4,955 research outputs found

    Implications of the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) with Liquid Argon

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    The CENNS-10 experiment of the COHERENT collaboration has recently reported the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in liquid Argon with more than 3σ3 \sigma significance. In this work, we exploit the new data in order to probe various interesting parameters which are of key importance to CEvNS within and beyond the Standard Model. A dedicated statistical analysis of these data shows that the current constraints are significantly improved in most cases. We derive a first measurement of the neutron rms charge radius of Argon, and also an improved determination of the weak mixing angle in the low energy regime. We also update the constraints on neutrino non-standard interactions, electromagnetic properties and light mediators with respect to those derived from the first COHERENT-CsI data.Comment: discussion expanded including light mediators and nuclear uncertainties, figures added, references added. V3: Fig. 7 corrected, conclusions unchange

    Prospects for single-molecule electrostatic detection in molecular motor gliding motility assays

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    Molecular motor gliding motility assays based on myosin/actin or kinesin/microtubules are of interest for nanotechnology applications ranging from cargo-trafficking in lab-on-a-chip devices to novel biocomputation strategies. Prototype systems are typically monitored by expensive and bulky fluorescence microscopy systems and the development of integrated, direct electric detection of single filaments would strongly benefit applications and scale-up. We present estimates for the viability of such a detector by calculating the electrostatic potential change generated at a carbon nanotube transistor by a motile actin filament or microtubule under realistic gliding assay conditions. We combine this with detection limits based on previous state-of-the-art experiments using carbon nanotube transistors to detect catalysis by a bound lysozyme molecule and melting of a bound short-strand DNA molecule. Our results show that detection should be possible for both actin and microtubules using existing low ionic strength buffers given good device design, e.g., by raising the transistor slightly above the guiding channel floor. We perform studies as a function of buffer ionic strength, height of the transistor above the guiding channel floor, presence/absence of the casein surface passivation layer for microtubule assays and the linear charge density of the actin filaments/microtubules. We show that detection of microtubules is a more likely prospect given their smaller height of travel above the surface, higher negative charge density and the casein passivation, and may possibly be achieved with the nanoscale transistor sitting directly on the guiding channel floor.Comment: Submitted to New Journal of Physic

    The constant-velocity highly collimated outflows of the planetary nebula He 2-90

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    We present high-dispersion echelle spectroscopic observations and a narrow-band [N II] image of the remarkable jet-like features of He 2-90. They are detected in the echelle spectra in the H-alpha and [N II] lines but not in other nebular lines. The [N II]/H-alpha ratio is uniformly high, ~1. The observed kinematics reveals bipolar collimated outflows in the jet-like features and shows that the southeast (northwest) component expands towards (away from) the observer at a remarkably constant line-of-sight velocity, 26.0+-0.5 km/s. The observed expansion velocity and the opening angle of the jet-like features are used to estimate an inclination angle of ~5 degrees with respect to the sky plane and a space expansion velocity of ~290 km/s. The spectrum of the bright central nebula reveals a profusion of Fe lines and extended wings of the H-alpha line, similar to those seen in symbiotic stars and some young planetary nebulae that are presumed to host a mass-exchanging binary system. If this is the case for He 2-90, the constant velocity and direction of the jets require a very stable dynamic system against precession and warping.Comment: 8 pages (emulate ApJ), 5 figure, 1 tabl

    Physics implications of a combined analysis of COHERENT CsI and LAr data

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    The observation of coherent elastic neutrino nucleus scattering has opened the window to many physics opportunities. This process has been measured by the COHERENT Collaboration using two different targets, first CsI and then argon. Recently, the COHERENT Collaboration has updated the CsI data analysis with a higher statistics and an improved understanding of systematics. Here we perform a detailed statistical analysis of the full CsI data and combine it with the previous argon result. We discuss a vast array of implications, from tests of the Standard Model to new physics probes. In our analyses we take into account experimental uncertainties associated to the efficiency as well as the timing distribution of neutrino fluxes, making our results rather robust. In particular, we update previous measurements of the weak mixing angle and the neutron root mean square charge radius for CsI and argon. We also update the constraints on new physics scenarios including neutrino nonstandard interactions and the most general case of neutrino generalized interactions, as well as the possibility of light mediators. Finally, constraints on neutrino electromagnetic properties are also examined, including the conversion to sterile neutrino states. In many cases, the inclusion of the recent CsI data leads to a dramatic improvement of bounds.Comment: 42 pages, 18 Figure

    Decoding negative affect personality trait from patterns of brain activation to threat stimuli

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    INTRODUCTION: Pattern recognition analysis (PRA) applied to functional magnetic resonance imaging (fMRI) has been used to decode cognitive processes and identify possible biomarkers for mental illness. In the present study, we investigated whether the positive affect (PA) or negative affect (NA) personality traits could be decoded from patterns of brain activation in response to a human threat using a healthy sample. METHODS: fMRI data from 34 volunteers (15 women) were acquired during a simple motor task while the volunteers viewed a set of threat stimuli that were directed either toward them or away from them and matched neutral pictures. For each participant, contrast images from a General Linear Model (GLM) between the threat versus neutral stimuli defined the spatial patterns used as input to the regression model. We applied a multiple kernel learning (MKL) regression combining information from different brain regions hierarchically in a whole brain model to decode the NA and PA from patterns of brain activation in response to threat stimuli. RESULTS: The MKL model was able to decode NA but not PA from the contrast images between threat stimuli directed away versus neutral with a significance above chance. The correlation and the mean squared error (MSE) between predicted and actual NA were 0.52 (p-value=0.01) and 24.43 (p-value=0.01), respectively. The MKL pattern regression model identified a network with 37 regions that contributed to the predictions. Some of the regions were related to perception (e.g., occipital and temporal regions) while others were related to emotional evaluation (e.g., caudate and prefrontal regions). CONCLUSION: These results suggest that there was an interaction between the individuals' NA and the brain response to the threat stimuli directed away, which enabled the MKL model to decode NA from the brain patterns. To our knowledge, this is the first evidence that PRA can be used to decode a personality trait from patterns of brain activation during emotional contexts

    Nutrient composition of Algerian strawberry-tree fruits (Arbutus unedo L.)

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    Arbutus unedo L. (strawberry-tree fruit) is indigenous plant in North Africa with few published works about the composition of its fruits. For their valorization, morphological and chemical characterizations were carried out for two harvesting seasons of four different areas of Algeria. Materials and methods. Wild strawberry-tree fruits were collected in four different sites located in Tell Atlas, and two different seasons. Fruit size and shape, pH, titratable acidity, moisture, total available carbohydrate (TAC), soluble sugars, dietary fiber, protein, lipid, ash, fatty acids and mineral composition (K, Na, Ca, Mg, Fe, Cu, Mn, Zn, Ni and Cd) were determined. Results and discussion. Fruit contents (in g kg−1) varied between 637.3 ± 33.8 to 741.3 ±12.0, 126.8 ± 11.1 to 189.3 ± 4.1, 22.6 ± 2.2 to 35.5 ± 2.1, 5.1 ± 0.3 to 8.8 ± 0.5 for moisture, TAC, protein and lipid, respectively. For iron, fruit weight and polyunsaturated fatty acids (PUFA), the contents varied between 7.01 ± 0.15 to 17.24 ± 0.74 mg kg−1 of fruit, 4.91 ± 1.58 to 6.76 ± 2.04 g and 56.34 ± 1.37 to 68.18 ± 0.14% of lipid, respectively. Conclusion. This study provides original data about the morphological and chemical composition of strawberry-tree fruits from Algeria. The results show that the fruits can be essentially a potential source of dietary fiber, PUFA and iron.The authors are grateful to the Algerian Ministry of Higher Education and Scientific Research for funding the study; to ALIMNOVA research group (UCMGR35/10A) for financial support and to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (Pest-OE/AGR/UI0690/2015) and L. Barros (SFRH/BPD/107855/2015)info:eu-repo/semantics/publishedVersio

    Early Developmental Trajectories of Functional Connectivity along the Visual Pathways in Rhesus Monkeys

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    Early social interactions shape the development of social behavior, although the critical periods or the underlying neurodevelopmental processes are not completely understood. Here, we studied the developmental changes in neural pathways underlying visual social engagement in the translational rhesus monkey model. Changes in functional connectivity (FC) along the ventral object and motion pathways and the dorsal attention/visuo-spatial pathways were studied longitudinally using resting-state functional MRI in infant rhesus monkeys, from birth through early weaning (3 months), given the socioemotional changes experienced during this period. Our results revealed that (1) maturation along the visual pathways proceeds in a caudo-rostral progression with primary visual areas (V1-V3) showing strong FC as early as 2 weeks of age, whereas higher-order visual and attentional areas (e.g., MT-AST, LIP-FEF) show weak FC; (2) functional changes were pathway-specific (e.g., robust FC increases detected in the most anterior aspect of the object pathway (TE-AMY), but FC remained weak in the other pathways (e.g., AST-AMY)); (3) FC matures similarly in both right and left hemispheres. Our findings suggest that visual pathways in infant macaques undergo selective remodeling during the first 3 months of life, likely regulated by early social interactions and supporting the transition to independence from the mother

    Electrochemical characterization of biodeterioration of paint films containing cadmium yellow pigment

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    [EN] The voltammetry of microparticles (VMP) methodology was used to characterize the biological attack of different bacteria and fungi to reconstructed egg tempera and egg linseed oil emulsion paint films containing cadmium yellow (CdS), which mimic historical painting techniques. When these paint films are in contact with aqueous acetate buffer, different cathodic signals are observed. As a result of the crossing of VMP data with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electrochemical microscopy (SECM), field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM), these voltammetric signals can be associated with the reduction of CdS and different complexes associated to the proteinaceous and fatty acid fractions of the binders. After biological attack with different fungi (Acremonium chrysogenum, Aspergillus niger, Mucor rouxii, Penicillium chrysogenum, and Trichoderma pseudokoningii) and bacteria (Arthrobacter oxydans, Bacillus amyloliquefaciens, and Streptomyces cellulofans), the observed electrochemical signals experience specific modifications depending on the binder and the biological agent, allowing for an electrochemical monitoring of biological attack.Financial support from the MINECO Projects CTQ2014-53736-C3-1-P and CTQ2014-53736-C3-2-P which are supported with ERDF funds is gratefully acknowledged. The authors also wish to thank Dr. José Luis Moya López, Mr. Manuel Planes Insausti, and Mrs. Alicia Nuez Inbernón (Microscopy Service of the Universitat Politècnica de València) for technical support.Ortiz-Miranda, A.; Domenech Carbo, A.; Domenech Carbo, MT.; Osete Cortina, L.; Valle-Algarra, FM.; Bolivar Galiano, F.; Martin Sanchez, I.... (2016). 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    Fine-tuning regulation of surface mobility by acrylate copolymers and its effect on cell adhesion and differentiation

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    Fibronectin (FN) mediates cell-material interactions during events such as tissue repair, and therefore the biomimetic modeling of this protein in vitro benefits regeneration. The nature of the interface is crucial in determining cell adhesion, morphology, and differentiation. Poly(ethyl acrylate) (PEA) spontaneously organizes FN into biological nanonetworks, resulting in exceptional bone regeneration in animal models. Spontaneous network organization of FN is also observed in poly(buthyl acrylate) (PBA) substrates that have higher surface mobility than PEA. C2C12 myoblasts differentiate efficiently on PEA and PBA substrates. In this study, we investigate if intermediate surface mobilities between PEA and PBA induce cell differentiation more efficiently than PEA. A family of P(EA-co-BA) copolymers were synthesized in the entire range of compositions to finely tune surface mobility between PEA and PBA. Surface characterization demonstrates that FN mobility steadily increased with the PBA content. All compositions allowed the biological organization of FN with similar exposure of cell binding domains. C2C12 myoblasts adhered well in all the materials, with higher focal adhesions in PEA and PBA. The increase of the interfacial mobility had an impact in cell adhesion by increasing the number of FAs per cell. In addition, cell differentiation decreased proportionally with surface mobility, from PEA to PBA
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