Kell and Kx are two quantitatively minor proteins from the human erythrocyte membrane which carry blood groups antigens and are thought to be a metalloprotease and a membrane transporter, respectively. In the red cell membrane, these proteins form a complex stabilized by disulfide bond(s). Phosphorylation status of these proteins was studied, in the presence or absence of effectors of several kinases, either on intact cells incubated with [32P]-orthophosphate or on ghosts incubated with [gamma-32P]ATP. Purification of Kell-Kx complex, by immunochromatography on an immobilized human monoclonal antibody of Kell blood group specificity allowed to establish that (i) neither protein is phosphorylated on tyrosine; (ii) the Kell protein is a putative substrate for Casein Kinase II (CKII) and Casein Kinase I (CKI) but not for protein kinase C (PKC), whereas Kx protein is phosphorylated by CKII and PKC but not by CKI; (iii) Protein Kinase A neither phosphorylates the Kell nor the Kx proteins. 相似文献
Software structure is the most important factor affecting the quality of a program.The evaluation of software structure is a foundational technique for software development.However,the traditional evaluation criteria,such as "high cohesion and low coupling",are no longer appropriate for the new web applications,which are designed with a hierarchical framework.A novel approach is proposed in this paper to evaluate software quality based on the interaction and encapsulation of methods.In particular,two criteria for high quality software,the functional and hierarchical structure,are proposed to support widely used web applications.The cohesion and coupling and layer matching ratios between methods within a software package are calculated to determine whether the package is well implemented in terms of functional or hierarchical structure.This approach enables us to quantify the quality of a software system according to the structural types of its packages.Experiments were carried out on 18 versions of Struts and six open-source software packages.Our evaluation concurs with the intuition that minor upgrades,aimed at fixing bugs and adding minor functionality quickly,reduce software quality,whereas major upgrades,which normally clean up messy code and re-construct the software,improve software quality. 相似文献
Recently many runoff models based on cellular automaton (CA) have been developed to simulate floods; however, the existing models cannot be readily applied to complex urban environments. This study proposes a novel rainfall-runoff model based on CA (RRCA) to simulate inundation. Its main contributions include a fine runoff generation process that considers 12 urban scenarios rather than a single land use type and the confluence process determined by the new transition rules considering water supply and demand (WS-WD transition rules). RRCA was compared with another CA based flood model (E2DCA). With the benchmark model, the results showed that there was good agreement, with an R-squared greater than 0.9, and that RRCA was more sensitive to waterlogging levels than E2DCA. Furthermore, the simulated vegetation interception, infiltration and drainage processes had varying degrees of impact on waterlogging. Corresponding measures can be taken in urban flood management according to the identification of areas experiencing drainage difficulties.