Catálogo de publicaciones - revistas

<jats:title>Once in a While</jats:title> <jats:p> Many regions at the edge of the Antarctic Ice Sheet have rapidly increased the rates at which they are sliding into the sea and thinning, raising concerns that global warming might cause the sudden collapse of some sections. <jats:bold> Johnson <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="999" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1247385">999</jats:related-article> , published online 20 February) present data from Pine Island Glacier, which has been thinning and retreating rapidly over the past two decades. The glacier experienced another rapid thinning around 8000 years ago, which occurred about as quickly as is happening now, and which lasted for 25 to 100 years. </jats:p>

<jats:title>Repeat Silencing</jats:title> <jats:p> Fragile X syndrome, a genetic cause of many cases of autism and mental retardation, involves expansion of a trinucleotide repeat in the <jats:italic>fragile X mental retardation 1 (FMR1)</jats:italic> gene. Working with human embryonic stem cells, <jats:bold> Colak <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1002" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1245831">1002</jats:related-article> ) found that the expanded repeat region was transcribed into the untranslated region of <jats:italic>FMR1</jats:italic> messenger RNA, which then bound to the DNA repeat region in the <jats:italic>FMR1</jats:italic> gene, inactivating the gene. The findings explain how the trinucleotide repeat expansion causes RNA-directed gene silencing during development in fragile X syndrome. </jats:p>

<jats:title>Deciphering Language</jats:title> <jats:p> Consonants and vowels represent basic building blocks of human language. How their characteristics are extracted from acoustic speech input is not well understood. Directly recording from the superior temporal gyrus of patients as part of their clinical evaluation for epilepsy surgery, <jats:bold> Mesgarani <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1006" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1245994">1006</jats:related-article> , published online 30 January; see the Perspective by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="978" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1251495"> <jats:bold>Grodzinsky</jats:bold> and <jats:bold>Nelken</jats:bold> </jats:related-article> ) investigated neural responses while the subjects listened to continuous speech. The findings reveal how both vowels and consonants of different phonetic categories are encoded. </jats:p>

<jats:title>Oncogenic Suspect Exposed</jats:title> <jats:p> It can be difficult logistically to study the genomics of rare variants of common cancers. Nevertheless, <jats:bold> Honeyman <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1010" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1249484">1010</jats:related-article> ) studied fibrolamellar hepatocellular carcinoma (FL-HCC), a rare and poorly understood liver tumor that affects adolescents and young adults and for which there is no effective treatment. FL-HCCs from 15 patients all expressed a chimeric RNA transcript and protein containing sequences from a molecular chaperone fused in frame with sequences from the catalytic domain of protein kinase A. The chimeric protein retained kinase activity in vitro. Such recurrent gene fusions in cancer may signal a role in pathogenesis and provide an opportunity for therapeutic intervention. </jats:p>

<jats:title>Know Your Enemy</jats:title> <jats:p> Fire ants accidentally introduced to North America from their native range in Argentina have been hugely invasive and difficult to eradicate and caused both environmental and economic damage. Recently, another accidentally introduced Argentine ant, the tawny crazy ant, appears to be displacing the fire ants. How? <jats:bold> LeBrun <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1014" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1245833">1014</jats:related-article> , published online 13 February; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="974" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1251272">Kaspari and Weiser</jats:related-article> </jats:bold> ) show that tawny crazy ants have a chemical and behavioral response to the toxic bite of fire ants that vastly reduces their mortality during confrontations and that allows the tawny crazy ants to outcompete their rivals. </jats:p>

<jats:title>Neandertal Shadows in Us</jats:title> <jats:p> Non-African modern humans carry a remnant of Neandertal DNA from interbreeding events that have been postulated to have occurred as humans migrated out of Africa. While the total amount of Neandertal sequence is estimated to be less than 3% of the modern genome, the specific retained sequences vary among individuals. Analyzing the genomes of more than 600 Europeans and East Asians, <jats:bold>Vernot and Akey</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1017" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1245938">1017</jats:related-article> , published online 29 January) identified Neandertal sequences within modern humans that taken together span approximately 20% of the Neandertal genome. Some Neandertal-derived sequences appear to be under positive selection in humans, including several genes associated with skin phenotypes. </jats:p>

<jats:title>Allergen Affinity</jats:title> <jats:p> Allergic responses are initiated by interaction of allergens with immunoglobulin E (IgE) antibodies, which in turn bind to IgE receptors on the surface of mast cells. <jats:bold> Suzuki <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1021" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1246976">1021</jats:related-article> , published online 6 February; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="982" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1251425">Daëron</jats:related-article> </jats:bold> ) explored how the signaling properties of such receptor complexes differ, depending on the affinity of the IgE antibody for the antigen leading to different allergic responses. </jats:p>

<jats:title>A Different Route</jats:title> <jats:p> The plant hormone auxin regulates a variety of developmental processes and responses to environmental inputs, often via changes in gene transcription. <jats:bold> Xu <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6174" page="1025" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1245125">1025</jats:related-article> ) analyzed a signaling pathway involving ABP1 (auxin-binding protein 1) that affects the cytoskeleton and endocytosis in <jats:italic>Arabidopsis</jats:italic> without changing gene transcription. Instead, ABP1 functions at the cell surface to bind auxin and a family of membrane kinases, thereby activating intracellular guanosine triphosphatases to initiate important developmental changes in cell shape. </jats:p>

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

<jats:p>This week's show features a segment on recent research into treatments for Down Syndrome and a roundup of shorts from our daily news site.</jats:p>