The Rise in Single-Mother Families and Children’s Cognitive Development: Evidence From Three British Birth Cohorts     

Susan Harkness  Paul Gregg  Mariña Fernández-Salgado 《Child development》2020,91(5):1762-1785

This article assessed changes in the association between single motherhood and children’s verbal cognitive ability at age-11 using data from three cohorts of British children, born in 1958 (n = 10,675), 1970 (n = 8,933) and 2000 (n = 9,989), and mediation analysis. Consistent with previous studies, direct effects were small and insignificant. For those born in 1958 and 1970 indirect effects, operating through reduced economic and parental resources, were associated with −.107-SD to −.156-SD lower attainment. Differences between the two cohorts, and by children’s age when parents separated, were insignificant. For the 2000 cohort, effect sizes for children born to single mothers did not change significantly (−.112-SD) but attenuated for children whose parents separated in early childhood (−.076-SD) or while of school age (−.054-SD).  相似文献   

Promoting a participatory convergence in a Spanish context: an inter-university action research project using visual narrative     

Elia Fernández-Díaz  Carlos Rodríguez-Hoyos  Adelina Calvo Salvador  Gloria Braga Blanco  Lorea Fernández-Olaskoaga  Prudencia Gutiérrez-Esteban 《Educational Action Research》2019,27(3):362-378

ABSTRACT

This article focuses on the deconstruction of an inter-university action research project that has allowed us to rethink our teaching and research, questioning the social, political and ethical dimensions of the university. Following the pre-assembly proposal to promote participatory convergence, organized within the framework of the 1^st Global Assembly for Knowledge Democracy (2017), an action research process was implemented in order to generate systematic inquiry around the current situation of the university and the need to act and rethink our commitment to promoting changes in this context. We have reflected on the meaning of democratization, rethinking the pedagogical relationship with our students and how we critically commit them to promote activism. We generated an environment where we look for the meaning of our practices by means of a visual narrative which has enabled us to weave and identify our own biography and become aware of where we are and why we act in one way or another. We have also focused on the search for the meaning of our actions in relation to the community we belong to and how to deal with the challenges of social justice, encouraging collaboration with other networks in a wider inter-university framework.  相似文献   

Quality flaw prediction in Spanish Wikipedia: A case of study with verifiability flaws     

Edgardo Ferretti  Leticia Cagnina  Viviana Paiz  Sebastián Delle Donne  Rodrigo Zacagnini  Marcelo Errecalde 《Information processing & management》2018,54(6):1169-1181

In this work, we present the first quality flaw prediction study for articles containing the two most frequent verifiability flaws in Spanish Wikipedia: articles which do not cite any references or sources at all (denominated Unreferenced) and articles that need additional citations for verification (so-called Refimprove). Based on the underlying characteristics of each flaw, different state-of-the-art approaches were evaluated. For articles not citing any references, a well-established rule-based approach was evaluated and interesting findings show that some of them suffer from Refimprove flaw instead. Likewise, for articles that need additional citations for verification, the well-known PU learning and one-class classification approaches were evaluated. Besides, new methods were compared and a new feature was also proposed to model this latter flaw. The results showed that new methods such as under-bagged decision trees with sum or majority voting rules, biased-SVM, and centroid-based balanced SVM, perform best in comparison with the ones previously published.  相似文献   

The role of task and ego-oriented climate in explaining students’ bright and dark motivational experiences in Physical Education     

Luis García-González  Javier Sevil-Serrano  Angel Abós  Nathalie Aelterman  Leen Haerens 《Physical Education & Sport Pedagogy》2019,24(4):344-358

Background: A distinction is made in Achievement Goal Theory (AGT) between task-oriented (i.e. effort, intra-individual progress, and self-comparison) and ego-oriented (i.e. inter-individual progress and normative comparison) climates. Combining insights from AGT and Self-Determination Theory (SDT), studies in the PE context have shown that a task-oriented climate positively relates to need satisfaction, although the findings regarding the motivating role of an ego-oriented climate are inconsistent. Moreover, little is known about the role of task- or ego-oriented climates in explaining experiences of basic psychological need frustration.

Purpose: Grounded in AGT and SDT, the aim of the present study was to examine if experiences of basic psychological need satisfaction and need frustration can explain why task- and ego-oriented climates elicit positive and negative motivational outcomes in PE, respectively.

Research design: Cross-sectional study.

Method: A sample of 524 secondary school students (51.1% boys, M_age?=?14.51; SD?=?1.81) from five different secondary schools participated in this study. Students reported on their perceptions of task- and ego-oriented climates, motivational regulations, basic psychological need satisfaction, and need frustration, as well as positive and negative outcomes in PE. Structural equation modeling was used to investigate our objective.

Results: We found that a task-oriented climate had a strong and positive relationship with basic psychological need satisfaction, eliciting a bright pathway to autonomous motivation and affective attitude. An ego-oriented climate was positively related to basic psychological need frustration, eliciting a dark pathway to amotivation and boredom. A negative cross-path from task-oriented climate to basic psychological need frustration was also found, while no significant cross-paths were found from ego-oriented climate to basic psychological need satisfaction.

Conclusions: This study provides a better understanding of the mechanisms that explain why task- and ego-oriented climates shape students’ motivational experiences in PE lessons. It is suggested that a task-oriented climate elicits a bright pathway towards more optimal functioning, because it fosters experiences of need satisfaction and buffers against experiences of need frustration. In contrast, an ego-oriented climate is primarily positively related to feelings of need frustration and negative motivational outcomes. Practical implications for PE teacher training are discussed.  相似文献   

Effect of different loading conditions on running mechanics at different velocities     

Germán Carretero-Navarro  Doménico Cherubini  Wolfgang Taube 《European Journal of Sport Science》2019,19(5):595-602

Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics.  相似文献   

Epistemic ideals     

Demeter  Tamás 《Metascience》2020,29(2):201-203

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3-min all-out effort on cycle ergometer is valid to estimate the anaerobic capacity by measurement of blood lactate and excess post-exercise oxygen consumption     

Alessandro Moura Zagatto  Paulo Eduardo Redkva  Rodrigo Araújo Bonetti de Poli  Joel Abraham Martinez González  Jeniffer Zanetti Brandani  Thiago Penedo 《European Journal of Sport Science》2019,19(5):645-652

The purpose of this study was to investigate the use of a single 3-min all-out maximal effort to estimate anaerobic capacity (AC) through the lactate and excess post-exercise oxygen consumption (EPOC) response methods (AC_{[La^?]+EPOCfast}) on a cycle ergometer. Eleven physically active men (age?=?28.1?±?4.0?yrs, height?=?175.1?±?4.2?cm, body mass?=?74.8?±?11.9?kg and ?O_2max?=?40.7?±?7.3?mL?kg^?1?min^?1), participated in the study and performed: i) five submaximal efforts, ii) a supramaximal effort at 115% of intensity of ?O_2max, and iii) a 3-min all-out maximal effort. Anaerobic capacity was estimated using the supramaximal effort through conventional maximal accumulated oxygen deficit (MAOD) and also through the sum of oxygen equivalents from the glycolytic (fast component of excess post-exercise oxygen consumption) and phosphagen pathways (blood lactate accumulation) (AC_{[La^?]+EPOCfast}), while during the 3-min all-out maximal effort the anaerobic capacity was estimated using the AC_{[La^?]+EPOCfast} procedure. There were no significant differences between the three methods (p?>?0.05). Additionally, the anaerobic capacity estimated during the 3-min all-out effort was significantly correlated with the MAOD (r?=?0.74; p?=?0.009) and AC_{[La^?]+EPOCfast} methods (r?=?0.65; p?=?0.029). Therefore, it is possible to conclude that the 3-min all-out effort is valid to estimate anaerobic capacity in physically active men during a single cycle ergometer effort.  相似文献   

Cardiorespiratory and perceptual responses of two interval training and a continuous training protocol in healthy young men     

João Pedro Araújo Naves  Ana Cristina Silva Rebelo  Lucas Raphael Bento E Silva  Maria Sebastiana Silva  Rodrigo Ramirez-Campillo  Robinson Ramírez-Vélez 《European Journal of Sport Science》2019,19(5):653-660

High Intensity Interval Training (HIIT) can be performed with different effort to rest time-configurations, and this can largely influence training responses. The purpose of the study was to compare the acute physiological responses of two HIIT and one moderate intensity continuous training (MICT) protocol in young men. A randomised cross-over study with 10 men [age, 28.3?±?5.5years; weight, 77.3?±?9.3?kg; height, 1.8?±?0.1?m; peak oxygen consumption (VO₂peak), 44?±?11?mL.kg^?1.min^?1]. Participants performed a cardiorespiratory test on a treadmill to assess VO₂peak, velocity associated with VO₂peak (vVO₂peak), peak heart rate (HRpeak) and perceived exertion (RPE). Then participants performed three protocols equated by distance: Short HIIT (29 bouts of 30s at vVO₂peak, interspersed by 30s of passive recovery, 29?min in total), Long HIIT (3 bouts of 4?min at 90% of vVO₂peak, interspersed by 3?min of recovery at 60% of vVO₂peak, 21?min in total) and MICT (21?min at 70% of vVO₂peak). The protocols were performed in a randomised order with ≥48 h between them. VO₂, HRpeak and RPE were compared. VO₂peak in Long HIIT was significantly higher than Short HIIT and MICT (43?±?11 vs 32?±?8 and 37?±?8?mL.kg^?1.min^?1, respectively, P?P?P?2, HR and RPE than Short HIIT and MICT, suggesting a higher demand on the cardiorespiratory system. Short HIIT and MICT presented similar physiologic and perceptual responses, despite Short HIIT being performed at higher velocities.  相似文献   

Effects of audiovisual stimuli on psychological and psychophysiological responses during exercise in adults with obesity     

Marcelo Bigliassi  João P. A. Greca  Vinícius Barreto-Silva  Priscila Chierotti  Arli R. de Oliveira  Leandro R. Altimari 《Journal of sports sciences》2019,37(5):525-536

The present experiment sought to further understanding of the effects of personalised audiovisual stimuli on psychological and psychophysiological responses during exercise in adults with obesity. Twenty-four participants (M_age = 28.3, SD = 5.5 years; M_BMI = 32.2, SD = 2.4) engaged in self-paced exercises on a recumbent cycle ergometer and three conditions (sensory stimulation [ST], sensory deprivation [DE], and control [CO]) were administered. Perceptual (attentional focus and perceived exertion), affective (affective state and perceived activation), and psychophysiological (heart rate variability) parameters were monitored throughout the exercise bouts. A one-way repeated measures analysis of variance was used to compare self-reported and psychophysiological variables (main and interaction effects [5 Timepoints × 3 Conditions]). The results indicate that ST increased the use of dissociative thoughts throughout the exercise session (η_p² = .19), ameliorated fatigue-related symptoms (η_p² = .15) and elicited more positive affective responses (η_p² = .12) than CO and DE. Accordingly, personally-compiled videos are highly effective in ameliorating exertional responses and enhancing affective valence during self-paced exercise in adults with obesity. Audiovisual stimuli could be used during the most critical periods of the exercise regimen (e.g., first training sessions) when individuals with obesity are more likely to focus on fatigue-related sensations.  相似文献   

The load-velocity profile differs more between men and women than between individuals with different strength levels     

Alejandro Torrejón  Carlos Balsalobre-Fernández  G. Gregory Haff 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):245-255

This study aimed to determine the suitability of the load-velocity relationship to prescribe the relative load (%1RM) in women, as well as to compare the load-velocity profile between sexes and participants with different strength levels. The load-velocity relationship of 14 men (1RM: 1.17 ± 0.19) and 14 women (1RM: 0.66 ± 0.13) were evaluated in the bench press exercise. The main findings revealed that: (I) the load-velocity relationship was always strong and linear (R² range: 0.987–0.993), (II) a steeper load-velocity profile was observed in men compared to women (Effect size [ES]: 1.09), with men showing higher velocities for light loads (ES: ? 0.81 and ? 0.40 for the y-intercept and 30%1RM, respectively), but women reporting higher velocities for the heavy loads (ES: 1.14 and 1.50 at 90%1RM and 100%1RM, respectively); and (III) while the slope of the load-velocity profile was moderately steeper for weak men compared to their strong counterpart (ES: 1.02), small differences were observed between strong and weak women (ES: ? 0.39). While these results support the use of the individual load-velocity relationship to prescribe the %1RM in the bench press exercise for women, they also highlight the large disparities in their load-velocity profile compared to men.  相似文献