Catálogo de publicaciones - revistas

<jats:title>Daughter Diversity</jats:title> <jats:p> Asymmetric cell division generates cell diversity and maintains tissue homeostasis. In early <jats:italic>Caenorhabditis elegans</jats:italic> embryos, the mitotic spindle is pulled toward one side of the cell by the molecular motor, dynein, and the cell divides into two unequally sized daughters. However, other types of asymmetric cell divisions (for example, in <jats:italic>Drosophila</jats:italic> neuroblasts) start with a centrally localized spindle. In this latter case, the mechanism by which two differently sized daughters are created is not understood. <jats:bold> Ou <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="677" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1196112">677</jats:related-article> , published online 30 September; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6004" page="597" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1198343">Grill</jats:related-article> </jats:bold> ) studied asymmetric cell divisions in the Q neuroblast lineage during <jats:italic>C. elegans</jats:italic> development and found that when the spindle was centred, myosin II accumulated at higher levels on the side of what will become the smaller daughter cell, giving rise to asymmetric myosin-based contractile forces acting on the membrane. </jats:p>

<jats:title>Processing Prion Phenotype</jats:title> <jats:p> How misfolding of a prion protein translates into transmissible changes in cellular physiology is unclear. <jats:bold> Derdowski <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="680" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1197785">680</jats:related-article> ) integrated a computational model of prion aggregate dynamics with an empirical analysis of the physical and functional dynamics of prion protein in yeast cells. Remarkably, they found that prion phenotypes resulted from fluctuations in the accumulation of aggregates and suggested that it is the process rather than the product of protein misfolding that is crucial in establishing the severity or stability of the resulting phenotype. </jats:p>

<jats:title>Touchy Typing</jats:title> <jats:p> Even the most able typist makes errors, and <jats:bold>Logan and Crump</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="683" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1190483">683</jats:related-article> ) have used this real-world task to probe for the existence of two error-detection mechanisms. They inserted errors into words that had been typed correctly by the subjects, and they corrected errors that had been made. By measuring implicit error detection as the slowing of movement just after an error had been committed and by eliciting explicit monitoring of errors by the output shown on the screen, they uncovered a double dissociation. Inserted errors did not lengthen the interval until the next letter was typed, but they were reported by the typist as errors; on the other hand, corrected errors did increase the interval, but were nevertheless claimed by the subjects as having been typed correctly. </jats:p>

<jats:title>Meeting of Minds</jats:title> <jats:p> The performance of humans across a range of different kinds of cognitive tasks has been encapsulated as a common statistical factor called <jats:italic>g</jats:italic> or general intelligence factor. What intelligence actually is, is unclear and hotly debated, yet there is a reproducible association of <jats:italic>g</jats:italic> with performance outcomes, such as income and academic achievement. <jats:bold> Woolley <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="686" related-article-type="in-this-issue" vol="330" xlink:href="10.1126/science.1193147">686</jats:related-article> , published online 30 September) report a psychometric methodology for quantifying a factor termed “collective intelligence” ( <jats:italic>c</jats:italic> ), which reflects how well groups perform on a similarly diverse set of group problem-solving tasks. The primary contributors to <jats:italic>c</jats:italic> appear to be the <jats:italic>g</jats:italic> factors of the group members, along with a propensity toward social sensitivity—in essence, how well individuals work with others. </jats:p>

<jats:p>The three-dimensional structure of a protein determines how it works and interacts with other molecules. To understand complete pathways, processes, and eventually entire organisms, researchers need to know the structure of every protein. For the human proteome alone, researchers estimate that it consists of about one million proteins, when including all of the posttranslational modifications. Determining so many structures–plus millions more added from other organisms–depends on integrating a range of high throughput technologies.</jats:p>

<jats:p>The show includes distribution of exoplanets, cancer epigenetics, how people detect errors, and more.</jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>