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Showing papers by "Louisiana State University published in 1980"


Journal ArticleDOI
TL;DR: The parameter concept in the term least squares mean is defined and given the more meaningful name population marginal mean; and its estimation is discussed in this article, where the estimation of its estimation was discussed.
Abstract: The parameter concept in the term least squares mean is defined and given the more meaningful name population marginal mean; and its estimation is discussed.

1,143 citations


Journal ArticleDOI
TL;DR: The results obtained indicate that the SGLDM is the most powerful algorithm of the four considered, and that the GLDM is more powerful than the PSM.
Abstract: An evaluation of the ability of four texture analysis algorithms to perform automatic texture discrimination will be described. The algorithms which will be examined are the spatial gray level dependence method (SGLDM), the gray level run length method (GLRLM), the gray level difference method (GLDM), and the power spectral method (PSM). The evaluation procedure employed does not depend on the set of features used with each algorithm or the pattern recognition scheme. Rather, what is examined is the amount of texturecontext information contained in the spatial gray level dependence matrices, the gray level run length matrices, the gray level difference density functions, and the power spectrum. The comparison will be performed in two steps. First, only Markov generated textures will be considered. The Markov textures employed are similar to the ones used by perceptual psychologist B. Julesz in his investigations of human texture perception. These Markov textures provide a convenient mechanism for generating certain example texture pairs which are important in the analysis process. In the second part of the analysis the results obtained by considering only Markov textures will be extended to all textures which can be represented by translation stationary random fields of order two. This generalization clearly includes a much broader class of textures than Markovian ones. The results obtained indicate that the SGLDM is the most powerful algorithm of the four considered, and that the GLDM is more powerful than the PSM.

957 citations


Journal ArticleDOI
12 Dec 1980-Science
TL;DR: There is a strong relation between embodied energy and dollar value for a 92-sector U.S. economy if the energy required to produce labor and government services is included.
Abstract: Input-output analysis has been adapted to calculate the total (direct plus indirect) energy required to produce goods and services in the U.S. economy; this quantity has been termed the embodied energy. Usually, the energy required to produce labor and government services and the solar energy input to the economy are ignored by analysts. The former omission can be traced to the assumption that traditional primary factors of economic production-land, labor, and capital-are independent. A strong case can be made that these input factors are not independent and that energy is required for their production. Embodied energies can be calculated in this case by using input-output data. The results of such an analysis show that there is a strong relation between embodied energy and dollar value for a 92-sector U.S. economy if the energy required to produce labor and government services is included.

620 citations


Journal ArticleDOI
15 Oct 1980-Cancer
TL;DR: This paper represents the first description of this form of dysplasia in non‐familial melanoma and suggests that these patients represent a distinctive syndrome, the Dysplastic Nevus Syndrome (DNS), and that they are at increased risk for development of primary cutaneous malignant melanoma.
Abstract: Clinical photographs of 79 prospectively studied cases of non-familial cutaneous malignant melanoma were reviewed; special attention was directed to the distribution pattern of coexistent melanocytic lesions. A group of 15 patients had moles on the covered buttock area. Seven of these patients had large clinically atypical nevi, and biopsies of these nevi showed severe melanocytic dysplasia. Residual elements of melanocytic dysplasia were identified in five of the primary melanomas in this group of patients. It is suggested that these patients represent a distinctive syndrome, the Dysplastic Nevus Syndrome (DNS) and that they are at increased risk for development of primary cutaneous malignant melanoma. The clinically and histologically distinctive dysplastic nevi of these patients are identical to the precursor lesion for melanoma that we have previously described in a familial context, the B-K mole syndrome. This paper represents the first description of this form of dysplasia in non-familial melanoma.

403 citations


Journal ArticleDOI
01 Apr 1980-Nature
TL;DR: In this paper, interior laminated conical mounds characterise a regionally extensive chert unit near the top of the 3,400-myr old Warrawoona Group in the Pilbara Block of Western Australia.
Abstract: Internally laminated conical mounds characterise a regionally extensive chert unit near the top of the 3,400-Myr old Warrawoona Group in the Pilbara Block of Western Australia The chert formed by silicification of a carbonate–evaporite sequence deposited in shallow subtidal to intertidal environments The morphology and internal organisation of the mounds described here suggests that they are conical stromatolites similar but not identical to members of the common Proterozoic group Conophyton Maslov

263 citations


Journal ArticleDOI
TL;DR: In this paper, an infant-modulated 3-compartment open model is proposed for drug distribution and elimination in the breast feeding woman and the concentration ratios of drugs in milk/plasma drug concentration ratios are projected on the basis of pH partitioning.
Abstract: The excretion of drugs in human breast milk is reviewed with regard to milk production, composition, feeding patterns and mechanisms of drug transfer into milk. Fundamental principles of breast milk excretion are used to construct a pharmacokinetic approach useful for the study of most drugs. An infant-modulated 3-compartment open model is proposed for drug distribution and elimination in the breast feeding woman. Milk/plasma drug concentration ratios are projected on the basis of pH partitioning. While some studies confirm these projections, other studies demonstrate a need to consider additional factors such as lipid solubility and protein binding characteristics of a drug in milk.

262 citations


Journal ArticleDOI
TL;DR: The higher blood pressures and higher prevalence of hypertension in blacks does not appear to be a function of a greater dietary sodium intake in blacks, but an increased susceptibility to the hypertensinogenic effects of sodium in blacks remains a possibility.

212 citations


Journal ArticleDOI
TL;DR: Sediment pH and oxidation-reduction potential were important factors in governing the population of hydrocarbon-degrading microorganisms in the sediment and subsequent mineralization rates.
Abstract: Microbial mineralization rates of two petroleum hydrocarbons, as affected by pH and oxidation-reduction potential, were determined in a Barataria Bay, Louisiana, sediment using 14C-labeled hydrocarbons. Hydrocarbon mineralization rates were inferred from the activity of respired 14CO2. Sediment pH and oxidation-reduction potential were important factors in governing the population of hydrocarbon-degrading microorganisms in the sediment and subsequent mineralization rates. Highest mineralization rates occurred at pH 8.0, and the lowest occurred at pH 5.0. At all pH levels mineralization decreased with decreasing oxidation-reduction potential (i.e., increasing sediment anaerobiosis). Generally, mineralization rates for octadecane were greater than those for naphthalene. Aerobic microorganisms in the oxidized sediment were more capable of degrading hydrocarbons than anaerobic microorganisms in reduced sediment of the same pH.

208 citations


Journal ArticleDOI
TL;DR: These studies show that adult ventricular cardiac muscle cells when placed in culture dedifferentiate and lose their highly organized morphology and then redifferentiate into spontaneously contracting myocytes with reorganized myofibrils.

181 citations


Journal ArticleDOI
TL;DR: The utility and documentation of traits and characteristics of Zebu, Bos indicus, cattle in beef production in the United States are discussed with reference to adaptation.
Abstract: The utility and documentation of traits and characteristics of Zebu, Bos indicus, cattle in beef production in the United States are discussed with reference to adaptation. Zebu cattle are uniquely suited to hot climates due to coat, hide, skin and hematological attributes. Form, growth and physiological aspects are unique genetic attributes which are different from those of Bos taurus cattle. Compared with Bos taurus cattle, Zebu cattle are lower in reproduction, later maturing, slower growing and lower in beef quality. Zebu cattle are valuable in crossbreeding, with adaptive aspects transmitted and large amounts of heterosis in growth, maternal effects and reproductive traits.

173 citations


Journal ArticleDOI
TL;DR: Dialyzed rat liver cytosol, when added along with 2.5 mM glutathione, blocked malonaldehyde formation in the NADPH-microsomal lipid peroxidation system, thus protecting against lipidperoxidation.

Journal ArticleDOI
TL;DR: Modifications of Barraquer's keratomileusis procedure using preserved, preground corneas may have definite indications for certain types of aphakia, such as monocular aphakia in children and in individuals who would otherwise require secondary implants.


Journal ArticleDOI
TL;DR: It is concluded that the neurons of the trunk ganglia are purely placodal in origin and are composed of a population of cells of the large‐cell type.
Abstract: By using the method of quail-to-chick transplantation of neural crest in one series (VNG) and placodal ectoderm in a second series (VPG) we were able to determine the relative contribution of cranial neural crest and placodal ectoderm to the formation of the Glossopharyngeal-vagal complex. In chimeric embryos, quail cells originating from cranial neural crest grafts of postotic levels end up in the root ganglia, while quail cells originating from placodal ectoderm of postotic levels end up in the trunk ganglia. The results clearly indicate that the caudal levels of the medulla and rostral cervical segments represent the site, and the neural crest the source, for the neurons of the root ganglia. The neurons form a homogenous population of the small-cell type. This clearly rules out any contribution to the root ganglia from placodal ectoderm. On the basis of our experiments, it is also concluded that the neurons of the trunk ganglia are purely placodal in origin and are composed of a population of cells of the large-cell type. Our experiments also provide convincing evidence for a neural crest origin for Schwann cell and ganglionic Satellite cells.


Journal ArticleDOI
TL;DR: A survey of dental students' perceptions of stress indicates that academic factors and faculty relationships with students are the areas that create the most stress.
Abstract: A survey of dental students' perceptions of stress indicates that academic factors and faculty relationships with students are the areas that create the most stress. Differences between the four classes in the ranking of several areas reflect the differences in academic and clinical requirements and experience associated with each class.

Journal ArticleDOI
17 Jan 1980-Nature
TL;DR: Treatment with dibutyryl cyclic GMP mimics muscle activity, directly inducing synaptic AChE appearance at newly formed nerve–muscle synapses.
Abstract: The appearance of acetylcholinesterase (AChE) at newly formed nerve–muscle synapses depends on synaptic transmission. Synapses form when cultures are grown in the presence of acetylcholine receptor antagonists, but AChE does not accumulate at these synapses. The important component of transmission seems to be muscle activity. Treatment with dibutyryl cyclic GMP mimics muscle activity, directly inducing synaptic AChE appearance.

Journal ArticleDOI
TL;DR: In this paper, the acquisition of motor skills: Information Processing Differences between Children and Adults are discussed. But the authors focus on the early stages of the learning process and do not consider the later stages.
Abstract: (1980). Acquisition of Motor Skills: Information Processing Differences between Children and Adults. Research Quarterly for Exercise and Sport: Vol. 51, No. 1, pp. 158-173.

Journal ArticleDOI
TL;DR: In this article, Nitrogen and phosphorus content ofSpartina alterniflora Loisel and soil nitrogen were measured along a transect perpendicular to a stream in a Louisiana salt marsh in order to provide information on differences between the so-called streamside and inland regions.
Abstract: Nitrogen and phosphorus content ofSpartina alterniflora Loisel and soil nitrogen were measured along a transect perpendicular to a stream in a Louisiana salt marsh in order to provide information on differences between the so-called streamside and inland regions. Total plant nitrogen and phosphorus levels in June and September tended to be greater at streamside than inland sites. Total soil nitrogen on a dry soil weight basis increased with distance inland from a natural stream toward an interdistributary basin in the marsh. Soil extractable ammonium-nitrogen levels measured in June were very low in vegetated streamside and inland areas, but they were much higher in inland areas devoid of plants. Nitrogen and phosphorus utilization byS. alterniflora was also investigated at an inland location in the salt marsh. Labelled ammonium-nitrogen and phosphate-phosphorus were added in May at a rate of 200 kg/ha to the soil of replicated plots. Added nitrogen significantly increased total above-ground plant biomass and plant height by 28 and 25%, respectively, 4 months after application. The ratio of belowground macro-organic matter to total aboveground biomass was decreased from 5.7 to 4.7 by the additional nitrogen. Added phosphorus did not significantly affect plant height and biomass. The use of15N-depleted nitrogen tracers showed that about half of the nitrogen in the aboveground portion ofS. alterniflora from 1 to 4 months after the nitrogen addition was derived from the added ammonium-nitrogen. After 4 months, 28 and 29% of the added labelled nitrogen was recovered in the aboverground and belowground biomass ofS. alterniflora, respectively. Recovery of added nitrogen was overestimated with a non-tracer method based on the difference in total nitrogen uptake between nitrogen-amended plots and untreated plots. Soil organic nitrogen comprised the majority of the nitrogen in the salt marsh. Nitrogen in the standing crop biomass ofS. alterniflora represented only about 2% of the total nitrogen in the plantsoil system of an inland marsh to a 20 cm soil depth.

Journal ArticleDOI
TL;DR: It was concluded that within the parameters of this study, small particles of FDBA enhance osteogenesis and particle size is a variable to be considered when comparing the osteogenic potential of freeze-dried bone allografts.
Abstract: This study was carried out to determine if particle size is a factor to be considered in the evaluation of the osteogenic activity of freeze-dried bone allografts (FDBA) and, if so, whether small particles enhance or inhibit osteogenesis. Small particle FDBA (100-300 microns) plus marrow and large particle FDBA (1000-2000 microns) plus marrow were placed in plexiglass diffusion chambers secured to the femurs of six Rhesus monkeys. Control chambers contained either marrow alone or were left empty. Two animals were given injections of oxytetracycline hydrochloride at 5 and 7 weeks to obtain intravital osseous labeling. All chambers were removed after 8 weeks. Ten chambers were evaluated for new bone formation by fluorescent microscopy. The contents of 15 additional chambers were evaluated by single blind technique for presence or absence of bone resorption and ossification. The results indicated that there was significantly more new bone formation associated with small particle FDBA (100-300 microns) plus autogenous marrow than with large particle FDBA (1000-2000 microns) plus autogenous marrow. In addition, small particle FDBA (100-300 microns) plus autogenous marrow tended to display more resorption than large particle FDBA (1000-2000 microns) plus autogenous marrow. It was concluded that within the parameters of this study, small particles of FDBA enhance osteogenesis. This study also demonstrated that particle size is a variable to be considered when comparing the osteogenic potential of freeze-dried bone allografts.

Journal ArticleDOI
TL;DR: The sciatic nerve was injected with regional anesthesia to examine possible toxic effects on peripheral nerve tissue of local anesthetic agents and found it to have no neurotoxic properties.
Abstract: Although regional anesthesia is generally considered to have no neurotoxic properties, significant nerve injury has been reported after its use. The present study was undertaken to examine possible toxic effects on peripheral nerve tissue of local anesthetic agents. We injected the sciatic nerve of

Journal ArticleDOI
TL;DR: To mathematically verify that the features used with the SGLDM can be used to characterize the unit pattern and placement rules of a periodic texture, a mathematical tiling theory model is proposed and allows one to develop the mathematical machinery necessary to prove the result.

Journal ArticleDOI
TL;DR: Biosynthesis of PG's in platelets can be influenced by the availability of precursors, and thus it can be modified by the manipulation of dietary fatty acids.

Journal ArticleDOI
TL;DR: Bacterial antagonism of the gastrointestinal population levels of certain indigenous bacteria, such as E. coli, by other members of the normal bacterial flora appears to be an important defense mechanism confining bacteria to the gastrointestinal tract.
Abstract: Escherichia coli C25 maintained population levels of 109 to 1010 per g of cecum and translocated to 100% of the middle mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli C25. Intragastric inoculation of these mice with the cecal contents from specific-pathogen-free mice reduced the population levels of E. coli C25 to 106 per g of cecum and completely inhibited translocation to the mesenteric lymph nodes. Intragastric inoculation with heat-treated, Formalintreated, or filtered cecal contents did not reduce the population levels of E. coli C25 or reduce the incidence of translocation of E. coli C25 to the mesenteric lymph nodes. Thus, viable bacteria apparently are required in the cecal contents inocula to reduce the population levels and the incidence of translocation of E. coli C25. Treatment with streptomycin plus bacitracin decreased the anaerobic bacterial levels in these gnotobiotic mice, allowing increased population levels of E. coli C25 and increased translocation to the mesenteric lymph nodes. E. coli C25 also translocated to the mesenteric lymph nodes of specific-pathogen-free mice treated with streptomycin and bacitracin before colonization with E. coli C25. The high cecal population levels of E. coli C25 in these antibiotic-decontaminated specific-pathogen-free mice apparently overwhelm any barrier to translocation exerted by the immunologically developed lamina propria of the specific-pathogen-free mice. Inoculation of gnotobiotic mice with a cecal flora also reduced the population levels of an indigenous strain of E. coli with a concomitant inhibition of translocation of the indigenous E. coli to the mesenteric lymph nodes. Thus, bacterial antagonism of the gastrointestinal population levels of certain indigenous bacteria, such as E. coli, by other members of the normal bacterial flora appears to be an important defense mechanism confining bacteria to the gastrointestinal tract.

Journal ArticleDOI
TL;DR: Randomly selected sera from 88 patients with systemic lupus erythematosus were studied for the frequency of antibodies to SS-A, SS-B, RANA, RNP, Sm, Sc-1, and dsDNA, except for an increased incidence of anti-SS-A antibody.
Abstract: Randomly selected sera from 88 patients with systemic lupus erythematosus (SLE) were studied for the frequency of antibodies to SS-A, SS-B, RANA, RNP, Sm, Sc-1, and dsDNA. Results were in agreement with previous reports except for an increased incidence of anti-SS-A antibody (33%). Nine of 14 patients with anti-SS-A antibody on whom serial studies were performed had fluctuating titers. Titer changes often correlated with disease activity and dsDNA antibody levels.

Journal ArticleDOI
TL;DR: The questionnaire demonstrates good internal consistency, test-retest reliability, and external validation with plasma thiocyanate, and for all sex and race groups the percentage of smokers increases with age.

Journal ArticleDOI
TL;DR: The amount of support given environmental protection relative to that given ten other problem areas did not decline between 1973 (immediately prior to the "energy crisis") and 1978 as mentioned in this paper, indicating that environmental protection was still popular.
Abstract: The amount of support given environmental protection relative to that given ten other problem areas did not decline between 1973 (immediately prior to the “energy crisis”) and 1978. Analysis of the...

Journal ArticleDOI
TL;DR: The in vivo inhibition of T. ni juvenile hormone esterases by O -ethyl- S -phenyl phosphoramidothiolate slows the in vivo hydrolysis of juvenile hormone and results in delayed pupation and malformed larvae that resemble larval-pupal intermediates.

Journal ArticleDOI
TL;DR: A number of new cyclometallated compounds of palladium with 2-arylpyridines have been synthesized and characterized as discussed by the authors, and the effect of varying substituents on the aryl nucleus supports the concept that after initial N-complexation, the 2-position of the anisotropic nucleus undergoes electrophilic attack by the palladium atom.

Book ChapterDOI
01 Jan 1980
TL;DR: A total of 21,734 fish from 121 species were taken in 173 collections from July 1976 to March 1979 as mentioned in this paper from the Lagoon National Museum of Natural History of the United States.
Abstract: A total of 21,734 fish from 121 species was taken in 173 collections from July 1976 to March 1979. Seventeen species had a broad distribution and comprised 82% of total numbers. Twelve species (10%) were thought to be permanent residents, 54 (45%) probably used the lagoon as a nursery or feeding ground or both, and 55 (45%) were occasional visitors. Twenty-two percent were herbivores, detritivores, or omnivores, 51% were second order consumers, and 27% were higher consumers. Clustering was used to construct a dendrogram of faunal similarity; it corresponded to major differences in the physical makeup of the lagoon and demarcated southern and northern shore groups of fish. There is an apparent pattern of migration within the lagoon reflecting prevailing currents. The season of maximum juvenile influx from the sea (Aug. to Oct.) was during maximum river flow. Diversity indices (H′, D, J′) reflected changes in numbers of species and individuals during the year, and some were highly correlated with temperature and salinity. Biomass at different sampling stations ranged from 0.95 to 11.3 g wet wt m –2 and H′ ranged from 0.53 to 2.50. Fishery productivity was as high as 12.0 g m –2 year –1 .