Proposing Kluyvera georgiana as the Origin of the Plasmid-Mediated Resistance Gene fosA4

A putative fosA gene in Kluyvera georgiana 14751 showed 99% nucleotide identity with plasmid-encoded fosA4. Due to a single-nucleotide insertion translating to a truncated protein, K. georgiana 14751 fosA does not confer fosfomycin resistance. However, analysis of another genome deposit (Kluyvera ascorbata WCH1410) that could be recategorized as K. georgiana after phylogenetic analysis revealed a fosA gene 100% identical to the plasmid-borne fosA4 gene. We suggest that Kluyvera georgiana represents the most probable origin of fosA4.Fil: Rodriguez, Maria Margarita. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ghiglione, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología; ArgentinaFil: Power, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología; ArgentinaFil: Naas, Thierry. Hôpital de Bicêtre. Service de Bactériologie Hygiène; FranciaFil: Gutkind, Gabriel Osvaldo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Eye Tracking Impact on Quality-of-Life of ALS Patients

Chronic neurological disorders in their advanced phase are characterized by a progressive loss of mobility (use of upper and lower limbs), speech and social life. Some of these pathologies, such as amyotrophic lateral sclerosis and multiple sclerosis, are paradigmatic of these deficits. High technology communication instruments, such as eye tracking, can be an extremely important possibility to reintroduce these patients in their family and social life, in particular when they suffer severe disability. This paper reports and describes the results of an ongoing experimentation about Eye Tracking impact on the quality of life of amyotrophic lateral sclerosis patients. The aim of the experimentation is to evaluate if and when eye tracking technologies have a positive impact on patients' live

Short-term temporal variations of heterotrophic bacterial abundance and production in the open NW Mediterranean Sea

International audienceWe present the vertical and temporal dynamics of total vs. particle-attached bacterial abundance and activity over a 5 week period under summer to autumn transition in NW Mediterranean Sea. By comparison to previous investigations in the same area but during different seasons, we found that total bacterial biomass and production values were consistent with the hydrological conditions of the summer-fall transition. At a weekly time scale, total bacterial biomass and production in the euphotic layers was significantly correlated with phytoplanktonic biomass. At an hourly time scale, total bacterial biomass responded very rapidly to chlorophyll-a fluctuations, suggesting a tight coupling between phytoplankton and bacteria for resource partitioning during summer-autumn transition. In contrast, no influence of diel changes on bacterial parameters was detected. Episodic events such as coastal water intrusions had a significant positive effect on total bacterial abundance and production, whereas we could not detect any influence of short wind events whatever the magnitude. Finally, we show that particle-attached bacteria can represent a large proportion (until 49%) of the total bacterial activity in the euphotic layer but display rapid and sporadic changes at hourly time scales. This study underlines the value of large datasets covering different temporal scales to clarify the biogeochemical role of bacteria in the cycling of organic matter in open seawater

Seasonal to hour variation scales in abundance and production of total and particle-attached bacteria in the open NW Mediterranean Sea (0–1000 m)

We present the vertical and temporal dynamics of total <i>vs.</i> particle-attached bacterial abundance and activity over a 5 week period under summer to autumn transition in NW Mediterranean Sea. At a weekly time scale, total bacterial biomass and production in the euphotic layers was significantly correlated with phytoplanktonic biomass. At an hourly time scale, total bacterial biomass responded very rapidly to chlorophyll <i>a</i> fluctuations, suggesting a tight coupling between phytoplankton and bacteria for resource partitioning during the summer-autumn transition. In contrast, no influence of diel changes on bacterial parameters was detected. Episodic events such as coastal water intrusions had a significant positive effect on total bacterial abundance and production, whereas we could not detect any influence of short wind events whatever the magnitude. Finally, we show that particle-attached bacteria can represent a large proportion (up to 49%) of the total bacterial activity in the euphotic layer but display rapid and sporadic changes at hourly time scales. In the mesopelagic layers, bacterial abundance and production linearly decreased with depth, except some production peaks at 400–750 m. This study underlines the value of large datasets covering different temporal scales to clarify the biogeochemical role of bacteria in the cycling of organic matter in open seawater

Le ferriere genovesi in età preindustriale: aspetti tecnici, innovazioni e declino

Working Paper Ircres-CNR 01/2016. These pages take up very briefly, the results of a series of research on "The steel industry of the Ligurian ancient regime (sec. XV-XIX): technical, settlement, language", one of the first activities developed by the Centre for Study of History Technology (CSST) of CNR of Genoa, since the early seventies. The study on the local production of iron in the pre-industrial age, has identified a number of production sites in particular settled Ligurian Apennines, the detecting method of reduction of iron ore - direct method of low fire - and technical innovations adopted in the production process, from bellows to idroeholic machine, the change in the composition of the charge: iron ore, scrap iron in different percentages and fluxes. They did not miss, in the course of research, comparisons with other steel settlements that used the same method of the low fire, particularly the ironworks Catalan and also references to other production sites that operated differently, with the indirect method or blast furnace, just in the neighboring Tuscan area. Research has achieved a sufficiently clear activity practiced by the genoese steel industry ironworks of old regime, considering all the technical-scientific difficulties accompanying historical aspects.Therefore, this paper highlights some moments, especially economic and technical, of a very broad research and aims to point out some possible interpretations that have emerged during that long period of investigation. However, the interpretation of the low fire Genoese as technical back, compared to the blast furnace "at the Brescian way" and that has been given by researchers from the CSST - while trying appreciation historic - a recent article that we point out in the course of these pages, provides useful information for the genoese technical not considering it outdated compared to contemporary blast furnace "at the Brescian way"; in fact, the Genoese being linked to the elbano mineral could not operate differently, demonstrating among other things, most suitable technique. Therefore, suggestions and criticisms in the historical re-reading of one of the oldest and main activity are welcomed, and all that requires further study, in view of the fact that the old genoese ironworks also lost the memory, in favor of more recent term "Catalan".Finally, to investigate historical technique of ancient genoese ironworks we also give here a small push to observe and investigate historically the subsequent to the current complex technical steel works (when it was possible to give more toughness to the steel using the alloys) in consideration that the steel industry and metallurgy, despite the increasing scientific knowledge of metal properties, is still today an essentially empirical activity in which the production of new alloys stimulates the search and, substantially, takes place proceeding by trial and error. 

Estudio de las bases bioquímicas y moleculares de la actividad hidrolítica de variantes salvajes y mutacionales de ß-lactamasas CTX-M sobre oximino-cefalosporinas : papel de mutaciones puntuales en la expansión del espectro de hidrólisis

Most CTX-M producing microorganisms are usually resistant to cefotaxime but susceptible to ceftazidime. Therefore, these enzymes are called "cefotaximases". However, there are emerging variants possessing the Asp240Gly mutation that are able to confer resistance to cefotaxime and ceftazidime simultaneously.\nIn this work we demonstrate that the Asp240Gly mutation is associated with a ceftazidime resistance phenotype only when Escherichia coli hyperproducing clones lacked porin OmpF in the outer membrane.\nSubstitution of glycine at position 240 does not visibly affect the conformation or the stability of the enzyme, resulting in conserved catalytic efficiencies against most ?-lactam antibiotics. However, the mutation leads to a higher conformational flexibility that allows ceftazidime to accommodate its bulky substituent in the active site cavity, so that it can be hydrolysed more efficiently. CTX-MAsp240Gly ?-lactamases have catalytic efficiencies towards ceftazidime between 5 and 15 times higher than those of their respective wild variants, although these are still at least 200 times lower than cefotaxime.\nDespite having subtle effects on the kinetic behavior, the Asp240Gly mutation can provide a selective advantage when combined with low permeability in a suitable selection environment.\nFil: Ghiglione, Bárbara. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaLa mayoría de los microorganismos productores de ?-lactamasas CTX-M suele ser resistente a cefotaxima pero sensible a ceftazidima. Por esta razón, estas enzimas se conocen como ?cefotaximasas?. Sin embargo, existen variantes ?emergentes? que poseen la mutación Asp240Gly y son capaces de conferir resistencia a cefotaxima y ceftazidima simultáneamente. \nEn este trabajo demostramos que la mutación Asp240Gly se asocia a un fenotipo claro de resistencia a ceftazidima sólo cuando clones hiperproductores de Escherichia coli carecían de porinas OmpF en la membrana externa. \nLa sustitución de glicina en la posición 240 no afecta visiblemente la conformación ni la estabilidad de la enzima, lo que se traduce en eficiencias catalíticas conservadas frente a los ?-lactámicos. Sin embargo, otorgaría mayor flexibilidad conformacional a la enzima, de manera tal que ceftazidima podría acomodar su sustituyente voluminoso en la cavidad del sitio activo para ser hidrolizado más eficientemente. Las ?-lactamasas CTX-MAsp240Gly tienen eficiencias catalíticas frente a ceftazidima entre 5 y 15 veces mayores que las de sus respectivas variantes salvajes, aunque éstas continúan siendo por lo menos 200 veces más bajas que las de cefotaxima. \nEs decir que a pesar de ejercer efectos sutiles en el comportamiento cinético, la mutación Asp240Gly puede otorgar una gran ventaja selectiva cuando se combina con impermeabilidad en el ambiente de selección adecuado. \