Showing papers by "Temple University published in 1984"

The Theory of Partitions

Abstract: Since the 18th century the theory of partitions has interested some of the best minds. While it seems to have little or no practical application, it has, in a certain sense, just the right degree of difficulty. The problems are far from trivial, but at the same time they are not so hard as to discourage any attempt at a solution. Besides, through the introduction by Euler (1707–1783) of generating functions, the highly developed apparatus of the theory of functions became available for the study of partitions. A further circumstance of great help in this study is the fact that the generating functions which occur in the theory of partitions and functions closely related to them belong to two important classes of functions, namely the theta functions and the modular functions, both of which have received much attention and have been most thoroughly investigated since the time of Jacobi (1804–1851).

Automatic processing of fundamental information: the case of frequency of occurrence.

Abstract: One view of memory supposes that several fundamental aspects of experience are stored in memory by an implicit or automatic encoding process. In this article we review the evidence that suggests that information about frequency of occur- rence is encoded in such a manner. This evidence shows that frequency information is stored for a wide variety of naturally occurring events. Laboratory research shows that usually powerful task variables (for example, instructions, practice) and subject vari- ables (for example, age, ability) do not influence the encoding process. Evidence is also reviewed that either directly or indirectly implicates the use of frequency information across issues in psychology ranging from the acquisition and representation of knowledge domains to decision making to sex role development.

Blood pressure and nutrient intake in the United States

Abstract: A data base of the National Center for Health Statistics, Health and Nutrition Examination Survey I (HANES I), was used to perform a computer-assisted, comprehensive analysis of the relation of 17 nutrients to the blood pressure profile of adult Americans. Subjects were 10,372 individuals, 18 to 74 years of age, who denied a history of hypertension and intentional modification of their diet. Significant decreases in the consumption of calcium, potassium, vitamin A, and vitamin C were identified as the nutritional factors that distinguished hypertensive from normotensive subjects. Lower calcium intake was the most consistent factor in hypertensive individuals. Across the population, higher intakes of calcium, potassium, and sodium were associated with lower mean systolic blood pressure and lower absolute risk of hypertension. Increments of dietary calcium were also negatively correlated with body mass. Even though these correlations cannot be accepted as proof of causation, they have implications for future studies of the association of nutritional factors and dietary patterns with hypertension in America.

Assessing Temperament in One-to Three-Year-Old Children

Abstract: The initial development of the Toddler Temperament Scale (TTS) for determining temperamental characteristics in 1- to 3-year-old children is reported. The 97-item questionnaire was based on the conceptualization of Thomas, Chess, and associates in the New York Longitudinal Study and standardized on 309 children in two pediatric practices. Test-retest reliability (1 month) and alpha reliability are both satisfactory, with median correlations of .81 and .70, respectively, for the nine categories. Preliminary evidence of external validity is presented. The instrument should provide more objective and organized temperament data for research and clinical purposes. Language: en

Differences, difficulties and adaptation: Stress and social networks in families with a handicapped child.

Abstract: This paper discusses differences in 100 families with and without a handicapped child with respect to three types of stress (individual, marital, and parenting) and three structural characteristics of their social support networks (size, density, and boundary density). Generally, higher levels of stress and distinct network structures were found for the families with handicapped children. Despite the presence of high levels of stress, the families were found to have successful coping strategies. The results are discussed in terms of recognizing family strengths, and incorporating existing adaptational patterns in clinical interventions.

The role of follicle-stimulating hormone in controlling Sertoli cell proliferation in testes of fetal rats.

Abstract: Proliferation of Sertoli cells in the rat testis occurs only during the perinatal period and is maximal during fetal life. This interval is thus of critical importance in establishing the complement of Sertoli cells that populates the adult testis. FSH has been implicated in this process, but direct evidence in support of its involvement is lacking. In the present study, we have used in vivo and in vitro approaches to determine whether FSH produced by the fetal pituitary has a role in regulating Sertoli cell division in the fetal testis of the rat. On day 18 of gestation, just before the onset of maximal Sertoli cell proliferation, fetuses were either decapitated in utero or given antiserum to FSH. Light microscope autoradiography was then used to compare uptake of [3H]thymidine by Sertoli cell nuclei in testes from decapitated or antiserum-treated fetuses to that in corresponding controls on the following day. Both treatments produced dramatic and equal reductions in the percentages of Sertoli cells preparing to divide on day 19, suggesting that FSH from the fetal pituitary stimulates Sertoli cell proliferation in fetal testes. The effect of FSH or (Bu)2cAMP on Sertoli cell proliferation was also studied in vitro by placing testes from intact or decapitated fetuses into organ culture, with or without exogenous hormone or cyclic nucleotide. In all cases, [3H]thymidine was present for the final 4 h of culture. When testes were placed into medium containing isotope immediately after their removal from the fetus, the difference in labeling between testes from intact and decapitated fetuses was similar to that measured in vivo. After testes from decapitated fetuses were cultured for 8 h with or without FSH or (Bu)2cAMP, labeling of Sertoli cells in the treated group increased markedly over that in untreated cultures. After 28 h of exposure to FSH or (Bu)2cAMP, labeling in testes from decapitated fetuses remained significantly higher than that in corresponding untreated controls. In contrast, when testes from intact rats were cultured for 8 h in the presence of either cAMP or FSH, (Bu)2cAMP, but not FSH, brought about an increase in the percentage of Sertoli cells labeled compared to the control value. However, after exposing these testes to either FSH or (Bu)2cAMP for 28 h, the percentage of Sertoli cells labeled was greatly enhanced. Taken together, the data obtained from these experiments identify FSH as a major factor in controlling expansion of the Sertoli cell population during fetal development of the rat.(ABSTRACT TRUNCATED AT 400 WORDS)

The free rider problem: Experimental evidence

Abstract: We have described a number of ‘invalidating factors,’ any one of which, if present, could account for the weakness or absence of the free rider problem in the voluntary provision of a public good. When any of these factors is present, the free rider phenomenon is not necessarily an implication of economic theory. These invalidatingg factors have been used as a guide in the construction of an experiment which, by avoiding all such factors, should exhibit the free rider phenomenon. The results of performing the experiment indicate that the free rider hypothesis should not be rejected. The contrast between this result and previous experimental results indicates that some of the factors we have identified will be important in attempting to explain the presence or absence of the free rider phenomenon in any particular situation in which a public good is to be financed by voluntary means.

Blood pressure and nutrient intake in the United States

Abstract: A data base of the National Center for Health Statistics, Health and Nutrition Examination Survey I (HANES I), was used to perform a computer-assisted, comprehensive analysis of the relation of 17 nutrients to the blood pressure profile of adult Americans. Subjects were 10,372 individuals, 18 to 74 years of age, who denied a history of hypertension and intentional modification of their diet. Significant decreases in the consumption of calcium, potassium, vitamin A, and vitamin C were identified as the nutritional factors that distinguished hypertensive from normotensive subjects. Lower calcium intake was the most consistent factor in hypertensive individuals. Across the population, higher intakes of calcium, potassium, and sodium were associated with lower mean systolic blood pressure and lower absolute risk of hypertension. Increments of dietary calcium were also negatively correlated with body mass. Even though these correlations cannot be accepted as proof of causation, they have implications for future studies of the association of nutritional factors and dietary patterns with hypertension in America.

The development of sex role stereotypes in the third year: relationships to gender labeling, gender identity, sex-typed toy preference, and family characteristics.

Abstract: The onset and development of preschoolers' awareness of sex role stereotypes, gender labeling, gender identity, and sex-typed toy preference were explored in 26-, 31-, and 36-month-old children. Gender labeling, gender identity, sex-typed toy preferences, and awareness of adult sex role differences were observed in significantly more 26-month-old children than would have been expected by chance. Verbal gender labeling was observed in a majority of 26-month-olds, while verbal and nonverbal gender identity were observed in a majority of 31-month-olds. Nonverbal gender labeling and awareness of adult sex role differences were observed in a majority of children by 36 months. No evidence of awareness of sex differences in children's toys was found in the majority of children at any age. Awareness of sex role differences in children's toys was not related to awareness of adult sex role differences. Brighter children were more aware of adult sex role differences. Sex-typed toy preference was not related to awareness of sex role differences but was related to gender identity. Predictors of sex role development included the mothers' employment, and the father's personality traits, attitudes toward women, and sex-typed activities in the home. Implications for theories of early sex role development are discussed.

Cell-cycle-specific cDNAs from mammalian cells temperature sensitive for growth.

Abstract: A library of double-stranded cDNA was constructed from ts13 cells, a G1-specific temperature-sensitive hamster cell line. The cDNAs, cloned into pBR322, were prepared from poly(A)+ mRNA isolated from ts13 cells 6 hr after serum stimulation at the permissive temperature of 34 degrees C. Differential screening of the library with G1-specific and G0-specific single-stranded cDNA probes prepared from the same cells identified five cDNA clones whose sequences were preferentially expressed in G1. Levels of RNA complementary to these clones were 3- to 6-fold higher in G1 than in other phases of the cell cycle. When ts13 cells were arrested in G1 at the restrictive temperature of 39.6 degrees C, the levels of RNA complementary to p13-2A9 and p13-4F1 were as high as 10 times that found in a resting population, while the expression of sequences complementary to p13-2A8 did not significantly change from levels found in G0. RNA and Southern gel blot analysis suggest that these cell-cycle-specific clones represent either low copy or moderately repetitive gene sequences. Results with another ts mutant of the cell cycle, tsAF8, which is a ts mutant of RNA polymerase II, showed that these cell-cycle-specific sequences have a rapid turnover. The use of G1-specific ts mutants of the cell cycle provides an approach to determine which cell-cycle-dependent genes are most relevant to cell cycle progression.

Some properties of the tukey g and h family of distributions

Abstract: The g and h family of distributions, introduced by J.W. Tukey, is generated by a single transformation of the standard normal which allows for symmetry and heavier tails. Selected percentage points are tabulated, and a closed-form solution for the moments, when they exist, is found. A comparison is made with the Pearson system of distributions. The g and h distributions cover most of the Pearson family to an adequate approximation, when the first four moments exist, and also generate a variety of other types of distributions. Selected distributions graphically illustrate the great variety of possible shapes.

Coronary thrombolysis by intravenous streptokinase in acute myocardial infarction: Acute and follow-up studies☆

Abstract: Coronary arteriography was performed before, immediately after, and 9 to 14 days after administering i.v. Streptokinase (850,000 to 1,500,000 IU) to 43 patients within 6 hours of myocardial infarction. Ventricular function was determined by contrast ventriculography before and 9 to 14 days later and by radionuclide studies at clinical follow-up 8 months later. Early reperfusion occurred in 49% of patients, but in only 35 % was it sustained. In patients with sustained reperfusion, early ventricular dysfunction was significantly reduced 9 to 14 days and 10 months later, and frequency of infarction, sudden death, and angina pectoris was not increased at follow-up. No serious bleeding occurred.

State Dependent Learning and Drug Discriminations

Abstract: In these words, Combe first described state dependent learning in 1830. During the last 20 years, state dependent learning (SDL) and drug discriminations (DD) have been the subject of several hundred published reports. The intent of this paper is to review our present state of knowledge regarding these two closely related phenomena.

α-Ketoglutarate and Malate Uptake and Metabolism by Synaptosomes: Further Evidence for an Astrocyte-to-Neuron Metabolic Shuttle

Abstract: This study was undertaken to provide further evidence relevant to the hypothesis that astrocytes supply one or more citric acid cycle intermediates to synaptic terminals, thereby serving an anaplerotic function necessitated by the synthesis and release of amino acid neurotransmitters. In our experiments, two populations of synaptosomes obtained from the brain of rats were separated from myelin and mitochondria by using Percoll to generate continuous density gradients. Both synaptosomal populations readily accumulated 14C-labelled alpha-ketoglutarate and L-malate by high-affinity transport systems. Hofstee plots of uptake velocity as a function of substrate concentration were highly nonlinear, indicating that uptake was mediated by two or more carriers, or was subject to negative cooperativity. At least one carrier was selective for alpha-ketoglutarate and another for malate, whereas a third carrier appeared to be present which transported both substrates. At low concentrations (approximately 1 microM), alpha-ketoglutarate transport was almost totally Na+-dependent, whereas malate uptake exhibited little Na+-dependency. The transport of alpha-ketoglutarate was associated with a net influx, and therefore was not due to a homoexchange process. alpha-Ketoglutarate and malate were metabolized rapidly to glutamate and aspartate, respectively, by both synaptosomal preparations; however, in all cases, label accumulated in gamma-aminobutyric acid rather slowly. The incorporation of label into glutamine from alpha-ketoglutarate was much greater in the high-density synaptosomes that in low-density synaptosomes, an indication that the former contained a higher proportion of astrogliasomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric dysplasia. Significance and pathologic criteria

Abstract: In view of uncertainty regarding the criteria and significance of gastric dysplasia as a precancerous lesion, members of the Pathology Panel of the International Study Group on Gastric Cancer (ISGGC) reviewed microslides of 93 gastric lesions showing varying degrees of mucosal abnormality, and reached the following consensus: (1) immature and proliferating gastric epithelium can be divided into two categories: hyperplastic and dysplastic; (2) the term dysplasia, especially of high-grade type, should be restricted to precancerous lesions, and hyperplasia is applied to regenerative changes; (3) regenerative hyperplasia may be simple or atypical, but dysplasia includes both moderate and severe abnormalities, since they often coexist and can not be sharply separated; and (4) occasionally the possibility of malignancy can not be excluded in a severely dysplastic epithelium; in such a case rebiopsy and diligent follow-up are necessary to establish the diagnosis. Criteria for diagnosing dysplasia and hyperplasia are presented and discussed. The opinions are offered as guidelines for establishing the diagnosis of gastric dysplasia and for prospective studies.

Inhibition of 1,2-dimethylhydrazine-induced colon tumorigenesis in Balb/c mice by dehydroepiandrosterone

Abstract: Long-term administration of dehydroepiandrosterone (DHEA) to Balb/c mice significantly inhibits the rate of appearance of 1,2-dimethylhydrazine (DMH)-induced macroscopic colon and anal tumors and microscopic precursor and malignant lesions. The steroid, which has previously been shown to inhibit spontaneous breast cancer and chemically induced lung tumors in mice, may find application as a chemopreventive in individuals at high risk for developing colon cancer.

The structure and function of social support networks in families with handicapped children

Abstract: Three structural characteristics of social support networks (size, density, and boundary density) and two relationship characteristics (reciprocity and dimensionality) were assessed in a sample of 56 families with a child with spina bifida and 53 matched comparison families. The results indicate that social networks of families with handicapped children tended to be smaller than the networks of comparison families, particularly with regard to mothers' total and friendship networks. The networks of families with handicapped children were more dense as well. As predicted, there was greater boundary density in spousal networks in families with handicapped children. Differences in network reciprocity were inconclusive while the results indicate that families with handicapped children tended to rely more heavily upon multidimensional network contacts than did comparison families. The results are discussed in light of our understanding of stress, social support, and the social ecological context of families.

Recommended curriculum for CS1, 1984

Abstract: Ce rapport offre un premier cours en informatique qui attire l'attention sur la methodologie de programmation et la resolution de probleme. Il est approprie pour les etudiants et autres interesses par une introduction disciplinee a la programmation