1,078 research outputs found

    Short communication: Effects of the addition of a marigold extract to diets fed to channel catfish (Ictalurus punctatus) on growth parameters

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    The expansion of aquaculture in the last 10 years has made it an important source of protein worldwide. However, increased production, and the culture intensification it carries, results in higher risk of infectious disease due to poor water quality and high stocking densities. ... Marigold (Tagetes erecta L.) is a plant native to Mexico whose flowers accumulate carotenoids. Natural carotenoids extracted from marigold have been used in aquaculture to help in the survival of fish juvenile stages by strengthening their immunological system, thus reducing mortality rates. The effect of carotenoids in fish health may exert a positive effect on fish growth indices; however, these effects on growth parameters have not been studied in channel catfish (Ictalurus punctatus), which is the most cultured fish species in north-eastern Mexico, and one of the most cultured on the southern United States. Consequently, the aim of this study was to investigate if there were significant differences in growth among channel catfish juveniles when fed diets containing various carotenoid doses from a natural source

    A 2.5MHz bandpass active complex filter With 2.4MHz bandwidth for wireless communications

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    Trabajo presentado al 23rd DCIS celebrado en grenoble del 12 al 14 de noviembre de 2008.This paper presents a fully differential 8th order transconductor-based active complex filter with 2.4MHz bandwidth and centered at 2.5MHz, designed in a 90nm 2.5V 7M and MIM capacitors CMOS process technology. The filter compliants with the requirements of the IEEE802.15.4 standard. Simulation results including mismatching and process variations over the extracted view of the circuit are shown. The filter has a nominal gain of 12dB, good selectivity (20dB@2MHz offset), high image rejection (51dB nominal) and low power consumption (3.6mA @2.5V).This work has been founded in part by the EC through the project A109-Medea+ WITNESS (Wireless technologies for small area networks with embedded security and safety), the Spanish Regional Government of Junta de Andalucía under project TIC-927 and the Spanish Government under project TEC2007-68072.Peer reviewe

    Deep crustal structure and continent-ocean boundary along the Galicia continental margin (NW Iberia)

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    The Galicia continental margin is a magma-poor rifted margin with an extremely complex structure. Its formation involves several rifting episodes during the Mesozoic in the vicinity of a ridge triple junction, which produces a change in the orientation of the main structures. In addition, there is an overimposed Cenozoic partial tectonic inversion along its northern border. Although this continental margin has been widely studied since the 70’s, most studies have focused on its western part in the transition to the Iberia Abyssal Plain, and there is a significant lack of information on the north and northwestern flanks of this margin. This fact, along with its great structural complexity, has resulted in the absence of a previous comprehensive regional geodynamic model integrating all the processes observed. In the present study we integrate a large volume of new geophysical data (gravity, swath bathymetry and 2D multichannel reflection seismic). Data come from the systematic mapping of the Spanish EEZ project which provides a dense grid of gravity data and full seafloor coverage with swath bathymetry, and from the ERGAP project which provides serially-arranged 2D seismic reflection profiles across the NW Iberia margin. The combined interpretation and modelling of this new information has arisen significant constraints on the origin, the deep crustal structure and the physiographic complexity of the margin, as well as on the characterization of the along- and across-strike variation of the ocean-continent transition along NW Iberia margin. The analysis of this information leads us to propose a conceptual model for the initiation of the tectonic inversion of a magma-poor rifted margin. Finally, a framework for the geodynamic evolution of the Galicia margin has been constructed, involving three main stages: A) an early stage from the end of rifting and oceanic drift in the Bay of Biscay (Santonian); B) an intermediate stage with the beginning of tectonic inversion in the north and northwestern Iberia margin (Campanian-Paleocene) mainly concentrated along the exhumed mantle zone; and C) a final stage of compressive deformation (Eocene-Oligocene) affecting both the continental and the oceanic crust, evidenced by large dip-slip thrusting.0,000

    Residualidad del herbicida integrity en maíz, y el efecto agcelence de Headline (pyraclostrobin) en la remisión de síntomas de fitotoxicidad en chile, jitomate y calabaza, en Cuautla, Morelos

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    Algunos herbicidas según su estructura y características fisicoquímicas persisten en el ambiente y es de gran importancia conocer con certeza el tiempo en el cual la molécula química persiste adherida a las partículas del suelo, para determinar el momento oportuno en el cual es posible establecer el siguiente cultivo sin que haya problemas de fitotoxicidad propiciando por la acumulación de residuos en agua y suelo principalmente subiendo después por la cadena trófica y llegando hasta los seres humanos por consumo de alimentos, principalmente hortalizas de pocos días de desarrollo. La presente investigación determinó el efecto residual del herbicida Integrity, así como el efecto del fungicida Headline como promotor del efecto Agcelence para la remisión de síntomas de fitotoxicidad en la rotación de maíz con hortalizas,  en  donde  los  resultados  fueron  los  siguientes:  Integrity  no  ocasionó  síntomas  de fitotoxicidad a la dosis comercial (1.5 L.ha-1) aplicado en post-emergencia al cultivo, sin embargo las plantas de maíz presentaron una menor altura, se observó efecto residual hasta los 75 dias después de la aplicación en el testigo sin Headline tanto en chile, calabaza y jitomate; se encontró que Headline (pyraclostrobin) en su dosis alta (2.5 mL.L-1) ayuda en la remisión de los síntomas de fitotoxicidad ocasionados por el herbicida Integrity en un nivel agronómicamente aceptable (< 12.5 % de fitotoxicidad) en jitomate y calabaza

    Lipofundin-Induced Hyperlipidemia Promotes Oxidative Stress and Atherosclerotic Lesions in New Zealand White Rabbits

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    Atherosclerosis represents a major cause of death in the world. It is known that Lipofundin 20% induces atherosclerotic lesions in rabbits, but its effects on serum lipids behaviour and redox environment have not been addressed. In this study, New Zealand rabbits were treated with 2 mL/kg of Lipofundin for 8 days. Then, redox biomarkers and serum lipids were determined spectrophotometrically. On the other hand, the development of atherosclerotic lesions was confirmed by eosin/hematoxylin staining and electron microscopy. At the end of the experiment, total cholesterol, triglycerides, cholesterol-LDL, and cholesterol-HDL levels were significantly increased. Also, a high index of biomolecules damage, a disruption of both enzymatic and nonenzymatic defenses, and a reduction of nitric oxide were observed. Our data demonstrated that Lipofundin 20% induces hyperlipidemia, which promotes an oxidative stress state. Due to the importance of these phenomena as risk factors for atherogenesis, we suggest that Lipofundin induces atherosclerosis mainly through these mechanisms

    <i>orsai</i>, the Drosophila homolog of human ETFRF1, links lipid catabolism to growth control

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    BACKGROUND: Lipid homeostasis is an evolutionarily conserved process that is crucial for energy production, storage and consumption. Drosophila larvae feed continuously to achieve the roughly 200-fold increase in size and accumulate sufficient reserves to provide all energy and nutrients necessary for the development of the adult fly. The mechanisms controlling this metabolic program are poorly understood. RESULTS: Herein we identified a highly conserved gene, orsai (osi), as a key player in lipid metabolism in Drosophila. Lack of osi function in the larval fat body, the regulatory hub of lipid homeostasis, reduces lipid reserves and energy output, evidenced by decreased ATP production and increased ROS levels. Metabolic defects due to reduced Orsai (Osi) in time trigger defective food-seeking behavior and lethality. Further, we demonstrate that downregulation of Lipase 3, a fat body-specific lipase involved in lipid catabolism in response to starvation, rescues the reduced lipid droplet size associated with defective orsai. Finally, we show that osi-related phenotypes are rescued through the expression of its human ortholog ETFRF1/LYRm5, known to modulate the entry of β-oxidation products into the electron transport chain; moreover, knocking down electron transport flavoproteins EtfQ0 and walrus/ETFA rescues osi-related phenotypes, further supporting this mode of action. CONCLUSIONS: These findings suggest that Osi may act in concert with the ETF complex to coordinate lipid homeostasis in the fat body in response to stage-specific demands, supporting cellular functions that in turn result in an adaptive behavioral response. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12915-022-01417-w

    Efectividad biológica de organofosforados y carbamatos en el control de nematodos en banano

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    En México el banano es el segundo frutal de mayor importancia económica, con una producción de 2.2 millones de toneladas anuales; los nematodos son las plagas más importantes del banano afectando el crecimiento y desarrollo debido al daño ocasionado en raíces y rizoma, los más reportados han sido: Radopholus similis (nematodo barrenador), Helicotylenchus multicinctus (nematodo del espiral) y Meloidogyne spp. (nematodo agallador). El principal método de control se ha basado en productos químicos  con  resultados  muy  variados.  En  este  estudio  se  evaluaron  la  eficacia  biológica  de nematicidas organofosforados y carbamatos para el control de estas tres especies mediante las variables densidad de nematodos en suelo cercano a raíz y en raíz, porcentaje de daño causado (severidad), peso de raíces muertas, peso de raíces sanas y vigor de hijuelos mediante el diámetro basal, altura y número de hojas. De acuerdo con los resultados obtenidos, el producto organoclorado (Terbufos) tuvo una eficacia por debajo del 80% a diferencia del carbamato (Oxamil) Oaxamil que en sus dosis de 2.7 ml/hijo mostró tener mayor eficacia en las especies de Radhopolus similis y Pratylenchus sp. en raíz, en tanto que para el control de Meloidogyne sp. fue mejor la dosis de 2.4 ml/hijo. Para el control de nematodos en suelo cerca de la raíz Oaxamil en dosis de 2.4 ml/hijo obtuvo mejor resultado para el control de Radhopolus similis y Meloidogyne sp. en tanto que para el control de Pratylenchus sp. fue mejor en su dosis de 2.7 ml/hijo

    35th International Cosmic Ray Conference, ICRC 2017

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    The extragalactic background light (EBL) is the radiation accumulated through the history of the Universe in the wavelength range from the ultraviolet to the far infrared. Local foregrounds make the direct measurement of the diffuse EBL notoriously difficult, while robust lower limits have been obtained by adding up the contributions of all the discrete sources resolved in deep infrared and optical galaxy observations. Gamma-ray astronomy has emerged in the past few years as a powerful tool for the study of the EBL: very-high-energy (VHE) photons traversing cosmological distances can interact with EBL photons to produce e+e- pairs, resulting in an energy-dependent depletion of the gamma-ray flux of distant sources that can be used to set constraints on the EBL density. The study of the EBL is one of the key scientific programs currently carried out by the MAGIC collaboration. We present here the results of the analysis of 32 VHE spectra of 12 blazars in the redshift range 0.03-0.94, obtained with over 300 hours of observations with the MAGIC telescopes between 2010 and 2016. A combined likelihood maximization approach is used to evaluate the density and spectrum of the EBL most consistent with the MAGIC observations. The results are compatible with state-of-the-art EBL models, and constrain the EBL density to be within ≈ 20% the nominal value in such models. The study reveals no anomalies in gamma-ray propagation in the large optical depth regime - contrary to some claims based on meta-analyses of published VHE spectra.</p

    Efectividad biológica de carbamatos para el control de (Meloidogyne sp.) en tomate y zanahoria en Morelos

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    El jitomate y la zanahoria son dos hortalizas muy susceptibles a nematodos agalladores como Meloidogyne spp. En zanahoria ocasionan serias reducciones en los rendimientos y pueden incluso llegar a la pérdida total del cultivo, cuando se presenta en zanahoria hay una deformación de las raíces adventicias y por tanto una deformación en la raíz principal, esto hace que se pierda la presentación y calidad de fruto. En tomate el comportamiento es similar, con la formación de agallas en las raíces impidiendo una buen absorción de agua y nutrientes. En este experimento se evaluaron dos productos del grupo químico de los carbamatos, más utilizados para el control de nematodo agallador para visualizar posibles efectos de resistencia a este grupo químico. Los resultados en zanahoria muestran que carbofuran en dosis de 2500 g. ha-1 es quien mejor eficacia tiene para el control de Meloidogyne, mientras que la dosis baja es la que menos control tiene. En el caso del tomate el Oaxamil en su dosis de 4.7 L.ha-1 es la que mejor controla la población de nematodos agalladores y por lo tanto aumenta el rendimiento en la producción

    Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy beta and nuclear recoils in liquid argon with DEAP-1

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    The DEAP-1 low-background liquid argon detector was used to measure scintillation pulse shapes of electron and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination (PSD) down to an electron-equivalent energy of 20 keV. In the surface dataset using a triple-coincidence tag we found the fraction of beta events that are misidentified as nuclear recoils to be <1.4×107<1.4\times 10^{-7} (90% C.L.) for energies between 43-86 keVee and for a nuclear recoil acceptance of at least 90%, with 4% systematic uncertainty on the absolute energy scale. The discrimination measurement on surface was limited by nuclear recoils induced by cosmic-ray generated neutrons. This was improved by moving the detector to the SNOLAB underground laboratory, where the reduced background rate allowed the same measurement with only a double-coincidence tag. The combined data set contains 1.23×1081.23\times10^8 events. One of those, in the underground data set, is in the nuclear-recoil region of interest. Taking into account the expected background of 0.48 events coming from random pileup, the resulting upper limit on the electronic recoil contamination is <2.7×108<2.7\times10^{-8} (90% C.L.) between 44-89 keVee and for a nuclear recoil acceptance of at least 90%, with 6% systematic uncertainty on the absolute energy scale. We developed a general mathematical framework to describe PSD parameter distributions and used it to build an analytical model of the distributions observed in DEAP-1. Using this model, we project a misidentification fraction of approx. 101010^{-10} for an electron-equivalent energy threshold of 15 keV for a detector with 8 PE/keVee light yield. This reduction enables a search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of 104610^{-46} cm2^2, assuming negligible contribution from nuclear recoil backgrounds.Comment: Accepted for publication in Astroparticle Physic
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