Diffraction and Low-Q^2 Physics Including Two-Photon Physics

Recent experimental results on the partonic structure of the photon and on the color singlet exchange in strong interaction processes are reviewed. At the LEP electron-positron and HERA lepton-proton colliders, complementary and consistent measurements have been achieved on the quark-gluon structure of quasi-real and virtual photons. At the HERA lepton-proton and Tevatron proton-antiproton colliders, the quark-gluon configuration of the diffractive exchange is consistently found to have a large gluon component. The rate of diffractive interactions observed by the HERA and Tevatron experiments, however, is largely different and challenges explanation (invited plenary talk at the XXIX International Conference on High Energy Physics, Vancouver, B.C. Canada (1998)).Comment: 36 pages (Latex), 35 figures (Postscript); in this replaced version the report on 'Structure Functions' by A.T.Doyle has been taken out and is available in hep-ex/981202

Lessons to Be Learned: Political Party Research and Political Party Assistance

Generally speaking, the effects of international political party assistance are viewed nega-tively, or at least controversially. This study attributes some of the shortcomings of political party aid to the poor relationship between assistance providers and political science party research. They simply operate in different worlds. Party assistance lacks clear-cut concepts and strategies in practice, which makes it difficult to adequately evaluate it. At issue is its “standard method,” with its “transformative” intention to change the party organization of the assistance receivers. At the same time, the scholarship on political parties can provide only limited help to assistance providers due to its own conceptual and methodological re-strictions, such as the Western European bias underlying its major concepts, the predomi-nance of a functionalist approach, and the scant empirical research on political parties out-side of Europe and the US. Taking a cue from recent political party research, we could begin to question the overarching role of political parties in the transition and consolidation proc-ess of new democracies. Other research findings emphasize the coexistence of different types of party organizations, and the possibility of different organizational developments, which might all be consistent with consolidating democracy. All this suggests the necessity of aban-doning the controversial aim of the “transformative impact” of political party aid.democratization, democracy promotion, political party assistance, political party research

The Cleavage Model, Ethnicity and Voter Alignment in Africa: Conceptual and Methodological Problems Revisited

Recent research on political parties and ethnicity has challenged the conventional wisdom about ethnicity as the major factor that explains voter alignment in Africa. The paper maintains that the cleavage model, although modified to include ethnicity, still provides heuristically the best foundation for the explanation of party formation and voting behaviour in Africa. It points out that inconclusive and contradicting research results about the salience of ethnicity can be attributed to a variety of unresolved methodological and conceptual problems linked to the ‘fluidity’ of the concept of ethnicity. To overcome these problems refined research designs and more sophisticated analytical tools are required. Finally, it is safe to assume that the relevance of ethnicity for the formation of party systems and voter alignment is not a uniform pattern across Africa, but will differ from one country to the other.Africa, social cleavages, cleavage model, ethnicity, political parties, party systems