Prenatal selection and dermatoglyphic patterns

Although human dermatoglyphics have been extensively studied, little is known of the prenatal origins of dermatoglyphic patterns. Digital patterns, i.e., loops, whorls, and arches, were obtained from 81 human abortuses, ranging in age from 11 to 25 weeks post-fertilization. Patterns were discernible with the earliest indications of epidermal ridge development. Findings indicate that pattern frequencies during early prenatal development differ from those of later fetal and postnatal periods. Furthermore, a high frequency of arches is seen associated with spontaneous abortion, suggesting evidence for prenatal selection in human abortuses.     

Palmar dermatoglyphic patterns in twins

The role of genetic factors in the determination of palmar dermatoglyphic patterns was investigated in a series of 49 MZ and 51 DZ twins, using Spearman's rank correlation and analysis of variance. Both methods indicated that the genetic effect in the distribution of patterns is highest in the interdigital III and lowest in the interdigital IV regions, the hypothenar and thenar showing intermediate values. As for interdigital II, no evaluation of genetic effects was possible using the nonparametric test, but the estimates of genetic variance indicate that inherited factors may play a relatively minor role in the pattern distribution of this area.     

Inbreeding effects on bilateral asymmetry of dermatoglyphic patterns

Bilateral correlations are higher and bilateral variances within individuals smaller in the samples of inbred individuals than in matched control groups of the same sex for pattern intensities on fingers in four series of data and also for pattern intensities on palms, toes, and soles and the palmer main line indices in the data collected from a Muslin population of West Bengal. This trend is not apparent in two series of data from the Yanadi tribe, in which the inbred and noninbred samples are not controlled for random variation of genes and environment. Increased variances between individuals and changes in means and distributions of the traits in the inbred samples of the matched data indicate some influence of homozygosity of genes for the traits on their asymmetry. The reduced variability of asymmetry of the traits in the inbred cannot be explained by homozygosity of genes for either directional or absolute asymmetry. One possible explanation is that heterozygotes for these dermatoglyphic triats are more responsive to environmental stress than homozygotes and/or increased selection in the homozygotes against genetic disorders associated with dermatoglyphic asymmetry may reduce the variability of such asymmetry.     

Genetic analysis of dermatoglyphic patterns in twins.

Analysis of variance was performed on 71 dermatoglyphic variables in 424 twin sets. Using a method of twin analysis estimates of genetic variance were obtained. 54 of the variables were quantitated using a scoring system with modifications of arch or no pattern = 0, loops = 1, whorl = 2. The results indicated a significant genetic influence in most pattern areas. Patterning was more genetically controlled in the hand than in the foot. The hallucal area had the most significant genetic component of the foot while the patterns in the thumb had nonsignificant components of genetic variance. The thumb deviated from patterning in the rest of the fingers and may be more closely related to big-toe patterning.     

Comparisons of dermatoglyphic patterns in monochorionic and dichorionic monozygotic twins

The data presented here indicate that different influences affect dermatoglyphic pattern development in MC-MZ and DC-MZ twins. Only five of 84 variables had significant mean differences but their clustering suggested a real difference in mean placement of the atd angle. Nineteen of 84 variables had significantly different within-pair mean squares for the two twin types. Larger numbers of twins will be required to obtain accurate estimates of the magnitude of the dermatoglyphic differences between MC-MZ and DC-MZ twins. Studies of dermatoglyphics in MC-MZ and DC-MZ twins are important to the understanding of factors which influence early embryonic development and when better documented may provide a mechanism for retrospectively diagnosing placental type of MZ twins.     

A comparison of dermatoglyphic methodologies in population studies

Use of dermatoglyphics in population studies has been marked by a great deal of methodological variation among investigators. We compare various dermatoglyphic approaches using data derived from four groups in the Kumaon region of India. Dermatoglyphic data included ridge-counts and other quantitative variables, and the classification systems of Cummins and Midlo and Penrose and Loesch. Results were evaluated against anthropometric and serological relationships. No clearly superior approach emerges, although it is generally true that palmar variables exhibit more intergroup heterogeneity than digital variables and produce more reasonable results than the other approaches. The conventional method of treating ridge-counts, that of choosing the larger of the two counts, was the most unsatisfactory of the quantitative approaches, leading to the recommendation that both radial and ulnar counts be retained. We conclude that environmental variation may contribute substantially to intergroup variation.     

Topological classification of RNA structures

We present a novel topological classification of RNA secondary structures with pseudoknots. It is based on the topological genus of the circular diagram associated to the RNA base-pair structure. The genus is a positive integer number whose value quantifies the topological complexity of the folded RNA structure. In such a representation, planar diagrams correspond to pure RNA secondary structures and have zero genus, whereas non-planar diagrams correspond to pseudoknotted structures and have higher genus. The topological genus allows for the definition of topological folding motifs, similar in spirit to those introduced and commonly used in protein folding. We analyze real RNA structures from the databases Worldwide Protein Data Bank and Pseudobase and classify them according to their topological genus. For simplicity, we limit our analysis by considering only Watson-Crick complementary base pairs and G-U wobble base pairs. We compare the results of our statistical survey with existing theoretical and numerical models. We also discuss possible applications of this classification and show how it can be used for identifying new RNA structural motifs.     

Parent-offspring resemblance of palmar and plantar dermatoglyphic patterns in Down syndrome

With the aim of investigating the influence of trisomy 21 on the expression of heritable morphological features, we recorded the palmar and plantar dermatoglyphic patterns in 48 children with Down syndrome (DS), in both their parents, and, as a control, in 57 of their siblings. Using the Kendall tau rank correlation test, a considerable parental influence on the frequency of true patterns in the interdigital areas (IDA) III and IV of the palms (P = 0.3%) and soles (P = 1.0% and 3.8%, respectively) is demonstrated for the control siblings. In the children with DS, this influence is discernible as well, although with no statistical significance. A greater number of families may be required to settle the question.     

Digital and palmar dermatoglyphic patterns among natives of extreme northwest Nepal

A dermatoglyphic study was made of two high-altitude populations inhabiting the same ecozone in extreme northwest Nepal. Despite cultural and linguistic differences there appears to be a significant amount of dermatoglyphic homology between the Buddhist-Tibetan villages and their Hindu-Caucasian neighbors.     

Lateral flagella of vibrios: serological classification and genetical similarity.

Lateral (L-) flagella-having vibrios were classified into 13 H-serogroups (flagellar antigen serogroups) by means of H-agglutination test. Vibrio parahaemolyticus was classified into 3 serogroups, HL1 to 3. V. alginolyticus and V. harveyi were classified into 5 and 3 serogroups, respectively, but 2 of those were serogroups common to the both species. V. fluvialis and V. furnissii constituted a same serogroup, HL8. Cross-reactivity between each serogroup was not observed in H-agglutination test, although some cross-reactivity was observed in gel diffusion test. Furthermore, similarity of DNA sequence of L-flagellar structure gene was demonstrated by dot blot hybridization test with a DNA probe of HL2 L-flagellar gene fragment. These results suggest conservation of DNA sequence of the L-flagellar gene of vibrios.     

Digital dermatoglyphic patterns of Eskimo and Amerindian populations: relationships between geographic, dermatoglyphic, genetic, and linguistic distances.

Dermatoglyphic traits have been used to assess population affinities and structure. Here, we describe the digital patterns of four Eskimo populations from Alaska: two Yupik-speaking villages from St. Lawrence Island and two Inupik groups presently residing on mainland Alaska. For a broader evolutionary perspective, these four Eskimo populations are compared to other Inuit groups, to North American Indian populations, and to Siberian aggregates. The genetic structures of 18 New and Old World populations were explored using R-matrix plots and Wright's FST values. The relationships between dermatoglyphic, blood genetic, geographic, and linguistic distances were assessed by comparing matrices through Mantel correlations and through partial and multiple correlations. Statistically significant relationships between dermatoglyphics and genetics, genetics and geography, and geography and language were revealed. In addition, significant correlations between dermatoglyphics and geography, with linguistic variation constant, were noted for females but not for males. These results attest to the usefulness of dermatoglyphics in resolving various evolutionary questions concerning normal human variation.     

Topological and phenomenological classification of bursting oscillations

We describe a classification scheme for bursting oscillations which encompasses many of those found in the literature on bursting in excitable media. This is an extension of the scheme of Rinzel (inMathematical Topics in Population Biology, Springer, Berlin, 1987), put in the context of a sequence of horizontal cuts through a two-parameter bifurcation diagram. We use this to describe the phenomenological character of different types of bursting, addressing the issue of how well the bursting can be characterized given the limited amount of information often available in experimental settings.     

Digital dermatoglyphic patterns in a sample of the Nigerian population

Eight hundred Nigerians (400 males and 400 females) were screened for the analysis of digital dermatoglyphic patterns. The frequency distribution of the patterns are 52.09%, 27.67%, 19.20% and 1.13% for ulnar loops, whorls, arches and radial loops respectively. Except for arches, the males have more of the patterns than females. The pattern intensity indices for males and females are 11.2 and 9.9 respectively. Bilateral symmetry is similar in both sexes and the percent distribution is as high as 81.5% and 84% on digit V in males and females respectively.