Proceedings of the National Academy of Sciences of the United States of America最新文献_第9页

Engineered bacteria that self-assemble bioglass polysilicate coatings display enhanced light focusing.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-10 DOI: 10.1073/pnas.2409335121

Lynn M Sidor, Michelle M Beaulieu, Ilia Rasskazov, B Cansu Acarturk, Jie Ren, Emerson Jenen, Lycka Kamoen, María Vázquez Vitali, P Scott Carney, Greg R Schmidt, Wil V Srubar, Elio A Abbondanzieri, Anne S Meyer

{"title":"Engineered bacteria that self-assemble bioglass polysilicate coatings display enhanced light focusing.","authors":"Lynn M Sidor, Michelle M Beaulieu, Ilia Rasskazov, B Cansu Acarturk, Jie Ren, Emerson Jenen, Lycka Kamoen, María Vázquez Vitali, P Scott Carney, Greg R Schmidt, Wil V Srubar, Elio A Abbondanzieri, Anne S Meyer","doi":"10.1073/pnas.2409335121","DOIUrl":"10.1073/pnas.2409335121","url":null,"abstract":"Cutting-edge photonic devices frequently rely on microparticle components to focus and manipulate light. Conventional methods used to produce these microparticle components frequently offer limited control of their structural properties or require low-throughput nanofabrication of more complex structures. Here, we employ a synthetic biology approach to produce environmentally friendly, living microlenses with tunable structural properties. We engineered Escherichia coli bacteria to display the silica biomineralization enzyme silicatein from aquatic sea sponges. Our silicatein-expressing bacteria can self-assemble a shell of polysilicate \"bioglass\" around themselves. Remarkably, the polysilicate-encapsulated bacteria can focus light into intense nanojets that are nearly an order of magnitude brighter than unmodified bacteria. Polysilicate-encapsulated bacteria are metabolically active for up to 4 mo, potentially allowing them to sense and respond to stimuli over time. Our data demonstrate that synthetic biology offers a pathway for producing inexpensive and durable photonic components that exhibit unique optical properties.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"121 51","pages":"e2409335121"},"PeriodicalIF":9.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142801697","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}

引用次数: 0

Hierarchical gradients of multiple timescales in the mammalian forebrain. 哺乳动物前脑多时间尺度的层次梯度。

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-13 DOI: 10.1073/pnas.2415695121

Min Song, Eun Ju Shin, Hyojung Seo, Alireza Soltani, Nicholas A Steinmetz, Daeyeol Lee, Min Whan Jung, Se-Bum Paik

{"title":"Hierarchical gradients of multiple timescales in the mammalian forebrain.","authors":"Min Song, Eun Ju Shin, Hyojung Seo, Alireza Soltani, Nicholas A Steinmetz, Daeyeol Lee, Min Whan Jung, Se-Bum Paik","doi":"10.1073/pnas.2415695121","DOIUrl":"10.1073/pnas.2415695121","url":null,"abstract":"Many anatomical and physiological features of cortical circuits, ranging from the biophysical properties of synapses to the connectivity patterns among different neuron types, exhibit consistent variation along the hierarchical axis from sensory to association areas. Notably, the temporal correlation of neural activity at rest, known as the intrinsic timescale, increases systematically along this hierarchy in both primates and rodents, analogous to the increasing scale and complexity of spatial receptive fields. However, how the timescales for task-related activity vary across brain regions and whether their hierarchical organization appears consistently across different mammalian species remain unexplored. Here, we show that both the intrinsic timescale and those of task-related activity follow a similar hierarchical gradient in the cortices of monkeys, rats, and mice. We also found that these timescales covary similarly in both the cortex and basal ganglia, whereas the timescales of thalamic activity are shorter than cortical timescales and do not conform to the hierarchical order predicted by their cortical projections. These results suggest that the hierarchical gradient of cortical timescales might represent a universal feature of intracortical circuits in the mammalian brain.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"121 51","pages":"e2415695121"},"PeriodicalIF":9.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142819012","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}

引用次数: 0

Structural stability and thermodynamics of artistic composition.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-13 DOI: 10.1073/pnas.2406735121

San To Chan, Eliot Fried

{"title":"Structural stability and thermodynamics of artistic composition.","authors":"San To Chan, Eliot Fried","doi":"10.1073/pnas.2406735121","DOIUrl":"10.1073/pnas.2406735121","url":null,"abstract":"Inspired by the way that digital artists zoom out of the canvas to assess the visual impact of their works, we introduce a conceptually simple yet effective metric for quantifying the clarity of digital images. This metric contrasts original images with progressively \"melted\" counterparts, produced by randomly flipping adjacent pixel pairs. It measures the presence of stable structures, assigning the value zero to completely uniform or random images and finite values for those with discernible patterns. This metric respects the color diversity of the original image and withstands image compression and color quantization. Its suitability for diverse image analysis problems is demonstrated through its effective evaluation of textural images, the identification of structural transitions in physical systems like the Potts model, and its consistency with color theory in digital arts. This allows us to demonstrate that color in visual art functions as a state variable, akin to the spin configuration in magnets, driving artistic designs to transition between states with distinct clarity. When combined with the Shannon entropy, which quantifies color diversity, the structural stability metric can serve as a navigation tool for artists to explore pathways on the complex structural information landscape toward the completion of their artwork. As a practical demonstration, we apply our metric to refine and optimize an emote design for a video game. The structural stability metric emerges as a versatile tool for extracting nuanced structural information from digital images, which may enhance decision-making and data analysis across scientific and creative domains.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"121 51","pages":"e2406735121"},"PeriodicalIF":9.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818909","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}

引用次数: 0

The legacy of DDT lives on in the Southern California Bight.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-09 DOI: 10.1073/pnas.2421473121

Amalia Aruda Almada

引用次数: 0

Sustainable production of bioplastic monomers using a microbial production chassis.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-09 DOI: 10.1073/pnas.2422178121

Mattheos A G Koffas

引用次数: 0

Facile construction of distal and diversified tertiary and quaternary stereocenters.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-12 DOI: 10.1073/pnas.2408541121

Chong Liu, Robbie Ge, Jun Chen, Hongmei Guo, Tyler A Bartholome, Debabrata Maiti, Haibo Ge

引用次数: 0

Probing iron in Earth's core with molecular-spin dynamics.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-12 DOI: 10.1073/pnas.2408897121

Svetoslav Nikolov, Kushal Ramakrishna, Andrew Rohskopf, Mani Lokamani, Julien Tranchida, John Carpenter, Attila Cangi, Mitchell A Wood

引用次数: 0

Plant chemical diversity enhances defense against herbivory.

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-11 DOI: 10.1073/pnas.2417524121

Xosé López-Goldar, Xuening Zhang, Amy P Hastings, Christophe Duplais, Anurag A Agrawal

{"title":"Plant chemical diversity enhances defense against herbivory.","authors":"Xosé López-Goldar, Xuening Zhang, Amy P Hastings, Christophe Duplais, Anurag A Agrawal","doi":"10.1073/pnas.2417524121","DOIUrl":"https://doi.org/10.1073/pnas.2417524121","url":null,"abstract":"Multiple hypotheses have been put forth to understand why defense chemistry in individual plants is so diverse. A major challenge has been teasing apart the importance of concentration vs. composition of defense compounds and resolving the mechanisms of diversity effects that determine plant resistance against herbivores. Accordingly, we first outline nonexclusive mechanisms by which phytochemical diversity may increase toxicity of a mixture compared to the average effect of each compound alone. We then leveraged independent in vitro, in vivo transgenic, and organismal experiments to test the effect of equimolar concentrations of purified milkweed toxins in isolation vs. mixtures on the specialist and sequestering monarch butterfly. We show that cardenolide toxin mixtures from milkweed plants enhance resistance against this herbivore compared to equal concentrations of single compounds. In mixtures, highly potent toxins dominated the inhibition of the monarch's target enzyme (Na+/K+-ATPase) in vitro, revealing toxin-specific affinity for the adapted enzyme in the absence of other physiological adaptations of the monarch. Mixtures also caused increased mortality in CRISPR-edited adult Drosophila melanogaster with the monarch enzyme in vivo, whereas wild-type flies showed lower survival regardless of mixture type. Finally, although experimentally administered mixtures were not more toxic to monarch caterpillars than single compounds overall, increasing caterpillar sequestration from mixtures resulted in an increasing burden for growth compared to single compounds. Phytochemical diversity likely provides an economical plant defense by acting on multiple aspects of herbivore physiology and may be particularly effective against sequestering specialist herbivores.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"121 51","pages":"e2417524121"},"PeriodicalIF":9.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807868","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}

引用次数: 0

The C-terminal activating domain promotes pannexin 1 channel opening. C 端激活结构域可促进 pannexin 1 通道开放。

IF 9.4 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 Epub Date: 2024-12-13 DOI: 10.1073/pnas.2411898121

Erik Henze, Jacqueline J Ehrlich, Janice L Robertson, Eric Gelsleichter, Toshimitsu Kawate

{"title":"The C-terminal activating domain promotes pannexin 1 channel opening.","authors":"Erik Henze, Jacqueline J Ehrlich, Janice L Robertson, Eric Gelsleichter, Toshimitsu Kawate","doi":"10.1073/pnas.2411898121","DOIUrl":"10.1073/pnas.2411898121","url":null,"abstract":"Pannexin 1 (Panx1) constitutes a large pore channel responsible for the release of adenosine triphosphate (ATP) from apoptotic cells. Strong evidence indicates that caspase-mediated cleavage of the C-terminus promotes the opening of the Panx1 channel by unplugging the pore. However, this simple pore-plugging mechanism alone cannot account for the observation that a Panx1 construct ending before the caspase cleavage site remains closed. Here, we show that a helical region located immediately before the caspase cleavage site, referred to as the \"C-terminal activating domain (CAD)\", plays a pivotal role in facilitating Panx1 activation. Electrophysiology and mutagenesis studies uncovered that two conserved leucine residues within the CAD play a pivotal role. Cryoelectron microscopy (Cryo-EM) analysis of the construct ending before reaching the CAD demonstrated that the N terminus extends into an intracellular pocket. In contrast, the construct including the CAD revealed that this domain occupies the intracellular pocket, causing the N terminus to flip upward within the pore. Analysis of electrostatic free energy landscape in the closed conformation indicated that the intracellular side of the ion permeation pore may be occupied by anions like ATP, creating an electrostatic barrier for anions attempting to permeate the pore. When the N terminus flips up, it diminishes the positively charged surface, thereby reducing the drive to accumulate anions inside the pore. This dynamic change in the electrostatic landscape likely contributes to the selection of permeant ions. Collectively, these experiments put forth a mechanism in which C-terminal cleavage liberates the CAD, causing the repositioning of the N terminus to promote Panx1 channel opening.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"121 51","pages":"e2411898121"},"PeriodicalIF":9.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818816","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}

引用次数: 0

Modeling how and why aquatic vegetation removal can free rural households from poverty-disease traps

IF 11.1 1区综合性期刊

Proceedings of the National Academy of Sciences of the United States of America Pub Date : 2024-12-17 DOI: 10.1073/pnas.2411838121

Molly J. Doruska, Christopher B. Barrett, Jason R. Rohr

{"title":"Modeling how and why aquatic vegetation removal can free rural households from poverty-disease traps","authors":"Molly J. Doruska, Christopher B. Barrett, Jason R. Rohr","doi":"10.1073/pnas.2411838121","DOIUrl":"https://doi.org/10.1073/pnas.2411838121","url":null,"abstract":"Infectious disease can reduce labor productivity and incomes, trapping subpopulations in a vicious cycle of ill health and poverty. Efforts to boost African farmers’ agricultural production through fertilizer use can inadvertently promote the growth of aquatic vegetation that hosts disease vectors. Recent trials established that removing aquatic vegetation habitat for snail intermediate hosts reduces schistosomiasis infection rates in children, while converting the harvested vegetation into compost boosts agricultural productivity and incomes. We develop a bioeconomic model that interacts an analytical microeconomic model of agricultural households’ behavior, health status, and incomes over time with a dynamic model of schistosomiasis disease ecology. We calibrate the model with field data from northern Senegal. We show analytically and via simulation that local conversion of invasive aquatic vegetation to compost changes the feedback among interlinked disease, aquatic, and agricultural systems, reducing schistosomiasis infection and increasing incomes relative to the current status quo, in which villagers rarely remove aquatic vegetation. Aquatic vegetation removal disrupts the poverty-disease trap by reducing habitat for snails that vector the infectious helminth and by promoting the production of compost that returns to agricultural soils nutrients that currently leach into surface water from on-farm fertilizer applications. The result is healthier people, more productive labor, cleaner water, more productive agriculture, and higher incomes. Our model illustrates how this ecological intervention changes the feedback between the human and natural systems, potentially freeing rural households from poverty-disease traps.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":"12 1","pages":""},"PeriodicalIF":11.1,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841058","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}

引用次数: 0