Experimental results on spectra and wave functions of a ray-splitting microwave billiard are presented. The billiard is formed by a flat rectangular microwave cavity with a quarter-circle insert made of teflon in one of the corners. Using the Gutzwiller trace formula, the contribution of the periodic orbits of the billiard to the density of states are determined. The wave functions, many of them showing scars associated with periodic orbits, are interpreted in terms of the semiclassical Green function.

Summary One aim of this paper is to provide an assessment of the recent attempts to interpret the development of Galileo's theory of motion in the late Paduan period 1604?1610. In addition to this a new interpretation of this process of development is advanced. This interpretation is the first that proves able to provide a full account of all the features on folio 152r of volume 72 of the Galilean manuscripts which has been claimed to be of crucial significance. The (...) major feature of the interpretation is that it is the first to account for the relationship between Galileo's theoretical and experimental work in the period 1604?1610. (shrink)

"We prove that any variety of relation algebras which contains an algebra with infinitely many elements below the identity, or which contains the full group relation algebra on some infinite group (or on arbitrarily large finite groups), must have an undecidable equational theory. Then we construct an embedding of the lattice of all subsets of the natural numbers into the lattice of varieties of relation algebras such that the variety correlated with a set [italic capital]X of natural numbers has a (...) decidable equational theory if and only if [italic capital]X is a decidable (i.e., recursive) set. Finally, we construct an example of an infinite, finitely generated, simple, representable relation algebra that has a decidable equational theory.'' -- Abstract. (shrink)

On April 26, 1995, the United States Supreme Court limited the reach of the preemption provision of ERISA in New York State Conference of Blue Cross & Blue Shield Plans v. Tavelers Insurance Co. ). In Travelers, the Supreme Court upheld the validity of a New York statute requiring hospitals to collect surcharges from patients covered by commercial insurers and requiring health maintenance organizations to pay a surcharge to the state's general fund that varies depending on the number of Medicaid-eligible (...) HMO members enrolled. Neither patients insured by Blue Cross/Blue Shield plans nor the plans themselves are similarly charged under the statute. Several commercial insurers and HMOs claimed the surcharges should be preempted under ERISA because they are levied on patients whose insurance or HMO membership premiums are purchased by an ERISA plan.The ERISA preemption clause means that federal regulation, or lack thereof, supersedes state regulation that is related to employee pension and benefit plans. This preemption clause prevents states from changing health care and benefit law for a significant portion of state residents. (shrink)

The Roman Senate in 144 B.C. instructed the urban praetor, Q. Marcius Rex, to repair the conduits of Rome's two existing aqueducts, the Appia and the Anio , and to put an end to illegal use of their water by private citizens. Urban growth now demanded a more copious water supply, and so the Senate further I instructed Marcius to secure additional water for the city. Money was appropriated for this work, and Marcius' praetorship was prorogued for 143. At this (...) point the decemviri objected to a plan for bringing water to the Capitol. The issue was debated in the Senate in 143, and again in 140; but on both occasions Marcius' gratia prevailed, and water reached the Capitol in a new aqueduct which Marcius himself had built. A statue of Marcius was erected in later times on the Capitol, behind the temple of Jupiter, to commemorate this grand achievement.1 An everlasting glory was in fact to be his in the name of the aqueduct whose waters earned poets' praises. (shrink)