Search Results - (Author, Cooperation:G. W. Robinson)
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1Latest Papers from Table of Contents or Articles in PressP. A. Northcott ; C. Lee ; T. Zichner ; A. M. Stutz ; S. Erkek ; D. Kawauchi ; D. J. Shih ; V. Hovestadt ; M. Zapatka ; D. Sturm ; D. T. Jones ; M. Kool ; M. Remke ; F. M. Cavalli ; S. Zuyderduyn ; G. D. Bader ; S. VandenBerg ; L. A. Esparza ; M. Ryzhova ; W. Wang ; A. Wittmann ; S. Stark ; L. Sieber ; H. Seker-Cin ; L. Linke ; F. Kratochwil ; N. Jager ; I. Buchhalter ; C. D. Imbusch ; G. Zipprich ; B. Raeder ; S. Schmidt ; N. Diessl ; S. Wolf ; S. Wiemann ; B. Brors ; C. Lawerenz ; J. Eils ; H. J. Warnatz ; T. Risch ; M. L. Yaspo ; U. D. Weber ; C. C. Bartholomae ; C. von Kalle ; E. Turanyi ; P. Hauser ; E. Sanden ; A. Darabi ; P. Siesjo ; J. Sterba ; K. Zitterbart ; D. Sumerauer ; P. van Sluis ; R. Versteeg ; R. Volckmann ; J. Koster ; M. U. Schuhmann ; M. Ebinger ; H. L. Grimes ; G. W. Robinson ; A. Gajjar ; M. Mynarek ; K. von Hoff ; S. Rutkowski ; T. Pietsch ; W. Scheurlen ; J. Felsberg ; G. Reifenberger ; A. E. Kulozik ; A. von Deimling ; O. Witt ; R. Eils ; R. J. Gilbertson ; A. Korshunov ; M. D. Taylor ; P. Lichter ; J. O. Korbel ; R. J. Wechsler-Reya ; S. M. Pfister
Nature Publishing Group (NPG)
Published 2014Staff ViewPublication Date: 2014-07-22Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Child ; Chromosomes, Human, Pair 9/genetics ; DNA-Binding Proteins/*genetics/metabolism ; Enhancer Elements, Genetic/*genetics ; Genomic Structural Variation/*genetics ; Humans ; Medulloblastoma/classification/*genetics/pathology ; Mice ; Oncogenes/*genetics ; Proto-Oncogene Proteins/*genetics/metabolism ; Repressor Proteins/*genetics/metabolism ; Transcription Factors/*genetics/metabolismPublished by: -
2Articles: DFG German National LicensesZhu, S.-B. ; Lee, J. ; Robinson, G. W. ; Lin, S. H.
College Park, Md. : American Institute of Physics (AIP)
Published 1989Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: A unified memory kernel function is proposed on the basis of molecular dynamics simulations and comparison with experimental data. A frozen-solvent-like friction arises from the near-neighbor solvent cage effect, while the interaction between the system and the disordered heat bath or "broken cage'' gives rise to a white-noise friction. On short time scales, the apparent friction is a "series addition'' of these two limits, each solute molecule experiencing either an intact cage or a broken cage environment. For longer time scale behavior, the solvent is able to evolve, and some system molecules can experience both types of environments during the course of their own dynamics: the effective friction for these molecules then appears as a "parallel addition'' of the same two contributions. This leads to a memory kernel having a simple exponential behavior. As the time scale for the system dynamics becomes still longer, the cage becomes indistinguishable from the heat bath, and a purely Markoffian relaxation with delta-function memory kernel ensues. This unified memory kernel model has been found to be applicable to ultrafast chemical reaction rates and diffusion properties both in molecular dynamics simulations and laboratory experiments.Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesZhu, S.-B. ; Lee, J. ; Zhu, J.-B ; Robinson, G. W.
College Park, Md. : American Institute of Physics (AIP)
Published 1990Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: A nonequilibrium computer simulation is performed to investigate the relaxation of a realistic polar solvent near a rapidly dissociating ion pair. The time evolution of the reaction coordinate, the ultrashort time scale changes in solvation energy and solvent forces, the local density response, the heating of certain librational degrees of freedom, and the time-dependent polarization are studied during the first 125 fs of the reaction. It is found that the relaxation behaviors in the anionic and cationic shells are very different. On average, the solvation process under study takes about 30-40 fs to break the original cage. After another 50 fs, the solvated ion pair reforms a new metastable structure, which feeds energy back into the reacting system to break the cage further. This procedure is apparently repeated many times until dissociation is complete. The results obtained in this work provide a graphic picture of some of the features of ultrashort dynamics of ionic photodissociation reactions in a polar medium.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesKrishnan, R. ; Singh, Surjit ; Robinson, G. W.
College Park, Md. : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: The Hamiltonian approach of Pollak–Grabert–Hänggi to the theory of activated rate processes is generalized to allow for different frictions in the well and the barrier regions. Estimates of the escape rate in the case of exponential friction can be determined from the derived equations of motion, which are exact for all values of the coupling in the well and barrier regions. The rate results are plotted in several cases.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: Using the recently developed SPC-FP water model (simple point charge model with flexible bonds and polarization) and the molecular dynamics method, we investigate the structure and properties of liquid water between two rigid plates. In one case the plates are neutral and in the other the plates are electrically charged. In both cases substantial differences from bulk state water are found, structurally and dynamically. We observe some anomalies compared with normal liquids and attribute these to the breakage of hydrogen bonds under the influence of the solid–liquid interface. Adding an external torque enhances such breakage through the attempted alignment of the water molecules. A combination of these two contributions determines the resultant dynamical behavior of water between charged plates. The information obtained from this work should be helpful in the understanding of "hydrophobic effects'' in aqueous solutions. The behavior of water near large polar or nonpolar molecular solutes is also revealed by these studies.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: Molecular dynamics techniques are used to study the structural changes in liquid carbon disulphide resulting from the introduction of a polar solute. It is found that both translational relaxation and rotational relaxation of the solvent in the shell surrounding the solute are faster than in the bulk liquid. Moreover, shifts in the intramolecular vibrational spectra and variations of the dielectric properties of the cage solvent are in evidence. The dynamical and spectroscopic behavior of the solute is also discussed. Microscopic friction experienced by the solute molecule for both translational and rotational motions is computed using the generalized stochastic theory. Information of this type is needed for constructing valid theories of ultrafast chemical reaction dynamics in condensed matter.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesZhu, S.-B. ; Lee, J. ; Robinson, G. W. ; Lin, S. H.
College Park, Md. : American Institute of Physics (AIP)
Published 1989Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: The time dependent friction (TDF) introduced in paper I for barrier crossing problems is used to derive a functional form of the angular velocity autocorrelation function (AVACF) associated with the reactive coordinate. This theoretical expression is then compared with AVACFs derived directly from molecular dynamics angular velocity data. A connection between this AVACF model and Zwanzig's waiting-time description can be made. The TDF functions from paper I can also be used to deduce barrier crossing rates using the Kramers–Grote–Hynes formalism. A special case leads to the "extended'' Kramers equation, which was found in previous work to be congruous with experimental barrier crossing results. Using methods introduced by Okuyama and Oxtoby, a generalized Smoluchowski equation can also be derived. This Smoluchowski equation permits an examination of free diffusion and of the approach to equilibrium. Throughout papers I and II the theme is raised concerning the effects of nonlinear coupling on the methodology for analyzing barrier crossing problems. Seemingly, the appealing Langevin approach can be retained providing the parameters in this formalism are considered strictly empirical.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesZhu, S.-B. ; Lee, J. ; Robinson, G. W.
College Park, Md. : American Institute of Physics (AIP)
Published 1988Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: The memory kernel in liquid phase cis–trans isomerization is examined from the point of view of existing experimental data as well as MD simulations. In agreement with nonlinear system/bath coupling theories, when the generalized Langevin equation is written in the conventional way, we find that the "effective'' memory kernel in this equation depends on the properties of the isomerizing particle, including the barrier height. In addition, it is found that the angular velocity distribution for the isomerizing molecule may be strongly influenced by "shape effects,'' caused by actual molecular differences between the cis and trans configurations. This distribution may not be Maxwellian when considered over a partial angular range, e.g., the "barrier region.'' If this is a general phenomenon, the selection of correct initial conditions in the reactive flux method would create uncertainties in the application of that method to the calculation of barrier crossing rates.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStatman, D. ; Robinson, G. W.
College Park, Md. : American Institute of Physics (AIP)
Published 1985Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: We present here some molecular dynamics results concerning the role of frequency-dependent friction in the barrier crossing problem. Friction along the reaction coordinate can be about a factor of 2 less than that for the bulk solvent. Another effect that has been found to cause disagreement between the Grote–Hynes theoretical isomerization rate and the molecular dynamics rate is an entropy contribution resulting from a change of hydrodynamic volume upon isomerization.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesLee, J. ; Griffin, R. D. ; Robinson, G. W.
College Park, Md. : American Institute of Physics (AIP)
Published 1985Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: Using picosecond spectroscopic techniques, the proton transfer process of 2-naphthol in its first excited singlet state is investigated in water/methanol mixtures at different temperatures. The proton transfer rate is found to increase as the temperature increases, and to decrease as the methanol concentration increases. A Markov random walk theory previously used to electron transfer kinetics is employed to analyze the data. By this method, a water cluster containing 4±1 members is shown to be the proton acceptor. Suggestively, a "four-cluster'' structure (H9O4)+ has been hypothesized as the most probable hydrating unit for the proton in acid–base equilibria, charge transfer, and other chemical systems. The observed activation energy of 3.45 kcal/mol in pure water is attributed to the energy required for rearrangement of the hydrogen bonding in the normal water structure to form the proton accepting cluster. Proton transfer kinetics thus exactly parallels electron transfer kinetics in aqueous media. The critical size of 4±1 molecules and a specific structure of the water cluster apparently determine the controlling rates for both electron and proton charge transfer processes in aqueous media.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesSiede, W. ; Robinson, G. W. ; Kalainov, D. ; Malley, T. ; Friedberg, E. C.
Oxford, UK : Blackwell Publishing Ltd
Published 1989Staff ViewISSN: 1365-2958Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyMedicineNotes: Regulation of the DNA damage-inducible RAD2 gene was investigated in yeast cells transformed with centromeric plasmids containing RAD2-lacZ fusion constructs. Deletion analysis defined several regions in the 350 bp region upstream of the translational start codon which are required for induction of β-galactosidase activity. No deletions resulted in constitutivety enhanced expression. We therefore conclude that induction of RAD2 by DNA-damaging agents is positively regulated. Two domains required for induction have a similar sequence and are located ∼70 and ∼140bp upstream of the major transcriptional start site. Four other sequence domains required for induction contain uninterrupted poly(dA) poly(dT) stretches 9-13 bp long. Deletion of some of these AT-rich domains also affects constitutive expression of RAD2. Expression of RAD2 is not cell-cycle-regulated in mitotic cells. However, meiosis is accompanied by increased steady-state levels of RAD2 mRNA in the absence of DNA damage. This enhanced transcription is not dependent on the presence of upstream sequences required for regulation of induction by DNA damage. Increased steady-state levels of RAD2 mRNA are induced by cycloheximide in asynchronously dividing populations of cells, but not in non-replicating cells arrested in G1 phase of the cell cycle. Following exposure to u.v. irradiation induction is also dramatically reduced in non-replicating cells.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] THE characteristic constituent of the natural substance, clay, has been the subject of numerous investigations both by chemists and by pedologists. It is generally believed to be colloidal, and the residual product of the hydrolytic decomposition of mineral silicates. Whilst attempts have been ...Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] AMONG the factors concerned in the development of soil profiles, erosion has, until recently, received comparatively little attention. I venture to direct attention to two possible examples of the influence of normal erosion, as distinct from catastrophic erosion, on the course of profile ...Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1572-9591Keywords: Dynamic enhancement of solid-state nuclear fusion ; non-Maxwellian distributions ; kinetic energy imbalanceSource: Springer Online Journal Archives 1860-2000Topics: Energy, Environment Protection, Nuclear Power EngineeringNotes: Abstract Determining velocity distribution functions for ensembles is one of the most fundamental problems in statistical mechanics. In this paper, based on the results of computer molecular dynamics (MD) methods, we point out that the velocity distribution of low-mass classical particles subjected to a strong force field in a heavy atom environment is generally noncanonical. When the system reaches equilibrium, a non-Maxwellian distribution persists. The effective temperature of some of the low-mass particles may be one or two orders of magnitude greater than the average temperature of the system. “Cold” fusion may thus be enhanced by as much as 30–50 orders of magnitude over that calculated on the basis of 300K Maxwell distributions.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] IN the modern study of soils, there is an urgent need for methods of analysis which will express quantitatively the fundamental properties and genetic relationships of the material examined. We are venturing to suggest a provisional method whereby an approximate estimate may be obtained of the ...Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] THE growth of interest in soil surveys of recent years and the impetus given to the natural study of soil by the work of the Russian pedologists have led to considerable discussion directed towards the formulation of a world system of classification. C. F. Marbut (Proc. Intern. Congr. Soil ...Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] DR. B. A. KEEN'S article in NATURE of September 5, p. 282, does well to invite the attention of research workers to the possible future developments in agricultural education and research in Great Britain. It may be regretted that Dr. Keen sought to restrict his remarks to arable agriculture. I ...Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesGrigorjew, P. N. ; Koshin, Je. I. ; Hecht, H. ; Maffei, F. J. ; Robinson, G. W.
Springer
Published 1942Staff ViewISSN: 1618-2650Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 1573-6776Source: Springer Online Journal Archives 1860-2000Topics: Process Engineering, Biotechnology, Nutrition TechnologyNotes: Summary Saccharomyces cerevisiae were observed to undergo drastic morphological changes when grown in continuous culture. Peak elongations and minimum cell volumes were found at intermediate dilution rates when it was believed the insitu glucose concentration was at its lowest. The shapes and sizes were reproducible and have been quantified at two different glucose feed concentrations.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 1573-5117Keywords: eutrophication ; nutrients ; algae ; Georgian Bay ; Great LakesSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract The phytoplankton and nutrient status of the embayments between Penetanguishene and Waubaushene in southern Georgian Bay (Severn Sound) were examined during the ice-free periods of 1973–1982 because the area showed symptoms of excessive nutrient enrichment. Four wastewater treatment plants currently discharge to the area, another is under construction and a sixth plant has been proposed. Except for Penetang Bay, the area is well-mixed by prevailing winds but is somewhat isolated from the main part of Georgian Bay. Average phytoplankton biomasses throughout the area were 10–20× higher than values from adjacent Nottawasaga Bay where, during 1980, total phytoplankton biomass ranged between 0.15 and 0.25 mm3 · l−1. Total phosphorus concentrations were highest in Penetang Bay, ranging between 30 and 49 µg P · l−1 (May–September means) over the 10 year period. Phosphorus concentrations in Nottawasaga Bay averaged 4–6 µg P · l−1 and no significant differences were detected among the sampling stations; however, phytoplankton densities at stations near urban centres and river inflows were significantly higher than at more remote offshore sites and attests to the use of phytoplankton as a sensitive measure of trophic status in Georgian Bay. Although improvement of Severn Sound water quality to a level comparable to that presently existing in Nottawasaga Bay may never be practical, steps are being taken to control high industrial phosphorus loading and to lessen bypassing of sewage treatment facilities previously hydraulically overloaded during periods of heavy runoff. These measures, along with an evaluation of other major sources of nutrients to Severn Sound, should enable a refinement of the nutrient management programme for Severn Sound and some improvement in trophic status.Type of Medium: Electronic ResourceURL: