17,260 research outputs found

    Editorial: Animal welfare, Volume I: Animal welfare in aquaculture - Physiological basis and recent findings

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    Since animal welfare is a multidisciplinary scientific discipline, the papers published in this special issue are based on diverse subjects, such as feeding and nutrition, behavior, immunology, reproduction, pathology, endocrinology, and neuroendocrinology. The studies targeting fish species have been the most frequent, being salmonids the main group. Nevertheless, only one out of the thirteen published articles deals with an invertebrate species, the lobster (Homarus americanus), which highlights the recent interest for crustaceans’ welfare. The results derived from these works state objectively the importance of animal welfare in both physiological and behavioral traits and responses, as well as in zootechnical parameters of interest for farmers.info:eu-repo/semantics/publishedVersio

    Experimental demonstration of a graph state quantum error-correction code

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    Scalable quantum computing and communication requires the protection of quantum information from the detrimental effects of decoherence and noise. Previous work tackling this problem has relied on the original circuit model for quantum computing. However, recently a family of entangled resources known as graph states has emerged as a versatile alternative for protecting quantum information. Depending on the graph's structure, errors can be detected and corrected in an efficient way using measurement-based techniques. In this article we report an experimental demonstration of error correction using a graph state code. We have used an all-optical setup to encode quantum information into photons representing a four-qubit graph state. We are able to reliably detect errors and correct against qubit loss. The graph we have realized is setup independent, thus it could be employed in other physical settings. Our results show that graph state codes are a promising approach for achieving scalable quantum information processing

    Engaging Older Youth: Program and City-Level Strategies to Support Sustained Participation in Out-of-School Time

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    With support from The Wallace Foundation, the Harvard Family Research Project and P/PV conducted a study of almost 200 out-of-school-time (OST) programs in six cities to better understand how they promote sustained participation among older youth.The resulting data indicated that two of the most important practices distinguishing high-retention programs were: ample leadership opportunities for youth and high levels of staff efforts to keep informed about participants' lives outside the programs. The study also compares and contrasts effective practices for middle school- versus high school-aged youth, noting the shortcomings of "one-size-fits-all" strategies. Finally, Engaging Older Youth details the influence of city-level OST initiatives on programs and identifies the types of city-level services that likely support participation

    Rank one discrete valuations of power series fields

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    In this paper we study the rank one discrete valuations of the field k((X1,...,Xn))k((X_1,..., X_n)) whose center in k\lcor\X\rcor is the maximal ideal. In sections 2 to 6 we give a construction of a system of parametric equations describing such valuations. This amounts to finding a parameter and a field of coefficients. We devote section 2 to finding an element of value 1, that is, a parameter. The field of coefficients is the residue field of the valuation, and it is given in section 5. The constructions given in these sections are not effective in the general case, because we need either to use the Zorn's lemma or to know explicitly a section σ\sigma of the natural homomorphism R_v\to\d between the ring and the residue field of the valuation vv. However, as a consequence of this construction, in section 7, we prove that k((\X)) can be embedded into a field L((\Y)), where LL is an algebraic extension of kk and the {\em ``extended valuation'' is as close as possible to the usual order function}

    Quantum singularity of Levi-Civita spacetimes

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    Quantum singularities in general relativistic spacetimes are determined by the behavior of quantum test particles. A static spacetime is quantum mechanically singular if the spatial portion of the wave operator is not essentially self-adjoint. Here Weyl's limit point-limit circle criterion is used to determine whether a wave operator is essentially self-adjoint. This test is then applied to scalar wave packets in Levi-Civita spacetimes to help elucidate the physical properties of the spacetimes in terms of their metric parameters

    The importance of non‐diffusional factors in determining photosynthesis of two contrasting quinoa ecotypes (Chenopodium quinoa willd.) subjected to salinity conditions

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    The broad distribution of quinoa in saline and non‐saline environments is reflected in variations in the photosynthesis‐associated mechanisms of different ecotypes. The aim of this study was to characterize the photosynthetic response to high salinity (0.4 M NaCl) of two contrasting Chilean genotypes, Amarilla (salt‐tolerant, salares ecotype) and Hueque (salt‐sensitive, coastal ecotype). Our results show that saline stress induced a significant decrease in the K+/Na+ ratio in roots and an increase in glycine betaine in leaves, particularly in the sensitive genotype (Hueque). Measurement of the photosynthesis‐related parameters showed that maximum CO2 assimilation (Amax) in control plants was comparable between genotypes (ca. 9–10 ÎŒmol CO2 m−2 s−1). However, salt treatment produced different responses, with Amax values decreasing by 65.1% in the sensitive ecotype and 37.7% in the tolerant one. Although both genotypes maintained mesophyll conductance when stomatal restrictions were removed, the biochemical components of Amarilla were impaired to a lesser extent under salt stress conditions: for example, the maximum rate of ribulose‐1,5‐ bisphosphate carboxylase/oxygenase (RubisCO; Vcmax) was not as affected in Amarilla, revealing that this enzyme has a higher affinity for its substrate in this genotype and, thus, a better carboxylation efficiency. The present results show that the higher salinity tolerance of Amarilla was also due to its ability to control non‐diffusional components, indicating its superior photosynthetic capacity compared to Hueque, particularly under salt stress conditions
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