681 research outputs found

    Effects of forage supplements on milk production and chemical properties, in vivo digestibility, rumen fermentation and N excretion in dairy cows offered red clover silage and corn silage or dry ground corn

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    peer-reviewedThis study concerned the effects of partial substitution of clover silage with high starch forages on milk production and chemical composition, in vivo digestibility, rumen fermentation pattern and nitrogen excretion of dairy cows. Sixteen dairy cows were separated into two groups and were assigned to treatments in a two-period crossover design. Two forage supplements were used: corn silage (CS) and dry ground corn (DG). All animals received 4.5 kg of concentrate dry matter per day. Results showed no significant difference between the forage supplements for milk production, while significant differences (P<0.01) were observed for milk fat, milk protein and nitrogen utilisation efficiency (42 v. 4.0 g/kg, 3.5 v. 3.3 g/kg and 222 v. 188 g/kg, respectively, for DG and CS). Faecal N excretion did not differ between forage supplements, but urinary N excretion was higher for CS (P<0.05). No significant differences were observed between treatments for rumen fluid pH or for rumen fluid concentrations of ammonium nitrogen or of acetic, propionic or butyric acids. Dry matter intake and the in vivo digestibility of dry matter, organic matter, acid detergent fibre and neutral detergent fibre were all higher for CS compared with DG.The authors are grateful to the Environmental Office of the Cantabrian Government for funding the project 05-640.02-2174

    Steel profiles for repairing deteriorated timber beam ends

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    Se describe un procedimiento para la consolidación de viguetas de forjado de madera con deterioro en las cabezas mediante perfiles de acero conectados a la madera desde la cara superior del forjado. La pieza de refuerzo es un perfil en U de acero S275 conformado en frío con pletinas soldadas insertadas en la madera y conectada mediante tirafondos. Se ensayaron 30 piezas a flexión obteniendo la rigidez y la capacidad de carga. Las probetas se dividieron en tres grupos. El primero compuesto por 10 piezas de madera laminada encolada de abeto con una sección de 180 x 200 mm y una longitud de 4.000 mm; el segundo consistía en 10 piezas de madera aserrada de pino silvestre con la misma sección y longitud y, el tercero, estaba formado por otras 10 piezas de madera del género Pinus con una sección de 130 x 150 mm y 3.000 mm de longitud, procedentes de un edificio de Madrid con 120 años de antigüedad. Cada grupo de 10 piezas se dividió a su vez en dos grupos de 5 piezas. El primer subgrupo estaba formado por las piezas completas de madera y constituía el grupo de referencia. Las piezas del segundo subgrupo tenían una longitud inferior que se salvaba con una extensión del refuerzo metálico. Los resultados indican que el sistema de refuerzo metálico permite resolver los problemas de falta de apoyo de la vigueta por deterioro de la madera que afecte en una longitud limitada (aproximadamente entre el 10 y el 20% de la longitud)

    Exergames for motor rehabilitation in older adults: an umbrella review

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    Background: Exergames have been used as an innovative motor rehabilitation method with the main aim of improving motivation and exercise. As research interest in exergaming for rehabilitation is rapidly growing, a review of existing systematic reviews is important to synthesize the available evidence and provide recommendations. Objectives: In this article, we systematically synthesized the information from reviews that have examined the effects if exergames on different body movement parameters in older adults with and without specific pathologies. Method: Searches were conducted in Web of Science, Scopus, PsycARTICLES, PsycINFO, Psychology and Behavioural Sciences Collection, PubMed, SciELO, B-On and Google Scholar, articulating different terms and Boolean operators. Systematic reviews, meta-analysis and literature reviews published until May 2017 that investigated exergame interventions on physical outcomes, such as balance, gait, limb movements, muscle strength, in healthy and non-healthy older adults. Results: Based on prior reviews, exergaming, as a standalone intervention, has a positive effect on balance, gait, muscle strength, upper limb function, and dexterity. When compared to traditional physiotherapy, exergaming has at least similar effects on these outcomes. Many of the investigated studies indicated low methodological quality for the evaluation of the effects of exergames on different outcomes related to motor rehabilitation. Conclusions: Exergames could be used as a complement to traditional forms of motor rehabilitation, but future individual studies and reviews should follow more rigorous methodological standards in order to improve the quality of the evidence and provide guidelines for the use of exergames in motor rehabilitation.info:eu-repo/semantics/acceptedVersio

    Deployment requirements for deorbiting electrodynamic tether technology

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    In the last decades, green deorbiting technologies have begun to be investigated and have raised a great interest in the space community. Among the others, electrodynamic tethers appear to be a promising option. By interacting with the surrounding ionosphere, electrodynamic tethers generate a drag Lorentz force to decrease the orbit altitude of the satellite, causing its re-entry in the atmosphere without using propellant. In this work, the requirements that drive the design of the deployment mechanism proposed for the H2020 Project E.T.PACK\u2014Electrodynamic Tether Technology for Passive Consumable-less Deorbit Kit\u2014are presented and discussed. Additionally, this work presents the synthesis of the reference profiles used by the motor of the deployer to make the tethered system reach the desired final conditions. The result is a strategy for deploying electrodynamic tape-shaped tethers used for deorbiting satellites at the end of their operational life

    Quantum Monte Carlo Studies of Relativistic Effects in Light Nuclei

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    Relativistic Hamiltonians are defined as the sum of relativistic one-body kinetic energy, two- and three-body potentials and their boost corrections. In this work we use the variational Monte Carlo method to study two kinds of relativistic effects in the binding energy of 3H and 4He. The first is due to the nonlocalities in the relativistic kinetic energy and relativistic one-pion exchange potential (OPEP), and the second is from boost interaction. The OPEP contribution is reduced by about 15% by the relativistic nonlocality, which may also have significant effects on pion exchange currents. However, almost all of this reduction is canceled by changes in the kinetic energy and other interaction terms, and the total effect of the nonlocalities on the binding energy is very small. The boost interactions, on the other hand, give repulsive contributions of 0.4 (1.9) MeV in 3H (4He) and account for 37% of the phenomenological part of the three-nucleon interaction needed in the nonrelativistic Hamiltonians.Comment: 33 pages, RevTeX, 11 PostScript figures, submitted to Physical Review

    Triple-Negative Breast Cancer: A Review of Conventional and Advanced Therapeutic Strategies

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    Triple-negative breast cancer (TNBC) cells are deficient in estrogen, progesterone and ERBB2 receptor expression, presenting a particularly challenging therapeutic target due to their highly invasive nature and relatively low response to therapeutics. There is an absence of specific treatment strategies for this tumor subgroup, and hence TNBC is managed with conventional therapeutics, often leading to systemic relapse. In terms of histology and transcription profile these cancers have similarities to BRCA-1-linked breast cancers, and it is hypothesized that BRCA1 pathway is non-functional in this type of breast cancer. In this review article, we discuss the different receptors expressed by TNBC as well as the diversity of different signaling pathways targeted by TNBC therapeutics, for example, Notch, Hedgehog, Wnt/b-Catenin as well as TGF-beta signaling pathways. Additionally, many epidermal growth factor receptor (EGFR), poly (ADP-ribose) polymerase (PARP) and mammalian target of rapamycin (mTOR) inhibitors effectively inhibit the TNBCs, but they face challenges of either resistance to drugs or relapse. The resistance of TNBC to conventional therapeutic agents has helped in the advancement of advanced TNBC therapeutic approaches including hyperthermia, photodynamic therapy, as well as nanomedicine-based targeted therapeutics of drugs, miRNA, siRNA, and aptamers, which will also be discussed. Artificial intelligence is another tool that is presented to enhance the diagnosis of TNBC

    Use of Native Grassland in Small-Scale Dairy Systems in the Highlands of Central Mexico. A Case Study

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    Small-scale dairy systems in Mexico comprise 78% of specialized dairy farms and provide 37% of national production. They are small farms with herds 3-35 cows plus replacements, and rely on family labour (Posadas-Domínguez et al., 2014). In the highlands, many farms have native grasslands, grazed during the rainy season, and supplemented with other feeds as maize straw, maize grain and maize ears. Native grasslands have not been studied in this context. This is a case study on the use of native grassland in a small-scale dairy farm. The objective was to determine how native grasslands are integrated in feeding milking dairy cows, and the feeding costs involved

    Relativistic effects and quasipotential equations

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    We compare the scattering amplitude resulting from the several quasipotential equations for scalar particles. We consider the Blankenbecler-Sugar, Spectator, Thompson, Erkelenz-Holinde and Equal-Time equations, which were solved numerically without decomposition into partial waves. We analyze both negative-energy state components of the propagators and retardation effects. We found that the scattering solutions of the Spectator and the Equal-Time equations are very close to the nonrelativistic solution even at high energies. The overall relativistic effect increases with the energy. The width of the band for the relative uncertainty in the real part of the scattering TT matrix, due to different dynamical equations, is largest for backward-scattering angles where it can be as large as 40%.Comment: Accepted for publication in Phys. Rev.

    Femtometer Toroidal Structures in Nuclei

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    The two-nucleon density distributions in states with isospin T=0T=0, spin SS=1 and projection MSM_S=0 and ±\pm1 are studied in 2^2H, 3,4^{3,4}He, 6,7^{6,7}Li and 16^{16}O. The equidensity surfaces for MSM_S=0 distributions are found to be toroidal in shape, while those of MSM_S=±\pm1 have dumbbell shapes at large density. The dumbbell shapes are generated by rotating tori. The toroidal shapes indicate that the tensor correlations have near maximal strength at r<2r<2 fm in all these nuclei. They provide new insights and simple explanations of the structure and electromagnetic form factors of the deuteron, the quasi-deuteron model, and the dpdp, dddd and αd\alpha d LL=2 (DD-wave) components in 3^3He, 4^4He and 6^6Li. The toroidal distribution has a maximum-density diameter of \sim1 fm and a half-maximum density thickness of \sim0.9 fm. Many realistic models of nuclear forces predict these values, which are supported by the observed electromagnetic form factors of the deuteron, and also predicted by classical Skyrme effective Lagrangians, related to QCD in the limit of infinite colors. Due to the rather small size of this structure, it could have a revealing relation to certain aspects of QCD.Comment: 35 pages in REVTeX, 25 PostScript figure

    Solutions of the Faddeev-Yakubovsky equations for the four nucleons scattering states

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    The Faddeev-Yakubowsky equations in configuration space have been solved for the four nucleon system. The results with an S-wave interaction model in the isospin approximation are presented. They concern the bound and scattering states below the first three-body threshold. The elastic phase-shifts for the N+NNN reaction in different (S,TS,T) channels are given and the corresponding low energy expansions are discussed. Particular attention is payed to the n+t elastic cross section. Its resonant structure is well described in terms of a simple NN interaction. First results concerning the S-matrix for the coupled N+NNN-NN+NN channels and the strong deuteron-deuteron scattering length are obtained.Comment: latex.tar.gz, 36 pages, 10 figures, 11 tables. To be published in Physical Review
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