bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretic quantum information entropies for the generalized hyperbolic potential
Authors: Ikot Akpan N. , Rampho Gaotsiwe Joel , Amadi Precious O. , Okorie Uduakobong S. , Sithole Makagamathe J. , Lekala Mantile L.
Published: August 2020

The Shannon entropy (S) and the Fisher Information (I) entropies are investigated for a generalized hyperbolic potential in position and momentum spaces. First, the Schrodinger equation is solved exactly using the Nikiforov‐Uvarov‐Functional Analysis method to obtain the energy spectra and the corresponding wave function. By Fourier transforming the position space wave function, the corresponding momentum wave function was obtained for the low‐lying states corresponding to the ground and first excited states. The positions and momentum of Shannon entropy and Fisher Information entropies were calculated numerically. Finally, the Bialynicki‐Birula and Mycielski and the Stam‐Cramer‐Rao inequalities for the Shannon entropy and Fisher Information entropies, respectively, were tested and were found to be satisfied for all cases considered.
Characterization of Quantum States Based on Creation Complexity
Authors: Hu Zixuan , Kais Sabre
Published: August 2020

The creation complexity of a quantum state is the minimum number of elementary gates required to create it from a basic initial state. The creation complexity of quantum states is closely related to the complexity of quantum circuits, which is crucial in developing efficient quantum algorithms that can outperform classical algorithms. A major question unanswered so far is what quantum states can be created with a number of elementary gates that scales polynomially with the number of qubits. In this work, it is first shown that for an entirely general quantum state it is exponentially hard (requires a number of steps that scales exponentially with the number of qubits) to determine if the creation complexity is polynomial. Then, it is shown that it is possible for a large class of quantum states with polynomial creation complexity to have common coefficient features such that, given any candidate quantum state, an efficient coefficient sampling procedure can be designed to determine if the state belongs to the class or not with arbitrarily high success probability. Consequently, partial knowledge of a quantum state's creation complexity is obtained, which can be useful for designing quantum circuits and algorithms involving such a state.
Ab initio quantum chemical studies of isotopic fractionation during acid digestion reaction of dolomite for clumped isotope application
Authors: Pramanik Chirantan , Ghosh Prosenjit , Banerjee Sanchita , Liang Mao‐Chang
Published: August 2020

Rationale

In ‘clumped isotope paleothermometry’ carbonates are reacted with anhydrous phosphoric acid to extract CO2 that carries the isotopic signature of the reacting carbonates, and the amount of clumping in the product CO2 is measured. Previous theoretical models for determining clumped isotopic fractionation in product CO2 during acid digestion of carbonates are independent of the cations present in the carbonate lattice. Hence further study is required to understand the cationic effect.

Methods

We studied the acid reaction mechanism based on the protonation of carbonates, calculated the acid fractionation factor for dolomite using the partition functions and vibrational frequencies obtained for the transition state structure, and determined the effect of cations on the acid fractionation factor. Experimentally, carbonates are reacted using the modified sealed vessel method and analyzed in the dual inlet of a ThermoFinnigan MAT 253 isotope ratio mass spectrometer.

Results

The oretically obtained acid fractionation factor can be expressed as Δ47 acid fractionation in dolomite = −0.28563 + 0.49508 * (105/T2) − 0.08231 * (105/T2)2 for a temperature range between 278.15 and 383.15 K. The theoretical slope of the dolomite–acid digestion curve is lower than that of the calcite–acid digestion curve obtained using the identical reaction mechanism. Our theoretical slope is consistent with the result from the common acid bath experiments but higher than the slope obtained in our experimental study using the modified sealed vessel method and in a previous theoretical study using the H2CO3 model.

Conclusions

The transition state structure, obtained in our study, includes the cations present in the carbonate minerals and provides distinct acid fractionation factors for calcite and dolomite. The observed gentler slope of the theoretically calculated dolomite–acid digestion curve than of the calcite curve is expected considering the stronger Mg–O bond. Our experimental approach invokes post‐digestion isotopic exchange and agrees with the previous theoretical estimates where post‐digestion isotopic fractionation was considered.
Endobronchial hamartoma coexisting with lung cancer
Authors: Miyoshi Seigo , Sugimoto Eiji , Kawakami Mayu , Taguchi Yoshihiro , Hamaguchi Naohiko , Yamaguchi Osamu
Published: August 2020

Key message

Clinicians should be careful when examining a case with endobronchial hamartoma with concurrent malignant disease because radiographic imaging and symptoms cannot clearly differentiate between both diseases.
Rejecting the effects of both input disturbance and measurement noise: A second‐order control system example
Authors: Zhu Yang , Zhu Bo , Liu Hugh H. T. , Qin Kaiyu
Published: August 2020

This article originates from the well‐accepted observations in practice: rejection of both input disturbance and measurement noise is practically important for high‐precision tracking control, and the classic estimators, such as the uncertainty and disturbance estimator (UDE) and disturbance observer, are proven to be inherently sensitive to measurement noises. Motivated by these observations, we develop a robust control solution and demonstrate the possibility of unifying the design of noise estimator (NE) and UDE for a class of second‐order systems. Interestingly, the NE and UDE have three important features in common: (i) the designs are based on system model and reliable state measurement; (ii) a first‐order filter is used to ensure that the design is physical realizable, rather than to filter out undesired signals; (iii) the filter parameters are readily determined by an introduced singular perturbation parameter. The performance of UDE is improved when augmented with NE to reject measurement noises. Then, a simple mapping for parameter tuning is presented, by which the estimation performance can be explicitly analyzed using the singular perturbation theory. Comparative simulation and experimental studies show that the proposed NE+UDE‐based solution is not only less sensitive to measurement noise than the classic UDE‐based control, but also able to deliver superior trajectory‐tracking performance over other robust output feedback control approaches.
Stochastic tracking control of multivariable nonlinear systems subject to external disturbances
Authors: Ma Tong
Published: August 2020

By incorporating a disturbance rejection control law with receding horizon optimization technique, this paper synthesizes a stochastic tracking nonlinear model predictive control (STNMPC) framework for multivariable nonlinear systems subject to external disturbances. In the control scheme, a cancellation strategy combined with a feedforward prefilter is adopted to drive the expected value of the output to the reference signal by compensating the undesired components in the feedback loop. Given the statistics of the stochastic disturbances, covariance evolution is involved to describe the propagation of uncertainties through the system model and a time‐varying feedback control law is designed to minimize the covariance. By employing the strong optimizing property of model predictive control (MPC), a stochastic MPC (SMPC) framework is formulated. By using the Schur complement, the nonlinear dependence of covariance evolution on time‐varying feedback control gains is removed and the cost function is reformulated as a linear one with linear matrix inequalities, which resolves the implementation issue existing in the numerical problem. To guarantee the convergence and recursive feasibility of the SMPC framework, terminal constraint with some tricks are applied, for example, Lyapunov equation. The well‐established theories and tricky techniques allow to cast the SMPC framework as a semidefinite programming, which reduces the computational cost and yields a feasible numerical solution. Numerical examples are provided to demonstrate the effectiveness of the proposed control method, comparisons with some adaptive control algorithm shows the superiority of the proposed approach.
A comparison of benthic algal and macroinvertebrate communities in a dammed and undammed Mediterranean river (Eel River watershed, California, USA)
Authors: Jansen Lara Stephanie , O'Dowd Alison , Bouma‐Gregson Keith
Published: August 2020

Flow regulation by dams can reduce hydrologic variability, and subsequently, alter river food webs. This study compared the summer algal and macroinvertebrate assemblages from the mainstem Eel River (Mainstem) below Cape Horn Dam to that of the unregulated Middle Fork Eel River (Middle Fork). Despite above average rainfall in 2017, flow regulation produced a steeper spring flow recession limb with only 15.72 cubic meter per second in the dammed Mainstem in late May, which was about half the undammed Middle Fork's discharge of 32.28 cubic meter per second at the same time of year. Peak summer water temperatures in the Mainstem (mid‐August) were later relative to the Middle Fork (late July) based on past years of monitoring. The regulated Mainstem supported less Cladophora with lower mid‐summer algal richness, resulting in a macroinvertebrate community less reliant on Cladophora, with fewer key invertebrates such as Chironominae compared to the unregulated Middle Fork. Dam systems that reduce flow variation in Mediterranean rivers may shift the downstream community away from seasonal proliferation of dense green filamentous algae and invertebrate grazers typical of rivers in this climate, and towards adnate epilithic algae and cyanobacteria and generalist invertebrates, due to the encroachment of riparian vegetation and reduced thermal variation.
Experiments on restoring alluvial cover in straight and meandering rivers using gravel augmentation
Authors: Welber Matilde , Papangelakis Elli , Ashmore Peter , MacVicar Bruce
Published: August 2020

Successful management of natural and engineered channels with discontinuous alluvial cover requires knowledge of how the cover develops and evolves. We report on physical model experiments designed to compare alluvial cover dynamics in straight and sinuous fixed‐bed channels at a range of gravel‐bed material supply rates and constant discharge conditions. Experiments investigated the formation of alluvial cover from a bare bed, relationships between equilibrium cover characteristics and sediment supply rate, and the evolution of an initial uniform cover of varying thickness. A stable partially‐alluviated state is achieved in both the straight and sinuous channels for a range of sediment supply rates. The areal extent and stored mass of the cover increase progressively with supply rate, and the rate of increase is higher in the straight channel. While alluvial cover develops from isolated patches in the straight channel, cover in the sinuous channel develops as well‐defined bars, with deposition on the inside of bends and expanding outwards along the channel as cover area increases. Artificially emplaced cover quickly adjusts to a cover extent within 4–20% of that formed from a bare bed at the same feed rate, with initial cover thickness only influencing the final cover in the sinuous channel. Neither the sinuous nor the straight channel can sustain an alluvial cover in the absence of upstream sediment supply. This study can inform the management of semi‐alluvial channels because it highlights the primary roles of sediment supply and planform geometry in maintaining an alluvial cover in natural and engineered channels.
Multiclass machine learning classification of functional brain images for Parkinson's disease stage prediction
Authors: Huang Guan‐Hua , Lin Chih‐Hsuan , Cai Yu‐Ren , Chen Tai‐Been , Hsu Shih‐Yen , Lu Nan‐Han , Chen Huei‐Yung , Wu Yi‐Chen
Published: August 2020

We analyzed a data set containing functional brain images from 6 healthy controls and 196 individuals with Parkinson's disease (PD), who were divided into five stages according to illness severity. The goal was to predict patients' PD illness stages by using their functional brain images. We employed the following prediction approaches: multivariate statistical methods (linear discriminant analysis, support vector machine, decision tree, and multilayer perceptron [MLP]), ensemble learning models (random forest [RF] and adaptive boosting), and deep convolutional neural network (CNN). For statistical and ensemble models, various feature extraction approaches (principal component analysis [PCA], multilinear PCA, intensity summary statistics [IStat], and Laws' texture energy measure) were employed to extract features, the synthetic minority over‐sampling technique was used to address imbalanced data, and the optimal combination of hyperparameters was found using a grid search. For CNN modeling, we applied an image augmentation technique to increase and balance data sizes over different disease stages. We adopted transfer learning to incorporate pretrained VGG16 weights and architecture into the model fitting, and we also tested a state‐of‐the‐art machine learning model that could automatically generate an optimal neural architecture. We found that IStat consistently outperformed other feature extraction approaches. MLP and RF were the analytic approaches with the highest prediction accuracy rate for multivariate statistical and ensemble learning models, respectively. Overall, the deep CNN model with pretrained VGG16 weights and architecture outperformed other approaches; it captured critical features from imaging, effectively distinguished between normal controls and patients with PD, and achieved the highest classification accuracy.
Discover ways to support students with ASD during the pandemic
Authors: Hope Joan
Published: August 2020

When classes went online this spring, programs for students on the spectrum had to quickly move to remote operations as well. Review what officials at the Autism Initiative at Mercyhurst and the Mosaic Program at the University of Tennessee at Chattanooga did to keep student support at a high level during the pandemic. Whether your institution has a program for students with autism spectrum disorder or not, their strategies could work for you.
Did court find dismissal of student violated ADA?
Authors: Lyerly Eric
Published: August 2020

The plaintiff matriculated as a medical student at the University of Hawaii at Manoa in July 2005. Shortly after enrolling, the plaintiff began to experience depression, receiving psychiatric care for his disability.
Sustainable development: Impacts of consumers' risk aversion on remanufacturing model selection and environmental performance
Authors: Deng Weisheng
Published: August 2020

Remanufacturing serves as an efficient way to achieve sustainable development and has become increasingly popular. Various types of services, such as extended warranties and full refunds, are provided to reduce consumers' concerns and promote the sale of remanufactured products. This work is motivated by the fact that consumers are risk‐averse to remanufactured products and prefer new products due to quality, safety, and environmental issues. Taking into account the risk‐averse consumers, we consider four models in which there is no remanufacturing (NR model) and in which remanufacturing is carried out by the supplier (SR model), the manufacturer (MR model), or an independent remanufacturer (IR model); then, we analyze the remanufacturing model choice. We find that consumers' risk aversion and the relative profitability of remanufacturing are two critical factors that drive the optimal results. In particular, depending on the relationship of these two critical factors, the supplier may prefer either the SR model or the IR model, the environment may prefer either the NR model or the SR model, and the manufacturer always prefers the MR model. We further identify the condition in which the SR model may simultaneously benefit the supplier and the environment.
Women and the rhetoric of safety: The impact of policy framing on attitudes toward discriminatory policies
Authors: Wemlinger Elizabeth
Published: August 2020

The expansion of the rights for many in the LGBT community across the US along with theObergefell v. HodgesSupreme Court ruling has created a backlash in many states against the LGBT community. This backlash has recently been furthered by even more restrictive policy, reflected in North Carolina's HB2 act in 2016 eliminating the power of localities to provide more inclusive environments for the LGBT community through multiple policy mechanisms. The rhetoric surrounding these policies focus on the safety of women and children. The purpose of this study is to analyze the relationship between gender and attitudes toward discriminatory policies. What impact does this framing have on a mother's attitudes toward LGBT policies? Utilizing US individual level survey data this study evaluates whether there are gender differences regarding attitudes toward restrictive gay and lesbian policy and a change in the success of these frames from 2008 to 2014.
Engineered Ferritin Nanoparticles for the Bioluminescence Tracking of Nanodrug Delivery in Cancer
Authors: Bellini Michela , Riva Benedetta , Tinelli Veronica , Rizzuto Maria Antonietta , Salvioni Lucia , Colombo Miriam , Mingozzi Francesca , Visioli Alberto , Marongiu Laura , Frascotti Gianni , Christodoulou Michael S. , Passarella Daniele , Prosperi Davide , Fiandra Luisa
Published: August 2020

The identification of a highly sensitive method to check the delivery of administered nanodrugs into the tumor cells is a crucial step of preclinical studies aimed to develop new nanoformulated cures, since it allows the real therapeutic potential of these devices to be forecast. In the present work, the ability of an H‐ferritin (HFn) nanocage, already investigated as a powerful tool for cancer therapy thanks to its ability to actively interact with the transferrin receptor 1, to act as an efficient probe for the monitoring of nanodrug delivery to tumors is demonstrated. The final formulation is a bioluminescent nanoparticle, where the luciferin probe is conjugated on nanoparticle surface by means of a disulfide containing linker (Luc‐linker@HFn) which is subjected to glutathione‐induced cyclization in tumor cell cytoplasm. The prolonged imaging of luciferase+ tumor models, demonstrated by an in vitro and an in vivo approach, associated with the prolonged release of luciferin into cancer cells by disulfide bridge reduction, clearly indicates the high efficiency of Luc‐linker@HFn for drug delivery to the tumor tissues.
Multiphase Assembly of Small Molecule Microcrystalline Peptide Hydrogel Allows Immunomodulatory Combination Therapy for Long‐Term Heart Transplant Survival
Authors: Majumder Poulami , Zhang Yichuan , Iglesias Marcos , Fan Lixin , Kelley James A. , Andrews Caroline , Patel Nimit , Stagno Jason R. , Oh Byoung Chol , Furtmüller Georg J. , Lai Christopher C. , Wang Yun‐Xing , Brandacher Gerald , Raimondi Giorgio , Schneider Joel P.
Published: August 2020

Combination therapies that target multiple pathways involved in immune rejection of transplants hold promise for patients in need of restorative surgery. Herein, a noninteracting multiphase molecular assembly approach is developed to crystallize tofacitinib, a potent JAK1/3 inhibitor, within a shear‐thinning self‐assembled fibrillar peptide hydrogel network. The resulting microcrystalline tofacitinib hydrogel (MTH) can be syringe‐injected directly to the grafting site during surgery to locally deliver the small molecule. The rate of drug delivered from MTH is largely controlled by the dissolution of the encapsulated microcrystals. A single application of MTH, in combination with systemically delivered CTLA4‐Ig, a co‐stimulation inhibitor, affords significant graft survival in mice receiving heterotopic heart transplants. Locoregional studies indicate that the local delivery of tofacitinib at the graft site enabled by MTH is required for the observed enhanced graft survival.
ZnO/Nanocarbons‐Modified Fibrous Scaffolds for Stem Cell‐Based Osteogenic Differentiation
Authors: Xia Yi , Fan Xin , Yang Hua , Li Ling , He Chao , Cheng Chong , Haag Rainer
Published: August 2020

Currently, mesenchymal stem cells (MSCs)‐based therapies for bone regeneration and treatments have gained significant attention in clinical research. Though many chemical and physical cues which influence the osteogenic differentiation of MSCs have been explored, scaffolds combining the benefits of Zn2+ ions and unique nanostructures may become an ideal interface to enhance osteogenic and anti‐infective capabilities simultaneously. In this work, motivated by the enormous advantages of Zn‐based metal–organic framework‐derived nanocarbons, C‐ZnO nanocarbons‐modified fibrous scaffolds for stem cell‐based osteogenic differentiation are constructed. The modified scaffolds show enhanced expression of alkaline phosphatase, bone sialoprotein, vinculin, and a larger cell spreading area. Meanwhile, the caging of ZnO nanoparticles can allow the slow release of Zn2+ ions, which not only activate various signaling pathways to guide osteogenic differentiation but also prevent the potential bacterial infection of implantable scaffolds. Overall, this study may provide new insight for designing stem cell‐based nanostructured fibrous scaffolds with simultaneously enhanced osteogenic and anti‐infective capabilities.
An Activatable Nano‐Prodrug for Treating Tyrosine‐Kinase‐Inhibitor‐Resistant Non‐Small Cell Lung Cancer and for Optoacoustic and Fluorescent Imaging
Authors: Xie Xin , Zhan Chenyue , Wang Jie , Zeng Fang , Wu Shuizhu
Published: August 2020

Non‐small cell lung cancer (NSCLC) is the most common type of lung cancer and the cause of high rate of mortality. The epidermal growth factor receptor (EGFR)‐targeted tyrosine kinase inhibitors are used to treat NSCLC, yet their curative effects are usually compromised by drug resistance. This study demonstrates a nanodrug for treating tyrosine‐kinase‐inhibitor‐resistant NSCLC through inhibiting upstream and downstream EGFR signaling pathways. The main molecule of the nanodrug is synthesized by linking a tyrosine kinase inhibitor gefitinib and a near‐infrared dye (NIR) on each side of a disulfide via carbonate bonds, and the nanodrug is then obtained through nanoparticle formation of the main molecule in aqueous medium and concomitant encapsulation of a serine threonine protein kinase (Akt) inhibitor celastrol. Upon administration, the nanodrug accumulates at the tumor region of NSCLC‐bearing mice and releases the drugs for tumor inhibition, and the dye for fluorescence and optoacoustic imaging. Through suppressing the phosphorylation of upstream EGFR and downstream Akt in the EGFR pathway by gefitinib and celastrol, respectively, the nanodrug exhibits high inhibition efficacy against orthotopic NSCLC in mouse models.
One‐Step Realization of Crystallization and Cyano‐Group Generation for g‐C3N4 Photocatalysts with Improved H2 Production
Authors: Yu Huogen , Ma Haiqin , Wu Xinhe , Wang Xuefei , Fan Jiajie , Yu Jiaguo
Published: August 2020

In contrast to conventional disordered g‐C3N4, the ordered arrangement of s‐triazine units and cyano‐group is important for its improved photocatalytic H2 evolution activity. However, the usual synthetic methods include complex, multiple‐step operations or containing the use of toxic materials. Herein, the ordered crystallization and cyano‐group generation are simultaneously realized for the g‐C3N4 photocatalyst (namely, cyano‐group‐modified crystalline g‐C3N4) by a facile and green one‐step Na2CO3‐assisted synthesis approach. It is found that Na2CO3 first effectively promotes the denitrification of dicyandiamide (DCDA) and accelerates its polymerization to produce highly crystalline g‐C3N4. When the temperature is over 500 °C, Na2CO3 facilitates the pyrolysis of partial s‐triazine units to produce cyano‐groups on the g‐C3N4 surface, resulting in the final generation of cyano‐group‐modified crystalline g‐C3N4. Consequently, the resulting cyano‐group‐modified crystalline g‐C3N4 presents a highly increased hydrogen production activity, about twofold higher than that of the bulk g‐C3N4. The increased hydrogen production activity is primarily because of the synergistic effect of the highly crystalline and cyano‐group functional for the resulting cyano‐group‐modified crystalline g‐C3N4. The current technology opens insights for the preparation of other crystalline photocatalysts.
Evidencing Interfacial Charge Transfer in 2D CdS/2D MXene Schottky Heterojunctions toward High‐Efficiency Photocatalytic Hydrogen Production
Authors: Ding Mingye , Xiao Rong , Zhao Chengxiao , Bukhvalov Danil , Chen Zupeng , Xu Haotian , Tang Hua , Xu Jingsan , Yang Xiaofei
Published: August 2020

Photocatalytic water splitting by heterojunction nanostructures is considered as one of the most favorable pathways for direct solar‐to‐hydrogen conversion. High‐efficiency solar hydrogen production demands an effective separation of charge carriers and their rapid transport to the interface, whereas the charge‐transfer pathway in heterojunction photocatalysts is largely elusive. Herein, 2D CdS/2D MXene Schottky heterojunctions are synthesized via a sequence of electrostatic self‐assembly process and solvothermal method. The composite photocatalysts exhibit highly efficient and robust hydrogen‐evolving performance, far superior than the pristine CdS nanosheets. Furthermore, density functional theory (DFT) calculations are adopted to unveil the charge‐transport pathway. It is revealed that an intimate Schottky contact is constructed between CdS and MXene, which further steers the formation of charge flow and expedites the charge migration from CdS to MXene, thus suppressing the recombination of photogenerated charge carriers and boosting the photocatalytic activity for hydrogen evolution.
Study on Mechanical Properties and Microstructure of the Ultrastrong Low Alloy Wear‐Resistant Steel
Authors: Zhang Congyang , Li Zhirui , Li Yunyang , Zhou Xiangman , Fang Dong , Ye Yongsheng , Yuan Youlu , Wu Haihua
Published: August 2020

Herein, a kind of the ultrastrong low alloy wear‐resistant steel suitable for excavator bucket teeth is prepared. The ultrastrong steel with good toughness and wear resistance is successfully prepared by the forging, quenching, and tempering processes. The yield strength, tensile strength, elongation, and hardness of the ultrastrong steel reached up to 1700, 1960 MPa, 7%, and 563HV, respectively. Optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM) are used to observe the microstructures of the ultrastrong steel. After the forging, quenching, and tempering, two types of martensite laths are formed in the matrix of the ultrastrong steel, i.e., the coarse laths with low‐density dislocations and the thin laths with high‐density dislocations and some ε‐carbides. Low‐temperature tempering allows the carbides to precipitate in large quantities, and maintains the matrix with high density dislocations in the thin laths, which is the micromechanism of the steel with high strength and high toughness, and good wear resistance.
High‐Temperature Deformation Behavior of a Novel Hot‐Rolled Transformation‐Induced Plasticity Alloy: Experiments, Constitutive Modeling, and Processing Maps
Authors: Zhang Bin , Dong Ying , Devesh Kumar Misra Raja , Liu Yue , Sun Chao , Du Lin Xiu
Published: August 2020

Hot deformation behavior of a novel hot‐rolled transformation‐induced plasticity (TRIP) alloy is studied by compression test in the temperature range of 1123–1323 K and strain rate range of 0.1–10 s−1, and the relation between flow stress and Zener–Hollomon parameter is systematically analyzed. The study indicates that the flow stress of experimental alloy increases with the decrease in deformation temperature and increase in strain rate. The value of stress exponent (n) and activation energy (Q) is 7.4 and 323.5 kJ mol−1. Processing maps developed using the dynamic material model at strains of 0.25, 0.40, and 0.55 predict optimum hot deformation temperature of 1273 K and strain rate of 0.8 s−1. The study of dynamic recrystallization (DRX) behavior under different deformation conditions by transmission electron microscope (TEM) suggests that two DRX mechanisms are operative—continuous dynamic recrystallization (CDRX) mechanism, which depends on high density of dislocations at the grain boundaries, and the second mechanism involves strain‐induced boundary migration (SIBM), governed by grain boundary bulging.
Simultaneous identification and estimation of glycyrrhizin, glabridin, and 18β‐glycyrrhetinic acid in de‐glycyrrhized Ayurvedic lipid‐based formulation of Glycyrrhiza glabra using dual wavelength reverse phase‐high‐performance liquid chromatography
Authors: Kumbhalkar Bhagyashri , Walunj Tanhaji , Chavan Sandeep , Gupta Vidya , Deshmukh Vineeta , Sardeshmukh Sadanand
Published: August 2020

Plant‐based Ayurvedic formulations such as medicated oils, confectioneries, etc. are developed with a rationale of selecting specific compounds for targeted action and minimal side effects. It is imperative to develop an analytical method to simultaneously identify and quantify the targeted compounds for good resolution with low retention time. The present assay using reverse phase‐high‐performance liquid chromatography is optimized to resolve glycyrrhizin, glabridin, and 18β‐glycyrrhetinic acid simultaneously at retention times of 6.6, 8.1, and 10.2 min, respectively, using acidified mobile phase from Glycyrrhiza glabra utilized in Ayurvedic lipid (cow's ghee and sesame oil) based formulations. Raw material, its decoction, and residues formed during preparation steps were extracted in methanol while lipid formulations were extracted using a binary solvent system of methanol and n‐hexane. The separation was performed on Hypersil gold column maintained at 40°C using 0.2% ortho‐phosphoric acid with pH 3.5 in water and acetonitrile as binary gradient mobile phase. The compounds were detected at wavelengths 230 (glabridin) and 254 (glycyrrhizin and 18β‐glycyrrhetinic acid) nm. The method revealed de‐glycyrrhized finished products containing glabridin and 18β‐glycyrrhetinic acid having medicinal value.
An orthogonal approach for method development and validation of three potential halo alkyl alcohol genotoxic impurities in miglitol drug substance by fast gas chromatography–mass spectrometry
Authors: Rajana Nagaraju , Ramana D.V. , Ganta Rama Rao , Devi Dharamasoth Rama , Deshpande Amol A. , Babu J. Moses , Basavaiah K.
Published: August 2020

Miglitol is an azasugar. It is the oral antidiabetic drug that inhibits the glucose generation from the polysaccharides and oligosaccharides. The miglitol structure includes 1‐deoxynojirimycin and ethyl alcohol, the alkyl alcohol part is a key starting material for miglitol. The moiety adds by halo alkyl alcohols such as 2‐bromo ethanol, 2‐chloro ethanol, and 2‐iodo ethanol to 1‐deoxynojirimycin. Miglitol's maximum dosage per day is 300 mg, hence any genotoxic impurity in the miglitol should control below 5 ppm. A fast gas chromatography and mass spectrometry analytical method was developed and validated for 2‐bromo ethanol, 2‐chloro ethanol, and 2‐iodo ethanol in miglitol drug substance by using DB‐1, 15 m, 0.25 mm, and 1 µm column, which constitutes the poly‐dimethyl siloxane stationary phase. The limits of detection and quantitation were achieved at 0.7 and 2.0 ppm, respectively. The recoveries were from 81.7 to 118.8% for all impurities. The method was linear from 2.0 to 15 ppm for all impurities and their correlation coefficient values were in the range of 0.992–0.996. The method was precise at limit of quantitation (2.0 ppm), 2.5, 5.0, and 7.5 ppm levels, the %RSD values were <13.5%, and analytical solutions were stable at 25˚C.
A stakeholder framework for evaluating the ‐ilities of autonomous behaviors in complex adaptive systems
Authors: Douglas Andre , Mazzuchi Thomas , Sarkani Shahram
Published: August 2020

Complex adaptive systems (CAS) exhibit emergent behaviors caused by the nonlinear actions between individual components within the system and their environment. These emergent behaviors are difficult to predict and measure making it very challenging to initially design from the start. Developing CASs, such as an autonomous swarming unmanned system, is a relevant key task today for solving hard problems with limited resources in a demanding economy. Swarming unmanned systems are valued by their unique capabilities, but how do stakeholders ensure their needs are considered during development? Certain stakeholders have interests that go beyond the initial delivery of the system, yet developers seem to focus efforts on designing autonomous behaviors to satisfy immediate mission needs. To close this gap, we propose a stakeholder focused framework for evaluating CASs over a full system life cycle for swarming unmanned systems. A goal‐oriented requirements engineering modeling methodology, Knowledge Acquisition in AutOmated Specification, is used to map requirements between stakeholder goals and autonomous behaviors. Behaviors are analyzed in an agent‐based simulation using NetLogo for quantifying stakeholder‐driven performance qualities (‐ilities). A case study was performed for a swarm of unmanned surface vessels called wave gliders to evaluate performance over the entire system life cycle.
An interdisciplinary strategy to advance systems engineering theory: The case of abstraction and elaboration
Authors: Topcu Taylan G. , Triantis Konstantinos , Malak Richard , Collopy Paul
Published: August 2020

Prior advances in systems engineering (SE) theory were instrumental in defining the discipline and its tools, but are limited in perspective. The SE community needs new theoretical advances to address its existing and emerging sociotechnical challenges. This communication paper is a product of an NSF/SERC/INCOSE funded workshop on theory building in SE with a focus on the use of abstraction and elaboration. The overarching goals of the workshop were twofold. First, to illustrate the nuances and complexities of the theory building process with an emphasis on developing theory about the SE discipline rather than about a particular system of interest. The second goal was to stimulate a new wave of SE theory by providing a set of frames that could be used for formal theory articulation in follow‐up research. The workshop focused on abstraction and elaboration due to their richness and pervasiveness in SE and investigated the concept in two interrelated contexts: (a) the social coordination of design teams and (b) its strategic use during system design. For each research context, we offer a structured guideline for theorizing, and provide an understanding and framing of some of the generalized abstraction and elaboration uses in SE. Research frames articulated in this workshop could serve as the first step for future research on SE theory, which necessitates hypotheses generation, data collection, validation, and refinement.
Evaluation of Visible Light as a Cue for Guiding Downstream Migrant Juvenile Sea Lamprey
Authors: Haro Alex , Miehls Scott , Johnson Nicholas S. , Wagner C. Michael
Published: August 2020

Light can modify orientation and locomotory behaviors in fish and has been applied to attract or repel migrant fish by inducing positive or negative phototaxis. Here, recently metamorphosed downstream‐migrating Sea Lamprey Petromyzon marinus were exposed to light cues in several orientations and intensities at night under controlled flowing‐water conditions in a laboratory flume. Behaviors and rates of downstream movement were monitored with overhead cameras and nets. When exposed to low‐intensity white light, 16–23% more Sea Lamprey were captured in a net closest to the light cue array compared to a dark control condition, suggesting some degree of positive phototaxis at low light levels (100 lx at a distance of 1 m from the light source). An interaction with the side of the flume (possibly due to varying flow conditions) and light treatment was also observed. At higher light intensities (1,000 lx at 1 m from the source), Sea Lamprey progressed downstream at a lower rate than was observed during dark conditions. After high‐intensity light treatments, fewer Sea Lamprey were observed in the nets at the downstream end of the flume and more Sea Lamprey were observed in the flume or in the release channel compared to dark control trials. Therefore, some photonegative behavior may be expressed at light levels of 1,000 lx or greater, perhaps as an attempt to avoid detection by predators by remaining stationary or seeking shelter. Light may have utility as a cue used for guidance devices to control Sea Lamprey, but further research is needed to define how light intensity and the environment (turbidity, depth, water velocity, and natural habitat features) influence locomotion, changes in swimming depth, and other behavioral responses of downstream‐migrating juvenile Sea Lamprey.
The Identity of Mapouria (Rubiaceae, Psychotrieae)
Authors: Taylor Charlotte M. , Gereau Roy E. , Callmander Martin
Published: August 2020

The genus Mapouria is synonymous with Psychotria, and based on Mapouria guianensis. The identity of M. guianensis, the correct name for P. mapourioides, and the identities of several other neotropical Psychotria names studied here have been unclear. The name M. guianensis corresponds to the plants currently treated as P. ernestii, and P. pedunculosa is an older name for P. mapourioides. The distinctions among the commonly confused species P. guianensis, P. carthagenensis, P. cupularis, and P. pedunculosa are clarified here, and typifications and identities are determined for several other names associated with these species.
Phylogenetic reconstruction of Ficus subg. Synoecia and its allies (Moraceae), with implications on the origin of the climbing habit
Authors: Zhang Zhen , Wang Xiao‐Mei , Liao Shuai , Zhang Jian‐Hang , Li Hong‐Qing
Published: August 2020

The infrageneric classification of Ficus (Moraceae) has raised concerns since Berg put forward his six subgenera system. Molecular analyses have revealed some unnatural groups within this system. The status of F. subg. Synoecia and the relationships between this subgenus and its allies are among the major challenges facing classification within the genus. To resolve these problems, we reconstructed the phylogenetic trees with three nuclear markers from 147 ingroup taxa (including approximately half of F. subg. Synoecia species and three‐fifths of F. subg. Ficus) and implemented ancestral area and life‐form reconstructions to trace the evolutionary history. Results showed that F. subg. Synoecia and F. subg. Ficus (except F. subsect. Ficus) constituted a well‐supported monophylum, which is sister to F. subg. Terega. This monophylum comprises two clades: one clade covers F. subsect. Frutescentiae of F. sect. Ficus and F. subsect. Plagiostigma of F. sect. Pogonotrophe, and the other covers F. sect. Eriosycea, F. sect. Apiosycea and the rest of F. sect. Pogonotrophe. Ancestral area reconstruction revealed that the first clade has a distinct origin in East Asia, but the second one shows fewer obvious signs. Ancestral life‐form reconstruction suggested that the climbing habit, a key trait used to divide F. subg. Ficus and F. subg. Synoecia, has evolved independently more than four times, rendering it an unsuitable characteristic to circumscribe the subgenera. Thus, we merged F. subg. Synoecia and F. subg. Ficus (excluding F. subsect. Ficus) into one subgenus, containing two newly delimited sections and six new synonyms.
Longitudinal impact of interactive science activities: Developing, implementing, and validating a graphing integration inventory
Authors: Boda Phillip A. , Bathia Shruti , Linn Marcia C.
Published: August 2020

Integrating sophisticated graphical analysis skills as they learn science is essential for K‐12 students and emphasized in current standards. In this study, we iteratively designed a Graphing Integration Inventory (GII) over a three‐year period, while also supporting students to develop their capabilities to use graphs to learn science content in complex ways through interactive curriculum materials implemented on a novel technology enhanced curriculum platform. We applied the Knowledge Integration framework to design the curriculum, the assessments, and the rubrics for scoring student explanations. The framework delineates ways to promote links among graphs and science ideas. The rubrics award students higher scores on their explanations based on the level of complexity of their connections between science concepts and, in this research, graphs. The GII and the aligned curriculum were implemented by over 300 middle school students (Grades 6–8) across a 3‐year period. We investigated the impact of the designed curriculum on the integration of graphing and science while also studying the psychometric properties of the GII to validate it for use in future studies. Findings suggest both that the curriculum used to support these students improved their Knowledge Integration capabilities significantly and that the GII instrument is suitable for use with populations across gender and native English language status demographics in Grades 6–8. Implications are discussed around using graphs to learn complex science ideas, as well as the affordances of technology enhanced platforms to support this type of learning and assessment.
Genome‐wide analysis of PmTCP4 transcription factor binding sites by ChIP‐Seq during pistil abortion in Japanese apricot
Authors: Iqbal Shahid , Pan Zhenpeng , Wu Xinxin , Shi Ting , Ni Xiaopeng , Bai Yang , Gao Jie , Khalil‐ur‐Rehman Muhammad , Gao Zhihong
Published: August 2020

The TCP4 transcription factor plays an important role in plant growth and development, especially in flower development. PmTCP4 is involved in the process of pistil abortion in Japanese apricot, but its molecular mechanism, particularly the DNA binding sites and co‐regulatory genes, are quite unknown. Therefore, to identify the genome‐wide binding sites of PmTCP4 transcription factors and their co‐regulatory genes, chromatin immunoprecipitation sequencing (ChIP‐Seq) was carried out. ChIP‐Seq data produced the maximum enriched peaks in two Japanese apricot cultivars ‘Daqiandi’ (DQD) and ‘Longyan’ (LY), which showed that the majority of DNA‐protein interactions are relevant and have a significant function in binding sites. Moreover, 720 and 251 peak‐associated genes regulated by PmTCP4 were identified in DQD and LY, respectively, and most of them were involved in the flower and pistil development process. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that photosynthesis and oxidative phosphorylation were the most enriched pathways in both cultivars and all identified genes related to these pathways were down‐regulated. This study will provide a reference for a better understanding of the PmTCP4 regulatory mechanism during pistil abortion in Japanese apricot.
Vacuum Challenges for Ion Thruster Testing
Authors: Lausberg Stefan
Published: August 2020

Electrical propulsion is the keyword for nowadays movement of space vehicles. Ionized particles, usually xenon ions, are accelerated by thrusters in an electric field. State‐of‐the‐art xenon thrusters emit a gas flow of 0.1 to 10 mg/sec. In order to maintain a high vacuum pressure at this flow in thruster test chambers, a large pumping speed is required, often in the range of 10'000 to 100'000 l/s for xenon.

The advantage of a large ion mass for the propulsion system is a major challenge for vacuum pumps.

Leybold has developed an optimized and simple cryogenic solution for Xe pumping. Strong single‐stage Gifford‐McMahon type cold heads carry metal discs which condense the Xe gas with a pumping speed at the edge of the theoretical limit. In this work, we will present the whole vacuum system for a thruster testing facility.
Troubled waters: Maori values and ethics for freshwater management and New Zealand's fresh water crisis
Authors: Stewart‐Harawira Makere W.
Published: August 2020

The landmass of Aotearoa New Zealand totals some 268,000 km2, including 425,000 km of rivers, more than 4,000 lakes and approximately 200 aquifers. For Aotearoa New Zealand's indigenous Maori, these freshwater bodies are part of a complex system of genealogical relationships from which derive the traditional Maori knowledge, values and ethics which shape Maori customary practices for freshwater monitoring and freshwater management. The rupture of these relationships through a century and a half of colonization and industrialization and the dispossession of Maori from their lands and waters also dispossessed Maori of their rights and responsibilities to enact traditional customary practices of kaitiakitanga, stewardship of the natural environment. In 2017 Aotearoa New Zealand's freshwater systems were designated as among the worst in the world. Today they are continuing to degrade. This article focuses on Maori traditional knowledge, ethics and values for freshwater monitoring and management. The article reviews the impact of colonization and development on Aotearoa New Zealand's freshwater systems, the extensive struggle by Maori for recognition of Maori traditional knowledge, rights and responsibilities regarding waterways, and the development of contemporary Maori models for freshwater monitoring and management. Treaty settlements and other legislative initiatives have also catalyzed changes in freshwater management. Faced with catastrophic climatic impacts on freshwater systems and implications for the wellbeing of species and communities, questions of how to ethically manage freshwater are critical. Maori freshwater ethics, values and practices provide a model of renewal and possibility, although one that is not without contest.

This article is categorized under:

Human Water > Water as Imagined and Represented

Human Water > Water Governance

Water and Life > Conservation, Management, and Awareness
A review of public water infrastructure financing in the United States
Authors: Greer Robert A.
Published: August 2020

The delivery of clean drinking water and the treatment of wastewater are critical public services, and in the United States, they are provided by a complex system of federal, state, and local governments. The process of water treatment and delivery requires significant investment in infrastructure both for initial capital requirements as well as the on‐going maintenance and operating costs. The quality of drinking water in the United States is, on average, relatively high, but according to the American Water Works Association, an estimated $1 trillion is necessary to maintain and expand service to meet demands over the next 25 years. The water infrastructure needs in the United States require both immediate attention and long‐term solutions, and the dollar cost is climbing rapidly. It remains unclear, however, where these funds will come from and how they will be allocated. The goal of this paper is to review the portfolio of financing options that exist for public entities responsible for the construction and maintenance of water infrastructure in the United States, including the municipal bond market, state revolving loan funds, federal grant and loan programs, public–private partnerships, and recent financing innovations.

This article is categorized under:

Engineering Water > Water, Health, and Sanitation

Human Water > Value of Water

Human Water > Water Governance