3,739 research outputs found
The pulsation spectrum of VX Hydrae
We present the results of a two-year, multisite observing campaign
investigating the high-amplitude delta Scuti star VX Hydrae during the 2006 and
2007 observing seasons. The final data set consists of nearly 8500 V-band
observations spanning HJD 2453763.6 to 2454212.7 (2006 January 28 to 2007 April
22). Separate analyses of the two individual seasons of data yield 25
confidently-detected frequencies common to both data sets, of which two are
pulsation modes, and the remaining 23 are Fourier harmonics or beat frequencies
of these two modes. The 2006 data set had five additional frequencies with
amplitudes less than 1.5 mmag, and the 2007 data had one additional frequency.
Analysis of the full 2006-2007 data set yields 22 of the 25 frequencies found
in the individual seasons of data. There are no significant peaks in the
spectrum other than these between 0 and 60 c/d. The frequencies of the two main
pulsation modes derived from the 2006 and 2007 observing seasons individually
do not differ at the level of 3-sigma, and thus we find no conclusive evidence
for period change over the span of these observations. However, the amplitude
of f(1) = 5.7898 c/d changed significantly between the two seasons, while the
amplitude of f(0) = 4.4765 c/d remained constant; amplitudes of the Fourier
harmonics and beat frequencies of f(1) also changed. Similar behavior was seen
in the 1950s, and it is clear that VX Hydrae undergoes significant amplitude
changes over time.Comment: 14 pages, 5 figures, published in Publications of the Astronomical
Society of the Pacific, v.121, p.1076 (October 2009
Using Cluster Analysis to Explore Associations between Cardiovascular Risk and Lifestyle Factors in a Workplace Wellness Program
Background: Cardiovascular disease (CVD) is the number one cause of death in the United States with risk factors including hypertension, hyperlipidemia, diabetes, obesity, smoking, physical inactivity, age, genetics, and unhealthy diets. A university-based workplace wellness program (WWP) consisting of an annual biometric screening assessment with targeted, individualized health coaching was implemented in an effort to reduce these risk factors while encouraging and nurturing ideal cardiovascular health.Objective: The purpose of this study was to examine and describe the prevalence of single and combined, or multiple, CVD risk factors within a workplace wellness dataset.Methods: Cluster analysis was used to determine CVD risk factors within biometric screening data (BMI, waist circumference, LDL, total cholesterol, HDL, triglycerides, blood glucose age, ethnicity, and gender) collected during WWP interventions.Results: The cluster analysis provided visualizations of the distributions of participants having specific CVD risk factors. Of the 8,802 participants, 1,967 (22.4%) had no CVD risk factor, 1,497 (17%) had a single risk factor, and 5,529 (60.5%) had two or more risk factors. The majority of sample members are described as having more than one CVD risk factor with 78% having multiple.Conclusion: Cluster analysis demonstrated utility and efficacy in categorizing participant data based on their CVD risk factors. A baseline analysis of data was captured and provided understanding and awareness into employee health and CVD risk. This process and analysis facilitated WWP planning to target and focus on education to promote ideal cardiovascular health
An optimized analytical method for the simultaneous detection of iodoform, iodoacetic acid, and other trihalomethanes and haloacetic acids in drinking water
An optimized method is presented using liquid-liquid extraction and derivatization for the extraction of iodoacetic acid (IAA) and other haloacetic acids (HAA9) and direct extraction of iodoform (IF) and other trihalomethanes (THM4) from drinking water, followed by detection by gas chromatography with electron capture detection (GC-ECD). A Doehlert experimental design was performed to determine the optimum conditions for the five most significant factors in the derivatization step: namely, the volume and concentration of acidic methanol (optimized values  = 15%, 1 mL), the volume and concentration of Na2SO4 solution (129 g/L, 8.5 mL), and the volume of saturated NaHCO3 solution (1 mL). Also, derivatization time and temperature were optimized by a two-variable Doehlert design, resulting in the following optimized parameters: an extraction time of 11 minutes for IF and THM4 and 14 minutes for IAA and HAA9; mass of anhydrous Na2SO4 of 4 g for IF and THM4 and 16 g for IAA and HAA9; derivatization time of 160 min and temperature at 40°C. Under optimal conditions, the optimized procedure achieves excellent linearity (R2 ranges 0.9990–0.9998), low detection limits (0.0008–0.2 µg/L), low quantification limits (0.008–0.4 µg/L), and good recovery (86.6%–106.3%). Intra- and inter-day precision were less than 8.9% and 8.8%, respectively. The method was validated by applying it to the analysis of raw, flocculated, settled, and finished waters collected from a water treatment plant in China
How distant? An experimental analysis of students’ COVID-19 exposure and physical distancing in university buildings
University buildings are significant closed built environments for COVID-19
spreading. As universities prepare to re-start in-class activities, students'
adherence to physical distancing requirements is a priority topic. While
physical distancing in classrooms can be easily managed, the movement of
students inside common spaces can pose higher risks due to individuals'
proximity. This paper provides an experimental analysis of unidirectional
student flow inside a case-study university building, by investigating
students' movements and grouping behaviour according to physical distancing
requirements. Results show general adherence with the minimum required physical
distancing guidance, but some spaces, such as corridors, pose higher exposure
than doorways. Their width, in combination with group behaviour, affects the
students' capacity to keep the recommended distance. Furthermore, students
report higher perceived vulnerability while moving along corridors.
Evidence-based results can support decision-makers in understanding
individuals' exposure in universities and researchers in developing behavioural
models in preparation of future outbreaks and pandemics.Comment: 22 pages, 5 figures, 1 table. Currently submitted to "International
Journal of Disaster Risk Reduction
Quantitative Differences in Alanine in Rice Panicles of Varieties Resistant and Susceptible to Kernel Smut
Recent physical conditions and health service utilization in people with common mental disorders and severe mental illness in England: Comparative cross-sectional data from a nationally representative sample
BACKGROUND.: Policies addressing the physical health of people with mental disorders have historically focused on those with severe mental illness (SMI), giving less prominence to the more prevalent common mental disorders (CMDs). Little is known about the comparative physical health outcomes of these patient groups. We aimed to first compare the: (a) number of past-year chronic physical conditions and (b) recent physical health service utilization between CMDs vs. SMI, and secondly compare these outcomes between people with CMDs vs. people without mental disorders. METHODS.: We analyzed cross-sectional data from the third Adult Psychiatric Morbidity Survey, a representative sample of the English population. We determined the presence of physical conditions and health service utilization by self-report and performed logistic regression models to examine associations of these outcomes between participant groups. RESULTS.: Past-year physical conditions were reported by the majority of participants (CMDs, n = 815, 62.1%; SMI = 27, 63.1%) with no variation in the adjusted odds of at least one physical condition between diagnoses (odds ratio [OR] = 0.96, 95% confidence intervals [CI] 0.42-1.98, p = 0.784). People with CMDs were significantly more likely to be recently hospitalized relative to with those with SMI (OR = 6.33, 95% CI 5.50-9.01, p < 0.05). Having a CMD was associated with significantly higher odds of past-year physical conditions and recent health service utilization (all p < 0.001) compared with the general population. CONCLUSIONS.: People with CMDs experience excess physical health morbidities in a similar pattern to those found among people with SMI, while their somatic hospitalization rates are even more elevated. Findings highlight the importance of recalibrating existing public health strategies to bring equity to the physical health needs of this patient group
How distant? An experimental analysis of students’ COVID-19 exposure and physical distancing in university buildings
Closed university buildings proved to be one of the main hot spots for virus transmission during pandemics. As shown during the COVID-19 pandemic, physical distancing is one of the most effective measures to limit such transmission. As universities prepare to manage in-class activities, students’ adherence to physical distancing requirements is a priority topic. Unfortunately, while physical distancing in classrooms can be easily managed, the movement of students inside common spaces can pose high risk of close proximity. This paper provides an experimental analysis of unidirectional student movement inside a case-study university building to investigate how physical distancing requirements impact student movement and grouping behaviour. Results show general adherence with the minimum required physical distancing guidance, but spaces such as corridors pose higher risk of exposure than doorways. Doorway width, in combination with group behaviour, affect the students' capacity to keep the recommended physical distance. Furthermore, questionnaire results show that students report higher perceived vulnerability while moving along corridors. Evidence-based results can support decision-makers in understanding individuals’ exposure to COVID-19 in universities and researchers in developing behavioural models in preparation of future outbreaks and pandemics
Techniques for data prediction, smoothing, and updating of operator errors in commercial nuclear power plants
http://www.worldcat.org/oclc/533896
- …