Regulating short-sales

Short-selling, the practice of selling a security the seller does not own, is done in an attempt to profit from an expected decline in the price of the security. During the recent financial turmoil, many press accounts blamed short-selling for declines in stock prices and even for the collapse of some firms. In "Regulating Short-Sales," Ronel Elul discusses the issue of short-selling. He notes that research has shown that short-selling plays a valuable role in setting accurate prices for securities but that it can also be used to facilitate market manipulation. This latter consideration may provide justification for restricting short-sales under certain circumstances.

Geo-Neutrinos: a short review

Geo-neutrino detection will determine the amount of long lived radioactive elements within our planet and fix the debated radiogenic contribution to the terrestrial heat. In addition, it will provide a direct test of the Bulk Silicate Earth model, a fundamental cosmochemical paradigm about the origin of the Earth. Unorthodox models of Earth's core (including the presence of potassium or the possibility of a giant reactor) can also be checked. This short review presents status and prospects of the field.Comment: 7 pages, 2 figures, presented at Neutrino 2004 in Pari

Chameleonic Theories: A Short Review

In the chameleon mechanism, a field (typically scalar) has a mass that depends on the matter density of the environment: the larger is the matter density, the larger is the mass of the chameleon. We briefly review some aspects of chameleonic theories. In particular, in a typical class of these theories, we discuss the lagrangian, the role of conformal transformations, the equation of motion and the thin-shell effect. We also discuss $f(R)$ theories and chameleonic quantum gravity.Comment: Invited contribution to the special issue "Modified Gravity Cosmology: from Inflation to Dark Energy", published in Universe. 30 pages. 2 figures. arXiv admin note: substantial text overlap with arXiv:hep-ph/0608078, arXiv:astro-ph/0611816 by other author

A Short Review on the Development of Salt Tolerant Cultivars in Rice

Rice is staple food for half of the world. With a population of almost 9.6 billion by the year 2050, there is a dire need of developing techniques to improve the crop plants, not only in terms of better yield but also to withstand harsh environmental conditions and stresses like drought, temperature, flood and salinity. Salinity is second to drought stress and hence it is very important to develop crops tolerant to salinity stress. This review discusses the mechanisms of salt tolerance and the recent developments in understanding the complex tolerance phenomena. One way to address the salinity issue is to develop tolerant rice varieties using conventional and modern breeding techniques for which screening the rice germplasm for the varieties with desired traits is critical. Conventional methods to develop tolerant rice varieties are discussed along with modern biotechnology techniques are also discussed. Quantitative Trait Loci (QTL) and Marker Assisted Selection (MAS) are promising techniques. In addition to these modern techniques, some recent developments in the fields of transgenic plants, haploid breeding and Somaclonal variations have also been discussed. The limited knowledge about molecular and genetic mechanisms to tolerate abiotic stresses, however is a barrier to efficiently develop tolerant cultivars. A combination of conventional and modern biotechnology techniques could possibly open up the new ways

A Short Review on Jet Identification

Jets can be used to probe the physical properties of the high energy density matter created in collisions at the Relativistic Heavy Ion Collider (RHIC). Measurements of strong suppression of inclusive hadron distributions and di-hadron correlations at high $p_{T}$ have already provided evidence for partonic energy loss. However, these measurements suffer from well-known geometric biases due to the competition of energy loss and fragmentation. These biases can be avoided if the jets are reconstructed independently of their fragmentation details - quenched or unquenched. In this paper, we discuss modern jet reconstruction algorithms (cone and sequential recombination) and their corresponding background subtraction techniques required by the high multiplicities of heavy ion collisions. We review recent results from the STAR experiment at RHIC on direct jet reconstruction in central Au+Au collisions at $\sqrt {s_{NN}}= 200$ GeV.Comment: Proceedings for the invited talk of Hot Quarks 2008, Estes Park, CO 18-23 August 200

The nova V1369 Cen -- a short review

We briefly present the spectroscopic evolution of the recent outburst of the classical nova V1369 Cen, and the presence of a narrow absorption line identified as due to the resonance of neutral lithium at 6708 \AA. We also discuss the consequences for the chemical evolution of lithium in the Galaxy.Comment: 8 pages, 5 figures, 2 tables. To appear in the proceedings of the conference "The Golden Age of Cataclysmic Variables and Related Objects - III" held in Palermo, Italy, 7-12 September 201