PNAS nexus最新文献_第10页

Hot temperature during development alters iridescence in Morpho butterflies. 发育期的高温会改变大闪蝶的虹彩。

IF 4.8

PNAS nexus Pub Date : 2026-07-23 eCollection Date: 2026-08-01 DOI: 10.1093/pnasnexus/pgag243

Juliette J Rubin, Leo T Camino, Yanileth F López-Tacoaman, Pushkar R Wagh, Greta C Hernández Campos, W Owen McMillan

{"title":"Hot temperature during development alters iridescence in Morpho butterflies.","authors":"Juliette J Rubin, Leo T Camino, Yanileth F López-Tacoaman, Pushkar R Wagh, Greta C Hernández Campos, W Owen McMillan","doi":"10.1093/pnasnexus/pgag243","DOIUrl":"10.1093/pnasnexus/pgag243","url":null,"abstract":"Environmental temperature during critical stages of development can define the phenotype of an individual, especially for ectotherms. Color is a particularly biologically important phenotypically plastic trait but has been primarily studied in the context of pigmentary, rather than structural, coloration. In Morpho butterflies (Nymphalidae), structural coloration created by nanostructures on the wing scales leads to their striking blue iridescent effect. We reared Morpho helenor larvae and exposed the pupae to three temperature regimes during development: control tropics, temperate cool, and hot house, with hotter temperatures simulating those predicted under a future climate change scenario. We hypothesized that the hot house treatment would be the most disruptive to iridescence. In support of this hypothesis, hot conditions reduced the brightness of adult butterfly wings and altered the color profile enough that they would look different from control butterflies to bird predators and conspecifics. For certain bird perceivers, hot conditions would obliterate the iridescent effect entirely. The mechanism underlying these shifts appears to be, at least in part, driven by a decrease in the gap between nanostructures on the wing scale and consequent narrowing of the entire scale. Our study highlights the ways in which structural color is alternately vulnerable or robust to environmental temperature during development. From this work, we can glean insight into the environments that would be most supportive of iridescence in tropical butterflies and make predictions about the effects that changing climate regimes will have on the diversity of some of the earth's most dazzling organisms.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 8","pages":"pgag243"},"PeriodicalIF":4.8,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13430421/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148671467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Finite-stage nonreciprocal thermal circulators for radiative energy harvesting: Benchmarks for isolation, termination, and etendue. 用于辐射能量收集的有限级非互反热循环器：隔离、终止和终止的基准。

IF 4.8

PNAS nexus Pub Date : 2026-07-21 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag249

Seungwoo Lee

{"title":"Finite-stage nonreciprocal thermal circulators for radiative energy harvesting: Benchmarks for isolation, termination, and etendue.","authors":"Seungwoo Lee","doi":"10.1093/pnasnexus/pgag249","DOIUrl":"10.1093/pnasnexus/pgag249","url":null,"abstract":"Reaching the Landsberg limit for radiative energy conversion requires controlling not only spectra but also the direction in which radiative entropy is transported. We develop a finite-stage nonreciprocal thermal-circulator framework for positive illumination (solar conversion) and negative illumination (radiative-cooling work extraction). The ideal theory is expressed in terms of open-system exergy and a minimal port-network picture: a three-port circulator with a cold termination acts as a two-port thermal isolator, and cascaded isolators enforce directed adjacency between effective photon reservoirs. In response to the central practical limitation of nonreciprocal radiative cooling, emphasized recently by Liu et al. we recast the problem as a benchmark map rather than a claim of immediate device-level cooling enhancement. The reported work output values (in unit of W m-2) are hemispherical-equivalent upper envelopes; experimentally relevant output is reduced by captured free-space etendue, coupling efficiency, finite isolation ratio, finite termination temperature, atmospheric transmission, and out-of-window loss. We therefore introduce explicit sensitivity factors for isolation, termination, and captured etendue and ask how good a nonreciprocal system must be before the finite-stage advantage remains measurable. Finite-stage calculations give temperature and wavelength targets for 3-5 stages, while the practical benchmark identifies the isolation, termination, and coupling requirements needed to make those targets consequential. This formulation links ideal Landsberg-type limits to testable design requirements for nonreciprocal thermal photonics.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag249"},"PeriodicalIF":4.8,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419078/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148623027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correction to: Nudging recommendation algorithms increases news consumption and diversity on YouTube. 更正：推动推荐算法增加了YouTube上的新闻消费和多样性。

IF 4.8

PNAS nexus Pub Date : 2026-07-21 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag241

引用次数: 0

Emphasizing society's expectations enhances charitable giving in NGO advertisements. 在公益广告中，强调社会期望能提高公益捐赠。

IF 4.8

PNAS nexus Pub Date : 2026-07-21 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag206

Toshiko Tanaka, Tsuyoshi Nihonsugi, Masahiko Haruno

引用次数: 0

Reduced integrity in the frontal aslant tract's premotor connections is associated with dysfluency severity in stuttering. 额斜束运动前连接完整性降低与口吃的流利障碍严重程度有关。

IF 4.8

PNAS nexus Pub Date : 2026-07-17 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag245

Maëva Michon, Fabrice Hirsch, Ivana Didirková, Davide Giampiccolo, Marie-Claude Monfrais-Pfauwadel, Anne-Laure Lemaitre, Jérémy Deverdun, Emmanuelle Lebars, Guillaume Herbet

{"title":"Reduced integrity in the frontal aslant tract's premotor connections is associated with dysfluency severity in stuttering.","authors":"Maëva Michon, Fabrice Hirsch, Ivana Didirková, Davide Giampiccolo, Marie-Claude Monfrais-Pfauwadel, Anne-Laure Lemaitre, Jérémy Deverdun, Emmanuelle Lebars, Guillaume Herbet","doi":"10.1093/pnasnexus/pgag245","DOIUrl":"10.1093/pnasnexus/pgag245","url":null,"abstract":"Stuttering is a neurodevelopmental disorder marked by impaired speech production and substantial interindividual variability in symptom severity. Although neuroimaging studies have identified abnormalities in the basal ganglia-thalamocortical circuitry, the specific white matter pathways that underpin dysfluent speech production remain poorly understood. Here, we focus on the frontal aslant tract (FAT), a dorsoventral intralobar tract connecting the superior and inferior frontal cortices and proposed to support both cognitive and motor functions. Using diffusion MRI, we first compared the quantitative anisotropy of the FAT and relevant control tracts in individuals who stutter (n = 30, mean age = 35.67, SD = 13.03) and fluent speakers (n = 22, mean age = 35.64, SD = 10.87) and observed no significant group-level differences in either hemisphere. To delineate the role of FAT subbundles in speech dysfluency, we then segmented the tract at its dorsal and ventral cortical terminations and assessed their relationships with stuttering severity (Stuttering Severity Instrument-Fourth Edition). We identified left FAT subbundles connecting the posteroventral frontal structures, particularly the rostroventral precentral gyrus and, to a lesser extent, the pars opercularis to a dorsal prefrontal region whose integrity predicts stuttering severity. The left-lateralized nature of these associations suggests that stuttering results, in part, from abnormal connectivity between prefrontal systems governing volitional control and the motor circuits engaged in speech production. Together, these findings refine current neurobiological models of stuttering by implicating frontofrontal white matter pathways underlying speech dysfluency and highlight a potential anatomical target for individualized therapeutic interventions.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag245"},"PeriodicalIF":4.8,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13398998/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148586059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Memorizing the future: Encoding anticipated interactions enhances human memory for dynamic stimuli. 记忆未来：对预期的相互作用进行编码可以增强人类对动态刺激的记忆。

IF 4.8

PNAS nexus Pub Date : 2026-07-16 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag244

Gonzalo Aparicio-Rodríguez, Daniel Ruiz Navalón, Paloma Manubens, Abel Sánchez-Jiménez, Carlos Calvo-Tapia, José Antonio Villacorta-Atienza

{"title":"Memorizing the future: Encoding anticipated interactions enhances human memory for dynamic stimuli.","authors":"Gonzalo Aparicio-Rodríguez, Daniel Ruiz Navalón, Paloma Manubens, Abel Sánchez-Jiménez, Carlos Calvo-Tapia, José Antonio Villacorta-Atienza","doi":"10.1093/pnasnexus/pgag244","DOIUrl":"10.1093/pnasnexus/pgag244","url":null,"abstract":"Survival in nature requires responding to rapidly changing situations, where memory is crucial for fast and reliable decision-making. This work explores human memory modulation under the hypothesis that in dynamic scenarios critical information is encoded as static maps of future interactions. Results show that dynamic stimuli containing future interactions are recalled 36% better than equivalent stimuli that do not and even 23% better than simpler dynamic stimuli. This aligns with a central prediction of the time-compaction hypothesis, suggesting that stimuli involving anticipated interactions may be more efficiently memorized and recalled because they are compatible with simplified static representations of future interactions-their maps of interactions. This effect is modulated by stimulus complexity: in simple scenarios, recall differences appear only in men, while in more complex situations, no gender bias emerges. This work reveals novel mechanisms by which memory can cope with dynamic situations, suggesting that those critical to survival-fighting, chasing, or fleeing-are preferentially remembered, enabling efficient learning and decision-making in a complex changing world.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag244"},"PeriodicalIF":4.8,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13398999/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148586100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional role of a structural water in the elevator domain of dicarboxylate transporter VcINDY. 结构水在二羧酸转运体VcINDY升降机结构中的功能作用。

IF 4.8

PNAS nexus Pub Date : 2026-07-16 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag242

Andrew Daab, Yan Li, Jennifer J Marden, Jinmei Song, David B Sauer, Da-Neng Wang, Christopher Mulligan

{"title":"Functional role of a structural water in the elevator domain of dicarboxylate transporter VcINDY.","authors":"Andrew Daab, Yan Li, Jennifer J Marden, Jinmei Song, David B Sauer, Da-Neng Wang, Christopher Mulligan","doi":"10.1093/pnasnexus/pgag242","DOIUrl":"10.1093/pnasnexus/pgag242","url":null,"abstract":"The divalent anion sodium symporter (DASS) family mediates the uptake of Krebs cycle intermediates and sulfate and influences adiposity, insulin resistance, and metabolism in mammals. While Na+:substrate stoichiometry is known for several DASS transporters, the location of key Na+-binding sites remains elusive; important information for understanding the mechanism. In VcINDY, a bacterial DASS protein, we visualized a nonprotein cryo-electron microscopy (cryo-EM) density in the middle of the transport domain. Its size and coordination suggest that it may represent either a third Na+ ion or a structural water molecule. Using a combination of in vitro binding and transport assays, cryo-EM structural determination, and molecular dynamic simulations, we show that the density is not a Na+ ion. Instead, the data indicate that the density likely represents a structural water molecule critical for transport domain integrity. Sequence and structural similarities suggest this feature may be conserved across human DASS transporters such as NaCT and NaDC3.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag242"},"PeriodicalIF":4.8,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13394699/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148581483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mineral biosignature identification from Raman spectroscopy using machine learning. 利用机器学习从拉曼光谱中识别矿物生物特征。

IF 4.8

PNAS nexus Pub Date : 2026-07-14 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag215

Yanzhang Li, Anirudh Prabhu, Bingxu Hou, Michael L Wong, Anhuai Lu, Jieqi Xing, Don Ngo, Bo Xu, Robert M Hazen

{"title":"Mineral biosignature identification from Raman spectroscopy using machine learning.","authors":"Yanzhang Li, Anirudh Prabhu, Bingxu Hou, Michael L Wong, Anhuai Lu, Jieqi Xing, Don Ngo, Bo Xu, Robert M Hazen","doi":"10.1093/pnasnexus/pgag215","DOIUrl":"10.1093/pnasnexus/pgag215","url":null,"abstract":"Biosignature detection remains a key challenge in astrobiology, yet robust mineral biosignatures remain limited. Raman spectroscopy is increasingly applied in planetary exploration, but its high-dimensional spectral information has not yet been fully exploited for biosignature discrimination using data-driven approaches. Here, we integrate Raman spectroscopy with interpretable machine learning to distinguish biotic from abiotic apatite, a ubiquitous phosphate mineral in terrestrial and extraterrestrial environments. We compile 331 apatite Raman spectra from abiotic and biotic sources and extract 21 band-resolved spectral features. Principal component analysis reveals systematic separation between abiotic and biotic endmembers. A random forest classifier achieves 96.8% accuracy on an independent test set. Robustness is confirmed by multiple validation schemes, including leave-one-source-out cross-validation across 60 independent data sources, indicating that model performance generalizes beyond source- or instrument-specific artifacts. Feature importance identifies two dominant controls: phosphate-band broadening as a structural indicator of disorder and the carbonate-band intensity as a chemical signature of substitution. Density-functional calculations reproduce these features in simulated spectra and indicate that carbonate substitution doubles phosphate-tetrahedral distortion and increases formation energies by two orders of magnitude. Mechanically, higher carbonate contents during biomineral apatite formation reduce crystallinity and broaden Raman bands. We propose that the trained machine-learning model and a two-feature decision map enable the rapid probabilistic discrimination of unknown apatite samples. Our Raman-based machine-learning framework establishes a broadly applicable and mission-relevant strategy for deep-time archives and future planetary missions.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag215"},"PeriodicalIF":4.8,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13366543/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148450907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

From Sputnik to Starship: Estimating the experience curve of space launch technology. 从人造卫星到星际飞船：空间发射技术经验曲线的估计。

IF 4.8

PNAS nexus Pub Date : 2026-07-14 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag217

Alessio Terzi, Francesco Nicoli

{"title":"From Sputnik to Starship: Estimating the experience curve of space launch technology.","authors":"Alessio Terzi, Francesco Nicoli","doi":"10.1093/pnasnexus/pgag217","DOIUrl":"10.1093/pnasnexus/pgag217","url":null,"abstract":"Space launch costs have fallen dramatically over the past six decades, opening new economic and scientific frontiers. Yet precise, long-term estimates of these cost reductions remain sparse, and the underlying rate of technological learning is poorly understood. We introduce the largest standardized dataset of rocket launches to date, covering more than 4,400 launches (1960 to 2025) across 16 spacefaring geographical entities and show that the average cost of sending a kilogram to orbit has dropped from 87,023 USD in 1960 to 3,868 USD in 2025. Using a Wright's Law framework, we estimate that for each doubling of cumulative payload to orbit, the average cost of sending a kilogram to orbit decreases by 21.2%, revealing an exceptionally steep experience curve, outpacing that of other transformative technologies, including 19th-century steamship freight and modern solar photovoltaics. We leverage our empirical model to produce out-of-sample projections under a set of scenario-based and data-driven approaches. In our central estimate, the average cost is expected to fall to 1,600 USD/kg by 2030 and 300 USD/kg by 2040. Nonetheless, geopolitical shifts, potential monopolistic behavior in commercial launch markets, and the rising challenges of orbital debris may temper these gains. Overall, our findings underscore the importance of continued research and policy focus on launch technology, given that breakthroughs in cost reduction could accelerate the evolution of the space economy and its diverse near-term applications.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag217"},"PeriodicalIF":4.8,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13366537/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148450888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ankyrin-B and ankyrin-G are required for synaptic integrity in the mouse outer retina. 锚蛋白b和锚蛋白g是小鼠外视网膜突触完整性所必需的。

IF 4.8

PNAS nexus Pub Date : 2026-07-09 eCollection Date: 2026-07-01 DOI: 10.1093/pnasnexus/pgag239

Ross M Perez, Jay Campbell, Martina Cavallini, Collin Todora, Daniela Becerril, Debalina Goswami-Sewell, Rajashree Venkatraman, Cesiah C Gomez, Caitlin Bagnetto, Audrey Lee, Marlon F Mattos, Yi-Rong Peng, Mrinalini Hoon, Elizabeth Zuniga-Sanchez

{"title":"Ankyrin-B and ankyrin-G are required for synaptic integrity in the mouse outer retina.","authors":"Ross M Perez, Jay Campbell, Martina Cavallini, Collin Todora, Daniela Becerril, Debalina Goswami-Sewell, Rajashree Venkatraman, Cesiah C Gomez, Caitlin Bagnetto, Audrey Lee, Marlon F Mattos, Yi-Rong Peng, Mrinalini Hoon, Elizabeth Zuniga-Sanchez","doi":"10.1093/pnasnexus/pgag239","DOIUrl":"10.1093/pnasnexus/pgag239","url":null,"abstract":"Retinal circuit assembly relies on the precise timing and positioning of key molecules between neuronal partners to mediate proper synapse formation. In the outer retina, horizontal cells (HCs) are important interneurons that make the first contacts with photoreceptors and begin to segregate visual information into two distinct pathways by selectively forming synapses to the different types of photoreceptors. Dendrites of HCs synapse exclusively to cone photoreceptors, whereas the axon terminal synapses to rod photoreceptors. Failure to properly form these early connections disrupts the downstream connectivity of other postsynaptic neurons and leads to abnormal visual function. Although these early events are critical for proper synapse development, little is known about how this process is coordinated in the outer retina. In the present study, we performed single-cell RNA sequencing and uncovered members of the cytoskeletal scaffolding family of ankyrins to be differentially expressed in HCs during development. Specifically, we found ankyrin-B to be highly expressed in HCs at early time points and ankyrin-G to be expressed at later stages. Genetic deletion of both ankyrin-B and ankyrin-G disrupts outer retinal synaptic integrity and leads to impaired in vivo retinal responses. In summary, our findings uncovered a new requirement for ankyrin-B and ankyrin-G in maintaining synaptic connectivity in the outer retina essential for normal visual function.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 7","pages":"pgag239"},"PeriodicalIF":4.8,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13378166/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148581536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0