bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ensuring the Sustainability of Biocatalysis
Authors: Woodley John M. 
Published: January 2022

AbstractAbstract: Biocatalysis offers many attractive features for the synthetic chemist. In many cases, the high selectivity and ability to tailor specific enzyme features via protein engineering already make it the catalyst of choice. From the perspective of sustainability, several features such as catalysis under mild conditions and use of a renewable and biodegradable catalyst also look attractive. Nevertheless, to be sustainable at a larger scale it will be essential to develop processes operating at far higher concentrations of product, and which make better use of the enzyme via improved stability. In this Concept, it is argued that a particular emphasis on these specific metrics is of particular importance for the future implementation of biocatalysis in industry, at a level that fulfills its true potential.
Across the Board: Gabriele Centi on Decoupling Electrocatalytic Reactions to Electrify Chemical Production
Authors: Centi Gabriele 
Published: January 2022

AbstractIn this series of articles, the board members of ChemSusChem discuss recent research articles that they consider of exceptional quality and importance for sustainability. This entry features Prof. G. Centi, who discusses the decoupling of the electrocatalytic reactions to realize spatiotemporal separation of the anodic and cathodic processes using redox mediators. This solution allows to potentially overcome the limitations due to intermittency of renewable energy production, besides a series of other advantages such as an improved energy efficiency.
Formation of energy spectra of electrons in a dense weakly ionized plasma generated by fission fragments
Authors: Shapiyeva Aigerim , Son Eduard , Kunakov Sandybek 
Published: January 2022

AbstractFor a weakly ionized dense plasma irradiated by fission fragments, the coupled self‐consistent Boltzmann equations for fission fragments and electrons are defined. The evolution of the energy spectra of fast particles in a plasma is investigated on the basis of these equations. Studies of the energy distribution function of fission fragments and primary electrons for a helium‐3 plasma irradiated by neutron flux, as well as their non‐stationary and stationary analytical solutions, are found and analysed.
MIRIAM: A machine and deep learning single‐cell segmentation and quantification pipeline for multi‐dimensional tissue images
Authors: McKinley Eliot T. , Shao Justin , Ellis Samuel T. , Heiser Cody N. , Roland Joseph T. , Macedonia Mary C. , Vega Paige N. , Shin Susie , Coffey Robert J. , Lau Ken S. 
Published: January 2022

AbstractIncreasingly, highly multiplexed tissue imaging methods are used to profile protein expression at the single‐cell level. However, a critical limitation is the lack of robust cell segmentation tools for tissue sections. We present Multiplexed Image Resegmentation of Internal Aberrant Membranes (MIRIAM) that combines (a) a pipeline for cell segmentation and quantification that incorporates machine learning‐based pixel classification to define cellular compartments, (b) a novel method for extending incomplete cell membranes, and (c) a deep learning‐based cell shape descriptor. Using human colonic adenomas as an example, we show that MIRIAM is superior to widely utilized segmentation methods and provides a pipeline that is broadly applicable to different imaging platforms and tissue types.
Climate change, land cover change, and overharvesting threaten a widely used medicinal plant in South Africa
Authors: Groner Vivienne P. , Nicholas Owen , Mabhaudhi Tafadzwanashe , Slotow Rob , Akçakaya H. Reşit , Mace Georgina M. , Pearson Richard G. 
Published: January 2022

AbstractMedicinal plants contribute substantially to the well‐being of people in large parts of the world, providing traditional medicine and supporting livelihoods from trading plant parts, which is especially significant for women in low‐income communities. However, the availability of wild medicinal plants is increasingly threatened; for example, the Natal Lily (Clivia miniata), which is one of the most widely traded plants in informal medicine markets in South Africa, lost over 40% of individuals over the last 90 years. Understanding the species’ response to individual and multiple pressures is essential for prioritizing and planning conservation actions. To gain this understanding, we simulated the future range and abundance of C. miniata by coupling Species Distribution Models with a metapopulation model (RAMAS‐GIS). We contrasted scenarios of climate change (RCP2.6 vs. RCP8.5), land cover change (intensification vs. expansion), and harvesting (only juveniles vs. all life‐stages). All our scenarios pointed to continuing declines in suitable habitat and abundance by the 2050s. When acting independently, climate change, land cover change, and harvesting each reduced the projected abundance substantially, with land cover change causing the most pronounced declines. Harvesting individuals from all life stages affected the projected metapopulation size more negatively than extracting only juveniles. When the three pressures acted together, declines of suitable habitat and abundance accelerated but uncertainties were too large to identify whether pressures acted synergistically, additively, or antagonistically. Our results suggest that conservation should prioritize the protection of suitable habitat and ensure sustainable harvesting to support a viable metapopulation under realistic levels of climate change. Inadequate management of C. miniata populations in the wild will likely have negative consequences for the well‐being of people relying on this ecosystem service, and we expect there may be comparable consequences relating to other medicinal plants in different parts of the world.
A domestic plant differs from its wild relative along multiple axes of within‐plant trait variability and diversity
Authors: Robinson Moria L. , Schilmiller Anthony L. , Wetzel William C. 
Published: January 2022

AbstractFor 10,000 years humans have altered plant traits through domestication and ongoing crop improvement, shaping plant form and function in agroecosystems. To date, studies have focused on how these processes shape whole‐plant or average traits; however, plants also have characteristic levels of trait variability among their repeated parts, which can be heritable and mediate critical ecological interactions. Here, we examine an underappreciated scale of trait variation—among leaves, within plants—that may have changed through the process of domestication and improvement. Variability at this scale may itself be a target of selection, or be shaped as a by‐product of the domestication process. We explore how levels of among‐leaf trait variability differ between cultivars and wild relatives of alfalfa (Medicago sativa), a key forage crop with a 7,000‐year domestication history. We grew individual plants from 30 wild populations and 30 cultivars, and quantified variability in a broad suite of physical, nutritive, and chemical leaf traits, including measures of chemical dissimilarity (beta diversity) among leaves within each plant. We find that trait variability has changed over the course of domestication, with effects often larger than changes in trait means. Domestic alfalfa had elevated among‐leaf variability in SLA, trichomes, and C:N; increased diversity in defensive compounds; and reduced variability in phytochemical composition. We also elucidate fundamental relationships between trait means and variability, and between overall production of secondary metabolites and patterns of chemical diversity. We conclude that within‐plant variability is an overlooked dimension of trait diversity in a globally critical agricultural crop. Trait variability is actually higher in cultivated plants compared to wild progenitors for multiple nutritive, physical, and chemical traits, highlighting a scale of variation that may mitigate loss of trait diversity at other scales in alfalfa agroecosystems, and in other crops with similar histories of domestication and improvement.
Remote sensing to characterize inundation and vegetation dynamics of upland lagoons
Authors: Brinkhoff James , Backhouse Gillian , Saunders Manu E. , Bower Deborah S. , Hunter John T. 
Published: January 2022

AbstractUnderstanding broad trends in the distribution and composition of wetlands is essential for making evidence‐based management decisions. Determining temporal change in the extent of inundation in wetlands using remote sensing remains challenging and requires on‐ground verification to determine accuracy and precision. Therefore, optimization and validation of remote sensing methods in threatened wetlands is a high priority for their conservation. Despite their ecological importance in the landscape, we have little knowledge of the variation in the spatial extent of inundation in upland lagoons, a threatened ecological community in New South Wales, Australia. Our project developed locally trained algorithms to predict the extent of water and emergent vegetation using imagery from the Landsat‐5, ‐7, and ‐8 satellites. The best model for upland lagoons used shortwave infrared reflectance (performing better than normalized difference spectral indices), with model accuracy against validation transects greater than 95%. We applied the model to images from 1988 to 2020 across 58 lagoons to generate a dataset that demonstrates the variable water regime and vegetation change in response to local rainfall over 32 years such as in the lagoons. Our results reduce threats to a dynamic threatened ecological community by filling an important knowledge gap and demonstrate a valuable method to understand historical and current changes in the hydrology of dynamic wetland systems more broadly.
Invasive grass litter suppresses a native grass species and promotes disease
Authors: Benitez Liliana , Kendig Amy E. , Adhikari Ashish , Clay Keith , Harmon Philip F. , Holt Robert D. , Goss Erica M. , Flory S. Luke 
Published: January 2022

AbstractPlant litter can alter ecosystems and promote plant invasions by altering resource availability, depositing phytotoxins, and transmitting microorganisms to living plants. Transmission of microorganisms from invasive plant litter to live plants may gain importance as invasive plants, which often escape pathogens upon introduction to a new range, acquire new pathogens over time. It is unclear, however, if invasive plant litter affects native plant communities by promoting disease. Microstegium vimineum is an invasive grass that suppresses native populations, in part through litter production, and has acquired new fungal leaf spot diseases since its introduction to the United States. In a greenhouse experiment, we evaluated how M. vimineum litter and its pathogens mediated competition with the native grass Elymus virginicus. M. vimineum litter promoted disease on E. virginicus and suppressed establishment and biomass of both species. Litter had stronger negative effects on E. virginicus than M. vimineum, increasing the relative biomass of M. vimineum. Live plant competition reduced biomass of both species and live M. vimineum increased disease incidence on E. virginicus. Altogether, invasive grass litter suppressed both species, ultimately favoring the invasive species in competition, and increased disease incidence on the native species.
Timing of prescribed burns impacts plant diversity but not investment in pollinator recruitment in a tallgrass prairie
Authors: Roberton Bethany , Rebar Darren 
Published: January 2022

AbstractPrescribed burns replicate the historic fires that played a key role in maintaining prairies. Spring‐applied burns are commonly employed for grazing and brush control and, therefore, much is known about their effects. However, prairie plants may be sensitive to the historically variable timing of burns and thus differentially respond to when prescribed burns are applied, an aspect that remains poorly understood. We performed three experimental seasonal burn treatments (summer, fall, or spring) in tallgrass prairie and examined (1) the response of the flowering forb community in terms of density and diversity, and (2) how individual milkweed plants (Asclepias spp.) invested in nectar to recruit pollinators. We found that burn timing did not affect flowering forb density but did impact flowering forb diversity: It was lowest following spring burns, whereas summer‐ and fall‐burned plots were more diverse. Nectar sucrose concentrations in milkweeds, however, were not affected by the timing of burns but rather seemed robust in their investment to recruit pollinators. Therefore, while individual plant investment strategies may be more sensitive to other factors, the timing of prescribed burns seems important in promoting flowering forb diversity, which could have important downstream consequences on the diversity of pollinators and other animal communities.
Metallocene Anions: From Electrochemical Curiosities to Isolable Complexes
Authors: Magnoux Corentin , Mills David P. 
Published: January 2022

AbstractSince the first reports and structural characterisation of ferrocene in the 1950s, metallocenes [M(Cp)2] (M=metal, Cp=cyclopentadienyl, C5H5) have become a workhorse of organometallic chemistry. The vast majority of metallocenes and derivatized metallocenes [M(CpR)2], where the CpR ring bears alternative substituents or incorporates heteroatoms in the ring itself, contain metal centres in a formal +II oxidation state, or +III for metallocenium cations, [M(CpR)2]+. Here we present an overview of metallocene anions and their derivatives, [M(CpR)2]−, where metal centres formally exhibit +I oxidation states. We focus on d‐block examples, from their origins as unstable intermediates in low temperature electrochemical studies to more recent examples of isolated complexes.
Energy dissipation in reinforced concrete members before or after yielding
Authors: Grammatikou Sophia , Fardis Michael N. , Biskinis Dionysis 
Published: January 2022

AbstractModels for the pre‐ and post‐yield energy dissipation in reinforced concrete (RC) members are developed using a database of about 1200 tests with over 18,000 load cycles. Before yielding, the equivalent viscous damping ratio exceeds 5%, especially if the member is initially uncracked. It can be considered by using either a dedicated pre‐yield hysteretic model with parameters established in the paper or global viscous damping and special provisions against double counting of energy dissipation. The post‐yield model can be combined with various post‐yield hysteretic laws. It accounts for the member's type, shear‐span‐to‐depth ratio and likely failure mode, the continuity, ratio, and surface characteristics of longitudinal bars, and for FRP wrapping, if any. Alternatively, it recognizes only four member types but accounts also for the transverse steel ratio and the normal stress due to the axial load.
Precast concrete column base with replaceable energy dissipation connectors: Quasi‐static tests and numerical research
Authors: Zhang Jinyang , Wu Jing , Xie Luqi , Li Chunyu , Zhu Yunqing 
Published: January 2022

AbstractA type of precast concrete column base with replaceable energy dissipation connectors (REDCs) is proposed in this study. The bottom of the column is reinforced with a square steel tube. REDCs can transfer the bending moment of the column base during frequent earthquakes and yield to dissipate most of the inputted seismic energy during major earthquakes. Several raised steel stoppers are arranged around the sides of the column base to limit lateral slippage. The load‐resisting mechanism, construction technology and post‐earthquake repair methods of the column base are introduced. Five quasi‐static tests were carried out on a full‐scale test specimen, in which the experimental variables include the axial compression ratio of the column and the size of the REDCs. The test results show that the damage was concentrated in the REDCs while the precast column suffered minor damage. The REDCs fractured after dozens of cycles at large lateral drift ratios, effectively exerting their excellent low‐cycle fatigue performance. Plump and stable hysteretic curves and bilinear skeleton curves were obtained in test results. The curves before and after seismic rehabilitation are similar. Furthermore, a simplified numerical analysis model of the column base is established using OpenSees. The hysteretic curves and skeleton curves obtained by simulation agree with the test results.
Predicting sediment connectivity in a mountain basin: A quantitative analysis of the index of connectivity
Authors: Martini Lorenzo , Cavalli Marco , Picco Lorenzo 
Published: January 2022

AbstractSediment connectivity underlies the relationships between sediment source areas and stream network and the use of topography‐based indices, such as the index of connectivity (IC), has become a common approach to investigate these relationships. However, few studies have tested the potential of the IC as an independent variable for predicting observable processes. In this study, the aim is the validation of the IC as a semi‐quantitative tool for depicting structural connectivity and predicting sediment dynamics linking sediment sources to the channel network after a large infrequent disturbance in the Rio Cordon catchment (Italy). First, the assessment of lateral connectivity was carried out using a combination of remote sensing data and field observations. In this way, it was possible to classify the sediment sources into disconnected, connected or functionally connected. Second, logistic regression analyses were performed using different IC variants, with different weighting factors and spatial resolutions as independent variables and connectivity status as dependent variable. Hence, the predictive capacity of the IC was tested and a threshold was derived to distinguish between low and high sediment connectivity. The results showed that only 15% of sediment sources are connected to the stream network. Moreover, the IC proved to be a reliable tool for depicting structural connectivity when using surface roughness as weighting factor and high‐resolution digital terrain models. On the contrary, it failed at predicting sediment dynamics as it did not classify correctly the functionally connected areas, so it cannot infer functional sediment connectivity in this case study. As a consequence, it was possible to obtain an IC threshold of −2.32, capable of differentiating between low and high structural sediment connectivity and useful for future management decisions. The threshold, in fact, represents an objective boundary between disconnected and connected sources in the Rio Cordon catchment.
Variable pulse position modulation receivers for visible light communication systems without the knowledge of dimming level
Authors: Sünnetci Kubilay Muhammed , Sönmez Mehmet 
Published: January 2022

AbstractThe dimming control is one of the most significant issues to provide both illumination and data transmission for visible light communication (VLC) systems. The receivers—such as variable pulse position modulation (VPPM) receiver—must know the dimming level of the received signal for the demodulation process. To provide a complete solution to this problem, we propose two VPPM receivers that can detect data bits without knowledge of dimming level (KDL). The first one, which is referred to as artificial neural network (ANN)‐VPPM, includes the ANN technique to achieve a proper step signal instead of traditional mask signals that are generated by using the perfect KDL. The ANN‐VPPM gives a successful bit error rate (BER) performance compared to the unsuitable traditional system (U‐TS), which is called the traditional system that decodes the VPPM signal using inappropriate mask signals. If the ANN‐VPPM is compared to traditional system (TS), which is the traditional system using a perfect mask signal, the TS has better BER performance than the ANN‐VPPM. Hence, the other one that is called the proposed estimation method (PEM) is improved to achieve the same BER performance compared to the TS. An estimation performance is given to indicate the 100% estimation rate and to prove that the BER performance of systems is the same at least signal‐to‐noise ratio of 22 dB. Additionally, the PEM is saving the optical power of the VPPM signal up to 23% at a BER of 10−3 when compared to U‐TS.
Discovery of granulite‐facies metamorphic rocks in the Yilan area, Heilongjiang Province, China: Geochronology, geochemistry, metamorphic characteristics, and geological implications
Authors: Yang Yan , Zheng Changqing , Liang Chenyue , Xu Xuechun , Zhou Jianbo , Zhou Xiao , Sun Xiaolei , Zhu Erlin , Jia Shiju 
Published: January 2022

The Mashan Complex of the Jiamusi Massif was traditionally considered as the oldest stratigraphic sequence in eastern NE China. However, the metamorphic degree of the Mashan Complex is different in different areas, which can be divided into Jixi–Mishan–Hulin granulite facies belt and Luobei–Huanan–Mudanjiang amphibolite facies belt. Here, we investigated the Mashan Complex in the Yilan area and present lots of new petrological, mineral chemical, geochemical, and U–Pb geochronological data, in addition to phase equilibria modelling, to constrain the timing of metamorphism, P–T conditions, and the P–T path of the Mashan Complex, and furthermore to deduce the crustal evolution of the Jiamusi Massif. The protoliths of the Mashan Complex in the Yilan area are greywackes and felsic sandstones, whose provenance is dominantly felsic rocks formed from a continental island arc. Petrographic observations, traditional thermobarometry, and quantitative phase equilibria modelling of the studied samples reveal P–T conditions from M2 to M3 of ~7.2 kbar/760–800°C and 4.5–5.0 kbar/585–610°C, respectively, which together define a clockwise P–T path involving decompressional cooling (M3) that followed the peak granulite‐facies metamorphism (M2). It reveals essential information related to the collision orogeny and post‐collision process. Zircon U–Pb dating of two felsic rocks yielded the peak of the granulite‐facies metamorphism in the Yilan area of the Jiamusi Massif that might have occurred at ~500 Ma. The overall deposition of the metamorphic rocks was later than ~760 Ma and that most of the detrital materials came from late Mesoproterozoic and early Neoproterozoic source rocks.