2,188 research outputs found
High-speed optical coherence tomography as a reliable adjuvant tool to grade ocular anterior chamber inflammation.
PURPOSE: To evaluate the high-speed anterior segment optical coherence tomography (AS-OCT) grading of the AS inflammation in patients with ocular inflammation.
METHODS: A retrospective consecutive case series study. Patients with clinically visible AS inflammation in at least one eye underwent AS-OCT (Visante; Zeiss Meditec) with three to eight line scans per eye, performed by a trained masked examiner. The images were reviewed for hyperreflective spots, noise, and artifact, and these were correlated to clinical examination.
RESULTS: Seventy-eight eyes of 41 patients were imaged. Forty-seven eyes had anterior chamber cells on clinical examination, and 68 had hyperreflective spots visible on AS-OCT. There was a significant correlation (Spearman r = 0.7274) between clinical examination and Visante OCT images. Several patterns of inflammation and artifacts were apparent.
CONCLUSION: The AS-OCT is a promising technique for grading anterior chamber cells. There was a significant correlation between clinical examination and Visante grading
Viral metacommunities associated to bats and rodents at different spatial scales
One of the main goals of community ecology is to measure the relative importance of environmental filters to understand patterns of species distribution at different temporal and spatial scales. Likewise, the identification of factors that shape symbiont metacommunity structures is important in disease ecology because resulting structures drive disease transmission. We tested the hypothesis that distributions of virus species and viral families from rodents and bats are defined by shared responses to host phylogeny and host functional characteristics, shaping the viral metacommunity structures at four spatial scales (Continental, Biogeographical, Zoogeographical, and Regional). The contribution of host phylogeny and host traits to the metacommunity of viruses at each spatial scale was calculated using a redundant analysis of canonical ordering (RDA). For rodents, at American Continental scale the coherence of viral species metacommunity increased while the spatial scale decreased and Quasi-Clementsian structures were observed. This pattern suggests a restricted distribution of viruses through their hosts, while in the Big Mass (Europe, Africa, and Asia), the coherence decreased as spatial scale decreased. Viral species metacommunities associated with bats was dominated by random structures along all spatial scales. We suggest that this random pattern is a result of the presence of viruses with high occupancy range such as rabies (73%) and coronavirus (27%), that disrupt such structures. At viral family scale, viral metacommunities associated with bats showed coherent structures, with the emergence of Quasi- Clementsian and Checkerboard structures. RDA analysis indicates that the assemblage of viral diversity associated with rodents and bats responds to phylogenetic and functional characteristics, which alternate between spatial scales. Several of these variations could be subject to the spatial scale, in spite of this, we could identify patterns at macro ecological scale. The application of metacommunity theory at symbiont scales is particularly useful for large-scale ecological analysis. Understanding the rules of host-virus association can be useful to take better decisions in epidemiological surveillance, control and even predictions of viral distribution and dissemination
Effect of a heterotrimeric G protein α subunit on conidia germination, stress response, and roquefortine C production in Penicillium roqueforti
Summary. Heterotrimeric G protein signaling regulates many processes in fungi, such as development, pathogenicity, and secondary metabolite biosynthesis. For example, the Gα subunit Pga1 from Penicillium chrysogenum regulates conidiation and secondary metabolite production in this fungus. The dominant activating allele, pga1G42R, encoding a constitutively active Pga1 Gα subunit, was introduced in Penicillium roqueforti by transformation, resulting in a phenotype characterized by low sporulation and slow growth. In this work, the effect of the constitutively active Pga1G42R Gα subunit on conidial germination, stress tolerance, and roquefortine C production of P. roqueforti was studied. Pga1G42R triggered germination in the absence of a carbon source, in addition to negatively regulating thermal and osmotic stress tolerance. The presence of the Pga1G42R Gα subunit also had an important effect on roquefortine C biosynthesis, increasing production and maintaining high levels of the mycotoxin throughout a culture period of 30 days. Together, the results suggest that G protein-mediated signaling participates in the regulation of these three processes in P. roqueforti. [Int Microbiol 2009; 12(2):123-129
Gamma rays from microquasars Cygnus X-1 and Cygnus X-3
Gamma-ray observations of microquasars at high and very-high energies can
provide valuable information of the acceleration processes inside the jets, the
jet-environment interaction and the disk-jet coupling. Two high-mass
microquasars have been deeply studied to shed light on these aspects: Cygnus
X-1 and Cygnus X-3. Both systems display the canonical hard and soft X-ray
spectral states of black hole transients, where the radiation is dominated by
non-thermal emission from the corona and jets and by thermal emission from the
disk, respectively. Here, we report on the detection of Cygnus X-1 above 60 MeV
using 7.5 yr of Pass8 Fermi-LAT data, correlated with the hard X-ray state. A
hint of orbital flux modulation was also found, as the source is only detected
in phases around the compact object superior conjunction. We conclude that the
high-energy gamma-ray emission from Cygnus X-1 is most likely associated with
jets and its detection allow us to constrain the production site. Moreover, we
include in the discussion the final results of a MAGIC long-term campaign on
Cygnus X-1 that reaches almost 100 hr of observations at different X-ray
states. On the other hand, during summer 2016, Cygnus X-3 underwent a flaring
activity period in radio and high-energy gamma rays, similar to the one that
led to its detection in the high-energy regime in 2009. MAGIC performed
comprehensive follow-up observations for a total of about 70 hr. We discuss our
results in a multi-wavelength context.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC
2017), Bexco, Busan, Korea (arXiv:1708.05153
Efecto de la composición química en el comportamiento mecánico de recubrimientos galvanizados por inmersión en caliente: una revisión
In recent years, a great interest has been generated in the investigation of galvanized coatings, modifying them in order to improve the performance in the conditions of service. These modifications seek a significant improvement in the properties of the galvanized coating, whether in corrosion resistance, weldability or mechanical properties. The demands generated by the multiple applications of these coatings, where the coated substrate is subjected to plastic deformations (stamping, bending and laminating), requires the greater ductility of the coatings. For this reason, chemical compositions of the immersion baths have been developed, making it possible to considerably modify the microstructure of the coatings and thus their mechanical properties. This work aims to perform a bibliographic review on the chemical composition of the immersion baths, their influence on the microstructure and techniques used to determine the ductility and adhesion in galvanized coatings by hot dip.En los últimos años se ha generado un amplio interés en la investigación de los recubrimientos galvanizados, modificándolos con el fin de mejorar el desempeño en condiciones de servicio. Estas modificaciones buscan una mejora significativa en las propiedades del recubrimiento galvanizado, bien sea en la resistencia a la corrosión, en la soldabilidad o en las propiedades mecánicas. Las exigencias generadas por las múltiples aplicaciones de estos recubrimientos, donde el sustrato recubierto es sometido a deformaciones plásticas (estampado, doblado y laminado), requieren de mayor ductilidad de los recubrimientos. Por esto se han desarrollado composiciones químicas de los baños de inmersión, logrando modificar considerablemente la microestructura de los recubrimientos y por ende sus propiedades mecánicas. Este trabajo tiene como objetivo realizar una revisión bibliográfica sobre la composición química de los baños de inmersión, su influencia en la microestructura y técnicas utilizadas para determinar la ductilidad y adherencia en recubrimientos galvanizados por inmersión en caliente
Survey of Revegetated Areas on the Fitzner/Eberhardt Arid Lands Ecology Reserve: Status and Initial Monitoring Results
During 2010, the U.S. Department of Energy (DOE), Richland Operations Office removed a number of facilities and debris from the Fitzner/Eberhardt Arid Lands Ecology Reserve (ALE), which is part of the Hanford Reach National Monument (HRNM). Revegetation of disturbed sites is necessary to stabilize the soil, reduce invasion of these areas by exotic weeds, and to accelerate re-establishment of native plant communities. Seven revegetation units were identified on ALE based on soils and potential native plant communities at the site. Native seed mixes and plant material were identified for each area based on the desired plant community. Revegetation of locations affected by decommissioning of buildings and debris removal was undertaken during the winter and early spring of 2010 and 2011, respectively. This report describes both the details of planting and seeding for each of the units, describes the sampling design for monitoring, and summarizes the data collected during the first year of monitoring. In general, the revegetation efforts were successful in establishing native bunchgrasses and shrubs on most of the sites within the 7 revegetation units. Invasion of the revegetation areas by exotic annual species was minimal for most sites, but was above initial criteria in 3 areas: the Hodges Well subunit of Unit 2, and Units 6 and 7
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