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Biomedical subjects

I Barrai

Publications and source records attributed to I Barrai.

At least 91 records · Page 5Linked to original sources
PubMed1973

Correlation between leprosy rates in villages different distances apart.

In order to study the role of genetic factors in susceptibility to leprosy infection, the prevalence of leprosy in 118 pairs of Burmese villages different distances apart was investigated. The distribution pattern of the correlation coefficients for leprosy rates was compared with that known to occur for genetic markers under similar conditions. The correlation coefficients decreased rapidly as the distance between the pairs of villages increased and then showed periodicity with distance, becoming negative at almost regular intervals of 4 km: negative values were preponderant for villages more than 25 km apart. Thus with this set of correlations it was not possible to fit a monotonically decreasing function of the type that would fit similar data for a genetic marker

Genetics, Population↗
PubMed1971

Equilibrium under inbreeding in balanced polymorphisms.

The results of a study on frequencies of genes causing lethal or sublethal disease are reported in relation to the level of consanguinity and heterozygote advantage in populations. The theoretical background of the population dynamics of genes under heterozygote advantage and in the presence of inbreeding is examined and the theoretical models are applied to the estimation of the level of heterosis for lethal and sublethal genes that are responsible for important public health problems in certain populations; these problems include beta-thalassaemia and sickle-cell anaemia. Estimates obtained from the proposed models show a high degree of internal consistency under widely different conditions; data on sickle-cell anaemia from several African populations and on beta-thalassaemia from Italy and Malta were analysed. The hypothesis that rare lethal genes, such as those for Tay-Sachs disease, are maintained in the human population by heterozygote advantage is examined and discussed.

Anemia, Sickle Cell↗
PubMedDate not supplied

Elements of the surname structure of Austria.

The isonymy structure of Austria was studied using the surname distributions in 1081002 private telephone users selected from about 4000000 registered in a 1996 commercial CD-ROM, which contains all Austrian users. The sample was distributed in 120 towns representing an approximately uniform distribution over the country. The number of different surnames found in the whole analysis was 140766. Lasker's distance, the negative value of the logarithm of isonymy between localities, was found to be linearly and significantly correlated with the log of geographic distance, with r = 0.565 +/- 0.011. A dendrogram was built with the matrix of isonymy distance, using the Unweighted Pair-Group Method using Arithmetic averages, UPGMA. It separates the Austrian towns in five main clusters, one along the central portion of the country, another one which occupies the northern region of central Austria; then comes a third cluster at the north-eastern part, a fourth cluster in the western region, and finally a small cluster towards the border with Slovenia. Within each, small subclusters with specific geographic distributions could be delimited. The main clusters correspond fairly well to the classic regions of Austria. The results were compared with those obtained in similar analyses of Switzerland, Germany, Italy and Venezuela. From the present analysis, isolation by distance emerges clearly, and it is stronger than in Germany but smaller than that observed in Italy, Switzerland and Venezuela. The random component of inbreeding estimated from isonymy, at the level of resolution used here, indicates that the inbreeding level in Austria is rather uniform.

Austria↗
PubMedDate not supplied

Family resemblance in blood pressure measurements.

The correlation for diastolic and systolic blood pressure was studied in two samples of quartets each consisting of two pairs. The first sample comprised pairs of sisters and their husbands, and the second sample was comprised of brothers and their wives. All siblings were between 30 and 55 years of age and had been married for at least 5 years. It was found that unrelated men married to sisters had a significant correlation in both diastolic (r = 0.28) and systolic (r = 0.41) pressure. For systolic blood pressure, the correlation between pairs of unrelated men married to sisters was significantly larger than the homologous correlation existing in pairs of brothers married to unrelated women. The correlations of systolic and diastolic pressure in sisters were significantly smaller than the same correlations measured in the wives of brothers. The correlations in height for men, used as an internal control to compare marital and genetic effects, were unaffected by marriage, as expected. The correlations in height for pairs of sisters, however, were no larger than those observed in pairs of unrelated women married to brothers. It was concluded that in adult married men and women of the Ferrara population, aged 30 to 55 years, the influence of genetic factors on blood pressure is less important than the influence of cultural factors.

Adult↗
PubMedDate not supplied

Surnames in Ferrara: distribution, isonymy and levels of inbreeding.

The distributions of surnames in populations of small and large towns are almost exactly linearized by a log-log transformation. This indicates probable fit of genetic models to most such distributions, even when the number of surnames is very large. Genetic parameters can then be conveniently calculated from surname distributions. It was found that inbreeding indicators calculated from isonymy are negatively correlated with the size of the towns from which the names were extracted. It was also found that the levels of inbreeding at present observed in Ferrara have little effect on the frequency of homozygotes for the beta-thalassaemia gene.

Consanguinity↗
PubMedDate not supplied

Isonymy in emigrants from Ferrara in 1981-1988.

The distribution of surnames in the emigrants from the population of the town of Ferrara in the period 1981-88 was studied by sex and place of birth, namely Ferrara versus other places. Emigrants born in Ferrara were defined as first time emigrants and those who had previously immigrated to Ferrara were defined second time emigrants. It was found that random isonymy is smaller in second time emigrants. Sex ratio is not different in the two types of emigrants. As indicators of the abundance of surnames in a distribution, the common ecological indexes derived from entropy were used and compared between types of emigrants. It was found that redundancy, as isonymy, is larger in the first time emigrants than in second time emigrants. It was observed that second time emigrants were consistently and significantly older than first time emigrants, and that a considerable fraction of them, (22.4%) returned to their place of birth. A sexual dimorphism in age at emigration was observed in second time emigrants, females emigrating at an older age than males.

Adult↗
PubMedDate not supplied

Comparisons of Lasker's coefficient of relationship in a Venezuelan town in two different periods.

A formula for the standard error of Lasker's coefficient of relationship Ri derived from isonymy is proposed, and used to test for differences in relationship in two groups of pairs of spouses from the town of Quibor in Venezuela sampled one century apart. From analysis of the relationship, it was possible to attribute population growth also to immigration. Further, the study of the values of Ri showed that the surnames belonging to the male line are more frequent and stable in this population, which is characterized by a predominantly agricultural activity. From the analysis of the coefficients of relationship, the population of Quibor is also classified as patrilocal.

Emigration and Immigration↗
PubMedDate not supplied

Isonymy in records of births and deaths in Ferrara.

Surname distributions were studied in records of male and female births in Ferrara in the period 1982-89, and in records of male and female deaths in the same period. Average year of birth and standard deviation was 1985 +/- 2.3 for the birth series, and 1912 +/- 14.4 for the death series. Then the surname distributions, in two independent samples at an average distance of 73 years, were compared. It was observed that random isonymy within series, which depends on the shape of the distribution, stays fairly constant at three generations of distance, indicating near-equilibrium of surname turnover. The migrational contribution is indicated by the significant decrease of random isonymy between series, measured with the method of Lasker. It was also observed that immigrants to Ferrara have a life-span significantly longer than people born in the town.

Aged↗
PubMedDate not supplied

Microevolution in Ferrara: isonymy 1890-1990.

The distribution of surnames in the population of the town of Ferrara, as it existed in the memory banks of the Municipality Computer in June 1990, was studied by sex, age and place of birth of residents. Random isonymy was studied separately in persons born before 1901, and in persons born in the nine decades thereafter, ending with the period 1981-90. Isonymy was higher in the older age groups studied. Also other indicators of the abundance of surnames in the distribution, the common ecological indexes derived from entropy, were calculated and compared between age groups. It was found that redundancy, as isonymy, is larger in older age classes than in younger classes. Surname effective number was defined as the inverse of isonymy corrected for sample size, and it was observed that it is practically identical with Fisher's alpha. It was then possible to separate random isonymy into two components, so that for sample size N its formulation becomes Ir = 1/alpha + 1/N It was found that in Ferrara alpha increased significantly in time, indicating enrichment of surnames in the population in the century 1890-1990.

Age Factors↗