Relating Baseball Seam Height to Carry Distance

AbstractPast work has shown large variation in the drag of baseballs. Little is known concerning the causes of variation in ball drag. Ball diameter, weight, seam height, surface roughness, and shape influence lift and drag, and therefore carry distance. The aim of this work was to quantify the effect of seam height and roundness on ball lift and drag, which, to our understanding, has never been done outside of a wind tunnel. A bespoke, non-contact, ball surface profiler, was used to measure ball radius, including seam height. The profiles were analyzed to describe ball roundness and seam height separately. Balls with three different seam heights were projected in an enclosed stadium 102-122 m (describing a typical fly ball). Redundant radar devices were used to measure launch angle, speed, and flight paths. High speed video was used to confirm launch angle and ball spin rate. Hit distance was verified with a physical tape measure. The ball's roundness influenced the effective height of a seam. Measurements of the non-seam area of a ball were necessary to characterize the seams of a ball. A strong correlation was observed between seam height and a ball's drag coefficient. Lift, however, was not sensitive to seam height or ball shape

Setting a common standard in clinical skills assessment: The experience of the California Consortium for the Assessment of Clinical Competence

Objective or purpose of innovation: To identify common clinical skills competency thresholds across schools by centralizing standard setting for a multi-institutional assessment. Background and/or theoretical framework and importance to the field: The California Consortium for the Assessment of Clinical Competence (CCACC) comprises 10 medical schools that administer a common multi-station clinical skills assessment (CPX). Previously, each institution determined their own, largely norm-referenced passing thresholds for the examination. With the elimination of USMLE Step 2 CS, there is a recognized need for robust clinical skills assessment beyond the individual institutional level. A collaboratively developed, multi-institutional examination with passing thresholds established via a rigorous process offers greater validity evidence for summative decisions made based on its results. Accordingly, the CCACC undertook centralized, criterion-based standard setting for the CPX. Design: Passing thresholds for the six core CPX cases were determined via two methods: modified Angoff, using expert raters from multiple institutions, and borderline regression, using global encounter ratings assigned by standardized patients. Results from the two methods were compared to each other and to institutions’ prior thresholds. Outcomes: Both methods yielded the same cumulative cut score based on averages across all cases (70%), but exhibited variation between individual cases, suggesting case-specificity. Compared with prior thresholds, some institutions’ pass rates would have been higher using the common criterion-referenced cut score, while others would have been lower. Innovation’s strengths and limitations: This study demonstrates the feasibility of centralizing standard setting across multiple institutions using two criterion-based methods. Standardized patient ratings may generate similar passing thresholds to those determined by clinicians. Further studies are necessary to determine whether these findings generalize to other case types and how best to apply centralized standards within each institution’s context. Feasibility and generalizability: The CCACC’s standard setting approaches may be applied across other institutions sharing an assessment, allowing for comparison of learner performance to a common standard. Given the similar results, the choice of method may be determined by resource availability

Expressions 1985

PRODUCTION STAFFLOUISE AUSTINDANA Z. BEHRENDSENAMBER HEWITTTOSHIA SOUTHRANDY STANDLEYSHELLY WILSONhttps://openspace.dmacc.edu/expressions/1006/thumbnail.jp

Unagreement is an illusion

This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s11049-015-9311-yThis paper proposes an analysis of unagreement, a phenomenon involving an apparent mismatch between a definite third person plural subject and first or second person plural subject agreement observed in various null subject languages (e.g. Spanish, Modern Greek and Bulgarian), but notoriously absent in others (e.g. Italian, European Portuguese). A cross-linguistic correlation between unagreement and the structure of adnominal pronoun constructions suggests that the availability of unagreement depends on whether person and definiteness are hosted by separate heads (in languages like Greek) or bundled on a single head (i.e. pronominal determiners in languages like Italian). Null spell-out of the head hosting person features high in the extended nominal projection of the subject leads to unagreement. The lack of unagreement in languages with pronominal determiners results from the interaction of their syntactic structure with the properties of the vocabulary items realising the head encoding both person and definiteness. The analysis provides a principled explanation for the cross-linguistic distribution of unagreement and suggests a unified framework for deriving unagreement, adnominal pronoun constructions, personal pronouns and pro

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

ScienceDirect Relating baseball seam height to carry distance

Abstract Past work has shown large variation in the drag of baseballs. Little is known concerning the causes of variation in ball drag. Ball diameter, weight, seam height, surface roughness, and shape influence lift and drag, and therefore carry distance. The aim of this work was to quantify the effect of seam height and roundness on ball lift and drag, which, to our understanding, has never been done outside of a wind tunnel. A bespoke, non-contact, ball surface profiler, was used to measure ball radius, including seam height. The profiles were analyzed to describe ball roundness and seam height separately. Balls with three different seam heights were projected in an enclosed stadium 102-122 m (describing a typical fly ball). Redundant radar devices were used to measure launch angle, speed, and flight paths. High speed video was used to confirm launch angle and ball spin rate. Hit distance was verified with a physical tape measure. The ball's roundness influenced the effective height of a seam. Measurements of the nonseam area of a ball were necessary to characterize the seams of a ball. A strong correlation was observed between seam height and a ball's drag coefficient. Lift, however, was not sensitive to seam height or ball shape

DESIGNING CAPITAL STRUCTURE TO CREATE SHAREHOLDER VALUE

In the past decade, many U.S. companies have launched aggressive share repurchase programs with the expectation that value can be created by returning excess capital to shareholders and moving the firm closer to its optimal capital structure. But how much capital does a company really need to support its business activities? 1997 Morgan Stanley.