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Regions Corresponding (regions + corresponding)

Distribution by Scientific Domains

Medical Sciences	37%
Life Sciences	37%

Selected Abstracts

Functional segregation of plural regions representing cardinal contours in cat primary visual cortex

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2004
Gang Wang
Abstract Our previous data based on an imaging study suggested that, in cat area 17, the representations of cardinal orientations overlap less than the representation of their nearby angles. The purpose of this study was to further investigate the underlying single-cell properties. Optical imaging was performed first to map the cortical regions corresponding to the four principal contours, the two cardinals and the two obliques. The cortical region activated by a principal orientation but not by the +10° or ,10° neighbouring angles, namely the area with optically relative independent orientation selectivity (RIOS), was mapped together with the regions that overlapped with the +10° and/or ,10° neighbouring angles (non-RIOS). Electrode penetrations were targeted to the RIOS and non-RIOS regions in each of the four orientations. A comparison between the RIOS and the non-RIOS regions documented a significantly higher percentage of cells with the orientation preference of the cardinal orientations in the cardinal RIOS region than that seen in the other regions. Additionally, the difference in the tuning width of cells between the RIOS and non-RIOS in the cardinal region was significantly larger than the difference between the RIOS and non-RIOS in the oblique region. The cells in the cardinal RIOS region were tuned more sharply and the cells in cardinal non-RIOS region more broadly than the oblique RIOS and/or the non-RIOS region, which showed no significant difference. These data strongly suggest the existence of functional segregation in the region corresponding to the cardinal contours. [source]

Dimensional accuracy of upper complete denture bases: the effect of metallic flask closure methods

GERODONTOLOGY, Issue 1 2009
Rafael Leonardo Xediek Consani
Objectives:, To verify the dimensional accuracy of upper complete denture bases under the effect of different methods of metallic flask closure. Materials and methods:, Wax record bases were assigned to six groups: 1,2: traditional clamp; 3,4: RS system; and 5,6: flask with screws. Flasks were immediately polymerised or bench stored for 6 h prior to polymerisation. Resin base-cast sets were sectioned at regions corresponding to the canines, first molars and posterior palatal zone. Gap discrepancies were measured at five points: right and left ridge crests, palatal midline, and right and left marginal limits of the flanges. An optical micrometer was used for measurement purposes. Results:, Data were submitted to anova, and the means compared by Tukey's test (, = 0.05). Results revealed significant differences in the flask closure technique, polymerisation time, section, and their interactions. Discrepancy values for the RS system and flask with screws were significantly lower than those related to the traditional clamp, regardless of whether resin polymerisation was immediate or delayed for 6 h. Conclusions:, Flask closure methods should be considered when the denture base stability and comfort of the patient are being assessed during clinical use of the dentures. [source]

Using a genome-wide scan and meta-analysis to identify a novel IBD locus and confirm previously identified IBD loci

INFLAMMATORY BOWEL DISEASES, Issue 6 2002
C. Noel Williams
Abstract Seven loci that potentially confer susceptibility to inflammatory bowel disease (IBD) or one of its subtypes have been identified to date; however, most are unconfirmed, and the complete set of loci contributing to disease susceptibility has not yet been determined. The authors aim to identify loci contributing to disease susceptibility in an IBD population from Canada and to compare their results in a systematic manner with those of previously published IBD data sets. The authors performed genome-wide linkage analysis on 63 IBD families from Nova Scotia, Canada. They then undertook a meta-analysis to combine the results of their study with those of the four previously published IBD genome-wide scans with complete data reported. Their genome-wide scan identified three regions of suggestive linkage to IBD: 11p, IBD3, and IBD1. The locus on chromosome 11p has not been previously reported. Meta-analysis of multiple scans revealed linked regions corresponding to the IBD1, IBD3, and IBD5 loci. Meta-analysis of linkage data is a powerful approach for identifying and confirming common susceptibility loci and specifically shows that IBD1, IBD3, and IBD5 are the major, common IBD susceptibility loci in the populations studied thus far. [source]

Some new considerations concerning the Rayleigh-wave velocity in auxetic materials

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2008
Fabrizio Scarpa
Abstract The Rayleigh wave velocity is examined in isotropic and non-isotropic auxetic (negative Poisson's ratio) solids. A novel approximation of the Rayleigh wave speed c versus the Poisson's ratio of an isotropic solid is derived using the concept of ellipticity. The Rayleigh wave propagation is investigated also for anisotropic incompressible solids, such as thick composite balanced symmetric cross-ply laminates, exhibiting through-the-thickness negative Poisson's ratio. The results show increased wave speed for auxetic laminate configurations, as well as increased sensitivity of the wave speed in the cross-ply regions corresponding to NPR values. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Computer-aided NMR assay for detecting natively folded structural domains,

PROTEIN SCIENCE, Issue 4 2006
Takayuki Hondoh
Abstract Structural genomics projects require strategies for rapidly recognizing protein sequences appropriate for routine structure determination. For large proteins, this strategy includes the dissection of proteins into structural domains that form stable native structures. However, protein dissection essentially remains an empirical and often a tedious process. Here, we describe a simple strategy for rapidly identifying structural domains and assessing their structures. This approach combines the computational prediction of sequence regions corresponding to putative domains with an experimental assessment of their structures and stabilities by NMR and biochemical methods. We tested this approach with nine putative domains predicted from a set of 108 Thermus thermophilus HB8 sequences using PASS, a domain prediction program we previously reported. To facilitate the experimental assessment of the domain structures, we developed a generic 6-hour His-tag-based purification protocol, which enables the sample quality evaluation of a putative structural domain in a single day. As a result, we observed that half of the predicted structural domains were indeed natively folded, as judged by their HSQC spectra. Furthermore, two of the natively folded domains were novel, without related sequences classified in the Pfam and SMART databases, which is a significant result with regard to the ability of structural genomics projects to uniformly cover the protein fold space. [source]

Mapping of direction and muscle representation in the human primary motor cortex controlling thumb movements

THE JOURNAL OF PHYSIOLOGY, Issue 9 2009
W. J. Z'Graggen
Larger body parts are somatotopically represented in the primary motor cortex (M1), while smaller body parts, such as the fingers, have partially overlapping representations. The principles that govern the overlapping organization of M1 remain unclear. We used transcranial magnetic stimulation (TMS) to examine the cortical encoding of thumb movements in M1 of healthy humans. We performed M1 mapping of the probability of inducing a thumb movement in a particular direction and used low intensity TMS to disturb a voluntary thumb movement in the same direction during a reaction time task. With both techniques we found spatially segregated representations of the direction of TMS-induced thumb movements, thumb flexion and extension being best separated. Furthermore, the cortical regions corresponding to activation of a thumb muscle differ, depending on whether the muscle functions as agonist or as antagonist for flexion or extension. In addition, we found in the reaction time experiment that the direction of a movement is processed in M1 before the muscles participating in it are activated. It thus appears that one of the organizing principles for the human corticospinal motor system is based on a spatially segregated representation of movement directions and that the representation of individual somatic structures, such as the hand muscles, overlap. [source]

Comparative mapping of chicken anchor loci orthologous to genes on human chromosomes 1, 4 and 9

ANIMAL GENETICS, Issue 1 2001
S. P. Suchyta
Comparative mapping of chicken and human genomes is described, primarily of regions corresponding to human chromosomes 1, 4 and 9. Segments of chicken orthologues of selected human genes were amplified from parental DNA of the East Lansing backcross reference mapping population, and the two parental alleles were sequenced. In about 80% of the genes tested, sequence polymorphism was identified between reference population parental DNAs. The polymorphism was used to design allele-specific primers with which to genotype the backcross panel and place genes on the chicken linkage map. Thirty-seven genes were mapped which confirmed the surprisingly high level of conserved synteny between orthologous chicken and human genes. In several cases the order of genes in conserved syntenic groups differs between the two genomes, suggesting that there may have been more frequent intrachromosomal inversions as compared with interchromosomal translocations during the separate evolution of avian and mammalian genomes. [source]

Noninvasive oximetry and glaucoma

ACTA OPHTHALMOLOGICA, Issue 2009
OB OLAFSDOTTIR
Purpose To investigate retinal vessel oxygen saturation in relation to glaucomatous visual field damage. Specifically, we examined whether oxygen saturation in retinal blood vessels differs between regions corresponding to glaucomatous visual field defects compared to regions without visual field defects. Methods A spectrophotometric retinal oximeter (Oxymap ehf, Reykjavík, Iceland) was used to measure oxygen saturation in retinal arterioles and venules. The oximeter consists of a fundus camera, beam splitter, light filters and software that evaluate the oxygen saturation. The glaucomatous defect was estimated from a visual field test using the Octopus 1-2-3 perimeter. One eye in 13 individuals with open angle glaucoma with or without pseudoexfoliation syndrome was examined. Results In retinal areas with no visual field defect, the mean oxygen saturation in arterioles was 102±6% and 65±9%, (mean±SD) in venules. The arteriovenous difference was 37±10%. In retinal areas corresponding to visual field defects, the mean oxygen saturation in arterioles was significantly lower; 98±5% (p=0.04, paired t-test, n=13). The venules were at 68±7% (p=0.3) and the arteriovenous difference was also significantly lower; 30±10% (p=0.04). Conclusion Arteriolar oxygen saturation and arteriovenous difference is statistically lower in areas with visual field defects compared to areas without visual field defects. This data suggests that visual field defects are associated with a reduction in retinal oxygen delivery and metabolism. [source]