152 research outputs found
A concentration phenomenon for semilinear elliptic equations
For a domain \Omega\subset\dR^N we consider the equation -\Delta u +
V(x)u = Q_n(x)\abs{u}^{p-2}u with zero Dirichlet boundary conditions and
. Here and are bounded functions that are positive
in a region contained in and negative outside, and such that the sets
shrink to a point as . We show that if
is a nontrivial solution corresponding to , then the sequence
concentrates at with respect to the and certain
-norms. We also show that if the sets shrink to two points and
are ground state solutions, then they concentrate at one of these points
Greenhouse microclimate real-time monitoring based on wireless sensor network and gis
Trabalho apresentado em XX IMEKO World Congress Metrology for Green Growth, 9-14 setembro de 2012, Busan, Coreia do SulThe usage of greenhouse with controlled
microclimate represents an important way to increase the
production of fruits and vegetables considering the plants
needs and has recently become one of the hottest topics in
precision agriculture. In order to know and to control the
greenhouse microclimate smart sensing nodes with wireless
communication capabilities represents the solution. As one
of promissory protocol associated with wireless sensor
network can be mentioned the ZigBee due to its low cost,
low power consumption, extended ranges and architecture
flexibility. In the present work a sensing and control sensing
nodes with ZigBee communication capabilities are
considered, while the microclimate is monitored using a set
of solid state sensors for temperature, relative humidity,
light intensity and CO2 concentration considering this
parameters with important role in plants growing. Every
sensor node uses energy from a solar cell through a battery
charger circuit considering also the powering of the sensing
and control node during the night periods. The data from
ZigBee network nodes are sent to Wireless-Ethernet
gateway connected to a computer that runs a LabVIEW
application that perform primary processing and web
geographic information system that provides information
about the greenhouse microclimate. Elements related power
harvesting for implemented wireless sensor network, as so
as a set of experimental results are included in the present
work.N/
Desempenho reprodutivo de vacas Nelore mantidas em pastagem nativa com suplementação na seca.
bitstream/item/131669/1/Comunicado-162-Desempenho-Reprodutivo-de-Vacas-Nelore.pd
Caracteristicas e criopreservação do semen de bovinos da raça pé-duro no Estado do Piaui.
bitstream/item/97566/1/PAND820001.pd
Bacterial cellulose as a support for the growth of retinal pigment epithelium
The feasibility of bacterial cellulose (BC) as a novel substrate for retinal pigment
epithelium (RPE) culture was evaluated. Thin (41.6 ± 2.2 m of average thickness) and heatdried BC substrates were surface modified via acetylation and polysaccharide adsorption, using chitosan and carboxymethyl cellulose. All substrates were characterized according to their surface chemistry, wettability, energy, topography and also regarding their permeability, dimensional stability, mechanical properties and endotoxin content. Then, their ability to promote RPE cell adhesion and proliferation in vitro was assessed. All surface-modified BC substrates presented similar permeation coefficients with solutes of up to 300 kDa. Acetylation of BC decreased its swelling and the amount of endotoxins. Surface modification of BC greatly enhanced the adhesion and proliferation of RPE cells. All samples showed similar stress-strain behavior; BC and acetylated BC showed the highest elastic modulus, but the latter exhibited a slightly smaller tensile strength and elongation at break as compared to pristine BC. Although similar proliferation rates were observed among the modified substrates, the acetylated ones showed higher initial cell adhesion. This difference may be mainly due to the moderately hydrophilic surface obtained after acetylation.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT, Portugal) for the financial support provided by the Research Grants SERH/BD/63578/2009, SFRH/BD/64901/2009, SFRH/BPD/64958/2009, and SFRH/BPD/63148/2009 for S.G., J.P., J.P.S., and V.S., respectively. The authors also acknowledge the Projects PEst-OE/EQB/LA0004/2013, PEst-OE/EQB/LA0023/2013, PTDC/BBB-BQB/2450/2012, and RECI/BBB-EBI/0179/2012 (Number: FCOMP-01-0124-FEDER-027462), cofunded by QREN, FEDER
Emerging Enteropathogenic Escherichia coli Strains?
Escherichia coli strains of nonenteropathogenic serogroups carrying eae but lacking the enteropathogenic E. coli adherence factor plasmid and Shiga toxin DNA probe sequences were isolated from patients (children, adults, and AIDS patients) with and without diarrhea in Brazil. Although diverse in phenotype and genotype, some strains are potentially diarrheagenic
High stretch induces endothelial dysfunction accompanied by oxidative stress and actin remodeling in human saphenous vein endothelial cells
The rate of the remodeling of the arterialized saphenous vein conduit limits the outcomes of coronary artery bypass graft surgery (CABG), which may be influenced by endothelial dysfunction. We tested the hypothesis that high stretch (HS) induces human saphenous vein endothelial cell (hSVEC) dysfunction and examined candidate underlying mechanisms. Our results showed that in vitro HS reduces NO bioavailability, increases inflammatory adhesion molecule expression (E-selectin and VCAM1) and THP-1 cell adhesion. HS decreases F-actin in hSVECs, but not in human arterial endothelial cells, and is accompanied by G-actin and cofilin’s nuclear shuttling and increased reactive oxidative species (ROS). Pre-treatment with the broad-acting antioxidant N-acetylcysteine (NAC) supported this observation and diminished stretch-induced actin remodeling and inflammatory adhesive molecule expression. Altogether, we provide evidence that increased oxidative stress and actin cytoskeleton remodeling play a role in HS-induced saphenous vein endothelial cell dysfunction, which may contribute to predisposing saphenous vein graft to failure
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