Showing papers by "University of Rochester published in 1970"
TL;DR: In vivo studies demonstrated that injections of PGE1 in parathyroidectomized rats did not increase serum calcium concentration, whileParathyroid extract (4–40 U/rat) was effective, and in vitro studies demonstrated the effects of P GE1 were inhibited by thyrocalcitonin and cortisol.
Abstract: Prostaglandins (PG’s) stimulated resorption of fetal rat bone in 48–96 hr tissue culture. The effects of several PG’s were compared to the stimulation of bone resorption caused by parathyroid hormone (PTH). PGE1 and PGE2 caused increased release of previously incorporated radioactive calcium into the medium, losses of stable and labeled Ca from the bone and morphologic changes of osteoclastic resorption at 10−5-10−8M. The effects of PGE1 and PGE2 were similar to those of PTH (10−7- 10−8M) but in some experiments the effects of maximal doses of PTH were larger at 48 hr. Like PTH, the effects of PGE1 were inhibited by thyrocalcitonin and cortisol. PGA1 and PGFlα also stimulated bone resorption but only at higher doses (10−5M). In vivo studies demonstrated that injections of PGE1 in parathyroidectomized rats did not increase serum calcium concentration, while parathyroid extract (4–40 U/rat) was effective. (Endocrinology 86: 1436, 1970)
941 citations
TL;DR: In this article, four variables are used as predictors of a President's popularity: length of time in office, international events, economic slump, and war, and the number of voters who approve or disapprove of the way the incumbent is handling his job as president.
Abstract: I think [my grandchildren] will be proud of two things. What I did for the Negro and seeing it through in Vietnam for all of Asia. The Negro cost me 15 points in the polls and Vietnam cost me 20.Lyndon B. JohnsonWith tenacious regularity over the last two and a half decades the Gallup Poll has posed to its cross-section samples of the American public the following query, “Do you approve or disapprove of the way (the incumbent) is handling his job as President?” The responses to this curious question form an index known as “Presidential popularity.” According to Richard Neustadt, the index is “widely taken to approximate reality” in Washington and reports about its behavior are “very widely read” there, including, the quotation above would suggest, the highest circles.Plotted over time, the index forms probably the longest continuous trend line in polling history. This study seeks to analyze the behavior of this line for the period from the beginning of the Truman administration in 1945 to the end of the Johnson administration in January 1969 during which time the popularity question was asked some 300 times.Four variables are used as predictors of a President's popularity. These include a measure of the length of time the incumbent has been in office as well as variables which attempt to estimate the influence on his rating of major international events, economic slump and war. To assess the independent impact of each of these variables as they interact in association with Presidential popularity, multiple regression analysis is used as the basic analytic technique.
941 citations
TL;DR: In this paper, a unified treatment for phonon sideband intensities, multiphonon relaxation transition probabilities, and phonon-assisted energy-transfer probabilities is given in the adiabatic approximation.
Abstract: A unified treatment is given in the adiabatic approximation for phonon sideband intensities, multiphonon relaxation transition probabilities, and phonon-assisted energy-transfer probabilities. The intensity distribution of phonon sidebands is determined by coupling constants of the vibrational modes with electrons or holes and a criterion for the appearance of discrete sidebands is given. Transition probabilities of multiphonon relaxation processes among various excited levels of an ion are shown to depend exponentially on the energy gap between these levels, in agreement with recent experimental results. A similar dependence is derived for the energy-transfer probabilities between two ions on the energy mismatch between excitation energies of these ions.
791 citations
TL;DR: The results of the experiment indicate the vast memory for pictures possessed by human beings and emphasize the need to determine mechanisms by which this is accomplished.
Abstract: Ss were shown 2,560 photographic Stimuli for 10 sec each; their recognition memory was then tested, using a two-alternative forced-choice task. Performance exceeded 90%, indicating retention of over 2,000 items, even when up to 3 days elapsed between learning and testing. Variants of the experiment showed that the presentation time could be reduced to 1 sec per picture without seriously affecting performance; also, that the stimuli could be reversed in orientation in the test situation without impairing recognition performance appreciably. The orientation of the stimuli could also be learned, although not as well as the identity of the pictures. These results indicate the vast memory for pictures possessed by human beings and emphasize the need to determine mechanisms by which this is accomplished.
658 citations
TL;DR: The magnitude of the decline in Lean body mass, as estimated from 40 K counting, declines progressively during adult life, and the sex difference in LBM great enough to suggest that age and sex should both be taken into account in such matters as drug dosage and nutritional requirements.
Abstract: Lean body mass, as estimated from 40 K counting, declines progressively during adult life. The rate of decline tends to speed up in later years, and is somewhat greater in the male. By age 65–70 the average male has 12 Kg. less LBM than at age 25; the female has 5 Kg. less. Longitudinal observations show that this trend is for the most part biological, not secular in origin. The magnitude of the decline is such, and the sex difference in LBM great enough to suggest that age and sex should both be taken into account in such matters as drug dosage and nutritional requirements.
643 citations
TL;DR: The largest group comprised 110 cases showing medial hypertrophy, laminar intimal fibrosis, and often fibrinoid necrosis, arteritis, and plexiform lesions, suggesting that they were initiated by vasoconstriction.
626 citations
TL;DR: A modified method for the isolation of the plasma membrane from rat liver has been developed and the concentration of Ca2+ and the degree of the homogenizing medium are critical factors in obtaining membranes in high yield and with high activity of the characteristic plasma membrane enzymes.
545 citations
TL;DR: In this paper, a calculus for functions of noncommuting operators is developed, based on the notion of mapping of functions of operators onto $c$-number functions, each of which is characterized by an entire analytic function of two complex variables.
Abstract: A new calculus for functions of noncommuting operators is developed, based on the notion of mapping of functions of operators onto $c$-number functions. The class of linear mappings, each member of which is characterized by an entire analytic function of two complex variables, is studied in detail. Closed-form solutions for such mappings and for the inverse mappings are obtained and various properties of these mappings are studied. It is shown that the most commonly occurring rules of association between operators and $c$-numbers (the Weyl, the normal, the antinormal, the standard, and the antistandard rules) belong to this class and are, in fact, the simplest ones in a clearly defined sense. It is shown further that the problem of expressing an operator in an ordered form according to some prescribed rule is equivalent to an appropriate mapping of the operator on a $c$-number space. The theory provides a systematic technique for the solution of numerous quantum-mechanical problems that were treated in the past by ad hoc methods, and it furnishes a new approach to many others. This is illustrated by a number of examples relating to mappings and ordering of operators.
506 citations
TL;DR: In this article, an algorithm is given which finds all optimal solutions, for a given set of criteria, to political redistricting problems, using "population units" as indivisible elements, where feasibility indicates contiguity, compactness and limited population deviation.
Abstract: An algorithm is given which finds all optimal solutions, for a given set of criteria, to political redistricting problems. Using “population units” as indivisible elements, the first phase generates all feasible districts, where feasibility indicates contiguity, compactness and limited population deviation. The second phase finds that set of M feasible districts which “covers” each population unit exactly once, and minimizes the maximum deviation of any district population from the mean district population. Computational results indicate that states with 40 counties or fewer can be solved in less than 10 minutes on an IBM 7094. However, our attempt to solve a 55 county state was unsuccessful.
280 citations
TL;DR: In this article, a new calculus for functions of noncommuting operators was developed, based on the notion of mapping of operators onto $c$-number functions, and a general theory was formulated, in the present paper, of phase-space representation of quantum-mechanical systems.
Abstract: In Paper I of this investigation a new calculus for functions of noncommuting operators was developed, based on the notion of mapping of operators onto $c$-number functions With the help of this calculus, a general theory is formulated, in the present paper, of phase-space representation of quantum-mechanical systems It is shown that there is a whole class of such representations, one associated with each type of mapping, the simplest one being the well-known representation due to Weyl For each representation, the quantum-mechanical expectation value of an operator is found to be expressible in the form of a phase-space average of classical statistical mechanics The phase-space distribution functions are, however, not true probabilities, in general The phase-space forms of the main quantum-mechanical equations of motion are obtained and are found to have the form of a generalized Liouville equation The phase-space form of the Bloch equation for the density operator of a quantum system in thermal equilibrium is also derived The generalized characteristic functions of boson systems are defined and their main properties are studied The equations of motion for the characteristic functions are also derived As an illustration of the theory, a generalized stochastic description of a quantized electromagnetic field is obtained
265 citations
TL;DR: The delay in the appearance of central nervous system disturbances following exposure to methyl mercury compounds could not be explained by accumulation of inorganic mercury in the tissue, and that the unique toxic effects of exposure tomethyl mercury salts are caused by the intact mercurial is supported.
Abstract: Biotransformation of organic mercury in the rat was followed by specific determination of inorganic mercury after exposure" Inorganic mercury was detected in plasma, brain, and tissues involved in excretion. Inorganic mercury released from the organomercurial redistributes in the body to conform to the pattern of organ distribution of injected mercuric salts" Biotransformation is important in the excretion of mercury after exposure to methyl mercury salts. Inorganic mercury was preferentially excreted in the feces. The delay in the appearance of central nervous system disturbances following exposure to methyl mercury compounds could not be explained by accumulation of inorganic mercury in the tissue. That the unique toxic effects of exposure to methyl mercury salts are caused by the intact mercurial is supported.
TL;DR: Since the advent of antibiotics, acute osteomyelitis has become a less frequent cause of admission to the hospital, and mortality from the disease has declined, but Chemotherapy is not a panacea and chronic osteomyeelitis still develops with disturbing frequency.
Abstract: Since the advent of antibiotics, acute osteomyelitis has become a less frequent cause of admission to the hospital, and mortality from the disease has declined [1] Chemotherapy is not, however, a panacea and chronic osteomyelitis still develops with disturbing frequency In several series, 153096 of individuals with acute osteomyelitis went on to develop chronic disease despite antibiotic therapy [1-3] Trauma to bone, with infection resulting from the trauma itself or occurring after corrective surgery, can also lead to chronic osteomyelitis [1, 4] As noted by Waldvogel et al [1], many major questions concerning osteomyelitis remain unanswered Reliable data relating to the optimal duration of antimicrobial therapy, the efficacy of one drug vs another, and the relative contributions of surgery and antibiotics to "success or failure" in treatment of osteomyelitis are not to be found in the literature Many of these uncertainties stem from the number of uncontrolled variables in human disease, ie, the age of the patients, the site of involvement, organisms and their patterns of antibiotic resistance, and the difficulties in establishing criteria for the success or failure of therapy For these reasons, an experimental model of osteomyelitis has been sought Most earlier animal studies have required considerable trauma to establish osteomyelitis, and animals have died within
TL;DR: The assumption of statistical independence of matrix elements leads to ensembles of Hamiltonians which involve simultaneous interactions between many particles as discussed by the authors, and the resultant (semicircular) spectra are quite different from the Gaussian spectra found for Ensembles properly restricted to involve only two-body interactions.
TL;DR: In this paper, a round jet cascade impactor with seven impaction stages and operating at 50-150 cm 2 /min is described, and details of design and operating characteristics are given.
TL;DR: Four cases that support the concept of a limited form of Wegener's granulomatosis are described, and pathologic and pulmonary findings represent a variant of classic Wegener’s granumatosis, lacking the renal involvement that occurs with the latter.
TL;DR: Endotoxins may play a role in the bone loss characteristic of human periodontal disease and are inhibited by serum and dependent upon the presence of albumin.
Abstract: Bacterial endotoxins can stimulate the release of previously incorporated calcium-45 and tritiated proline from fetal rat bone in tissue culture. Endotoxin from Bacteroides melaninogenicus, an organism regularly found in the gingival crevice of man, produces a response similar to parathyroid hormone and is effective at doses as low as 0.1 microgram per milliliter. This response is inhibited by serum and dependent upon the presence of albumin. Endotoxins may play a role in the bone loss characteristic of human periodontal disease.
TL;DR: The crystal structures of 8-bromoguanosine-2H 2 O and 8- bromoadenosine have been determined by X-ray analysis and it is suggested that this rotational isomerism specifically reflects close contacts introduced by the bromine atom at the 8-position on these purine nucleosides.
TL;DR: Tests of a new adhesive material that hardens when exposed to ultraviolet light showed 100% caries protection after one year in 200 deciduous and permanent teeth.
Abstract: Complete protection against caries was obtained when tooth surfaces were shielded from exposure to the oral environment. Tests of a new adhesive material that hardens when exposed to ultraviolet light showed 100% caries protection after one year in 200 deciduous and permanent teeth. Forty-two percent of the matched contralateral control teeth developed caries. This simple preventive measure requires only a few minutes per tooth, and lends itself to use by the dental hygienist after routine prophylaxis.
TL;DR: Passive cutaneous anaphylaxis in guinea pigs demonstrated a strong cross-reaction between ragweed antigen and cantaloupe antibody, suggesting common antigenic determinants as an explanation for the melon sensitivity-ragweed pollinosis syndrome.
TL;DR: Normal gastrointestinal histologic appearance was found in all instances and permitted the differentiation of idiopathic intestinal pseudo-obstruction as an entity distinct from scleroderma, suggesting a functional failure of the myenteric plexus.
TL;DR: A clinicopathologic study was made of 25 cases of struma ovarii, finding that significant ascites was present in nine cases, only four of which were malignant.
Abstract: A clinicopathologic study was made of 25 cases of struma ovarii. Significant ascites was present in nine cases, only four of which were malignant. Pleural effusion was present in two cases...
TL;DR: From diffraction theory, an expression is derived for the radius of a gaussian beam, in an output plane of a single lens, on-axis optical system, as a function of input waist radius, lens focal length, input waist to lens spacing, and lens to output plane spacing.
Abstract: From diffraction theory, an expression is derived for the radius of a gaussian beam, in an output plane of a single lens, on-axis optical system, as a function of input waist radius, lens focal length, input waist to lens spacing, and lens to output plane spacing. Several special cases are discussed and plots of the important cases are included. The choice of the plots, and their scaling, was made on the basis of providing useful information to those people involved with typical problems in laser scanning systems, such as the location and size of the focused spot. The derivation includes a discussion of truncation effects.
Journal Article•
TL;DR: Talon cusp is an anomaly occurring in permanent incisors of either arch that represents a problem of clinical significance rather than being merely a dental oddity.
TL;DR: In this article, the authors derived a Fokker-planck equation to describe the time evolution of the phase-space distribution function associated with the reduced density operator of the atomic system.
Abstract: Spontaneous emission from a system of $N$ identical two-level atoms is considered using a master equation recently derived by the author. The master equation describing the time evolution of the phase-space distribution function associated with the reduced density operator of the atomic system is obtained. This master equation, which is of the type of a Fokker-Planck equation, is used to derive the equation of motion for the mean values of various atomic operators characterizing the physical properties of the system. This leads to a hierarchy of equations, which is decoupled by making a suitable approximation. The intensity of the spontaneously emitted radiation is then calculated. Next, the spontaneous emission from geometrically small systems is considered. For this case, the master equation is solved exactly, and an exact expression for the radiation rate is obtained. The exact solution of the master equation is also used to calculate the normally ordered correlation functions for the electric field. Section V deals with the spontaneous emission from a system of harmonic oscillators, the size of the system being small compared to a wavelength. The master equation for this problem is also solved exactly, and it is shown that this system also leads to superradiant emission in some cases, e.g., if all the oscillstors are excited initially to some coherent state $|{z}_{0}〉$.
TL;DR: In this paper, an extension of the $c$-number calculus for functions of noncommuting operators, developed in Paper I and employed in Paper II to formulate a general phase-space description of boson systems, was presented for the treatment of problems involving boson operators at two or more instants of time.
Abstract: The new $c$-number calculus for functions of noncommuting operators, developed in Paper I and employed in Paper II to formulate a general phase-space description of boson systems, deals with situations involving equal-time operators only. In the present paper extensions are presented for the treatment of problems involving boson operators at two or more instants of time. The mapping of time-ordered products onto $c$-number functions is studied in detail. The results make it possible to evaluate time-ordered products of boson operators by phase-space techniques. The usual Wick theorem for boson systems is obtained as a special case of a much more general theorem on time ordering. Our method of derivation appears to provide the first direct proof of Wick's theorem as well as a clear insight into its true meaning. A closed expression is also obtained for the time-evolution operator in terms of the solution of the $c$-number differential equation for the phase-space equivalent of this operator. The new calculus is also applied to the problem of evaluating normally ordered time-ordered, and also the antinormally ordered time-ordered, correlation functions.