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<jats:p> In 1957, T. D. Lee and C. N. Yang received the Nobel Prize in physics for their discovery that the basic forces of nature distinguish slightly between left and right. This parity violation means that in another universe, identical to our own but mirror-reversed, the laws of physics would be slightly different. In his Perspective, Haxton describes results presented in the same issue by Wood <jats:italic>et al</jats:italic> . ( <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1759" related-article-type="in-this-issue" vol="275" xlink:href="10.1126/science.275.5307.1759" xlink:type="simple">p. 1759</jats:related-article> ) on high-precision measurement of this fundamental symmetry principle in cesium atoms. At the same time, the experiments have provided the first measurement of a long-sought phenomenon called the anapole moment, which results from parity violation coupling to an electromagnetic field. The precision of these observations is such that they now offer tests of the standard model of particle physics. </jats:p>

<jats:p>The use of genetic information in the workplace poses societal risks that have an impact on employment possibilities, health insurance, and privacy. Individuals who might otherwise believe they can benefit from genetic testing may decline it because of their fear of employment discrimination and lack of privacy in the workplace. As a consequence, the future of research on the benefits and risks of predictive genetic testing may also be compromised. Thus, policy-makers need to evaluate legislative and regulatory strategies to address these concerns. This paper analyzes state and federal legislative approaches to genetic information in the workplace and concludes with a discussion of policy considerations and recommendation.</jats:p>

<jats:p> The amplitude of the parity-nonconserving transition between the 6 <jats:italic>S</jats:italic> and 7 <jats:italic>S</jats:italic> states of cesium was precisely measured with the use of a spin-polarized atomic beam. This measurement gives Im(E1 <jats:sub>pnc</jats:sub> )/β = −1.5935(56) millivolts per centimeter and provides an improved test of the standard model at low energy, including a value for the <jats:italic>S</jats:italic> parameter of −1.3(3) <jats:sub>exp</jats:sub> (11) <jats:sub>theory</jats:sub> . The nuclear spin-dependent contribution was 0.077(11) millivolts per centimeter; this contribution is a manifestation of parity violation in atomic nuclei and is a measurement of the long-sought anapole moment. </jats:p>

<jats:p> Large-amplitude electron density oscillations were observed on a Be(0001) surface by means of variable-temperature scanning tunneling microscopy. Fourier transforms of the images showed a ring of radius 2 <jats:italic>k</jats:italic> <jats:sub>F</jats:sub> , where <jats:italic>k</jats:italic> <jats:sub>F</jats:sub> is the Fermi wave vector of the Be(0001) surface state. This wavelength was expected from Friedel oscillations caused by electronic screening of surface defects, but the amplitude of the waves for energies near the Fermi energy was anomalously large and inconsistent with the Friedel concept of screening. The enhanced amplitude of the waves must be a many-body effect, either in the electron gas (possibly an incipient charge density wave) or in the response of the lattice (electron-phonon coupling). </jats:p>

<jats:p>The local effects of isolated magnetic adatoms on the electronic properties of the surface of a superconductor were studied with a low-temperature scanning tunneling microscope. Tunneling spectra obtained near magnetic adsorbates reveal the presence of excitations within the superconductor's energy gap that can be detected over a few atomic diameters around the impurity at the surface. These excitations are locally asymmetric with respect to tunneling of electrons and holes. A model calculation based on the Bogoliubov-de Gennes equations can be used to understand the details of the local tunneling spectra.</jats:p>

<jats:p>Small water droplets dispersed in a nematic liquid crystal exhibit a novel class of colloidal interactions, arising from the orientational elastic energy of the anisotropic host fluid. These interactions include a short-range repulsion and a long-range dipolar attraction, and they lead to the formation of anisotropic chainlike structures by the colloidal particles. The repulsive interaction can lead to novel mechanisms for colloid stabilization.</jats:p>

<jats:p>Airborne radiometric measurements were used to determine tropospheric profiles of the clear sky greenhouse effect. At sea surface temperatures (SSTs) larger than 300 kelvin, the clear sky water vapor greenhouse effect was found to increase with SST at a rate of 13 to 15 watts per square meter per kelvin. Satellite measurements of infrared radiances and SSTs indicate that almost 52 percent of the tropical oceans between 20°N and 20°S are affected during all seasons. Current general circulation models suggest that the increase in the clear sky water vapor greenhouse effect with SST may have climatic effects on a planetary scale.</jats:p>

<jats:p>Airborne measurements in smoke from biomass burning in Brazil have yielded optical parameters that permit an improved assessment of the effects of smoke on Earth's radiation balance. The global-mean direct radiative forcing due to smoke from biomass burning worldwide is estimated to be no more than about −0.3 watt per square meter (cooling), compared with +2.45 watts per square meter (warming) due to anthropogenic greenhouse gases. On regional scales, direct radiative forcing due to smoke can be large and might indirectly affect global climate.</jats:p>

<jats:p> Measurements of electrical conductivity at high pressure and temperature were taken on the lower mantle phase magnesiowüstite with varying Fe <jats:sup>3+</jats:sup> content. Although previous measurements at atmospheric pressure suggest Fe <jats:sup>2+</jats:sup> -Fe <jats:sup>3+</jats:sup> hopping (small polaron) as the dominant conductivity mechanism, the present experiments show a change in charge transport mechanism with temperature. The lower temperature measurements are consistent with small polaron conduction, but at higher temperatures, which are more applicable to the lower mantle, a large polaron mechanism is suggested. Because these mechanisms have different temperature and compositional dependencies, this transition has important implications for extrapolation to mantle conditions. </jats:p>

<jats:p> Protein kinase C (PKC) signaling is highly conserved among eukaryotes and has been implicated in the regulation of cellular processes such as cell proliferation and growth. In the budding yeast, <jats:italic>PKC1</jats:italic> functions to activate the <jats:italic>SLT2(MPK1)</jats:italic> mitogen-activated protein (MAP) kinase cascade, which is required for the maintenance of cell integrity during asymmetric cell growth. Genetic studies, coimmunoprecipitation experiments, and analysis of protein phosphorylation in vivo and in vitro indicate that the SBF transcription factor (composed of Swi4p and Swi6p), an important regulator of gene expression at the G <jats:sub>1</jats:sub> to S phase cell cycle transition, is a target of the Slt2p(Mpk1p) MAP kinase. These studies provide evidence for a direct role of the <jats:italic>PKC1</jats:italic> pathway in the regulation of the yeast cell cycle and cell growth and indicate that conserved signaling pathways can act to control key regulators of cell division. </jats:p>