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Analysis of watersheds and river systems: short course
Get PDFShort course: Analysis of Watersheds and River Systems, Session I and II, held on May 28-June 1, 1979 and June 4-June 8, 1979 at Colorado State University, Fort Collins, Colorado.Speakers: Dr. E. V. Richardson, Dr. David Duttweiller, Mr. Lee Mulkey, Dr. Stanley A. Schumm, Dr. Daryl B. Simons, Dr. Ross Carder.Includes bibliographical references.This short course is designed for individuals dealing with the analysis of watersheds and rivers. Practical applications concerning physical processes will be emphasized.Chapter 1. General introduction / Daryl B. Simons and Ruh-Ming Li -- Chapter 2. Introduction to watershed and river analysis / Daryl B. Simons and Ruh-Ming Li -- Chapter 3. Physical processes governing response of watersheds and rivers / Daryl B. Simons, Timothy J. Ward and Ruh-Ming Li -- Chapter 4. Sediment transport / H. W. Shen -- Chapter 5. Alluvial bed roughness / H. W. Shen -- Chapter 6. Overview of flood routing methods / Ruh-Ming Li and V. Miguel Ponce -- Chapter 7. Water routing and yield from watersheds, Part I and II / Ruh-Ming Li, Daryl B. Simons, and Kenneth G. Eggert -- Chapter 8. Water routing in rivers / Yung-Hai Chen -- Chapter 9. Stage discharge relations / Robert K. Simons, Ruh-Ming Li, and Daryl B. Simons -- Chapter 10. Watershed sediment yield / Ruh-Ming Li, Daryl B. Simons, and Timothy J. Ward -- Chapter 11. Unsteady sediment routing models in rivers / Yung-Hai Chen and Daryl B. Simons -- Chapter 12. Known discharge sediment routing / Glenn O. Brown and Ruh-Ming Li -- Chapter 13. Landslide potential delineation / Timothy J. Ward, Ruh-Ming Li, and Daryl B. Simons -- Chapter 14. Application of Kalman filtering in watershed and river analysis / Nguyen Duong -- Chapter 15. Handheld calculator programs for analysis / Kenneth G. Eggert, Ruh-Ming Li, and Daryl B. Simons -- Chapter 16. Overview of case studies and data management / Daryl B. Simons, Ruh-Ming Li, and Nguyen Duong -- Chapter 17. Canal and channel design and river response analysis / Daryl B. Simons, Ruh-Ming Li, and Yung-Hai Chen -- Chapter 18. Degradation and aggradation analysis / Ruh-Ming Li and Daryl B. Simons -- Chapter 19. Watershed best management analysis / Ruh-Ming Li, Timothy J. Ward, and Daryl B. Simons -- Chapter 20. Large river basin analysis: Yazoo River Sedimentation Study / Daryl B. Simons and Ruh-Ming Li
Mechanisms of top-down facilitation in perception of visual objects studied by fMRI
Get PDFPrior knowledge regarding the possible identity of an object facilitates its recognition from a degraded visual input, though the underlying mechanisms are unclear. Previous work implicated ventral visual cortex but did not disambiguate whether activity-changes in these regions are causal to or merely reflect an effect of facilitated recognition. We used functional magnetic resonance imaging to study top-down influences on processing of gradually revealed objects, by preceding each object with a name that was congruent or incongruent with the object. Congruently primed objects were recognized earlier than incongruently primed, and this was paralleled by shifts in activation profiles for ventral visual, parietal, and prefrontal cortices. Prior to recognition, defined on a trial-by-trial basis, activity in ventral visual cortex rose gradually but equivalently for congruently and incongruently primed objects. In contrast, prerecognition activity was greater with congruent priming in lateral parietal, retrosplenial, and lateral prefrontal cortices, whereas functional coupling between parietal and ventral visual (and also left lateral prefrontal and parietal) cortices was enhanced in the same context. Thus, when controlling for recognition point and stimulus information, activity in ventral visual cortex mirrors recognition success, independent of condition. Facilitation by top-down cues involves lateral parietal cortex interacting with ventral visual areas, potentially explaining why parietal lesions can lead to deficits in recognizing degraded objects even in the context of top-down knowledge
UNUSUAL NEGATIVE MOLECULAR IONS AND DIANIONS AND CHEMICAL BONDS INVOLVING RYDBERG ORBITALS
No full text1. Maciej Gutowski, Piotr Skurski, Kenneth D. Jordan, Jack Simons; Int J. Quant. Chem.; 64, 183 (1997). 2. P. Skurski, M. Gutowski and J. Simons, Int J. Quant Chem. 76. 197 (2000). 3. Alexander I. Boldyrev, Maciej Gutowski, and Jack Simons; Acc. Chem. Res.; 29, 497 (1996). 4. Jack Simons and Maciej Gutowski, Chem. Rev. 91, 669 (1991). 5. A. I. Boldyrev and J. Simons; J. Phys. Chem. 96, 8840 (1992); A. I. Boldyrev and J. Simons. J. Phys. Chem., 103, 3575 (1999).Author Institution: Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of UtahIn this presentation, our work and that of several other groups on the species listed in the title will be discussed. Particular emphasis will be given to: (a) dipole bound (which have also been the subject of numerous experimental studies), (b) dipole bound (which remain theoretical speculation), (c) resonance states of anions that can be made stable via ``solvation'', (d) dianions such as that have extremely high second electron binding (which occur in the solid state and in solution), (e) anions in which the ``extra'' electron occupies a Rydberg-like molecular (which have been seen experimentally), and (f) chemical bonds that arise when a Rydberg-like orbital is
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A probabilistic assessment of sea level variations within the Last Interglacial stage
No full textThe Last Interglacial (LIG) stage (ca. 130–115 ka) provides a relatively recent example of a world with both poles characterized by greater-than- Holocene temperatures similar to those expected later in this century under a range of greenhouse gas emission scenarios. Previous analyses inferred that LIG mean global sea level (GSL) peaked 6–9 m higher than today (Kopp et al. 2009; Dutton & Lambeck 2012). Here, we extend our earlier work to perform a probabilistic assessment of sea level variability within the LIG highstand. Using the terminology for probability employed in the Intergovernmental Panel on Climate Change (IPCC) assessment reports, we find it extremely likely (95% probability) that the paleo-sea level record allows resolution of at least two intra-LIG sea level peaks and likely (67% probability) that the magnitude of low-to-high swings exceeded 4 m. Moreover, it is likely that there was a period during the LIG in which GSL rose at a 1000-year average rate exceeding 3 m/ky, but unlikely (33% probability) that the rate exceeded 7 m/ky and extremely unlikely (5% probability) that it exceeded 11 m/ky. These rate estimates can provide insight into rates of Greenland and/or Antarctic melt under climate conditions partially analogous to those expected in the twenty- first century.This is the authors’ preprint version of the manuscript: 23 January 2013. Originally submitted 18 September 2012. Accepted for publication in Geophysical Journal International, published by Oxford University Press.Peer reviewe
Neural basis for priming of pop-out during visual search revealed with fMRI
No full textMalikovic and Nakayama first showed that visual search efficiency can be influenced by priming effects. Even "pop-out" targets (defined by unique color) are judged quicker if they appear at the same location and/or in the same color as on the preceding trial, in an unpredictable sequence. Here, we studied the potential neural correlates of such priming in human visual search using functional magnetic resonance imaging (fMRI). We found that repeating either the location or the color of a singleton target led to repetition suppression of blood oxygen level-dependent (BOLD) activity in brain regions traditionally linked with attentional control, including bilateral intraparietal sulci. This indicates that the attention system of the human brain can be "primed," in apparent analogy to repetition-suppression effects on activity in other neural systems. For repetition of target color but not location, we also found repetition suppression in inferior temporal areas that may be associated with color processing, whereas repetition of target location led to greater reduction of activation in contralateral inferior parietal and frontal areas, relative to color repetition. The frontal eye fields were also implicated, notably when both target properties (color and location) were repeated together, which also led to further BOLD decreases in anterior fusiform cortex not seen when either property was repeated alone. These findings reveal the neural correlates for priming of pop-out search, including commonalities, differences, and interactions between location and color repetition. fMRI repetition-suppression effects may arise in components of the attention network because these settle into a stable 1. attractor state" more readily when the same target property is repeated than when a different attentional state is required
Two-loop Sudakov form factor in ABJM
No full textThis article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited
A K-theoretic approach to Chern-Cheeger-Simons invariants
Get PDFsummary:The aim of this paper is to construct a natural mapping \check C\sb k, , from the multiplicative -theory of a differential manifold , associated to the trivial filtration of the de Rham complex, as defined by {\it M. Karoubi} in [C. R. Acad. Sci., Paris, S\'er. I 302, 321-324 (1986; Zbl 0593.55004)] to the odd cohomology H\sb s\sp{2k-1} (X;C\sp*). By using this mapping, the author associates to any flat complex vector bundle on characteristic classes \check C\sb k(E) \in H\sb{dR}\sp{2k-1} (X;C\sp*) analogous to the classes studied by {\it S. Chern}, {\it J. Cheeger} and {\it J. Simons} in [Differential characters and geometric invariants, in `Geometry and topology', Lect. Notes Math. 1167, 50-80 (1985; Zbl 0621.57010), Characteristic forms and geometric invariants, Ann. Math., II. Ser. 99, 48-69 (1974; Zbl 0283.53036)]
Retinitis Pigmentosa GTPase Regulator (RPGR) protein isoforms in mammalian retina:insights into X-linked Retinitis Pigmentosa and associated ciliopathies
Get PDFMutations in the cilia-centrosomal protein Retinitis Pigmentosa GTPase Regulator (RPGR) are a frequent cause of retinal degeneration. The RPGR gene undergoes complex alternative splicing and encodes multiple protein isoforms. To elucidate the function of major RPGR isoforms (RPGR 1-19 and RPGR ORF15), we have generated isoform-specific antibodies and examined their expression and localization in the retina. Using sucrose-gradient centrifugation, immunofluorescence and co-immunoprecipitation methods, we show that RPGR isoforms localize to distinct sub-cellular compartments in mammalian photoreceptors and associate with a number of cilia-centrosomal proteins. The RCC1-like domain of RPGR, which is present in all major RPGR isoforms, is sufficient to target it to the cilia and centrosomes in cultured cells. Our findings indicate that multiple isotypes of RPGR may perform overlapping yet somewhat distinct transport-related functions in photoreceptors
Ceramic material under ballistic loading: A numerical approach to sphere impact on ceramic armour material
No full textArmour systems for ballistic protection can be made from many materials. One type of material used in armour systems is ceramic. Ceramic materials, such as alumina and silicon carbide, can be beneficial in an armour system because of their high hardness and relatively low weight. The high hardness of the ceramic potentially causes a projectile to deform heavily and fracture upon impact with the armour, thereby reducing or even eliminating the threat. The ceramic itself may also damage during the interaction. Although ceramics can damage under impact, they contribute to the protective capability of the armour system as long as they exert a force on the projectile to deformand deceleration it. In order to improve an armour system one does not only need to know when the ceramic component fails, but also how it fails. Once the failure mechanisms of the ceramic are known the armour design may be modified to delay or in an ideal scenario even prevent catastrophic failure of the ceramic. This will eventually result in stronger and lighter armour systems.Applied Mechanic
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