Power supply conditioning circuit

A power supply conditioning circuit that can reduce Periodic and Random Deviations (PARD) on the output voltages of dc power supplies to -150 dBV from dc to several KHz with no measurable periodic deviations is described. The PARD for a typical commercial low noise power supply is -74 dBV for frequencies above 20 Hz and is often much worse at frequencies below 20 Hz. The power supply conditioning circuit described here relies on the large differences in the dynamic impedances of a constant current diode and a zener diode to establish a dc voltage with low PARD. Power supplies with low PARD are especially important in circuitry involving ultrastable frequencies for the Deep Space Network

Hearts Of Promise : Waltzes

https://digitalcommons.library.umaine.edu/mmb-ps/2517/thumbnail.jp

Prosomal-width-to-weight relationships in American horseshoe crabs (Limulus polyphemus): examining conversion factors used to estimate landings

Horseshoe crabs (Limulus polyphemus) are valued by many stakeholders, including the commercial fishing industry, biomedical companies, and environmental interest groups. We designed a study to test the accuracy of the conversion factors that were used by NOAA Fisheries and state agencies to estimate horseshoe crab landings before mandatory reporting that began in 1998. Our results indicate that the NOAA Fisheries conversion factor consistently overestimates the weight of male horseshoe crabs, particularly those from New England populations. Because of the inaccuracy of this and other conversion factors, states are now mandated to report the number (not biomass) and sex of landed horseshoe crabs. However, accurate estimates of biomass are still necessary for use in prediction models that are being developed to better manage the horseshoe crab fishery. We recommend that managers use the conversion factors presented in this study to convert current landing data from numbers to biomass of harvested horseshoe crabs for future assessments

Impacts of Climate Change on the Energy Performance of Buildings in the United States

15 p.This study uses computer simulation techniques to assess the impacts of climate change on building energy demand. This analysis allows for the characterization of the potential for reducing the energy use of buildings in a quantitative manner and therefore improving building design. Six cities and five building types representing a range of climates and building occupancies were modeled. Three design strategies for improving energy performance under warmed conditions are compared to a basecase. The study concludes that annual cooling loads will increase at a much greater rate than heating loads will decrease; The timing, magnitude and duration of short term changes, peaks, is as large a concern as the sheer magnitude of the large annual changes in demand due to Global Warming; . new methods of resource acquisition will have to be implemented to respond to the new energy resource demands; and a new set of incremental measures, conservation targets, will have to be developed to support new resources. The results of the study indicate that research and demonstration regional, building unit area weighted, zero energy growth, energy demand targets should be developed. These regional energy conservation targets should emphasize the saving of lost opportunity resources in the design of the most permanent of the building systems, the building's exterior skin geometry. assembly and interiors. The study indicates that the clearest specific target for reducing energy use under Global Warming is the design of windows. The research, design. and demonstration of windows that act as an integrated lighting system with the electric lighting; admitting daylight. view. and cooling ventilation without admitting sunlight; should be a major thrust for research and development of the 1990's.This research was accomplished under contract to the Office of Technology Assessment of the United States Congress. For a complete copy of this report to Office of Technology Assessment, contact the College of Architecture & Urban Planning, University of Washington, Seattle, WA

Retina: Helping Students and Instructors Based on Observed Programming Activities

t is difficult for instructors of CS1 and CS2 courses to get accurate answers to such critical questions as 'how long are students spending on programming assignments?', or 'what sorts of errors are they making?' At the same time, students often have no idea of where they stand with respect to the rest of the class in terms of time spent on an assignment or the number or types of errors that they encounter. In this paper, we present a tool called Retina, which collects information about students' programming activities, and then provides useful and informative reports to both students and instructors based on the aggregation of that data. Retina can also make real-time recommendations to students, in order to help them quickly address some of the errors they make. In addition to describing Retina and its features, we also present some of our initial findings during two trials of the tool in a real classroom setting

The Relationships Among Different Traits of Masculinity and Intimate Partner Violence

Research has shown that distinct yet overlapping concepts of dominance, hostility towards women, and sexism—all indices of masculinity—influence the occurrence of intimate partner violence (IPV), although the mechanisms are unclear. This paper seeks to explore the relationship between these individual-level trait measures of masculinity and two aspects of IPV, physical violence and coercive control. With inconsistent findings and the limited study of clinical populations, further examination of these concepts may provide increased understanding of the mechanisms behind IPV perpetration. Results will provide a greater understanding of the complexity of this violence in order to better assist individuals experiencing IPV

Time-Clamped, RPE-Matched Treadmill Activity and Interactive Video Game Dancing Differ in Step Count But Not Heart Rate Response

Background: Participation in regular moderate or vigorous physical activity (MVPA) results in numerous health benefits. Task enjoyment is a known antecedent and promoter of regular activity engagement. Participation in interactive video gaming has increased in recent years. Purpose: The aims of the present investigation were to: 1) determine heart rate (HR) and step count outcomes of time-clamped and RPE-matched interactive video game dancing (VGD) and treadmill activity; 2) characterize the suitability of VGD to achieve MVPA designation; and, 3) investigate step count outcomes recorded by pedometry and accelerometry. Methods: Subjects underwent three testing sessions with the latter two randomized. During the familiarization visit, the perceived exertion (Borg RPE) of an interactive VGD activity was determined and a treadmill speed that resulted in an RPE-matched exertion level was identified through incremental increases in treadmill speed. On subsequent visits, subjects completed 15 minutes of VGD or RPE-matched treadmill activity. HR and step count were measured during both sessions. Results: Nine participants (Age 19.8 ± 1.6; 5 males; 4 females) volunteered. With time-clamped and RPE-matched, the average HR for dancing 154.7 (± 21.8) and treadmill activity 157.8 (± 25.1) were not different (p = 0.698). The selected dances for the VGD activity resulted in 8/9 subjects exercising at MVPA intensity according to percent of predicted maximal HR (threshold of 64% maximal HR; equation: 207 – 0.7*Age). Steps completed during dancing and treadmill activity according to pedometry were 1510 (± 488) and 2066 (± 247), respectively, with the difference being significant (p = 0.001). Steps completed during dancing and the treadmill activity according to accelerometry were 988 (± 256) and 1938 (± 119), respectively, with the difference again significant (p \u3c 0.001). The within-mode, between-device step count (pedometer vs. accelerometer, respectively) were also of interest. For dancing, a significant difference (p \u3c 0.001) was noted as 1510 (± 488) vs. 988 (± 256) steps. For treadmill activity, the disparity between 2066 (± 247) vs. 1938 (± 119) was also different (p = 0.042). Discussion: The HR response of a VGD activity was not different than a time-clamped, RPE-matched treadmill activity. Furthermore, VGD achieved designation as MVPA intensity in 8/9 subjects with the lone subject failing to achieve moderate designation by a single beat. Of note, objectively determined step count varied by mode and measuring device illustrating the need to employee prudency when selecting measuring technique for step count during rhythmic vs. non-rhythmic PA

Squamous cell carcinoma of the nipple following radiation therapy for ductal carcinoma in situ: a case report

<p>Abstract</p> <p>Introduction</p> <p>Radiation-induced nonmelanoma skin cancer was first reported seven years after the discovery of X-rays, but has received relatively little consideration in the literature. Specifically, nonmelanoma skin cancer after conservative surgery and radiation for early stage breast cancer has not been well studied. We report the case of a woman who developed squamous cell carcinoma of the nipple nine years after conservative surgery and radiation for ductal carcinoma <it>in situ </it>of the ipsilateral breast. We also review the relevant literature available to date.</p> <p>Case presentation</p> <p>A 66-year-old African-American woman presented to the hospital with a non-healing ulcer of the right nipple. Her past medical history was significant for right breast ductal carcinoma <it>in situ </it>for which she had undergone lumpectomy and whole breast radiation therapy nine years previously. Mammography and magnetic resonance imaging studies were negative for recurrent breast cancer. However, the latter demonstrated abnormal enhancement in the nipple-areolar region. An incisional biopsy of the lesion demonstrated invasive squamous cell carcinoma. Subsequently, the patient underwent wide excision of the nipple-areolar complex. Sentinel lymph-node biopsy was offered but our patient declined. She was considered to have local disease and hence no further treatment was recommended.</p> <p>Conclusion</p> <p>This case represents the first reported occurrence of squamous cell carcinoma of the nipple to follow conservative surgery and radiation for ductal carcinoma <it>in situ </it>of the ipsilateral breast. It is likely that radiation overexposure resulted in a radiation burn and subsequent radiodermatitis, placing it at risk for squamous cell carcinoma. A diagnosis of squamous cell carcinoma should be considered in a patient with a nipple lesion following radiation therapy for breast cancer.</p