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Showing papers by "University of Connecticut published in 1975"



Journal ArticleDOI
TL;DR: It is demonstrated that it is possible in dogs to establish and maintain a normal gingiva simply by eliminating calculus and then subjecting the animals to daily repeated and carefully performed tooth cleanings.
Abstract: The present investigation was carried out in order to study some aspects of the clinical, roentgenographical and histopathological alterations of periodontal tissues in dogs which during a 4-year period were allowed freely to accumulate plaque. Twenty inbred Beagle dogs, at the start of the study 10 months of age, were used. During a preparatory period of eight weeks the animals were once weekly subjected to a careful prophylaxis and had their teeth brushed twice daily. At the end of this period the dogs were divided into two groups of ten (test and control). From day zero of experimentation and onwards the teeth of the control dogs were twice daily subjected to meticulous toothbrushing, whereas the teeth of the test dogs were not cleaned. Examinations of the periodontal tissues were performed at days 0, 7, 14, 21, 28 and after 2, 4, 6, 8, 12, 18, 24, 36 and 48 months. Biopsies of different tooth regions were made on day zero and after 6, 12, 18, 24, 36 and 48 months of experiment. In the sections were measured (i) the distance from the cemento-enamel junction (CEJ) to the most apical cells of the dento-gingival epithelium, and (ii) the distance from CEJ to the level of the marginal alveolar bone. The study demonstrated that it is possible in dogs to establish and maintain a normal gingiva simply by eliminating calculus and then subjecting the animals to daily repeated and carefully performed tooth cleanings. Dogs allowed freely to accumulate plaque rapidly developed signs of gingivitis and eventually also clinical, radiographical and histopathological signs of periodontal tissue breakdown. The observations show that at least one type of periodontal disease is induced by factors within the dental plaque.

392 citations


Journal ArticleDOI
TL;DR: In this article, the particle paths are studied for various types of simultaneous combinations of pure shear and simple shear, and the angles between the slide direction of the simple-shear part and the principal strain rate ϵ x of the pure-Shear part are 45°.

254 citations


Journal ArticleDOI
01 Jan 1975
TL;DR: The problem of inferring a stochastic grammar to model the behavior of an information source is introduced and techniques for carrying out the inference process are presented for a class of Stochastic finite-state and context-free grammars.
Abstract: Inference of high-dimensional grammars is discussed. Specifically, techniques for inferring tree grammars are briefly presented. The problem of inferring a stochastic grammar to model the behavior of an information source is also introduced and techniques for carrying out the inference process are presented for a class of stochastic finite-state and context-free grammars. The possible practical application of these methods is illustrated by examples.

254 citations



Journal ArticleDOI
TL;DR: In this paper, the authors suggest that intra-group diversity in behavioral repertoires and cognitive orientations, like genetic diversity within populations, is of great significance for on-going processes of human adaptation.
Abstract: Recent anthropological research includes a growing number of studies which focus directly on issues of intra-cultural and intra-community diversity, rather than simply recording passing mention of “deviations” from norms or cultural patterns that are presumed to be standardized. Studies of behavioral and cognitive diversity are essential for understanding differential processes of social change, as well as other theoretical problems. We suggest that intra-group diversity in behavioral repertoires and cognitive orientations, like genetic diversity within populations, is of great significance for on-going processes of human adaptation.

211 citations


Journal ArticleDOI
08 Aug 1975-Science
TL;DR: The tissue response is uniform throughout the epiphyses of tibiae, whereas the cell response varies according to the area of origin.
Abstract: Compressive forces of physiological magnitude (60 grams per square centimeter) reduce the adenosine 39,59-monophosphate and guanosine 39,59-monophosphate content of the epiphyses of tibiae from 16-day-old chick embryos. An equivalent hydrostatic pressure applied directly to cells isolated from this tissue also affects cyclic nucleotide accumulation. The tissue response is uniform throughout the epiphysis, whereas the cell response varies according to the area of origin.

195 citations



Journal ArticleDOI
TL;DR: For instance, this paper found that primiparous females that raised litters to weaning and were tested for responsiveness to donor's pups 25 days postweaning exhibited an immediate onset of maternal responsiveness.

167 citations


Journal ArticleDOI
TL;DR: Use of the "discrimination value" for the results of a laboratory test in a specified clinical situation provides the optimal discrimination between the "healthy" and the "diseased," or between "those who need not be investigated further" and " those who do."
Abstract: The term "normal values" is seriously afflicted by sylleptic ambiguities and conceptual problems, and it is gradually being discarded from the lexicon of clinical chemistry. The neutral term "reference values" preferable on semantic and scientific grounds, and its use in clinical chemistry is rapidly gaining acceptance. The term "discrimination value" has been added to the lexicon of clinical chemistry. Use of the "discrimination value" for the results of a laboratory test in a specified clinical situation provides the optimal discrimination between the "healthy" and the "diseased," or between "those who need not be investigated further" and "those who do."

157 citations


Journal ArticleDOI
10 Apr 1975-Nature
TL;DR: Using polyacrylamide gel electrophoresis, it is found that a band which contains one of these proteins is selectively labelled by a water-transport inhibitor.
Abstract: CLASSICAL interpretations of the mechanism of water transport across mammalian red cell membranes assume the existence of aqueous membrane pores1–3. As the permeability coefficient to water measured under an osmotic pressure gradient is usually significantly higher than the corresponding value measured under diffusional flow, the human red cell membrane is thought to act both as a selective solvent and a molecular sieve. Its ability to function as a molecular sieve depends on the existence of the pores, which could be assembled from aggregates of integral membrane proteins which span the membrane4. It is generally agreed that at least two proteins span the human red cell membrane5–7. Using polyacrylamide gel electrophoresis we have found that a band which contains one of these proteins is selectively labelled by a water-transport inhibitor.

Journal ArticleDOI
TL;DR: A group of 22 unselected adults and a group of 30 right-handed male adults were tested on a series of handedness measures and on a dichotic CV-syllable test and multiple regression methods were used to determine a correlation coefficient between handedness Measures and dichotic ear advantages.

Journal ArticleDOI
06 Feb 1975-Nature
TL;DR: Cells which do cap can be distinguished as lymphocytes1 and rabbit exudate polymorphonuclear leukocytes (PMN) that cap directly when incubated with low concentrations of con A, and cells which cap only after incubation with colchicine which disrupts microtubules (MT).
Abstract: TREATMENT of a variety of cell types with concanavalin A (con A) leads to the aggregation of the lectin into one region or pole of the cell, forming a so-called cap Not all cells cap (erythrocytes and normal cultured fibroblasts do not) Cells which do cap can be distinguished as (a) lymphocytes1 and rabbit exudate polymorphonuclear leukocytes (PMN) (our data) that cap directly when incubated with low concentrations of con A at 37° C, and (b) cells exemplified by SV40-transformed fibroblasts2 and lymphocytes incubated with high (more than 5 µg ml−1) concentrations of con A1 that cap only after incubation with colchicine which disrupts microtubules (MT) These differences between cell types are not understood


Journal ArticleDOI
TL;DR: It is concluded that aphasia is best understood as a general impairment of symbolic communication that includes nonverbal as well as verbal deficits.
Abstract: A pantomime recognition test was developed to study the extent of impairment of pantomime recognition and the relationship between pantomime recognition and verbal deficits in aphasics. This test r...

Journal ArticleDOI
TL;DR: In this article, a two-state configuration coordinate diagram is used to explain the occurence or non-occurence of F-center luminescence in ionic crystals.

Journal ArticleDOI
TL;DR: Prostaglandins appear to be synthesized by human PMN during phagocytosis, and their release from cells may help regulate the inflammatory response.
Abstract: Human PMNs release prostaglandins E and F to the surrounding medium when these cells are exposed to zymosan. PGE1 is the prostaglandin compound found in highest concentration in the medium, and the PGE/PGF balance is approximately 3∶1. Release of prostaglandins is not due to platelet contamination. Agents which inhibit prostaglandin synthesis (indomethacin, aspirin) prevent release of prostaglandins from phagocytic cells. Addition to cells of dibutyryl cyclic 3′,5′-adenosine monophosphate produces striking increases in concentrations of prostaglandins released during ingestion of zymosan. Prostaglandins appear to be synthesized by human PMN during phagocytosis, and their release from cells may help regulate the inflammatory response.

Journal ArticleDOI
TL;DR: The local anesthetics tetracain and butacaine increased the fluidity of lipid dispersions, natural membranes and intact ascites tumor cell membranes, and the effect of anesthetic appears to be due to an increased disordering of lipid structure.

Journal ArticleDOI
01 May 1975
TL;DR: The most abundant nudibranchs in southern New England are small aeolids and sacoglossans, characteristically sub-annual species with asynchronous growth, continuous egg production and recruitment.
Abstract: 1 The most abundant nudibranchs in southern New England are small aeolids and sacoglossans These gastropods are characteristically sub-annual species with asynchronous growth, continuous egg production and recruitment Growth of individuals is notably rapid for molluscs, and is probably related to the possession of cerata, which appear to be an adaptation permitting increased rates of assimilation and metabolism These characteristics represent adaptations to transient food sources which appear early in the microsuccession of fouling communities Larger species, almost entirely dorids, have slower growth, restricted periods of egg production, synchronous growth cycles, and lower metabolic rates These feed on more stable, longlived food sources characteristic of later successional stages 2 The cerata represent convergent adaptations in four major taxa (Sacoglossa, Dendronotacea, Arminacea, and Aeolidacea) permitting an increase in growth and nonhomeostatic respiration This is accomplished by an increase in both respiratory and digestive surface area 3 The major component of recruitment of nudibranch populations is due to allochthonously-produced larvae This may be of great value in repopulation of areas similar to southern New England, where temperature instability may preclude survival of a population for more than a few months 4 High thermal sensitivity is characteristic of most nudibranchs of the western Atlantic, as indicated by high Q10 values This sensitivity does not always cause mortality in natural populations, but is related to the rapid changes in population activity, and may represent a further adaptation to prey-species' life cycles The interaction of high thermal sensitivity and a wide environmental temperature range, however, does limit the zoogeographic ranges and accounts for the low species diversity of the west Atlantic littoral fauna Thermal sensitivity also explains the scarcity of intertidal species in southern New England, and accounts for the vernal disappearance of a few species 5 Most species have type 1 (planktotrophic) development, which is of value in dispersal to and exploitation of new fouling growths Some evidence is given that the proportion of type 1 development is higher in the western Atlantic than in the eastern Atlantic, which may relate to a greater instability of food species 6 The widely-reported sudden appearances of populations are due to arrival of large numbers of larvae, followed by rapid growth to visible size A critical temperature may stimulate settling and metamorphosis 7 Sudden disappearances of adult populations are due to several causes Small exploitist species normally overgraze food supplies following peak recruitment periods This leads to destruction of the microhabitat and reduction of absolute population size, with apparent disappearance of individuals Annual species normally die following periods of egg production, probably due to physiological weakening caused by extreme gonad output

Journal ArticleDOI
TL;DR: Results demonstrate that glucocorticoids may directly act on nerve terminals in the regulation of 5-HT synthesis through an action on the uptake of tryptophan.

Journal ArticleDOI
10 Apr 1975-Nature
TL;DR: Using fluorescent polarisation techniques, it is found that the membranes of muscle, liver and erythrocytes of dystrophic chicks have a significantly higher microviscosity than normal controls, and the greatest difference was in muscle, the site of the clinical symptoms of this genetic disease.
Abstract: WE have demonstrated recently several functional differences between membrane-bound enzymes from tissues of muscular dystrophic chicks and of controls1. Several other membrane anomalies have been associated with this disease2–7, but so far the only known biochemical anomaly in the affected membranes is a difference in lipid composition8,9. This could cause all the observed functional defects, including those in enzyme activities and permeability, through an alteration in the membrane microenvironment10. Certain physical properties of the microenvironment can be studied by fluorescent polarisation techniques that measure the mobility of a lipid-soluble fluorescent dye11,12. The basis for this approach is the fact that membrane cholesterol, which strongly affects the microviscosity of liposomes10, is present in significantly greater than normal amounts in genetic muscular dystrophy. Using this approach, we found (Table 1) that the membranes of muscle, liver and erythrocytes of dystrophic chicks have a significantly higher microviscosity than normal controls. The greatest difference was in muscle, the site of the clinical symptoms of this genetic disease. The higher cholesterol :phospholipid ratio characteristic of the diseased membrane is sufficient to account for the observed increase in microviscosity11.

Journal ArticleDOI
21 Nov 1975-Science
TL;DR: When compared to their housemates that subsequently developed leukemia, cats that remained healthy had five-to tenfold higher (geometric mean) humoral antibody titers to the feline oncornavirus-associated cell membrane antigen.
Abstract: When compared to their housemates that subsequently developed leukemia, cats that remained healthy had five-to tenfold higher (geometric mean) humoral antibody titers to the feline oncornavirus-associated cell membrane antigen. This is compatible with the application of the immunosurveillance hypothesis to the natural development of leukemia in an outbred mammalian species.


Journal Article
TL;DR: The chemotactic factor inactivator (CFI) has been isolated from whole human serum by a combination of techniques including salt precipitation, anionic exchange, and gel filtration chromatography, obtaining two inactivators that have a specificity for inactivation of theChemotactic activity associated with the C3 fragments.
Abstract: The chemotactic factor inactivator (CFI) has been isolated from whole human serum by a combination of techniques including salt precipitation, anionic exchange, and gel filtration chromatography. Two inactivators have been obtained, a β-globulin with a sedimentation velocity of approximately 7S and an α-globulin with a sedimentation velocity of approximately 4S. The former has a specificity for inactivation of the chemotactic activity associated with the C3 fragments, whereas the C5 chemotactic fragment is specifically inactivated by the α-globulin CFI. CFI in crude fractions of human serum is heat labile, time and temperature dependent for its activity, and pH dependent, expressing optimal activity at a pH range of 7.2 to 7.4.

Journal Article
TL;DR: Evidence is provided that monocytes can adsorb basophil chemotactic activity but not vice versa, and some of the ways in which lymphocytes can influence basophils through lymphokine-dependent mechanisms are underscore.
Abstract: Guine pigs basophils obtained from blood or bone marrow have been studied for their chemotactic responsiveness. Chemotactic factors for basophils include a substance (lymphokine) present in culture fluids from antigen-stimulated lymphocytes, a material generated in zymosan-activated guinea pig serum, a C5 cleavage factor, and a bacterial factor. When compared with homologous neutrophils and monocytes, basophils respond most rapidly to a chemotactic stimulus. The lymphokine basophil chemotactic factor is physicochemically similar to the previously described monocyte chemotactic factor but appears to be distinct from it as well as MIF and neutrophil chemotactic factor present in the same fluids, Part of the evidence for this is the ability to detect basophil chemotactic factor in the absence of other lymphokine activities under appropriate experimental conditions. More evidence, specifically relating to the monocyte factor, is that monocytes can adsorb basophil chemotactic activity but not vice versa. This latter observation may have implications for the mechanism whereby the accumulation of basophils is controlled and limited in vivo. In addition, it was noted that specific antigen could also suppress basophil chemotaxis. Although the mechanism of this phenomenon is unclear, it could serve as a second means by which basophil accumulation may be controlled in the intact animal. Taken together, these observations provide further definition of the chemotactic behavior of basophils in general, and underscore some of the ways in which lymphocytes can influence basophils through lymphokine-dependent mechanisms.


Journal ArticleDOI
TL;DR: The results indicate that acyclicity induced by lactation or exposure to a short photoperiod is characterized by similar diurnal patterns of circulating hormones in the hamster.
Abstract: Levels of LH, FSH, and progesterone in serum were measured in lactating hamsters and in hamsters in which acyclicity was induced with altered photoperiod. Lactating hamsters were found to have low titers of LH, FSH, and progesterone in serum at 0900 (lights on 0500-1900) on Days 4, 9, 14, and 19 of lactation and increased levels of these hormones at 1600. Levels of LU and FSH in serum at both 0900 and 1600 remained relatively constant throughout lactation. In contrast, levels of progesterone in serum obtained at both 0900 and 1600 sampling times increased as lactation progressed. Ovariectomy on Day 9 of lactation reduced serum levels of progesterone at both 0900 and 1600 and eliminated the afternoon surge in progesterone in animals bled 5 days after surgery. The levels and pattern of LH in serum remained unchanged after ovariectomy in lactating hamsters. However, serum FSH levels in the ovariectomized, lactating animals were elevated at both 0900 and 1600 when compared to levels present in intact, lactating hamsters bled at the same times. Females which were acyclic due to altered photoperiod displayed similar patterns of LH, FSH, and progesterone in serum. Levels of LH, FSH, and progesterone in serum were low at 1000 (lights on 0500-1500) and were increased 2 to 10 fold at 1500. Ovariectomy was followed by lower progesterone levels in serum at 1000 and 1500 and eliminated the afternoon rise of this hormone. Serum levels of LH were unaffected by ovariectomy. As in lactating hamsters, levels of FSH in serum were elevated 3-4 days following ovariectomy at both bleeding times, but the levels were higher at 1500. These results indicate that acyclicity induced by lactation or exposure to a short photoperiod is characterized by similar diurnal patterns of circulating hormones in the hamster.

Journal ArticleDOI
31 Oct 1975-Science
TL;DR: The demonstration of the ejaculatory pattern in perinatally untreated female rats indicates that the potential for the expression ofThe ejaculatory or "orgasmic" pattern is not dependent on exogenous androgen at any stage of development and is more widely represented among female mammals than previously believed.
Abstract: Adult female rats receiving long-term estrogen treatment displayed the species-typical motor pattern of ejaculation during copulation. This hormone treatment produced pituitary hypertrophy and concomitant pressure damage to brain areas dorsal to the pituitary, but did not cause clitoral hypertrophy. The demonstration of the ejaculatory pattern in perinatally untreated female rats indicates that the potential for the expression of the ejaculatory or "orgasmic" pattern is not dependent on exogenous androgen at any stage of development and is more widely represented among female mammals than previously believed.

Journal ArticleDOI
TL;DR: The prescription and administration of drugs (especially of the neuroactive class) was observed in 131 patients in an extended care facility and Questionable prescribing practices were demonstrated by the fact that 30 patients had prescriptions for 38 “not‐recommended” drugs.
Abstract: The prescription and administration of drugs (especially of the neuroactive class) was observed in 131 patients in an extended care facility. The average number of neuroactive drugs prescribed (2.1) was distinctly different from the average number administered (1.3) because of the large number of pro re nata (prn) prescriptions. More neuroactive substances were prescribed for patients with superior mentation and minimal physical disability; the difference between low and high groups was 1.7 (mentation) and 2.8 (physical status). The most common neuroactive drugs prescribed were: 1) analgesics, 2) major tranquilizers, and 3) hypnotics. Questionable prescribing practices were demonstrated by the fact that 30 patients had prescriptions for 38 "not-recommended"drugs; 23 of these prescriptions were for propoxyphene compound. After requiring physicians to rewrite drug orders every thirty days, a survey made ten months later showed that there was a decline (0.8) in the number of drugs prescribed per patient and a slight increase (0.45) in the number of drugs administered. Professional drug surveillance is crucial for improving the therapeutic process. At least two modifications of current prescribing practices are recommended: 1) a record should always be made of the precise condition(s) under which a drug prescribed "prn" is to be administered; and 2) a strong effort should be made to reduce the total number of drug prescriptions. The results of this survey suggest that certain procedural matters necessitating change are not in themselves the most substantive factors in improvement. Present "third party" review mechanisms likely will not ameliorate the current situation. It will be necessary to implement complex organizational changes in most extended care facilities.

Journal ArticleDOI
01 Jan 1975-Virology
TL;DR: It appears likely that formation of a putative cell killing factor requires at least two reactants: (1) primary transcripts and (2) transcriptase molecules, functioning in a reaction(s) subsequent to primary transcription which could be replicative or transcriptive in nature.