Effects of unsteady conditions on propulsion generated by the hand’s motion in swimming: a systematic review     

Lara Elena Gomes  Jefferson Fagundes Loss 《Journal of sports sciences》2015,33(16):1641-1648

The understanding of swimming propulsion is a key factor in the improvement of performance in this sport. Propulsive forces have been quantified under steady conditions since the 1970s, but actual swimming involves unsteady conditions. Thus, the purpose of the present article was to review the effects of unsteady conditions on swimming propulsion based on studies that have compared steady and unsteady conditions while exploring their methods, their limitations and their results, as well as encouraging new studies based on the findings of this systematic review. A multiple database search was performed, and only those studies that met all eligibility criteria were included. Six studies that compared steady and unsteady conditions using physical experiments or numerical simulations were selected. The selected studies verified the effects of one or more factors that characterise a condition as unsteady on the propulsive forces. Consequently, much research is necessary to understand the effect of each individual variable that characterises a condition as unsteady on swimming propulsion, as well as the effects of these variables as a whole on swimming propulsion.  相似文献   

Which Setting to Choose: Comparison of Whole-Class vs. Small-Group Computer Simulation Use     

Lara K. Smetana  Randy L. Bell 《Journal of Science Education and Technology》2014,23(4):481-495

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Preschool outcomes of children of depressed mothers: role of maternal behavior,contextual risk,and children's brain activity     

Dawson G  Ashman SB  Panagiotides H  Hessl D  Self J  Yamada E  Embry L 《Child development》2003,74(4):1158-1175

Children of depressed mothers are at risk for behavioral and emotional problems. Infants of depressed mothers exhibit behavioral disturbances and atypical frontal brain activity. The mechanisms by which children develop such vulnerabilities are not clear. Three-year-old children of mothers with (N = 65) and without (N = 59) a history of depression were assessed in terms of behavior problems and brain electrical activity. Children of mothers with chronic depression exhibited lower frontal and parietal brain activation compared with children of mothers without depression and those whose depression remitted. Depressed mothers reported higher contextual risk (e.g., marital discord and stress) and their children had more behavior problems. Children's frontal brain activation and contextual risk level mediated the relation between maternal depression and child behavior problems.  相似文献   

Learning how to implement and manage SME marketing networks: a qualitative analysis     

Lara Agostini 《知识管理研究与实践》2016,14(2):225-235

The theme of SME marketing networks acquires high relevance because of their positive influence over internationalization and market competitiveness. Within this stream of research, how partners learn to implement and manage collaborations has received little attention. This article aims to bridge this gap, first, by analysing the mechanisms partners use throughout their learning process, and, second, by investigating whether this learning process may have an association with the network ability to explore new market opportunities, which is the ultimate objective of SMEs willing to overcome the liability of smallness. The results of this article unveils the different structures, processes and tools, which are used to create new knowledge on how to implement and manage SME marketing networks; furthermore, it suggests that an effective learning process may have a positive association with the exploration of new market opportunities through networks.  相似文献   

Childhood trauma and suicide risk in a sample of young individuals aged 14–35 years in southern Brazil     

Luana Porto Barbosa  Luciana Quevedo  Giovanna Del Grande da Silva  Karen Jansen  Ricardo Tavares Pinheiro  Jerônimo Branco  Diogo Lara  Jean Oses  Ricardo Azevedo da Silva 《Child abuse & neglect》2014

Suicide is among the main causes of death of people aged between 15 and 44 years old. Childhood trauma is an important risk factor for suicide. Hence, the objective of this study was to verify the relationship between childhood trauma and current suicide risk (suicidal behavior and ideation) in individuals aged 14–35 years, in the city of Pelotas, Brazil. This is a cross-sectional, population-based study. Sample selection was performed by clusters. Suicide risk was evaluated using the Mini International Neuropsychiatric Interview (MINI) and Childhood trauma was assessed with the Childhood Trauma Questionnaire (CTQ). Moreover, the participants responded to a questionnaire concerning socioeconomic status, work, and substance use. The sample was composed of 1,380 individuals. The prevalence of suicide risk was 11.5%. The prevalence figures of childhood trauma were 15.2% (emotional neglect), 13.5% (physical neglect), 7.6% (sexual abuse), 10.1% (physical abuse), and 13.8% (emotional abuse). Suicide risk was associated (p < .001) with gender, work, alcohol abuse, tobacco use, and all types of childhood trauma. The odds of suicide risk were higher in women (OR = 1.8), people who were not currently working (OR = 2.3), individuals who presented alcohol abuse (OR = 2.6), and among tobacco smokers (OR = 3.4). Moreover, suicide risk was increased in all types of trauma: emotional neglect (OR = 3.7), physical neglect (OR = 2.8), sexual abuse (OR = 3.4), physical abuse (OR = 3.1), and emotional abuse (OR = 6.6). Thus, preventing early trauma may reduce suicide risk in young individuals.  相似文献   

Targeting Parenting in Early Childhood: A Public Health Approach to Improve Outcomes for Children Living in Poverty          下载免费PDF全文

Amanda Sheffield Morris  Lara R. Robinson  Jennifer Hays‐Grudo  Angelika H. Claussen  Sophie A. Hartwig  Amy E. Treat 《Child development》2017,88(2):388-397

In this article, the authors posit that programs promoting nurturing parent–child relationships influence outcomes of parents and young children living in poverty through two primary mechanisms: (a) strengthening parents' social support and (b) increasing positive parent–child interactions. The authors discuss evidence for these mechanisms as catalysts for change and provide examples from selected parenting programs that support the influence of nurturing relationships on child and parenting outcomes. The article focuses on prevention programs targeted at children and families living in poverty and closes with a discussion of the potential for widespread implementation and scalability for public health impact.  相似文献   

Effortful Control,Behavior Problems,and Peer Relations: What Predicts Academic Adjustment in Kindergartners from Low-Income Families?     

Amanda Sheffield Morris  Aesha John  Amy L. Halliburton  Michael D. S. Morris  Lara R. Robinson  Sonya S. Myers 《Early education and development》2013,24(6):813-828

This study used a short-term longitudinal design to examine the role of effortful control, behavior problems, and peer relations in the academic adjustment of 74 kindergarten children from primarily low-income families. Teachers completed standardized measures of children's effortful control, internalizing and externalizing problems, school readiness, and academic skills. Children participated in a sociometric interview to assess peer relations. Research Findings: Correlational analyses indicate that children's effortful control, behavior problems in school, and peer relations are associated with academic adjustment variables at the end of the school year, including school readiness, reading skills, and math skills. Results of regression analyses indicate that household income and children's effortful control primarily account for variation in children's academic adjustment. The associations between children's effortful control and academic adjustment do not vary across the sex of the child or ethnicity. Mediational analyses indicate an indirect effect of effortful control on school readiness through children's internalizing problems. Practice or Policy: Effortful control emerged as a strong predictor of academic adjustment among kindergarten children from low-income families. Strategies for enhancing effortful control and school readiness among low-income children are discussed.  相似文献   

“Hidden Treasures”: Librarian Office Hours for Three Health Sciences Schools     

Lara Handler  Mellanye Lackey  K. T. L. Vaughan 《Medical reference services quarterly》2013,32(4):336-350

The changing needs of students and faculty have prompted UNC Chapel Hill's Health Sciences Library to reconsider the delivery of library services. Several years of outreach and office hours have yielded an array of “hidden treasures,” or secondary outcomes, of both online and in-person office hours. The online office hours are tailored for the Schools of Medicine, Pharmacy, and Public Health. This article examines the benefits that go beyond simple consultation statistics and encompass more qualitative aspects of success resulting from increased outreach, goodwill, and stronger library-departmental partnerships.  相似文献   

Blogging in Support of Health Information Outreach     

Lara Sapp  Keith Cogdill 《Medical reference services quarterly》2013,32(3):240-248

Social media technologies are transforming the way librarians are collaborating, creating, and disseminating information. This article discusses how librarians at the University of Texas Health Science Center at San Antonio created a blog to support their health information outreach activities. Launched in 2007, the Staying Well Connected blog was established with the goal of promoting access to biomedical and health information for consumers and health professionals in the South Texas region. Postings highlight relevant health news, conferences, funding opportunities, and outreach events.  相似文献   

Circular formation control for cooperative target tracking with limited information     

Lara Briñón-Arranz  Alexandre Seuret  António Pascoal 《Journal of The Franklin Institute》2019,356(4):1771-1788

This paper addresses the problem of encircling and tracking a moving target with a fleet of unicycle-like vehicles. A new control law is developed to steer the vehicles to an evenly spaced formation along a circumference, the center of which tracks the motion of the target. The strategy proposed relies only on the relative positions of the agents with respect to the target, expressed in the local frame of each vehicle. The absolute position, velocity and acceleration of the target are unknown. Additionally, the robustness of the proposed control law in the presence of external disturbances is analyzed. Communication among agents is used to maintain the vehicles equally spaced in the circular formation. Simulation results illustrate the effectiveness of the proposed strategies.  相似文献