Showing papers by "University of Miami published in 1993"

How coping mediates the effect of optimism on distress : a study of women with early stage breast cancer

Abstract: At diagnosis, 59 breast cancer patients reported on their overall optimism about life; 1 day presurgery, 10 days postsurgery, and at 3-, 6-, and 12-month follow-ups, they reported their recent coping responses and distress levels. Optimism related inversely to distress at each point, even controlling for prior distress. Acceptance, positive reframing, and use of religion were the most common coping reactions; denial and behavioral disengagement were the least common reactions. Acceptance and the use of humor prospectively predicted lower distress; denial and disengagement predicted more distress. Path analyses suggested that several coping reactions played mediating roles in the effect of optimism on distress. Discussion centers on the role of various coping reactions in the process of adjustment, the mechanisms by which dispositional optimism versus pessimism appears to operate, third variable issues, and applied implications.

Coral reef bleaching: ecological perspectives

Abstract: Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt physiologically or genetically to such marked and rapid temperature increases.

Social Anxiety Scale for Children-Revised: Factor Structure and Concurrent Validity

Abstract: Examined the factor structure, internal reliabilities, and concurrent validity of a revised form of the Social Anxiety Scale for Children (SASC-R) with fourth through sixth graders (N = 587). Factor analysis on a subsample (n = 459) yielded three factors: Fear of Negative Evaluation From Peers, Social Avoidance and Distress Specific to New Situations, and Generalized Social Avoidance and Distress. Confirmatory factor analysis with another subsample (n = 128)revealed a good fit for the three-factor model of social anxiety. In addition, high-socially-anxious children perceived their social acceptance and global self-worth to be low. Neglected and rejected children reported more social anxiety than accepted classmates. The data support the reliability and validity of the SASC-R.

Population structure in Daphnia obtusa: quantitative genetic and allozymic variation.

Abstract: Quantitative genetic analyses for body size and for life history characters within and among populations of Daphnia obtusa reveal substantial genetic variance at both hierarchical levels for all traits measured. Simultaneous allozymic analysis on the same population samples indicate a moderate degree of differentiation: GST = 0.28. No associations between electrophoretic genotype and phenotypic characters were found, providing support for the null hypothesis that the allozymic variants are effectively neutral. Therefore, GST can be used as the null hypothesis that neutral phenotypic evolution within populations led to the observed differentiation for the quantitative traits, which I call QST. The results of this study provide evidence that natural selection has promoted diversification for body size among populations, and has impeded diversification for relative fitness. Analyses of population differentiation for clutch size, age at reproduction, and growth rate indicate that neutral phenotypic evolution cannot be excluded as the cause.

Lexical Development in Bilingual Infants and Toddlers: Comparison to Monolingual Norms

Abstract: This study compares lexical development in a sample of 25 simultaneous bilingual and 35 monolingual children for whom semilongitudinal data were collected between the ages of 8 and 30 months. A standardized parent report form, the MacArthur Communicative Development Inventory (1989), was used to assess the children's receptive and productive vocabulary in English and/or Spanish. A methodology was devised to assess the degree of overlap between the bilingual children's lexical knowledge in one language and their knowledge in the other. Using the measures presented here, there was no statistical basis for concluding that the bilingual children were slower to develop early vocabulary than was the monolingual comparison group. The wide range of vocabulary sizes observed at these ages in normally developing children (Fenson et al., 1991) was observed in these bilingual children as well. The close correspondence of the pattern of the bilinguals' growth in two languages at once to monolinguals' growth in one suggests that norms for lexical development in bilinguals should be made with reference to the children's performance in two languages together.

Regulation of connective tissue growth factor gene expression in human skin fibroblasts and during wound repair.

Abstract: Connective tissue growth factor (CTGF) is a cysteine-rich peptide that exhibits platelet-derived growth factor (PDGF)-like biological and immunological activities. CTGF is a member of a family of peptides that include serum-induced immediate early gene products, a v-src-induced peptide, and a putative avian transforming gene, nov. In the present study, we demonstrate that human foreskin fibroblasts produce high levels of CTGF mRNA and protein after activation with transforming growth factor beta (TGF-beta) but not other growth factors including PDGF, epidermal growth factor, and basic fibroblast growth factor. Because of the high level selective induction of CTGF by TGF-beta, it appears that CTGF is a major autocrine growth factor produced by TGF-beta-treated human skin fibroblasts. Cycloheximide did not block the large TGF-beta stimulation of CTGF gene expression, indicating that it is directly regulated by TGF-beta. Similar regulatory mechanisms appear to function in vivo during wound repair where there is a coordinate expression of TGF-beta 1 before CTGF in regenerating tissue, suggesting a cascade process for control of tissue regeneration and repair.

Selective expression of Ly-6G on myeloid lineage cells in mouse bone marrow. RB6-8C5 mAb to granulocyte-differentiation antigen (Gr-1) detects members of the Ly-6 family.

Abstract: Mouse Ly-6 proteins are characterized by lineage-restricted patterns of expression on lymphoid cells. A mAb (1A8) was produced to Ly-6G, a newly described member of the Ly-6 locus. Based on selective reactivity to cloned Ly-6 gene products expressed in EL4J cells, 1A8 was determined to be specific for Ly-6G. Furthermore, mAb to other Ly-6 specificities did not bind to Ly-6G-transfected EL4J cells, indicating that Ly-6G is distinct from other serologically defined Ly-6 specificities. FACS analysis using 1A8 demonstrated that Ly-6G was expressed in bone marrow but not substantially on other lymphoid tissues, including activated T and B cells. In the bone marrow, Ly-6G expression was primarily restricted to the cells with more forward angle light scatter, which are mostly granulocytes. The RB6-8C5 mAb, previously described to detect a myeloid-restricted Ag (Gr-1) on more differentiated granulocytes, also reacted with Ly-6G- and Ly-6C-transfected EL4J cells. Both 1A8 and RB6-8C5 selectively precipitate a M(r) 21 to 25 kDa, glycosylphosphatidylinositol-anchored protein. Collectively, these data indicate that the Gr-1 Ag is a member of the Ly-6 family and further link expression of individual Ly-6 genes with distinct lineages in mouse bone marrow cells.

Body Fat Distribution and 5-Year Risk of Death in Older Women

Abstract: Objective. —To test the hypothesis that both body mass index (expressed as the ratio of weight in kilograms per height in meters squared) and the ratio of waist circumference to hip circumference are positively associated with mortality risk in older women. Design. —Prospective cohort study with a 5-year follow-up period. Setting. —General community. Participants. —Random sample of 41 837 Iowa women aged 55 to 69 years. Main Outcome Measure. —Total mortality (1504 deaths). Main Results. —Body mass index, an index of relative weight, was associated with mortality in a J-shaped fashion: rates were elevated in the leanest as well as in the most obese women. In contrast, waist/hip circumference ratio was strongly and positively associated with mortality in a dose-response manner. Adjusted for age, body mass index, smoking, education level, marital status, estrogen use, and alcohol use, a 0.15-unit increase in waist/hip circumference ratio (eg, a 15-cm [6-in] increase in waist measurement in a woman with 100-cm [40-in] hips) was associated with a 60% greater relative risk of death. The observed associations were not explained to any great degree by bias from weight loss prior to baseline or higher early deaths among lean participants. Conclusions. —Waist/hip circumference ratio is a better marker than body mass index of risk of death in older women. Waist/hip circumference ratio should be measured as part of routine surveillance and risk monitoring in medical practice. JAMA . 1993;269:483-487)

On the Power of Positive Thinking: The Benefits of Being Optimistic

Abstract: If believing in something can I make it so, then there really would be power in positive thinking. From the little train in the children's tale who said, "I think I can," to popular writers such as Norman Cousins and Norman Vincent Peale, to wise grandmothers everywhere?many people have espoused the benefits of positive thinking. But are these ben efits real? Do people who think pos itively really fare better when facing challenge or adversity? Do they re cover from illness more readily? If so, how and why do these things happen? We and a number of other psy chologists who are interested in is sues surrounding stress, coping, and health have for several years focused our research attention on questions such as these. The primary purpose of this brief review is to provide a taste of the research conducted on this topic. We first document that positive thinking can be beneficial. We then consider why an optimistic orientation to life might confer ben efits. After considering how individ ual differences in optimism might arise, we take up the question of whether optimism is always good and pessimism always bad. We close by discussing the similarities between our own approach and other related approaches. CHARACTERIZING POSITIVE THINKING

Sudden Cardiac Death: Epidemiology, Transient Risk, and Intervention Assessment

Abstract: Purpose: To integrate information from the various disciplines that contribute to the understanding of the cause and prevention of sudden cardiac death: identification of new approaches from applie...

Intraischemic but Not Postischemic Brain Hypothermia Protects Chronically following Global Forebrain Ischemia in Rats

Abstract: We investigated whether postischemic brain hypothermia (30 degrees C) would permanently protect the hippocampus following global forebrain ischemia. Global ischemia was produced in anesthetized rats by bilateral carotid artery occlusion plus hypotension (50 mm Hg). In the postischemic hypothermic group, brain temperature was maintained at 37 degrees C during the 10-min ischemic insult but reduced to 30 degrees C starting 3 min into the recirculation period and maintained at 30 degrees C for 3 h. In normothermic animals, intra- and postischemic brain temperature was maintained at 37 degrees C. After recovery for 3 days, 7 days, or 2 months, the extent of CA1 hippocampal histologic injury was quantitated. At 3 days after ischemia, postischemic hypothermia significantly protected the hippocampal CA1 sector compared with normothermic animals. For example, within the medial, middle, and lateral CA1 subsectors, the numbers of normal neurons were increased 20-, 13-, and 9-fold by postischemic hypothermia (p < 0.01). At 7 days after the ischemic insult, however, the degree of postischemic hypothermic protection was significantly reduced. In this case, the numbers of normal neurons were increased an average of only threefold compared with normothermia. Ultrastructural analysis of 7-day postischemic hypothermic rats demonstrated CA1 pyramidal neurons showing variable degrees of injury surrounded by reactive astrocytes and microglial cells. At 2 months after the ischemic insult, no trend for protection was demonstrated. In contrast to postischemic hypothermia, significant protection was seen at 2 months following intraischemic hypothermia. These data indicate that intraischemic, but not postischemic, brain hypothermia provides chronic protection to the hippocampus after transient brain ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of human heat shock genes is accompanied by oligomerization, modification, and rapid translocation of heat shock transcription factor HSF1.

Abstract: Transcriptional activity of heat shock (hsp) genes is controlled by a heat-activated, group-specific transcription factor(s) recognizing arrays of inverted repeats of the element NGAAN. To date genes for two human factors, HSF1 and HSF2, have been isolated. To define their properties as well as the changes they undergo during heat stress activation, we prepared polyclonal antibodies to these factors. Using these tools, we have shown that human HeLa cells constitutively synthesize HSF1, but we were unable to detect HSF2. In unstressed cells HSF1 is present mainly in complexes with an apparent molecular mass of about 200 kDa, unable to bind to DNA. Heat treatment induces a shift in the apparent molecular mass of HSF1 to about 700 kDa, concomitant with the acquisition of DNA-binding ability. Cross-linking experiments suggest that this change in complex size may reflect the trimerization of monomeric HSF1. Human HSF1 expressed in Xenopus oocytes does not bind DNA, but derepression of DNA-binding activity, as well as oligomerization of HSF1, occurs during heat treatment at the same temperature at which hsp gene expression is induced in this organism, suggesting that a conserved Xenopus protein(s) plays a role in this regulation. Inactive HSF1 resides in the cytoplasm of human cells; on activation it rapidly translocates to a soluble nuclear fraction, and shortly thereafter it becomes associated with the nuclear pellet. On heat shock, activatable HSF1, which might already have been posttranslationally modified in the unstressed cell, undergoes further modification. These different process provide multiple points of regulation of hsp gene expression.

Comparison of numerical models for computing underwater light fields

Abstract: Seven models for computing underwater radiances and irradiances by numerical solution of the radiative transfer equation are compared. The models are applied to the solution of several problems drawn from optical oceanography. The problems include highly absorbing and highly scattering waters, scattering by molecules and by particulates, stratified water, atmospheric effects, surface-wave effects, bottom effects, and Raman scattering. The models provide consistent output, with errors (resulting from Monte Carlo statistical fluctuations) in computed irradiances that are seldom larger, and are usually smaller, than the experimental errors made in measuring irradiances when using current oceanographic instrumentation. Computed radiances display somewhat larger errors.

Issues of taxonomy and comorbidity in the development of conduct disorder

Abstract: A developmental approach to the classification of antisocial behavior is necessary for two reasons. First, although the continuity of antisocial behavior is strong for many individuals, the topography of antisocial behavior changes during the course of development. Second, antisocial behavior apparently develops in at least two separate pathways — child-onset versus adolescent-onset — that differ markedly regarding types of antisocial behavior displayed, persistence, and perhaps etiology. The development of antisocial behavior must also be understood within the context of co-occurring disorders and conditions. Comorbid attention-deficit hyperactivity disorder appears to be associated with greater aggression and a worse prognosis, and comorbid academic underachievement is also associated with a negative course. Emerging evidence also suggests that comorbid anxiety disorder is associated with level of aggression, but the direction of the correlation appears to differ at different ages. In all, full understanding of conduct disorder requires developmentally sensitive classification as well as consideration of comorbid conditions.

ENRICH Marital Satisfaction Scale: A brief research and clinical tool.

Abstract: This article presents reliability and validity data for the 15-item ENRICH (evaluation and nurturing relationship issues, communication and happiness) Marital Satisfaction (EMS) Scale. The scale was found to be reliable and to have strong correlations with other measures of marital satisfaction and moderate relationships with measures of family satisfaction and consideration of divorce. The EMS Scale offers an important alternative to researchers who require a brief but, nevertheless, valid and reliable measure of marital quality. It provides a means to obtain both dyadic and individual satisfaction scores. Ten of the scale’s items survey 10 domains of marital quality. The other 5 items compose a marital conventionalization scale to correct for the tendency to endorse unrealistically positive descriptions of the marriage. National norms based on 2,112 couples are presented for the EMS Scale.

Controls on Sonic Velocity in Carbonates

Abstract: Compressional and shear-wave velocities (V p and V s ) of 210 minicores of carbonates from different areas and ages were measured under variable confining and pore-fluid pressures. The lithologies of the samples range from unconsolidated carbonate mud to completely lithified limestones. The velocity measurements enable us to relate velocity variations in carbonates to factors such as mineralogy, porosity, pore types and density and to quantify the velocity effects of compaction and other diagenetic alterations.

The psychobiology of undersocialized aggressive conduct disorder: A theoretical perspective

Abstract: Undersocialized aggressive conduct disorder is conceptualized within the framework for personality and motivation of Jeffrey Gray. The disorder is seen as reflecting a dominance of the reward system over the behavioral inhibition system. Evidence for this conceptualizing coming from behavioral, psychophysiological, biochemical, and pharmacological studies is reviewed. Relevant findings from these studies include perseverative responding for reward, indices of inefficient noradrenergic and serotonergic functioning, and electrodermal underresponding. Additional research to test the proposed hypothesis is suggested.

Changing middle school students' conceptions of matter and molecules

Abstract: The purpose of this study was two-fold: (1) to understand the conceptual frameworks that sixth-grade students use to explain the nature of matter and molecules, and (2) to assess the effectiveness of two alternative curriculum units in promoting students' scientific understanding. The study involved 15 sixth-grade science classes taught by 12 teachers in each of two successive years. Data were collected through paper-and-pencil tests and clinical interviews. The results revealed that students' entering conceptions differed from scientific conceptions in various ways. These differences included molecular conceptions concerning the nature, arrangement, and motion of molecules as well as macroscopic conceptions concerning the nature of matter and its physical changes. The results also showed that the students taught by the revised unit in Year 2 performed significantly better than the students taught by the original commercial curriculum unit in Year 1 for 9 of the 10 conceptual categories. Implications for science teaching and curriculum development are discussed.

Pantropical trends in mangrove above-ground biomass and annual litterfall.

Abstract: A major paradigm in biosphere ecology is that organic production, carbon turnover and, perhaps, species diversity are highest at tropical latitudes, and decrease toward higher latitudes. To examine these trends in the pantropical mangrove forest vegetation type, we collated and analysed data on above-ground biomass and annual litterfall for these communities. Regressions of biomass and litterfall data show significant relationships with height of the vegetation and latitude. It is suggested that height and latitude are causally related to biomass, while the relationship with litterfall reflects the specific growing conditions at the respective study sites. Comparison of mangrove and upland forest litterfall data shows similar trends with latitude but indicates that mangrove litterfall is higher than upland forest litterfall. The regression equations allow the litterfall/biomass ratio to be simulated, and this suggests that the patterns of organic matter partitioning differ according to latitude.