Showing papers by "University of Florida published in 1971"
TL;DR: A theoretical model to explain the interfacial bonding is based upon in-vitro studies of glass-ceramic solubility in interfacial hydroxyapatite crystallization mechanisms, compared with in- vivo rat femur implant histology and ultrastructure results.
Abstract: The development of a bone-bonding calcia-phosposilicate glass-ceramic is discussed. A theoretical model to explain the interfacial bonding is based upon in-vitro studies of glass-ceramic solubility in interfacial hydroxyapatite crystallization mechanisms, compared with in-vivo rat femur implant histology and ultrastructure results.
2,619 citations
TL;DR: In this paper, four methods of combining independent tests of hypothesis are compared via exact Bahadur relative efficiency: Fisher's method, the mean of the normal transforms of the significance levels, the maximum significance level, and the minimum significance level.
Abstract: Four methods of combining independent tests of hypothesis are compared via exact Bahadur relative efficiency. The methods considered are Fisher's method, the mean of the normal transforms of the significance levels, the maximum significance level, and the minimum significance level. None of these is uniformly more powerful than the others, but, according to Bahadur efficiency, Fisher's method is the most efficient of the four. In some cases, Fisher's method is most efficient of all tests based on the data, but this is not generally true.
259 citations
TL;DR: Sleep periods that begin at times other than the regular onset time tend to produce less stage 4 sleep; this decrease suggests a circadian effect.
Abstract: Age, length of prior wakefulness, length of time asleep, and a circadian influence all affect stage 4 sleep. The amount of stage 4 sleep decreases as subject's age increases and as time asleep increases. Longer periods of wakefulness before sleep result in greater amounts of stage 4 sleep in the first 3 hours of sleep. Sleep periods that begin at times other than the regular onset time tend to produce less stage 4 sleep; this decrease suggests a circadian effect.
219 citations
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01 Jan 1971TL;DR: In this paper, the authors define a distinctive blend of enlightened despotism and entrepreneurial talent which created Bourbon Mexico, a period in the colonial history of Mexico that was characterized by an unprecedented mining boom which made Mexico the world's chief silver producer.
Abstract: The aim of this study is to define that distinctive blend of enlightened despotism and entrepreneurial talent which created Bourbon Mexico. The period 1763-1810 was a crucial and distinctive stage in the colonial history of Mexico. Jose de Galvez, the dynamic minister of the Indies, transformed the system of government and restructured the economy. The ensuing 'golden age', far from being the culmination of two hundred years of steady development, sprang rather from a profound regeneration of the New World's Hispanic society. The chief success of Galvez's policy was the unprecedented mining boom which made Mexico the world's chief silver producer. It was this silver boom which largely financed the revival of the political and economic power of the Spanish monarchy and, in Mexico itself, created a new aristocracy of merchant capitalists and silver millionaires.
156 citations
TL;DR: Extensive experiments indicate that the application of heat to flint materials may have conferred an advantage to primitive man in the manufacture of chipped-stone implements.
Abstract: Extensive experiments indicate that the application of heat to flint materials may have conferred an advantage to primitive man in the manufacture of chipped-stone implements. When Florida cherts are slowly heated to between 350° and 400°C and maintained at this temperature for sustained periods, a desirable change occurs in the fracture properties. This alteration takes place when the melting point of the impurities within the intercrystalline spaces is reached; thus the microcrystals of quartz are fitted closer together when materials other than quartz serve as fluxes.
151 citations
TL;DR: Prolonged consumption of alcohol concomitant with adequate nutrition was found to impair the acquisition of shuttle box avoidance in rats, resulting in severely impaired learning of the avoidance task.
145 citations
TL;DR: The hippocampectomized rats did not perseverate the alternation response and failed to enter a relatively novel alley when tested after maze training, and animals in both control groups entered the novel alley with equal frequency on tests given both before and after Maze training.
138 citations
TL;DR: In this paper, the p K of cationic weak acids BH + in binary mixed solvents was analyzed and the results confirmed the earlier conclusion that solute-solvent interactions rather than electrostatic effects associated with the change in dielectric constant, are largely responsible for the changes of p K with composition of the solvent mixtures.
137 citations
TL;DR: In this paper, general matrix expressions for solution properties such as chemical potential, partial molal volume and compressibility are developed in terms of (radial) pair distribution functions and of direct correlation functions.
Abstract: General matrix expressions for solution properties such as the chemical potential, partial molal volume and compressibility are developed in terms of (radial) pair distribution functions and of direct correlation functions.
135 citations
TL;DR: The Fink-Heimer stain reveled that a limited number of axons regenerated from long tracts into the reactive neural zone, and most regenerated axons appear to be axonal sprouts from the operated and unoporated portions of the spinal cord.
TL;DR: On small Caribbean islands there seems to be a fundamental partitioning of food that includes one fruit bat, two nectar bats, two insect bats, and one fishing bat; other food habits are not generally present because of the apparent absence of these foods in sufficient quantities.
Abstract: The species that constitute a tropical bat fauna partition the food available in an environment in an orderly manner, the two most important parameters of partitioning being the type of food and food particle size. On small Caribbean islands there seems to be a fundamental partitioning of food that includes one fruit bat, two nectar bats, two insect bats, and one fishing bat; other food habits, such as blood and meat, are not generally present because of the apparent absence of these foods in sufficient quantities. Mainland tropical bat faunas are similarly structured in terms of food type and size, but it is not possible to make a complete analysis due to the many rare species, whose habits are generally unknown. See full-text article at JSTOR
TL;DR: Enamel deposition begins when a complete layer of calcified dentin is present and large droplets of extracellular material appear at the apex of ameloblasts in preparation for the formation of Tomes' processes.
TL;DR: Macaca speciosa monkeys trained to escape electrical stimulation of either hindlimb were given the alternative of witholding the response for 10 sec to receive food reward, and it was inferred that pain reactivity was altered if the force or latency curves or both were shifted by a lesion.
Abstract: Macaca speciosa monkeys were trained to escape electrical stimulation of either hindlimb, and they were given the alternative of witholding the response for 10 sec to receive food reward. The force, latency and threshold of escape responses were measured as a function of stimulation intensity before and after lesions of the spinal cord. The stimulus range was set so that pain was certainly evoked by some portion of the intensities above escape threshold, and it was inferred that pain reactivity was altered if the force or latency curves or both were shifted by a lesion. Ipsilateral dorsal column lesions decreased pain reactivity as revealed by higher latencies and lower forces of escape responses. Thresholds were generally unaffected. Ipsilateral lesions of the dorsolateral column produced hyperesthesia, or reduced latencies and increased forces. Thresholds were again unaffected. Contralateral lesions of the lateral column elevated thresholds, and this effect was magnified by inclusion of the dorsal columns in the lesion.
TL;DR: The giant grouper, Epinephelus itaira, was shown to synthesize 16 and 6.4S antibodies specific for the dinitrophenyl determinant (DNP), suggesting that, although considerable evolution of immunoglobulin classes has occurred between fish and rabbits, the antibody combining site may have remained relatively unchanged during a large part of evolutionary time.
TL;DR: The concept that local cellular immunity can be initiated independently of systemic cellular immunity is supported.
Abstract: The cell-mediated immune response on the secretory surface of the lower respiratory tract was investigated and compared to the systemic cell-mediated immune response and to the secretory and systemic antibody responses. Guinea pigs were immunized either parenterally or locally with dinitrophenylated human IgG. The effect of rendering animals tolerant on the local cell-mediated response and on the local antibody response was also studied. The antibody response in the bronchial washing fluids was predominantly of the IgA class. In the animals rendered tolerant by administering large doses of the antigen intravenously, the secretory antibody response was significantly reduced to about 40% of the levels in the animals which were not tolerant. Cellular immunity was assayed using the inhibition of macrophage migration. In animals which were immunized subcutaneously, splenic lymphocytes strongly inhibited the migration of normal guinea pig macrophages; however cells obtained from bronchial washings from the same animals exhibited little or no inhibition of macrophage migration in the presence of antigen. In the animals which were immunized by nose drops, splenic lymphocytes showed virtually no inhibition of macrophage migration; however, bronchial washing lymphocytes strongly inhibited the migration of normal macrophages. Thus, nose drop immunization gave rise to a significantly greater local cellular immune response than did parenteral immunization. In those animals which were immunized by nose drops after a tolerizing dose of antigen, there was virtually no inhibition of macrophage migration by either the cells from the spleens or bronchial washings. Studies were done which demonstrated that a substance similar to macrophage-inhibition factor was liberated by the bronchial washing cells on incubation with the antigen. Studies were also done which indicated that secretory antibody played no role in the inhibition of macrophage migration when bronchial washing lymphocytes were used. Lymphocytes were purified from bronchial washings and were found to inhibit normal macrophage migration in the presence of antigen to the same extent that the mixed population of lymphocytes and pulmonary macrophages did. Thus this study supports the concept that local cellular immunity can be initiated independently of systemic cellular immunity.
TL;DR: It is postulated that the periodicity observed in the molecular weights reflects the structural limitations imposed upon these macromolecules by the apoprotein which determines the amount of lipid which may be bound.
TL;DR: In this article, an analytic form for the energy transfer rate from photoelectrons to thermal electrons is given, which fits the classical formulation of Itakawa and Aono (1966) at low energies and gives a smooth transition to fit the quantum mechanical equation of Schunk and Hays (1971) at higher energies.
Abstract: An analytic form is given for the energy-transfer rate from photoelectrons to thermal electrons. The expression fits the classical formulation of Itakawa and Aono (1966) at low energies and gives a smooth transition to fit the quantum mechanical equation of Schunk and Hays (1971) at higher energies. The corresponding loss function or stopping power has a form that is convenient in auroral and dayglow calculations.
TL;DR: The first systematic application of a hybrid sleep EEG scoring system is reported and it is indicated further that frequency spectrum analysis is not practical in sleep staging, since the amplitude of delta activity and spindles changes throughout a given night.
TL;DR: Dissociation studies show that the 55 S ribosome is a mitochondrial monosome, composed of a 28 S small subunit and a 39 S subunit, and these mammalian 55 S mitochondrial ribosomes are the smallest monosomes known.
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TL;DR: The electrical, birefringence, and nuclear magnetic resonance data are in agreement with the proposed mechanism of change in the structure of water from water spheres to water cylinders to water lamellae.
Abstract: Microemulsions, which are optically transparent oil-water dispersions, were produced by mixing hexadecane, hexanol, potassium oleate, and water. As the amount of water is increased, the microemulsion exhibits a clear to turbid to clear transition. In contrast to the clear regions, the turbid region possesses birefringence. The development of birefringence is also accompanied by a sharp decrease in the electrical resistance. The high-resolution (220 megacycle) nuclear magnetic resonance data suggest that water exists in two distinct molecular environments in the birefringent region; the first environment is characterized by relatively less mobile water molecules than oil molecules, whereas in the second environment oil molecules are less mobile than water molecules. The electrical, birefringence, and nuclear magnetic resonance data are in agreement with the proposed mechanism of change in the structure of water from water spheres to water cylinders to water lamellae. The chemical shift of water protons suggests that the molecular environment of water in spheres is different from that of water in cylinders or that of water in lamellae.
TL;DR: The results showed that neodecorticate and normal rats switched responses to obtain appropriate rewards but hippocampal rats were deficient in learning this and had a strikingly high proportion of such errors were committed consecutively.
TL;DR: This paper reports data on the phonational frequency ranges of 332 male and 202 female adults, ages 18–36, who were required to produce a series of consecutive phonations with the f0 corres for each subject.
Abstract: This paper reports data on the phonational frequency ranges of 332 male and 202 female adults, ages 18–36. Each subject was required to produce a series of consecutive phonations with the f0 corres...
TL;DR: It is proposed that an analogous mechanism may control female oestrous behaviour in rats and that the inhibition of male copulatory patterns by anterior portions of the nervous system is mediated by brain monoamines.
Abstract: IT has been proposed that the inhibition of male copulatory patterns by anterior portions of the nervous system1 is mediated by brain monoamines2–4, for reserpine facilitates certain aspects of the male pattern in rats3–5 although monoamine oxidase inhibitors retard copulatory behaviour (D. A. D., H. N. Davis and P. E. Jansen, results submitted for publication). Meyerson has proposed6 that an analogous mechanism may control female oestrous behaviour in rats.
TL;DR: In this paper, the effects of mixed surfactants on various interfacial phenomena are described, and it is proposed that these striking changes are due to two-dimensional hexagonal packing of molecules resulting in a closer molecular packing and a greater stability of mixed films at interfaces.
TL;DR: Exposure-adjusted break frequencies for chromosome aberrations produced in circulating blood lymphocytes were the quantitative indicator of damage, agreeing well with data from in vitro exposure of human cells.
TL;DR: In this paper, the results of an experimental program systematically evaluating the deformation and fracture of steel wire reinforced epoxy composite systems are presented, which involved mechanical testing in the strain rate range 10-5 to 103/sec and impact testing of composite specimens using massive elastic targets at strain rates approximately 104/sec.
Abstract: Results of an experimental program systematically evaluating the deformation and fracture of steel wire reinforced epoxy composite systems are presented. The program involved mechanical testing in the strain rate range 10-5 to 103/sec and impact testing of composite specimens using massive elastic targets at strain rates approximately 104/sec. Specific results presented include static and dynamic prop erties, strain rate sensitivity, information on the nature and character of dynamic fracture, influence of specimen geometry and reinforce ment spacing, and high speed photographs of dynamic failure modes. Further, a simplified energy criterion is proposed for predicting failure modes and critical velocities.
TL;DR: In this paper, the authors used the analytic atomic independent-particle model (IPM) as a basis for calculating generalized oscillator strengths for the singleparticle excitations of Ne, Ar, Kr, and Xe.
Abstract: We utilize the analytic atomic independent-particle model (IPM) of Green, Sellin, and Zachor as a basis for calculating generalized oscillator strengths for the single-particle excitations of Ne, Ar, Kr, and Xe. First, we establish averages of the experimental energy levels to arrive at single-particle states. We then adjust the two parameters so that the IPM potentials accurately characterize these excited-state energies. Using the wave functions associated with these potentials and the Born approximation, we calculate the generalized oscillator strengths for excitations to ${p}^{5}\mathrm{ns}$ states. A very complex nodal structure is apparent at large values of momentum transfer and a rapid decline in magnitude occurs after the second node. We may accurately characterize the results up to the second node with a convenient analytic form which leads to analytic total excitation cross sections. We use available optical oscillator strengths to normalize our results. The systematics and regularities of the parameters for various Rydberg series are discussed and approximate scaling laws are given.
01 Jan 1971
TL;DR: An overview of pollen growth suggests that the tube nucleus and probably the generative nucleus are involved in RNA synthesis and protein formation in the elongating pollen tube.
Abstract: Publisher Summary This chapter discusses pollen chemistry and the growth responses of pollen to specific chemicals. Proteins vary widely with species, usually accounting for 10%–30% of the pollen dry weight. Mineral analyses are usually run on pollen ashed in concentrated acid. Trace elements in pollen vary with species and conditions during maturation. Simple sugars are the principal metabolic substrates used by germinating pollen. Soluble sugars in pollen change markedly with storage and handling conditions. An overview of pollen growth suggests that the tube nucleus and probably the generative nucleus are involved in RNA synthesis and protein formation in the elongating pollen tube. Enzymes produced and activated during germination metabolise internal and external substrates. In binucleate pollens, the division of the generative nucleus precedes bursting of the tube.