Fragmentation and Limits to Dynamical Scaling in Viscous Coarsening: An Interrupted in situ X-Ray Tomographic Study

X-Ray microtomography was used to follow the coarsening of the structure of a ternary silicate glass experiencing phase separation in the liquid state. The volumes, surfaces, mean and Gaussian curvatures of the domains of minority phase were measured after reconstruction of the 3D images and segmentation. A linear growth law of the characteristic length scale $\ell \sim t$ was observed. A detailed morphological study was performed. While dynamical scaling holds for most of the geometrical observables under study, a progressive departure from scaling invariance of the distributions of local curvatures was evidenced. The latter results from a gradual fragmentation of the structure in the less viscous phase that also leads to a power-law size distribution of isolated domains

Size-assortative mating in simultaneous hermaphrodites: an experimental test and a meta-analysis

Assortative mating by size has been argued to be widespread in the animal kingdom. However, the strength of size-assortative mating is known to vary considerably between species and the underlying mechanisms promoting this inter-specific variation remain largely unexplored. Size-assortative mating has been proposed to be particularly strong in simultaneous hermaphrodites, i.e. organisms that produce male and female gametes at the same time. Here, we build on this hypothesis by arguing that size-assortative mating mediated by sexual selection is generally stronger in reciprocally mating hermaphrodites compared with unilaterally mating species and separate-sexed organisms. We report a series of empirical tests suggesting that size-assortative mating in the unilaterally copulating freshwater snail Physa acuta is caused by spatial clustering of similar-sized individuals and not by mate choice. In addition, we present a meta-analysis testing, for the first time, the hypothesis that sexual selection-mediated size-assortative mating is stronger in reciprocally copulating simultaneous hermaphrodites. Overall, we found significant size-assortative mating across 18 tested species and substantial inter-specific variation. Importantly, part of this variation can be explained by mating type, providing support for the hypothesis that size-assortative mating is stronger in reciprocally mating hermaphrodites compared with unilaterally mating species. We highlight potential pitfalls when testing for sexual selection-mediated size-assortative mating and discuss the need for more experimental and comparative approaches in order to resolve the observed variation in the strength of size-assortative mating among species.Fil: Graham, Stuart. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Université Paul-Valéry Montpellier; Francia. Centre National de la Recherche Scientifique; FranciaFil: Chapuis, Elodie. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Centre National de la Recherche Scientifique; Francia. Institut de Recherche pour le Développement,. Intéractions Plantes-Microrganismes-Environement; Francia. Université Paul-Valéry Montpellier; FranciaFil: Meconcelli, Stefania. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Centre National de la Recherche Scientifique; Francia. Università di Torino; ItaliaFil: Bonel, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Zoología de Invertebrados I; Argentina. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Université Paul-Valéry Montpellier; FranciaFil: Sartori, Kevin. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Centre National de la Recherche Scientifique; Francia. Université Paul-Valéry Montpellier; FranciaFil: Christophe, Ananda. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Centre National de la Recherche Scientifique; Francia. Université Paul-Valéry Montpellier; FranciaFil: Alda, Maria del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Patrice David. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Centre National de la Recherche Scientifique; Francia. Université Paul-Valéry Montpellier; FranciaFil: Janicke, Tim. Université de Montpellier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Centre National de la Recherche Scientifique; Francia. Université Paul-Valéry Montpellier; Franci

Environmental effects on the genetic architecture of fitness components in a simultaneous hermaphrodite

Understanding how environmental change affects genetic variances and covariances of reproductive traits is key to formulate firm predictions on evolutionary responses. This is particularly true for sex-specific variance in reproductive success, which has been argued to affect how populations can adapt to environmental change. Our current knowledge on the impact of environmental stress on sex-specific genetic architecture of fitness components is still limited and restricted to separate-sexed organisms. However, hermaphroditism is widespread across animals and may entail interesting peculiarities with respect to genetic constraints imposed on the evolution of male and female reproduction. We explored how food restriction affects the genetic variance-covariance (G) matrix of body size and reproductive success of the simultaneously hermaphroditic freshwater snail Physa acuta. Our results provide strong evidence that the imposed environmental stress elevated the opportunity for selection in both sex functions. However, the G matrix remained largely stable across the tested food treatments. Importantly, our results provide no support for cross-sex genetic correlations suggesting no strong evolutionary coupling of male and female reproductive traits. We discuss potential implications for the adaptation to changing environments and highlight the need for more quantitative genetic studies on male and female fitness components in simultaneous hermaphrodites.Fil: Janicke, Tim. Technische Universität Dresden; Alemania. Centre National de la Recherche Scientifique; FranciaFil: Chapuis, Elodie. Université de Montpellier; FranciaFil: Meconcelli, Stefania. Centre National de la Recherche Scientifique; Francia. Università di Torino; ItaliaFil: Bonel, Nicolás. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Delahaie, Boris. University of Cambridge; Estados UnidosFil: David, Patrice. Centre National de la Recherche Scientifique; Franci

0292: Endothelial protein tyrosine phosphatase 1B deficiency reduces both endothelial and cardiac dysfunction of in a mouse model of aging

IntroductionAging is associated with an endothelial dysfunction, characterized by a decrease of nitric oxide (NO) production, which is a risk factor of development of cardiovascular diseases. However, the direct link between endothelial dysfunction and aggravation of cardiac function in aging is not established. We reported previously a new potent therapeutic approach of cardiovascular disease, based on inhibition of protein tyrosine phosphatase 1B (PTP1B), which both increases NO production (via restored PI3K/Akt/eNOS signaling) and reduces cardiac dysfunction in both post-ischemic heart failure and aging, however the exact role of endothelial PTP1B in this setting is unknown. To evaluate the endothelial and cardiac consequences of endothelial PTP1B deficiency (endoPTP1B-/-) in a mouse model of aging.Material and methodsEndoPTP1B-/- mice were developed by crossing LOX-P PTP1B mice with mice expressing CRE under the control of the endothelial promoter Tie2, or wild-type (WT). The evolution of cardiac function was assessed by echocardiography at different time points and the vascular function was evaluated ex vivo at 24 months.ResultsCompared to young (3 month-old), WT mice aged (24 month-old) showed a markedly impaired flow-mediated dilatation of isolated mesenteric arteries (3 months: 40±4%; 24 months: 1±1%; p<0.001), which was improved in endoPTP1B-/- mice (17±3%; p<0.001 vs. WT 24 months). This restored response in aged endoPTP1B-/- mice was abolished by a NO-synthase inhibitor, suggesting a restored NO production. In WT mice, aging decreased stroke volume (3 months: 0,070±0,002%; 24 months: 0,065±0,005%; p<0.001) and cardiac output (3 months: 37±1%; 24 months: 29±2%; p<0.001) and these parameters were improved in endoPTP1B-/- mice (24 months: 0.081±0,011% and 34±2%; respectively, p<0.05).ConclusionIn aged mice, endoPTP1B deficiency induced an improvement of endothelial function, and also tended to improved cardiac function. These results provide a direct demonstration of the beneficial effect of endothelial protection in aging

Evaluation of PD-L1 expression on vortex-isolated circulating tumor cells in metastatic lung cancer.

Metastatic non-small cell lung cancer (NSCLC) is a highly fatal and immunogenic malignancy. Although the immune system is known to recognize these tumor cells, one mechanism by which NSCLC can evade the immune system is via overexpression of programmed cell death ligand 1 (PD-L1). Recent clinical trials of PD-1 and PD-L1 inhibitors have returned promising clinical responses. Important for personalizing therapy, patients with higher intensity staining for PD-L1 on tumor biopsies responded better. Thus, there has been interest in using PD-L1 tumor expression as a criterion for patient selection. Currently available methods of screening involve invasive tumor biopsy, followed by histological grading of PD-L1 levels. Biopsies have a high risk of complications, and only allow sampling from limited tumor sections, which may not reflect overall tumor heterogeneity. Circulating tumor cell (CTC) PD-L1 levels could aid in screening patients, and could supplement tissue PD-L1 biopsy results by testing PD-L1 expression from disseminated tumor sites. Towards establishing CTCs as a screening tool, we developed a protocol to isolate CTCs at high purity and immunostain for PD-L1. Monitoring of PD-L1 expression on CTCs could be an additional biomarker for precision medicine that may help in determining response to immunotherapies

Evolutionary History and Attenuation of Myxoma Virus on Two Continents

The attenuation of myxoma virus (MYXV) following its introduction as a biological control into the European rabbit populations of Australia and Europe is the canonical study of the evolution of virulence. However, the evolutionary genetics of this profound change in host-pathogen relationship is unknown. We describe the genome-scale evolution of MYXV covering a range of virulence grades sampled over 49 years from the parallel Australian and European epidemics, including the high-virulence progenitor strains released in the early 1950s. MYXV evolved rapidly over the sampling period, exhibiting one of the highest nucleotide substitution rates ever reported for a double-stranded DNA virus, and indicative of a relatively high mutation rate and/or a continually changing selective environment. Our comparative sequence data reveal that changes in virulence involved multiple genes, likely losses of gene function due to insertion-deletion events, and no mutations common to specific virulence grades. Hence, despite the similarity in selection pressures there are multiple genetic routes to attain either highly virulent or attenuated phenotypes in MYXV, resulting in convergence for phenotype but not genotype. © 2012 Kerr et al

Collecte de parole pour l’étude des langues peu dotées ou en danger avec l’application mobile Lig-Aikuma

International audienceNous rapportons dans cet article les travaux en cours portant sur la collecte de langues africaines peu dotées ou en danger. Une collecte de données a été menée à l'aide d'une version modifiée de l'application Android AIKUMA, initialement développée par Steven Bird et coll. (Bird et al., 2014). Les modifications apportées suivent les spécifications du projet franco-allemand ANR/DFG BULB 1 pour faciliter la collecte sur le terrain de corpus de parole parallèles. L'application résultante, appelée LIG-AIKUMA, a été testée avec succès sur plusieurs smartphones et tablettes et propose plusieurs modes de fonctionnement (enregistrement de parole, respeaking de parole, traduction et élicitation). Entre autres fonctionnalités, LIG-AIKUMA permet la génération et la manipulation avancée de fichiers de métadonnées ainsi que la prise en compte d'informations d'alignement entre phrases prononcées parallèles dans les modes de respeaking et de traduction. L'application a été utilisée aux cours de campagnes de collecte sur le terrain, au Congo-Brazzaville, permettant l'acquisition de 80 heures de parole. La conception de l'application et l'illustration de son usage dans deux campagnes de collecte sont décrites plus en détail dans cet article

Children's Independent Mobility: Survey in French Brittany (2011)

The study contributes to an international survey carried out in 16 countries: Australia, Brazil, Denmark, England, Finland, France, Germany, Ireland, Israel, Italy, Japan, Norway, Portugal, South Africa, Sri Lanka, Sweden(Shaw & Watson, 2010). The international survey was initiated by the Political Study Institute of London as an extended geographical replication of the original study of Hillman & al (1990).The general objective of this study is to investigate how children's independent mobility develops between age 7-15. The degree of independent mobility is assessed through the examination of children's statements about six licences related to outside trips without adult supervision. The objective is to provide a detailed picture of the current state of independent mobility in primary and secondary school children of French Brittany (North-West of France). In this respect, the study contributes to an international survey carried out in 16 countries (Shaw & Watson, 2010). The international survey was initiated by the Political Study Institute of London as an extended geographical replication of the original study of Hillman & al (1990). Method A total of 947 children participated in the French survey. Specifically, in primary school 484 children--48,8% girls, 51,2% boys--filled up the questionnaire, age ranging from 6 to 12, mean = 8,79 (sd =1,27). In secondary school 463 young people--49,7% girls, 50,3% boys--responded to the questionnaire, age ranging from 10 to 16, mean = 12,9 (sd =1,29). The survey was conducted in different types of living environment varying in relation to the size and density of the dwelling area. Five types of areas were considered: (1) inner district of a major city, (2) suburban area of a major city, (3) small town, (4) rural market town and (5) rural area. In the French survey, the five types of areas were selected in the same region, namely the district (département) of Ille-et-Vilaine in French Brittany. Therefore, the survey design, which gathered data from different types of areas, was likely to provide a comprehensive picture of the independent mobility of the children living in that particular region. Children's independent mobility was assessed through the examination of six licences: (1) Licence to cross roads alone, (2) Licence to travel to and from school alone, (3) Licence to go on their own to places other than school, (4) Licence to cycle on main roads, (5) Licence to use buses, (6) Licence to go out after dark. Results The comparison of the licences granted by parents to Psc and to Ssc reveals marked difference for all the six licences. This denotes important changes in the parental attitude towards these children's independent mobility within the considered age range. Interestingly the hierarchy of the six licences is almost the same for the two groups. For both groups the licence to cross main roads is the most frequently granted, whereas licence to go out after dark is the least granted. Even in the secondary school, only a few French children are allowed to go out after dark. The analysis of the children's responses also puts forward that independent mobility develop markedly after 11 years when children are in secondary school. Specifically, four of the six licences are held by a large majority of the secondary school children: to go to other places than school on their own, to cross main roads, to use public transport, and to cycle on main roads. However, only one third of these older children declared to go to and from school on their own. This result is probably due to the size of the secondary school catchment areas which were particularly large in four of the five survey areas. Therefore, the distances from the children's homes to secondary school constrained the older children to use the school bus or to be driven by their parents. The primary school children's independent mobility is particularly restricted; four of the six licences examined were hold by less than one third of these children. The licence to go to other places than school is the most frequently mentioned by the 7-to-11-year olds. But only half of primary school children can benefit from such a basic and critical licence that can be seen as a prerequisite to the development of activities independently from adults in the dwelling area. For the other half of the primary school children, this result supports the idea that most out-of-school activities are likely to take place in adult-controlled settings, where children must be accompanied by their parents. Both primary and secondary school children claim to have a particular licence more often than parents declare to grant their children that licence. The differences between children's and parents' responses are particularly obvious as regard to the licence to ride on main roads and, to a lesser degree, the licence to go out after dark. A cluster analysis permitted to isolate five contrasted types of independent mobility defined by various combinations of licences ranging from a quasi-total dependent mobility to the largest independent mobility. Age is the principal factor significantly associated with each of the five clusters, whereas gender is only associated to one cluster. The type of area and the children's perception of safety in their local area also seem to account for the nature and degree of independent mobility. Overall, these results support the view that a complex array of factors intervenes in the development of children independent mobility, including environmental attributes of the living context such as city size, density and outdoor urban facilities

Parallel Speech Collection for Under-resourced Language Studies Using the Lig-Aikuma Mobile Device App

International audienceThis paper reports on our ongoing efforts to collect speech data in under-resourced or endangered languages of Africa. Data collection is carried out using an improved version of the Android application Aikuma developed by Steven Bird and colleagues 1. Features were added to the app in order to facilitate the collection of parallel speech data in line with the requirements of the French-German ANR/DFG BULB (Breaking the Unwritten Language Barrier) project. The resulting app, called Lig-Aikuma, runs on various mobile phones and tablets and proposes a range of different speech collection modes (recording, respeaking, translation and elicitation). Lig-Aikuma's improved features include a smart generation and handling of speaker metadata as well as respeaking and parallel audio data mapping. It was used for field data collections in Congo-Brazzaville resulting in a total of over 80 hours of speech. Design issues of the mobile app as well as the use of Lig-Aikuma during two recording campaigns, are further described in this paper

Orthology guided transcriptome assembly of Italian ryegrass and meadow fescue for single-nucleotide polymorphism discovery

Single-nucleotide polymorphisms (SNPs) represent natural DNA sequence variation. They can be used for various applications including the construction of high-density genetic maps, analysis of genetic variability, genome-wide association studies, and mapbased cloning. Here we report on transcriptome sequencing in the two forage grasses, meadow fescue (Festuca pratensis Huds.) and Italian ryegrass (Lolium multiflorum Lam.), and identification of various classes of SNPs. Using the Orthology Guided Assembly (OGA) strategy, we assembled and annotated a total of 18,952 and 19,036 transcripts for Italian ryegrass and meadow fescue, respectively. In addition, we used transcriptome sequence data of perennial ryegrass (L. perenne L.) from a previous study to identify 16,613 transcripts shared across all three species. Large numbers of intraspecific SNPs were identified in all three species: 248,000 in meadow fescue, 715,000 in Italian ryegrass, and 529,000 in perennial ryegrass. Moreover, we identified almost 25,000 interspecific SNPs located in 5343 genes that can distinguish meadow fescue from Italian ryegrass and 15,000 SNPs located in 3976 genes that discriminate meadow fescue from both Lolium species. All identified SNPs were positioned in silico on the seven linkage groups (LGs) of L. perenne using the GenomeZipper approach. With the identification and positioning of interspecific SNPs, our study provides a valuable resource for the grass research and breeding community and will enable detailed characterization of genomic composition and gene expression analysis in prospective Festuca Lolium hybrids