Efficient problem-solving in any physical domain requires two main capabilities : the ability to ignore detail by reasoning at different levels of resolutio n (abstraction), and the ability to ignore irrelevant information by incorporatin g constraints and assumptions (simplification) . Existing analysis methods for mechanical devices derive qualitative descriptions of a mechanism's kinemati c ...

I n our first review on chemokines (1), we suggested that blockade of the IL-8 receptor or inhibition of IL-8 gene expression could be a new principle for designing antiin-flammatory agents. The unexpected growth of the chemo-kine family and consequent redundancy of the system eventually made it clear that acting at the level of chemo-kine gene expression was rather hopeless, but the idea of in...

Error analysis is an important issue in parallel kinematic synthesis because manufacturing and assembly errors have a significant impact on the mechanical precision of the manipulator. In this paper we propose a method to describe the displacements of the tool center point (TCP) in terms of error amplifications for uncertainties in all kinematic parameters. This is done by using the differentia...

Wang and colleagues provide functional immunologic data on a molecular pathway for glucocorticoid resistance in systemic lupus erythematosus (SLE) [1]. Gluco corti-coids have broad and powerful eff ects on the immune response and, despite the advent of biologic therapies, remain the most important and frequently used immuno-suppressive agents in clinical practice [2]. Indeed, if it were not for...

Keywords: Ruled surface Structure function Pitch function Angle function of pitch Weingarten surface Binormal ruled surface a b s t r a c t In this paper, using the elementary method we study ruled surfaces, the simplest foliated submanifolds, in Euclidean 3-space. We define structure functions of the ruled surfaces, the invariants of non-developable ruled surfaces and discuss geometric propert...

This study explores the historical and architectural heritage of Wukro Medhane Alem, a least-known monolithic rock-hewn church in South Gondar. Primary secondary sources were collected through fieldwork, interviews, literature review. The shows that it is one medieval churches traditionally attributed to King Lalibela (r. 1181-1221). hypogeum has rectangular plan being deeply excavated out bedr...