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Showing papers by "University of New Mexico published in 1976"


Book ChapterDOI
01 Jan 1976
TL;DR: In this paper, it was concluded that since a definitive metabolic role could not be assigned to alkaloids, they best be considered as plant waste products, and more recent workers in the field of alkaloid biochemistry have concurred with this evaluation44,83 and the "waste product hypothesis" has been expanded to include plant secondary substances in general.
Abstract: Much research has been conducted in an attempt to fit the so-called plant secondary substances into the general framework of plant metabolism. Though some success has been achieved in this area, e.g., chlorogenic acid as a regulator of plant metabolic systems under stress21, most such studies have met with a conspicuous lack of success. Possible metabolic roles for the plant alkaloids as intermediate metabolites have probably received the greatest such attention and it was concluded at an early stage44 that, since a definitive metabolic role could not be assigned to alkaloids, they best be considered as plant waste products. More recent workers in the field of alkaloid biochemistry have concurred with this evaluation44,83 and the “waste product hypothesis” has been expanded, principally by Muller (1969, 1970), to include plant secondary substances in general.

1,176 citations


Book ChapterDOI
TL;DR: This chapter considers the interrelationships between radiation and the various components of the immune response from three perspectives: the effect of irradiation on normal lymphoid tissues and on isolated lymphocytes, the effect on antibody production, transplantation immunity, and other forms of cellular immunity.
Abstract: Publisher Summary This chapter illustrates several ways in which radiation may be employed to dissect several individual cellular components of the immune response. The chapter considers the interrelationships between radiation and the various components of the immune response from three perspectives: (1) the effect of irradiation on normal lymphoid tissues and on isolated lymphocytes, (2) the effect of irradiation on antibody production, transplantation immunity, and other forms of cellular immunity, and (3) the effect of irradiation upon tolerance with specific references to putative autoimmune consequences after radiation-induced alterations in normal immunological homeostasis. A wide variety of approaches are available to characterize and define distinct populations of lymphocytes. These include biophysical and functional methods and characterization of antigenic and cell surface receptor components. The mechanisms of radiation effects in biological systems, particularly in humans, have been derived from experiments utilizing cells exposed in vitro and maintained in tissue culture. Such cells can be examined for: (1) loss of viability, (2) alterations in biophysical structure, (3) loss of functional capabilities, (4) biochemical changes, and (5) evidence of injury to subcellular components.

408 citations


Journal ArticleDOI
TL;DR: This paper is concerned with the problem of obtaining the optimal linear vector coding (transformation) method that matches an r -dimensional vector signal and a k -dimensional channel under a given channel power constraint and mean-squared-error criterion.
Abstract: This paper is concerned with the problem of obtaining the optimal linear vector coding (transformation) method that matches an r -dimensional vector signal and a k -dimensional channel under a given channel power constraint and mean-squared-error criterion. The encoder converts the r correlated random variables into r independent random variables and selects at most k independent random variables which correspond to the k largest eigenvaiues of the signal covariance matrix Q . The encoder reinserts cross correlation into the k random variables in such a way that the largest eigenvalue of Q is assigned to the smallest eigenvalue of the channel noise covariance matrix R and the second largest eigenvalue of Q to the second smallest eigenvalue of R , etc. When only the total power for all k channels is prescribed, the optimal individual channel power assignments are obtained in terms of the total power, the eigenvalues of Q , and the eigenvalues of R . When the individual channel power limits are constrained by P_{1}, ..., P_{k} and R is a diagonal matrix, the necessary conditions of an inverse eigenvalue problem must be satisfied to optimize the vector signal transmission system. An iterative numerical method has been developed for the case of correlated channel noise.

245 citations


Journal ArticleDOI
TL;DR: Several new in vitro techniques for isolation, preservation, and permeability determination of these membranous tissues are described, agreeing well with published results on water permeabilities of human epidermis and dermis.

219 citations


Journal ArticleDOI
TL;DR: In this paper, a bidding game was applied to estimate aesthetic damages from possible construction of the Kaiparowits power plant near Lake Powell, and three problems associated with the interpretation of bidding games were explored theoretically and empirically: (1) incentives for biased responses, (2) divergences between compensating and equivalent variation and (3) problems of interpersonal comparison in the aggregation of individual bids.

214 citations


Journal ArticleDOI
17 Dec 1976-Science
TL;DR: Elemental analyses of fines in the Martian regolith at two widely separated landing sites, Chryse Planitia and Utopia Planitia, produced remarkably similar results.
Abstract: Elemental analyses of fines in the Martian regolith at two widely separated landing sites, Chryse Planitia and Utopia Planitia, produced remarkably similar results. At both sites, the uppermost regolith contains abundant Si and Fe, with significant concentrations of Mg, Al, S, Ca, and Ti. The S concentration is one to two orders of magnitude higher, and K(<0.25 percent by weight) is at least 5 times lower than the average for the earth's crust. The trace elements Sr, Y, and possibly Zr, have been detected at concentrations near or below 100 parts per million. Pebblesized fragments sampled at Chryse contain more S than the bulk fines, and are thought to be pieces of a sulfate-cemented duricrust.

206 citations


Journal ArticleDOI
TL;DR: The forest floor is a major reservoir of organic matter and nutrients for the ecosystem and as such it influences or regulates most of the functional processes occurring throughout the ecosystem.
Abstract: The forest floor is a major reservoir of organic matter and nutrients for the ecosystem and as such it influences or regulates most of the functional processes occurring throughout the ecosystem. This study reports on the nutrient and organic matter content of the forest floor of the Hubbard Brook Experimental Forest during different seasons and attempts to correlate results from studies of vegetation, litter, decomposition, stemflow, throughfall, and soil. An organic matter budget is presented for an undisturbed watershed. Average weight of the forest floor on an undisturbed watershed ranged from 25,500 to 85,500 kg/ha. The weighted watershed average was 46,800 kg/ha. Although the F and H horizons did not vary significantly with time, the L horizon increased significantly during the period June to August largely as a result of a severe hail storm. The order of abundance of elements in the forest floor was Nτ;Ca≷Fe>S>P>Mn>K>Mg>Na>Zn>Cu. The concentrations of Ca, K, and Mn decreased with depth in the forest floor while N, P, S, Na, Fe, Zn, and Cu concentrations increased. N:P ratios were similar in decomposing leaf tissue, the forest floor, litterfall, and net stemflow plus throughfall suggesting a similar pattern of cycling. S was proportional to N and P in decomposing leaf tissue, the forest floor, and litterfall. Net stemflow and throughfall were affected by a relatively large input of SO4=-S from the atmosphere. Residence times for elements in the forest floor were affected by inputs other than litterfall (precipitation, stemflow, and throughfall). Calculation of residence times using all inputs caused smaller values than if litterfall alone was used. While all residence times were reduced, the major differences occurred for K, S, and Na. N and P showed relatively long residence times as a result of retranslocation and immobilization by decomposers. The slow turnover rate because of the strong demand and retention by all biota must account for the efficiency of the intrasystem cycling process for N and P. K showed the shortest residence time. A rapid and efficient uptake of K by vegetation seems to account for the efficient cycling of this element. The patterns of nutrient cycling are several depending on the chemical properties of the forest floor, and nutritional requirements of the biota.

190 citations


Journal ArticleDOI
TL;DR: To remove connective tissue elements from human skin and both kidney, and an autonomic ganglion of the rat with hydrochloric acid and collagenase, the HCl‐collagenase method has the advantage of the removal of collagen and basement membrane while preserving the structural integrity of the cell surface.
Abstract: The application of scanning electron microscopy to the study of cell surfaces is limited in intact tissues, because extracellular material may often obscure the details of nonluminal surfaces. To remove connective tissue elements we have treated human skin and both kidney, and an autonomic ganglion of the rat with hydrochloric acid and collagenase. Regional variations in the basal surface of the nephron are noted following removal of the basement membrane. The basilar interdigitations of the cells of the proximal tubule appeared as parallel ridges encircling the tubule. Ridges on the parietal epithelium of Bowman's capsule were randomly arranged and alternated with smooth surfaces. The dermal surface of the human epidermis has an alveolar or honeycomb appearance due to the elevation of the epidermal ridges and numerous pits for the dermal pegs. At higher magnifications the basal surface of cells of the stratum germinativum possessed numerous and irregular projections. Neurons with their processes are evident in the autonomic ganglion. The soma of the neurons are enclosed by flattened satellite cells. Irregular spaces between opposed satellite cells are interpreted as regions for the passage of processes related to the ganglion cells. Nodes of Ranvier were clearly seen along nerve fibers. Some pitting of the nerve fibers was also noted. The HCl-collagenase method has the advantage of the removal of collagen and basement membrane while preserving the structural integrity of the cell surface.

180 citations


Journal ArticleDOI
TL;DR: In this paper, a cybernetic model of factors involved in the fossilization of grammatical and lexical forms in learner grammars is offered, and a distinction between affective and cognitive dimensions of a multidimensional channel of human communication is made between expected and unexpected feedback.
Abstract: A cybernetic model of factors involved in the fossilization of grammatical and lexical forms in learner grammars is offered. A distinction is made between affective and cognitive dimensions of a multidimensional channel of human communication. A distinction is also made between expected and unexpected feedback. It is argued that expected negative feedback on the cognitive dimension of language usage is the principal de-stabilizing factor in the development of learner grammars. When the configuration of feedback to the learner becomes predominantly expected positive feedback on the cognitive dimension it is predicted that the learner's level of proficiency will tend to fossilize. Thus, the tendency toward fossilization of either correct or incorrect forms is governed by feedback principally on the cognitive dimension. However, if feedback on the affective dimension is not predominantly as expected, and predominantly positive, the feedback on the cognitive dimension will lose much of its force. Predominantly negative affective feedback whether expected or unexpected is likely to result in abortion of further communication attempts.

176 citations


Journal ArticleDOI
17 Sep 1976-Science
TL;DR: The H-Y (male) antigen is expressed on 50 percent of eight-cell embryos (2 days old) of the mouse, strain C57BL/6, providing additional evidence that H-y expression is not dependent on male differentiation.
Abstract: The H-Y (male) antigen is expressed on 50 percent of eight-cell embryos (2 days old) of the mouse, strain C57BL/6. This work provides additional evidence that H-Y expression is not dependent on male differentiation.

176 citations


Journal ArticleDOI
TL;DR: The epidemiologic or statistical foundation of most clinical studies of alcohol and infection has generally been weak or lacking and the mere enumeration of alcoholics present among patients with a specific infection has often been taken as sufficient evidence to establish a relationship.

Journal ArticleDOI
17 Dec 1976-Science
TL;DR: The mafic nature of the present martian fines (distributed globally) and their probable source rocks seems to preclude large-scale planetary differentiation of a terrestrial nature as discussed by the authors, and a mineralogic model, derived from computer mixing studies and laboratory analog preparations, suggests that Mars fines could be an intimate mixture of about 80 percent iron-rich clay, about 10 percent magnesium sulfate (kieserite?), about 5 percent carbonate (calcite), and about five percent iron oxides (hematite, magnetite, maghemite, goethite?).
Abstract: Chemical results from four samples of martian fines delivered to Viking landers 1 and 2 are remarkably similar in that they all have high iron; moderate magnesium, calcium, and sulfur; low aluminum; and apparently very low alkalies and trace elements. This composition is best interpreted as representing the weathering products of mafic igneous rocks. A mineralogic model, derived from computer mixing studies and laboratory analog preparations, suggests that Mars fines could be an intimate mixture of about 80 percent iron-rich clay, about 10 percent magnesium sulfate (kieserite?), about 5 percent carbonate (calcite), and about 5 percent iron oxides (hematite, magnetite, maghemite, goethite?). The mafic nature of the present fines (distributed globally) and their probable source rocks seems to preclude large-scale planetary differentiation of a terrestrial nature.

Journal ArticleDOI
TL;DR: The data suggest that the 1‐demethylation of theophylline to 3‐methylxanthine is the dominant reaction determining serum theophylla, and the former may give rise to the latter by a rate‐limiting demethylation reaction.
Abstract: Using high‐pressure liquid chromatography, we have quantitated the theophylline metabolites in the 24‐hr urines of 15 patients in a clinical ward who had been receiving 800 or 1,200 mg of aminophylline /24 hr in divided oral doses. Mean values for the theophylline‐derived urine products were as follows: unchanged theophylline, 7.7 ± 6.1%; 3‐methylxanthine, 36.2 ± 7.3%; 1,3‐dimethyluric acid, 39.6 ± 4.5%; and 1‐methyluric acid, 16.5 ± 3.3%. These data are consistent with those earlier reported for theophylline metabolism in man with other methodology. The fractional contents of urine products were variably related to trough serum theophylline levels, the latter determined by the Schack and Waxler method. There was a significant direct correlation between serum theophylline levels and the urine theophylline fraction, and a significant inverse correlation between serum theophylline and the urine 3‐methylxanthine fraction. Urinary 3‐methylxanthine and 1,3‐dimethyluric acid were inversely related, implicating competition for substrate. The urine content of 1,3‐dimethyluric acid and 1‐methyluric acid diverged as serum theophylline increased, suggesting that the former may give rise to the latter by a rate‐limiting demethylation reaction. The data suggest that the 1‐demethylation of theophylline to 3‐methylxanthine is the dominant reaction determining serum theophylline.

Journal ArticleDOI
TL;DR: The topography of the ectoderm was examined by scanning electron microscopy during neurulation in hamster and mouse embryos to reflect changes in the membrane properties of the altered cells which are correlated with both neural crest formation and initial adhesion between the folds.
Abstract: The topography of the ectoderm was examined by scanning electron microscopy during neurulation in hamster and mouse embryos. Stages from the appearance of the neural folds to closure of the posterior neuropore were studied. Progressive development of a zone of altered cellular morphology was observed along the crests of the neural folds. This zone evolved from and abrupt transition between surface and neural regions of the ectoderm to a narrow band of flattened cells which exhibited numerous membranous “ruffles” in the mouse, or blebs and presumably degenerating cells in the hamster, immediately prior to contact between the folds. These alterations were more prominent along the anterior than the posterior portions of the folds. Contact of the folds occurred first between the flattened cells with subsequent union of the surface cells. Stages of neural crest cell formation were observed subjacent to the zone of alterations in histological sections. It is suggested that the observed surface alterations may reflect changes in the membrane properties of the altered cells which are correlated with both neural crest formation and initial adhesion between the folds.

Journal ArticleDOI
TL;DR: In this article, the convergence rate of interpolatory tension splines with variable tension was shown to be O( h 4 ) for uniformly bounded tension parameters, where h 4 is the number of points in the spline.

Journal ArticleDOI
TL;DR: Kenna ureilite as discussed by the authors is a typical UREILite with the requisite mineralogical and chemical properties of the group, including a greater density, the occurrence of exceedingly minute quantities of feldspar, and a very strong elongation lineation of the silicate minerals.

Journal ArticleDOI
TL;DR: The Plainview meteorite as discussed by the authors is a polymict-brecciated H-group chondrite composed of recrystallized light-colored portions embedded in a well-compacted, dense, somewhat recystallized, dark-colored matrix.

Journal ArticleDOI
TL;DR: Synovial tissues from 5 patients with rheumatoid arthritis (RA) were examined with immunofluorescence microscopy for the presence of lymphocytes with either bone marrow-derived (B) or thymus- derived (T) surface markers, and predominantly T lymphocytes were identified as T cells.
Abstract: Synovial tissues from 5 patients with rheumatoid arthritis (RA) were examined with immunofluorescence microscopy for the presence of lymphocytes with either bone marrow-derived (B) or thymus-derived (T) surface markers. Five synovial tissues with severe to mild lymphocytic infiltrations by bright field microscopy were examined in parallel with immunofluorescence. B cells were identified with a pepsin-digested fluoresceinated anti-F (ab')2 antiserum and T cells were detected with a specific rabbit anti-T lymphocyte antiserum. By these techniques 75-90% of the lymphocytes in these frozen sections were identified as T cells. Cell suspensions were also prepared by collagenase digestion of two of the five synovial tissues. The lymphocytes in these cell suspensions were predominantly T lymphocytes (78-85%) as shown by their ability to form spontaneous rosettes with sheep erythrocytes (E rosettes).

Journal ArticleDOI
08 Oct 1976-Science
TL;DR: The hypothesis that pesticides have contributed to recent declines in populations of this bat is supported.
Abstract: Organochlorine residues in the fat of young Mexican free-tailed bats, Tadarida brasiliensis, reached the brain and caused symptoms of poisoning after the fat mobilization that takes place during migratory flight was simulated. These chemical body burdens were obtained naturally under free-living conditions at the maternity roost. The data obtained support the hypothesis that pesticides have contributed to recent declines in populations of this bat.

Journal ArticleDOI
TL;DR: The [14C]galactose test is simpler than the standard intravenous galactose tolerance test, and, like the latter, appears superior to some other tests for recognition of cirrhosis.

Journal ArticleDOI
TL;DR: The generating function of R. P. Stanley for reverse plane partitions on a tableau shape is obtained by a direct method that clearly shows the combinatorial significance of the hook numbers for the shape.

Journal ArticleDOI
TL;DR: In this article, the authors compare Adams' (1965) ratio definition and Walster et al.'s (1970, 1972, 1973) formula with respect to the fundamental criterion that, when equity holds, outcome should be an increasing function of input.

Journal ArticleDOI
TL;DR: Analysis of genetic variation and covariation at nine polymorphic loci in a large random sample of rural Finns, partitioned into either 8 countries or 27 geographic districts, showed that all of the essential features of the genetic structure suggested by the archaeological and historical data could be distinguished.
Abstract: The Finnish gene pool derives primarily from a relatively homogeneous Finno-Ugric population established during the Iron Age (100 B.C.-800 A.D.) in the southwest and southeast of Finland. Gene flow from Sweden to the southwest coastal areas, dating from prehistoric times, as well as the patterns of settlement and migration throughout Finland during the past 1000 years, appear to have been the major biosocial factors underlying the genetic structure of the contemporary population. Analysis of genetic variation and covariation at nine polymorphic loci in a large random sample of rural Finns, partitioned into either 8 countries or 27 geographic districts, showed that all of the essential features of the genetic structure suggested by the archaeological and historical data could be distinguished. Procedures for obtaining inference on the genetic structure of such a population are reviewed, including coefficients of similarity and (genetic) distance among subpopulations, the relation between linear or planar geographic structure and genetic covariation, and the methods for describing allelic differentiation. Bias resulting from the inappropriate assumption of a simple phylogenetic model can be substantial, expecially for the analysis of isolation by distance; procedures for avoiding misleading inference on the genetic structure are demonstrated.

Journal ArticleDOI
TL;DR: The presence of subcellular structures that distinguish the inductively active apical ectoderm from adjacent dorsal and ventral ectoderms is reported, including bundles of microfilaments that are oriented in the dorsal-ventral plane in the basal cytoplasm of the cells.

Journal ArticleDOI
TL;DR: Results indicate that when in allopatry, M. evotis and M. auriculus have similar food habits, and competition for food is avoided by changes in food preferences of M.evotis .
Abstract: Two extremely similar insectivorous bats, Myotis evotis and M. auriculas , differ in food preferences when sympatric (Black, 1974). Myotis auriculus preys generally upon moths and some beetles, whereas M. evotis specializes on beetles. Does this specialization of M. evotis persist in allopatry, indicating that it has evolved as a food specialist, or in the absence of its close competitor, does it eat both moths and beetles without a strong preference? What sort of effect, if any, does M. evotis exert on the diet of M. auriculus in areas of sympatry? Both species were captured in areas of allopatry during the summer of 1972. Fecal samples were collected and analyzed using Black's (1974) technique. My results indicate that when in allopatry, M. evotis and M. auriculus have similar food habits. Thus, in sympatry, competition for food is avoided by changes in food preferences of M. evotis . Furthermore, each species exhibits sexual differences in foods taken in areas of allopatry, indicating that intraspecific niche subdivision occurs in each of these bats only in the absence of the potential competitor.

Journal ArticleDOI
TL;DR: The data support the safety of thiothixene therapy for geriatric patients; however, there is no conclusive evidence of its efficacy in the treatment of chronic organic brain syndrome.
Abstract: Thiothixene was used in a four-week double-blind placebo-controlled study of 42 geriatric patients with chronic organic brain syndrome (psychotic or nonpsychotic). The results, according to several rating measures, showed no significant difference between placebo and thiothixene. Side effects were mild and few. These data support the safety of thiothixene therapy for geriatric patients; however, there is no conclusive evidence of its efficacy in the treatment of chronic organic brain syndrome.


Journal ArticleDOI
TL;DR: An interesting and unexpected finding was a statistically significantly lower incidence of drinking at the time of commission of the offense in male-child molesters compared with female-childmolesters.
Abstract: This study shows a high association among drinking, alcoholism, and child molestation. Forty-nine percent of the child molesters were drinking at the time of commission of the offense, and 34% were drinking heavily, defined as 10 or more beers or the equivalent. The alcoholism rate for the group was 52% based on the MAST or 33% based on the more stringent Pokorny shortened version of it. An interesting and unexpected finding was a statistically significantly lower incidence of drinking at the time of commission of the offense in male-child molesters compared with female-child molesters. In addition, the male-child molesters had a definitely lower alcoholism rate compared with female-child molesters. The importance of these findings for treatment programs is emphasized.

Journal ArticleDOI
TL;DR: In this article, laser-melted magnesium silicate droplets were supercooled 400-750 C below their equilibrium liquidus temperatures before crystallization and their texture was compared with that of meteoritic and lunar chondrules.

Journal ArticleDOI
01 Oct 1976-Science
TL;DR: Iron, calcium, aluminum, silicon, and sulfur are major elements in the first surface sample of Mars that has been analyzed by the Viking x-ray fluorescence spectrometer, and preliminary determinations indicate the following abundances.
Abstract: Iron, calcium, aluminum, silicon, and sulfur are major elements in the first surface sample of Mars that has been analyzed by the Viking X-ray fluorescence spectrometer. Titanium is present in minor quantities. This is consistent with the sample's being a mixture of fine silicate and oxide mineral grains, with a significant proportion of sulfates, possibly hydrated. Ferric oxide is regarded as the red pigmenting agent on the Martian surface, but if it coats silicate grains, the coatings must be very thin or discontinuous. A high abundance of Fe, relatively low abundances of Al, Rb, Sr, and Zr, and a high Ca/K ratio are distinctive features of the spectra. Preliminary determinations indicate the following abundances (as percentages by weight): Fe, 14 plus or minus 2; Ti, less than 1; S, 2 to 5; the Ca/K ratio by weight is greater than 5.