A computational model for estimating the performance of flat plane low concentration systems

The implementation of PV systems is one of the feasible alternatives to meet the energy supply in communities far from the conventional electric grid. Several studies have shown that a flat plane concentrator can produce better electrical behaviour in a PV system, due to the reduction of the effective panel surface needed for the operation of the system. As the cost of a PV system is strongly conditioned by the cost of the PV panels, it can lead to an increase of the PV market. This work describes the computational model developed to represent the concentration pattern over a collector, generated by a flat plane reflector. A useful 3D representation of the system has been programmed to visualize the concentration system. The computational model was developed in Mathematica Programming Language Environment. The simulation tool created shows that Mathematica is a quick and powerful tool to represent the low-concentrating photovoltaic systems

Hubble Space Telescope STIS spectrum of RW Aurigae A: Evidence for an ionized beltlike structure and mass ejection in timescales of a few hours

Profiles of the UV semiforbidden lines of C III](1908) and Si III](1892) of RW Aur have been obtained with the Hubble Space Telescope (HST) STIS. The C III](1908) profile shows two high-velocity components at upsilon = +/-170 km s(-1) and a central one. The Si III](1892) profile is very broad (FWHM = 293 km s(-1)), and the high-velocity components are unresolved. The high-velocity components are most probably produced in a rotating belt similar to that detected in other sources of bipolar outflows. A radius between 2.7 R-* and the corotation radius (6.1 R-*) is derived, and a log T-e(K) similar or equal to 4.7 and log n(e)(cm(-3)) = 11.6 are estimated. The belt is clumpy, and the most likely source of heating is local X-ray radiation, probably associated with the release of magnetic energy. In addition, profiles of the optical lines of He I, Fe II, and Halpha retrieved from the HST archive have been analyzed. The spectra were obtained by shifting the STIS slit between exposures in the transverse direction to the flow. Two features vary from one exposure to another: a blueshifted emission feature (detected in the Fe II and He I lines) and a redshifted absorption feature (detected in Halpha), which are observed at the velocity of the blueshifted and redshifted components of the jet, respectively. There is a clear-cut correlation between the equivalent widths of these two components. These components are not associated with the flaring activity of the source, since they remain stable timescales of similar or equal to40 minutes. They are most likely associated with variations in the stellar/circumstellar environment in timescales of a few (similar or equal to5) hours, consistent with reports by other authors for variations of the veiling and the appearance of shell signatures in the optical spectrum

Severe Neurological Abnormalities in a Young Boy with Impaired Thyroid Hormone Sensitivity Due to a Novel Mutation in the MCT8 Gene

Monocarboxylate transporter 8 (MCT8) is an active and specific thyroid hormone transporter into neurons. MCT8 mutations cause an X-linked condition known as Allan-Herndon-Dudley syndrome and are characterized by impaired psychomotor development and typical abnormal thyroid function. We describe a 10-year-old boy with severe cognitive disability, axial hypotonia, spastic quadriplegia and sporadic dyskinetic episodes. He initially presented with thyroid dysfunction (high FT3, low rT3, low FT4 and normal TSH) and generalized retardation of the cerebral and cerebellar myelination in brain magnetic resonance imaging. The clinical and laboratory findings led to sequencing of the SLC16A2/MCT8 gene, which identified a novel missense mutation in exon 5. The study of peripheral markers of thyroid function suggests a paradoxical state of thyrotoxicosis in some peripheral tissues. Our patient had a typical clinical presentation at birth but because of the rarity of his disease his diagnosis was not made until the age of 7. The delay can also be explained by the omission of the free T3 assay in the first thyroid evaluation performed. This case therefore highlights the possible benefit of including the T3 assay in the study of patients with severe psychomotor disability of unknown etiology, thus eliminating extra costs for unnecessary complementary diagnostic tests.info:eu-repo/semantics/publishedVersio

Seleção de isolados de vírus e determinação da concentração letal média (CL50) para controle de S. Eridania, S. Cosmioides e S. frugiperda.

Os lepidópteros desfolhadores principalmente do gênero Spodoptera são atualmente um dos mais importantes problemas entomológicos em várias culturas de expressão econômica. Como alternativa ao controle químico, podem ser utilizados microrganismos entomopatogênicos, incluindo bactérias, vírus, fungos e protozoários. Este trabalho teve como objetivo avaliar isolados de vírus para as espécies de S. cosmioides, S. eridania e S. frugiperda. Lagartas de 3º instar (n=50), foram inoculadas com uma suspensão viral [1,0 x 107 corpos poliédricos de inclusão do vírus (CPI/mL)] incorporada na dieta artificial a fim de analisar a mortalidade causada por diferentes isolados de vírus. Para a determinação da CL50 seguiu-se a mesma metodologia, porém utilizando 80 lagartas por concentração (concentrações de 4.000; 8.000; 16.000; 32.000; 64.000 e 128.000 CPI/mL). Os dados de mortalidade foram submetidos à análise Probit, para a estimação CL50, bem como dos parâmetros associados (Intervalo de confiança (IC 95%) e ?2). Para a espécie S. cosmioides o isolado VPN 72 isolado desta mesma espécie resultou em mortalidade de 20%. Os isolados VNP 143, 144 e 152 obtidos de outros hospedeiros, mataram 24, 100 e 80% respectivamente. As lagartas de S. frugiperda apresentaram mortalidade de 100% somente com os isolados obtidos da mesma espécie VPN 76 e VG 89. S. eridania teve 20% de mortalidade com o isolado VPN 144, sendo este isolado o único que provocou mortalidade nas duas espécies. Os valores de ?2 calculados não foram significativos, indicando a homogeneidade dos dados e, principalmente, que os dados adaptaram-se ao modelo de análise Probit. O VPN 144 de A. californica inoculado em S. albula, testado em S. cosmioides apresentou a menor CL50, caracterizando-se como o mais virulento, quando comparado ao VPN 152 que resultou em CL50 de 49,13 CPI/mL ou seja foi duas vezes menos virulento que o VPN 144. Esse mesmo isolado testado em S. eridania foi 67 vezes menos virulento quando comparado com a espécie de S. cosmioides. Esta espécie apresentou-se a mais suscetível a isolados de vírus provenientes de outros hospedeiros.SICONBIOL 2011

CIGB-300, a proapoptotic peptide, inhibits angiogenesis in vitro and in vivo

We have previously demonstrated that a proapoptotic cyclic peptide CIGB-300, formerly known as P15-Tat delivered into the cells by the cell-penetrating peptide Tat, was able to abrogate the CK2-mediated phosphorylation and induce tumor regression when injected directly into solid tumors in mice or by systemic administration. In this work, we studied the role of CIGB-300 on the main events that take place in angiogenesis. At non-cytotoxic doses, CIGB-300 was able to inhibit adhesion, migration, and tubular network formation induced by human umbilical vein endothelial cells (HUVEC) growing upon Matrigel in vitro. Likewise, we evaluated the cellular penetration and localization into the HUVEC cells of CIGB-300. Our results confirmed a quick cellular penetration and a cytoplasmic accumulation in the early minutes of incubation and a translocation into the nuclei beginning at 12h of treatment, with a strong presence in the perinuclear area. A microarray analysis was used to determine the genes affected by the treatment. We observed that CIGB-300 significantly decreased four genes strongly associated with tubulogenesis, growth, and differentiation of endothelial cells. The CIGB-300 was tested in vivo on chicken embryo chorioallantoic membranes (CAM), and a large number of newly formed blood vessels were significantly regressed. The results suggested that CIGB-300 has a potential as an antiangiogenic treatment. The mechanism of action may be associated with partial inhibition of VEGF and Notch pathways.Fil: Farina, Hernán Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Benavent Acero, Fernando Rodrigo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Perera, Yasser. Center for Genetic Engineering and Biotechnology; CubaFil: Rodríguez, Arielis. Center for Genetic Engineering and Biotechnology; CubaFil: Perea, Silvio E.. Center for Genetic Engineering and Biotechnology; CubaFil: Acevedo Castro, Boris. Center for Genetic Engineering and Biotechnology; CubaFil: Gomez, Roberto. No especifíca;Fil: Alonso, Daniel F.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Steam oxidation of ferritic steels : kinetics and microstructure

The ferritic 2.25Cr–1Mo steel has been subjected to isothermal and non-isothermal oxidation treatments in water steam at several temperatures ranging from 550 to 700 °C for up to 56 days. Under isothermal conditions this steel follows a parabolic oxidation kinetics, with an activation energy of 324 kJ mol –1 . This value corresponds to an apparent activation energy for the global process, which includes both outward diffusion of Fe cations and inward diffusion of oxygen. The oxidation products present in the oxide scales, which were characterised by X-ray diffraction and SEM, are in total agre - ement with the Fe-O phase diagram. Thus, magnetite is the most stable oxide at low temperatures and wustite starts to form above 570 °C. Further studies of the effect of cooling rate have shown that wustite formed at 700 °C transforms into magne - tite during a slow cooling, whereas a rapid cooling inhibits this transformation to a certain extent. For non-isothermal oxidation treatments consisting of a holding period at 550 °C followed by a single or double 4 hours exposure at 700 °C, the oxidation process seems to occur in sequence, thus presenting an additive effect of the oxidation treatments carried out at each temperature. This effect was observed both, for the type of oxide grown, and for the kinetics of the process. Microscopic observations of the oxide scales formed after the various oxidation treatments revealed that the oxide scales are constituted by sublayers of distinct microstructure and chemical composition changing from their surface to the substrate interface

Observations of T-Tauri Stars using HST-GHRS: I. Far Ultraviolet Emission Lines

We have analyzed GHRS data of eight CTTS and one WTTS. The GHRS data consists of spectral ranges 40 A wide centered on 1345, 1400, 1497, 1550, and 1900 A. These UV spectra show strong SiIV, and CIV emission, and large quantities of sharp (~40 km/s) H2 lines. All the H2 lines belong to the Lyman band and all the observed lines are single peaked and optically thin. The averages of all the H2 lines centroids for each star are negative which may indicate that they come from an outflow. We interpret the emission in H2 as being due to fluorescence, mostly by Ly_alpha, and identify seven excitation routes within 4 A of that line. We obtain column densities (10^12 to 10^15 cm^-2) and optical depths (~1 or less) for each exciting transition. We conclude that the populations are far from being in thermal equilibrium. We do not observe any lines excited from the far blue wing of Ly_alpha, which implies that the molecular features are excited by an absorbed profile. SiIV and CIV (corrected for H2 emission) have widths of ~200 km/s, and an array of centroids (blueshifted lines, centered, redshifted). These characteristics are difficult to understand in the context of current models of the accretion shock. For DR Tau we observe transient strong blueshifted emission, perhaps the a result of reconnection events in the magnetosphere. We also see evidence of multiple emission regions for the hot lines. While CIV is optically thin in most stars in our sample, SiIV is not. However, CIV is a good predictor of SiIV and H2 emission. We conclude that most of the flux in the hot lines may be due to accretion processes, but the line profiles can have multiple and variable components.Comment: 67 pages, 19 figures, Accepted in Ap

New constraints on protostellar jet collimation from high-density gas UV tracers

The analysis of high-resolution profiles of the semiforbidden UV lines of C III](1908) and Si III](1892) in the spectra of T Tauri stars (TTSs) shows the following : (1) There is C III](1908) and Si III](1892) emission at velocities that are similar to those observed in the optical forbidden lines formed in the TTSs jets. The luminosity of the UV lines is comparable to that of the optical lines. (2) The comparison between the optical and UV light curves indicates that the C III](1908) and Si III](1892) emission of RY Tau is not associated with accretion shocks, but it is produced farther than 2 R-* from the star. (3) The profiles of the UV semiforbidden lines are significantly broader than those of the optical forbidden lines. These profiles cannot be produced in a narrow collimated beam, and they are most likely produced in a bow-shaped shock wave formed at the base of the optical jet, where the hot gas emits in a broad range of projected radial velocities. (4) The atmosphere of RU Lup contributes significantly to the Si III](1892) emission. (5) A puzzling narrow feature is observed close to the C III](1908) line. The feature is blueshifted by -260 km s(-1), which corresponds to the wind terminal velocity measured in the P Cygni profile of the Mg II (UV1) lines. Moreover, constraints are derived on the characteristics of the C III](1908) and Si III](1892) emitting region in RY Tau. It is shown that 4.7 less than or equal to log T-e less than or equal to 5.0 and 10(9) cm(-3) less than or equal to N-e less than or equal to 10(11) cm(-3) provided that the emission is produced in a collisional plasma and that the 1665 Angstrom feature observed in low-dispersion International Ultraviolet Explorer (IUE) spectra is confirmed to be O III](1665) emission produced in the wind. These very high densities are difficult to generate in the shocks produced by the magnetic pinching of centrifugally driven magnetized disk winds. The data also suggest that the shocked layer has a radius of some few stellar radii and it is closer than similar to 38 R-* to the star

Mechanisms of innate immune activation by gluten peptide p31-43 in mice

Celiac disease (CD) is an immune-mediated enteropathy triggered by gluten in genetically susceptible individuals. Innate immunity contributes to the pathogenesis of CD, but the mechanisms remain poorly understood. Although previous in vitro work suggests that gliadin peptide p31-43 acts as an innate immune trigger, the underlying pathways are unclear and have not been explored in vivo. Here we show that intraluminal delivery of p31-43 induces morphological changes in the small intestinal mucosa of normal mice consistent with those seen in CD, including increased cell death and expression of inflammatory mediators. The effects of p31-43 were dependent on MyD88 and type I IFNs, but not Toll-like receptor 4 (TLR4), and were enhanced by coadministration of the TLR3 agonist polyinosinic:polycytidylic acid. Together, these results indicate that gliadin peptide p31-43 activates the innate immune pathways in vivo, such as IFN-dependent inflammation, relevant to CD. Our findings also suggest a common mechanism for the potential interaction between dietary gluten and viral infections in the pathogenesis of CD

Epi-and Mesopelagic Fishes, Acoustic Data, and SST Images Collected Off Lanzarote, Fuerteventura, and Gran Canaria, Canary Islands, During Cruise La Bocaina 04-97

During cruise La Bocaina 0497 a series of 14 tows with a commercial pelagic trawl at depths between 20 and 700 m and an acoustic survey with a SIMRAD EK-500 echosounder were carried out in neritic and adjacent oceanic waters off Lanzarote, Fuerteventura, and Gran Canaria, Canary islands. In addition, SST images were obtained to get some informations on the prevailing hydrological conditions in the study area. Of the 14 trawl tows ten were successful and resulted in capture of a total of 2166 fishes belonging to 81 species, 53 genera and 28 families. Ten species proved to be new records for the area of the Canary Islands. The acoustic survey covered a total of 2404 nm2 and allowed to obtain estimates of the abundance and biomass of fishes. Both the fishing results and the acoustic study revealed considerable spatial variability in biomass of chub mackerel, Scomber japonicus, an epipelagic species of particular fisheries interest, showing clear variations in the numerical dominance of certain age- or size classes among different collecting localities. Furthermore, some juveniles in the first year of life occurred in the oceanic epipelagic during night together with vertically migrating mesopelagic fishes. Preliminary analyses of the stomach and intestinal content suggest that these juveniles fed close to the bottom during the day before and hence may undertake diurnal horizontal migrations between the shelf and adjacent oceanic waters. It is concluded that the great spatial flexibility of this species requires further monitoring surveys at regular intervals as a basis for establishing a sustainable fisheries management. The acoustic data together with the trawling results demonstrate the existence of a dense deep scattering layer at depths between 400 and 700 m which is composed of mesopelagic fishes and invertebrates. Clear indications of diurnal vertical migrations were found in several species with formation of a shallow scattering layer in less than 150 m depth during night. Together with typical mesopelagic species such as stomiids and myctophids also juveniles of three benthopelagic species, which typically undergo a pelagic stage during early life, were collected. Several individuals of mesopelagic species were collected above the shelf what may reflect the ecological boundary situation at ocean rims typical for oceanic islands and seamounts. Some mesopelagic species collected in this study may be closely associated with distinct hydrological conditions such as the myctophid Ceratoscopelus maderensis which was discovered in the SE of Fuerteventura in an area of possible local upwelling. This finding points to the existence of micro-zoogeographic zones within the Canary islands which derserve further investigation using a small-scaled comparative approach