Aeolian tones from circular cylinders of non-uniform cross section

Lighthill's theory of aerodynamic sound is reviewed. Applications of this theory to different cylinder classes are synthesized and extended to cylinder types not addressed previously. An experiment wherein cylinders are placed in an open jet, permitting simultaneous measurement of total lift force, correlation parameters and radiated sound intensity, was conducted. Over the Reynolds number range 10 3 to 5 x10 4 , the theory of aerodynamic sound is validated for uniform, roughened, skewed, finned and notched cylinders and for cylinders with splitter plates. Reduction of lift force, by any means, is shown to reduce radiated sound intensity, and local lift force is found to vary monotonically with the two dimensionality of the vortex wake.http://archive.org/details/aeolitonesfromci1094547502Lieutenant Commander, United States NavyApproved for public release; distribution is unlimited

Measurement of the visco-elastic properties of water-saturated clay sediments.

The complex shear modulus of both kaolin-water and bentonite-water mixtures has been determined in the laboratory. The method involved measuring the reaction on a torsional elastic wave propagated down a metal rod when the rod was immersed in sediment. Observations were made over the frequency range two to forty-three kHz. Dispersed sediments behaved like Newtonian liquids. Undispersed sediments, however, were viscoelastic in character, and their shear moduli exhibited no dependence on frequency. For undispersed kaolin mixtures, a typical result is (21.6 + i 1.2) x 1,000 dynes per square centimeter at 32 percent concentration. In bentonite, a modulus of (4.6 + i 2.0) x 10,000 dynes per square centimeter at 19 percent concentration is representative.http://archive.org/details/measurementofvis1094540051Lieutenant, United States NavyApproved for public release; distribution is unlimited

Implications of microstructure theory for empirical research in stock price behavior

This paper examines the implications of microstructure theory for empirical research on stock price behaviorMicrostructure theory; empirical research on stock price behavior

Dysbindin-1 in dorsolateral prefrontal cortex of schizophrenia cases is reduced in an isoform-specific manner unrelated to altered dysbindin-1 gene expression

DTNBP1 (dystrobrevin binding protein 1) remains one of the top candidate genes in schizophrenia. Reduced expression of this gene and the protein it encodes, dysbindin-1, has been reported in the dorsolateral prefrontal cortex (DLPFC) of schizophrenia cases. It has not been established, however, if all dysbindin-1 isoforms are reduced in the DLPFC or if the reduction is associated with reduced DTNBP1 gene expression. Using Western blotting of whole-tissue lysates of the DLPFC with antibodies differentially sensitive to the three major isoforms of this protein (dysbindin-1A, -1B, and -1C), we found no significant differences between our schizophrenia cases and matched controls in dysbindin-1A or -1B, but did find a mean 46% reduction in dysbindin-1C in 71% of 28 case-control pairs (p = 0.022). This occurred in the absence of the one DTNBP1 risk haplotype for schizophrenia reported in the US and without alteration in levels of dysbindin-1C transcripts. Conversely, the absence of changes in the dysbindin-1A and -1B isoforms was accompanied by increased levels of their transcripts. We thus found no correspondence between alterations in dysbindin-1 gene and protein expression, the latter of which might be due to posttranslational modifications such as ubiquitination. Reduced DLPFC dysbindin-1C in schizophrenia probably occurs in PSDs, where we find dysbindin-1C to be heavily concentrated in the human brain. Given known postsynaptic effects of dysbindin-1 reductions in the rodent homolog of the prefrontal cortex, these findings suggest that reduced dysbindin-1C in the DLPFC may contribute to cognitive deficits of schizophrenia by promoting NMDA receptor hypofunction

Sex and sexual orientation disparities in adverse childhood experiences and early age at sexual debut in the United States: Results from a nationally representative sample

Adverse childhood experiences (ACEs) have been linked to early sexual debut, which has been found to be associated with multiple adverse health outcomes. Sexual minorities and men tend to have earlier sexual debut compared to heterosexual populations and women, respectively. However, studies examining the association between ACEs and early sexual debut among men and sexual minorities are lacking. The aim of this study was to examine the sex and sexual orientation disparities in the association between ACEs and age at sexual debut. Data were obtained from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. Logistic and linear regression model were used to obtain crude and adjusted estimates and 95% confidence intervals adjusting for age, race/ethnicity, income, education, insurance and marital status for the association between ACEs (neglect, physical/psychological abuse, sexual abuse, parental violence, and parental incarceration and psychopathology) and early sexual debut. Analyses were stratified by sex and sexual orientation. Larger effect estimates depicting the association between ACEs and sexual debut were seen for women compared to men, and among sexual minorities, particularly among men who have sex with men (MSM) and women who have sex with women (WSW), compared to heterosexuals. Sexual health education programs with a focus on delaying sexual debut among children and adolescents should also consider addressing ACEs, such as neglect, physical, psychological and sexual abuse, witnessing parental violence, and parental incarceration and psychopathology. Public health practitioners, researchers and sexual health education curriculum coordinators should consider these differences by sex and sexual orientation when designing these programs

Metallicities of Emission-Line Galaxies from HST ACS PEARS and HST WFC3 ERS Grism Spectroscopy at 0.6 < z < 2.4

Galaxies selected on the basis of their emission line strength show low metallicities, regardless of their redshifts. We conclude this from a sample of faint galaxies at redshifts between 0.6 < z < 2.4, selected by their prominent emission lines in low-resolution grism spectra in the optical with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) and in the near-infrared using Wide-Field Camera 3 (WFC3). Using a sample of 11 emission line galaxies (ELGs) at 0.6 < z < 2.4 with luminosities of -22 < M_B < -19, which have [OII], H\beta, and [OIII] line flux measurements from the combination of two grism spectral surveys, we use the R23 method to derive the gas-phase oxygen abundances: 7.5 < 12+log(O/H) < 8.5. The galaxy stellar masses are derived using Bayesian based Markov Chain Monte Carlo (\piMC^2) fitting of their Spectral Energy Distribution (SED), and span the mass range 8.1 < log(M_*/M_\sun) < 10.1. These galaxies show a mass-metallicity (M-L) and Luminosity-Metallicity (L-Z) relation, which is offset by --0.6 dex in metallicity at given absolute magnitude and stellar mass relative to the local SDSS galaxies, as well as continuum selected DEEP2 samples at similar redshifts. The emission-line selected galaxies most resemble the local "green peas" galaxies and Lyman-alpha galaxies at z~0.3 and z~2.3 in the M-Z and L-Z relations and their morphologies. The G-M_{20} morphology analysis shows that 10 out of 11 show disturbed morphology, even as the star-forming regions are compact. These galaxies may be intrinsically metal poor, being at early stages of formation, or the low metallicities may be due to gas infall and accretion due to mergers.Comment: 24 pages with 7 figure

Impact of Draft Order on Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers: An 18-Year Study

Background: The MLB draft is a common route for players to enter professional baseball in the United States. Individuals taken in earlier rounds are typically higher-performing players. When looking at pitchers specifically, higher performance at the amateur level may be associated with increased frequency of adaptive change in the throwing elbow. Purpose/Hypothesis: To determine if players taken in earlier rounds of the MLB draft have a greater frequency or extent of pathological change in the elbow, as measured by dynamic stress ultrasound. Study Design: Retrospective Cohort Study Methods: Dynamic stress ultrasounds (SUS) were performed over an 18-year period on the dominant and nondominant arms of 651 professional pitchers. The 383 players who were drafted were grouped according to which round they were drafted in (rounds 1-5, 6-10, 11-20, 21+). Groups were compared with respect to “relative” ulnar collateral ligament thickness (dominant – nondominant), “relative” ulnohumeral joint laxity (joint space distance under stress – distance at rest), and the presence of pathology (calcifications, tears, hypoechoic foci, osteophytes). Additionally, a subgroup analysis was done to compare progression of SUS findings over a 3-year period in players for which data was available. Results: Draft round groups did not differ by age, number of prior spring trainings, or handedness. Comparing baseline measurements, there was no significant relationship between draft round and relative UCL thickness (P = .932), relative laxity (P = .996), or presence of pathology detectable on SUS (P = .642). However, increased relative UCL thickness was significantly associated with the presence of pathology on SUS (OR: 1.45, 95% CI [1.26-1.69], P \u3c .001). Longitudinally, there was no significant relationship between draft round and 3-year progression of relative laxity, relative UCL thickness, or clinical progression of pathology. Conclusion: Higher-performing pitchers are drafted earlier in the MLB draft. This may be attributable to peak pitch velocity, in-game performance, visibility gained during player showcases, or any number of other sport-specific variables. However, despite this, there was no significant relationship between draft round and adaptive changes to the elbow on SUS

Adaptive Changes of the Ulnar Collateral Ligament of Professional Baseball from Different Climates Over Multiple Seasons: An 18-Year Study

Background: The ulnar collateral ligament (UCL) is put under high levels of stress through the overhead throwing motion typical of professional baseball pitchers. In response to repetitive stress the UCL undergoes adaptive changes including thickening of the ligament and increased joint laxity under valgus stress. Studies examining the adaptive changes in the elbows of professional pitchers over multiple seasons are limited. Investigations such as this one offer insight into the changes in the UCL of professional pitchers over multiple years of professional play as well as the risk for injuries that may be associated with these changes. Purpose/Hypothesis: The purpose of this study was to compare stress ultrasound findings between warm and cold climate pitchers and to assess for significant differences that may predispose players from either climate to future injury. Study Design: Retrospective Cohort Study Methods: Dynamic stress ultrasounds (SUS) of professional baseball pitchers were taken over an 18 year period. Player demographics were collected to determine climate of origin. SUS measurements of the same player taken 3 years apart were examined to determine changes in relative UCL thickness and laxity between the dominant and nondominant arms. The term ‘relative’ refers to (dominant – non-dominant), laxity (joint space distance under stress - joint space distance at rest). SUS were also examined at time of measurements for pathologic findings. Results: Players from colder and warmer climates did not differ from one another in the progression of relative UCL thickness (0.72 mm vs 0.55 mm, P = .748) of relative laxity (-0.01 mm vs 0.03 mm, P = .904). Both groups did not differ in rates of pathology development including calcifications (P = .412), hypoechoic foci (P = .084), osteophyte (P = .892). Conclusion: Adaptive changes of the UCL in professional baseball pitchers originating from colder and warmer climates did not significantly differ from one another. Although there is potential for those from warmer climates to throw year-round the effect may not be enough to cause noticeable changes over a 3 year period. Future studies should expand on this investigation with examination of injuries of players from different climates to determine if any correlation exists with UCL changes in an expanded cohort

Kerlan-Jobe Orthopaedic Clinic overhead athlete scores in asymptomatic professional baseball pitchers.

BACKGROUND: The Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow score is a subjective questionnaire that has been validated and been shown to be more specific in overhead athletes than the American Shoulder and Elbow Surgeons scale. The purpose of this study was to determine a mean KJOC score and reasonable range of KJOC scores within which a healthy asymptomatic professional baseball pitcher will fall. It was hypothesized that healthy professional baseball pitchers would have very high KJOC scores. MATERIALS AND METHODS: KJOC questionnaires were given to all healthy pitchers before the start of the season at all levels in 1 professional Minor League system. Pitchers were asked to complete the questionnaire upon reporting to their AAA, AA, or A affiliate team. Any pitcher starting the season on the disabled list was excluded from the study. RESULTS: KJOC scores were returned by 44 pitchers. The mean score for all pitchers was 94.82 (95% confidence interval, 92.94-96.70). The mean score for each question was greater than 9 of 10. The mean score for the AAA affiliate was significantly higher than that for the AA affiliate (P = .015). No other significant differences in scores were found between class levels or groups based on professional playing experience. CONCLUSION: Only 7 of 44 healthy asymptomatic pitchers (16%) had a KJOC score below 90. Therefore, we believe that the KJOC score is an accurate assessment for overhead athletes and normal values should be greater than 90. Anything below this value could be a potential cause for concern for team physicians. LEVEL OF EVIDENCE: Basic Science, Survey Study, Healthy Subjects