Cryptic diversity among Western Palearctic tree frogs: postglacial range expansion, range limits, and secondary contacts of three European tree frog lineages (Hyla arborea group).

We characterize divergence times, intraspecific diversity and distributions for recently recognized lineages within the Hyla arborea species group, based on mitochondrial and nuclear sequences from 160 localities spanning its whole distribution. Lineages of H. arborea, H. orientalis, H. molleri have at least Pliocene age, supporting species level divergence. The genetically uniform Iberian H. molleri, although largely isolated by the Pyrenees, is parapatric to H. arborea, with evidence for successful hybridization in a small Aquitanian corridor (southwestern France), where the distribution also overlaps with H. meridionalis. The genetically uniform H. arborea, spread from Crete to Brittany, exhibits molecular signatures of a postglacial range expansion. It meets different mtDNA clades of H. orientalis in NE-Greece, along the Carpathians, and in Poland along the Vistula River (there including hybridization). The East-European H. orientalis is strongly structured genetically. Five geographic mitochondrial clades are recognized, with a molecular signature of postglacial range expansions for the clade that reached the most northern latitudes. Hybridization with H. savignyi is suggested in southwestern Turkey. Thus, cryptic diversity in these Pliocene Hyla lineages covers three extremes: a genetically poor, quasi-Iberian endemic (H. molleri), a more uniform species distributed from the Balkans to Western Europe (H. arborea), and a well-structured Asia Minor-Eastern European species (H. orientalis).

Can we continue to neglect genomic variation in introgression rates when inferring the history of speciation? A case study in a Mytilus hybrid zone.

The use of molecular data to reconstruct the history of divergence and gene flow between populations of closely related taxa represents a challenging problem. It has been proposed that the long-standing debate about the geography of speciation can be resolved by comparing the likelihoods of a model of isolation with migration and a model of secondary contact. However, data are commonly only fit to a model of isolation with migration and rarely tested against the secondary contact alternative. Furthermore, most demographic inference methods have neglected variation in introgression rates and assume that the gene flow parameter (Nm) is similar among loci. Here, we show that neglecting this source of variation can give misleading results. We analysed DNA sequences sampled from populations of the marine mussels, Mytilus edulis and M. galloprovincialis, across a well-studied mosaic hybrid zone in Europe and evaluated various scenarios of speciation, with or without variation in introgression rates, using an Approximate Bayesian Computation (ABC) approach. Models with heterogeneous gene flow across loci always outperformed models assuming equal migration rates irrespective of the history of gene flow being considered. By incorporating this heterogeneity, the best-supported scenario was a long period of allopatric isolation during the first three-quarters of the time since divergence followed by secondary contact and introgression during the last quarter. By contrast, constraining migration to be homogeneous failed to discriminate among any of the different models of gene flow tested. Our simulations thus provide statistical support for the secondary contact scenario in the European Mytilus hybrid zone that the standard coalescent approach failed to confirm. Our results demonstrate that genomic variation in introgression rates can have profound impacts on the biological conclusions drawn from inference methods and needs to be incorporated in future studies.

Genetic loci influencing kidney function and chronic kidney disease.

Using genome-wide association, we identify common variants at 2p12-p13, 6q26, 17q23 and 19q13 associated with serum creatinine, a marker of kidney function (P = 10(-10) to 10(-15)). Of these, rs10206899 (near NAT8, 2p12-p13) and rs4805834 (near SLC7A9, 19q13) were also associated with chronic kidney disease (P = 5.0 x 10(-5) and P = 3.6 x 10(-4), respectively). Our findings provide insight into metabolic, solute and drug-transport pathways underlying susceptibility to chronic kidney disease.

Natural genetic variation of root system architecture from Arabidopsis to Brachypodium: towards adaptive value.

Root system architecture is a trait that displays considerable plasticity because of its sensitivity to environmental stimuli. Nevertheless, to a significant degree it is genetically constrained as suggested by surveys of its natural genetic variation. A few regulators of root system architecture have been isolated as quantitative trait loci through the natural variation approach in the dicotyledon model, Arabidopsis. This provides proof of principle that allelic variation for root system architecture traits exists, is genetically tractable, and might be exploited for crop breeding. Beyond Arabidopsis, Brachypodium could serve as both a credible and experimentally accessible model for root system architecture variation in monocotyledons, as suggested by first glimpses of the different root morphologies of Brachypodium accessions. Whether a direct knowledge transfer gained from molecular model system studies will work in practice remains unclear however, because of a lack of comprehensive understanding of root system physiology in the native context. For instance, apart from a few notable exceptions, the adaptive value of genetic variation in root system modulators is unknown. Future studies should thus aim at comprehensive characterization of the role of genetic players in root system architecture variation by taking into account the native environmental conditions, in particular soil characteristics.

Impact of social structure variation on population genetics, social conflicts and life histories in ants

Summary The evolution of social structures and breeding systems in animals is a complex process that combines ecological, genetical and social factors. This thesis sheds light on important changes in population genetics, life-history and social behavior that are associated with variation in social structure in ants. The socially polymorphic ant Formica selysi was chosen as the model organism because single- and multiple-queen colonies occur in close proximity within a single large population. The shift from single- to multiple-queen colonies is generally associated with profound changes in dispersal behavior and mode of colony founding. In chapter 1, we examine the genetic consequences of variation in social structure at both the colony and population levels. A detailed microsatellite analysis reveals that both colony types have similar mating systems, with few or no queen turnover. Furthermore, the complete lack of genetic differentiation observed between single- and multiple-queen colonies provides no support to the hypothesis that change in queen number leads to restricted gene flow between social forms. Besides changes in the genetic composition of the colony, the variation in the number of queens per colony is associated with changes in a network of behavioral and life-history traits that have been described as forming a "polygyny syndrome". In chapter 2, we demonstrate that multiple-queen colonies profoundly differ from single-queen ones in terms of size, nest density and lifespan of colonies, in weight of queens produced, as well as in allocation to reproductive individuals relative to workers. These multifaceted changes in life-history traits can provide various fitness benefits to members of multiple-queen colonies. Increasing the number of queens in a colony usually results in a decreased level of aggression towards non-nestmates. The phenotype matching hypothesis predicts that, compared to single-queen colonies, multiple-queen colonies have more diverse genetically-derived cues used for recognition, resulting in a lower ability to discriminate non-nestmates. In sharp contrast to this hypothesis, we show in chapter 3 that single- and multiple-queen colonies exhibit on average similar levels of aggression. Moreover, stronger aggression is recorded between colonies of different social structure than between colonies of the same social structure. Several hypotheses propose that the evolution of multiple-queen colonies is at least partly due to benefits resulting from an increase in colony genetic diversity. The task-efficiency hypothesis holds that genetic variation improves task performance due to a more complete or more sensitive expression of the genetically-based division of labor. In .chapter 4, we evaluate if higher colony genetic diversity increases worker size polymorphism and thus may improve division of labor. We show that despite the fact that worker size has a heritable component, higher levels of genetic diversity do not result in more polymorphic workers. The smaller size and lower polymorphism levels of workers of multiple-queen colonies compared to single-queen ones further indicate that an increase in colony genetic diversity does not increase worker size polymorphism but might improve colony homeostasis. In chapter 5, we provide clear evidence for an ongoing conflict between queens and workers on sex allocation, as predicted by kin selection theory. Our data show that queens of F. selysi strongly influence colony sex allocation by biasing the sex ratio of their eggs. However, there is also evidence that workers eliminated some male brood, resulting in a population sex-investment ratio that is between the queens' and workers' equilibria. Résumé L'évolution des structures sociales et systèmes d'accouplement chez les animaux est un processus complexe combinant à la fois des facteurs écologiques, génétiques et sociaux. Cette thèse met en lumière des changements importants dans la génétique des populations, les traits d'histoire de vie et les comportements sociaux qui sont associés à des variations de structure sociale chez les fourmis. Durant ce travail, nous avons étudié une population de Formica selysi composée à la fois de colonies à une reine et de colonies à plusieurs reines. La transition de colonie à une reine à colonie à plusieurs reines est généralement associée à des changements profonds dans le comportement de dispersion ainsi que le mode de fondation des sociétés. Dans le chapitre 1, nous examinons les conséquences génétiques de la variation de structure sociale tant au niveau de la colonie qu'au niveau de la population. Une analyse détaillée à l'aide de marqueurs microsatellites nous révèle que les deux types de colonies ont des systèmes d'accouplements similaires avec peu ou pas de renouvellement de reines. L'absence totale de différenciation génétique entre les colonies à une et à plusieurs reines n'apporte aucun support à l'hypothèse selon laquelle un changement dans le nombre de reines conduit à un flux de gènes restreint entre les deux formes sociales. A côté de changements dans la composition génétique de la colonie, la variation du nombre de reines dans une colonie est associée à une multitude de changements comportementaux et de traits d'histoire de vie qui ont été décrits comme formant un "syndrome polygyne". Dans le chapitre 2, nous démontrons que les colonies à plusieurs reines diffèrent profondément des colonies à une reine en terme de taille, densité de nids, longévité des colonies, poids des nouvelles reines produites ainsi que dans l'allocation entre les individus reproducteurs et les ouvrières. Ces changements multiples dans les traits d'histoire de vie peuvent apporter des bénéfices variés en terme de fitness aux colonies à plusieurs reines. L'augmentation du nombre de reines dans une colonie est généralement associée à une baisse du degré d'agressivité envers les fourmis étrangères au nid. L'hypothèse "phénotype matching" prédit que les colonies à plusieurs reines ont une plus grande diversité dans les facteurs d'origine génétique utilisés pour la reconnaissance, résultant en une capacité diminuée à discriminer une fourmi étrangère au nid. Contrairement à cette hypothèse, nous montrons dans le chapitre 3 que les colonies à une et à plusieurs reines ont des niveaux d'agressivité similaires. De plus, une agressivité accrue est observée entre colonies de structures sociales différentes comparée à des colonies de même structure sociale. Plusieurs hypothèses ont proposé que l'évolution de colonies ä plusieurs reines soit en partie due aux bénéfices résultant d'une augmentation de la diversité génétique dans la colonie. L'hypothèse "task efficiency" prédit que la diversité génétique améliore l'efficacité à effectuer certaines tâches grâce à une expression plus complète et plus souple d'une division du travail génétiquement déterminée. Nous évaluons dans le chapitre 4 si un accroissement de la diversité génétique augmente le polymorphisme de taille des ouvrières, d'où peut ainsi découler une meilleure division du travail. Nous montrons qu'en dépit du fait que la taille des ouvrières soit un caractère héritable, une forte diversité génétique ne se traduit pas par un plus fort polymorphisme chez les ouvrières. Les ouvrières de colonies à plusieurs reines sont plus petites et moins polymorphes que celles des colonies à une seule reine. Dans le chapitre 5, nous démontrons l'existence d'un conflit ouvert entre reines et ouvrières à propos de l'allocation dans les sexes, comme le prédit la théorie de la sélection de parentèle. Nos données révèlent que les reines de F. selysi influencent fortement l'allocation dans les sexes en biaisant la sexe ratio des oeufs. Cependant, certains indices indiquent que les ouvrières éliminent une partie du couvain mâle, ce qui a pour effet d'avoir un investissement dans les sexes au niveau de la population intermédiaire entre les intérêts des reines et des ouvrières.

Partitioning of genetic (Rapd) variability among sexes and populations of the Barn Owl (Tyto alba) in Europe

The white Barn Owl subspecies (Tyto alba alba) is found in southern Europe and the reddish-brown subspecies (T a. guttata) in northern and eastern Europe. In central Europe, the two subspecies interbreed producing a large range of phenotypic variants. Because of the different ratios of the subspecies in different geographic regions, we predict that genetic variation should be greater in Switzerland than in Hungary. We tested this hypothesis by measuring genetic variation with the RAPD method. As predicted, the genetic differentiation within a Swiss population of Barn Owls was significantly greater than the variation within a Hungarian population. This suggests that gene flow is greater in central Europe than at the eastern limit of the Barn Owl distribution in Hungary. In both countries genetic variation was more pronounced in females than in males. As in other birds, this is probably because female Barn Owls are less philopatric than males. The number of migrants between Hungary and Switzerland is ca. 1 individual per generation; if calculated separately for the sexes, then 0.525 for males and ca. I for females (Nm values). The difference in the number of migrants between genders again is likely a consequence of higher male philopatry. The sexual differentiation is greater in the Swiss population than in the Hungarian and the genetic substructuring of the populations of the species is substantial. The reason for the considerable population substructuring could be the nonmigratory behavior and socially monogamous pairing of the species, as well as the geographical barriers (Alps) between the populations examined.

Rhinovirus Genome Variation during Chronic Upper and Lower Respiratory Tract Infections.

Routine screening of lung transplant recipients and hospital patients for respiratory virus infections allowed to identify human rhinovirus (HRV) in the upper and lower respiratory tracts, including immunocompromised hosts chronically infected with the same strain over weeks or months. Phylogenetic analysis of 144 HRV-positive samples showed no apparent correlation between a given viral genotype or species and their ability to invade the lower respiratory tract or lead to protracted infection. By contrast, protracted infections were found almost exclusively in immunocompromised patients, thus suggesting that host factors rather than the virus genotype modulate disease outcome, in particular the immune response. Complete genome sequencing of five chronic cases to study rhinovirus genome adaptation showed that the calculated mutation frequency was in the range observed during acute human infections. Analysis of mutation hot spot regions between specimens collected at different times or in different body sites revealed that non-synonymous changes were mostly concentrated in the viral capsid genes VP1, VP2 and VP3, independent of the HRV type. In an immunosuppressed lung transplant recipient infected with the same HRV strain for more than two years, both classical and ultra-deep sequencing of samples collected at different time points in the upper and lower respiratory tracts showed that these virus populations were phylogenetically indistinguishable over the course of infection, except for the last month. Specific signatures were found in the last two lower respiratory tract populations, including changes in the 5'UTR polypyrimidine tract and the VP2 immunogenic site 2. These results highlight for the first time the ability of a given rhinovirus to evolve in the course of a natural infection in immunocompromised patients and complement data obtained from previous experimental inoculation studies in immunocompetent volunteers.

"INTERMED": a method to assess health service needs. I. Development and reliability.

The purpose of this paper is to describe the development and to test the reliability of a new method called INTERMED, for health service needs assessment. The INTERMED integrates the biopsychosocial aspects of disease and the relationship between patient and health care system in a comprehensive scheme and reflects an operationalized conceptual approach to case mix or case complexity. The method is developed to enhance interdisciplinary communication between (para-) medical specialists and to provide a method to describe case complexity for clinical, scientific, and educational purposes. First, a feasibility study (N = 21 patients) was conducted which included double scoring and discussion of the results. This led to a version of the instrument on which two interrater reliability studies were performed. In study 1, the INTERMED was double scored for 14 patients admitted to an internal ward by a psychiatrist and an internist on the basis of a joint interview conducted by both. In study 2, on the basis of medical charts, two clinicians separately double scored the INTERMED in 16 patients referred to the outpatient psychiatric consultation service. Averaged over both studies, in 94.2% of all ratings there was no important difference between the raters (more than 1 point difference). As a research interview, it takes about 20 minutes; as part of the whole process of history taking it takes about 15 minutes. In both studies, improvements were suggested by the results. Analyses of study 1 revealed that on most items there was considerable agreement; some items were improved. Also, the reference point for the prognoses was changed so that it reflected both short- and long-term prognoses. Analyses of study 2 showed that in this setting, less agreement between the raters was obtained due to the fact that the raters were less experienced and the scoring procedure was more susceptible to differences. Some improvements--mainly of the anchor points--were specified which may further enhance interrater reliability. The INTERMED proves to be a reliable method for classifying patients' care needs, especially when used by experienced raters scoring by patient interview. It can be a useful tool in assessing patients' care needs, as well as the level of needed adjustment between general and mental health service delivery. The INTERMED is easily applicable in the clinical setting at low time-costs.

Genetic variation at CHRNA5-CHRNA3-CHRNB4 interacts with smoking status to influence body mass index.

BACKGROUND: Cigarette smoking is associated with lower body mass index (BMI), and a commonly cited reason for unwillingness to quit smoking is a concern about weight gain. Common variation in the CHRNA5-CHRNA3-CHRNB4 gene region (chromosome 15q25) is robustly associated with smoking quantity in smokers, but its association with BMI is unknown. We hypothesized that genotype would accurately reflect smoking exposure and that, if smoking were causally related to weight, it would be associated with BMI in smokers, but not in never smokers. METHODS: We stratified nine European study samples by smoking status and, in each stratum, analysed the association between genotype of the 15q25 SNP, rs1051730, and BMI. We meta-analysed the results (n = 24 198) and then tested for a genotype × smoking status interaction. RESULTS: There was no evidence of association between BMI and genotype in the never smokers {difference per T-allele: 0.05 kg/m(2) [95% confidence interval (95% CI): -0.05 to 0.18]; P = 0.25}. However, in ever smokers, each additional smoking-related T-allele was associated with a 0.23 kg/m(2) (95% CI: 0.13-0.31) lower BMI (P = 8 × 10(-6)). The effect size was larger in current [0.33 kg/m(2) lower BMI per T-allele (95% CI: 0.18-0.48); P = 6 × 10(-5)], than in former smokers [0.16 kg/m(2) (95% CI: 0.03-0.29); P = 0.01]. There was strong evidence of genotype × smoking interaction (P = 0.0001). CONCLUSIONS: Smoking status modifies the association between the 15q25 variant and BMI, which strengthens evidence that smoking exposure is causally associated with reduced BMI. Smoking cessation initiatives might be more successful if they include support to maintain a healthy BMI.

Variation de la mortalité périnatale selon l'heure de naissance en Suisse. [Variations in perinatal mortality according to the hour of birth in Switzerland].

In Switzerland like in most developed countries, the number of births is strongly related to the hour of the day and the day of the week: this pattern is very probably related to the current practice in obstetrics. Less expected is the fact that the perinatal mortality shows a striking circadian rhythm according to the hour of birth. The paper presents this pattern and comments some related issues.

Demographic and geographic vascular risk factor differences in European young adults with ischemic stroke: the 15 cities young stroke study.

BACKGROUND AND PURPOSE: We compared among young patients with ischemic stroke the distribution of vascular risk factors among sex, age groups, and 3 distinct geographic regions in Europe. METHODS: We included patients with first-ever ischemic stroke aged 15 to 49 years from existing hospital- or population-based prospective or consecutive young stroke registries involving 15 cities in 12 countries. Geographic regions were defined as northern (Finland, Norway), central (Austria, Belgium, France, Germany, Hungary, The Netherlands, Switzerland), and southern (Greece, Italy, Turkey) Europe. Hierarchical regression models were used for comparisons. RESULTS: In the study cohort (n=3944), the 3 most frequent risk factors were current smoking (48.7%), dyslipidemia (45.8%), and hypertension (35.9%). Compared with central (n=1868; median age, 43 years) and northern (n=1330; median age, 44 years) European patients, southern Europeans (n=746; median age, 41 years) were younger. No sex difference emerged between the regions, male:female ratio being 0.7 in those aged <34 years and reaching 1.7 in those aged 45 to 49 years. After accounting for confounders, no risk-factor differences emerged at the region level. Compared with females, males were older and they more frequently had dyslipidemia or coronary heart disease, or were smokers, irrespective of region. In both sexes, prevalence of family history of stroke, dyslipidemia, smoking, hypertension, diabetes mellitus, coronary heart disease, peripheral arterial disease, and atrial fibrillation positively correlated with age across all regions. CONCLUSIONS: Primary preventive strategies for ischemic stroke in young adults-having high rate of modifiable risk factors-should be targeted according to sex and age at continental level.

Genetic variation in LIN28B is associated with the timing of puberty.

The timing of puberty is highly variable. We carried out a genome-wide association study for age at menarche in 4,714 women and report an association in LIN28B on chromosome 6 (rs314276, minor allele frequency (MAF) = 0.33, P = 1.5 x 10(-8)). In independent replication studies in 16,373 women, each major allele was associated with 0.12 years earlier menarche (95% CI = 0.08-0.16; P = 2.8 x 10(-10); combined P = 3.6 x 10(-16)). This allele was also associated with earlier breast development in girls (P = 0.001; N = 4,271); earlier voice breaking (P = 0.006, N = 1,026) and more advanced pubic hair development in boys (P = 0.01; N = 4,588); a faster tempo of height growth in girls (P = 0.00008; N = 4,271) and boys (P = 0.03; N = 4,588); and shorter adult height in women (P = 3.6 x 10(-7); N = 17,274) and men (P = 0.006; N = 9,840) in keeping with earlier growth cessation. These studies identify variation in LIN28B, a potent and specific regulator of microRNA processing, as the first genetic determinant regulating the timing of human pubertal growth and development.

Evaluation of bedbath in critically ill patients: impact of water temperature on the pulse oximetry variation

This is a participant study, quasi-experimental, of a before and after type. A quantitative approach of biophysiological measures was used, represented by the saturation of oxygen measured by pulse oximeter (SpO2), and recorded on three occasions: before, during and after the bedbath in critically ill patients hospitalized at the ICU of a University Hospital in Brazil. Objective: to compare the SpO2 in various stages of the bath, with and without control of water temperature. Data collection was performed between December 2007 and April 2008 on a convenience sample consisting of 30 patients aged over 18 who had classification in TISS-28 from level II. Results show that water temperature control means a lower variation of SpO2 (p<0.05). No marked differences in variation of saturation between men and women or between age groups were established. In conclusion, heated and constant water temperature during the bedbath is able to minimize the fall of SpO2 that occurs while handling patients during procedures.

The political economy of childcare in OECD countries : Explaining cross-national variation in spending and coverage rates

If childcare policy has become topical in most OECD countries over the last ten years or so, actual developments display huge cross-national variations. Countries like Sweden and Denmark spend around 2 per cent of GDP on this service, and provide affordable childcare places to most children below school age. At the other extreme, in Southern Europe, only around 10 per cent of this age group has access to formal daycare. Against this background, this article aims to account for cross-national variations in childcare services. It distinguishes two dependent variables: the coverage rate and the proportion of GDP spent subsidising childcare services. Using a mix of cross-sectional and pooled times-series methods, it tests a series of hypotheses concerning the determinants of the development of this policy. Its main conclusion for the coverage rate is that key factors are public spending and wage dispersion (both positive). For spending, key factors are the proportion of women in parliaments (positive) and spending on age-related policies (negative).