Bone Mineral Density at the Distal Radius in Female Collegiate Ice Hockey Athletes

Honorable Mention 2014 Denman Undergraduate Research Forum in HealthBackground: Low bone density in the distal radius has been associated with higher risk for fracture. Research suggests that bone density can be increased through weight-loading the bone via resistance training. In the Ohio State sports nutrition lab, female collegiate hockey players have previously demonstrated low bone mass at the wrist in many players. Because women’s ice hockey is a contact sport, players are subjected to frequent high-impact collisions, increasing their risk of injury. Aim: This protocol was designed to formally monitor the distal radius bone mass of female collegiate hockey players over the course of the season. It was expected that by implementing a program designed to add extra loading to the forearm and wrist over the second half of the 2013-2014 season, we would see a trend to increase BMD at the distal radius from midseason to postseason. Methods: A pre-test/mid-test/post-test design was implemented, with measurements taken in September, December, and March. Dietary intakes were estimated using the Vioscreen computerized Food Frequency, and athletes were measured for serum vitamin D in early January. Bone density was measured prior to beginning the program pre-season, mid-season, and post-season using the GE Lunar iDXA scan. The first half of season did not include any extra weight-loading exercises of the upper extremities to act as a control time period while plan for the second half of season included a higher volume of wrist weight-bearing exercises. Results: Pre-season measures of this athlete cohort demonstrated 33% (6/18) had low bone mass at the wrist. The mid-season wrist measures demonstrated lower densities for many players, with half of the athletes showing decreased bone density at the wrist and 8 players meeting criteria for low bone mass. The post-season wrist measures showed increased bone densities in 9 players, with 4 players maintaining mid-season bone density. However, there were no statistically significant changes in radial BMD across the season when evaluated using repeated measures statistical procedures. Conclusion: Based on the results of this pilot study, more loading of the distal radius may have benefitted players’ bone mass. However, there was likely not enough power to the study due to its short length and the relatively small number of participants.No embargoAcademic Major: Exercise Science Educatio

Development and application of an UHPLC-MS/MS method for the simultaneous determination of 17 steroidal hormones in equine serum

A new, fast and simple analytical method that is able to identify and quantify simultaneously 17 steroid hormones and metabolites (Pregnenolone, 17-OH-Pregnenolone, Progesterone, 17-OH Progesterone, Androsterone, Androstenedione, DHEA, DHEAS, Testosterone, Cortisol, Corticosterone, Aldosterone, 11-Deoxycortisol, 11-Deoxycorticosterone, Dihydrotestosterone, Estrone, Estradiol) has been developed in equine serum using the UHPLC-MS/MS technique. 400 μL of sample were deproteinized with 1000 µl of acetonitrile, evaporated, restored with 50 µl of a solution of 25% methanol and injected in UHPLC-MS/MS triple quadrupole. The recovery percentage obtained by spiking the matrix at two different concentrations with a standard mixture of steroid hormones was in all cases higher than 85.60 % and with the percentage of coefficient of variation (CV) lower than 8.37%. The range of the correlation coefficients of the calibration curves of the analyzed compounds was 0.9922–0.9986, and the limits of detection (LODs) and limits of quantification (LOQs) were in the range of 0.002–2 ng ml-1 and 0.0055-5.5 ng ml-1, respectively. The detected LOQ for testosterone (i.e. 50 pg ml-1) is two-fold lower with respect to its threshold admitted in geldings plasma (100 pg ml-1 free testosterone). The high sensitivity and the quantitative aspect of the method permitted to detect most of steroids in equine serum. Once validated, the method was used to quantify 17 steroid hormones in mare, stallion and gelding serum samples. The main steroids detected were corticosterone (range 37.25-51.26 ng ml-1) and cortisol (range 32.57-52.24 ng ml-1), followed by 17-OH-pregnenolone, dihydrotestosterone and pregnenolone

Microwave Gaseous Discharges

Contains reports on three research projects.Atomic Energy Commission under Contract AT(30-1)- 184

Embedded Ribbons of Graphene Allotropes: An Extended Defect Perspective

Four fundamental dimer manipulations can be used to produce a variety of localized and extended defect structures in graphene. Two-dimensional templates result in graphene allotropes, here viewed as extended defects, which can exhibit either metallic or semiconducting electrical character. \emph{Embedded allotropic ribbons}--i.e. thin swaths of the new allotropes--can also be created within graphene. We examine these ribbons and find that they maintain the electrical character of their parent allotrope even when only a few atoms in width. Such extended defects may facilitate the construction of monolithic electronic circuitry.Comment: 24 pages, 21 figure

Epigenetic Chromatin Silencing: Bistability and Front Propagation

The role of post-translational modification of histones in eukaryotic gene regulation is well recognized. Epigenetic silencing of genes via heritable chromatin modifications plays a major role in cell fate specification in higher organisms. We formulate a coarse-grained model of chromatin silencing in yeast and study the conditions under which the system becomes bistable, allowing for different epigenetic states. We also study the dynamics of the boundary between the two locally stable states of chromatin: silenced and unsilenced. The model could be of use in guiding the discussion on chromatin silencing in general. In the context of silencing in budding yeast, it helps us understand the phenotype of various mutants, some of which may be non-trivial to see without the help of a mathematical model. One such example is a mutation that reduces the rate of background acetylation of particular histone side-chains that competes with the deacetylation by Sir2p. The resulting negative feedback due to a Sir protein depletion effect gives rise to interesting counter-intuitive consequences. Our mathematical analysis brings forth the different dynamical behaviors possible within the same molecular model and guides the formulation of more refined hypotheses that could be addressed experimentally.Comment: 19 pages, 5 figure

Electron Bernstein waves in spherical tokamak plasmas with "magnetic wells"

In addition to traditional regimes with monotonously increasing magnetic field, regimes with "magnetic wells" also occur in spherical tokamaks (STs). The magnetic field profile inversion modifies significantly the whole picture of the wave propagation and damping. Since the magnetic wells may become quite common with further improvement of ST performance, analysis of such configurations is of interest for assessment of EBW plasma heating an CD perspectives. In this paper the basic features of the EBWs propagation and damping for the second cyclotron harmonic in a slab model are considered.Comment: Proc. of 13-th Joint Workshop on ECE and ECRH, N.Novgorod, Russia May 17-20, 2004, 8 pages, 4 fig