bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction acceleration in microdroplet mass spectrometry: Inlet capillary and solvent composition effects
Authors: Ju Yun , He Yuwei , Kan Guangfeng , Yu Kai , Jiang Jie , Wang Xiaofei , Zhang Hong
Published: March 2023

Rationale

Microdroplet chemistry has attracted tremendous interest in recent years. We have previously reported that microdroplet mass spectrometry (MS) achieves reaction acceleration. Here we systematically investigated the effect of capillary heating of MS inlet and solvent polarity of microdroplets on the conversion ratios of dehydration and phosphorylation reactions.

Methods

The micron‐sized droplets generated by high‐speed gas encapsulated the compounds. The conversion ratios of dehydration and phosphorylation reactions were investigated at different capillary temperatures of MS inlet between 30°C and 300°C. Subsequently, the effects of solvent polarity of different microdroplets (acetonitrile, acetonitrile/water [v/v: 9:1], and water) on microdroplet reactions were investigated.

Results

The microdroplets could be used as reaction vessels for rapid dehydration and phosphorylation reactions. Microdroplet MS is characterized by the completion of the reaction in microseconds. The increase in capillary temperature increased the conversion ratio of dehydration reactions but had little effect on phosphorylation reactions. The stability of compounds supports this phenomenon. In addition, the increase in solvent polarity in microdroplets promoted the dehydration reaction but inhibited the nucleophilic substitution reaction (phosphorylation reaction).

Conclusions

Microdroplet MS achieved an acceleration of the reaction, which was attributed to capillary temperature, microdroplet solvents, and the stability of reaction products. This finding suggested that the inlet capillary and solvent system should be considered in the study and interpretation of microdroplet MS.
Equilibrium isotope fractionation factors of H exchange between steam and soil clay fractions
Authors: Merseburger Stefan , Kessler Arnim , Oelmann Yvonne , Wilcke Wolfgang
Published: March 2023

Rationale

Steam equilibration overcomes the problem of the traditional measurements of H isotope compositions, which leave an arbitrary amount of adsorbed water in the sample, by controlling for the entire exchangeable H pool, including adsorbed water and hydroxyl‐H. However, the use of steam equilibration to determine nonexchangeable stable H isotope compositions in environmental media (expressed as δ2Hn values) by mathematically eliminating the influence of exchangeable H after sample equilibration with waters of known H‐isotopic composition requires the knowledge of the equilibrium isotope fractionation factor between steam‐H and exchangeable H of the sample (αex‐w), which is frequently unknown.

Methods

We developed a new method to determine the αex‐w values for clay minerals, topsoil clay fractions, and mica by manipulating the contributions of exchangeable H to the total H pool via different degrees of post‐equilibration sample drying. We measured the δ2H values of steam‐equilibrated mineral and soil samples using elemental analyzer‐pyrolysis‐isotope ratio mass spectrometry.

Results

The αex‐w values of seven clay minerals ranged from 1.071 to 1.140, and those of 19 topsoil clay fractions ranged from 0.885 to 1.216. The αex‐w value of USGS57 biotite, USGS58 muscovite, and of cellulose was 0.965, 0.871, and 1.175, respectively. The method did not work for kaolinite, because its small exchangeable H pool did not respond to the selected drying conditions. Structurally different mineral groups such as two‐ and three‐layer clay minerals or mica showed systematically different αex‐w values. The αex‐w value of the topsoil clay fractions correlated with the soil clay content (r = 0.63, P = 0.004), the local mean annual temperature (r = 0.68, P = 0.001), and the δ2H values of local precipitation (r = 0.72, P < 0.001), likely to reflect the different clay mineralogy under different weathering regimes.

Conclusions

Our new αex‐w determination method yielded realistic results in line with the few previously published values for cellulose. The determined αex‐w values were similar to the widely assumed values of 1.00–1.08 in the literature, suggesting that the adoption of one of these values in steam equilibration approaches is appropriate.
Sliding mode output feedback control for continuous systems without rank constraint
Authors: Zhang Jinhui
Published: March 2023

This paper addresses the sliding mode control problem for continuous systems in the output feedback framework. To remove the conventional rank constraint imposed on the input and output matrices, a novel compensator‐based sliding surface is proposed firstly. Then, by designing an unmeasured state and disturbance (USD) observer to estimate the lumped unmeasurable state and external disturbance, both the discontinuous and continuous sliding mode output feedback controllers are synthesized. Finally, the validity of the proposed methods is illustrated by two simulation examples.
Field‐based robotic leaf angle detection and characterization of maize plants using stereo vision and deep convolutional neural networks
Authors: Xiang Lirong , Gai Jingyao , Bao Yin , Yu Jianming , Schnable Patrick S. , Tang Lie
Published: March 2023

Maize (Zea mays L.) is one of the three major cereal crops in the world. Leaf angle is an important architectural trait of crops due to its substantial role in light interception by the canopy and hence photosynthetic efficiency. Traditionally, leaf angle has been measured using a protractor, a process that is both slow and laborious. Efficiently measuring leaf angle under field conditions via imaging is challenging due to leaf density in the canopy and the resulting occlusions. However, advances in imaging technologies and machine learning have provided new tools for image acquisition and analysis that could be used to characterize leaf angle using three‐dimensional (3D) models of field‐grown plants. In this study, PhenoBot 3.0, a robotic vehicle designed to traverse between pairs of agronomically spaced rows of crops, was equipped with multiple tiers of PhenoStereo cameras to capture side‐view images of maize plants in the field. PhenoStereo is a customized stereo camera module with integrated strobe lighting for high‐speed stereoscopic image acquisition under variable outdoor lighting conditions. An automated image processing pipeline (AngleNet) was developed to measure leaf angles of nonoccluded leaves. In this pipeline, a novel representation form of leaf angle as a triplet of keypoints was proposed. The pipeline employs convolutional neural networks to detect each leaf angle in two‐dimensional images and 3D modeling approaches to extract quantitative data from reconstructed models. Satisfactory accuracies in terms of correlation coefficient (r) and mean absolute error (MAE) were achieved for leaf angle () and internode heights (). Our study demonstrates the feasibility of using stereo vision to investigate the distribution of leaf angles in maize under field conditions. The proposed system is an efficient alternative to traditional leaf angle phenotyping and thus could accelerate breeding for improved plant architecture.
Ownership competence: The enabling and constraining role of institutions
Authors: Foss Nicolai J. , Klein Peter G. , Lien Lasse B. , Zellweger Thomas , Zenger Todd
Published: March 2023

Research Summary

Monteiro and Miranda (2022) argue that owners differ in their ability to select and work within a particular institutional environment, suggesting “institutional competence” as a dimension of ownership competence distinct from what we call governance, matching, and timing competence. We agree that institutions matter and welcome the chance to describe their role in detail. However, rather than treating institutional competence as a separate channel by which owners create value from their assets, we think institutional features can be modeled as “shift parameters” that moderate the effect of ownership competencies on outcomes. In developing this argument, we reflect more broadly on the interplay between ownership competence and institutional uncertainty, noting that society at large benefits from individual‐level ownership competence, ownership by some owners may cause harm to other owners, and property‐rights enforcement and ownership competence are complements in generating private and societal benefits.

Managerial Summary

In “Ownership Competence” (Foss et al., 2021) we argued that business owners vary in their ability to create value out of the assets they own, distinguishing between governance, matching, and timing competence. Monteiro and Miranda (2022) argue that we should add “institutional competence” as a fourth kind of competence, describing the ability of owners to choose countries, regions, or environments where they can best exercise their ownership skills. We agree that these external conditions are important but argue that they work by modifying the impact of governance, matching, and timing competence rather than acting as an independent channel. In our response, we also comment on broader issues related to social and institutional aspects of ownership.
RhRu Alloy‐Anchored MXene Nanozyme for Synergistic Osteosarcoma Therapy
Authors: Liang Yanling , Liao Chuanan , Guo Xinqi , Li Guanhua , Yang Xin , Yu Jing , Zhong Jingping , Xie Ying , Zheng Li , Zhao Jinmin
Published: March 2023

Noble metal nanozymes hold promise in cancer therapy due to adjustable enzyme‐like activities, unique physicochemical properties, etc. But catalytic activities of monometallic nanozyme are confined. In this study, 2D titanium carbide (Ti3C2Tx)‐supported RhRu alloy nanoclusters (RhRu/Ti3C2Tx) are prepared by a hydrothermal method and utilized for synergistic therapy of chemodynamic therapy (CDT), photodynamic therapy (PDT), and photothermal therapy (PTT) on osteosarcoma. The nanoclusters are small in size (3.6 nm), uniform in distribution, and have excellent catalase (CAT) and peroxidase (POD)‐like activities. Density functional theory calculations show that there is a significant electron transfer interaction between RhRu and Ti3C2Tx, which has strong adsorption to H2O2 and is beneficial to enhance the enzyme‐like activity. Furthermore, RhRu/Ti3C2Tx nanozyme acts as both PTT agent for converting light into heat, and photosensitizer for catalyzing O2 to 1O2. With the NIR‐reinforced POD‐ and CAT‐like activity, excellent photothermal and photodynamic performance, the synergistic CDT/PDT/PTT effect of RhRu/Ti3C2Tx on osteosarcoma is verified by in vitro and in vivo experiments. This study is expected to provide a new research direction for the treatment of osteosarcoma and other tumors.
An Activatable Phototheranostic Nanoplatform for Tumor Specific NIR‐II Fluorescence Imaging and Synergistic NIR‐II Photothermal‐Chemodynamic Therapy
Authors: Dai Yeneng , Zhang Fan , Chen Kai , Sun Zhiquan , Wang Zhihang , Xue Yuwen , Li Meixing , Fan Quli , Shen Qingming , Zhao Qi
Published: March 2023

The phototheranostics in the second near‐infrared window (NIR‐II) have proven to be promising for the precise cancer theranostics. However, the non‐responsive and “always on” imaging mode lacks the selectivity, leading to the poor diagnosis specificity. Herein, a tumor microenvironment (TME) activated NIR‐II phototheranostic nanoplatform (Ag2S‐Fe(III)‐DBZ Pdots, AFD NPs) is designed based on the principle of Förster resonance energy transfer (FRET). The AFD NPs are fabricated through self‐assembly of Ag2S QDs (NIR‐II fluorescence probe) and ultra‐small semiconductor polymer dots (DBZ Pdots, NIR‐II fluorescence quencher) utilizing Fe(III) as coordination nodes. In normal tissues, the AFD NPs maintain in “off” state, due to the FRET between Ag2S QDs and DBZ Pdots. However, the NIR‐II fluorescence signal of AFD NPs can be rapidly “turn on” by the overexpressed GSH in tumor tissues, achieving a superior tumor‐to‐normal tissue (T/NT) signal ratio. Moreover, the released Pdots and reduced Fe(II) ions provide NIR‐II photothermal therapy (PTT) and chemodynamic therapy (CDT), respectively. The GSH depletion and NIR‐II PTT effect further aggravate CDT mediated oxidative damage toward tumors, achieving the synergistic anti‐tumor therapeutic effect. The work provides a promising strategy for the development of TME activated NIR‐II phototheranostic nanoprobes.
Enhanced Thermoelectric Performance of Rare‐Earth‐Free n‐Type Oxide Perovskite Composite with Graphene Analogous 2D MXene
Authors: Dixit Pragya , Jana Subhra Sourav , Maiti Tanmoy
Published: March 2023

Here, the first experimental demonstration on the effect of incorporating new generation 2D material, MXene, on the thermoelectric performance of rare‐earth‐free oxide perovskite is reported. The charge localization phenomenon is predominant in the electron transport of doped SrTiO3 perovskites, which deters from achieving a higher thermoelectric power factor in these oxides. In this work, it is shown that incorporating Ti3C2Tx MXene in a matrix of SrTi0.85Nb0.15O3 (STN) facilitates the delocalization of electrons resulting in better than single‐crystal‐like electron mobility in polycrystalline composites. A 1851% increase in electrical conductivity and a 1000% enhancement in power factor are attained. Besides, anharmonicity caused by MXene in the STN matrix has led to enhanced Umklapp scattering giving rise to lower lattice thermal conductivity. Hence, 700% ZT enhancement is achieved in this composite. Further, a prototype of thermoelectric generator (TEG) using only n‐type STN + MXene is fabricated and a power output of 38 mW is obtained, which is higher than the reported values for oxide TEG.
MMP9‐Responsive Graphene Oxide Quantum Dot‐Based Nano‐in‐Micro Drug Delivery System for Combinatorial Therapy of Choroidal Neovascularization
Authors: Huang Keke , Liu Xin , Lv Ziru , Zhang Di , Zhou Yuling , Lin Zhiqing , Guo Juan
Published: March 2023

Age‐related macular degeneration (AMD), especially wet AMD with choroidal neovascularization (CNV), commonly causes blindness in older patients and disruption of the choroid followed by second‐wave injuries, including chronic inflammation, oxidative stress, and excessive matrix metalloproteinase 9 (MMP9) expression. Increased macrophage infiltrate in parallel with microglial activation and MMP9 overexpression on CNV lesions is shown to contribute to the inflammatory process and then enhance pathological ocular angiogenesis. Graphene oxide quantum dots (GOQDs), as natural antioxidants, exert anti‐inflammatory effects and minocycline is a specific macrophage/microglial inhibitor that can suppress both macrophage/microglial activation and MMP9 activity. Herein, an MMP9‐responsive GOQD‐based minocycline‐loaded nano‐in‐micro drug delivery system (C18PGM) is developed by chemically bonding GOQDs to an octadecyl‐modified peptide sequence (C18‐GVFHQTVS, C18P) that can be specifically cleaved by MMP9. Using a laser‐induced CNV mouse model, the prepared C18PGM shows significant MMP9 inhibitory activity and anti‐inflammatory action followed by antiangiogenic effects. Moreover, C18PGM combined with antivascular endothelial growth factor antibody bevacizumab markedly increases the antiangiogenesis effect by interfering with the “inflammation‐MMP9‐angiogenesis” cascade. The prepared C18PGM shows a good safety profile and no obvious ophthalmic or systemic side effects. The results taken together suggest that C18PGM is an effective and novel strategy for combinatorial therapy of CNV.
Single‐Crystal Nanowire Cesium Tin Triiodide Perovskite Solar Cell
Authors: Dai Letian , Roca i Cabarrocas Pere , Ban Huaxia , Zhang Zhiguo , Sun Qiang , Li Xiongjie , Gu Anjie , Yang Wanpeng , Yu Haixuan , Shen Yan , Wang Mingkui
Published: March 2023

This work reports for the first time a highly efficient single‐crystal cesium tin triiodide (CsSnI3) perovskite nanowire solar cell. With a perfect lattice structure, low carrier trap density (≈5 × 1010 cm−3), long carrier lifetime (46.7 ns), and excellent carrier mobility (>600 cm2 V−1 s−1), single‐crystal CsSnI3 perovskite nanowires enable a very attractive feature for flexible perovskite photovoltaics to power active micro‐scale electronic devices. Using CsSnI3 single‐crystal nanowire in conjunction with highly conductive wide bandgap semiconductors as front‐surface‐field layers, an unprecedented efficiency of 11.7% under AM 1.5G illumination is achieved. This work demonstrates the feasibility of all‐inorganic tin‐based perovskite solar cells via crystallinity and device‐structure improvement for the high‐performance, and thus paves the way for the energy supply to flexible wearable devices in the future.
Precise Control of Crystallization and Phase‐Transition with Green Anti‐Solvent in Wide‐Bandgap Perovskite Solar Cells with Open‐Circuit Voltage Exceeding 1.25 V
Authors: Zhang Xinpeng , Li Xiangyu , Tao Lei , Zhang Zemin , Ling Hao , Fu Xue , Wang Shibo , Ko Min Jae , Luo Jingshan , Chen Jiangzhao , Li Yuelong
Published: March 2023

Wide‐bandgap perovskite solar cells (PSCs) have attracted a lot of attention due to their application in tandem solar cells. However, the open‐circuit voltage (VOC) of wide‐bandgap PSCs is dramatically limited by high defect density existing at the interface and bulk of the perovskite film. Here, an anti‐solvent optimized adduct to control perovskite crystallization strategy that reduces nonradiative recombination and minimizes VOC deficit is proposed. Specifically, an organic solvent with similar dipole moment, isopropanol (IPA) is added into ethyl acetate (EA) anti‐solvent, which is beneficial to form PbI2 adducts with better crystalline orientation and direct formation of α‐phase perovskite. As a result, EA‐IPA (7‐1) based 1.67 eV PSCs deliver a power conversion efficiency of 20.06% and a VOC of 1.255 V, which is one of the remarkable values for wide‐bandgap around 1.67 eV. The findings provide an effective strategy for controlling crystallization to reduce defect density in PSCs.
Stimuli‐Responsive Multifunctional Nanomedicine for Enhanced Glioblastoma Chemotherapy Augments Multistage Blood‐to‐Brain Trafficking and Tumor Targeting
Authors: Martins Cláudia , Araújo Marco , Malfanti Alessio , Pacheco Catarina , Smith Stuart J. , Ucakar Bernard , Rahman Ruman , Aylott Jonathan W. , Préat Véronique , Sarmento Bruno
Published: March 2023

Minimal therapeutic advances have been achieved over the past two decades for glioblastoma (GBM), which remains an unmet clinical need. Here, hypothesis‐driven stimuli‐responsive nanoparticles (NPs) for docetaxel (DTX) delivery to GBM are reported, with multifunctional features that circumvent insufficient blood‐brain barrier (BBB) trafficking and lack of GBM targeting—two major hurdles for anti‐GBM therapies. NPs are dual‐surface tailored with a i) brain‐targeted acid‐responsive Angiopep‐2 moiety that triggers NP structural rearrangement within BBB endosomal vesicles, and ii) L‐Histidine moiety that provides NP preferential accumulation into GBM cells post‐BBB crossing. In tumor invasive margin patient cells, the stimuli‐responsive multifunctional NPs target GBM cells, enhance cell uptake by 12‐fold, and induce three times higher cytotoxicity in 2D and 3D cell models. Moreover, the in vitro BBB permeability is increased by threefold. A biodistribution in vivo trial confirms a threefold enhancement of NP accumulation into the brain. Last, the in vivo antitumor efficacy is validated in GBM orthotopic models following intratumoral and intravenous administration. Median survival and number of long‐term survivors are increased by 50%. Altogether, a preclinical proof of concept supports these stimuli‐responsive multifunctional NPs as an effective anti‐GBM multistage chemotherapeutic strategy, with ability to respond to multiple fronts of the GBM microenvironment.
Spectrum‐based fault localization using empirical mode decomposition algorithm
Authors: Fan Xin , Chen Qi , Yu Li , Liu Fangqi , Zhu Jiahao , Zheng Wei
Published: March 2023

Spectrum‐based fault localization (SBFL) is considered as the most popular lightweight fault localization method. However, pure SBFL is proved to be tedious and time‐consuming for programmers to detect faults. This is because the suspiciousness is duplicated and they usually involve only the first few suspicious elements in the debugging process before losing patience. For this reason, benefiting from abundant spectrum information created by SBFL, we propose a new spectral fault localization technique using empirical mode decomposition method (EMD) to improve the accuracy of automatic software debugging. To accomplish that, the faulty program is evaluated by SBFL, and then, the resultant suspiciousness scores are taken as signals and nonfaulty elements as noise. Next, EMD is employed to decompose the suspicious scores of SBFL to eliminate massively repeated ones. Hence, elements are reranked according to new scores, and the ranking list is reconstructed by enlarging the high‐performance range (checking 5% elements) and TOP‐5 region to detect more faults. The performance of EMD‐SBFL is tested and compared with pure SBFL with EXAM scores and Top‐n ranks both on Siemens programs with seeded faults and large‐sized Defects4j programs with real faults. The result reveals that EMD‐SBFL is significantly effective to locate nearly over doubled faults by only check Top‐1 and outperforms the state‐of‐the art SBFL techniques.
Recent Progress and Perspectives of Direct Ink Writing Applications for Mass Transfer Enhancement in Gas‐Phase Adsorption and Catalysis
Authors: Chen Qiwei , Tian Enze , Wang Yan , Mo Jinhan , Xu Guiyin , Zhu Meifang
Published: March 2023

Conventional adsorbents and catalysts shaped by granulation or extrusion have high pressure drop and poor flexibility for chemical, energy, and environmental processes. Direct ink writing (DIW), a kind of 3D printing, has evolved into a crucial technique for manufacturing scalable configurations of adsorbents and catalysts with satisfactory programmable automation, highly optional materials, and reliable construction. Particularly, DIW can generate specific morphologies required for excellent mass transfer kinetics, which is essential in gas‐phase adsorption and catalysis. Here, DIW methodologies for mass transfer enhancement in gas‐phase adsorption and catalysis, covering the raw materials, fabrication process, auxiliary optimization methods, and practical applications are comprehensively summarized. The prospects and challenges of DIW methodology in realizing good mass transfer kinetics are discussed. Ideal components with a gradient porosity, multi‐material structure, and hierarchical morphology are proposed for future investigations.
High‐Efficiency Binary Organic Solar Cells Enabled by Pseudo‐Bilayer Configuration in Dilute Solution
Authors: Li Shufang , Shi Changzhou , Luo Xiaoyan , Li Dongxu , Lu Xinhui , Hu Yunbin , Yuan Jun , Zou Yingping
Published: March 2023

Forming proper film morphology in organic solar cells (OSCs) is important to govern the exciton dissociation and charge transport. Herein, high‐performance pseudo‐bilayer heterojunction (PBHJ) OSCs with donor:acceptor (D:A) bilayer architecture are reported by sequentially depositing two layers of diluted active solution with different D:A ratios. Such pseudo‐bilayer films can not only enable the cascaded components distributed in the vertical direction, but also afford large donor and acceptor (D/A) interfaces for efficient exciton dissociation. Additionally, the D:A active layer on the bottom substrate can act as a seed to promote the crystallization process of the upper film during the sequential casting process. The PBHJ strategy on two representative D:A blends, PM6:Y6 and PTQ10:Y6, is implemented. Benefiting from the synergetic effects of efficient exciton dissociation and balanced charge transport, the devices based on PM6:Y6 and PTQ10:Y6 show high power conversion efficiencies of 17.73% and 17.81%, respectively. Notably, the presented PBHJ devices are fabricated by using dilute chloroform solution (4 mg mL−1 for donor), demonstrating the excellent potential for poorly soluble donors and acceptors in future OSCs applications.
Nonlinear finite element modeling of bridge piers under the combined effect of corrosion, freeze–thaw cycles, and service load
Authors: Zaghian Sepideh , Martín‐Pérez Beatriz , Almansour Husham , Shirkhani Hamidreza
Published: March 2023

Corrosion of reinforcing steel in reinforced concrete (RC) infrastructure is one of the most concerning durability problems affecting its serviceability and ultimate capacity in North America. The rise of greenhouse emissions in recent decades and the use of de‐icing salts during the winter increase the potential risk of corrosion. Furthermore, global warming could lead to higher freeze–thaw cycles (FTC) frequency in cold regions. The combined effects of corrosion and frost damage tend to affect aging RC infrastructure's structural performance and service life. The present study adopts comprehensive reinforcement corrosion and frost damage models from the literature and proposes a stage‐based damage analysis scenario. Three‐dimensional nonlinear finite element analyses using the commercially available finite element program DIANA are conducted to evaluate the structural performance of RC bridge piers under the synergetic effects of FTCs, corrosion, and service load during their service life. The proposed methodology for each damage mechanism is assessed by comparison with available experimental data from the literature. The synergetic effects cannot be validated because there is no data, but the methodology highlights the deterioration rate at which several mechanisms acting at the same time can affect the structural performance of these members.
Construction of strut‐and‐tie models for members under complex stress states based on topology optimization
Authors: Fang Yumin , Zhang Huzhi , Yin Bin
Published: March 2023

The construction of strut‐and‐tie models (STMs) is the key, but also the difficulty when the model is used to describe the force mechanism and guide the reinforcement layout design of concrete disturbed regions (D‐regions). Topology optimization is a promising way to guide STMs construction. Different from the existing construction methods of predetermining nodes, the angle of inclination of the truss elements is first determined to ensure that it is consistent with that of the principal stresses in a 2D finite element model of the structure. The constructed model can well reflect the force transmission path of structural members, and it is better than the existing methods when it is evaluated through the principle of minimum strain energy. To verify the validity of the STM, a reinforcement layout scheme is adopted completely according to the position of the tension ties. On this basis, another reinforcement layout scheme adds additional transverse reinforcements in the bottle‐shaped stress field. The nonlinear finite element comparative analysis of an irregular deep beam designed by the two schemes is carried out. The results show that the two ultimate loads are close. Brittle failure occurs in the former, while the latter has higher deformability and eventually ductile failure occurs.
Using conjoint analysis to incorporate heterogeneous preferences into multimodal transit trip simulations
Authors: Zhao Lujin , Szajnfarber Zoe , Broniatowski David , Helveston John Paul
Published: March 2023

Urban transportation systems involve thousands of individuals making choices between routes with multiple modes and transfers. For transportation system simulations to produce realistic results, modelers need to incorporate these users and their choices. Choice‐based conjoint surveys provide an attractive solution for obtaining flexible utility models that can be used to predict choices for a wide variety of trips. In this study, we demonstrate an example using conjoint survey data of commuter mode choice in the Washington, D.C. metro area (N = 1651). We sample commuters who primarily drive and those that take transit. We examine preferences for different types of multimodal trips, including those with intramodal and intermodel transfers. We find that trips involving a bus transfer are the least preferred while both drivers and transit users both value metro similarly to driving. We also find that walking during transit trips is an important barrier, with the travel time penalty for walking being 60% higher than that of time in a vehicle. Our findings highlight the significance of accounting for differences in modal transfer types in transportation system simulations. Reducing arrival time uncertainty was not a significant factor in commuter mode choice, and commuters' value of time was similar across all vehicle types, suggesting that increasing the relative speed of transit modes may only have a marginal effect on commuter substitution away from personal vehicles.
Is the Ollerenshaw fasciolosis forecasting model fit for the 21st century?
Authors: Howell Alison , Caminade Cyril , Brülisauer Franz , Mitchell Sian , Williams Diana
Published: March 2023

Background

The Ollerenshaw forecasting model is based on rainfall and evapotranspiration and has been in use to predict losses from fasciolosis since 1959. We evaluated the performance of the model against observed data.

Methods

Weather data were used to calculate, map and plot fasciolosis risk values for each year from 1950 to 2019. We then compared the model's predictions with recorded acute fasciolosis losses in sheep from 2010 to 2019 and calculated the sensitivity and specificity of the model.

Results

The forecast risk has varied over time but has not markedly increased over the past 70 years. The model correctly forecasted the highest and lowest incidence years at both the regional and national (Great Britain) levels. However, the sensitivity of the model for predicting fasciolosis losses was poor. Modification to include the full May and October rainfall and evapotranspiration values made only a small improvement.

Limitations

Reported acute fasciolosis losses are subject to bias and error due to unreported cases and variations in region size and livestock numbers.

Conclusion

The Ollerenshaw forecasting model, in either its original or modified forms, is insufficiently sensitive to be relied upon as a standalone early warning system for farmers.
Enhanced flame retardancy, smoke suppression, and acid resistance of polypropylene/magnesium hydroxide composite by expandable graphite and microencapsulated red phosphorus
Authors: Wang Sen , Liang Shitong , Wang Kesong , Liu Jichun , Luo Jie , Peng Shuge
Published: March 2023

Low flame retardant efficiency and poor acid resistance of filled polymer composites are two main drawbacks of magnesium hydroxide (MH) as a flame retardant (FR). To solve these problems, expandable graphite (EG) and microencapsulated red phosphorus (MRP) were introduced into polypropylene/magnesium hydroxide (PP/MH) composite by melt compounding. The obtained PP/MH/EG/MRP quadruple composite was studied regarding its fire behavior as well as acid resistance. Obvious flame retardant synergism among MH, EG, and MRP is found in PP, which diminishes the loading of FR from 63.0 to 37.5 wt% to obtain V‐0 rating in UL‐94 test and low smoke release. Compact intumescent char with high thermo‐oxidative stability was generated on composite surface, which plays a vital role in flame retardancy. The removal of MH by acid erosion on PP/MH/EG/MRP composite surface does not affect production of intumescent char and fire behavior of this composite. The composite displays good fire retardancy, smoke inhibition, and acid resistivity concurrently. This article renders an easy and cheap route to overcome the main faults of MH.
Mice deficient in synaptic protease neurotrypsin show impaired spaced long-term potentiation and blunted learning-induced modulation of dendritic spines
Authors: Ferrer-Ferrer Maura , Jia Shaobo , Kaushik Rahul , Schneeberg Jenny , Figiel Izabela , Aleshin Stepan , Mironov Andrey , Safari Motahareh , Frischknecht Renato , Wlodarczyk Jakub , Senkov Oleg , Dityatev Alexander
Published: March 2023

Neurotrypsin (NT) is a neuronal trypsin-like serine protease whose mutations cause severe mental retardation in humans. NT is activated in vitro by Hebbian-like conjunction of pre- and postsynaptic activities, which promotes the formation of dendritic filopodia via proteolytic cleavage of the proteoglycan agrin. Here, we investigated the functional importance of this mechanism for synaptic plasticity, learning, and extinction of memory. We report that juvenile neurotrypsin-deficient (NT−/−) mice exhibit impaired long-term potentiation induced by a spaced stimulation protocol designed to probe the generation of new filopodia and their conversion into functional synapses. Behaviorally, juvenile NT−/− mice show impaired contextual fear memory and have a sociability deficit. The latter persists in aged NT−/− mice, which, unlike juvenile mice, show normal recall but impaired extinction of contextual fear memories. Structurally, juvenile mutants exhibit reduced spine density in the CA1 region, fewer thin spines, and no modulation in the density of dendritic spines following fear conditioning and extinction in contrast to wild-type littermates. The head width of thin spines is reduced in both juvenile and aged NT−/− mice. In vivo delivery of adeno-associated virus expressing an NT-generated fragment of agrin, agrin-22, but not a shorter agrin-15, elevates the spine density in NT−/− mice. Moreover, agrin-22 co-aggregates with pre- and postsynaptic markers and increases the density and size of presynaptic boutons and presynaptic puncta, corroborating the view that agrin-22 supports the synaptic growth.
A comparison of methods for training population optimization in genomic selection
Authors: Fernández-González Javier , Akdemir Deniz , Isidro y Sánchez Julio
Published: March 2023

Key message

Maximizing CDmean and Avg_GRM_self were the best criteria for training set optimization. A training set size of 50–55% (targeted) or 65–85% (untargeted) is needed to obtain 95% of the accuracy. 

With the advent of genomic selection (GS) as a widespread breeding tool, mechanisms to efficiently design an optimal training set for GS models became more relevant, since they allow maximizing the accuracy while minimizing the phenotyping costs. The literature described many training set optimization methods, but there is a lack of a comprehensive comparison among them. This work aimed to provide an extensive benchmark among optimization methods and optimal training set size by testing a wide range of them in seven datasets, six different species, different genetic architectures, population structure, heritabilities, and with several GS models to provide some guidelines about their application in breeding programs. Our results showed that targeted optimization (uses information from the test set) performed better than untargeted (does not use test set data), especially when heritability was low. The mean coefficient of determination was the best targeted method, although it was computationally intensive. Minimizing the average relationship within the training set was the best strategy for untargeted optimization. Regarding the optimal training set size, maximum accuracy was obtained when the training set was the entire candidate set. Nevertheless, a 50–55% of the candidate set was enough to reach 95–100% of the maximum accuracy in the targeted scenario, while we needed a 65–85% for untargeted optimization. Our results also suggested that a diverse training set makes GS robust against population structure, while including clustering information was less effective. The choice of the GS model did not have a significant influence on the prediction accuracies.
Clinical Practices Following Train‐The‐Trainer Trauma Course Completion in Uganda: A Parallel‐Convergent Mixed‐Methods Study
Authors: Tang Zeyu , Kayondo Derick , Ullrich Sarah J. , Namugga Martha , Muwanguzi Peter , Klazura Gregory , Ozgediz Doruk , Armstrong‐Hough Mari
Published: March 2023

Background

Despite the growth of trauma training courses worldwide, evidence for their impact on clinical practice in low‐ and middle‐income countries (LMICs) is sparse. We investigated trauma practices by trained providers in Uganda using clinical observation, surveys, and interviews.

Methods

Ugandan providers participated in the Kampala Advanced Trauma Course (KATC) from 2018 to 2019. Between July and September of 2019, we directly evaluated guideline‐concordant behaviors in KATC‐exposed facilities using a structured real‐time observation tool. We conducted 27 semi‐structured interviews with course‐trained providers to elucidate experiences of trauma care and factors that impact adoption of guideline‐concordant behaviors. We assessed perceptions of trauma resource availability through a validated survey.

Results

Of 23 resuscitations, 83% were managed without course‐trained providers. Frontline providers inconsistently performed universally applicable assessments: pulse checks (61%), pulse oximetry (39%), lung auscultation (52%), blood pressure (65%), pupil examination (52%). We did not observe skill transference between trained and untrained providers. In interviews, respondents found KATC personally transformative but not sufficient for facility‐wide improvement due to issues with retention, lack of trained peers, and resource shortages. Resource perception surveys similarly demonstrated profound resource shortages and variation across facilities.

Conclusions

Trained providers view short‐term trauma training interventions positively, but these courses may lack long‐term impact due to barriers to adopting best practices. Trauma courses should include more frontline providers, target skill transference and retention, and increase the proportion of trained providers at each facility to promote communities of practice. Essential supplies and infrastructure in facilities must be consistent for providers to practice what they have learned.
Towards safe and effective femtosecond laser cleaning for the preservation of historic monuments
Authors: Brand Julia , Wain Alison , Rode Andrei V. , Madden Steve , Rapp Ludovic
Published: March 2023

We explore femtosecond laser cleaning of materials used in the construction of historic monuments, such as stone and steel covered in typical contaminants caused by harsh environments that may be found in urban areas. We address the cleaning of these materials from a conservation perspective, taking as examples the preservation and cleaning of iconic structures such as the steel and the granite of the Sydney Harbour Bridge, Hawkesbury sandstone, a popular building material of a variety of monuments in Sydney (Australia), Makrana marble taken from the Soami Bagh Samadh temple of Agra in India, and also graffiti removal. We demonstrate that femtosecond laser pulses can clean a range of different contaminants such as biofilm, environmental soiling, rust, and spray paints, while preserving the integrity of the underlying substrates. Femtosecond laser cleaning is a fast and effective method and a safer alternative to lasers with longer pulse durations for the preservation of historic monuments.
Parameters not empirically identifiable or distinguishable, including correlation between Gaussian observations
Authors: Hennig Christian
Published: March 2023

It is shown that some theoretically identifiable parameters cannot be empirically identified, meaning that no consistent estimator of them can exist. An important example is a constant correlation between Gaussian observations (in presence of such correlation not even the mean can be empirically identified). Empirical identifiability and three versions of empirical distinguishability are defined. Two different constant correlations between Gaussian observations cannot even be empirically distinguished. A further example are cluster membership parameters in k-means clustering. Several existing results in the literature are connected to the new framework. General conditions are discussed under which independence can be distinguished from dependence.
Sobolev-Type Embeddings for Neural Network Approximation Spaces
Authors: Grohs Philipp , Voigtlaender Felix
Published: March 2023

We consider neural network approximation spaces that classify functions according to the rate at which they can be approximated (with error measured in $$L^p$$

L
p

) by ReLU neural networks with an increasing number of coefficients, subject to bounds on the magnitude of the coefficients and the number of hidden layers. We prove embedding theorems between these spaces for different values of p. Furthermore, we derive sharp embeddings of these approximation spaces into Hölder spaces. We find that, analogous to the case of classical function spaces (such as Sobolev spaces, or Besov spaces) it is possible to trade “smoothness” (i.e., approximation rate) for increased integrability. Combined with our earlier results in Grohs and Voigtlaender (Proof of the theory-to-practice gap in deep learning via sampling complexity bounds for neural network approximation spaces, 2021. arXiv preprint arXiv:2104.02746), our embedding theorems imply a somewhat surprising fact related to “learning” functions from a given neural network space based on point samples: if accuracy is measured with respect to the uniform norm, then an optimal “learning” algorithm for reconstructing functions that are well approximable by ReLU neural networks is simply given by piecewise constant interpolation on a tensor product grid.
Extraordinary diversity among allopatric species in the genus Goniurosaurus (Squamata: Eublepharidae): understanding niche evolution and the need of conservation measures
Authors: Ngo Hai Ngoc , Rödder Dennis , Grismer Lee , Nguyen Truong Quang , Le Minh Duc , Qi Shuo , Ziegler Thomas
Published: March 2023

Given the high degrees of adaptation to specific microhabitats and restricted-range endemism, Goniurosaurus (Tiger geckos) serves as a unique model to study the complex evolution in lizards. Using phylogenetic analyses, we estimated the first divergence date of Goniurosaurus to the Eocene (~ 45.3 mya). The diversification within four monophyletic species groups began in the mid-Miocene between ~ 13.4 and 7.7 mya and continued to at least the early Pleistocene (~ 2 mya). Their ancestor was predicted to originate somewhere in contiguous continental Eastern Asia, whereas the current regions in which each monophyletic Goniurosaurus species group radiated are respectively their own ancestral regions. Together with factors of altitudinal gradient and climate conditions, we reconstructed relevant niche models of Goniurosaurus including ancestral reconstructions. Consequently, low elevations were predicted to be the most probable ancestral state for Goniurosaurus and all its groups as well. Both climatic niche conservatism and divergence have shaped the extraordinary species richness of allopatric Chinese and Vietnamese tiger geckos. In terms of endangerment, Goniurosaurus has been considered one of the most susceptible lizard groups under severe human impacts, especially climate change. The assessments of their niche evolution can provide a science-based pre-signal of vulnerability, thereby improving the efficacy of conservation measures to safeguard species of Goniurosaurus in the future. Accordingly, almost all closely related species of Goniurosaurus in China and Vietnam were identified with a high rate of niche conservatism, which should be included in conservation priorities under potential impacts of climate change.
Investigating the Validity of the Australian Early Development Census
Authors: Howells Sarah , Nguyen Ha Trong , Brinkman Sally , Mitrou Francis
Published: March 2023

This article continues evaluation of the construct validity of the Australian Early Development Census (AEDC) through comparison with linked data from a sample of 2216 4–5 year old children collected as part of the Longitudinal Study of Australian Children (LSAC). This builds on the construct validity assessment of Brinkman et al. (Early Educ Dev 18(3):427–451, 2007) based on a smaller sample of linked Australian Early Development Instrument (AvEDI) and LSAC children, in which moderate to large correlations were apparent between teacher-rated AvEDI domains and subconstructs and LSAC measures, with lower levels apparent for parent reported LSAC measures. In the current study, the data showed moderate to low correlations between the domains and subdomains from the AEDC and teacher reported LSAC data. Differences in testing times, data sources (e.g. teachers versus carers) and levels of exposure to formal schooling at the time of testing are all discussed to account for the observed outcomes.
How narratives about the secondary-tertiary transition shape undergraduate tutors’ sense-making of their teaching
Authors: Kontorovich Igor’ , Ovadiya Tikva
Published: March 2023

Drawing on the commognitive framework, we construe the secondary-tertiary transition (STT) as a distinctive element in the pedagogical discourses of various communities. Our interest rests with university tutors in light of the emergent recognition of their impact on undergraduates’ mathematics learning in many tertiary contexts worldwide. We aim to understand the roles of STT communication in tutors’ reflections on incidents that took place in their tutorials. Our participants were undergraduate students in the advanced stages of their mathematics degrees in a large New Zealand university and who were enrolled in a mathematics education course. Throughout the semester, the participants led tutorial sessions for first-year students and wrote reflections on classroom incidents that drew their attention. Our data corpus consisted of 58 reflections from 38 tutors collected over four semesters. The analysis revealed that STT communication featured in tutors’ descriptions of classroom incidents, assisted them in making sense of unexpected events, positioned their instructional actions as replications of what was familiar to them from their own STT experience, and contributed toward generating new pedagogical narratives. We situate these findings in the literature concerning undergraduate tutoring and teachers’ perspectives on STT.
Innovation facilitators and sustainable development: a country comparative approach
Authors: Chaparro-Banegas Nuria , Ibañez Escribano Ana Maria , Mas-Tur Alicia , Roig-Tierno Norat
Published: March 2023

National and international organizations have introduced policies aimed at sustainable development. These policies are designed to encourage sustainable forms of business to meet the Sustainable Development Goals (SDGs) of the 2030 Agenda. Regional inequalities in sustainable development may be exacerbated by disparate levels of innovation. This paper analyzes the variations between clusters of countries according to the degree to which they have achieved the SDGs and their levels of innovation facilitators. Two types of analyses were employed. First, cluster analysis was used to examine changes in groups of regions with similar innovation characteristics between 2015 and 2020. Data for 122 countries were gathered from the World Bank, the SDG Index, and the Global Innovation Index. Second, multiple linear regression analysis was used to assess the power of the variables in the model to explain the level of sustainable development. The results reveal four clusters (low, medium, high, and very high innovative facilitators and sustainable development), as well as movements between those clusters from 2015 to 2020. The multiple linear regression analysis shows that the variables have explanatory power with respect to the dependent variable of sustainable development. This analysis also reveals different degrees of importance of the variables for each cluster. The findings highlight the need to consider the limitations of economic growth in terms of innovation facilitators to promote sustainable development. If policymakers recognize the limitations of economic growth and the physical ecosystem, degradation of the environment can be avoided, even when there is innovation. Global and individual social welfare can thus be ensured. This study offers valuable insights into how to achieve sustainable development through innovation facilitators by providing in-depth knowledge of the individual characteristics of innovation systems and considering the limitations of economic growth.