bluuebunny/crossref_metadata_2025 huggingface dataset:
The performance analysis of NOMA in LEO satellite rain attenuation and fading hybrid channel
Authors: Ning Qian , Yang Xinjing , Chen Bingcai , Zhou Xinzhi
Published: December 2021

In the fifth‐generation (5G) and future sixth‐generation (6G) networks, improving spectral efficiency and system capacity is still the main concern. Adding LEO satellite to the construction of 5G and 6G can make the network structure three‐dimensional, which lets the network construction get rid of the limitation of ground space propagation distance and makes the wider area enjoy the convenience of 5G and 6G. However, due to the large link distance between space and the ground, the communication of LEO satellite in Ka band is greatly affected by rain attenuation and shadow fading. In order to improve the ergodic capacity of LEO satellite downlink, this paper attempts to apply nonorthogonal multiple access (NOMA) to hybrid channels with rainfall fading and shadow fading. In the simulation results, the ergodic capacity of orthogonal frequency division multiple access (OFDMA) and NOMA is compared, and it is found that the system capacity of hybrid channel can be improved by increasing the power allocation factor of NOMA. The experiments have studied the influence of LEO satellite's orbital height, fading degree, and transmission power in the communication link on the performance of LEO satellite system in this paper. The experimental results show that the lower the orbit height is, the better system performance will become under the same fading degree. Moreover, the energy consumed gradually decreases with the transmission power becoming small.
A detailed view of the Gaussian–Lorentzian sum and product functions and their comparison with the Voigt function
Authors: Major George H. , Fernandez Vincent , Fairley Neal , Linford Matthew R.
Published: December 2021

The Gaussian–Lorentzian sum (GLS) and product (GLP) functions remain important in X‐ray photoelectron spectroscopy (XPS) peak fitting. Here, we present a detailed view of these functions, comparing them with each other and with the Voigt function (the “LA(m)” function). First, we show the GLS, GLP, and LA(m) functions as a function of their mixing parameters, m, which reveals differences between them. We then illustrate the use of these functions to fit a series of spectra acquired at different pass energies (resolutions). Next, we show the underlying Gaussian and Lorentzian components of a series of GLS and GLP functions as a function of m, which confirms that the GLS is a simple linear combination of Gaussian and Lorentzian functions. However, one of the two functions used to make the GLP can be very wide, that is, at its extremes, one of these functions has infinite width. We then discuss a plot of the areas of the GLS, GLP, and LA(m) functions as a function of m, which reveals the expected, linear increase in area of the GLS, but nonlinear changes in the areas of the other two functions. Finally, to better understand them, we fit these functions to each other. These results indicate that the GLS and GLP better match the LA(m) function at lower and higher values of the mixing parameter, respectively.
Recent Advances in the Functionalization of Azulene Through Pd‐Catalyzed Cross‐Coupling Reactions
Authors: Elwahy Ahmed H. M. , Abdelhamid Ismail A. , Shaaban Mohamed R.
Published: December 2021

Azulene derivatives have important physical and physicochemical features, as well as advantageous biological qualities. The metal‐catalyzed processes have proven to be a highly practical method for azulene functionalization. The development in the synthesis of azulene derivatives, including (aryl)heteroaryl‐substituted and hetero‐fused azulene derivatives, through Pd‐catalyzed coupling techniques over the previous two decades is discussed in this research. Alkyl‐, alkenyl‐, and alkynylazulenes synthesized via Pd‐catalyzed cross‐coupling processes are also included.
Theoretical Predictions, Experimental Modulation Strategies, and Applications of MXene‐Supported Atomically Dispersed Metal Sites
Authors: Gu Hongfei , Li Xinyuan , Zhang Jiatao , Chen Wenxing
Published: December 2021

Atomically dispersed metal sites (ADMSs) attract immense attention because they can be used in the fields of energy and environmental protection as they are characterized by high atomic utilization efficiency and exhibit high activity. Various supports for anchoring isolated metal atoms are developed to construct ADMSs characterized by highly stable and well‐defined structures. This can be achieved by increasing the number of anchoring sites and reinforcing metal–support interactions. MXenes, a new series of 2D nanomaterials, exhibit promising potential in stabilizing isolated metal atoms because of their large specific surface areas and unique surface properties. The high conductivity and hydrophilicity of MXenes can be attributed to the nature of surface functionalization and the properties of tunable structures of the materials. Benefiting from these excellent properties, MXenes can find their applications in various fields. Herein, the precise characterization methods that can be followed to study ADMSs, the construction of MXene‐supported ADMSs using theoretical predictions, and experimental modulation strategies are summarized, and their corresponding applications in electrocatalysis, organocatalysis, and advanced battery systems are systematically illustrated. It is hoped that this review will provide insights that can be used for the further development of MXene‐supported ADMSs.
Metallic Copper‐Containing Composite Photocatalysts: Fundamental, Materials Design, and Photoredox Applications
Authors: Zhu Xueteng , Xiong Jinyan , Wang Zhiyuan , Chen Rong , Cheng Gang , Wu Yuen
Published: December 2021

Semiconductor photocatalysis has long been regarded as a potential solution to tackle the energy and environmental challenges since the first discovery of water splitting by TiO2 almost 50 years ago. The past few years have seen a tremendous flurry of research interest in the modification of semiconductors because of their shortcomings in the aspects of solar harvesting, electron‐hole pairs separation, and utilization of photogenerated carriers. Among the various strategies, the introduction of metallic copper into the photocatalysis system can not only enhance the absorption of sunlight and the separation efficiency of photogenerated electrons and holes, but also increase the adsorption ability of substrate and the number of active sites, so as to realize the high solar to chemical energy conversion efficiency. This review focuses on the rational design of copper‐based composites and their applications in photoredox catalysis. First, the preparation methods of metallic copper‐containing composites are discussed. Then, the applications of different types of copper‐based composites in the photocatalytic removal of pollutants, splitting of water to hydrogen production, reduction of carbon dioxide, and conversion of organic matter are introduced. Finally, the opportunities and challenges in the design and synthesis of copper‐based composites and their applications in the photocatalysis are prospected.
1,3,5‐Triphenylbenzene Based Porous Conjugated Polymers for Highly Efficient Photoreduction of Low‐Concentration CO2 in the Gas‐Phase System
Authors: Dai Chunhui , Zhong Lixiang , Wu Wei , Zeng Chao , Deng Yue , Li Shuzhou
Published: December 2021

Herein, three 1,3,5‐triphenylbenzene based porous conjugated polymers (PCPs) are designed for photochemical reduction of CO2 in simulated flue gas in the mild gas−solid reaction system. By tuning the nature of the comonomers, the PCPs present high surface areas, high CO2/N2 selectivity, and broad visible light absorptions with bandgaps of 1.81−2.07 eV. At 1 bar and 273 K, the CO2 uptake capacity of PCPs is enhanced from 1.28 to 2.18 mmol g−1, with an increase in CO2 adsorption heat from 21.8 to 28.3 KJ mol−1. In the presence of gaseous water, SO‐TPB demonstrates the highest CO production rate of 40.12 μmol h−1 g−1 and nearly 100% product selectivity without using organic sacrificial reagent and additional cocatalyst (>420 nm). Moreover, SO‐TPB can be recovered while well retaining the photocatalytic activity and reused at least five runs, indicating good recyclability.
The logic of semiotics applied to mathematical and social interaction in operational research consulting practice: Towards a foundational view
Authors: Ormerod Richard John
Published: December 2021

The paper investigates semiotics as an integrative, foundational framework for operational research (OR). To this end, the semiotics of the pragmatist C.S. Peirce is explained and its application in OR research, and consulting practice is explored. It is the fourth in a series of papers each seeking to ground OR in a different logic: philosophic/mathematical logic, pragmatic logic, economic logic and now semiotic logic. For Peirce, semiotics is a logic, and as such it is argued in the paper that it can embrace philosophical/mathematical, pragmatic and economic logics. The comprehensive nature of semiotics is such that it brings to a close the research programme aimed at establishing foundations for OR. However, the closure of one programme opens up another—the application of semiotics in OR practice and academic research. Possible avenues for further research include learning from, and collaboration with, neighbouring disciplines such as information systems and computer science.
Nanobainite Generated in Low‐ and Medium‐Carbon Steels via an Economical Alloying Strategy
Authors: Akram Mohamad , Palkowski Heinz , Soliman Mohamed
Published: December 2021

A low‐cost strategy for generating fast transforming nanobainitic (nB) steels in low‐ and medium‐carbon alloys is investigated. Accelerating the bainite transformation relies on adding 0.7–3 wt% Al. Alloys and heat treatments are designed via thermodynamic calculations and dilatometry. nB microstructures are generated via isothermal holding and continuous cooling. The microstructures generated are investigated via microscopy and mechanical characterization. Incubation periods less than 150 s as well as isothermal transformation times ranging from 2000 to 4000 s are recorded for all conditions. Increasing the Al content from 0.7 to 2.8 wt% lowers the incubation and transformation times from 150 to 15 s and 3000 to 2000 s, respectively, at a cost of a reduction in tensile strength and elongation % (EL%) from 1330 to 1270 MPa and from 13.5 to 7.7%, respectively. The introduction of δ‐ferrite to the microstructure of the high Al alloy increased EL% up to 16% and reduced the tensile strength to 1105 MPa. Continuous cooling at a rate of 0.03 K s−1 increased the tensile strength by 100 MPa at similar EL%. Lowering the cooling rate to 0.003 K s−1 yielded similar properties as isothermal treatment because most of the transformation is concluded near the starting temperature.
Effects of the higher concentrate ratio on the production performance, ruminal fermentation, and morphological structure in male cattle‐yaks
Authors: Jiang Yahui , Dai Peng , Dai Qindan , Ma Jian , Wang Zhisheng , Hu Rui , Zou Huawei , Peng Quanhui , Wang Lizhi , Xue Bai
Published: December 2021

Background

The present study evaluated the effects of the different concentrate‐to‐forage ratio on the parameters of production, ruminal fermentation, blood biochemical indices, and ruminal epithelial morphological structure of the male cattle‐yaks.

Methods

Eight male cattle‐yaks (280 ± 10 kg of body weight) were randomly divided into the high concentrate (HighC, 70% concentrate feeds on a dry matter basis) and low concentrate (LowC, 50% concentrate feeds on a dry matter basis) groups. All the animals were regularly provided rations twice a day at 08:00 and 16:00 h and had free access to water. The experiment lasted for 37 days.

Results

The dry matter intake and average daily gain of the HighC group were higher (p < 0.05) than those of LowC group. Moreover, a high concentrate diet was found to significantly increase (p < 0.05) the total volatile fatty acid (TVFA) production, and the ratio of propionate and butyrate in TVFA. On the contrary, the ruminal pH, the ratio of isobutyrate and isovalerate, and the acetate‐to‐propionate were significantly decreased (p < 0.05) after high concentrate feeding. The lipopolysaccharide concentrations of the ruminal fluid and plasma in the HighC group were higher (p < 0.05) than those of the LowC group. The results of the ruminal histomorphology showed the rumen to possess an inflammatory reaction.

Conclusion

These findings revealed that upon higher dry matter intake and average daily gain, high concentrate feeding altered the rumen fermentation and morphology, inducing the ruminal inflammation of the cattle‐yak.
Application of local anaesthesia and cryosurgery for eyelid masses in dogs
Authors: Han Myung‐Gyun , Kim Joon‐Young
Published: December 2021

Background

Eyelid mass removal and cryotherapy application using only local anaesthesia and restraint may benefit patients with high anaesthesia risks.

Objective

To evaluate and validate cryosurgery application using the CryoPen XL® on palpebral masses under local anaesthesia for patients not suitable for general anaesthesia.

Methods

Thirty patients underwent the procedure between November 2015 and April 2020. The procedure steps were as follows: skin preparation and local anaesthesia of the affected eyelid; debulking by resection and/or squeezing out the inspissated material; cryosurgery and post‐operative care using topical medication, antibiotics and anti‐inflammatory ointment. The medical records of the patients who underwent the operation were evaluated. Moreover, a telephonic survey with the pet owners was performed to determine recurrence, time to recurrence, survivability and side effects.

Results

Among the 30 owners, 29 responded to the survey. Ten (10/38, 26.3%) masses recurred with an average time to recurrence of 6.0 months. The estimated average depths for all, non‐recurred, and recurred masses were 1.89, 1.88 and 1.90 mm, respectively. The average recurrence rate and time to recurrence were higher and earlier, respectively, than previously reported values. However, no patient presented intra‐ or post‐operative complications.

Conclusion

These findings suggest that local anaesthesia and cryosurgery using the CryoPen XL® can be used in patients with eyelid masses who are not suitable for general anaesthesia. Compared with the surgical eyelid mass removal and blepharoplasty procedure, the reported procedure is time‐ and cost‐effective, with the additional benefit of not requiring general anaesthesia.
Haematogenous synovial sepsis of the digital flexor tendon sheath following contralateral limb foot abscessation in a horse
Authors: Byrne Christian A. , Tannahill Victoria J. , Voute Lance C.
Published: December 2021

A 5‐year‐old Shire mare was presented for investigation of severe right hindlimb lameness and was diagnosed with extensive right hind subsolar and submural foot abscessation. The mare developed severe contralateral limb lameness 11 days following right hind abscess debridement, with investigation revealing synovial sepsis of the left hind digital flexor tendon sheath. Synovial sepsis persisted despite aggressive surgical and medical treatment, resulting in euthanasia. Microbial culture of synovial fluid isolated Bacteroides sp., consistent with haematogenous synovial sepsis. This is the first report to describe haematogenous synovial sepsis as a cause of contralateral limb lameness during the management of foot abscessation in the horse.
Can One Hear a Matrix? Recovering a Real Symmetric Matrix from Its Spectral Data
Authors: Macia̧żek Tomasz , Smilansky Uzy
Published: December 2021

The spectrum of a real and symmetric$$N\times N$$N×Nmatrix determines the matrix up to unitary equivalence. More spectral data is needed together with some sign indicators to remove the unitary ambiguities. In the first part of this work, we specify the spectral and sign information required for a unique reconstruction of general matrices. More specifically, the spectral information consists of the spectra of theNnested main minors of the original matrix of the sizes$$1,2,\ldots ,N$$1,2,…,N. However, due to the complicated nature of the required sign data, improvements are needed in order to make the reconstruction procedure feasible. With this in mind, the second part is restricted to banded matrices where the amount of spectral data exceeds the number of the unknown matrix entries. It is shown that one can take advantage of this redundancy to guarantee unique reconstruction ofgenericmatrices; in other words, this subset of matrices is open, dense and of full measure in the set of real, symmetric and banded matrices. It is shown that one can optimize the ratio between redundancy and genericity by using the freedom of choice of the spectral information input. We demonstrate our constructions in detail for pentadiagonal matrices.
Magnetic Resonance Imaging Characteristics of Molecular Subgroups in Pediatric H3 K27M Mutant Diffuse Midline Glioma
Authors: Hohm Annika , Karremann Michael , Gielen Gerrit H. , Pietsch Torsten , Warmuth-Metz Monika , Vandergrift Lindsey A. , Bison Brigitte , Stock Annika , Hoffmann Marion , Pham Mirko , Kramm Christof M. , Nowak Johannes
Published: December 2021

Purpose

Recent research identified histone H3 K27M mutations to be associated with a dismal prognosis in pediatric diffuse midline glioma (pDMG); however, data on detailed MRI characteristics with respect to H3 K27 mutation status and molecular subgroups (H3.1 and H3.3 K27M mutations) are limited.

Methods

Standardized magnetic resonance imaging (MRI) parameters and epidemiologic data of 68 pDMG patients (age <18 years) were retrospectively reviewed and compared in a) H3 K27M mutant versus H3 K27 wildtype (WT) tumors and b) H3.1 versus H3.3 K27M mutant tumors.

Results

Intracranial gliomas (n = 58) showed heterogeneous phenotypes with isointense to hyperintense signal in T2-weighted images and frequent contrast enhancement. Hemorrhage and necrosis may be present. Comparing H3 K27M mutant to WT tumors, there were significant differences in the following parameters: i) tumor localization (p = 0.001), ii) T2 signal intensity (p = 0.021), and iii) T1 signal homogeneity (p = 0.02). No significant imaging differences were found in any parameter between H3.1 and H3.3 K27M mutant tumors; however, H3.1 mutant tumors occurred at a younger age (p = 0.004). Considering spinal gliomas (n = 10) there were no significant imaging differences between the analyzed molecular groups.

Conclusion

With this study, we are the first to provide detailed MR imaging data on H3 K27M mutant pDMG with respect to molecular subgroup status in a large patient cohort. Our findings may support diagnosis and future targeted therapeutic trials of pDMG within the framework of the radiogenomics concept.
Some explicit solutions of the three-dimensional Euler equations with a free surface
Authors: Martin Calin I.
Published: December 2021

We present a family of radial solutions (given in Eulerian coordinates) to the three-dimensional Euler equations in a fluid domain with a free surface and having finite depth. The solutions that we find exhibit vertical structure and a non-constant vorticity vector. Moreover, the flows described by these solutions display a density that depends on the depth. While the velocity field and the pressure function corresponding to these solutions are given explicitly through (relatively) simple formulas, the free surface defining function is specified (in general) implicitly by a functional equation which is analysed by functional analytic methods. The elaborate nature of the latter functional equation becomes simpler when the density function has a particular form leading to an explicit formula of the free surface. We subject these solutions to a stability analysis by means of a Wentzel–Kramers–Brillouin (WKB) ansatz.
Closure relations of Newton strata in Iwahori double cosets
Authors: Trentin Stefania , Viehmann Eva
Published: December 2021

We consider the Newton stratification on Iwahori double cosets for a connected reductive group. We prove the existence of Newton strata whose closures cannot be expressed as a union of strata, and show how this is implied by the existence of non-equidimensional affine Deligne–Lusztig varieties. We also give an explicit example for a group of type $$A_4$$

A
4

.
Passive-Sampler-Based Bioavailability Assessment of PCB Congeners Associated with Aroclor-Containing Paint Chips in the Presence of Sediment
Authors: Lotufo Guilherme R. , Gidley Philip T. , McQueen Andrew D. , Moore David W. , Edwards Deborah A. , Hardenstine Jeffery , Uhler Allen D.
Published: December 2021

This is the first investigation of the bioavailability of PCBs associated with paint chips (PC) dispersed in sediment. Bioavailability of PCB-containing PC in sediment was measured using ex situ polyethylene passive samplers (PS) and compared to that of PCBs from field-collected sediments. PC were mixed in freshwater sediment from a relatively uncontaminated site with no known PCB contamination sources and from a contaminated site with non-paint PCB sources. PC < 0.045 mm generated concentrations in the PS over one order of magnitude higher than coarser chips. The bioavailable fraction was represented by the polymer-sediment accumulation factor (PSAF), defined as the ratio of the PCB concentrations in the PS and organic carbon normalized sediment. The PSAF was similar for both field sediments. The PSAFs for the field sediments were ~ 50–60 and ~ 5 times higher than for the relatively uncontaminated sediment amended with PC for the size fractions 0.25–0.3 mm and < 0.045 mm, respectively. These results indicate much lower bioavailability for PCBs associated with PC compared to PCBs associated with field-collected sediment. Such information is essential for risk assessment and remediation decision-making for sites where contamination from non-paint PCBs sources is co-located with PCB PC.
DTYMK is essential for genome integrity and neuronal survival
Authors: Vanoevelen Jo M. , Bierau Jörgen , Grashorn Janine C. , Lambrichs Ellen , Kamsteeg Erik-Jan , Bok Levinus A. , Wevers Ron A. , van der Knaap Marjo S. , Bugiani Marianna , Frisk Junmei Hu , Colnaghi Rita , O’Driscoll Mark , Hellebrekers Debby M. E. I. , Rodenburg Richard , Ferreira Carlos R. , Brunner Han G. , van den Wijngaard Arthur , Abdel-Salam Ghada M. H. , Wang Liya , Stumpel Constance T. R. M.
Published: December 2021

Nucleotide metabolism is a complex pathway regulating crucial cellular processes such as nucleic acid synthesis, DNA repair and proliferation. This study shows that impairment of the biosynthesis of one of the building blocks of DNA, dTTP, causes a severe, early-onset neurodegenerative disease. Here, we describe two unrelated children with bi-allelic variants in DTYMK, encoding dTMPK, which catalyzes the penultimate step in dTTP biosynthesis. The affected children show severe microcephaly and growth retardation with minimal neurodevelopment. Brain imaging revealed severe cerebral atrophy and disappearance of the basal ganglia. In cells of affected individuals, dTMPK enzyme activity was minimal, along with impaired DNA replication. In addition, we generated dtymk mutant zebrafish that replicate this phenotype of microcephaly, neuronal cell death and early lethality. An increase of ribonucleotide incorporation in the genome as well as impaired responses to DNA damage were observed in dtymk mutant zebrafish, providing novel pathophysiological insights. It is highly remarkable that this deficiency is viable as an essential component for DNA cannot be generated, since the metabolic pathway for dTTP synthesis is completely blocked. In summary, by combining genetic and biochemical approaches in multiple models we identified loss-of-function of DTYMK as the cause of a severe postnatal neurodegenerative disease and highlight the essential nature of dTTP synthesis in the maintenance of genome stability and neuronal survival.
The retrocalcarine sulcus maps different retinotopic representations in macaques and humans
Authors: Arcaro Michael J. , Livingstone Margaret S. , Kay Kendrick N. , Weiner Kevin S.
Published: December 2021

Primate cerebral cortex is highly convoluted with much of the cortical surface buried in sulcal folds. The origins of cortical folding and its functional relevance have been a major focus of systems and cognitive neuroscience, especially when considering stereotyped patterns of cortical folding that are shared across individuals within a primate species and across multiple species. However, foundational questions regarding organizing principles shared across species remain unanswered. Taking a cross-species comparative approach with a careful consideration of historical observations, we investigate cortical folding relative to primary visual cortex (area V1). We identify two macroanatomical structures—the retrocalcarine and external calcarine sulci—in 24 humans and 6 macaque monkeys. We show that within species, these sulci are identifiable in all individuals, fall on a similar part of the V1 retinotopic map, and thus, serve as anatomical landmarks predictive of functional organization. Yet, across species, the underlying eccentricity representations corresponding to these macroanatomical structures differ strikingly across humans and macaques. Thus, the correspondence between retinotopic representation and cortical folding for an evolutionarily old structure like V1 is species-specific and suggests potential differences in developmental and experiential constraints across primates.
S-DFP: shifted dynamic fixed point for quantized deep neural network training
Authors: Sakai Yasufumi , Tamiya Yutaka
Published: December 2021

Recent advances in deep neural networks have achieved higher accuracy with more complex models. Nevertheless, they require much longer training time. To reduce the training time, training methods using quantized weight, activation, and gradient have been proposed. Neural network calculation by integer format improves the energy efficiency of hardware for deep learning models. Therefore, training methods for deep neural networks with fixed point format have been proposed. However, the narrow data representation range of the fixed point format degrades neural network accuracy. In this work, we propose a new fixed point format named shifted dynamic fixed point (S-DFP) to prevent accuracy degradation in quantized neural networks training. S-DFP can change the data representation range of dynamic fixed point format by adding bias to the exponent. We evaluated the effectiveness of S-DFP for quantized neural network training on the ImageNet task using ResNet-34, ResNet-50, ResNet-101 and ResNet-152. For example, the accuracy of quantized ResNet-152 is improved from 76.6% with conventional 8-bit DFP to 77.6% with 8-bit S-DFP.
Board committees and non-financial information assurance services
Authors: García-Sánchez Isabel-María , Raimo Nicola , Amor-Esteban Víctor , Vitolla Filippo
Published: December 2021

The objective of this study is to examine the role that the specialized committees, created within the board of directors, and the auditor play in relation to the hiring of a non-financial information assurance service and in relation to the choices of the assurance provider for such non-financial information. Specifically, this study analyses the effect of the independence and specialisation of the audit committee, the existence of a CSR committee, and the reputation of the financial auditor associated with its classification as Big4. The results indicate that those responsible for financial information do not show interest in contracting an assurance service, especially if it is realized by an accountant provider, except that the information is standardised according to the Global Reporting Initiative guidelines and the contracted service is comparable to the financial audit standards, has assurance for a reasonable/high level, and is carried out according to the ISAE3000 standard.
An Analysis of Spikes in Atmospheric Imaging Assembly (AIA) Data
Authors: Young Peter R. , Viall Nicholeen M. , Kirk Michael S. , Mason Emily I. , Chitta Lakshmi Pradeep
Published: December 2021

The Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) returns high-resolution images of the solar atmosphere in seven extreme ultraviolet (EUV) wavelength channels. The images are processed on the ground to remove intensity spikes arising from energetic particles hitting the instrument, and the despiked images are provided to the community. In this article, a three-hour series of images from the 171 Å channel obtained on 28 February 2017 was studied to investigate how often the despiking algorithm gave false positives caused by compact brightenings in the solar atmosphere. The latter were identified through spikes appearing in the same detector pixel for three consecutive frames. 1096 examples were found from the 900 image frames. These “three-spikes” were assigned to 126 dynamic solar features, and it is estimated that the three-spike method identifies 19% of the total number of features affected by despiking. For any ten-minute sequence of AIA 171 Å images there are around 37 solar features that have their intensity modified by despiking. The features are found in active regions, quiet Sun, and coronal holes and, in relation to solar surface area, there is a greater proportion within coronal holes. In 96% of the cases, the despiked structure is a compact brightening with a size of two arcsec or less, and the remaining 4% have narrow, elongated structures. By applying an EUV burst detection algorithm, we found that 96% of the events could be classified as EUV bursts. None of the spike events are rendered invisible by the AIA processing pipeline, but the total intensity over an event’s lifetime can be reduced by up to 67%. Users are recommended to always restore the original intensities in AIA data when studying short-lived or rapidly evolving features that exhibit fine-scale structure.
Systems epidemiology of metabolomics measures reveals new relationships between lipoproteins and other small molecules
Authors: Drenos Fotios
Published: December 2021

Introduction

The study of lipoprotein metabolism at the population level can provide valuable information for the organisation of lipoprotein related processes in the body. To use this information towards interventional hypotheses generation and testing, we need to be able to identify the mechanistic connections among the large number of observed correlations between the measured components of the system.

Objectives

To use population level metabolomics information to gain insight on their biochemical networks and metabolism.

Methods

Genetic and metabolomics information for 230 metabolic measures, predominately lipoprotein related, from a targeted nuclear magnetic resonance approach, in two samples of an established European cohort, totalling more than 9400 individuals analysed using phenotypic and genetic correlations, as well as Mendelian Randomisation.

Results

More than 20,500 phenotypic correlations were identified in the data, with almost 2000 also showing evidence of strong genetic correlation. Mendelian randomisation, provided evidence for a causal effect between 9496 pairs of metabolic measures, mainly between lipoprotein traits. The results provide insights on the organisation of lipoproteins in three distinct classes, the heterogeneity between HDL particles, and the association, or lack of, between CLA, glycolysis markers, such as glucose and citrate, and glycoproteins with lipids subfractions. Two examples for the use of the approach in systems biology of lipoproteins are presented.

Conclusions

Genetic variation can be used to infer the underlying mechanisms for the associations between lipoproteins for hypothesis generation and confirmation, and, together with biological information, to map complex biological processes.
Thermal convection with generalized friction
Authors: Straughan Brian
Published: December 2021

A model for thermal convection with generalized friction is investigated. It is shown that the linear instability threshold is the same as the global stability one. In addition, decay of the energy in the$$L^2$$L2norm is shown for the perturbation velocity and temperature fields. However, due to the presence of the generalized friction we establish exponential decay in the$$L^{\beta +1}$$Lβ+1norm for the perturbation temperature, where$$\beta >1$$β>1.
A new method to specify the mitigated acoustic test conditions from flight telemetry based on the equivalence of vibro-acoustic response
Authors: Shimazaki Shingo , Shi Qinzhong
Published: December 2021

Ground acoustic tests using stationary sound pressure level spectrum have been conducted to verify the spacecraft survivability against acoustic environment acting on a spacecraft during launch, which is a non-stationary and random dynamic load. In general, a stationary spectrum used in ground acoustic test is traditionally determined by a method called maximax spectrum, which is the enveloped spectrum of time varying non-stationary short-time Fourier transform. However, the maximax spectrum is more or less an excessively conservative test condition because this spectrum focuses on processing of a time-varying acoustic signal itself to extract maximum value, rather than on how the vibro-acoustic response of an excited structure is. In this paper, a new method is proposed to specify a stationary spectrum equivalent to a structural vibro-acoustic response under a non-stationary and random acoustic environment based on extreme response spectrum and fatigue damage spectrum. This proposed method was applied to flight telemetry of both liquid- and solid-propellant launch vehicles developed by JAXA, to show its effect to mitigate the acoustic test conditions compared to the maximax spectrum while maintaining the equivalence of the structural vibro-acoustic response. Furthermore, the maximum predicted environment, which is the statistical upper percentiles of the flight telemetry of eight liquid-propellant launch vehicles, by the proposed method achieved a mitigation of about 2.5 and 6.8 dB in the extreme stress and cumulative fatigue, respectively, compared to the that which is calculated by the conventional maximax spectrum.
Impacts of climate warming on reindeer herding require new land-use strategies
Authors: Rosqvist Gunhild C. , Inga Niila , Eriksson Pia
Published: December 2021

Climate in the Arctic has warmed at a more rapid pace than the global average over the past few decades leading to weather, snow, and ice situations previously unencountered. Reindeer herding is one of the primary livelihoods for Indigenous peoples throughout the Arctic. To understand how the new climate state forces societal adaptation, including new management strategies and needs for preserved, interconnected, undisturbed grazing areas, we coupled changes in temperature, precipitation, and snow depth recorded by automatic weather stations to herder observations of reindeer behaviour in grazing areas of the Laevas Sámi reindeer herding community, northern Sweden. Results show that weather and snow conditions strongly determine grazing opportunities and therefore reindeer response. We conclude that together with the cumulative effects of increased pressures from alternative land use activities, the non-predictable environmental conditions that are uniquely part of the warming climate seriously challenge future reindeer herding in northern Sweden.
Sociality, resilience and agency: how did young Australians experience online learning during Covid-19?
Authors: Naidoo Loshini , D’warte Jacqueline , Gannon Susanne , Jacobs Rachael
Published: December 2021

In 2020 when schooling was abruptly reconfigured by the pandemic, young people were required to demonstrate new capabilities to manage their learning and their wellbeing. This paper reports on the feelings, thoughts and experiences of eight Year 9 and 10 students in NSW and Victoria about the initial period of online learning in Australian schools that resulted from the Covid-19 pandemic. Beyond dominant narratives of vulnerability and losses in learning, our participants offered counternarratives that stressed their capacities to rise and meet the times. We trace three central themes on how they: found moments of agency that increased their confidence, reconfigured resilience as a socially responsible set of practices, deployed sociality as a resource for the benefit of themselves and others. The pandemic opened up conversations with young people about where and how learning takes place and how schools might adapt and respond to young people’s growing sense of urgency about the future of schooling.
Multivariable connected sums and multiple polylogarithms
Authors: Kawamura Hanamichi , Maesaka Takumi , Seki Shin-ichiro
Published: December 2021

We introduce the multivariable connected sum which is a generalization of Seki–Yamamoto’s connected sum and prove the fundamental identity for these sums by series manipulation. This identity yields explicit procedures for evaluating multivariable connected sums and for giving relations among special values of multiple polylogarithms. In particular, our class of relations contains Ohno’s relations for multiple polylogarithms.
Deterministic Dual Control of Phase Competition in Strained BiFeO3: A Multiparametric Structural Lithography Approach
Authors: Black Nathan , Edwards David , Browne Niall , Guy Joseph G. M. , Sharma Niyorjyoti , Holsgrove Kristina M. , Naden Aaron B. , McQuaid Raymond G. P. , Rodriguez Brian J. , Kumar Amit
Published: December 2021

The realization of a mixed-phase microstructure in strained BiFeO3 (BFO) thin films has led to numerous novel effects derived from the coexistence of the tetragonal-like monoclinic phase (T phase) and rhombohedral-like monoclinic phase (R phase). Strong strain and polarization differences between the phases should result in a high level of transformation plasticity, which enables the continuous alteration of the relative proportion of R and T states in response to external forces. Although the potential for utilizing such plasticity to control mixed-phase populations under external stimuli is evident, direct experimental evidence backed by equilibrium predictions has not yet been fully demonstrated. Here we demonstrate deterministic control of mixed-phase populations in an epitaxially strained BFO thin film through the application of localized stresses and electric fields in a reversible manner. The results illustrate and rationalize deterministic control of mixed phases in strained BFO films, which could be crucial in tuning their functional properties. The findings also highlight a new multiparametric technique in the scanning probe lithography toolbox based on tip-assisted electric and strain field manipulation of functional properties that might find application beyond the ferroelectric domain and structural phase lithography.
Wie können Abrufübungen (nicht) für das Lernen in Schule und Hochschule relevant gemacht werden?
Authors: Roelle Julian , Endres Tino , Renkl Alexander
Published: December 2021

Es gibt eine beeindruckende Menge an Evidenz dafür, dass Abrufübungen das langfristige Behalten von Wissen bedeutend fördern können (oftmals als Testungs- oder Abrufübungseffekt bezeichnet). Es gibt allerdings auch Arbeiten, die zu kritischeren Schlüssen in Bezug auf den Nutzen von Abrufübungen kommen – insbesondere, was den Nutzen in Kontexten anbetrifft, in denen ein tiefes Verständnis komplexer Lerninhalte erworben werden soll. In diesem Beitrag werden die verschiedenen Sichtweisen auf den Nutzen von Abrufübungen mit einer zweifachen Zielsetzung reflektiert. Zum einen werden drei zentrale zu klärende Fragenkomplexe herausgearbeitet, deren Beantwortung von großer Relevanz für die breite Anwendung von Abrufübungen im Rahmen schulischen und hochschulischen Lernens wäre und es wird herausgestellt, inwiefern die Beiträge dieses Themenhefts zur Beantwortung dieser Fragenkomplexe beitragen. Zum anderen werden, ebenfalls informiert von den vier Beiträgen dieses Themenhefts, fünf Empfehlungen für Lehrkräfte formuliert, um bei der Gestaltung von Lehrveranstaltungen vom Erkenntnisstand zu Effekten von Abrufübungen profitieren zu können.
Putin, der Cliotherapeut. Überdosis an Geschichte und politisierte Erinnerungskonflikte in Osteuropa
Authors: Gestwa Klaus
Published: December 2021

Der Beitrag trägt verschiedene geschichtspolitische Interventionen in Osteuropa zusammen und diskutiert vor allem am Beispiel der Geschichtspolitik des russischen Präsidenten Putin Versuche, durch historische Umdeutungen politische Ziele zu legitimieren und von gesellschaftlichen Krisen abzulenken. Zunächst werden die zivilgesellschaftlichen Ursprünge sowie Kommerzialisierung und Institutionalisierung des geschichtlichen Interesses in den post-sowjetischen Ländern skizziert. Anschließend analysiert der Beitrag am Beispiel des russisch-estnischen Denkmalstreits sowie einer Auseinandersetzung über die Interpretation des Zweiten Weltkriegs die Bedeutung von Geschichtspolitik als Mittel von Spaltung oder Versöhnung. Die geschichtspolitische Landschaft in Osteuropa wird als umkämpftes „Schlachtfeld der Erinnerungen“ charakterisiert.
Middle and Late Byzantine sigillographic evidence from western Anatolia: eighth- to early twelfth-century lead seals from Bergama (ancient Pergamon)
Authors: Laflı Ergün , Seibt Werner , Çağlayan Doğukan
Published: December 2021

This article presents 19 lead seals from the Museum of Bergama (ancient Pergamon), dating from the early eighth to the early twelfth century. We offer a descriptive catalogue of these Middle and Late Byzantine seals preserved in a western Turkish museum. The owners of these seals were primarily ecclesiastical, legal or military dignitaries who were probably active in Pergamon, in southwestern Mysia, Aeolis or Lydia. The catalogue is followed by an appendix on a Byzantine magical amulet.
The immunology and immunotherapy for COVID-19
Authors: Liu Yixin , Zhou Xinsheng , Liu Xuan , Jiang Xiaotao
Published: December 2021

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and significantly impacts the world economy and daily life. Symptoms of COVID-19 range from asymptomatic to fever, dyspnoea, acute respiratory distress and multiple organ failure. Critical cases often occur in the elderly and patients with pre-existing conditions. By binding to the angiotensin-converting enzyme 2 receptor, SARS-CoV-2 can enter and replicate in the host cell, exerting a cytotoxic effect and causing local and systemic inflammation. Currently, there is no specific treatment for COVID-19, and immunotherapy has consistently attracted attention because of its essential role in boosting host immunity to the virus and reducing overwhelming inflammation. In this review, we summarise the immunopathogenic features of COVID-19 and highlight recent advances in immunotherapy to illuminate ideas for the development of new potential therapies.
Sustained reductions in unnecessary antimicrobial administration and hospital Clostridioides difficile rates via stewardship in a nonacademic setting
Authors: Gaffin Neil , Spellberg Brad
Published: December 2021

A large community hospital sought to reduce its burden of hospital-acquired Clostridioides difficile infection (CDI). We implemented an antimicrobial stewardship program (ASP), resulting in marked reductions in unnecessary antimicrobial use, CDI rates, antimicrobial acquisition costs, with preservation of gram-negative susceptibilities. ASP programs are effective in a community setting.
Optimisation of the geometry of axisymmetric point-absorber wave energy converters
Authors: Edwards Emma C. , Yue Dick K.-P.
Published: December 2021

We propose a scientifically rigorous framework to find realistic optimal geometries of wave energy converters (WECs). For specificity, we assume WECs to be axisymmetric point absorbers in a monochromatic unidirectional incident wave, all within the context of linearised potential theory. We consider separately the problem of a WEC moving and extracting wave energy in heave only and then the more general case of motion and extraction in combined heave, surge and pitch. We describe the axisymmetric geometries using polynomial basis functions, allowing for discontinuities in slope. Our framework involves ensuring maximum power, specifying practical motion constraints and then minimising surface area (as a proxy for cost). The framework is robust and well-posed, and the optimisation produces feasible WEC geometries. Using the proposed framework, we develop a systematic computational and theoretical approach, and we obtain results and insights for the optimal WEC geometries. The optimisation process is sped up significantly by a new theoretical result to obtain roots of the heave resonance equation. For both the heave-only, and the heave-surge-pitch combined problems, we find that geometries which protrude outward below the waterline are generally optimal. These optimal geometries have up to 73 % less surface area and 90 % less volume than the optimal cylinders which extract the same power.
Commodity Shocks and Incumbency Effects
Authors: Novaes Lucas M. , Schiumerini Luis
Published: December 2021

Why do incumbents enjoy an electoral advantage in some political settings but suffer from a disadvantage in others? We propose a novel explanation linking variation in incumbency effects with exogenous commodity shocks. While voters attempt to sanction incumbents for economic performance, changes in commodity prices affect their evaluations and condition the electoral fortunes of incumbents vis-à-vis challengers. We test our argument in Brazilian municipalities, combining a plausibly exogenous measure of variation in commodity prices with a close election regression discontinuity design. Our results show that increases in the price of agricultural commodities greatly enhance the prospects of incumbents, while negative shocks exacerbate their incumbency disadvantage, especially in rural municipalities. Further investigation suggests that commodity shocks do not operate via voter learning about candidate quality, changes in the pool of candidates, shifts in voter preferences, or strategic elite investments. Instead, we find suggestive evidence that commodity shocks affect voters' evaluations through their effect on local economic growth.
Phantom Pains: The Effect of Police Killings of Black Americans on Black British Attitudes
Authors: Laniyonu Ayobami
Published: December 2021

What effect does black politics in the United States have on the attitudes of black citizens in other national contexts? Literature on the black diaspora and transnationalism has characterized cultural and political linkages between black communities in North America, the Caribbean, and Europe, especially during the mid-20th century. In this article, I exploit random timing in the administration of a public attitudes survey to demonstrate that such linkages persist and that the police killing of Eric Garner in 2014 negatively affected black Londoners’ attitudes toward the Metropolitan Police. Notably, I find the effect was largely concentrated among black Londoners: estimates of an effect on white and South Asian Londoners were small and largely insignificant. The evidence presented here demonstrates that racial violence in the United States can affect racial politics in other national contexts and helps frame the emergence of Black Lives Matter chapters and protests beyond the United States.