Anisotropic evolution of D-dimensional FRW spacetime

We examine the time evolution of the D=d+4 dimensional Einstein field equations subjected to a flat Robertson-Walker metric where the 3D and higher-dimensional scale factors are allowed to evolve at different rates. We find the exact solution to these equations for a single fluid component, which yields two limiting regimes offering the 3D scale factor as a function of the time. The fluid regime solution closely mimics that described by 4D FRW cosmology, offering a late-time behavior for the 3D scale factor after becoming valid in the early universe, and can give rise to a late-time accelerated expansion driven by vacuum energy. This is shown to be preceded by an earlier volume regime solution, which offers a very early-time epoch of accelerated expansion for a radiation-dominated universe for d=1. The time scales describing these phenomena, including the transition from volume to fluid regime, are shown to fall within a small fraction of the first second when the fundamental constants of the theory are aligned with the Planck time. This model potentially offers a higher-dimensional alternative to scalar-field inflationary theory and a consistent cosmological theory, yielding a unified description of early- and late-time accelerated expansions via a 5D spacetime scenario.Comment: Title changed from "A possible higher-dimensional alternative to scalar-field inflationary theory". Several new results have been added including a predicted lower- and upper-bound on the time scales marking the end of an early-time inflationary epoch and the beginning of an FRW epoch for d=

Curricular Influence on Professional Formation in Physical Therapy Students

Professionalism is needed from each healthcare professional to meet the needs of patients, society, and the expectation that the profession has for its members. Professionalism comprises many attributes and is developed explicitly and implicitly over time through a variety of influential factors. Professional formation education should be an intentional emphasis in any professional program. However, in the academic preparation of healthcare professionals, including physical therapists, a lack of consistency exists in professionalism curricula. It does not appear there are published studies that have specifically compared the effect of curricular approaches in physical therapy education on students’ professional formation. The purpose of this quantitative causal-comparative study was to explore the influence of curricular design on professional formation, including ethical or moral reasoning and civic-mindedness in physical therapy students from two university-based institutions that utilize different curricular approaches. The researcher invited students from the graduating and incoming cohorts at each institution to complete the two online instruments used in this study. The Defining Issues Test (DIT-2) was used to assess moral reasoning. The Civic-Minded Professional (CMP) scale was used to assess the service/civic construct of professional formation in physical therapy students. Nearly half of the students from the four cohorts completed the surveys. The researcher analyzed the data using descriptive statistics and differences between groups (independent t tests, two-way ANOVA). The results did not show a statistically significant difference between the graduating cohorts in moral reasoning scores and civic-mindedness. However, gender demonstrated a significant main effect between the graduating cohorts. Additionally, gender showed significance between the graduating and incoming cohorts. A programmatic cultural investigation revealed a strong service culture within each physical therapy program. The results indicated that the curricular type may not be a significant factor in the differences of professional formation found among physical therapists and, potentially, academic programs for health professions. However, male participants were found to have significantly less moral reasoning and civic-mindedness than female participants, indicating a potential need to engage male students differently in the educational process of moral issues and civic opportunities

Magnetic anisotropy in the Trenton Limestone: Results of a new technique, anisotropy of anhysteretic susceptibility

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95332/1/grl2909.pd

A Statistical Method for Estimating Luminosity Functions using Truncated Data

The observational limitations of astronomical surveys lead to significant statistical inference challenges. One such challenge is the estimation of luminosity functions given redshift $z$ and absolute magnitude $M$ measurements from an irregularly truncated sample of objects. This is a bivariate density estimation problem; we develop here a statistically rigorous method which (1) does not assume a strict parametric form for the bivariate density; (2) does not assume independence between redshift and absolute magnitude (and hence allows evolution of the luminosity function with redshift); (3) does not require dividing the data into arbitrary bins; and (4) naturally incorporates a varying selection function. We accomplish this by decomposing the bivariate density into nonparametric and parametric portions. There is a simple way of estimating the integrated mean squared error of the estimator; smoothing parameters are selected to minimize this quantity. Results are presented from the analysis of a sample of quasars.Comment: 30 pages, 9 figures, Accepted for publication in Ap

Cost Effective, Flexible Ground Architecture Using Software Defined Radio and GNU Radio

GNU Radio is a free software library that provides the software tools to implement software defined radios. Using GNU Radio and commercially available software defined radios the team at The Naval Research Laboratory (NRL) implemented a cost effective, flexible ground station. In November 2017 NRL launched the CHEFSat CubeSat aboard the OA-8 ISS resupply mission. Since the deployment of CHEFSat in December 2017 this ground architecture has supported all satellite operations without the need of traditional ground equipment. The CHEFSat mission required multiple downlink bitrates (50-400 kbps) as well as the option for forward error correction. This paper will go over the design and test processes used to go from concept to operations using GNU Radio. The merits and risks of using GNU Radio will be discussed as well

Lower Extremity Proprioception and Physical Performance Testing: A Correlation Study

Proprioception is a function of the somatosensory system which has implications for activities of daily living, athletic endeavors, and risk of injury. It has been suggested that athletes who sustain injuries may have decreased proprioception and a corresponding increase in the risk of re-injury. Interventions for injury prevention and/or recovery may include, but are not limited to, emphasis on proprioceptive ability via joint position awareness. The purpose of this investigation was to determine if a correlation exists between proprioceptive ability and other components of physical performance such as lower body muscular power and change of direction. It was hypothesized that significant correlations would exist. Participants included 7 males and 2 females (age 15 ± 2 yrs., height 1.51 ± .15 m, mass 68.2 ± 17.14 kg) who did not have a lower extremity injury or surgery within 6 months of this investigation. Proprioceptive testing included the Stork Standing test (SST) and ankle Joint Position Sense (JPS). Lower extremity proprioceptive testing was performed unilaterally in both eyes closed and open conditions. Lower body muscular power and change of direction were assessed via the vertical jump (VJ), one step vertical jump (1VJ), standing long jump (SLJ), 9.14 m (10-yard) dash, and pro agility (PA). Associations were determined via a Pearson Product Moment Correlation and the criterion alpha was set a priori at p ≤ 0.05. Significant correlations were observed between SST with eyes closed on the non-dominant leg and both VJ (r = -0.82) and 1VJ (r =-0.82). In addition, a significant correlation was observed between SST with eyes closed on the dominant leg and the 9.14 m dash (r = -0.90). The results of our investigation suggest a link between proprioception and lower body muscular power. Additional investigations should examine the causal relationships between these variables to attempt to determine the efficacy of interventions designed to improve one or more of the aforementioned characteristics as well as any potential influence on injury risk

Orion Rendezvous, Proximity Operations, and Docking Design and Analysis

The Orion vehicle will be required to perform rendezvous, proximity operations, and docking with the International Space Station (ISS) and the Earth Departure Stage (EDS)/Lunar Landing Vehicle (LLV) stack in Low Earth Orbit (LEO) as well as with the Lunar Landing Vehicle in Low Lunar Orbit (LLO). The RPOD system, which consists of sensors, actuators, and software is being designed to be flexible and robust enough to perform RPOD with different vehicles in different environments. This paper will describe the design and the analysis which has been performed to date to allow the vehicle to perform its mission. Since the RPOD design touches on many areas such as sensors selection and placement, trajectory design, navigation performance, and effector performance, it is inherently a systems design problem. This paper will address each of these issues in order to demonstrate how the Orion RPOD has been designed to accommodate and meet all the requirements levied on the system

Grip Strength Symmetries in Division I College Baseball Pitchers and Hitters

Integrating strength and conditioning coaches and programs for baseball athletes has yielded positive performance outcomes for both hitting and throwing. Among a variety of baseball-specific testing batter, grip strength has shown to significantly correlate with increased swing and throwing velocity. However, no investigations have examined grip strength asymmetries for hitters and pitchers. PURPOSE: The purpose of this study was to examine differences between right and left arm grip strength of baseball pitchers and hitters. METHODS: Division I collegiate baseball players (n = 45, height. (183.52 ± 11.77 cm) weight. (85.96 ± 17.73 kg.) performed dominate and non-dominate maximal grip strength at position specific arm and forearm orientation utilizing the Jamar Hydraulic Hand Dynamometer. Hitters (n = 22) performed grip strength assessments at 90-degree elbow flexion, neutral forearm orientation (NDN). Pitchers (n = 23) performed grip strength assessments at 90-degree elbow flexion, pronated forearm orientation (NDP). Three attempts were permitted to exert maximal force, recorded in kilograms (kg) – highest exerted force was recorded and used for analysis. An independent samples t-test (p \u3c .05) was employed to assess dominate and non-dominate grip strength differences. RESULT: The results indicated no significant differences between pitchers’ dominate NDP (57.39 ± 7.49 kg) and non-dominate NDP (56.0 ± 7.63 kg), t(44) = .624, p = .966. Likewise, hitters presented no significant difference between dominate NDN (60.68 ± 10.15 kg) and non-dominate NDN (55.27 ± 11.31 kg) t(42) = 1.669, p = .264. CONCLUSION: Contrary to common belief, these results suggest baseball players do not present significant grip strength asymmetries. While baseball skills (i.e., throwing, hitting) require adequate grip strength to produce favorable performances outcomes, these single arm/hand movements do not place baseball players in a concerning asymmetrical grip strength state. Utilization of both hands during hitting provides reasonable explanations for the results of hitters. For pitchers, glove movement and skill, along with typical strength and conditioning may contribute to improvements in non-dominate grip strength. Furthermore, these results suggest equivalent bilateral strength may be a necessity of collegiate baseball players

Correlation Between Grip Strength at Various Arm Orientations and Hitting Performance Metrics of Division I Collegiate Baseball Players

Dominate and non-dominate grip strength (GS) significantly correlated with bat speed (BS) in the sport of baseball. Various arm orientations occur throughout the swing; moreover, additional metrics beyond BS are indicative of baseball hitting performance. The correlation between various GS and hitting outcomes have not been empirically examined. PURPOSE: The aim of the current investigation was to examine the relationship of GS at various arm angles to various hitting performance metrics. METHODS: Division I collegiate baseball players (n = 17; height: 180.92 ± 5.61 cm; weight: 82.1 ± 11.12 kg) performed dominate and non-dominate maximal GS at five different arm and forearm orientations utilizing the Jamar Hydraulic Hand Dynamometer: 90-degree elbow flexion with (1) neutral (NDN), (2) supinated (NDS), and (3) pronated (NDP) forearm placement, as well as 120-degree elbow extension with 90-degree shoulder abduction with (4) supinated (AS) and (5) neutral (AN) forearm grips. At each angle, three attempts were permitted to exert maximal force, recorded in kg. Hitting metrics were gathered via Blast Motion Bat Sensors and Yakkertek Ball-Tracking System - metrics included: BS, peak hand speed (PHS), vertical bat angle (VBA), time to contact (TTC), attack angle (AA), power (PW), on plane efficiency (OPE), plane score (PS), rotational acceleration (RA), early connection (EC), connection at impact (CAI), as well as average exit-velocity (AEV), peak exit-velocity (PEV), hard hit percentage (HHP), damage percentage (DP), and average launch angle (ALA). A Pearson product-moment correlation coefficient (p \u3c .05) was employed to assess the relationship between GS and hitting performance. RESULT: Positive significant correlations were recognized between the following variables: dominate NDN and HHP (r = .559, p = .02), DP (r = .647, p = .007), and BS (r = .515, p = .034); non-dominate NDP and HHP (r = .497, p = .042), DP (r = .664, p = .005), and TTC (r = .519, p = .033); and non-dominate NDS and DP (r = .770, p \u3c .001), PS (r = .515, p = .035), OPE (r = .510, p = .036). A negative significant relationship was identified between non-dominate NDS and EC (r = -.629, p = -.007), and CAI (r = -.587, p = -.013). CONCLUSION: Supporting previous investigations, these results suggest dominate NDN, non-dominate NDP, and non-dominate NDS yielded the greatest influence on hitting performance among the tested GS positions; thus, potentially providing coaches with arm orientation specific GS training recommendation for baseball hitters

Success With Extended-Infusion Meropenem After Recurrence of Baclofen Pump-Related Achromobacter Xylosoxidans Meningitis in an Adolescent

A 13-year-old female experienced a recurrence of baclofen pump-related central nervous system (CNS) infection caused by Achromobacter, despite absence of retained foreign material. Due to the failure of meropenem (120 mg/kg/d in divided doses every 8 hours and infused over 30 minutes) in the initial infection, the dose was infused over 4 hours during the recurrence. Meropenem is an antibiotic for which efficacy is time dependent, and 4-hour versus 30-minute infusions have been shown to prolong the time the concentration of the antibiotic exceeds the minimum inhibitory concentration (MIC) of the organism at the site of infection (T\u3eMIC). Meropenem serum concentrations were obtained and indicated that T\u3eMIC was at least 75% of the dosing interval. Our patient improved with no noted recurrences or adverse effects on the extended-infusion meropenem regimen. Utilization of extended-infusion beta-lactam dosing whenever possible in the treatment of serious infections caused by gram-negative organisms should be considered, as this dosing appears to be safe and improves the probability of achieving pharmacokinetic/pharmacodynamic goals