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Selection of putative probiotics based on antigen-antibody cross-reaction with Photobacterium damselae subsp. piscicida and Vibrio harveyi for use in Senegalese sole (Solea senegalensis)

Probiotics can be used to reduce disease outbreaks in aquaculture. Some of them are characterised by their antagonistic activity against pathogens or the stimulation of the fish immune response, including the production of specific antibodies. If a probiotic has common antigens with a determined pathogen, it could produce antibodies with a cross-reaction to that pathogen. Thus, a probiotic with these characteristics could be used in a similar way to a live vaccine. The aim of this study was to select bacteria with antigenic similarity and antagonistic activity against the pathogens Photobacterium damselae subsp. piscicida and Vibrio harveyi, and to determine their ability to stimulate the production of antibodies in sole (Solea senegalensis, Kaup) with crossreaction against these pathogens. Dot blot was used to detect strains with cross-reaction using sera immunized against P. damselae subsp. piscicida Lg41.01 and V. harveyi Lg16.00. A total of 138 strains were selected from 718 strains, based on the intensity of the dot blot reaction. A second selection was performed to detect their ability to inhibit the pathogens growth. Five strains inhibited the growth of P. damselae subsp. piscicida, four strains inhibited the growth of V. harveyi, while two strains inhibited both pathogens. A Western blot confirmed the cross-reactions of the selected strains with the pathogens. Selected strains were subsequently inoculated into sole specimens by intraperitoneal injection. Four strains produced antibodies with cross-reaction against the pathogens. None mortality was observed in the inoculated fish. Further research demonstrated the storage capability of the selected strains in saline solution and feed, their growth at low pH, and identified their enzymatic characteristics. In conclusion, the selected strains showed antimicrobial activity and capacity to activate a specific immune response against fish pathogens

Los incentivos extrínsecos y el cumplimiento fiscal

This paper models the impact of extrinsic incentives in a tax compliance model. It also provides experimental evidence that confirms the existence of a positive relationship between rewards and tax compliance. If individuals are audited, rewards for honest taxpayers are effective in increasing the level of tax compliance. These results are particularly relevant in countries where there is little respect for tax law since rewards can contribute to crowding in the intrinsic motivation to comply

Política fiscal en el manejo de los recursos hidráulicos: Un modelo de equilibrio general computable

We examine the impact of fiscal policy in the management of water resources by using a computable general equilibrium model. Several comparative static exercises are carried out to assess the effects of a particular fiscal policy on economic welfare. Finally, we state a set of fiscal policy recommendations for the efficient management of water in the production process for the Mexican case.

Effect of the potential probiotic Vibrio proteolyticus DCF12.2 on the immune system of Solea senegalensis and protection against Photobacterium damselae subsp. piscicida and Vibrio harveyi

Some of the characteristics of probiotics used in aquaculture are the antagonistic activity against pathogens and the activation of the immune response. Moreover, some probiotics with common antigens to pathogens can produce antibodies that react with these pathogens. One of those potential probiotics is Vibrio proteolyticus DCF12.2, a strain with the capacity to produce antibodies in soles (Solea senegalensis) that react with Photobacterium damselae subsp. piscicida and Vibrio harveyi antigens. Therefore, the objective of the work was to determine the capacity of DCF12.2 to activate the immune response in the sole, providing protection against both pathogens. For this purpose, DCF12.2 was administered to cultured soles by intraperitoneal injection, bath, and diet. The DCF12.2 strain activated the gene expression related to the fish immune response and increased the antibody production with cross-reaction to P. damselae subsp. piscicida and V. harveyi cells. Challenges with P. damselae subsp. piscicida resulted in a 30–40% relative percent survival (RPS) through DCF12.2 treatments. After challenge with V. harveyi, only intraperitoneal treatment protected the fish (67% RPS). In conclusion, the DCF12.2 strain showed great potential to be used to prevent diseases caused by both pathogens, and indicates a way to use probiotics as live vaccines.Ministry of Science of Spain (Plan Nacional de Investigación, AGL2010-17789

Detection of specific immune response in sole (Solea senegalensis) against Photobacterium damselae subsp. piscicida antigens.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/11293The pathogenic bacteria Photobacterium damselae subsp. piscicida affects the development of Solea senegalensis culture. Vaccines made with inactivated cells have produced a relative protection against the sickness, however the administration of subcellular and purified antigens as vaccine could increase the effectiveness of the immune response. Thus, the aim of this work was the determination of antigens of P. damselae subsp. piscicida involved in the specific immune response of S. senegalensis. Fish were immunized by intraperitoneal injection (i.p.) with inactivated extracellular polymeric substances (ECP) and whole cells of P. damselae subsp. piscicida, and Freund's incomplete adjuvant. Two months later fish were boosted with the same antigens. Serum from fish was collected to determine by ELISA the title of antibodies against subcellular fractions of bacteria (ECP, capsule, outer membrane proteins, O antigen and formalized whole cells). Significant differences were found between control and immunized fish, but differences between first immunization and booster were only found for O antigen and capsule. Western blots derived from 2D-PAGE of ECP and Outer Membrane Proteins (OMP), using sole immunized serum, detected two high reactive antigens from ECP. Proteins were identified, by mass spectrometry, as ATP-dependent metalloprotease and Telurite resistance proteins. In the case of OMP, three antigenic proteins were detected and identified as Nrfa Y218f, Anti-oxidant AhpC/TSA, and a protein domain DNA binding heat shock related

Un Algoritmo Evolutivo para Resolver el Problema de Coloración Robusta

Let G and \bar{G} be two complementary graphs. Given a penalty function defined over the edges of \bar{G}, it is said that the rigidity of a k-coloring of G is the summation ofthe penalties of the edges of G that join vertices whose endpoint are equally colored. Based on this previous definition, the Robust Coloring Problem is set when searching the valid k-coloring of minimum rigidity. Yáñez and Ramírez proved that this is an NP-hard problem. In this work we present an evolutive algorithm based in the scatter search technique, which obtains optimal solutions for those instances for which an optimal solution is known, and obtains the best known solutions compared to other heuristics, such as: simulated annealing, tabu search and partial enumeration.Sean G y bar{G} un par de gráficas complementarias. Dada una función de peso definida sobre las aristas de \bar{G}, se dice que la rigidez de una k-coloración válida de G es la suma de los pesos de las aristas de \bar{G} que unen vértices del mismo color. Con base en la anterior definición, se plantea el Problema de Coloración Robusta al buscar la k-coloración válida de rigidez mínima. Yáñez y Ramírez probaron que este problema es NP-duro. En este trabajo se presenta un algoritmo evolutivo basado en la técnica de búsqueda dispersa, la cual obtiene soluciones óptimas, en las instancias para las que se conoce la solución óptima, y obtiene las mejores soluciones conocidas comparadas con otras heurísticas, tales como: recocido simulado, búsqueda tabú y enumeración parcial

Lineamientos generales de solución para programación lineal con coeficientes borrosos

This work introduce to the Possibilistic Programming and the Fuzzy Programming as paradigms that allow to resolve problems of linear programming when the coefficients of the model or the restrictions on the same are presented as fuzzy numbers, rather than exact numbers (crisp). This work presents some examples based on [1].En este trabajo se introduce tanto a la Programación Posibilıística como a la Programación Borrosa como paradigmas que permiten resolver problemas de optimización cuando los coeficientes del modelo de programación lineal o las restricciones del mismo se presentan como números borrosos, en lugar de números exactos (crisp, en inglés). Se presentan algunos ejemplos basados en [1

Asignación de frecuencias en telefonía celular aplicando el problema de coloracion robusta

    The Robust Coloring Problem (RCP) is a NP-Hard Problem for which fast andefficient heuristic algorithms has been developed. In this work we present as a PCRthe problem of assignment of frequencies for a cellphone grid. Some instances for thismodel are proposed and solved using a GRASP algorithm. Evidence shows that theintermittent interruptions in service can be eliminated and the overall capacity can beincreased in approximately 25%.Keywords: Graph coloring, Robust coloring problem, Heuristics, GRASP.El Problema de Coloraci ?n Robusta (PCR), es un problema combinatorio del tipo                             oNP-duro del cual ya se conocen varios algoritmos heur ??sticos r ?pidos y eficientes que lo                                                               aresuelven. En el presente trabajo se plantea el problema de asignaci ?n de frecuencias                                                                      opara telefon ? celular como un PCR: se proponen algunas instancias con este modelo            ?apara una red de celulares y se resuelven estas instancias con un algoritmo GRASP.Los resultados indican que se pueden disminuir las interrupciones intermitentes en elservicio y adem ?s aumentar la capacidad de la red en aproximadamente un 25%.                aPalabras clave: Coloraci ?n de gr ?ficas, Coloraci ?n Robusta, GRASP, Heur ?                           o       a               o                           ?sticas

Procedimiento de preparación, conservación, y uso en peces, del probiótico SHEWANELLA PUTREFACIENS PDP 11 para el control de enfermedades y la mejora en el crecimiento

Número de solicitud 201100385Procedimiento de preparación, conservación, y uso en peces, del probiótico Shewanella putresfaciens Pdp11 para el control de enfermedades y la mejora en el crecimiento. Preferentemente, el probiótico, compuesto por células enteras de la cepa Pdp11, se cultiva en TSAs durante 24 h a 22ºC. La preparación de una suspensión del probiótico, preferentemente sin proceso previo de liofilización o de inactivación física o química, se realiza mediante su incorporación en una matriz de alginato, preferentemente alginato sádico al 0,5%. La suspensión preparada se puede conservar sin pérdida significativa de viabilidad durante 20 - 30 días a 4ºC. Los productos alimenticios para peces son preparados mediante la adición en agitación de la suspensión de probiótico y, adicionalmente, CaCl2 50 mM, preferentemente mediante atomización.Universidad de Málaga (50%). Universidad de Almería (50%