117 research outputs found
The human GINS complex associates with Cdc45 and MCM and is essential for DNA replication
The GINS complex, originally discovered in Saccharomyces cerevisiae and Xenopus laevis, binds to DNA replication origins shortly before the onset of S phase and travels with the replication forks after initiation. In this study we present a detailed characterization of the human GINS (hGINS) homolog. Using new antibodies that allow the detection of endogenous hGINS in cells and tissues, we have examined its expression, abundance, subcellular localization and association with other DNA replication proteins. Expression of hGINS is restricted to actively proliferating cells. During the S phase, hGINS becomes part of a Cdc45âMCMâGINS (CMG) complex that is assembled on chromatin. Down-regulation of hGINS destabilizes CMG, causes a G1âS arrest and slows down ongoing DNA replication, effectively blocking cell proliferation. Our data support the notion that hGINS is an essential component of the human replisome
Mitochondrial dynamics and disease, OPA1
AbstractThe mitochondria are dynamic organelles that constantly fuse and divide. An equilibrium between fusion and fission controls the morphology of the mitochondria, which appear as dots or elongated tubules depending the prevailing force. Characterization of the components of the fission and fusion machineries has progressed considerably, and the emerging question now is what role mitochondrial dynamics play in mitochondrial and cellular functions. Its importance has been highlighted by the discovery that two human diseases are caused by mutations in the two mitochondrial pro-fusion genes, MFN2 and OPA1. This review will focus on data concerning the function of OPA1, mutations in which cause optic atrophy, with respect to the underlying pathophysiological processes
Additional Amphivasal Bundles in Pedicel Pith Exacerbate Central Fruit Dominance and Induce Self-Thinning of Lateral Fruitlets in Apple
珏1038ććèć»ćŠäŒäŸäŒă»ćčłæ13ćčŽćșŠćè性ćŠć€§ćŠéąć»ćŠç 究éąèžéšć€ç§ćŠă»ćșç€ç çćŠäŸäŒ
Heatmap of data sets correlation. Heatmap of correlation between selected genes expression profiles and monosaccharide content of cell wall (%NSP) or oligosaccharides relative content in glucanase digest during apple development and ripening. Positive and negative correlations are respectively shown in red and blue colours. (XLSX 28ĂÂ kb
Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species
Abstract
Background: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in
the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial
infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved
in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in
particular in the intensive care unit; this persistence could be partially explained by the capacity of these
microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types
of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different
species.
Findings: Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter
spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid
interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus
5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface;
between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the
biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than
for Acinetobacter G3 (36%, 27% & 9% respectively).
Conclusions: Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of
biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to
their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the
ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not
observed in other Acinetobacter species
ÎČ1A Integrin Is a Master Regulator of Invadosome Organization and Function
Use of patterned surfaces, reverse genetics, and time-controlled photoinactivation showed that ÎČ1 but not ÎČ3 integrins are required for invadosome formation, self-assembly, and stabilization into a ring structure. The activation state of ÎČ1 as well as its phosphorylation by protein kinase C on Ser785 control these process and link to the degradative function
On-grid - Off-grid : Emerging electricity configurations in diffuse urbanareas (Senegal and Tanzania)
Les dĂ©cennies 1990-2000 ont Ă©tĂ© marquĂ©es, dans de nombreux pays dâAfrique subsaharienne, par lâadoption de politiques nĂ©olibĂ©rales rĂ©putĂ©es favorables aux objectifs de dĂ©veloppement (OMD). Le SĂ©nĂ©gal et la Tanzanie ne font pas exception. Dans le secteur de lâĂ©lectricitĂ©, les faibles taux dâĂ©lectrification, dâune part, lâincapacitĂ© des opĂ©rateurs publics Ă Ă©tendre rapidement le rĂ©seau conventionnel, dâautre part, ont conduit leurs gouvernements Ă engager des rĂ©formes institutionnelles caractĂ©risĂ©es par la libĂ©ralisation du secteur et la crĂ©ation dâagences dĂ©diĂ©es Ă lâĂ©lectrification rurale. Dâabord prĂ©rogative des gros opĂ©rateurs nationaux ou internationaux, lâĂ©lectrification rurale est dĂ©sormais ouverte Ă de plus petits opĂ©rateurs privĂ©s. Assortie dâun allĂšgement des contraintes administratives et de nouvelles sources de financement, la libĂ©ralisation profite aux solutions dĂ©centralisĂ©es (mini-rĂ©seaux et kits solaires en particulier). En rĂ©sulte, dans les deux pays, une diversification des modes de fourniture dâĂ©lectricitĂ© reposant sur des dispositifs, des acteurs, des ressources et des modes de gouvernance pluriels, qui coexistent localement et que la recherche analyse comme des arrangements de coproduction. A travers une Ă©tude comparative multiscalaire menĂ©e, au SĂ©nĂ©gal et en Tanzanie, dans des aires dâurbanisation diffuse, la thĂšse propose un cadre conceptuel et une mĂ©thodologie pour repenser la nature et les conditions de fourniture dâun service essentiel Ă partir des arrangements hĂ©tĂ©rogĂšnes observĂ©s. Elle mobilise ainsi le notion de configurations locales de fourniture pour apprĂ©hender de maniĂšre dĂ©cloisonnĂ©e lâensemble des solutions dâĂ©lectrification en prĂ©sence, comprendre leurs interdĂ©pendances et examiner les conditions dâune possible rĂ©gulation des divers modes de fourniture dâĂ©lectricitĂ© Ă cette Ă©chelle. En croisant une approche sociotechnique situĂ©e des configurations de fourniture dâaccĂšs Ă lâĂ©lectricitĂ© et une approche socioĂ©conomique des marchĂ©s locaux de lâĂ©lectricitĂ©, la thĂšse propose une conceptualisation des gĂ©ographies Ă©mergentes de la fourniture Ă©lectrique dans des territoires marquĂ©s par une urbanisation rapide et diffuse. Dâun cĂŽtĂ©, elle dĂ©montre que les politiques nĂ©olibĂ©rales dâĂ©lectrification ont conduit Ă une diversification de lâoffre Ă©lectrique, plus adaptĂ©e Ă la pluralitĂ© des demandes, Ă un accroissement moyen des taux de couverture et des taux dâaccĂšs dans ces espaces, ainsi quâĂ une amĂ©lioration â au moins partielle â de la qualitĂ© des services fournis sous lâeffet de la concurrence de marchĂ©. Dâun autre cĂŽtĂ©, elle souligne les limites de ces politiques et de leurs logiques marchandes, qui aboutissent Ă un accroissement des inĂ©galitĂ©s socio-spatiales Ă toutes les Ă©chelles et Ă lâexclusion des plus pauvres de toute forme dâaccĂšs Ă lâĂ©lectricitĂ©. Lâanalyse de ces Ă©cueils met en exergue la nĂ©cessitĂ© de mĂ©canismes de rĂ©gulation, dont la thĂšse scrute les prĂ©misses, encore fragiles et disparates. Interrogeant qui obtient quel service et oĂč, elle esquisse enfin des pistes de rĂ©flexion sur ce que pourrait ĂȘtre la transition vers un futur service (public) essentiel de lâĂ©lectricitĂ© dans ces environnements urbains en mutationThe decades from 1990 to 2000 were marked in many sub-Saharan African countries by the adoption of neo-liberal policies that were deemed to be conducive to achieving the development goals (MDGs). Senegal and Tanzania are no exception. In the electricity sector, low electrification rates on the one hand, and the inability of public operators to rapidly extend the conventional network on the other, have led their governments to undertake institutional reforms characterised by the liberalisation of the sector and the creation of agencies dedicated to rural electrification. Initially the prerogative of large national or international operators, rural electrification is now open to smaller private operators. With fewer administrative constraints and new sources of funding, liberalisation benefits decentralised solutions (mini-grids and solar home systems in particular). The result, in both countries, is a diversification of the modes of electricity supply based on multiple systems, actors, resources and modes of governance, which coexist locally and which the research analyses as co-production arrangements. Through a multiscalar comparative study conducted in Senegal and Tanzania, in areas of diffuse urbanisation, the thesis proposes a conceptual framework and a methodology to rethink the nature and conditions of provision of an essential service based on the heterogeneous arrangements observed. I mobilise the notion of local supply configurations to understand in a decompartmentalised manner all the electrification solutions present, to understand their interdependencies and to examine the conditions of a possible regulation of the various modes of electricity supply at this scale.By crossing a socio-technical approach of the configurations of electricity access and a socio-economic approach of local electricity markets, the thesis proposes a conceptualisation of the emerging geographies of electricity supply in territories marked by a rapid and diffuse urbanisation. On the one hand, it demonstrates that neoliberal electrification policies have led to a diversification of electricity supply, more adapted to the plurality of demands, to an average increase in coverage and access rates in these areas, as well as to an improvement - at least partial - in the quality of services provided under the effect of market competition. On the other hand, it highlights the limits of these policies and their market logic, which lead to an increase in socio-spatial inequalities at all levels and to the exclusion of the poorest from any form of access to electricity. The analysis of these pitfalls highlights the need for regulatory mechanisms, the premises of which are still fragile and disparate. Questioning who gets what service and where, it finally sketches out avenues of reflection on what could be the transition towards a future essential electricity (public) service in these changing urban environment
Paysages électriques hétérogÚnes et expériences d'accÚs spatialisées dans les aires d'urbanisation diffuse : mise en perspective des politiques publiques d'électrification rurale au Sénégal
Publication rĂ©alisĂ©e dans le cadre du sĂ©minaire doctoral « LâĂ©nergie et lâespace » organisĂ© les 14 juin, 17 mai et 12 avril 2019 par le groupe transversal « Ville et Ă©nergie » du Labex Futurs Urbains (UniversitĂ© Paris-Est). https://villeenergie.hypotheses.org/Cet article s'inscrit dans une recherche doctorale en cours en amĂ©nagement de l'espace, qui entend analyser les processus d'Ă©lectrification dans des espaces intermĂ©diaires appelĂ©s aires d'urbanisation diffuse dans deux pays : le SĂ©nĂ©gal et la Tanzanie. Dans cet article, nous nous concentrons sur le processus d'Ă©lectrification tel qu'il est mis en oeuvre au SĂ©nĂ©gal, en se plaçant Ă un moment particulier de ce processus. A travers l'analyse des politiques publiques d'Ă©lectrification rurale, c'est la trajectoire Ă©nergĂ©tique des zones rurales, et plus particuliĂšrement celle de la concession Kaolack-Nioro-Fatick-Gossas, qui nous intĂ©resse. Une analyse spatiale de l'application de ces politiques d'Ă©lectrification Ă l'Ă©chelle locale permet de mettre en Ă©vidence la fragmentation territoriale et sociale induite par ces politiques, et leurs consĂ©quences sur les modalitĂ©s rĂ©elles d'accĂšs aux services Ă©lectriques dans ces espaces. Nous montrons que les orientations politiques et les actions non-linĂ©aires et non-coordonnĂ©es des acteurs de l'Ă©lectrification, au niveau central et au niveau local, viennent influencer la forme des marchĂ©s observĂ©s, les assemblages sociotechniques Ă l'oeuvre et les expĂ©riences d'accĂšs Ă l'Ă©lectricitĂ© des populations rurales
En réseau - Hors réseau : configurations électriques émergentes dans lesaires d'urbanisation diffuse (Sénégal et Tanzanie)
The decades from 1990 to 2000 were marked in many sub-Saharan African countries by the adoption of neo-liberal policies that were deemed to be conducive to achieving the development goals (MDGs). Senegal and Tanzania are no exception. In the electricity sector, low electrification rates on the one hand, and the inability of public operators to rapidly extend the conventional network on the other, have led their governments to undertake institutional reforms characterised by the liberalisation of the sector and the creation of agencies dedicated to rural electrification. Initially the prerogative of large national or international operators, rural electrification is now open to smaller private operators. With fewer administrative constraints and new sources of funding, liberalisation benefits decentralised solutions (mini-grids and solar home systems in particular). The result, in both countries, is a diversification of the modes of electricity supply based on multiple systems, actors, resources and modes of governance, which coexist locally and which the research analyses as co-production arrangements. Through a multiscalar comparative study conducted in Senegal and Tanzania, in areas of diffuse urbanisation, the thesis proposes a conceptual framework and a methodology to rethink the nature and conditions of provision of an essential service based on the heterogeneous arrangements observed. I mobilise the notion of local supply configurations to understand in a decompartmentalised manner all the electrification solutions present, to understand their interdependencies and to examine the conditions of a possible regulation of the various modes of electricity supply at this scale.By crossing a socio-technical approach of the configurations of electricity access and a socio-economic approach of local electricity markets, the thesis proposes a conceptualisation of the emerging geographies of electricity supply in territories marked by a rapid and diffuse urbanisation. On the one hand, it demonstrates that neoliberal electrification policies have led to a diversification of electricity supply, more adapted to the plurality of demands, to an average increase in coverage and access rates in these areas, as well as to an improvement - at least partial - in the quality of services provided under the effect of market competition. On the other hand, it highlights the limits of these policies and their market logic, which lead to an increase in socio-spatial inequalities at all levels and to the exclusion of the poorest from any form of access to electricity. The analysis of these pitfalls highlights the need for regulatory mechanisms, the premises of which are still fragile and disparate. Questioning who gets what service and where, it finally sketches out avenues of reflection on what could be the transition towards a future essential electricity (public) service in these changing urban environmentsLes dĂ©cennies 1990-2000 ont Ă©tĂ© marquĂ©es, dans de nombreux pays dâAfrique subsaharienne, par lâadoption de politiques nĂ©olibĂ©rales rĂ©putĂ©es favorables aux objectifs de dĂ©veloppement (OMD). Le SĂ©nĂ©gal et la Tanzanie ne font pas exception. Dans le secteur de lâĂ©lectricitĂ©, les faibles taux dâĂ©lectrification, dâune part, lâincapacitĂ© des opĂ©rateurs publics Ă Ă©tendre rapidement le rĂ©seau conventionnel, dâautre part, ont conduit leurs gouvernements Ă engager des rĂ©formes institutionnelles caractĂ©risĂ©es par la libĂ©ralisation du secteur et la crĂ©ation dâagences dĂ©diĂ©es Ă lâĂ©lectrification rurale. Dâabord prĂ©rogative des gros opĂ©rateurs nationaux ou internationaux, lâĂ©lectrification rurale est dĂ©sormais ouverte Ă de plus petits opĂ©rateurs privĂ©s. Assortie dâun allĂšgement des contraintes administratives et de nouvelles sources de financement, la libĂ©ralisation profite aux solutions dĂ©centralisĂ©es (mini-rĂ©seaux et kits solaires en particulier). En rĂ©sulte, dans les deux pays, une diversification des modes de fourniture dâĂ©lectricitĂ© reposant sur des dispositifs, des acteurs, des ressources et des modes de gouvernance pluriels, qui coexistent localement et que la recherche analyse comme des arrangements de coproduction. A travers une Ă©tude comparative multiscalaire menĂ©e, au SĂ©nĂ©gal et en Tanzanie, dans des aires dâurbanisation diffuse, la thĂšse propose un cadre conceptuel et une mĂ©thodologie pour repenser la nature et les conditions de fourniture dâun service essentiel Ă partir des arrangements hĂ©tĂ©rogĂšnes observĂ©s. Elle mobilise ainsi le notion de configurations locales de fourniture pour apprĂ©hender de maniĂšre dĂ©cloisonnĂ©e lâensemble des solutions dâĂ©lectrification en prĂ©sence, comprendre leurs interdĂ©pendances et examiner les conditions dâune possible rĂ©gulation des divers modes de fourniture dâĂ©lectricitĂ© Ă cette Ă©chelle. En croisant une approche sociotechnique situĂ©e des configurations de fourniture dâaccĂšs Ă lâĂ©lectricitĂ© et une approche socioĂ©conomique des marchĂ©s locaux de lâĂ©lectricitĂ©, la thĂšse propose une conceptualisation des gĂ©ographies Ă©mergentes de la fourniture Ă©lectrique dans des territoires marquĂ©s par une urbanisation rapide et diffuse. Dâun cĂŽtĂ©, elle dĂ©montre que les politiques nĂ©olibĂ©rales dâĂ©lectrification ont conduit Ă une diversification de lâoffre Ă©lectrique, plus adaptĂ©e Ă la pluralitĂ© des demandes, Ă un accroissement moyen des taux de couverture et des taux dâaccĂšs dans ces espaces, ainsi quâĂ une amĂ©lioration â au moins partielle â de la qualitĂ© des services fournis sous lâeffet de la concurrence de marchĂ©. Dâun autre cĂŽtĂ©, elle souligne les limites de ces politiques et de leurs logiques marchandes, qui aboutissent Ă un accroissement des inĂ©galitĂ©s socio-spatiales Ă toutes les Ă©chelles et Ă lâexclusion des plus pauvres de toute forme dâaccĂšs Ă lâĂ©lectricitĂ©. Lâanalyse de ces Ă©cueils met en exergue la nĂ©cessitĂ© de mĂ©canismes de rĂ©gulation, dont la thĂšse scrute les prĂ©misses, encore fragiles et disparates. Interrogeant qui obtient quel service et oĂč, elle esquisse enfin des pistes de rĂ©flexion sur ce que pourrait ĂȘtre la transition vers un futur service (public) essentiel de lâĂ©lectricitĂ© dans ces environnements urbains en mutatio
En réseau - Hors réseau : configurations électriques émergentes dans lesaires d'urbanisation diffuse (Sénégal et Tanzanie)
The decades from 1990 to 2000 were marked in many sub-Saharan African countries by the adoption of neo-liberal policies that were deemed to be conducive to achieving the development goals (MDGs). Senegal and Tanzania are no exception. In the electricity sector, low electrification rates on the one hand, and the inability of public operators to rapidly extend the conventional network on the other, have led their governments to undertake institutional reforms characterised by the liberalisation of the sector and the creation of agencies dedicated to rural electrification. Initially the prerogative of large national or international operators, rural electrification is now open to smaller private operators. With fewer administrative constraints and new sources of funding, liberalisation benefits decentralised solutions (mini-grids and solar home systems in particular). The result, in both countries, is a diversification of the modes of electricity supply based on multiple systems, actors, resources and modes of governance, which coexist locally and which the research analyses as co-production arrangements. Through a multiscalar comparative study conducted in Senegal and Tanzania, in areas of diffuse urbanisation, the thesis proposes a conceptual framework and a methodology to rethink the nature and conditions of provision of an essential service based on the heterogeneous arrangements observed. I mobilise the notion of local supply configurations to understand in a decompartmentalised manner all the electrification solutions present, to understand their interdependencies and to examine the conditions of a possible regulation of the various modes of electricity supply at this scale.By crossing a socio-technical approach of the configurations of electricity access and a socio-economic approach of local electricity markets, the thesis proposes a conceptualisation of the emerging geographies of electricity supply in territories marked by a rapid and diffuse urbanisation. On the one hand, it demonstrates that neoliberal electrification policies have led to a diversification of electricity supply, more adapted to the plurality of demands, to an average increase in coverage and access rates in these areas, as well as to an improvement - at least partial - in the quality of services provided under the effect of market competition. On the other hand, it highlights the limits of these policies and their market logic, which lead to an increase in socio-spatial inequalities at all levels and to the exclusion of the poorest from any form of access to electricity. The analysis of these pitfalls highlights the need for regulatory mechanisms, the premises of which are still fragile and disparate. Questioning who gets what service and where, it finally sketches out avenues of reflection on what could be the transition towards a future essential electricity (public) service in these changing urban environmentsLes dĂ©cennies 1990-2000 ont Ă©tĂ© marquĂ©es, dans de nombreux pays dâAfrique subsaharienne, par lâadoption de politiques nĂ©olibĂ©rales rĂ©putĂ©es favorables aux objectifs de dĂ©veloppement (OMD). Le SĂ©nĂ©gal et la Tanzanie ne font pas exception. Dans le secteur de lâĂ©lectricitĂ©, les faibles taux dâĂ©lectrification, dâune part, lâincapacitĂ© des opĂ©rateurs publics Ă Ă©tendre rapidement le rĂ©seau conventionnel, dâautre part, ont conduit leurs gouvernements Ă engager des rĂ©formes institutionnelles caractĂ©risĂ©es par la libĂ©ralisation du secteur et la crĂ©ation dâagences dĂ©diĂ©es Ă lâĂ©lectrification rurale. Dâabord prĂ©rogative des gros opĂ©rateurs nationaux ou internationaux, lâĂ©lectrification rurale est dĂ©sormais ouverte Ă de plus petits opĂ©rateurs privĂ©s. Assortie dâun allĂšgement des contraintes administratives et de nouvelles sources de financement, la libĂ©ralisation profite aux solutions dĂ©centralisĂ©es (mini-rĂ©seaux et kits solaires en particulier). En rĂ©sulte, dans les deux pays, une diversification des modes de fourniture dâĂ©lectricitĂ© reposant sur des dispositifs, des acteurs, des ressources et des modes de gouvernance pluriels, qui coexistent localement et que la recherche analyse comme des arrangements de coproduction. A travers une Ă©tude comparative multiscalaire menĂ©e, au SĂ©nĂ©gal et en Tanzanie, dans des aires dâurbanisation diffuse, la thĂšse propose un cadre conceptuel et une mĂ©thodologie pour repenser la nature et les conditions de fourniture dâun service essentiel Ă partir des arrangements hĂ©tĂ©rogĂšnes observĂ©s. Elle mobilise ainsi le notion de configurations locales de fourniture pour apprĂ©hender de maniĂšre dĂ©cloisonnĂ©e lâensemble des solutions dâĂ©lectrification en prĂ©sence, comprendre leurs interdĂ©pendances et examiner les conditions dâune possible rĂ©gulation des divers modes de fourniture dâĂ©lectricitĂ© Ă cette Ă©chelle. En croisant une approche sociotechnique situĂ©e des configurations de fourniture dâaccĂšs Ă lâĂ©lectricitĂ© et une approche socioĂ©conomique des marchĂ©s locaux de lâĂ©lectricitĂ©, la thĂšse propose une conceptualisation des gĂ©ographies Ă©mergentes de la fourniture Ă©lectrique dans des territoires marquĂ©s par une urbanisation rapide et diffuse. Dâun cĂŽtĂ©, elle dĂ©montre que les politiques nĂ©olibĂ©rales dâĂ©lectrification ont conduit Ă une diversification de lâoffre Ă©lectrique, plus adaptĂ©e Ă la pluralitĂ© des demandes, Ă un accroissement moyen des taux de couverture et des taux dâaccĂšs dans ces espaces, ainsi quâĂ une amĂ©lioration â au moins partielle â de la qualitĂ© des services fournis sous lâeffet de la concurrence de marchĂ©. Dâun autre cĂŽtĂ©, elle souligne les limites de ces politiques et de leurs logiques marchandes, qui aboutissent Ă un accroissement des inĂ©galitĂ©s socio-spatiales Ă toutes les Ă©chelles et Ă lâexclusion des plus pauvres de toute forme dâaccĂšs Ă lâĂ©lectricitĂ©. Lâanalyse de ces Ă©cueils met en exergue la nĂ©cessitĂ© de mĂ©canismes de rĂ©gulation, dont la thĂšse scrute les prĂ©misses, encore fragiles et disparates. Interrogeant qui obtient quel service et oĂč, elle esquisse enfin des pistes de rĂ©flexion sur ce que pourrait ĂȘtre la transition vers un futur service (public) essentiel de lâĂ©lectricitĂ© dans ces environnements urbains en mutatio
- âŠ