6,008 research outputs found
Cathedral Chimes : Reverie For Piano
https://digitalcommons.library.umaine.edu/mmb-ps/1438/thumbnail.jp
Evaluating Negotiation Behavior and Results: Can We Identify What We Say We Know?
This article was presented at the Columbus Community Legal Services Anniversary Symposium on Clinical Legal Education at the Catholic University of America, October 198
Evaluating Negotiation Behavior and Results: Can We Identify What We Say We Know?
This article was presented at the Columbus Community Legal Services Anniversary Symposium on Clinical Legal Education at the Catholic University of America, October 198
Saggitarius: A DSL for Specifying Grammatical Domains
Common data types like dates, addresses, phone numbers and tables can have
multiple textual representations, and many heavily-used languages, such as SQL,
come in several dialects. These variations can cause data to be misinterpreted,
leading to silent data corruption, failure of data processing systems, or even
security vulnerabilities. Saggitarius is a new language and system designed to
help programmers reason about the format of data, by describing grammatical
domains -- that is, sets of context-free grammars that describe the many
possible representations of a datatype. We describe the design of Saggitarius
via example and provide a relational semantics. We show how Saggitarius may be
used to analyze a data set: given example data, it uses an algorithm based on
semi-ring parsing and MaxSAT to infer which grammar in a given domain best
matches that data. We evaluate the effectiveness of the algorithm on a
benchmark suite of 110 example problems, and we demonstrate that our system
typically returns a satisfying grammar within a few seconds with only a small
number of examples. We also delve deeper into a more extensive case study on
using Saggitarius for CSV dialect detection. Despite being general-purpose, we
find that Saggitarius offers comparable results to hand-tuned, specialized
tools; in the case of CSV, it infers grammars for 84% of benchmarks within 60
seconds, and has comparable accuracy to custom-built dialect detection tools.Comment: OOPSLA 202
Jacobi Fields on Statistical Manifolds of Negative Curvature
Two entropic dynamical models are considered. The geometric structure of the
statistical manifolds underlying these models is studied. It is found that in
both cases, the resulting metric manifolds are negatively curved. Moreover, the
geodesics on each manifold are described by hyperbolic trajectories. A detailed
analysis based on the Jacobi equation for geodesic spread is used to show that
the hyperbolicity of the manifolds leads to chaotic exponential instability. A
comparison between the two models leads to a relation among statistical
curvature, stability of geodesics and relative entropy-like quantities.
Finally, the Jacobi vector field intensity and the entropy-like quantity are
suggested as possible indicators of chaoticity in the ED models due to their
similarity to the conventional chaos indicators based on the Riemannian
geometric approach and the Zurek-Paz criterion of linear entropy growth,
respectively.Comment: 22 page
Estrogen activation of microglia underlies the sexually dimorphic differences in Nf1 optic glioma-induced retinal pathology
Children with neurofibromatosis type 1 (NF1) develop low-grade brain tumors throughout the optic pathway. Nearly 50% of children with optic pathway gliomas (OPGs) experience visual impairment, and few regain their vision after chemotherapy. Recent studies have revealed that girls with optic nerve gliomas are five times more likely to lose vision and require treatment than boys. To determine the mechanism underlying this sexually dimorphic difference in clinical outcome, we leveraged Nf1 optic glioma (Nf1-OPG) mice. We demonstrate that female Nf1-OPG mice exhibit greater retinal ganglion cell (RGC) loss and only females have retinal nerve fiber layer (RNFL) thinning, despite mice of both sexes harboring tumors of identical volumes and proliferation. Female gonadal sex hormones are responsible for this sexual dimorphism, as ovariectomy, but not castration, of Nf1-OPG mice normalizes RGC survival and RNFL thickness. In addition, female Nf1-OPG mice have threefold more microglia than their male counterparts, and minocycline inhibition of microglia corrects the retinal pathology. Moreover, pharmacologic inhibition of microglial estrogen receptor-β (ERβ) function corrects the retinal abnormalities in female Nf1-OPG mice. Collectively, these studies establish that female gonadal sex hormones underlie the sexual dimorphic differences in Nf1 optic glioma–induced retinal dysfunction by operating at the level of tumor-associated microglial activation
Egalitarian despots: hierarchy steepness, reciprocity and the grooming-trade model in wild chimpanzees (Pan troglodytes)
Biological-markets theory models the action of natural selection as a marketplace in which animals are viewed as traders with commodities to offer and exchange. Studies of female Old World monkeys have suggested that grooming might be employed as a commodity to be reciprocated or traded for alternative services, yet previous tests of this grooming-trade model in wild adult male chimpanzees (Pan troglodytes) have yielded mixed results. Here we provide the strongest test of the model to date for male chimpanzees: we use data drawn from two social groups (communities) of chimpanzees from different populations, and give explicit consideration to variation in dominance hierarchy steepness as such variation results in differing conditions for biological markets. First, analysis of data from published accounts of other chimpanzee communities, together with our own data, showed that hierarchy steepness varied considerably within and across communities and that the number of adult males in a community aged 20-30 years predicted hierarchy steepness. The two communities in which we tested predictions of the grooming-trade model lay at opposite extremes of this distribution. Second, in accord with the grooming-trade model, we found evidence that male chimpanzees trade grooming for agonistic support where hierarchies are steep (despotic) and consequent effective support is a rank-related commodity, but not where hierarchies are shallow (egalitarian). However, we also found that grooming was reciprocated regardless of hierarchy steepness. Our findings also hint at the possibility of agonistic competition, or at least exclusion, in relation to grooming opportunities compromising the free market envisioned by Biological Markets theory. Our results build on previous findings across chimpanzee communities to emphasise the importance of reciprocal grooming exchanges among adult male chimpanzees, which can be understood in a biological markets framework if grooming by or with particular individuals is a valuable commodity
Measurement in Economics and Social Science
The paper discusses measurement, primarily in economics, from both analytical and historical perspectives. The historical section traces the commitment to ordinalism on the part of economic theorists from the doctrinal disputes between classical economics and marginalism, through the struggle of orthodox economics against socialism down to the cold-war alliance between mathematical social science and anti-communist ideology. In economics the commitment to ordinalism led to the separation of theory from the quantitative measures that are computed in practice: price and quantity indexes, consumer surplus and real national product. The commitment to ordinality entered political science, via Arrow’s ‘impossibility theorem’, effectively merging it with economics, and ensuring its sterility. How can a field that has as its central result the impossibility of democracy contribute to the design of democratic institutions?
The analytical part of the paper deals with the quantitative measures mentioned above. I begin with the conceptual clarification that what these measures try to achieve is a restoration of the money metric that is lost when prices are variable. I conclude that there is only one measure that can be embedded in a satisfactory economic theory, free from unreasonable restrictions. It is the Törnqvist index as an approximation to its theoretical counterpart the Divisia index.
The statistical agencies have at various times produced different measures for real national product and its components, as well as related concepts. I argue that all of these are flawed and that a single deflator should be used for the aggregate and the components. Ideally this should be a chained Törnqvist price index defined on aggregate consumption.
The social sciences are split. The economic approach is abstract, focused on the assumption of rational and informed behavior, and tends to the political right. The sociological approach is empirical, stresses the non-rational aspects of human behavior and tends to the political left. I argue that the split is due to the fact that the empirical and theoretical traditions were never joined in the social sciences as they were in the natural sciences. I also argue that measurement can potentially help in healing this split
Quantum Phase Diagram for Homogeneous Bose-Einstein Condensate
We calculate the quantum phase transition for a homogeneous Bose gas in the
plane of s-wave scattering length a_s and temperature T. This is done by
improving a one-loop result near the interaction-free Bose-Einstein critical
temperature T_c^{(0)} with the help of recent high-loop results on the shift of
the critical temperature due to a weak atomic repulsion using variational
perturbation theory. The quantum phase diagram shows a nose above T_c^{(0)}, so
that we predict the existence of a reentrant transition above T_c^{(0)}, where
an increasing repulsion leads to the formation of a condensate.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of
paper (including all PS fonts) at
http://www.physik.fu-berlin.de/~kleinert/34
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