Hypocone reduction and Carabelli's traits in contemporary Jordanians and the association between Carabelli's trait and the dimensions of the maxillary first permanent molar

The objective of this study is to determine the prevalence of expression and bilateralism of two dental morphological traits in contemporary Jordanians: The hypocone reduction trait on the maxillary second permanent molar and Carabelli's trait on maxillary permanent first and second molars. Furthermore, inter-trait correlation and the relationship of Carabelli's traits with upper first molar dimensions were investigated. Three hundred subjects of school children at their 10th grade and of an average age of 15.5 +/- 0.4 years were involved. Alginate impressions for the maxillary arch were taken, dental casts were reproduced. The selected accurate casts were of 132 male- and 155 female-students. The frequencies of hypocone reduction trait on the maxillary second molar and Carabelli's trait on the maxillary molars were examined. Buccolingual and mesiodistal diameters of the maxillary first molar were measured and recorded. Paired Sample t test and Nonparametric Correlation analysis were used for data analysis. Hypocone reduction trait on the maxillary second molar was found in 29.8% of the examined students. Positive forms of Carabelli's trait on first and second molars were observed in 65.0% and 3.8%, respectively. Nonparametric correlation analysis revealed positive association between Carabelli's trait on first molar and hypocone reduction trait on the maxillary second molar. The presence of Carabelli's trait on first molar was strongly associated with the increase of buccolingual, but not the mesiodistal, diameter. Bilateralism was found highly significant in the tested traits and both genders (p < 0.001). This finding might be a sign of relatively low environmental stresses in the living Jordanian population and/or great ability of its individuals to buffer the adverse effects of such stresses.     

Logistic analysis of the effects of shovel trait on Carabelli's trait in a mongoloid population

Mongoloid populations differ from Caucasoids by having a high prevalence of shovel trait and a low prevalence of Carabelli's trait. This study was conducted to investigate the effects of the shovel trait on Carabelli's trait in a Mongoloid population. The research design sought a population that resides in an isolated area and exhibits low admixture with neighboring populations. The Mongoloid group selected for study was the Bunun tribe of aborigines who inhabit an alpine area in Taiwan. The effects of sex and age on Carabelli's trait were controlled in this investigation, as was the association between tooth size and Carabelli's trait. Results show that males were more likely to have Carabelli's trait expressed on teeth than females. The buccolingual diameter of Carabelli's trait teeth was larger than that of teeth without the trait. After adjusting for sex, age, and tooth size, the existence of the shovel trait increased the likelihood of having Carabelli's trait by a factor of three, an effect that is significant. © 1996 Wiley-Liss, Inc.     

Complex segregation analysis of Carabelli's trait in a melanesian population

A complex segregation analysis was performed on Carabelli's trait on the upper first molar utilizing 358 nuclear families from the Solomon Islands of Bougainville and Malaita. Simultaneous estiamtion of three sources of variation by the method of maximum likelihood demonstrates a significant effect of shared sibling environment which accounts for over 19% of the variance in liability for the trait. In addition, a statistically significant major gene influence is discussed and suggestions for quantifying individual liability levels for this and other dental traits are outlined.     

Incidence of Carabelli's trait in Kenyan Africans and Asians

Examination for incidence of Carabelli's trait was done on 1267 Africans and 781 Asian school children, 298 dental plaster casts and 248 skulls of Africans. The African sample is composed of 80% Bantu, 20% Nilote, and Nilo-Hamitic people. When observed intraorally, the trait is present in 31–35% of Africans and 26–27% of Asians. In the dental casts and skull sample of Africans, the trait is present as pit in 23–28%, groove in 20%, and as tubercle and cusp in 22%. The total trait frequency in Africans is 68%.     

High frequencies and grade expressions of Carabelli's trait in a sample of the Croatian population

Although it is generally accepted that Europeans exhibit the highest frequencies of Carabelli's trait (70-90%), these values represent the expression of all possible morphological grades. When only a well-defined trait expression is considered (grades 5th, 6th and 7th), the frequency is much lower, not more than 19.2% for the 5th grade, and significantly less for the 6th and 7th grades. Our observations based on the study of the Croatian (Central European) populations show the highest frequencies for grade of the trait (exceeding 23%). Comparative data for European or European derived populations demonstrate significant variation in grade expression. While the previously published data suggest that the highest grade of the trait expression does not exceed 10%, our figures show the highest yet known frequency of a well-defined trait.     

Relative spraint density and genetic structure of otter (Lutra lutra) along the Drava River in Hungary

In this study, we used genetic-based approaches to estimate population size and structure of Eurasian otter along the Drava River in Hungary, and compared these results to traditional survey-based methods. The relative spraint density of otter was estimated based on the number of fresh (D_f) and total number (D_t) of spraints collected on standard routes over a 2-year period. Nine microsatellite loci were screened, generating 17 individual otter genotypes composed of 45 different alleles. The expected heterozygosity ranged from 0.53 to 0.89 and observed heterozygosity from 0.25 to 0.92. The mean density (D_g) estimated over six different sites was 0.17 individuals per km of shoreline. A close correlation was found between the number of genotypes and spraint counts along a standard route (fresh spraints: r_P=0.85, P<0.01; total spraints r_P=0.76, P<0.05). All genotypes found within the 50 km-long study area were closely related (D_m ranged between 0.08 and 0.21).     

The Patterning Cascade Model and Carabelli's trait expression in metameres of the mixed human dentition: exploring a morphogenetic model

Since ancient times the Mediterranean island of Sardinia has been known for harboring a population with an average body height shorter than almost every other ethnic group in Europe. After over a century of investigations, the cause(s) at the origin of this uniqueness are not yet clear. The shorter stature of Sardinians appears to have been documented since prehistoric times, as revealed by the analysis of skeletal remains discovered in archaeological sites on the island. Recently, a number of genetic, hormonal, environmental, infective and nutritional factors have been put forward to explain this unique anthropometric feature, which persisted for a long time, even when environmental and living conditions improved around 1960. Although some of the putative factors are supported by sound empirical evidence, weaker support is available for others. The recent advent of whole genome analysis techniques shed new light on specific variants at the origin of this short stature. However, the marked geographical variability of stature across time and space within the island, and the well‐known presence of pockets of short height in the population of the southern districts, are still puzzling findings that have attracted the interest of anthropologists and geneticists. The purpose of this review is to focus on the state‐of‐the‐art research on stature, as well as the factors that made Sardinians the shortest among Europeans.     

Last Remnants of Riparian Wooded Meadows along the Middle Drava River (Slovenia): Species Composition Is a Response to Light Conditions and Management

In the present study, we investigated the species richness and species composition in relation to light and management regime in remnants of wooded meadows within the riparian forests along the middle Drava River in Slovenia. 41 plots of still managed and, at different time periods (<5 yrs, 5–15 yrs, >15 yrs), abandoned riparian wooded meadows (RWM) were sampled. In addition to vegetation relevés, light intensity (PAR) was also measured in plots. Within the still-managed RWM, two floristically distinct types were recognized using TWINSPAN analysis: meadow-like and forest-like. Light intensity differed significantly between types. The CCA of active RWM showed a significant relation between species composition and light conditions. The number of species per relevé on active RWM was negatively correlated with light intensity – in contrast to North European wooded grasslands. This could be explained by the influence of species-rich riparian hornbeam forests that contribute many understorey species, in contrast to naturally mesotrophic meadows. CCA of both active and abandoned RWM demonstrated that light was a good predictor of RWM species composition and that abandonment caused profound changes in floristic composition. The species turnover during succession was more pronounced in less shaded meadow-like RWM where more light-requiring (grassland) species occurred. Species richness was the highest in active forest-like RWM. There were no significant differences in species richness between active meadow-like RWM and groups of abandoned RWM. The remains of riparian forests stretching along the flood plains of Central and Eastern Europe are considered one of the most natural ecosystems in the prevailing agricultural landscape. But naturalness could be in many cases only the consequence of abandonment of ancient land-use practices, like grazing of livestock, cutting between the trees, litter collecting, etc. Examination of the middle Drava River in Slovenia suggests the need to recognize the remains of ancient cultural landscape.     

First dendro-archaeological evidence of a completely excavated medieval settlement in the extreme north of Western Siberia

The Buchta Nakhodka settlement is the only archaeological site in the northern part of Western Siberia that has been fully excavated. This well-preserved settlement on Russia’s Yamal Peninsula around 67° N and 72° E, however, has not yet been calendar dated, and the cultural identity of its inhabitants still remains unknown. Here we apply, for the first time, dendrochronological techniques to absolutely date 13 of the most important archaeological timbers from the Buchta Nakhodka settlement. Statistical robust cross-dating results place the construction into the second quarter of the 13th century. The Buchta Nakhodka settlement reveals no obvious connection with the modern, nomadic population of Yamal, the Nenets. Together with a careful literature review, this study indicates that the closest construction techniques and subsequent settlement forms can be found on Iceland and across northern Fennoscandia, where Sami people are building their houses in a similar way. Our combined archaeological, dendrochronological, ethnographical and (archaeo)zoological evidence suggests that the ancient inhabitants of Buchta Nakhodka were closely related to the Sihirtya people that were often mentioned in ancient Nenets folklore as legendary people who inhabited the Yamal Peninsula previously. In providing unique insights into the medieval settlement history of the northern part of Western Siberia, we hope to encourage further interdisciplinary research projects to be launched at Eurasia’s high-northern latitudes.     

Spatial pattern of native species Myriophyllum spicatum and invasive alien species Elodea nuttallii after introduction of the latter one into the Drava River (Slovenia)

Invasive alien species Elodea nuttallii was introduced into the Drava River (Slovenia) in 2007. The spatial distribution of native macrophyte species Myriophyllum spicatum and the invasive alien species E. nuttallii was studied in two impoundments, HPP Vuhred and HPP Mariborski otok in the years 2009, 2010 and 2011. The very heterogeneous environment of the Drava River had resulted in dynamic and non-uniform distributions of E. nuttalli and M. spicatum in both impoundments. The distribution of E. nuttalli was shown to be suppressed in river stretches exposed to great turbulence. It had, however, successfully invaded areas with gentle slope of littoral, low exposition to main water flow and muddy sediment and prevailed against the native species M. spicatum. The latter was more abundant than E. nuttallii in stretches exposed to higher flow velocity. Thus, the competitive success of M. spicatum and E. nuttallii depended on environmental conditions. Our results lead to the prediction that E. nuttallii will increase further in the river Drava, causing serious economic problems.     

Genetics of the quantitative Lp(a) lipoprotein trait

The Lp(a) lipoprotein is a complex particle composed of a low density lipoprotein (LDL)-like lipoprotein and the disulfide bonded Lp(a) glycoprotein. The complex represents a quantitative genetic trait. SDS gel electrophoresis under reducing conditions of sera followed by immunoblotting with affinity-purified polyclonal anti-Lp(a) demonstrated inter- and intra-individual size heterogeneity of the glycoprotein with apparent Mr in the range 400-700kDa. According to their relative mobilities compared to apo B-100 the Lp(a) patterns were categorized into phenotypes F, B, S1, S2, S3 und S4 and into the respective double-band phenotypes. This size heterogeneity seems to be controlled by multiple alleles designated LpF, LpB, LpS1, LpS2, LpS3, LpS4 and a null allele (LpO) at a single locus. Phenotype frequencies observed in 441 unrelated subjects were in good agreement with those expected from the genetic hypothesis. Comparison of Lp(a) lipoprotein concentrations in the different phenotypes revealed a highly significant association of phenotypes B, S1 and S2 with high, and phenotypes S3 und S4 with intermediate Lp(a) concentrations. A third mode is represented by the null phenotype were no Lp(a) band is detected upon immunoblotting and Lp(a) lipoprotein is low or absent. We conclude that the same gene locus is involved in determining Lp(a) glycoprotein phenotype and Lp(a) lipoprotein concentrations in plasma. This major gene seems to be the Lp(a) glycoprotein structural gene locus.     

Genetics of the quantitative Lp(a) lipoprotein trait

Summary Lp(a) glycoprotein exhibits an apparent size polymorphism that is associated with genetically controlled Lp(a) lipoprotein concentrations in plasma (Utermann et al. 1988). We have tested the hypothesis that this polymorphism is genetically controlled by studying 15 matings with a total of 44 offspring. This confirmed our conclusion that Lp(a) types are controlled by a series of codominant alleles Lp^F, Lp^B, Lp^S1, Lp^S2, Lp^S3 and Lp^S4 and by a null allele Lp^o. Together with the data from the accompanying paper this indicates that the structural gene for the Lp(a) protein is the major gene locus determining Lp(a) lipoprotein concentrations in plasma.     

Genetics of the quantitative Lp(a) lipoprotein trait

Summary Apolipoprotein(a) [apo(a)] is a large serum glycoprotein with several genetically determined isoforms differing in their apparent molecular weight. We determined the effects of the apo(a) isoforms on total cholesterol, high-density lipo-protein (HDL)-cholesterol, lipoprotein(a), and triglyceride levels in a sample of 473 unrelated Tyrolean adults. Average lipoprotein(a) and total cholesterol levels were significantly different among apo(a) types. These significant differences were found among the 13 apo(a) isoform patterns observed in this sample and among several logical subsets of the isoform patterns (e.g. considering only the single band types). The data suggest that the effects of apo(a) alleles on Lp(a) levels are additive. The effects of apo(a) on total cholesterol levels cannot be entirely explained by the cholesterol fraction estimated to be contained in the lipoprotein(a) particle. We estimate that the apo(a) glycoprotein polymorphism accounts for 41.9% and 9.6% of the variability in lipoprotein(a) and total cholesterol levels, respectively. This is the strongest effect of a single polymorphic gene on plasma lipid and lipoprotein levels reported so far.     

Didymosphenia geminata (Lyngbye) M. Schmidt (Bacillariophyta) in the Danube basin: New data from the Drava river (northern Italy)

Abstract

The presence of Didymosphenia geminata (Lyngbye) M. Schmidt (Bacillariophyta) was revealed in the Drava river and in its affluent Rio Sesto, both flowing in the Alto Adige/Südtirol region of Italy and belonging to the Danube basin. New data are given on the distribution of the species in the Danube basin.     

Early medieval cattle remains from a Scandinavian settlement in Dublin: genetic analysis and comparison with extant breeds

A panel of cattle bones excavated from the 1000-year-old Viking Fishamble Street site in Dublin was assessed for the presence of surviving mitochondrial DNA (mtDNA). Eleven of these bones gave amplifiable mtDNA and a portion of the hypervariable control region was determined for each specimen. A comparative analysis was performed with control region sequences from five extant Nordic and Irish cattle breeds. The medieval population displayed similar levels of mtDNA diversity to modern European breeds. However, a number of novel mtDNA haplotypes were also detected in these bone samples. In addition, the presence of a putative ancestral sequence at high frequency in the medieval population supports an early post-domestication expansion of cattle in Europe.     

Estimation of the contribution of quantitative trait loci (QTL) to the variance of a quantitative trait by means of genetic markers

The estimation of the contribution of an individual quantitative trait locus (QTL) to the variance of a quantitative trait is considered in the framework of an analysis of variance (ANOVA). ANOVA mean squares expectations which are appropriate to the specific case of QTL mapping experiments are derived. These expectations allow the specificities associated with the limited number of genotypes at a given locus to be taken into account. Discrepancies with classical expectations are particularly important for two-class experiments (backcross, recombinant inbred lines, doubled haploid populations) and F₂ populations. The result allows us firstly to reconsider the power of experiments (i.e. the probability of detecting a QTL with a given contribution to the variance of the trait). It illustrates that the use of classical formulae for mean squares expectations leads to a strong underestimation of the power of the experiments. Secondly, from the observed mean squares it is possible to estimate directly the variance associated with a locus and the fraction of the total variance associated to this locus (r _l ² ). When compared to other methods, the values estimated using this method are unbiased. Considering unbiased estimators increases in importance when (1) the experimental size is limited; (2) the number of genotypes at the locus of interest is large; and (3) the fraction of the variation associated with this locus is small. Finally, specific mean squares expectations allows us to propose a simple analytical method by which to estimate the confidence interval of r _l ² . This point is particularly important since results indicate that 95% confidence intervals for r _l ² can be rather wide:2–23% for a 10% estimate and 8–34% for a 20% estimate if 100 individuals are considered.     

Palaeoecology of a medieval fishpond system (Vajgar, Czech Republic)

A palaeoecological investigation of a sediment core obtained from an artificial lake — the fishpond Vajgar (40 ha) near the town of Jind?ich?v Hradec, southern Bohemia, has been carried out in connection with extensive multidisciplinary research preceding the removal of its sediment. Samples from selected standard profile were subjected to chemical, pollen, and palaeoalgological analyses in order to study the chronology of vegetation development, anthropogenic impact on the landscape, and the development of an artificial fishpond ecosystem. The palaeoecological record under study comprises the period of extensive change from pre-cultural, silver fir-dominated forest vegetation into managed, agricultural landscape dominated by cereal fields and pastures. After Medieval colonization, the proportion between wooded and open landscape changed, and the composition of original forests shifted to pine. Pollen spectra from the High Middle Ages are characterized by high percentages of anthropogenic indicators and closely resemble the results from urban deposits (cesspits, wells, communication horizons, etc.). This period can be subdivided into a first phase correlated with the High and Late Middle Ages and a second phase correlated with the post Medieval period and partly maybe also with the agricultural collectivization of the 20th century. The earlier phase has a rather uniform character with a significant presence of grazing indicators and cereal weeds. After the collectivization of the 1950s and later, a substantial change in agricultural practices can be detected: the large-scale use of herbicides affecting the composition of agricultural ruderal species (e.g. decline of cornflower (Centaurea cyanus), rye (Secale), etc.). The development of the aquatic system of the fishpond Vajgar was studied by means of chemical and palaeoalgological analyses. On the basis of observed changes in the composition of subfossil algal communities, the fishpond history can be split into four distinct phases. It is assumed that the progression over individual phases was caused by changes in water chemistry that can be interpreted as shifts in water quality caused by the urbanization of the surrounding areas as well as by changes in agricultural practices. The results of the investigation of some chemical elements (especially heavy metals) show stratigraphic patterns that can be related to historical events. These results show that the mixing and bioturbation of the sediment was not so significant as might be expected.