Sidewise force exerted on slowly falling spheres inside a circular cylinder

Numerical values are provided for the forces that must be applied to a reference sphere to prevent its sidewise motion when two equal-sized spheres settle through a viscous liquid bounded by a cylindrical tube. These values are presented for two independent set of circumstances: - the spheres are translating but not rotating- the spheres are rotating but not translating Forces have been calculated assuming various distances between the sphere centers and with the line of centers at various angles to the horizontal. The results are discussed for the case where the spheres are both translating and rotating and compared to previous theoretical predictions as well as experimental results

Canadian Jewish Poetry: A Roundtable

Is Canadian Jewish Poetry a meaningful category of study? Are there particular traits that differentiate Canadian Jewish poets from poets of other countries, or from writers in other genres? How do contemporary poets confront the looming legacy of Irving Layton, Leonard Cohen, and A.M. Klein? Six prominent poets and scholars conduct a roundtable discussion to articulate recent developments in the field.La poésie juive canadienne est-elle une catégorie d’étude significative? Y a-t-il des traits particuliers qui différencient les poètes juifs canadiens des poètes d’autres pays, ou des écrivains d’autres genres? Comment les poètes contemporains font-ils face à l’héritage imminent d’Irving Layton, Leonard Cohen et A.M. Klein ? Six poètes et universitaires éminents organisent une table ronde pour exposer les développements récents dans ce domaine

Changes in the Frontotemporal Cortex and Cognitive Correlates in First-Episode Psychosis

Background: Loss of cortical volume in frontotemporal regions has been reported in patients with schizophrenia and their relatives. Cortical area and thickness are determined by different genetic processes, and measuring these parameters separately may clarify disturbances in corticogenesis relevant to schizophrenia. Our study also explored clinical and cognitive correlates of these parameters.Methods: Thirty-seven patients with first-episode psychosis (34 schizophrenia, 3 schizoaffective disorder) and 38 healthy control subjects matched for age and sex took part in the study. Imaging was performed on an magnetic resonance imaging 1.5-T scanner. Area and thickness of the frontotemporal cortex were measured using a surface-based morphometry method (Freesurfer). All subjects underwent neuropsychologic testing that included measures of premorbid and current IQ, working and verbal memory, and executive function.Results: Reductions in cortical area, more marked in the temporal cortex, were present in patients. Overall frontotemporal cortical thickness did not differ between groups, although regional thinning of the right superior temporal region was observed in patients. There was a significant association of both premorbid IQ and IQ at disease onset with area, but not thickness, of the frontotemporal cortex, and working memory span was associated with area of the frontal cortex. These associations remained significant when only patients with schizophrenia were considered.Conclusions: Our results suggest an early disruption of corticogenesis in schizophrenia, although the effect of subsequent environmental factors cannot be excluded. In addition, cortical abnormalities are subject to regional variations and differ from those present in neurodegenerative diseases

Characterization of N-acetyltransferase 1 and 2 polymorphisms and haplotype analysis for inflammatory bowel disease and sporadic colorectal carcinoma

<p>Abstract</p> <p>Background</p> <p>N-acetyltransferase 1 (NAT1) and 2 (NAT2) are polymorphic isoenzymes responsible for the metabolism of numerous drugs and carcinogens. Acetylation catalyzed by NAT1 and NAT2 are important in metabolic activation of arylamines to electrophilic intermediates that initiate carcinogenesis. Inflammatory bowel diseases (IBD) consist of Crohn's disease (CD) and ulcerative colitis (UC), both are associated with increased colorectal cancer (CRC) risk. We hypothesized that <it>NAT1 </it>and/or <it>NAT2 </it>polymorphisms contribute to the increased cancer evident in IBD.</p> <p>Methods</p> <p>A case control study was performed with 729 Caucasian participants, 123 CRC, 201 CD, 167 UC, 15 IBD dysplasia/cancer and 223 controls. <it>NAT1 </it>and <it>NAT2 </it>genotyping were performed using Taqman based techniques. Eight single nucleotide polymorphisms (SNPs) were characterized for <it>NAT1 </it>and 7 SNPs for <it>NAT2</it>. Haplotype frequencies were estimated using an Expectation-Maximization (EM) method. Disease groups were compared to a control group for the frequencies at each individual SNP separately. The same groups were compared for the frequencies of <it>NAT1 </it>and <it>NAT2 </it>haplotypes and deduced NAT2 phenotypes.</p> <p>Results</p> <p>No statistically significant differences were found for any comparison. Strong linkage disequilibrium was present among both the <it>NAT1 </it>SNPs and the <it>NAT2 </it>SNPs.</p> <p>Conclusion</p> <p>This study did not demonstrate an association between <it>NAT1 </it>and <it>NAT2 </it>polymorphisms and IBD or sporadic CRC, although power calculations indicate this study had sufficient sample size to detect differences in frequency as small as 0.05 to 0.15 depending on SNP or haplotype.</p