Adaptive Sequential Optimization with Applications to Machine Learning

A framework is introduced for solving a sequence of slowly changing optimization problems, including those arising in regression and classification applications, using optimization algorithms such as stochastic gradient descent (SGD). The optimization problems change slowly in the sense that the minimizers change at either a fixed or bounded rate. A method based on estimates of the change in the minimizers and properties of the optimization algorithm is introduced for adaptively selecting the number of samples needed from the distributions underlying each problem in order to ensure that the excess risk, i.e., the expected gap between the loss achieved by the approximate minimizer produced by the optimization algorithm and the exact minimizer, does not exceed a target level. Experiments with synthetic and real data are used to confirm that this approach performs well.Comment: submitted to ICASSP 2016, extended versio

Deposit Market Competition, Wholesale Funding, and Bank Risk

In this paper we revisit the long debate on the risk effects of bank competition and propose a new approach to the empirical estimation of the relation between deposit market competition and bank risk. Our approach accounts for the opportunity of banks to shift to wholesale funding when deposit market competition is intense. The analysis is based on a unique comprehensive dataset which combines retail deposit rates data with data on bank characteristics and with data on local deposit market features for a sample of 589 U.S. banks. Our results support the notion of a risk-enhancing effect of deposit market competition.bank competition;wholesale funding;bank risk;deposit rates

A Perspective on Hadron Physics

The phenomena of confinement and dynamical chiral symmetry breaking are basic to understanding hadron observables. They can be explored using Dyson-Schwinger equations. The existence of a systematic, nonperturbative and symmetry preserving truncation of these equations enables the proof of exact results in QCD, and their illustration using simple but accurate models. We provide a sketch of the material qualitative and quantitative success that has been achieved in the study of pseudoscalar and vector mesons. Efforts are now turning to the study of baryons, which we exemplify via a calculation of nucleon weak and pionic form factors.Comment: 16 pages, 5 figures. Contribution to the proceedings of the "Xth Mexican Workshop on Particles and Fields," Morelia, Mexico, 6-12 Nov. 200

Levels and Variations of Violation in Rape.

This chapter investigates the variations in crime scene behaviour revealed in a sample of victim statements in cases of stranger sexual assault. Building on previous findings by Canter and Heritage (1990), and Canter (1994), it was hypothesised that there existed a scale of differing levels of violation by the offender. This scale, based upon actions in the offence, ranged from personal violation, through to physical violation and finally, at the most extreme level, sexual violation. Offences could also be differentiated at the personal and physical levels in terms of hostile, controlling, stealing or involving thematic emphases to the criminal’s actions. To test these hypotheses, crime scene data from the first detected offences of 112 British rapists were analysed using a multi-dimensional scaling procedure to explore the relationships amongst crime scene actions. The results provided empirical support for the four action themes as different expressions of various intensities of violation. The implications that these findings have for the investigation of stranger sexual assault and treatment of victims are discussed

Reheating in the Presence of Noise

Explosive particle production due to parametric resonance is a crucial feature of reheating in inflationary cosmology. Coherent oscillations of the inflaton field act as a periodically varying mass in the evolution equation for matter fields which couple to the inflaton. This in turn results in the parametric resonance instability. Thermal and quantum noise will lead to a nonperiodic perturbation in the mass. We study the resulting equation for the evolution of matter fields and demonstrate that noise (at least if it is temporally uncorrelated) will increase the rate of particle production. We also estimate the limits on the magnitude of the noise for which the resonant behavior is qualitatively unchanged.Comment: 26 pages, 2 figures, uses LATE

Golgi localized β1-adrenergic receptors stimulate Golgi PI4P hydrolysis by PLCε to regulate cardiac hypertrophy.

Increased adrenergic tone resulting from cardiovascular stress leads to development of heart failure, in part, through chronic stimulation of β1 adrenergic receptors (βARs) on cardiac myocytes. Blocking these receptors is part of the basis for β-blocker therapy for heart failure. Recent data demonstrate that G protein-coupled receptors (GPCRs), including βARs, are activated intracellularly, although the biological significance is unclear. Here we investigated the functional role of Golgi βARs in rat cardiac myocytes and found they activate Golgi localized, prohypertrophic, phosphoinositide hydrolysis, that is not accessed by cell surface βAR stimulation. This pathway is accessed by the physiological neurotransmitter norepinephrine (NE) via an Oct3 organic cation transporter. Blockade of Oct3 or specific blockade of Golgi resident β1ARs prevents NE dependent cardiac myocyte hypertrophy. This clearly defines a pathway activated by internal GPCRs in a biologically relevant cell type and has implications for development of more efficacious β-blocker therapies

Magnetic-induced phonon anisotropy in ZnCr2_2O4_4 from first principles

We have studied the influence of magnetic order on the optical phonons of the geometrically frustrated spinel ZnCr$_2$O$_4$ from first-principles. By mapping the first-principles phonon calculations onto a Heisenberg-like model, we developed a method to calculate exchange derivatives and subsequently the spin-phonon couping parameter from first-principles. All calculations were performed within LSDA+U