223 research outputs found

    Evaluación del comportamiento productivo a la fertilización de dos clones de ajo (Allium sativum L.) en la provincia de La Pampa

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    The garlic (Alium sativum L.), it is a species belonging to the family of the Allied. Argentina is one of the principal producing countries and the second world exporter of garlic, after China, the major quantity is exported from January to June, To evaluate the culture, in not traditional zones as La Pampa, it is a valuable contribution, where environmental factors conjugate not alone but also characteristics of soil, quality of water, managing of culture, workforce, and response to fertilization, plagues, diseases, crop, yields and marketing. The aim of the work was to evaluate the productive behavior of two clowns of garlic, "Chinese" and "Colorado" and his response to the fertilization with sulphate of ammonium in one and two applications. The plantation was realized in the garden of the Facultad de Agronomía, UNLPam, April 15, 2005, in a design of complete blocks at random by 4 repetitions, the experimental unit consisted of a plot of two lines of 5 m. Of length, to 0.60 m between lines, with two lines of bordure. There were fertilized by sulphate of ammonium 30/7 in the treatments 1 (the only application) and 2, and 30/9 in the treatment 2 (double application) because of 50 kg.ha-1 every time. The values were compared by means of ANOVA, and Tukey's test with a = 0,05. Bearing in mind the weight of dry clean garlic, the results indicate that both clowns answered favorably to the double fertilization, obtaining significant differences between treatments, obtaining major production with double fertilization, with regard to the unique fertilization, and in turn the plots with an alone fertilization produced more in weight that the plots witness without fertilizing. Also significant differences between clowns were obtained. The results reveal the major yield of the "Chinese" clown in the different treatments respect of the clown "Colorado".El Ajo (Allium sativum L), es una especie perteneciente a la familia de las Aliáceas. Argentina es uno de los principales países productores y el segundo exportador mundial de ajo, después de China, el período de exportación se extiende de enero a junio. Evaluar el cultivo en zonas no tradicionales como La Pampa, es un aporte valioso, donde se conjugan no solo factores ambientales sino también características de suelo, calidad de agua, manejo de cultivo, mano de obra, respuesta a fertilización, plagas, enfermedades, cosecha, rendimientos y comercialización. El objetivo del trabajo fue evaluar el comportamiento productivo de dos clones de ajo, "Chino" y "Colorado" y su respuesta a la fertilización con sulfato de amonio en una y dos aplicaciones. La plantación se realizó en la huerta de la Facultad de Agronomía de la UNLPam, el 15 de Abril de 2005, en un diseño de bloques completos al azarcón 4 repeticiones, la unidad experimental consistió en una parcela de dos líneas de 5 m. de largo, a 0,60 m entre líneas, con dos líneas de bordura. Se fertilizó con sulfato de amonio el 30/7 en los tratamientos 1 (única aplicación) y 2, y el 30/9 en el tratamiento 2 (doble aplicación) a razón de 50 kg.ha-1 cada vez. Los valores de los resultados fueron comparados mediante ANOVA, y test de Tukey con a = 0,05. Teniendo en cuenta el peso de ajo seco limpio, los resultados indican que ambos clones respondieron favorablemente a la doble fertilización, obteniendo diferencias significativas entre tratamientos, obteniendo mayor producción con doble fertilización, con respecto a fertilización única, y a su vez las parcelas con una sola fertilización produjeron más en peso que las parcelas testigo sin fertilizar. También se obtuvieron diferencias significativas entre clones. Los resultados ponen de manifiesto el mayor rendimiento del clon "Chino" en los distintos tratamientos respecto del clon "Colorado"

    Intranasal peptide-induced tolerance and linked suppression: consequences of complement deficiency.

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    A role for complement, particularly the classical pathway, in the regulation of immune responses is well documented. Deficiencies in C1q or C4 predispose to autoimmunity, while deficiency in C3 affects the suppression of contact sensitization and generation of oral tolerance. Complement components including C3 have been shown to be required for both B-cell and T-cell priming. The mechanisms whereby complement can mediate these diverse regulatory effects are poorly understood. Our previous work, using the mouse minor histocompatibility (HY) model of skin graft rejection, showed that both C1q and C3 were required for the induction of tolerance following intranasal peptide administration. By comparing tolerance induction in wild-type C57BL/6 and C1q-, C3-, C4- and C5-deficient C57BL/6 female mice, we show here that the classical pathway components including C3 are required for tolerance induction, whereas C5 plays no role. C3-deficient mice failed to generate a functional regulatory T (Treg) -dendritic cell (DC) tolerogenic loop required for tolerance induction. This was related to the inability of C3-deficient DC to up-regulate the arginine-consuming enzyme, inducible nitric oxide synthase (Nos-2), in the presence of antigen-specific Treg cells and peptide, leading to reduced Treg cell generation. Our findings demonstrate that the classical pathway and C3 play a critical role in the peptide-mediated induction of tolerance to HY by modulating DC function

    First light of the VLT planet finder SPHERE. I. Detection and characterization of the sub-stellar companion GJ 758 B

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    GJ758 B is a brown dwarf companion to a nearby (15.76 pc) solar-type, metal-rich (M/H = +0.2 dex) main-sequence star (G9V) that was discovered with Subaru/HiCIAO in 2009. From previous studies, it has drawn attention as being the coldest (~600K) companion ever directly imaged around a neighboring star. We present new high-contrast data obtained during the commissioning of the SPHERE instrument at the VLT. The data was obtained in Y-, J-, H-, and Ks-bands with the dual-band imaging (DBI) mode of IRDIS, providing a broad coverage of the full near-infrared (near-IR) range at higher contrast and better spectral sampling than previously reported. In this new set of high-quality data, we report the re-detection of the companion, as well as the first detection of a new candidate closer-in to the star. We use the new 8 photometric points for an extended comparison of GJ758 B with empirical objects and 4 families of atmospheric models. From comparison to empirical object, we estimate a T8 spectral type, but none of the comparison object can accurately represent the observed near-IR fluxes of GJ758 B. From comparison to atmospheric models, we attribute a Teff = 600K ±\pm 100K, but we find that no atmospheric model can adequately fit all the fluxes of GJ758 B. The photometry of the new candidate companion is broadly consistent with L-type objects, but a second epoch with improved photometry is necessary to clarify its status. The new astrometry of GJ758 B shows a significant proper motion since the last epoch. We use this result to improve the determination of the orbital characteristics using two fitting approaches, Least-Square Monte Carlo and Markov Chain Monte Carlo. Finally, we analyze the sensitivity of our data to additional closer-in companions and reject the possibility of other massive brown dwarf companions down to 4-5 AU. [abridged]Comment: 20 pages, 15 figures. Accepted for publication in A&

    Post conjunction detection of β\beta Pictoris b with VLT/SPHERE

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    With an orbital distance comparable to that of Saturn in the solar system, \bpic b is the closest (semi-major axis \simeq\,9\,au) exoplanet that has been imaged to orbit a star. Thus it offers unique opportunities for detailed studies of its orbital, physical, and atmospheric properties, and of disk-planet interactions. With the exception of the discovery observations in 2003 with NaCo at the Very Large Telescope (VLT), all following astrometric measurements relative to \bpic have been obtained in the southwestern part of the orbit, which severely limits the determination of the planet's orbital parameters. We aimed at further constraining \bpic b orbital properties using more data, and, in particular, data taken in the northeastern part of the orbit. We used SPHERE at the VLT to precisely monitor the orbital motion of beta \bpic b since first light of the instrument in 2014. We were able to monitor the planet until November 2016, when its angular separation became too small (125 mas, i.e., 1.6\,au) and prevented further detection. We redetected \bpic b on the northeast side of the disk at a separation of 139\,mas and a PA of 30^{\circ} in September 2018. The planetary orbit is now well constrained. With a semi-major axis (sma) of a=9.0±0.5a = 9.0 \pm 0.5 au (1 σ\sigma ), it definitely excludes previously reported possible long orbital periods, and excludes \bpic b as the origin of photometric variations that took place in 1981. We also refine the eccentricity and inclination of the planet. From an instrumental point of view, these data demonstrate that it is possible to detect, if they exist, young massive Jupiters that orbit at less than 2 au from a star that is 20 pc away.Comment: accepted by A&

    In-depth study of moderately young but extremely red, very dusty substellar companion HD206893B

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    Accepted for publication in Astronomy & Astrophysics. Reproduced with permission from Astronomy & Astrophysics. © 2018 ESO.The substellar companion HD206893b has recently been discovered by direct imaging of its disc-bearing host star with the SPHERE instrument. We investigate the atypical properties of the companion, which has the reddest near-infrared colours among all known substellar objects, either orbiting a star or isolated, and we provide a comprehensive characterisation of the host star-disc-companion system. We conducted a follow-up of the companion with adaptive optics imaging and spectro-imaging with SPHERE, and a multiinstrument follow-up of its host star. We obtain a R=30 spectrum from 0.95 to 1.64 micron of the companion and additional photometry at 2.11 and 2.25 micron. We carried out extensive atmosphere model fitting for the companions and the host star in order to derive their age, mass, and metallicity. We found no additional companion in the system in spite of exquisite observing conditions resulting in sensitivity to 6MJup (2MJup) at 0.5" for an age of 300 Myr (50 Myr). We detect orbital motion over more than one year and characterise the possible Keplerian orbits. We constrain the age of the system to a minimum of 50 Myr and a maximum of 700 Myr, and determine that the host-star metallicity is nearly solar. The comparison of the companion spectrum and photometry to model atmospheres indicates that the companion is an extremely dusty late L dwarf, with an intermediate gravity (log g 4.5-5.0) which is compatible with the independent age estimate of the system. Though our best fit corresponds to a brown dwarf of 15-30 MJup aged 100-300 Myr, our analysis is also compatible with a range of masses and ages going from a 50 Myr 12MJup planetary-mass object to a 50 MJup Hyades-age brown dwarf...Peer reviewedFinal Accepted Versio

    SLEPR: A Sample-Level Enrichment-Based Pathway Ranking Method — Seeking Biological Themes through Pathway-Level Consistency

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    Analysis of microarray and other high throughput data often involves identification of genes consistently up or down-regulated across samples as the first step in extraction of biological meaning. This gene-level paradigm can be limited as a result of valid sample fluctuations and biological complexities. In this report, we describe a novel method, SLEPR, which eliminates this limitation by relying on pathway-level consistencies. Our method first selects the sample-level differentiated genes from each individual sample, capturing genes missed by other analysis methods, ascertains the enrichment levels of associated pathways from each of those lists, and then ranks annotated pathways based on the consistency of enrichment levels of individual samples from both sample classes. As a proof of concept, we have used this method to analyze three public microarray datasets with a direct comparison with the GSEA method, one of the most popular pathway-level analysis methods in the field. We found that our method was able to reproduce the earlier observations with significant improvements in depth of coverage for validated or expected biological themes, but also produced additional insights that make biological sense. This new method extends existing analyses approaches and facilitates integration of different types of HTP data

    Correlating Global Gene Regulation to Angiogenesis in the Developing Chick Extra-Embryonic Vascular System

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    International audienceBACKGROUND: Formation of blood vessels requires the concerted regulation of an unknown number of genes in a spatial-, time- and dosage-dependent manner. Determining genes, which drive vascular maturation is crucial for the identification of new therapeutic targets against pathological angiogenesis. METHOLOGY/PRINCIPAL FINDINGS: We accessed global gene regulation throughout maturation of the chick chorio-allantoic membrane (CAM), a highly vascularized tissue, using pan genomic microarrays. Seven percent of analyzed genes showed a significant change in expression (>2-fold, FDR<5%) with a peak occurring from E7 to E10, when key morphogenetic and angiogenic genes such as BMP4, SMO, HOXA3, EPAS1 and FGFR2 were upregulated, reflecting the state of an activated endothelium. At later stages, a general decrease in gene expression occurs, including genes encoding mitotic factors or angiogenic mediators such as CYR61, EPAS1, MDK and MYC. We identified putative human orthologs for 77% of significantly regulated genes and determined endothelial cell enrichment for 20% of the orthologs in silico. Vascular expression of several genes including ENC1, FSTL1, JAM2, LDB2, LIMS1, PARVB, PDE3A, PRCP, PTRF and ST6GAL1 was demonstrated by in situ hybridization. Up to 9% of the CAM genes were also overexpressed in human organs with related functions, such as placenta and lung or the thyroid. 21-66% of CAM genes enriched in endothelial cells were deregulated in several human cancer types (P<.0001). Interfering with PARVB (encoding parvin, beta) function profoundly changed human endothelial cell shape, motility and tubulogenesis, suggesting an important role of this gene in the angiogenic process. CONCLUSIONS/SIGNIFICANCE: Our study underlines the complexity of gene regulation in a highly vascularized organ during development. We identified a restricted number of novel genes enriched in the endothelium of different species and tissues, which may play crucial roles in normal and pathological angiogenesis
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