EPR Test with Photons and Kaons: Analogies

We present a unified formalism describing EPR test using spin 1/2 particles, photons and kaons. This facilitates the comparison between existing experiments using photons and kaons. It underlines the similarities between birefringence and polarization dependent losses that affects experiments using optical fibers and mixing and decay that are intrinsic to the kaons. We also discuss the limitation these two characteristics impose on the testing of Bell's inequality.Comment: 12 pages, 5 figure

Multiplicative random walk Metropolis-Hastings on the real line

In this article we propose multiplication based random walk Metropolis Hastings (MH) algorithm on the real line. We call it the random dive MH (RDMH) algorithm. This algorithm, even if simple to apply, was not studied earlier in Markov chain Monte Carlo literature. The associated kernel is shown to have standard properties like irreducibility, aperiodicity and Harris recurrence under some mild assumptions. These ensure basic convergence (ergodicity) of the kernel. Further the kernel is shown to be geometric ergodic for a large class of target densities on $\mathbb{R}$. This class even contains realistic target densities for which random walk or Langevin MH are not geometrically ergodic. Three simulation studies are given to demonstrate the mixing property and superiority of RDMH to standard MH algorithms on real line. A share-price return data is also analyzed and the results are compared with those available in the literature

Study of unstable particle through the spectral function in O(4) ϕ4\phi^4 theory

We test application of the maximum entropy method to decompose the states contributing to the unstable $\sigma$ correlation function through the spectral function in the four dimensional O(4) $\phi^4$ theory. Reliable results are obtained for the $\sigma$ mass and two-particle $\pi\pi$ state energy using only the $\sigma$ correlation function. We also find that the property of the $\sigma$ particle is different between the unstable ($m_{\sigma}/m_{\pi}>2$) and stable ($m_{\sigma}/m_{\pi}<2$) cases.Comment: Lattice2002(spectrum), 3 page

Noisy Monte Carlo: Convergence of Markov chains with approximate transition kernels

Monte Carlo algorithms often aim to draw from a distribution $\pi$ by simulating a Markov chain with transition kernel $P$ such that $\pi$ is invariant under $P$. However, there are many situations for which it is impractical or impossible to draw from the transition kernel $P$. For instance, this is the case with massive datasets, where is it prohibitively expensive to calculate the likelihood and is also the case for intractable likelihood models arising from, for example, Gibbs random fields, such as those found in spatial statistics and network analysis. A natural approach in these cases is to replace $P$ by an approximation $\hat{P}$. Using theory from the stability of Markov chains we explore a variety of situations where it is possible to quantify how 'close' the chain given by the transition kernel $\hat{P}$ is to the chain given by $P$. We apply these results to several examples from spatial statistics and network analysis.Comment: This version: results extended to non-uniformly ergodic Markov chain

Bell inequality violation with two remote atomic qubits

We observe violation of a Bell inequality between the quantum states of two remote Yb ions separated by a distance of about one meter with the detection loophole closed. The heralded entanglement of two ions is established via interference and joint detection of two emitted photons, whose polarization is entangled with each ion. The entanglement of remote qubits is also characterized by full quantum state tomography.Comment: 4 pages, 4 figure

Exploring the complexities of gender roles and psychological wellbeing in farm-families: implications for agricultural extension, management and research

Premised on the recognition that psychological wellbeing is a vital component of optimal productivity, and the need for agricultural extension to enhance farmers' welfare, the study was motivated by a dearth of research on the construction and determinants of psychological wellbeing and gender roles in farm-families. The intention was to gain insight and understanding of the farmers' life experiences, peculiar needs, problems and aspirations, in their unique socio-historical and cultural contexts. The study explored the complexities of the socio-cultural construction of gender roles and psychological wellbeing in farm-families of Ogun state Nigeria. The study is interdisciplinary in nature, drawing from and contributing to the bodies of knowledge in gender-based research, social psychology, family studies, and agricultural extension. Findings reveal a need for the development of gender-sensitive and culture-specific strategies in the agricultural extension system, aimed at improving psychological wellbeing and livelihood security of farm-families and ultimately enhancing sustainable agricultural and national development. Keywords: gender, farm-families, implications for extension, Nigeria South African Journal of Agricultural Extension Vol. 34(1) 2005: 122-13

CRANKITE: a fast polypeptide backbone conformation sampler

Background: CRANKITE is a suite of programs for simulating backbone conformations of polypeptides and proteins. The core of the suite is an efficient Metropolis Monte Carlo sampler of backbone conformations in continuous three-dimensional space in atomic details. Methods: In contrast to other programs relying on local Metropolis moves in the space of dihedral angles, our sampler utilizes local crankshaft rotations of rigid peptide bonds in Cartesian space. Results: The sampler allows fast simulation and analysis of secondary structure formation and conformational changes for proteins of average length

Management Measures of Shrimp Trawling Fishery in Arafura Sea, Indonesia: a Challenge

Since there were many evidences on trawling impact to the environment and society, government has banned trawl operations in Indonesian waters except for those in the Arafura Sea. It is not solely acquitted trawl operation in the area without restrain, but it has been put together with the measures taken to exploit the shrimp resources in optimal manner. Those are input controls, output controls and technical measures. This paper examines two major challenges in applying these management measures: declining of shrimp stock and lack of legal enforcement. Come what may the fishing regulations impose in the shrimp trawling, without effective enforcement, the purpose of fisheries management unlikely will be achieved

SGR 0418+5729: a low-magnetic-field magnetar

Soft gamma-ray repeaters and anomalous X-ray pulsars are a small (but growing) group of X-ray sources characterized by the emission of short bursts and by a large variability in their persistent flux. They are believed to be magnetars, i.e. neutron stars powered by extreme magnetic fields 1E14-1E15 G). We found evidence for a magnetar with a low magnetic field, SGR 0418+5729, recently detected after it emitted bursts similar to those of soft gamma-ray repeaters. New X-ray observations show that its dipolar magnetic field cannot be greater than 8E12 G, well in the range of ordinary radio pulsars, implying that a high surface dipolar magnetic field is not necessarily required for magnetar-like activity. The magnetar population may thus include objects with a wider range of magnetic-field strengths, ages and evolutionary stages than observed so far.Comment: 4 pages, 2 figures; to appear in the Proceedings of the Pulsar Conference 2010, Chia, Sardinia (Italy), 10-15 October 201