Showing papers by "University of Arizona published in 1972"

Archaeological Context and Systemic Context

Abstract: The cultural aspect of the processes responsible for forming the archaeological record is argued to be an underdeveloped branch of archaeological theory. A flow model is presented by which to view the "life history" or processes of systemic context of any material element. This model accounts for the production of a substantial portion of the archaeological record. The basic processes of this model are: procurement, manufacture, use, maintenance, and discard. Refuse labels the state of an element in archaeological context. The spatial implications of the model suggest a largely untapped source of behavioral information. Differential refuse disposal patterns are examined as they affect artifact location and association. The meaning of element relative frequencies in refuse is discussed.

Restoring with Maximum Likelihood and Maximum Entropy

Abstract: Given M sampled image values of an incoherent object, what can be deduced as the most likely object? Using a communication-theory model for the process of image formation, we find that the most likely object has a maximum entropy and is represented by a restoring formula that is positive and not band limited. The derivation is an adaptation to optics of a formulation by Jaynes for unbiased estimates of positive probability functions. The restoring formula is tested, via computer simulation, upon noisy images of objects consisting of random impulses. These are found to be well restored, with resolution often exceeding the Rayleigh limit and with a complete absence of spurious detail. The proviso is that the noise in each image input must not exceed about 40% of the signal image. The restoring method is applied to experimental data consisting of line spectra. Results are consistent with those of the computer simulations.

Determination of aerosol height distributions by lidar

Abstract: A new analytic solution to the lidar equation is presented, which realistically considers the scattering properties of the aerosols and the molecular atmosphere individually. With this solution, it is shown, in turbid atmospheres where the aerosols dominate the scattering properties, that accurate vertical profiles of the volume extinction cross section can be obtained with an uncalibrated lidar, provided that the total transmittance of the atmospheric layer being investigated is known. This solution is applied to data samples collected under very clear and under very dusty conditions.

Patterns of Cardiovascular Dysfunction in Chronic Obstructive Lung Disease

Abstract: A longitudinal seven-year study of 50 patients with chronic airway obstruction, whose cardiovascular function had been evaluated by cardiac catheterization when their condition was stable, showed that their survival was inversely related to pulmonary vascular resistance. Fourteen patients with high vascular resistances showed two different patterns of cardiovascular abnormality. Nine had relatively normal blood gases, low cardiac outputs, and near normal resting pulmonary-artery pressures; they had an emphysematous type of lung disease. The five with more severe blood gas abnormalities who had a more bronchitic type of disease, had well maintained cardiac outputs and more severe pulmonary hypertension. They more regularly presented the classic clinical and electrocardiographic features of cor pulmonale. Left ventricular dysfunction appeared to be an important determinant of pulmonary hypertension in only one patient.

Dominant Mutations (lex) in Escherichia coli K-12 Which Affect Radiation Sensitivity and Frequency of Ultraviolet Light-Induced Mutations

Abstract: Three mutations, denoted lex-1, -2 and -3, which increase the sensitivity of Escherichia coli K-12 to ultraviolet light (UV) and ionizing radiation, have been found by three-factor transduction crosses to be closely linked to uvrA on the E. coli K-12 linkage map. Strains bearing these mutations do not appear to be defective in genetic recombination although in some conjugational crosses they may fail to produce a normal yield of genetic recombinants depending upon the time of mating and the marker selected. The mutagenic activity of UV is decreased in the mutant strains. After irradiation with UV, cultures of the strains degrade their deoxyribonucleic acid at a high rate, similar to recA(-) mutant strains. Stable lex(+)/lec(-) heterozygotes are found to have the mutant radiation-sensitive phenotype of haploid lex(-) strains.

Regulation of the bacterial cell wall: analysis of a mutant of Bacillus subtilis defective in biosynthesis of teichoic acid.

Abstract: Bacillus subtilis 168ts-200B is a temperature-sensitive mutant of B. subtilis 168 which grows as rods at 30 C but as irregular spheres at 45 C. Growth at the nonpermissive temperature resulted in a deficiency of teichoic acid in the cell wall. A decrease in teichoic acid synthesis coupled with the rapid turnover of this polymer led to a progressive loss until less than 20% of the level found in wild-type rods remained in spheres. Extracts of cells grown at 45 C contained amounts of the enzymes involved in the biosynthesis and glucosylation of teichoic acids that were equal to or greater than those found in normal rods. Cell walls of the spheres were deficient also in the endogenous autolytic enzyme (N-acyl muramyl-l-alanine amidase). Genetic analysis of the mutant by PBS1-mediated transduction and deoxyribonucleic acid-mediated transformation demonstrated that the lesion responsible for these effects (tag-1) is tightly linked to the genes which regulate the glucosylation of teichoic acid in the mid-portion of the chromosome of B. subtilis.

Neuronal microtubules, neurofilaments, and microfilaments.

Abstract: Publisher Summary Interest in the structural proteins of neurons has increased in past years as a result of the convergence of three lines of investigation First, with improved methods of fixation, microtubules and neurofilaments have been described as constant components of nerve cells and thus neuronal organelles Such recognition has led to their isolation and partial chemical characterization Second, both microtubules and neurofilaments have been implicated in the nonrandom movement of substances within the cytoplasm, a process termed “axoplasmic flow” Now it is clear that this directed circulation of cytoplasm occurs not only in axons but also in the cell body and dendrites Third, disorders of these proteins lead to the pathological condition known as “neurofibrillary degeneration,” which occurs in aging This chapter considers the normal distribution, configuration, structure, and the composition of microtubules and neurofilaments and the relation between their distribution, function, and pathology The identification of these images as axons, dendrites, cell bodies, or synapses depends on the distribution of organelles in the structure Practically, the microscopist learns to identify profiles from their overall size and shape Thus, a dendrite is usually larger than its neighboring, unmyelinated axon

The effect of zinc and other metals on the stability of lysosomes.

Abstract: SummaryThe effects of zinc, certain other metals (Cu, Hg, Pb, Cd, Ni and Au), 8-hydroxyquinoline (8-HQ), and various stoichiometric complexes of Zn:8-HQ on the release of β-glucuronidase from lysosomes isolated from rat liver were tested. Zinc and Zn:8-HQ (1:1 and 1:2 complexes) markedly stabilized lysosomes in a concentration-related fashion. The saturated 1:3 complex and 8-HQ alone showed a labilizing effect, while the nonchelating substitute of 8-HQ (8-methoxyquinoline) did not affect lysosomal stability. Cd and Pb also stabilized lysosomes, although they were both less effective than zinc.The distribution of zinc between the membrane and the interior of isolated liver lysosomes is 2:1. After treatment with zinc, the distribution is unchanged but the total content of zinc increased 10-fold. In samples treated with unsaturated complexes of Zn:8-HQ (1:1 or 1:2) the total amount of zinc present is the same as in zinc-treated particles, but the metal is bound exclusively to the membrane fraction.The effect...

Lunar Color Boundaries and Their Relationship to Topographic Features: A Preliminary Survey

Abstract: By combining UV negatives with IR positives of the full Moon, it is possible to suppress albedo differences and to enhance color differences between various lunar regions. Areas within the lunar maria exhibit the greatest color variations, and many have sharp boundaries. In contrast, the terrae in general show only feeble color variations, although small terra regions situated near or surrounded by maria sometimes display enhanced redness.

Effective Atmospheric Emissivity under Clear Skies

Abstract: The effective atmospheric emissivity, F↓/(σT04), where F↓ is the downward radiative flux density and σT04 the blackbody flux density at the surface temperature T0, is computed for clear skies and straight temperature and dew-point soundings by means of emissivity integrations. Emissivity data by Jurica and by Staley and Jurica were used, and separate computations made for H2O, CO2, H2O-CO2 overlap, and O3. The effective atmospheric emissivity depends almost entirely on surface vapor pressure, decreases slightly with increasing surface elevation, and is essentially independent of surface temperature. The contribution by CO2 decreases from about 0,19 to about 0.17 as surface elevation increases from sea level to 710 mb. The contribution of overlap is negative and increases rapidly with increasing surface vapor pressure, becoming comparable to the CO2 contribution for very large vapor pressures. Measurements support the computations, but suggest, as has been found before, additional downward flux de...

Socioeconomic Behavior of Cattle Ranchers, with Implications for Rural Community Development in the West

Abstract: This paper extends the argument that cattle ranching and ranchers can be better understood by viewing the ranch resource as generating both production and consumption outputs. It was found that nonmonetary outputs of ranch ownership are the most significant factors in explaining high sale prices of Arizona ranches. Land fundamentalism, rural fundamentalism, and conspicuous consumption/speculative attitudes are the most important of these consumption outputs. The analysis suggests that small town viability and growth in the arid Southwest, and possibly in the West as a whole, may be more likely to occur if rural development policies are not predicated on the economic impact of surrounding ranches.

Lunar mare ridges, rings and volcanic ring complexes

Abstract: Mare ridges often consist of two separate but related features: (1) a broad gentle arch overlain by (2) a sharper, more contorted ridge Often these sharper, secondary ridges have flowed into craters in the adjacent terrain indicating they are extrusions Major flows in Mare Imbrium appear to have issued from several prominent mare ridges These flows show color differences which may be related to their abundance of titanium The association of flows with mare ridges, the broad arching linked with many ridges and the coincidence of linear ridges with the directions of major fracture patterns in the highlands indicates that arched mare ridges are dike, sill or laccolithic-type intrusions along major fractures In many cases these intrusions appear to have broken through the surface to form short flows and bulbous lava extrusions Mare ridges unassociated with arching are probably lava extrusions only

Winter Foraging Ecology of Mixed Insectivorous Bird Flocks in Oak Woodland in Southern Arizona

Abstract: birds during winter in north temperate regions is widely recognized (see Morse 1970 for references). However, there have been few attempts to quantify the interspecific relationships of members of foraging flocks. Most previous studies considered foraging behavior of members of the same genus during the breeding season (see Sturman 1968 for references), although Gibb (1954, 1960) discussed the foraging ecology of several species throughout the year, and Morse (1967a, b) studied the foraging ecology of unrelated species in summer and winter, respectively. Notably, Morse (1970) presented extensive data on foraging and interactions of mixed winter flock members in eastern North America.

The Effects of Prostaglandins on ACTH Secretion

Abstract: We have tested several prostaglandins for stimulatory effects on ACTH secretion by injecting them into the anterior pituitary, the hypothalamic median eminence, or a tail vein of female rats. Plasma corticosterone levels were used as an index of ACTH secretion. In dexamethasone-pretreated rats, PGs E1, F1a and F2a (1.0, 0.5 and 0.5 jig, respectively) increased ACTH secretion to similar levels when injected into the median eminence. These doses were ineffective when injected into nearby regions of the basal hypothalamus, the anterior pituitary, or a tail vein. The responses were abolished by pretreatment with morphine, and partially inhibited by a higher dose of the dexamethasone. In contrast, upon iv administration to rats not pretreated with dexamethasone, PGEX was more than 30 times as potent as PGF1a in stimulating ACTH secretion. The responses to these PGs given intravenously were equally suppressible by dexamethasone and were absent in hypophysectomized rats. The stimulatory effect of PGF1a when inje...

First integrals in the discrete variational calculus

Abstract: The intent of this paper is to show that first integrals of the discrete Euler equation can be determined explicitly by investigating the invariance properties of the discrete Lagrangian. The result obtained is a discrete analog of the classical theorem of E. Noether in the Calculus of Variations.

The Hadamard Maximum Determinant Problem

Abstract: (1972). The Hadamard Maximum Determinant Problem. The American Mathematical Monthly: Vol. 79, No. 6, pp. 626-630.

Lunar Rilles and Hawaiian Volcanic Features: Possible Analogues

Abstract: In this paper we consider the origin of rilles on the lunar maria, both sinuous and those having straight line segments, from the point of view of lava tubes formed in surface lava flows, and also in terms of collapses along active fissures. Terrestrial examples of tube formation and collapse, as well as the large-scale collapse of a chain of craters built over an active fissure were observed on the Island of Hawaii by the writers and serve as the basis of comparison with lunar topography shown on Orbiter photographs of the Moon. We also consider the origin of apparent flow channels on steep slopes on the Moon, and conclude that these are often related to early stages in the formation of covered lava tubes.

Mechanical arrangement and transducing properties of Golgi tendon organs.

Abstract: 1. The mechanical arrangement and transducing properties of Golgi tendon organs in soleus and anterior tibial muscles of anesthetized cats have been studied by noting responses of their Ib afferents to muscle stretch (passive force) and contraction (active force) of small portions of the muscle including functionally isolated motor units. 2. Tendon organs were shown to be arranged both in-series and in-parallel with adjacent muscle fibers. There were gradations in these relations, the tightest arrangements involving the response to contraction of a single motor unit, brisk discharge from an in-series receptor and pause in the stretch-activated firing of an in-parallel receptor. Other arrangements included those in which groups of muscle fibers neither directly in-series nor in-parallel with a receptor were still found capable of influencing its firing pattern. If in-series muscle fibers maintained their contraction while in-parallel fibers were also contracting, the receptor usually responded slightly less actively than it did to the in-series force alone. 3. Tendon organs were found to have a very low threshold to in-series force developed by muscle contraction. Responses were observed to as little as 0.5 gm of twitch tension. Minimum active force thresholds were similar for the two muscles studied, but thresholds to dynamic stretch were lower for anterior tibial receptors. Division of the dynamic stretch threshold by the minimum active force threshold gave a measure of the extent to which each tendon organ was more sensitive to active than passive force. These values (generally less than 50) did not negate the physiological significance of responses to passive stretch. 4. The present data, together with those of Houk and his co-workers (1967, 1971) emphasize that tendon organs can participate in the moment to moment reflex control of normal muscle activity.

Secondary nucleation in a class II system: Ammonium sulfate-water

Abstract: Secondary nucleation at low supersaturation for the ammonium sulfate-water system was studied using a seeded continuous crystallizer. Counter size distribution measurements in the subsieve size range indicated that nuclei are formed by microattrition of seed crystals and that the growth rate of the nuclei is very small. Nucleaion rate was correlated with the characteristics of the secondary environment. The results of this correlation, which shows strong dependence on stirring rate and essentially linear dependence on solids concentration, indicate that secondary nuclei are generated by collisions of the seed crystals with the impeller blades.

Comparison of time, frequency, and phase measurements in induced polarization*

Abstract: In comparing the similarity between time, frequency, and phase measurements as used in the induced polarization method of geophysical prospecting, parameters must first be defined and the basis for comparison established. The conditions for mathematical equivalence then follow in a natural sequence. Laboratory measurements are made on a variety of rock samples to indicate the type of comparison and correlation expected from field measurements. Results indicate that frequency domain and phase measurements are equivalent, but two frequency domain measurements are needed to produce the same amount of polarization information as a single phase measurement. Frequency and time domain measurements will be similar but never equivalent due to the basic differences in their respective parameter definitions.

Stimulation of mutation in phage T 4 by lesions in gene 32 and by thymidine imbalance.

Abstract: Summary In bacteriophage T 4 , temperature-sensitive ( ts ) mutations in gene 32 as well as in gene 43 have previously been shown to stimulate reversion of frame-shift mutations. We show here that two ts mutations in gene 32 increase reversion of base substitution mutations. ts mutations in several other genes with DNA-related functions were not observed to have significant mutator or antimutator effects. A recombinational map of gene 32 was constructed using II mutations including the two ts alleles with mutator effects. The length of the map suggests that gene 32 specified a protein of roughly 30 000 molecular weight. It was also shown that a phage mutant with defective thymidylate synthetase has a mutator effect on base substitution mutation when grown under conditions of limiting thymine or thymidine. In addition, these experiments suggested that high levels of exogenous thymine or thymidine stimulate mutation if added to phage with a normal thymidylate synthetase.