3,209 research outputs found
THE ROLE OF STATED PREFERENCES AND DISCRETE CHOICE MODELS IN IDENTIFYING COMMUNITY PREFERENCES FOR TRAFFIC MANAGEMENT DEVICES
Responsible local governments recognise the need to be sensitive to the local environmental implications of decisions taken in the course of developing strategies to ensure the efficient use of scarce resources. Rather than rely on the pressures of lobby groups to direct government behaviour in relation to community concerns, a preferred strategy is to identify the preferences and choices of the community as a whole and to use information from a representative cross-section from the community to aid in making environmentally-linked decisions which maximise the benefits to the affected community. This paper demonstrates how discrete-choice models can be used to identify community choices amongst alternative traffic management devices designed to improve the traffic environment within and in the vicinity of local residential streets. Using a "before" and "after" survey strategy, the study provides evidence to support the view that a set of guidelines representing the communities preferences for different devices should be based on an empirical model estimated on a sample of residents who have already had exposure to a range of devices
Tandem concentrator solar cells with 30 percent (AMO) power conversion efficiency
Very high efficiency concentrator solar panels are envisioned as economical and reliable electrical power subsystems for space based platforms of the future. GaAs concentrator cells with very high efficiencies and good sub-bandgap transmissions can be fabricated on standard wafers. GaSb booster cell development is progressing very well; performance characteristics are still improving dramatically. Consistent GaAs/GaSb stacked cell AMO efficiencies greater than 30 percent are expected
Probing the Relation Between X-ray-Derived and Weak-Lensing-Derived Masses for Shear-Selected Galaxy Clusters: I. A781
We compare X-ray and weak-lensing masses for four galaxy clusters that
comprise the top-ranked shear-selected cluster system in the Deep Lens Survey.
The weak-lensing observations of this system, which is associated with A781,
are from the Kitt Peak Mayall 4-m telescope, and the X-ray observations are
from both Chandra and XMM-Newton. For a faithful comparison of masses, we adopt
the same matter density profile for each method, which we choose to be an NFW
profile. Since neither the X-ray nor weak-lensing data are deep enough to well
constrain both the NFW scale radius and central density, we estimate the scale
radius using a fitting function for the concentration derived from cosmological
hydrodynamic simulations and an X-ray estimate of the mass assuming
isothermality. We keep this scale radius in common for both X-ray and
weak-lensing profiles, and fit for the central density, which scales linearly
with mass. We find that for three of these clusters, there is agreement between
X-ray and weak-lensing NFW central densities, and thus masses. For the other
cluster, the X-ray central density is higher than that from weak-lensing by 2
sigma. X-ray images suggest that this cluster may be undergoing a merger with a
smaller cluster. This work serves as an additional step towards understanding
the possible biases in X-ray and weak-lensing cluster mass estimation methods.
Such understanding is vital to efforts to constrain cosmology using X-ray or
weak-lensing cluster surveys to trace the growth of structure over cosmic time.Comment: 14 pages, 7 figures, matches version in Ap
Comparison of Glucose Monitoring Methods during Steady-State Exercise in Women
Data from Continuous Glucose Monitoring (CGM) systems may help improve overall daily glycemia; however, the accuracy of CGM during exercise remains questionable. The objective of this single group experimental study was to compare CGM-estimated values to venous plasma glucose (VPG) and capillary plasma glucose (CPG) during steady-state exercise. Twelve recreationally active females without diabetes (aged 21.8 ± 2.4 years), from Central Washington University completed the study. CGM is used by individuals with diabetes, however the purpose of this study was to first validate the use of this device during exercise for anyone. Data were collected between November 2009 and April 2010. Participants performed two identical 45-min steady-state cycling trials (~60% Pmax) on non-consecutive days. Glucose concentrations (CGM-estimated, VPG, and CPG values) were measured every 5 min. Two carbohydrate gel supplements along with 360 mL of water were consumed 15 min into exercise. A product-moment correlation was used to assess the relationship and a Bland-Altman analysis determined error between the three glucose measurement methods. It was found that the CGM system overestimated mean VPG (mean absolute difference 17.4 mg/dL (0.97 mmol/L)) and mean CPG (mean absolute difference 15.5 mg/dL (0.86 mmol/L)). Bland-Altman analysis displayed wide limits of agreement (95% confidence interval) of 44.3 mg/dL (2.46 mmol/L) (VPG compared with CGM) and 41.2 mg/dL (2.29 mmol/L) (CPG compared with CGM). Results from the current study support that data from CGM did not meet accuracy standards from the 15197 International Organization for Standardization (ISO)
LESSONS FROM THE MOTORIZED MIGRATIONS
Ten experiments have been conducted to determine if cranes can be led on migration and if those so trained will repeat migrations on their own. Results have been mixed as we have experienced the mishaps common to pilot studies. Nevertheless, we have learned many valuable lessons. Chief among these are that cranes can be led long distances behind motorized craft (air and ground), and those led over most or the entire route will return north come spring and south in fall to and from the general area of training. However, they will follow their own route. Groups transported south and flown at intervals along the route will migrate but often miss target termini. If certain protocol restrictions are followed, it is possible to make the trained cranes wild, however, the most practical way of so doing is to introduce them into a flock of wild cranes. We project that it is possible to create or restore wild migratory flocks of cranes by first leading small groups from chosen northern to southern termini
Does Racism Make Us Sick? 13th Annual Summer Public Health Research Institute and Videoconference on Minority Health
Live, interactive broadcast via Internet (webcast) and c-band satellite from the UNC Sonja Haynes Stone Center for Black Culture and History (SCBCH)
Comparative Study of Groundwater-Induced Subsidence for London and Delhi Using PSInSAR
Groundwater variation can cause land-surface movement, which in turn can cause significant and recurrent harm to infrastructure and the water storage capacity of aquifers. The capital cities in the England (London) and India (Delhi) are witnessing an ever-increasing population that has resulted in excess pressure on groundwater resources. Thus, monitoring groundwater-induced land movement in both these cities is very important in terms of understanding the risk posed to assets. Here, Sentinel-1 C-band radar images and the persistent scatterer interferometric synthetic aperture radar (PSInSAR) methodology are used to study land movement for London and National Capital Territory (NCT)-Delhi from October 2016 to December 2020. The land movement velocities were found to vary between −24 and +24 mm/year for London and between −18 and +30 mm/year for NCT-Delhi. This land movement was compared with observed groundwater levels, and spatio-temporal variation of groundwater and land movement was studied in conjunction. It was broadly observed that the extraction of a large quantity of groundwater leads to land subsidence, whereas groundwater recharge leads to uplift. A mathematical model was used to quantify land subsid-ence/uplift which occurred due to groundwater depletion/rebound. This is the first study that compares C-band PSInSAR-derived land subsidence response to observed groundwater change for Lon-don and NCT-Delhi during this time-period. The results of this study could be helpful to examine the potential implications of ground-level movement on the resource management, safety, and economics of both these cities
Epidural Hematoma Following Cervical Spine Surgery.
STUDY DESIGN: A multicentered retrospective case series.
OBJECTIVE: To determine the incidence and circumstances surrounding the development of a symptomatic postoperative epidural hematoma in the cervical spine.
METHODS: Patients who underwent cervical spine surgery between January 1, 2005, and December 31, 2011, at 23 institutions were reviewed, and all patients who developed an epidural hematoma were identified.
RESULTS: A total of 16 582 cervical spine surgeries were identified, and 15 patients developed a postoperative epidural hematoma, for a total incidence of 0.090%. Substantial variation between institutions was noted, with 11 sites reporting no epidural hematomas, and 1 site reporting an incidence of 0.76%. All patients initially presented with a neurologic deficit. Nine patients had complete resolution of the neurologic deficit after hematoma evacuation; however 2 of the 3 patients (66%) who had a delay in the diagnosis of the epidural hematoma had residual neurologic deficits compared to only 4 of the 12 patients (33%) who had no delay in the diagnosis or treatment (P = .53). Additionally, the patients who experienced a postoperative epidural hematoma did not experience any significant improvement in health-related quality-of-life metrics as a result of the index procedure at final follow-up evaluation.
CONCLUSION: This is the largest series to date to analyze the incidence of an epidural hematoma following cervical spine surgery, and this study suggest that an epidural hematoma occurs in approximately 1 out of 1000 cervical spine surgeries. Prompt diagnosis and treatment may improve the chance of making a complete neurologic recovery, but patients who develop this complication do not show improvements in the health-related quality-of-life measurements
Anemia is an independent risk for mortality after acute myocardial infarction in patients with and without diabetes
INTRODUCTION: Anemia and diabetes are risk factors for short-term mortality following an acute myocardial infarction(AMI). Anemia is more prevalent in patients with diabetes. We performed a retrospective study to assess the impact of the combination of diabetes and anemia on post-myocardial infarction outcomes. METHODS: Data relating to all consecutive patients hospitalized with AMI was obtained from a population-based disease-specific registry. Patients were divided into 4 groups: diabetes and anemia (group A, n = 716), diabetes and no anemia (group B, n = 1894), no diabetes and anemia (group C, n = 869), and no diabetes and no anemia (group D, n = 3987). Mortality at 30 days and 31 days to 36 months were the main outcome measures. RESULTS: 30-day mortality was 32.3% in group A, 16.1% in group B, 21.5% in group C, 6.6% in group D (all p < 0.001). 31-day to 36-month mortality was 47.6% in group A, 20.8% in group B, 34.3% in group C, and 10.4% in group D (all p < 0.001). Diabetes and anemia remained independent risk factors for mortality with odds ratios of 1.61 (1.41–1.85, p < 0.001) and 1.59 (1.38–1.85, p < 0.001) respectively at 36 months. Cardiovascular death from 31-days to 36-months was 43.7% of deaths in group A, 54.1% in group B, 47.0% in group C, 50.8% group D (A vs B, p < 0.05). INTERPRETATION: Patients with both diabetes and anemia have a significantly higher mortality than those with either diabetes or anemia alone. Cardiovascular death remained the most likely cause of mortality in all groups
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