Catálogo de publicaciones - revistas

<jats:p>After a long decline, the threatened bay checkerspot butterfly has disappeared from Stanford University's Jasper Ridge preserve. While this local extinction isn't yet a certainty, it has raised entomological eyebrows: Paul Ehrlich and others at Stanford chose to watch the population die off, saying more could be learned from watching it disappear than from intervening to try to save it. Their decision highlights a dilemma that many conservation biologists face—when should scientists studying a shrinking population intervene to try to save it?</jats:p>

<jats:p> A new microscopy technique may open new vistas for researchers who want to peer into living cells. On <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="530" related-article-type="in-this-issue" vol="275" xlink:href="10.1126/science.275.5299.530" xlink:type="simple">page 530</jats:related-article> , a research team from Cornell University describes how they used the additive energies of multiple photons to excite fluorescence from molecules that previously couldn't be observed with damaging or killing cells. In the current work, the researchers measured serotonin concentrations in living cells, but the technique should have a much broader application than that. </jats:p>

<jats:p> <jats:bold>OSAKA, JAPAN</jats:bold> —New results from Japan on boosting electrons to record energy levels could hasten the arrival of a new generation of compact particle accelerators powered by laser pulses—if they hold up. The problem is that theorists so far haven't been able to explain theachievement. </jats:p>

<jats:p> Traditional cancer treatments seek to attack cancer cells directly, with surgery, radiation, or chemotherapy. But a new wave of therapies is attempting an indirect strike: shutting off the blood vessels through which tumors get the oxygen and nutrients they need to live and grow. Recent work suggests that this might be done with drugs, some naturally occurring, that can prevent tumors from forming the new blood vessels they need. Alternately, as a report appearing on <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="547" related-article-type="in-this-issue" vol="275" xlink:href="10.1126/science.275.5299.547" xlink:type="simple">page 547</jats:related-article> suggests, it might be possible to shrink or even eliminate tumors by administering agents that trigger clot formation in tumor-feeding vessels. </jats:p>