I want to thank my supervisor, Martin Grohe, for his patience, many illuminative discussions and for encouraging me to develop questions of my own. I would like to thank Dzifa Ametowobla for supporting me throughout this work especially by reading several parts of it and helping me greatly with the design. Furthermore, I am indebted to Bettina Hepp and Kay Thurley for helpful comments on earlie...

Later on in [2], Grekos refined the previous results, in some cases, by introducing the infimum of the radii of curvature r(Γ ) of the curve. He succeeded in showing an upper bound of the shape N(Γ ) l(Γ )r(Γ )−1/3 and conversely constructed a family of curves Γ0 with N(Γ0) l(Γ0)r(Γ0)−1/3. Naturally, Grekos’ results suppose that the curve has at least C2-regularity. In fact, this is the maximal...

We answer a question of Golumbic, Monma and Trotter by constructing proper tolerance graphs that are not unit tolerance graphs. An infinite family of graphs that are minimal in this respect is specified.

An increase in intracellular Ca2+ concentration ([Ca2+]) and morphological were simultaneously observed by epifluorescence and differential interference contrast (DIC) microscopy during fertilization of the sand dollar, Clypeaster japonicus. [Ca2+], which was detected by a Ca2+ indicator, Fluo-3, initially increased just beneath the sperm-attached site on the egg surface 8.6 sec after attachmen...

We summarize information concerning Recent and Pleistocene-Holocene Uruguayan sand dollars (Mellitidae), as well as Miocene taxa (Monophorasteridae). Recent and Pleistocene-Holocene species (Encope emarginata, Mellita quinquiesperforata, and Leodia sexisperforata) are at their southernmost limits of distribution, with only E. emarginata recorded further south than Uruguay. Lower temperatures to...

Many larvae and other plankton have complex and variable morphologies of unknown functional significance. We experimentally and theoretically investigated the functional consequences of the complex morphologies of larval sand dollars, Dendraster excentricus (Eschscholtz), for hydrodynamic interactions between swimming and turbulent water motion. Vertical shearing flows (horizontal gradients of ...

We examined developmental and behavioural plasticity of sand martin (Riparia riparia) nestlings hand-reared under laboratory conditions. We created six broods of six 4-day-old nestlings and randomly assigned them to one of the two following feeding regimens, each lasting for 3 days: (1) all nestmates fed a similar, limited amount of food (FR nestlings). This simulated synchronous hatching under...

This edition of “Ask the Author” features a discussion with Andrew Martin, who is a professor of law and chair of the political science department at Washington University in St. Louis. Andrew has done some very influential work on the Supreme Court, including co-authoring a paper on ideological drift of Supreme Court Justices, see [1] here, that will appear in issue four of the Northwestern Un...