveis , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto JovemRESUMO
Exploratory factor analysis (EFA) is widely used by researchers in the social sciences to characterize the latent structure underlying a set of observed indicator variables. One of the primary issues that must be resolved when conducting an EFA is determination of the number of factors to retain. There exist a large number of statistical tools designed to address this question, with none being universally optimal across applications. Recently, researchers have investigated the use of model fit indices that are commonly used in the conduct of confirmatory factor analysis to determine the number of factors to retain in EFA. These results have yielded mixed results, appearing to be effective when used in conjunction with normally distributed indicators, but not being as effective for categorical indicators. The purpose of this simulation study was to compare the performance of difference values for several fit indices as a method for identifying the optimal number of factors to retain in an EFA, with parallel analysis, which is one of the most reliable such extant methods. Results of the simulation demonstrated that the use of fit index difference values outperformed parallel analysis for categorical indicators, and for normally distributed indicators when factor loadings were small. Implications of these findings are discussed.
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The Covid-19 pandemic in the winter and spring of 2020 represents a major challenge to the world health care system that has not been seen perhaps since the influenza pandemic in 1918. The virus has spread across the world, claiming lives on all continents with the exception of Antarctica. Since its arrival in the United States, attention has been paid to how Covid-19 cases and deaths have been distributed across varying socioeconomic and ethnic groups. The goal of this study was to examine this issue during the early weeks of the pandemic, with the hope of shedding some light on how the number of cases and the number of deaths were, or were not related to poverty. Results of this study revealed that during the early weeks of the pandemic more disadvantaged counties in the United States had a larger number of confirmed Covid-19 cases, but that over time this trend changed so that by the beginning of April, 2020 more affluent counties had more confirmed cases of the virus. The number of deaths due to Covid-19 were associated with poorer and more urban counties. Discussion of these results focuses on the possibility that testing for the virus was less available in more disadvantaged counties later in the pandemic than was the case earlier, as the result of an overall lack of adequate testing resources across the nation.
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Much of the research on identifying feigning in psychological assessment has focused on adults with less attention to adolescents. The purpose of the present study is to expand the limited literature on detecting feigning in adolescents using the Personality Assessment Inventory - Adolescent. The study included 114 nonclinical adolescents (ages 15 to 18) recruited from high schools in the Midwest who were randomly assigned to experimental groups: honest nonclinical, uncoached feigning, and coached feigning. 50 randomly selected individuals with depression from the PAI-A clinical standardization sample were included as the honest clinical group. Sample demographics included a mean age of 16.64 years; 51.2% young men, 48.2% young women; 85.4% Caucasian, 6.7% African American, 5.5% Hispanic, and 2.4% Asian. 80% of feigning profiles reported clinical levels of depression. MANOVA results showed strong support for the Rogers Discriminant Function (RDF; d range = 1.85-2.05). The Negative Impression Management (NIM) scale also demonstrated promise (d range = 0.77-1.08), while the smallest effects for detecting feigning were found for the Malingering Index (d range = 0.58-0.70). The negative distortion indices showed good utility in differentiating between groups. Cut-scores and pragmatic implications are presented.
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Simulação de Doença/diagnóstico , Testes Neuropsicológicos/normas , Determinação da Personalidade/normas , Inventário de Personalidade/normas , Adolescente , Feminino , Humanos , Masculino , Distribuição Aleatória , Reprodutibilidade dos TestesRESUMO
We examined the influence of lifelong aerobic exercise on skeletal muscle size, function, and adiposity. Young exercisers [YE; n = 20, 10 women (W), 25 ± 1 yr], lifelong exercisers (LLE; n = 28, 7 W, 74 ± 2 yr), and old healthy nonexercisers (OH; n = 20, 10 W, 75 ± 1 yr) were studied. On average, LLE exercised 5 days/wk for 7 h/wk over the past 52 ± 1 yr. The LLE men were subdivided by exercise intensity [Performance (LLE-P), n = 14; Fitness (LLE-F), n = 7]. Upper and lower leg muscle size and adiposity [intermuscular adipose tissue (IMAT)] were determined via MRI, and quadriceps isotonic and isometric function was assessed. For the quadriceps, aging decreased muscle size, isotonic and isometric strength, contraction velocity (men only), and power (P < 0.05). In women, LLE did not influence muscle size or function. In men, LLE attenuated the decline in muscle size and isometric strength by ~50% (P < 0.05). LLE did not influence other aspects of muscle function, nor did training intensity influence muscle size or function. For the triceps surae, aging decreased muscle size only in the women, whereas LLE (both sexes) and training intensity (LLE men) did not influence muscle size. In both sexes, aging increased thigh and calf IMAT by ~130% (P < 0.05), whereas LLE attenuated the thigh increase by ~50% (P < 0.05). In the LLE men, higher training intensity decreased thigh and calf IMAT by ~30% (P < 0.05). In summary, aging and lifelong aerobic exercise influenced muscle size, function, and adipose tissue infiltration in a sex- and muscle-specific fashion. Higher training intensity throughout the life span provided greater protection against adipose tissue infiltration into muscle.NEW & NOTEWORTHY This is the first study to examine skeletal muscle size, function, and adiposity in women and men in their eighth decade of life that have engaged in lifelong aerobic exercise. The findings reveal sex and upper and lower leg muscle group-specific benefits related to skeletal muscle size, function, and adiposity and that exercise intensity influences intermuscular adiposity. This emerging cohort will further our understanding of the health implications of maintaining exercise throughout the life span.
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Adiposidade , Exercício Físico , Músculo Esquelético/fisiologia , Tecido Adiposo , Adulto , Idoso , Envelhecimento , Feminino , Humanos , Extremidade Inferior/fisiologia , Masculino , Força Muscular , Adulto JovemRESUMO
Social scientists routinely collect data using questionnaires and surveys. Items on these instruments frequently involve scales with multiple ordered options that respondents use to report intensity of feelings or behaviors. Given their popularity, a variety of statistical models have been developed for analyzing data collected using these items. A model that has been recently described for working with ordinal items is the covariates in a uniform and shifted binomial mixture (CUB). The CUB model characterizes responses to ordinal items as a function of two parameters: (a) response feeling (or intensity), and (b) response uncertainty. This model has been extended to include a third parameter measuring likelihood of respondents selecting a socially desirable or safe response, known as the shelter option. This model has been primarily used to investigate items measuring political opinions or product preferences. However, the CUB with a shelter parameter and covariates generalized covariates in a uniform and shifted ninomial mixture model (GeCUB) seems particularly well suited for characterizing self-reported behaviors, particularly those that are not considered positive (i.e., substance abuse). The purpose of this study is to apply this extension of the CUB to the modeling of self-reported substance use behavior by teenagers. Results from the GeCUB model estimation revealed that subjects used the "no use" response as a shelter option at relatively high rates for marijuana use but not for cigarettes or alcohol. In addition, females reported less use and less certainty in their responses than did males. (PsycINFO Database Record (c) 2020 APA, all rights reserved).