We show that in the worst case, Q(nd) sidedness queries are required to determine whether a set of n points in Rd is affinely degenerate, i .e . , whether it contains d + 1 points on a common hyperplane. This matches known upper bounds. We give a straightforward adversary argument, based on the explicit construction of a point set containing Q(nd) “collapsible” simplices, any one of which can b...

OBJETIVE To establish association between socioeconomic status and plasmatic markers of lipoperoxidation and antioxidants in Venezuelan school-age children from the middle-class and in critical poverty. METHODS Cross-sectional study with a sample of 114 school-age children (aged 7-9). The socioeconomic status, dietary intake of macro and micro-nutrients, weight, height, lipid profile, indicat...

We investigate the timing properties necessary to guarantee synchronous message deadlines in a token ring network such as FDDI (Fibre Distributed Data Interface) where the timed token medium access control protocol (MCA) is employed. We present a tighter upper bound, than previously published, for the worst case achievable utilisation of the MCA scheme. We also found that, under the condition t...

BACKGROUND Characteristics of the physical environment can be classified into two broad categories: macro- ("raw" urban planning features influenced on a regional level) and micro- (features specifically within a streetscape influenced on a neighborhood level) environmental factors. In urban planning applications, it is more feasible to modify conditions at the neighborhood level than at the re...

BACKGROUND Animal models of focal cerebral ischemia are widely used in stroke research. The purpose of our study was to evaluate and compare the cerebral macro- and microvascular architecture of rats in two different models of permanent middle cerebral artery occlusion using an innovative quantitative micro- and nano-CT imaging technique. METHODS 4h of middle cerebral artery occlusion was per...

background: serologic screening of gastric cancer (gc) by serum pepsinogens (spg) levels and helicobacter pylori (hp) sero-status, though highly informative, has provided heterogeneous results. here, we have evaluated the modifying effects of demographic factors on the risk impact of hp sero-status/spg levels in gastric cancer, with particular emphasis on age. methods: a cross-sectional study w...