Propagation of ultrahigh-energy neutrinos through the Earth

The dispersion relation in matter of ultrahigh-energy neutrinos above the pole of the $W$ resonance (E_{\nu} \gsim {\rm 10}^{7} {\rm GeV} ), is studied. We perform our calculation using the real-time formulation of Thermal Field Theory in which the massless limit for the $W$ boson is taken. The range of active-to-sterile neutrino oscillation parameters for which there is significant mixing enhancement during propagation through the interior of the Earth, and therefore significant attenuation of neutrino beams in the Earth at high energies, is estimated. Finally, this range is considered in view of the cosmological and astrophysical constraints.Comment: 8 pages, some comments and references added, to appear in Phys. Lett.

Disciplining Voluntary Environmental Standards At The WTO - An Indian Legal Viewpoint

This paper looks into the proliferation of privately-formulated environmental product standards and analyses whether Indian industry has a legal recourse under the WTO dispute settlement mechanism if such standards are used as disguised restrictions on trade. The paper highlights some of the issues faced by Indian manufacturers when confronted with voluntary product requirements such as eco-labeling, packaging and recycling requirements in markets of key export interest to them and highlights the role of non-state actors in the formulation of such environmental product standards. Since some of these product standards are capable of being misused as protectionist devices, the paper examines whether the WTO dispute settlement mechanism can be used to resolve an issue which cannot be directly attributed to governmental action (or inaction). In doing so the paper studies the representations made by India and other developing countries at meetings of various WTO Committees; and past decisions of WTO Panels and the Appellate Body to establish the magnitude of the problem and look for possible legal solutions. The paper looks at the issue from a developing country perspective- the assumption being that developing countries are standard-takers, not standard-setters; and are unable to afford the costs of compliance associated with voluntary environmental standards. The analysis focuses predominantly on the use and interpretation of the GATT Agreement and the Agreement on Technical Barriers to Trade and discusses a possible legal strategy that may be adopted in any future dispute.India, Environment, Law, Voluntary Environmental Standards

A Review of the Role of Melatonin in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a troubling disease experienced worldwide. The presentation of symptoms varies from patient to patient, and current prescription treatments can be inadequate in resolving symptoms. This article explores the available scientific literature supporting the use of melatonin in alleviating IBS symptoms

Jets and Jet Multiplicities in High Energy Photon-Nucleon Inetraction:

We discuss the theory of jet events in high-energy photon-proton interactions using a model which gives a good description of the data available on total inelastic $\gamma p$ cross sections up to $\sqrt{s}$=210 GeV. We show how to calculate the jet cross sections and jet multiplicities and give predictions for these quantities for energies appropriate for experiments at the HERA $ep$ collider and for very high energy cosmic ray observations.Comment: 12 pages + 4 figs, MAD/TH/92-8, submitted to Phys. Rev. D(Rapid Communications), figs. available on request from [email protected]

Improved Approximation Algorithms for Stochastic Matching

In this paper we consider the Stochastic Matching problem, which is motivated by applications in kidney exchange and online dating. We are given an undirected graph in which every edge is assigned a probability of existence and a positive profit, and each node is assigned a positive integer called timeout. We know whether an edge exists or not only after probing it. On this random graph we are executing a process, which one-by-one probes the edges and gradually constructs a matching. The process is constrained in two ways: once an edge is taken it cannot be removed from the matching, and the timeout of node $v$ upper-bounds the number of edges incident to $v$ that can be probed. The goal is to maximize the expected profit of the constructed matching. For this problem Bansal et al. (Algorithmica 2012) provided a $3$-approximation algorithm for bipartite graphs, and a $4$-approximation for general graphs. In this work we improve the approximation factors to $2.845$ and $3.709$, respectively. We also consider an online version of the bipartite case, where one side of the partition arrives node by node, and each time a node $b$ arrives we have to decide which edges incident to $b$ we want to probe, and in which order. Here we present a $4.07$-approximation, improving on the $7.92$-approximation of Bansal et al. The main technical ingredient in our result is a novel way of probing edges according to a random but non-uniform permutation. Patching this method with an algorithm that works best for large probability edges (plus some additional ideas) leads to our improved approximation factors