Nuclear markers confirm taxonomic status and relationships among highly endangered and closely related right whale species.

Right whales (genus: Eubalaena) are among the most endangered mammals, yet their taxonomy and phylogeny have been questioned. A phylogenetic hypothesis based on mitochondrial DNA (mtDNA) variation recently prompted a taxonomic revision, increasing the number of right whale species to three. We critically evaluated this hypothesis using sequence data from 13 nuclear DNA (nuDNA) loci as well as the mtDNA control region. Fixed diagnostic characters among the nuclear markers strongly support the hypothesis of three genetically distinct species, despite lack of any diagnostic morphological characters. A phylogenetics analysis of all data produced a strict consensus cladogram with strong support at nodes that define each right whale species as well as relationships among species. Results showed very little conflict among the individual partitions as well as congruence between the mtDNA and nuDNA datasets. These data clearly demonstrate the strength of using numerous independent genetic markers during a phylogenetics analysis of closely related species. In evaluating phylogenetic support contributed by individual loci, 11 of the 14 loci provided support for at least one of the nodes of interest to this study. Only a single marker (mtDNA control region) provided support at all four nodes. A study using any single nuclear marker would have failed to support the proposed phylogeny, and a strong phylogenetic hypothesis was only revealed by the simultaneous analysis of many nuclear loci. In addition, nu DNA and mtDNA data provided complementary levels of support at nodes of different evolutionary depth indicating that the combined use of mtDNA and nuDNA data is both practical and desirable.

Biochemical evidence for a P2Y-like receptor in Tetrahymena thermophila.

Extracellular nucleotides are ubiquitous signaling molecules. ATP signals through two receptor types: the ionotropic P2X receptors, and the metabotropic P2Y receptors. ATP acts as a chemorepellent in Tetrahymena thermophila, where it causes a distinct avoidance response. The intracellular mechanisms by which ATP causes avoidance in this organism, however, are unknown. In this study, we use in vivo pharmacological assays along with enzyme immuno-assays to obtain information about the ATP chemorepellent pathway and its associated second messenger systems. Our data show strong similarities between the presumed ATP receptor of T. thermophila and members of the P2Y family of receptors. The ATP response of T. thermophila appears to be coupled to phospholipase C, a defining characteristic of the P2Y receptor family. In addition, the ATP chemoresponse appears to be linked to a G(i/o) protein, nitric oxide synthase, and adenylyl cyclase, all of which are characteristic of some P2Y receptors. This is an important first step in describing the pathways involved in ATP chemoresponse of this organism.

The completeness, validity, and timeliness of AIDS surveillance data.

PURPOSE: To assess the completeness, validity, and timeliness of the AIDS surveillance system after the 1993 change in the surveillance case definition. METHODS: To assess completeness of AIDS case reporting, three study sites conducted a comparison of their AIDS surveillance registries with an independent source of information. To evaluate validity, the same sites conducted record reviews on a sample of reported AIDS cases, we then compared agreement between the original report and the record review for sex, race, and mode of transmission. To evaluate timeliness, we calculated the median delay from time of diagnosis to case report, before and after the change in case definition, in each of the three study sites. RESULTS: After expansion of the case definition, completeness of AIDS case reporting in hospitals (> or = 93%) and outpatient settings (> or = 90%) was high. Agreement between the information provided on the original case report and the medical record was > 98% for sex, > 83% for each race/ethnicity group; and > 67% for each risk group. The median reporting delay after the change was four months, but varied by site from three to six months. CONCLUSIONS: The completeness, validity, and timeliness of the AIDS surveillance system remains high after the 1993 change in the surveillance case definition. These findings might be useful for programs implementing integrated HIV and AIDS surveillance systems.

Higher risk of HIV transmission during trauma resuscitations.

Despite an appreciation of the potential for blood borne pathogen exposure, compliance of universal precautions is low. While reports of HIV positive rates in trauma patients have varied from 0.15% to 7.8%, the estimated prevalence of HIV in Louisiana is 0.32%. We made use of two unique, complimentary data sources: the Trauma Registry and the HIV/AIDS Reporting System database of known HIV positive patients to estimate the relative prevalence of HIV which may indicate an increase risk of blood borne pathogen transmission to health care workers during trauma resuscitations. In one year, 1031/1159 patients were evaluated from the Trauma Registry Database and 22 similar patients (2.13%) were found in both the Trauma Registry and the HIV/AIDS Reporting System Database. Our prevalence is an indicator of the minimum risk since it is based on only reported cases of HIV and justifies intensification of education and enforcement of the practice of universal precautions.

Retaining ethnic minority nursing students (REMNS): a multidimensional approach.

The under-representation of minority nurses in the nation is of critical concern for nurse educators. The high attrition rate of minority nursing students, on a local and national level, has not been effectively addressed. Project REMNS (Retaining Ethnic Minority Nursing Students), an innovative, comprehensive project, was designed to increase the retention of minority nursing students at Prairie View A&M University. Pre-clinical nursing students were provided strategies to improve critical thinking, stress management, and reading comprehension skills. This was accomplished by the development and implementation of content relevant computer modules on stress management, nutrition, and critical thinking. Implementation of Project REMNS resulted in an increased number of pre-nursing students admitted and retained in the nursing program.

Clearing up the "concept fog".

This article discusses concept mapping as a useful tool for teaching difficult concepts. Definitions, advantages, and further uses of concept mapping are provided. Directions for constructing maps and sample maps are included.

Adolescent-parent conflict in middle-class African American families.

Everyday conflicts between adolescents and parents were examined in 95 middle-class African American families, 44 with preadolescents and 51 with early adolescents, who were further divided into two groups based on family income. The incidence, frequency, and intensity of conflicts were assessed using the Issues Checklist, and content, justifications, and resolutions were coded from individual interviews. Conflicts were relatively frequent, low in intensity, and occurred over issues such as the adolescent's room, chores, choice of activities, and homework. Early adolescents rated conflicts as more intense than did preadolescents, but mothers' ratings of conflict intensity and families' ratings of conflict frequency differed by family income. African American adolescents primarily reasoned about conflicts as issues of personal jurisdiction, whereas their mothers primarily appealed to social conventions. Nearly all conflicts were resolved by adolescents giving in to parents, but adolescent concession declined with age, whereas unresolved conflicts and use of punishment increased. Number and intensity of conflicts and adolescent concession were predicted by both parenting practices and sociodemographic background; conflict frequency and joint resolution were predicted only by parents' educational attainment. Although conflict may reflect normative developmental processes of individuation, the cultural and ecological context of middle-class African American families influences its expression and resolution.

Mediators of long-term memory performance across the life span.

An individual-differences approach was used to examine the component processes that predict episodic long-term memory performance. A total of 301 participants ages 20-90 received a 7-hr cognitive battery across 3 days. Key constructs hypothesized to affect long-term memory function were assessed, including multiple measures of working memory and perceptual speed. Latent-construct, structural equation modeling was used to examine the relationship of these measures and age to different types of long-term memory tasks. Speed was a key construct for all 3 types of memory tasks, mediating substantial age-related variance; working memory was a fundamental construct for free and cued recall but not spatial memory. The data suggest that both speed and working memory are fundamental to explaining age-related changes in cognitive aging but that the relative contributions of these constructs vary as a function of the type of memory task.

Concept mapping and synthesizers: instructional strategies for encoding and recalling.

The process of knowledge acquisition requires that nursing students obtain concepts which must be encoded, stored, and later recalled from long-term memory. To assist students with these processes, teaching strategies that structure content should be used throughout the curriculum. This article describes how the instructional strategies of concept mapping and synthesizers were used to facilitate nursing students' encoding and recalling of pharmacology concepts in an undergraduate pharmacology course.

The Nurse Entrance Test (NET): an early predictor of academic success.

The purpose of this study is to determine whether a relationship exists between beginning nursing students' Nurse Entrance Test (NET) scores and their academic success within the first year of professional study. The major goal is to identify predictors of academic success so that supportive academic strategies could be implemented for the at-risk student. A statistically significant relationship is found between NET reading comprehension, math and composite scores and nursing grades during the first semester. Test-taking skills, social stressors and learning styles were also significantly related to course performance. Successful students had significantly higher reading, math, and composite scores and lower family and social stress scores than unsuccessful students. NET scores were also predictive of nursing grades, accounting for 10-33% of the variance when entered into a multiple regression equation.

Nonpalpable breast lesions: association of mammographic abnormalities with diagnosis after needle-directed biopsy.

We reviewed the experience with needle-directed breast biopsies (NDBB) in a military medical center. In 195 patients, 207 NDBBs were done; 49 of these biopsies (24%) rendered a diagnosis of malignancy. The majority of patients (78%) had invasive cancer; 44% of them were found to have associated malignant axillary adenopathy. Mammographic indications were examined; 65% of the biopsies were done for microcalcifications with or without an associated mass/density. Approximately one third of these lesions harbored malignancy or high-risk hyperplasia. Discrete nodular densities had a low rate of malignancy (7%), while spiculated/stellate masses proved almost uniformly to be invasive cancer. NDBB should be considered in all women with mammographic abnormalities. The associated risk of malignancy may vary depending on the specific mammographic appearance of the lesion. Unfortunately, a significant number of women may have relatively advanced malignancy when first seen, despite having nonpalpable disease.

Gender roles, social support, and postpartum depressive symptomatology. The benefits of caring.

Although women are assumed to be particularly vulnerable to depressive symptomatology after childbirth, the extent to which this symptomatology predominates over that found in men at this life cycle stage has not been addressed. This study examined gender differences in postpartum depressive symptomatology and the link between postpartum symptomatology and gender roles and relationships in a sample obtained from childbirth preparation classes. The data show no gender difference in depressive symptomatology at 2 months after childbirth. Women manifested a decrease in depressive symptomatology and men showed a slight increase from the preparenthood point. We partially link women's equivalent rather than higher distress levels to the protective effects of their varied social supports. By contrast, men depended primarily on their spouses, but both genders experienced a decrease in spouse support after childbirth. Female lack of support was more strongly associated with symptomatology in homemakers compared with employed women or women on maternity leave. Within the context of gender role changes, the data highlight benefits of female bonding in contrast to the "costs of caring" depicted by other researchers.

Patterns of depressive symptoms in expectant and new parents.

Depressive symptoms were assessed in 86 couples during pregnancy and after childbirth. Although 59.3% (N = 51) of the couples contained at least one symptomatic spouse during the transition to parenthood, both spouses were symptomatic in only 11.1% (N = 4) of the affected couples during pregnancy and 12.5% (N = 4) after childbirth.

A new visual-verbal saccade test: the development eye movement test (DEM).

The use of presently available clinical oculomotor tests of a visual-verbal format are limited because they do not evaluate automaticity of number naming. There is a significant relationship between automaticity of number naming and reading performance. Presented is a new oculomotor test that has a specific method to factor out the consequences of automaticity on oculomotor performance. Normative data for children age 6-13 years is provided, in addition to reliability and validity information. Clinical utilization of this test for diagnosis and management in visually related learning problems is offered.

Effects of nearpoint visual stress on psycholinguistic processing in reading.

To date, there have been few studies to evaluate directly the relationship between binocular visual stress and reading performance. This study employed the cloze procedure to demonstrate the effects of nearpoint stress on performance and efficiency in reading comprehension. Using 19 third year optometry students as subjects, binocular stress was simulated by -2.00 D lenses. Performance, as determined by the time to complete the task, was significantly reduced (p less than .03), but no significant differences in accuracy scores were measured.

Genetic and molecular characterization of the guaC-nadC-aroP region of Escherichia coli K-12.

The guaC (GMP reductase), nadC (quinolinate phosphoribosyltransferase), and aroP (aromatic amino acid permease) genes of Escherichia coli K-12 were located in the 2.5-min region of the chromosome (muT-guaC-nadC-aroP-aceE) by a combination of linkage analysis, deletion mapping, restriction analysis, and plasmid subcloning. The guaC locus expressed a product of Mr 37,000 with a clockwise transcriptional polarity, and the GMP reductase activities of guaC+ plasmid-containing strains were amplified 15- to 20-fold.