Showing papers by "University of Vermont published in 1976"
01 Jan 1976
TL;DR: Ohanian and Ruffini's Gravitation and Spacetime, Second Edition, the authors is the best book on the market today of 500 pages or less on gravitation and general relativity.
Abstract: Now more than ever, Gravitation and Spacetime, Second Edition, by Hans C. Ohanian and new coauthor Remo Ruffini, deserves John Wheeler's praise as "the best book on the market today of 500 pages or less on gravitation and general relativity." Gravitation and Spacetime has been thoroughly updated with the most exciting finds and hottest theoretical topics in general relativity and cosmology. Highlights of the revision include the rise and fall of the fifth force, principles and applications of gravitational lensing, COBE's spectacular confirmation of the blackbody spectrum of the cosmic thermal radiation, theories of dark matter and inflation, and the early universe as a testing ground for particle physicists' unification theories, and much, much more. The ideal choice for a graduate-level introduction to general relativity, Gravitation and Spacetime is also suitable for an advanced undergaduate course.
547 citations
TL;DR: In this paper, a two-stage method is proposed for investigating the independence of two covariance-stationary time series, which involves, first, fitting univariate models to each of the series, and then cross-correlating the two residual series thereby obtained.
Abstract: A two-stage method is proposed for investigating the independence of two covariance-stationary time series. It involves, first, fitting univariate models to each of the series, and then cross-correlating the two residual series thereby obtained. The asymptotic distribution of such a set of lagged residual cross-correlations is established to be of a very simple form under the null hypothesis of the two series' independence. A Monte Carlo study verifies the applicability of this distribution for series of length N = 50, 100, and 200. An attendant chi-square test statistic is discussed.
462 citations
TL;DR: A technique to obtain mechanical data from a smooth muscle preparation which only contains about 1,000 smooth muscle cells, and which is thin enough for the cells to be visualised by Nomarski interference microscopy, provides for the first time the means to study the mechanical properties of Smooth muscle cells in situ.
Abstract: ALTHOUGH the histology and ultrastructure of smooth muscle cells have been studied extensively there is little direct evidence concerning their mechanical properties. Their small size1,2 and lack of tendon connections have prevented them from being mounted on a myograph, as has been done with striated muscle fibres3. Moreover, their multiplicity and optical properties make it difficult to visualise them in whole smooth muscle preparations. Although isolated smooth muscle cells4–6 can be seen to contract when stimulated, it has not been possible to measure the forces they develop. There are, therefore, still serious doubts about the extent to which the mechanical properties of whole smooth muscle preparations are an accurate reflection of the properties of smooth muscle cells. We have therefore developed a technique to obtain mechanical data from a smooth muscle preparation which only contains about 1,000 smooth muscle cells, and which is thin enough for the cells to be visualised by Nomarski interference microscopy7. This technique provides for the first time the means to study the mechanical properties of smooth muscle cells in situ.
336 citations
TL;DR: A sensitive, highly reproducible method for tissue tocopherol analysis that combines saponification in the presence of large amounts of ascorbic acid to remove interfering substances, extraction of the nonsaponifiable lipids with hexane, and fluorometric measurement of the toCopherol is presented.
Abstract: A sensitive, highly reproducible method for tissue tocopherol analysis that combines saponification in the presence of large amounts of ascorbic acid to remove interfering substances, extraction of the nonsaponifiable lipids with hexane, and fluorometric measurement of the tocopherol is presented. The nonsaponifiable lipid phase contained only one fluorochrome in the 290 nm excitation and 330 nm emission range, and it was identified as tocopherol by thin layer and column chromatography. Column chromatography of the hexane extract of a saponified,14C-tocopherolspiked microsomal fraction showed that no measurable oxidation to tocopherylquinone has occurred. The fluorometric method for tocopherol analysis was applied to homogenates and subcellular fractions from rat liver, kidney, lung, and heart and red blood cells. The heavy mitochondrial and microsomal fractions had the highest subcellular concentrations of tocopherol.
320 citations
Book•
01 Jan 1976TL;DR: Ohanian and Ruffini's Gravitation and Spacetime, Second Edition, the authors is the best book on the market today of 500 pages or less on gravitation and general relativity.
Abstract: Now more than ever, Gravitation and Spacetime, Second Edition, by Hans C. Ohanian and new coauthor Remo Ruffini, deserves John Wheeler's praise as "the best book on the market today of 500 pages or less on gravitation and general relativity." Gravitation and Spacetime has been thoroughly updated with the most exciting finds and hottest theoretical topics in general relativity and cosmology. Highlights of the revision include the rise and fall of the fifth force, principles and applications of gravitational lensing, COBE's spectacular confirmation of the blackbody spectrum of the cosmic thermal radiation, theories of dark matter and inflation, and the early universe as a testing ground for particle physicists' unification theories, and much, much more. The ideal choice for a graduate-level introduction to general relativity, Gravitation and Spacetime is also suitable for an advanced undergaduate course.
302 citations
TL;DR: The importance of the deep fibers of the medial collateral in the anterior-posterior, rotational and valgus directions is demonstrated and the rotational stability derived from the anterior cruciate ligament is shown.
179 citations
TL;DR: The composition, cellularity and anatomical site of adipose depots in a mammal can influence both the amount of fat stored and its availability and usefulness in any given situation.
Abstract: Adipose tissue plays a critical role in mammalian life history strategies, serving as an organ for the storage of food and energy, as a source of heat and water and as thermal insulation. The food and energy storage roles are especially important in allowing the animals to survive food shortages and stresses associated with competition for mates, territorial defense, gestation and lactation, and to accomplish migrations. The composition, cellularity and anatomical site of adipose depots in a mammal can influence both the amount of fat stored and its availability and usefulness in any given situation. The fatty acids and complex lipids in adipose tissue, blood vessels, nerves and brain change in response to ambient temperature and the low body temperatures during hibernation. Early nutrition may influence the number of fat cells developed by a mammal, and thus affect its ability to survive adversity. Desert species develop localized depots which will not interfere with temperature regulation, while animals in cold environments use their extensive superficial fat layers as insulation.
171 citations
TL;DR: The results indicate that sarcomere length redistributions probably do not account for the non-hyperbolic force-velocity relation and an explanation for the behavior based on the geometry of the contractile filament lattice is discussed.
Abstract: The force-velocity relation has been studied in sixteen single fibres from frog semitendinosus muscle with particular attention to the high-force portion of the curve. The force-velocity curve was hyperbolic except for a reversal of curvature near 80% measured isometric tension (PO). Rectangular hyperbolas fitted (linear, least-squares method) these data well only when values below 0.78 PO were considered. Extrapolation of these hyperbolas above 0.78 PO gave predicted isometric tensions (P*O) which averaged 32+/-6% above the measured PO values. Hill's constants (1.84 degrees C) for these hyperbolas were: a/P*O=0.177+/-0.021, b=0.329+/- 0.035 M.L./sec, Vmax=1.91+/-0.074 M.L./sec. The reversal of curvature persisted when force-velocity data were obtained using: 1 or 60 min response intervals, afterloaded isotonic responses, grid stimulation, electrically induced contractures and bundles of fibres. The reversal of curvature diminished when force-velocity data were obtained from slightly stretched fibres (about 2.3 mum sarcomere length as compared to 2.1 mum in the control). The results indicate that sarcomere length redistributions probably do not account for the non-hyperbolic force-velocity relation. An explanation for the behavior based on the geometry of the contractile filament lattice is discussed.
170 citations
TL;DR: Time-lapse cinematographic analysis of clones of human diploid fibroblasts indicate heterogeneity in clonal division behaviour, and a consistent division pattern at all population doubling levels is one of low average inter division time for early and late generations of a clone and high average interdivision time for the middle range of generations ofA clone.
134 citations
TL;DR: Results indicate that drill point geometry is critical when attempting to minimize drilling forces and that there appears to be a softening effect in bone when drilled at relatively high speeds.
133 citations
TL;DR: An ongoing research project concerning the doctor's communication of information about illness to the patient develops a research design linked to sociological perspectives, which allows reproducible and generalizable conclusions about the informative process in a variety of clinical settings.
TL;DR: The blood pressure response to graded infusions of angiotensin II was assessed under control conditions and following short term indomethacin treatment utilizing normal men equilibrated on a constant diet of normal sodium and potassium content, suggesting that prostaglandins modulate the systemic vasoconstrictor effects of angiotsin II.
TL;DR: In this paper, it was shown that the solubility of hydrogen is unaffected in palladium samples which had been quenched from near their melting points and concluded that the stress field about the dislocation array is the principal cause of the solusability enhancement.
Abstract: Measurable, and reproducible solubility enhancements have been observed for hydrogen in cold-worked palladium in the low content α-phase (273–363 K). It is shown that the solubility of hydrogen is unaffected in palladium samples which had been quenched from near their melting points. It is concluded that the stress field about the dislocation array is the principal cause of the solubility enhancement. Absorption of hydrogen at the cores of dislocations is believed to be insignificant. From absorption isotherms measured at various temperatures, the relative partial molar enthalpies and entropies of solution of hydrogen into deformed palladium have been determined. The heat of solution of hydrogen by 78% deformed palladium is approximately 880 J/H more exothermic than for well-annealed palladium in the low hydrogen content α-phase.
TL;DR: It is demonstrated that virus-infected suppression of pulmonary antibacterial activity against S. aureus is related primarily to defects in intracellular processing mechanisms.
Abstract: Bacterial multiplication associated with virus infections is related to defects in in situ bactericidal (phagocytic) mechanisms of the lung. To determine whether the phagocytic defect was in bacterial ingestion and/or intracellular digestion, mice were infected with a sublethal dose of aerosolized Sendai virus and challenged 7 days later with a finely dispersed aerosol of Staphylococcus aureus. Groups of uninfected and virus-infected mice were sacrificed at 0, 6, 12, and 24 h after challenge, the lungs were perfused with formalin in situ, and the intra- or extracellular location of the bacteria was determined histologically. At 0 h, 49% and 51% of the staphylococci had an intracellular location in virus and nonvirus-infected lungs, respectively. With time, decreasing numbers of staphylococci were observed within the phagocytic cells of nonvirus-infected lungs, mostly as single organisms or in small clusters of less than four. In contrast, in focal area of virus-infected lungs, increasing numbers of phagocytic cells showed clumps of more than 25 bacteria/cell. These data demonstrate that virus-infected suppression of pulmonary antibacterial activity against S. aureus is related primarily to defects in intracellular processing mechanisms.
TL;DR: Renal medullary cells from the rat were used to establish a cell culture line that produced substantial amounts of PGE when provided with arachidonic acid or fetal calf serum and was sensitive to and stimulated by changing the media.
TL;DR: In this article, the authors proposed that the stress field of the dislocation array is the principal cause of the solubility enhancement observed in the low hydrogen content, α-phase of cold-worked palladium.
Abstract: It is proposed that the stress-field of the dislocation array is the principal cause of the solubility enhancement observed in the low hydrogen content, α-phase of cold-worked palladium. With an assumed uniform dislocation density of 9 × 10 11 cm −2 , the observed solubility enhancement of 1.65 (298 K) for heavily cold-worked palladium can be reproduced if the core radius is assumed to be 2 × Burgers vector. The temperature dependence of the solubility enhancement is also reasonably well predicted. The significance of measured relative partial molar enthalpies and entropies of absorption of hydrogen into cold-worked palladium is examined.
TL;DR: Responding was less readily reduced by differential reinforcement of other behavior than by the specific alternative-response procedure, and extinction alone was slightly more effective than extinction alone.
Abstract: In Experiment I, (a) extinction, (b) extinction plus reinforcement of a discrete alternative response, and (c) differential reinforcement of other behavior were each correlated with a different stimulus in a three-component multiple schedule. The alternative-response procedure more rapidly and completely suppressed behavior than did differential reinforcement of other behavior. Differential reinforcement of other behavior was slightly more effective than extinction alone. In Experiment II, reinforcement of specific alternative behavior during extinction and differential reinforcement of other behavior were used in two components, while one component continued to provide reinforcement for the original response. Once again, the alternative-response procedure was most effective in reducing responding as long as it remained in effect. However, the responding partially recovered when reinforcement for competing behavior was discontinued. In general, responding was less readily reduced by differential reinforcement of other behavior than by the specific alternative-response procedure.
TL;DR: In this article, the deuterium absorption and desorption of H2(D2) on Pd layers are controlled successively by a chemisorption step (second order kinetics) in the early stage of the processes and by a surface migration step in the subsequent stage of processes.
TL;DR: Social competence data from four target groups of vulnerable children strongly suggest that peer-rated social incompetence and presence of externalizing behavior disorders are the best predictors of which vulnerable children run the greatest risk of poor adult outcome.
Abstract: Social competence data from four target groups of vulnerable children--children of schizophrenic mothers; children of neurotic mothers; clinic children with externalizing symptomology; clinic children with internalizing symptomology--and from a large control group of their public school classmates, strongly suggest that peer-rated social incompetence and presence of externalizing behavior disorders are the best predictors of which vulnerable children run the greatest risk of poor adult outcome.
TL;DR: Measurement of intraventricular pressure, ventricular wet and dry weights and histologic examination of the liver demonstrated substantial hypertrophy with no signs of congestive failure 3 to 6 weeks following constriction in rabbits, consistent with a subtle conformational change at or near the active site.
TL;DR: The results indicate that in this group of patients with Crohn's disease involving different areas of the intestine, calcium malabsorption occurred infrequently and that the levels of calcium excretion correlated best with enteric protein loss.
TL;DR: A complex rheological model describing the behavior of the knee both statically and dynamically is given and the knee was found to behave dynamically as a Kelvin body.
TL;DR: An ultrastructural study of the cells that line air spaces in human pulmonary fibrosis suggests a dynamic interaction between certain mesenchymal and epithelial elements in the fibrotic lung.
Abstract: An ultrastructural study of the cells that line air spaces in human pulmonary fibrosis is reported. Intimate associations between these cells and cellular elements in the interstitium were consistently found in biopsies from 25 cases. Cytoplasmic extensions of cuboidal pneumocytes protruded through discontinuities in the subjacent basement membrane. Attenuated cells having structural properties of fibroblasts were situated on connective tissue that formed the walls of numerous air spaces. In this situation, a basement membrane was not demonstrable. These heretofore undescribed features suggest a dynamic interaction between certain mesenchymal and epithelial elements in the fibrotic lung.
TL;DR: The esophageal airway has gained increasing acceptance in airway management during cardiopulmonary resuscitation, and its enthusiastic advocates are urging expansion of its use.
TL;DR: The proposed inhibitory effects of hydrocortisone on prostaglandin production by synovium may be the resulf of an alteration of enzyme substrate or cofactor concentration rather than a direct effect on prostagslandin synthetase.
TL;DR: The knee was found to behave dynamically as a Kelvin body in intact and injured human knees in varus-valgus and axial rotation assessed by means of mechanical impedance techniques.
TL;DR: In this paper, a series of six palladium alloys (f.c.) in the composition range from 1 to 8 at.c. were examined for the absorption of hydrogen, and for the formation of the nonstoichiometric hydride phase from the hydrogen-saturated alloy.
Abstract: Pressure-composition isotherms (273–373K) have been determined for the absorption of hydrogen by a series of six palladium alloys (f.c.c.) in the composition range from 1 to 8 at.% vanadium. At a given hydrogen content, the equilibrium hydrogen pressure progressively increases with vanadium content. Thermodynamic parameters for the absorption of hydrogen are reported at infinite dilution of hydrogen, and for the formation of the nonstoichiometric hydride phase from the hydrogen-saturated alloy. The relative, partial molar enthalpy of solution of hydrogen at infinite dilution increases slightly with vanadium content, e.g., for V(5%)-Pd, Δ H ° H = −8,500 j H compared with −10,040 j H for palladium. The presence of vanadium, which absorbs hydrogen itself in its normal b.c.c. structure, greatly inhibits the ability of palladium to absorb hydrogen. For example, the isobaric solubility of hydrogen (1 atm, 298 K) decreases from H Pd = 0.7 (palladium) to 0.024 (V(6%)-Pd). The lattice expansion due to the presence of interstitial hydrogen has been determined by X-ray diffraction. From these data it can be concluded that the formation of two non-stoichiometric hydride phases does not occur at vanadium contents greater than 5 at.% (298 K). Electrical resistance has been measured as a function of the hydrogen content of the alloys. The electrical resistance increases more markedly with hydrogen content for these alloys than for any of the palladium alloys previously examined.
Journal Article•
TL;DR: Sources of variability are described for a method used for the quantitative measurement of pulmonary resistance to inhaled bacteria in individual animals, demonstrating that with appropriate modifications in protocol, statistical design and analysis experiments can be performed with increased accuracy, thereby reducing the number of animals needed for each experiment.
TL;DR: In this article, the subjective contours were manipulated by varying the type of monocular configuration as well as the magnitude and direction of disparity, and the depth and subjective contour clarity was influenced significantly.
Abstract: Stereoscopic depth and subjective contour clarity were manipulated by varying the type of monocular configuration as well as magnitude and direction of disparity. The clarity of the subjective contours was influenced significantly by both magnitude and direction of disparity and by the type of monocular configuration. Subjective contours were always less clear when the objective monocular contour was discontinuous regardless of disparity. Stereoscopic depth estimates varied directly with magnitude and direction of disparity; however, depth magnitude reports were truncated when the disparity was carried by discontinuously defined patterns.
TL;DR: The acceptance of horsemeat as an appealing food for humans is one of the few documented cases of a change in attitude from aversion to qualified approval of a meat as mentioned in this paper, from a taboo with religious and sentimental connotations, there evolved the notion that horsemeat was intrinsically unclean and then unhealthy.
Abstract: The acceptance of horsemeat as an appealing food for humans is one of the few documented cases of a change in attitude from aversion to qualified approval of a meat. From a taboo with religious and sentimental connotations, there evolved the notion that horsemeat was intrinsically unclean and then unhealthy. Resistance to hippophagy was abandoned during food shortage crises in France, and this eroded the prejudice against it in normal times. Beginning in the nineteenth century, the hygienic, therapeutic, culinary, economic and social arguments for hippophagy crystallized thanks to previous acceptance in other European countries, a promotional crusade and commercial segregation. By 1910 France had become the horseflesh center of the Western world. Hippophagy in France has remained urban‐centered and working class oriented. Even though no more than a third of Frenchmen eat it, changing sources and reliability of supply, rising prices and shifting consumer habits suggest that use of this meat has reached its...