Biomedical subjects

T D Murray

Publications and source records attributed to T D Murray.

10 recordsLinked to original sources

PubMed2005

Resistance to eyespot of wheat, caused by Tapesia yallundae, derived from Thinopyrum intermedium homoeologous group 4 chromosome.

Thinopyrum intermedium was identified previously as resistant to Tapesia yallundae, cause of eyespot of wheat. Using GUS-transformed isolates of T. yallundae as inoculum, we determined that wheat lines carrying Th. intermedium chromosome 4 Ai#2 or the short arm of chromosome 4 Ai#2 were as resistant to the pathogen as the eyespot-resistant wheat- Th. ponticum chromosome substitution line SS 767 (PI 611939) and winter wheat cultivar Madsen, which carries gene Pch 1 for eyespot resistance. Chromosome 4 E from Th. elongatum and chromosome 4 J from Th. bessarabicum did not confer resistance to T. yallundae. Genome-specific PCR primers confirmed the presence of Thinopyrum chromatin in these wheat- Thinopyrum lines. Genomic in situ hybridization using an St genomic probe from Pseudoroegneria strigosa demonstrated that chromosome 4 Ai#2 belongs to the J(s) genome of Thinopyrum. The eyespot resistance in the wheat- Th. intermedium lines is thus controlled by the short arm of this J(s) chromosome. This is the first report of resistance to T. yallundae controlled by a J(s) genome chromosome of Th. intermedium.

Ascomycota↗

PubMed2002

Multilocus population structure of Tapesia yallundae in Washington State.

Population genetic structure of the fungal wheat pathogen Tapesia yallundae in Washington State was determined using genetically characterized amplified fragment length polymorphic (AFLP) markers and mating-type (MAT1-1 or MAT1-2). Segregation and linkage relationships among 164 AFLP markers and MAT were analysed using 59 progeny derived from an in vitro cross. Alleles at 158 AFLP loci and the mating-type locus segregated in a 1:1 ratio. Ten unlinked markers were chosen to determine genetic and genotypic diversity and to test the hypothesis of random mating and population differentiation among five subpopulations of T. yallundae representative of the geographical distribution of wheat production in eastern Washington. Among 228 isolates collected, overall gene diversity was high (h = 0.425) and a total of 91 unique multilocus genotypes (MLG) were identified, with 32 MLG occurring at least twice. The overall population genetic structure was consistent with random mating based on the segregation of mating-type, index of association (IA), parsimony tree length permutation test (PTLPT) and genotypic diversity analyses. However, clonal genotypes were found within each subpopulation and were also distributed among the five subpopulations. No significant differences in allele frequencies were found among the five subpopulations for all 10 loci based on contingency table analysis (G2) and Wier & Cockerham's population differentiation statistic theta (theta = -0.008, P = 0.722). T. yallundae appears to consist of a large homogeneous population throughout eastern Washington with both sexual and asexual reproduction contributing to the observed population genetic structure despite no report of sexual fruiting bodies of T. yallundae occurring under natural field conditions.

Ascomycota↗

PubMed2001

A multiplex PCR test for determination of mating type applied to the plant pathogens Tapesia yallundae and Tapesia acuformis.

A multiplex PCR test for determining mating type of the pathogens Tapesia yallundae and Tapesia acuformis is described. The test involves three primers: a "common" primer annealing to DNA sequence conserved in the flanking region of both mating-type idiomorphs and two specific primers annealing to sequence in either the MAT-1 or the MAT-2 idiomorphs. Locating the specific primers in different positions relative to the common primer yielded PCR products of 812 or 418 bp from MAT-1 and MAT-2 isolates, respectively. The test was used successfully to determine the mating type of 118 isolates of T. yallundae and T. acuformis from Europe, North America, and New Zealand. Isolates of both mating types were found on all continents for both species despite the rarely observed occurrence of sexual reproduction of T. acuformis. The multiplex test design should be applicable to other ascomycete species, of use in studies of MAT distribution and facilitating sexual crossing by identifying compatible isolates.

Ascomycota↗

PubMed1999

The energy cost of horizontal walking and running in adolescents.

PURPOSE: This study developed and cross-validated generalized equations for predicting VO2 (mL x kg(-1) x min(-1)) and caloric expenditure (kcal x kg(-1) x min(-1)) during horizontal walking and running in adolescents. METHODS: Subjects were 47 male and 35 female adolescent volunteers, ages 12-18. Each subject underwent a submaximal treadmill exercise test to determine VO2 at randomly selected walking and jogging speeds (67-215 m x min(-1)). Caloric expenditure was estimated from VO2 and RER. Multiple regression was used to develop prediction equations for estimating VO2 and caloric expenditure from a derivation sample of 77 random observations, both walking and running. RESULTS: The group relationship between running speed and energy cost in the derivation sample was linear, whereas the relationship between walking speed and energy cost was quadratic. Gender, age, and height each failed to account for significant additional variation in energy cost after speed and mode were considered. Skinfolds accounted for a small yet significant amount of additional variation in energy cost. The derived equations were cross-validated on a sample of 76 separate random observations. The cross-validation statistics are: for VO2, R = 0.95, error = 3.58 mL x kg(-1) x min(-1), and for caloric expenditure, R = 0.94, error = 0.019 kcal x kg(-1) x min(-1). Most selected adult equations consistently underestimated both VO2 and caloric expenditure in the cross-validation sample. CONCLUSIONS: These results suggest that in adolescents, within the range of speeds tested, the relationship between speed of movement and energy cost for running is linear, but for walking is curvilinear. Also, adult models for estimating VO2 or caloric expenditure do not account for the higher relative energy cost of walking and running in adolescents.

Adolescent↗

PubMed1998

Molecular cytogenetic characterization of Thinopyrum and wheat-Thinopyrum translocated chromosomes in a wheat-Thinopyrum amphiploid.

The wheat-Thinopyrum amphiploid 'Agrotriticum # 3425' (AT 3425), which is highly resistant to Cephalosporium stripe, was identified to carry seven pairs of Thinopyrum chromosomes, three pairs of wheat-Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes. Fluorescence genomic in situ hybridization (FGISH), C-banding, sequential C-banding and FGISH, and denaturing polyacrylamide gel electrophoresis (SDS-PAGE) were used to characterize and identify the chromosomes. The Thinopyrum chromosomes in AT 3425 were designated as T1 through T7 based on their C-banding patterns. The FGISH and C-banding patterns of mitotic chromosomes in AT 3425 and meiotic chromosomes in the hybrid between AT 3425 and wheat cultivar 'Chinese Spring' (CS) revealed that wheat chromosomes 1D, 2B and 3D were involved in the three wheat-Thinopyrum chromosome translocations designated as (W-T)1, (W-T)2, and (W-T)3 respectively. The analysis of high-molecular-weight glutenin subunits in single seeds of AT 3425 confirmed the involvement of wheat chromosome 1D in the translocation (W-T)1. The designations 1DSx1DL-1TL, 2BSx2BL-2TL and 3DSx3DL-3TL were suggested for the wheat-Thinopyrum translocated chromosomes (W-T)1, (W-T)2 and (W-T)3 in AT 3425 respectively.

Chromosome Banding↗

PubMed1997

Alcohol withdrawal.

There are three concurrent processes involved in the withdrawal from alcohol in an alcohol-dependent person. The first process is the hippocampal calcium channel mechanism diagnosed by the coarse tremor leading, sometimes precipitously, to convulsions. The second process is commonly referred to as alcoholic hallucinosis, and involves the psychoactive biogenic amine, harmine. The third process involves the locus coeruleus and presents as irritability, a fine tremor, autonomic storm, and diaphoresis. Magnesium and phenobarbital are usually sufficient to treat the syndrome of alcohol withdrawal, although neuroleptics may be required.

Alcoholism↗

PubMed1995

Energy expenditure of below-knee amputees during harness-supported treadmill ambulation.

Traditional rehabilitation of amputees is primarily aimed at strengthening remaining musculature necessary for prosthetic use and gait training. Available gait training time, however, is often limited by pain, residual limb skin tolerance, and the patient's cardiovascular endurance. Harness-supported treadmill ambulation is a rehabilitation technique being used by physical therapists to decrease an individual's body weight by a given percentage during exercise. This, theoretically, allows an amputee to ambulate on a prosthesis at a lower energy cost. The purpose of this study was to compare the energy expenditure of healthy below-knee amputee volunteers with healthy able-bodied volunteers during harness-supported treadmill ambulation in order to determine if energy conservation is achieved. Subjects were tested on a treadmill, walking at .67 m/sec (1.5 mph) and 1.34 m/sec (3.0 mph) during each of the following randomized harness-supported treadmill ambulation situations: full body weight, 20% body weight supported, and 40% body weight supported. During the last minute of each trial, rate of perceived exertion, heart rate, and standardized indirect calorimetry oxygen consumption (VO2, ml/kg/min) measures were collected. Caloric expenditure (kl/min) was calculated using metabolic conversion equations. Peak heart rate, peak VO2, and peak kl/min were measured after the conclusion of the last walking trial by taking each subject to volitional fatigue. Data were analyzed for each harness-supported treadmill ambulation situation and group using analysis of variance (ANOVA). The researchers identified significantly lower ratings of perceived exertion, heart rates, and VO2s for able-bodied subjects vs. below-knee amputees for all trials. Both groups demonstrated significantly lower heart rates, VO2s, and kl/min at 1.34 m/sec with 40% body weight supported.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Validation of a 20-minute steady-state jog as an estimate of peak oxygen uptake in adolescents.

Distance run tests are often used to estimate peak oxygen uptake (peak VO2) in children. This study examined the concurrent validity of a 20-min steady-state jog (20MSSJ). The sample consisted of 43 boys and 32 girls who performed a 20MSSJ and completed a maximal treadmill test 1 week later. Peak VO2 was measured by indirect calorimetry. Subject characteristics were as follows: boys, mean age = 15.1 +/- 1.0 years, mean peak VO2 = 46.4 +/- 7.7 ml.kg-1 x min-1, mean 20MSSJ = 2.3 +/- 0.5 miles; girls, mean age = 15.3 +/- 1.1 years, mean peak VO2 = 40.4 +/- 5.1 ml.kg-1 x min-1, mean 20MSSJ = 2.1 +/- 0.5 miles. The correlation between 20MSSJ and peak VO2 was .68 across boys and girls. The regression slopes of the boys and girls were common, but the intercepts differed, F (1, 72) = 10.9, p < .05. The influence of weight and skinfold fat was examined. Separate models were developed, and the R for each was increased to .79 (SEE = 4.45 ml.kg-1 x min-1) for the model using weight and .80 (SEE = 4.36 ml.kg-1 x min-1) for the model using sum of skinfolds. The regression equations are as follows: peak VO2 = 35.10 + 6.19 (Run) + 2.96 (Gender) -0.26 (Skinfold fat) peak VO2 = 33.94 + 7.64 (Run) + 5.84 (Gender) -0.18 (Weight) (Run = 20MSSJ performance in miles; Gender; females = 0, males = 1; Skinfold fat = sum of two-site skinfolds in mm; Weight = body weight in kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1976

Production of larval tanypodinae (Insecta: Chironomidae) in the mud at Loch Leven, Kinross.

Life histories and production of the five common species of Tanypodinae (Pentaneura monilis, Procladius simplicistilus, P. crassinervis, P. choreus and Psilotanypus rufovittatus) in the mud at Loch Leven were measured from March 1971 to March 1972. The methods used to identify each species of larva are described. All were univoltine except Pentaneura monilis which had two generations per year, but the seasonal patterns of the life cycles were different. The average density of third and fourth instar Tanypodinae was 3100/m2 and densities of individual species exceeded 2500/m2 for short periods in Procladius crassinervis and P. choreus. Net annual dry weight production by this subfamily was 2-6 g/m2 (57 KJ/m2), with individual species ranging from 1-1 g/m2 (P. crassinervis) to 0-16 g/m2 (Pentaneura monilis). These results are discussed briefly and compared with production estimates for other zoobenthos.

Animals↗

PubMedDate not supplied

Psychological profile of college students who use smokeless tobacco.

The purpose of this study was to develop a psychological profile of smokeless tobacco users. We surveyed 1991 college students regarding their use of tobacco products. Twenty-one percent of the white males used smokeless tobacco compared to only 10.4% of blacks, 5.4% of Hispanics, and 5.4% of others, primarily Asians. Although the prevalence of smokeless tobacco use reported by Asians was relatively low, their rate of reported smoking was over twice as high as any other ethnic group, 43.6%. The most important reasons for beginning to use smokeless tobacco were to "see if I would enjoy it," "most friends used it," and "try something new." The personality profile of the smokeless tobacco users differed from that of smokers and non-users of tobacco. College students with the highest probability of being a smokeless tobacco user were white males who scored higher in extraversion and neuroticism but lower on state anxiety than non-users.

Adult↗