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Biomedical subjects

G J Hunt

Publications and source records attributed to G J Hunt.

33 records · Page 2Linked to original sources
PubMed1990

Evaluation of membranes for feeding Culicoides variipennis (Diptera: Ceratopogonidae) with an improved artificial blood-feeding apparatus.

An artificial blood-feeding apparatus for Culicoides variipennis (Coquillett) was improved by developing a simpler design to heat and mix the blood meal and by increasing the surface area for insect feeding. The skin from a 1- to 3-d-old chick and a reinforced silicone membrane were the most satisfactory of nine membranes evaluated for C. variipennis, with 81 and 83% mean blood-feeding rates, respectively. The operational advantages of the reinforced silicone membrane for feeding C. variipennis included its composition of readily available synthetic materials, easy fabrication, faster preparation than the chick skin, and its suitability for repeated use in colony maintenance and virus infection studies.

Animals↗
PubMed1989

Environmental factors affecting mortality of adult Culicoides variipennis (Diptera: Ceratopogonidae) in the laboratory.

The effects of several environmental factors on mortality of adult Culicoides variipennis in the laboratory were evaluated. Daily mortality rates significantly increased when adult midges were maintained at an elevated constant temperature (26 degrees C). Adult C. variipennis handled the least during routine maintenance procedures had the lowest daily mortality rate. Survival was not significantly affected by varying density levels of adult midges in the size of container routinely used in our laboratory. Implications of these observations using adult C. variipennis for future studies are discussed.

Analysis of Variance↗
PubMed1986

Transfer of environmental plutonium and americium across the human gut.

Data on gut transfer factors for environmental forms of radionuclides are essential for estimates of public radiation exposures following ingestion, and thus in decisions on controlling waste discharges. Dose estimates for transuranic nuclides are particularly sensitive to uncertainties stemming from gut transfer data being related to non-environmental forms and/or derived from animal experiments. We have measured human gut transfer factors for plutonium and americium in two experiments using marine foods obtained near Sellafield, Cumbria. Firstly, the urine of volunteer members of the critical group of shellfish consumers was analysed for transuranics and the results related to their consumption rates. Secondly, remotely-based volunteers ate single quantities of shellfish obtained near Sellafield, and their urine was analysed. An overall result for the gut transfer factor for environmental plutonium of 0.8 X 10(-4) indicates no need to increase the value of 1 X 10(-4), currently used by the International Commission on Radiological Protection (ICRP) for soluble forms. Results for americium show that the ICRP value of 5 X 10(-4) is maximising, and that a value of 1 X 10(-4) would be supportable. The results from the study of critical group members provide confidence in our habits survey techniques and reassurance that there are no significant pathways for intake of transuranics by these people that have not been recognised.

Adult↗
PubMed1982

The identification of critical groups and its application to fish and shellfish consumers in the coastal area of the North-East Irish Sea.

Control of radioactive waste disposal to the environment, based on the recommendations of the International Commission on Radiological Protection (ICRP), necessitates an identification of the critical group of members of the public exposed from a given practice. Criteria for identification of critical groups based mainly on ICRP recommendations are discussed. Methods existing up to 1974 are briefly reviewed in the light of these criteria. Two more recent methods are described and compared on the basis of previous data; these methods, which are complementary, are based on homogeneity considerations and satisfy the criteria generally rather better than do the earlier methods. The application of the newer techniques to recent surveys of fish and shellfish consumption in the coastal area of the North-East Irish Sea is described, in relation to discharges from the Windscale reprocessing plant. The results of this survey are presented, and estimates are given of the effective dose equivalent to members of these critical groups in recent years, to show the effect of liquid discharges from Windscale in terms of public radiation exposure.

Animals↗
PubMed1982

Intensive medical student support groups: format, outcome, and leadership guidelines.

The authors report on a five-year experience with process-oriented discussion groups at annual four-day, off-campus retreats attended by students, faculty members, and "significant others." Group sessions comprised 17 hours of each retreat, which also included community activities and recreation time. Group leaders represented a diversity of professional backgrounds. In response to questionnaires sent from one to two months after the retreats, participants rated group experiences highly, although they also considered a significant amount of time for unstructured interpersonal interaction and recreation important. Participants enjoyed meeting students and faculty members in a relatively "role-free" setting, and students derived an enhanced sense of self-awareness from group discussions. The most highly valued group leader behaviors were participation as a group member, facilitation of interpersonal communication, and attention to group members' needs. Guidance and direction by the leaders were also considered valuable, provided that they did not impose inappropriate expectations on their groups.

Education, Medical↗
PubMed1973

Voices 73.

Explore the source record for details and available documents.

Attitude to Health↗
PubMedDate not supplied

Quantitative trait loci influencing honeybee alarm pheromone levels.

Quantitative trait loci (QTL) mapping procedures were used to identify loci that influence the levels of alarm pheromones found in the stinging apparatus of worker honeybees. An F1 queen was produced from a cross between a queen of European origin and a drone descended from an African subspecies. Haploid drones from the hybrid queen were individually backcrossed to European queens to produce 172 colonies. Samples of stings were taken from backcross workers of these colonies. Alarm pheromone levels were determined by gas chromatography. RAPD markers were scored from the haploid drone fathers of these colonies. The multiple-QTL model (MQM) of MapQTL was used to identify QTLs that influence the levels of four alarm pheromone components. Seven independent, potential QTLs were identified with LOD scores greater than two, and one at LOD 1.88. We identified one QTL for n-decyl acetate, three for n-octanol, four for isopentyl acetate, and one for hexyl acetate. One region of linkage group XI shows a strong influence on body size and the levels of three alarm pheromone components. This locus explained 40% of the variance for the amount of n-decyl acetate (LOD 6.57). In general, the QTLs influencing alarm pheromone levels were independent of previously identified loci that influenced the stinging behavior of these colonies. The only exception was a potential locus influencing levels of n-octanol, which was inversely correlated with stinging behavior.

1-Octanol↗
PubMedDate not supplied

Genetic dissection of honeybee (Apis mellifera L.) foraging behavior.

We demonstrate the effects of a new quantitative trait locus (QTL), designated pln3, that was mapped in a backcross population derived from strains of bees selected for the amount of pollen they store in combs. We independently confirmed pln3 by demonstrating its effects on individual foraging behavior, as we did previously for QTLs pln1 and pln2 (Hunt et al. 1995). QTL pln2 is very robust in its effects on foraging behavior. In this study, pln2 was again shown to affect individual foraging behavior of workers derived from a hybrid backcross of the selected strains. In addition, pln2 was shown to affect the amount of pollen stored in combs of colonies derived from a wide cross of European and Africanized honeybees. This is noteworthy because it demonstrates that we can map QTLs for behavior in interstrain crosses derived from selective breeding and study their effects in unselected, natural populations. The results we present also demonstrate the repeatability of finding QTLs with measurable effects, even after outcrossing selected strains, suggesting that there is a relatively small subset of QTLs with major effects segregating in the population from which we selected our founding breeding populations. The different QTLs, pln1, pln2, and pln3, appear to have different effects, revealing the complex genetic architecture of honeybee foraging behavior.

Animals↗