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A number of materials with essentially ionic binding exhibit a transition in the solid state to a high conductivity state which has been identified with positional disorder of one of the ionic species. In this paper the contrasting roles of the disorder dependence of energy and entropy in determining the nature of the transition are examined within the mean field approximation at high point defect concentration. A generalization of the Mott-Littleton defect theory is used to illustrate the role of various physical characteristics such as polarizability, elastic properties, etc., and two types of phenomenological description of the transition are discussed. [ABSTRACT FROM AUTHOR]

An inhibition of root growth, a decrease in the amount of potassium (as Rb) and phosphate (P) accumulation by the root, and a partial depolarization of transmembrane electropotential were observed to develop with a similar time course and to a similar extent when intact maize ( Zea mays L.) roots were treated with 10 M abscisic acid (ABA). Potassium uptake was inhibited by ABA when excised, low-salt roots were bathed in KCl, KHPO, or KSO. ABA did not affect the ATP content of the tissues, the activity of isolated mitochondria, nor the activity of microsomal K-stimulated ATPases. [ABSTRACT FROM AUTHOR]

The discovery of immense organic clouds of gas embedded in the dusty regions of our Galaxy is of tremendous importance to the origin of life. It is within these clouds that the formation of stars and planetary systems is believed to take place. The collapse of these clouds to form stars takes place in a very small fraction of the astronomical lifetime of a star. It is precisely at this moment that the clouds of organic molecules appear. [ABSTRACT FROM AUTHOR]

Copyright of Calcified Tissue Research is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This review covers important developments in abiological synthesis of biomonomers and biopolymers since about 1967. The significance of these experiments to the field of chemical evolution and the origin of life is also discussed. [ABSTRACT FROM AUTHOR]

Copyright of Beiträge zur Klinik der Tuberkulose und Spezifischen Tuberkulose-forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The two-element interferometer at Hat Creek Observatory was used at 1.3 cm wavelength to study the fine structure of the radio emissive regions on the Sun. Observations of the quiet Sun at 1.3 cm show sudden changes in the fringe amplitude and phase, lasting for typically about 5-8 min. Assuming that these events are identical in nature, a plot of peak amplitude vs the projected baseline at the time of the event suggests emission from a region of angular size of about 10″. The corresponding brightness temperature is 50000 K. It is possible that these events may be related to the appearance and disappearance of groups of spicules or mottles. [ABSTRACT FROM AUTHOR]

An analysis was made of X-ray powder pattern peaks from a bulk, polycrystalline Ag-9at. pct Sn alloy that was plastically deformed by compression. The shapes and positions of all available ( hkl) reflections were recorded using the focusing, Bragg-Brentano X-ray geometry. Fourier analysis of the profiles were carried out on (111)-(222), (200)-(400), and (220)-(440) pairs of reflections. The effective particle sizes D (hkl) decreased rapidly with increasing deformation and reached values of D (111)=110Å, D (100)=40Å, and D (110)=90Å beyond 20 pct reduction in thickness. The anistropy of the particle sizes is interpreted as a consequence of faulting in the deformed alloy. The mean square strains in the [111] direction were of the order of 10 after more than 20 pct reduction in thickness. Lattice parameter measurements yield the deformation fault probability (α≈0.02), and the residual stresses. The variation of the true lattice parameter a with increasing deformation indicated that segregation occurred in the deformed alloy. From the ratio of 〈ε〉/α (≈ 6 × 10), a nominal stacking fault energy of 6 erg per sq cm was calculated. [ABSTRACT FROM AUTHOR]

An analysis of X-ray powder pattern peaks of plastically deformed fcc metals and alloys allows the determination of the stacking fault probability α and the dislocation density ρ. The changes in position of the peak maxima are produced by residual or applied stresses ρ, by α, and by a redistribution of the alloying elements, whereas the broadening of the peak profiles results from the reduction of the size of the coherently diffracting domains, from the microstains ∈, and from α. Values of ρ are deduced from ∈, and α is correlated with the faulted area in the cold worked crystals. ρ/α is directly proportional to the stacking fault energy γ. Estimates of the proportionality constant are made which lead to values of γ consistent with dislocation node measurements. [ABSTRACT FROM AUTHOR]

Evaporative, radiant and convective heat losses, metabolism and heat storage were determined on 8 unclothed reclining fasting subjects during 24 h in a climatic chamber maintained at a strictly constant and neutral temperature. In these conditions, a basal evolution of the body heat content and the rectal temperature were observed with nearly a disappearance of the diurnal thermal increase but persistency of a nocturnal falling followed by an early moring increase. Nocturnal cooling could be linked essentially with a rising skin temperature very likely through skin vasodilatation. Thus, the increase in radiant and convective heat losses was initially, constantly and predominantly involved for cooling the body in the evening and at night. The part played by the various skin areas was variable with the time, hands and feet temperature varying paradoxically in an opposite way to temperatures in other skin areas. Effects of an increase in evaporation and a decrease in basal metabolic rate were added later on but less systematically. It is proposed that sweating acts significantly only when thermal body state passes beyond the basal level. As this overpassing is essentially a function of metabolism, these two factors, metabolism and sweating seem to be tied in the mechanism controlling the body temperature rhythm. Body temperature is increased in the morning, principally by an increase in metabolism and a decrease in radiation and convection heat losses. [ABSTRACT FROM AUTHOR]

The exact sequence of events can well be postvilated in our patient. Many years of chronic constipation favored the elongation of the colon. The large colon, or megacolon, in turn, due to its load of feces, kinked at the rectosigmoid junction. The mesenteric anomaly in turn permitted the volvulus to proceed. The diagnosis in the pregnant patient is somewhat difficult, especially since diagnostic x-rays must be limited to avoid undue fetal exposure. The diagnosis of recurrent volvulus being somewhat easier to ascertain we were able to act with rapidity, permitting mother and fetus to survive. Final remedial surgery, namely, subtotal colectomy was performed in the immediate postpartum period. [ABSTRACT FROM AUTHOR]

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Copyright of Deutsche Zeitschrift für Nervenheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archiv für Dermatologie und Syphilis is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A study has been made of the radiation-induced paramagnetic color centers in calcium fluorapatite on annealing. It is found that there is an anomalous increase in the center concentration during isothermal annealing. An explanation is given via a model for diffusion of point defects and groups involving charge redistribution. It is found that the dislocation structure affects the thermal bleaching of the color centers. [ABSTRACT FROM AUTHOR]

1418 individuals from 8 different populations have been typed for their red cell Esterase D phenotypes using starch gel electrophoresis. The results have been tabulated along with other published data in an attempt to discover any significant pattern in the distribution of the two common alleles (Es D and Es D). [ABSTRACT FROM AUTHOR]