436 research outputs found
Phenological and physiological responses to drought stress and subsequent rehydration cycles in two raspberry cultivars
AbstractRaspberry (Rubus idaeus L.) is a deciduous plant with perennial roots, 75% of which are concentrated in the upper level of the soil. Its shallow rooting system requires a regular water supply; a water deficit can affect fructification as well as cane growth and yield for the following season. Despite the demonstrated drought stress impact on the raspberry, there is little information about the phenological and physiological responses to drought stress. The main goal of this study was to evaluate the effects of drought stress on the phenological phases, physiological parameters and yield of two raspberry cultivars: Heritage (remontant type) and Meeker (non-remontant type). All plants were grown in pots under greenhouse conditions, and the following watering treatments were applied: (T1) well-watered, 100% irrigation and (T2) a controlled drought-stress cycle. The volumetric soil water content (θ), phenological phases, leaf net photosynthetic rate (A), transpiration rate (T), and stomatal conductance (gs) were registered periodically. The free proline and total soluble sugars were also determined. Based on the phenological study, Heritage under drought-stress (T2) showed earlier flowering and a shorter fruit production period in relation to well-watered plants (T1). In Meeker, T2 extended the cane and summer lateral elongation, showing earlier senescence. Leaf gas exchange decreased with drought stress, A declined after 28-day period under drought stress, from 9.2μmolCO2m−2s−1 to 3.0μmolCO2m−2s−1 in Heritage, and from 12.2μmolCO2m−2s−1 to 3.0μmolCO2m−2s−1 in Meeker. In both cultivars, the free proline and total soluble sugars increased with drought stress. The fruit production was also affected in the next season under T2 condition, decreasing in 34 and 38% in relation to well-watered plants
Changes in Number and Weight of Wheat and Triticale Grains to Manipulation in Source-Sink Relationship
The source-sink ratio experimental manipulation has helped to define whether a crop is limited by source or sink or co-limited by both. There is no evidence in triticale of source-sink manipulations effects on yield and yield components. Two experiments were accomplished during 2008 and 2009 growing seasons at the Universidad Autónoma del Estado de México, México, and one in 2010 at the National Institute of Agricultural Technology in Pergamino, Argentina. Two triticale cultivars (line 4 and 7) and one wheat cultivar (Tollocan) were used. Source-sink relations were modified at anthesis by thinning, degraining, shading, and total defoliation procedures. Changes in the source-sink relation affected yields in both species differentially. The changes in yield due to cultivars and treatments were explained mainly by the number of grains rather than by their individual grain weight. The number of grains was affected by all treatments in both species, while the individual grain weight was increased by thinning and degraining mainly in triticale. A greater number of fertile florets in triticale were associated with their higher rate of abortion compared to wheat. These results could help to better understand crop management and genetic improvement.Fil: Ballesteros Rodriguez, E.. Universidad Nacional Autónoma de México; MéxicoFil: Martinez Rueda, C.G.. Universidad Nacional Autónoma de México; MéxicoFil: Morales Rosales, E.J.. Universidad Nacional Autónoma de México; MéxicoFil: Estrada Campuzano, G.. Universidad Nacional Autónoma de México; MéxicoFil: González, Fernanda Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Pergamino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Chemical composition, nutritional value, and biological evaluation of tunisian okra pods (abelmoschus esculentus L. moench)
The aim of this work was to perform an unprecedented in-depth study on the bioactive phytochemicals of Abelmoschus esculentus L. Moench Tunisian landrace (Marsaouia). For this purpose, its nutritional, aroma volatile, and phenolic profiles were characterized, and sundry biological activities were assessed in vitro. The approximate composition revealed that total dietary fiber as the most abundant macronutrient, mainly insoluble dietary fiber, followed by total carbohydrates and proteins. In addition, okra pods were rich in K, Ca, Mg, organic acids, tocopherols, and chlorophylls. Gas Chromatography-Electron Impact Mass Spectrometry (GC-EIMS) analysis showed that oxygenated monoterpenes, sesquiterpene hydrocarbons, and phenylpropanoids were the predominant essential volatile components in A. esculentus pods. A total of eight flavonols were detected by High-Performance Liquid Chromatography coupled to a DAD detector and mass spectrometry by electrospray ionization (HPLC-DAD-MS/ESI); with quercetin-3-O-glucoside being the majority phenolic component, followed by quercetin-O-pentosyl-hexoside and quercetin-dihexoside. This pioneering study, evidences that Tunisian okra display promising antioxidant and cytotoxic actions, in addition to relevant inhibitory effects against α-amylase and α-glucosidase enzymes, and interesting analgesic activity.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial
support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); National funding by FCT, P.I., through
the institutional scientific employment program-contract for L. Barros and M.I. Dias contract; to FEDER-Interreg
España-Portugal programme for financial support through the project 0377_Iberphenol_6_E. and to ALIMNOVA
UCM Research group (Reference 951505) and OTRI UCM-F Sabor y Salud (252-2017) project. R.C.G. Corrêa is a
research grant recipient of Cesumar Institute of Science Technology and Innovation (ICETI).info:eu-repo/semantics/publishedVersio
Evaluación y comparación de geopolimeros obtenidos de dos cenizas volantes mexicanas
Esta investigación se realizó con el fin de determinar las diferencias existentes en los geopolimeros obtenidos de dos tipos de cenizas volantes, las cuales fueron caracterizadas mediante FRX, DRX, FT-IT, del mismo modo se determinaron sus propiedades físicas por picnometría, adsorción de gases (método BET), DTP y MEB. El proceso de activación se llevó a cabo con NaOH 8M a 80°C por 3, 7, 14, 21, 28 y 90 días, realizando ensayos de compresión y módulo dinámico a los mismos, obteniendo una mejora en los resultados conforme aumenta el tiempo de curado, además se demostró que la variación de los contenidos óxidos y las propiedades físicas de las cenizas de partida, juegan uno de los factores más importantes en el desarrollo de los geles producto de reacción (determinado por TGA, FT-IR, DRX y MEB) y por ello la obtención de mejores propiedades mecánicas. (ANGLÈS) This research was conducted in order to determine the differences in the geopolymer obtained from two types of fly ash, which were characterized by XRF, XRD, FT-IR, just as its physical properties were determined by pycnometry, gas adsorption (BET method), PSD and SEM. The activation process was conducted with NaOH 8M at 80°C for 3, 7, 14, 21, 28 and 90 days, to performing compression tests and dynamic module, obtaining a improved results with increasing cure time, also it showed that the variation of oxide content and the physical properties of the starting ash, play one of the most important factors in the development of the reaction product gels (determined by TGA, FT-IR, XRD and SEM) and thus obtaining better mechanical properties.Postprint (published version
Product-Group Unification in Type IIB String Thoery
The product-group unification is a model of unified theories, in which
masslessness of the two Higgs doublets and absence of dimension-five proton
decay are guaranteed by a symmetry. It is based on SU(5) x U(N) (N=2,3) gauge
group. It is known that various features of the model are explained naturally,
when it is embedded in a brane world. This article describes an idea of how to
accommodate all the particles of the model in Type IIB brane world. The
GUT-breaking sector is realized by a D3--D7 system, and chiral quarks and
leptons arise from intersection of D7-branes. The D-brane configuration can be
a geometric realization of the non-parallel family structure of quarks and
leptons, an idea proposed to explain the large mixing angles observed in the
neutrino oscillation. The tri-linear interaction of the next-to-minimal
supersymmetric standard model is obtained naturally in some cases.Comment: 33 pages, 5 figure
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at TeV
The elliptic, , triangular, , and quadrangular, , azimuthal
anisotropic flow coefficients are measured for unidentified charged particles,
pions and (anti-)protons in Pb-Pb collisions at TeV
with the ALICE detector at the Large Hadron Collider. Results obtained with the
event plane and four-particle cumulant methods are reported for the
pseudo-rapidity range at different collision centralities and as a
function of transverse momentum, , out to GeV/.
The observed non-zero elliptic and triangular flow depends only weakly on
transverse momentum for GeV/. The small dependence
of the difference between elliptic flow results obtained from the event plane
and four-particle cumulant methods suggests a common origin of flow
fluctuations up to GeV/. The magnitude of the (anti-)proton
elliptic and triangular flow is larger than that of pions out to at least
GeV/ indicating that the particle type dependence persists out
to high .Comment: 16 pages, 5 captioned figures, authors from page 11, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at TeV
The inclusive transverse momentum () distributions of primary
charged particles are measured in the pseudo-rapidity range as a
function of event centrality in Pb-Pb collisions at
TeV with ALICE at the LHC. The data are presented in the range
GeV/ for nine centrality intervals from 70-80% to 0-5%.
The Pb-Pb spectra are presented in terms of the nuclear modification factor
using a pp reference spectrum measured at the same collision
energy. We observe that the suppression of high- particles strongly
depends on event centrality. In central collisions (0-5%) the yield is most
suppressed with at -7 GeV/. Above
GeV/, there is a significant rise in the nuclear modification
factor, which reaches for GeV/. In
peripheral collisions (70-80%), the suppression is weaker with almost independently of . The measured nuclear
modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/284
Angle-resolved photoemission study of USb2: the 5f band structure
Single crystal antiferromagnetic USb2 was studied at 15K by angle-resolved
photoemission with an overall energy resolution of 24 meV. The measurements
unambiguously show the dispersion of extremely narrow bands situated near the
Fermi level. The peak at the Fermi level represents the narrowest feature
observed in 5f-electron photoemission to date. The natural linewidth of the
feature just below the Fermi level is not greater than 10 meV. Normal emission
data indicate a three dimensional aspect to the electronic structure of this
layered material.Comment: 22 pages including figure
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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