Event Shapes and Power Corrections in ep DIS

Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are used to study the event shape variables thrust, jet broadening, jet mass, C parameter, and two kinds of differential two-jet rates over a large range of ``relevant energy'' Q between 7 GeV and 100 GeV. The Q dependence of the mean values is fit to second order calculations of perturbative QCD applying power law corrections proportional to 1/Q^p to account for hadronization effects. The concept of these power corrections is tested by a systematic investigation in terms of a non-perturbative parameter alpha_{p-1} and the strong coupling constant.Comment: 3 pages, 1 table (latex, including npb.sty), 3 figures (eps), to be published in the Proc. of the DIS99 Workshop, Berlin, 199

Anchoring a Lexicalized Tree-Adjoining Grammar for Discourse

We here explore a ``fully'' lexicalized Tree-Adjoining Grammar for discourse that takes the basic elements of a (monologic) discourse to be not simply clauses, but larger structures that are anchored on variously realized discourse cues. This link with intra-sentential grammar suggests an account for different patterns of discourse cues, while the different structures and operations suggest three separate sources for elements of discourse meaning: (1) a compositional semantics tied to the basic trees and operations; (2) a presuppositional semantics carried by cue phrases that freely adjoin to trees; and (3) general inference, that draws additional, defeasible conclusions that flesh out what is conveyed compositionally.Comment: 7 pages, uses aclcol.st

QCD Scaling Violation at Small x

We investigate the evolution of parton densities at small values of the momentum fraction, x, by including resummed anomalous dimensions in the renormalization group equations. The resummation takes into account the leading-logarithmic contributions (\alpha_S \ln x)^k given by the BFKL equation and the next-to-leading-logarithmic corrections from quark evolution. We present numerical results for the parton densities and the deep inelastic structure function F_2.Comment: 8 pages, Latex, 3 uuencoded figure

Plankton Ecology and Productivity in Jamaican Waters with New and Unique Applications

Unique applications of plankton ecology and productivity in Jamaican waters are presented. While traditional indices were inadequate descriptors of mangrove lagoon water quality, planktonic indices (total Chlorophyll a, zooplankton groups and species) were more reliable. Phytoplankton biomass was used to indicate a longitudinal gradient along the Hellshire Coastline, identifying non-point sources of enrichment, and movement of water masses in the absence of expensive Eulerian current meters. Along that same coast, mean primary production, determined by 14C techniques, confirmed a gradient from the eutrophic Kingston Harbour (21.1 g C m−2year−1) to the oligotrophic control site (0.52 g C m−2 year−1). Maximum inshore station values (36.75–18.39 g C m−2 year−1) were more than 20 times greater than offshore and exceeded Harbour values, confirming non-point sources and localized mechanisms as important inshore sources of eutrophication. The novel use of Ecopath with Ecosim (EwE) software to model trophic flows within planktonic communities was done in two bays. For Discovery Bay, on Jamaica’s north coast, the model indicated a developing ecosystem with open mineral cycles and poor nutrient conservation while in Foul and Folly Bays on the southeastern coast the model indicated greater resilience and ability to recover from perturbations. These applications have facilitated informed management decisions for sustainable use in Jamaican coastal ecosystems

Signatures of four-particle correlations associated with exciton-carrier interactions in coherent spectroscopy on bulk GaAs

Transient four-wave mixing studies of bulk GaAs under conditions of broad bandwidth excitation of primarily interband transitions have enabled four-particle correlations tied to degenerate (exciton-exciton) and nondegenerate (exciton-carrier) interactions to be studied. Real two-dimensional Fourier-transform spectroscopy (2DFTS) spectra reveal a complex response at the heavy-hole exciton emission energy that varies with the absorption energy, ranging from dispersive on the diagonal, through absorptive for low-energy interband transitions to dispersive with the opposite sign for interband transitions high above band gap. Simulations using a multilevel model augmented by many-body effects provide excellent agreement with the 2DFTS experiments and indicate that excitation-induced dephasing (EID) and excitation-induced shift (EIS) affect degenerate and nondegenerate interactions equivalently, with stronger exciton-carrier coupling relative to exciton-exciton coupling by approximately an order of magnitude. These simulations also indicate that EID effects are three times stronger than EIS in contributing to the coherent response of the semiconductor

The Impact of EU Unfair Contract Terms Law on U.S. Business-to-Consumer Internet Merchants

This article focuses on the application of European Union unfair contract terms law to retail Internet transactions that U.S. businesses might engage in with European consumers. It compares attitudes toward consumer protection regulation in the U.S. and the EU to provide some context within which the specific provisions of unfair contract terms law can be understood. While many lawyers and legal academics in the U.S. who study the development of online markets are aware of the profound differences in U.S. and EU information privacy laws, the magnitude of the divergence in consumer electronic contracting law is not as widely recognized. The development of contract law on unfair terms in Europe over the last 25 years is an important change in EU contract law that has no direct counterpart in U.S. contract law. The application of contract law on unfair terms to online transactions is not at all surprising to lawyers in the EU, but may come as quite a surprise to U.S. businesses and the lawyers who advise them if they have mistakenly assumed that cross-border variations in consumer contract law are not great. As some have learned to their detriment, it is not sufficient for businesses to simply deploy U.S. versions of their online terms and conditions in their European operations

Reconstructing particle masses from pairs of decay chains

A method is proposed for determining the masses of the new particles N,X,Y,Z in collider events containing a pair of effectively identical decay chains Z to Y+jet, Y to X+l_1, X to N+l_2, where l_1, l_2 are opposite-sign same-flavour charged leptons and N is invisible. By first determining the upper edge of the dilepton invariant mass spectrum, we reduce the problem to a curve for each event in the 3-dimensional space of mass-squared differences. The region through which most curves pass then determines the unknown masses. A statistical approach is applied to take account of mismeasurement of jet and missing momenta. The method is easily visualized and rather robust against combinatorial ambiguities and finite detector resolution. It can be successful even for small event samples, since it makes full use of the kinematical information from every event.Comment: 12 pages, 5 figure

Myths about HIV and AIDS among serodiscordant couples in Malawi

Purpose: The paper reports on research that uncovered myths about HIV and AIDS held by serodiscordant couples in Malawi, and the sources of these myths. The paper reflects on how the myths affect serodiscordant couples’ engagement with HIV and AIDS information. Design Van Manen's (1997) approach to analysis of phenomenological data is used to analyse data from indepth interviews conducted in Malawi with 21 serodiscordant couples and 3 individuals who had separated from their partners because of serodiscordance. Findings Serodiscordant couples in Malawi believe and hold on to some inaccurate HIV and AIDS information that can be seen as ‘myths’. Some of these myths are perpetuated by official HIV and AIDS information when it is translated into the local languages. Other myths derive from social norms of the societies where the couples live. Practical implications: The findings of this paper have practical implications for how HIV and AIDS information providers should engage with target audiences to understand the origins of the myths they hold. The findings also imply that some myths have technical, religious, moral and cultural bases which need to be addressed before challenging the myth itself. Originality/Value: Using real-life descriptions of experiences of HIV and AIDS information provided by serodiscordant couples, the authors reveal how myths can affect engagement with the information. The authors make recommendations on how to address myths in ways that contribute to a positive experience of HIV and AIDS information by serodiscordant couple

Myths about HIV and AIDS among serodiscordant couples in Malawi

Purpose: The paper reports on research that uncovered myths about HIV and AIDS held by serodiscordant couples in Malawi, and the sources of these myths. The paper reflects on how the myths affect serodiscordant couples’ engagement with HIV and AIDS information. Design Van Manen's (1997) approach to analysis of phenomenological data is used to analyse data from indepth interviews conducted in Malawi with 21 serodiscordant couples and 3 individuals who had separated from their partners because of serodiscordance. Findings Serodiscordant couples in Malawi believe and hold on to some inaccurate HIV and AIDS information that can be seen as ‘myths’. Some of these myths are perpetuated by official HIV and AIDS information when it is translated into the local languages. Other myths derive from social norms of the societies where the couples live. Practical implications: The findings of this paper have practical implications for how HIV and AIDS information providers should engage with target audiences to understand the origins of the myths they hold. The findings also imply that some myths have technical, religious, moral and cultural bases which need to be addressed before challenging the myth itself. Originality/Value: Using real-life descriptions of experiences of HIV and AIDS information provided by serodiscordant couples, the authors reveal how myths can affect engagement with the information. The authors make recommendations on how to address myths in ways that contribute to a positive experience of HIV and AIDS information by serodiscordant couple