The effect of plyometric training on handspring vault performance in adolescent female gymnasts

Purpose: Despite the huge amount of force exerted by both the upper and lower extremity musculature in gymnastic vaulting, there is scant research investigating the benefits that plyometric training can induce. The handspring vault is of paramount importance for a gymnast’s vaulting development, and requires both technical skill and power production to achieve success. The aim of this study was to determine the effects that plyometric training can have when added to habitual training on handspring vault performance variables in female adolescent gymnasts. Methods: Twenty female competitive gymnasts (mean ± SD: age 12.5 ± 1.7 years; stature 1.46 ± 0.11 m; mass 40.5kg ± 9.7 kg) volunteered to partake in this study. Participants were randomly assigned to two independent groups. The experimental plyometric training group (PT) pursued a six-week plyometric program, consisting of two additional 45 minute sessions a week, alongside their habitual training. The control group (CG) continued their regular habitual training only. Videography was used (120 Hz) in the sagittal plane, both pre and post training intervention, to assess key performance indicators attributed to the technical performance and competence required to execute a successful handspring vault. In addition, participants completed a countermovement vertical jump (CMJ) as an assessment of lower body power. Results: Significant improvements (P < 0.05) were found for the PT in comparison to CG for run-up velocity, take-off velocity, distance from take-off to springboard, duration of foot contact on board, duration of hand contact on vault, duration of post flight and CMJ height. However, no significant differences were found between groups for first flight time, shoulder angle or hip angle on the vault. Furthermore, the CG demonstrated no significant improvement for handspring vault measures or CMJ height. Conclusions: The results demonstrated that the implementation of plyometric training led to improvements of several key variables which are associated to successful handspring vault performance. It can be suggested that implementing plyometric training can improve handspring vault performance in adolescents, appropriately preparing gymnasts for the development and progression of vaulting in the future

Exposing the Roots of Low Self-Efficacy for Math: A Multi-Case Study of Students in an Urban Middle School

This multi-case study of historically low-performing 7th grade students in a math class at an urban middle school employed a theoretical framework based upon Bandura’s Social Cognitive Theory to discover the causes of low self-efficacy for math. The study utilized a cross-case analysis of four students who demonstrated varying degrees of self-efficacy. To serve students similarly situated, Christian teachers need to know what these students are experiencing and an understanding of the causes of low self-efficacy can inform their professional practice. Christian teacher educators can also benefit from understanding the context into which teachers of such students will serve so as to aptly prepare them for effective practice

Trust with Private and Common Property: Effects of Stronger Property Right Entitlements

Is mutually beneficial cooperation in trust games more prevalent with private property or common property? Does the strength of property right entitlement affect the answer? Cox, Ostrom, Walker, et al. [1] report little difference between cooperation in private and common property trust games. We assign stronger property right entitlements by requiring subjects to meet a performance quota in a real effort task to earn their endowments. We find that cooperation is lower in common property trust games than in private property trust games, which is an idiosyncratic prediction of revealed altruism theory [2].

Regulation of AQP0 water permeability is enhanced by cooperativity.

Aquaporin 0 (AQP0), essential for lens clarity, is a tetrameric protein composed of four identical monomers, each of which has its own water pore. The water permeability of AQP0 expressed in Xenopus laevis oocytes can be approximately doubled by changes in calcium concentration or pH. Although each monomer pore functions as a water channel, under certain conditions the pores act cooperatively. In other words, the tetramer is the functional unit. In this paper, we show that changes in external pH and calcium can induce an increase in water permeability that exhibits either a positive cooperativity switch-like increase in water permeability or an increase in water permeability in which each monomer acts independently and additively. Because the concentrations of calcium and hydrogen ions increase toward the center of the lens, a concentration signal could trigger a regulatory change in AQP0 water permeability. It thus seems plausible that the cooperative modes of water permeability regulation by AQP0 tetramers mediated by decreased pH and elevated calcium are the physiologically important ones in the living lens

Resistance, reluctance, and revelation: examining faculty perceptions of online learning options at a faith-based university

Despite the growth of online education and its seemingly fixed place in higher education, online education is still opposed, or at least viewed with suspicion by many faculty (Allen & Seaman, 2013). Faculty opposition of online education can be expressed in myriad ways, most prominently through shared governance, which can directly limit or completely block online education from occurring at an institution. This case study revolved around a non-profit, Faith-Based university (FBU) that is a newcomer to the inclusion of online coursework. This study sought to investigate the rationale faculty may have towards their support or opposition to online education by using mixed methods to bring to light the beliefs faculty have about online education. In examining the beliefs faculty at FBU have towards online education, this study also prompted faculty to reflect on whether their beliefs about online education have changed since the inclusion of online coursework at FBU, and if so, what factors may have contributed to the evolving beliefs. Data collected from 54 survey respondents and 12 faculty interviews helped to capture these beliefs. The findings showed that faculty, on average, felt that the impact of online education on the quality of educational experience would be slightly diminished at the undergraduate level but slightly enhanced at the graduate level. Faculty who indicated evolving beliefs or opinions about online education cited various catalysts. These catalysts fell into 3 categories: external factors- related to economic viability, changes in the higher education environment, and access; information and opinions gather from trusted sources- which would include literature, colleagues, and professional organizations; and personal experience- which stemmed from a direct personal involvement in teaching and/or learning experiences within the online environment. Findings were examined through the theoretical framework of Rokeach\u27s (1989) model of belief systems. This model may suggest that beliefs about teaching and learning are closely connected to one\u27s identity and are thus highly resistant to change. Accepting and implementing new or different methods of teaching and learning, such as the teaching and learning occurring in online education, might require a major reorganization of beliefs about oneself

Maybe the Real Prize Was the Connections They Built Along the Way: A Legal Analysis of the Role of Privateering in the Creation of the Trans-Imperial Greater Caribbean

While study of the eighteenth-century Caribbean has traditionally focused on the stark separation between the European empires of the region, this thesis seeks to reveal privateering’s role as an important force in creating what has come to be referred to as the trans-imperial or trans-national Caribbean. This will be based in an analysis of the legal structure of British privateering as a means of both drawing attention to the practice’s intrinsically legalistic nature as well as highlighting the fact that this regional creation was a result of colonists working within imperial guidelines as much as it was an act of implicit rebellion. This is to say that the connective nature of prize taking arose both from aspects of the legal structure that defined it as well as the unlawful (but widely accepted) activities that it facilitated, most notably contraband trade. In addition to better connecting denizens of the region separated by imperial boundaries, privateering also played a major role in separating the region from direct imperial rule. This can be seen most clearly in the heavy use of letters of marque by newly independent states in the region during the early-to-mid nineteenth-century. This thesis seeks to synthesize research done on privateering’s impact as a military, political, and commercial tool to present its importance in defining the social fabric of the region during the 18th and early 19th centuries

The Characterization of Hematopoiesis in Murine Fetal Bone Marrow

Hematopoietic stem cells (HSCs) and their downstream progenitors are a heterogeneous population of cells that are indispensable for lifelong hematopoiesis and are often utilized in the clinic for the treatment of hematologic maladies via hematopoietic stem cell transplantation (HSCT). Over several decades, it has been discovered that HSCs arise in the dorsal aorta of the developing embryo, migrate to the fetal liver (FL), and undergo a large expansion before reaching their final resting place in the bone marrow (BM). Many resources have been invested in understanding the roles of the different niches HSCs encounter along their journey. A greater understanding of HSC niche regulation could provide clues for HSC maintenance and expansion in vitro. One critical niche during HSC ontogeny that has been greatly overlooked is the fetal BM (FBM), of which the hematopoietic and HSC niche compartments are poorly understood. For this reason, we meticulously characterized the hematopoietic progenitor compartment of the whole skeleton FBM from its colonization until after birth via competitive transplantation, immunophenotypic analysis of the hematopoietic stem and progenitor cell (HSPC) compartment, functional assessment of specific progenitor populations, and single-cell RNA-sequencing (scRNA-Seq) of the hematopoietic and stromal FBM environment. Here, we provide the first report of the presence of bona fide HSCs within the E15.5 FBM. We also found that HSCs were present in the all sources of BM, including the forelimbs, hindlimbs, and trunk of E15.5 embryos. We are also the first to assess the BM immunophenotypic HSPC compartment from initial seeding to adulthood and found that specific multipotent progenitor (MPP) cells (MPP2s) are the predominant HSPC population in the FBM, appearing to have the ability to migrate to and seed the FBM directly from the FL. Interestingly, immunophenotypic MPP2s are not functional in vitro or in vivo until birth (E18.5-P0), and display reduced repopulating capacity compared to adult BM and time-matched FL MPP2s. Also, the frequencies of the different FBM HSPCs shift around birth from an MPP2-dominant phenotype to the MPP3/MPP4-dominant phenotype seen in adult BM. To identify the intrinsic and extrinsic mechanisms controlling MPP2 functional maturation, we isolated stromal and hematopoietic progenitor (HP) populations from E16.5, E18.5, P0, and adult BM, and constructed the first known scRNA-Seq dataset spanning the HP and stromal compartment across BM ontogeny. Preliminary analysis of our scRNA-Seq datasets show that the FBM stroma and HP compartments are compositionally distinct from the adult BM compartments, and this disparity in composition is even more drastic at E16.5, suggesting that the reduced function of FBM MPP2s may be due to a semi-incompatible FBM niche. Our future studies will focus on identifying intrinsic differences between immunophenotypic HSPC populations across FBM ontogeny in our HP scRNA-Seq dataset, as well as defining putative niches for HSPCs in the FBM. We hope that these analyses will identify novel hematopoietic factors in the FBM niche that can be therapeutically exploited to enhance HSC expansion/function/differentiation in the clinic