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Showing papers by "University of North Carolina at Chapel Hill published in 1975"


Book
01 Jan 1975
TL;DR: The Mythical Man-Month, Addison-Wesley, 1975 (excerpted in Datamation, December 1974), gathers some of the published data about software engineering and mixes it with the assertion of a lot of personal opinions.
Abstract: The book, The Mythical Man-Month, Addison-Wesley, 1975 (excerpted in Datamation, December 1974), gathers some of the published data about software engineering and mixes it with the assertion of a lot of personal opinions. In this presentation, the author will list some of the assertions and invite dispute or support from the audience. This is intended as a public discussion of the published book, not a regular paper.

3,875 citations


Journal ArticleDOI
TL;DR: In this paper, the authors proposed a temporal dimension and locational properties that are derived from age data: (a) the individual life time or life span from birth to death-chronological or developmental age as an approximate index of stage in the aging process; (b) the social timetable of the life course (e.g. entry into marriage, retirement), which is defined by age criteria in norms and social roles; and (c) historical time in the course of social change-birth year or entry into the system as an index of historical location.
Abstract: Age has long been recognized as a basic element in social structure and the life course, but we have only recently achieved some appreciation of its diverse meanings and implications. To interpret the effects or correlates of age and birth year we must specify the variables they represent. The complexity of this task is suggested by the following temporal dimensions and locational properties that are derived from age data: (a) the individual life time or life span from birth to death-chronological or developmental age as an approximate index of stage in the aging process; (b) the social timetable of the life course (e.g. entry into marriage, retirement), which is defined by age criteria in norms and social roles; and (c) historical time in the course of social change-birth year or entry into the system as an index of historical location.1 The focal point of the lifetime framework is the inevitable and irreversible process of aging; that of social time, age differentiation in the sequential patterning, and configuration of social roles; and that of historical time, cohort membership, differentiation, and succession, with their implications for life histories, aging, and social change. Each temporal focus is associated with a distinctive tradition of theory and research: lifetime, BUhler (1935), the biological cycle of life as reflected in attitudes toward life (see also BUhler & Massarik 1968); social time, theoretical analyses by Linton (1942) and Parsons (1942), and Eisenstadt's (1956) influential synthesis of ethnographic materials on age differentiation; and historical, Mannheim's (1952, orig. 1928) essay on "The Problem of Generations." Continuities within the social time perspective are illustrated by theoretical formulations of social transitions in the life course, from Cottrell's (1942) propositional inventory on adjustment to age

611 citations


Journal ArticleDOI
01 May 1975
TL;DR: The Stability of Globular Protein: A Critical Review in Biochemistry as discussed by the authors, Vol. 3, No. 1, pp. 1-43, was the first publication of this paper.
Abstract: (1975). The Stability of Globular Protein. CRC Critical Reviews in Biochemistry: Vol. 3, No. 1, pp. 1-43.

609 citations


Journal ArticleDOI
TL;DR: The diuresis and natriuresis seen after acute renal denervation were caused by a marked depression of sodium and water reabsorption in the proximal tubule with partial compensation in more distal nephron segments.
Abstract: Studies were undertaken to characterize the renal responses to acute unilateral renal denervation and the mechanisms involved in these responses. Denervation was produced in anesthetized nondiuretic rats by application of phenol to the left renal artery. Studies were also performed in sham-denervated nondiuretic rats. Whole kidney and individual nephron studies were performed before and after denervation or sham denervation. Denervation increased urine volume from the left kidney to about twice its control value (P less than 0.001) and increased urinary sodium excretion from 332 neq min minus -1 to 1,887 neq min minus -1 (P less than 0.001). Glomerular filtration rate (GFR) and renal plasma flow (RPF) remained unchanged in both kidneys after the procedure. The innervated right kidney showed no changes in urine volume or in sodium excretion. After denervation, late proximal ratio of tubular fluid inulin concentration to that of plasma [(F/P)In] decreased from 2.23 to 1.50 (P less than 0.001) while single nephron GFR remained unchanged. Absolute reabsorption decreased from 16.5 to 9.9 n. min minus -1 (P less than 0.001). (F/P)In ratios were also decreased in early distal (from 6.21 to 3.18, P less 0.001) and late distal convolutions (from 16.41 to 8.33, P less than 0.001) during the experimental period. (F/P)Na ratios remained unchanged in the early distal convolutions, but increased from 0.18 to 0.38 (P less than 0.01) in late distal convolutions after denervation. Absolute Na reabsorption after denervation increased in the loop of Henle, distal convolution, and collecting ducts. Any changes in intrarenal hydrostatic pressures after denervation were always small. There were no changes in GFR, RPF, urine volume, urinary sodium excretion, or late proximal (F/P)In after sham denervation. We conclude that the diuresis and natriuresis seen after acute renal denervation were caused by a marked depression of sodium and water reabsorption in the proximal tubule with partial compensation in more distal nephron segments. These responses appeared to be unrelated to systemic or intrarenal hemodynamic changes. The results demonstrate an effect of the renal nerves on proximal tubular function.

386 citations


Proceedings ArticleDOI
01 Jan 1975
TL;DR: The author will list some of the assertions in the book and invite dispute or support from the audience in this public discussion of the published book.
Abstract: The book, The Mythical Man-Month, Addison-Wesley, 1975 (excerpted in Datamation, December 1974), gathers some of the published data about software engineering and mixes it with the assertion of a lot of personal opinions. In this presentation, the author will list some of the assertions and invite dispute or support from the audience. This is intended as a public discussion of the published book, not a regular paper.

361 citations


Journal ArticleDOI
TL;DR: The junction serves the following functions: (1) epidermal-dermal adherence, (2) mechanical support for the epidermis, and (3) a barrier to the exchange of cells and of some large molecules across the junction.

335 citations


Journal ArticleDOI
TL;DR: There was a clear developmental progression in the ability to analyze spoken language in this way, and the skills of analyzing sentences into words and words into syllables were highly related and somewhat independent of sentence and word analysis items.
Abstract: Fifty children aged 3–7 years were asked to repeat spoken sentences and then to divide up these sentences into words, the words into syllables, and the syllables into speech sounds. There was a clear developmental progression in the ability to analyze spoken language in this way. The skills of analyzing sentences into words and words into syllables were highly related. Items requiring analysis of syllables into phonemes were highly correlated with each other and somewhat independent of sentence and word analysis items. The results are related to Gibson's model of reading, in which the acquisition of grapheme-phoneme correspondences is a crucial process.

331 citations


Journal ArticleDOI
TL;DR: In this paper, a computer method for calculating recurrence under the polygenic threshold model is explained, which permits accurate risk evaluation for pedigrees of arbitrary structure and large enough size.
Abstract: A computer method for calculating recurrence under the polygenic threshold model is explained. This approach permits accurate risk evaluation for pedigrees of arbitrary structure and large enough size

313 citations


Book ChapterDOI
TL;DR: In this paper, it was shown that the Poincare-Bendixson Theorem can be generalized to foliations of codimension one provided that the leaves of the foliation satisfy a growth condition.
Abstract: It has been known for some time that qualitative results concerning flows in the plane do not fully generalize, either to flows on arbitrary manifolds or to foliations of codimension one. On the other hand, in [11] it was shown that the Poincare-Bendixson Theorem can be generalized to foliations of codimension one provided that the leaves of the foliation satisfy a growth condition. In the classical situation of flows in the plane this condition is trivially satisfied. If a foliation comes from a finite dimensional Lie group action then the growth condition may be interpreted in terms of the ergodic properties of the group. Of course, for arbitrary foliations we do not necessarily have such a group action, but we do have a pseudogroup, called the holonomy pseudogroup, which acts transversely to the leaves. Growth conditions on the leaves can be interpreted as conditions on the holonomy pseudogroup which, in some cases, imply the existence of a measure which is invariant under the action of the pseudogroup. It is such invariant measures that capture the essence of the classical qualitative theory of flows on surfaces. The basic idea of using invariant measures to study qualitative aspects of foliations goes back to the rotation numbers of Poincare. A modern treatment of these notions for flows on metric spaces which clearly brings out the role of invariant measures is in Schwartzman [22]. This last work is based on Kryloff-Bogoliuboff [7] in which the space of invariant measures of a dynamical system is studied at length and is recognized to be a topological invariant of the dynamical system itself. Invariant measures have also appeared earlier in the qualitative study of foliations. Sacksteder [21] uses the notion of an invariant measure to describe the structure of smooth codimension one foliations having trivial holonomy groups, and Sinai [23] considers invariant measures for the foliations invariant under a transitive Anosov diffeomorphism. In both cases the invariant measures involved were "positive on open sets." Hirsch and Thurston [4] consider more general invariant measures for foliated bundles

306 citations


Journal Article
TL;DR: Results provide evidence that TRH acts on brain independent of an effect on the pituitary, and suggest that cholinergic mechanisms may contribute to the effects of TRH.
Abstract: Thyrotropin-releasing hormone (TRH) was found to antagonize pentobarbital-induced sleeping time and hypothermia. While 3 to 100 mg/kg of TRH reduced pentobarbital sleeping time when administered prior to the barbiturate, a dose-response relationship to TRH could not be established. However, doses of 10 to 100 mg/kg of TRH enhanced the lethality of pentobarbital when these compounds were administered simultaneously. Thyrotropin or L-triiodothyronine did not imitate and hypophysectomy did not reduce the effects of TRH, indicating that the pituitary is not essential for its antagonism of pentobarbital. Studies of TRH analogs provided further support of this view. In addition, TRH reduced the sleep and hypothermia produced by thiopental, amobarbital, secobarbital and phenobarbital, and it antagonized the hypothermia and reduced motor activity produced by chloral hydrate, reserpine, chlorpromazine and diazepam. Intracisternally administered TRH also reduced pentobarbital sleeping time and hypothermia, but melanocyte-stimulating hormone release-inhibiting factor and somatostatin administered by this route did not. While reduction of pentobarbital sleeping time by TRH could not be attributed to an affect on monoamine systems or to deamidated TRH, this action was reduced by intracisternally administered atropine, suggesting that cholinergic mechanisms may contribute to the effects of TRH. Thus, the results provide evidence that TRH acts on brain independent of an effect on the pituitary.

291 citations


Journal ArticleDOI
TL;DR: The life distribution properties of a device subject to wear occurring randomly in time as a gamma process are related to the corresponding properties of the probability of surviving a specified amount of wear as mentioned in this paper.
Abstract: Life distribution properties of a device subject to wear occurring randomly in time as a gamma process are related to the corresponding properties of the probability of surviving a specified amount of wear.


Journal ArticleDOI
TL;DR: In this article, a vector definition of multivariate hazard rate and associated definitions of increasing and decreasing hazard rate distributions are presented, and the results of these definitions are worked out in a number of special cases.

Journal ArticleDOI
TL;DR: The data suggest that in this population under 30 years, weight is a risk factor for hypertension, and that maintenance of ideal weight, instituted in youth, may be a preventive measure.
Abstract: This study is concerned with blood pressure behavior in young adults (aged 15 to 29 years) in the biracial community of Evans County, Ga., on two occasions 7 years apart. On the basis of casual blood pressure recordings the prevalence of systolic pressure equal to or greater than 140 mm Hg or diastolic pressure equal to or greater than 90 mm Hg, or both, showed race/sex differences as follows: white males 19.0 percent, white females 12.7 percent, black males 34.0 percent, black females 31.6 percent. Similar differences were noted in the incidence during the 7 year interval. The problem presented by the variability of the casual blood pressure recording is apparent in this interval study. Of particular interest is the association of weight with blood pressure in this youthful group, particularly among white males and females and black females, in relation to both initial and subsequent pressure levels. The data suggest that in this population under 30 years, weight is a risk factor for hypertension, and that maintenance of ideal weight, instituted in youth, may be a preventive measure.

Journal ArticleDOI
TL;DR: There is a great deal of confusion about the history of women's work outside the home and about the origin and meaning of women' traditional place within the home as discussed by the authors, and most interpretations of either of these questions depend on assumptions about the other.
Abstract: There is a great deal of confusion about the history of women's work outside the home and about the origin and meaning of women's traditional place within the home. Most interpretations of either of these questions depend on assumptions about the other. Usually, women at home in any time period are assumed to be non-productive, the antithesis of women at work. In addition, most general works on women and the family assume that the history of women's employment, like the history of women's legal and political rights, can be understood as a gradual evolution from a traditional place at home to a modern position in the world of work. Some historians cite changes in employment opportunities created by industrialization as the precursors of legal emancipation. Others stress political rights as the source of improved economic status. In both cases, legal-political and economic ‘emancipation’ usually are linked to changes in cultural values. Thus William Goode, whose World Revolution and Family Patterns makes temporal and geographic comparisons of family patterns, remarks on what he calls ‘the statistically unusual status of western women today, that is their high participation in work outside of the home’.

Journal ArticleDOI
TL;DR: The present data suggest that an environmental cause common to sibships is possibly important in causing the disorder, and longevity analysis demonstrated elongation of life expectancy for kindred members, and there was an apparent rarity of premature cardiac events.
Abstract: A newly recognized familial hyperlipoproteinemia, familial hyper-alpha-lipoproteinemia, is described in 18 kindreds. Affected probands and relatives had distinctive elevations of alpha-lipoprotein cholesterol (C-HDL), slight elevations of total cholesterol, no elevation of LDL and VLDL cholesterol, and normal triglyceride levels. The proband and at least one additional first degree relative had distinctive elevations of C-HDL in 16 of 18 kindreds. Simple segregation analysis involving 84 offspring of 22 hyper-alpha X normal-alpha matings from these 16 kindreds revealed a ratio of hyper-alpha to normal of 37:47, a ratio not significantly different from 1:1 (chi 2(1) = 1.2), the ratio consistent with autosomal dominant transmission. Despite the suggestion of a major gene effect by this analysis, evaluation of the C-HDL distribution in kindred members failed to reveal bimodality, and familial correlation analysis revealed no parent-offspring correlation. The present data suggest that an environmental cause common to sibships is possibly important in causing the disorder. Longevity analysis demonstrated elongation of life expectancy for kindred members, and there was an apparent rarity of premature cardiac events.

Journal ArticleDOI
TL;DR: For instance, this article found that third graders tended to rehearse the item currently being presented either alone or in minimal combination with other words, whereas sixth graders (and older subjects) rehearsed several different items together.
Abstract: ORNSTEIN, PETER A.; NAUS, MARY J.; and LIBERTY, CHARLES. Rehearsal and Organizational Processes in Children's Memory. CHILD DEVELOPMENT, 1975, 46, 818-830. An overt rehearsal procedure was used to study the relationship between children's rehearsal strategies and recall performance in a free recall task. 2 experiments were conducted, 1 employing unrelated words and the other taxonomically related materials, so that rehearsal could be examined under different conditions of list organization. In both experiments, developmental changes in rehearsal content were observed. Third graders tended to rehearse the item currently being presented either alone or in minimal combination with other words. In contrast, sixth graders (and older subjects) rehearsed several different items together. These changes in rehearsal technique were related to developmental differences in the magnitude of the primacy effect. However, the role of rehearsal seemed to vary as a function of list structure. When categorical items were employed, ninth graders were better able than younger subjects to use taxonomic information to rehearse related words together. This rehearsal of category items was related to improved recall, but blocked presentation of the taxonomic materials facilitated the recall of the third graders, without corresponding changes in rehearsal being observed.

Journal ArticleDOI
TL;DR: The amino acid composition determined in the present study indicates that the content of cysteine is identical in the two forms of the enzyme thus permitting the proposal of a structure for β-thrombin which differs from that currently in the literature.

Journal ArticleDOI
TL;DR: In this paper, a multivariate generalization of the farlie-Gumbel-Morgenstern bivariate system of distribution is described, and properties of orthant dependence are investigated.
Abstract: A multivariate generalization of the farlie-Gumbel-Morgenstern bivariate system of distribution is described. Certain properties, particularly those concerning orthant dependence, are investigated.

Journal ArticleDOI
TL;DR: The observed rhythms produced and perceived in spoken language are closely related to rhythms of other human behavior as mentioned in this paper, and this relationship is examined in terms of the types of rhythmic structures observed, the rate of succession of the rhythmic units, and a perceptual tendency toward equalization of physically unequal intervals.

Journal ArticleDOI
TL;DR: 5,7-DHT treatment was found to enhance the depressant effects of 5-hydroxytryptophan on a fixed-ratio barpress response, suggesting that 5,7,DHT treated rats are supersensitive to serotonin in the central nervous system.

Journal ArticleDOI
TL;DR: Low-level resistance to tetracycline or chloramphenicol was due to similar additive effects between mutations at the nonspecific ery and penB loci and a locus specific for resistance to each drug (tet and chl, respectively).
Abstract: The genetics of low-level resistance to penicillin and other antibiotics in a clinical isolate and a multistep laboratory mutant of Neisseria gonorrhoea was studied by transformation. Mutations at three loci affected sensitivity to penicillin. Mutation at penA resulted in an eightfold increase in resistance to penicillin without affecting response to other antimicrobial agents. Mutation at ery resulted in a two- to fourfold increase in resistance to penicillin and similar increases in resistance to many other antibiotics, dyes, and detergents. Mutation at penB resulted in a fourfold increase in resistance to penicillin and tetracycline, the phenotypic expression of which was dependent on the presence of mutation at ery. The cumulative effect of mutations at penA, ery, and penB was an approximate 128-fold increase in penicillin resistance, to a minimum inhibitory concentration of 1.0 mug/ml. Low-level resistance to tetracycline or chloramphenicol was due to similar additive effects between mutations at the nonspecific ery and penB loci and a locus specific for resistance to each drug (tet and chl, respectively). No evidence was found for penicillinases or other drug-inactivating enzymes.



Journal ArticleDOI
TL;DR: It is demonstrated that anchoring fibrils were not formed by EBD-R dermis when combined with E BD-R epidermis or normalEpidermolysis bullosa dystrophica-recessive, and that the defect may be associated with impaired formation of anchoringfibrils.

Journal ArticleDOI
TL;DR: The present paper introduces a quantitative method for analyzing data on medication use and misuse among patients with either adult onset diabetes mellitus or congestive heart failure.

Journal ArticleDOI
TL;DR: It is concluded that echocardiography can be utilized to follow up changes in left ventricular wall motion and dimensions after surgery for valvular heart disease, and that it may be of value in assessing the early and late postoperative results.
Abstract: Echocardiograms obtained from 50 patients after valvular heart surgery (in 33 cases within 2 months of the procedure) were examined to study patterns of interventricular septal motion and left ventricular dimensional changes. Preoperative echograms were available in 28 cases. Before and after mitral commissurotomy septal motion and left ventricular diameters as well as the percent systolic shortening of the echocardiographic transverse axis were within normal limits. Before operation, aortic and mitral regurgitation were associated with increases in end-diastolic and end-systolic diameters, septal motion and percent systolic shortening of the left ventricular diameter. Septal dyssynergy, defined as paradoxical motion or marked hypokinesia, was seen within 2 months of operation in 91 percent of patients after aortic valve replacement and in 42 percent after mitral valve replacement. Of subjects studied more than 2 months postoperatively, none with mitral valve replacement and only 33 percent with aortic valve replacement manifested septal dyssynergy. After valve replacement for aortic or mitral regurgitation there were significant decreases in end-diastolic diameter, septal excursion and total and percent left ventricular systolic shortening. Two subjects not having valve replacement also demonstrated paradoxical septal motion postoperatively. The cause of septal dyssynergy after valvular surgery was not apparent although the use of cardiopulmonary bypass was an esential condition. We conclude that echocardiography can be utilized to follow up changes in left ventricular wall motion and dimensions after surgery for valvular heart disease, and that it may be of value in assessing the early and late postoperative results.

Journal ArticleDOI
TL;DR: The black-white lipoprotein fraction differences in Evans County are consistent with a negative, coronary risk factor role of elevated HDL cholesterol, which has been postulated based on other experimental and prevalence studies.

Journal ArticleDOI
TL;DR: Microelectrode techniques were employed to measure the electrical resistance of the cell membranes and the shunt pathway, and the equivalent electromotive forces at both cell borders in Necturus gallbladder epithelium, indicating that the latter measurements yield adequate information on the properties of theShunt.
Abstract: Microelectrode techniques were employed to study the ionic permeability of the apical cell membrane ofNecturus gallbladder epithelium. Results obtained from continuous records in single cells, and from several cellular impalements shortly after a change in solution, were similar and indicate that both the apical membrane equivalent electromotive force (Va) and electrical resistance (Ra) strongly depend on external [K]. Cl substitutions produced smaller effects, while the effects of Na substitutions with N-methyl-d-glucamine on bothVa andRa were minimal. These results indicate that the permeability sequence of the apical membrane isPK>PCl>PNa. From the calculated absolute value ofPNa it is possible to estimate the diffusional Na flux from the mucosal solution into the cells (from the cell potential and an assumed intracellular Na concentration). The calculated flux is roughly three orders of magnitude smaller than the measured net transepithelial flux in this tissue and in gallbladders of other species. Thus, only a minimal portion of Na entry can be attributed to independent diffusion. From estimations of the electrochemical potential gradient across the apical membrane, Cl transport at that site must be active. At the serosal cell membrane, Na transport takes place against both chemical and electrical potentials, while a significant portion of the Cl flux can be passive, if this membrane has a significant Cl conductance. The changes in shunt electromotive force and in transepithelial potential after mucosal substitutions were very similar, indicating that transepithelial bi-ionic potentials yield appropriate results on the properties of the shunt pathway.

Journal ArticleDOI
TL;DR: It is concluded that some Lamina I neurons form part of an ascending projection which follows the spinal pathway of the spinothalamic tract and thereby contribute to the mechanical nociceptive and thermoreceptive features of this pathway.
Abstract: A search for postsynaptic elements, excited only by slowly-conducting afferent fibers (Aδ and C), was made by recording from the dorsal horn of cats and monkeys with dye-filled microelectrodes. Units identified by afferent responsiveness were tested for antidromic invasion by electrical stimulation of the opposite ventrolateral funiculus at the midcervical level. Recording points were marked by iontophoretically passing dye from the recording electrode and subsequently located in histologically-prepared material. Evidence for antidromic excitation from spinal cord stimulation was found for five of 21 units in cat and 13 of 31 neurons in monkey. Antidromically excited cells were located within the distribution of the large posteromarginal neurons of the dorsal marginal zone (Lamina I). Although recording loci for a number of the elements studied were unequivocally located within Laminae II (substantia gelatinosa) or III, none could be antidromically excited. All antidromically driven units received a powerful input from Aδ primary afferent units and upon testing with natural stimuli responded specifically to stimuli of the type initiating activity either for high threshold mechanoreceptors or for low threshold thermoreceptors. It is concluded that some Lamina I neurons form part of an ascending projection which follows the spinal pathway of the spinothalamic tract and thereby contribute to the mechanical nociceptive and thermoreceptive features of this pathway. The absence of antidromic response is argued to be uncertain and evidence for a lack of projection is open to alternative explanation.