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Relative Height (relative + height)
Selected AbstractsInfant Perception of Surface Texture and Relative Height as Distance Information: A Preferential-Reaching StudyINFANCY, Issue 1 2010Laura Hemker Two preferential-reaching experiments explored 5- and 7-month-olds' sensitivity to pictorial depth cues. In the first experiment, infants viewed a display in which texture gradients, linear perspective of the surface contours, and relative height in the visual field provided information that two objects were at different distances. Five- and 7-month-old infants reached preferentially for the apparently nearer object under monocular but not binocular viewing conditions, indicating that infants in both age groups respond to pictorial depth cues. In the second experiment, texture gradients and linear perspective of the surface contours were eliminated from the experimental display, making relative height the sole pictorial depth cue. Seven-month-olds again reached more often for the apparently nearer object under monocular, but not binocular viewing conditions. By contrast, the 5-month-olds' reaching behavior did not differ between viewing conditions. These results indicate that 7-month-olds respond to the depth cue of relative height but provide no evidence of responsiveness to relative height in 5-month-olds. Both age groups responded more consistently to pictorial depth in Experiment 1 than in Experiment 2. [source] Purification and structure of the major product obtained by reaction of NADPH and NMNH with the myeloperoxidase/hydrogen peroxide/chloride systemFEBS JOURNAL, Issue 10 2001Françoise Auchère The first spectrophotometric study of the reaction of the myeloperoxidase/H2O2/Cl, system with NADPH and NMNH showed that the reaction products were not the corresponding oxidized nucleotides and that modifications would take place on the nicotinamide part of the molecule [Auchère, F. & Capeillère-Blandin, C. (1999) Biochem. J. 343, 603,613]. In this report, in order to obtain more precise information on the structural modifications and mechanism of the reaction, we focus on the purification and isolation of products derived from NADPH and NMNH by RP-HPLC. Electrospray ionization mass spectra indicated that the relative height of the peaks reflected that of the natural isotopic abundance of 35Cl and 37Cl, providing evidence that the products derived from NADPH and NMNH were monochlorinated. Moreover, calculated masses revealed the 1 : 1 addition of HOCl to the molecule. Various 1D and 2D NMR experiments provided data for the assignments of the chemical shifts of protons and carbons and the coupling constants of the protons of the chlorinated nucleotides. Further NOESY experiments allowed the characterization of the spatial structure of the chlorinated product and showed that trans HOCl addition occurred at the C5=C6 carbon double bond of the nicotinamide ring, leading to a chlorohydrin. [source] Infant Perception of Surface Texture and Relative Height as Distance Information: A Preferential-Reaching StudyINFANCY, Issue 1 2010Laura Hemker Two preferential-reaching experiments explored 5- and 7-month-olds' sensitivity to pictorial depth cues. In the first experiment, infants viewed a display in which texture gradients, linear perspective of the surface contours, and relative height in the visual field provided information that two objects were at different distances. Five- and 7-month-old infants reached preferentially for the apparently nearer object under monocular but not binocular viewing conditions, indicating that infants in both age groups respond to pictorial depth cues. In the second experiment, texture gradients and linear perspective of the surface contours were eliminated from the experimental display, making relative height the sole pictorial depth cue. Seven-month-olds again reached more often for the apparently nearer object under monocular, but not binocular viewing conditions. By contrast, the 5-month-olds' reaching behavior did not differ between viewing conditions. These results indicate that 7-month-olds respond to the depth cue of relative height but provide no evidence of responsiveness to relative height in 5-month-olds. Both age groups responded more consistently to pictorial depth in Experiment 1 than in Experiment 2. [source] Discrimination of extant Pan species and subspecies using the enamel,dentine junction morphology of lower molarsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Matthew M. Skinner Abstract Previous research has demonstrated that species and subspecies of extant chimpanzees and bonobos can be distinguished on the basis of the shape of their molar crowns. Thus, there is potential for fossil taxa, particularly fossil hominins, to be distinguished at similar taxonomic levels using molar crown morphology. Unfortunately, due to occlusal attrition, the original crown morphology is often absent in fossil teeth, and this has limited the amount of shape information used to discriminate hominin molars. The enamel,dentine junction (EDJ) of molar teeth preserves considerable shape information, particularly in regard to the original shape of the crown, and remains present through the early stages of attrition. In this study, we investigate whether the shape of the EDJ of lower first and second molars can distinguish species and subspecies of extant Pan. Micro-computed tomography was employed to non-destructively image the EDJ, and geometric morphometric analytical methods were used to compare EDJ shape among samples of Pan paniscus (N = 17), Pan troglodytes troglodytes (N = 13), and Pan troglodytes verus (N = 18). Discriminant analysis indicates that EDJ morphology distinguishes among extant Pan species and subspecies with a high degree of reliability. The morphological differences in EDJ shape among the taxa are subtle and relate to the relative height and position of the dentine horns, the height of the dentine crown, and the shape of the crown base, but their existence supports the inclusion of EDJ shape (particularly those aspects of shape in the vertical dimension) in the systematic analysis of fossil hominin lower molars. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Fitting atomic models into electron-microscopy mapsACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2000Michael G. Rossmann Combining X-ray crystallographically determined atomic structures of component domains or subunits with cryo-electron microscopic three-dimensional images at around 22,Å resolution can produce structural information that is accurate to about 2.2,Å resolution. In an initial step, it is necessary to determine accurately the absolute scale and absolute hand of the cryo-electron microscopy map, the former of which can be off by up to 5%. It is also necessary to determine the relative height of density by using a suitable scaling function. Difference maps can identify, for instance, sites of glycosylation, the position of which helps to fit the component structures into the EM density maps. Examples are given from the analysis of alphaviruses, rhinovirus,receptor interactions and poliovirus,receptor interactions. [source] Two-hourly surface change on supra-tidal rock (Marengo, Victoria, Australia)EARTH SURFACE PROCESSES AND LANDFORMS, Issue 1 2007Lluís Gómez-Pujol Abstract A traversing micro-erosion meter was used to measure rock surface micro-topography over 40 cm2 on a supra-tidal cliff face from early morning to late evening in late spring. From 06:00 hours to 22:00 hours the relative heights of 188 coordinates were obtained using the meter at 2-hour intervals, resulting in a data set of 1607 readings. Monitoring shows that rock surfaces are dynamic entities, with significant rise and fall relative to the first measurement at shorter timescales than previously reported. The maximum positive rise between readings was 0·261 mm and lowering was 0·126 mm. The pattern of change did not relate as expected to environmental variables such as temperature or insolation. Rather, the surface showed greater surface change in the early morning and late afternoon. It is hypothesized that this pattern relates to the expansion and contraction of lichen thalli as moisture is absorbed during higher humidity in the morning and late afternoon. The implications of these results for weathering studies are considered. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||