Health Assessment of Weddell Seals, <i>Leptonychotes weddellii</i>, in McMurdo Sound, Antarctica

The demography of Weddell seals in eastern McMurdo Sound, Antarctica, has been well studied during the past three decades (e.g. Stirling 1971; Siniff et al. 1977; Testa and Siniff 1987; Hastings and Testa 1998; Gelatt et al. 2001). Detailed life-history data are available on thousands of seals tagged as pups in McMurdo Sound, making this population a rich resource for wildlife health studies because health parameters can be evaluated in the light of reproductive histories and genetic relationships of several generations of tagged seals. Recently, evidence of exposure to diseases generally associated with domestic animals and feral wildlife has been detected in Antarctic wildlife (Austin and Webster 1993; Olsen et al. 1996; Gardner et al. 1997; Retamal et al. 2000; Foster et al. 2002) and this has generated concern and debate regarding the risks of disease introduction to Antarctic wildlife. Antibodies to viruses that have caused large die-offs in phocids in other areas of the world have been detected in Weddell seals (Bengtson et al. 1991), and there is a historical report of a mass die-off of crabeater seals that may have had a viral etiology (Laws and Taylor 1957).

Phylogeographic analysis in populations of Protonectarina sylveirae (Saussure, 1854) (Hymenoptera, Vespidae, Polistinae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diversity of the KIR gene cluster in an urban Brazilian population

The activity of natural killer cells depends on the balance between activating and inhibitory signals coming from their receptors. Among these are the killer cell immunoglobulin-like receptors (KIR) that recognize specific HLA class I allotypes. Here we characterized KIR genetic diversity and their HLA ligands in the population of Curitiba, Parana State (n = 164), and compared it with other worldwide populations. The distribution of 2DL4 alleles was also analyzed. The Curitiba population did not differ significantly from European and Euro-descendant populations, but as an admixed population showed higher genetic diversity. We found 27 KIR profiles, many of them uncommon in European populations, in agreement with the elevated historically recent gene flow in the study population. The frequencies of KIR genes and their respective HLA ligands were distributed independently and none of the analyzed individuals lacked functional KIR-HLA ligand combinations. KIR gene frequencies of 33 worldwide populations were consistent with geographic and ethnic distribution, in agreement with demography being the major factor shaping the observed gene content diversity of the KIR locus.

Phylogeography of an Atlantic forest passerine reveals demographic stability through the last glacial maximum

In this study we analyzed the phylogeographic pattern and historical demography of an endemic Atlantic forest (AF) bird, Basileuterus leucoblepharus, and test the influence of the last glacial maximum (LGM) on its population effective size using coalescent simulations. We address two main questions: (i) Does B. leucoblepharus present population genetic structure congruent with the patterns observed for other AF organisms? (ii) How did the LGM affect the effective population size of B. leucoblepharus? We sequenced 914 bp of the mitochondrial gene cytochrome b and 512 bp of the nuclear intron 5 of beta-fibrinogen of 62 individuals from 15 localities along the AF. Both molecular markers revealed no genetic structure in B. leucoblepharus. Neutrality tests based on both loci showed significant demographic expansion. The extended Bayesian skyline plot showed that the species seems to have experienced demographic expansion starting around 300,000 years ago, during the late Pleistocene. This date does not coincide with the LGM and the dynamics of population size showed stability during the LGM. To further test the effect of the LGM on this species, we simulated seven demographic scenarios to explore whether populations suffered specific bottlenecks. The scenarios most congruent with our data were population stability during the LGM with bottlenecks older than this period. This is the first example of an AF organism that does not show phylogeographic breaks caused by vicariant events associated to climate change and geotectonic activities in the Quaternary. Differential ecological, environmental tolerances and habitat requirements are possibly influencing the different evolutionary histories of these organisms. Our results show that the history of organism diversification in this megadiverse Neotropical forest is complex. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.

The influence of career histories on team perfomance in new product development: a study of the video game industry

The purpose of this research is to contribute to the literature on organizational demography and new product development by investigating how diverse individual career histories impact team performance. Moreover we highlighted the importance of considering also the institutional context and the specific labour market arrangements in which a team is embedded, in order to interpret correctly the effect of career-related diversity measures on performance. The empirical setting of the study is the videogame industry, and the teams in charge of the development of new game titles. Video games development teams are the ideal setting to investigate the influence of career histories on team performance, since the development of videogames is performed by multidisciplinary teams composed by specialists with a wide variety of technical and artistic backgrounds, who execute a significant amounts of creative thinking. We investigate our research question both with quantitative methods and with a case study on the Japanese videogame industry: one of the most innovative in this sector. Our results show how career histories in terms of occupational diversity, prior functional diversity and prior product diversity, usually have a positive influence on team performance. However, when the moderating effect of the institutional setting is taken in to account, career diversity has different or even opposite effect on team performance, according to the specific national context in which a team operates.

First assessment on genetic structure and phylogeography of Mediterranean blue shark (prionace glauca, L. 1758) population using mitochondrial gene variation: a comparison with the Atlantic.

The blue shark, Prionace glauca, is one of the most vagile shark species worldwide distributed. The particular body shape allows blue sharks make transoceanic movements, leading to a circumglobal distribution. Due to its reproductive cycle, an extraordinarily high number of specimens is globally registered but, even if it is still a major bycatch of longline fishery rather than a commercial target, it is characterized by a high vulnerability. In this perspective it is important to increase the amount of informations regarding its population extent in the different worldwide areas, evaluating the possible phylogeographic patterns between different locations. This study, included in the "MedBlueSGen" European project, aims exactly at filling a gap in knowledges regarding the genetic population structure of the Mediterranean blue sharks, which has never been investigated before, with a comparison with the North-Eastern Atlantic blue shark population. To reach this objective, we used a dataset of samples from different Mediterranean areas implementing it with some samples from North-Eastern Atlantic. Analyzing the variability of the two mitochondrial markers control region and cytochrome b, with the design of new species-specific primer pairs, we assessed the mitochondrial genetic structure of Mediterranean and North-Eastern Atlantic samples, focusing on the analysis of their possible connectivity, and we tried to reconstruct their demographic history and population size. Data analyses highlighted the absence of a genetic structuring within the Mediterranean and among it and North-Eastern Atlantic, suggesting that the Strait of Gibraltar doesn't represent a phylogeographic barrier. These results are coherent to what has been found in similar investigations on other worldwide blue shark populations. Analysis of the historical demographic trend revealed a general stable pattern for the cytochrome-b and a slightly population expansion for the control region marker.

Extensive clonal spread and extreme longevity in saw palmetto, a foundation clonal plant

The lack of effective tools has hampered our ability to assess the size, growth and ages of clonal plants. With Serenoa repens (saw palmetto) as a model, we introduce a novel analytical frame work that integrates DNA fingerprinting and mathematical modelling to simulate growth and estimate ages of clonal plants. We also demonstrate the application of such life-history information of clonal plants to provide insight into management plans. Serenoa is an ecologically important foundation species in many Southeastern United States ecosystems; yet, many land managers consider Serenoa a troublesome invasive plant. Accordingly, management plans have been developed to reduce or eliminate Serenoa with little understanding of its life history. Using Amplified Fragment Length Polymorphisms, we genotyped 263 Serenoa and 134 Sabal etonia (a sympatric non-clonal palmetto) samples collected from a 20 x 20 m study plot in Florida scrub. Sabal samples were used to assign small field-unidentifiable palmettos to Serenoa or Sabal and also as a negative control for clone detection. We then mathematically modelled clonal networks to estimate genet ages. Our results suggest that Serenoa predominantly propagate via vegetative sprouts and 10000-year-old genets maybe common, while showing no evidence of clone formation by Sabal. The results of this and our previous studies suggest that: (i) Serenoa has been part of scrub associations for thousands of years, (ii) Serenoa invasions are unlikely and (ii) once Serenoa is eliminated from local communities, its restoration will be difficult. Reevaluation of the current management tools and plans is an urgent task.

Health insurance coverage of Hispanic adults: An assessment of subgroup difference and the impact of immigration

This research explores the health insurance coverage of various Hispanic subgroups in comparison to non-Hispanic whites and blacks. The impact of immigration status is also considered as we hypothesize that nativity, duration, and naturalization tap a possible process of structural acculturation that increases access to insurance coverage for Hispanic groups. We find that the immigration variables impact the type of insurance reported. However, race/ethnic disparities continue to exist, with the various Hispanic subgroups more likely to report miscellaneous government health insurance or no health insurance coverage as compared to non-Hispanic whites.

Who Will Provide Long-Term Care in the Future?

Projects that long-term-care delivery system will face substantial barriers in the future in finding staff to provide services even without an increase in demand due to public or private insurance. Shift of the economy toward skilled service jobs; Changing demography of the work force; Policy elements and cohorts effects that shape the demand for long-term care personnel in the year 2000 and beyond.

Genomic Data Reveal a Complex Making of Humans

In the last few years, two paradigms underlying human evolution have crumbled. Modern humans have not totally replaced previous hominins without any admixture, and the expected signatures of adaptations to new environments are surprisingly lacking at the genomic level. Here we review current evidence about archaic admixture and lack of strong selective sweeps in humans. We underline the need to properly model differential admixture in various populations to correctly reconstruct past demography. We also stress the importance of taking into account the spatial dimension of human evolution, which proceeded by a series of range expansions that could have promoted both the introgression of archaic genes and background selection.

The Sociolinguistics of Hungarian Outside Hungary

This study describes the sociolinguistic situation of the indigenous Hungarian national minorities in Slovakia (c. 600,000), Ukraine (c. 180,000), Romania (c. 2,000,000), Yugoslavia (c. 300,000), Slovenia (c. 8,000) and Austria (c. 6,000). Following the guidelines of Hans Goebl et al, the historical sociolinguistic portrait of each minority is presented from 1920 through to the mid-1990s. Each country's report includes sections on geography and demography, history, politics, economy, culture and religion, language policy and planning, and language use (domains of minority and/or majority language use, proficiency, attitudes, etc.). The team's findings were presented in the form of 374 pages of manuscripts, articles and tables, written in Hungarian and English. The core of the team's research results lies in the results of an empirical survey designed to study the social characteristics of Hungarian-minority bilingualism in the six project countries, and the linguistic similarities and differences between the six contact varieties of Hungarian and Hungarian in Hungary. The respondents were divided by age, education, and settlement group - city vs. village and local majority vs. local minority. The first thing to be observed is that Hungarian is tending to be spoken less to children than to parents and grandparents, a familiar pattern of language shift. In contact varieties of Hungarian, analytic constructions may be used where monolingual Hungarians would use a more synthetic form. Mr Kontra gives as an example the compound tagdij, which in Standard Hungarian means "membership fee" but which is replaced in contact Hungarian by the two-word phrase tagsagi dij. Another similar example concerns the synthetic verb hegedult "played the violin" and the analytic expression hegedun jatszott. The contrast is especially striking between the Hungarians in the northern Slavic countries, who use the synthetic form frequently, and those in the southern Slavic countries, who mainly use the analytic form. Mr. Kontra notes that from a structural point of view, there is no immediate explanation for this, since Slovak or Ukrainian are as likely to cause interference as is Serbian. He postulates instead that the difference may be attributable to some sociohistoric cause, and points out that the Turkish occupation of what is today Voivodina caused a discontinuity of the Hungarian presence in the region, with the result that Hungarians were resettled in the area only two and a half centuries ago. However, the Hungarians in today's Slovakia and Ukraine have lived together with Slavic peoples continuously for over a millennium. It may be, he suggests, that 250 years of interethnic coexistence is less than is needed for such a contact-induced change to run its course. Next Mr. Kontra moved on to what he terms "mental maps and morphology". In Hungarian, the names of cities and villages take the surface case (eg. Budapest-en "in Budapest") whereas some names denoting Hungarian settlements and all names of foreign cities take the interior case (eg. Tihany-ban "in Tihany" and Boston-ban "in Boston). The role of the semantic feature "foreign" in suffix-choice can be illustrated by such minimal pairs as Velence-n "in Velence, a village in Hungary" versus Velence-ben "in Velence [=Venice], a city in Italy", and Pecs-en "in Pecs, a city in Hungary" vs. Becs-ben "in Becs, ie. Vienna". This Hungarian vs. foreign distinction is often interpreted as "belonging to historical (pre-1920) Hungary" vs. "outside historical Hungary". The distinction is also expressed in the dichotomy "home" vs. "abroad'. The 1920 border changes have had an impact on both majority and minority Hungarians' mental maps, the maps which govern the choice of surface vs. interior cases with placenames. As there is a growing divergence between the mental maps of majority and minority Hungarians, so there will be a growing divergence in their use of the placename suffixes. Two placenames were chosen to scratch the surface of this complex problem: Craiova (a city in Oltenia, Romania) and Kosovo (Hungarian Koszovo) an autonomous region in southeast Yugoslavia. The assumption to be tested was that both placenames would be used with the inessive (interior) suffixes categorically by Hungarians in Hungary, but that the superessive suffix (showing "home") would be used near-categorically by Hungarians in Romania and Yugoslavia (Voivodina). Minority Hungarians in countries other than Romania and Yugoslavia would show no difference from majority Hungarians in Hungary. In fact, the data show that, contrary to expectation, there is considerable variation within Hungary. And although Koszovo is used, as expected, with the "home" suffix by 61% of the informants in Yugoslavia, the same suffix is used by an even higher percentage of the subjects in Slovenia. Mr. Kontra's team suggests that one factor playing a role in this might be the continuance of the former Yugoslav mentality in the Hungarians of Slovenia, at least from the geographical point of view. The contact varieties of Hungarian show important grammatical differences from Hungarian in Hungary. One of these concerns the variable use of Null subjects (the inclusion or exclusion of the subject of the verb). When informants were asked to insert either megkertem or megkertem ot - "I asked her" - into a test sentence, 54.9% of the respondents in the Ukraine inserted the second phrase as opposed to only 27.4% in Hungary. Although Mr. Kontra and his team concentrated more on the differences between Contact Hungarian and Standard Hungarian, they also discovered a number of similarities. One such similarity is demonstrable in the distribution of what Mr. Kontra calls an ongoing syntactic merger in Hungarian in Hungary. This change means effectively that two possibilities merge to form a third. For instance, the two sentences Valoszinuleg kulfoldre fognak koltozni and Valoszinu, hogy kulfoldre fognak koltozni merge to form the new construction Valszinuleg, hogy kulfoldre fognak koltozni ("Probably they will move abroad."). When asked to choose "the most natural" of the sentences, one in four chose the new construction, and a chi-square test shows homogeneity in the sample. In other words, this syntactic change is spreading across the entire Hungarian-speaking region in the Carpathian Basin Mr. Kontra believes that politicians, educators, and other interested parties now have reliable and up-to-date information about each Hungarian minority. An awareness of Hungarian as a pluricentric language is being developed which elevates the status of contact varieties of Hungarian used by the minorities, an essential process, he believes, if minority languages are to be maintained.

Statistical evaluation of alternative models of human evolution

An appropriate model of recent human evolution is not only important to understand our own history, but it is necessary to disentangle the effects of demography and selection on genome diversity. Although most genetic data support the view that our species originated recently in Africa, it is still unclear if it completely replaced former members of the Homo genus, or if some interbreeding occurred during its range expansion. Several scenarios of modern human evolution have been proposed on the basis of molecular and paleontological data, but their likelihood has never been statistically assessed. Using DNA data from 50 nuclear loci sequenced in African, Asian and Native American samples, we show here by extensive simulations that a simple African replacement model with exponential growth has a higher probability (78%) as compared with alternative multiregional evolution or assimilation scenarios. A Bayesian analysis of the data under this best supported model points to an origin of our species approximately 141 thousand years ago (Kya), an exit out-of-Africa approximately 51 Kya, and a recent colonization of the Americas approximately 10.5 Kya. We also find that the African replacement model explains not only the shallow ancestry of mtDNA or Y-chromosomes but also the occurrence of deep lineages at some autosomal loci, which has been formerly interpreted as a sign of interbreeding with Homo erectus.

Fine-scale genetic structure and dispersal in the common vole (Microtus arvalis)

The genetic structure and demography of local populations is tightly linked to the rate and scale of dispersal. Dispersal parameters are notoriously difficult to determine in the field, and remain often completely unknown for smaller organisms. In this study, we investigate spatial and temporal genetic structure in relation to dispersal patterns among local populations of the probably most abundant European mammals, the common vole (Microtus arvalis). Voles were studied in six natural populations at distances of 0.4-2.5 km in three different seasons (fall, spring, summer) corresponding to different life-history stages. Field observations provided no direct evidence for movements of individuals between populations. The analysis of 10 microsatellite markers revealed a persistent overall genetic structure among populations of 2.9%, 2.5% and 3% FST in the respective season. Pairwise comparisons showed that even the closest populations were significantly differentiated from each other in each season, but there was no evidence for temporal differentiation within populations or isolation by distance among populations. Despite significant genetic structure, assignment analyses identified a relatively high proportion of individuals as being immigrants for the population where they were captured. The immigration rate was not significantly lower for females than for males. We suggest that a generally low and sex-dependent effective dispersal rate as the consequence of only few immigrants reproducing successfully in the new populations together with the social structure within populations may explain the maintenance of genetic differentiation among populations despite migration.

Genetic variation and demographic history of the Haplochromis laparogramma group of Lake Victoria-An analysis based on SINEs and mitochondrial DNA

More than 500 endemic haplochromine cichlid species inhabit Lake Victoria. This striking species diversity is a classical example of recent explosive adaptive radiation thought to have happened within the last similar to 15,000 years. In this study, we examined the population structure and historical demography of 3 pelagic haplochromine cichlid species that resemble in morphology and have similar niche, Haplochromis (Yssichromis) laparogramma, Haplochromis (Y.) pyrrhocephalus, and Haplochromis (Y.) sp. "glaucocephalus". We investigated the sequences of the mitochondrial DNA control region and the insertion patterns of short interspersed elements (SINEs) of 759 individuals. We show that sympatric forms are genetically differentiated in 4 of 6 cases, but we also found apparent weakening of the genetic differentiation in areas with turbid water. We estimated the timings of population expansion and species divergence to coincide with the refilling of the lake at the Pleistocene/Holocene boundary. We also found that estimates can be altered significantly by the choice of the shape of the molecular clock. If we employ the nonlinear clock model of evolutionary rates in which the rates are higher towards the recent, the population expansion was dated at around the event of desiccation of the lake ca. 17,000 YBP. Thus, we succeeded in clarifying the species and population structure of closely related Lake Victoria cichlids and in showing the importance of applying appropriate clock calibrations in elucidating recent evolutionary events. (C) 2009 Elsevier B.V. All rights reserved.

The contribution of intra- and interspecific tolerance variability to biodiversity changes along toxicity gradients

The worldwide distribution of toxicants is an important yet understudied driver of biodiversity, and the mechanisms relating toxicity to diversity have not been adequately explored. Here, we present a community model integrating demography, dispersal and toxicant-induced effects on reproduction driven by intraspecific and interspecific variability in toxicity tolerance. We compare model predictions to 458 species abundance distribu- tions (SADs) observed along concentration gradients of toxicants to show that the best predictions occur when intraspecific variability is five and ten times higher than interspecific variability. At high concentrations, lower settings of intraspecific variability resulted in predictions of community extinction that were not supported by the observed SADs. Subtle but significant species losses at low concentrations were predicted only when intraspecific variability dominated over interspecific variability. Our results propose intraspecific variability as a key driver for biodiversity sustenance in ecosystems challenged by environmental change.