Presence of New Delhi metallo-β-lactamase gene (NDM-1) in a clinical isolate of Acinetobacter junii in Argentina

Here we report the presence of a clinically significant A. junii blaNDM-1 positive in a 38-year-old woman who was admitted to the emergency department with a fever and leg ulcers with signs of infection. The NDM-1 carbapenemase has been dramatically spread among Gram-negative bacilli, thus imposing a new challenge on the health system to fight bacterial infections.These data expand the number of Acinetobacter species harbouring blaNDM-1. The wide existence of Acinetobacter harbouring and dispersing this carbapenemase emphasizes the importance of non-previously recognized pathogens as reservoirs of dangerous resistance determinants. These resistance determinants can be later easily transferred to other menacing pathogens.Fil: Montaña, Sabrina Daiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Cittadini, Roxana. Sanatorio Mater Dei; ArgentinaFil: Del Castillo M,. Sanatorio Mater Dei; ArgentinaFil: Uong, S.. California State University; Estados UnidosFil: Lazzaro, T.. California State University; Estados UnidosFil: Almuzara, Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Barberis, Claudia. Sanatorio Mater Dei; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Vay, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Ramírez, M. S.. California State University; Estados Unido

Mitigation of 42^{42}Ar/42^{42}K background for the GERDA Phase II experiment

Background coming from the $^{42}$Ar decay chain is considered to be one of the most relevant for the GERDA experiment, which aims to search of the neutrinoless double beta decay of $^{76}$Ge. The sensitivity strongly relies on the absence of background around the Q-value of the decay. Background coming from $^{42}$K, a progeny of $^{42}$Ar, can contribute to that background via electrons from the continuous spectrum with an endpoint of 3.5 MeV. Research and development on the suppression methods targeting this source of background were performed at the low-background test facility LArGe. It was demonstrated that by reducing $^{42}$K ion collection on the surfaces of the broad energy germanium detectors in combination with pulse shape discrimination techniques and an argon scintillation veto, it is possible to suppress the $^{42}$K background by three orders of magnitude. This is sufficient for Phase II of the GERDA experiment

Enhancing the significance of gravitational wave bursts through signal classification

The quest to observe gravitational waves challenges our ability to discriminate signals from detector noise. This issue is especially relevant for transient gravitational waves searches with a robust eyes wide open approach, the so called all- sky burst searches. Here we show how signal classification methods inspired by broad astrophysical characteristics can be implemented in all-sky burst searches preserving their generality. In our case study, we apply a multivariate analyses based on artificial neural networks to classify waves emitted in compact binary coalescences. We enhance by orders of magnitude the significance of signals belonging to this broad astrophysical class against the noise background. Alternatively, at a given level of mis-classification of noise events, we can detect about 1/4 more of the total signal population. We also show that a more general strategy of signal classification can actually be performed, by testing the ability of artificial neural networks in discriminating different signal classes. The possible impact on future observations by the LIGO-Virgo network of detectors is discussed by analysing recoloured noise from previous LIGO-Virgo data with coherent WaveBurst, one of the flagship pipelines dedicated to all-sky searches for transient gravitational waves

Mineralogical Characterization of Baptistina Asteroid Family: Implications for K/T Impactor Source

Bottke et al. (2007) linked the catastrophic formation of Baptistina Asteroid Family (BAF) to the K/T impact event. This linkage was based on dynamical and compositional evidence, which suggested the impactor had a composition similar to CM2 carbonaceous chondrites. However, our recent study (Reddy et al. 2009) suggests that the composition of (298) Baptistina is similar to LL-type ordinary chondrites rather than CM2 carbonaceous chondrites. This rules out any possibility of it being related to the source of the K/T impactor, if the impactor was of CM-type composition. Mineralogical study of asteroids in the vicinity of BAF has revealed a plethora of compositional types suggesting a complex formation and evolution environment. A detailed compositional analysis of 16 asteroids suggests several distinct surface assemblages including ordinary chondrites (Gaffey SIV subtype), primitive achondrites (Gaffey SIII subtype), basaltic achondrites (Gaffey SVII subtype and V-type), and a carbonaceous chondrite. Based on our mineralogical analysis we conclude that (298) Baptistina is similar to ordinary chondrites (LL-type) based on olivine and pyroxene mineralogy and moderate albedo. S-type and V-type in and around the vicinity of BAF we characterized show mineralogical affinity to (8) Flora and (4) Vesta and could be part of their families. Smaller BAF asteroids with lower SNR spectra showing only a 'single' band are compositionally similar to (298) Baptistina and L/LL chondrites. It is unclear at this point why the silicate absorption bands in spectra of asteroids with formal family definition seem suppressed relative to background population, despite having similar mineralogy

Flavor SU(3) analysis of charmless B meson decays to two pseudoscalar mesons

Global fits to charmless B --> PP decays in the framework of flavor SU(3) symmetry are updated and improved without reference to the \sin2\beta measured from the charmonium decay modes. Fit results directly constrain the (\bar\rho,\bar\eta) vertex of the unitarity triangle, and are used to predict the branching ratios and CP asymmetries of all decay modes, including those of the B_s system. Different schemes of SU(3) breaking in decay amplitude sizes are analyzed. The major breaking effect between strangeness-conserving and strangeness-changing decays can be accounted for by including a ratio of decay constants in tree and color-suppressed amplitudes. The possibility of having a new physics contribution to K \pi decays is also examined from the data fitting point of view.Comment: 22 pages and 2 figures; some comments and references added; more references added, version to appear in journa

First principles fluid modelling of magnetic island stabilization by ECCD

International audienceTearing modes are MHD instabilities that reduce the performances of fusion devices. They can however be controlled and suppressed using Electron Cyclotron Current Drive (ECCD) as demonstrated in various tokamaks. In this work, simulations of islands stabilization by ECCD-driven current have been carried out using the toroidal nonlinear 3D full MHD code XTOR-2F, in which a current-source term modeling the ECCD has been implemented. The efficiency parameter is computed and its variations with respect to source width and location are computed. The influence of parameters such as current intensity, source width and position with respect to the island is evaluated and compared to the Modified Rutherford Equation. We retrieve a good agreement between the simulations and the analytical predictions concerning the variations of control efficiency with source width and position. We also show that the 3D nature of the current source term can lead to the onset of an island if the source term is precisely applied on a rational surface. We report the observation of a flip phenomenon in which the O-and X-Points of the island rapidly switch their position in order for the island to take advantage of the current drive to grow

Consistency of impact assessment protocols for non-native species

Standardized tools are needed to identify and prioritize the most harmful non-native species (NNS). A plethora of assessment protocols have been developed to evaluate the current and potential impacts of non-native species, but consistency among them has received limited attention. To estimate the consistency across impact assessment protocols, 89 specialists in biological invasions used 11 protocols to screen 57 NNS (2614 assessments). We tested if the consistency in the impact scoring across assessors, quantified as the coefficient of variation (CV), was dependent on the characteristics of the protocol, the taxonomic group and the expertise of the assessor. Mean CV across assessors was 40%, with a maximum of 223%. CV was lower for protocols with a low number of score levels, which demanded high levels of expertise, and when the assessors had greater expertise on the assessed species. The similarity among protocols with respect to the final scores was higher when the protocols considered the same impact types. We conclude that all protocols led to considerable inconsistency among assessors. In order to improve consistency, we highlight the importance of selecting assessors with high expertise, providing clear guidelines and adequate training but also deriving final decisions collaboratively by consensus

The TMS Map Scales with Increased Stimulation Intensity and Muscle Activation

One way to study cortical organisation, or its reorganisation, is to use transcranial magnetic stimulation (TMS) to construct a map of corticospinal excitability. TMS maps are reported to be acquired with a wide variety of stimulation intensities and levels of muscle activation. Whilst MEPs are known to increase both with stimulation intensity and muscle activation, it remains to be established what the effect of these factors is on the map's centre of gravity (COG), area, volume and shape. Therefore, the objective of this study was to systematically examine the effect of stimulation intensity and muscle activation on these four key map outcome measures. In a first experiment, maps were acquired with a stimulation intensity of 110, 120 and 130% of resting threshold. In a second experiment, maps were acquired at rest and at 5, 10, 20 and 40% of maximum voluntary contraction. Map area and map volume increased with both stimulation intensity (P 0.09 in all cases). This result indicates the map simply scales with stimulation intensity and muscle activation

First results on light readout from the 1-ton ArDM liquid argon detector for dark matter searches

ArDM-1t is the prototype for a next generation WIMP detector measuring both the scintillation light and the ionization charge from nuclear recoils in a 1-ton liquid argon target. The goal is to reach a minimum recoil energy of 30\,keVr to detect recoiling nuclei. In this paper we describe the experimental concept and present results on the light detection system, tested for the first time in ArDM on the surface at CERN. With a preliminary and incomplete set of PMTs, the light yield at zero electric field is found to be between 0.3-0.5 phe/keVee depending on the position within the detector volume, confirming our expectations based on smaller detector setups.Comment: 14 pages, 10 figures, v2 accepted for publication in JINS