Adhesion mechanisms of Actinobacillus pleuropneumoniae to the porcine respiratory system and biofilm formation

Actinobacillus pleuropneumoniae is a Gram-negative bacterium and the causative agent of porcine pleuropneumonia, a highly contagious disease of pigs characterised by fibrinohaemorrhagic necrotising pneumonia. Although it has been well controlled in some developed countries, outbreaks can occur in pigs of all ages in contact with asymptomatic carriers, leading to significant economic losses to the swine industry due to the high morbidity and mortality rates. Adhesion is a critical step in the colonisation of the swine respiratory tract and the pathogenesis of the porcine pleuropneumonia; however, a literature review of this process is not available to date. Therefore, this review aims to provide information regarding the molecules that have been described in the adhesion of A. pleuropneumoniae to cells and tissues of the porcine respiratory tract. Since adhesion is the first step in biofilm formation, we included a section to describe the genes involved in this process; some of these genes could participate directly or indirectly in the adhesion of A. pleuropneumoniae to the porcine respiratory system. Although the role of biofilms in porcine pleuropneumonia is still not clear, these molecules could be considered in the future as candidates for vaccine development

Primera aproximación a las moscas blancas (Hemiptera: Aleyrodidae) sus plantas hospedantes y parasitoides asociados en Huánuco, Perú

Whiteflies are considered insects of great economic importance, because they cause direct and indirect damage that reduce the yields of various crops in some cases by 100%. Collections were made in the Huánuco valley (2013-2016), taking the leaves of various plants containing immature stages of the IV instar of whitefly, which were processed using the technique of Martin (1987) modified by Caballero (1996). For identification, the keys of Hodges and Evans (2005), Valencia (2000), Dooley (2006) and Nakahara (2002) were used; and for the identification of parasitoids, codes from Evans (2008) and Valencia (2000) were used. 10 species of whitefly distributed in the Huánuco valley were identified. The recovered parasitoids were Amitus sp., Encarsia sp., E. formosa and Cales sp. 30 host plants were recorded in 21 botanical families. Whitefly species, host plants, and associated parasitoids are recorded for the first time for Huánuco. Keywords: Aleyrodidae, whitefly, host plants, parasitoids, HuánucoLas moscas blancas son consideradas insectos de gran importancia económica, debido a que causan daños directos e indirectos que reducen los rendimientos de los diversos cultivos en algunos casos en un 100%. Se realizaron colectas en el valle de Huánuco (2013-2016), tomando las hojas de diversas plantas conteniendo estados inmaduros del IV instar de mosca blanca, los cuales fueron procesados mediante la técnica de Martin (1987) modificado por Caballero (1996). Para la identificación se emplearon las claves de Hodges y Evans (2005), Valencia (2000), Dooley (2006) y Nakahara (2002); y para la identificación de parasitoides se emplearon claves de Evans (2008) y Valencia (2000). Se identificaron 10 especies de mosca blanca distribuidos en el valle de Huánuco. Los parasitoides recuperados fueron Amitus sp., Encarsia sp., E. formosa y Cales sp. Se registraron 30 plantas hospedantes en 21 familias botánicas. Las especies de mosca blanca, las plantas hospedantes y los parasitoides asociados se registran por primera vez para Huánuco

Dynamic equivalence between atomic and colloidal liquids

We show that the kinetic-theoretical self-diffusion coefficient of an atomic fluid plays the same role as the short-time self-diffusion coefficient D_S in a colloidal liquid, in the sense that the dynamic properties of the former, at times much longer than the mean free time, and properly scaled with D_S, will indistinguishable from those of a colloidal liquid with the same interaction potential. One important consequence of such dynamic equivalence is that the ratio D_L/ D_S of the long-time to the short-time self-diffusion coefficients must then be the same for both, an atomic and a colloidal system characterized by the same inter-particle interactions. This naturally extends to atomic fluids a well-known dynamic criterion for freezing of colloidal liquids[Phys. Rev. Lett. 70, 1557 (1993)]. We corroborate these predictions by comparing molecular and Brownian dynamics simulations on (soft- and hard-sphere) model systems, representative of what we may refer to as the "hard-sphere" dynamic universality class

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

Digestabilidad, energía digestible y metabolizable del sacha inchi (Plukenetia volubilis L) peletizado y extruido en cuyes (Cavia porcellus)

El estudio tuvo como objetivo evaluar la digestibilidad de los nutrientes y energía digestible y metabolizable de la semilla y torta de sacha inchi (Plukenetia volubilis L) precocida y procesada (peletizado y extruido) en cuyes. En cada ensayo se utilizaron 15 cuyes machos, de 3 meses edad y peso promedio de 700 g. El peletizado se realizó a 87 °C y la extrusión a 105 °C. La digestibilidad y metabolicidad fue determinada utilizando el método de sustitución y colección total de excretas (heces y orina). Los valores de digestibilidad aparente (%) para materia seca, proteína bruta, fibra cruda y extracto etéreo para la semilla peletizada fueron de 54.4, 79.6, 27.0, 76.1 y semilla extruida de 48.7, 83.5, 16.2 y 81.7 respectivamente; mientras que para torta peletizada fueron de 82.5, 81.2, 98.7, 65.9 y torta extruida 76.7, 83.2, 92.8 y 62.4. La energía digestible en la semilla peletizada y extruida fue de 3296 y 3681 kcal/kg de materia seca, y en la torta peletizada y extruida fue de 4621 y 4161 kcal/kg de materia seca, respectivamente. La energía metabolizable en la semilla peletizada y extruida fue de 2676 y 3243 kcal/kg de materia seca, y en la torta peletizada y extruida fue de 4346 y 4137 kcal/kg de materia seca, respectivamente. El tipo de procesamiento no afectó los valores energéticos en la semilla y torta de sacha inchi

Geology of La Reforma caldera complex, Baja California, Mexico

A new geological map at 1:50,000 scale of La Reforma Caldera Complex has been produced applying modern survey methodologies to volcanic areas. This map aims to represent a reliable and objective tool to understand the geological evolution of the region. La Reforma Caldera Complex is a Pleistocene nested caldera located in the central part of the Baja California peninsula, Mexico. The twelve formations defined within the Quaternary volcanic record were grouped into three phases (pre-caldera, caldera, and post-caldera). The pre-caldera phase (>1.35 Ma) is characterized by scattered eruptions, mostly occurred in submarine environment. The caldera phase (1.35–0.96 Ma) groups several distinct explosive and effusive eruptions that formed the present-day caldera depression. The post caldera phase includes scattered effusive eruptions (ended at 0.28 Ma) and resurgence, characterized by several hundred meters of uplift of the central block within the caldera depression

Decrease of virulence for BALB/c mice produced by continuous subculturing of Nocardia brasiliensis

<p>Abstract</p> <p>Background</p> <p>Subculturing has been extensively used to attenuate human pathogens. In this work we studied the effect of continuous subculturing of <it>Nocardia brasiliensis </it>HUJEG-1 on virulence in a murine model.</p> <p>Methods</p> <p><it>Nocardia brasiliensis </it>HUJEG-1 was subcultured up to 130 times on brain heart infusion over four years. BALB/c mice were inoculated in the right foot pad with the bacteria subcultured 0, 40, 80, 100 and 130 times (T₀, T₄₀, T₈₀T₁₀₀and T₁₃₀). The induction of resistance was tested by using T₁₃₀to inoculate a group of mice followed by challenge with T0 12 weeks later. Biopsies were taken from the newly infected foot-pad and immunostained with antibodies against CD4, CD8 and CD14 in order to analyze the in situ immunological changes.</p> <p>Results</p> <p>When using T₄₀, T₈₀T₁₀₀and T₁₃₀as inoculums we observed lesions in 10, 5, 0 and 0 percent of the animals, respectively, at the end of 12 weeks. In contrast, their controls produced mycetoma in 80, 80, 70 and 60% of the inoculated animals. When studying the protection of T₁₃₀, we observed a partial resistance to the infection. Immunostaining revealed an intense CD4+ lymphocytic and macrophage infiltrate in healing lesions.</p> <p>Conclusions</p> <p>After 130 in vitro passages of <it>N. brasiliensis </it>HUJEG-1 a severe decrease in its virulence was observed. Immunization of BALB/c mice, with these attenuated cells, produced a state of partial resistance to infection with the non-subcultured isolate.</p

MEGARA, the new intermediate-resolution optical IFU and MOS for GTC: getting ready for the telescope

MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma that is being built by a Consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). The instrument is currently finishing AIV and will be sent to GTC on November 2016 for its on-sky commissioning on April 2017. The MEGARA IFU fiber bundle (LCB) covers 12.5x11.3 arcsec2 with a spaxel size of 0.62 arcsec while the MEGARA MOS mode allows observing up to 92 objects in a region of 3.5x3.5 arcmin2 around the IFU. The IFU and MOS modes of MEGARA will provide identical intermediate-to-high spectral resolutions (RFWHM~6,000, 12,000 and 18,700, respectively for the low-, mid- and high-resolution Volume Phase Holographic gratings) in the range 3700-9800ÅÅ. An x-y mechanism placed at the pseudo-slit position allows (1) exchanging between the two observing modes and (2) focusing the spectrograph for each VPH setup. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts a 4kx4k 15-μm CCD. The unique characteristics of MEGARA in terms of throughput and versatility and the unsurpassed collecting are of GTC make of this instrument the most efficient tool to date to analyze astrophysical objects at intermediate spectral resolutions. In these proceedings we present a summary of the instrument characteristics and the results from the AIV phase. All subsystems have been successfully integrated and the system-level AIV phase is progressing as expected