Background Rejection in the DMTPC Dark Matter Search Using Charge Signals

The Dark Matter Time Projection Chamber (DMTPC) collaboration is developing low-pressure gas TPC detectors for measuring WIMP-nucleon interactions. Optical readout with CCD cameras allows for the detection for the daily modulation in the direction of the dark matter wind, while several charge readout channels allow for the measurement of additional recoil properties. In this article, we show that the addition of the charge readout analysis to the CCD allows us too obtain a statistics-limited 90% C.L. upper limit on the $e^-$ rejection factor of $5.6\times10^{-6}$ for recoils with energies between 40 and 200 keV$_{\mathrm{ee}}$. In addition, requiring coincidence between charge signals and light in the CCD reduces CCD-specific backgrounds by more than two orders of magnitude.Comment: 8 pages, 6 figures. For proceedings of DPF 2011 conferenc

Germination bioassay of Lactuca sativa (L.) : to determine water quality in irrigation dams.

En el norte de la provincia de Entre Ríos se ha desarrollado un modelo de producción de arroz basado en el uso de agua superficial mediante la construcción de presas de tierra: existen más de 60 con superficies variables. El uso de agroquímicos en esa zona podría introducir un factor de contaminación en el suelo y en el agua de las represas. El objetivo de este trabajo fue determinar la calidad del agua de 19 represas para riego del centro norte de Entre Ríos, mediante bioensayos de germinación de Lactuca sativa var. mantecosa. Los bioensayos se realizaron en cajas de Petri, con papel de filtro en la base humedecido con 3 ml de agua de la muestra correspondiente. Se sembraron 20 semillas por caja, distribuyéndose los tratamientos en bloques al azar con 4 repeticiones, en cámara de germinación con alternancia de luz y oscuridad. Se registró el porcentaje de germinación y la longitud promedio de la raíz; se calculó un índice de germinación. El porcentaje de germinación promedio de los tratamientos fue de 96,07% y de 97,9% en el testigo. El índice de germinación en todos los casos fue superior al 60% y no se detectó toxicidad en el agua proveniente de las distintas represas.In the North of the Entre Ríos province, a model for rice production has been developed, based in the use of superficial water from more than 60 land dams with variable surfaces. The usage of agrochemicals in the area might bring a contamination factor to the soil and dam water. The objective of this work was to determine water quality from 19 irrigation dams situated in the Central North of the Entre Ríos province through germination bioassays of Lactuca sativa, butterhead variety. Bioassays were carried out in Petri boxes with filter paper at the bottom, wet with 3 ml of corresponding sample water. Twenty seeds were sowed per box, treatments being distributed in blocks at random with 4 repetitions in germination chamber under alternating light and dark condition. Germination percentage was recorded and the average root length; was estimated a germination index. The average germination percentage of treatments was 96.07% and 97.9% in the control treatment. The germination index in all cases was higher than 60% and toxicity was not detected in the water from different dams.Fil: Lallana, María del C..Fil: Billard, Cristina E..Fil: Elizalde, José H..Fil: Lallana, Víctor H.

Synthesizing robotic handwriting motion by learning from human demonstrations

This paper contributes a novel framework that enables a robotic agent to efficiently learn and synthesize believable handwriting motion. We situate the framework as a foundation with the goal of allowing children to observe, correct and engage with the robot to learn themselves the handwriting skill. The framework adapts the principle behind ensemble methods - where improved performance is obtained by combining the output of multiple simple algorithms - in an inverse optimal control problem. This integration addresses the challenges of rapid extraction and representation of multiple-mode motion trajectories, with the cost forms which are transferable and interpretable in the development of the robot compliance control. It also introduces the incorporation of a human movement inspired feature, which provides intuitive motion modulation to generalize the synthesis with poor robotic written samples for children to identify and correct. We present the results on the success of synthesizing a variety of natural-looking motion samples based upon the learned cost functions. The framework is validated by a user study, where the synthesized dynamical motion is shown to be hard to distinguish from the real human handwriting.info:eu-repo/semantics/publishedVersio

Determination of root length reduction (EC50) by a glyphosate formulation using lettuce and wheat as biological indicator species

El objetivo fue determinar la concentración efectiva media de reducción del crecimiento radical (CE50), de una formulación del herbicida glifosato mediante bioensayos de germinación con semillas de lechuga y de trigo. Para lechuga se probaron 9 dosis/tratamientos decrecientes entre 1.215 y 0,01215 g i.a.ha-1 (formulado: Sal amónica de la N-Fosfonometil glicina, 40,5 [g e.a. glifosato 36,9% p/v]) y para trigo 5 dosis decrecientes (entre 12,15 y 1,215 g i.a.ha-1) y su respectivo control negativo (agua destilada). Se utilizaron cajas de Petri, con papel de filtro en la base humedecido con 3 ml de la solución correspondiente. Se sembraron 20 semillas por caja, distribuyéndose los tratamientos en bloques al azar con 4 repeticiones, en cámara de crecimiento a 20°C con alternancia de luz y oscuridad. Se midió la longitud radicular de todas las semillas de cada tratamiento con calibre digital. Se determinó el porcentaje de germinación y se calculó el índice de germinación. Las CE50, es decir, las dosis que redujeron en un 50% el crecimiento radical para lechuga y trigo, fueron 6,682 y 9,416 g i.a.ha-1, respectivamente. Los materiales probados resultaron sensibles a distintas dosis de glifosato y por lo tanto pueden utilizarse como indicadores biológicos de toxicidad específica.The objective of this work was to determine a glyphosate formulation effects on the root length reduction (average effective concentration: EC50) using germination bioassays with lettuce and wheat seeds. For lettuce nine decreasing doses/treatments between 1,215 and 0.01215 g a.i.ha-1 (formulated as: N phosphonometyl glycine ammonium salt 40.5 [g e.a. glyphosate 36.9% p/v]) and for wheat five decreasing doses (12.15 and 1.215 g a.i.ha‑1) and their respective negative controls (distilled water) were tested. Bioassays were carried out in Petri boxes with wet filter paper with 3 ml of corresponding solution. Twenty seeds were sowed per box, treatments being distributed in blocks at random with 4 repetitions in germination chamber under alternating light and dark condition at 20°C. All seed average root length and repetition were estimated with a digital caliper. The average germination percentage of treatments and the germination index was also determined. EC50 or doses reducing 50% their radical growth for lettuce and wheat were 6.682 and 9.416 g a.i.ha-1. Plant materials tested resulted sensitive to the different glyphosate doses and they can be used as biological indicators of the specific toxicity.Fil: Lallana, María del C.. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Cátedra de Fisiología VegetalFil: Lallana, Víctor H.. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Cátedra de Fisiología VegetalFil: Billard, Cristina E.. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Cátedra de Fisiología VegetalFil: Foti, María Natalia. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Cátedra de Fisiología VegetalFil: Elizalde, José H.. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias. Cátedra de Fisiología Vegeta

IMPACT OF D-SERINE DEPLETION IN THE β-AMYLOID CASCADERELATED TO ALZHEIMER’S DISEASE

International audienceD-serine, as a co-agonist of N-methyl-D-aspartate subtype of glutamate receptors (NMDAR), is a key regulator of their activation and hence involves in functional brain plasticity and memory process. The homeostasis of these receptors is affected by soluble oligomers of the beta-amyloid peptide (Aß) in Alzheimer´s disease (AD). In the course of AD, early functional dysregulations of NMDAR are well known, even though contribution of D-serine remains so far to be determined. In 3-4 month-old transgenic mice model of amyloïdogenesis (5xFAD) showing marked increase in Aß rates and apparent unaffected D-serine levels, extracellular electrophysiological recordings reveal impaired NMDAR-dependent long-term potentiation at CA1/CA3 hippocampal synapses, without significant changes in basal synaptic transmission. This deficit persists at 12 month of age when amyloid deposits are present with concomitant disabilities in cognitive functions. Generating 5xFAD mice with depletion of D-serine (through invalidation of the synthesis enzyme: Serine Racemase), we observed that these functional alterations and the long-term behavioral impairment were prevented whereas Aßo rates remain significantly elevated and comparable to 5xAFD mice. Therefore, these results provide convincing evidence for a critical and transient involvement of D-serine in hippocampal network dysfunctions and related cognitive disabilities driven by increased amyloidogenesis

A lower bound for the BCS functional with boundary conditions at infinity

We consider a many-body system of fermionic atoms interacting via a local pair potential and subject to an external potential within the framework of BCS theory. We measure the free energy of the whole sample with respect to the free energy of a reference state which allows us to define a BCS functional with boundary conditions at infinity. Our main result is a lower bound for this energy functional in terms of expressions that typically appear in Ginzburg-Landau functionals.Comment: 32 page

D-­‐SERINE IS INVOLVED IN THE β-­‐AMYLOID-­‐RELATED PATHOPHYSIOLOGYIN ALZHEIMER’S DISEASE

International audienc

Positronium chemistry studied by AMOC measurements using a relativistic positron beam

Beam-based Age-Momentum Correlation (β+γΔE AMOC) measurements using an MeV positron beam have become a powerful tool to study chemical reactions of positronium by time-domain observations of the different positron states tagged by the Doppler-broadening (ΔE) characteristics of the 511 keV annihilation radiation. As an example, the investigation of the spin-conversion reaction in the system HTEMPO/methanol is reported. The experimental data for small HTEMPO concentrations can be fitted quite well to a rate-equation model containing the conversion rate as the only adjustable parameter. This model can presumably be applied not only to spin conversion but also to other chemical reactions and to inhibition of positronium. Possible effects of oxidation, complex formation, and inhibition are discussed by way of examples