2,155 research outputs found
Spinoza
"Spinoza", second edition.
Encyclopedia entry for the Springer Encyclopedia of EM Phil and the Sciences, ed. D. Jalobeanu and C. T. Wolfe
Connecting up strategy: are senior strategy directors a missing link?
With companies being exhorted to become more strategically agile and internally connected, this article examines the role of the Senior Strategy Director, the executive tasked specifically with internal strategy. In particular, it explores what they do, what specific capabilities they deploy to enable effective contribution to the company, and in what ways they facilitate the connectedness of strategy. An analysis of multiple interviews over time with Senior Strategy Directors of large companies shows the vital and challenging role these executives play in both shaping, connecting up, and executing strategy. This article identifies the particular capabilities necessary for Senior Strategy Directors to perform their role and shows how it all depends upon their skilful deployment. These findings have significant implications for understanding unfolding micro-processes of strategy in large organizations, for assumptions about the skills and capabilities necessary to be an effective Senior Strategy Director, and for business schools in terms of the content and style of strategy courses they provide
Generalized Ensemble and Tempering Simulations: A Unified View
From the underlying Master equations we derive one-dimensional stochastic
processes that describe generalized ensemble simulations as well as tempering
(simulated and parallel) simulations. The representations obtained are either
in the form of a one-dimensional Fokker-Planck equation or a hopping process on
a one-dimensional chain. In particular, we discuss the conditions under which
these representations are valid approximate Markovian descriptions of the
random walk in order parameter or control parameter space. They allow a unified
discussion of the stationary distribution on, as well as of the stationary flow
across each space. We demonstrate that optimizing the flow is equivalent to
minimizing the first passage time for crossing the space, and discuss the
consequences of our results for optimizing simulations. Finally, we point out
the limitations of these representations under conditions of broken ergodicity.Comment: 11 pages Latex, 2 eps figures, revised version, typos corrected, PRE
in pres
Diffusion in the Continuous-Imaginary-Time Quantum World-Line Monte Carlo Simulations with Extended Ensembles
The dynamics of samples in the continuous-imaginary-time quantum world-line
Monte Carlo simulations with extended ensembles are investigated. In the case
of a conventional flat ensemble on the one-dimensional quantum S=1 bi-quadratic
model, the asymmetric behavior of Monte Carlo samples appears in the diffusion
process in the space of the number of vertices. We prove that a local
diffusivity is asymptotically proportional to the number of vertices, and we
demonstrate the asymmetric behavior in the flat ensemble case. On the basis of
the asymptotic form, we propose the weight of an optimal ensemble as
, where denotes the number of vertices in a sample. It is shown
that the asymmetric behavior completely vanishes in the case of the proposed
ensemble on the one-dimensional quantum S=1 bi-quadratic model.Comment: 4 pages, 2 figures, update a referenc
Monte Carlo Methods for Rough Free Energy Landscapes: Population Annealing and Parallel Tempering
Parallel tempering and population annealing are both effective methods for
simulating equilibrium systems with rough free energy landscapes. Parallel
tempering, also known as replica exchange Monte Carlo, is a Markov chain Monte
Carlo method while population annealing is a sequential Monte Carlo method.
Both methods overcome the exponential slowing associated with high free energy
barriers. The convergence properties and efficiency of the two methods are
compared. For large systems, population annealing initially converges to
equilibrium more rapidly than parallel tempering for the same amount of
computational work. However, parallel tempering converges exponentially and
population annealing inversely in the computational work so that ultimately
parallel tempering approaches equilibrium more rapidly than population
annealing.Comment: 10 pages, 3 figure
Development of a Molecular Signature to Monitor Pharmacodynamic Responses Mediated by In Vivo Administration of Glucocorticoids
© 2018 American College of Rheumatology. Objective: To develop an objective, readily measurable pharmacodynamic biomarker of glucocorticoid (GC) activity. Methods: Genes modulated by prednisolone were identified from in vitro studies using peripheral blood mononuclear cells from normal healthy volunteers. Using the criteria of a \u3e2-fold change relative to vehicle controls and an adjusted P value cutoff of less than 0.05, 64 up-regulated and 18 down-regulated genes were identified. A composite score of the up-regulated genes was generated using a single-sample gene set enrichment analysis algorithm. Results: GC gene signature expression was significantly elevated in peripheral blood leukocytes from normal healthy volunteers following oral administration of prednisolone. Expression of the signature increased in a dose-dependent manner, peaked at 4 hours postadministration, and returned to baseline levels by 48 hours after dosing. Lower expression was detected in normal healthy volunteers who received a partial GC receptor agonist, which is consistent with the reduced transactivation potential of this compound. In cohorts of patients with systemic lupus erythematosus and patients with rheumatoid arthritis, expression of the GC signature was negatively correlated with the percentages of peripheral blood lymphocytes and positively correlated with peripheral blood neutrophil counts, which is consistent with the known biology of the GC receptor. Expression of the signature largely agreed with reported GC use in these populations, although there was significant interpatient variability within the dose cohorts. Conclusion: The GC gene signature identified in this study represents a pharmacodynamic marker of GC exposure
Finite size scaling in neural networks
We demonstrate that the fraction of pattern sets that can be stored in
single- and hidden-layer perceptrons exhibits finite size scaling. This feature
allows to estimate the critical storage capacity \alpha_c from simulations of
relatively small systems. We illustrate this approach by determining \alpha_c,
together with the finite size scaling exponent \nu, for storing Gaussian
patterns in committee and parity machines with binary couplings and up to K=5
hidden units.Comment: 4 pages, RevTex, 5 figures, uses multicol.sty and psfig.st
Simulations of grafted polymers in a good solvent
We present improved simulations of three-dimensional self avoiding walks with
one end attached to an impenetrable surface on the simple cubic lattice. This
surface can either be a-thermal, having thus only an entropic effect, or
attractive. In the latter case we concentrate on the adsorption transition, We
find clear evidence for the cross-over exponent to be smaller than 1/2, in
contrast to all previous simulations but in agreement with a re-summed field
theoretic -expansion. Since we use the pruned-enriched Rosenbluth
method (PERM) which allows very precise estimates of the partition sum itself,
we also obtain improved estimates for all entropic critical exponents.Comment: 5 pages with 9 figures included; minor change
Photoswitchable diacylglycerols enable optical control of protein kinase C.
Increased levels of the second messenger lipid diacylglycerol (DAG) induce downstream signaling events including the translocation of C1-domain-containing proteins toward the plasma membrane. Here, we introduce three light-sensitive DAGs, termed PhoDAGs, which feature a photoswitchable acyl chain. The PhoDAGs are inactive in the dark and promote the translocation of proteins that feature C1 domains toward the plasma membrane upon a flash of UV-A light. This effect is quickly reversed after the termination of photostimulation or by irradiation with blue light, permitting the generation of oscillation patterns. Both protein kinase C and Munc13 can thus be put under optical control. PhoDAGs control vesicle release in excitable cells, such as mouse pancreatic islets and hippocampal neurons, and modulate synaptic transmission in Caenorhabditis elegans. As such, the PhoDAGs afford an unprecedented degree of spatiotemporal control and are broadly applicable tools to study DAG signaling
- …