4,532 research outputs found
Comparison of Lightning Activity and Radar-Retrieved Microphysical Properties in EULINOX Storms
A combined analysis of microphysical thunderstorm properties derived by C-band polarimetric Doppler radar measurements and lightning observations from two ground-based systems are presented. Three types of storms, a multicell, a supercell, and a squall line, that were observed during the European Lightning Nitrogen Oxides project (EULINOX) are investigated. Correlations are sought between the mass of rain, graupel, hail, and snow derived form radar observations at different height levels and the electrical activity, represented either by cloud-to-ground or intracloud flashes. These relationships are explained by connecting the radar-derived properties with the non-inductive charging process. For the multicell and the supercell storm, the lightning activity can be linearly correlated to both the hydrometeor total mass and class specific mass in the upper part of the storm. It is shown that the fractions of graupel and hail above the −20 °C-level in these storms positively correlate with the intracloud flash activity in the supercell, and negatively for the cloud-to-ground lightning frequency in the multicell. No such relation can be established for the squall line, indicating that the convective organization plays a crucial role in the lightning development. The analysis of the masses in the different storms shows that lightning activity cannot be parameterized by total mass alone, other parameters have to be identified. The results provide important information for all lightning studies that rely on bulk properties of thunderstorms, e.g., the parameterization of lightning in mesoscale models or the nowcasting of lightning by radar
Social Preferences and the Efficiency of Bilateral Exchange
Under what conditions do social preferences, such as altruism or a concern for fair outcomes, generate efficient trade? I analyze theoretically a simple bilateral exchange game: Each player sequentially takes an action that reduces his own material payoff but increases the other player’s. Each player’s preferences may depend on both his/her own material payoff and the other player’s. I identify necessary conditions and sufficient conditions on the players’ preferences for the outcome of their interaction to be Pareto efficient. The results have implications for interpreting the rotten kid theorem, gift exchange in the laboratory, and gift exchange in the field
Complete Insecurity of Quantum Protocols for Classical Two-Party Computation
A fundamental task in modern cryptography is the joint computation of a
function which has two inputs, one from Alice and one from Bob, such that
neither of the two can learn more about the other's input than what is implied
by the value of the function. In this Letter, we show that any quantum protocol
for the computation of a classical deterministic function that outputs the
result to both parties (two-sided computation) and that is secure against a
cheating Bob can be completely broken by a cheating Alice. Whereas it is known
that quantum protocols for this task cannot be completely secure, our result
implies that security for one party implies complete insecurity for the other.
Our findings stand in stark contrast to recent protocols for weak coin tossing,
and highlight the limits of cryptography within quantum mechanics. We remark
that our conclusions remain valid, even if security is only required to be
approximate and if the function that is computed for Bob is different from that
of Alice.Comment: v2: 6 pages, 1 figure, text identical to PRL-version (but reasonably
formatted
Competition in Electricity Spot Markets. Economic Theory and International Experience.
The main purpose of this survey paper is to consider the attempts that have been ,ade to apply economic theory snd empirical methods to the analysis of electricity markets, and to evaluate them in light of theoretical considerations and empirical evidence. We describe the key features of the markets in England and Wales, Norway and Australia in order to allow for a comparison of design issues and evaluation of competitive performance
Option Values in Sequential Markets
We consider competitive behaviour in sequential markets when current success or failure may affect the probability of future market opportunities. The analysis is conducted in a set up which may be interpreted as two private-value, sealed-bid, second-price sequential auctions. We demonstrate that whether agents price higher or lower than in the corresponding static context depends on the relative magnitudes of the 'winner's option value' and the 'loser's option value' of participating in the later market
Basic research on the biology of meta-tetra(hydroxyphenyl) chlorin for photodynamic therapy in gynaecology: Somatic genotoxicity assayed with Drosophila melanogaster
The well-established SMART test, a somatic mutation and recombination assay of Drosophila, was applied to assess the possible genotoxicity of sublethal meta-tetra(hydroxyphenyl) chlorin (mTHPC) photodynamic therapy (PDT) to clonogenic cells in situ. The SMART assay monitors the loss of heterozygosity (LOH) at selected cell-marker loci in clonogenic cells of the larval wing primordia. No evidence of genotoxicity was observed under conditions that killed between 38 and 86% of the exposed test larvae. Since the SMART assay is based on the oral uptake of the suspected genotoxic agent, the uptake kinetics of mTHPC by the assay's specific target cells must be known. Therefore, relevant studies are being carried out at present in order to draw final conclusions from this negative test result for genotoxicit
Multicentric Castleman's disease as a cause for unclear febrile episodes in a 55-year-old HIV-infected man
Our case illustrates the difficulties involved in diagnosing multicentric Castleman's disease (MCD) in a human immunodeficiency virus-infected man with febrile episodes and malaise. In the absence of well-established treatment protocols, we have chosen a new treatment algorithm with rituximab, etoposide, and valganciclovir, which led to the remission of clinical symptoms. Yet, we advocate focused exploration for MCD in immunosuppressed patients with unclear febrile episodes, as recent advances in treatment are promisin
Inequality and Procedural Justice in Social Dilemmas
This study investigates the influence of resource inequality and the fairness
of the allocation procedure of unequal resources on cooperative behavior in
social dilemmas. We propose a simple formal behavioral model that incorporates
conflicting selfish and social motivations. This model allows us to predict how
inequality influences cooperative behavior. Allocation of resources is manipulated
by three treatments that vary in terms of procedural justice: allocating resources
randomly, based on merit, and based on ascription. As predicted, procedural
justice influences cooperation significantly. Moreover, gender is found to be an
important factor interacting with the association between procedural justice and
cooperative behavior.
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