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<jats:p>Recent results with Tokamak experiments provide insights into the problem of magnetic confinement. They demonstrate how to avoid anomalous transport and thus solve the major problems of Tokamak reactors: size, the production of 14-megaelectron volt neutrons, and maintenance. An alternate confinement system, the field-reversed configuration, confines beams of protons and boron-11. For the proton–boron-11 fusion reaction, the fusion products are all charged particles for which direct conversion is feasible and neutron flux is negligible.</jats:p>

<jats:p> Carbon-isotope values of bulk organic matter from high-altitude lakes on Mount Kenya and Mount Elgon, East Africa, were 10 to 14 per mil higher during glacial times than they are today. Compound-specific isotope analyses of leaf waxes and algal biomarkers show that organisms possessing CO <jats:sub>2</jats:sub> -concentrating mechanisms, including C <jats:sub>4</jats:sub> grasses and freshwater algae, were primarily responsible for this large increase. Carbon limitation due to lower ambient CO <jats:sub>2</jats:sub> partial pressures had a significant impact on the distribution of forest on the tropical mountains, in addition to climate. Hence, tree line elevation should not be used to infer palaeotemperatures. </jats:p>

<jats:p> Electronic Raman scattering from high- and low-energy excitations was studied as a function of temperature, extent of hole doping, and energy of the incident photons in Bi <jats:sub>2</jats:sub> Sr <jats:sub>2</jats:sub> CaCu <jats:sub>2</jats:sub> O <jats:sub>8±δ</jats:sub> superconductors. For underdoped superconductors, short-range antiferromagnetic (AF) correlations were found to persist with hole doping, and doped single holes were found to be incoherent in the AF environment. Above the superconducting (SC) transition temperature <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> , the system exhibited a sharp Raman resonance of <jats:italic>B</jats:italic> <jats:sub> 1 <jats:italic>g</jats:italic> </jats:sub> symmetry and energy of 75 millielectron-volts and a pseudogap for electron-hole excitations below 75 millielectron-volts, a manifestation of a partially coherent state forming from doped incoherent quasi particles. The occupancy of the coherent state increases with cooling until phase ordering at <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> produces a global SC state. </jats:p>

<jats:p> Polarized and unpolarized neutron scattering was used to measure the wave vector– and frequency-dependent magnetic fluctuations in the normal state (from the superconducting transition temperature, <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> = 35 kelvin, up to 350 kelvin) of single crystals of La <jats:sub>1.86</jats:sub> Sr <jats:sub>0.14</jats:sub> CuO <jats:sub>4</jats:sub> . The peaks that dominate the fluctuations have amplitudes that decrease as <jats:italic>T</jats:italic> <jats:sup>−2</jats:sup> and widths that increase in proportion to the thermal energy, <jats:italic>k</jats:italic> <jats:sub>B</jats:sub> <jats:italic>T</jats:italic> (where <jats:italic>k</jats:italic> <jats:sub>B</jats:sub> is Boltzmann's constant), and energy transfer added in quadrature. The nearly singular fluctuations are consistent with a nearby quantum critical point. </jats:p>

<jats:p> Direct measurements of the current-phase relation, <jats:italic>I</jats:italic> versus Δφ, for a weak link coupling two reservoirs of B-phase superfluid helium-3 ( <jats:sup>3</jats:sup> He-B) were made over a wide range of temperatures. The weak link consists of a square array of 100-nanometer-diameter apertures. For temperatures <jats:italic>T</jats:italic> such that <jats:italic>T</jats:italic> / <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> ≥ 0.6 (where <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> is the superfluid transition temperature), <jats:italic>I</jats:italic> ∝ sin(Δφ). At lower temperatures, <jats:italic>I</jats:italic> (Δφ) approaches a straight line. Several remarkable phenomena heretofore inaccessible to superconducting Josephson junctions, including direct observation of quantum oscillations and continuous knowledge of Δφ, were also observed. </jats:p>

<jats:p> A small, well-preserved dentary of a tribosphenic mammal with the most posterior premolar and all three molars in place has been found in Aptian (Early Cretaceous) rocks of southeastern Australia. In most respects, dental and mandibular anatomy of the specimen is similar to that of primitive placental mammals. With the possible exception of a single tooth reported as Eocene in age, terrestrial placentals are otherwise unknown in Australia until the Pliocene. This possible Australian placental is similar in age to <jats:italic>Prokennalestes</jats:italic> from the late Aptian/early Albian Khoboor Beds of Mongolia, the oldest currently accepted member of the infraclass Placentalia. </jats:p>

<jats:p> Stream channel erosion has long been suspected as the major contributor to long-term sediment yield from urbanizing watersheds. For San Diego Creek in southern California, measurements from 1983 to 1993 showed that stream channel erosion furnished 10 <jats:sup>5</jats:sup> megagrams per year of sediment, or about two-thirds of the total sediment yield. Thus, because channel erosion can be a major source of sediment yield from urbanizing areas, channel stabilization should be a priority in managing sediment yield. </jats:p>

<jats:p>With the use of scanning tunneling microscopy, it is shown that germanium atoms adsorbed on the (100) surface of silicon near room temperature form chainlike structures that are tilted from the substrate dimer bond direction and that consist of two-atom units arranged in adjoining substrate troughs. These units are distinctly different from surface dimers. They may provide the link missing in our understanding of the elementary processes in epitaxial film growth: the step between monomer adsorption and the initial formation of two-dimensional growth islands.</jats:p>