Psychosocial predictors of visceral adiposity

Psychosocial factors are thought to influence health through primarily direct physiological mechanisms or the alteration of health related behaviors. Three factors hypothesized to negatively impact health include arousal, life stress, and depressive symptomatology. One recent theorist suggests that the interaction between psychological stress and stress hormones on the neuroendocrine system may result in adverse changes to body composition, most notably the increased deposition of visceral adipose tissue (Bjorntorp, 1993). The current study prospectively examined the relationship between self-reported stressful life events, depressive symptoms and trait arousal on the deposition of visceral fat, as measured by computerized tomography (CT). Subjects were obtained from a sample of middle-aged males and females (n = 120). Stress measures included the Weekly Stress Inventory (WSI), a life-events measure of minor stressors, and the Life Events Survey (LES) a measure of major life events. Depression symptoms were measured with the Center for Epidemiological Studies Depression Scale (CES-D). Stress and depression were assessed at baseline, 6 and 12 months, and the CT images of visceral fat were obtained at baseline and 12 months. Trait arousal was measured with the Arousal Predisposition Scale at baseline. Arousal, stress and depression scores over 12 months were then standardized and averaged, and entered into a hierarchical multiple regression model in order to predict changes in visceral adiposity from baseline to 12 months. The model was significant in predicting visceral fat, accounting for 16.9% of the variance. Further examination of the model indicated the presence of a significant 3-way interaction between arousal, stress and depression, such that visceral fat was predicted by the interaction of low arousal, high stress and high depression. When the interaction terms were added to the regression analysis as additional steps, the model continued to be significant, accounting for 20.9% of the variance. Interestingly, these models were significant in predicting visceral adiposity despite the fact that the relationships observed were not all in the expected directions. These findings have implications for both researchers and clinicians, who may wish to incorporate more specific psychosocial measures and interventions in the study and treatment of overweight and obesity

The Globular Cluster System of the Spiral Galaxy NGC7814

We present the results of a wide-field photometric study of the globular cluster (GC) system of the edge-on Sab spiral NGC7814. This is the first spiral to be fully analyzed from our survey of the GC systems of a large sample of galaxies beyond the Local Group. NGC7814 is of particular interest because a previous study estimated that it has 500-1000 GCs, giving it the largest specific frequency (S_N) known for a spiral. Understanding this galaxy's GC system is important in terms of our understanding of the GC populations of spirals in general and has implications for the formation of massive galaxies. We observed the galaxy in BVR filters with the WIYN 3.5-m telescope, and used image classification and three-color photometry to select GC candidates. We also analyzed archival HST WFPC2 images of NGC7814, both to help quantify the contamination level of the WIYN GC candidate list and to detect GCs in the inner part of the galaxy halo. Combining HST data with high-quality ground-based images allows us to trace the entire radial extent of this galaxy's GC system and determine the total number of GCs directly through observation. We find that rather than being an especially high-S_N spiral, NGC7814 has <200 GCs and S_N ~ 1, making it comparable to the two most well-studied spirals, the Milky Way and M31. We explore the implications of these results for models of the formation of galaxies and their GC systems. The initial results from our survey suggest that the GC systems of typical ellipticals can be accounted for by the merger of two or more spirals, but that for highly-luminous ellipticals, additional physical processes may be needed.Comment: 28 pages, incl. 4 figures; accepted for publication in The Astronomical Journal, November 2003 issu

Effects of Aquatic and Land Plyometrics on Athletic Performance: A Systematic Review

The purpose of this study was to systematically review literature to determine whether aquatic plyometric training (APT) increases athletic performance compared to land-based plyometric training (LPT). We identified 6 articles from PubMed, CINAHL, MEDLINE, and single-citation matching from January, 1995 through January, 2017 using search words “aquatic plyometric training OR aquatic plyometric OR aquatic plyometrics.” After screening (title, abstract), 6 articles were reviewed for inclusion criteria: (1) full-report/abstract, (2) peer-reviewed RCTs/clinical trials, (3) English language, (4) focused on healthy individuals (free of current, lower-extremity, musculoskeletal injuries) ages 16-30 years, and (6) included strength, power, and/or vertical jump [VJ] dependent variables. Six (of 6) studies met inclusion criteria (LOE, 1b = 6; PEDro score = 6.3±0.3). Reported pooled sample size was 182, mean age 22.46±3.67 (range 17-27). Studies found significant (p\u3e.05) performance increases in the LPT and APT groups, with no significant (p\u3e.05) differences in the amount of performance increase between experimental groups. Results demonstrated both LPT and APT can improve measures of athletic performance; however, neither appears to produce significantly better performance than the other

Global Properties of the Globular Cluster Systems of Four Spiral Galaxies

We present results from a wide-field imaging study of the globular cluster (GC) systems of a sample of edge-on, Sb-Sc spiral galaxies ~7-20 Mpc away. This study is part of a larger survey of the ensemble properties of the GC populations of giant galaxies. We imaged the galaxies in BVR filters with large-format CCD detectors on the WIYN 3.5-m telescope, to projected radii of ~20-40 kpc. For four galaxies (NGC 2683, NGC 3556, NGC 4157, and NGC 7331), we quantify the radial distributions of the GC systems and estimate the total number, luminosity- and mass-normalized specific frequencies (S_N and T), and blue (metal-poor) fraction of GCs. A fifth galaxy (NGC 3044) was apparently too distant for us to have detected its GC system. Our S_N for NGC 2683 is 2.5 times smaller than the previously-published value, likely due in part to reduced contamination from non-GCs. For the spiral galaxies analyzed for the survey to date, the average number of GCs is 170+/-40 and the weighted mean values of S_N and T are 0.8+/-0.2 and 1.4+/-0.3. We use the survey data to derive a relationship between radial exent of the GC system and host galaxy mass over a factor of 20 in mass. Finally, we confirm the trend, identified in previous survey papers, of increasing specific frequency of metal-poor GCs with increasing galaxy mass. We compare the data with predictions from a simple model and show that carefully quantifying the numbers of metal-poor GCs in galaxies can constrain the formation redshifts of the GCs and their host galaxies.Comment: 30 pages, including 14 figures and 13 tables; accepted for publication in The Astronomical Journal, Oct 2007 issu

Beyond the Brim of the Hat: Kinematics of Globular Clusters out to Large Radius in the Sombrero Galaxy

We have obtained radial velocity measurements for 51 new globular clusters around the Sombrero galaxy. These measurements were obtained using spectroscopic observations from the AAOmega spectrograph on the Anglo-Australian Telescope and the Hydra spectrograph at WIYN. Combined with our own past measurements and velocity measurements obtained from the literature we have constructed a large database of radial velocities that contains a total of 360 confirmed globular clusters. Previous studies' analyses of the kinematics and mass profile of the Sombrero globular cluster system have been constrained to the inner ~9' (~24 kpc or ~5 effective radii), but our new measurements have increased the radial coverage of the data, allowing us to determine the kinematic properties of M104 out to ~15' (~41 kpc or ~9 effective radii). We use our set of radial velocities to study the GC system kinematics and to determine the mass profile and V-band mass-to-light profile of the galaxy. We find that the V-band mass-to-light ratio increases from 4.5 at the center to a value of 20.9 at 41 kpc (~9 effective radii or 15'), which implies that the dark matter halo extends to the edge of our available data set. We compare our mass profile at 20 kpc (~4 effective radii or ~7.4') to the mass computed from x-ray data and find good agreement. We also use our data to look for rotation in the globular cluster system as a whole, as well as in the red and blue subpopulations. We find no evidence for significant rotation in any of these samples.Comment: Accepted for publication in the Astronomical Journal; 23 pages, 14 figures, and 2 table

Rotation in the Orion Nebula Cluster

Eighteen fields in the Orion Nebula Cluster (ONC) have been monitored for one or more observing seasons from 1990-99 with a 0.6-m telescope at Wesleyan University. Photometric data were obtained in Cousins I on 25-40 nights per season. Results from the first 3 years of monitoring were analyzed by Choi & Herbst (1996; CH). Here we provide an update based on 6 more years of observation and the extensive optical and IR study of the ONC by Hillenbrand (1997) and Hillenbrand et al. (1998). Rotation periods are now available for 134 ONC members. Of these, 67 were detected at multiple epochs with identical periods by us and 15 more were confirmed by Stassun et al. (1999) in their study of Ori OBIc/d. The bimodal period distribution for the ONC is confirmed, but we also find a clear dependence of rotation period on mass. This can be understood as an effect of deuterium burning, which temporarily slows the contraction and thus spin-up of stars with M <0.25 solar masses and ages of ~1 My. Stars with M <0.25 solar masses have not had time to bridge the gap in the period distribution at ~4 days. Excess H-K and I-K emission, as well as CaII infrared triplet equivalent widths (Hillenbrand et al. 1998), show weak but significant correlations with rotation period among stars with M >0.25 solar masses. Our results provide new observational support for the importance of disks in the early rotational evolution of low mass stars. [abridged]Comment: 18 pages of text, 17 figures, and 4 tables; accepted for publication in The Astronomical Journa

Simulation of haemodynamic flow in head and neck cancer chemotherapy

<p>Abstract</p> <p>Background</p> <p>In recent years, intra arterial chemotherapy has become an important component in head and neck cancer treatment. However, therapy success can vary significantly and consistent treatment guidelines are missing. The purpose of this study was to create a computer simulation of the chemical agent injection in the head and neck arteries to investigate the distribution and concentration of the chemical.</p> <p>Methods</p> <p>Realistic three dimensional patient specific geometry was created from image scan data. Pulsatile blood flow, turbulence, the chemical agent injection via a catheter, and the mixture between blood and the chemical were then simulated through the arterial network by computational fluid dynamics software.</p> <p>Results</p> <p>The results show a consistent chemical distribution throughout all the arteries and this is ineffective. In addition, due to high wall shear stress and turbulence at the inner bifurcation wall, serious complications during the treatment could occur, for instance haemolysis or thrombosis.</p> <p>Conclusions</p> <p>The modelled catheter position is insufficient to provide a high chemical agent concentration in the desired tumour feeding artery, which is vital for therapy success.</p

Porosity in as-cast U-Al alloy

This memorandum documents a study that showed a cyclic occurrence of porosity in U-Al alloys produced in Building 321-M. Review of process data shows that the extent of porosity is more pronounced in months of warm, humid weather and less pronounced in cooler, drier months. This porosity is most likely caused by hydrogen, which becomes dissolved in the molten U-Al alloy during casting. Although excessive porosity was the cause of some observed process anomalies, this type of porosity has no significant effect on yield or fuel tube quality