Showing papers by "Pennsylvania State University published in 1979"
TL;DR: Insomnia, nightmares, and hypersomnia were correlated with more frequent general physical and mental health problems and were often chronic and usually started early in life.
Abstract: The authors determined the prevalence of sleep disorders in a general population through a survey of 1,006 representative households in the Los Angeles metropolitan area. They found an overall prevalence of current or previous sleep disorders in adults of 52.1%. Specifically, they found a 42.5% prevalence of insomnia, 11.2% of nightmares, 7.1% of excessive sleep, 5.3% of sleeptalking, and 2.5% of sleepwalking. These conditions were often chronic and usually started early in life. Insomnia was more frequent in older people, particularly older women, and in people of lower educational socioeconomic status. Insomnia, nightmares, and hypersomnia were correlated with more frequent general physical and mental health problems.
836 citations
TL;DR: It is suggested that the time required to stretch the series elastic component (SEC) represents the major portion of the measured delay and that during eccentric muscle activity the SEC is in a more favorable condition for rapid force development.
Abstract: In contraction of skeletal muscle a delay exists between the onset of electrical activity and measurable tension. This delay in electromechanical coupling has been stated to be between 30 and 100 ms. Thus, in rapid movements it may be possible for electromyographic (EMG) activity to have terminated before force can be detected. This study was designed to determine the dependence of the EMG-tension delay upon selected initial conditions at the time of muscle activation. The right forearms of 14 subjects were passively oscillated by a motor-driven dynamometer through flexion-extension cycles of 135 deg at an angular velocity of approximately equal to 0.5 rad/s. Upon presentation of a visual stimulus the subjects maximally contracted the relaxed elbow flexors during flexion, extension, and under isometric conditions. The muscle length at the time of the stimulus was the same in all three conditions. An on-line computer monitoring surface EMG (Biceps and Brachioradialis) and force calculated the electromechanical delay. The mean value for the delay under eccentric condition, 49.5 ms, was significantly different (p less than 0.05) from the delays during isometric (53.9 ms) and concentric activity (55.5 ms). It is suggested that the time required to stretch the series elastic component (SEC) represents the major portion of the measured delay and that during eccentric muscle activity the SEC is in a more favorable condition for rapid force development.
714 citations
TL;DR: In this paper, a linear index of food selection is proposed which avoids most of the statistical and mathematical inadequacies of these indices, and the statistical reliability of each index is shown to be a function of the absolute and relative sample sizes and the relative abundances of the prey species in the environment.
Abstract: Ivlev's electivity index and the forage ratio, two commonly used measures of food selection, are significantly biased when the sizes of the prey samples from the gut of the predator and the habitat are unequal. Approximate confidence-interval expressions are derived for these indices. A stochastic (Monte Carlo) model was used to validate these expressions and to explore the statistical properties of the indices. The statistical reliability of each index is shown to be a function of the absolute and relative sample sizes and the relative abundances of the prey species in the environment. A linear index of food selection is proposed which avoids most of the statistical and mathematical inadequacies of these indices. Regardless of the index used, however, inadequate habitat sampling, differential availability of prey to the predator, and differential digestion of prey may be significant sources of error in the interpretation of food selection data.
522 citations
01 Jan 1979
TL;DR: In this article, the authors present a review of spray combustion in rocket engine, gas turbine, diesel engine and industrial furnace applications, highlighting the need for improved injector characterization methods, more information of droplet transport characteristics in turbulent flow and continued development of more complete two-phase turbulent models.
Abstract: The present understanding of spray combustion in rocket engine, gas turbine, Diesel engine and industrial furnace applications is reviewed. In some cases, spray combustion can be modeled by ignoring the details of spray evaporation and treating the system as a gaseous diffusion flame; however, in many circumstances, this simplification is not adequate and turbulent two-phase flow must be considered. The behavior of individual droplets is a necessary component of two-phase models and recent work on transient droplet evaporation, ignition and combustion is considered, along with a discusssion of important simplifying assumptions involved with modeling these processes. Methods of modeling spray evaporation and combustion processes are also discussed including: one-dimensional models for rocket engine and prevaporized combustion systems, lumped zone models (utilizing well-stirred reactor and plug flow regions) for gas turbine and furnace systems, locally homogeneous turbulent models, and two-phase models. The review highlights the need for improved injector characterization methods, more information of droplet transport characteristics in turbulent flow and continued development of more complete two-phase turbulent models.
410 citations
TL;DR: In this article, the authors examined general features and susceptability to fits by linear, power, and exponential functions, and made separate fits to below-target and above-target data.
Abstract: Thirty empirically assessed utility functions on changes in wealth or return on investment were examined for general features and susceptability to fits by linear, power, and exponential functions. Separate fits were made to below-target data and above-target data. The usual “target” was the no-change point.
The majority of below-target functions were risk seeking; the majority of above-target functions were risk averse; and the most common composite shape was convex-concave, or risk seeking in losses and risk averse in gains. The least common composite was concave-concave. Below-target utility was generally steeper than above-target utility with a median below-to-above slope ratio of about 4.8. The power and exponential fits were substantially better than the linear fits. Power functions gave the best fits in the majority of convex below-target and concave above-target cases, and exponential functions gave the best fits in the majority of concave below-target and convex above-target cases. Several implications of these results for decision making under risk are mentioned.
373 citations
TL;DR: A fresh look is taken at the antipyrine test and a critical reassessment of its applications and limitations is warranted.
Abstract: Since its introduction 11 years ago,75, 77 the antipyrine test, devised to determine quantitatively the effect of individual environmental factors on hepatic drug‐metabolizing capacity in normal subjects, has been widely used by clinical pharmacologists, as indicated by the large number of applications listed in Table 1. Yet there have been several technical modifications, new extensions and unresolved problems, and an increasing number of apparently conflicting results. This warrants a fresh look at the antipyrine test and a critical reassessment of its applications and limitations.
367 citations
TL;DR: Titania-supported nickel catalysts exhibit unusual properties in CO-H2 reactions relative to conventional Ni catalysts as mentioned in this paper, indicating a unique metal-support interaction in the Ni TiO 2 system.
343 citations
TL;DR: This paradigm, developed for use with fishes, can also be applied to other ectothermic taxa, although it is most easily employed with aquatic organisms because of the simplicity of specifying aquatic thermal environments in terms of water temperature alone.
Abstract: Wider attention to Fry's (1947) “final preferendum” paradigm would facilitate comparative studies of temperature preference (behavioral thermoregulation) among different animal groups. According to Fry's bipartite definition, the final preferendum is that temperature at which preference and acclimation are equal, and to which an animal in a thermal gradient will finally gravitate regardless of its prior thermal experience (acclimation). This paradigm is helpful in distinguishing between acute thermal preferenda (measured within 2 hr or less after placing an animal in a thermal gradient), which are influenced by acclimation temperature, and the species-specific final preferendum (measured 24–96 hr after placement in the gradient), which is essentially independent of prior acclimation because reacclimation occurs during the gravitation process. The paradigm does not take into account non-thermal acclimatization influences (e.g., season, photoperiod, age, light intensity, salinity, disease, nutrition, pollutants, biotic interactions) which can also affect temperature preference. However, a graph of acutely preferred temperatures versus acclimation temperatures can be employed to determine an equivalent acclimation temperature for any given acclimatization state, as a simple means of quantifying acclimatization states resulting from interactions of many influences. This paradigm, developed for use with fishes, can also be applied to other ectothermic taxa, although it is most easily employed with aquatic organisms because of the simplicity of specifying aquatic thermal environments in terms of water temperature alone. Methodologies used in studies of behavioral thermoregulation should take the paradigm into account (especially with respect to length of tests) to enhance the comparative value of data across taxa.
315 citations
TL;DR: To-work transition among a nationally representative sample of black and white male youth has been studied in this paper, and the analysis involves estimating the parameters in a standard recursive model of schooling and wage rates, and considers two issues which have not been fully explored in previous empirical analyses.
Abstract: to-work transition among a nationally representative sample of black and white male youth. The analysis involves estimating the parameters in a standard recursive model of schooling and wage rates, and considers two issues which have not been fully explored in previous empirical analyses. First, the transition year may involve an intervening period of unemployment during which the school leaver searches for a job. This search behavior is included in the model as an added
296 citations
01 Jan 1979
285 citations
TL;DR: Yamanaka and Brindley as mentioned in this paper showed that Na-montmorillonite with zirconyl chloride solutions give products with basal spacings near 18 A which are stable to 500~ and have surface areas of the order of 300-400 m2/g.
Abstract: Exchange reactions of Na-montmorillonite with zirconyl chloride solutions give products with basal spacings near 18 A which are stable to 500~ and have surface areas of the order of 300-400 m2/g. The Na ions are exchanged with tetrameric hydroxy cations (Zr4(OH)I( nH~O) 2+. The high surface area is attributed to the porosity formed by stable zir- conium oxide" pillars" formed by dehydroxylatlon of the complex cation. The nitrogen adsorption isotherms are of Lang- muir type and are consistent with adsorption in interlayer micropores. Reduced-charge montmorillonites, formed by ap- plication of the Hofmann-Klemen procedure, give either similar or slightly smaller surface areas. was used. The same montmorillonite was used in a pre- vious study (Yamanaka and Brindley, 1978) where the chemical analysis and structural formula are given. Na- and Li-saturated samples were prepared by treatment with the respective 1 N chloride solutions, with sub- sequent washing by centrifugation and dialysis to re- move excess chloride.
TL;DR: In this article, Fourier transform infrared (FTIR) studies of poly(ϵ-caprolactone) (PCL) and polyvinyl chloride (PVC) blend systems are presented.
Abstract: Fourier-transform infrared (FTIR) studies of the poly(ϵ-caprolactone) (PCL)–poly(vinyl chloride) (PVC) blend system are presented. The results indicate that there are specific interactions between the PCL and PVC in both the molten and solid states which could be responsible for the apparent compatibility of the amorphous component of these blends. Additionally, FTIR difference spectra are presented to illustrate the potential of this technique for following the kinetics of crystallinity in polymer blend systems.
TL;DR: Changes in neutral sugar, uronic acid, and protein content of tomato cell walls during ripening were characterized and the ripening-related decline in galactose and arabinose content appeared to be separate from polyuronide solubilization.
Abstract: Changes in neutral sugar, uronic acid, and protein content of tomato (Lycopersicon esculentum Mill) cell walls during ripening were characterized. The only components to decline in amount were galactose, arabinose, and galacturonic acid. Isolated cell walls of ripening fruit contained a water-soluble polyuronide, possibly a product of in vivo polygalacturonase action. This polyuronide and the one obtained by incubating walls from mature green fruit with tomato polygalacturonase contained relatively much less neutral sugar than did intact cell walls. The ripening-related decline in galactose and arabinose content appeared to be separate from polyuronide solubilization. In the rin mutant, the postharvest loss of these neutral sugars occurred in the absence of polygalacturonase and polyuronide solubilization. The enzyme(s) responsible for the removal of galactose and arabinose was not identified; a tomato cell wall polysaccharide containing galactose and arabinose (6:1) was not hydrolyzed by tomato β-galactosidase.
TL;DR: In this paper, methods for estimating mutual diffusion coefficients for polymer-solvent systems are reviewed and procedures are recommended for the determination of the temperature, concentration, and molecular weight dependences of diffusivities both for dilute and concentrated solutions.
Abstract: Methods for estimating mutual diffusion coefficients for polymer-solvent systems are reviewed. Procedures are recommended for the determination of the temperature, concentration, and molecular weight dependences of diffusivities both for dilute and concentrated solutions.
TL;DR: In this article, a monochromator-based approach was proposed to select a set of wavelengths to use for prediction for each different type of forage or feedstuff, such as legume, grass-legume, heat damaged protein, and boron.
TL;DR: In this article, an Introduction to Ramanujan's "Lost" Notebook is given, along with a discussion of its relationship to the lost notebook and the lost notebook.
Abstract: (1979). An Introduction to Ramanujan's “Lost” Notebook. The American Mathematical Monthly: Vol. 86, No. 2, pp. 89-108.
TL;DR: The incidence of trigeminal ganglion infection after corneal inoculation of guinea pigs with thymidine kinase-negative mutants of herpes simplex virus was markedly reduced compared to infection after inoculation to suggest that thymazine kinase expression of herpessimplex virus may be important in infections of sensory ganglia.
Abstract: The incidence of trigeminal ganglion infection after corneal inoculation of guinea pigs with thymidine kinase-negative mutants of herpes simplex virus was markedly reduced compared to infection after inoculation of thymidine kinase-positive virus. Thymidine kinase-negative herpes simplex virus replicated well in ocular tissues in which dividing or potentially dividing cells were present, but not in trigeminal ganglion infection of nondividing neurons. Thymidine kinase-positive virus, however, replicated well in ocular tissues as well as in trigeminal ganglion. These results suggest that thymidine kinase expression of herpes simplex virus may be important in infections of sensory ganglia.
TL;DR: The need for measures of variables which assess marital quality, and the history of measurements in this area, is reviewed, some conceptual and methodological issues of relevance are identified, and then the Dyadic Adjustment Scale developed by Spanier is focused on.
Abstract: The quality of marital relationships is the most studied topic pertaining to marriage and family life. Moreover, clinicians have become increasingly interested in this variable as divorce rates have climbed and as services for counseling and therapy have become more readily available and more widely accepted. These research and clinical needs necessitate the availability of measures of variables which assess marital quality (e.g., marital adjustment, satisfaction, and happiness). This article discusses the need for such measures, reviews the history of measurements in this area, identifies some conceptual and methodological issues of relevance, and then focuses most specifically on the Dyadic Adjustment Scale developed by Spanier. Some cautions for clinicians are noted, and a discussion of future measurement needs is presented.
TL;DR: The production of a fertile rooster which lacks avian leukosis virus-related endogenous viral genes and which seems to be completely normal and healthy is reported, apparently not essential for the normal development of the chicken.
Abstract: DNA sequences homologous to the genomes of type C retroviruses are widespread among vertebrates. Ten genetic loci containing endogenous viral DNA sequences have been documented in the white Leghorn chicken alone. Six of these genetic loci are associated with the production of virus or of viral proteins in embryonic fibroblasts (refs 2--4, and S.M.A., L, B. Crittenden and E.G.B., in preparation) and one of the loci may be expressed in the erythroblasts of 5-day-old embryos. The abiquitous presence of endogenous viral genes among vertebrate species and the association of their expression with development of the haematopoietic system in the mouse have led to the proposal that these genes are involved in ontogeny. In addition, the genes may be implicated in oncogenesis as in the case of the AKR mouse in which a high incidence of spontaneous leukaemia is associated with the expression of endogenous murine laukaemia virus genomes. We report here the production of a fertile rooster which lacks avian leukosis virus-related endogenous viral genes and which seems to be completely normal and healthy. Thus, endogenous viral genes are apparently not essential for the normal development of the chicken. An endogenous virus-free state has also been reported for three species of jungle fowl and for the B-type viral genes of the mouse.
TL;DR: Which of three alternative hypotheses explains the proximate factors involved in a high ratio of flowers to fruits is tested and several ultimate factors that infer the adaptive significance of this pattern are tested.
Abstract: Those plant species that rely on animals to mediate the transfer of pollen usually attract pollinators with visual and/or aromatic stimuli and then reward them with pollen, nectar, or some other food (Faegri and van der Pijl, 1971; Proctor and Yeo, 1973). Under some circumstances (i.e., competition for pollinators) there may be selective pressures to increase the size of the attractants and rewards in order to secure more visits by the pollinators. One possible response of a plant to these pressures is to cluster flowers in time and space. This would make the plant more conspicuous to pollinators and it would also increase the pollinator's reward by decreasing the search time and distance between food sources (see Burtt, 1961; Janzen, 197 la; Heinrich and Raven, 1972; Gentry, 1974; Willson and Rathcke, 1974; Heinrich, 1975). There are many plant species that regularly produce inflorescences consisting of many flowers but initiate only a few fruits. Species with this flowering and fruiting pattern include Albizia lebbeck (Maheshwari, 1931), Aesculus spp. (Percival, 1965; Benseler, 1975), Cassia grandis (Janzen, 197 la), Eucalyptus spp. (Carr et al., 1971), various orchard trees (see Kozlowski, 1973), Asclepias spp. (Willson and Rathcke, 1974; Wilbur, 1976; Willson and Price, 1977) and Catalpa spp. (Stephenson, 1978). Because each flower on these species has a low probability of setting fruit, there is the possibility that inflorescence size has been selected for factors other than a flower's ability to set fruit (see Willson and Price, 1977). In this study, I use Catalpa speciosa (Warder ex Barney) Engelm. (Bignoniaceae) to test which of three alternative hypotheses explains the proximate factors involved in a high ratio of flowers to fruits and then to test several ultimate factors that infer the adaptive significance of this pattern.
TL;DR: Infection of the trigeminal ganglion was investigated using standard thymidine kinase-positive (TK + ) herpes simplex virus (HSV) and two TK − mutants and results obtained were interpreted as being consistent with impaired axonal transport of Tk − HSV from cornea to trigeminals ganglions neurons or more likely, with impaired replication of TK + HSV in ganglionic neurons.
TL;DR: Tumors derived from human metastases were no more prone to metastasizing in nude mice than were tumors derived from primary sites, but deep penetration of the body wall during growth of the tumor transplant was highly correlated with metastasis.
Abstract: The incidence of metastasis of xenogeneic tumors transplanted to nude mice is controversial. We studied 106 malignant human tumor lines in a total of 1,045 nude mice, and observed metastasis in only 14 instances (1.3%), involving 11 different tumor lines. Three of the lines showed repeated metastasis. Breast tumor lines metastasized with significantly greater frequency than other tumor types. None of the sarcoma lines metastasized. Tumors derived from human metastases were no more prone to metastasizing in nude mice than were tumors derived from primary sites. However, deep penetration of the body wall during growth of the tumor transplant was highly correlated with metastasis (p less than 0.001). Such factors as nude mouse health, tumor size and growth rate, and age and sex of the host mouse were not correlated with metastasis. Serial passage in nude mice did not select for a more malignant tumor line, since the incidence of metastasis did not differ at various passage levels. Thus, metastasis of human malignant tumors in nude mice would appear to depend primarily upon the site of tumor growth in the nude mouse, and upon the intrinsic metastasizing capability of the tumor line employed.
TL;DR: Mothers who were overweight at the start of pregnancy had the fewest fetal and neonatal deaths with a 16 pound weight gain at term, and once one of these disorders was established, mortality rates from it usually increased severalfold when mothers had very low or very high weight gains.
TL;DR: In this article, an ionic diffusion model, similar to one proposed by workers in ceramics, is described and applied to the evaluation of diffusion coefficients, Dij, from tracer diffusion values.
01 Jul 1979
TL;DR: In this paper, the major photochemistry consisted of solar EUV and photoelectrons comprising 70 percent and 30 percent respectively, of the initial source of CO2(+) and O(+).
Abstract: The major photochemistry consisted of solar EUV and photoelectrons comprising 70 percent and 30 percent respectively, of the initial source of CO2(+) and O(+). The energetic O2(+) provided a substantial source of energy to the ambient ions, distributing of the order of 1.6 x 10 to the -7 power W/sq m at an average of 160 km. This input can be compared to that from the ambient electrons of 1.3 x 10 to the -7 power W/sq m with average deposition at 145 km and from the calculated thermal conduction of 1 x 10 to the -9 power W/sq m at 270 km and 1 x 10 to the -8 power at 230 km for assumed dip angles of 2 deg and 12 deg respectively, for a 10nT magnetic field. At altitudes above 250 km upward, vertical fluxes of the order 6 x 10 to the 10th power/sq m/sec for the thermal ions were calculated. The net ionization of O(+) and CO2(+) by charge exchange with incoming solar wind protons varied from 5 x 10 to the 8th power to 5 x 10 to the 12th power /sq m/sec for assumed field strengths of 50nT to 2nT on the dayside of the planet.
TL;DR: A mechanism for the hydrolysis reactions catalzyed by the venom phosphodiesterase involving at least a single covalent phosphoryl-enzyme intermediate is in accord with this result.
Abstract: The hydrolysis reaction of ATP alpha S by snake venom phosphodiesterase is highly specific for the B diastereomer and proceeds with 88% retention of configuration at phosphorus. Since this enzyme also catalyzes the hydrolysis of the S enantimoer of O-p-nitrophenyl phenylphosphonothioate, the absolute configuration at A alpha of ATP alpha S (B) is assigned as the R configuration provided the two substrates are processed identically. A mechanism for the hydrolysis reactions catalzyed by the venom phosphodiesterase involving at least a single covalent phosphoryl-enzyme intermediate is in accord with this result.
TL;DR: In this article, the authors used limiting, model cases to describe dissociative, dual-site adsorption and showed that the values obtained for ΔSa0 must conform to certain rules in order to have any physical meaning.
TL;DR: Sex differences in the processes of identity and intimacy development among college youth are examined in the context of Eriksonian theory, which seemed more adequate in explaining male than female development.
Abstract: This study examined sex differences in the processes of identity and intimacy development among college youth. Fifty males, and 50 females were given measures of identity status, intimacy status, and self-esteem. Males were found to focus on intrapersonal aspects of identity status, intimacy status, and self-esteem. Males were found to focus on intrapersonal aspects of identity, females on interpersonal aspects. The pursuit of various identity development pathways affected self-esteem differentially for the two sexes. More females than males were found to be intimate and the achievement of intimacy seemed more closely related to identity in males than in females. The findins were interpreted in the context of Eriksonian theory, which seemed more adequate in explaining male than female development.
TL;DR: This paper proves the conjecture true if n = pq where p and q are distinct primes true, and shows that the conjecture is false in most cases when n is divisible by p2 where p is an odd prime, or n isdivisible by 24.