1,054 research outputs found
Understanding the beliefs and intentions in search and purchase functions in an e-commerce web site
10.1109/TEM.2008.922641IEEE Transactions on Engineering Management561106-114IEEM
Modulation of Ca2+-dependent anion secretion by protein kinase C in normal and cystic fibrosis pancreatic duct cells
AbstractThe study investigated the role of protein kinase C (PKC) in the modulation of agonist-induced Ca2+-dependent anion secretion by pancreatic duct cells. The short-circuit current (ISC) technique was used to examine the effect of PKC activation and inhibition on subsequent ATP, angiotensin II and ionomycin-activated anion secretion by normal (CAPAN-1) and cystic fibrosis (CFPAC-1) pancreatic duct cells. The ISC responses induced by the Ca2+-mobilizing agents, which had been previously shown to be attributed to anion secretion, were enhanced in both CAPAN-1 and CFPAC-1 cells by PKC inhibitors, staurosporine, calphostin C or chelerythrine. On the contrary, a PKC activator, phorbol 12-myristate 13-acetate (PMA), was found to suppress the agonist-induced ISC in CFPAC-1 cells and the ionomycin-induced ISC in CAPAN-1 cells. An inactive form of PMA, 4αd-phorbol 12,13-didecanote (4αD), was found to exert insignificant effect on the agonist-induced ISC, indicating a specific effect of PMA. Our data suggest a role of PKC in modulating agonist-induced Ca2+-dependent anion secretion by pancreatic duct cells. Therapeutic strategy to augment Ca2+-activated anion secretion by cystic fibrosis pancreatic duct cells may be achieved by inhibition or down-regulation of PKC
Influence of Al doping on random lasing in ZnO nanorods
Random lasing was demonstrated from aluminum doped ZnO nanorods fabricated on ITO coated glass substrates using simple chemical deposition technique. Different
Aluminum (Al) doping parameters were explored in an attempt to realize low threshold ZnO random lasers. Results confirm threshold was strongly dependent
on doping concentration and suggestive of resonant coupling with Al in lowering the threshold by 2 orders of magnitude when compared to undoped ZnO nanorods.
Lowest threshold was obtained from ZnO nanorods doped with 10 mM of aluminum, suggesting best doping concentration for ZnO random lasers formed by nanorod
array. Results further indicate possibility of controlling random lasing properties by adjusting the doping concentration
Characterizing Scales of Genetic Recombination and Antibiotic Resistance in Pathogenic Bacteria Using Topological Data Analysis
Pathogenic bacteria present a large disease burden on human health. Control
of these pathogens is hampered by rampant lateral gene transfer, whereby
pathogenic strains may acquire genes conferring resistance to common
antibiotics. Here we introduce tools from topological data analysis to
characterize the frequency and scale of lateral gene transfer in bacteria,
focusing on a set of pathogens of significant public health relevance. As a
case study, we examine the spread of antibiotic resistance in Staphylococcus
aureus. Finally, we consider the possible role of the human microbiome as a
reservoir for antibiotic resistance genes.Comment: 12 pages, 6 figures. To appear in AMT 2014 Special Session on
Advanced Methods of Interactive Data Mining for Personalized Medicin
CLUTCH SIZE AND INCUBATION TEMPERATURES OF GREEN TURTLE EGGS
Southeast Asia Sea Turtle Associative ResearchBangkok, Thailand, 16-19 December 2002Since clutch size of sea turtle eggs, through metabolic heating, can affect incubation temperatures, a study was conducted on Redang Island, Malaysia to look into the magnitude of this effect and its possible influence on sex determination of hatchlings. Miniature self-recording temperature loggers were used to monitor the incubation temperatures of relocated green turtle nests with 0, 5, 25, 50, 75, and 100 eggs at 60cm depth. Incubation temperatures were not constant but changed depending on weather, season, period of incubation and clutch size. The differential effects of metabolic heating on nest temperature due to clutch size only became evident after the first-third of incubation. These effects increase as the incubation progresses until hatching. Metabolic heating effects were greater in larger clutches compared to smaller clutch sizes. Incubation temperature reached its maximum after approximately 45 days of incubation. Clutch size can have a significant impact on incubation temperature through metabolic heating but may not necessarily influence significantly the sex ratio output of hatchlings
Study of self-alignment of μBGA packages
In this paper, a detailed study of the self-alignment
of BGA packages is presented. Complete self-alignment can be
achieved even for a misalignment of the package of larger than
50% off the test board pad centres. A small residual displacement
of the package from perfect alignment after reflow is observed.
The reason for this displacement is the action of gas flow viscous
drag on the package during reflow. The use of eutectic SnPb solder
paste slightly reduces self-aligning ability, due to the increase in
the solder volume, which reduces the restoring force. Exposure of
the solder paste to a 25 C and 85% RH humidity environment
also has a detrimental effect on the self-alignment of the BGA
package, due to solvent evaporation and moisture absorption in
the paste causing solderability degradation. The self-alignment of
the package is also affected when there is slow spreading of molten
solder on the pad surface. This is attributed to the reduction of
restoring force due to the decrease in effective wetting surface area
of the board pad
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