Catálogo de publicaciones - revistas

<jats:title>Shifting forest dynamics</jats:title> <jats:p> Forest dynamics are the processes of recruitment, growth, death, and turnover of the constituent tree species of the forest community. These processes are driven by disturbances both natural and anthropogenic. McDowell <jats:italic>et al.</jats:italic> review recent progress in understanding the drivers of forest dynamics and how these are interacting and changing in the context of global climate change. The authors show that shifts in forest dynamics are already occurring, and the emerging pattern is that global forests are tending toward younger stands with faster turnover as old-growth forest with stable dynamics are dwindling. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aaz9463">eaaz9463</jats:related-article> </jats:p>

<jats:p> Amrute <jats:italic>et al</jats:italic> . (Reports, 25 October 2019, p. 485) claimed that no methods were able to produce high-purity α-Al <jats:sub>2</jats:sub> O <jats:sub>3</jats:sub> with surface areas greater than 100 m <jats:sup>2</jats:sup> g <jats:sup>–1</jats:sup> , even though much higher surface areas up to 253 m <jats:sup>2</jats:sup> g <jats:sup>–1</jats:sup> have been reported. Moreover, the materials they obtained could be porous aggregates and may not be 13-nm nanoparticles, as claimed. </jats:p>

<jats:title>A structurally ordered spin glass</jats:title> <jats:p> Spin glasses that form in disordered materials such as magnetic alloys have locally varying magnetic patterns, and their spin relaxation occurs over time scales spanning many orders of magnitude. Kamber <jats:italic>et al.</jats:italic> used spin-polarized scanning tunneling microscopy to image the magnetism on the (0001) surface of thick, single-crystal films of neodymium as a function of temperature and magnetic field. Despite the lack of structural disorder, they found a spectral distribution of degenerate magnetic wave vectors, or <jats:italic>Q</jats:italic> states, that exhibited spatiotemporal variation. In this spin-Q glass, pockets of nearly degenerate spin spiral states formed with varying periodicity. Ab initio electronic structure coupled to atomistic spin dynamics calculations suggests that the double hexagonal closed packed crystal structure in neodymium drove strongly frustrated magnetism that created these pockets. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aay6757">eaay6757</jats:related-article> </jats:p>

<jats:title>Granzyme A lights a fire</jats:title> <jats:p> Cytotoxic T cells and natural killer cells use several strategies to kill infected or transformed cells. One such pathway entails the delivery of a family of serine proteases called granzymes to target cells through perforin-mediated pores to induce a form of programmed cell death called apoptosis. Zhou <jats:italic>et al.</jats:italic> show that granzyme A cleaves and activates gasdermin B (GSDMB), a central player in the highly inflammatory cell death process known as pyroptosis (see the Perspective by Nicolai and Raulet). GSDMB expression was highly expressed in some tissues and could be up-regulated by interferon-γ. Enforced expression of GSDMB in cancer cells enhanced tumor clearance in a mouse model, suggesting that this pathway may be a target for future cancer immunotherapies. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aaz7548">eaaz7548</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6494" page="943" related-article-type="in-this-issue" vol="368" xlink:href="10.1126/science.abc2502">943</jats:related-article> </jats:p>