399 research outputs found
Potential for macro and micronutrients extraction from tomato plants with different soil water stresses
Different tomato cultivars may present differentiated water needs, making it
indispensable to study water demand. Thus, the objective of this work was to evaluate the
influence of six water stresses in the soil on the extraction potential of macro and micronutrients
in the aerial part of tomato in vegetative stage, cultivar âDominadorâ F1, under protected
cultivation and drip. The experiment was installed in a greenhouse with a randomized block
design with four replications. The treatments consisted of six soil water stresses as indicative of
the time of irrigation. The preset stresses were 20, 45, 70, 95, 120 and 145 kPa at 20 cm depth.
At 140 days after transplanting, the variables evaluated were: the macro and micronutrient content
of shoots. The results showed that to obtain higher levels of macro (P and S) and micronutrients
(B and Cu) of the total aerial part of the âDominadorâ tomato plant F1, it was obtained at a voltage
of 20 kPa, and its value was reduced linearly with the increase of the water tension in the soil
Star Models with Dark Energy
We have constructed star models consisting of four parts: (i) a homogeneous
inner core with anisotropic pressure (ii) an infinitesimal thin shell
separating the core and the envelope; (iii) an envelope of inhomogeneous
density and isotropic pressure; (iv) an infinitesimal thin shell matching the
envelope boundary and the exterior Schwarzschild spacetime. We have analyzed
all the energy conditions for the core, envelope and the two thin shells. We
have found that, in order to have static solutions, at least one of the regions
must be constituted by dark energy. The results show that there is no physical
reason to have a superior limit for the mass of these objects but for the ratio
of mass and radius.Comment: 20 pages, 1 figure, references and some comments added, typos
corrected, in press GR
A Peer-reviewed Newspaper About_ Machine Research
About research on machines, research with machines, and research as a machine.
Publication resulting from research workshop at Brussels World Trade Center, organised in collaboration with Constant, Association for Arts and Media, Brussels, and transmediale festival for art and digital culture, Berlin
Coupled oscillators as models of phantom and scalar field cosmologies
We study a toy model for phantom cosmology recently introduced in the
literature and consisting of two oscillators, one of which carries negative
kinetic energy. The results are compared with the exact phase space picture
obtained for similar dynamical systems describing, respectively, a massive
canonical scalar field conformally coupled to the spacetime curvature, and a
conformally coupled massive phantom. Finally, the dynamical system describing
exactly a minimally coupled phantom is studied and compared with the toy model.Comment: 18 pages, LaTeX, to appear in Physical Review
Overexpression of KLC2 due to a homozygous deletion in the non-coding region causes SPOAN syndrome
SPOAN syndrome is a neurodegenerative disorder mainly characterized by spastic paraplegia, optic atrophy and neuropathy (SPOAN). Affected patients are wheelchair bound after 15 years old, with progressive joint contractures and spine deformities. SPOAN patients also have sub normal vision secondary to apparently non-progressive congenital optic atrophy. A potential causative gene was mapped at 11q13 ten years ago. Here we performed next-generation sequencing in SPOAN-derived samples. While whole-exome sequencing failed to identify the causative mutation, whole-genome sequencing allowed to detect a homozygous 216-bp deletion (chr11.hg19:g.66,024,557_66,024,773del) located at the non-coding upstream region of the KLC2 gene. Expression assays performed with patientâs fibroblasts and motor neurons derived from SPOAN patients showed KLC2 overexpression. Luciferase assay in constructs with 216-bp deletion confirmed the overexpression of gene reporter, varying from 48 to 74%, as compared with wild-type. Knockdown and overexpression of klc2 in Danio rerio revealed mild to severe curly-tail phenotype, which is suggestive of a neuromuscular disorder. Overexpression of a gene caused by a small deletion in the non-coding region is a novel mechanism, which to the best of our knowledge, was never reported before in a recessive condition. Although the molecular mechanism of KLC2 up-regulation still remains to be uncovered, such example adds to the importance of non-coding regions in human pathologyFil: Melo, Uira S.. Universidade de Sao Paulo; BrasilFil: Macedo Souza, Lucia I.. Universidade de Sao Paulo; BrasilFil: Figueiredo, Thalita. Federal University of Paraiba; Brasil. Paraiba State University; BrasilFil: Muotri, Alysson R. University of California at San Diego; Estados UnidosFil: Gleeson, Joseph G.. The Rockefeller University; Estados UnidosFil: Coux, Gabriela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: Armas, Pablo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: Calcaterra, Nora Beatriz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: Kitajima, JoĂŁo P.. Mendelics Genomic Analysis; BrasilFil: Amorim, Simone. Universidade de Sao Paulo; BrasilFil: OlĂĄvio, Thiago R.. Universidade de Sao Paulo; BrasilFil: Griesi Oliveira, Karina. Universidade de Sao Paulo; BrasilFil: Coatti, Giuliana C.. Universidade de Sao Paulo; BrasilFil: Rocha, Clarissa R.R. Universidade de Sao Paulo; BrasilFil: Martins Pinheiro, Marinalva. Universidade de Sao Paulo; BrasilFil: Menck, Carlos F.M.. Universidade de Sao Paulo; BrasilFil: Zaki, Maha S.. National Research Center. EL Cairo; EgiptoFil: Kok, Fernando. Universidade de Sao Paulo; BrasilFil: Zatz, Mayana. Universidade de Sao Paulo; BrasilFil: Santos, Silvana. Federal University of Paraiba; Brasil. Paraiba State University; Brasi
Vitamin E-analog Trolox prevents endoplasmic reticulum stress in frozen-thawed ovarian tissue of capuchin monkey (Sapajus apella)
Ovarian fragments were exposed to 0.5 M sucrose
and 1 M ethylene glycol (freezing solution; FS) with or
without selenium or Trolox. Histological and ultrastructural
analyses showed that the percentages of normal follicles in
control tissue and in tissue after exposure to FS+50 ÎŒM
Trolox were similar. Trolox prevented endoplasmic reticulum
(ER)-related vacuolization, which is commonly observed in
oocytes and stromal tissue after exposure to FS. From the evaluated stress markers, superoxide dismutase 1 (SOD1)
was up-regulated in ovarian tissue exposed to FS+10 ng/ml
selenium. Ovarian fragments were subsequently frozenthawed
in the presence of FS with or without 50 ÎŒM Trolox,
followed by in vitro culture (IVC). Antioxidant capacity in
ovarian fragments decreased after freeze-thawing in Troloxfree
FS compared with FS+50 ÎŒMTrolox. Although freezing
itself minimized the percentage of viable follicles in each solution, Trolox supplementation resulted in higher rates of
viable follicles (67 %), even after IVC (61 %). Furthermore,
stress markers SOD1 and ERp29 were up-regulated in ovarian
tissue frozen-thawed in Trolox-free medium. Relative mRNA
expression of growth factors markers was evaluated after
freeze-thawing followed by IVC. BMP4, BMP5, CTGF,
GDF9 and KL were down-regulated independently of the
presence of Trolox in FS but down-regulation was less pronounced
in the presence of Trolox. Thus, medium supplementation
with 50 ÎŒMTrolox prevents ER stress and, consequently,
protects ovarian tissue from ER-derived cytoplasmic
vacuolization. ERp29 but not ERp60, appears to be a key
marker linking stress caused by freezing-thawing and cell
vacuolization.http://link.springer.com/journal/441hb201
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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