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<jats:p>The key intermediate in the oxidation of carbon-hydrogen bonds by cytochrome P450 has been characterized.</jats:p>

<jats:p>A mathematician's revelation about visual irregularities in nature spawned the field of fractal geometry, now widely used to interpret patterns in diverse fields.</jats:p>

<jats:title>The Making of Amazonian Diversity</jats:title> <jats:p> The biodiversity of the Amazon Basin is legendary, but the processes by which it has been generated have been debated. In the late 20th century the prevalent view was that the engine of diversity was repeated contraction and expansion of forest refugia during the past 3 million years or so. <jats:bold> Hoorn <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="927" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1194585">927</jats:related-article> ) analyze findings from a diverse range of disciplines, including molecular phylogeny, ecology, sedimentology, structural geology, and palaeontology, to offer an overview of the entire history of this region during the Cenozoic era (66 million years ago). The uplift of the Andes was a pivotal event in the evolution of Amazonian landscapes because it continually altered river drainage patterns, which in turn put a variety of pressures on organisms to adapt to changing conditions in a multiplicity of ways. Hence, the diversity of the modern biota of the Amazon has more ancient origins than previously thought. </jats:p>

<jats:p>The iPhone Hap App reveals that wandering thoughts lead to unhappiness.</jats:p>

<jats:title>The Power Behind P450</jats:title> <jats:p> Drugs, toxins and a range of metabolic substrates are detoxified in the liver by family of iron-containing enzymes called cytochrome P450. The iron component transfers oxygen to compounds that are often highly resistant to chemical reaction, but we know very little about the mechanism of this vital detoxification process. <jats:bold>Rittle and Green</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="933" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1193478">933</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="6006" page="924" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1197881">Sligar</jats:related-article> </jats:bold> ) have managed to capture the P450 reaction intermediate by freezing a solution of the enzyme as it reacts with an oxidant. Spectroscopic techniques and kinetic studies then revealed an iron(IV)oxo intermediate that passes its oxygen along to the substrate with remarkable speed. </jats:p>

<jats:title>Adding CCA</jats:title> <jats:p> Translation of a gene sequence into protein is mediated by transfer RNA (tRNA), which has a specific cytosine-adenine (CCA) tail to which amino acids attach and is recognized by enzymes. The tail, however, does not have a DNA template, and instead CCA-adding enzymes bolt on the additional nucleosides. Crystal structures have shown how these enzymes achieve specificity for cytosine, but we did not know how they select the final adenine until <jats:bold> Pan <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="937" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1194985">937</jats:related-article> ) described CCA-adding enzyme structures captured at several stages of the reaction. Crystallized enzymes were complexed with a tRNA mimic and the respective cytosine or adenine triphosphate. The final adenine was discovered to be incorporated by the mediation of a single Mg <jats:sup>2+</jats:sup> ion in the enzyme, but no more cytosine could be attached because its triphosphate could not then get into the right position for the reaction. </jats:p>

<jats:title>Few-Body Problem</jats:title> <jats:p> Seemingly simple, quantum mechanical few-body systems are notoriously difficult to describe. Efimov trimers, three-body bound states with interactions tuned to be in close vicinity of the formation of two-body bound states, are the most tractable of these systems, with relevance, for example, in nuclear physics. Observed recently in ultracold atomic gases through their signatures in the rate of inelastic three-body collisions, Efimov trimers are predicted to appear at interaction strengths whose ratios are universally specified. By measuring binding energy as a function of interaction strength, <jats:bold> Lompe <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="940" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1193148">940</jats:related-article> ) directly observed the association of three distinguishable atoms into a bound state. This technique may enable more precise studies of the trimer state, potentially revealing the nature of nonuniversal corrections suggested by prior experiments. </jats:p>

<jats:title>Odd Magnetar</jats:title> <jats:p> Magnetars are neutron stars that are widely thought to be powered by extremely high magnetic fields. Using data from three different x-ray observatories, <jats:bold> Rea <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="944" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1196088">944</jats:related-article> , published online 14 October) show that a previously known magnetar has a magnetic field that is much smaller than those of other magnetars. A strong magnetic field is thus not a necessary requirement for a neutron star to show magnetar-like behavior, implying that this population is wider than was previously thought. </jats:p>

<jats:title>Perfect Imperfections</jats:title> <jats:p> Graphene is composed of six-atom rings, but will include a number of five- and seven-atom rings as defects. Using simulations, <jats:bold> Grantab <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="946" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1196893">946</jats:related-article> ) show that more defects do not necessarily lead to greater deterioration of mechanical properties. Mismatches caused by differences in the orientation of neighboring crystals are divided into low- and high-angle grain boundaries, and typically it is the lower-angle boundaries that are stronger. In graphene, by contrast, the larger-angle boundaries, which consist of higher-defect densities, are better able to accommodate the strain and prevent failure that originates in the breakup of the seven-member graphene rings. This suggests ways for synthesizing imperfect graphene sheets that will have mechanical properties that are close to those of perfect graphene. </jats:p>

<jats:title>Liquid Rock Beginnings</jats:title> <jats:p> It has long been known that the lunar farside highlands constitute the highest region on the Moon. <jats:bold> Garrick-Bethell <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="949" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1193424">949</jats:related-article> ) show that the topography and crustal thickness variations of this elevated region obey a single, simple mathematical function that overall describes one-quarter of the Moon. The key to explaining this find may lie with a similarity between the hot, ancient Moon and one of the icy moons of Jupiter, Europa. Like today's Europa, the Moon's crust once floated on a subsurface ocean, except that it was made of liquid rock, not water. The same tidal effect that operates on Europa's crust, caused by Jupiter's gravitational force, would have also operated on the early Moon because of Earth's influence, and would have produced a pattern of crustal thickness variations similar to that observed in the farside highlands. </jats:p>