229 research outputs found

    How to Create Conditioned Taste Aversion for Grazing Ground Covers in Woody Crops with Small Ruminants

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    Conditioned taste aversion (CTA) is a learning behavior process where animals are trained to reject certain feed after gastrointestinal discomfort has been produced. Lithium chloride (LiCl) is the preferred agent used in livestock to induce CTA because it specifically stimulates the vomit center. In addition, LiCl is commercially available, and easy to prepare and administer using a drenching gun. Nevertheless, some factors have to be considered to obtain an effective long-lasting CTA, which allows small ruminants to graze during the cropping season. A key aspect is to use animals with no previous contact with the target plant (the plant chosen to be avoided; new feed). Due to their native neophobic feeding behavior, small ruminants can easily associate the negative feedback effects with the new feed, resulting in a strong and persistent CTA. The recommended doses are 200 and 225 mg LiCl/kg body weight (BW) for goats and sheep, respectively. To induce CTA, 100 g of the target plant should be individually offered for at least 30 min, and LiCl administered thereafter if the intake is greater than 10 g. Each time the animal eats the target plant without negative consequences, the CTA becomes weaker. Consequently, to minimize the risk of target plant consumption, it is essential to have sufficient palatable ground cover available. The presence of an alternative feed (of quality and quantity) prevents the accidental consumption of the target plant. A close monitoring of the flock is recommended to remove and re-dose any animal consuming more than 4 bites or 10 g of the target plant. At the beginning of each grazing season, check the CTA status of each animal before moving them to the crop

    Pasturatge en oliverars: aplicació de l'aversió condicionada a l'olivera en cabres

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    Cada dia l'agricultura incorpora noves pràctiques més respectuoses amb el medi ambient intentant aprofitar millor els recursos naturals i preservar-los de cara al futur. En el cas de l'oliverar, l'erosió que pateix el sòl, a causa de les pràctiques tradicionals de conreu, ha propiciat la implantació de cobertes vegetals que es controlen mitjançant l'ús de maquinària, o bé amb herbicides. L'inconvenient que comporten aquestes pràctiques i la inquietud per pràctiques més sostenibles han afavorit l'estudi de l'ús de bestiar per pasturar els camps d'oliveres. L'inconvenient és que les fulles de les oliveres són un aliment molt atractiu per a cabres i ovelles i poden malmetre l'arbre. Amb la finalitat que les cabres rebutgin menjar fulles d'olivera, es planteja la possibilitat de modificar el seu comportament alimentari, utilitzant diferents dosis de clorur de liti (LiCl), 175 mg LiCl/kg PV i 200 mg LiCl/kg PV. Els resultats obtinguts en cabres murcianogranadines mostren la possibilitat de generar aversió a les fulles d'olivera, que es va mantenir durant catorze mesos. L'aversió va ser més efectiva en el cas de les cabres que van rebre la dosi de 200 mg LiCl/kg PV.Each day brings new and more environmentally friendly practices to farming, trying to make better use of natural resources and to preserve them for the future. In the case of olive groves, the soil erosion to which this crop is exposed because of traditional farming systems is offset by the introduction of groundcover which is controlled by the use of machinery or herbicides. The drawback involved by these practices and concerns about more sustainable systems has encouraged the study of the use of grazing animals in olive groves. However, olive leaves are very attractive to goats and sheep, which could damage the trees. In order to make goats reject olive leaves, the aim of this study was to modify their feeding behaviour using lithium chloride (LiCl) in various doses (175 mg LiCl/kg BW and 200 mg LiCl/kg BW). The results obtained with Murciano-Granadina goats show that it is possible to generate a conditioned taste aversion to olive leaves, which was maintained for 14 months. Aversion was more effective in goats which received the 200 mg LiCl/kg BW dose.Cada día la agricultura incorpora nuevas prácticas más respetuosas con el medio ambiente intentando aprovechar mejor los recursos naturales y preservarlos de cara al futuro. En el caso del olivar, la erosión que sufre el terreno, debido a las prácticas tradicionales de cultivo, ha propiciado la implantación de cubiertas vegetales que se controlan mediante el uso de maquinaria, o bien con herbicidas. El inconveniente que conllevan estas prácticas y la inquietud por prácticas más sostenibles han favorecido el estudio del uso de animales para el pastoreo en los campos de olivos. El inconveniente es que las hojas de los olivos son un alimento muy atractivo para las cabras y ovejas y pueden dañar el árbol. Con la finalidad de que las cabras rechacen consumir hojas de olivo, se plantea la posibilidad de modificar su comportamiento alimentario, utilizando diferentes dosis de cloruro de litio (LiCl), 175 mg LiCl/kg PV y 200 mg LiCl/kg PV. Los resultados obtenidos en cabras murciano-granadinas muestran la posibilidad de generar aversión a las hojas de olivo, que se mantuvo durante catorce meses. La aversión fue más efectiva en el caso de las cabras que recibieron la dosis de 200 mg LiCl/kg PV

    Riqualificazione di alcune piazze e vie a Trezzano Rosa (Milano). Progetto 1° classificato.

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    Pubblicazione del progetto primo classificato al concorso per la "Riqualificazione di alcune piazze e vie a Trezzano Rosa (Milano)". Questo concorso ha avuto lo scopo di promuovere la riqualificazione della zona centrale e nevralgica del paese della provincia di Milano. La piazza San Gottardo dovrà tornare ad essere uno spazio ad intenso uso collettivo, con un nuovo sagrato e accessi alla chiesa. Il progetto vincitore ha come obiettivo quello di rafforzare l’identità del luogo e consolidarne i caratteri distintivi di insediamento rurale dal punto di vista morfologico e della qualità dello spazio. All’interno di una strategia urbana unitaria e riconoscibile, il lavoro si è concentrato in particolare su tre questioni principali: gli assi stradali (via Roma, via Dante, via Madonna); il sistema delle piazze (piazza San Gottardo, piazza XXV Aprile); il sistema del verde pubblico e il viale di circonvallazione

    Sorafenib sensitizes hepatocellular carcinoma cells to physiological apoptotic stimuli

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    Sorafenib increases survival rate of patients with advanced hepatocellular carcinoma (HCC). The mechanism underlying this effect is not completely understood. In this work we have analyzed the effects of sorafenib on autocrine proliferation and survival of different human HCC cell lines. Our results indicate that sorafenib in vitro counteracts autocrine growth of different tumor cells (Hep3B, HepG2, PLC-PRF-5, SK-Hep1). Arrest in S/G2/M cell cycle phases were observed coincident with cyclin D1 down-regulation. However, sorafenib's main anti-tumor activity seems to occur through cell death induction which correlated with caspase activation, increase in the percentage of hypodiploid cells, activation of BAX and BAK and cytochrome c release from mitochondria to cytosol. In addition, we observed a rise in mRNA and protein levels of the pro-apoptotic BH3-domain only PUMA and BIM, as well as decreased protein levels of the anti-apoptotic MCL1 and survivin. PUMA targeting knock-down, by using specific siRNAs, inhibited sorafenib-induced apoptotic features. Moreover, we obtained evidence suggesting that sorafenib also sensitizes HCC cells to the apoptotic activity of transforming growth factor-beta (TGF-beta) through the intrinsic pathway and to tumor necrosis factor-a (TNF) through the extrinsic pathway. Interestingly, sensitization to sorafenib-induced apoptosis is characteristic of liver tumor cells, since untransformed hepatocytes did not respond to sorafenib inducing apoptosis, either alone or in combination with TGF-beta or TNF. Indeed, sorafenib effectiveness in delaying HCC late progression might be partly related to a selectively sensitization of HCC cells to apoptosis by disrupting autocrine signals that protect them from adverse conditions and pro-apoptotic physiological cytokines. J. Cell. Physiol. 227: 1319-1325, 2012. (C) 2011 Wiley Periodicals, Inc

    Aversión condicionada a aroma de fresa en ovino

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    La neofobia alimentaria es un mecanismo adaptativo que permite aprender de las consecuencias postingestivas al ingerir un alimento nuevo (Provenza y Balph, 1988; Van Tien et al., 1999). Cuando un animal consume un alimento nuevo, comienza por pequeñas cantidades y, en caso de percibir una retroalimentación positiva, incrementa el consumo según su apetecibilidad (Thorhallsdottir et al., 1987). Si la retroalimentación es negativa, el animal asocia las características sensoriales del alimento (gusto, olfato, tacto y vista) con el malestar postingestivo, lo que genera aversión condicionada al alimento (Frutos et al., 2001; Manuelian et al., 2014). Aromas, sabores y flavores se utilizan habitualmente para estimular el consumo de alimento en ganadería. Así, corderos adaptados a aromas y/o flavores (i.e., cebolla, ajo, hierba) aumentaron el consumo de alimentos nuevos tratados con el mismo aroma o flavor (Provenza et al., 1995; Nolte y Provenza, 1992; Van Tien et al., 1999). Sin embargo, la generalización de la aversión mediante aromas, sabores o flavores ha sido poco estudiada. La aversión al agua con aroma de almendra, inducida en ratas mediante 190 mg LiCl /kg PV, fue menor que con sabor dulce (sacarina), pero se potenció al utilizar un alimento con aroma y sabor (Palmerino et al., 1980). Por otro lado, ovejas con aversión a harina de arroz con flavor a canela, utilizando 250 mg LiCl/kg PV, mostraron aversión a harina de trigo con el mismo flavor (Launchbaugh y Provenza, 1993). La generalización de la aversión se mantuvo al incorporar el aroma a canela en harina de soja (Launchbaugh y Provenza, 1993). El objetivo del presente estudio fue crear aversión condicionada a un concentrado utilizando aromas y LiCl, a fin de evaluar la capacidad del ganado ovino de generalizar la aversión a otros alimentos con un mismo aroma

    Caveolin-1 is required for TGF-β-induced transactivation of the EGF receptor pathway in hepatocytes through the activation of the metalloprotease TACE/ADAM17

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    Transforming growth factor-beta (TGF-β) plays a dual role in hepatocytes, inducing both pro- and anti-apoptotic responses, whose balance decides cell fate. Survival signals are mediated by the epidermal growth factor receptor (EGFR) pathway, which is activated by TGF-β in these cells. Caveolin-1 (Cav1) is a structural protein of caveolae linked to TGF-β receptors trafficking and signaling. Previous results have indicated that in hepatocytes, Cav1 is required for TGF-β-induced anti-apoptotic signals, but the molecular mechanism is not fully understood yet. In this work, we show that immortalized Cav1(-/-) hepatocytes were more sensitive to the pro-apoptotic effects induced by TGF-β, showing a higher activation of caspase-3, higher decrease in cell viability and prolonged increase through time of intracellular reactive oxygen species (ROS). These results were coincident with attenuation of TGF-β-induced survival signals in Cav1(-/-) hepatocytes, such as AKT and ERK1/2 phosphorylation and NFκ-B activation. Transactivation of the EGFR pathway by TGF-β was impaired in Cav1(-/-) hepatocytes, which correlated with lack of activation of TACE/ADAM17, the metalloprotease responsible for the shedding of EGFR ligands. Reconstitution of Cav1 in Cav1(-/-) hepatocytes rescued wild-type phenotype features, both in terms of EGFR transactivation and TACE/ADAM17 activation. TACE/ADAM17 was localized in detergent-resistant membrane (DRM) fractions in Cav1(+/+) cells, which was not the case in Cav1(-/-) cells. Disorganization of lipid rafts after treatment with cholesterol-binding agents caused loss of TACE/ADAM17 activation after TGF-β treatment. In conclusion, in hepatocytes, Cav1 is required for TGF-β-mediated activation of the metalloprotease TACE/ADAM17 that is responsible for shedding of EGFR ligands and activation of the EGFR pathway, which counteracts the TGF-β pro-apoptotic effects. Therefore, Cav1 contributes to the pro-tumorigenic effects of TGF-β in liver cancer cells.This work was supported by grants from: (1) the Ministry of Economy and Competitiveness (MINECO), Spain (BFU2012-35538 and ISCIII-RTICC: RD12-0036-0029 to IF; SAF2013-43713 to PM-S; BFU2012-33932 to GE; SAF2011-25047 and CSD2009-00016 to MAdP); (2) AGAUR-Generalitat de Catalunya (2009SGR-312 to IF); and (3) People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no. PITN-GA-2012-316549 (IT LIVER) to IF JM-C and RM-V were recipients of pre-doctoral fellowships from the FPU program (Ministry of Education, Culture and Sport, Spain) and the FPI program (associated to SAF201125047, MINECO, Spain), respectively. We acknowledge the review and suggestions of Dr. Christoph Meyer (University of Heidelberg, Mannheim, Germany).S

    Aplicació de l'aversió condicionada a l'olivera en cabres

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    Cada dia l'agricultura incorpora noves pràctiques més respectuoses amb el medi ambient intentant aprofitar millor els recursos naturals i preservar-los de cara al futur. En el cas de l'oliverar, l'erosió que pateix el sòl, a causa de les pràctiques tradicionals de conreu, ha propiciat la implantació de cobertes vegetals que es controlen mitjançant l'ús de maquinària, o bé amb herbicides. L'inconvenient que comporten aquestes pràctiques i la inquietud per pràctiques més sostenibles han afavorit l'estudi de l'ús de bestiar per pasturar els camps d'oliveres. L'inconvenient és que les fulles de les oliveres són un aliment molt atractiu per a cabres i ovelles i poden malmetre l'arbre. Amb la finalitat que les cabres rebutgin menjar fulles d'olivera, es planteja la possibilitat de modificar el seu comportament alimentari, utilitzant diferents dosis de clorur de liti (LiCl), 175 mg LiCl/kg PV i 200 mg LiCl/kg PV. Els resultats obtinguts en cabres murcianogranadines mostren la possibilitat de generar aversió a les fulles d'olivera, que es va mantenir durant catorze mesos. L'aversió va ser més efectiva en el cas de les cabres que van rebre la dosi de 200 mg LiCl/kg PV

    Moth Mating: Modeling Female Pheromone Calling and Male Navigational Strategies to Optimize Reproductive Success

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    Male and female moths communicate in complex ways to search for and to select a mate. In a process termed calling, females emit small quantities of pheromones, generating plumes that spread in the environment. Males detect the plume through their antennae and navigate toward the female. The reproductive process is marked by female choice and male–male competition, since multiple males aim to reach the female but only the first can mate with her. This provides an opportunity for female selection on male traits such as chemosensitivity to pheromone molecules and mobility. We develop a mathematical framework to investigate the overall mating likelihood, the mean first arrival time, and the quality of the first male to reach the female for four experimentally observed female calling strategies unfolding over a typical one-week mating period. We present both analytical solutions of a simplified model as well as results from agent-based numerical simulations. Our findings suggest that, by adjusting call times and the amount of released pheromone, females can optimize the mating process. In particular, shorter calling times and lower pheromone titers at onset of the mating period that gradually increase over time allow females to aim for higher-quality males while still ensuring that mating occurs by the end of the mating period

    Creación y persistencia de la aversión condicionada a hojas de vid en ovino. Aplicación al pastoreo de viñedos en primavera

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    El pastoreo en viñedos se ve limitado por el daño que las ovejas pueden provocar en el cultivo, dada la alta palatabilidad de las hojas de vid. El objetivo del presente trabajo fue crear aversión a hojas de vid y evaluar su persistencia en ovejas (Manchega, n = 12; Lacaune, n = 12) durante tres años. El estudio incluyó la creación y validación de la aversión en condiciones experimentales en el primer año y en pastoreo en viñedos comerciales los años dosytres. Lostratamientos consistieron en ovejas avertidas (AV, 225 mg LiCl/kg PV) y ovejas control (C, tratadas con agua). Durante el año uno la aversión se validó (30 min/prueba) en el aprisco y en viña simulada. Los siguientes años, las ovejas AV pastaron dos viñedos comerciales con cubierta espontánea (viñedo A y B). El tratamiento con LiCl dio lugar a que las ovejas AV rechazaran consumir las hojas de vid (AV vs. C; 0 vs. 95 ± 5 g/d). En los viñedos comerciales, las ovejas AV redujeron la materia seca de la cubierta vegetal en un 68 ± 8% y 44 ± 4% para A y B respectivamente. Sin embargo, cuando la cubierta fue poco palatable y escasa, las ovejas AV empezaron a consumir las hojas y brotes de vid,siendo necesaria una nueva dosis de LiCl (A, 100%; B, 50% ovejas). En conclusión, la AV fue una herramienta efectiva para controlar la cubierta vegetal del viñedo en primavera,siendo necesaria una supervisión de los animales
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