We prove that the approximation ratio of the greedy algorithm for the metric Traveling Salesman Problem is Θ(log n). Moreover, we prove that the same result also holds for graphic, euclidean, and rectilinear instances of the Traveling Salesman Problem. Finally we show that the approximation ratio of the ClarkeWright savings heuristic for the metric Traveling Salesman Problem is Θ(log n). keywor...

Standard immune responses are the sum of many clonal responses, cross-reactive and specific. Any study of clonal expression as well as analysis of its products requires the separation of clones. There are several approaches to this goal (1-3). The one we used was to generate immune responses of restricted heterogeneity where a limited number ofclonotypes determine the response (4, 5). The prere...

Jeri Wright studies the neural basis of behaviour and the nutritional ecology of honeybees in the Institute of Neuroscience at Newcastle University. A Wyoming native, she studied botany at the University of Wyoming while working as an assistant researcher in the entomology museum. As an undergraduate, she first combined her interest in plants and insects by studying insect nutrition as a Rhodes...

The Catmull-Clark subdivision algorithm consists of an operator that can be decomposed into a refinement operator and a successively executed smoothing operator, where the refinement operator splits each face with m vertices into m quadrilateral subfaces and the smoothing operator replaces each internal vertex with an affine combination of its neighboring vertices and itself. Over regular meshe...

Category II tracings, the second most common cause of cesarean delivery, are indeterminate resulting in significant variation how these tracings managed. Use category tracing algorithms such as those created by Clark et Al, (2013) have potential to aid decision making and thus decrease section for indication abnormal/indeterminate/non reassuring fetal tracing. WellSpan York Hospital is a tertia...

Rivers shape continental surfaces; they erode continental reliefs, transport erosion products and finally deposit them in plains. As a consequence, understanding physics of sediment transport is of fundamental importance in earth sciences. However, sediment transport occurs at the dynamical interface between fluid and granular mechanics, which makes its full understanding challenging. Over the ...

the incidence of brucellosis has been increased in recent years. this imposes many economical and health related problems among rural and tribe people. khuzestan province is in low infected range of iran provinces. we reviewed the epidemiological, clinical and demographical specialty of patient referred to health centers and laboratories of andimeshk township in year 2006. medical records of 50...

background: although one of the most serious mononuclear meningitis is tuberculosis and the most prevalent one is viral meningitis, but the most treatable one is brucellar meningitis. methods: in this cross sectional study we considered documents of 39 patients who have been diagnosed during 1988-2005. patients were confirmed using positive agglutination tests of serum, spinal fluid or positive...

Popular subdivision algorithms like Catmull-Clark and Loop are C almost everywhere, but suffer from shape artifacts and reduced smoothness exactly near the so-called “extraordinary vertices” that motivate their use. Subdivision theory explains that inherently, for standard stationary subdivision algorithms, curvature-continuity and the ability to model all quadratic shapes requires a degree of ...

neurobrucellosis (n.b) is a rare and severe form of systemic brucella infection. we introduced an unusual case that “psychologic symptoms” was the most prominent complaints of his family. he was a 50-year-old man who has worked in butchery. his problems had begun 2 months prior to his admission with mood disorders, arthralgia, weakness, headache, and night sweats; he has recurrent crying with n...