Showing papers by "University of Wisconsin-Madison published in 1993"

The Occurrence of Sleep-Disordered Breathing among Middle-Aged Adults

Abstract: Background Limited data have suggested that sleep-disordered breathing, a condition of repeated episodes of apnea and hypopnea during sleep, is prevalent among adults. Data from the Wisconsin Sleep Cohort Study, a longitudinal study of the natural history of cardiopulmonary disorders of sleep, were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health. Methods A random sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep (the apnea-hypopnea score). We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score (≥ 5, ≥ 10, and ≥ 15); we used logistic regression to investigate risk factors. Results The estimated prevalence of sleep-disordered breathing, defined as an apnea-hypopnea score of 5 or higher, was 9 percent for w...

Adolescence-limited and life-course-persistent antisocial behavior: A developmental taxonomy.

Abstract: This chapter suggests that delinquency conceals two distinct categories of individuals, each with a unique natural history and etiology: A small group engages in antisocial behavior of one sort or another at every life stage, whereas a larger group is antisocial only during adolescence. According to the theory of life-course-persistent antisocial behavior, children's neuropsychological problems interact cumulatively with their criminogenic environments across development, culminating m a pathological personality. According to the theory of adolescence-limited antisocial behavior, a contemporary maturity gap encourages teens to mimic antisocial behavior in ways that are normative and adjustive. There are marked individual differences in the stability of antisocial behavior. The chapter reviews the mysterious relationship between age and antisocial behavior. Some youths who refrain from antisocial behavior may, for some reason, not sense the maturity gap and therefore lack the hypothesized motivation for experimenting with crime.

Identification of Endogenous Social Effects: The Reflection Problem

Abstract: This paper examines the reflection problem that arises when a researcher observing the distribution of behaviour in a population tries to infer whether the average behaviour in some group influences the behaviour of the individuals that comprise the group. It is found that inference is not possible unless the researcher has prior information specifying the compisition of reference groups. If this information is available, the prospects for inference depend critically on the population relationship between the variables defining reference groups and those directly affecting outcomes. Inference is difficult to implossible if these variables are functionally dependent or are statistically independent. The prospects are better if the variables defining reference groups and those directly affecting outcomes are moderately related in the population.

Compendium of physical activities: classification of energy costs of human physical activities.

Abstract: A coding scheme is presented for classifying physical activity by rate of energy expenditure, i.e., by intensity. Energy cost was established by a review of published and unpublished data. This coding scheme employs five digits that classify activity by purpose (i.e., sports, occupation, sel

Factors affecting trust in market research relationships.

Abstract: Building on previous work suggesting that trust is critical in facilitating exchange relationships, the authors describe a comprehensive theory of trust in market research relationships. This theor...

Psychological impact of biculturalism: Evidence and theory.

Abstract: A vital step in the development of an equal partnership for minorities in the academic, social, and economic life of the United States involves moving away from assumptions of the linear model of cultural acquisition. In this article we review the literature on the psychological impact of being bicultural. Assimilation, acculturation, alternation, multicultural, and fusion models that have been used to describe the psychological processes, social experiences, and individual challenges and obstacles of being bicultural are reviewed and summarized for their contributions and implications for investigations of the psychological impact of biculturalism. Emphasis is given to the alternation model, which posits that an individual is able to gain competence within 2 cultures without losing his or her cultural identity or having to choose one culture over the other. Finally, a hypothetical model outlining the dimensions of bicultural competence is presented.

Three-dimensional structure of myosin subfragment-1: a molecular motor

Abstract: Directed movement is a characteristic of many living organisms and occurs as a result of the transformation of chemical energy into mechanical energy. Myosin is one of three families of molecular motors that are responsible for cellular motility. The three-dimensional structure of the head portion of myosin, or subfragment-1, which contains both the actin and nucleotide binding sites, is described. This structure of a molecular motor was determined by single crystal x-ray diffraction. The data provide a structural framework for understanding the molecular basis of motility.

Structure of the actin-myosin complex and its implications for muscle contraction.

Abstract: Muscle contraction consists of a cyclical interaction between myosin and actin driven by the concomitant hydrolysis of adenosine triphosphate (ATP). A model for the rigor complex of F actin and the myosin head was obtained by combining the molecular structures of the individual proteins with the low-resolution electron density maps of the complex derived by cryo-electron microscopy and image analysis. The spatial relation between the ATP binding pocket on myosin and the major contact area on actin suggests a working hypothesis for the crossbridge cycle that is consistent with previous independent structural and biochemical studies.

Biological Nitrogen Fixation

Abstract: Biological nitrogen fixation (BNF) is the process of the reduction of dinitrogen from the air to ammonia carried out by a large number of species of free-living and symbiotic microbes called diazotrophs. BNF presents an inexpensive and environmentally sound, sustainable approach to crop production and constitutes one of the most important Plant Growth Promotion (PGP) scenarios. Here I will summarize various aspects of BNF, including the dinitrogen reduction catalysed reaction carried out by “nitrogenase” and the enzymes/genes involved and their regulation, the inherent “oxygen paradox” , the identification of diazotrophs, sustainable agricultural uses of BNF, symbiotic plant-diazotroph interactions and endophytic diazotrophs, data from the field, and future prospects in BNF.

Official Knowledge: Democratic Education in a Conservative Age

Abstract: 1. Introduction: The Politics of Official Knowledge 2. The Politics of Common-sense: Why the Right is Winning 3. Cultural Politics and the Text 4. Regulating Official Knowledge 5. Creating the Captive Audience: Channel One and the Political Economy of the Text 6. Whose Curriculum is This Anyway? (with Susan Jungck) 7. Hey Man, I'm Good! The Art and Politics of Creating New Knowledge in Schools 8. The Politics of Pedagogy and the Building of Community Appendix Education, Power, and Personal Biography: An Interview.

The prevalence by staged severity of various types of diabetic neuropathy, retinopathy, and nephropathy in a population‐based cohort The Rochester Diabetic Neuropathy Study

Abstract: The magnitude of the health problem from diabetic neuropathies remains inadequately estimated due to the lack of prospective population-based studies employing standardized and validated assessments of the type and stage of neuropathy as compared with background frequency. All Rochester, Minnesota, residents with diabetes mellitus on January 1, 1986, were invited to participate in a cross-sectional and longitudinal study of diabetic neuropathies (and also of other microvascular and macrovascular complications). Of 64,573 inhabitants on January 1, 1986 in Rochester, 870 (1.3%) had clinically recognized diabetes mellitus (National Diabetes Data Group criteria), of whom 380 were enrolled in the Rochester Diabetic Neuropathy Study. Of these, 102 (26.8%) had insulin-dependent diabetes mellitus (IDDM), and 278 (73.2%) had non-insulin-dependent diabetes mellitus (NIDDM). Approximately 10% of diabetic patients had neurologic deficits attributable to nondiabetic causes. Sixty-six percent of IDDM patients had some form of neuropathy; the frequencies of individual types were as follows: polyneuropathy, 54%; carpal tunnel syndrome, asymptomatic, 22%, and symptomatic, 11%; visceral autonomic neuropathy, 7%, and other varieties, 3%. Among NIDDM patients, 59% had various neuropathies; the individual percentages were 45%, 29%, 6%, 5%, and 3%. Symptomatic degrees of polyneuropathy occurred in only 15% of IDDM and 13% of NIDDM patients. The more severe stage of polyneuropathy, to the point that patients were unable to walk on their heels and also had distal sensory and autonomic deficits (stage 2b) occurred even less frequently--6% of IDDM and 1% of NIDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Spreads, Depths, and the Impact of Earnings Information: An Intraday Analysis

Abstract: For a sample of NYSE firms, we show that wide spreads are accompanied by low depths, and that spreads widen and depths fall in response to higher volume. Spreads widen and depths fall in anticipation of earnings announcements; these effects are more pronounced for announcements with larger subsequent price changes. Spreads are also wider following earnings announcements, but this effect dissipates quickly after controlling for volume. Collectively, our results suggest liquidity providers are sensitive to changes in information asymmetry risk and use both spreads and depths to actively manage this risk.

Gender differences in sexuality: a meta-analysis.

Abstract: This meta-analysis surveyed 177 usable sources that reported data on gender differences on 21 different measures of sexual attitudes and behaviors. The largest gender difference was in incidence of masturbation: Men had the greater incidence (d = .96). There was also a large gender difference in attitudes toward casual sex: Males had considerably more permissive attitudes (d = .81). There were no gender differences in attitudes toward homosexuality or in sexual satisfaction. Most other gender differences were in the small-to-moderate range. Gender differences narrowed from the 1960s to the 1980s for many variables. Chodorow's neoanalytic theory, sociobiology, social learning theory, social role theory, and script theory are discussed in relation to these findings.

How Native Is a "Native" Anthropologist?

Abstract: L'A. s'eleve contre la distinction faite entre les anthropologues « indigenes » (interne a la societe) et « non indigenes » (externe a la societe). Si a l'epoque du colonialisme, les etudes faites par, ou a l'aide, des autochtones etaient davantage estimees car refletant une soit-disant meilleure realite, une approche hybride, ou narration et analyse rigoureuse sont melees, aurait tout autant de valeur.

Tomotherapy: A new concept for the delivery of dynamic conformal radiotherapy

Abstract: Tomotherapy, literally ‘‘slice therapy,’’ is a proposal for the delivery of radiation therapy with intensity‐modulated strips of radiation. The proposed method employs a linear accelerator, or another radiation‐emitting device, which would be mounted on a ring gantry like a CT scanner. The patient would move through the bore of the gantry simultaneously with gantry rotation. The intensity modulation would be performed by temporally modulated multiple independent leaves that open and close across the slit opening. At any given time, any leaf would be (1) closed, covering a portion of the slit, (2) open, allowing radiation through, or (3) changing between these states. This method would result in the delivery of highly conformal radiation. Overall treatment times should be comparable with contemporary treatmentdelivery times. The ring gantry would make it convenient to mount a narrow multisegmented megavoltage detectorsystem for beam verification and a CT scanner on the treatment unit. Such a treatment unit could become a powerful tool for treatment planning, conformal treatment, and verification using tomographic images. The physical properties of this treatmentdelivery are evaluated and the fundamental design specifications are justified.

Risk factors for primary dysfunction after liver transplantation--a multivariate analysis.

Abstract: In a retrospective analysis on 323 orthotopic liver transplant procedures performed between July 1984 and October 1991 the incidence of two forms of primary dysfunction (PDF) of the liver: primary nonfunction (PNF), and initial poor function (IPF) were studied. The incidence of PDF was 22% (73/323) with 6% PNF (20/323) and 16% IPF (53/323), while 78% (250/323) had immediate function (IF). Occurrence of both IPF and PNF resulted in a higher graft failure rate (P 3 days), older donor age (> 49 years), extended preservation times (> 18 hr), and fatty changes in the donor liver biopsy, as well as reduced-size livers, younger recipient age, and renal insufficiency prior to OLTx, significantly affected the incidence of IPF and PNF. Multivariate analysis of potential risk factors showed that reduced-size liver (P = 0.0001), fatty changes on donor liver biopsy (P = 0.001), older donor age (P = 0.009), retransplantation (P = 0.01), renal insufficiency (P = 0.02), and prolonged cold ischemia times (P = 0.02) were independently associated with a higher incidence of IPF and PNF. No statistical correlation was found between PDF and etiology of ESLD, nutritional status of the recipient, UNOS status, and Child-Pugh classification in this study. We conclude that PNF and IPF are both separate clinical entities that have a significant effect on outcome after OLTx. Routine donor liver biopsies are recommended to decrease the rate of IPF and PNF. The combination of risk factors shown to be significant for PDF should be avoided--and, if that is not possible, the only variable that can be controlled, the preservation time, should be kept as short as possible.

Localization using nonindividualized head‐related transfer functions

Abstract: A recent development in human-computer interfaces is the virtual acoustic display, a device that synthesizes three-dimensional, spatial auditory information over headphones using digital filters constructed from head-related transfer functions (HRTFs). The utility of such a display depends on the accuracy with which listeners can localize virtual sound sources. A previous study [F. L. Wightman and D. J. Kistler, J. Acoust. Soc. Am. 85, 868-878 (1989)] observed accurate localization by listeners for free-field sources and for virtual sources generated from the subjects' own HRTFs. In practice, measurement of the HRTFs of each potential user of a spatial auditory display may not be feasible. Thus, a critical research question is whether listeners can obtain adequate localization cues from stimuli based on nonindividualized transforms. Here, inexperienced listeners judged the apparent direction (azimuth and elevation) of wideband noisebursts presented in the free-field or over headphones; headphone stimuli were synthesized using HRTFs from a representative subject of Wightman and Kistler. When confusions were resolved, localization of virtual sources was quite accurate and comparable to the free-field sources for 12 of the 16 subjects. Of the remaining subjects, 2 showed poor elevation accuracy in both stimulus conditions, and 2 showed degraded elevation accuracy with virtual sources. Many of the listeners also showed high rates of front-back and up-down confusions that increased significantly for virtual sources compared to the free-field stimuli. These data suggest that while the interaural cues to horizontal location are robust, the spectral cues considered important for resolving location along a particular cone-of-confusion are distorted by a synthesis process that uses nonindividualized HRTFs.

Rational Cooperation in the Finitely Repeated Prisoner's Dilemma: Experimental Evidence

Abstract: This paper presents experiments designed to examine the sequential equilibrium reputation hypothesis in the finitely repeated prisoner's dilemma. The authors test the hypothesis by controlling the subjects' ability to build reputations and by manipulating their beliefs that their opponent is irrational or altruistic. The responses of subjects strongly support the sequential equilibrium prediction. The results also suggest an important role for 'homemade altruism,' that is, a natural tendency to cooperate that subjects bring to the experiment from the outside. The authors find that there may be no difference between the beliefs that an opponent is altruistic and the actual chance it is so. Copyright 1993 by Royal Economic Society.

A third recognition element in bacterial promoters: DNA binding by the alpha subunit of RNA polymerase

Abstract: A DNA sequence rich in (A+T), located upstream of the -10, -35 region of the Escherichia coli ribosomal RNA promoter rrnB P1 and called the UP element, stimulates transcription by a factor of 30 in vivo, as well as in vitro in the absence of protein factors other than RNA polymerase (RNAP). When fused to other promoters, such as lacUV5, the UP element also stimulates transcription, indicating that it is a separate promoter module. Mutations in the carboxyl-terminal region of the alpha subunit of RNAP prevent stimulation of these promoters by the UP element although the mutant enzymes are effective in transcribing the "core" promoters (those lacking the UP element). Protection of UP element DNA by the mutant RNAPs is severely reduced in footprinting experiments, suggesting that the selective decrease in transcription might result from defective interactions between alpha and the UP element. Purified alpha binds specifically to the UP element, confirming that alpha acts directly in promoter recognition. Transcription of three other promoters was also reduced by the COOH-terminal alpha mutations. These results suggest that UP elements comprise a third promoter recognition region (in addition to the -10, -35 recognition hexamers, which interact with the sigma subunit) and may account for the presence of (A+T)-rich DNA upstream of many prokaryotic promoters. Since the same alpha mutations also block activation by some transcription factors, mechanisms of promoter stimulation by upstream DNA elements and positive control by certain transcription factors may be related.

The Beaver Dam Health Outcomes study: Initial Catalog of Health-state Quality Factors

Abstract: The Beaver Dam Health Outcomes Study (BDHOS) is an ongoing longitudinal cohort study of health status and health-related quality of life for a random sample of adults (age range at interview was 45 to 89 years; mean = 64.1, SD = 10.8) in a community population. In a face-to-face interview lasting approximately an hour, each participant responds to several batteries of questions. Included are a history of chronic medical conditions, current medications, and past surgeries; the SF-36 (a general health-status questionnaire); the Quality of Well-being index; self-rated health status on a five-point scale from "excellent" to "poor"; and evaluation of current health using the method of time tradeoffs. The authors present results from 1,356 interviews on these four principal measures, reporting mean scores by sex, by age, and for persons reporting being affected by various medical conditions. They believe data from the BDHOS will provide researchers and policy makers a reference collection of vital statistics for health-related quality of life. Additionally, the data provide a way to compare results from studies that utilize different indices from among the four principal measures of the BDHOS.

Beyond simple pessimism: effects of sadness and anger on social perception.

Abstract: In keeping with cognitive appraisal models of emotion, it was hypothesized that sadness and anger would exert different influences on causal judgments. Two experiments provided initial support for this hypothesis. Sad Ss perceived situationally caused events as more likely (Experiment 1) and situational forces more responsible for an ambiguous event (Experiment 2) than angry Ss, who, in contrast, perceived events caused by humans as more likely and other people as more responsible. Experiments 3, 4, and 5 showed that the experience of these emotions, rather than their cognitive constituents, mediates these effects. The nonemotional exposure to situational or human agency information did not influence causal judgments (Experiment 3), whereas the induction of sadness and anger without explicit agency information did (Experiments 4 and 5). Discussion is focused on the influence of emotion on social judgment. The idea that emotions influence human thoughts, judgments, and decisions is as old as literature, and probably older. Most obviously, one's thoughts about the person or event that caused the emotion are affected; when someone has angered us, our judgment of that person's character is likely to emphasize vices and faults. Somewhat less obviously, while the emotion lasts, our interpretation of new events—even those unrelated to the source of the emotion—may be altered. For example, a person angered in the morning by a quarrel at home may find subsequent experiences to be more irritating: The bank teller or grocer seems a little more sluggish than usual, the boss more finicky, and the other drivers on the highway more thickheaded. Some residue of the prior emotion influences the person's perception of the events that follow. There is considerable evidence that global positive and negative moods have residual effects on cognition. In fact, positive and negative moods have been shown to influence a wide range of judgments, including evaluations of personal efficacy, Thematic Apperception Test scenes, and social performance (see Forgas & Bower, 1987, for a review), as well as judgments of satisfaction with consumer items (Isen, Shalker, Clark, & Karp, 1978), political figures, and general life circumstances (Forgas & Moylan, 1987; Keltner, Locke, & Audrain, 1993; Schwarz & Clore, 1983). Positive moods result in a more optimistic, positive outlook and negative moods a more pessimistic, negative one.

Parenting Practices and Peer Group Affiliation in Adolescence

Abstract: Social scientists have often assumed that parental influence is sharply curtailed at adolescence because of the rising counterinfluence of peer groups, over which parents have little control. The present study tested a conceptual model that challenged this view by arguing that parents retain a notable but indirect influence over their teenage child's peer associates. Data from a sample of 3,781 high school students (ages 15–19) indicated that specific parenting practices (monitoring, encouragement of achievement, joint decision making) were significantly associated with specific adolescent behaviors (academic achievement, drug use, self-reliance), which in turn were significantly related to membership in common adolescent crowds (jocks, druggies, etc.). Findings encourage investigators to assess more carefully parents' role in adolescents' peer group affiliations.

A prospective, randomized study of lumbar fusion : preliminary results

Abstract: One hundred, twenty-four patients undergoing lumbar or lumbosacral fusion for degenerative conditions were entered into a prospective study. The patients were randomly assigned to one of three treatment groups. Group I underwent posterolateral fusion using autogenous bone graft. Group II had autogenous posterolateral fusions supplemented by a semi-rigid pedicle screw/plate fixation system (Luque II; Danek Medical, Memphis, Tennessee). Group III patients underwent posterolateral autogenous fusion with a rigid pedicle screw/rod fixation system (Texas Scottish Rite Hospital [TSRH]-Danek Medical, Memphis, Tennessee). All the patients were operated on by the same surgeon, identical bone grafting technique was used in all, and all were treated in an identical fashion postoperatively. Fusion status was determined from the anteroposterior, oblique, and flexion-extension radiographs obtained at 1 year. Clinical results were rated as excellent if the patients were pain-free and had returned to work; good if the patients had mild backache requiring non-narcotic analgesics and had returned to work; fair if continuing back pain prevented a return to work; or poor if the pain was worse than that which the patient experienced preoperatively or the patient required revision surgery. Nine patients who were originally assigned to Group II or Group III were placed in Group I intraoperatively. This change was due to the identification of severe osteopenia and the determination that pedicle screw purchase was poor. One patient was lost to follow-up. Thus, 51 patients were in Group I, 35 in Group II, and 37 in Group III. Follow-up ranged from 9 to 28 months, averaging 16 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Patient-related barriers to management of cancer pain

Abstract: Patients' reluctance to report pain and to use analgesics are considered major barriers to pain management. To explore this problem, 270 patients with cancer completed a 27-item self-report questionnaire (BQ) that assessed the extent to which they have concerns about reporting pain and using pain medication. The 8 specific concerns included fear of addiction, beliefs that 'good' patients do not complain about pain, and concern about side effects. Patients also completed a measure of pain severity and pain interference (the BPI). The percentages of patients having concerns assessed by the BQ ranged from 37% to 85%. Those who were older, less educated, or had lower incomes were more likely to have concerns. Higher levels of concern were correlated with higher levels of pain. Based on their reports of pain medications used in the past week and on their reports of pain severity, patients were categorized as under-medicated versus adequately medicated. Those who were under-medicated reported significantly higher levels of concern. The data are discussed in terms of implications for research and practice.

Oxygen tension in the oviduct and uterus of rhesus monkeys, hamsters and rabbits

Abstract: Oxygen tension was measured using flexible polarographic microelectrodes within the oviductal and uterine lumen in rhesus monkeys (n = 9), golden hamsters (n = 21) and rabbits (n = 6), during the reproductive cycle (monkey), during oestrus and pseudopregnancy (hamsters, rabbits) and during pregnancy (hamsters). In general, oxygen tensions in each species were much less than half of atmospheric O2, ranging from high values of about 60 mm Hg (8.7% O2) in the rabbit oviduct, rabbit and hamster uterus, to as low as 11 mm Hg (1.5% O2) in the monkey uterus. Oxygen tensions did not vary significantly between left and right sides of the reproductive tracts (all species), nor between pregnant and pseudopregnant states nor between oviduct and uterus (hamsters). Differences owing to reproductive stage were found in the monkey oviduct, hamster oviduct and uterus, and rabbit uterus. Oxygen tensions were consistently very low (11-14 mm Hg) in the monkey uterus throughout the menstrual cycle. In hamsters and rabbits, intrauterine O2 decreased significantly at about the normal time of blastocyst formation and implantation, to 37 mm Hg (5.3% O2) and 24 mm Hg (3.5% O2), respectively. This study indicates that embryos develop in vivo under low oxygen concentrations, especially during the peri-implantation period. The data have implications for investigations of embryo metabolism and for improving embryo development in vitro.

Chemical structure of the hexapeptide chromophore of the Aequorea green-fluorescent protein

Abstract: The green-fluorescent proteins (GFP) are a unique class of proteins involved in bioluminescence of many cnidaria. The GFPs serve as energy-transfer acceptors, receiving energy from either a luciferase-oxyluciferin complex or a Ca(2+)-activated photoprotein, depending on the organism. Upon mechanical stimulation of the organism, GFP emits green light spectrally identical to its fluorescence emission. These highly fluorescent proteins are unique due to the nature of the covalently attached chromophore, which is composed of modified amino acid residues within the polypeptide. This report describes the characterization of the Aequorea victoria GFP chromophore which is released as a hexapeptide upon digestion of the protein with papain. The chromophore is formed upon cyclization of the residues Ser-dehydroTyr-Gly within the polypeptide. The chromophore structure proposed here differs from that described by Shimomura [(1979) FEBS Lett. 104, 220] in a number of ways.