Cluster Growth in two- and three-dimensional Granular Gases

Dissipation in granular media leads to interesting phenomena as there are cluster formation and crystallization in non-equilibrium dynamical states. The freely cooling system is examined concerning the energy decay and the cluster evolution in time, both in two and three dimensions. Interesting parallels to percolation theory are obtained in three dimensions.Comment: 9 pages, 12 figure

The public impact of impacts: How the media play in the mass extinction debates

“Mass media” presentations of the dinosaurs and their co-inhabitants have been around for some 200 years. The question of what exterminated the dinosaurs and allowed mammals to take their leading place on Earth has a similarly lengthy history in the scientific arena and in public. However, there are amazingly few communication studies of the debates around mass extinctions and impacts. Those that do exist have picked up on the fact that these debates involve scientists from several disciplines, scientists who are often unused to reading each other’s research. Under these circumstances, more public or leading journals play a key role, not only in getting ideas out into the public arena, but in informing scientists across disciplinary boundaries. “Normal” communication processes, in which articles in peer-reviewed journals inform the scientific community and “simplified” versions may trickle out to the public via the mass media, become more complex. The dramatic impact answer to the question of the death of the dinosaurs seems to have attracted limited media attention at the time, confined to the “elite” newspapers. This paper analyzes the newspaper coverage of the death of the dinosaurs during the period from 1980 to 2008. I find that the period from 1991 to 1995 was critical in terms of changing public perceptions, insofar as they are determined/reflected in articles in general newspapers. I argue that the “Great Crash of 1994,” when Comet Shoemaker-Levy 9 collided with the giant planet Jupiter, played an important role in propelling the impact scenario for the death of the dinosaurs into the (mass) public eye, and that the news value co-option was important in this process

An efficient, simple dialyzer

Easily assembled, efficient, countercurrent, sandwich-type barrier dialyzer was developed. Dialyzer contains six blood chambers that provide 500 sq cm membrane area. Design membranes are cuprammonium cellulose film. Unit performance was compared with thirteen other dialyzers

Characteristics of ocean-reflected short radar pulses with application to altimetry and surface roughness determination

Current work related to geodetic altimetry is summarized. Special emphasis is placed on the effects of pulse length on both altimetry and sea-state estimation. Some discussion is also given of system tradeoff parameters and sea truth requirements to support scattering studies. The problem of analyzing signal characteristics and altimeter waveforms arising from rough surface backscattering is also considered

Conflicts of Interest in Derivatives Clearing

[Excerpt] The financial crisis implicated the over-the-counter (OTC) derivatives market as a source of systemic risk. In the wake of the crisis, lawmakers sought to reduce systemic risk to the financial system by regulating this market. One of the reforms that Congress introduced in the Dodd-Frank Act (P.L. 111-203) was mandatory clearing of OTC derivatives through clearinghouses, in an effort to remake the OTC market more in the image of the regulated futures exchanges. Clearinghouses require traders to put down cash or liquid assets, called margin, to cover potential losses and prevent any firm from building up a large uncapitalized exposure, as happened in the case of the American International Group (AIG). Clearinghouses thus limit the size of a cleared position based on a firm’s ability to post margin to cover its potential losses. As lawmakers focused on clearing requirements to reduce systemic risk, concerns also arose as to whether the small number of large swaps dealers in existence—mostly the largest banks—might influence clearinghouses or trading platforms in ways that could undermine the efficacy of the approach. Concerns about conflicts of interest in clearing center around whether, if large swap dealers dominate a clearinghouse, they might directly or indirectly restrict access to the clearinghouse; whether they might limit the scope of derivatives products eligible for clearing; or whether they might influence a clearinghouse to lower margin requirements. Trading in OTC derivatives is in fact concentrated around a dozen or so major dealers. The Office of the Comptroller of the Currency (OCC) estimated that, as of the third quarter of 2010, five large commercial banks in the United States represented 96% of the banking industry’s total notional amounts of all derivatives; and those five banks represented 81% of the industry’s net credit exposure to derivatives. The first group of Troubled Asset Relief Program (TARP) recipients included nearly all the large derivatives dealers. As a result of the high degree of market concentration, the failure of a large swaps dealer still has the potential to result in the nullification of tens of billions of dollars worth of contracts, which could pose a systemic threat. A 2009-proposed amendment proposed to H.R. 4173, which passed the House, would have limited ownership interest and governance of the new derivatives clearinghouses by certain large financial institutions and major swap participants. Sections 726 and 765 in the final version of the Dodd-Frank Act mandate that the Commodity Futures Trading Commission (CFTC) and Securities and Exchange Commission (SEC), respectively, must adopt rules to mitigate conflicts of interest. However, it allowed the agencies to decide whether those rules include strict numerical limits on ownership or control. In the CFTC’s proposed rules to mitigate conflicts of interest, published on October 18, 2010, and on January 6, 2011, the CFTC did choose to adopt strict ownership limits, along the lines of the Lynch amendment. The SEC’s proposed rule, published on October 13, 2010, does the same. This report examines how conflicts of interest may arise and analyzes the measures that the CFTC and SEC proposed to address them. It discusses what effect, if any, ownership and control limits may have on derivatives clearing; and whether such limits effectively address the types of conflicts of interest that are of concern to some in the 112th Congress. These rulemakings may interest the 112th Congress as part of its oversight authority for the CFTC and SEC. Trends in clearing and trading derivatives, and the ownership of swap clearinghouses, are discussed in the Appendix

Introduction to Section on Services

published or submitted for publicatio

A qualitative evaluation of a mentoring reading programme for 9-10 year olds in Northern Ireland

This paper discusses the qualitative evaluation of a mentoring reading programme for 9-10 year olds, which was part of a larger evaluation that used a mixed-methods approach including a Randomised Controlled Trial to determine whether there was evidence of improved outcomes for children participating in the scheme (Miller et al. 2009). The mentoring reading programme started in 1999 with 3 schools and by the time of this evaluation had more than 130 schools involved, with an emphasis on socially deprived areas. The programme consisted of volunteers from businesses in Northern Ireland, who were going one hour a week to schools to read books with children with the aim of improving the children’s reading skills and develop their enjoyment of reading. Each volunteer mentored two children for 30 minutes weekly, and stayed with the same children for the duration of the programme. This type of support scheme is perceived as very timely because the need to improve the children’s opportunities, particularly in socially deprived areas, where conditions are in part exacerbated due to recent historical events

Cyclic AMP modulation of ion transport across frog retinal pigment epithelium. Measurements in the short-circuit state.

In the frog retinal pigment epithelium (RPE), the cellular levels of cyclic AMP (cAMP) were measured in control conditions and after treatment with substances that are known to inhibit phosphodiesterase (PDE) activity (isobutyl-1-methylxanthine, SQ65442) or stimulate adenylate cyclase activity (forskolin). The cAMP levels were elevated by a factor of 5-7 compared with the controls in PDE-treated tissues and by a factor of 18 in forskolin-treated tissues. The exogenous application of cAMP (1 mM), PDE inhibitors (0.5 mM), or forskolin (0.1 mM) all produced similar changes in epithelial electrical parameters, such as transepithelial potential (TEP) and resistance (Rt), as well as changes in active ion transport. Adding 1 mM cAMP to the solution bathing the apical membrane transiently increased the short-circuit current (SCC) and the TEP (apical side positive) and decreased Rt. Microelectrode experiments showed that the elevation in TEP is due mainly to a depolarization of the basal membrane followed by, and perhaps also accompanied by, a smaller hyperpolarization of the apical membrane. The ratio of the apical to the basolateral membrane resistance increased in the presence of cAMP, and this increase, coupled with the decrease in Rt and the basolateral membrane depolarization, is consistent with a conductance increase at the basolateral membrane. Radioactive tracer experiments showed that cAMP increased the active secretion of Na (choroid to retina) and the active absorption of K (retina to choroid). Cyclic AMP also abolished the active absorption of Cl across the RPE. In sum, elevated cellular levels of cAMP affect active and passive transport mechanisms at the apical and basolateral membranes of the bullfrog RPE