Catálogo de publicaciones - revistas

<jats:p> P-i-n geometry perovskite solar cells (PSCs) offer simplified fabrication, greater amenability to charge extraction layers, and low-temperature processing over n-i-p counterparts. Self-assembled monolayers (SAMs) can enhance the performance of p-i-n PSCs but ultrathin SAMs can be thermally unstable. We report a thermally robust hole-selective layer comprised of nickel oxide (NiO <jats:sub>x</jats:sub> ) nanoparticle film with a surface-anchored (4-(3,11-dimethoxy-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid (MeO-4PADBC) SAM that can improve and stabilize the NiO <jats:sub>x</jats:sub> /perovskite interface. The energetic alignment and favorable contact and binding between NiO <jats:sub>x</jats:sub> /MeO-4PADBC and perovskite reduced the voltage deficit of PSCs with various perovskite compositions and led to strong interface toughening effects under thermal stress. The resulting 1.53–electron-volt devices achieved 25.6% certified power conversion efficiency and maintained &gt;90% of their initial efficiency after continuously operating at 65 degrees Celsius for 1200 hours under 1-sun illumination. </jats:p>

<jats:p>Habitat conversion and climate change are fundamental drivers of biodiversity loss worldwide but are often analyzed in isolation. We used a continental-scale, decades-long database of more than 150,000 bird nesting attempts to explore how extreme heat affects avian reproduction in forests, grasslands, and agricultural and developed areas across the US. We found that in forests, extreme heat increased nest success, but birds nesting in agricultural settings were much less likely to successfully fledge young when temperatures reached anomalously high levels. Species that build exposed cup nests and species of higher conservation concern were particularly vulnerable to maximum temperature anomalies in agricultural settings. Finally, future projections suggested that ongoing climate change may exacerbate the negative effects of habitat conversion on avian nesting success, thereby compromising conservation efforts in human-dominated landscapes.</jats:p>

<jats:p> Fast radio bursts (FRBs) are millisecond-duration pulses of radio emission originating from extragalactic distances. Radio dispersion is imparted on each burst by intervening plasma, mostly located in the intergalactic medium. In this work, we observe the burst FRB 20220610A and localize it to a morphologically complex host galaxy system at redshift 1.016 ± 0.002. The burst redshift and dispersion measure are consistent with passage through a substantial column of plasma in the intergalactic medium and extend the relationship between those quantities measured at lower redshift. The burst shows evidence for passage through additional turbulent magnetized plasma, potentially associated with the host galaxy. We use the burst energy of 2 × 10 <jats:sup>42</jats:sup> erg to revise the empirical maximum energy of an FRB. </jats:p>

<jats:p> Polyolefins are the most important and largest volume plastics produced. Unfortunately, the enormous use of plastics and lack of effective disposal or recycling options have created a plastic waste catastrophe. In this work, we report an approach to create chemically recyclable polyolefin-like materials with diverse mechanical properties through the construction of multiblock polymers from hard and soft oligomeric building blocks synthesized with ruthenium-mediated ring-opening metathesis polymerization of cyclooctenes. The multiblock polymers exhibit broad mechanical properties, spanning elastomers to plastomers to thermoplastics, while integrating a high melting transition temperature ( <jats:italic>T</jats:italic> <jats:sub>m</jats:sub> ) and low glass transition temperature ( <jats:italic>T</jats:italic> <jats:sub>g</jats:sub> ), making them suitable for use across diverse applications ( <jats:italic>T</jats:italic> <jats:sub>m</jats:sub> as high as 128°C and <jats:italic>T</jats:italic> <jats:sub>g</jats:sub> as low as –60°C). After use, the different plastics can be combined and efficiently deconstructed back to the fundamental hard and soft building blocks for separation and repolymerization to realize a closed-loop recycling process. </jats:p>

<jats:p>Once every 13 or 17 years within eastern North American deciduous forests, billions of periodical cicadas concurrently emerge from the soil and briefly satiate a diverse array of naive consumers, offering a rare opportunity to assess the cascading impacts of an ecosystem-wide resource pulse on a complex food web. We quantified the effects of the 2021 Brood X emergence and report that more than 80 bird species opportunistically switched their foraging to include cicadas, releasing herbivorous insects from predation and essentially doubling both caterpillar densities and accumulated herbivory levels on host oak trees. These short-lived but massive emergence events help us to understand how resource pulses can rewire interaction webs and disrupt energy flows in ecosystems, with potentially long-lasting effects.</jats:p>

<jats:p> Climate change poses severe impacts on and risks to agriculture, food, and nutrition, particularly for smallholders. Agricultural researchers are tasked with deciphering interconnected variables—from soil characteristics and nutrient cycles to water and biodiversity—to create a robust framework for technological advancements. Increasing sustainability, resilience, and productivity is an urgent need that requires approaches to research and innovation tailored to both regional and country-specific challenges. One compelling model of regional collaboration is <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://www.fontagro.org/en/">FONTAGRO</jats:ext-link> , the Regional Fund for Agricultural Technology, which for 25 years has combined public and private institutions in supporting science, technology, and innovation within the agrifood sector in Latin American and the Caribbean. The science-based evidence that emerges is strategic not only for its local application but also for its potential in other regions of the world and capacity to accelerate the transformation of agrifood systems. </jats:p>

<jats:p>Among mammals, post-reproductive life spans are currently documented only in humans and a few species of toothed whales. Here we show that a post-reproductive life span exists among wild chimpanzees in the Ngogo community of Kibale National Park, Uganda. Post-reproductive representation was 0.195, indicating that a female who reached adulthood could expect to live about one-fifth of her adult life in a post-reproductive state, around half as long as human hunter-gatherers. Post-reproductive females exhibited hormonal signatures of menopause, including sharply increasing gonadotropins after age 50. We discuss whether post-reproductive life spans in wild chimpanzees occur only rarely, as a short-term response to favorable ecological conditions, or instead are an evolved species-typical trait as well as the implications of these alternatives for our understanding of the evolution of post-reproductive life spans.</jats:p>

<jats:p>Although trustees and administrators at universities in the United States are acutely aware of the mental health crisis on their campuses and consistently rate it as one of the most pressing challenges, it usually only gets attention when a tragedy strikes a member of the student body. Those moments illuminate the lack of adequate mental health care for undergraduate and graduate students, but are hastily followed up with meetings admonishing administrators to hire more counselors. Despite the constant drumbeat of these episodes, hardly any universities have prioritized mental health in a comprehensive and proactive way. The newly appointed president of Dartmouth College, Sian Beilock, has taken a refreshing approach in naming campus mental health as the first priority in her inaugural address. It’s long past time.</jats:p>

<jats:p>Billions of gigabytes from accelerators and x-ray sources could swamp national labs</jats:p>

<jats:p>By adding coral genes to a nonmineralizing relative, team aims to show how reefs are built</jats:p>