20 research outputs found

    Responses of fruit physiology and virgin oil quality to cold storage of mechanically harvested ‘Arbequina’ olives cultivated in hedgerow

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    The increase in olive fruit production (Olea europaea L. cv. ‘Arbequina’), due to the increasing use of super-intensive cultivation and the need for a rapid fruit processing will force the industry to make a considerable investment in machinery for processing in order to maintain the level of quality of virgin olive oil (VOO). This work aims to study how the storage temperature affects the physiology of the olive and the quality of the oil, in order to use fruit storage as a cheaper and more versatile alternative to the increase in processing capacity. ‘Arbequina’ fruit did not present symptoms of chilling injury during 15 days of cold-storage. Postharvest decay, de-greening, softening, respiration and ethylene production of the olive fruit increased in direct relationship as the storage temperature increased. These facts determined a proportional deterioration of the free acidity and the sensory quality of the VOOs. Furthermore, the contents of tocopherols and of the main phenolic compounds in the VOO exhibited a reduction during fruit storage according to the increase in the temperature used. Storage at 2 °C preserved the integrity of the olive to maintain the best “Extra” level of VOO quality for a period of 12 days.El aumento de la producción de aceituna (Olea europaea L. cv. ‘Arbequina’), debido al uso creciente del cultivo superintensivo y la necesidad de un rápido procesamiento del fruto forzará a la industria a hacer una considerable inversión en maquinaria para el procesado, para mantener el nivel de calidad del aceite de oliva virgen (AOV). Este trabajo pretende estudiar cómo la temperatura de almacenamiento afecta a la fisiología de la aceituna y a la calidad del aceite, en orden de usar la conservación del fruto como una alternativa más barata y versátil al aumento de la capacidad de procesamiento. La aceituna ‘Arbequina’ no presentó síntomas de daños por frío durante 15 días de frigoconservación. La podredumbre, el desverdizado, el ablandamiento, la respiración y la producción de etileno de la aceituna aumentaron en relación directa a como aumentaba la temperatura de conservación. Estos hechos determinaron un deterioro proporcional de la acidez libre y de la calidad sensorial de los AOVs. Además, los contenidos de tocoferoles y de los principales grupos de compuestos fenólicos en los AOVs experimentaron una reducción durante la conservación del fruto en razón directa a la temperatura de almacenamiento utilizada. La frigoconservación a 2 °C preservó la integridad del fruto para mantener el nivel «Extra» de calidad durante un periodo de 12 días.This experiment was funded by the Spanish Ministry of Science and Innovation, research project AGL2009-11310/AGR and by the European Regional Development Fund (ERDF) research project 0042-RISE-5-E. Thanks are due to the owners of Internacional Olivarera, S.A. (Interoliva), for allowing us to conduct the experiments in the Sanabria farm. Antonio Montero helped us with the field measurements and M. C. Martinez for technical assistance in the laboratory. We also thank Silvia Seller, agronomist, and Juan Francisco Bernal* foreman, for their technical assistance

    Harnessing high density lipoproteins to block transforming growth factor beta and to inhibit the growth of liver tumor metastases

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    Transforming growth factor β (TGF-β) is a powerful promoter of cancer progression and a key target for antitumor therapy. As cancer cells exhibit active cholesterol metabolism, high density lipoproteins (HDLs) appear as an attractive delivery system for anticancer TGFβ-inhibitory molecules. We constructed a plasmid encoding a potent TGF-β-blocking peptide (P144) linked to apolipoprotein A-I (ApoA-I) through a flexible linker (pApoLinkerP144). The ApoLinkerP144 sequence was then incorporated into a hepatotropic adeno-associated vector (AAVApoLinkerP144). The aim was to induce hepatocytes to produce HDLs containing a modified ApoA-I capable of blocking TGF-β. We observed that transduction of the murine liver with pApoLinkerP144 led to the appearance of a fraction of circulating HDL containing the fusion protein. These HDLs were able to attenuate TGF-β signaling in the liver and to enhance IL-12 -mediated IFN-γ production. Treatment of liver metastasis of MC38 colorectal cancer with AAVApoLinkerP144 resulted in a significant reduction of tumor growth and enhanced expression of IFN-γ and GM-CSF in cancerous tissue. ApoLinkerP144 also delayed MC38 liver metastasis in Rag2-/-IL2rγ-/- immunodeficient mice. This effect was associated with downregulation of TGF-β target genes essential for metastatic niche conditioning. Finally, in a subset of ret transgenic mice, a model of aggressive spontaneous metastatic melanoma, AAVApoLinkerP144 delayed tumor growth in association with increased CD8+ T cell numbers in regional lymph nodes. In conclusion, modification of HDLs to transport TGF-β-blocking molecules is a novel and promising approach to inhibit the growth of liver metastases by immunological and non-immunological mechanisms

    Effect of implementation of irrigation on raptor and corvid populations in a Mediterranean agrosystem

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    We analyzed changes in the composition of the community of birds of prey and corvids in a rainfed agrosystem after the transformation of 37.2 % of the sampled area into irrigated land between 2005 and 2020. We sampled 57 transects (372 km per year) and fitted generalized linear mixed models (GLMM) to study changes in species occurrence. Our results showed that specific richness and the Shannon index did not vary significantly between rainfed and irrigated transects, but there was a certain positive trend when comparing the years 2005 and 2020. Regarding the differences detected for each species, the occurrence of Montagu’s harrier Circus pygargus, hen harrier Circus cyaneus, Eurasian short-toed eagle Circaetus gallicus, griffon vulture Gyps fulvus and carrion crow Corvus corone was significantly lower in irrigated land than in rainfed land, while magpie Pica pica, Western marsh harrier Circus aeruginosus, common kestrel Falco tinnunculus and black kite Milvus migrans showed a significantly higher occurrence in the irrigated transects. In addition, our findings confirm a significant decrease in occurrence between 2005 and 2020 both in rainfed and irrigated areas for Montagu’s harrier, hen harrier and magpie, while Western marsh harrier, golden eagle Aquila chrysaetos, common buzzard Buteo buteo, red kite Milvus milvus, griffon vulture Gyps fulvus, red-billed chough Pyrrhocorax pyrrhocorax and Western jackdaw Coloeus monedula were detected significantly more frequently in 2020 than in 2005. These results suggest that assessment of the impact of a new irrigation system should focus on the most characteristic species of rainfed agrosystems because the apparently positive effect on other species, equally protected but more generalist, may mask the real effect on conservation

    Advantages and insights from a hierarchical Bayesian growth and dynamics model based on salmonid electrofishing removal data

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    Growth is a fundamental ecological process of stream-dwelling salmonids which is strongly interrelated to critical life history events (emergence, mortality, sexual maturity, smolting, spawning). The ability to accurately model growth becomes critical when making population predictions over large temporal (multi-decadal) and spatial (meso) scales, e.g., investigating the effect of global change. Body length collection by removal sampling is a widely-used practice for monitoring fish populations over such large scales. Such data can be efficiently integrated into a Hierarchical Bayesian Model (HBM) and lead to interesting findings on fish dynamics. We illustrate this approach by presenting an integrated HBM of brown trout (Salmo trutta) growth, population dynamics, and removal sampling data collection processes using large temporal and spatial scales data (20 years; 48 sites placed along a 100 km latitudinal gradient). Growth and population dynamics are modelled by ordinary differential equations with parameters bound together in a hierarchical structure. The observation process is modelled with a combination of a Poisson error, a binomial error, and a mixture of Gaussian distributions. Absolute fit is measured using posterior predictive checks, those results indicate that our model fits the data well. Results indicate that growth rate is positively correlated to catchment area. This result corroborates those of other studies (laboratory, exploratory) that identified factors besides water temperature that are related to daily ration and have a significant effect on stream-dwelling salmonid growth at a large scale. Our study also illustrates the value of integrated HBM and electrofishing removal sampling data to study in situ fish populations over large scales

    Dynamic pan, tilt and zoom adjustment for perception triggered response

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    Natural environmental cues can properly guide the robot towards its goal. But often landmarks are difficult to be recognised by the robot when it is moving. Dynamic orientation of the camera's parameters, fixing the attention of the visual system on relevant environmental features, can greatly improve vision based landmark identification. This paper present an approach for sonar and compass based dynamic selection of pan, tilt and zoom values

    Adapting the Point of View for Behavior-based Navigation

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    Perception triggered response behavior together with the selection of the appropriate environmental cues can properly guide the robot towards its goal

    A Multi-Object Grasp Technique for Placement of Objects in Virtual Reality

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    Some daily tasks involve grasping multiple objects in one hand and releasing them in a determined order, for example laying out a surgical table or distributing items on shelves. For training these tasks in Virtual Reality (VR), there is no technique for allowing users to grasp multiple objects in one hand in a realistic way, and it is not known if such a technique would benefit user experience. Here, we design a multi-object grasp technique that enables users to grasp multiple objects in one hand and release them in a controlled way. We tested an object placement task under three conditions: real life, VR with single-object grasp and VR with multi-object grasp. Task completion time, distance travelled by the hands and subjective experience were measured in three scenarios: sitting in front of a desktop table, standing up in front of shelves and a room-size scenario where walking was required. Results show that the performance in a real environment is better than in Virtual Reality, both for single-object and multi-object grasping. The single-object technique performs better than the multi-object, except for the room scenario, where multi-object leads to less distance travelled and reported physical demand. For use cases where the distances are small (i.e., desktop scenario), single-object grasp is simpler and easier to understand. For larger scenarios, the multi-object grasp technique represents a good option that can be considered by other application designers

    Edited Naive Bayes

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    Naive Bayes is a well-known and studied algorithm both in statistics and machine learning. Bayesian learning algorithms represent each concept with a single probabilistic summary. This paper presents a variant of the Naive Bayes method, in which the original training set is augmented in the following fashion: Leave-One-Out procedure is applied over the training set, and incorrectly classified instances according to Naive Bayes model are duplicated. The augmented dataset is used to induce the model. The motivation behind this idea is that giving more importance to hard instances (in this case, duplicating them) might contribute to make the model more accurate over that subset of the instance space. We have tested this algorithm over 41 UCI datasets. The results suggest that the chance of obtaining a significant better performance than with the original Naive Bayes approach are much greater than the opposite

    Kinetic and dynamic computational model-based characterization of new proteins in mice: application to interferon alpha linked to apolipoprotein a-I

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    Interferon alpha linked to apolipoprotein A-I has been recently proposed as an improved interferon-based therapy. In the present study, we aimed to develop a computational model to gain further insight into the in vivo behaviour of this new fusion protein. In order to facilitate in vivo evaluation of interferon and the fusion protein without altering their biological properties, green fluorescent protein was incorporated into their structures. Kinetic and dynamic behaviour of both compounds was successfully described after plasmid hydrodynamic administration and in situ synthesis of the studied proteins. Results from the modelling exercise showed that apolipoprotein A-I conferred a modified kinetic behaviour, varying molecule distribution and prolonging half-life without altering liver dynamic performance. However, differences in the gene expression activity were observed at brain level between both compounds. Those differences could be explained by modifications in the dynamic, but also in the biodistribution properties, which would be worth evaluating in future experiments. Therefore, the modelling approach provided a global comprehension of a complex system and allowed us to compare the in vivo behaviour of both compounds and to identify critical aspects that might be important to understand the system better and suggests a need for new model-based experiments
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