综合性期刊最新文献

{"title":"Laundering and evasion in response to antislavery policies in Brazil's cattle sector.","authors":"Tara Mittelberg, Marin E Skidmore, Juliana L S C Brandão, Lisa L Rausch, Holly K Gibbs","doi":"10.1073/pnas.2532121123","DOIUrl":"https://doi.org/10.1073/pnas.2532121123","url":null,"abstract":"<p><p>Modern slavery remains pervasive across many economic sectors. Progress toward eradicating it has been partially hindered by a lack of tested, comprehensive policy responses. Using data on millions of cattle transactions in Brazil, we evaluated how ranchers changed their selling behavior after being added to the \"Dirty List,\" a public registry that names and shames employers found to use modern slavery. Dirty Listed ranchers significantly reduced direct sales to slaughterhouses that signed sustainable supply chain commitments but evaded sanctions by laundering cattle through compliant intermediaries or selling to nonsignatory slaughterhouses. These responses weakened the financial cost of listing to ranchers, and likely allowed beef and leather linked to modern slave labor to enter international supply chains. Our findings highlight the limits of downstream enforcement and underscore the need to monitor upstream suppliers to ensure slavery-free supply chains.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2532121123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149169590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ice-ray pentagonal packing of pseudo-fivefold helices.","authors":"Lida Aeindartehran, Luke Kwan, Ibrahim Tahir, Daniel K Unruh, Maria Petrov, William B Stoll, Alejandro Alvarez, Jia-Sen Hu, Ejaz Ahmed, Nilanjan Seal, Nathan Taton, Anja Milenkova, Robert E Dinnebier, Murillo Longo Martins, Yongqiang Cheng, Anibal J Ramirez-Cuesta, Jin S Zhang, Michael T Ruggiero, Panče Naumov, Tomče Runčevski","doi":"10.1073/pnas.2608878123","DOIUrl":"https://doi.org/10.1073/pnas.2608878123","url":null,"abstract":"<p><p>While fivefold point symmetry is common in nature, fivefold spatial symmetry is seldom observed. Regular pentagons cannot tile a plane without leaving voids, and even the densest \"ice-ray\" packing is exceptionally rare. Fivefold helices are equally elusive. We report a small molecule that self-assembles into hydrogen-bonded pseudo-fivefold helices and adopts an ice-ray pentagonal packing motif over crystallographic length scales using peripheral disorder that partially occupies regions that would otherwise be void in an ideal pentagonal tessellation. The resulting structure exhibits weak and nondirectional interhelical interactions within the (<i>bc</i>) plane and comparatively strong and directional intrahelical hydrogen bonding along the <i>a</i> axis. This structural anisotropy gives rise to single crystals with large aspect ratios and distinct mechanical behavior. This realization of two rare structural motifs within a single crystal shows the capability of simple organic molecules to form complex structures and highlights an untapped potential for symmetry engineering in molecular solids through the interplay of intermolecular interactions with pronounced differences in strength and directionality.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2608878123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shading enhances Se accumulation in tea leaves through promoting CsMYB7-like-mediated conversion of Se (VI) to Se (IV).","authors":"Jianhui Ye, An Yan, Qiting Fang, Yijie Liu, Chunyang Li","doi":"10.1073/pnas.2535927123","DOIUrl":"https://doi.org/10.1073/pnas.2535927123","url":null,"abstract":"<p><p>Limited selenium (Se) accumulation in agricultural products contributes to widespread dietary Se deficiency, posing a global nutritional threat. Efficient agronomic strategies to enhance Se biofortification in crops are still lacking. Here, we reveal the synergistic effects of shading and Se nanoparticles application on Se biofortification in tea leaves. Field experiments demonstrate that shading enhances Se accumulation in tea leaves under sufficient Se supply, through activating Se metabolism pathway. We identify CsAPR1 functions at the early stage of Se assimilation, catalyzing the reduction of Se (VI). The transcription of <i>CsAPR1</i> is activated by CsMYB7-like and is further promoted by shading through interaction with CsbHLH70. Under sunlight, CsHY5 competes with CsbHLH70 for binding to CsMYB7-like, thereby attenuating CsMYB7-like-mediated transcription of <i>CsAPR1</i> and suppressing Se accumulation in tea plants. Our findings reveal the molecular mechanisms underlying shade-induced enhancement of Se biofortification, offering insights and strategies for Se-enriched crop production.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2535927123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved assessment of Alaskan Arctic coastal wave exposure accounting for landfast ice.","authors":"Martin Henke, Zhaoqing Yang, Ruth Branch","doi":"10.1073/pnas.2612829123","DOIUrl":"https://doi.org/10.1073/pnas.2612829123","url":null,"abstract":"<p><p>Simulations of the ocean wave climate are critical for assessment of coastal processes and hazards in observation sparse regions such as the Arctic. While the multidecade wind and ice datasets necessary for driving long-term wave simulations have proven reliable for such efforts, the presence of landfast ice along shorelines at scales not represented by these data has been a persistent uncertainty impeding accurate analysis of impacts to Arctic coasts. Here, we explore this uncertainty by producing a historical high-resolution wave simulation and combining simulation outputs with landfast ice data for the Alaskan Arctic. The resulting dataset yields an improved assessment of coastal waves and identifies stark contrasts in the seasonal wave exposure of the Chukchi and Beaufort regions. Notably, analysis shows that absent supplemented landfast ice, coastal ice cover is broadly underestimated by 10 to 25 d, resulting in wave energy being overestimated by 5 to 10% in shallow depths nearshore. Notably, these figures can reach up to 70 d of underestimation for ice cover and 48% overestimation of wave energy in certain locations. The persistent overestimation and potential for extreme positive biases in coastal wave assessment highlight the need for representation of landfast ice in Arctic coastal analysis efforts and our analysis reveals the spatial and temporal biases for related research.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2612829123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149165253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct physical contacts with epithelial cells regulate leukocyte actin dynamics to facilitate intraepithelial motility in vivo.","authors":"Jonathan H Schrope, Tanner F Robertson, Adam Horn, Jack J Stevens, Clyde W Tinnen, Julie Rindy, Nicholas Garcia, Yiran Hou, Emilie Rochon, David J Beebe, Anna Huttenlocher","doi":"10.1073/pnas.2612028123","DOIUrl":"https://doi.org/10.1073/pnas.2612028123","url":null,"abstract":"<p><p>Efficient immune cell migration requires physical interactions with surrounding tissues. While tissue matrix mechanics influence leukocyte motility, it is unknown how leukocytes exert pushing and pulling forces to traverse cell-dense epithelial tissues in vivo. Here, we leverage the optical transparency of larval zebrafish to identify how physical interactions with epithelial cells regulate mechanisms of neutrophil force generation to navigate cell-dense tissues. Confining forces from epithelial cells induce a mechanosensitive central actin network, mediated by Cdc42 and Wiskott-Aldrich Syndrome Protein, which exerts expansile forces on surrounding cells to dilate a path for migration. In concert, direct cell-to-cell (leukocyte-epithelial) contacts mediated by integrin ɑE recognition of epithelial cadherin generate traction forces to enable forward motility. Together, our findings identify how physical interactions with the surrounding cellular environment regulate leukocyte motility through epithelial tissue in vivo.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2612028123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149170316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Invariances in an ever-variant environment.","authors":"Priyom Adhyapok, Stefano Di Talia","doi":"10.1073/pnas.2631476123","DOIUrl":"https://doi.org/10.1073/pnas.2631476123","url":null,"abstract":"","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2631476123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149171746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic partitioning shapes the in vivo organization of the <i>Escherichia coli</i> RNA degradosome.","authors":"Laura Troyer, Yu-Huan Wang, Kevin Wu, Seunghyeon Kim, Sangjin Kim","doi":"10.1073/pnas.2621525123","DOIUrl":"https://doi.org/10.1073/pnas.2621525123","url":null,"abstract":"<p><p>The bacterial RNA degradosome is a central mediator of RNA turnover, yet how its components are organized and regulated in living cells remains unclear. Using live-cell single-molecule imaging, we quantified the spatial distribution and dynamics of the four major <i>Escherichia coli</i> degradosome components: RNase E, RhlB, PNPase, and enolase. These proteins occupied distinct membrane-associated and cytoplasmic pools whose relative abundance varied among proteins and changed with physiological state. In particular, PNPase underwent pronounced redistribution between membrane-associated and cytoplasmic states in response to altered RNA availability and growth conditions, whereas RNase E and RhlB remained largely membrane associated. To determine the functional consequences of this organization, we examined the degradation of <i>lacZ</i> reporter transcripts with different translation initiation strengths. PNPase and RhlB preferentially promoted degradation of weakly translated transcripts, whereas strongly translated transcripts were largely insensitive to their loss. Together, these results reveal that the bacterial RNA degradosome is not a static, uniformly assembled molecular machine. Instead, RNA decay is organized through dynamic intracellular partitioning of degradosome components, linking physiological state and translation status to transcript degradation.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2621525123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149207540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A \"knob-in-hole\" gate in the antibody C_H1 domain underlies subclass-independent IgA hinge cleavage by the commensal metallopeptidase IgAse.","authors":"Juan Sebastián Ramírez-Larrota, Guillem Arasa Estivill, Mario López-Martín, Gregory Effantin, Marcos Gragera, Carlos Óscar Sánchez Sorzano, Enrique Marcos, Ulrich Eckhard, Francesc Xavier Gomis-Rüth","doi":"10.1073/pnas.2626241123","DOIUrl":"https://doi.org/10.1073/pnas.2626241123","url":null,"abstract":"<p><p>Human immunoglobulin (Ig) A (IgA) protects ≈400 m² of mucosae from microbes. Bacterial IgA-peptidases subvert this defense by cleaving the F_ab-F_c hinge of subclass IgA1 while sparing the hinge-divergent, colon-dominant IgA2 subclass. The exception is IgAse, a ≈140-kDa, seven-domain, membrane-bound metallopeptidase from the colonic commensal <i>Thomasclavelia ramosa</i> that targets both subclasses but no other protein. We previously narrowed the minimal functional assembly down to the IgAse catalytic and wrapping domains (CD and WD) plus the IgA1/2 F_ab', i.e., the hinge and a F_ab of light and heavy chains (LC, HC), each with a variable and a constant Ig domain (V_L + C_L, V_H + C_H1). The transient interaction culminates in cleavage of a proline-valine bond within the first two hinge residues, downstream of a conserved C-terminal C_H1 disulfide (SS2). Here, single-particle cryoelectron microscopy of a disulfide-stabilized minimal IgAse:IgA2 F_ab' complex yielded high-quality density strongly supporting two states along the cleavage reaction coordinate, a \"recognition complex\" and a subsequent \"precatalytic complex,\" in which F_ab' binds frontally to the IgAse CD via a C_H1 β-sheet and overhang loop LβEβF. This loop binds like a knob to a preformed hole in the active-site cleft. Binding rearranges the knob and rotates SS2 ≈ 180°, enabling access of the hinge into the cleft of the otherwise unaffected precatalytic complex. Together, this work defines a unique, C_H1-mediated hinge-delivering \"gate\" mechanism, validated by a crystal structure of unbound IgA2 F_ab, point mutations disrupting the C_H1:CD interface, and molecular dynamics calculations, which provide the structural framework for subclass-independent IgA cleavage.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2626241123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149207899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A-to-I RNA editing-mediated stop codon read-through in <i>Fusarium graminearum</i> is not generally adaptive.","authors":"Jiachen Li, Jianzhi Zhang","doi":"10.1073/pnas.2628617123","DOIUrl":"https://doi.org/10.1073/pnas.2628617123","url":null,"abstract":"","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2628617123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149149043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating cooperative breeding with reciprocity and culture extends Hamilton's rule to humans.","authors":"Alessandra Cassar, Daniel Friedman, Shreeja Guha, Timothy Wilkins","doi":"10.1073/pnas.2617040123","DOIUrl":"https://doi.org/10.1073/pnas.2617040123","url":null,"abstract":"<p><p>We study how kinship and reciprocity shape giving and child care support in societies with limited access to markets. Extending Hamilton's rule to incorporate reciprocity, we test it using behavioral data from dictator games and surveys in remote matrilocal and patrilocal villages of northeast India (N = 406 parents of young children). We replicate with data from urban Manila neighborhoods (N = 301) and the Solomon Islands (N = 624). Consistent with predictions, transfers to recipients increase with genetic relatedness to the donor and even more with relatedness to the donor's child-a hallmark of reciprocity anchored in shared genetic investment. Nonanonymous conditions amplify giving, especially to nonkin. Cultural norms shape cooperation, but do not trump genetic relatedness. These results underscore the role of affinal ties and reciprocal exchange in sustaining cooperation, and suggest a mechanism through which cooperative breeding could contribute to the emergence of generalized reciprocity and human sociality.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"123 42","pages":"e2617040123"},"PeriodicalIF":9.5,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}