Biomedical subjects

M D Barnes

Publications and source records attributed to M D Barnes.

11 recordsLinked to original sources

PubMed2001

Three-dimensional photonic "molecules" from sequentially attached polymer-blend microparticles.

We report the observation of 3D linear or branched chains of polymer-blend microspheres generated from liquid droplets of solution where the modified surface structure of the polymer composite results in highly robust interparticle bonds. Using a linear quadrupole to precisely position particles in space, we are able to take advantage of this novel material property to actively assemble particles in programmable three-dimensional architectures. The robust interlocking nature of interparticle linkage gives rise to strongly coupled morphology-dependent resonances in bisphere and trisphere systems, suggesting the possibility of three-dimensional photonic "molecules" and microscale optical manipulation applications.

Journal Article↗

PubMed2000

Health-related variables and academic performance among first-year college students: implications for sleep and other behaviors.

The authors analyzed the effect of several health behaviors and health-related variables on grade point averages of a random sample of 200 students living in on-campus residence halls at a large private university. The set of variables included exercise, eating, and sleep habits; mood states; perceived stress; time management; social support; spiritual or religious habits; number of hours worked per week; gender; and age. Of all the variables considered, sleep habits, particularly wake-up times, accounted for the largest amount of variance in grade point averages. Later wake-up times were associated with lower average grades. Variables associated with the 1st-year students' higher grade point averages were strength training and study of spiritually oriented material. The number of paid or volunteer hours worked per week was associated with lower average grades.

Adolescent↗

PubMed2000

Spindle cell angiosarcoma of the oropharynx.

Angiosarcomas are uncommon malignant tumours of vascular endothelium. In the head and neck, the scalp is the commonest site of origin. A rare case of spindle-cell angiosarcoma of the oropharynx, treated by surgery and post-operative radiotherapy, is reported. We discuss the clinical presentation and histopathological diagnosis of this lesion.

Aged↗

PubMed1999

Fluorescence imaging of single molecules in polymer microspheres.

We report on far-field fluorescence imaging of single molecules in spherical polymer microparticles produced from solution by using microdroplet techniques. The fluorescence photobleaching quantum yields of rhodamine 6G in a common water-soluble polymer (polyvinyl alcohol) are at least five times smaller, corresponding to proportionally larger average fluorescence signals, than those in ethanolic solvents. This allows for acquisition of multiple images from a single molecule on a time scale of several minutes. We also show that fluorescent images of single molecules in microspheres can be calculated from semiclassic electrodynamics, which may ultimately be useful in retrieving dynamical information from experimental images.

Fluorescence↗

PubMed1998

Generalizability theory: a unified approach to assessing the dependability (reliability) of measurements in the health sciences.

The reliability of health promotion program evaluation measures, behavioral and attitudinal measures, and clinical measures is a concern to many health educators. Classical reliability coefficients, such as Cronbach's alpha, apply to narrowly defined, prespecified measurement situations. Classical theory does not provide adequate reliability assessments for criterion-referenced measures, for measurement situations having multiple sources of error, or for aggregate-level variables. Generalizability theory can be used to assess the reliability of measures in these situations that are not adequately modeled by Classical theory. Additionally, Generalizability theory affords a broader view and a deeper understanding of the dependability of measurements and the role of different sources of error in the variability of measures.

Health Promotion↗

PubMed1996

Using storyboarding to determine components of wellness for university students.

Using a needs-assessment technique called storyboarding to determine characteristics of health promotion and wellness among university students is discussed. Storyboarding allows students to work together as they generate ideas and eliminates the territorial defensiveness that often occurs when new ideas are suggested. Sixteen graduate students in a health education teaching methods course demonstrated the use of the technique to identify characteristics of wellness for university students. In addition, they identified content areas and outlined key programs, services, personal habits, and skills useful for enhancing university students' wellness.

Focus Groups↗

PubMed1991

Glimpses into measurements of the microcirculation in skin.

There are instances when chronic disease states manifest as microvascular disturbances of the skin. Objective assessment of these disturbances would permit a better understanding of the causative factors and, in certain circumstances, influence decisions of clinical management. Recent advances in technology that permit such assessment non-invasively are evaluated in this review.

Adolescent↗

PubMed1991

Effectiveness of antibiotic prophylaxis in preventing bacteriuria after multichannel urodynamic investigations: a blind, randomized study in 124 female patients.

One hundred twenty-four women with chronic, persistent lower urinary tract symptoms who had been scheduled for elective urodynamic investigations at Mount Sinai's Urodynamic Investigative Unit were divided into two blind, randomized groups, receiving either a placebo or prophylactic antibiotic. At the time of urodynamic testing, the rate of unsuspected urinary tract infection was 8.1%. There was no statistically significant decrease in postinstrumentation infection rate in the group who received prophylactic antibiotics. We conclude that, given in the fashion described in the study, prophylactic antibiotics are not effective in preventing urinary tract infections caused by urodynamic testing.

Adult↗

PubMed1983

Birth dates of trigeminal motoneurons and metamorphic reorganization of the jaw myoneural system in frogs.

Drastic alterations in oral behavior characterize metamorphosis of anuran amphibians. Changes cascade through all components of the jaw apparatus from bone to muscle to nerve. In this investigation, tritiated thymidine autoradiography was used to determine the production schedule of the trigeminal motoneurons in the leopard frog, Rana pipiens. The time of origin of these neurons and their subsequent fate are of special interest given the breakdown of the larval jaw muscles and the de novo generation of adult muscle fibers during metamorphosis. Specifically, we wanted to learn whether trigeminal motoneurons are added, deleted, or reused during metamorphic climax. The entire complement of trigeminal motoneurons was produced over a 4-day span commencing at embryonic stage 13 and terminating at stage 20. Newly formed neurons are added to the primordial trigeminal nucleus in an orderly pattern. Firstborn neurons settle in the ventrorostral region of the nucleus; cells with progressively later birth dates were added in a posterodorsal direction. No additional trigeminal motoneurons are generated during larval maturation or at metamorphosis, thus indicating that the same population of neurons is present throughout the lifespan of the animal. From these observations we suggest that, during metamorphosis, the trigeminal motoneurons that supply the larval muscles switch their allegiance to the newly formed adult jaw muscles. This change of peripheral targets can be viewed as a respecification of the trigeminal motoneurons.

Animals↗

PubMed1983

Maturation and recycling of trigeminal motoneurons in anuran larvae.

Development of the trigeminal motor system was analyzed in Rana pipiens larvae and adults. The aim of this investigation was to determine the postmetamorphic fate of the primary motoneurons that innervate the larval jaw muscles. Specifically, we wanted to ascertain whether these neurons were deleted in conjunction with their muscular targets during metamorphosis or reused to innervate the adult jaw muscles. Cell counts and horseradish peroxidase tracer were used to distinguish between these two possibilities. The number of trigeminal motoneurons was relatively constant in premetamorphic and prometamorphic larvae. A small reduction in the cellular complement of the motor nucleus occurred during metamorphic climax, but the majority (approximately equal to 90%) of the primary motoneurons were retained from the larval to the adult nervous system. The cell loss may represent motoneurons that innervated specific larval muscles that have no adult successors and thus the entire myoneural unit degenerates. Retrograde tracers indicated that all trigeminal motoneurons extended axons into the jaw muscles of both premetamorphic larvae and adult frogs. These observations provide further support for the recycling of the trigeminal motoneurons.

Animals↗

PubMedDate not supplied

The relationship of economic factors and stress among employed, married women with children.

A convenience sample of 62 married women with children at home were measured on five economic variables and three stress-related variables: mother/marital role satisfaction, mother work role fulfillment and physical indicators of stress. The analysis reveals several significant relationships for the fulfillment and stress variables. Regression analysis also was used to model the relationship among economic and stress-related variables. The study suggests that financial health modules be integrated into stress management and other health enhancement programs for married, employed women.

Adult↗