Showing papers by "University of Connecticut published in 1977"
TL;DR: In this article, the authors estimate the social benefits of product innovations used by firms and households, and the gap between social and private rates of return between the two groups is discussed.
Abstract: I. Introduction, 221.—II. The sample of innovations, 222.—III. Estimation of social benefits: product innovations used by firms, 222.—IV. Parallel innovative efforts, time horizon, and rates of return, 226.—V. Product innovations used by households, 229.—VI. Process innovations, 231.—VII. Social and private rates of return, 233.—VIII. Factors associated with the gap between social and private rates of return, 235.—IX. Unemployment, repercussions on other markets, and future changes in technology, 238.—X. Conclusion, 239.
676 citations
TL;DR: In beagle dogs (1) periodontal probes do not precisely measure connective tissue attachment levels, (2) inflammation has a significant influence on the degree of probe penetration, and (3) histological and clinical sulcus depths differ significantly.
Abstract: . The purpose of this study was to determine how accurately periodontal probes measure connective tissue attachment levels in beagle dogs with (1) clinically healthy gin-givae, (2) experimental gingivitis, and (3) periodontitis. In the healthy and experimental gingivitis specimens die probes were inserted with a standardized force of 25 ponds. In periodontitis specimens the probes were inserted with a gentle, but non standardized force After insertion, 120 plastic periodontal probes (40 in each group) were held in place by fusing them to the teeth. Blocks of periodontal tissue with the probes in situ were subsequently processed and serially sectioned. Histometric measurements were made from the sections in order to compare the level of connective tissue attachment to the level of probe penetration. In healthy specimens the probes consistently failed to reach the apical termination of the junctional epithelium (x =−0.39 mm). In the experimental gingivitis group most probes came closer to the apical termination of the junctional epithelium, but on the average stilt fell short by x =−0.10 mm. In periodontitis specimens the probes consistently went past the most apical cells of the junctional epithelium (x =+0.24 mm). A significant relationship between the degree of inflammation and level of probe penetration was found. No relationship was observed between histological and clinical sulcus depths. It is concluded that in beagle dogs (1) periodontal probes do not precisely measure connective tissue attachment levels, (2) inflammation has a significant influence on the degree of probe penetration, and (3) histological and clinical sulcus depths differ significantly.
382 citations
263 citations
TL;DR: It is shown here that the proton spin–lattice relaxation behaviour in hydrated collagen is dominated by cross relaxation between the water protons and the macromolecular protons as a result of spin diffusion, which contributes significantly to the water proton R1.
Abstract: PROTON NMR of water is being used extensively to probe the molecular dynamics of water molecules in biological systems such as protein solutions, hydrated macromolecules, cells and tissue. The nuclear magnetic relaxation rates R1 (spin–lattice) and R2 (spin–spin) can be analysed in terms of the rotational motions of the water molecules1–3. A crucial assumption in this analysis is that the proton relaxation of the water proceeds independently of that of the macromolecules. Kimmich and Noack4–6 claim that this assumption may be incorrect for proton spin–lattice relaxation because of spin diffusion, but clear evidence of spin diffusion in hydrated biological samples has not been reported. We show here that the proton spin–lattice relaxation behaviour in hydrated collagen is dominated by cross relaxation between the water protons and the macromolecular protons as a result of spin diffusion; the macromolecular spin–lattice relaxation contributes significantly to the water proton R1.
250 citations
TL;DR: The pattern of development in the embryoid bodies is remarkably similar to that in normal mouse embryogenesis up to the time of formation of the third germ layer, the mesoderm, which in most cases arises by a process which has not previously been described.
216 citations
TL;DR: Defective interfering particles of vesicular stomatitis virus which contain covalently linked complementary [+]message and [−]anti-message RNA as a single-stranded ribonucleoprotein complex within the particle, are extremely efficient inducers of interferon.
Abstract: Defective interfering (DI) particles of vesicular stomatitis virus which contain covalently linked complementary [+]message and [-]anti-message RNA as a single-stranded ribonucleoprotein complex within the particle, are extremely efficient inducers of interferon. A single particle can induce a quantum yield of interferon. A single molecule of double-stranded RNA presumed to form, at least in part, on entry into the cell is thought to induce interferon synthesis. Conventional [-]RNA DI particles with the same polypeptide composition as [+/-]RNA DI particles fail to induce interferon.
176 citations
TL;DR: Secretory proteins, fibroin and sericin, extracted with disulfide cleavage from the lumen of several sections of the silk gland of the mature silkworm, Bombyx mori, were separated individually by gel electrophoresis at acid pH containing 4 M urea.
172 citations
TL;DR: Steady-state diazepam plasma concentration-time profiles suggested that once daily administration of the total daily dose at bedtime might be a satisfactory dosing regimen.
Abstract: Six healthy subjects between the ages of 21 and 31 years received diazepam tablets orally at a dose of 5 mg t.i.d. atO, 5, and 10hr on days 1–13. On day 14, the dose was 5 mg at 0 and 5 hr and 15 mg at 10 hr. Subsequently, the dose was 15 mg once daily on days 15–24. Numerous plasma samples were obtained during the multiple-dose regimen, and appropriate equations were fitted to all the multiple-dose data. Diazepam absorption was satisfactorily described by a first-order process, with disposition characterized by a linear two-compartment open model. The harmonic mean absorption half-life was 32 min, and the harmonic mean terminal exponential half-life was 57hr. The mean apparent oral total drug plasma clearance was 22.7ml/hr/kg. Steady-state plasma levels of the primary metabolite, desmethyldiazepam, were reached after 5–8 days of dosing. Steady-state diazepam plasma concentration-time profiles suggested that once daily administration of the total daily dose at bedtime might be a satisfactory dosing regimen.
162 citations
Journal Article•
TL;DR: It was found that several chemotactically active agents rapidly induce rabbit peritoneal polymorphonuclear neutrophils in suspension to aggregate reversibly, paralleled their in vitro chemotactic- and in vivo neutropenia-inducing potencies.
Abstract: Chemotactic agents may also induce polymorphonuclear neutrophils to increase in volume; this effect appears to be independent of aggregation. The volume change develops more slowly and does not appear reversible under the conditions employed. The volume increase may be an expression of pseudopodia formation and membrane ruffling known to develop in neutrophils exposed to chemotactic agents.
157 citations
TL;DR: In this article, it is argued that the vehicle domain guides a novel schematization of the topic domain, and that the perceived resemblance is a higher-order relation among entities (both explicit and implicit) in each domain.
155 citations
TL;DR: Data on oral and "gastric" lipases in calves, humans, and rats suggests that gastric lipase is oral lipase, and data on pH and temperature optima as well as activation and inhibition of oral lipases is contradictory but appears to vary considerably between species.
TL;DR: Decidua may be a major source of amniotic fluid Prolactin and sufficient prolactin is present in the decidua to account for that found in amniotics fluid at term.
TL;DR: In this paper, the local equilibrium-steady diffusion model of Fisher was used to calculate the stochastic coefficients of layer growth reactions in a ternary system, and the authors showed that the fraction of the width of a layer produced by internal precipitation is determined by temperature and the relative fluxes of components that diffuse in opposite directions.
TL;DR: Results are similar to those observed when hamsters are exposed to a short photoperiod, suggesting that melatonin may be acting as a hormone in mediating the effects ofPhotoperiod on the reproductive system of the Syrian hamster.
Abstract: Pinealectomized Syrian hamsters were injected thrice daily with 25 micrograms of melatonin per injection. The injections were administered at 3-hour intervals either during the day or during the night of a photoperiodic cycle of 14 hours of light and 10 hours of darkness. After 6 weeks of treatment with melatonin during the night, both pinealectomized and intact hamsters had reduced testis weight, and pinealectomized hamsters showed decreased levels of serum gonadotropins. Injection of melatonin during the day for 7 weeks either once (75 micrograms) a day or thrice (25 micrograms per injection) daily caused a reduction in testis weight in pinealectomized hamsters. Both pinealectomized and intact females injected with melatonin thrice daily during the day became anovulatory by week 7 of treatment. These results are similar to those observed when hamsters are exposed to a short photoperiod, suggesting that melatonin may be acting as a hormone in mediating the effects of photoperiod on the reproductive system of the Syrian hamster.
TL;DR: Insulin appeared to have a direct effect on collagen synthesis and not on collagen breakdown, and parathyroid hormone and dibutyryl cyclic-3',5'-adenosine monophosphate and to a lesser extent, the inhibitory effect of isobutylmethylxanthine on the labeling of CDP.
Abstract: The direct effects of porcine insulin and glucagon on bone collagen and non-collagen protein synthesis have been examined in cultures of calvaria obtained from 21-day fetal rats. Bones were incubated for 24 to 96 h and [3H]proline was added for the last 2 h of culture. Incorporation of the label into collagenase-digestible protein (CDP) and noncollagenprotein (NCP) was determined using purified bacterial collagenase. Insulin increased the labeling of CDP by 60 to 115% at concentrations of 10−9 to 10−6M. A smaller stimulatory effect was observed on NCP. The effect on CDP appeared after 12 to 24 h of culture, was maintained for 96 h in the continuous presence of the hormone, but was lost within 3 h of removal of insulin from the culture medium. Insulin appeared to have a direct effect on collagen synthesis and not on collagen breakdown. Insulin did not affect the incorporation of [3H]uridine or [3H]thymidine into the RNA and DNA fractions of bone at 24 h. Insulin opposed the inhibitory effects of parathyroi...
TL;DR: The data suggest that survival of NZB/NZW mice is prolonged when treatment with PGE1 is begun at 24 weeks, an age at which mice already show evidence of nephritis, and the mechanisms whereby P GE1 treatment influences the course of disease are not known.
Abstract: NZB/NZW F1 hybrid mice were treated with pharmacologic doses of prostaglandin E1 (PGE1) (200 microng subcutaneously either once or twice daily) from 6 through 52 weeks of age. PGE1-treated mice were protected against development anemia, clinical nephritis, and death. At 52 weeks 18 of 19 treated mice were alive, wherase only 2 of 19 untretreated control mice were alive. None of the 10 mice treated with PGE1 twice daily exhibited significant (greater than 2+) proteinuria at 1 year of age. PGE1 treatment did not prevent development of antibodies to nuclear antigens. The data also suggest that survival of NZB/NZW mice is prolonged when treatment with PGE1 is begun at 24 weeks, an age at which mice already show evidence of nephritis. Thus all 6 mice treated with PGE1 (200 microng sc twice daily) from 24 weeks were alive at 52 weeks, whereas only 2 of 6 untreated control mice were alive. The mechanisms whereby PGE1 treatment influences the course of disease in NZB/NZW mice are not known.
TL;DR: The structure of the precursor provides strong support for the conclusion that KDO incorporation occurs at an early stage in lipid A biosynthesis prior to the incorporation of ester-linked saturated fatty acids.
01 Jan 1977
TL;DR: The purpose of this paper is to bring together the largely anecdotal literature on anuran courtship and to outline a number of problems that require more detailed investigation.
Abstract: Frogs were once thought to have relatively uninteresting social behavior, but recent studies on tropical and temperate zone species have revealed a surprising diversity of social systems. There is a growing literature on anuran mating systems, aggression, spacing behavior, and territoriality (Wells 1977b). Unfortunately, many aspects of courtship have been neglected. I use the term “courtship” to refer to interactions between males and females leading to pair formation and mating, and I include the use of both long-range and short-range signals by courting males. The purpose of this paper is to bring together the largely anecdotal literature on anuran courtship and to outline a number of problems that require more detailed investigation.
TL;DR: In this paper, a simple reliable method has been developed for producing solutions of [Ru(dipy)(py) 4 ] 2+ (Dipy = 2,2′-dipyridyl; py = pyridine).
Journal Article•
TL;DR: Neutropenia-inducing activity and chemotactic activity seem to be related physiologic responses of neutrophils, and in vivo margination and/or agglutination of leukocytes may underlie this phenomenon of neutropenIA.
Abstract: Autologous plasma, when exposed to complement-activating agents that generate leukotactic activity, induces transient neutropenia after infusion into rabbits. Trypsinized human C5 as well as the chemotactic fragment isolated from zymosan-activated human serum also induces transient neutropenia in rabbits, as do chemotactically active synthetic tripeptides. In each instance the neutropenia-inducing activity parallels the chemotactic activity. Thus, neutropenia-inducing activity and chemotactic activity seem to be related physiologic responses of neutrophils. In vivo margination and/or agglutination of leukocytes may underlie this phenomenon of neutropenia.
TL;DR: The F1 hybrid of New Zealand black and New Zealand white mice (NZB/NZW mice) developed a disease similar to human systemic lupus erythematous, characterized by impaired cell-mediated and enhanced humoral immune responses, development of antibodies to nuclear antigens, and immune complex glomerulonephritis.
Abstract: The F1 hybrid of New Zealand black and New Zealand white mice--the NZB/NZW mouse--spontaneously develops a disease similar to human systemic lupus erythematous, characterized by impaired cell-mediated and enhanced humoral immune responses, development of antibodies to nuclear antigens, and immune complex glomerulonephritis. Because there is experimental evidence that prostaglandin E1 (PGE1) can enhance T-cell function and cell-mediated responses and suppress B-cell activity, NZB/NZW mice were treated with 200 microgram PGE1 subcutaneously once or twice daily from 6 weeks of age. PGE1 treatment of female and male mice prevents giomerular deposition of immunoglobulins and complement (monitored by immunofluorescence), and development of the proliferative glomerulonephritis (determined by light and electron microscopy) characteristic of untreated NZB/NZW mice. After 1 year of treatment, 18 of 19 female mice survived, whereas only 2 of 19 untreated control mice were alive. Male mice treated with 200 microgram PGE1 daily were also protected: 9 of 11 versus 2 of 9 untreated mice were alive at 65 weeks. PGE1 treatment did not prevent development of antibodies to nuclear material in any of the treated groups.
TL;DR: In this paper, the authors derived the interaction rate of four-phonon processes at high temperatures in terms of the Gruneisen constant and its dilational derivative, and found that the fourphonons relaxation rate varies as the square of the frequency and the squared of the temperature.
Abstract: The interaction rate of four-phonon processes at high temperatures is derived in terms of the Gr\"uneisen constant and its dilational derivative. The interaction arises in part from quartic anharmonicities and in part from cubic anharmonicities to second order. The four-phonon relaxation rate varies as the square of the frequency and the square of the temperature. It is compared to the three-phonon relaxation rate and found to be weaker by at least a factor 30 at 1000 K. The anharmonic interaction between two acoustic phonons and one optical phonon does not only limit the lifetime of optical phonons, but also contributes to the relaxation rate of acoustic modes in thermal conduction. It is shown that this relaxation rate is similar in magnitude and temperature dependence to the relaxation rate due to processes involving three acoustic phonons. The frequency dependence is also similar except at low frequencies, since the interaction is forbidden at lowest frequencies. Neither of the interactions considered here can quantitatively explain the observation that the thermal resistance of many dielectric crystals at high temperatures varies more rapidly than linearly with temperature.
TL;DR: Chovnick et al. as mentioned in this paper used the rosy locus of Drosophila melanogaster to test the electrophoretic mobility of XDH and found that the XDH produced by ry+O serves as a mobility standard and is designated XDH1.
TL;DR: No significant change in the amount of cell death in the EGL could be found to explain this apparent discrepancy between the rate of cell proliferation (cell cycle length) and cell acqusiition, and the answer to this puzzle appears to lie in the mitotic index, which is not affected to the same extent as the labeling index, although it is also slightly reduced.
TL;DR: Radioimmunoassay of serum testosterone was used to characterize circulating T levels in mice from birth to sexual maturity and it is apparent that additional factors are related to the onset of fighting and the establishment of dominance/ subordinance relationships in mice.
TL;DR: A review if presented of viral arthritis/tenosynovitis, one of the clinical manifestations of avian reovirus infection in chickens, which includes inflammatory lesions in the extensor and flexor tendons and tendon sheaths of the posterior limbs and in the tibiotarsal joints.
Abstract: A review if presented of viral arthritis/tenosynovitis, one of the clinical manifestations of avian reovirus infection in chickens. Since the detection of a viral etiology of arthritis/tenosynovitis in 1957, the disease has been reported in various parts of the world. Pathological features of the disease include inflammatory lesions in the extensor and flexor tendons and tendon sheaths of the posterior limbs and in the tibiotarsal joints. Hepatitis, myocarditis, hydropericardium, as well as intestinal and respiratory tract involvement are described in association with avian reovirus infection. The epizootiology, horizontal and vertical transmission of reovirus, as well as the role of maternal immunity and its application in breeder vaccination for the control of viral arthritis/tenosynovitis are described.
01 Jan 1977
TL;DR: This work has examined the effects of treating male dwarf mice with PRL on plasma and pituitary levels of LH and FSH, on the concentration of testosterone (T) in testes and plasma, and on T production in response to hCG in vitro.
Abstract: Hereditary dwarf mice (Snell dwarf, dw/dw and Ames dwarf, dfldf) are genetically prolactin-deficient and sterile. Treatment with prolactin (PRL) stimulates testicular growth and activity, and induces fertility in these animals. To elucidate the mechanism of this action of PRL, and to identify the possible physiological functions of this hormone during sexual maturation, we have examined the effects of treating male dwarf mice with PRL on plasma and pituitary levels of LH and FSH, on the concentration of testosterone (T) in testes and plasma, and on T production in response to hCG in vitro. Both Snell and Ames male dwarf mice had a significantly lower concentration of FSH in the pituitary and the peripheral plasma, and of LH in the pituitary, than did the normal adult males of the same strain. Treatment with ovine PRL, or with a PRL-producing ectopic homograft of the anterior pituitary from a normal animal, produced a significant elevation in plasma FSH levels in male dwarf mice of both strains. The same i...
TL;DR: The oxide of chromium (IV), Cr02, is a highly interesting compound for materials investigation in that it is ferromagnetic at room temperature and a good electrical conductor.
Abstract: The oxide of chromium (IV), Cr02, is a highly interesting compound for materials investigation in that it is ferromagnetic at room temperature and a good electrical conductor. The Curie temperature is 118°C, and the material can readily be demagnetized with little energy input. The electrical conductivity of this black compound is quite high for an oxide; it even rivals some of the metal conductors such as Mn and Gd at roomtemperature. Thls review describes procedures for preparing Cr02, presents its chemical and physical properties including the modifications observed with metal-ion substitutions, and discusses the reactions of Cr02 with other metal oxides together with the physical properties of the ternary products containing tetravalent chromium.
TL;DR: The hypothesis that good and poor readers do differ in their ability to access a phonetic representation is supported, with performance of the good readers more affected by phonetic similarity than that of the poor readers.
Abstract: The results of a recent study (Liberman, Shankweiler, Liberman, Fowler, & Fischer, 1977) suggest that good beginning readers are more affected than poor readers by the phonetic characteristics of visually presented items in a recall task. The good readers made significantly more recall errors on strings of letters with rhyming letter names than on nonrhyming sequences; in contrast, the poor readers made roughly equal numbers of errors on the rhyming and nonrhyming letter strings. The purpose of the present study was to determine whether the interaction between reading ability and phonetic similarity is solely determined by different rehearsal strategies of the two groups. Accordingly, good and poor readers were tested on rhyming and nonrhyming words using a recognition memory paradigm that minimized the opportunity for rehearsal. Performance of the good readers was more affected by phonetic similarity than that of the poor readers, in agreement with the earlier study. The present findings support the hypothesis that good and poor readers do differ in their ability to access a phonetic representation.