Showing papers by "University of Texas at Austin published in 1970"
TL;DR: Most of the methods outlined here have been used primarily for tissue extracts from mammalian species, and a few have been developed only on plants or lower animals, but this is not to say that they will not work on higher organisms.
Abstract: The technique of starch gel electrophoresis of enzymes with specific staining for activity in the gel, the so-called zymogram method developed by Hunter and Markert (1957), has found many research applications. Screening studies, comparing relatively large numbers of enzymes among a variety of tissues and organisms, are finding increasing use in research on population genetics, taxonomy, etc. The methods presently available are scattered through the literature. This compilation is published in response to numerous requests from investigators in many fields. Most of the methods outlined here have been used primarily for tissue extracts from mammalian species. A few have been developed only on plants or lower animals, but this is not to say that they will not work on higher organisms. The buffer systems have been for the most part empirically arrived at. All are probably subject to improvement. The techniques of making the gels and carrying out the electrophoresis are not described here. These have been amply presented in a number of publications. The vertical system is essentially that described by Shaw and Koen (1968b). The horizontal system is essentially as described by Beckman and Johnson (1964). The horizontal method has the advantage of employing simpler and less expensive apparatus, and it can be run at room temperature using ice trays to keep the gels cold. For many enzyme systems, it provides as good results as the vertical. Both Connaught starch (Connaught Laboratories, Toronto) and Electrostarch (Otto Hiller Company, Madison, Wisconsin) will give satisfactory results with either technique. Unfortunately, different batches of starch may produce varying results, both in rate of migration and in resolution; also, some batches contain substances
2,341 citations
01 Jan 1970
1,104 citations
TL;DR: In this article, five hypotheses were proposed and tested to account for Reicher's finding that recognition of letters is more accurate in the context of a meaningful word than alone, even with redundancy controlled by a forced-choice design.
707 citations
TL;DR: In this paper, Gravel, sand, silt, and clay are end members of triangular diagrams that are divided into named textural categories in accord with apparent natural groupings.
Abstract: Grain-size distribution and mineralogical composition are independent variables in most detrital sediments. Separate classifications are necessary to describe these sediment attributes. Essential characteristics are given when the following format is used: (sorting term) (size term): (cement) (prominent nondetrital) (detrital composition). This polynomial evokes a clear mental image of the sediment. Descriptive nomenclature and procedure are modified from earlier Folk publications. The resultant classification system is objective and practical. Gravel, sand, silt, and clay are end members of triangular diagrams that are divided into named textural categories in accord with apparent natural groupings. Modal size and sorting terms supplement the names of some categories. Rudite, arenite, and lutite are used in a compositional sense for detrital sediments whose texture is respectively indicated by the terms gravel (conglomerate or breccia), sand (sandstone), and mud (mudstone, siltstone, or clayston...
657 citations
TL;DR: In this paper, it was shown that every type of vacuum solution of Einstein's equations admits a quadratic first integral of the null geodesic equations (conformal Killing tensor of valence 2), which is independent of the metric and of any Killing vectors arising from symmetries.
Abstract: It is shown that every type {22} vacuum solution of Einstein's equations admits a quadratic first integral of the null geodesic equations (conformal Killing tensor of valence 2), which is independent of the metric and of any Killing vectors arising from symmetries. In particular, the charged Kerr solution (with or without cosmological constant) is shown to admit a Killing tensor of valence 2. The Killing tensor, together with the metric and the two Killing vectors, provides a method of explicitly integrating the geodesics of the (charged) Kerr solution, thus shedding some light on a result due to Carter.
564 citations
TL;DR: In this article, carbon and oxygen isotopes and magnesium between coexisting dolomite and calcite have been determined for marbles and calcareous schists of a wide variety of metamorphic environments from Vermont and the Grenville Province of Ontario.
Abstract: Fractionations of carbon and oxygen isotopes and magnesium between coexisting dolomite and calcite have been determined for marbles and calcareous schists of a wide variety of metamorphic environments from Vermont and the Grenville Province of Ontario. Concordant equilibrium fractionations are given by 83% of the samples. Calibration of the isotopic thermometers using the Mg-calcite solvus thermometer gave in the temperature range: 650°>T°>100°C
$$ \begin{gathered} 1,000\ln \alpha _{D - Ct}^{O^{18} } = 0.45 (10^6 T^{ - 2} ) - 0.40 \hfill \\ 1,000\ln \alpha _{D - Ct}^{O^{18} } = 0.18 (10^6 T^{ - 2} ) + 0.17. \hfill \\ \end{gathered} $$
453 citations
TL;DR: In this paper, a generalization of the Reissner-Nordstrom solution of general relativity and the Born solution of classical electrodynamics is discussed. But the authors do not consider the solution as asymptotically flat.
Abstract: We discuss a type-{22} solution of the Einstein-Maxwell equations which represents the field of a uniformly accelerating charged point mass. It contains three arbitrary parameters $m$, $e$, and $A$, representing mass, charge, and acceleration, respectively. The solution is a direct generalization of the Reissner-Nordstrom solution of general relativity and the Born solution of classical electrodynamics. The external "mechanical" force necessary to produce the acceleration appears in the form of a timelike nodal two-surface extending from the particle's world line to infinity. This does not prevent us from regarding the solution as asymptotically flat and calculating the radiation pattern of its electromagnetic and gravitational waves. We find as well a maximal analytic extension of the solution and discuss its properties. Except for an extra "outer" Killing horizon due to the accelerated motion, the horizon structure closely resembles the Reissner-Nordstrom case.
361 citations
TL;DR: Methods are developed for computing three dimensional density maps from transmission electron micrographs using Fourier transforms, which gives clear reconstructions of their surface structures when applied to negatively stained spherical viruses.
Abstract: Methods are developed for computing three dimensional density maps from transmission electron micrographs using Fourier transforms. The reconstructions objectively combine data from several different views of one or more particles. When applied to negatively stained spherical viruses, the technique gives clear reconstructions of their surface structures.
321 citations
TL;DR: Samples of bacterial deoxyribonucleic acid from bacteria having guanine plus cytosine (GC) contents in the range of 27 to 72 moles per cent GC were analyzed by optical melting (T(m)) and equilibrium buoyant density methods and the relation between these properties is shown to be linear.
Abstract: Samples of bacterial deoxyribonucleic acid from bacteria having guanine plus cytosine (GC) contents in the range of 27 to 72 moles per cent GC were analyzed by optical melting (T(m)) and equilibrium buoyant density methods. The relation between these properties is shown to be linear. The relative value of 1.99 moles per cent GC per degree C change in T(m) is calculated, and a reference method for the calculation of GC contents relative to a standard is derived.
309 citations
TL;DR: In this paper, the authors compare the sedimentary structures in modern point bar deposits of the Amite River in Louisiana and the Colorado River in Texas are analogous to features observed in Eocene Simsboro and Pleistocene Colorado River deposits.
Abstract: SUMMARY
Primary sedimentary structures in modern point bar deposits of the Amite River in Louisiana and the Colorado River in Texas are analogous to features observed in Eocene Simsboro and Pleistocene Colorado River deposits of the Texas Gulf Coastal Plain.
Short-duration peak flow, channel pattern, average stream gradient of about 2–3 ft./mile, and bank stabilization by dense vegetation are major parameters controlling the depositional pattern of coarse sand and pebble gravel of the Amite and Colorado rivers. Stratification is directly related to specific depositional features and consists of: large-scale trough-fill cross-stratification in the scour pool; trough-fill cross-stratification and foreset cross-stratification in the lower point bar; parallel laminae, large foreset cross-stratification, and trough-fill cross-stratification in the chute bar; parallel inclined laminae, climbing ripple laminae, and mud drapes in the chute fill; and parallel inclined laminae, mud drape, and foreset cross-stratification in overbank, flood-plain deposits.
Fundamental differences between point bars of bed-load streams (low suspended load/bed load ratio) and mixed-load streams (high suspended load/bed load ratio) are that upper point bar sediments with small trough sets and parallel inclined laminae occur only in fine-grained (mixed load) fluvial deposits, and large scale foresets of chute bars are common to coarse-grained (bed load) fluvial deposits but are not found in fine-grained fluvial deposits. Upward fining sequences, characteristic of fine-grained fluvial deposits, are uncommon in sediments deposited by bed-load streams such as the Amite and Colorado rivers.
The Simsboro Sandstone consists mainly of scour pool, lower point bar, and chute bar sediments. Chute fill and flood-plain deposits are preserved only in the highest stratigraphic sequence. Pleistocene Colorado River deposits display the same sequence of stratification types as the Simsboro but are composed of coarser material.
265 citations
TL;DR: Seven isolated large populations of Drosophila belonging to five different species were examined by starch gel electrophoresis for allozyme variation and linkage disequilibrium, a measure of genome integration, was computed between an enzyme locus and an inversion segment of the same chromosome.
Abstract: Seven isolated large populations of Drosophila belonging to five different species were examined by starch gel electrophoresis for allozyme variation Six to eleven enzyme loci in the glucose-metabolizing system (group I) and six to eight enzyme loci (group II) which were not directly involved in the above-mentioned system were assayed The parameters estimated were the average number of alleles per locus, allele frequencies, proportions of polymorphic loci, and average heterozygosity per population for group I and group II loci The major finding is that genetic variability measured by allozyme variations is much higher for group II than for group I enzymes in terms of every parameter in all the populations This is consistent with the earlier findings in D ananassae by Gillespie and Kojima (1968) Linkage disequilibrium, a measure of genome integration, was computed between an enzyme locus and an inversion segment of the same chromosome The preliminary analysis of this aspect of the study indicates that no substantial linkage disequilibrium builds up between the chromosomal segments unless the pair of segments is less than 10 centimorgan units apart
TL;DR: A rapid isolation procedure for chromosomes, mitotic apparatus, or nuclei from mammalian fibroblasts has been developed at a near neutral pH in a simple buffer solution and it is possible to obtain as the desired end product either metaphase chromosomes, intact mitotic equipment, or interphase nuclei by slight modifications of the isolation procedure.
TL;DR: In this article, a means of interpreting the Weyl coordinates for static axially symmetric metrics is presented, which allows a reasonable physical interpretation of any given Weyl metric, if the standard coordinate descriptions are used.
Abstract: One of the major problems in understanding solutions of the gravitational field equations is to determine the physical meaning of the coordinates involved. In particular, for the Weyl solutions if the standard coordinate descriptions are used, then physical interpretation becomes difficult. A means of interpreting the Weyl coordinates for static axially symmetric metrics is presented which allows a reasonable physical interpretation of any given Weyl metric.
TL;DR: Among the parameters which were found to influence the individual and over-all reactions and which were studied to establish optimal conditions were the concentrations of oxidant, iodide, and protein as well as pH, time, temperature, ionic strength, and particular batch of protein.
01 Jan 1970
TL;DR: Grimshaw (1901, 1902) and Perkins (1910) first focused the attention of dipterists on the aberrant characteristics and abundance of the Hawaiian Drosophilidae.
Abstract: Grimshaw (1901, 1902) and Perkins (1910) first focused the attention of dipterists on the aberrant characteristics and abundance of the Hawaiian Drosophilidae. They described 47 species; additionally, Perkins’ extensive descriptions (1913) of the biotic habitat in which the insects live alerted biologists to the unique but unknown ecology of the flies.
01 Jan 1970
TL;DR: The methanol spectra of flavones and flavonols exhibit two major absorption peaks in the region 240 - 400 nm1 as discussed by the authors, and these two peaks are commonly referred to as Band I (usually 300 − 380 nm, Table V-1 records the λmaxvalues for Band I for all flavones examined in the present investigation), and Band II (usually 240 - 280 nm).
Abstract: The methanol spectra of flavones and flavonols exhibit two major absorption peaks in the region 240 – 400 nm1. These two peaks are commonly referred to as Band I (usually 300 – 380 nm, Table V-1 records the λmaxvalues for Band I for all flavones and flavonols examined in the present investigation), and Band II (usually 240 – 280 nm). Band I is considered to be associated with absorption due to the B-ring cinnamoyl system, and Band II with absorption involving the A-ring benzoyl system (see III) [1].
TL;DR: To compare degrees of protein polymorphism and underlying genic heterozygosity in a classic phylogenetic "relic," the horseshoe or king crab (Limulus polyphemus), and in several representatives of horotelic lines (those evolving at standard rates) for which data are already available, a test of the mutationists' thesis is allowed.
Abstract: To many early evolutionists, particularly those of the mutationist school, the existence of evolutionarily stable forms ("living fossils" or phylogenetic "relics") posed a difficult problem, and, even among contemporary biologists, the feeling that "a long-standing stability of organization seems antithetical to the concept of evolution" may persist (Volpe, 1967:140). In the early part of this century, it was popularly believed that stable or slowly evolving (bradytelic) lines lacked the genetic variation necessary for more rapid evolution as a result of having abnormally low mutation rates; as Mayr (1963) puts it, a lack of variation in time and space was interpreted as a reflection of genotypic stability. Largely because of the influence of Simpson (1944), Stebbins (1944), Schmalhausen (1949), and Dobzhansky (1951), the mutationists' interpretation of bradytely has now been all but abandoned by evolutionists in favor of the view that the principal factors controlling rates of evolution are to be found in the organism-environment relationship. Additionally, Mayr (1963 :304) has suggested that phenotypic "uniformity in space and time is due to a highly perfected 'buffering system,' in other words, to genetic homeostasis." The ecological hypothesis is well expressed in Simpson's (1944:141) conclusions that "the final and probably the most fundamental factor in the relationship is that bradytelic groups are so well adapted to a particular, continuously available environment that almost any mutation occurring in them must be disadvantageous" and that "bradytely results from the equilibrium of large breeding populations of animals specifically adapted to a continuously available environment that is relatively invariable . . . ." Yet, as Mayr (1963) notes, there is no evidence to refute (or to support) the hypothesis that bradytely results from loss of mutability. The recent development of electrophoretic techniques for demonstrating allelic variation at loci controlling enzymes and other proteins in natural populations (Hubby and Lewontin, 1966; Lewontin and Hubby, 1966) permits a test of the mutationists' thesis. The purpose of this study is to compare degrees of protein polymorphism and underlying genic heterozygosity in a classic phylogenetic "relic," the horseshoe or king crab (Limulus polyphemus), and in several representatives of horotelic lines (those evolving at standard rates) for which data are already available. Evidence of a level of genetic variation in Limulus similar to that in horotelic forms will support the modern ecological and homeostatic interpretations of bradytely. But if the mutationists' thesis is valid, Limulus should show an unusually low degree of polymorphism at its genetic loci. Limulus polyphemus is one of five living species of the Subclass Xiphosura, a group of marine arthropods usually placed with the Subclass Eurypterida (extinct giant water scorpions) in the Class Merostomata of the Subphylum Chelicerata. Following a period of adaptive radiation in the early and middle Paleozoic, the Merostomata became much less prominent after the Permian. Several Mesozoic forms are known in the Family Mesolimulidae, but by the Tertiary the fossil record is all but absent. There are presently three living genera, all belonging to the Family Limulidae, only one of which, Tachypleus, is known from the fossil record (Stormer,
TL;DR: For example, the authors showed that the large-scale distribution of galaxies most of the time is homogeneous and isotropic, and most astonomers believe that the expansion of the universe proceeds at a uniform rate measured by the Hubble constant.
Abstract: Once upon a time philosophers and cosmographers insisted that the motions of the planets must be circular and uniform. An irrelevant aesthetic concept of ‘perfection’ and a more valid mathematical need for simplicity were at the root of this long-held error. Nowadays, theoretical cosmologists insist that the large-scale distribution of galaxies most be homogeneous and isotropic, and most astonomers believe that the expansion of the universe is linear and isotropic and that it proceeds at a uniform rate measured by the Hubble ‘constant’ H.1, 2
01 Jan 1970
TL;DR: A great deal of information is available from the literature as to the location and appearance of calcium deposits in plants, but surprisingly little can be found about the mechanism of calcification, and still less about the ultrastructural features of the event.
Abstract: Raphides of calcium oxalate were among the first objects to be observed under the optical microscope. Leeuwenhoek described the raphides which occur in Arum in a letter to Mr. H. Oldenberg written August 14, 1675. One of the first signs of life in Precambrian rocks were the calcareous filamentous algae of thin limestone reefs which are scarcely different from their counterparts in a modern coralline community. Yet in spite of the fact that deposits of calcium salts in plants are abundant, diverse, and complex and the mineral matter, chemically and physically, indistinguishable from the same substances in animals, there seems to be a lack of studies on the metabolism and structure of plants, comparable to those of bone and shell. A great deal of information is available from the literature as to the location and appearance of calcium deposits in plants, but surprisingly little can be found about the mechanism of calcification, and still less about the ultrastructural features of the event.
TL;DR: Survival data on 78 children with rhabdomyosarcoma indicated that age, histology, primary site, extent of disease, and treatment each had a significant influence on prognosis.
Abstract: Survival data on 78 children with rhabdomyosarcoma indicated that age, histology, primary site, extent of disease, and treatment each had a significant influence on prognosis. The best survival occurred in patients with sarcoma botryoides, the poorest with alveolar rhabdomyosarcoma, and the intermediate with embryonal rhabdomyosarcoma. Tumors of the orbit had the best prognosis and tumors of other structures of the head and neck had the worst prognosis. Children under 7 years of age had better survival curves than those older than 7 years. The median duration of survival for the entire group was 19.2 months (5-year survival rate of 35%). The median duration of survival among 54 children with localized disease was 53.3 months; none of the 24 children with extensive or metastatic disease at diagnosis survived as long as 30 months.
TL;DR: It is concluded that at least minimally effective techniques have been devised for answering questions from natural language subsets in small scale experimental systems and that a useful paradigm has evolved to guide research efforts in the field.
Abstract: Recent experiments in programming natural language question-answering systems are reviewed to summarize the methods that have been developed for syntactic, semantic, and logical analysis of English strings. It is concluded that at least minimally effective techniques have been devised for answering questions from natural language subsets in small scale experimental systems and that a useful paradigm has evolved to guide research efforts in the field. Current approaches to semantic analysis and logical inference are seen to be effective beginnings but of questionable generality with respect either to subtle aspects of meaning or to applications over large subsets of English. Generalizing from current small-scale experiments to language-processing systems based on dictionaries with thousands of entries—with correspondingly large grammars and semantic systems—may entail a new order of complexity and require the invention and development of entirely different approaches to semantic analysis and question answering.
TL;DR: Findings justify designation of this group of tumors of the upper respiratory tract, oral cavity, and skin of face as spindle‐cell variants of squamous carcinomas.
Abstract: Thirteen spindle-cell tumors of the upper respiratory tract, oral cavity, and skin of face have been studied with light and electron microscopy. Five were primary neoplasms, and 8 had recurred following radiation therapy. The primary lesions were superficially located, and, in light microscopic sections, sites of apparent continuity between tumor and overlying epithelium were observed. The electron micrographs demonstrated the presence in many tumor cells of aggregates of keratohyaline and slender bundles of tonofilaments, and occasional premelanosomes were seen. Desmosomes were present, but were few in number and poorly developed. No evidence could be found to support the concept of malignant connective tissue component. Findings justify designation of this group of tumors as spindle-cell variants of squamous carcinomas.
TL;DR: The Middle Pleistocene Belmont Formation of Bermuda consists in part of beach-dune biocalcarenites which underwent intense contemporaneous cementation and diagenesis.
Abstract: SUMMARY
The Middle Pleistocene Belmont Formation of Bermuda consists in part of beach-dune biocalcarenites which underwent intense contemporaneous cementation and diagenesis. The beach deposits were contemporaneously cemented by fibrous isophacous cement to form beachrock, whereas previously deposited eolianites further inland underwent intense meteoric phreatic diagenesis, resulting in coarse-grained cementation and stabilization of most of the metastable components of the rock. Above the Belmont water table, vadose diagenesis was relatively ineffective in cementing and altering the biocalcarenites. Phreatic meteoric diagenesis is interpreted to be a very rapid process, relative to vadose meteoric diagenesis, and to result in a much coarser-grained sparite.
TL;DR: The consolidation characteristics of clays are controlled by mechanical and physico-chemical effects as discussed by the authors, and one-dimensional consolidation tests indicate that one or the other usually dominates in clays.
Abstract: The consolidation characteristics of clays are controlled by mechanical and physico-chemical effects. Although these effects operate simultaneously one-dimensional consolidation tests indicate that one or the other usually dominates. The consolidation characteristics of sands, mica, and kaolinite are mechanically controlled whereas those of smectite are physico-chemically controlled. Illite occupies an intermediate position in that the virgin compression curve seems to be controlled by mechanical variables, whereas the swelling curve is influenced by both effects; the physico-chemical effect is more important when the adsorbed cations are monovalent and the pore water electrolyte concentration is low.
01 Jan 1970
TL;DR: This paper found that measures of Protestant missionary activity in the past are more correlated with schooling variables today than similar measures of Catholic missionary activity, as previous papers have suggested, and that this effect is mainly driven by differences in Catholic areas.
Abstract: Using regional data for about 180 African provinces, we find that measures of Protestant missionary activity in the past are more correlated with schooling variables today than similar measures of Catholic missionary activity, as previous papers have suggested. However, we find that this effect is mainly driven by differences in Catholic areas (i.e., areas in which Catholic missionaries were protected from competition from Protestant missionaries in the past). This is not surprising because most former Catholic colonies had a number of restrictions to the operation of Protestant missionaries that benefited Catholic missionaries. Therefore, our results are consistent with an economic rationale in which different rules created differences in competitive pressures faced by Catholic and Protestant missionaries.
TL;DR: A tentative scheme for n-octane hydroxylation in the Corynebacterium 7E1C system is proposed and it was shown that molecular oxygen is incorporated into the substrate during hydroxYLation.
TL;DR: In this article, it was shown that the conservation of canonical angular momentum requires that all trapped particles drift towards the magnetic axis with velocity ρ(c{c{E}_{\ensuremath{\phi}}}{{B}_{ \ensureMath{\theta}}}$ (${E]_{\enuremath{phi}}$ is the toroidal electric field; ${B}{Enuremath''theta}}$ the poloidal magnetic field).
Abstract: Conservation of canonical angular momentum is shown to require that all trapped particles drift towards the magnetic axis with velocity $\frac{c{E}_{\ensuremath{\phi}}}{{B}_{\ensuremath{\theta}}}$ (${E}_{\ensuremath{\phi}}$ is the toroidal electric field; ${B}_{\ensuremath{\theta}}$ the poloidal magnetic field). This property, plus an amplification process for the number of trapped particles, will explain the relaxation oscillations which occur for $ql3$. In addition, there is experimental evidence that it is an important contribution to the good containment when $qg3$.
TL;DR: Patients with invasive squamous carcinoma of the vulva were studied for the success and safety when inguinal lymphadenectomy is omitted for patients with favorable lesion and increased operative risk.