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<jats:p>A potential gene therapy approach could restore some vision to patients with retinitis pigmentosa.</jats:p>

<jats:p>Fluid dynamics similar to those known to drive smoke rings shoot moss spores far and wide.</jats:p>

<jats:p>Stimulating erythropoietin production in the mouse liver points to a treatment for anemia caused by chronic kidney disease.</jats:p>

<jats:title>Pulsar Clocks</jats:title> <jats:p> Pulsars are rotating neutron stars whose rotation rates can be extremely stable, sometimes rivaling the precision atomic clock. Unfortunately, not all pulsars are this precise—most show irregularities in their rotation rates. Using a large data set collected over many years at Jodrell Bank in the United Kingdom, <jats:bold> Lyne <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="408" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1186683">408</jats:related-article> , published online 24 June) show that the rotation of pulsars is not modulated by a single spin-down rate but typically by two, each accompanied by a unique pulse profile. The irregularities are linked to abrupt quasiperiodic changes in the pulsar's magnetosphere, observed as changes in pulse shape and spin-down rate. Thus, it may be possible to use pulse-shape information to improve the precision of pulsars as stable clocks that can be used as probes of gravitational physics. </jats:p>

<jats:title>Let There Be Light</jats:title> <jats:p> Retinitis pigmentosa, a disease that can result from a wide variety of genetic defects, causes degeneration of photoreceptor cells in the retina and leads to blindness. In the course of the disease, it is generally the rod photoreceptor cells that degenerate first. Cone photoreceptor cells may persist, but in a damaged and nonfunctional state. <jats:bold> Busskamp <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="413" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1190897">413</jats:related-article> , published online 24 June; see the cover; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="5990" page="403" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1194086">Cepko</jats:related-article> </jats:bold> ) have now applied a gene therapy approach to mouse models of retinitis pigmentosa. Inducing expression of a bacterial light-activated ion pump, halorho dopsin, in the damaged cone cells improved visual responses in the diseased mouse retinas. Thus, it may be possible to rescue cone photoreceptors therapeutically, even after they have already been damaged. </jats:p>

<jats:title>Quantum Mechanics Born to Be Linear</jats:title> <jats:p> Two pillars of modern physics, quantum mechanics and gravity, have so far resisted attempts to be reconciled into one grand theory. This has prompted suggestions that theories about either or both need to be modified at a fundamental level. <jats:bold> Sinha <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="418" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1190545">418</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="5990" page="396" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1192624">Franson</jats:related-article> </jats:bold> ) looked at the interference pattern resulting from a number of slits, to test the “Born rule” of quantum mechanics. They verified that Born holds true—that the interference pattern is built up by the interference from two paths, and two paths only, with no higher-order paths interfering. The result rules out any nonlinear theories of quantum mechanics; thus, any modification of theory will need to take into account that quantum mechanics is linear. </jats:p>

<jats:title>Ancient Carbonate Minerals on Mars</jats:title> <jats:p> The historical presence of liquid water on Mars together with a CO <jats:sub>2</jats:sub> -rich atmosphere should have resulted in the accumulation of large deposits of carbonate minerals. Yet, evidence for the presence of carbonates on the surface of Mars has been scarce. Using data collected by the Mars Exploration Rover, Spirit, <jats:bold> Morris <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="421" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1189667">421</jats:related-article> , published online 3 June; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="5990" page="400" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1192828">Harvey</jats:related-article> </jats:bold> ) now present evidence for carbonate-rich outcrops in the Comanche outcrops within the Gusev crater. The carbonate is a major outcrop component and may have formed in the Noachian era (∼4 billion years ago) by precipitation from hydrothermal solutions that passed through buried carbonate deposits. Thus, it is likely that extensive aqueous activity under neutral pH conditions did occur on Mars. </jats:p>

<jats:title>Network Approaches to Highly Porous Materials</jats:title> <jats:p> Metal-organic frameworks (MOFs), in which inorganic centers are bridged by organic linkers, can achieve very high porosity for gas absorption. However, as the materials develop larger void spaces, there is also more room for growing interpenetrating networks—filling the open spaces not with gas molecules but with more MOFs. <jats:bold> Furukawa <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="424" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1192160">424</jats:related-article> , published online 1 July) describe the synthesis of a MOF in which zinc centers are bridged with long, highly conjugated organic linkers, but in which the overall symmetry of the networks created prevents formation of interpenetrating networks. Extremely high surface areas and storage capacities for hydrogen, carbon dioxide, and methane were observed. </jats:p>

<jats:title>Acidification of the Ancient Oceans</jats:title> <jats:p> Ocean acidification fueled by rising levels of atmospheric CO <jats:sub>2</jats:sub> is likely to become a major challenge for ocean ecosystems. Understanding how marine biota responded to similar events in Earth's history may provide clues as to what to expect—and what to prevent—in the future. To this end, <jats:bold> Erba <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="428" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1188886">428</jats:related-article> ) present a detailed stratigraphic and geochemical characterization of 120-million-year-old marine sediments from a time when the oceans acidified because of a massive outgassing of volcanic CO <jats:sub>2</jats:sub> . Microscopic fossils in the sediments, such as calcareous nannoplankton, show evidence of having responded to this major disruption through species-specific adaptations like deforming and shrinking their cells. These changes allowed these abundant and diverse organisms to avoid extinction, even through a subsequent global depletion of ocean oxygen levels. </jats:p>

<jats:title>A New Look at Old Data</jats:title> <jats:p> Although the full genome of <jats:italic>Caenorhabditis elegans</jats:italic> has been available for over 10 years, only a portion of the full-length messenger RNAs (mRNAs) and their expression through development has been analyzed. By combining multiple methods, involving a careful reannotation of existing data sets, sequencing of poly-A captured RNAs from multiple developmental stages, as well as cloning and deep sequencing of a subset of genes, <jats:bold> Mangone <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="432" related-article-type="in-this-issue" vol="329" xlink:href="10.1126/science.1191244">432</jats:related-article> , published online 3 June) defined ∼26,000 distinct mRNA three-prime untranslated regions (3′UTRs) for ∼85% of the protein-coding genes. Most <jats:italic>C. elegans</jats:italic> genes have more than one 3′UTR, arising through different mechanisms including trans-splicing–coupled cleavage and polyadenylation. The work highlights the importance of the 3'UTRs in the regulation of mRNA stability and translation. </jats:p>