A Schism in Youth Baseball and its Lingering Effects: A Case Study of One Community’s Experience

This case study explored the experience of parent coaches in an urban, Midwestern youth baseball setting. Data collection included personal communication with fifteen expert coaches, along with an examination of historical emails, league records and newspaper articles. The initial research questions focused on how coaches create meaning for youth sport participants. However, a schism event and its effects emerged as a significant theme, along with the resulting challenges faced by Little League coaches. The Little League organization operated as the sole option for youth baseball since 1951. In 2001, an alternative “Traveling” option began competing with Little League by branding itself as “competing at the highest level of competition.” Little League symbolically became a “recreational” option, inconsistent with the myth of the Little League World Series. This increasingly competitive context made the job of a Little League coach more difficult. Participants discussed managing perceived favoritism and balancing the objectives of “competing” and “having fun” as the top challenges, and identified the attributes of an effective coach as relating to others, managing talent and leveraging rules. A dynamic coaching model emerged with four coach types, differentiated by baseball intelligence and talent management skills. Findings suggest additional research on the value of a child committing to a single sport, how to improve youth coach recruiting and development, and to better understand the business of youth sports

A Deficit of Faint Red Galaxies in the Possible Large-Scale Structures around the RDCS J1252.9-2927 Cluster at z=1.24

(Abridged) We report a discovery of possible large-scale structures around the RDCS J1252.9-2927 cluster at z=1.24 based on photometric redshifts. We carried out multi-band wide-field imaging with Suprime-Cam on the Subaru Telescope and WFCAM on the United Kingdom Infra-Red Telescope (UKIRT). The distribution of photo-z selected galaxies reveals clumpy structures surrounding the central cluster. We compare the observed structure with an X-ray map and find that two of the four plausible clumps show significant X-ray emissions and one with a marginal detection, which strongly suggest that they are dynamically bound systems. Following the discovery of the possible large-scale structure, we carried out deeper SOFI K_s-band imaging with New Technology Telescope on the four plausible clumps. We construct the optical-to-near-infrared colour-magnitude diagrams of the galaxies in the clumps, and find that the colour-magnitude relation (CMR) of the red galaxies in the clumps is sharply truncated below K_s=22. Interestingly, the main cluster shows a clear relation down to K_s=23 (Lidman et al. 2004). We suggest that galaxies follow the 'environment-dependent down-sizing' evolution. Massive galaxies in high density environments first stop forming stars and become red. Less massive galaxies in less dense environments become red at later times. Based on a few assumptions, we predict that the brightest tip of the CMR appears at z~2.5.Comment: 10 pages, 8 figures, accepted for publication in MNRA

Finite width coplanar waveguide patch antenna with vertical fed through interconnect

The paper presents the design, fabrication and characterization of a finite width Coplanar waveguide (FCPW) patch antenna and a FCPW-to-FCPW vertical interconnect. The experimental results demonstrate the antenna and interconnect performance. A scheme to integrate an eight element FCPW patch array with MMIC phase shifters and amplifiers using vertical interconnects is described. The antenna module has potential applications in an advanced satellite to ground transmit phased array at K-Band

Machine learning for automated quality assurance in radiotherapy: A proof of principle using EPID data description

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149320/1/mp13433_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149320/2/mp13433.pd

A method for the identification of COVID-19 biomarkers in human breath using Proton Transfer Reaction Time-of-Flight Mass Spectrometry

Background: COVID-19 has caused a worldwide pandemic, making the early detection of the virus crucial. We present an approach for the determination of COVID-19 infection based on breath analysis. Methods: A high sensitivity mass spectrometer was combined with artificial intelligence and used to develop a method for the identification of COVID-19 in human breath within seconds. A set of 1137 positive and negative subjects from different age groups, collected in two periods from two hospitals in the USA, from 26 August, 2020 until 15 September, 2020 and from 11 September, 2020 until 11 November, 2020, was used for the method development. The subjects exhaled in a Tedlar bag, and the exhaled breath samples were subsequently analyzed using a Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-ToF-MS). The produced mass spectra were introduced to a series of machine learning models. 70% of the data was used for these sub-models\u27 training and 30% was used for testing. Findings: A set of 340 samples, 95 positives and 245 negatives, was used for the testing. The combined models successfully predicted 77 out of the 95 samples as positives and 199 out of the 245 samples as negatives. The overall accuracy of the model was 81.2%. Since over 50% of the total positive samples belonged to the age group of over 55 years old, the performance of the model in this category was also separately evaluated on 339 subjects (170 negative and 169 positive). The model correctly identified 166 out of the 170 negatives and 164 out of the 169 positives. The model accuracy in this case was 97.3%. Interpretation: The results showed that this method for the identification of COVID-19 infection is a promising tool, which can give fast and accurate results

Applications of exact solution for strongly interacting one dimensional bose-fermi mixture: low-temperature correlation functions, density profiles and collective modes

We consider one dimensional interacting bose-fermi mixture with equal masses of bosons and fermions, and with equal and repulsive interactions between bose-fermi and bose-bose particles. Such a system can be realized in current experiments with ultracold bose-fermi mixtures.We apply the Bethe-ansatz technique to find the exact ground state energy at zero temperature for any value of interaction strength and density ratio between bosons and fermions. We use it to prove the absence of the demixing, contrary to prediction of a mean field approximation. Combining exact solution with local density approximation (LDA) in a harmonic trap, we calculate the density profiles and frequencies of collective modes in various limits. In the strongly interacting regime, we predict the appearance of low-lying collective oscillations which correspond to the counterflow of the two species. In the strongly interacting regime we use exact wavefunction to calculate the single particle correlation functions for bosons and fermions at low temperatures under periodic boundary conditions. We derive an analytical formula, which allows to calculate correlation functions at all distances numerically for a polynomial time in the system size. We investigate numerically two strong singularities of the momentum distribution for fermions at $k_f$ and $k_f+2k_b.$ We show, that in strongly interacting regime correlation functions change dramatically as temperature changes from 0 to a small temperature $\sim E_f/\gamma.$ A strong change of the momentum distribution in a small range of temperatures can be used to perform a thermometry at very small temperatures.Comment: v2 More extensive discussion of collective modes, newfigures adde

Stellar Masses of Lyman Break Galaxies, Lyman Alpha Emitters and Radio Galaxies in Overdense Regions at z=4-6

We present new information on galaxies in the vicinity of luminous radio galaxies and quasars at z=4,5,6. These fields were previously found to contain overdensities of Lyman Break Galaxies (LBGs) or spectroscopic Lyman alpha emitters. We use HST and Spitzer data to infer stellar masses, and contrast our results with large samples of LBGs in more average environments as probed by the Great Observatories Origins Deep Survey (GOODS). The following results were obtained. First, LBGs in both overdense regions and in the field at z=4-5 lie on a very similar sequence in a z'-[3.6] versus [3.6] color-magnitude diagram. This is interpreted as a sequence in stellar mass (log[M*/Msun] = 9-11) in which galaxies become increasingly red due to dust and age as their star formation rate (SFR) increases. Second, the two radio galaxies are among the most massive objects (log[M*/Msun]~11) known to exist at z~4-5, and are extremely rare based on the low number density of such objects as estimated from the ~25x larger area GOODS survey. We suggest that the presence of these massive galaxies and supermassive black holes has been boosted through rapid accretion of gas or merging inside overdense regions. Third, the total stellar mass found in the z=4 ``proto-cluster'' TN1338 accounts for <30% of the stellar mass on the cluster red sequence expected to have formed at z>4, based on a comparison with the massive X-ray cluster Cl1252 at z=1.2. Although future near-infrared observations should determine whether any massive galaxies are currently being missed, one possible explanation for this mass difference is that TN1338 evolves into a smaller cluster than Cl1252. This raises the interesting question of whether the most massive protocluster regions at z>4 remain yet to be discovered.Comment: The Astrophysical Journal, In Press (17 pages, 7 figures