Showing papers on "Population published in 1984"

Analysis of Survival Data

Abstract: The objective of this book is to give a concise account of the analysis of survival data. The book is intended both for the applied statistician and for a wider statistical audience wanting an introduction to this field. Particular attention is paid to new theory on the relationship between survival factors and identified explanatory variables. Each chapter concludes with bibliographic notes and outline statements of further results that can be used for student exercises. (ANNOTATION)

Some elements of a sociology of translation: domestication of the scallops and the fishermen of St Brieuc Bay

Abstract: This paper outlines a new approach to the study of power, that of the sociology of translation. Starting from three principles, those of agnosticism (impartiality between actors engaged in controversy), generalised symmetry (the commitment to explain conflicting viewpoints in the same terms) and free association (the abandonment of all a priori distinctions between the natural and the social), the paper describes a scientific and economic controversy about the causes for the decline in the population of scallops in St. Brieuc Bay and the attempts by three marine biologists to develop a conservation strategy for that population. Four ‘moments’ of translation are discerned in the attempts by these researchers to impose themselves and their definition of the situation on others: (a) problematisation: the researchers sought to become indispensable to other actors in the drama by denning the nature and the problems of the latter and then suggesting that these would be resolved if the actors negotiated the ‘obl...

Ribosomal DNA spacer-length polymorphisms in barley: mendelian inheritance, chromosomal location, and population dynamics.

Abstract: Spacer-length (sl) variation in ribosomal RNA gene clusters (rDNA) was surveyed in 502 individual barley plants, including samples from 50 accessions of cultivated barley, 25 accessions of its wild ancestor, and five generations of composite cross II (CCII), an experimental population of barley. In total, 17 rDNA sl phenotypes, made up of 15 different rDNA sl variants, were observed. The 15 rDNA sl variants comprise a complete ladder in which each variant differs in length from adjacent variants by approximately equal to 115 nucleotide pairs. Studies of four rDNA sl variants in an F2 population showed that these variants are located at two unlinked loci, Rrn1 and Rrn2, each with two codominant alleles. Using wheat-barley addition lines, we determined that Rrn1 and Rrn2 are located on chromosomes 6 and 7, respectively. The nonrandom distribution of sl variants between loci suggests that genetic exchange occurs much less frequently between than within the two loci, which demonstrates that Rrn1 and Rrn2 are useful as new genetic markers. Frequencies of rDNA sl phenotypes and variants were monitored over 54 generations in CCII. A phenotype that was originally infrequent in CCII ultimately became predominant, whereas the originally most frequent phenotype decreased drastically in frequency, and all other phenotypes originally present disappeared from the population. We conclude that the sl variants and/or associated loci are under selection in CCII.

Nonparametric estimation of the number of classes in a population

Abstract: On applique la methode d'Efron (1981, 1982) a la construction d'intervalles de confiance bases sur des distributions du bootstrap

The determinants of parenting: A process model.

Abstract: This essay is based on the assumption that a long-neglected topic of socialization, the determinants of individual differences in parental functioning, is illuminated by research on the etiology of child maltreatment. Three domains of determinants are identified (personal psychological resources of parents, characteristics of the child, and contextual sources of stress and support), and a process model of competent parental functioning is offered on the basis of the analysis. The model presumes that parental functioning is multiply determined, that sources of contextual stress and support can directly affect parenting or indirectly affect parenting by first influencing individual psychological well-being, that personality influences contextual support/stress, which feeds back to shape parenting, and that, in order of importance, the personal psychological resources of the parent are more effective in buffering the parent-child relation from stress than are contextual sources of support, which are themselves more effective than characteristics of the child.

Detection, Isolation, and Continuous Production of Cytopathic Retroviruses (HTLV-III) from Patients with AIDS and Pre-AIDS

Abstract: A cell system was developed for the reproducible detection of human T-lymphotropic retroviruses (HTLV family) from patients with the acquired immunodeficiency syndrome (AIDS) or with signs or symptoms that frequently precede AIDS (pre-AIDS). The cells are specific clones from a permissive human neoplastic T-cell line. Some of the clones permanently grow and continuously produce large amounts of virus after infection with cytopathic (HTLV-III) variants of these viruses. One cytopathic effect of HTLV-III in this system is the arrangement of multiple nuclei in a characteristic ring formation in giant cells of the infected T-cell population. These structures can be used as an indicator to detect HTLV-III in clinical specimens. This system opens the way to the routine detection of HTLV-III and related cytopathic variants of HTLV in patients with AIDS or pre-AIDS and in healthy carriers, and it provides large amounts of virus for detailed molecular and immunological analyses.

The ontogenetic niche and species interactions in size-structured populations

Abstract: Body size is manifestly one of the most important attributes of an organism from an ecological and evolutionary point of view. Size has a predominant influence on an animal's energetic requirements, its potential for resource exploitation, and its susceptibility to natural enemies. A large literature now exists on how physiological, life history, and population parameters scale with body dimensions (24, 131). The ecological literature on species interactions and the structure of animal communities also stresses the importance of body size. Differences in body size are a major means by which species avoid direct overlap in resource use (153), and size-selective predation can be a primary organizing force in some communities (20, 70). Size thus imposes important constraints on the manner in which an organism interacts with its environment and influences the strength, type, and symmetry of interactions with other species (152, 207). Paradoxically, ecologists have virtually ignored the implications of these observations for interactions among species that exhibit size-distributed populations. For instance, it has been often suggested that competing species

On the Average Value of Correlated Time Series, with Applications in Dendroclimatology and Hydrometeorology

Abstract: In a number of areas of applied climatology, time series are either averaged to enhance a common underlying signal or combined to produce area averages. How well, then, does the average of a finite number (N) of time series represent the population average, and how well will a subset of series represent the N-series average? We have answered these questions by deriving formulas for 1) the correlation coefficient between the average of N time series and the average of n such series (where n is an arbitrary subset of N) and 2) the correlation between the N-series average and the population. We refer to these mean correlations as the subsample signal strength (SSS) and the expressed population signal (EPS). They may be expressed in terms of the mean inter-series correlation coefficient r as SSS ≡ (Rn,N)2 ≈ n(1 + (N − 1)r)/ N(1 + (N − 1)r), EPS ≡ RN)2 ≈ Nr/1 + (N − 1)r.Similar formulas are given relating these mean correlations to the fractional common variance which arises as a parameter in a...

Ecological determinants of genetic structure in plant populations

Abstract: Plant populations are not randomly arranged assemblages of genotypes but are structured in space and time (2, 29, 49, 58, 84, 112). This structure may be manifested among geographically distinct populations, within a local group of plants, or even in the progeny of individuals. Genetic structure results from the joint action of mutation, migration, selection, and drift, which in tum must operate within the historical and biological context of each plant species. Ecological factors affecting reproduction and dispersal are likely to be particularly important in determining genetic structure (2, 31, 58). Reproduction is the process that translates the current genotypic array into that of subsequent generations, while the dispersal of pollen and seeds determines the postreproductive pattems of gene dispersion within and among populations. Although the concept of genetic structure has been used in various ways (58, 130, 154), we limit our definition to the nonrandom distribution of alleles or genotypes in space or time and disregard genome organization and meiotic processes that can also affect allele and genotype frequencies. Because of the limited mobility of plants, their genetic structure implies spatial structure, or the actual physical distribution of individuals. While spatial pattems often have genetic implications, nonrandom genetic pattems can exist without a nonrandom distribution of individuals. Conversely, a population may have a nonrandom spatial distribution without any accompanying genetic structure. Spatial and genetic patterns are often assumed to result from environmental heterogeneity and differential selection pressures (22, 53, 131, 132). Selection is a ubiquitous feature of natural populations; it alters gene and

Field and laboratory methods for general ecology

Abstract: Unit 1*Collecting, Analyzing, and Reporting Ecological Data 1a. Ecological Sampling 1b. Data Analysis 1c. Writing Research Reports Unit 2*Analysis of Habitats 2a. Microhabitat Analysis 2b. Atmospheric Analysis 2c. Substrate Analysis 2d. Analysis of Aquatic Habitats 2e. Chemical Analysis of Habitats 2f. Habitat Assessment Unit 3*Biotic Sampling Methods 3a. Plot Sampling 3b. Transect Sampling 3c. Point-quarter Sampling 3d. Terrestrial Invertebrate Sampling 3e. Aquatic Sampling 3f. Capture-recapture Sampling 3g. Removal Sampling 3h. Terrestrial Vertebrate Sampling Unit 4*Analysis of Populations 4a. Age Structure and Survivorship 4b. Population Growth 4c. Population Dispersion 4d. Competition 4e. Predation Unit 5* Analysis of Communities 5a. Community Structure 5b. Species Diversity 5c. Community Similarity Unit 6*Analysis of Production 6a. Biomass Measurements 6b. Aquatic Productivity 6c. Aquatic Microecosystems Appendixes A. Symbols and Abbreviations B. Equivalents for Units of Measurements C. Atomic Weights of Elements D. Common Logarithm E. Microcomputer Programming

Optimal Foraging Theory: A Critical Review

Abstract: Proponents of optimal foraging theory attempt to predict the behavior of animals while they are foraging; this theory is based on a number of assump­ tions ( 133 , 155 , 2 10, 23 1 ) . First, an individual's contribution to the next generation (i.e. its "fitness") depends on its behavior while foraging. This contribution may be measured genetically or culturally as the proportion of an individual's genes or "ideas", respectively, in the next generation. In the former case, the theory is simply an extension of Darwin's theory of evolution. Second, it is assumed that there should be a heritable component of foraging behavior, i.e. an animal that forages in a particular manner should be likely to have offspring that tend to forage in the same manner. This heritable compo­ nent can be either the actual foraging responses made by an animal or the rules by which an animal learns to make such responses. In other words, optimal foraging theory may apply regardless of whether the foraging behavior is learned or innate. Given these first two assumptions, it follows that the proportion of individuals in a population foraging in ways that enhance their fitness will tend to increase over time. Unless countervailed by sufficiently strong group selection (see 287, 242), foraging behavior will therefore evolve, and the average foraging behavior will increasingly come to be characterized by those characteristics that enhance individual fitness. The third assumption is that the relationship between foraging behavior and fitness is known. This relationship is usually referred to as the currency of fitness (23 1 ) . In general, any such currency will include a time scale, although in some cases it may be assumed that fitness is a function of some rate.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy: II. Prevalence and Risk of Diabetic Retinopathy When Age at Diagnosis Is Less Than 30 Years

Abstract: In a population-based study in southern Wisconsin, 996 insulin-taking, younger-onset diabetic persons were examined using standard protocols to determine the prevalence and severity of diabetic retinopathy and associated risk variables. The prevalence of diabetic retinopathy varied from 17% to 97.5% in persons with diabetes for less than five years and 15 or more years, respectively. Proliferative retinopathy varied from 1.2% to 67% in persons with diabetes for less than ten years and 35 or more years, respectively. For persons with diabetes of 10 years' duration or less, the Cox regression model relates the severity or retinopathy to longer duration, older age at examination, and higher levels of glycosylated hemoglobin. After ten years of diabetes, severity of retinopathy was related to longer duration, high levels of glycosylated hemoglobin, presence of proteinuria, higher diastolic BP, and male sex.

The Wisconsin epidemiologic study of diabetic retinopathy. III. Prevalence and risk of diabetic retinopathy when age at diagnosis is 30 or more years.

Abstract: • In a population-based study in southern Wisconsin, 1,370 patients given diagnoses of diabetes at age 30 years or older were examined using standard protocols to determine the prevalence and severity of diabetic retinopathy and associated risk variables. The prevalence of diabetic retinopathy varied from 28.8% in persons who had diabetes for less than five years to 77.8% in persons who had diabetes for 15 or more years. The rate of proliferative diabetic retinopathy varied from 2.0% in persons who had diabetes for less than five years to 15.5% in persons who had diabetes for 15 or more years. By using the Cox regression model, the severity of retinopathy was found to be related to longer duration of diabetes, younger age at diagnosis, higher glycosylated hemoglobin levels, higher systolic BP, use of insulin, presence of proteinuria, and small body mass.

Biomechanical analysis of human ligament grafts used in knee-ligament repairs and reconstructions.

Abstract: Virtually all types of collagenous tissues have been transferred in and around the knee joint for intra-articular and extra-articular ligament reconstructions. However, the mechanical properties (in particular, strength) of such grafts have not been determined in tissues from young adult donors, where age and disuse-related effects have been excluded. To provide this information, we subjected ligament graft tissues to high-strain-rate failure tests to determine their strength and elongation properties. The results were compared with the mechanical properties of anterior cruciate ligaments from a similar young-adult donor population. The study indicated that some graft tissues used in ligament reconstructions are markedly weak and therefore are at risk for elongation and failure at low forces. Grafts utilizing prepatellar retinacular tissues (as in certain anterior-cruciate reconstructions) and others in which a somewhat narrow width of fascia lata or distal iliotibial tract is utilized are included in this at-risk group. Wider grafts from the iliotibial tract or fascia lata would of course proportionally increase ultimate strength. The semitendinosus and gracilis tendons are stronger, having 70 and 49 per cent, respectively, of the initial strength of anterior cruciate ligaments. The bone-patellar tendon-bone graft (fourteen to fifteen millimeters wide, medial or central portion) was the strongest, with a mean strength of 159 to 168 per cent of that of anterior cruciate ligaments. Patellar tendon-bone units, based on grip-to-grip motions, were found to be three to four times stiffer than similarly gripped anterior cruciate ligaments, while gracilis and semitendinosus tendon preparations had values that were nearly identical to those of anterior cruciate ligaments.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulus-selective properties of inferior temporal neurons in the macaque

Abstract: Previous studies have reported that some neurons in the inferior temporal (IT) cortex respond selectively to highly specific complex objects. In the present study, we conducted the first systematic survey of the responses of IT neurons to both simple stimuli, such as edges and bars, and highly complex stimuli, such as models of flowers, snakes, hands, and faces. If a neuron responded to any of these stimuli, we attempted to isolate the critical stimulus features underlying the response. We found that many of the responsive neurons responded well to virtually every stimulus tested. The remaining, stimulus-selective cells were often selective along the dimensions of shape, color, or texture of a stimulus, and this selectivity was maintained throughout a large receptive field. Although most IT neurons do not appear to be “detectors” for complex objects, we did find a separate population of cells that responded selectively to faces. The responses of these cells were dependent on the configuration of specific face features, and their selectivity was maintained over changes in stimulus size and position. A particularly high incidence of such cells was found deep in the superior temporal sulcus. These results indicate that there may be specialized mechanisms for the analysis of faces in IT cortex.

Optimal Transmission Ranges for Randomly Distributed Packet Radio Terminals

Abstract: In multihop packet radio networks with randomly distributed terminals, the optimal transmission radii to maximize the expected progress of packets in desired directions are determined with a variety of transmission protocols and network configurations. It is shown that the FM capture phenomenon with slotted ALOHA greatly improves the expected progress over the system without capture due to the more limited area of possibly interfering terminals around the receiver. The (mini)slotted nonpersistent carrier-sense-multiple-access (CSMA) only slightly outperforms ALOHA, unlike the single-hop case (where a large improvement is available), because of a large area of "hidden" terminals and the long vulnerable period generated by them. As an example of an inhomogeneous terminal distribution, the effect of a gap in an otherwise randomly distributed terminal population on the expected progress of packets crossing the gap is considered. In this case, the disadvantage of using a large transmission radius is demonstrated.

Dairy chemistry and physics

Abstract: "Milk and products made from it affect the lives of a large proportion of the world's population. Many dairy products are consumed at times and in places far removed from the point at which the milk was produced. This is made possible by the chemical and physical treatments and fractionations applied to milk by modern technology. These treatments are designed to preserve the nutritional value of the milk constituents in the form of palatable products. As food technology in general becomes more advanced and more sophisticated, there is less need for specific commodity technology; on the other hand, there is more need for specific knowledge of raw materials and the effects of various processing treatments on them." - From the Preface to Dairy Chemistry and Physics

An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando Earthquake Sequence

Abstract: The orientations of fault planes and slip directions indicated by a population of earthquake focal mechanisms can be used to determine best fit regional principal stress directions and R = (σ2–σ1)/(σ3–σ1), a measure of relative stress magnitudes, under the assumption of uniform stress in the source region. This analysis allows for the possibility that failure occurs on preexisting zones of weakness of any orientation. In the inversion we perform a grid search of stress models to find the one which requires the smallest total rotation of all the fault planes that is needed to match the observed and predicted slip directions; the method allows for errors in orientations of both the fault planes and slip directions. We have an objective means for identifying the more likely of the two possible fault planes from each focal mechanism relative to a given stress model; thus we do not face the problem of ambiguity of nodal planes which plagues other analyses of this kind. By using a grid search of stress models rather than a linearization scheme, we are able to perform a realistic error analysis and thus establish confidence limits for the preferred regional stresses. The method can be used to investigate possible stress inhomogeneities during earthquake sequences by analyzing subsets of the data population. The technique has been applied to 76 events from the San Fernando earthquake sequence for which we have found best fit stresses (plunge and azimuth): σ1, = 7,187; σ2 = 27,281; σ3 = 62,84; and R = 0.65. The average misfit between this stress model and all the data is about 8°, and all but eight of the aftershocks have misfits of less than 20°. These values are considerably less than the uncertainty of the focal mechanism determinations; therefore significant stress inhomogeneities are not required by the data. Our analysis does not support the suggestion of a change in stresses during the aftershock sequence, as proposed by others on the basis of an apparent change in focal mechanisms.

Powder surface area and porosity

Abstract: I Theoretical.- 1 Introduction.- 1.1 Real surfaces.- 1.2 Factors affecting surface area.- 1.3 Surface area from size distributions.- 2 Gas adsorption.- 2.1 Introduction.- 2.2 Physical and chemical adsorption.- 2.3 Physical adsorption forces.- 3 Adsorption isotherms.- 4 Langmuir and BET theories.- 4.1 The Langmuir isotherm, type I.- 4.2 The Brunauer, Emmett and Teller (BET) theory.- 4.3 Surface areas from the BET equation.- 4.4 The meaning of monolayer coverage.- 4.5 The BET constant and site occupancy.- 4.6 Applicability of the BET theory.- 4.7 Some criticism of the BET theory.- 5 The single point BET method.- 5.1 Derivation of the single-point method.- 5.2 Comparison of the single-point and multipoint methods.- 5.3 Further comparisons of the multi- and single-point methods.- 6 Adsorbate cross-sectional areas.- 6.1 Cross-sectional areas from the liquid molar volume.- 6.2 Nitrogen as the standard adsorbate.- 6.3 Some adsorbate cross-sectional areas.- 7 Other surface area methods.- 7.1 Harkins and Jura relative method.- 7.2 Harkins and Jura absolute method.- 7.3 Permeametry.- 8 Pore analysis by adsorption.- 8.1 The Kelvin equation.- 8.2 Adsorption hysteresis.- 8.3 Types of hysteresis.- 8.4 Total pore volume.- 8.5 Pore-size distributions.- 8.6 Modelless pore-size analysis.- 8.7 V?t curves.- 9 Microporosity.- 9.1 Introduction.- 9.2 Langmuir plots for microporous surface area.- 9.3 Extensions of Polanyi's theory for micropore volume and area.- 9.4 The t-method.- 9.5 The MP method.- 9.6 Total micropore volume and surface area.- 10 Theory of wetting and capillarity for mercury porosimetry.- 10.1 Introduction.- 10.2 Young and Laplace equation.- 10.3 Wetting or contact angles.- 10.4 Capillarity.- 10.5 Washburn equation.- 11 Interpretation of mercury porosimetry data.- 11.1 Application of the Washburn equation.- 11.2 Intrusion-extrusion curves.- 11.3 Common features of porosimetry curves.- 11.4 Solid compressibility.- 11.5 Surface area from intrusion curves.- 11.6 Pore-size distribution.- 11.7 Volume In radius distribution function.- 11.8 Pore surface area distribution.- 11.9 Pore length distribution.- 11.10 Pore population.- 11.11 Plots of porosimetry functions.- 11.12 Comparisons of porosimetry and gas adsorption.- 12 Hysteresis, entrapment, and contact angle.- 12.1 Introduction.- 12.2 Contact angle changes.- 12.3 Porosimetric work.- 12.4 Theory of porosimetry hysteresis.- 12.5 Pore potential.- 12.6 Other hysteresis theories.- 12.7 Equivalency of mercury porosimetry and gas adsorption.- II Experimental.- 13 Adsorption measurements-Preliminaries.- 13.1 Reference standards.- 13.2 Other preliminary precautions.- 13.3 Representative samples.- 13.4 Sample conditioning.- 14 Vacuum volumetric measurements.- 14.1 Nitrogen adsorption.- 14.2 Deviation from ideality.- 14.3 Sample cells.- 14.4 Evacuation and outgassing.- 14.5 Temperature control.- 14.6 Isotherms.- 14.7 Low surface areas.- 14.8 Saturated vapor pressure, P0 of nitrogen.- 15 Dynamic methods.- 15.1 Influence of helium.- 15.2 Nelson and Eggertsen continuous flow method.- 15.3 Carrier gas and detector sensitivity.- 15.4 Design parameters for continuous flow apparatus.- 15.5 Signals and signal calibration.- 15.6 Adsorption and desorption isotherms by continuous flow.- 15.7 Low surface area measurements.- 15.8 Data reduction-continuous flow.- 15.9 Single-point method.- 16 Other flow methods.- 16.1 Pressure jump method.- 16.2 Continuous isotherms.- 16.3 Frontal analysis.- 17 Gravimetric method.- 17.1 Electronic microbalances.- 17.2 Buoyancy corrections.- 17.3 Thermal transpiration.- 17.4 Other gravimetric methods.- 18 Comparison of experimental adsorption methods.- 19 Chemisorption.- 19.1 Introduction.- 19.2 Chemisorption equilibrium and kinetics.- 19.3 Chemisorption isotherms.- 19.4 Surface titrations.- 20 Mercury porosimetry.- 20.1 Introduction.- 20.2 Pressure generators.- 20.3 Dilatometer.- 20.4 Continuous-scan porosimetry.- 20.5 Logarithmic signals from continuous-scan porosimetry.- 20.6 Low pressure intrusion-extrusion scans.- 20.7 Scanning porosimetry data reduction.- 20.8 Contact angle for mercury porosimetry.- 21 Density measurement.- 21.1 True density.- 21.2 Apparent density.- 21.3 Bulk density.- 21.4 Tap density.- 21.5 Effective density.- 21.6 Density by mercury porosimetry.- References.

Age-Related Macular Degeneration and Blindness due to Neovascular Maculopathy

Abstract: Age-related macular degeneration (AMD) is one of the four most common causes of blindness in the United States. Retinal manifestations of AMD can be categorized as either atrophic or neovascular/exudative. To the best of our knowledge, the proportion of patients legally blind due to the neovascular/exudative manifestations of this disease has not been previously reported. Data from two studies, the Framingham Eye Study and a large case-control study, demonstrate that the vast majority of patients with legal blindness due to AMD have the neovascular/exudative form of the disease. Seventy-nine percent of eyes legally blind due to AMD in the Framingham population and 90% of eyes legally blind due to AMD in the case-control study had neovascular/exudative retinopathy. This is in spite of the fact that neovascular/exudative retinopathy is a relatively infrequent complication of AMD.

Muscle fiber type composition of the rat hindlimb

Abstract: The purpose of this study was to estimate the absolute and relative masses of the three types of skeletal muscle fibers in the total hindlimb of the male Sprague-Dawley rat (Rattus norvegicus). For six rats, total body mass was recorded and the following weights taken from dissection of one hindlimb: 32 individual major muscles or muscle parts, remaining skeletal musculature (small hip muscles and intrinsic foot muscles), bone, inguinal fat pad, and skin. The fibers from the 32 muscles or muscle parts (which constituted 98% of the hindlimb skeletal muscle mass) were classified from histochemistry as fast-twitch oxidative glycolytic (FOG), fast-twitch glycolytic (FG), or slow-twitch oxidative (SO), and their populations were determined. Fiber cross-sectional areas from the same muscles were measured with a digitizer. Mass of each of the fiber types within muscles and in the total hindlimb was then calculated from fiber-type population, fiber-type area, and muscle-mass data. Skeletal muscle made up 71% of the total hindlimb mass. Of this, 76% was occupied by FG fibers, 19% by FOG fibers, and 5% by SO fibers. Thus, the FG fiber type is clearly the predominant fiber type in the rat hindlimb in terms of muscle mass. Fiber-type mass data are compared with physiological (blood flow) and biochemical (succinate dehydrogenase activities) data for the muscles taken from previous studies, and it is demonstrated that these functional properties are closely related to the proportions of muscle mass composed of the various fiber types.

The Body Esteem Scale: multidimensional structure and sex differences in a college population.

Abstract: Norms and reliability and validity data are presented for an objectively scored Body Esteem Scale. Factor analysis of the scale revealed that body esteem is a multidimensional construct which differs for males and females. For males, the body esteem dimensions dealt with physical attractiveness, upper body strength, and physical condition. For females, the dimensions dealt with sexual attractiveness, weight concern, and physical condition. The three aspects of males' body esteem were more highly intercorrelated than those of the females, indicating a greater degree of body esteem differentiation for females than for males.

The Karnofsky Performance Status Scale. An examination of its reliability and validity in a research setting.

Abstract: The Karnofsky Performance Status Scale (KPS) is widely used to quantify the functional status of cancer patients. However, limited data exist documenting its reliability and validity. The KPS is used in the National Hospice Study (NHS) as both a study eligibility criterion and an outcome measure. As part of intensive training, interviewers were instructed in and tested on guidelines for determining the KPS levels of patients. After 4 months of field experience, interviewers were again tested based on narrative patient descriptions. The interrator reliability of 47 NHS interviewers was found to be 0.97. The construct validity of the KPS was analyzed, and the KPS was found to be strongly related (P less than 0.001) to two other independent measures of patient functioning. Finally, the relationship of the KPS to longevity (r = 0.30) in a population of terminal cancer patients documents its predictive validity. These findings suggest the utility of the KPS as a valuable research tool when employed by trained observers.

Psychosocial influences on mortality after myocardial infarction.

Abstract: Psychosocial interviews with 2320 male survivors of acute myocardial infarction, participants in the beta-Blocker Heart Attack Trial, permitted the definition of two variables strongly associated with an increased three-year mortality risk. With other important prognostic factors controlled for, the patients classified as being socially isolated and having a high degree of life stress had more than four times the risk of death of the men with low levels of both stress and isolation. An inverse association of education with mortality in this population reflected the gradient in the prevalence of the defined psychosocial characteristics. High levels of stress and social isolation were most prevalent among the least-educated men and least prevalent among the best-educated. The increase in risk associated with stress and social isolation applied both to total deaths and to sudden cardiac deaths and was noted among men with both high and low levels of ventricular ectopy during hospitalization for the acute infarction.

Social Dynamics: Models and Methods

Abstract: This book attempts to provide a broad framework for thinking about and conducting quantitative empirical studies of social change processes. The goals of this book are 1) to clarify and develop models and methods for causal analysis of dynamic social processes 2) to formulate continuous-time models of change in both quantitative and qualitative outcomes and to develop suitable methods for estimating these models from the kinds of data commonly available to sociologists 3) to develop a stochastic framework for analyzing both qualitative and quantitative outcomes and 4) to alter the way that sociologists think about the empirical study of social change processes. Part I provides general background for what follows; it includes both a discussion of the substantive importance of dynamic analyses in sociology and a review of models and methods previously used by sociologists interested in the empirical study of social dynamics. Part II contains 8 chapters on models and methods for anallyzing change in qualitative outcomes; it concentrates mainly on methods based on analysis of event-history data. Part III contains 6 chapters on comprable models and methods for analyzing change in quantitative outcomes; it focuses primarily on methods based on analysis of panel data.

The injury fact book

Abstract: This book includes detailed information on many of the factors surrounding injuries--the man-made systems and products involved, the groups at greatest risk, and effective ways to protect people from injuries. The circumstances under which injuries occur, the etiologic agents, and the characteristics of the people involved are examined. Chapter 2 summarizes the importance of injuries in relation to other prominent health problems. Subsequent chapters describe injury mortality and, in cases where good population-based studies are available, nonfatal injuries. The analyses in Chapters 3-15 are primarily of injury deaths during 1977-1979, the most recent years for which detailed mortality data were available in mid-1983 for deaths other than those related to motor vehicles. Most of these data were collected by the U.S. Department of Health and Human Services, National Center for Health Statistics (NCHS). Chapters 16-20 summarize data on deaths from motor vehicle-related injuries. Most of these detailed data were obtained from the U.S. Department of Transportation, National Highway Traffic Safety Administration (NHTSA). Data from the 1980 census provided denominators for the rates throughout the book, except for trendline calculations which were based on interpolations between census years. The purpose of this book is to improve understanding of the nature and magnitude of the injury problem in the United States. Although it includes some discussion of ameliorative approaches, there is no comprehensive coverage of injury research, theory, or prevention, since these have been comprehensively discussed elsewhere. This book is a thorough documentation of the injury problem. Most of the information presented is new, the product of analyses not previously published in any form.

Inequality decomposition by population subgroups

Abstract: This paper examines the implications of imposing a weak aggregation condition on inequality indices, so that the overall inequality value can be computed from information concerning the size, mean, and inequality value of each population subgroup. It is shown that such decomposable inequality measures must be monotonic transformations of additively decomposable indices. The general functional form of decomposable indices is derived without assuming that the measures are differentiable. The analysis is suitable for extension to the many other kinds of indices for which a similar relationship between the overall index value and subaggregates is desirable.