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R J Rose

Publications and source records attributed to R J Rose.

At least 127 records · Page 7Linked to original sources
PubMed1992

Likelihood-based analyses of longitudinal twin and family data: experiences with pedigree-based approaches.

Substantial progress has been made recently in analyses of longitudinal twin and family data, principally for two reasons. The first is the continuing development of more refined models for describing longitudinal data; the second is the widespread availability of analytic methods (e.g. LISREL) with which to implement these models. Computational restrictions have limited likelihood-based analyses of longitudinal genetic data to analyses of covariance matrices or mean squares; however, advances in computer technology now make it feasible to conduct likelihood analyses of longitudinal pedigree data. We consider potential advantages of using pedigree-based methods. Our initial experiences with the application of these methods to simulated twin data, using the FISHER (Lange, K.L., et al., Genet. Epidemiol. 5:471, 1988) quantitative genetics package, are discussed, with particular attention to practical details such as running times on several computers. Preliminary results of the pedigree-based analyses, including robust estimation methods, convincingly demonstrate the failure of methods assuming the multivariate normal distribution for simulated twin data provided by Carey (this issue).

Adolescent↗
PubMed1992

Indirect myosin immunocytochemistry for the identification of fibre types in equine skeletal muscle.

The histochemical ATPase method for muscle fibre typing was first described by Brooke and Kaiser in 1970. However, problems have been found with the subdivision of type II fibres using this technique. To determine whether indirect myosin immunocytochemistry using anti-slow (5-4D), anti-fast (1A10) and anti-fast red (5-2B) monoclonal antibodies with cross reactivity for type I, II and IIa fibres, respectively, in a number of species, could identify three fibre types in equine skeletal muscle, data on fibre type composition and fibre size obtained using the two different techniques were compared. Results indicate that different myosin heavy chains can coexist in single equine muscle fibres. Type I and type II fibres were identified by immunocytochemistry, but subdivision of type II fibres was not possible. Although the percentage of type I and type II fibres was not significantly different for the two techniques, a few fibres reacted with both the 1A10 and 5-4D antibodies.

Animals↗
PubMed1992

Consistency and change in patterns of social drinking: a 6-year follow-up of the Finnish Twin Cohort.

In 1975 and again in 1981, all adult twins in the population-based Finnish Twin Cohort were administered postal questionnaires yielding data on self-reported frequency and quantity of alcohol use. The longitudinal results provide information on the age-to-age stability of social drinking patterns among 13,404 (twin) individuals aged 18 to 43 at baseline; model-fitting the cross-temporal consistency of the twins' reported alcohol use yields unique estimates of the contribution of genetic and environmental factors to their individual age-to-age stabilities. Mean consumption levels did not change between 1975 and 1981. Patterns of social drinking were more stable in older (aged 24-43 at baseline) than younger (aged 18-23 at baseline) adult twins, and were more stable among men than women. Heritabilities were significant at both baseline and follow-up for all three alcohol measures in both genders and both age groups, with a median magnitude of 0.48. Both longitudinal genetic and environmental covariances were significant, and both were generally higher among older pairs. Genetic covariances (median magnitude = 0.68) were significantly higher than environmental covariances (median = 0.36). Analyses of absolute changes in alcohol use revealed heritable influences on the disposition to change. We conclude that genes contribute to both consistency and change in patterns of alcohol use from early to midadulthood.

Adult↗
PubMed1992

Degree of learning, interpolated tests, and rate of forgetting.

The purpose of the two experiments reported here was to observe the effects of degree of learning, interpolated tests, and retention interval, primarily on the rate of forgetting of a list of words, and secondarily on hypermnesia for those words. In the first experiment, all the subjects had one study trial on a list of 20 common words, followed by two tests of recall. Half of the subjects had further study and test trials until they had learned the words to a criterion of three correct consecutive recalls. Two days later, half of the subjects under each learning condition returned for four retention tests, and 16 days later, all the subjects returned for four tests. Experiment 2 was similar, except that all the subjects had at least three study trials followed by four recall tests on Day 1, intermediate tests were given 2 or 7 days later, and they all had final tests 14 days later. The results showed that rate of forgetting was attenuated by an additional intermediate set of tests but not by criterion learning. Hypermnesia was generally found over the tests that were given after a retention interval of 2 or more days. The best predictor of the amount of hypermnesia over a set of tests was the difference between overall cumulative recall and net recall on the first test of the set.

Achievement↗
PubMed1991

Estimation of blood alcohol concentrations in young male drinkers.

This research examined individual differences in the ability to self-monitor the effects of alcohol. Thirty-nine male subjects consumed 0.75 ml/kg alcohol and estimated their blood alcohol concentrations (BACs) at peak BAC and on the ascending and descending limbs of the blood alcohol curve. Family history of alcohol dependence did not affect the accuracy of estimation of BACs. Subjects who reported lower levels of subjective intoxication underestimated their BACs more than did subjects who reported higher levels of subjective intoxication. Subjects with less behavioral impairment underestimated their BACs more than subjects with greater behavioral impairment on the ascending limb of the blood alcohol curve. Accuracy was better on the ascending limb compared with peak BAC and the descending limb, and accuracy became worse over time on the descending limb. It appears that cues to the effects of alcohol rapidly become unavailable on the descending limb, which may contribute to decisions concerning further alcohol consumption and driving after drinking.

Adult↗
PubMed1991

Genetics of alcoholism: effects of migration on concordance rates among male twins.

We have extended linkage of the population-based Finnish Twin Cohort to alcohol-related hospital discharge data through 1985. The sample included 10,680 individual male twins > or = age 30 at time of linkage; 269 of these twins (2.5%) had received an alcohol-related hospital diagnosis. Twin analyses confirm significant genetic variance in alcohol-related disorders, but suggest that concordance for these disorders is greater for twins living within limited geographic areas, perhaps due to restricted social mobility among those who abuse alcohol.

Adult↗
PubMed1990

Thylakoid-bound chloroplast DNA from spinach is enriched for replication forks.

Chloroplast DNA is bound to the thylakoids of spinach chloroplasts. To examine a possible role for thylakoid-bound DNA in chloroplast DNA replication, vesicles formed by treating chloroplasts in 3.5 mM MgCl2 were used. Chloroplast DNA fragments are bound to the surface of these vesicles. Chloroplast DNA isolated from vesicles that had been first treated with Eco R1 contained 10% of branched fragments whereas chloroplast DNA isolated from intact chloroplasts and treated with Eco R1 contained 2% of branched fragments. This result is consistent with the growing replication fork of chloroplast DNA being associated with the chloroplast internal membrane system. Branched fragments from the chloroplast DNA digested with Eco R1 prior to the isolation from the vesicle contained fragments of unequal length. Membrane binding in chloroplasts may have a similar role in DNA replication as it does in bacteria.

Chloroplasts↗
PubMed1990

Respiratory and metabolic responses in the horse during moderate and heavy exercise.

Thoroughbred horses were exercised to fatigue on a treadmill at 62% and 100% of their VO2max. Hypoxemia occurred at the onset of exercise under both exercise conditions. This hypoxemia persisted to fatigue during the heavy exercise but progressively diminished as the exercise continued and had disappeared by the end of exercise at the lighter load. As a result of the hypoxemia the oxygen content of arterial blood during exercise at VO2max was 17% below its carrying capacity. However, under both experimental conditions the CaO2 still exceeded that of rest owing to an elevation in hemoglobin concentration. The temperature of blood at the point of fatigue was similar, 41.0 +/- 0.2 degrees C and 41.1 +/- 0.2 degrees C, for exercise at 62% and 100% VO2max, respectively. Muscle samples collected at rest and at the termination of exercise did not demonstrate major differences between the exercise conditions except for a higher [lactate] and lower pH following the heavy exercise. From these results it can be suggested that the combined effects of an elevated body temperature, changes in muscle pH, and oxygen delivery may all be factors contributing to limit exercise capacity in the horse.

Adenosine Triphosphate↗
PubMed1990

Social contact and sibling similarity: facts, issues, and red herrings.

We consider evidence that shared experience is associated with sibling resemblance and report new analyses of our earlier data to assess the magnitude and meaning of that association. We cite recent Swedish studies of early separated twins and present new data from reared-apart twins in Finland. Results of these analyses confirm our earlier conclusion that, for some dimensions of personality and life-style, twins who cohabit longer into adulthood and twins who retain closer contact after separation are more alike. Further, new analyses here reported are consistent with our earlier inference that, for neuroticism and consumption of alcohol, cotwin differences in contact precede, and causally contribute to, differences in behavioral similarity.

Female↗
PubMed1990

Change in cohabitation and intrapair similarity of monozygotic (MZ) cotwins for alcohol use, extraversion, and neuroticism.

We have reported cross-sectional evidence that behavioral similarities of adult monozygotic (MZ) cotwins are associated with their age at initial separation and the frequency of their subsequent social interaction (Kaprio et al., 1987; Rose et al., 1988; Rose and Kaprio, 1988). Twins who separated early and twins in infrequent interaction were less alike. Data for those reports came from a 1981 survey of the Finnish Twin Cohort. The Finnish cohort had been surveyed in 1975 with a similar questionnaire, and we now report a longitudinal analysis of the 1975-1981 surveys. All cohabiting MZ cotwins, ages 18-25 at the 1975 baseline, were followed up in 1981, and pairwise similarities at baseline and follow-up were compared for three groups: MZ pairs that remained cohabiting, separated pairs in which the cotwins retained regular contact with one another, and separated cotwins whose social interactions at follow-up were infrequent. For alcohol consumption and EPI Neuroticism scores, relative similarities of the MZ cotwins at follow-up paralleled the relative frequencies of their social contact; baseline differences in resemblance for Extraversion scores preceded follow-up differences in social interaction. These findings clarify the directional nature of associations found in our cross-sectional data and provide new, more compelling evidence of effects of shared experience on sibling resemblance for some dimensions of adult behavior.

Adolescent↗
PubMed1990

Electrolytes: clinical applications.

Many factors can influence electrolytes in the horse. With the major electrolytes (sodium and potassium), alterations in serum or plasma values do not reflect changes in total body status. However, estimates of electrolyte alterations may be made by combining assessments of body weight changes with plasma sodium values by using the formula of Edelman et al. In planning electrolyte therapy, it has to be remembered that access to green feed or hay is important in correcting any total body potassium depletion and that diets marginal in sodium may interfere with exercise capacity by limiting sweat production. Free access to salt would seem to be the simplest method to ensure adequate sodium availability. Despite the widespread use of various commercial electrolyte supplements administered in horses' feed, most would appear to be unwarranted. Extensive electrolyte deficits are most likely in endurance horses in which substantial electrolyte losses can occur in the sweat. In such cases and when access to grass or hay is limited, supplementation with sodium and potassium chloride may be useful. Bicarbonate administration appears to have no clinical role in endurance or pleasure horses. However, its use as a buffer to limit the extent of lactic acidosis during galloping exercise has not been resolved.

Animals↗
PubMed1990

Population-based twin registries: illustrative applications in genetic epidemiology and behavioral genetics from the Finnish Twin Cohort Study.

The population-based twin registries of Denmark, Finland, Norway and Sweden represent an extraordinary resource for scientific research. Although each register has its own history and composition, they share certain common qualities. All the Nordic countries have a long tradition of population registration, a high standard of living and health-related registers of high quality. The large size of the registers means that they are uniquely placed for representative studies of rare occurrences. Examples of studies that these registers make possible are illustrated with data from the Finnish Twin Cohort, which in its first phase consisted of over 17,000 like-sexed twin pairs born before 1958. It has been recently expanded to include multiple births between 1958 and 1986 (nearly 23,000 sets) and their first-degree relatives. During this period the DZ/MZ ratio decreased, while an increase in MZ twinning rates was observed between 1974 and 1986.

Adult↗
PubMed1990

Clinical exercise testing in the normal thoroughbred racehorse.

To evaluate normal cardiorespiratory and metabolic responses of Thoroughbred horses to a standardised treadmill exercise test, we examined 28 horses ranging in age from 1 to 4 years. The group consisted of eight yearlings, eight 2-year-olds and twelve 3 and 4-year-olds. All horses except the yearlings were in training, and either racing or ready to race, at the time of examination. None of the horses had histories of performance problems. On the first day the horses received a full physical examination, resting electrocardiogram, upper respiratory tract endoscopy and either one or two acclimatisation runs on the treadmill. The following day they were given an exercise test on a treadmill inclined at 6 degrees (+10% slope). The test consisted of 3 min at 4 m/sec, 90 sec at 6 m/sec and 60 sec intervals at 8, 10, 11, 12 and 13 m/sec. During the last 15 sec of each step, blood samples were collected for plasma lactate determination, expired respiratory gases were obtained using an open flow mask system for measurement of oxygen uptake, and heart rate was measured using telemetry electrocardiogram. From these measurements, various derived values were calculated, which have been used by others as indices of exercise capacity. These values included: V200 (speed at HR of 200 bpm), VHRmax (speed at which horses reached maximum HR), VO2-200 (oxygen uptake at a HR of 200 bpm), VO2max (maximum oxygen uptake), VLA4 (speed at which horses reached a plasma lactate of 4 mmol/l) and HRLA4 (HR at which horses reached a plasma lactate of 4 mmol/l). The yearlings had significantly lower values than the older age groups for most of the derived values.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗