1,822 research outputs found
IP3 production in the hypersensitive response of lemon seedlings against Alternaria alternata involves active protein tyrosine kinases but not a G-protein
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000100011&lng=es&nrm=isoIP3 increase and de novo synthesis of scoparone are produced in the hypersensitive response (HR) of lemon seedlings against the fungus Alternaria alternata. To elucidate whether a G-protein and/or a protein tyrosine kinase (PTK) are involved in signal transduction leading to the production of such a defensive response, we studied the HR in this plant system after treatment with G-protein activators alone and PTK inhibitors in the presence of fungal conidia. No changes in the level of IP3 were detected in response to the treatment with the G-protein activators cholera toxin or mastoparan, although the HR was observed in response to these compounds as determined by the scoparone synthesis. On the contrary, the PTK inhibitors lavendustin A and 2,5-dihidroxy methyl cinnamate (DHMC) not only prevented the IP3 changes observed in response to the fungal inoculation of lemon seedlings but also blocked the development of the HR. These results suggest that the IP3 changes observed in response to A. alternata require a PTK activity and are the result of a G-protein independent Phospholipase C activity, even though the activation of a G-protein can also lead to the development of a HR. Therefore, it appears that more than one signaling pathway may be activated for the development of HR in lemon seedlings: one involving a G-protein and the other involving a PTK-dependent PLC
Occupational Health and Safety Prevention Plan in Water Treatment Plant
The research was carried out at the "El Guarumo" drinking water plant located in Santa Ana, province of Manabí, Ecuador. The objective of the investigation was the proposal of a plan of prevention of occupational risks that allows the management of the labor risks in said plant. The main tools used were: survey, interview, checklist, LEST questionnaire for the diagnosis of the current situation in terms of working conditions, the risk identification matrix and the binary method of risk assessment. The main results obtained were the identification of the risks in their different categories, observing that the critical risk factors are related to the physical overexertion, the uncomfortable postures and the manual lifting of the load. Among the important risks are falling objects, skin contact with toxic substances and mental overwork, closely related to work pressures and job security? It was possible to carry out the proposal of preventive and corrective measures in order to properly manage the risks and contribute to the safety and health of the workers
Aporte al conocimiento de la conectividad del manglar de Las Lisas-La Barrona, Guatemala
El presente estudio es una primera aproximación al conocimiento de la conectividad del ecosistema manglar de Las Lisas-La Barrona, departamentos de Santa Rosa y Jutiapa. La conectividad es la característica del paisaje que facilita la dispersión de las especies a través del hábitat, la pérdida de esta conectividad, podría poner en peligro la sobrevivencia de las poblaciones de aves. El objetivo de este estudio fue determinar la conectividad del manglar a través de análisis basados en las teorías de grafos y circuitos. Se incluyó en el análisis la conectividad en sus componentes estructural y funcional. El componente estructural se determinó mediante el Análisis del Patrón Espacial Morfológico (MSPA por sus siglas en inglés). El componente funcional fue evaluado con el Diferencial del êndice Integral de Conectividad (dIIC), evaluando el aporte de cada parche a la conectividad del manglar. Se encontró que la conectividad del área está determinada por parches nœcleo con alto aporte a la conectividad como los parches de vegetación de mangle de La Barrona y El Jiote, parche puente o corredor como el canal de Chiquimulilla y un cuello de botella en el segmento Las Lisas-El ahumado, los cuales son elementos estratégicos a considerar en la planificación e intervenciones futuras en el área
Una estética de la vivienda de interés social: desarrollos progresivos en Palmira, Colombia (2000-2017)
This case study explores the progressive development of social housing projects in the city of Palmira (Colombia) between 2000 and 2017. Here particular attention is paid to aesthetic parameters through three main concepts: perception, form and function. The methodological approach brought together four qualitative tools for data gathering and analysis: document review, field observations (field diaries, notes and photographic record); interviews (with users representatives of constructors and public servants), and; the development of urban profiles. The findings suggest that social housing units constitute an unfinished project, that, shaped by the subjectivity of their inhabitants’, generates conflict with public spaces. Despite their diversity, the interventions follow identifiable patterns, commonly linked to inadequacies in the original designs.Este estudio de caso explora los desarrollos progresivos de la vivienda de interés social (VIS) en la ciudad de Palmira (Colombia) entre los años 2000 y 2017, prestando particular atención a su dimensión estética, a partir de tres ejes fundamentales: percepción, forma y función. La aproximación metodológica agrupó cuatro herramientas cualitativas de recolección y análisis de datos: revisión documental, observación in situ (diarios de campo, levantamientos y registro fotográfico), entrevistas (a usuarios, representantes de constructoras y servidores públicos) y desarrollo de perfiles urbanos. Los hallazgos sugieren que la VIS constituye un proyecto inacabado, que, determinado por la subjetividad de los habitantes, genera relaciones conflictivas con el espacio público. Pesa a su diversidad, las intervenciones siguen patrones asociados a la solución de carencias en los diseños originales
Multicenter study of plastic vs. self-expanding metal stents in endoscopic ultrasound-guided drainage of walled-off pancreatic necrosis - PROMETHEUS: a randomized controlled trial protocol.
Background: It seems that lumen-apposing metal stents (LAMS) are displacing plastic stents in the therapy of pancreatic-fluid collection in walled-off necrosis (WON). To date, there is no quality of evidence to recommend LAMS as the standard treatment in the management of WON. The theoretical benefit of LAMS over plastic stents needs to be proven. Methods/design: This is a randomized controlled, multicenter, prospective clinical trial with two parallel groups, without masking. One-hundred and fourteen patients with WON will undergo endoscopic ultrasound (EUS)-guided transmural draining in nine tertiary hospitals in Spain and will be randomized to the LAMS or plastic-stent group. The primary endpoint is the short-term (4 weeks) clinical success determined by the reduction of the collection (to < 50% or < 5 cm in size), along with clinical improvement. Secondary endpoints: long-term (4 months) clinical success (total resolution or 5 cm), procedure duration, level of difficulty, safety, and recurrences. Discussion: The PROMETHEUS trial has been designed to determine whether LAMS are superior to plastic stents in EUS-guided transmural drainage of WON
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at , 2.76 and 7 TeV
Measurements of the sphericity of primary charged particles in minimum bias
proton--proton collisions at , 2.76 and 7 TeV with the ALICE
detector at the LHC are presented. The observable is linearized to be collinear
safe and is measured in the plane perpendicular to the beam direction using
primary charged tracks with GeV/c in . The
mean sphericity as a function of the charged particle multiplicity at
mid-rapidity () is reported for events with different
scales ("soft" and "hard") defined by the transverse momentum of the leading
particle. In addition, the mean charged particle transverse momentum versus
multiplicity is presented for the different event classes, and the sphericity
distributions in bins of multiplicity are presented. The data are compared with
calculations of standard Monte Carlo event generators. The transverse
sphericity is found to grow with multiplicity at all collision energies, with a
steeper rise at low , whereas the event generators show the
opposite tendency. The combined study of the sphericity and the mean with multiplicity indicates that most of the tested event generators
produce events with higher multiplicity by generating more back-to-back jets
resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with
tune PERUGIA-2011 exhibits a noticeable improvement in describing the data,
compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16,
published version, figures from
http://aliceinfo.cern.ch/ArtSubmission/node/308
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
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Measurement of charm production at central rapidity in proton-proton collisions at TeV
The -differential production cross sections of the prompt (B
feed-down subtracted) charmed mesons D, D, and D in the rapidity
range , and for transverse momentum GeV/, were
measured in proton-proton collisions at TeV with the ALICE
detector at the Large Hadron Collider. The analysis exploited the hadronic
decays DK, DK, DD, and their charge conjugates, and was performed on a
nb event sample collected in 2011 with a
minimum-bias trigger. The total charm production cross section at TeV and at 7 TeV was evaluated by extrapolating to the full phase space
the -differential production cross sections at TeV
and our previous measurements at TeV. The results were compared
to existing measurements and to perturbative-QCD calculations. The fraction of
cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/307
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