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1.
Wireless Personal Communications - The ongoing technological developments have totally transformed the lives of human beings. With the emergence of the smart era and the smart city concept, a few... 相似文献
2.
Short term regulation of hepatic cholesterol ester hydrolase by reversible phosphorylation is described. Two different kinase
systems seem to be involved in this regulation. The addition of ATP, cyclic AMP and Mg2+ to rat liver 104,000× g supernatant (S104) produced a 100–140% increase in cholesterol ester hydrolase activity. This stimulation
was abolished when protein kinase inhibitor was added prior to the addition of ATP, cyclic AMP and Mg2+. Cholesterol ester hydrolase activity was also stimulated when calcium ions, phosphatidylserine, and diolein were added to
S104 along with ATP and Mg2+. Diolein in this reaction could be substituted by phorbol 12-myristate 13-acetate. Preincubation of S104 with alkaline phosphatase
resulted in a deactivation of cholesterol ester hydrolase. The addition of increasing concentrations of Mg2+ to S104 produced increasing inhibition of cholesterol ester hydrolase activity, and this effect was blocked by NaF.
It is suggested that rat liver cholesterol ester hydrolase is activated by cyclic AMP dependent protein kinase and protein
kinase C. Deactivation is accomplished by dephosphorylation catalyzed by a phosphoprotein phosphatase, dependent on Mg2+.
This work was presented at the Twenty-Third Southeastern Regional Lipid Conference, held October 26–28, in Cashiers, North
Carolina. 相似文献
3.
G. Shobha M. Krishna S.C. Sharma 《软件学报》2006,17(8):1824-1836
1 Introduction Reliability in personal authentication is key to the security in any transactional database. Many physiological characteristics of humans i.e., biometrics, are typically time invariant, easy to acquire, and unique for every individual. Biom… 相似文献
4.
Development and analysis of a 12-year daily 1-km forest fire dataset across North America from NOAA/AVHRR data 总被引:1,自引:0,他引:1
Ruiliang Pu Zhanqing Li Peng Gong Robert Fraser Shobha Kondragunta 《Remote sensing of environment》2007,108(2):198-208
Fires in boreal and temperate forests play a significant role in the global carbon cycle. While forest fires in North America (NA) have been surveyed extensively by U.S. and Canadian forest services, most fire records are limited to seasonal statistics without information on temporal evolution and spatial expansion. Such dynamic information is crucial for modeling fire emissions. Using the daily Advanced Very High Resolution Radiometer (AVHRR) data archived from 1989 to 2000, an extensive and consistent fire product was developed across the entire NA forest regions on a daily basis at 1-km resolution. The product was generated following data calibration, geo-referencing, and the application of an active fire detection algorithm and a burned area mapping algorithm. The spatial-temporal variation of forest fire in NA is analyzed in terms of (1) annual and monthly patterns of fire occurrences in different eco-domains, (2) the influence of topographic factors (elevation zones, aspect classes, and slope classes), and (3) major forest types and eco-regions in NA. It was found that 1) among the 12 years analyzed, 1989 and 1995 were the most severe fire years in NA; 2) the majority of burning occurred during June-July and in low elevation zones (< 500 m) with gentle slopes (< 10°), except in the dry eco-domain where more fires occurred in higher elevation zones (> 2000 m); 3) most fires occurred in the polar eco-domain, sub-arctic eco-division, and in the taiga ( boreal forests), forest-tundras and open woodlands eco-provinces in the boreal forests of Canada. The tendency for multiple burns to occur increases with elevation and slope until about 2500 m elevation and 24° slope, and decreases therefore. In comparison with ground observations, the omission and commission errors are on the order of 20%. 相似文献
5.
While extensive research has been conducted on young people’s peer interaction via online communication, the focus has been on mainstream youths, with marginalized youth communities being understudied. To help address this inadequacy, the current study conducted interviews with Singaporean male juvenile delinquents (n = 36) to understand the role of online communication in their peer interactions and the salient characteristics of such interactions. Our findings show that Facebook was the principal tool of online peer interaction. However, given the particular circumstances of juvenile delinquents, online social networking presents issues that may compromise efforts to rehabilitate them. These include extending the time and opportunities for unstructured and unsupervised peer socialization, peer endorsement of delinquent acts and the pressure of having to display group loyalty in the online space. Even after rehabilitation, youths who attempt to distance themselves from their delinquent peers are challenged by the persistence of their online social networks. 相似文献
6.
This article examines the inclined magnetic field effect on the flow of micropolar nanofluids in a vertical channel with convective boundary conditions and heat source or sink. Thermodynamics second law is employed to analyze the aspects of entropy generation. The governing differential equations are modified into dimensionless form by using suitable nondimensional variables. These transformed equations are solved by implementing the differential transform technique. The results are analyzed graphically. Skin friction and Nusselt number values are evaluated at the boundary walls of the channel. The major findings of the study are material parameter enhances the microrotation but suppresses both velocity and temperature. Magnetic parameter and angle of the implication of magnetic field decrease the velocity and microrotation. Material parameter and angle of imposed magnetic field minimize the entropy generation. 相似文献
7.
Though red blood cells are essential to deliver oxygen to tissue, abnormally high levels can have deadly consequences. High hematocrit (Hct)—the percentage of total blood volume occupied by red blood cells (RBCs)—can occur in arterial flow due to a variety of causes. Examples include: dehydration, polycythemia vera, and exogenous use of recombinant human erythropoietin. In this phenomenological study, we present a simplified quantitative analysis of the physiological effects of increased hematocrit, especially for small arteries. In particular, we are primarily interested in the potential relation between the exogenous use of recombinant human erythropoietin by athletes (blood ‘doping’) and the not insignificant numbers of sudden heart attacks suffered by these otherwise superbly conditioned contestants. We proceed as follows: An expression for the variation of the viscosity of blood with both shear rate and hematocrit is obtained using the low and high shear experimental measurements of Chien and Çinar, respectively. This is done in a two-step process: (i) curve fits of shear rate dependent viscosity for hematocrits ranging from 40% to 80% are derived with resulting R-squared values greater than 0.99; (ii) viscosity is shown to be well-represented as an exponential function of shear rate for various hematocrit levels. The resulting relationship is used, in a simplified analysis, to calculate velocity profiles in a generic coronary artery as a non-linear function of viscosity for various hematocrit levels. Using these relationships, increasing hematocrit is shown to dramatically decrease and flatten velocity profiles in a small artery. The resulting velocity profiles of slower flow with greater area of low shear rate due to increased hematocrit makes likely a corresponding increased risk of thrombus formation. 相似文献
8.
Xerographic characteristics such as (i) maximum acceptance potential, (ii) quantum efficiency, (iii) reciprocity nature and (iv) dynamic law have been evaluated for a polymeric double layer system. The double layer consists of poly(9-vinyl anthracene) base on aluminium substrate, having an over-layer of 1.0μm poly(n-vinyl carbazole). It was found to have good xerographic properties and can be used effectively in xerography. 相似文献
9.
Polyphenols and tannins in Indian pulses: Effect of soaking,germination and pressure cooking 总被引:1,自引:0,他引:1
Shweta Khandelwal Shobha A. Udipi Padmini Ghugre 《Food research international (Ottawa, Ont.)》2010,43(2):526-530
Polyphenols and tannins have implications for health and nutrition. There is limited information on their content in pulses, raw or post-processing. We estimated the concentrations of polyphenols and tannins in different cultivars of four pulses commonly consumed in India – Phaseolus aureus, Cajanus cajan, Lens esculenta and Cicer arietinum – and examined the effects of domestic processing. Means and standard deviations were calculated and results were analyzed by ANOVA. There were significant differences (P < 0.001) in the polyphenol and tannin contents of cultivars of the same pulse, with the exception of the tannin contents of pressure-cooked red gram cultivars (P = 0.3103). Processing reduced the concentrations of polyphenols by 19–59% and of tannins by 22–59%. A trend was observed in the degree to which processing reduced polyphenol and tannin contents (germination > pressure-cooking > soaking). Soaking, germination and pressure-cooking proved to be effective household strategies to reduce the levels of polyphenols and tannins in pulse-based foods, thereby enhancing the bioavailability of pulse protein. There is a need to determine the extent to which the remaining polyphenols and tannins are rendered unavailable by these processing techniques. 相似文献
10.
Paciorek CJ Liu Y Moreno-Macias H Kondragunta S 《Environmental science & technology》2008,42(15):5800-5806
We analyze the strength of association between aerosol optical depth (AOD) retrievals from the GOES aerosol/smoke product (GASP) and ground-level fine particulate matter (PM2.5) to assess AOD as a proxy for PM2.5 in the United States. GASP AOD is retrieved from a geostationary platform, giving half-hourly observations every day, in contrast to once per day snapshots from polar-orbiting satellites. However, GASP AOD is based on a less-sophisticated instrument and retrieval algorithm. We find that daily correlations between GASP AOD and PM2.5 over time at fixed locations are reasonably high, except in the winter and in the western U.S. Correlations over space at fixed times are lower. Simple averaging to the month and year actually reduces correlations over space, but statistical calibration allows averaging over time that produces moderately strong correlations. These results and the data density of GASP AOD highlight its potential to help improve exposure estimates for epidemiological analyses. On average 39% of days in a month have a GASP AOD retrieval compared to 11% for MODIS and 5% for MISR. Furthermore, GASP AOD has been retrieved since November 1994, providing a long-term record that predates the availability of most PM2.5 monitoring data and other satellite instruments. 相似文献