The Biomechanics of Spear Throwing: An Analysis of the Effects of Anatomical Variation on Throwing Performance, with Implications for the Fossil Record

Accurate, high velocity throwing is a skill unique to humans among living species. It likely provided an adaptive advantage for our hominin ancestors, either in the context of hunting, or protection from predators. Thus, understanding how variation in body form and anatomy influences throwing ability may provide insight into the evolution of human morphology. Research has been done on various forms of ball and javelin throwing, yet the biomechanics of spear throwing were completely unknown. Moreover, it has been suggested that early modern humans had lesser effective mechanical advantage: EMA, the ratio of moment arm to load arm) than Neandertals, as a result of selection for throwing, as this could provide increased joint angular velocity at the cost of strength. However the biomechanical principles underpinning this assertion had not been tested empirically. Thus, the purpose of this dissertation is to establish the patterns of kinetics and kinematics used during spear throwing, to examine the morphological correlates of throwing performance and strength in living humans, and to consider the implications of the patterns observed for Paleolithic fossil hominins. Throwing performance, measured as the energy imparted to a thrown object: kinetic energy, Ke), was assessed in 41 experienced throwers throwing balls and spear-like objects. Joint linear and angular velocities, torques, and kinetic energies were calculated using high-speed infrared cameras. Subject anthropometrics, including body mass, height, and segment lengths, were measured externally, and arm muscle cross-sectional areas and EMA of the elbow and wrist were measured from magnetic resonance images. The maximum isometric strength of the elbow and wrist were measured using a load cell. Additionally, EMA of the elbow and wrist were estimated skeletally for available early Homo, Neandertal, Middle Paleolithic, Upper Paleolithic, and recent human specimens. It was demonstrated that the shoulder experiences very low angular velocities and torques, and the elbow is relatively less mobile during spear as compared with ball throwing. Thus, the literature on the arm in ball throwing will be of less relevance to the evolution of throwing. Furthermore, there is no direct correlation between spear Ke and any morphological or anatomical variable of the arm: including EMA). Instead, spear Ke is primarily produced by the legs and torso, where musculature, leg length, and shoulder breadth are correlated with greater Ke. This implies that research on throwing should focus on the legs and torso, and variation in the morphology of the arm should not be used to infer differential selection for throwing in Paleolithic hominins. No correlation was found between the EMA of the elbow or wrist and joint strength independent of muscle cross-sectional area. This is likely due to variation in muscle recruitment and activation, and because r is correlated with muscle size independent of body size. Furthemore, it was demonstrated that EMA cannot be measured reliably in the fossil record, as load arms are highly variable within and between individuals, even performing a highly trained activity like throwing. Consequently, they cannot be predicted from skeletal dimensions available in the fossil record. Furthermore, although there is a trend towards greater EMA of the elbow in Neandertals as compared with other fossil hominin samples, this variation is not functionally or adaptively relevant. No significant differences exist for moment arms between groups; rather, the difference in EMA is due to variation in load arms: ulna length). However, load arms measured skeletally are not relevant to living behaviors, and variation in load arms between these groups is due to known differences in brachial indices, which reflect climatic adaptations. Thus, EMA of the arm is not a useful measure of performance in Paleolithic fossil hominins

Rural Primary Care and the Diagnostic Resolution of Abnormal Screening Mammograms: A Mixed Methods Study in Rural Missouri

Rural health clinics (RHCs) and federally qualified health centers (FQHCs) play a vital role in initiating cancer screening in underserved, rural settings. Yet there is limited information about their involvement in diagnostic tests when a mammogram result is abnormal. Diagnostic resolution of abnormal mammograms varies widely by geographic location and resources, and timely resolution is important for addressing rural-urban cancer disparities. This mixed methods study in a rural region of Missouri with high rates of cancer mortality examined the roles of primary care providers during follow-up after an abnormal mammogram, the processes they used, and the clinic specific variations among these roles and processes. Our data show substantial involvement of primary care during follow-up, with differences in resources and formalized and informal strategies between FQHCs and RHCs. Elucidating roles and processes is a necessary step before evidence based strategies, often developed in urban settings, can be adapted for rural settings

Retiring on the House? Cross-Cohort Differences in Housing Wealth

This chapter evaluates the role of housing wealth in Baby Boomers’ retirement prospects, to determine what role housing wealth will play in their retirement wellbeing. Our approach compares the wealth position of the leading edge of the Boomers with that of the generation immediately preceding it, in the years just prior to retirement. We rely on the Health and Retirement Survey (HRS) and compare persons age 51-61 in 1992, whom we refer to as the original HRS cohort, with the Early Baby Boomers interviewed at age 51-56 interviewed in 2004. We find that Boomers do have more valuable homes, but they have also borrowed more against them, so they have a similar fraction of assets allocated to home equity as their predecessors. Unlike prior studies, we find that people do view housing as a source of wealth that can help them finance their retirement needs. Indeed, a substantial fraction of older households do move, and in the process, they appear to liquidate some home equity which they convert to financial assets. Consequently, some of the home equity extraction observed in recent years may be related to the aging of the population, rather than a cyclical response to rapid house appreciation

Using segmented regression analysis of interrupted time series data to assess colonoscopy quality outcomes of a web-enhanced implementation toolkit to support evidence-based practices for bowel preparation: A study protocol

BACKGROUND: While there is convincing evidence on interventions to improve bowel preparation for patients, the evidence on how to implement these evidence-based practices (EBPs) in outpatient colonoscopy settings is less certain. The Strategies to Improve Colonoscopy (STIC) study compares the effect of two implementation strategies, physician education alone versus physician education plus an implementation toolkit for staff, on adoption of three EBPs (split-dosing of bowel preparation, low-literacy education, teach-back) to improve pre-procedure and intra-procedure quality measures. The implementation toolkit contains a staff education module, website containing tools to support staff in delivering EBPs, tailored patient education materials, and brief consultation with staff to determine how the EBPs can be integrated into the existing workflow. Given adaptations to the implementation plan and intentional flexibility in the delivery of the EBPs, we utilize a pragmatic study to balance external validity with demonstrating effectiveness of the implementation strategies. METHODS/DESIGN: Participants will include all outpatient colonoscopy physicians, staff, and patients from a convenience sample of six endoscopy settings. Aim #1 will explore the relative effect of two strategies to implement patient-level EBPs on adoption and clinical quality outcomes. We will assess the change in level and trends of clinical quality outcomes (i.e., adequacy of bowel preparation, adenoma detection) using segmented regression analysis of interrupted time series data with two groups (intervention and delayed start). Aim #2 will examine the influence of organizational readiness to change on EBP implementation. We use a PRECIS diagram to reflect the extent to which each indicator of the study was pragmatic versus explanatory, revealing a largely pragmatic study. DISCUSSION: Implementation challenges have already motivated several adaptations to the original plan, reflecting the nature of implementation in real-world healthcare settings. The pragmatic study responds to the evolving needs of its healthcare partners and allows for flexibility in intervention delivery, thereby informing clinical decision-making in real-world settings. The current study will provide information about what works (intervention effectiveness), for whom it works (influence of Medicaid versus other insurance), in which contexts it works (setting characteristics that influence implementation), and how it works best (comparison of implementation strategies). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13012-015-0276-3) contains supplementary material, which is available to authorized users

Technology-delivered adaptations of motivational interviewing for the prevention and management of chronic diseases: Scoping review

BACKGROUND: Motivational interviewing (MI) can increase health-promoting behaviors and decrease health-damaging behaviors. However, MI is often resource intensive, precluding its use with people with limited financial or time resources. Mobile health-based versions of MI interventions or technology-delivered adaptations of MI (TAMIs) might increase reach. OBJECTIVE: We aimed to understand the characteristics of existing TAMIs. We were particularly interested in the inclusion of people from marginalized sociodemographic groups, whether the TAMI addressed sociocontextual factors, and how behavioral and health outcomes were reported. METHODS: We employed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for scoping reviews to conduct our scoping review. We searched PubMed, CINAHL, and PsycInfo from January 1, 1996, to April 6, 2022, to identify studies that described interventions incorporating MI into a mobile or electronic health platform. For inclusion, the study was required to (1) describe methods/outcomes of an MI intervention, (2) feature an intervention delivered automatically via a mobile or electronic health platform, and (3) report a behavioral or health outcome. The exclusion criteria were (1) publication in a language other than English and (2) description of only in-person intervention delivery (ie, no TAMI). We charted results using Excel (Microsoft Corp). RESULTS: Thirty-four studies reported the use of TAMIs. Sample sizes ranged from 10 to 2069 participants aged 13 to 70 years. Most studies (n=27) directed interventions toward individuals engaging in behaviors that increased chronic disease risk. Most studies (n=22) oversampled individuals from marginalized sociodemographic groups, but few (n=3) were designed specifically with marginalized groups in mind. TAMIs used text messaging (n=8), web-based intervention (n=22), app + text messaging (n=1), and web-based intervention + text messaging (n=3) as delivery platforms. Of the 34 studies, 30 (88%) were randomized controlled trials reporting behavioral and health-related outcomes, 23 of which reported statistically significant improvements in targeted behaviors with TAMI use. TAMIs improved targeted health behaviors in the remaining 4 studies. Moreover, 11 (32%) studies assessed TAMI feasibility, acceptability, or satisfaction, and all rated TAMIs highly in this regard. Among 20 studies with a disproportionately high number of people from marginalized racial or ethnic groups compared with the general US population, 16 (80%) reported increased engagement in health behaviors or better health outcomes. However, no TAMIs included elements that addressed sociocontextual influences on behavior or health outcomes. CONCLUSIONS: Our findings suggest that TAMIs may improve some health promotion and disease management behaviors. However, few TAMIs were designed specifically for people from marginalized sociodemographic groups, and none included elements to help address sociocontextual challenges. Research is needed to determine how TAMIs affect individual health outcomes and how to incorporate elements that address sociocontextual factors, and to identify the best practices for implementing TAMIs into clinical practice

Consistent use of proactive control and relation with academic achievement in childhood

As children become older, they better maintain task-relevant information in preparation of upcoming cognitive demands. This is referred to as proactive control, which is a key component of cognitive control development. However, it is still uncertain whether children engage in proactive control consistently across different contexts and how proactive control relates to academic abilities. This study used two common tasks—the AX Continuous Performance Task (AX-CPT) and the Cued Task-Switching Paradigm (CTS)—to examine whether proactive control engagement in 102 children (age range: 6.91–10.91 years) converges between the two tasks and predicts academic abilities. Proactive control indices modestly correlated between tasks in higher but not lower working-memory children, suggesting that consistency in proactive control engagement across contexts is relatively low during childhood but increases with working memory capacity. Further, working memory (but not verbal speed) predicted proactive control engagement in both tasks. While proactive control as measured by each task predicted math and reading performance, only proactive control measured by CTS additionally predicted reasoning, suggesting that proactive control can be used as a proxy for academic achievements

Genomic imprinting in mouse blastocysts is predominantly associated with H3K27me3.

In mammalian genomes, differentially methylated regions (DMRs) and histone marks including trimethylation of histone 3 lysine 27 (H3K27me3) at imprinted genes are asymmetrically inherited to control parentally-biased gene expression. However, neither parent-of-origin-specific transcription nor imprints have been comprehensively mapped at the blastocyst stage of preimplantation development. Here, we address this by integrating transcriptomic and epigenomic approaches in mouse preimplantation embryos. We find that seventy-one genes exhibit previously unreported parent-of-origin-specific expression in blastocysts (nBiX: novel blastocyst-imprinted expressed). Uniparental expression of nBiX genes disappears soon after implantation. Micro-whole-genome bisulfite sequencing (µWGBS) of individual uniparental blastocysts detects 859 DMRs. We further find that 16% of nBiX genes are associated with a DMR, whereas most are associated with parentally-biased H3K27me3, suggesting a role for Polycomb-mediated imprinting in blastocysts. nBiX genes are clustered: five clusters contained at least one published imprinted gene, and five clusters exclusively contained nBiX genes. These data suggest that early development undergoes a complex program of stage-specific imprinting involving different tiers of regulation

The effect of metacognitive executive function training on children's executive function, proactive control, and academic skills

The current study investigated the effects of metacognitive and executive function (EF) training on childhood EF (inhibition, working memory [WM], cognitive flexibility, and proactive/reactive control) and academic skills (reading, reasoning, and math) among children from disadvantaged backgrounds. Children (N = 134, Mage = 8.70 years) were assigned randomly to the three training groups: (a) metacognitive training of basic EF processes (meta-EF), (b) training of basic EF processes (basic-EF), and (c) active controls (active control). They underwent 16 training sessions over the course of 2 months. No effects of EF and/or metacognitive training were found for academic outcomes. However, both meta-EF and basic-EF groups demonstrated greater gains than the active control group on proactive control engagement and WM, suggesting that EF training promotes a shift to more mature ways of engaging EF. Our findings suggest minimal near- and far-transfer effects of metacognitive training but highlight that proactive engagement of EF can be promoted through EF training in children

Altering gait by way of stimulation of the plantar surface of the foot: the immediate effect of wearing textured insoles in older fallers

Background: Evidence suggests that textured insoles can alter gait and standing balance by way of enhanced plantar tactile stimulation. However, to date, this has not been explored in older people at risk of falling. This study investigated the immediate effect of wearing textured insoles on gait and double-limb standing balance in older fallers.Methods: Thirty older adults >65 years (21 women, mean [SD] age 79.0 [7.1]), with self-reported history of ≥2 falls in the previous year, conducted tests of level-ground walking over 10 m (GAITRite system), and double-limb standing with eyes open and eyes closed over 30 seconds (Kistler force platform) under two conditions: wearing textured insoles (intervention) and smooth (control) insoles in their usual footwear.Results: Wearing textured insoles caused significantly lower gait velocity (P = 0.02), step length (P = 0.04) and stride length (P = 0.03) compared with wearing smooth insoles. No significant differences were found in any of the balance parameters (P > 0.05).Conclusions: A textured insole worn by older adults with a history of falls significantly lowers gait velocity, step length and stride length, suggesting that this population may not have an immediate benefit from this type of intervention. The effects of prolonged wear remain to be investigated