1,171 research outputs found
Behavior of a Model Dynamical System with Applications to Weak Turbulence
We experimentally explore solutions to a model Hamiltonian dynamical system
derived in Colliander et al., 2012, to study frequency cascades in the cubic
defocusing nonlinear Schr\"odinger equation on the torus. Our results include a
statistical analysis of the evolution of data with localized amplitudes and
random phases, which supports the conjecture that energy cascades are a generic
phenomenon. We also identify stationary solutions, periodic solutions in an
associated problem and find experimental evidence of hyperbolic behavior. Many
of our results rely upon reframing the dynamical system using a hydrodynamic
formulation.Comment: 22 pages, 14 figure
Inhalation of growth factors and apo-transferrin to protect and repair the hypoxic-ischemic brain
Hypoxic-ischemic brain damage is a major contributor to chronic neurological dysfunction and acute mortality in infants as well as in adults. In this review, we summarize recent publications demonstrating that the intranasal administration (INA) of apo-transferrin (aTf) and different growth factors provides neuroprotection to the mouse and rat brain after a hypoxic-ischemic event. The intranasal delivery of growth factors such as insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) has been found to improve neurological function and reduce infarct size in adult rats after a hypoxic-ischemic event. On the other hand, INA of aTf and epidermal growth factor (EGF) were effective in reducing white matter damage and inflammation and in promoting the proliferation and survival of oligodendroglial progenitor cells (OPCs) in a model of hypoxic-ischemic encephalopathy. Therefore, data summarized in this review suggest that INA of growth factors and aTf can be used in combination in clinical treatment in order to protect and repair the hypoxic-ischemic brain.Fil: Guardia Clausi, Mariano. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; Argentina. Rutgers-New Jersey Medical School; Estados UnidosFil: Paez, P. M.. State University of New York; Estados UnidosFil: Pasquini, Laura Andrea. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Pasquini, Juana Maria. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentin
Production management model through MPS and line balancing to reduce the non-fulfillment of orders in lingerie clothing MSEs in Peru
The focus of this research is to establish control and planning management in the sewing production process of lingerie clothing to better prepare companies for demand growth. The lack of improvement tools in this sector, the lack of staff training and a lack of quality culture has led to companies, especially MYPES, not being able to meet the established delivery times and non-fulfillment of orders with the customers, which represents 80% of dissatisfied orders due to the limited production capacity and non-productive time in the plant. This problem is due to limited production capacity, deficient production planning, and lack of materials. In order to solve this problem, industrial engineering tools were used. The application of these tools improved production from 79% to 95%
Surfactant effects in monodisperse magnetite nanoparticles of controlled size
Monodisperse magnetite Fe3O4 nanoparticles of controlled size within 6 and 20
nm in diameter were synthesized by thermal decomposition of an iron organic
precursor in an organic medium. Particles were coated with oleic acid. For all
samples studied, saturation magnetization Ms reaches the expected value for
bulk magnetite, in contrast to results in small particle systems for which Ms
is usually much smaller due to surface spin disorder. The coercive field for
the 6 nm particles is also similar to that of bulk magnetite. Both results
suggest that the oleic acid molecules covalently bonded to the nanoparticle
surface yield a strong reduction in the surface spin disorder. However,
although the saturated state may be similar, the approach to saturation is
different and, in particular, the high-field differential susceptibility is one
order of magnitude larger than in bulk materials. The relevance of these
results in biomedical applications is discussed.Comment: 3 pages, 3 figures. Presented at JEMS 2006 (San Sebastian, Spain).
Submitted to JMM
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A research-informed dialogic-teaching approach to early secondary school mathematics and science: the pedagogical design and field trial of the epiSTEMe intervention
The project undertook pedagogical research aimed at improving pupil engagement and learning in early secondary school physical science and mathematics. Using principles identified as effective in the research literature and drawing on a range of existing pedagogical resources, the project designed and trialled a classroom intervention, with associated professional development, in a form intended to be suited to implementation at scale. The most distinctive feature of the pedagogical approach is its inclusion of a component of dialogic teaching. Aimed at the first year of secondary education in English schools (covering ages 11â12), the intervention consists of a short introductory module designed to prepare classes for this dialogic teaching component, and topic modules which employ the pedagogical approach to cover two curricular topics in each of science and mathematics. A field trial was conducted over the 2010/2011 school year in 25 volunteer schools, randomly assigned to intervention and control groups. Within the intervention group, observation of lessons indicated that the level of dialogic teaching was higher for one of the topic modules than others. Evaluation focused on the effectiveness of the topic modules, each trialled in more than 10 classes containing a total of over 300 pupils, and compared with a group of similar composition. Overall, at this first implementation, learning gains under the intervention were no greater, although for individual topic modules the effects ranged from small negative to small positive. No difference was found between intervention and control groups either in the opinion of pupils about their classroom experience or in changes in their attitude towards subjects.Thanks are due to the Economic and Social Research Council which provided funding for the epiSTEMe project (RES-179-25-0003), to the teachers who generously volunteered to review, pilot and trial versions of the modules, to Christine Howe for her contribution to design and analysis, and to Andy Tolmie and Anna Vignoles for statistical advice.This is the final version of the article. It first appeared from Taylor & Francis via https://doi.org/10.1080/02671522.2015.112964
Plasma membrane redox system in the erythrocytes of rowers: Pilot study
The oxidative stress results from a change in the
physiological balance between oxidant and antioxidant
species. This type of stress is a chemical
change in the redox state of cells.
The increased production of reactive species is
related to an excessive metabolic activation, for
example, from an intense physical exercise or an
excessive caloric intake (1). In physiological conditions,
muscle fibers are provided with an antioxidant
system able to keep under control the excessive
production of Reactive Oxygen Species
(ROS)
Evaluation of a Multicommuted Flow System for Photometric Environmental Measurements
A portable flow analysis instrument is described for in situ
photometric measurements. This system is based on light-emitting
diodes (LEDs) and a photodiode detector, coupled to a multipumping
flow system. The whole equipment presents dimensions of 25 âcm Ă 22 âcm Ă
10 âcm, weighs circa 3 kg,
and costs 650 âŹ. System performance was evaluated for
different chemistries without changing hardware configuration for
determinations of (i) Fe3+ with SCN-, (ii)
iodometric nitrite determination, (iii) phenol with sodium
nitroprusside, and (iv) 1-naphthol-N-methylcarbamate
(carbaryl) with p-aminophenol. The detection limits were
estimated as 22, 60, 25, and 60 ng mL -1 for iron,
nitrite, phenol, and carbaryl at the 99.7% confidence level with
RSD of 2.3, 1.0, 1.8, and 0.8%, respectively. Reagent and waste
volumes were lower than those obtained by flow systems with
continuous reagent addition. Sampling rates of 100, 110, 65, and
72 determinations per hour were achieved for iron, nitrite,
phenol, and carbaryl determination
The draft genome of Andean Rhodopseudomonas sp. strain AZUL predicts genome plasticity and adaptation to chemical homeostasis
The genus Rhodopseudomonas comprises purple non-sulfur bacteria with extremely versatile metabolisms. Characterization of several strains revealed that each is a distinct ecotype highly adapted to its specific micro-habitat. Here we present the sequencing, genomic comparison and functional annotation of AZUL, a Rhodopseudomonas strain isolated from a high altitude Andean lagoon dominated by extreme conditions and fluctuating levels of chemicals. Average nucleotide identity (ANI) analysis of 39 strains of this genus showed that the genome of AZUL is 96.2% identical to that of strain AAP120, which suggests that they belong to the same species. ANI values also show clear separation at the species level with the rest of the strains, being more closely related to R. palustris. Pangenomic analyses revealed that the genus Rhodopseudomonas has an open pangenome and that its core genome represents roughly 5 to 12% of the total gene repertoire of the genus. Functional annotation showed that AZUL has genes that participate in conferring genome plasticity and that, in addition to sharing the basal metabolic complexity of the genus, it is also specialized in metal and multidrug resistance and in responding to nutrient limitation. Our results also indicate that AZUL might have evolved to use some of the mechanisms involved in resistance as redox reactions for bioenergetic purposes. Most of those features are shared with strain AAP120, and mainly involve the presence of additional orthologs responsible for the mentioned processes. Altogether, our results suggest that AZUL, one of the few bacteria from its habitat with a sequenced genome, is highly adapted to the extreme and changing conditions that constitute its niche.Fil: Guardia, Aisha E. IngenierĂa de Interfases y Bioprocesos. Instituto de TecnologĂa de Materiales (INTEMA-CONICET-UNMdP); Argentina.Fil: Busalmen, Juan P. IngenierĂa de Interfases y Bioprocesos. Instituto de TecnologĂa de Materiales (INTEMA-CONICET-UNMdP); Argentina.Fil: Wagner, AgustĂn. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina.Fil: Di Capua, Cecilia Beatriz. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario (IBR-CONICET-UNR); Argentina.Fil: Cortez, NĂ©stor. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario (IBR-CONICET-UNR); Argentina.Fil: Beligni, MarĂa V. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones BiolĂłgicas (IIB-CONICET-UNMdP); Argentina
Diversidad de polen de Pinus aerovagante y patrón anual de su polinización en España
The authors wish to thank to different projects and entities for financing this study: COST ES0603 EUPOL; Laboratorios LETI S.A.; Proyecto EOLO-PAT; European Commission for «ENV4-CT98-0755»; Spanish Ministry of Science and Technology I+D+I for «AMB97-0457-CO7-021», «REN2001-10659-CO3-01», «BOS2002-03474», «CGL2004-21166-E», «CGL2005-07543/CLI», «CGL2009-11205» and CONSOLIDER CSD2007_00067 GRACCIE; Andalusian Government for «RNM-5058»; and Catalan Government AGAUR for «2002SGR00059», «2005SGR00519» and «2009SGR1102»
Cardiovascular and Gastrointestinal Safety of NSAIDs: a Systematic Review of Meta-Analyses of Randomized Clinical Trials.
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