Protective Yeasts Control V. anguillarum Pathogenicity and Modulate the Innate Immune Response of Challenged Zebrafish (Danio rerio) Larvae

Indexación: Web of ScienceWe investigated mechanisms involved in the protection of zebrafish (Danio rerio) larvae by two probiotic candidate yeasts, Debaryornyces hansenii 97 (Dh97) and Yarrowia Iypolitica 242 (YI242), against a Vibrio anguillarum challenge. We determined the effect of different yeast concentrations (10(4)-10(7) CFU/mL) to: (i) protect larvae from the challenge, (ii) reduce the in vivo pathogen concentration and (iii) modulate the innate immune response of the host. To evaluate the role of zebrafish microbiota in protection, the experiments were performed in conventionally raised and germ free larvae. In vitro co-aggregation assays were performed to determine a direct yeast-pathogen interaction. Results showed that both yeasts significantly increased the survival rate of conventionally raised larvae challenged with V. anguillarum. The concentration of yeasts in larvae tended to increase with yeast inoculum, which was more pronounced for Dh97. Better protection was observed with Dh97 at a concentration of 106 CFU/mL compared to 104 CFU/mL. In germ-free conditions V anguillarum reached higher concentrations in larvae and provoked significantly more mortality than in conventional conditions, revealing the protective role of the host microbiota. Interestingly, yeasts were equally (Dh97) or more effective (YI242) in protecting germ-free than conventionally-raised larvae, showing that protection can be exerted only by yeasts and is not necessarily related to modulation of the host microbiota. Although none of the yeasts co aggregated with V anguillarum, they were able to reduce its proliferation in conventionally raised larvae, reduce initial pathogen concentration in germ-free larvae and prevent the upregulation of key components of the inflammatory/anti-inflammatory response (il1b, tnfa, c3, mpx, and il10, respectively). These results show that protection by yeasts of zebrafish larvae challenged with V anguillarum relates to an in vivo anti-pathogen effect, the modulation of the innate immune system, and suggests that yeasts avoid the host-pathogen interaction through mechanisms independent of co-aggregation. This study shows, for the first time, the protective role of zebrafish microbiota against V. anguillarum infection, and reveals mechanisms involved in protection by two non-Saccharomyces yeasts against this pathogen.http://journal.frontiersin.org/article/10.3389/fcimb.2016.00127/ful

El enfriamiento evaporativo y las pozas de aspersión

La transferencia acoplada de calor y masa en una poza de enfriamiento por aspersión es descrita y calculada a través de las ecuaciones básicas de continuidad y energía. Se establecen las relaciones que describen el movimiento y distribución espacial de gotas, la interacción de éstas con el aire circundante y los coeficientes de transferencia de calor y masa. El sistema álgebro diferencial de ecuaciones modela los campos de temperatura y humedad absoluta, mientras que el campo de velocidad del aire es supuesto constante y se estima a partir de valores obtenidos de literatura. Esta simplificación permite desacoplar, en el cálculo numérico, las variables de velocidad y temperatura. El tratamiento acoplado de estas variables es reportado en otro trabajo de los autores [18]. El modelo obtenido se aplica a una poza circular de enfriamiento por aspersión con viento nulo. Los perfiles de velocidad del aire se proponen invariables y su magnitud y sentido se obtienen de otros trabajos de los autores. La solución simultánea de los campos térmicos y másico se obtiene por medio del método numérico de diferencias finitas. Las ecuaciones de transporte se resuelven usando el método matricial de dirección alternada implícita (ADI). La estabilidad numérica del sistema se alcanza utilizando un factor de amortiguamiento en los coeficientes de la matriz de coeficientes de las ecuaciones discretizadas. Se analizan los resultados que entrega el modelo al variar la viscosidad turbulenta del aire, puesto que influye en los valores de temperatura y humedad del aire, con el correspondiente impacto sobre las características de disipación de la poza

Non-critically squeezed light via spontaneous rotational symmetry breaking

We theoretically address squeezed light generation through the spontaneous breaking of the rotational invariance occuring in a type I degenerate optical parametric oscillator (DOPO) pumped above threshold. We show that a DOPO with spherical mirrors, in which the signal and idler fields correspond to first order Laguerre-Gauss modes, produces a perfectly squeezed vacuum with the shape of a Hermite-Gauss mode, within the linearized theory. This occurs at any pumping level above threshold, hence the phenomenon is non-critical. Imperfections of the rotational symmetry, due e.g. to cavity anisotropy, are shown to have a small impact, hence the result is not singular.Comment: 4 pages, 1 figure, replaced with resubmitted versio

Tricofagia en chinchillas (chinchilla lanígera): un problema de bienestar animal

Las estereotipias son desórdenes conductuales que se desarrollan en los animales como consecuencia de ambientes sub-óptimos, sobre los cuales no tienen control. Al estar asociadas con problemas de manejo que afectan el bienestar de los animales, y muchas veces resultar en un deterioro del fitness del animal estas pueden ser utilizadas como un indicador directo (basado en el animal) de bienestar animal. En el caso de la chinchilla la conducta de tricofagia (chinchillas come-pelo) ha sido asociada con problemas de manejo cuando estas son mantenidas en criaderos con fines comerciales y algunos factores individuales. A pesar de que se le ha dado menos atención en los estudios de estereotipias a la chinchilla, es importante su estudio ya que aún existe un importante número de criaderos de esta especie con fines peleteros, y la conducta de tricofagia no sólo afecta el bienestar del individuo, si no que además afecta su producto principal, la piel, por lo que es una patología conductual de importancia económica para el productor. El objetivo de la presente revisión es dar a conocer algunos posibles factores causales de la conducta de tricofagia en chinchillas y las implicancias de las estereotipias sobre el bienestar animal

SpectroscopicTechniques and DFT Calculations to Understand Charge Transport Mechinisms in OFETs

The organic electronics research field has advanced tremendously in the last decades, but there is still an incomplete understanding of the main mechanisms governing charge injection and transport in such devices. The performance of organic semiconductors is governed not only by their molecular structures but also by their intermolecular assembly in the solid state. Here we use a combination of Raman spectroscopy and charge modulation spectroscopy (CMS) to gather information on molecular and supramolecular levels, of organic semiconductors [1,2] (Figure 1) [3]. This last one is an optical-spectroscopy technique conducted on a real OFETs, that allows us to study in situ the charge carriers present at the semiconductor-dielectric interface, where the largest contribution to charge transport occurs. [3] In this communication we will present the study of the bithiophene imide (BTIn) molecules which exhibit encouraging electron mobilities in OFETs [1,2], by using the spectroscopic techniques presented above, supported by DFT quantum chemical calculations in order to shed light on the mechanism of charge transport in OFETs.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Structural basis of the allergenicity to strawberries due to Fra a 1.02

Strawberry fruits are highly valued due to their flavor, aroma, and benefits for human health. Despite this, 30% of the population with food hypersensitivity also shows adverse reactions to strawberry (Franz-Oberdorf et al, 2016). The FaFra a 1 protein family, homologs of the major birch pollen allergen Bet v 1, is involved in this allergenicity to strawberry. By RNAseq we have identified transcripts for 18 members of the FaFra a 1 family (from 1.01 to 1.18) in strawberry fruits. Although expressed in all tissues analyzed, each family member presents a unique pattern of expression, which suggests functional specialization for each FaFra a 1 protein. FaFra a 1.02 (Fra2 from now on) is the most expressed one in red fruits and is also the most allergenic among the family members tested (Muñoz et al. 2010; Franz- Oberdorf et al, 2016). In order to understand the molecular bases of this allergenicity we crystalized Fra2 and obtained its structure by X-ray diffraction. Fra2 showed a very high structural homology to Bet v 1, and we asked whether the two proteins were recognized by the immune system in a similar way. For this, we generated five different mutant versions of Fra2 in sites described as important for allergenicity in Bet v 1 (Fernandes et al, 2016), and studied their potential allergenicity as well as their crystal structures. Three of the mutants had substitutions in loop 4 (E46R, D48R, E46/48A) and the other two facing the cavity (A141F and Q64W). Compared to Fra2, all the mutants showed a significant reduction in their capacity to be recognized by the serum of patients with allergies to Bet v 1, and their crystal structures revealed conformational changes in the Bet v 1- IgG interaction sites. Together, these results support that Fra2 and Bet v 1 have similar allergenic determinants We hope this research will aid in understanding how human IgGs interact with Fra2 and might help in the development of new cultivars with a lesser allergenic potential.Grants BIO2013-44199R and BES-2014-068723 (MINECO). The authors also acknowledge the support by the Plan Propio from University of Malaga, Campus de Excelencia Internacional de Andalucía