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Corn fiber as a biomass feedstock for production of succinic acid

Bioresource Technology Reports 2021年 16卷

作者： Vallecilla-Yepez, Lisbeth Ramchandran, Divya Long, Dianna Saha, Rajib Wilkins, Mark R. Department of Biological Systems Engineering University of Nebraska Lincoln NE68583 United States Complex Biosystems Program University of Nebraska Lincoln NE68588 United States Department of Chemical and Biomolecular Engineering University of Nebraska Lincoln NE68588 United States Department of Food Science and Technology University of Nebraska Lincoln NE68588 United States Industrial Agricultural Products Center University of Nebraska Lincoln NE68583 United States

The selection of an economical carbon source is a fundamental parameter to establish a successful industrial succinic acid (SA) bioprocess. In this work, corn fiber (CF), a renewable and an inexpensive source of carbohydrates, was successfully used for bioproduction of SA. Optimized liquid hot water (LHW) pretreatment followed by enzymatic hydrolysis were used to obtain corn fiber hydrolysate (CFH). Results in batch fermentation with Actinobacillus succinogenes showed that a control solution mimicking CFH produced 28.7 g/L of SA with a yield of 0.67 g SA/g sugars, while fermentation of CFH produced 27.8 g/L of SA with a yield of 0.61 g SA/g sugars. It was found that culture pH was a critical factor affecting SA production. In sodium acetate buffered media, SA was the major end-product with lower levels of acetic acid (AA) and formic acid (FA). When unbuffered media was used, lactic acid (LA) and ethanol were also detected. © 2021 Elsevier Ltd

关键词： Sugars

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On the social and cognitive dimensions of wicked environmental problems characterized by conceptual and solution uncertainty

arXiv

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arXiv 2021年

作者： Arroyave, Felber J. Goyeneche, Oscar Yandy Romero Gore, Meredith Heimeriks, Gaston Jenkins, Jeffrey Petersen, Alexander M. Department of Management of Complex Systems Ernest and Julio Gallo Management Program School of Engineering University of California MercedCA95343 United States Utrecht University Centre for Global Challenges Netherlands Department of Geographical Sciences University of Maryland College ParkMD20742 United States Copernicus Institute of Sustainable Development Utrecht University Netherlands

We develop a quantitative framework for understanding the class of wicked problems that emerge at the intersections of natural, social, and technological complex systems. Wicked problems reflect our incomplete understanding of interdependent global systems and the systemic risk they pose;such problems escape solutions because they are often ill-defined, and thus mis-identified and under-appreciated by communities of problem-solvers. While there are well-documented benefits to tackling boundary-crossing problems from various viewpoints, the integration of diverse approaches can nevertheless contribute confusion around the collective understanding of the core concepts and feasible solutions. We explore this paradox by analyzing the development of both scholarly (social) and topical (cognitive) communities - two facets of knowledge production studies here that contribute towards the evolution of knowledge in and around a problem, termed a knowledge trajectory - associated with three wicked problems: deforestation, invasive species, and wildlife trade. We posit that saturation in the dynamics of social and cognitive diversity growth is an indicator of reduced uncertainty in the evolution of the comprehensive knowledge trajectory emerging around each wicked problem. Informed by comprehensive bibliometric data capturing both social and cognitive dimensions of each problem domain, we thereby develop a framework that assesses the stability of knowledge trajectory dynamics as an indicator of wickedness associated with conceptual and solution uncertainty. As such, our results identify wildlife trade as a wicked problem that may be difficult to address given recent instability in its knowledge trajectory. © 2021, CC BY.

关键词： Deforestation

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Critical pore radius and transport properties of disordered hard- and overlapping-sphere models

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Physical Review E 2021年第1期104卷 014127-014127页

作者： Michael A. Klatt Robert M. Ziff Salvatore Torquato Department of Physics Princeton University Princeton New Jersey 08544 USA Institut für Theoretische Physik FAU Erlangen-Nürnberg Staudtstr. 7 91058 Erlangen Germany Center for the Study of Complex Systems and Department of Chemical Engineering University of Michigan Ann Arbor Michigan 48109 USA Department of Chemistry Princeton Institute for the Science and Technology of Materials and Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA

Transport properties of porous media are intimately linked to their pore-space microstructures. We quantify geometrical and topological descriptors of the pore space of certain disordered and ordered distributions of spheres, including pore-size functions and the critical pore radius δc. We focus on models of porous media derived from maximally random jammed sphere packings, overlapping spheres, equilibrium hard spheres, quantizer sphere packings, and crystalline sphere packings. For precise estimates of the percolation thresholds, we use a strict relation of the void percolation around sphere configurations to weighted bond percolation on the corresponding Voronoi networks. We use the Newman-Ziff algorithm to determine the percolation threshold using universal properties of the cluster size distribution. The critical pore radius δc is often used as the key characteristic length scale that determines the fluid permeability k. A recent study [Torquato, Adv. Wat. Resour. 140, 103565 (2020)] suggested for porous media with a well-connected pore space an alternative estimate of k based on the second moment of the pore size 〈δ2〉, which is easier to determine than δc. Here, we compare δc to the second moment of the pore size 〈δ2〉, and indeed confirm that, for all porosities and all models considered, δc2 is to a good approximation proportional to 〈δ2〉. However, unlike 〈δ2〉, the permeability estimate based on δc2 does not predict the correct ranking of k for our models. Thus, we confirm 〈δ2〉 to be a promising candidate for convenient and reliable estimates of the fluid permeability for porous media with a well-connected pore space. Moreover, we compare the fluid permeability of our models with varying degrees of order, as measured by the τ order metric. We find that (effectively) hyperuniform models tend to have lower values of k than their nonhyperuniform counterparts. Our findings could facilitate the design of porous media with desirable transport properties via targete

关键词： Geophysical networks Materials Patterns in complex systems

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Impact of inter-city interactions on disease scaling

arXiv

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arXiv 2025年

作者： Loureiro, Nathalia A. Neto, Camilo R. Sutton, Jack Perc, Matjaž Ribeiro, Haroldo V. Complex Systems Modeling Program School of Arts Sciences and Humanities University of São Paulo São Paulo Brazil College of Science and Engineering University of Derby Markeaton Street DerbyDE22 3AW United Kingdom Faculty of Natural Sciences and Mathematics University of Maribor Koroška cesta 160 Maribor2000 Slovenia Community Healthcare Center Dr. Adolf Drolc Maribor Vošnjakova ulica 2 Maribor2000 Slovenia Complexity Science Hub Vienna Josefstädterstraße 39 Vienna1080 Austria Department of Physics Kyung Hee University 26 Kyungheedae-ro Dongdaemun-gu Seoul Korea Republic of Departamento de Física Universidade Estadual de Maringá PR Maringá87020-900 Brazil

Inter-city interactions are critical for the transmission of infectious diseases, yet their effects on the scaling of disease cases remain largely underexplored. Here, we use the commuting network as a proxy for inter-city interactions, integrating it with a general scaling framework to describe the incidence of seven infectious diseases across Brazilian cities as a function of population size and the number of commuters. Our models significantly outperform traditional urban scaling approaches, revealing that the relationship between disease cases and a combination of population and commuters varies across diseases and is influenced by both factors. Although most cities exhibit a less-than-proportional increase in disease cases with changes in population and commuters, more-than-proportional responses are also observed across all diseases. Notably, in some small and isolated cities, proportional rises in population and commuters correlate with a reduction in disease cases. These findings suggest that such towns may experience improved health outcomes and socioeconomic conditions as they grow and become more connected. However, as growth and connectivity continue, these gains diminish, eventually giving way to challenges typical of larger urban areas - such as socioeconomic inequality and overcrowding - that facilitate the spread of infectious diseases. Our study underscores the interconnected roles of population size and commuter dynamics in disease incidence while highlighting that changes in population size exert a greater influence on disease cases than variations in the number of commuters. Copyright © 2025, The Authors. All rights reserved.

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Topological photonics and beyond:introduction

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Photonics Research 2021年第1期9卷 I0001-I0002页

作者： ANDREA ALù LAURA PILOZZI HAITAN XU JINGYUN FAN Photonics Initiative Advanced Science Research CenterCity University of New YorkNew York 10031USA Physics Program Graduate CenterCity University of New YorkNew YorkNew York 10016USA Institute for Complex Systems National Research Council(ISC-CNR)Via dei Taurini 1900185 RomeItaly Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China

Topological photonics has been opening exciting opportunities in recent optics *** this feature issue,we present a collection of papers outlining state-of-the-art and application perspectives for this thriving field o... 详细信息

关键词： beyond optics photonics

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Unifying femtosecond and picosecond single-pulse magnetic switching in Gd-Fe-Co

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Physical Review B 2021年第10期103卷 104422-104422页

作者： F. Jakobs T. A. Ostler C.-H. Lambert Y. Yang S. Salahuddin R. B. Wilson J. Gorchon J. Bokor U. Atxitia Dahlem Center for Complex Quantum Systems and Fachbereich Physik Freie Universität Berlin 14195 Berlin Germany Département de Physique Universitè de Liége (B5) B-4000 Liége Belgium College of Business Technology and Engineering Sheffield Hallam University Howard Street Sheffield S1 1WB United Kingdom Department of Electrical Engineering and Computer Sciences University of California Berkeley California 94720 USA Department of Materials Science and Engineering University of California Berkeley California 94720 USA Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley California 94720 USA Department of Mechanical Engineering and Materials Science and Engineering Program University of California Riverside California 92521 USA

Many questions are still open regarding the physical mechanisms behind the magnetic switching in Gd-Fe-Co alloys by single optical pulses. Phenomenological models suggest a femtosecond scale exchange relaxation between sublattice magnetization as the driving mechanism for switching. The recent observation of thermally induced switching in Gd-Fe-Co by using both several picosecond optical laser pulse as well as electric current pulses has questioned this previous understanding. This has raised the question of whether or not the same switching mechanics are acting at the femtosecond and picosecond scales. In this work, we aim at filling this gap in the understanding of the switching mechanisms behind thermal single-pulse switching. To that end, we have studied experimentally thermal single-pulse switching in Gd-Fe-Co alloys, for a wide range of system parameters, such as composition, laser power, and pulse duration. We provide a quantitative description of the switching dynamics using atomistic spin dynamics methods with excellent agreement between the model and our experiments across a wide range of parameters and timescales, ranging from femtoseconds to picoseconds. Furthermore, we find distinct element-specific damping parameters as a key ingredient for switching with long picosecond pulses and argue that switching with pulse durations as long as 15 ps is possible due to a low damping constant of Gd. Our findings can be easily extended to speed up dynamics in other contexts where ferrimagnetic Gd-Fe-Co alloys have been already demonstrated to show fast and energy-efficient processes, e.g., domain-wall motion in a track and spin-orbit torque switching in spintronics devices.

关键词： Demagnetization Magnetic interactions Magnetic order Magnetism Spin dynamics Ultrafast magnetic effects

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Estimating source-detect or distance using coincidence events

Estimating source-detect or distance using coincidence event...

引用

2020 Transactions of the American Nuclear Society Winter Meeting, ANS 2020

作者： Greulich, Christopher Patel, Dhaval Rodriguez, Shirly Baciak, James Complex Systems Group Oak Ridge National Laboratory P.O. Box 2008 Oak RidgeTN United States CEETHERM Laboratory Georgia Institute of Technology AtlantaGA United States GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Road WilmingtonNC28401 United States Nuclear Engineering Program University of Florida 1929 Stadium Road GainesvilleFL32611 United States

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Renormalizing individual performance metrics for cultural heritage management of sports records

arXiv

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arXiv 2020年

作者： Petersen, Alexander M. Penner, Orion Management of Complex Systems Department Ernest and Julio Gallo Management Program School of Engineering University of California MercedCA95343 United States Chair of Innovation and Intellectual Property Policy College of Management of Technology Ecole Polytechnique Federale de Lausanne Lausanne Switzerland

Individual performance metrics are commonly used to compare players from different eras. However, such cross-era comparison is often biased due to significant changes in success factors underlying player achievement rates (e.g. performance enhancing drugs and modern training regimens). Such historical comparison is more than fodder for casual discussion among sports fans, as it is also an issue of critical importance to the multibillion dollar professional sport industry and the institutions (e.g. Hall of Fame) charged with preserving sports history and the legacy of outstanding players and achievements. To address this cultural heritage management issue, we report an objective statistical method for renormalizing career achievement metrics, one that is particularly tailored for common seasonal performance metrics, which are often aggregated into summary career metrics – despite the fact that many player careers span different eras. Remarkably, we find that the method applied to comprehensive Major League Baseball and National Basketball Association player data preserves the overall functional form of the distribution of career achievement, both at the season and career level. As such, subsequent re-ranking of the top-50 all-time records in MLB and the NBA using renormalized metrics indicates reordering at the local rank level, as opposed to bulk reordering by era. This local order refinement signals time-independent mechanisms underlying annual and career achievement in professional sports, meaning that appropriately renormalized achievement metrics can be used to compare players from eras with different season lengths, team strategies, rules – and possibly even different sports. Copyright © 2020, The Authors. All rights reserved.

关键词： Sports

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An inactivated SARS-CoV-2 vaccine induced cross-neutralizing persisting antibodies and protected against challenge in small animals

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iScience 2023年第2期26卷 105949页

作者： Offersgaard, Anna Duarte Hernandez, Carlos Rene Feng, Shan Marichal-Gallardo, Pavel Holmbeck, Kenn Pihl, Anne Finne Fernandez-Antunez, Carlota Alzua, Garazi Peña Hartmann, Katrine Top Pham, Long V. Zhou, Yuyong Gammeltoft, Karen Anbro Fahnøe, Ulrik Schneider, Uffe Vest Pedersen, Gabriel Kristian Jensen, Henrik Elvang Christensen, Jan Pravsgaard Ramirez, Santseharay Bukh, Jens Gottwein, Judith Margarete Copenhagen Hepatitis C Program (CO-HEP) Department of Infectious Diseases Copenhagen University Hospital–Hvidovre Hvidovre 2650 Denmark CO-HEP Department of Immunology and Microbiology Faculty of Health and Medical Sciences University of Copenhagen Copenhagen N 2200 Denmark Bioprocess Engineering Max Planck Institute for Dynamics of Complex Technical Systems Magdeburg 39106 Germany Department of Veterinary and Animal Sciences University of Copenhagen Frederiksberg C 1870 Denmark Department of Clinical Microbiology Copenhagen University Hospital–Hvidovre Hvidovre 2650 Denmark Center for Vaccine Research Statens Serum Institut Copenhagen S 2300 Denmark Department of Immunology and Microbiology Faculty of Health and Medical Sciences University of Copenhagen Copenhagen N 2200 Denmark

Vaccines have relieved the public health burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and globally inactivated vaccines are most widely used. However, poor vaccination accessibility and waning immunity maintain the pandemic, driving emergence of variants. We developed an inactivated SARS-CoV-2 (I-SARS-CoV-2) vaccine based on a viral isolate with the Spike mutation D614G, produced in Vero cells in a scalable bioreactor, inactivated with β-propiolactone, purified by membrane-based steric exclusion chromatography, and adjuvanted with MF59-like adjuvant AddaVax. I-SARS-CoV-2 and a derived split vaccine induced persisting neutralizing antibodies in mice;moreover, lyophilized antigen was immunogenic. Following homologous challenge, I-SARS-CoV-2 immunized hamsters were protected against disease and lung pathology. In contrast with reports for widely used vaccines, hamster plasma similarly neutralized the homologous and the Delta (B.1.617.2) variant viruses, whereas the Omicron (B.1.1.529) variant was neutralized less efficiently. Applied bioprocessing approaches offer advantages regarding scalability and production, potentially benefitting worldwide vaccine coverage. © 2023 The Authors

关键词： Immune response Immunology Virology

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Leveraging multivariate information for community detection in functional brain networks

Communications biology

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Communications biology 2025年第1期8卷 840页

作者： Maria Grazia Puxeddu Maria Pope Thomas F Varley Joshua Faskowitz Olaf Sporns Department of Psychological and Brain Sciences Indiana University Bloomington IN USA. mpuxeddu@iu.edu. Department of Computer Control and Management Engineering "Antonio Ruberti" Sapienza University of Rome Rome Italy. mpuxeddu@iu.edu. Program in Neuroscience Indiana University Bloomington IN USA. Luddy School of Informatics Indiana University Bloomington IN USA. Department of Psychological and Brain Sciences Indiana University Bloomington IN USA. Vermont Complex Systems Institute University of Vermont Burlington VT USA.

Brain functioning relies on specialized systems whose integration enables cognition and behavior. Network science provides tools to model the brain as a set of interconnected brain regions wherein those segregated systems (modules) can be identified by optimizing the weights of pairwise connections within them. However, knowledge alone of these pairwise connections might not suffice: brain dynamics are also engendered by higher-order interactions that simultaneously involve multiple brain areas. Here, we propose a community detection algorithm that accounts for multivariate interactions and finds modules of brain regions whose activity is maximally redundant. We compared redundancy-dominated modules to those identified with conventional methods, uncovering a new organization of the transmodal cortex. Moreover, by identifying a spatial resolution where within-module redundancy and between-module synergy are maximally balanced, we captured a higher-order manifestation of the interplay between segregation and integration of information. Finally, we distinguish brain regions with high and low topological specialization based on their contribution to within- or between-module redundancy, and we observed how redundant modules reconfigure across the lifespan. Altogether, the results show a modular organization of the brain that accounts for higher-order interactions and pave the way for future investigations that might link it to cognition, behavior, or disease.

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