Surnames in Argentina: a population study through isonymy

In order to study the isonymic structure of Argentina, the surname distributions of 22.6 million electors registered for the year 2001 were analyzed in the 24 districts (distritos) and 541 municipalities (municipios) of the country. The number of different surnames found was 414,441. Matrices of isonymic distances between districts were constructed and tested for correlation with the geographic distance between the capital towns of the districts. We found that, for the whole of Argentina, Euclidean distance was correlated with the log of geographic distance (r=0.480+/- 0.067). A dendrogram of the 24 regions was built from the matrix of Euclidean distances, using the UPGMA method. The clusters identified by the dendrogram are coincident with conterminous geographical regions of the country. Random inbreeding calculated from isonymy, F(ST), was highest in La Rioja, Corrientes, and Santiago del Estero. It was lowest in the area of Buenos Aires and in the north-central region of Santa Fé. Average Fisher's alpha for municipalities was 358; for districts, it was 422; and for Argentina as a unit, it was 602. The geographical distribution of alpha in 541 municipalities, high in the east and lower in the west of the country, is compatible with the settlement in the 20th century of subsequent waves of immigrants moving from the North Atlantic coast toward the foot of the Andes and toward the south. The present structure of Argentina indicates that migration dominates over drift.     

Identification of volatile emissions from Platypus mutatus (=sulcatus) (Coleoptera: Platypodidae) and their behavioral activity

We report here the identification and behavioral activity of volatile compounds emitted by male Platypus mutatus (=sulcatus) Chapuis while boring galleries in living poplar, Populus deltoides Marshall, trees. Headspace analysis using solid phase microextraction techniques showed the presence of 6-methyl-5-hepten-2-ol (sulcatol) and 6-methyl-5-hepten-2-one (sulcatone). Only one enantiomer of sulcatol, retusol, was found to be part of the volatile emission. Behavioral assays showed that females are more attracted than males to galleries with boring males inside. Both sulcatol and sulcatone elicited electroantennographic responses by female P. mutatus. Furthermore, behavioral bioassays showed that both sulcatol and sulcatone elicit behaviorally attractive responses by females. These results suggest that male P. mutatus releases a sex pheromone composed mainly of retusol and sulcatone.     

The ontogeny of the spinning apparatus of Tengella perfuga (Araneae: Zoropsidae)

Silk is the most recognizable trait of spiders, and silk use has changed throughout spider evolutionary history. While morphology of the adult silk spigot has been a useful character for systematics, few studies have examined the ontogeny of the spinning apparatus, and none of these included cribellate spiders. Here, we report the first published full ontogeny of the spinning apparatus of a cribellate spider, Tengella perfuga. We found the presence of expected spigots: major ampullate gland and piriform gland spigots on the anterior lateral spinneret, minor ampullate gland and aciniform gland spigots on the posterior median spinneret, and aciniform gland spigots on the posterior lateral spinneret. Females, but not males, possessed cylindrical gland spigots on both the posterior median and lateral spinnerets. Spiderlings did not possess a functioning cribellum until the third instar. The cribellum grew with increasing numbers of spigots, but functionality was lost in adult males. Most intriguingly, second instars possessed a distinct triad of pre‐spigots on the posterior lateral spinneret. From the third instar onward, these structures formed the modified spigot along with two flanking spigots (in females) or formed nubbins (in males). We suggest that the modified spigot serves as the source of axial lines in the cribellate silk produced in T. perfuga. We also compare spigot ontogeny from previous studies of ecribellate spiders. These comparisons warrant further exploration using the recent spider tree of life in a phylogenetic comparative analysis of spigot ontogeny datasets, which could yield evidence for homologous spigots across the Araneomorphae, notably the Araneoidea and the Retrolateral Tibial Apophysis (RTA) clades.     

Effect of undernutrition on the distribution of progesterone in the uterus of ewes during the luteal phase of the estrous cycle

The effect of undernutrition on ovarian and uterine venous progesterone concentrations and endometrial progesterone content on Days 5 and 10 of the estrous cycle were studied. Forty ewes were synchronized using progestagen pessaries. At pessary withdrawal, the ewes were fed diets to provide either 1.5 or 0.5 times the daily maintenance requirement (Group H, n = 20 and Group L, n = 20, respectively). Ewes fed the low nutrition diet (Group L) had higher mean peripheral progesterone concentrations than those fed the high plane diet (Group H; P < 0.05) but lower endometrial progesterone content on Day 5 (P < 0.05). Neither ovarian nor uterine venous levels were affected by nutrition on either Day 5 or 10. Progesterone concentrations in blood samples collected ipsilateral to ovaries bearing a corpus luteum (CL) were higher than in the contralateral samples (P < 0.001). It is concluded that undernutrition can produce a reduction of endometrial content of progesterone the first week after mating. Since no differences in ovarian venous concentrations were observed, it remains to be shown whether this variation is due to other variables, such as the population of endometrial progesterone receptors or other nonhormonal factors.     

Disentangling vegetation diversity from climate–energy and habitat heterogeneity for explaining animal geographic patterns

Broad‐scale animal diversity patterns have been traditionally explained by hypotheses focused on climate–energy and habitat heterogeneity, without considering the direct influence of vegetation structure and composition. However, integrating these factors when considering plant–animal correlates still poses a major challenge because plant communities are controlled by abiotic factors that may, at the same time, influence animal distributions. By testing whether the number and variation of plant community types in Europe explain country‐level diversity in six animal groups, we propose a conceptual framework in which vegetation diversity represents a bridge between abiotic factors and animal diversity. We show that vegetation diversity explains variation in animal richness not accounted for by altitudinal range or potential evapotranspiration, being the best predictor for butterflies, beetles, and amphibians. Moreover, the dissimilarity of plant community types explains the highest proportion of variation in animal assemblages across the studied regions, an effect that outperforms the effect of climate and their shared contribution with pure spatial variation. Our results at the country level suggest that vegetation diversity, as estimated from broad‐scale classifications of plant communities, may contribute to our understanding of animal richness and may be disentangled, at least to a degree, from climate–energy and abiotic habitat heterogeneity.     

On a nonlocal system for vegetation in drylands

Journal of Mathematical Biology - Several mathematical models are proposed to understand spatial patchy vegetation patterns arising in drylands. In this paper, we consider the system with nonlocal...     

Equine pythiosis in Costa Rica: Report of 39 cases

Thirty-nine pythiosis equine cases, were studied at the Veterinary Medicine School of the National University of Costa Rica, between 1981 and 1984. Lesions were located in different parts of their anatomy: anterior and posterior extremities, abdomen, thorax, breast and mammary gland, and were characterized by their tumoral appearance with necrotic tissue in which yellow-white coral-like necrotic masses, called kunker or leeches were shown. Splendore-Hoeppli like phenomenon and eosinophilic inflammatory reaction aroud the hyphae, was microscopically observed. Pythium sp. (Hyphomyces destruens) was isolated in Sabouraud dextrose agar from ground kunkers. Immunodiffusion (ID) to diagnose this disease in equines, was performed with succes. Immunotherapy was applied to 5 of affected horses, and three were cured. Some epizootiological aspects of the the pythiosis are also discussed.     

Seed germination traits can contribute better to plant community ecology

Analyses of functional traits have become fundamental tools for understanding patterns and processes in plant community ecology. In this context, regenerative seed traits play an important, yet overlooked, role because they largely determine the ability of plants to disperse and re‐establish. A survey of recent publications in community ecology suggests that seed germination traits in particular are neglected at the expense of other relevant but overused traits based only on seed morphology. As a response to this bias, we discuss the functional significance of seed germination traits in comparison with morphological and biophysical seed traits, and advocate their use in vegetation science. We also demonstrate how research in community assembly, climate change and restoration ecology can benefit from the inclusion of germination traits, encompassing functions that cannot be explained solely by adult plant traits. Seed germination experiments conducted in the laboratory or field to quantify these traits provide ecologically meaningful and relatively easy‐to‐obtain information about the functional properties of plant communities. We argue that bridging the gap between seed physiologists and community ecologists will improve the prediction of plant assemblages, and propose further perspectives for including seed traits into the research agenda of functional community ecologists.