3,492 research outputs found
ADAM-Anchorage Data: Are They Representative?
This paper presents the results of a study designed to assess the representativeness of realized samples of recent arrestees selected for the Arrestee Drug Abuse Monitoring (ADAM) program in Anchorage, Alaska. Because one of the most important goals of the ADAM program is to produce scientific information on the prevalence of alcohol and drug use behaviors among arrestees that is generalizable to an entire local arrestee population, establishing the representativeness of realized samples (or isolating inherent biases) is an essential first step to meaningful use of these data to address locally defined problems. In order to determine the reasonableness of inferences grounded in realized samples of ADAM respondents, an analysis was done comparing various characteristics between each stage of the sample selection process including the census of eligible arrestee population, the designed ADAM arrestee sample, arrestees available for interview, arrestees actually interviewed (“realized” sample), and arrestees that provided urine sample (“realized” sample). If the realized samples are similar to the census we can have a greater degree of confidence in our capacity to describe the population of Anchorage arrestees using ADAM data. Also, if it happens that departures are detected between realized samples and the arrestee census we are better positioned to condition the inferences made by integrating these discerned biases into our conclusions.Abstract /
The ADAM-Anchorage Program /
ADAM Sample Attrition /
Representativeness of the Realized Male Arrestee Samples /
Representativeness of the Realized Female Samples /
Conclusions /
Appendix [supplementary tables and figure
Police Alcohol-Related Services Study (PASS), Phase II: A Description of the Beliefs, Perceptions and Attitudes of Anchorage Police Department Employees
The principal aim of the Police Alcohol-related Services Study (PASS) was to expand knowledge about the fiscal, organizational, and cultural impact of citizen alcohol use on the Anchorage Police Department (APD). Phase II of the study employed a voluntary, self-administered questionnaire provided to all members of the APD regardless of rank, sworn status, or operational division. The questionnaire was designed to explore respondents' perceptions of their alcohol-related workload; perceptions of community problems; perceived links between alcohol use and selected social problems; attitudes, perceptions, and beliefs about the policing of alcohol-related incidents and the people involved with them; and personal and vicarious experience with alcohol-related incidents. The report describes survey response through comparison of APD employee responses across divisions within the department: operations vs. administration, patrol vs. non-patrol, and sworn vs. non-sworn.Part I. Project Overview & Summary of Findings / Part II. Alcohol-Related Workload: APD Employee Perspectives / Appendice
The Police Alcohol-Related Services Study (PASS): A Study of the Intersection of Public Alcohol Use and Routine Police Patrol
The principal aim of the Police Alcohol-related Services Study (PASS) was to expand knowledge about the fiscal, organizational, and cultural impact of citizen alcohol use on the Anchorage Police Department (APD). This report presents results from Phase I of the study, which examines the impact of citizen alcohol use as it relates directly to police patrol with a primary focus on issues of time-task allocations among Anchorage patrol officers. Data was collected through direct field observations of routine patrol operations of Anchorage police officers by professionally trained and certified interviewers.Acknowledgements / Chapter One: Study Overview / Chapter Two: Characteristics of P.A.S.S. Sample / Chapter Three: Patrol Work in Anchorage: A Brief Description of Time-Task Allotment / Chapter Four: Alcohol Involvement in Patrol Work: Number of Discrete Events / Chapter Five: Alcohol Involvement in Patrol Work: Time Spent on Alcohol-related Activities / Chapter Six: Estimating the Costs of Public Alcohol Use Incurred by the Anchorage Police Departmen
Long-Period Building Response to Earthquakes in the San Francisco Bay Area
This article reports a study of modeled, long-period building responses to ground-motion simulations of earthquakes in the San Francisco Bay Area. The earthquakes include the 1989 magnitude 6.9 Loma Prieta earthquake, a magnitude 7.8 simulation of the 1906 San Francisco earthquake, and two hypothetical magnitude 7.8 northern San Andreas fault earthquakes with hypocenters north and south of San Francisco. We use the simulated ground motions to excite nonlinear models of 20-story, steel, welded moment-resisting frame (MRF) buildings. We consider MRF buildings designed with two different strengths and modeled with either ductile or brittle welds. Using peak interstory drift ratio (IDR) as a performance measure, the stiffer, higher strength building models outperform the equivalent more flexible, lower strength designs. The hypothetical magnitude 7.8 earthquake with hypocenter north of San Francisco produces the most severe ground motions. In this simulation, the responses of the more flexible, lower strength building model with brittle welds exceed an IDR of 2.5% (that is, threaten life safety) on 54% of the urban area, compared to 4.6% of the urban area for the stiffer, higher strength building with ductile welds. We also use the simulated ground motions to predict the maximum isolator displacement of base-isolated buildings with linear, single-degree-of-freedom (SDOF) models. For two existing 3-sec isolator systems near San Francisco, the design maximum displacement is 0.5 m, and our simulations predict isolator displacements for this type of system in excess of 0.5 m in many urban areas. This article demonstrates that a large, 1906-like earthquake could cause significant damage to long-period buildings in the San Francisco Bay Area
Radial Velocity Confirmation of a Binary Detected from Pulse Timings
A periodic variation in the pulse timings of the pulsating hot subdwarf B
star CS 1246 was recently discovered via the O-C diagram and suggests the
presence of a binary companion with an orbital period of two weeks. Fits to
this phase variation, when interpreted as orbital reflex motion, imply CS 1246
orbits a barycenter 11 light-seconds away with a velocity of 16.6 km/s. Using
the Goodman spectrograph on the SOAR telescope, we decided to confirm this
hypothesis by obtaining radial velocity measurements of the system over several
months. Our spectra reveal a velocity variation with amplitude, period, and
phase in accordance with the O-C diagram predictions. This corroboration
demonstrates that the rapid pulsations of hot subdwarf B stars can be adequate
clocks for the discovery of binary companions via the pulse timing method.Comment: Accepted for publication in ApJ Letters; 5 pages, 2 figures, 3
tables; uses emulateap
Wind erosion in semiarid landscapes: Predictive models and remote sensing methods for the influence of vegetation
Wind erosion in semi-arid regions is a significant problem for which the sheltering effect of rangeland vegetation is poorly understood. Individual plants may be considered as porous roughness elements which absorb or redistribute the wind's momentum. The saltation threshold is the minimum wind velocity at which soil movement begins. The dependence of the saltation threshold on geometrical parameters of a uniform roughness array was studied in a wind tunnel. Both solid and porous elements were used to determine relationships between canopy structure and the threshold velocity for soil transport. The development of a predictive relation for the influence of vegetation canopy structure on wind erosion of soil is discussed
Wind erosion in semiarid landscapes: Predictive models and remote sensing methods for the influence of vegetation
The objectives of this research are: to develop and test predictive relations for the quantitative influence of vegetation canopy structure on wind erosion of semiarid rangeland soils, and to develop remote sensing methods for measuring the canopy structural parameters that determine sheltering against wind erosion. The influence of canopy structure on wind erosion will be investigated by means of wind-tunnel and field experiments using structural variables identified by the wind-tunnel and field experiments using model roughness elements to simulate plant canopies. The canopy structural variables identified by the wind-tunnel and field experiments as important in determining vegetative sheltering against wind erosion will then be measured at a number of naturally vegetated field sites and compared with estimates of these variables derived from analysis of remotely sensed data
Cool Customers in the Stellar Graveyard IV: Spitzer Search for Mid-IR excesses Around Five DAs
Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, require
external accretion of material to explain the presence of weak metal line
absorption in their photospheres. The source of this material is currently
unknown, but could come from the interstellar medium, unseen companions, or
relic planetesimals from asteroid belt or Kuiper belt analogues. Accurate
mid-infrared photometry of these white dwarfs provide additional information to
solve the mystery of this accretion and to look for evidence of planetary
systems that have survived post main sequence evolution. We present {\em
Spitzer} IRAC photometry accurate to 3% for four DAZs and one DA with
circumstellar absorption lines in the UV. We search for excesses due to unseen
companions or circumstellar dust disks. We use {\em Hubble Space Telescope}
NICMOS imaging of these white dwarfs to gauge the level of background
contamination to our targets as well as rule out common proper motion
companions to WD 1620-391. All of our targets show no excesses due to
companions 20 M, ruling out all but very low mass companions to these
white dwarfs at all separations. No excesses due to circumstellar disks are
observed, and we place limits on what types of disks may still be present.Comment: 18 pages, 8 figures, Accepted to A
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