Hopf algebras up to homotopy and the Bockstein spectral sequence

Anick proved that every q-mild Hopf algebra up to homotopy is isomorphic to a primitively-generated chain Hopf algebra. We provide a new proof, that involves extensive use of the Bockstein spectral sequence.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-7.abs.htm

The spectra of the laplacians of fractal graphs not satisfying spectral decimation

We consider the spectra of the Laplacians of two sequences of fractal graphs in the context of the general theory introduced by Sabot in 2003. For the sequence of graphs associated with the pentagasket, we give a description of the eigenvalues in terms of the iteration of a map from (C-2)(3) to itself. For the sequence of graphs introduced in a previous paper by the author, we show that the results found therein can be related to Sabot's theory

The Invincible (1758) site: an integrated geophysical assessment

Chirp sub-bottom profiler and repeat sidescan sonar imaging of the Invincible wreck site (1758) in the Solent (U.K.), interpretation, and implications for management of the site

Liquidity Constraints and Imperfect Information in Subprime Lending

We present new evidence on consumer liquidity constraints and the credit market conditions that might give rise to them. Our analysis is based on unique data from a large auto sales company that serves the subprime market. We first document the role of short-term liquidity in driving purchasing behavior, including sharp increases in demand during tax rebate season and a high sensitivity to minimum down payment requirements. We then explore the informational problems facing subprime lenders. We find that default rates rise significantly with loan size, providing a rationale for lenders to impose loan caps because of moral hazard. We also find that borrowers at the highest risk of default demand the largest loans, but the degree of adverse selection is mitigated substantially by effective risk-based pricing.

International collaboration clusters in Africa

Recent discussion about the increase in international research collaboration suggests a comprehensive global network centred around a group of core countries and driven by generic socio-economic factors where the global system influences all national and institutional outcomes. In counterpoint, we demonstrate that the collaboration pattern for countries in Africa is far from universal. Instead, it exhibits layers of internal clusters and external links that are explained not by monotypic global influences but by regional geography and, perhaps even more strongly, by history, culture and language. Analysis of these bottom-up, subjective, human factors is required in order to provide the fuller explanation useful for policy and management purposes.Comment: 12 pp, 5 Figs including map links to viewe

Global Research Report – South and East Asia

Global Research Report – South and East Asia by Jonathan Adams, David Pendlebury, Gordon Rogers & Martin Szomszor. Published by Institute for Scientific Information, Web of Science Group

China's absorptive State: research, innovation and the prospects for China-UK collaboration

China's innovation system is advancing so rapidly in multiple directions that the UK needs to develop a more ambitious and tailored strategy, able to maximise opportunities and minimise risks across the diversity of its innovation links to China. For the UK, the choice is not whether to engage more deeply with the Chinese system, but how. This report analyses the policies, prospects and dilemmas for Chinese research and innovation over the next decade. It is designed to inform a more strategic approach to supporting China-UK collaboration

PASS-GLM: polynomial approximate sufficient statistics for scalable Bayesian GLM inference

Generalized linear models (GLMs) -- such as logistic regression, Poisson regression, and robust regression -- provide interpretable models for diverse data types. Probabilistic approaches, particularly Bayesian ones, allow coherent estimates of uncertainty, incorporation of prior information, and sharing of power across experiments via hierarchical models. In practice, however, the approximate Bayesian methods necessary for inference have either failed to scale to large data sets or failed to provide theoretical guarantees on the quality of inference. We propose a new approach based on constructing polynomial approximate sufficient statistics for GLMs (PASS-GLM). We demonstrate that our method admits a simple algorithm as well as trivial streaming and distributed extensions that do not compound error across computations. We provide theoretical guarantees on the quality of point (MAP) estimates, the approximate posterior, and posterior mean and uncertainty estimates. We validate our approach empirically in the case of logistic regression using a quadratic approximation and show competitive performance with stochastic gradient descent, MCMC, and the Laplace approximation in terms of speed and multiple measures of accuracy -- including on an advertising data set with 40 million data points and 20,000 covariates.Comment: In Proceedings of the 31st Annual Conference on Neural Information Processing Systems (NIPS 2017). v3: corrected typos in Appendix

Jews in East Norse Literature

This book explores the portrayal of Jews and Judaism in medieval Danish and Swedish literary and visual culture. Drawing on over 100 manuscripts and incunabula as well as runic inscriptions and religious art, the author describes the various, often contradictory, images ranging from antisemitism and anti-Judaism to the elevation of Jews as morally exemplary figures. It includes new editions of 54 East Norse texts with English translations