119. [Rule for finding the number of quarts not greater than a given number N (a quart being a number which cannot be expressed a the sum of one, two, or three squares).]

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Exploring Resistance Training as a Potential Standalone Treatment for Anxious Adults Who Screen Positive for Posttraumatic Stress Disorder

Introduction: Posttraumatic stress disorder (PTSD) is a disabling psychological disorder that affects about 7% of adults in the United States. PTSD and its symptoms have consistently been shown to have an inverse relationship with exercise participation. The strongest reported associations have been between high intensity exercise, and the hyperarousal and avoidance symptom clusters. Importantly, resistance training (i.e., weight lifting) is thought to have beneficial effects for several conditions that commonly co-occur with PTSD, such as anxiety, depression, and poor sleep quality. However, no studies have examined the effects of high intensity resistance training on PTSD symptoms. Purpose: This study sought to examine the effects of a 3-week high intensity resistance training program on the PTSD hyperarousal and avoidance symptom clusters, sleep quality, anxiety, and depression symptoms in anxious adults who screened positive for PTSD. Additionally, this study explored potential mechanisms of action (e.g., cognitive appraisal, perceived exertion, acute changes in affect, arousal, and distress) between exercise and PTSD. Methods: Thirty trait anxious individuals who screened positive for PTSD were randomly assigned to either a 3-week high intensity resistance training intervention, or a 3-week time-matched attention control group, while blocking for gender. Both groups were required to attend 3 on-site sessions per week, for 3 weeks (i.e., 9 total sessions). Each resistance training session consisted of a 5-minute warm-up, 20 minutes of high intensity resistance training, and a 5-minute cool-down. Each control session consisted of a brief 30-minute educational video on topics not relating to exercise or PTSD. Changes in PTSD symptoms, sleep quality, anxiety and depression were analyzed using repeated measures ANOVA, and potential mechanisms of action were explored with a series of longitudinal mixed-effects regression models. Results: Participants were 73.3% female, with a mean age of 29.1 years (SD = 7.4), and 63.3% identified as a racial minority. Groups did not significantly differ at baseline. There was a Time*Group interaction for hyperarousal symptoms (F = 4.7, p = .04, η2 .18), demonstrating a significantly larger reduction in hyperarousal symptoms for the resistance training group (d = -1.84) relative to the control (d = -1.13). The Time*Group interaction for avoidance symptoms was not significant (F = 1.7, p = .20, η2 = .08); however, the effect size of resistance training was larger (d = -2.71) than the control (d = -1.16). There was a significant Time*Group interaction for sleep quality (F = 4.7, p = .04, η2 = .19), demonstrating greater improvements in global sleep quality for resistance training (d = -1.06) relative to the control (d = -.15). However, there was no significant effect of Time on PTSD-related sleep disturbances (F = 3.0, p = .1, η2 = .13) nor was there a significant Time*Group interaction (F = .09, p = .80, η2 .05). Conclusion: This is the first randomized attention-controlled trial testing the effects of high intensity resistance training on PTSD symptoms. The overall results support the hypothesis that resistance training can beneficially affect PTSD symptoms and its commonly co-occurring conditions, such as poor sleep quality. Future adequately powered studies are warranted

Time maintenance of user clocks via the tracking and data relay satellite system

A system is described which uses the Tracking and Data Relay Satellite System (TDRSS) itself to compare the user satellite clock with a clock at the White Sands station that is referenced to Universal Time Coordinated (UTC). No command of the spacecraft by the system is required, and actual on-board clock corrections are made by the spacecraft control center at its discretion. Computer models were constructed using basic orbital parameters for user and TDRS satellites. With only first-order corrections and simple averaging techniques for constant clock rates, error measurement precision of better than one microsecond was obtained. More sophisticated computations should allow considerable improvement over this

High reliability dc amplifier Final report

Design and fabrication of high reliability differential dc amplifier for Saturn hydraulic engine contro

Preparing Students to be Effective Information Technology Project Managers: Can More Focus on Dialogue and Communication Processes Help?

The overall importance of dialogue and communication processes to scientific and technical problem solving is already well established in communication and project management literature (e.g., Bohm, 1999; Isaacs, 1999; Schwalbe, 1999; Kerzner, 1998). However, very little of this literature has been specifically applied to the fast-growing field of Information Technology/Information Systems (IT/IS) project management and to the pedagogical issues surrounding the teaching of students how to be more effective in working together as a team to solve IT/IS systems development problems. Many of the articles and books that address the subject have focused on some of the more obvious needs for better listening skills, more effective written and oral communication skills, techniques for helping to get your point across, etc. These are important but there is also a need for a more in depth look at the problem by applying some of the more ideological concepts related to “dialogue” introduced by Bohm and Isaacs

Massive star formation via high accretion rates and early disk-driven outflows

We present an investigation of massive star formation that results from the gravitational collapse of massive, magnetized molecular cloud cores. We investigate this by means of highly resolved, numerical simulations of initial magnetized Bonnor-Ebert-Spheres that undergo collapse and cooling. By comparing three different cases - an isothermal collapse, a collapse with radiative cooling, and a magnetized collapse - we show that massive stars assemble quickly with mass accretion rates exceeding 10^-3 Msol/yr. We confirm that the mass accretion during the collapsing phase is much more efficient than predicted by selfsimilar collapse solutions, i.e. dM/dt ~ c^3/G. We find that during protostellar assembly the mass accretion reaches 20 - 100 c^3/G. Furthermore, we determined the self-consistent structure of bipolar outflows that are produced in our three dimensional magnetized collapse simulations. These outflows produce cavities out of which radiation pressure can be released, thereby reducing the limitations on the final mass of massive stars formed by gravitational collapse. Moreover, we argue that the extraction of angular momentum by disk-threaded magnetic fields and/or by the appearance of bars with spiral arms significantly enhance the mass accretion rate, thereby helping the massive protostar to assemble more quickly.Comment: 22 pages, 12 figures, aastex style, accepted for publication in ApJ, see http://www.ita.uni-heidelberg.de/~banerjee/publications/MassiveStars.pdf for high resolution figure

Submicrosecond comparison of international clock synchronization by VLBI and the NTS satellite

The intercontinental clock synchronization capabilities of Very Long Baseline Interferometry (VLBI) and the Navigation Technology Satellite (NTS) were compared using both methods to synchronize the Cesium clocks at the NASA Deep Space Net complexes at Madrid, Spain and Goldstone, California. Verification of the accuracy of both systems was examined. The VLBI experiments used the Wideband VLBI Data Acquisition System developed at the NASA Jet Propulsion Laboratory. The NTS Satellites were designed and built by the Naval Research Laboratory used with NTS Timing Receivers developed by the Goddard Space Flight Center. The two methods agreed at about the one-half microsecond level

Assessing the association between oral hygiene and preterm birth by quantitative light-induced fluorescence

The aim of this study was to investigate the purported link between oral hygiene and preterm birth by using image analysis tools to quantify dental plaque biofilm. Volunteers (η = 91) attending an antenatal clinic were identified as those considered to be “at high risk” of preterm delivery (i.e., a previous history of idiopathic preterm delivery, case group) or those who were not considered to be at risk (control group). The women had images of their anterior teeth captured using quantitative light-induced fluorescence (QLF). These images were analysed to calculate the amount of red fluorescent plaque (ΔR%) and percentage of plaque coverage. QLF showed little difference in ΔR% between the two groups, 65.00% case versus 68.70% control, whereas there was 19.29% difference with regard to the mean plaque coverage, 25.50% case versus 20.58% control. A logistic regression model showed a significant association between plaque coverage and case/control status (Ρ = 0.031), controlling for other potential predictor variables, namely, smoking status, maternal age, and body mass index (BMI)

Kriged and modeled ambient air levels of benzene in an urban environment: an exposure assessment study

<p>Abstract</p> <p>Background</p> <p>There is increasing concern regarding the potential adverse health effects of air pollution, particularly hazardous air pollutants (HAPs). However, quantifying exposure to these pollutants is problematic.</p> <p>Objective</p> <p>Our goal was to explore the utility of kriging, a spatial interpolation method, for exposure assessment in epidemiologic studies of HAPs. We used benzene as an example and compared census tract-level kriged predictions to estimates obtained from the 1999 U.S. EPA National Air Toxics Assessment (NATA), Assessment System for Population Exposure Nationwide (ASPEN) model.</p> <p>Methods</p> <p>Kriged predictions were generated for 649 census tracts in Harris County, Texas using estimates of annual benzene air concentrations from 17 monitoring sites operating in Harris and surrounding counties from 1998 to 2000. Year 1999 ASPEN modeled estimates were also obtained for each census tract. Spearman rank correlation analyses were performed on the modeled and kriged benzene levels. Weighted kappa statistics were computed to assess agreement between discretized kriged and modeled estimates of ambient air levels of benzene.</p> <p>Results</p> <p>There was modest correlation between the predicted and modeled values across census tracts. Overall, 56.2%, 40.7%, 31.5% and 28.2% of census tracts were classified as having 'low', 'medium-low', 'medium-high' and 'high' ambient air levels of benzene, respectively, comparing predicted and modeled benzene levels. The weighted kappa statistic was 0.26 (95% confidence interval (CI) = 0.20, 0.31), indicating poor agreement between the two methods.</p> <p>Conclusions</p> <p>There was a lack of concordance between predicted and modeled ambient air levels of benzene. Applying methods of spatial interpolation for assessing exposure to ambient air pollutants in health effect studies is hindered by the placement and number of existing stationary monitors collecting HAP data. Routine monitoring needs to be expanded if we are to use these data to better assess environmental health risks in the future.</p