Biomedical subjects

B A May

Publications and source records attributed to B A May.

9 recordsLinked to original sources

PubMed2006

The kinetics of Lagenidium giganteum growth in liquid and solid cultures.

AIMS: Production of the mosquito biolarvacide Lagenidium giganteum in solid culture has been proposed as an economic alternative to production in liquid culture because of observations of improved shelf life and efficacy upon storage. Understanding the differences between these production systems and estimating growth rate in solid culture are important for commercialization. In order to address these needs a logistic model was developed to describe the growth kinetics of L. giganteum produced in solid and liquid cultures. METHODS AND RESULTS: Kinetic parameters in the logistic model were estimated by nonlinear regression of CO2 evolution rate (CER) and biomass data from solid and liquid cultivation experiments. Lagenidium giganteum biomass was measured using DNA extracted directly from samples. The logistic model was fit to experimental biomass and CER data with low standard errors for parameter estimates. The model was validated in two independent experiments by examining prediction of biomass using on-line CER measurements. CONCLUSIONS: There were significant differences between maximum biomass density, maintenance coefficients, and specific growth rates for liquid and solid cultures. The maximum biomass density (mg dw ml-1) was 11 times greater for solid cultivation compared with liquid cultivation of L. giganteum; however, the maintenance coefficient (mg CO2 h-1 (mg dw)-1) was six times greater for liquid cultivation than in solid cultivation. The specific growth rate at 30 degrees C was approximately 30% greater in liquid cultivation compared with solid cultivation. Slower depletion of substrate and lower endogenous metabolism may explain the longer shelf life of L. giganteum produced in solid culture. SIGNIFICANCE AND IMPACT OF THE STUDY: A simple logistic model was developed which allows real-time estimation of L. giganteum biomass from on-line CER measurements. Parameter estimates for liquid and solid cultivation models also elucidated observations of longer shelf life for production in solid culture.

Biomass↗

PubMed2001

A predictor variable for efficacy of Lagenidium giganteum produced in solid-state cultivation.

Lagenidium giganteum was cultivated on solid media in the absence of free water and evaluated for efficacy against second-instar Aedes aegypti mosquito larvae in 100-ml bioassays. Bioassay variables included level of media addition, CO(2) evolution rate (CER) and cell density. Logistic regression was performed on bioassay infection observations to determine if the tested variables were correlated to the probability of attaining at least 80% infection. Both CER (p=0.003) and number of cells (p=0.017) were significantly correlated, while level of media addition was not (p=0.42). Although media addition did not correlate with efficacy, media levels greater than 2 g/l reduced water clarity and infection. Media from cultures younger than 3 days performed poorly under all conditions tested.

Aedes↗

PubMed2000

Basic empathy in older adults: conceptualization, measurement, and application.

Older adults comprise the most rapidly increasing age group in America. In addition, an increasing number of older adults are involved in helping behaviors or volunteering. Although empathy has been identified as a critical component of a helping relationship, few studies concerning empathy have been conducted with older adults and few instruments have been developed that can be used with this population. The purpose of this study was to explore the relationship between two measures of empathy in older adults. The Hogan Empathy Scale and an Adjective Check List Empathy Scale were used to assess basic empathy in 43 older adults between the ages of 63 and 96. Results indicated that the mean scores of older adults were lower than mean scores in younger populations. Scores on both measures were comparable suggesting that both instruments could be used to measure basic empathy in older adults.

Aged↗

PubMed2000

A nursing theory of personal system empathy: interpreting a conceptualization of empathy in King's interacting systems.

This article presents a theory of empathy discovered through rational hermeneutic interpretation within King's personal system. Personal system concepts from King's general systems framework include perception, self, growth and development, body image, space, time, and learning. Propositions for each concept in the personal system were explicated and a theory of nursing empathy was developed. This nursing theory proposes that empathy organizes perceptions; facilitates awareness of self and others; increases sensitivity; promotes shared respect, mutual goals, and social awareness; cultivates understanding of individuals within a historical and social context; and affects learning.

Awareness↗

PubMed1999

Critical thinking and clinical competence: a study of their relationship in BSN seniors.

National nursing organizations and nurses in the workplace identify critical thinking skills as essential to competent nursing practice. This study sets out to test the relationship between critical thinking skills and clinical competence because it seems that competent practice depends on critical thinking abilities. This study focuses on one school of nursing's response to the challenge of defining and measuring critical thinking and clinical competence and examining their relationship. An exploratory nonexperimental design was used with a heterogeneous sample consisting of two graduating nursing classes (N = 143). While the group of participants was able to think critically and practice competently according to set standards, there were no statistically significant correlations between critical thinking and clinical competence total scores. One conclusion for these findings is that critical thinking may not emerge as an associated factor with clinical competence until some time after nursing students become practicing nurses.

Adult↗

PubMed1993

A novel antiviral strategy for HIV infection.

The replication of human immunodeficiency virus (HIV) may be modulated in part by host factors such as DNA methylation. Hypermethylation of the HIV provirus may suppress viral replication and play a role in the establishment of latency. HIV seropositive individuals have decreased levels of metabolites involved in methylation. It is proposed that metabolites such as S-adenosylmethionine (SAM), methylcobalamin and methyltetrahydrofolate be explored as potential therapeutic agents in HIV infected individuals.

Acquired Immunodeficiency Syndrome↗

PubMed1983

Aspects of secretory phenomena within the sinus gland of Carcinus maenas (L.). An ultrastructural study.

The sinus gland of Carcinus maenas contains small numbers of neurosecretory neurones ("intrinsic cells") as well as glial cells and nerve terminals. Intrinsic cells may be of the same cell type as some extrinsic cells, but are probably multipolar. Exocytosis is a common phenomenon, and may be either "basal" or "interterminal", and either "simple" or "compound" in character. Elementary neurosecretory granules may apparently fuse within the terminals to form "secondary" granules, and these also release their contents by exocytosis. A distinction is drawn between populations of vesicular inclusions which include elements of diverse size and form, and aggregations of synaptoid vesicles. The mixed populations may be involved in the retrieval of granule membranes. Typical synaptoid complexes are present in a minority of terminals and are characterized by a zonation of vesicular and granular inclusions, the aggregation of vesicles of fairly uniform size and shape adjacent to membrane thickenings, and an affinity of vesicle contents for the ZIO reagent. Granules within one type of fibre differ from typical peptidergic granules, but react negatively to cytochemical tests for amines.

Amines↗

PubMedDate not supplied

The IPR inventory: development and psychometric characteristics.

The purpose of this study was to develop, validate, and norm a measure of dimensions of interpersonal relationships that are salient to nursing: social support, reciprocity, and conflict. The selection of these concepts was guided by social exchange and equity theories. In the first phase of the study, 44 respondents were interviewed to provide narrative data from which to develop items so that items would be grounded in lived experience. Content validity of items was judged by a panel of 11 experts. The revised 39-item instrument was tested in successive steps with a total of 340 students, patients, and community residents for reliability and validity, including internal consistency reliability, test-retest reliability, factor analysis, and three forms of validity assessment (theory testing, contrasted groups, and multitrait-multimethod comparison). The three subscales of social support, reciprocity, and conflict demonstrated repeated internal consistency and test-retest reliability. Strong evidence of construct validity was demonstrated for the social support and the conflict subscales; validity of the reciprocity subscale was equivocal.

Adult↗

PubMedDate not supplied

Use of qualitative methods to enhance content validity.

Qualitative methods to enhance the content validity of a new psychometric measure are described in this report. Qualitative data collected in interviews with respondents familiar with a concept helps to enrich and extend what is known about the concept and serves as a valuable source of items. Qualitative data were collected from 44 respondents on aspects of interpersonal relationships, including social support, reciprocity, and conflict. Data were used to generate items for the new measure, the Interpersonal Relationship Inventory. Content validity of items and of scales was judged by a panel of experts, and initial psychometric properties of items were evaluated before developing the final measure.

Attitude↗