OBJECTIVES To define the clinical, neuropsychological, and radiological features of bilateral parietal lobe atrophy. METHODS Four patients underwent a comprehensive longitudinal neuropsychological assessment, as well as MRI and HMPAO-SPECT. RESULTS The consistent findings in the patients were early visuospatial problems, agraphia of a predominantly peripheral (or apraxic) type, and difficul...

We show that for integers k ≥ 2 and n ≥ 3, the diameter of the Cayley graph of SLn(Z/kZ) associated to a standard two-element generating set, is at most a constant times n 2 ln k. This answers a question of A. Lubotzky concerning SLn(Fp) and is unexpected because these Cayley graphs do not form an expander family. Our proof amounts to a quick algorithm for finding short words representing eleme...

We derive a new upper bound for the diameter of a k-regular graphG as a function of the eigenvalues of the adjacency matrix. Namely, supposethe adjacency matrix of G has eigenvalues AI , A2 .••.• An with lAd:::: IA21 ::::... :::: IAnl where AI = k, A = IA21. Then the diameter D(G) must satisfy D(G) :::; rlog(n 1)f1og(k/A)l. We wilJ consider families of graphs whose eigenvalues can b...

We study the relation between the diameter, the first positive eigenvalue of the discrete p-Laplacian and the `p-distortion of a finite graph. We prove an inequality relating these three quantities and apply it to families of Cayley and Schreier graphs. We also show that the `p-distortion of Pascal graphs, approximating the Sierpinski gasket, is bounded, which allows to obtain estimates for the...

The matching criteria were gestation (using an ultrasound crown–rump length or biparietal diameter measurement), duration of storage, and centre. Screening performance of the individual markers and combinations of markers together with maternal age was assessed using standard methods. In addition pairs of first and second trimester serum samples from 600 controls were tested to secure a larger ...

Alterations of head shape in preterm, small-for-dates, and term normal infants were studied by measuring occipitofrontal circumference (OFC), biparietal diameter (BPD), and occipitofrontal diameter (OFD) at intervals after birth. In 9 preterm infants born by elective caesarean section ther was a 5-2% reduction in BPD and 2-0% reduction in OFC at the age of 7 days. In 18 term infants born by ele...