Combined potential of future long-baseline and reactor experiments

We investigate the determination of neutrino oscillation parameters by experiments within the next ten years. The potential of conventional beam experiments (MINOS, ICARUS, OPERA), superbeam experiments (T2K, NOvA), and reactor experiments (D-CHOOZ) to improve the precision on the ``atmospheric'' parameters $\Delta m^2_{31}$, $\theta_{23}$, as well as the sensitivity to $\theta_{13}$ are discussed. Further, we comment on the possibility to determine the leptonic CP-phase and the neutrino mass hierarchy if $\theta_{13}$ turns out to be large.Comment: 4 pages, 4 figures, Talk given by T.S. at the NOW2004 workshop, Conca Specchiulla (Otranto, Italy), 11--17 Sept. 200

East African pholcid spiders: an overview, with descriptions of eight new species (Araneae, Pholcidae)

This paper summarizes current knowledge about East African pholcids. East Africa is defined as the area from 12°S to 5°N and from 28° to 42°E, including all of Uganda, Kenya, Burundi, Rwanda, and Tanzania. An annotated list of the 15 genera and 87 species recorded from this area is given, together with distribution maps and an identification key to genera. Most East African species (90%) belong to one of only six genera: Buitinga Huber, 2003 (21 species); Smeringopus Simon, 1890 (18); Pholcus Walckenaer, 1805 (17); Spermophora Hentz, 1841 (12); Leptopholcus Simon, 1893 (5) and Quamtana Huber, 2003 (4). Eight species for which DNA sequence data have been published recently are newly described: Buitinga batwa sp. nov., B. wataita sp. nov., Spermophora mau sp. nov., S. maathaiae sp. nov., S. bukusu sp. nov., S. kirinyaga sp. nov., S. kyambura sp. nov. and Quamtana nyahururu sp. nov. Crossopriza johncloudsleyi Deeleman-Reinhold & van Harten, 2001, previously only known from Yemen, is redescribed based on specimens from Kenya. Additional new records are given for 21 previously described species

Stimulated emission and excited-state absorption at room temperature on the 550 nm-laser transition in Er3+ doped YAlO3

A pump- and probe-beam technique is used for measuring time-resolved and cw-pumped excited-state absorption (ESA) and stimulated-emission (SE) spectra of Er3+:YAlO3 with high resolution. In combination with absorption and fluorescence spectra, detailed information on the wavelengths and cross-sections of ESA and SE at the 550 nm laser transition is provided

Market-based Instruments for Environmental Policymaking in Latin America and the Caribbean: Lessons from Eleven Countries

This report is a summary of country studies in Latin America and the Caribbean, addressing the use of market-based instruments (MBIs) and command-and-control (CAC) measures for environmental management in the region. Even though MBIs can significantly add efficiency to existing CAC mechanisms, the scope of MBIs should match the countries institutional capacity to implement them. Gradual and flexible reforms are likely to succeed within the current regional context of continued institutional changes. A key function of MBIs is usually revenue collection, though it does not necessarily lead to successful environmental management. The study suggests that revenues should be channeled to local authorities for an effective MBI's implementation. The report also critiques the regular practice of international donor agencies in recommending the solutions suitable for developed countries, without considering the institutional conditions in developing countries. Further, the study explores both the successes and difficulties experienced in the region regarding regulations, macro-policies, and MBIs; the institutional frameworks of the countries under review; and, the issues considered in the design of MBIs, in order to promote a beneficial dialogue among them

Suppression of the Charge-Density-Wave State in Sr10_{10}Ca4_{4}Cu24_{24}O41_{41} by External Pressure

The influence of external pressure on the charge-density-wave (CDW) ground state of the quasi-one-dimensional two-leg ladder compound Sr$_{10}$Ca$_{4}$Cu$_{24}$O$_{41}$ has been studied by optical reflectivity measurements as a function of temperature (10 - 300~K) and pressure $P$ (0.3 - 4.3~GPa) over the spectral range 580 - 6000 cm$^1$. With increasing pressure the CDW transition temperature $T_{CDW}$ decreases with the linear pressure coefficient $\approx$-70~K/GPa, and above $\approx$3~GPa the CDW phase is suppressed at all temperatures. This behavior is similar to that in compounds Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$ with increasing Ca content $x$ at ambient pressure, with the simple scaling $x \approx 3\cdot P(GPa)$. The size of the CDW gap decreases with increasing pressure, whereas the dimensionality of the high-temperature insulating phase in Sr$_{10}$Ca$_{4}$Cu$_{24}$O$_{41}$ within the ladder plane is hardly affected by external pressure.Comment: accepted for publication in Phys. Rev.

Corner overgrowth: Bending a high mobility two-dimensional electron system by 90 degrees

Introducing an epitaxial growth technique called corner overgrowth, we fabricate a quantum confinement structure consisting of a high-mobility GaAs/AlGaAs heterojunction overgrown on top of an ex-situ cleaved substrate corner. The resulting corner-junction quantum-well heterostructure effectively bends a two-dimensional electron system (2DES) at an atomically sharp $90^{\rm o}$ angle. The high-mobility 2DES demonstrates fractional quantum Hall effect on both facets. Lossless edge-channel conduction over the corner confirms a continuum of 2D electrons across the junction, consistent with Schroedinger-Poisson calculations of the electron distribution. This growth technique differs distinctly from cleaved-edge overgrowth and enables a complementary class of new embedded quantum heterostructures.Comment: 3 pages, 4 figures, latest version accepted to AP