3,289 research outputs found
Ameliorative effects of salt resistance on physiological parameters in the halophyte Salicornia bigelovii torr. with plant growth-promoting rhizobacteria
Salicornia bigelovii is a promising resource to cultivate under extreme climatic conditions of arid-desert regions. However, the production of Salicornia depends on the appropriate supplementation of nitrogen rich synthetic fertilizers. Application of specific halotolerant nitrogen-fixing bacteria associated with S. bigelovii could be an important practice for crop production in salt-affected regions. Seedlings of S. bigelovii were inoculated and developed with plant growth promoting rhizobacteria (Klebsiella pnseumoniae) at different salinities (0 and 0.25 M NaCl) grown under in vitro conditions. The inoculation increased growth and physiological activity at a high salinity. The major benefits of inoculation were observed on total seedlings biomass (320 and 175 g at 0 and 0.25 M NaCl, respectively) and adjacent branches of stem biomass (150 and 85 g at 0 and 0.25 M NaCl, respectively). The inoculation with Klebsiella pneumoniae also significantly improved seedlings salinity tolerance compared to the noninoculated controls. In non-salinity conditions, the inoculated seedlings enhanced the CO2 fixation and O2 evolution. The non-inoculated controls were more sensitive to salinity than inoculated seedlings exposed to salinity, as indicated by several measured parameters. Moreover, inoculated seedlings had significantly increase on proline, phenolics content, but not significant in starch compared to noninoculated controls. In conclusion, K. pneumoniae inoculation mitigates the salinity effects and promotes the Salicornia growth.Keywords: Salicornia bigelovii, Klebsiella pneumoniae, halophyte, ecotype, stress salinity. African Journal of Biotechnology Vol. 12(34), pp. 5278-528
Behavior of market prices and analysis of volatility for peach (Prunus persica [L.] Batsch.) produced in Boyaca, Colombia
Páginas 48-62En la actualidad, se encuentran diferentes estudios de caducifolios, y en este caso de durazno en temas como
producción, cosecha, poscosecha, mercados. Sin embargo al desarrollar la formulación de los proyectos de
inversión, no se conoce el comportamiento del precio de la fruta en los últimos años, en los mercados más
representativos del país. Es así como se desarrolló esta investigación centrada en el análisis de los precios
de durazno en tres mercados de Colombia: (a) Central de Abastos de Bogotá, (b) Mayorista de Antioquia,
Medellín y (c) Reten sur de Tunja, con el objetivo de comprobar si durante el periodo 2006 al 2011, se ha
presentado estacionalidad y volatilidad en los precios de mercados, más aun cuando los pequeños productores
manifiestan que cada vez este agronegocio es menos rentable y al elaborar nuevos proyectos para invertir
en esta especie, se presenta la dificultad en la asignación de los precios de venta. Este aspecto incrementa el
riesgo en la toma de decisiones para los productores. El estudio inició desde el análisis de las generalidades de
la producción de caducifolios y del durazno, producto que se concentra principalmente en el departamento de
Boyacá, Colombia, en agroempresas de tipo minifundistas, de economía campesina. Continuó con la relación
de datos de precios por kg/mes, entre el año 2006 y 2011. En los tres mercados, la metodología utilizada fue
un análisis exploratorio de los precios por medio del Análisis Espectral Singular, utilizando el Método de Loess.
Además, se empleó la metodología de Box y Jenkins. Se logró determinar el comportamiento de tendencia y
estacionalidad en los precios del durazno. De otra parte, se identificó que el comportamiento estacional y de
tendencia no está presente en los mercados Corabastos de Bogotá y Central mayorista de Antioquia, si se
encontró estacionalidad en el mercado de Tunja Cabe resaltar que la volatilidad de los precios no se observó en los tres mercados estudiados, se determinó que el precio promedio actual de duraznos per kg en el mercado de Reten Sur Tunja es de 3.500 (USD 1,17) en los mercados de Bogotá y Medellín.ABSTRACT: At present, there are different studies on deciduous fruits, including the peach, for subjects such as production, harvest, postharvest, and markets. However, for developing the formulation of investment projects, the behavior of fruit prices in the most representative markets of the country are unknown for recent years. This research focused on the analysis of peach prices in three markets in Colombia: (a) Central de Abastos of Bogota, (b) Wholesaler of Antioquia, Medellín and (c) Reten Sur de Tunja, with the objective of verifying whether seasonality and volatility in market prices have occurred during the period 2006 to 2011, even more so when small producers report that agribusiness is becoming less profitable. When new projects are developed to invest in these species, difficulty in the allocation of sales prices is seen. This increases risk in decision making for producers. The study began with the analysis of the generalities of production of deciduous fruits and peaches, a product that is concentrated mainly in the department of Boyacá, Colombia, in agribusinesses of smallholders with a rural economy. It continued with the relation of data of prices per kg/month between the years 2006 and 2011. In the three markets, the methodology used an exploratory analysis of the prices by means of the Singular Spectral Analysis, along with the Loess Method
and the Box and Jenkins methodology. It was possible to determine the trend behavior and seasonality in the peach prices. On the other hand, it was observed that a seasonal and trend behavior was not present in the markets of Corabastos of Bogota or Central Wholesale of Antioquia, but seasonality was seen in the market of Tunja. It should be emphasized that the price volatility was not observed in the three markets; it was determined that the current average price per kg of peach fruits in the Reten Sur de Tunja market is 3,500 Colombian Pesos (USD 1.17) in the Bogotá and Medellin markets, respectivelyBibliografía: páginas 61-62.Artículo revisado por pares
Functional divergence in the role of N-linked glycosylation in smoothened signaling
The G protein-coupled receptor (GPCR) Smoothened (Smo) is the requisite signal transducer of the evolutionarily conserved Hedgehog (Hh) pathway. Although aspects of Smo signaling are conserved from Drosophila to vertebrates, significant differences have evolved. These include changes in its active sub-cellular localization, and the ability of vertebrate Smo to induce distinct G protein-dependent and independent signals in response to ligand. Whereas the canonical Smo signal to Gli transcriptional effectors occurs in a G protein-independent manner, its non-canonical signal employs Gαi. Whether vertebrate Smo can selectively bias its signal between these routes is not yet known. N-linked glycosylation is a post-translational modification that can influence GPCR trafficking, ligand responsiveness and signal output. Smo proteins in Drosophila and vertebrate systems harbor N-linked glycans, but their role in Smo signaling has not been established. Herein, we present a comprehensive analysis of Drosophila and murine Smo glycosylation that supports a functional divergence in the contribution of N-linked glycans to signaling. Of the seven predicted glycan acceptor sites in Drosophila Smo, one is essential. Loss of N-glycosylation at this site disrupted Smo trafficking and attenuated its signaling capability. In stark contrast, we found that all four predicted N-glycosylation sites on murine Smo were dispensable for proper trafficking, agonist binding and canonical signal induction. However, the under-glycosylated protein was compromised in its ability to induce a non-canonical signal through Gαi, providing for the first time evidence that Smo can bias its signal and that a post-translational modification can impact this process. As such, we postulate a profound shift in N-glycan function from affecting Smo ER exit in flies to influencing its signal output in mice
Inferring stabilizing mutations from protein phylogenies : application to influenza hemagglutinin
One selection pressure shaping sequence evolution is the requirement that a protein fold with sufficient stability to perform its biological functions. We present a conceptual framework that explains how this requirement causes the probability that a particular amino acid mutation is fixed during evolution to depend on its effect on protein stability. We mathematically formalize this framework to develop a Bayesian approach for inferring the stability effects of individual mutations from homologous protein sequences of known phylogeny. This approach is able to predict published experimentally measured mutational stability effects (ΔΔG values) with an accuracy that exceeds both a state-of-the-art physicochemical modeling program and the sequence-based consensus approach. As a further test, we use our phylogenetic inference approach to predict stabilizing mutations to influenza hemagglutinin. We introduce these mutations into a temperature-sensitive influenza virus with a defect in its hemagglutinin gene and experimentally demonstrate that some of the mutations allow the virus to grow at higher temperatures. Our work therefore describes a powerful new approach for predicting stabilizing mutations that can be successfully applied even to large, complex proteins such as hemagglutinin. This approach also makes a mathematical link between phylogenetics and experimentally measurable protein properties, potentially paving the way for more accurate analyses of molecular evolution
GHOST Commissioning Science Results II: a very metal-poor star witnessing the early Galactic assembly
This study focuses on Pristine (hereafter P180956,
[Fe/H] ), a star selected from the Pristine Inner Galaxy Survey
(PIGS), and followed-up with the recently commissioned Gemini High-resolution
Optical SpecTrograph (GHOST) at the Gemini South telescope. The GHOST
spectrograph's high efficiency in the blue spectral region (~\AA)
enables the detection of elemental tracers of early supernovae (e.g. Al, Mn,
Sr, Eu), which were not accessible in the previous analysis of P180956. The
star exhibits chemical signatures resembling those found in ultra-faint dwarf
systems, characterised by very low abundances of neutron-capture elements (Sr,
Ba, Eu), which are uncommon among stars of comparable metallicity in the Milky
Way. Our analysis suggests that P180956 bears the chemical imprints of a small
number (2 or 4) of low-mass hypernovae (\sim10-15\msun), which are needed to
reproduce the abundance pattern of the light-elements (e.g. [Si, Ti/Mg, Ca]
), and one fast-rotating intermediate-mass supernova (\sim300\kms,
\sim80-120\msun). Both types of supernovae explain the high [Sr/Ba] of
P180956 (). The small pericentric (\sim0.7\kpc) and apocentric
(\sim13\kpc) distances and its orbit confined to the plane (\lesssim
2\kpc), indicate that this star was likely accreted during the early Galactic
assembly phase. Its chemo-dynamical properties suggest that P180956 formed in a
system similar to an ultra-faint dwarf galaxy accreted either alone, as one of
the low-mass building blocks of the proto-Galaxy, or as a satellite of
Gaia-Sausage-Enceladus. The combination of Gemini's large aperture with GHOST's
high efficiency and broad spectral coverage makes this new spectrograph one of
the leading instruments for near-field cosmology investigations.Comment: Submitted to MNRAS. 8 figures, 15page
A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007
We present the results of the first search for gravitational wave bursts
associated with high energy neutrinos. Together, these messengers could reveal
new, hidden sources that are not observed by conventional photon astronomy,
particularly at high energy. Our search uses neutrinos detected by the
underwater neutrino telescope ANTARES in its 5 line configuration during the
period January - September 2007, which coincided with the fifth and first
science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed
for candidate gravitational-wave signals coincident in time and direction with
the neutrino events. No significant coincident events were observed. We place
limits on the density of joint high energy neutrino - gravitational wave
emission events in the local universe, and compare them with densities of
merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at
http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000
Ptc6 is required for proper rapamycin-induced down-regulation of the genes coding for ribosomal and rRNA processing proteins in S. cerevisiae
Ptc6 is one of the seven components (Ptc1-Ptc7) of the protein phosphatase 2C family in the yeast Saccharomyces cerevisiae. In contrast to other type 2C phosphatases, the cellular role of this isoform is poorly understood. We present here a comprehensive characterization of this gene product. Cells lacking Ptc6 are sensitive to zinc ions, and somewhat tolerant to cell-wall damaging agents and to Li+. Ptc6 mutants are sensitive to rapamycin, albeit to lesser extent than ptc1 cells. This phenotype is not rescued by overexpression of PTC1 and mutation of ptc6 does not reproduce the characteristic geneti
Reflexiones universitarias. San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos. Otoño 2015
Los trabajos que aquí se presentan se elaboraron por las y los estudiantes como parte de las actividades del Proyecto de Aplicación Profesional (PAP) “San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos”, durante el periodo de Otoño de 2015. A lo largo del periodo los autores compartieron sus reflexiones en torno a su percepción sobre el contexto en el que actúa el PAP; sobre las alternativas posibles a la problemática detectada y lo que significa pensar una alternativa; sobre los sujetos con los que se ha interactuado a lo largo de la experiencia de trabajo y sobre el papel del profesionista y del ciudadano en un mundo como el que nos tocó vivir. La obra está compuesta por reflexiones personales de las y los estudiantes que, explorando estas temáticas, comparten sus aprendizajes y observaciones de forma vívida.ITESO, A.C
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
- …