Showing papers by "Emory University published in 1990"

Construction and Validation of a Scale to Measure Celebrity Endorsers' Perceived Expertise, Trustworthiness, and Attractiveness

Abstract: The purpose of this study was to develop a scale for measuring celebrity endorsers' perceived expertise, trustworthiness, and attractiveness. Accepted psychometric scale-development procedures were followed which rigorously tested a large pool of items for their reliability and validity. Using two exploratory and two confirmatory samples, the current research developed a 15-item semantic differential scale to measure perceived expertise, trustworthiness, and attractiveness. The scale was validated using respondents' self-reported measures of intention to purchase and perception of quality for the products being tested. The resulting scale demonstrated high reliability and validity.

PVM: a framework for parallel distributed computing

Abstract: The PVM system is a programming environment for the development and execution of large concurrent or parallel applications that consist of many interacting, but relatively independent, components. It is intended to operate on a collection of heterogeneous computing elements interconnected by one or more networks. The participating processors may be scalar machines, multiprocessors, or special-purpose computers, enabling application components to execute on the architecture most appropriate to the algorithm. PVM provides a straightforward and general interface that permits the description of various types of algorithms (and their interactions), while the underlying infrastructure permits the execution of applications on a virtual computing environment that supports multiple parallel computation models. PVM contains facilities for concurrent, sequential, or conditional execution of application components, is portable to a variety of architectures, and supports certain forms of error detection and recovery.

Total absence of colony-stimulating factor 1 in the macrophage-deficient osteopetrotic (op/op) mouse.

Abstract: Osteopetrotic (op/op) mutant mice suffer from congenital osteopetrosis due to a severe deficiency of osteoclasts. Furthermore, the total number of mononuclear phagocytes is extremely low in affected mice. Serum, 11 tissues, and different cell and organ conditioned media from op/op mice were shown to be devoid of biologically active colony-stimulating factor 1 (CSF-1), whereas all of these preparations from littermate control +/+ and +/op mice contained the growth factor. The deficiency was specific for CSF-1 in that serum or conditioned media from op/op mice possessed elevated levels of at least three other macrophage growth factors. Partial correction of the op/op defect was observed following intraperitoneal implantation of diffusion chambers containing L929 cells, which in culture produce CSF-1 as their sole macrophage growth factor. No rearrangement of the CSF-1 gene in op/op mice was detected by Southern analysis. However, in contrast to control lung fibroblasts, which contained 4.6- and 2.3-kilobase CSF-1 mRNAs, only the 4.6-kilobase species was detected in op/op cells. An alteration in the CSF-1 gene is strongly implicated as the primary defect in op/op mice because they do not contain detectable CSF-1, their defect is correctable by administration of CSF-1, the op locus and the CSF-1 gene map within the same region of mouse chromosome 3, their CSF-1 mRNA biosynthesis is altered, and the op/op phenotype is consistent with the phenotype expected in a CSF-1 deficient mouse.

Intermittent cyclical etidronate treatment of postmenopausal osteoporosis.

Abstract: Background. To determine the effects of etidronate (a bisphosphonate that inhibits osteoclast-mediated bone resorption) in the treatment of postmenopausal osteoporosis, we conducted a prospective, two-year, double-blind, placebo-controlled, multicenter study in 429 women who had one to four vertebral compression fractures plus radiographic evidence of osteopenia. Methods. The patients were randomly assigned to treatment with phosphate (1.0 g) or placebo twice daily on days 1 through 3, etidronate (400 mg) or placebo daily on days 4 through 17, and supplemental calcium (500 mg) daily on days 18 through 91 (group 1, placebo and placebo; group 2, phosphate and placebo; group 3, placebo and etidronate; and group 4, phosphate and etidronate). The treatment cycles were repeated eight times. The bone density of the spine was measured by dual-photon absorptiometry, and the rates of new vertebral fractures were determined from sequential radiographs. Results. After two years, the patients receiving etidro...

Clinical Methods: The History, Physical and Laboratory Examinations

Abstract: Cardiovascular system pulmonary system neurological system autonomic nervous system gastrointestinal system skin and appendages eye ear nose, mouth and throat endocrine system haematopoietic system musculoskelatal system female genitalia general.

Wound healing after excimer laser keratomileusis (photorefractive keratectomy) in monkeys.

Abstract: Laser myopic keratomileusis (photorefractive keratectomy) was performed on 29 rhesus monkey corneas with an argon fluoride (193-nm) excimer laser and a computer-controlled, moving slit delivery system. The 4-mm-diameter central ablation zone ranged in depth from 11 microns (-2 diopters effect) to 46 microns (-8 diopters effect). Corneas were studied for the 9 months postoperatively by clinical slit-lamp microscopy, and periodically with light and transmission electron microscopy. By 6 weeks, mild to moderate subepithelial haze was apparent in 93% of the corneas, with considerable variability in density. Progressive clearing occurred so that by 6 to 9 months 12 of 13 surviving corneas (92%) were either completely clear (4 corneas) or trace hazy (8 corneas). The epithelium was thickened at 21 days after ablation and returned to normal thickness by 3 months. At 3 weeks, subepithelial fibroblasts were three times the density of normal keratocytes and returned to nearly normal numbers by 9 months. We concluded that the anterior monkey cornea demonstrated a mild, typical wound healing response after excimer laser keratomileusis.

Elevation of C-reactive protein in "active" coronary artery disease.

Abstract: Unstable angina occurs most commonly in the setting of atherosclerotic coronary artery disease (CAD), but there is little information concerning the mechanisms responsible for the transition from clinically stable to unstable coronary atherosclerotic plaque. Recently, increased focal infiltration of inflammatory cells into the adventitia of coronary arteries of patients dying suddenly from CAD and activation of circulating neutrophils in patients with unstable angina have been observed. To characterize the presence of inflammation in “active” atherosclerotic lesions, the acute phase reactant C-reactive protein (CRP) was measured in 37 patients admitted to the coronary care unit with unstable angina, 30 patients admitted to the coronary care unit with nonischemic illnesses and 32 patients with stable CAD. CRP levels were significantly elevated (normal

Sero-epidemiological and -sociological patterns of herpes simplex virus infection in the world.

Abstract: A newly developed Herpes simplex virus (HSV) type 1 and type 2 enzyme immunoassay has been applied to over 40,000 sera from different populations in the US and 17 other countries on all 5 continents The HSV-1 antibody patterns found permit the current and past socioeconomic status, as well as the extent of oral-genital sexual contact, to be deduced for various populations The HSV-2 antibody results provide an objective measure of various aspects of sexual behavior: extent of polypartnerism in the subjects tested (or their contacts), early age of sexual experience and acquisition rates of genital herpes It has thus been possible to extend sero-epidemiology to sero-sociology which can provide objective markers for sexual behavior and effects of intervention or educational approaches Besides such markers having potential applicability for monitoring other STDs, such as HIV infection, recent studies also support a possible role for HSV infections to increase the transmissibility, not only of HIV-1, but also of HTLV-1

Identity Processes among Racial and Ethnic Minority Children in America

Abstract: A synthesis of the literature related to identity processes among American ethnic and racial minority children and adolescents is presented. In general, ethnic and racial identification, preferences, and attitudes have been studied among younger children, while the constructs of ego identity and ethnic identity have been generally studied among adolescents. The literature is unequally distributed across ethnic groups, with more research on African Americans and American Indians, and on Hispanics and Asians. Methodological concerns, such as problems of nonequivalence across groups, are identified in the conduct of research on ethnic and racial minorities. The synthesis concludes with an identification of intervention efforts along with an articulation of conceptual issues salient for promoting and theorizing about identity development processes among ethnic and racial minority children and adolescents.

Universal reaction-limited colloid aggregation

Abstract: We study slow, or reaction-limited, colloid aggregation (RLCA) with both static and dynamic light scattering and develop a self-consistent interpretation of the results. Static light scattering is used to determine the fractal dimension of the clusters and the cutoff mass of the power-law cluster-mass distribution. Using this same cutoff cluster mass, we can predict the shape of the temporal autocorrelation function measured by dynamic light scattering. Good agreement with experiments is obtained provided the effects of rotational diffusion are included. In addition, we determine the ratio of the hydrodynamic radius to the radius of gyration of individual RLCA clusters and find \ensuremath{\beta}=1.0. A scaling method is used for the q-dependent first cumulants of the temporal autocorrelation functions to obtain a single master curve for data obtained at different times in the aggregation process. The shape of this master curve is very sensitive to several key features of the process of reaction-limited colloid aggregation. It allows us to unambiguously determine the exponent for the power-law cluster-mass distribution, \ensuremath{\tau}=1.5\ifmmode\pm\else\textpm\fi{}0.05. Furthermore, we show that the master curves for three completely different colloids, gold, silica, and polystyrene, are indistinguishable. In addition, the fractal dimensions of their RLCA clusters, as measured by static light scattering, are all ${d}_{f}$=2.1\ifmmode\pm\else\textpm\fi{}0.05, while the aggregation kinetics for each colloid are exponential. This demonstrates that reaction-limited colloid aggregation is universal, independent of the detailed chemical nature of the colloid system.

Oxidative phosphorylation diseases. Disorders of two genomes.

Abstract: The mitochondrial cytopathies are a heterogeneous group of diseases associated with defects in mitochondrial ATP production that affect the brain, skeletal muscle, heart, kidney, and liver. Mitochondria produce ATP by oxidative phosphorylation (OXPHOS). OXPHOS involves approximately 100 polypeptides, most of which are encoded in the Mendelian-inherited nuclear genes, but 13 of which are encoded in the maternally-inherited mitochondrial DNA (mtDNA).

The enzymology of apurinic/apyrimidinic endonucleases

Abstract: Studies on the enzymology of apurinic/apyrimidinic (AP) endonucleases from procaryotic and eucaryotic organisms are reviewed. Emphasis will be placed on the enzymes from Escherichia coli from which a considerable portion of our knowledge has been derived. Recent studies on similar enzymes from eucaryotes will be discussed as well. In addition, we will discuss the chemical and physical properties of AP sites and review studies on peptides and acridine derivatives which incise DNA at AP sites.

Amerindian mitochondrial DNAs have rare Asian mutations at high frequencies, suggesting they derived from four primary maternal lineages

Abstract: The mitochondrial DNA (mtDNA) sequence variation of the South American Ticuna, the Central American Maya, and the North American Pima was analyzed by restriction-endonuclease digestion and oligonucleotide hybridization. The analysis revealed that Amerindian populations have high frequencies of mtDNAs containing the rare Asian RFLP HincII morph 6, a rare HaeIII site gain, and a unique AluI site gain. In addition, the Asian-specific deletion between the cytochrome c oxidase subunit II (COII) and tRNA(Lys) genes was also prevalent in both the Pima and the Maya. These data suggest that Amerindian mtDNAs derived from at least four primary maternal lineages, that new tribal-specific variants accumulated as these mtDNAs became distributed throughout the Americas, and that some genetic variation may have been lost when the progenitors of the Ticuna separated from the North and Central American populations.

Ubiquitin carboxyl-terminal hydrolase (PGP 9.5) is selectively present in ubiquitinated inclusion bodies characteristic of human neurodegenerative diseases.

Abstract: The recent discovery that brain PGP 9.5 is a ubiquitin carboxyl-terminal hydrolase suggests that the role of this protein should be studied in relation to ubiquitinated cellular inclusions characteristic of several chronic human degenerative diseases. Formalin-fixed, paraffin-processed sections known to contain ubiquitin-protein conjugate immunoreactivity in cortical Lewy bodies, neurofibrillary tangles, Rosenthal fibres, Pick bodies, spinal inclusions in motor neurone disease, and Mallory's hyaline in alcoholic liver disease were immunostained to localize PGP 9.5. The majority of cortical Lewy bodies in diffuse Lewy body disease showed immunoreactivity for PGP 9.5. In Alzheimer's disease, only a minority of loosely arranged globose-type neurofibrillary tangles were immunostained together with a minority of neurites surrounding senile plaques. In cerebellar astrocytomas, the periphery of the majority of Rosenthal fibers was immunostained in addition to strong diffuse cytoplasmic immunostaining in some astrocytes lacking apparent Rosenthal fibers. In Pick's disease, there was no immunostaining of inclusions but there was intense immunostaining of swollen Pick cells. No spinal inclusions in motor neurone disease were stained; however, anterior horn neurones appear to show increased levels of PGP 9.5 compared with those from control cases. No immunostaining of hepatic Mallory's hyaline was demonstrable, which accords with suggestions that PGP 9.5 is a tissue-specific ubiquitin C-terminal hydrolase isoenzyme. The differential detection of a ubiquitin C-terminal hydrolase in different forms of ubiquitinated inclusion body in the nervous system may form the basis of a method for assessment of the staging of inclusion body biogenesis and give insight into the dynamics of inclusion body formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cultural transmission in the tool use and communicatory signaling of chimpanzees

Abstract: One of the most exciting findings to emerge from recent observations of freeranging chimpanzees in equatorial Africa is that different populations behave differently: They eat different foods, use different tools, and communicate in different ways. These differences seem to persist across generations, and their geographical distribution (neighbors often differ more than do populations living a continent apart) makes it unlikely that they are due to genetic factors. Some researchers have therefore taken to speaking of chimpanzee “culture” (e.g., Goodall, 1973, 1986; McGrew, 1983; McGrew & Tutin, 1978; McGrew, Tutin, & Baldwin, 1979; Nishida, 1980; Nishida, Wrangham, Goodall, & Uehara, 1983; Sugiyama, 1985). It is clear, however, that not all population differences are cultural in origin. Although the term culture is not easy to define, either when applied to human societies (e.g., White, 1959) or when applied to animal populations (e.g., Booner, 1980; Mainardi, 1980; Washburn & Benedict, 1979), at the very least culture would seem to require some form of social learning. Thus, no one would claim cultural transmission if all members of a population learned a particular behavior only because they each had been exposed to the same set of contingencies from the physical environment. For example, naturalistic observations have revealed that one population of wild rats dives into the Po River (in Italy) for mollusks, whereas another population of rats living on that same river does not.

Extracellular concentrations of cocaine and dopamine are enhanced during chronic cocaine administration.

Abstract: Chronic cocaine administration produces significant increases in cocaine-induced locomotor activity and stereotypy. In vivo microdialysis procedures were used to monitor extracellular dopamine (DA) and cocaine concentrations in the nucleus accumbens (N ACC) and cocaine concentrations in plasma of animals that received chronic or acute cocaine treatments. Following a cocaine challenge injection, concentrations of both cocaine and DA increased to significantly higher levels over time in animals that had received daily cocaine injections for 10 or 30 days than in control animals that received daily injections of saline. Concentrations of cocaine and DA in the N ACC reached maximum levels in the first 30 min following a challenge injection of cocaine. The maximum cocaine concentrations of 10- and 30-day chronic animals were, respectively, 186% and 156%, whereas the maximum DA concentrations were 264% and 216% above the maximum values observed in acute control animals. The results indicate that reverse tolerance effects observed following chronic cocaine administration may in part be accounted for by increased cocaine concentrations. Furthermore, chronic cocaine administration (over a 10- or 30-day period) increased the concentration of cocaine detected in plasma above control levels following a challenge injection. The increase in brain concentrations of cocaine in chronic animals is apparently due to increased concentrations of cocaine in plasma. A physiological change occurs in the periphery as a result of chronic cocaine administration that increases cocaine concentrations in plasma, increases extracellular cocaine levels in the brain, and increases the extracellular concentration of DA in the N ACC.

Schizophrenic and Depressed Mothers: Relational Deficits in Parenting.

Abstract: Schizophrenic (n=53), depressed (n=25), and well women (n=23) were studied to determine the quality of their parenting and its affect on their 3-month to 5-year-old child's social and intellectual development. Most of the women were single parents; all were poor and Black. Parenting behavior was studied with observations in the lab and the HOME Inventory. Children's behavior was measured with an IQ test and social competence observation

Helping Teenagers Postpone Sexual Involvement

Abstract: In 1983, the Henry W. Grady Memorial Hospital in Atlanta began a family planning-based outreach program for eighth graders in a local school system. The program is led by older teenagers and focuses on helping students resist peer and social pressures to initiate sexual activity. Evaluation of the program, based on telephone interviews with 536 students from the hospital's low-income population, revealed that among students who had not had sexual intercourse, those who participated in the program were significantly more likely to continue to postpone sexual activity through the end of the ninth grade than were similar students who did not participate in the program. Because of their lower rate of sexual activity, program students also experienced comparatively fewer pregnancies than no-program students.

Prediction of adult-onset schizophrenia from childhood home movies of the patients.

Abstract: In a preliminary study of developmental precursors of schizophrenia, home movies of adult-onset schizophrenic patients and their healthy siblings filmed during their childhood were viewed by judges who were blind to the psychiatric outcome of the subjects. The films began with the infancy of all subjects and extended through at least the first 5 years of their lives. Although none of the subjects had any psychiatric disorder in childhood, the preschizophrenic children were reliably identified by the viewers. This represents the first demonstration that preschizophrenic subjects can be distinguished from sibling control subjects within the first 8 years of life by observing their behavior.

Classification of Normal Corneal Topography Based on Computer-Assisted Videokeratography

Abstract: • We evaluated the topography of 399 normal corneas in 212 subjects with computer-assisted videokeratography. The mean subject age was 37 years (range, 8 to 79 years). Mean spherical equivalent refraction was −1.00 diopters (range, +5.50 to −8.37 diopters). A qualitative classification system for corneal topography was derived based on patterns seen on color-coded topographic maps. Corneas were classified into groups by three independent masked ophthalmologists based on this system. Patterns included round (22.6%), oval (20.8%), symmetric bow tie (17.5%), asymmetric bow tie (32.1%), and irregular (7.1%). All corneas were steeper centrally and flatter peripherally. There was a statistically significant difference among patterns for keratometric astigmatism, but not for spherical equivalent refraction, mean keratometric power, or age of subject. Classification of normal corneal topography is an important step in the process of characterizing the shape of normal and pathologic corneas.

Localizing the site of magnetic brain stimulation in humans.

Abstract: Magnetic stimulation of the human brain is performed in clinical and research settings, but the site of activation has not been clearly localized in humans or other species. We used a set of magnetic stimulus coils with different field profiles to isolate movement of single digits at motor threshold and to calculate corresponding electric field strengths at various distances beneath the scalp. Two coils could produce the same electric field intensity at only 1 point. Thus, we could estimate the depth of stimulation by finding the intersection of the electric field plots, which were then superimposed on MRIs of the underlying brain. In each of 3 subjects the field plots intersected at the crown of a gyrus, in the region of the central sulcus, an near the level of the gray-white junction. This position and the electric field orientation support localization to layer VI of cerebral cortex.