1,483 research outputs found

    Utilizacion de grasas de origen vegetal en raciones de vacas lecheras: rendimentos productivos, reproductivos y composición de la grasa

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    El objetivo del presente trabajo fue estudiar los efectos de la incorporación de aceites vegetales con distinto grado de saturación en raciones de vacas lecheras, sobre la producción, composición de la leche y de la grasa, y sobre los rendimientos reproductivos. Las raciones experimentales fueron: CONTROL (sin grasa añadida, TC), SOJA (con un 4% de aceite de soja en el concentrado, TS) y LINAZA (con un 4% de aceite de linaza en el concentrado, TL). La incorporación de aceite no afectó la producción de leche, pero redujo el contenido en grasa y proteína. Las raciones con aceite de SOJA y LINAZA presentaron un mayor contenido en ácido Vaccénico y CLA; y una mejor relación poli insaturados/saturados y n6/n3 que las raciones control. Las raciones con aceite de LINAZA dieron lugar a una mayor producción de leche al pico y tardaron menos días en alcanzar el pico de producción que las dietas CONTROL y SOJA. En general, la incorporación de aceite en las raciones dio lugar a una mejora significativa en los índices reproductivos

    Recent Developments in Chiral Unitary Dynamics of Resonances

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    In this talk I summarize recent findings made on the description of axial vector mesons as dynamically generated states from the interaction of peseudoscalar mesons and vector mesons, dedicating some attention to the two K1(1270)K_1(1270) states. Then I review the generation of open and hidden charm scalar and axial states. Finally, I present recent results showing that the low lying 1/2+1/2^+ baryon resonances for S=-1 can be obtained as bound states or resonances of two mesons and one baryon in coupled channels dynamics.Comment: Talk at the International Conference on Hadron Physics, Troia07, Canakkale, Turkey, Sep. 2007 and at the Chiral Symmetry in Hadron and Nuclear Physics Workshop, Chiral07, Osaka, November 200

    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

    Detection and Classification of Floating Plastic Litter Using a Vessel-Mounted Video Camera and Deep Learning

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    Marine plastic pollution is a major environmental concern, with significant ecological, economic, public health and aesthetic consequences. Despite this, the quantity and distribution of marine plastics is poorly understood. Better understanding of the global abundance and distribution of marine plastic debris is vital for global mitigation and policy. Remote sensing methods could provide substantial data to overcome this issue. However, developments have been hampered by the limited availability of in situ data, which are necessary for development and validation of remote sensing methods. Current in situ methods of floating macroplastics (size greater than 1 cm) are usually conducted through human visual surveys, often being costly, time-intensive and limited in coverage. To overcome this issue, we present a novel approach to collecting in situ data using a trained object-detection algorithm to detect and quantify marine macroplastics from video footage taken from vessel-mounted general consumer cameras. Our model was able to successfully detect the presence or absence of plastics from real-world footage with an accuracy of 95.2% without the need to pre-screen the images for horizon or other landscape features, making it highly portable to other environmental conditions. Additionally, the model was able to differentiate between plastic object types with a Mean Average Precision of 68% and an F1-Score of 0.64. Further analysis suggests that a way to improve the separation among object types using only object detection might be through increasing the proportion of the image area covered by the plastic object. Overall, these results demonstrate how low-cost vessel-mounted cameras combined with machine learning have the potential to provide substantial harmonised in situ data of global macroplastic abundance and distribution

    Dynamically generated resonances

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    In this talk I report on recent work related to the dynamical generation of baryonic resonances, some made up from pseudoscalar meson-baryon, others from vector meson-baryon and a third type from two meson-one baryon systems. We can establish a correspondence with known baryonic resonances, reinforcing conclusions previously drawn and bringing new light on the nature of some baryonic resonances of higher mass.Comment: Talk given at the Workshop on physics of the excited nucleon-NSTAR 2009, Beijing, april 200

    Chiral Unitary Dynamics of Hadrons and Hadrons in a Nuclear Medium

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    In this talk I summarize recent findings around the description of axial vector mesons as dynamically generated states from the interaction of pseudoscalar mesons and vector mesons, dedicating some attention to the two K1(1270)K_1(1270) states. Then I review the generation of open and hidden charm scalar and axial states, and how some recent experiment supports the existence of the new hidden charm scalar state predicted. I present recent results showing that the low lying 1/2+1/2^+ baryon resonances for S=-1 can be obtained as bound states or resonances of two mesons and one baryon in coupled channels. Then show the differences with the S=0 case, where the N(1710)N^*(1710) appears also dynamically generated from the two pion one nucleon system, but the N(1440)N^*(1440) does not appear, indicating a more complex structure of the Roper resonance. Finally I shall show how the state X(2175), recently discovered at BABAR and BES, appears naturally as a resonance of the ϕKKˉ\phi K \bar{K} system.Comment: Lectures delivered at the Fourth DAE-BRNS workshop on Hadron Physics, Aligarh, India, Feb. 200

    Effect of Supplementation of Dairy Cows under Cut and Carry or Grazing of Irrigated Cultivated Pastures in Small Scale Dairy Systems in the Highlands of Central Mexico

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    Small-scale dairy systems in Mexico represent over 78% of dairy farms and produce 37% of the nation’s milk, and have an important role in reducing rural poverty. Small-scale dairy systems are defined by having herds of 3 to 35 cows plus replacements, and rely mostly on the family for labour. In the central highlands, many small-scale dairy farms base the feeding of herds on irrigated cultivated pastures of ryegrass (Lolium multiflorum, L. perenne) – white clover (Trifolium repens), mostly under cut-and-carry by hand with scythes, straws, and large amounts of commercial compound concentrates that result in high feeding costs and low economic sustainability (Fadul-Pacheco et al., 2013). One option to optimize the use of resources in these systems is to change the use of grasslands to intensive grazing that result in lower feeding costs when compared to cut-and-carry strategies. Also, the high protein content of pasture may meet requirements for moderate yields by dairy cows, so that commercial concentrates may be substituted by lower protein, lower cost supplements like ground maize grain and remove the straws of the diets

    Optimal Cyanobacterial Pigment Retrieval from Ocean Colour Sensors in a Highly Turbid, Optically Complex Lake

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    To date, several algorithms for the retrieval of cyanobacterial phycocyanin (PC) from ocean colour sensors have been presented for inland waters, all of which claim to be robust models. To address this, we conducted a comprehensive comparison to identify the optimal algorithm for retrieval of PC concentrations in the highly optically complex waters of Lake Balaton (Hungary). MEdium Resolution Imaging Spectrometer (MERIS) top-of-atmosphere radiances were first atmospherically corrected using the Self-Contained Atmospheric Parameters Estimation for MERIS data v.B2 (SCAPE-M_B2). Overall, the Simis05 semi-analytical algorithm outperformed more complex inversion algorithms, providing accurate estimates of PC up to ±7 days from the time of satellite overpass during summer cyanobacteria blooms (RMSElog 0.66, p < 0.001). In-depth analysis of the Simis05 algorithm using in situ measurements of inherent optical properties (IOPs) revealed that the Simis05 model overestimated the phytoplankton absorption coefficient [aph(λ)] by a factor of ~2. However, these errors were compensated for by underestimation of the mass-specific chlorophyll absorption coefficient [a*chla(λ)]. This study reinforces the need for further validation of algorithms over a range of optical water types in the context of the recently launched Ocean Land Colour Instrument (OLCI) onboard Sentinel-3
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