Showing papers by "University of Arizona published in 1976"
TL;DR: The content of main theorems is presented in a tutorial form aimed at a broad audience of engineers and applied mathematicians interested in control, estimation and optimization of dynamic systems.
892 citations
TL;DR: Combination chemotherapy with CHOP and HOP was used as treatment for patients with pathologically staged, advanced non‐Hodgkin's lymphoma, and patients with nodular lymphoma had higher rates of complete remission than their counterparts with diffuse lymphoma.
Abstract: Combination chemotherapy with CHOP (cyclophosphamide, Adriamycin, vin-cristine, and prednisone) and HOP (Adriamycin, vincristine, and prednisone) was used as treatment for patients with pathologically staged, advanced non-Hodgkin's lymphoma. Among 204 evaluable patients treated on CHOP there were 71% complete remissions with 92% overall responses. Among the 216 evaluable patients on HOP there were 61% complete remissions and 88% responses. Complete remission rates among patients with histiocytic lymphoma were comparable to those of patients with lymphocytic disease. Patients with nodular lymphoma had higher rates of complete remission than their counterparts with diffuse lymphoma. This was noted with both CHOP (78% vs. 67%) and HOP (67% vs. 60%) induction therapy. Rapid responses were common, as more than 14% of complete remissions and 66% of overall responses were achieved with the first course of treatment. Patients in complete remission have been maintained with either cyclophosphamide, vincristine, and prednisone (COP) or arabinosyl cytosine, vincristine, and prednisone (OAP). After 1 year, 86% of patients on COP and 80% on OAP are projected to be free of disease.
820 citations
TL;DR: An hypothetical structural complex of cytochromes c and b5 which optimizes intermolecular complementary charge and steric interactions was generated by a least-squares fitting process which constrain the two heme prosthetic groups to be nearly coplanar at a closest approach distance.
342 citations
TL;DR: In this paper, a new set of canonically conjugate variables 1s was introduced for the Korteweg-de Vries equation and the periodic Toda lattice, which were used for reducing both equations to a nonlinear system which can be integrated in terms of theta functions.
Abstract: A new set of canonically conjugate variables 1s introduced for the penoclic Korteweg-de Vries equation and the periodic Toda lattice. These vanables are used for reducing both equations to a nonlinear system which can be integrated in terms of theta functions. It becomes clear that the discrete and the continuous problems are, in a sense, Jsomorph1c. Action variables are defined by loop integrals, and the basic oscillation frequencies are computed. In the infinite-period limit, these action variables tend to the ones used in the canonical description of the inverse-scattering solution method.
288 citations
TL;DR: In this article, the vibration-rotational spectrum of the hydrogen molecular ion H${\mathrm{D}}+}$ has been observed by means of a new ion-beam laser-resonance method employing Doppler effect tuning and collisional detection.
Abstract: The vibration-rotational spectrum of the hydrogen molecular ion H${\mathrm{D}}^{+}$ has been observed by means of a new ion-beam laser-resonance method employing Doppler-effect tuning and collisional detection Six transition-frequency groups between 1642 and 1869 ${\mathrm{cm}}^{\ensuremath{-}1}$, exhibiting partially resolved hyperfine structure, have been measured to \ifmmode\pm\else\textpm\fi{} 1 ppm The accuracy exceeds that of present theoretical calculations of H${\mathrm{D}}^{+}$ energy levels
260 citations
TL;DR: It is concluded that hypervitaminosis D is not a result of abnormal plasma levels of 1 alpha, 25-dihydroxyvitamin D3 but may be cuased by an excessive circulating concentration of 25-OHD.
Abstract: A competitive protein binding assay for measurement of the plasma concentration of 1 alpha, 25-dihydroxyvitamin D3 [1alpha, 25-(OH)2D3] has been extended to include the immediate precursor of this hormone, 25-hydroxyvitamin D3 (25-OHD3). In addition, the assay system is capable of measuring the two metabolic products of ergocalciferol, namely. 25-hydroxyvitamin D2 (25-OHD2) and 1alpha, 25-dihydroxyvitamin D2 [1alpha, 25-(OH)2D2]. The target tissue assay system consists of a high affinity cytosol receptor protein that binds the vitamin D metabolites and a limited number of acceptor sites on the nuclear chromatin. By utilizing a series of chromatographic purification steps, a single plasma sample can be assayed for any of the four vitamin D metabolites either individually or combined. Therefore, the assay procedure allows for both the quantitative and qualitative assessment of the total active vitamin D level in a given plasma sample. To show that the binding assay was capable of measuring 1alpha, 25-(OH)2D2 as well as 1alpha, 25 (OH)2D3, two groups of rats were raised. One group, supplemented with vitamin D3, produced assayable material that represented 1alpha, 25-(OH)2D3. The other group, fed only vitamin D2 in the diet, yielded plasma containing only 1alpha, 25-(OH)2D2 as the hormonal form of the vitamin. The circulating concentrations of the two active sterols were nearly identical (15 ng/100 ml) in both groups, indicating that the competitive binding assay can be used to measure both hormonal forms in plasma. In a separate experiment, 1alpha, 25-(OH)2D2 was generated in an in vitro kidney homogenate system using 25-OHD2 as substrate. Comparison of this sterol with 1alpha, 25-(OH)2D3 in the assay system showed very similar binding curves; the D2 form was slightly less efficient (77%). Comparison of the respective 25-hydroxy forms (25-OHD2 vs. 25-OHD3) at concentrations 500-fold that of 1alpha, 25-(OH)2D3, again suggested that the binding of the D2 metabolite was slightly less efficient (71%). Finally, the assay was employed to measure the total active vitamin D metabolite pools in the plasma of normal subjects and patients with varying degrees of hypervitaminosis D. The normal plasma levels of 25-OHD and 1alpha, 25-(OH)2D measured in Tucson adults were 25-40 ng/ml and 2.1-4.5 ng/100 ml, respectively. Both sterols were predominately (greater than 90%) in the form of vitamin D3 metabolites in this environment. Typical cases of hypervitaminosis D exhibited approximately a 15-fold increase in the plasma 25-OHD concentration, and a dramatic changeover to virtually all metabolites existing in the form of D2 vitamins. In contrast, the circulating concentration of 1alpha, 25-(OH)2D was not substantially enhanced in vitamin D-intoxicated patients. We therefore conclude that hypervitaminosis D is not a result of abnormal plasma levels of 1alpha, 25-(OH)2D but may be cuased by an excessive circulating concentration of 25-OHD.
242 citations
TL;DR: In this paper, an ecological approach to the persistence of communal tenure in a Swiss village suggests that such rights are neither historical anachronisms nor aspects of the closed corporate community.
Abstract: An ecological approach to the persistence of communal tenure in a Swiss village suggests that such rights are neither historical anachronisms nor aspects of the closed corporate community. The adaptive value of group holdings in alpine pasture, forest, water, and access routes is compared to that of individual rights in arable land, meadows, and buildings within the same community. The nature and exploitation of resources are related to communal acquisition, conservation, and distribution.
239 citations
229 citations
TL;DR: In this article, a magnetic direction finder was developed which utilizes only the initial few microseconds of wideband return stroke waveforms to provide accurate directions to the channel bases of lightning discharges to ground.
Abstract: A magnetic direction finder has been developed which utilizes only the initial few microseconds of wideband return stroke waveforms to provide accurate directions to the channel bases of lightning discharges to ground. Bearing errors are minimized because, near the ground, most channels tend to be straight and vertical with no large branches or horizontal sections. Tests on a number of lightning storms at distances of 10 to 100 km indicate the angular resolution is in the range 1-2 deg, with little or no systematic dependence on azimuth or distance.
228 citations
TL;DR: In this paper, the authors describe an investigation of consultant services rendered by school psychologists to teachers and analyze their success in achieving stated problem-solving goals using predictor variables measuring consultant efficiency, interviewing skills, and flexibility in applying psychological principles.
223 citations
TL;DR: Data on a wide range of biochemical and hematological parameters showed that this simple technique can be used to fractionate the cells according to their densities in their own plasma, and significant variability in the activity levels of the ouabain sensitive as well as the Ca2+ -stimulated ATPase was observed.
TL;DR: From measurements in rats and humans, it appears that circulating 1α,25‐(OH)2D3 is regulated by PTH and/or phosphate and that abnormal plasma 1β‐dihydroxyvitamin D3 is a part of the pathophysiology of renal osteodystrophy and parathyroid disorders.
Abstract: A sensitive radioreceptor assay for 1alpha,25-dihydroxyvitamin D3 (1alpha,25-(OH)2D3) is utilized to quantitate the circulating concentration of this sterol in experimental animals and humans. When weanling rats are grown for 2 weeks on low calcium or low phosphate diets, limited availability of either ion elicits a five-fold increase in the plasma level of 1alpha,25-(OH)2D3. The enhancement of 1alpha,25-(OH)2D3 in calcium deficiency is dependent upon the presence of the parathyroid and/or thyroid glands, which is consistent with parathyroid hormone (PTH) mediation of this effect. In contrast, the response to phosphate deficiency is independent of these glands and may result from a direct action of low phosphate on the renal synthesis of 1alpha,25-(OH)2D3. Studies in humans indicate that the normal level of 1alpha,25-(OH)2D is 2.1--4.5 ng/100 ml plasma. Patients with chronic renal failure have markedly lower circulating 1alpha,25-(OH)2D and this kidney hormone is undetectable in anephric subjects, but returns to normal within 1 day after successful renal transplantation. Hypoparathyroidism and pseudohypoparathyroidism are associated with reduced plasma 1alpha,25-(OH)2D while patients with primary hyperparathyroidism have significantly elevated sterol hormone levels. Thus, from measurements in rats and humans, it appears that circulating 1alpha,25-(OH)2D3 is regulated by PTH and/or phosphate and that abnormal plasma 1alpha,25-(OH)2D3 is a part of the pathophysiology of renal osteodystrophy and parathyroid disorders.
TL;DR: The electrical behavior of thunderstorms triggered by local heating and sea-breeze convergence, a low pressure disturbance, and a weak frontal passage has been studied at the NASA Kennedy Space Center, Florida.
Abstract: The electrical behavior of thunderstorms triggered by local heating and sea-breeze convergence, a low pressure disturbance, and a weak frontal passage has been studied at the NASA Kennedy Space Center, Florida. A nonlinear least-squares minimization procedure has been developed to describe changes in the total electrostatic field produced by lightning in terms of point charge models for the cloud charge distributions. The results indicate that discharges to ground usually neutralize cloud charges in the range from -10 to -40 C. The computed charge altitudes for Florida are somewhat higher than for other geographical locations, 6 to 9.5 km, but the corresponding ambient air temperatures, -10 to -34 C, are similar. A large fraction of the discharges to ground show total field changes which are small or even reversed in polarity within 3 km of the discharges. It is suggested that ground discharges often neutralize a small positive charge, 0.5 to 4 C at altitudes of 1 to 3 km, in addition to the larger negative charge higher in the cloud.
TL;DR: The refractive indexes and their variations with temperature for silicon and germanium have been measured over the 95-298-K and 2.5-12-microm ranges and data are given in reasonable agreement with those of previous investigators.
Abstract: The refractive indexes and their variations with temperature for silicon and germanium have been measured over the 95–298-K and 2.5–12-μm ranges. Data are given for the refractive index that are in reasonable agreement with those of previous investigators. For dn/dT the values are independent of wavelength and are approximately 1.5 × 10−4 (K)−1 and 4.0 × 10−4 (K)−1 for silicon and germanium, respectively.
TL;DR: In this article, the authors applied the previously presented theory (1) of the forward osmosis extractor to this case and compared that theory with experiment, finding that the volume of water obtained per mass of nutrient meets the human requirement for fluids and nutrient.
TL;DR: In this paper, the relationship between sexual status and self-reported delinquent action was explored and a small statistically significant relationship persisted and can be given a variety of sociological and nonspciological interpretations.
Abstract: This paper explores a much neglected issue in delinquency research—the relationship between sexual status and self-reported delinquent action. Utilizing questionnaire data from a large sample of black and white adolescents, females were found to report less delinquent activity than males. However, sexual status explained very little variance in delinquent action and when controls for “intervening” sociological variables were implemented the impact of sexual status ws reduced even more. When introduced in a multivariate analysis together with measures of an adolescent's relationships with conventional and unconventional persons, values and institutions sexual status explained between 0.5% and 2% of the variance in delinquency within the two racial categories. Nevertheless, a small statistically significant relationship persisted and can be given a variety of sociological and nonspciological interpretations.
01 Jan 1976
TL;DR: In this article, specific binding of 1 alpha,25-dihydroxyvitamin D3 to macromolecular components in the cytoplasm and nucleus is demonstrated in parathyroid glands of vitamin-D-deficient chicks.
Abstract: Specific binding of 1 alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3] to macromolecular components in the cytoplasm and nucleus is demonstrated in parathyroid glands of vitamin-D-deficient chicks. The interaction of 1alpha,25-(OH)2D3 with the cytoplasmic binding component is of high affinity (Kd = 3.2 X 10(-10) M) and high specificity [1alpha,25-(OH)2D3 greater than 25-hydroxyvitamin D3 greater than 1alpha-hydroxyvitamin D3 greater than vitamin D3 in competing with radioactive 1alpha,25-(OH)2D3]. Both cytoplasmic and nuclear hormone-macromolecular complexes sediment at 3.1 S in 0.3 M KC1-sucrose gradients, and agarose gel filtration of the components indicates an apparent molecular weight of 58,000. The 3.1S binding molecules are not observed in adrenal gland, testes, liver, or kidney, but similar receptors for 1alpha,25-(OH)2D3 have been found previously in intestine. Macromolecular species with a high affinity and preference for 25-hydroxyvitamin D3 [25-(OH)D3] are also identified in parathyroid cytosol and differ from the parathyroid 1alpha,25-(OH)2D3-binding component in that: (1) they sediment at 6 S in 0.3 M KC1-sucrose gradients, (2) they are observed in all tissues examined, (3) they have a higher affinity for 25-(OH)D3 than 1alpha,25-(OH)2d3, and (4) they are not found in the nucleus of the parathyroid glands, in vitro. The discovery of unique 1alpha,25-(OH)2D3-binding components in the parathyroid glands is consistent with the sterol hormone's action at this endocrin site and possible involvement in the regulation of parathyroid hormone synthesis and secretion.
TL;DR: In this article, the ozone absorption optical depths, and hence the ozone content of the atmosphere, can be inferred directly from the spectral variation of total optical depth using a computerized curve-fitting method.
Abstract: A solar radiometer has been used to monitor solar irradiance at eight discrete wavelengths. From these monochromatic measurements at varying zenith angles the total optical depth has been deduced by a computerized curve-fitting method. A unique technique will be described whereby the ozone absorption optical depths, and hence total ozone content of the atmosphere, can be inferred directly from the spectral variation of total optical depth. This procedure permits a systematic determination of total ozone content on a daily basis when other measurements are not available. Using the ozone absorption optical depths determined in this manner, the values of aerosol optical depth may be obtained more accurately by subtracting the molecular scattering and estimated ozone absorption contributions from the total optical depth. A technique is also described for estimating the absorption optical depths at wavelengths where additional molecular absorption other than ozone occurs. Results are presented as 1) d...
TL;DR: The abdomen occupies an especially important role in running conversational speech in that it mechanically tunes the diaphragm to increase the latter's inspiratory efficiency and thus enables man to minimally interrupt his ongoing speech for needed inspiratory pauses.
Abstract: Anteroposterior diameters of the rib cage and abdomen and esophageal and gastric pressures were measured in normal subjects in upright and supine body positions during respiratory maneuvers and utt...
TL;DR: The development of necrosis in the pars recta appears to be a relatively late event, possibly due to further accumulation of Hg++ in this region, and the necrosis appears pathogenetically dissociable from the mechanism of acute renal failure.
Abstract: Acute renal failure was induced in male rats by the subcutaneous injection of 4 mg HgCl2 per kg body weight. Enzyme activities of the proximal tubule were studied histochemically at six time intervals from 15 min to 24 h. The enzymes studied were alkaline phosphatase, 5′-nucleotidase, acid phosphatase, α-glycerophosphate dehydrogenase (NAD-independent), malic dehydrogenase, succinic dehydrogenase, latic dehydrogenase, glucose-6-phosphate dehydrogenase and glucose-6-phosphatase. Decreases in activity were observed for alkaline phosphatase and 5′-nucleotidase after 15 min. Acid phosphatase was decreased after 30 min. These three enzymes returned to control levels after 3 h, but malic dehydrogenase and α-glycerophosphate dehydrogenase were decreased at this time interval. Succinic dehydrogenase was first decreased after 6 h. The earliest morphological changes detectable by light microscopy were observed in pars recta tubules in the medullary rays after 6 h, a time when all enzymes studied showed widespread decreased activity throughout the proximal tubule. After 24 h, the pars convoluta appeared morphologically normal but the pars recta was necrotic and exhibited calcification, whereas enzyme activity was decreased (absent in some cases) in both pars convoluta and pars recta.
TL;DR: In this article, the results of experiments investigating the crystallization of plagioclase from natural and synthetic melts are presented and analyzed in terms of empirical and semiquantitative mixing models for the melt.
TL;DR: Polarimetric observations for a total of 94 asteroids were presented and analyzed in this paper, where numerical parameters describing the polarization-plane curve, the maximum depth of the negative branch, geometric albedo, and diameter were presented.
Abstract: Polarimetric observations are presented and analyzed for a total of 94 asteroids. The data include numerical parameters describing the polarization-plane curve, the maximum depth of the negative branch, geometric albedo, and diameter. With few exceptions, the polarizations are found to be repeatable from hour to hour, night to night, and apparition to apparition at the same solar phase angle within an observational accuracy of plus or minus 0.05%. It is shown that over a range of more than a factor of 50 in diameter or a factor of 100,000 in mass, all the asteroids seem to have microscopically very rough or particulate surface textures. In terms of their polarimetric properties, the asteroids are classified as follows: 48 in the broad S class, with compositions corresponding to stony-iron meteorites or ordinary chondrites; 34 in the C class, probably corresponding to carbonaceous chondrites; three to five M asteroids with surfaces rich in free metal; two with low-opacity surfaces (class E) attributable to pure enstatite; and five of other types.
TL;DR: In this article, the authors considered a family of solutions with a limit in some sense as l + 0, where l is the number of vertices in the solution and E is the length of the transition from the limit to the boundary.
TL;DR: In this article, the authors present a completely classical analysis of the small-signal regime of a free-electron laser and show that the amplification is due to stimulated scattering produced by a bunching of the electron distribution.
TL;DR: It is concluded that this intertidal fish community, dominated by r -selected species, is more physically controlled than biologically accommodated and the temperate species play an important role in regulating the stability of this fish assemblage.
TL;DR: The data indicate that the hypocalcemia and bone disease in PsH are due to active vitamin D deficiency, possibly resulting from the genetic renal lesion.
Abstract: Pseudohypoparathyroidism (PsH) is a genetic disease characterized by hypocalcemia, hyperphosphatemia, and metabolic unresponsiveness to parathyroid hormone (PTH). The administration of PTH elicits neither a significant rise in serum calcium (calcemic response) nor a decrease in the renal tubule reabsorption of phosphorus (phosphaturic response). The diminished phosphaturic response is due to an inability of PTH to generate cyclic AMP in renal tubule cells. We investigated the question of whether hypocalcemia and deficient calcemic response to PTH are due to a similar cyclic AMP defect in bone or to an acquired vitamin D deficiency. Four patients were studied. The active form of vitamin D (1,25-dihydroxycholecalciferol) was measured in 3 and was low. Treatment with vitamin D2 restored the serum calcium and the calcemic response to PTH to normal without changing the impaired renal response. Bone biopsy was performed in 2 patients and showed morphologic evidence of increased osteoclastic activity and osteomalacia. The data indicate that the hypocalcemia and bone disease in PsH are due to active vitamin D deficiency, possibly resulting from the genetic renal lesion.
TL;DR: A model for the process of hypertrophy based on studies of a considerable number of mammalian growth systems is proposed and the mechanism of parallel regulation of polyamines and RNA appears to be initiated by the direct effect of ornithine decarboxylase on RNA polymerase I.
TL;DR: Experimental design permitted examination of effects due to treatments, time, differences in colostrum, and climatic environment in an analysis of variance, and calves that died had serum immunoglobulin IgG1 falling below the mean for all experimental calves.