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  • Open Access English
    Authors: 
    Ivano Baronchelli; G. Rodighiero; Harry I. Teplitz; Claudia Scarlata; Alberto Franceschini; S. Berta; Laia Barrufet; Mattia Vaccari; Matteo Bonato; Laure Ciesla; +15 more
    Publisher: HAL CCSD
    Countries: France, Italy, United States
    Project: EC | HELP (607254)

    For a sample of star forming galaxies in the redshift interval 0.15$<$z$<$0.3, we study how both the relative strength of the AGN infra-red emission, compared to that due to the star formation (SF), and the numerical fraction of AGNs, change as a function of the total stellar mass of the hosting galaxy group (M$^{*}_{\mathrm{group}}$), between $10^{10.25}$ and $10^{11.9}$M$_{\odot}$. Using a multi-component SED fitting analysis, we separate the contribution of stars, AGN torus and star formation to the total emission at different wavelengths. This technique is applied to a new multi-wavelength data-set in the SIMES field (23 not redundant photometric bands), spanning the wavelength range from the UV (GALEX) to the far-IR (Herschel) and including crucial AKARI and WISE mid-IR observations (4.5 \mu m$<\lambda<$24 \mu m), where the BH thermal emission is stronger. This new photometric catalog, that includes our best photo-z estimates, is released through the NASA/IPAC Infrared Science Archive (IRSA). Groups are identified through a friends of friends algorithm ($\sim$62% purity, $\sim$51% completeness). We identified a total of 45 galaxies requiring an AGN emission component, 35 of which in groups and 10 in the field. We find BHAR$\propto ($M$^{*}_{\mathrm{group}})^{1.21\pm0.27}$ and (BHAR/SFR)$\propto ($M$^{*}_{\mathrm{group}})^{1.04\pm0.24}$ while, in the same range of M$^{*}_{\mathrm{group}}$, we do not observe any sensible change in the numerical fraction of AGNs. Our results indicate that the nuclear activity (i.e. the BHAR and the BHAR/SFR ratio) is enhanced when galaxies are located in more massive and richer groups. Comment: 31 pages, 23 figures

  • Open Access English
    Authors: 
    Marie-Josèphe Giraud-Panis; M. Teresa Teixeira; Vincent Géli; Eric Gilson;
    Publisher: HAL CCSD
    Country: France

    Telomere protection in budding yeast requires the heterotrimer named CST (for Cdc13-Stn1-Ten1). Recent data show that CST components are conserved and required for telomere stability in a wide range of eukaryotes, even those utilizing the shelterin complex to protect their telomeres. A common function of these proteins might be to stimulate priming at the C-strand gap that remains after telomerase elongation, replication termination, and terminal processing. In light of the budding yeast situation, another conserved function of CST might well be the regulation of telomerase. The cohabitation at telomeres of CST and shelterin components highlights the complexity of telomere biology.

  • Open Access English
    Authors: 
    Alexis Khripounoff; Annick Vangriesheim; Philippe Crassous; Joel Etoubleau;
    Publisher: Elsevier
    Country: France

    This study aimed to analyze the role river floods play in triggering gravity flows and to investigate the role of submarine canyon systems as a conduit for terrigenous material to the deep sea. Two years of measurements in the Var canyon at depths ranging from 1200 m to 2350 m indicate that six floods of the Var River triggered hyperpycnal flows, an important mechanism for transporting particulate matter to the deep-sea floor. These sediment gravity flows were characterized by a sudden increase of current velocity that lasted 8 to 22 h and by downward particle fluxes that reached up to 600 g m(-2)d(-1) of particles and 3.1 g m(-2)d(-1) in terms of organic carbon. These large inputs of sediment and organic carbon may have a significant impact on deep-sea ecosystems and carbon storage in the Mediterranean Sea.

  • Open Access English
    Authors: 
    Ally Aukauloo; Philipp Gotico; Loïc Roupnel; Régis Guillot; Marie Sircoglou; Winfried Leibl; Zakaria Halime;
    Publisher: HAL CCSD
    Country: France

    International audience; The manipulation of the second coordination sphere for improving the electrocatalytic CO2 reduction has led to amazing breakthroughs with hydrogen bonding, local proton source, or electrostatic effects. We have developed two atropisomers of an iron porphyrin complex holding two urea functions acting as multiple hydrogen bonding tweezers to lock the metal bound CO2 in a similar fashion found in the carbon monoxide dehydrogenase (CODH) enzyme. We found that the  topological isomer with the two urea groups on the same side of the porphyrin platform provides a stronger binding affinity to tether the incoming CO2 substrate in comparison to the  disposition. However, the electrocatalytic activity of the  atropisomer outperforms its congener with one of the highest reported turnover frequency at low overpotential. The strong H/D KIE observed for the system indicates the existence of a tight water hydrogen bonding network for proton delivery which is disrupted upon addition of exogenous acid source. While the small H/D KIE for the  isomer and the enhanced electrocatalytic performance upon addition of stronger acid pertain the free access of protons to the bound CO2 on the opposite side of the urea arm.

  • Open Access English
    Authors: 
    Ari Asmi; Alfred Wiedensohler; Paolo Laj; A. M. Fjaeraa; Karine Sellegri; Wolfram Birmili; Ernest Weingartner; Urs Baltensperger; V. Zdimal; Nadezda Zikova; +27 more
    Countries: Netherlands, Norway, France, Ireland
    Project: EC | ATMNUCLE (227463)

    Two years of harmonized aerosol number size distribution data from 24 European field monitoring sites have been analysed. The results give a comprehensive overview of the European near surface aerosol particle number concentrations and number size distributions between 30 and 500 nm of dry particle diameter. Spatial and temporal distribution of aerosols in the particle sizes most important for climate applications are presented. We also analyse the annual, weekly and diurnal cycles of the aerosol number concentrations, provide log-normal fitting parameters for median number size distributions, and give guidance notes for data users. Emphasis is placed on the usability of results within the aerosol modelling community. <br></br> We also show that the aerosol number concentrations of Aitken and accumulation mode particles (with 100 nm dry diameter as a cut-off between modes) are related, although there is significant variation in the ratios of the modal number concentrations. Different aerosol and station types are distinguished from this data and this methodology has potential for further categorization of stations aerosol number size distribution types. <br></br> The European submicron aerosol was divided into characteristic types: Central European aerosol, characterized by single mode median size distributions, unimodal number concentration histograms and low variability in CCN-sized aerosol number concentrations; Nordic aerosol with low number concentrations, although showing pronounced seasonal variation of especially Aitken mode particles; Mountain sites (altitude over 1000 m a.s.l.) with a strong seasonal cycle in aerosol number concentrations, high variability, and very low median number concentrations. Southern and Western European regions had fewer stations, which decreases the regional coverage of these results. Aerosol number concentrations over the Britain and Ireland had very high variance and there are indications of mixed air masses from several source regions; the Mediterranean aerosol exhibit high seasonality, and a strong accumulation mode in the summer. The greatest concentrations were observed at the Ispra station in Northern Italy with high accumulation mode number concentrations in the winter. The aerosol number concentrations at the Arctic station Zeppelin in Ny-AA lesund in Svalbard have also a strong seasonal cycle, with greater concentrations of accumulation mode particles in winter, and dominating summer Aitken mode indicating more recently formed particles. Observed particles did not show any statistically significant regional work-week or weekday related variation in number concentrations studied. <br></br> Analysis products are made for open-access to the research community, available in a freely accessible internet site. The results give to the modelling community a reliable, easy-to-use and freely available comparison dataset of aerosol size distributions.

  • Open Access English
    Authors: 
    Suelen Gasparin; Julien Berger; Denys Dutykh; Nathan Mendes;
    Country: France

    Implicit schemes require important sub-iterations when dealing with highly nonlinear problems such as the combined heat and moisture transfer through porous building elements. The computational cost rises significantly when the whole-building is simulated, especially when there is important coupling among the building elements themselves with neighbouring zones and with HVAC (Heating Ventilation and Air Conditioning) systems. On the other hand, the classical Euler explicit scheme is generally not used because its stability condition imposes very fine time discretisation. Hence, this paper explores the use of an improved explicit approach - the Dufort-Frankel scheme - to overcome the disadvantage of the classical explicit one and to bring benefits that cannot be obtained by implicit methods. The Dufort-Frankel approach is first compared to the classical Euler implicit and explicit schemes to compute the solution of nonlinear heat and moisture transfer through porous materials. Then, the analysis of the Dufort-Frankel unconditionally stable explicit scheme is extended to the coupled heat and moisture balances on the scale of a one- and a two-zone building models. The Dufort-Frankel scheme has the benefits of being unconditionally stable, second-order accurate in time O(dt^2) and to compute explicitly the solution at each time step, avoiding costly sub-iterations. This approach may reduce the computational cost by twenty, as well as it may enable perfect synchronism for whole-building simulation and co-simulation. 38 pages, 19 figures, 3 tables, 28 references. Other author's papers can be downloaded at http://www.denys-dutykh.com/

  • Publication . Article . Other literature type . 2013
    Open Access English
    Authors: 
    Léa Touri; Hélène Marchetti; Irène Sari-Minodier; Nicolas Molinari; Pascal Chanez;
    Publisher: HAL CCSD
    Country: France

    International audience; IAir traffic is increasing, raising concern about local pollution and its adverse health effects on the people living in the vicinity of large airports. However, the highest risk is probably occupational exposure due to proximity. Jet exhaust is one of the main concerns at an airport and may have a health impact, particularly on the respiratory tract. Current studies are neither numerous enough nor strong enough to prove this kind of association. Yet, more and more people work in airports, and occupational exposure to jet exhaust is a fact. The aim of this review was to evaluate the existing knowledge regarding the impact of airport pollution on respiratory health. We conducted systematic literature searches to examine workplace exposures.

  • Open Access English
    Authors: 
    Albert Benveniste; Claude Jard; Ajay Kattepur; Sidney Rosario; John A. Thywissen;
    Publisher: HAL CCSD
    Country: France

    International audience; We study QoS-aware management of service orchestrations, specifically for orchestrations having a data-dependent workflow. Our study supports multi-dimensional QoS. To capture uncertainty in performance and QoS, we provide support for probabilistic QoS. Under the above assumptions, orchestrations may be non-monotonic with respect to QoS, meaning that strictly improving the QoS of a service may strictly decrease the end-to-end QoS of the orchestration, an embarrassing feature for QoS-aware management. We study monotonicity and provide sucient conditions for it. We then propose a comprehensive theory and methodology for monotonic orchestrations. Generic QoS composition rules are developed via a QoS Calculus, also capturing best service binding/service discovery, however, is not within the scope of this work. Monotonicity provides the rationale for a contract-based approach to QoS-aware management. Although function and QoS cannot be separated in the design of complex orchestrations, we show that our framework supports separation of concerns by allowing the development of function and QoS separately and then "weaving" them together to derive the QoSenhanced orchestration. Our approach is implemented on top of the Orc script language for specifying service orchestrations.

  • Open Access English
    Authors: 
    M. Karamitros; Shuang Luan; Mario A. Bernal; John Allison; G. Baldacchino; Marie Davídková; Ziad Francis; Werner Friedland; V. Ivantchenko; A. Ivantchenko; +6 more
    Publisher: HAL CCSD
    Country: France

    International audience; Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system.To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage.Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k–d tree data structure for quickly locating, for a given molecule, its closest reactants. The performance advantage is presented in terms of complexity, and the accuracy of the new algorithm is demonstrated by simulating radiation chemistry in the context of the Geant4-DNA project.Application The time-dependent radiolytic yields of the main chemical species formed after irradiation are computed for incident protons at different energies (from 50 MeV to 500 keV). Both the time-evolution and energy dependency of the yields are discussed. The evolution, at one microsecond, of the yields of hydroxyls and solvated electrons with respect to the linear energy transfer is compared to theoretical and experimental data. According to our results, at high linear energy transfer, modeling radiation chemistry in the trading compartment representation might be adopted.

  • Open Access English
    Authors: 
    Louise Laure Mariani; Pierre Lozeron; Marie Théaudin; Zoia Mincheva; Aissatou Signate; Béatrice Ducot; Vincent Algalarrondo; Christian Denier; Clovis Adam; Guillaume Nicolas; +5 more
    Publisher: John Wiley and Sons Inc.
    Country: France

    International audience; Objective To compare the natural history of familial transthyretin amyloid polyneuropathies (FAP) due to the Val30Met, Ser77Tyr, and Ile107Val mutations in France with the classical Portuguese Val30Met FAP. Methods We compared 84 French patients with a control group of 110 Portuguese patients carrying the Val30Met mutation also living in France, all referred to and followed at the French National FAP Reference Center from 1988 to 2010. Clinical examination, functional and walking disability scores, nerve conduction studies, and muscle biopsies are reported. We also conducted a comprehensive literature review to further determine the range of phenotypic expression. Results By comparison with Portuguese Val30Met FAP, French Ile107Val, Ser77Tyr, and LateVal30Met FAP showed more rapid and severe disease progression; onset of gait disorders was 3 times more rapid (p 50 years; LateMet30) FAP (p = 0.0005). Other distinctive features relative to the Portuguese patients included atypical clinical presentations, demyelination on nerve conduction studies (p = 0.0005), and difficult identification of amyloid deposits in nerve and muscle biopsies. Interpretation Ile107Val and LateMet30 mutations are associated with the most debilitating and severe FAP ever described, with rapid onset of tetraparesis and shorter median survival. It could be explained by frequent large‐fiber involvement and associated demyelination and more severe axonal loss. These findings have major implications for genetic counseling and patient management as new therapeutic options are being assessed in clinical trials (TTR gene silencing). Ann Neurol 2015;78:901–916

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
530,059 Research products, page 1 of 53,006
  • Open Access English
    Authors: 
    Ivano Baronchelli; G. Rodighiero; Harry I. Teplitz; Claudia Scarlata; Alberto Franceschini; S. Berta; Laia Barrufet; Mattia Vaccari; Matteo Bonato; Laure Ciesla; +15 more
    Publisher: HAL CCSD
    Countries: France, Italy, United States
    Project: EC | HELP (607254)

    For a sample of star forming galaxies in the redshift interval 0.15$<$z$<$0.3, we study how both the relative strength of the AGN infra-red emission, compared to that due to the star formation (SF), and the numerical fraction of AGNs, change as a function of the total stellar mass of the hosting galaxy group (M$^{*}_{\mathrm{group}}$), between $10^{10.25}$ and $10^{11.9}$M$_{\odot}$. Using a multi-component SED fitting analysis, we separate the contribution of stars, AGN torus and star formation to the total emission at different wavelengths. This technique is applied to a new multi-wavelength data-set in the SIMES field (23 not redundant photometric bands), spanning the wavelength range from the UV (GALEX) to the far-IR (Herschel) and including crucial AKARI and WISE mid-IR observations (4.5 \mu m$<\lambda<$24 \mu m), where the BH thermal emission is stronger. This new photometric catalog, that includes our best photo-z estimates, is released through the NASA/IPAC Infrared Science Archive (IRSA). Groups are identified through a friends of friends algorithm ($\sim$62% purity, $\sim$51% completeness). We identified a total of 45 galaxies requiring an AGN emission component, 35 of which in groups and 10 in the field. We find BHAR$\propto ($M$^{*}_{\mathrm{group}})^{1.21\pm0.27}$ and (BHAR/SFR)$\propto ($M$^{*}_{\mathrm{group}})^{1.04\pm0.24}$ while, in the same range of M$^{*}_{\mathrm{group}}$, we do not observe any sensible change in the numerical fraction of AGNs. Our results indicate that the nuclear activity (i.e. the BHAR and the BHAR/SFR ratio) is enhanced when galaxies are located in more massive and richer groups. Comment: 31 pages, 23 figures

  • Open Access English
    Authors: 
    Marie-Josèphe Giraud-Panis; M. Teresa Teixeira; Vincent Géli; Eric Gilson;
    Publisher: HAL CCSD
    Country: France

    Telomere protection in budding yeast requires the heterotrimer named CST (for Cdc13-Stn1-Ten1). Recent data show that CST components are conserved and required for telomere stability in a wide range of eukaryotes, even those utilizing the shelterin complex to protect their telomeres. A common function of these proteins might be to stimulate priming at the C-strand gap that remains after telomerase elongation, replication termination, and terminal processing. In light of the budding yeast situation, another conserved function of CST might well be the regulation of telomerase. The cohabitation at telomeres of CST and shelterin components highlights the complexity of telomere biology.

  • Open Access English
    Authors: 
    Alexis Khripounoff; Annick Vangriesheim; Philippe Crassous; Joel Etoubleau;
    Publisher: Elsevier
    Country: France

    This study aimed to analyze the role river floods play in triggering gravity flows and to investigate the role of submarine canyon systems as a conduit for terrigenous material to the deep sea. Two years of measurements in the Var canyon at depths ranging from 1200 m to 2350 m indicate that six floods of the Var River triggered hyperpycnal flows, an important mechanism for transporting particulate matter to the deep-sea floor. These sediment gravity flows were characterized by a sudden increase of current velocity that lasted 8 to 22 h and by downward particle fluxes that reached up to 600 g m(-2)d(-1) of particles and 3.1 g m(-2)d(-1) in terms of organic carbon. These large inputs of sediment and organic carbon may have a significant impact on deep-sea ecosystems and carbon storage in the Mediterranean Sea.

  • Open Access English
    Authors: 
    Ally Aukauloo; Philipp Gotico; Loïc Roupnel; Régis Guillot; Marie Sircoglou; Winfried Leibl; Zakaria Halime;
    Publisher: HAL CCSD
    Country: France

    International audience; The manipulation of the second coordination sphere for improving the electrocatalytic CO2 reduction has led to amazing breakthroughs with hydrogen bonding, local proton source, or electrostatic effects. We have developed two atropisomers of an iron porphyrin complex holding two urea functions acting as multiple hydrogen bonding tweezers to lock the metal bound CO2 in a similar fashion found in the carbon monoxide dehydrogenase (CODH) enzyme. We found that the  topological isomer with the two urea groups on the same side of the porphyrin platform provides a stronger binding affinity to tether the incoming CO2 substrate in comparison to the  disposition. However, the electrocatalytic activity of the  atropisomer outperforms its congener with one of the highest reported turnover frequency at low overpotential. The strong H/D KIE observed for the system indicates the existence of a tight water hydrogen bonding network for proton delivery which is disrupted upon addition of exogenous acid source. While the small H/D KIE for the  isomer and the enhanced electrocatalytic performance upon addition of stronger acid pertain the free access of protons to the bound CO2 on the opposite side of the urea arm.

  • Open Access English
    Authors: 
    Ari Asmi; Alfred Wiedensohler; Paolo Laj; A. M. Fjaeraa; Karine Sellegri; Wolfram Birmili; Ernest Weingartner; Urs Baltensperger; V. Zdimal; Nadezda Zikova; +27 more
    Countries: Netherlands, Norway, France, Ireland
    Project: EC | ATMNUCLE (227463)

    Two years of harmonized aerosol number size distribution data from 24 European field monitoring sites have been analysed. The results give a comprehensive overview of the European near surface aerosol particle number concentrations and number size distributions between 30 and 500 nm of dry particle diameter. Spatial and temporal distribution of aerosols in the particle sizes most important for climate applications are presented. We also analyse the annual, weekly and diurnal cycles of the aerosol number concentrations, provide log-normal fitting parameters for median number size distributions, and give guidance notes for data users. Emphasis is placed on the usability of results within the aerosol modelling community. <br></br> We also show that the aerosol number concentrations of Aitken and accumulation mode particles (with 100 nm dry diameter as a cut-off between modes) are related, although there is significant variation in the ratios of the modal number concentrations. Different aerosol and station types are distinguished from this data and this methodology has potential for further categorization of stations aerosol number size distribution types. <br></br> The European submicron aerosol was divided into characteristic types: Central European aerosol, characterized by single mode median size distributions, unimodal number concentration histograms and low variability in CCN-sized aerosol number concentrations; Nordic aerosol with low number concentrations, although showing pronounced seasonal variation of especially Aitken mode particles; Mountain sites (altitude over 1000 m a.s.l.) with a strong seasonal cycle in aerosol number concentrations, high variability, and very low median number concentrations. Southern and Western European regions had fewer stations, which decreases the regional coverage of these results. Aerosol number concentrations over the Britain and Ireland had very high variance and there are indications of mixed air masses from several source regions; the Mediterranean aerosol exhibit high seasonality, and a strong accumulation mode in the summer. The greatest concentrations were observed at the Ispra station in Northern Italy with high accumulation mode number concentrations in the winter. The aerosol number concentrations at the Arctic station Zeppelin in Ny-AA lesund in Svalbard have also a strong seasonal cycle, with greater concentrations of accumulation mode particles in winter, and dominating summer Aitken mode indicating more recently formed particles. Observed particles did not show any statistically significant regional work-week or weekday related variation in number concentrations studied. <br></br> Analysis products are made for open-access to the research community, available in a freely accessible internet site. The results give to the modelling community a reliable, easy-to-use and freely available comparison dataset of aerosol size distributions.

  • Open Access English
    Authors: 
    Suelen Gasparin; Julien Berger; Denys Dutykh; Nathan Mendes;
    Country: France

    Implicit schemes require important sub-iterations when dealing with highly nonlinear problems such as the combined heat and moisture transfer through porous building elements. The computational cost rises significantly when the whole-building is simulated, especially when there is important coupling among the building elements themselves with neighbouring zones and with HVAC (Heating Ventilation and Air Conditioning) systems. On the other hand, the classical Euler explicit scheme is generally not used because its stability condition imposes very fine time discretisation. Hence, this paper explores the use of an improved explicit approach - the Dufort-Frankel scheme - to overcome the disadvantage of the classical explicit one and to bring benefits that cannot be obtained by implicit methods. The Dufort-Frankel approach is first compared to the classical Euler implicit and explicit schemes to compute the solution of nonlinear heat and moisture transfer through porous materials. Then, the analysis of the Dufort-Frankel unconditionally stable explicit scheme is extended to the coupled heat and moisture balances on the scale of a one- and a two-zone building models. The Dufort-Frankel scheme has the benefits of being unconditionally stable, second-order accurate in time O(dt^2) and to compute explicitly the solution at each time step, avoiding costly sub-iterations. This approach may reduce the computational cost by twenty, as well as it may enable perfect synchronism for whole-building simulation and co-simulation. 38 pages, 19 figures, 3 tables, 28 references. Other author's papers can be downloaded at http://www.denys-dutykh.com/

  • Publication . Article . Other literature type . 2013
    Open Access English
    Authors: 
    Léa Touri; Hélène Marchetti; Irène Sari-Minodier; Nicolas Molinari; Pascal Chanez;
    Publisher: HAL CCSD
    Country: France

    International audience; IAir traffic is increasing, raising concern about local pollution and its adverse health effects on the people living in the vicinity of large airports. However, the highest risk is probably occupational exposure due to proximity. Jet exhaust is one of the main concerns at an airport and may have a health impact, particularly on the respiratory tract. Current studies are neither numerous enough nor strong enough to prove this kind of association. Yet, more and more people work in airports, and occupational exposure to jet exhaust is a fact. The aim of this review was to evaluate the existing knowledge regarding the impact of airport pollution on respiratory health. We conducted systematic literature searches to examine workplace exposures.

  • Open Access English
    Authors: 
    Albert Benveniste; Claude Jard; Ajay Kattepur; Sidney Rosario; John A. Thywissen;
    Publisher: HAL CCSD
    Country: France

    International audience; We study QoS-aware management of service orchestrations, specifically for orchestrations having a data-dependent workflow. Our study supports multi-dimensional QoS. To capture uncertainty in performance and QoS, we provide support for probabilistic QoS. Under the above assumptions, orchestrations may be non-monotonic with respect to QoS, meaning that strictly improving the QoS of a service may strictly decrease the end-to-end QoS of the orchestration, an embarrassing feature for QoS-aware management. We study monotonicity and provide sucient conditions for it. We then propose a comprehensive theory and methodology for monotonic orchestrations. Generic QoS composition rules are developed via a QoS Calculus, also capturing best service binding/service discovery, however, is not within the scope of this work. Monotonicity provides the rationale for a contract-based approach to QoS-aware management. Although function and QoS cannot be separated in the design of complex orchestrations, we show that our framework supports separation of concerns by allowing the development of function and QoS separately and then "weaving" them together to derive the QoSenhanced orchestration. Our approach is implemented on top of the Orc script language for specifying service orchestrations.

  • Open Access English
    Authors: 
    M. Karamitros; Shuang Luan; Mario A. Bernal; John Allison; G. Baldacchino; Marie Davídková; Ziad Francis; Werner Friedland; V. Ivantchenko; A. Ivantchenko; +6 more
    Publisher: HAL CCSD
    Country: France

    International audience; Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system.To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage.Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k–d tree data structure for quickly locating, for a given molecule, its closest reactants. The performance advantage is presented in terms of complexity, and the accuracy of the new algorithm is demonstrated by simulating radiation chemistry in the context of the Geant4-DNA project.Application The time-dependent radiolytic yields of the main chemical species formed after irradiation are computed for incident protons at different energies (from 50 MeV to 500 keV). Both the time-evolution and energy dependency of the yields are discussed. The evolution, at one microsecond, of the yields of hydroxyls and solvated electrons with respect to the linear energy transfer is compared to theoretical and experimental data. According to our results, at high linear energy transfer, modeling radiation chemistry in the trading compartment representation might be adopted.

  • Open Access English
    Authors: 
    Louise Laure Mariani; Pierre Lozeron; Marie Théaudin; Zoia Mincheva; Aissatou Signate; Béatrice Ducot; Vincent Algalarrondo; Christian Denier; Clovis Adam; Guillaume Nicolas; +5 more
    Publisher: John Wiley and Sons Inc.
    Country: France

    International audience; Objective To compare the natural history of familial transthyretin amyloid polyneuropathies (FAP) due to the Val30Met, Ser77Tyr, and Ile107Val mutations in France with the classical Portuguese Val30Met FAP. Methods We compared 84 French patients with a control group of 110 Portuguese patients carrying the Val30Met mutation also living in France, all referred to and followed at the French National FAP Reference Center from 1988 to 2010. Clinical examination, functional and walking disability scores, nerve conduction studies, and muscle biopsies are reported. We also conducted a comprehensive literature review to further determine the range of phenotypic expression. Results By comparison with Portuguese Val30Met FAP, French Ile107Val, Ser77Tyr, and LateVal30Met FAP showed more rapid and severe disease progression; onset of gait disorders was 3 times more rapid (p 50 years; LateMet30) FAP (p = 0.0005). Other distinctive features relative to the Portuguese patients included atypical clinical presentations, demyelination on nerve conduction studies (p = 0.0005), and difficult identification of amyloid deposits in nerve and muscle biopsies. Interpretation Ile107Val and LateMet30 mutations are associated with the most debilitating and severe FAP ever described, with rapid onset of tetraparesis and shorter median survival. It could be explained by frequent large‐fiber involvement and associated demyelination and more severe axonal loss. These findings have major implications for genetic counseling and patient management as new therapeutic options are being assessed in clinical trials (TTR gene silencing). Ann Neurol 2015;78:901–916

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