Non-strategic nuclear weapons: the next step in multilateral arms control

This paper by Crispin Rovere and Kalman A Robertson addresses the many barriers to including tactical nuclear weapons in disarmament talks. It considers the difficulty of bringing other emerging powers such as China into the nuclear arms control equation. The study proposes a new arms control treaty that would ban outright the development and possession of a special kind of tactical nuclear weapon called \u27low-yield nuclear weapons\u27 that the authors argue carries an increasingly grave risk of starting a nuclear war. The paper says that Australia should take the lead in promoting a new treaty banning low-yield nuclear weapons. A longer discussion paper, which includes a more thorough exploration of the technical, strategic and legal issues, as well as many references for further reading is available below

Do correlations create an energy gap in electronic bilayers? Critical analysis of different approaches

This paper investigates the effect of correlations in electronic bilayers on the longitudinal collective mode structure. We employ the dielectric permeability constructed by means of the classical theory of moments. It is shown that the neglection of damping processes overestimates the role of correlations. We conclude that the correct account of damping processes leads to an absence of an energy gap.Comment: 4 page

Divorce : the accountant as financial expert

https://egrove.olemiss.edu/aicpa_guides/1811/thumbnail.jp

Income reconstruction : a guide to discovering unreported incom

https://egrove.olemiss.edu/aicpa_guides/1641/thumbnail.jp

Single shot parameter estimation via continuous quantum measurement

We present filtering equations for single shot parameter estimation using continuous quantum measurement. By embedding parameter estimation in the standard quantum filtering formalism, we derive the optimal Bayesian filter for cases when the parameter takes on a finite range of values. Leveraging recent convergence results [van Handel, arXiv:0709.2216 (2008)], we give a condition which determines the asymptotic convergence of the estimator. For cases when the parameter is continuous valued, we develop quantum particle filters as a practical computational method for quantum parameter estimation.Comment: 9 pages, 5 image

Power-Law Statistics Of Driven Reconnection In The Magnetically Closed Corona

Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since magnetic reconnection is the driving mechanism for many energetic solar phenomena, it is likely that reconnection events themselves display such power-law distributions. In this work, we perform numerical simulations of the solar corona driven by simple convective motions at the photospheric level. Using temperature changes, current distributions, and Poynting fluxes as proxies for heating, we demonstrate that energetic events occurring in our simulation display power-law frequency distributions, with slopes in good agreement with observations. We suggest that the braiding-associated reconnection in the corona can be understood in terms of a self-organized criticality model driven by convective rotational motions similar to those observed at the photosphere.Comment: Accepted by Ap

Driven transverse shear waves in a strongly coupled dusty plasma

The linear dispersion properties of transverse shear waves in a strongly coupled dusty plasma are experimentally studied by exciting them in a controlled manner with a variable frequency external source. The dusty plasma is maintained in the strongly coupled fluid regime with (1 < Gamma << Gamma_c) where Gamma is the Coulomb coupling parameter and Gamma_c is the crystallization limit. A dispersion relation for the transverse waves is experimentally obtained over a frequency range of 0.1 Hz to 2 Hz and found to show good agreement with viscoelastic theoretical results.Comment: The manuscripts contains five pages and 6 figure

Magnetometry via a double-pass continuous quantum measurement of atomic spin

We argue that it is possible in principle to reduce the uncertainty of an atomic magnetometer by double-passing a far-detuned laser field through the atomic sample as it undergoes Larmor precession. Numerical simulations of the quantum Fisher information suggest that, despite the lack of explicit multi-body coupling terms in the system's magnetic Hamiltonian, the parameter estimation uncertainty in such a physical setup scales better than the conventional Heisenberg uncertainty limit over a specified but arbitrary range of particle number N. Using the methods of quantum stochastic calculus and filtering theory, we demonstrate numerically an explicit parameter estimator (called a quantum particle filter) whose observed scaling follows that of our calculated quantum Fisher information. Moreover, the quantum particle filter quantitatively surpasses the uncertainty limit calculated from the quantum Cramer-Rao inequality based on a magnetic coupling Hamiltonian with only single-body operators. We also show that a quantum Kalman filter is insufficient to obtain super-Heisenberg scaling, and present evidence that such scaling necessitates going beyond the manifold of Gaussian atomic states.Comment: 17 pages, updated to match print versio

Measuring salivary cortisol in the behavioral neuroscience laboratory

As instructors who teach laboratory courses in biological psychology/behavioral neuroscience, we have often been at a loss to find appropriate experiments where students are able to play both the role of experimenter and subject. The difficulty arises because there are few biological parameters representing CNS activity that can ethically be examined in human participants. As a result, the go-to experiments that allow students to act as both experimenter and subject tend to be electrophysiological in nature (e.g., EEG, GSR, etc.). It was our desire to create a laboratory module that would allow students to collect and analyze a biochemical measure of human neural activity. We report here the development of an experiment module that utilizes an easily obtainable enzyme immunoassay (EIA) kit (nearly identical to the ELISA) to measure human salivary cortisol. Cortisol is a hormone of the adrenal cortex that can be used as a peripheral indicator of hypothalamic neural activity. Plasma (and salivary) cortisol levels rise due to circadian influences as well as perturbations in the organism’s environment (i.e., stressors) that make it possible to detect rather robust experimental effects. Also, there has been much debate on the role of cortisol and hypothalamic-pituitary-adrenal axis dysregulation in the pathophysiology of depression making for a clinically relevant extension to the lecture portion dealing with the “stress axis” (hypothalamic-pituitary-adrenal or HPA axis). Collection of salivary cortisol is simple, painless, and non-invasive and can be performed at any time the subject desires. Sample storage is convenient as the samples can be kept in a home freezer. Repeated freeze-thaws do not adversely affect the determination of cortisol levels, so the students can just bring them in on the day of the assay without need of in-transport refrigeration or instructor/student coordination. The assay can be performed successfully by anyone with access to a plate reader and a few commonly-used laboratory items. A single plate assay can be completed in two hours (two to three hours by an inexperienced group of students under supervision). With the available cortisol kit, our students have examined both circadian effects and stressor/relaxation effects on salivary cortisol levels in a laboratory class setting. The module has been employed twice and we intend to include it in each semester that the course is taught. One further impact of the module is that studen

Elastic positronium-atom scattering using the stochastic variational method

The stochastic variational method is used in conjunction with stabilization ideas to compute the low energy phase shifts and scattering lengths for positronium-atom scattering. Results are obtained for the Ps-H, Ps-Li+, Ps-He, and Ps-Ps systems. The Ps-H scattering lengths are probably accurate to better than 5% and are the most accurate so far computed. The results for Ps-Li+ and Ps-Ps scattering represent the first published scattering lengths for these systems. The positive scattering length for completely spin-aligned (3)Ps-(3)Ps scattering, namely 2.95a(o), is particularly significant since it demonstrates the feasibility of forming a stable Bose-Einstein condensate of (3)Ps atoms