Catálogo de publicaciones - revistas

<jats:title>Carbon cycling after boreal forest fire</jats:title> <jats:p> Wildfire activity has been increasing in the boreal forests of the Northern Hemisphere, releasing carbon into the atmosphere from biomass and soil, with potential feedback to climate warming. In a long-term study, Mack <jats:italic>et al.</jats:italic> analyzed wildfire impacts on the carbon balance of boreal forest in Alaska, with particular focus on forest-regeneration patterns. After fire, the species composition in most of the study sites changed from black spruce to a mixture of conifers and deciduous broadleaf tree species. The stands that had shifted to deciduous dominance stored fivefold more soil carbon than stands that returned to black spruce dominance. Therefore, the functional traits of deciduous trees compensated for the combustion loss of soil carbon, pointing to a potential mitigation of the feedback effect of boreal forest fire to climate warming. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6539" page="280" related-article-type="in-this-issue" vol="372">280</jats:related-article> </jats:p>

<jats:title>Estimating dinosaur abundance</jats:title> <jats:p> Estimating the abundance of a species is a common practice for extant species and can reveal many aspects of its ecology, evolution, and threat level. Estimating abundance for species that are extinct, especially those long extinct, is a much trickier endeavor. Marshall <jats:italic>et al.</jats:italic> used a relationship established between body size and population density in extant species to estimate traits such as density, distribution, total biomass, and species persistence for one of the best-known dinosaurs, <jats:italic>Tyrannosaurus rex</jats:italic> , revealing previously hidden aspects of its population ecology. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6539" page="284" related-article-type="in-this-issue" vol="372">284</jats:related-article> </jats:p>

<jats:title>Genomes reveal nutrient stress patterns</jats:title> <jats:p> Within the surface ocean, nitrogen, iron, and phosphorous can all be limiting nutrients for phytoplankton depending on location. Ustick <jats:italic>et al.</jats:italic> used the prevalence of <jats:italic>Prochlorococcus</jats:italic> genes involved in nutrient acquisition to develop maps of inferred nutrient stress across the global ocean (see the Perspective by Coleman). They found broad patterns of limitation consistent with an Earth system model and nutrient addition experiments. Leveraging metagenomic data in this manner is an appealing approach that will help to expand our understanding of the biogeochemistry in the vast open ocean. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6539" page="287" related-article-type="in-this-issue" vol="372">287</jats:related-article> ; see also p. <jats:related-article issue="6539" page="239" related-article-type="in-this-issue" vol="372">239</jats:related-article> </jats:p>

<jats:title>Circuit design for control of metabolism</jats:title> <jats:p> A transcriptional control mechanism in yeast that allows cells to respond to changes in nutrient concentrations works very much like a household light-dimmer switch. That is, the system separately controls whether gene expression is “on” or “off” and the extent of gene expression. The galactose-responsive pathway is activated when yeast need to switch from metabolizing glucose to metabolizing galactose. Ricci-Tam <jats:italic>et al.</jats:italic> found that, rather than using two separate elements for the switch and dimmer controls, yeast use a single transcription factor, Gal4p, separately regulating its abundance (through transcriptional regulation) and its catalytic activity (through interaction with a protein-binding partner). Such regulation may be common and can allow responses to the environment on physiological and evolutionary time scales. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6539" page="292" related-article-type="in-this-issue" vol="372">292</jats:related-article> </jats:p>

<jats:title>One-step purification and desalination</jats:title> <jats:p> The purification of water for drinking purposes can require multiple filtration steps and technologies to remove contaminants such as salts and heavy metals. Some contaminants could have value if recovered, but these are often discharged in the waste streams. Uliana <jats:italic>et al.</jats:italic> describe a general approach for the fabrication of robust, tunable, adsorptive membranes through the incorporation of porous aromatic framework (PAF) nanoparticles into ion exchange membranes such as those made from sulfonated polymers. Salts are removed using a series of cation and anion exchange membranes, and the PAF particles can be selected to capture specific target ions, such as those of copper, mercury, or iron. This allows for simultaneous desalination and decontamination of the water. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6539" page="296" related-article-type="in-this-issue" vol="372">296</jats:related-article> </jats:p>

<jats:title>Paleontology for conservation</jats:title> <jats:p> Human activities are leading to broad species and system declines. Prevention of such declines has led us to focus on either protection for species or protection for ecosystem function. Looking at past patterns of species and system change can help to inform our understanding of the long-term impacts of these strategies. Blanco <jats:italic>et al.</jats:italic> studied mammals from the last 21 million years on the Iberian Peninsula, finding long periods of functional stasis, even in the face of taxonomic variability (see the Perspective by Roopnarine and Banker). Functional ecosystems were more resistant to ecosystem collapse. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6539" page="300" related-article-type="in-this-issue" vol="372">300</jats:related-article> ; see also p. <jats:related-article issue="6539" page="237" related-article-type="in-this-issue" vol="372">237</jats:related-article> </jats:p>

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