Catálogo de publicaciones - revistas

<jats:title>Pulses with a twist and torque</jats:title> <jats:p> Structured light beams can serve as vortex beams carrying optical angular momentum and have been used to enhance optical communications and imaging. Rego <jats:italic>et al.</jats:italic> generated dynamic vortex pulses by interfering two incident time-delayed vortex beams with different orbital angular momenta through the process of high harmonic generation. A controlled time delay between the pulses allowed the high harmonic extreme-ultraviolet vortex beam to exhibit a time-dependent angular momentum, called self-torque. Such dynamic vortex pulses could potentially be used to manipulate nanostructures and atoms on ultrafast time scales. </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.aaw9486">eaaw9486</jats:related-article> </jats:p>

<jats:p>South Asian countries are often at odds with each other for political, economic, and emotional reasons. The conflicts are a frustrating contrast to the promise of the region. Covering only 3.5% of Earth's landmass, but inhabited by 23.7% of humanity, the region has the highest rate of economic growth, is rich in knowledge-based institutions, and is home to many indigenous and technological innovations. Sadly, at the same time, South Asian countries have the highest poverty rate, lowest human development index (except for sub-Saharan Africa), the most polluted air, the greatest burden of diseases, and increased vulnerability to climate change. It's time to reinvent science diplomacy in this part of the world to spur collaborations that can help resolve conflicts that are preventing South Asia from achieving its potential.</jats:p>

<jats:p>A roundup of weekly science policy and related news.</jats:p>

<jats:p>Nation has long denied the presence of the virus. But new report says it's being spread by drug use and tainted blood.</jats:p>

<jats:p>Ancient plateaus, armored against erosion by impermeable minerals, hold clues to Earth's deep history.</jats:p>

<jats:p>Chimera experiments tackle basic interaction between foreign and host cells.</jats:p>

<jats:p>Designers propose benchmarks and metrics for not-yet-useful machines.</jats:p>

<jats:p>Thirty Meter Telescope surmounts last legal hurdle, but protesters plan to disrupt construction.</jats:p>

<jats:p>New shots could protect more people, but also create confusion and stretch resources.</jats:p>

<jats:p>By doing more than defense, Jason hopes it will live on as an elite government advisory group.</jats:p>