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Search Results: 1 - 10 of 9991 matches for " Simon Ducatez "
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Patterns of Research Effort in Birds
Simon Ducatez, Louis Lefebvre
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0089955
Abstract: Between species differences in research effort can lead to biases in our global view of evolution, ecology and conservation. The increase in meta-taxonomic comparative analyses on birds underlines the need to better address how research effort is distributed in this class. Methods have been developed to choose which species should be studied to obtain unbiased comparative data sets, but a precise and global knowledge of research effort is required to be able to properly apply them. We address this issue by providing a data set of research effort (number of papers from 1978 to 2008 in the Zoological Record database) estimates for the 10 064 species of birds. We then test whether research effort is associated with phylogeny, geography and eleven different life history and ecological traits. We show that phylogeny accounts for a large proportion of the variance, while geographic range and all the tested traits are also significant contributors to research effort variance. We identify avian taxa that are under- and overstudied and address the importance of research effort biases in evaluating vulnerability to extinction, with non-threatened species studied twice as much as threatened ones. Our research effort data set covering the entire class Aves provides a tool for researchers to incorporate this potential confounding variable in comparative analyses.
Fitness Costs of Thermal Reaction Norms for Wing Melanisation in the Large White Butterfly (Pieris brassicae)
Audrey Chaput-Bardy, Simon Ducatez, Delphine Legrand, Michel Baguette
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0090026
Abstract: The large white butterfly, Pieris brassicae, shows a seasonal polyphenism of wing melanisation, spring individuals being darker than summer individuals. This phenotypic plasticity is supposed to be an adaptive response for thermoregulation in natural populations. However, the variation in individuals’ response, the cause of this variation (genetic, non genetic but inheritable or environmental) and its relationship with fitness remain poorly known. We tested the relationships between thermal reaction norm of wing melanisation and adult lifespan as well as female fecundity. Butterflies were reared in cold (18°C), moderate (22°C), and hot (26°C) temperatures over three generations to investigate variation in adult pigmentation and the effects of maternal thermal environment on offspring reaction norms. We found a low heritability in wing melanisation (h2 = 0.18). Rearing families had contrasted thermal reaction norms. Adult lifespan of males and females from highly plastic families was shorter in individuals exposed to hot developmental temperature. Also, females from plastic families exhibited lower fecundity. We did not find any effect of maternal or grand-maternal developmental temperature on fitness. This study provides new evidence on the influence of phenotypic plasticity on life history-traits’ evolution, a crucial issue in the context of global change.
El jardín del placer de OMA Oma′s Pleasure Garden
Ducatez Vicent
Bitácora Urbano-Territorial , 2011,
Abstract: Este artículo aborda el tema del proyecto urbano en OMA. Para ello aborda la propuesta presentada por el grupo de arquitectos holandeses para el concurso del Parque de la Villete en Paris, y lo compara con el del Bernard Tschumi, arquitecto ganador. El autor explora los conceptos que OMA maneja en su dise o, los compara con los de Tschumi y, nos introduce en el proyecto urbano de OMA, esquematizando los elementos que el grupo de arquitectos, dirigido por Rem Koolhaas, maneja. This article goes inside the OMA′s urban project. For that reason, it re-examines the project by the Netherlands architects group for the Park La Villette competition. The author a comparison between this does project and that of the winner, the architect Bernard Tschumi. He introduces us to the history of the urban project in OMA′s work, and he also makes an analysis of the architectural elements used by Rem Koolhaas.
Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus
Ducatez MF, Fabrizio TP, Webby RJ
Virus Adaptation and Treatment , 2011, DOI: http://dx.doi.org/10.2147/VAAT.S9656
Abstract: lution and adaptation of the pandemic A/H1N1 2009 influenza virus Review (4453) Total Article Views Authors: Ducatez MF, Fabrizio TP, Webby RJ Published Date July 2011 Volume 2011:3 Pages 45 - 53 DOI: http://dx.doi.org/10.2147/VAAT.S9656 Mariette F Ducatez, Thomas P Fabrizio, Richard J Webby Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA Abstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1)pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1)pdm09 viruses. However, as the A(H1N1)pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1)pdm09 and seasonal A(H1N1) or A(H3N2) viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1) pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1)pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.
Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus
Ducatez MF,Fabrizio TP,Webby RJ
Virus Adaptation and Treatment , 2011,
Abstract: Mariette F Ducatez, Thomas P Fabrizio, Richard J WebbyDepartment of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USAAbstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1)pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1)pdm09 viruses. However, as the A(H1N1)pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1)pdm09 and seasonal A(H1N1) or A(H3N2) viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1) pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1)pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.Keywords: influenza, pandemic, evolution, adaptation
Development of an improved polykaryon-based influenza virus rescue system
Bourret Vincent,Lyall Jon,Ducatez Mariette F,Guérin Jean-Luc
BMC Biotechnology , 2012, DOI: 10.1186/1472-6750-12-69
Abstract: Background Virus rescue from transfected cells is an extremely useful technique that allows defined viral clones to be engineered for the purpose of rational vaccine design or fundamental reverse genetics studies. However, it is often hindered by low primary rescue success rates or yields, especially with field-derived viral strains. Approach We investigated the possibility of enhancing influenza virus rescue by eliciting cell fusion to increase the chances of having all necessary plasmids expressed within the same polykaryon. To this end we used the Maedi-Visna Virus envelope protein which has potent fusion activity in cells from a wide range of different species. Results Co-transfecting cells with the eight plasmids necessary to rescue influenza virus plus a plasmid expressing the Maedi-Visna Virus envelope protein resulted in increased rescue efficiency. In addition, partial complements of the 8-plasmid rescue system could be transfected into two separate populations of cells, which upon fusion led to live virus rescue. Conclusion The simple modification described here has the potential to improve the efficiency of the virus rescue process and expand the potential applications for reverse genetic studies.
An Instance of Somatoform Disorder  [PDF]
Armando Simon
Open Journal of Medical Psychology (OJMP) , 2013, DOI: 10.4236/ojmp.2013.21004
Abstract: A case study is presented of a prison inmate with Somatoform Disorder, a relatively rare type of mental illness. In this particular case symptomatology revolved around his claim that some of his teeth were rotten, resulting in great pain, in spite of several diagnoses by dentists. When said teeth were extracted, inmate would express satisfaction, whereupon several weeks later the same complaint would resurface and the cycle began anew. Of the various types of mental illnesses listed in the DSM, there are some that are infrequently seen [1,2] One of these is Somatoform Disorder, a category of mental illness for which there is a paucity of research, partly due to diagnostic difficulties and controversies [3,4] and we would like to present a case study of just such an instance.
Model for a UV Laser Based Local Polymer Surface Halogenation Process Using a Gaseous Precursor  [PDF]
Simon Kibben
Modeling and Numerical Simulation of Material Science (MNSMS) , 2014, DOI: 10.4236/mnsms.2014.41003
Abstract: An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges at the interfaces to areas where no halogenation is desired. This is achieved via a nonreactive halogen-containing gaseous precursor and a UV source providing photons which dissociate the precursor photolytically. Thus, only where the UV photons affect the precursor, halogens are generated and the polymer is being halogenated.
Dehumanization, Racial Minority and Female Leadership: An Analysis of Global Trends  [PDF]
Simon Raymond
Advances in Applied Sociology (AASoci) , 2016, DOI: 10.4236/aasoci.2016.68022
Abstract: Purpose: The use of dehumanization, directed toward racial minorities, impresses as a global trend of significance, spanning from broad generalisations with regards to black community members holding a lower status through to Russian politicians terming Barack Obama and Michelle Obama as mammalian apes (or, monkeys). This report analyses the use of dehumanization and the validity of racial degradation. Female leadership is also analysed. Methods: A comparative analysis was performed assessing the achievements of African Americans in comparison with white (including caucasian) society, with a gender comparison to assess for consistency across genders. The categorisation of racial minorities based on the satisfying of criteria for conscious being recognition was also considered. Results: African Americans have held positions, and achieved success, equally respectable with that of the white (including caucasian) community. These members of society also satisfy the criteria for conscious beings. There appears to be no validity to support black or Asian people as representative of a being less than that of a human being. Conclusion: There appears to be no validity behind categorisation of certain races as lesser members of society. Furthermore, there appears no validity behind the use of dehumanization.
Why Do Voters Change Their Mind during an Election Campaign? An Analysis of the Determinants of Campaign Volatility at the 2014 Belgian Federal Elections  [PDF]
Simon Willocq
Open Journal of Political Science (OJPS) , 2016, DOI: 10.4236/ojps.2016.64033
Abstract: This article examines the causes of stability and change in vote intentions during the 2014 Belgian federal election campaign. Drawing on data from the 2014 Parti Rep Belgian Voter Survey, our study aims to explain why a large number of voters have switched their vote intention in the weeks preceding the federal elections. To this end, we test a series of hypotheses drawn from different theories often referred to in the literature to account for campaign volatility. The results of our analysis reveal that voters can decide to change their vote preferences during the campaign due to strategic considerations related to their perceptions of the coalition potentials of parties. We also find that voters with a low level of political interest are more likely than highly interested voters to switch from one party to another in the weeks preceding the electoral contest. Unsurprisingly, a high degree of affection for the favourite party proves to be a barrier against campaign volatility. The higher the level of affect directed to the most preferred party, the more stable will be the vote intention. Moreover, results show that citizens with a low level of external political efficacy are more prone than others to switch parties in the last weeks of the campaign. By contrast, the ideological profile of the voter has no significant impact on campaign volatility.
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