Recognition in ants: social origin matters.

The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens) is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has an effect on their acceptance in conspecific colonies remains poorly explored. Using egg-acceptance bioassays, we tested the influence of social origin of queen-laid eggs on their acceptance by foreign workers in the ant Formica selysi. We showed that workers from both single- and multiple-queen colonies discriminated against foreign eggs from single-queen colonies, whereas they surprisingly accepted foreign eggs from multiple-queen colonies. Chemical analyses then demonstrated that social origins of eggs and workers could be discriminated on the basis of their chemical profiles, a signal generally involved in nestmate discrimination. These findings provide the first evidence in social insects that social origins of eggs interfere with nestmate discrimination and are encoded by chemical signatures.

O grau de orientação para o mercado dos hotéis em Cabo Verde

Dada a importância do conceito de orientação para o mercado e a inexistência de estudos que estudem o seu grau de implementação nas empresas Cabo-Verdianas, este estudo visa medir o grau de orientação para o mercado dos hotéis em Cabo Verde. O estudo foi aplicado às unidades hoteleiras do sector turístico em Cabo Verde com o objectivo de: (i) determinar o grau de orientação para o mercado dos hotéis em Cabo Verde e (ii) verificar a existência de diferenças significativas no grau de orientação para o mercado dos hotéis em função da existência de departamento de marketing nos hotéis, a área funcional dos respondentes, a localização geográfica dos hotéis e a procedência do capital social maioritário. As conclusões do estudo sugerem que em termos gerais, os hotéis, em Cabo Verde, segundo as percepções dos gestores, tem um nível médio de orientação para o mercado. Os resultados mostraram ainda que apenas existe uma diferença significativa no grau de geração e resposta ao mercado, entre os hotéis nacionais e os estrangeiros. Igualmente, constatou-se que, existe uma diferença significativa, no grau de geração e disseminação de informação de mercado, entre a percepção da área comercial e ou marketing e as restantes áreas das unidades hoteleiras. Entretanto, relativamente à localização dos hotéis e à existência ou não de departamentos de marketing, não foi confirmada a existência de diferenças significativas no grau de geração, disseminação de informação e resposta ao mercado. Due to the importance given to the concept of market orientation and the lack of studies which examine its level of implementation in Cape Verdean companies, this research aims to measure the level of market orientation of hotels in Cape Verde. This study was applied to hotel units in Cape Verde with the aim of: (i) determining the level of market orientation in Cape Verde hotels and (ii) verifying the existence of significant differences in the degree of market orientation of hotels which have or not a marketing department, the professional area of the respondents, the geographic location of the hotels and the origin of the majority funds. According to the managers’ perceptions, the results suggest that in general terms, the hotels, in Cape Verde, , have an intermediate level of market orientation. The results also show that there is a significant difference between national and foreign hotels regarding information generation and responsiveness to market. In the same way, there is as significant difference on the degree of generation and dissemination of information between the functional commercial areas and the others functional hotel areas. However, there was no significant difference on what concerns generation, dissemination and market responsiveness, regarding hotels location and the existence or not of marketing departments.

Geographic variation in sex-chromosome differentiation in the common frog (Rana temporaria).

In sharp contrast with birds and mammals, sex-determination systems in ectothermic vertebrates are often highly dynamic and sometimes multifactorial. Both environmental and genetic effects have been documented in common frogs (Rana temporaria). One genetic linkage group, mapping to the largest pair of chromosomes and harbouring the candidate sex-determining gene Dmrt1, associates with sex in several populations throughout Europe, but association varies both within and among populations. Here, we show that sex association at this linkage group differs among populations along a 1500-km transect across Sweden. Genetic differentiation between sexes is strongest (FST  = 0.152) in a northern-boreal population, where male-specific alleles and heterozygote excesses (FIS  = -0.418 in males, +0.025 in females) testify to a male-heterogametic system and lack of X-Y recombination. In the southernmost population (nemoral climate), in contrast, sexes share the same alleles at the same frequencies (FST  = 0.007 between sexes), suggesting unrestricted recombination. Other populations show intermediate levels of sex differentiation, with males falling in two categories: some cluster with females, while others display male-specific Y haplotypes. This polymorphism may result from differences between populations in the patterns of X-Y recombination, co-option of an alternative sex-chromosome pair, or a mixed sex-determination system where maleness is controlled either by genes or by environment depending on populations or families. We propose approaches to test among these alternative models, to disentangle the effects of climate and phylogeography on the latitudinal trend, and to sort out how this polymorphism relates to the 'sexual races' described in common frogs in the 1930s.

Origin of mineralizing fluids of the sediment-hosted Navachab gold mine, Namibia: Constraints from stable (O, H, C, S) isotopes

The Navachab gold mine in the Damara belt of central Namibia is characterized by a polymetallic Au-Bi-As-Cu-Ag ore assemblage, including pyrrhotite, chalcopyrite, sphalerite, arsenopyrite, bismuth, gold, bismuthinite, and bismuth tellurides. Gold is hosted by quartz sulfide veins and semimassive sulfide lenses that are developed in a near-vertical sequence of shelf-type metasedimentary rocks, including marble, calcsilicate rock, and biotite schist. The sequence has been intruded by abundant syntectonic lamprophyre, aplite, and pegmatite dikes, documenting widespread igneous activity coeval with mineralization. The majority of quartz from the veins has delta(18)O values of 14 to 15 per mil (V-SMOW). The total variations in delta(18)O values of the biotite schist and calcsilicate rock are relatively small (12-14 parts per thousand), whereas the marble records steep gradients in delta(18)O values (17-21 parts per thousand), the lowest values being recorded at the vein margins. Despite this, there is no correlation between delta(18)O and delta(13)C values and the carbonate content of the rocks, indicating that fluid-rock interaction alone cannot explain the isotopic gradients. In addition, the marble records increased delta(13)C values at the contact to the veins, possibly related to a change in the physicochemical conditions during fluid-rock interaction. Gold is interpreted to have precipitated in equilibrium with metamorphic find (delta(18)O 12-14 parts per thousand; delta D = -40 to -60 parts per thousand) at peak metamorphic conditions of ca. 550 degrees C and 2 kbars, consistent with isotopic fractionations between coexisting calcite, garnet, and clinopyroxene in the alteration halos. The most likely source of the mineralizing fluid was a midcrustal fluid in equilibrium with the Damaran metapelites that underwent prograde metamorphism at amphibolite- to granulite-facies grades. Although there is no isotopic evidence for the contribution of magmatic fluids, they may have been important in contributing to the overall hydraulic regime and high apparent geothermal gradients (ca. 80 degrees C/km(-1)) in the mine area.

The role of gene duplication in the origin and evolution of new biological functions

Abstract : Gene duplication is an essential source of material for the origin of genetic novelty and the evolution of lineage- or species-specific phenotypic traits. The reverse transcription of source gene mRNA followed by the genomic insertion of the resulting cDNA - retroposition - has provided the human genome with a significant number of gene copies during the last ~63 million years (MYA) of primate evolution. We estimated that at least 1 new functional gene (retrogene) per MYA emerged by retroposition in the primate lineage leading to humans. Using a combination of comparative sequencing and evolutionary simulations, we obtained strong evidence of functionality for 7 primate specific retrogenes. Most of these genes are specifically expressed in testis suggesting that retroposition has contributed with genetic raw material necessary for the evolution ofmale-specific functions in primates. We characterized CDC14Bretro (identified in the previous survey) that originated from the retroposition of a cell cycle gene - CDC14B - in the common ancestor of humans and apes. We demonstrate that CDC14Bretro experienced a period of intense positive selection in the African ape ancestor. By virtue of the amino acid substitutions that occurred during this period CDC 14Bretro adapted to a new subcellular compartment in African apes. Further analyses indicate that this subcellular shift reflects the evolution of anew functional role of CDC 14Bretro. Prompted by this result, we used yeast (Saccharomyces cerevisiae) to investigate on a global scale the extent of functional diversification of duplicate genes through the subcellular adaptation of their encoded proteins. We found that duplicate proteins frequently evolved new cellular localization patterns, either by partitioning of ancestral localizations ("sublocalization"), or more frequently by relocalization to previously unoccupied compartments ("neolocalization"). Interestingly, proteins involved in processes with a wider subcellular distribution more frequently evolved new localization patterns suggesting that subcellular localization changes are dependent on progenitor gene functions. Relocated proteins adapted to their new subcellular environments and evolved new functional roles through changes of their physio-chemical properties, expression levels, and interaction partners. Our work suggests an important role of subcellular adaptation for the emergence of new gene functions.

Targeting of DNA polymerase to the adenovirus origin of DNA replication by interaction with nuclear factor I.

Efficient initiation by the DNA polymerase of adenovirus type 2 requires nuclear factor I (NFI), a cellular sequence-specific transcription factor. Three functions of NFI--dimerization, DNA binding, and activation of DNA replication--are colocalized within the N-terminal portion of the protein. To define more precisely the role of NFI in viral DNA replication, a series of site-directed mutations within the N-terminal domain have been generated, thus allowing the separation of all three functions contained within this region. Impairment of the dimerization function prevents sequence-specific DNA binding and in turn abolishes the NFI-mediated activation of DNA replication. NFI DNA-binding activity, although necessary, is not sufficient to activate the initiation of adenovirus replication. A distinct class of NFI mutations that abolish the recruitment of the viral DNA polymerase to the origin also prevent the activation of replication. Thus, a direct interaction of NFI with the viral DNA polymerase complex is required to form a stable and active preinitiation complex on the origin and is responsible for the activation of replication by NFI.

Post-traumatic stimulus suppressible myoclonus of peripheral origin.

A patient is described who presented with myoclonus of the first dorsal interosseus muscle of the right foot. This myoclonus occurred 18 months after trauma of the cutaneous branch of the deep peroneal nerve on the dorsal aspect of the foot. Tactile stimulation in the dermatome of this nerve, or an anaesthetic block of the deep peroneal nerve stopped the myoclonus. The different innervation between the efferent motor activity responsible for the movements and the sensory afference suppressing it points firmly towards involvement of central connections. However, abolition of the movement by anaesthesia suggests the presence of a peripheral ectopic generator. This finding confirms that focal myoclonus can have its origin in the peripheral nervous system and may be modulated by sensory inputs.

How geographic distance and depth drive ecological variability and isolation of demersal fish communities in an archipelago system (Cape Verde, Eastern Atlantic Ocean)

Cape Verde is a tropical oceanic ecosystem, highly fragmented and dispersed, with islands physically isolated by distance and depth. To understand how isolation affects the ecological variability in this archipelago, we conducted a research project on the community structure of the 18 commercially most important demersal fishes. An index of ecological distance based on species relative dominance (Di) is developed from Catch Per Unit Effort, derived from an extensive database of artisanal fisheries. Two ecological measures of distance between islands are calculated: at the species level, DDi, and at the community level, DD (sum of DDi). A physical isolation factor (Idb) combining distance (d) and bathymetry (b) is proposed. Covariance analysis shows that isolation factor is positively correlated with both DDi and DD, suggesting that Idb can be considered as an ecological isolation factor. The effect of Idb varies with season and species. This effect is stronger in summer (May to November), than in winter (December to April), which appears to be more unstable. Species react differently to Idb, independently of season. A principal component analysis on the monthly (DDi) for the 12 islands and the 18 species, complemented by an agglomerative hierarchical clustering, shows a geographic pattern of island organization, according to Idb. Results indicate that the ecological structure of demersal fish communities of Cape Verde archipelago, both in time and space, can be explained by a geographic isolation factor. The analytical approach used here is promising and could be tested in other archipelago systems.

New species of Bakeriella (Hymenoptera, Bethylidae) from the New World and new data on geographic distribution

Bakeriella lata sp. nov. (Brazil, Rondônia), Bakeriella aurata sp. nov. (Brazil, Amazonas) and Bakeriella sulcaticeps sp. nov. (Brazil, Amazonas) are described and illustrated. New geographic records and variation data for B. cristata Evans, 1964, B. floridana Evans, 1964, B. flavicornis Kieffer, 1910, B. incompleta Azevedo, 1994, B. mira Evans, 1997, B. montivaga (Kieffer, 1910), B. olmeca Evans, 1964 and B. subcarinata Evans, 1965 are provided. The male of B. incompleta is described for the first time.

Prevalence of overweight and obesity among migrants in Switzerland: association with country of origin.

Migrants tend to present higher overweight and obesity levels, but whether this relationship applies to all nationalities has seldom been studied. The present study aimed to assess the prevalence of overweight and obesity according to nationality in adults. Cross-sectional population-based samples. Five-year nationwide interview surveys (Swiss Health Surveys - SHS) from 1992 to 2007 (n 63 766) and a local examination survey (CoLaus Study in Lausanne 2004-2006, n 6743). Participants were separated into Swiss, French, German, Italian, Portuguese, Spanish nationals, those from the former Republic of Yugoslavia and from other European and other countries. Compared with Swiss nationals, German and French nationals presented a lower prevalence of overweight and obesity, whereas nationals from Italy, Spain, Portugal and the former Republic of Yugoslavia presented higher levels. Adjusting the SHS data for age, gender, education, smoking, leisure-time physical activity and survey year, a lower risk for overweight and obesity was found for German (OR = 0·80, 95 % CI 0·70, 0·92) and French (OR = 0·74, 95 % CI 0·61, 0·89) nationals, whereas higher risks were found for participants from Italy (OR = 1·45, 95 % CI 1·33, 1·58), Spain (OR = 1·36, 95 % CI 1·15, 1·61), Portugal (OR = 1·25, 95 % CI 1·06, 1·47) and the former Republic of Yugoslavia (OR = 1·98, 95 % CI 1·69, 2·32). Similar findings were observed in the CoLaus Study for Italian (OR = 1·63, 95 % CI 1·29, 2·06), Spanish (OR = 1·54, 95 % CI 1·17, 2·04) and Portuguese (OR = 1·49, 95 % CI 1·16, 1·91) participants and for those from the former Republic of Yugoslavia (OR = 5·34, 95 % CI 3·00, 9·50). Overweight and obesity are unevenly distributed among migrants in Switzerland. Migrants from Southern Europe and from the former Republic of Yugoslavia present higher prevalence rates. This suggests that preventive messages should be tailored to these specific populations.

Unravelling the enigmatic origin of calcitic nanofibres in soils and caves: purely physicochemical or biogenic processes?

Calcitic nanofibres are ubiquitous habits of sec- ondary calcium carbonate (CaCO3 ) accumulations observed in calcareous vadose environments. Despite their widespread occurrence, the origin of these nanofeatures remains enig- matic. Three possible mechanisms fuel the debate: (i) purely physicochemical processes, (ii) mineralization of rod-shaped bacteria, and (iii) crystal precipitation on organic templates. Nanofibres can be either mineral (calcitic) or organic in na- ture. They are very often observed in association with needle fibre calcite (NFC), another typical secondary CaCO3 habit in terrestrial environments. This association has contributed to some confusion between both habits, however they are truly two distinct calcitic features and their recurrent asso- ciation is likely to be an important fact to help understanding the origin of nanofibres. In this paper the different hypotheses that currently exist to explain the origin of calcitic nanofibres are critically reviewed. In addition to this, a new hypothe- sis for the origin of nanofibres is proposed based on the fact that current knowledge attributes a fungal origin to NFC. As this feature and nanofibres are recurrently observed together, a possible fungal origin for nanofibres which are associated with NFC is investigated. Sequential enzymatic digestion of the fungal cell wall of selected fungal species demonstrates that the fungal cell wall can be a source of organic nanofibres. The obtained organic nanofibres show a striking morpho- logical resemblance when compared to their natural coun- terparts, emphasizing a fungal origin for part of the organic nanofibres observed in association with NFC. It is further hy- pothesized that these organic nanofibres may act as templates for calcite nucleation in a biologically influenced mineraliza- tion process, generating calcitic nanofibres. This highlights the possible involvement of fungi in CaCO3 biomineraliza- tion processes, a role still poorly documented. Moreover, on a global scale, the organomineralization of organic nanofi- bres into calcitic nanofibres might be an overlooked process deserving more attention to specify its impact on the biogeo- chemical cycles of both Ca and C.

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition.

The three phases of the ensemble forecasting of niche models: geographic range and shifts in climatically suitable areas of Utetheisa ornatrix (Lepidoptera, Arctiidae)

Species' geographic ranges are usually considered as basic units in macroecology and biogeography, yet it is still difficult to measure them accurately for many reasons. About 20 years ago, researchers started using local data on species' occurrences to estimate broad scale ranges, thereby establishing the niche modeling approach. However, there are still many problems in model evaluation and application, and one of the solutions is to find a consensus solution among models derived from different mathematical and statistical models for niche modeling, climatic projections and variable combination, all of which are sources of uncertainty during niche modeling. In this paper, we discuss this approach of ensemble forecasting and propose that it can be divided into three phases with increasing levels of complexity. Phase I is the simple combination of maps to achieve a consensual and hopefully conservative solution. In Phase II, differences among the maps used are described by multivariate analyses, and Phase III consists of the quantitative evaluation of the relative magnitude of uncertainties from different sources and their mapping. To illustrate these developments, we analyzed the occurrence data of the tiger moth, Utetheisa ornatrix (Lepidoptera, Arctiidae), a Neotropical moth species, and modeled its geographic range in current and future climates.

Market structure and hospital efficiency: Evaluating potential effects of deregulation in a national health service

In this article we examine the potential effect of market structureon hospital technical efficiency as a measure of performance controlled byownership and regulation. This study is relevant to provide an evaluationof the potential effects of recommended and initiated deregulation policiesin order to promote market reforms in the context of a European NationalHealth Service. Our goal was reached through three main empirical stages.Firstly, using patient origin data from hospitals in the region of Cataloniain 1990, we estimated geographic hospital markets through the Elzinga--Hogartyapproach, based on patient flows. Then we measured the market level ofconcentration using the Herfindahl--Hirschman index. Secondly, technicaland scale efficiency scores for each hospital was obtained specifying aData Envelopment Analysis. According to the data nearly two--thirds of thehospitals operate under the production frontier with an average efficiencyscore of 0.841. Finally, the determinants of the efficiency scores wereinvestigated using a censored regression model. Special attention waspaid to test the hypothesis that there is an efficiency improvement in morecompetitive markets. The results suggest that the number of competitors inthe market contributes positively to technical efficiency and there is someevidence that the differences in efficiency scores are attributed toseveral environmental factors such as ownership, market structure andregulation effects.