Publications by authors named "Churchill S"

Purpose: This article describes the planning, implementation, and evaluation of a 2-day conference designed to examine the factors related to the participation of African Americans in cancer clinical trials.

Methods: Pre-conference formative evaluations (e.g.

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Despite intensive study and a number of remarkable discoveries in the last two decades of the 20th century, our understanding of the cultural and biological processes that resulted in the emergence of the Upper Paleolithic and the establishment of modern humans in Interpleniglacial Europe remains far from complete. There is active debate concerning the timing and location of the origins of the Aurignacian, the nature of the origins of Initial Upper Paleolithic industries (whether by autochthonous development or through acculturation by Aurignacian peoples), the timing of the appearance of early modern humans and the disappearance of the Neandertals, and the relationship of archeologically defined cultures to these different types of hominids. Frustrating our attempts to address these latter two questions is a general paucity of taxonomically diagnostic human fossil material from early Upper Paleolithic contexts.

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The ghost bat, Macroderma gigas, and the orange leaf-nosed bat, Rhinonycteris aurantius, occupy similar ranges across northern Australia and are often found in the same roost caves. Both species are considered rare and vulnerable to further population decline. A third small species, the large bent-wing bat, Miniopterus schreibersii, has a similar body mass to R.

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For non-hyperbaric purposes, the Baxter Flo-Gard 6201 volumetric pump is capable of infusing multiple types of fluids at rates of 1-1,999 ml x h(-1). We designed a study to determine flow accuracy of this pump at variable rates, fluid viscosities, and volumes over a range of chamber pressures. For hyperbaric use, the pump pressure sensor was adjusted.

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Implicit in much of the discussion of the cultural and population biological dynamics of modern human origins in Europe is the assumption that the Aurignacian, from its very start, was made by fully modern humans. The veracity of this assumption has been challenged in recent years by the association of Neandertal skeletal remains with a possibly Aurignacian assemblage at Vindija Cave (Croatia) and the association of Neandertals with distinctly Upper Paleolithic (but non-Aurignacian) assemblages at Arcy-sur-Cure and St. C¿esaire (France).

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This study examined the influence that residential dislocations have on child behavior problems, depression, peer competence, cognitive competence, and the quality of sibling relations in a sample of 70 Head Start children, aged 32 to 67 months, and their older brothers and sisters, aged 48 to 155 months. This was the first study to investigate the sibling relationship in the context of high residential mobility. Information on child characteristics was obtained from mothers and teachers.

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Mycobacterium sp. strain CH1 was isolated from polycyclic aromatic hydrocarbon (PAH)-contaminated freshwater sediments and identified by analysis of 16S rDNA sequences. Strain CH1 was capable of mineralizing three- and four-ring PAHs including phenanthrene, pyrene, and fluoranthene.

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The initial Upper Paleolithic (Châtelperronian) of western Europe was associated with late European Neandertals, best known through the Saint-Césaire 1 partial skeleton. Biomechanical cross-sectional analysis of the Saint-Césaire 1 femoral diaphysis at the subtrochanteric and midshaft levels, given the plasticity of mammalian diaphyseal cortical bone, provides insights into the habitual levels and patterns of loading on the lower limbs from body mass, proportions, and locomotion. The overall robustnesses of the femoral diaphyses of European Neandertals and early modern humans are similar once contrasts in body proportions are incorporated into the body size scaling.

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Modern humans possess a distinct and well-developed flexor pollicis longus muscle, an extrinsic thumb flexor which is "either rudimentary or absent" in great apes (Straus, 1942, p. 228). Previous workers (e.

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Seven measurements were taken on 414 Euro-American, Afro-American, and Amerindian palates in an attempt to evaluate differences in dental arcade shape among these three groups. Width measurements across the palate at the first incisor, canine, second premolar, and second molar were taken directly on the dental arcade. The distances along the sagittal plane from the front of the palate to the level of these teeth were calculated from measurements taken between the right central incisor and the canine, second premolar and second molar.

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Evolutionary biologists are largely polarized in their approaches to integrating microevolutionary and macroevolutionary processes. Neo-Darwinians typically seek to identify population-level selective and genetic processes that culminate in macroevolutionary events. Epigeneticists and structuralists, on the other hand, emphasize developmental constraints on the action of natural selection, and highlight the role of epigenetic shifts in producing evolutionary change in morphology.

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The analysis of humeral asymmetry in Recent human skeletal samples and an extant tennis-player sample documents minimal asymmetry in bone length, little asymmetry in distal humeral articular breadth, but pronounced and variable asymmetry in mid- and distal diaphyseal cross-sectional geometric parameters. More specifically, skeletal samples of normal modern Euroamericans, prehistoric and early historic Amerindians, and prehistoric Japanese show moderate (ca. 5-14%) median asymmetry in diaphyseal cross-sectional areas and polar second moments of area, whereas the tennis-player sample, with pronounced unilateral physical activity, exhibits median asymmetries of 28-57% in the same parameters.

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D-beta-Hydroxybutyrate dehydrogenase (BDH), a lipid-requiring enzyme, has been cloned into pUC18, expressed in Escherichia coli, and purified to homogeneity. The apoenzyme, i.e.

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The present study examined the effect of repeated gestation and lactation on the levels of long-chain n-6 polyunsaturated fatty acids in rat milk fat, and examined whether such levels might be modulated by supplementing the diet of the lactating dams with either (g/kg) 50 safflower oil (SFO; containing 800 g 18:2n-6/kg), or 50 evening primrose oil (EPO; containing 720 g 18:2n-6 and 90 g 18:3n-6/kg). The milk was collected at three different times (days 1, 8 and 15) in each given lactation period from female Sprague-Dawley rats which were successively bred for four pregnancies and lactations. Results showed that dietary fat and breeding frequency had no significant effects on milk triacylglycerol content, but they modified the pattern of milk fatty acids in both triacylglycerol and phospholipid fractions.

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The amino acid sequence of D-beta-hydroxybutyrate dehydrogenase (BDH), a phosphatidyl-choline-dependent enzyme, has been determined for the enzyme from rat liver by a combination of nucleotide sequencing of cDNA clones and amino acid sequencing of the purified protein. This represents the first report of the primary structure of this enzyme. The largest clone contained 1435 base pairs and encoded the entire amino acid sequence of mature BDH and the leader peptide of precursor BDH.

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A rat liver bacteriophage lambda expression library was probed using polyclonal antibodies raised to purified rat liver D-beta-hydroxybutyrate dehydrogenase (BDH). A clone was selected that contained a 1.2-kb insert.

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The purpose of this study was to characterize the renal response to central volume expansion using lower body positive pressure (LBPP) in the adult male squirrel monkey (Saimiri sciureus). Urinary excretion of sodium, potassium, and water and plasma aldosterone concentrations were measured during a control day, 7 days of LBPP, and a recovery day. Time control experiments in the same animals included chair sitting without exposure to LBPP.

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The properties of D-beta-hydroxybutyrate dehydrogenase (BDH) from rat liver and brain mitochondria were compared to determine if isozymes of this enzyme exist in these tissues. The BDHs from these tissues behaved similarly during the purification process. The enzymes were indistinguishable by sodium dodecyl sulfate-polyacrylamide or acid-urea-polyacrylamide gel electrophoresis and they had identical isoelectric points.

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Analysis of Neandertal and recent human scapular glenoid fossae reveals that the former had long, narrow, and flat glenoid articular surfaces relative to those of modern humans. Comparison of glenoid length, breadth, and curvature to humeral articular dimensions demonstrates that Neandertal glenoid length and curvature scale to proximal and distal humeral articular dimensions in the same manner as those of modern humans. The remaining contrast is in the relatively greater glenoid fossa width seen in modern humans.

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The activities of ketone-metabolizing enzymes in rat brain increase 3- to 5-fold during the suckling period before decreasing to the adult level after weaning. We have observed that a similar developmental pattern also exists for D-beta-hydroxybutyrate dehydrogenase (BDH) in rat liver. Utilizing antibodies prepared against the purified protein we determined that the changes in BDH activities in both brain and liver are due to changes in the amount of BDH in the mitochondria.

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Quantitation of D-beta-hydroxybutyrate dehydrogenase (BDH) in normal rat hepatocytes was compared with that in two rat hepatoma cell lines, H4-II-EC3 and RLT-3C. BDH activity in normal rat hepatocyte mitochondria was 321 nmol/min/mg, which was greatly reduced to 10.7 nmol/min/mg and 1.

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