Showing papers by "RAND Corporation published in 1992"
TL;DR: In this article, factor analysis of two widely used instruments revealed that optimism and pessimism are empirically differentiable, but related, constructs and that optimism was primarily associated with extraversion and positive affect while pessimism was principally associated with neuroticism and negative affect.
Abstract: Contrary to unidimensional conceptions of optimism and pessimism, factor analysis of 2 widely used instruments revealed that optimism and pessimism are empirically differentiable, but related, constructs. Moreover, consistent with expectations, optimism and pessimism were differentially linked with fundamental dimensions of mood and personality. Pessimism was principally associated with neuroticism and negative affect. Optimism was primarily associated with extraversion and positive affect. Findings are discussed with reference to current conceptual and measurement models of optimism and pessimism and their relations to broad dimensions of mood and personality
559 citations
TL;DR: Patients who were distressed about their health, used avoidant coping strategies, or who reported worse physical and role functioning were less likely to adhere in general, but patient satisfaction with two features of care was positively related to adherence in some models, but satisfaction with the technical quality of carewas negatively associated with adherence to specific recommendations among heart disease patients.
Abstract: A longitudinal study of patients with chronic medical diseases (hypertension, diabetes, heart disease) was conducted to identify antecedents of adherence to medical recommendations. Data are from 1198 patients in three health-care provision systems in Los Angeles, Chicago, and Boston. Nonadherence at the beginning of the study was the strongest predictor of nonadherence 2 years later. Other significant predictors varied by type of adherence outcome. Patients who were younger and who relied upon avoidant coping strategies tended to be less likely to follow their doctor's specific recommendations. Patients who were distressed about their health, used avoidant coping strategies, or who reported worse physical and role functioning were less likely to adhere in general. Patient satisfaction with two features of care (interpersonal quality and financial aspects) was positively related to adherence in some models, but satisfaction with the technical quality of care was negatively associated with adherence to specific recommendations among heart disease patients. Social support contributed to specific adherence among diabetic patients. Implications of the study for medical care providers are discussed.
534 citations
TL;DR: Although variations in patient mix should be a major determinant of variations in resource use, the independent effects of specialty training, payment system, and practice organization on utilization rates need further explication.
Abstract: Objective. —To examine whether specialty and system of care exert independent effects on resource utilization. Study Design. —Cross-sectional analysis of just over 20 000 patients (≥18 years of age) who visited providers' offices during 9-day periods in 1986. Patient- and physician-provided information was obtained by self-administered questionnaires. Setting. —Offices of 349 physicians practicing family medicine, internal medicine, endocrinology, and cardiology within health maintenance organizations, large multispecialty groups, and solo practices or small single-specialty group practices in three major US cities. Outcome Measures. —Indicators of the intensity of resource utilization were examined among four medical specialties (family practice, general internal medicine, cardiology, and endocrinology) and five systems of care (health maintenance organization, multispecialty group—fee-for-service, multispecialty group—prepaid; solo practice and single-specialty group—fee-for-service, and solo practice and single-specialty group—prepaid) before and after controlling for the mix of patients seen in these offices. The indicators of resource utilization were hospitalizations, annual office visits, prescription drugs, and common tests and procedures, with rates estimated on both a per-visit and per-year basis. Results. —Variation in patient mix was a major determinant of the large variations in resource use. However, increased utilization was also independently related to specialty (cardiology and endocrinology), fee-for-service payment plan, and solo and single-specialty group practice arrangements. After adjusting for patient mix, solo practice/single-specialty groups—fee-for-service had 41% more hospitalizations than health maintenance organizations. General internists had utilization rates somewhat greater than family physicians on some indicators. Conclusion. —Although variations in patient mix should be a major determinant of variations in resource use, the independent effects of specialty training, payment system, and practice organization on utilization rates need further explication. The 2- and 4-year outcomes now being analyzed will provide information critical to interpretation of the variations reported herein. ( JAMA . 1992;267:1624-1630)
519 citations
TL;DR: The findings emphasize the poor prognosis associated with dysthymia even in the absence of major depression; the prognostic significance of subthreshold depressive symptoms; and the clinical significance of assessing level of severity of symptoms as well as functional status and well-being, regardless of type of depressive disorder.
Abstract: • Objective.— To compare the course of depression during a 2-year period in adult outpatients (n=626) with current major depression, dysthymia, and either both current disorders ("double depression") or depressive symptoms with no current depressive disorder. Methods.— Depressed patients visiting 523 clinicians (mental health specialists and general medical providers) were identified using a two-stage screening procedure including the Diagnostic Interview Schedule. The course of depression was assessed in 2 follow-up years with a structured telephone interview based on the format of the Diagnostic Interview Schedule. Results.— Baseline severity of depressive symptoms was greatest in patients with double depression, but initial functional status was poor in those with dysthymia with or without concurrent major depression. Patients with dysthymia had the worst outcomes, those with current major depression alone had intermediate outcomes, and those with subthreshold depressive symptoms had the best outcomes. Even the latter group, however, had a high incidence (25%) of major depressive episode over 2 years. Initial depression severity and level of functional status accounted for more explained variance in outcomes than did type of depressive disorder. Conclusions.— The findings emphasize the poor prognosis associated with dysthymia even in the absence of major depression; the prognostic significance of subthreshold depressive symptoms; and the clinical significance of assessing level of severity of symptoms as well as functional status and well-being,` regardless of type of depressive disorder.
497 citations
TL;DR: Spinal manipulation is of short-term benefit in some patients, particularly those with uncomplicated, acute low- back pain, and data are insufficient concerning the efficacy of spinal manipulation for chronic low-back pain.
Abstract: ▪Purpose:To review the use, complications, and efficacy of spinal manipulation as a treatment for low-back pain. ▪Data Identification:Articles were identified through a MEDLINE search, rev...
450 citations
TL;DR: Quality varies from state to state, but teaching, larger, and more urban hospitals have better quality in general than nonteaching, small, and rural hospitals.
Abstract: Objective. —To compare quality of care measured by explicit criteria, implicit review, and sickness-adjusted outcomes at different types of hospitals. Design. —Further analysis of data retrospectively abstracted from medical records to evaluate the effects of prospective payment on quality of care for hospitalized Medicare patients. Setting. —Hospitals in five states were sampled to represent the national Medicare admissions along many dimensions. Patients. —A total of 14008 elderly patients with one of the following five diseases: congestive heart failure, acute myocardial infarction, pneumonia, stroke, or hip fracture. These patients were randomly sampled from those with these diseases in 297 hospitals in two time periods, 1981 to 1982 and 1985 to 1986. Outcome Measures. —Explicit criteria, implicit review, and mortality within 30 days of admission adjusted for sickness at admission. Results. —Quality of care ratings for hospital types are similar using explicit criteria, implicit review, and outcomes adjusted for sickness at admission. Quality differences between types of hospitals were large, with the lowest group estimated to have four percentage points higher mortality than major teaching hospitals in a cohort of patients with average mortality of 16%. Quality varies from state to state, but teaching, larger, and more urban hospitals have better quality in general than nonteaching, small, and rural hospitals. Hospital quality persists overtime, but small nonteaching hospitals narrowed the gap with better quality hospitals between 1981 and 1986. Conclusions. —The different measures led to consistent and plausible relationships between quality and hospital characteristics. Thus, valid information about hospital quality can be obtained. We need to develop ways to use such information to improve care. ( JAMA . 1992;268:1709-1714)
410 citations
TL;DR: A broad range of strategies for implementing clinical practice guidelines based on the social influences that affect health practitioner behavior are described and issues surrounding the selection and use of individual strategies or combinations of strategies in specific efforts to improve the quality of health care are examined.
369 citations
TL;DR: In this article, both acidification and trophic position enhanced the bioaccumulation of methyl-Hg in the plankton in Little Rock Lake, and a consistant pattern of methylHg enrichment (2−4 ×) in water, bulk phytoplankton, and individual zooplankston was associated with a 1.5 unit pH decrease in Little-rock Lake.
Abstract: Using trace-metal-clean sampling and handling techniques along with ultrasensitive analytical procedures, it is possible to measure both total Hg and monomethylmercury (methyl-Hg) in natural planktonic communities with the same level of taxonomic, ontogenic, and trophic resolution that is currently possible in fish communities. In an experimentally manipulated lake, both acidification and trophic position enhanced the bioaccumulation of methyl-Hg in the plankton. A consistant pattern of methyl-Hg enrichment (2−4 ×) in water, bulk phytoplankton, and individual zooplankton was associated with a 1.5 unit pH decrease in Little Rock Lake. Regardless of pH, bioconcentration factors [Bf = log(Cb/Cw), where Cb and Cw are Hg concentrations in biota and water] were substantially higher for methyl-Hg than those for total Hg or nonmethyl-Hg at three pelagic trophic levels (~10−100×). Between each trophic level, the Bf(methyl-Hg) increased by ~0.5 log units, clearly indicating biomagnification. Although somewhat higher in the acidified basin, Bf(methyl-Hg) was more strongly influenced by trophic position than by pH. This suggests that methyl-Hg was bioaccumulated largely in proportion to supply and that acidification may have directly increased supply to the base of the food chain.
353 citations
TL;DR: In this article, a 4-year prospective longitudinal follow-up study of functionally impaired community-dwelling elderly persons was conducted to assess the value of functional status questions in predicting mortality.
349 citations
TL;DR: In this paper, the dominant Lyapunov exponent (LE) is estimated for biological and economic systems that are subjected to random perturbations and observed over a limited amount of time.
Abstract: In the past twenty years there has been much interest in the physical and biological sciences in nonlinear dynamical systems that appear to have random, unpredictable behavior. One important parameter of a dynamic system is the dominant Lyapunov exponent (LE). When the behavior of the system is compared for two similar initial conditions, this exponent is related to the rate at which the subsequent trajectories diverge. A bounded system with a positive LE is one operational definition of chaotic behavior. Most methods for determining the LE have assumed thousands of observations generated from carefully controlled physical experiments. Less attention has been given to estimating the LE for biological and economic systems that are subjected to random perturbations and observed over a limited amount of time. Using nonparametric regression techniques (Neural Networks and Thin Plate Splines) it is possible to consistently estimate the LE. The properties of these methods have been studied using simulated data and are applied to a biological time series: marten fur returns for the Hudson Bay Company (1820-1900). Based on a nonparametric analysis there is little evidence for lowdimensional chaos in these data. Although these methods appear to work well for systems perturbed by small amounts of noise, finding chaos in a system with a significant stochastic component may be difficult.
331 citations
TL;DR: It is found that as the importance of a hospital to the PPO in an area increases, the price rises substantially, and the common practice of using counties to define the market leads to an underestimate of the price-increasing effects of a merger.
TL;DR: The ability of a quality of life instrument to detect clinically important changes over time, “responsiveness”, is a distinct psychometric property from the measure's reliability and validity, and it is argued that responsiveness is actually one indication of a measure's validity.
Abstract: Assessment of health-related quality of life is accelerating in naturalistic observational studies, clinical trials, and clinical practice. Some researchers have argued that the ability of a quality of life instrument to detect clinically important changes over time, “responsiveness”, is a distinct psychometric property from the measure's reliability and validity. We discuss the important implications of this argument and counter that responsiveness is actually one indication of a measure's validity.
TL;DR: Patient mix is related to utilization and differs significantly across medical specialties and systems of care and must be taken into account when interpreting variations in utilization and outcomes across specialty and systems, and when considering alternative policies for payment.
Abstract: Objective. —To determine differences in the mix of patients among medical specialties and among organizational systems of care. Study Design. —Cross-sectional analysis of 20 158 adults (≥18 years of age) who visited providers' offices during 9-day screening periods in 1986. Patient and physician information was obtained by self-administered, standardized questionnaires. Setting. —Offices of 349 physicians practicing family medicine, internal medicine, endocrinology, and cardiology within health maintenance organizations, large multispecialty groups, and solo or small single-specialty group practices in three major US cities. Outcome Measures. —Demographic characteristics, prevalence of chronic disease, disease-specific severity of illness, and functional status and well-being. Results. —Among patients with selected physician-reported chronic illnesses (diabetes, hypertension, recent myocardial infarction, or congestive heart failure), increasing levels of severity were associated with decreasing levels of functional status and well-being and with increased hospitalizations, more physician visits, and higher numbers of prescription drugs. Compared with patients of general internists, patients of cardiologists were older (56 vs 47 years, P P P P P P P P P Conclusion. —Patient mix is related to utilization and differs significantly across medical specialties and systems of care. These differences must be taken into account when interpreting variations in utilization and outcomes across specialties and systems, and when considering alternative policies for payment. ( JAMA . 1992;267:1617-1623)
TL;DR: A problematic aspect of blind signatures is discussed, showing that this perfect solution to protect the identity and privacy of a user can potentially lead to perfect crime.
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01 Jan 1992TL;DR: In this article, the authors examined the impact of public policies on three anthropometric outcomes: height for age and weight for height of children as well as body mass index of adults.
Abstract: Using data from Cote d'Ivoire, this paper examines the impact of public policies on three anthropometric outcomes: height for age and weight for height of children as well as body mass index of adults. During the eighties, low growth rates in Cote d'Ivoire were accompanied by an economic adjustment program which included substantial cuts in public spending together with increases in the relative price of foods. If reductions in social spending resulted in lower availability and quality of health care services, then results suggest that child health (particularly height for age) will have been adversely affected. The provision of basic services (such as immunizations) and ensuring facilities are equipped with simple materials (such as having basic drugs in stock) will yield high social returns in terms of improved child health. Food prices have tended to rise in Cote d'Ivoire during the eighties and the authors find that higher food prices have had a significantly detrimental impact on the health of Ivorian children (as measured by weight for height) and adults (as indicated by lower body mass indices). In contrast, the effects of income on health are significant but quite small, except in the case of adult women.
TL;DR: Galileo images of Gaspra reveal it to be an irregularly shaped object that appears to have been created by a catastrophic collisional disruption of a precursor parent body.
Abstract: Galileo images of Gaspra reveal it to be an irregularly shaped object (19 by 12 by 11 kilometers) that appears to have been created by a catastrophic collisional disruption of a precursor parent body. The cratering age of the surface is about 200 million years. Subtle albedo and color variations appear to correlate with morphological features: Brighter materials are associated with craters especially along the crests of ridges, have a stronger 1-micrometer absorption, and may represent freshly excavated mafic materials; darker materials exhibiting a significantly weaker 1-micrometer absorption appear concentrated in interridge areas. One explanation of these patterns is that Gaspra is covered with a thin regolith and that some of this material has migrated downslope in some areas.
TL;DR: Results show that expenditure had a positive, significant effect on the height of children 2 years and older, and was a significant determinant for literate and illiterate mothers, and not well educated mothers.
TL;DR: In this article, the effects of a sequential decision strategy (1992-2002) consisting of a near-term period (1992−2002) during which either moderate emissions reductions (achieved by energy conservation only) or aggressive reductions (energy conservation coupled with switching to other fuel sources) are begun, and a subsequent longterm period during which a least-cost abatement policy is followed to limit global mean temperature change to an optimal target ΔT*.
Abstract: CURRENT debate on policies for limiting climate change due to greenhouse-gas emissions focuses on whether to take action now or later, and on how stringent any emissions reductions should be in the near and long term. Any reductions policies implemented now will need to be revised later as scientific understanding of climate change improves. Here we consider the effects of a sequential-decision strategy (Fig. 1) consisting of a near-term period (1992–2002) during which either moderate emissions reductions (achieved by energy conservation only) or aggressive reductions (energy conservation coupled with switching to other fuel sources) are begun, and a subsequent long-term period during which a least-cost abatement policy is followed to limit global mean temperature change to an optimal target ΔT*. For each policy we calculate the global mean surface temperature change ΔT(t) using a simple climate/ocean model for climate sensitivities ΔT2x. (the response to doubled CO2, concentrations) of 4.5,2.5,1.5 and 0.5 °C. The policy beginning with moderate reductions is less expensive than that with aggressive reductions if ΔT*>2.9, 2.1, 1.5 and 0.9 °C respectively; otherwise, the aggressive-reductions policy is cheaper. We suggest that this approach should assist in choosing realistic targets and in determining how best to implement emissions reductions in the short and long term.
TL;DR: Examination of the extent to which social support and stressful life events were more or less beneficial for the long-term physical functioning and emotional well-being of chronically ill patients showed that social support was beneficial for health over time regardless of age.
Abstract: There is substantial evidence of individual variation in health-related quality of life measures that is not accounted for by age or disease condition. An understanding of factors that determine good health is necessary for maintained function and improved quality of life. This study examines the extent to which social support and stressful life events were more or less beneficial for the long-term physical functioning and emotional well-being of 1402 chronically ill patients. Analyses, conducted separately in three age groups, showed that social support was beneficial for health over time regardless of age. In addition, low levels of support were particularly damaging for the physical functioning of older patients. Stressful life events impacted differentially on health-related quality of life: relationship events had an immediate effect on well-being which diminished with time; financial events had an immediate negative effect on functioning and well-being which persisted over time for middle-aged patients; bereavement had a delayed impact on quality of life, with the youngest patients especially vulnerable to its negative effects; work-related events had both negative and positive effects, depending on age group. Results reinforce the importance of identifying and dealing with psychosocial problems among patients with chronic disease.
TL;DR: Analysis of pattern of drug involvement among 4,145 West Coast adolescents over the 4-year span from Grades 7-10 found no evidence that cocaine has become a gateway drug, but provided some support for treating cocaine initiation as a separate stage that precedes the onset of hard drugs other than pills.
Abstract: Using a new technique for tracing the sequence of use over time, this study examined the pattern of drug involvement among 4,145 West Coast adolescents over the 4-year span from Grades 7-10. During the period covered, the mid- to late 1980s, we found no evidence that cocaine has become a gateway drug. However, the data provided some support for treating cocaine initiation as a separate stage that precedes the onset of hard drugs other than pills. The analysis also showed that increased involvement with legal drugs constitutes an important step in the transition to hard drug use for most adolescents. Weekly alcohol use followed marijuana use and preceded use of all other illicit drugs for Hispanic, White, and Black youth. However, it followed use of hard drugs for Asians. Weekly smoking formed a distinct stage between initial use of pills and other hard drugs for non-Hispanic Whites. The results underscore the importance of prevention efforts aimed at curbing the transition to regular use of alcohol and cigarettes, as well as their initial use.
TL;DR: In this paper, the dominant Lyapunov exponent λ 1 is estimated from time series data generated by a nonlinear autoregressive system with additive noise, which is the defining feature of chaotic dynamics.
Abstract: We discuss procedures based on nonparametric regression for estimating the dominant Lyapunov Exponent λ1 from time series data generated by a nonlinear autoregressive system with additive noise. For systems with bounded fluctuations, λ1 > 0 is the defining feature of chaos. Thus our procedures can be used to examine time series data for evidence of chaotic dynamics. We show that a consistent estimator of the partial derivatives of the autoregression function can be used to obtain a consistent estimator of λ1. The rate of convergence we establish is quite slow; a better rate of convergence is derived heuristically and supported by simulations. Simulation results from several implementations—one “local” (thin-plate splines) and three “global” (neural nets, radial basis functions, and projection pursuit)—are presented for two deterministic chaotic systems. Local splines and neural nets yield accurate estimates of the Lyapunov exponent; however, the spline method is sensitive to the choice of the emb...
TL;DR: Instruments examined include the Quality of Well-Being Scale, the HIV Overview of Problems/Evaluation System, the COOP Charts, and six Medical Outcomes Study-based measures: the SF-20, SF-30, AIDS-HAQ,SF-36,sf-38 and SF-56.
Abstract: This paper provides a selective review of instruments currently being employed to evaluate generic health-related quality of life in studies of persons with human immunodeficiency virus (HIV). Instruments examined include the Quality of Well-Being Scale, the HIV Overview of Problems/Evaluation System, the COOP Charts, and six Medical Outcomes Study-based measures: the SF-20, SF-30, AIDS-HAQ, SF-36, SF-38 and SF-56. Relative strengths and weaknesses of the measures are discussed.
TL;DR: In this article, the authors compared the performance of a state's peer review organization (PRO) with an independent, credible judgment of quality of care (QoC) based on blinded, structured, implicit reviews of hospital records.
Abstract: Objective. —To determine how well one state's peer review organization (PRO) judged the quality of hospital care compared with an independent, credible judgment of quality of care. Design. —Retrospective study comparing a PRO's review, including initial screening, physician review, and final judgments, with an independent "study judgment" based on blinded, structured, implicit reviews of hospital records. Setting. —One state's medical and surgical Medicare hospitalizations during 1985 through 1987 audited randomly by the state's PRO. Sample. —Stratified random sampling of records: 62 records that passed the PRO initial screening process and were not referred for PRO physician review; 50 records that failed PRO screen and then were confirmed by PRO physicians to be "quality problems." Intervention. —None. Main Outcome Measure. —A study judgment of below standard or standard or above based on the mean of overall ratings by five internists for records in medical diagnosis related groups (DRGs) and by five internists and five surgeons for surgical DRGs. Each step in the PRO review was evaluated for how many records passing or failing that step were judged standard or above or below standard in the study (positive and negative predictive value) and how well that step classified records that the study judged below standard or standard or above (sensitivity and specificity). Results. —An estimated 18% of records reviewed by the PRO were below standard according to the study judgment, compared with 6.3% quality problems according to the PRO's final judgment (difference, 12%; 95% confidence interval, 1 to 23). The PRO's initial screening process failed to detect and refer for PRO physician review two of three records that the study judged below standard. In addition, only one of three of the records that PRO physicians judged to be quality problems were judged below standard by the study judgment. Therefore, the PRO's final quality of care judgment and the study judgment agreed little more than expected by chance, especially about poor quality of care. Although the PRO correctly classified 95% of the records that the study judged standard or above, it detected only 11% of records judged below standard by the study. Conclusions. —Most of all, this PRO review process would be improved by additional preliminary screens to identify the 67% of records that the study judged below standard but that passed its initial screening. The screening process also must be more accurate in order to be cost-effective, as it was only slightly better than random sampling at correctly identifying below standard care. More reproducible physician review is also needed and might be accomplished through improved reviewer selection and training, a structured review method, and more physician reviewers per record. ( JAMA . 1992;267:2349-2354)
TL;DR: Data from a national survey of mandated reporters that included vignettes in which case and personal characteristics were systematically varied reveal that respondents noticed and responded to case characteristics, and three case characteristics were powerful predictors of vignette outcomes.
TL;DR: The all-surgical panel was more likely to favor operative treatment for carotid disease than the multispecialty panel, but that concensus judgments of inappropriateness by the two panels were very similar.
Abstract: The current interest in the development of practice guidelines raises an important question about the effect of expert panel composition on the outcome of the guideline development process. We compared the ratings of appropriateness of indications for carotid endarterectomy produced by two panels: an all-surgical panel and a "balanced" panel composed of four surgeons, two neurologists, and one specialist each from family practice, internal medicine, and radiology. We then compared the effect of the two sets of ratings when used to evaluate 1302 patients who had undergone carotid endarterectomy. The all-surgical panel found more indications "appropriate" (24 versus 14%) and fewer indications "inappropriate" (61 versus 70%) than the balanced panel (p less than 0.01). The all-surgical panel also more often reached agreement. When ratings were applied to patients, 70% were appropriate by the all-surgical criteria versus 38% by the balanced panel, while 19% of the operations were inappropriate by all-surgical criteria, versus 31% by the balanced panel ratings. However, the percentage of procedures judged "inappropriate with agreement" was 15% for all-surgical and 16% for the balanced panel. We conclude that the all-surgical panel was more likely to favor operative treatment for carotid disease than the multispecialty panel, but that concensus judgments of inappropriateness by the two panels were very similar.
TL;DR: The Solid State Imaging (SSI) experiment on the Galileo Orbiter spacecraft utilizes a high-resolution (1500 mm focal length) television camera with an 800 × 800 pixel virtual-phase, charge-coupled detector.
Abstract: The Solid State Imaging (SSI) experiment on the Galileo Orbiter spacecraft utilizes a high-resolution (1500 mm focal length) television camera with an 800 × 800 pixel virtual-phase, charge-coupled detector It is designed to return images of Jupiter and its satellites that are characterized by a combination of sensitivity levels, spatial resolution, geometric fiedelity, and spectral range unmatched by imaging data obtained previously The spectral range extends from approximately 375 to 1100 nm and only in the near ultra-violet region (~350nm) is the spectral coverage reduced from previous missions The camera is approximately 100 times more sensitive than those used in the Voyager mission, and, because of the nature of the satellite encounters, will produce images with approximately 100 times the ground resolution (ie, ~50mlp−1) on the Galilean satellites We describe aspects of the detector including its sensitivity to energetic particle radiation and how the requirements for a large full-well capacity and long-term stability in operating voltages led to the choice of the virtual phase chip The F/85 camera system can reach point sources of F(mag) ~ 11 with S/N ~ 10 and extended sources with surface brightness as low as 20 kR in its highest gain state and longest exposure mode We describe the performance of the system as determined by ground calibration and the improvements that have been made to the telescope (same basic catadioptric design that was used in Mariner 10 and the Voyager high-resolution cameras) to reduce the scattered light reaching the detector The images are linearly digitized 8-bits deep and, after flat-fielding, are cosmetically clean Information ‘preserving’ and ‘non-preserving’ on-board data compression capabilities are outlined A special “summation” mode, designed for use deep in the Jovian radiation belts, near Io, is also described The detector is ‘preflashed’ before each exposure to ensure the photometric linearity The dynamic range is spread over 3 gain states and an exposure range from 417 ms to 512 s A low-level of radial, third-order, geometric distortion has been measured in the raw images that is entirely due to the optical design The distortion is of the pincushion type and amounts to about 12 pixels in the corners of the images It is expected to be very stable
TL;DR: Results indicate that clinical interventions to improve quality of life in this population should include family psychoeducational programs and better detection, evaluation, and treatment of both depressive symptoms and side effects of medication.
Abstract: improving the quality of life of persons with chronic mental illness is becoming an important treatment goal. in this study, 101 former acute care psychiatric inpatients with serious mental illness who were living in Mississippi communities were interviewed using portions of Lehman's Quality of Life interview. A particular focus was whether clinical characteristics, such as medication compliance and social skills, that could be changed by interventions were associated with patients' ratings of their quality of life. Self-reports of better quality of life were associated with fewer depressive symptoms, fewer medication side effects, and better family interactions. Results indicate that clinical interventions to improve quality of life in this population should include family psychoeducational programs and better detection, evaluation, and treatment of both depressive symptoms and side effects of medication.
TL;DR: The authors explored the relation between gender and education in rural Peru using data from the 1985-86 Peru Living Standards Survey and developed a model of educational choice to assess the impact of user fees on demand and revenues.
Abstract: In most of the developing world the education of women lags behind that of men. This could come about from a lack of parental desire for educated daughters or from a perception by the parents that there is a lower net return to education for girls. The relation between gender and education in rural Peru is explored using data from the 1985-86 Peru Living Standards Survey. A model of educational choice is developed. The estimated demand functions are used to assess the impact of user fees on demand and revenues. The empirical evidence indicates that parents are more willing to pay for reduced travel time to secondary school for boys than for girls. However, parents are willing to pay increased fees for girls' schooling sufficient to generate teachers' salaries. Copyright 1992 by Oxford University Press.
TL;DR: A model of the process of becoming involved with drugs during junior high provides support for hypotheses drawn from both social and cognitive theories and indicates that both generic and drug-specific effects are needed to explain adolescent drug use.
Abstract: We tested a model of the process of becoming involved with drugs during junior high. The sample included 698 students who were not using alcohol, cigarettes, or marijuana during Grade 7 (T1); the follow-up data points were 12 and 15 months later (T2 and T3). The final model, which predicted 72% of the variance in drug use at T3, provides support for hypotheses drawn from both social and cognitive theories. Weak familial and school attachments fostered use by increasing the likelihood of exposure to pro-drug social influences (drug use offers); weak bonds with school also directly affected cognitive motivations (lower resistance self-efficacy [RSE] and more positive outcome expectancies). In turn, social influences at T1 played a dominant role in initial use at T2, but cognitive motivations were also significant. At T3, prior use assumed the most prominent position. Drug-specific measures of RSE and expected use directly affected later use of that substance. The results indicate that both generic and drug-specific effects are needed to explain adolescent drug use. Implications for prevention programs are discussed. Language: en
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TL;DR: In this paper, the authors compared the legitimate and criminal earnings of mid-rate and high-rate burglars, robbers, auto thieves, swindlers, and mixed types (mostly drug dealers) among state prison inmates in California, Michigan, and Texas and compared to the inmates' perceptions of their earnings.
Abstract: The legitimate and the criminal earnings of mid-rate and high-rate burglars, robbers, auto thieves, swindlers, and mixed types (mostly drug dealers) among state prison inmates in California, Michigan, and Texas are estimated and compared to the inmates' perceptions of their earnings. Crime appears to pay less than legitimate work for most mid-rate offenders; the reverse is true for most high-rate offenders. Inmates believe that they receive from crime much more than they do in fact. The earnings from crime per day spent in prison decrease as the number of crimes increases, suggesting that high-rate offenders commit crimes with little regard to the net yield. We suggest that career criminals do not maximize the net benefits of crime because they are highly present-oriented and quite opportunistic.