bluuebunny/crossref_metadata_2025_split huggingface dataset:
Consensus problem for continuous‐time multiagent systems with nonconvex control input and velocity constraints
Authors: Duan Mengmeng , Lin Peng , Yang Chunhua 
Published: July 2020

SummaryIn this work, a consensus problem with nonconvex control input and velocity constraints is studied for continuous‐time multiagent systems. In order to solve this problem, a fully distributed nonlinear algorithm is provided and an analysis approach is proposed based on the contraction property of an equivalent time‐varying system after a model transformation. It is shown that consensus can be achieved under the condition that there exists a directed spanning tree in the union of the communication graphs in each certain time interval. A numerical simulation is provided to show the obtained result.
Two‐layer distributed formation‐containment control strategy for linear swarm systems: Algorithm and experiments
Authors: Hu Junyan , Bhowmick Parijat , Lanzon Alexander 
Published: July 2020

SummaryThis article addresses the problem of designing a two‐layer distributed formation‐containment control scheme for linear time‐invariant swarm systems with directed communication topology, where the states of the leaders attain a prespecified time‐varying/stationary formation and the states of the followers converge into the convex hull spanned by the states of the leaders. To achieve formation‐containment, a set of distributed control protocols is developed utilizing the neighboring state information, which enables the proposed scheme operate without using global information about the entire interaction topology. The conditions to achieve formation‐containment are suggested and a theoretical proof of the proposed scheme is also derived exploiting the Lyapunov stability approach. An algorithm is written to provide systematic guidelines on how to implement the control protocols in practice. It is argued that the consensus problem, formation tracking problem, and containment control problem can all be viewed as special cases of formation‐containment. A simulation case study has been presented to demonstrate the usefulness and effectiveness of the proposed scheme and moreover, lab‐based hardware experiments involving networked mobile robots were performed to test the feasibility of the scheme in real‐time implementation.
Methanation Performance of Unsupported MoP Catalysts Prepared with Phytic Acid under Low H2/CO
Authors: Wang Baowei , Wang Yu , Zhao Jun , Li Zhenhua , Xu Yan , Ma Xinbin 
Published: July 2020

AbstractIn this paper, using phytic acid as the precursor, the effects of the reduction temperature and post‐treatment conditions on the methanation performance of unsupported MoP catalysts were investigated. The synthesis mechanism and structure‐activity relationship of the catalyst were investigated by correlation characterization, such as N2 adsorption‐desorption, XRD, Raman analysis, element analysis and XPS. At the reduction temperature of 650 °C, MoP catalysts showed the higher methanation activity due to its smaller crystallite size and large specific surface area. After H2 post‐treatment at 750 °C, the CO conversion increased by 16.2% because of the higher specific surface area and lower contents of the carbon and phosphorus species in MoP‐750‐H. The MoP‐750‐H catalysts show good stability without H2S. The sulfur‐resistant methanation tests indicated that the inactivation of the catalysts was more serious with the higher H2S concentration, due to the sulfidation from MoP to MoS2.
Student Movements and Autocracies in Africa
Authors: Rukato Wadeisor 
Published: July 2020

AbstractThis chapter offers a historical mapping of student movements and youth-led protests against autocracies in African countries. It focuses on student movements in Senegal, Tanzania and Sudan from the period before independence to the present day to consider the intersections of youth-hood, power, higher education institutions and the state in each of these cases. It highlight the various continuities and disjunctures in the ways that university student movements have challenged autocracy to consider how “successful” student protests can be in shifting political bases of power.
Achronal averaged null energy condition for extremal horizons and (A)dS
Authors: Rosso Felipe 
Published: July 2020

Abstract
We prove the achronal averaged null energy condition for general quantum field theories in the near horizon geometry of spherical extremal black holes (i.e. AdS2× Sd−2), de Sitter and anti-de Sitter. The derivation follows from monotonicity of relative entropy after computing the modular hamiltonian of a null deformed region. For incomplete (but maximally extended) achronal null geodesics in AdS2× Sd−2, we prove the positivity of a different light-ray operator for arbitrary CFTs. This agrees with a constraint recently derived for the Lorentzian cylinder.
Twisted form hierarchies, Killing-Yano equations and supersymmetric backgrounds
Authors: Papadopoulos G. 
Published: July 2020

Abstract
We show that the Killing spinor equations of all supergravity theories which may include higher order corrections on a (r,s)-signature spacetime are associated with twisted covariant form hierarchies. These hierarchies are characterized by a connection on the space of forms which may not be degree preserving. As a consequence we demonstrate that the form Killing spinor bi-linears of all supersymmetric backgrounds satisfy a suitable generalization of conformal Killing-Yano equation with respect to this connection. To illustrate the general proof the twisted covariant form hierarchies of some supergravity theories in 4, 5, 6, 10 and 11 dimensions are also presented.
Hybrid TRUS/CT with optical tracking for target delineation in image-guided adaptive brachytherapy for cervical cancer
Authors: Smet Stéphanie , Nesvacil Nicole , Knoth Johannes , Sturdza Alina , Najjari-Jamal Dina , Jelinek Filip , Kronreif Gernot , Pötter Richard , Widder Joachim , Kirisits Christian , Schmid Maximilian P. 
Published: July 2020

Abstract
Objective
To prospectively compare the interobserver variability of combined transrectal ultrasound (TRUS)/computed tomography (CT)- vs. CT only- vs. magnetic resonance imaging (MRI) only-based contouring of the high-risk clinical target volume (CTVHR) in image-guided adaptive brachytherapy (IGABT) for locally advanced cervical cancer (LACC).

Methods
Five patients with LACC (FIGO stages IIb–IVa) treated with radiochemotherapy and IGABT were included. CT, TRUS, and T2-weighted MRI images were performed after brachytherapy applicator insertion. 3D-TRUS image acquisition was performed with a customized ultrasound stepper device and software. Automatic applicator reconstruction using optical tracking was performed in the TRUS dataset and TRUS and CT images were fused with rigid image registration with the applicator as reference structure. The CTVHR (based on the GEC-ESTRO recommendations) was contoured by five investigators on the three modalities (CTVHR_CT, CTVHR_TRUS-CT, and CTVHR_MRI). A consensus reference CTVHR_MRI (MRIref) was defined for each patient. Descriptive statistics and overlap measures were calculated using RTslicer (SlicerRT Community and Percutaneous Surgery Laboratory, Queen’s University, Canada), comparing contours of every observer with one another and with the MRIref.

Results
The interobserver coefficient of variation was 0.18 ± 0.05 for CT, 0.10 ± 0.04 for TRUS-CT, and 0.07 ± 0.03 for MRI. Interobserver concordance in relation to the MRIref expressed by the generalized conformity index was 0.75 ± 0.04 for MRI, 0.51 ± 0.10 for TRUS-CT, and 0.48 ± 0.06 for CT. The mean CTVHR_CT volume of all observers was 71% larger than the MRIref volume, whereas the mean CTVHR_TRUS-CT volume was 15% larger.

Conclusion
Hybrid TRUS-CT as an imaging modality for contouring the CTVHR in IGABT for LACC is feasible and reproducible among multiple observers. TRUS-CT substantially reduces overestimation of the CTVHR volume of CT alone while maintaining similar interobserver variability.
Dose–volume parameters of MRI-based active bone marrow predict hematologic toxicity of chemoradiotherapy for rectal cancer
Authors: Kuncman Łukasz , Stawiski Konrad , Masłowski Michał , Kucharz Jakub , Fijuth Jacek 
Published: July 2020

Abstract
Purpose
Magnetic resonance imaging (MRI) is routinely used for locoregional staging of rectal cancer and offers promise for the prediction of hematologic toxicity. The present study compares the clinical utility of MRI-based active bone marrow (BMact) delineation with that of CT-based bone marrow total (BMtot) delineation for predicting hematologic toxicity.

Methods
A prospective cohort study was performed. Eligible patients had stage II/III rectal cancer and qualified for preoperative chemoradiotherapy. The BMact areas on T1-weighted MRI were contoured. The impact of the dose–volume parameters of BMact/BMtot and clinical data on hematologic toxicity were assessed. Basic endpoints were the occurrence of grade 3/4 hematologic toxicity and peripheral blood parameters reaching a nadir. Linear regression models were generated for the nadirs and receiver operating characteristic (ROC) curves for the occurrence of grade 3/4 hematologic toxicity.

Results
Thirty-five patients were enrolled. Women presented higher dose–volume parameters of BMact, BMtot, and lymphocyte nadir (ALCnadir%) than men. Models for the prediction of ALCnadir% (V5-V20BMtot, V5-V30BMact) and platelet nadir (PLTnadir%; V5-V10BMtot, V5-V20BMact) were statistically significant. In the ROC curves, a baseline lymphocyte level of 1.81 × 103/ml was adopted as the cutoff for predicting grade 3/4 lymphopenia, with specificity of 77.8% and sensitivity of 73.1%. The multivariate linear regression model for ALCnadir% had R2 = 0.53, p = 0.038. In the tenth step of selection, V5BMact (p = 0.002) and gender (p = 0.019) remained. The multivariate linear regression model for PLTnadir% had R2 = 0.20, p = 0.34. In the sixth step of selection, V15BMact remained (p = 0.026).

Conclusion
The dose–volume parameters of BMact serve as better predictors of ALCnadir% and PLTnadir% than BMtot.
Reduced accuracy of MRI deep grey matter segmentation in multiple sclerosis: an evaluation of four automated methods against manual reference segmentations in a multi-center cohort
Authors: de Sitter Alexandra , Verhoeven Tom , Burggraaff Jessica , Liu Yaou , Simoes Jorge , Ruggieri Serena , Palotai Miklos , Brouwer Iman , Versteeg Adriaan , Wottschel Viktor , Ropele Stefan , Rocca Mara A. , Gasperini Claudio , Gallo Antonio , Yiannakas Marios C. , Rovira Alex , Enzinger Christian , Filippi Massimo , De Stefano Nicola , Kappos Ludwig , Frederiksen Jette L. , Uitdehaag Bernard M. J. , Barkhof Frederik , Guttmann Charles R. G. , Vrenken Hugo ,   the MAGNIMS Study Group
Published: July 2020

Abstract
Background
Deep grey matter (DGM) atrophy in multiple sclerosis (MS) and its relation to cognitive and clinical decline requires accurate measurements. MS pathology may deteriorate the performance of automated segmentation methods. Accuracy of DGM segmentation methods is compared between MS and controls, and the relation of performance with lesions and atrophy is studied.

Methods
On images of 21 MS subjects and 11 controls, three raters manually outlined caudate nucleus, putamen and thalamus; outlines were combined by majority voting. FSL-FIRST, FreeSurfer, Geodesic Information Flow and volBrain were evaluated. Performance was evaluated volumetrically (intra-class correlation coefficient (ICC)) and spatially (Dice similarity coefficient (DSC)). Spearman's correlations of DSC with global and local lesion volume, structure of interest volume (ROIV), and normalized brain volume (NBV) were assessed.

Results
ICC with manual volumes was mostly good and spatial agreement was high. MS exhibited significantly lower DSC than controls for thalamus and putamen. For some combinations of structure and method, DSC correlated negatively with lesion volume or positively with NBV or ROIV. Lesion-filling did not substantially change segmentations.

Conclusions
Automated methods have impaired performance in patients. Performance generally deteriorated with higher lesion volume and lower NBV and ROIV, suggesting that these may contribute to the impaired performance.
Extensor tendon ruptures in rheumatoid wrists
Authors: Biehl C. , Rupp M. , Kern S. , Heiss C. , ElKhassawna T. , Szalay G. 
Published: July 2020

Abstract
Background and aims
Rheumatoid arthritis is a chronic inflammatory disease. The associated involvement of hands and tendons is over 90% and impairs overall function. In the course of the disease, the joints are often operated on. During this operation, ruptures of the extensor tendons are found by chance without the patients noticing them. The aim of this retrospective study is the prevalence of extensor tendon rupture. Which tendon is destroyed most frequently? How can the functional outcome be measured after reconstruction?

Materials and methods
From 1572 operations on rheumatoid wrists, 61 extensor tendon ruptures were identified in 41 patients. The average time between the first rheumatic symptoms of the hand and surgery was 6.4 years. The average duration of RA was 7.8 years. 26 patients with 27 tendon reconstructions were included in the follow-up with an average postoperative duration of 4.6 years (3 to 14.2 years).

Results
Extensor tendons ruptures typically occurred at mechanically stressed sites. The most frequent rupture was found in the extensor pollicis longus tendon (21 tendons), followed by the small finger extensor tendon (14 tendons). A transfer was performed on 7 tendons. Fifty-five tendon lesions were sutured at other intact tendons. Free grafts were not used. The results in Clayton and QuickDASH scores were significantly different. Functional improvement was consistent with the results of tendon reconstructions in healthy control groups.

Conclusion
In rheumatoid patients, a rupture of an extensor tendon must be expected at 4%. Patients tolerate and compensate this damage for a long time. The function of the hand including the tendon function is the most important factor in assessing the success of the operation. The subjective patient acceptance depends on the progress of the underlying disease, postoperative care (ergotherapy, physiotherapy, orthosis) and the patients' demands.
Evoking emotions in virtual reality: schema activation via a freeze-frame stimulus
Authors: Lipp Natalia , Dużmańska-Misiarczyk Natalia , Strojny Agnieszka , Strojny Paweł 
Published: July 2020

AbstractVirtual reality can be used for educational purposes, particularly in demanding professions such as firefighting. Such virtual training may be useful for preparing trainees for distress, fear, or frustration experienced during real rescue operations. Evoking cognitive schemas, especially of other people, during training appears to be crucial as well, as the greatest stressors in the firefighting profession are social. Based on interviews with firefighters, two types of people (children and young women) were chosen as stimuli in the research design. In an experimental study with three iterations, the stimuli designed to evoke the schema of a significant other were implemented in a virtual reality simulator to evoke a cognitive schema in firefighters through emotions (positive and negative) and several dimensions of stress. The first iteration of the study did not yield expected results, as the stimulus (a child’s toy) was not as suggestive and vivid as it was expected. In the second attempt, the stimulus was improved and evoked feelings of challenge, harm, and loss in the participants. In the third iteration, the stimulus was changed once more (to a white dress) and this time it evoked negative emotions of fear, anger, guilt, and sadness. However, after correcting for multiple comparisons, only results regarding emotional response remained statistically significant. The results are discussed in light of cognitive schemas’ activation, and perspectives for further research in this scope are proposed. Due to research outcomes, the issues of manipulation checks in experimental psychology and limitations of the VR technology are taken into consideration.
Submucosal gland neoplasms of the esophagus: an update and review
Authors: Nie Ling , Li Wei , Xue Liyan , Wang Lin , Shen Yonghua , Fan Xiangshan 
Published: July 2020

AbstractSubmucosal glands (SMGs) present throughout human esophagus with clusters at either the upper third or lower third of the organ. SMGs tend to atrophy with age, and neoplasms arising in these glands are rare. In order to bring convenience to diagnosis, we summarize the histopathologic characteristics of all esophageal submucosal gland tumors (SGTs). Due to the morphological similarity, the nomenclature of salivary tumors is adopted for SGTs. However, there is great confusion about the definition and histogenesis of these tumors, especially the malignant subtypes. In the literature, esophageal mucoepidermoid carcinoma and adenoid cystic carcinoma usually adjoin the surface squamous epithelium and coexist with intraepithelial neoplasia or invasive squamous cell carcinoma (SCC). In addition, the typical gene alterations of salivary tumors have not been reported in these SGTs. Therefore, we propose to apply stringent diagnostic criteria to esophageal SGTs so as to exclude mimickers that are SCCs with various degree of SMG differentiation.
The Impact of Delivering Mindfulness-Based Programmes in Schools: A Qualitative Study
Authors: Norton Katie R. , Griffith Gemma M. 
Published: July 2020

AbstractThere has been an increased interest in the delivery of Mindfulness-Based Programmes (MBPs) in schools yet little is known about how people who deliver MBPs in schools carry out and experience implementation. In this qualitative study, we aimed to examine the experiences of school staff who have a personal mindfulness practice, and who also deliver MBPs to their students. We recruited eight school staff (age range 34–64) who taught students mindfulness, and carried out semi-structured interviews focusing on investigating their positive and negative experiences of delivering mindfulness in schools, how practicing and delivering mindfulness affected their work-life, and their experiences of implementing school-based MBPs. School staff reported that delivering MBPs deepened their own mindfulness practice. The practice enabled them to feel better attuned to others, increased compassion for both themselves and students, helped their emotional regulation, and enhanced resilience to stress. Unexpectedly, half of the participants reported making changes to their work roles and several explicitly linked these changes to the increased self-compassion developed through mindfulness practice. They reported enjoying teaching school students MBPs (and noted that some students embraced mindfulness, and some were reluctant to engage) and sometimes found driving the implementation of MBPs in their school challenging. There appear to be numerous benefits of a personal mindfulness practice for school staff and delivering school-based MBPs can increase feelings of personal accomplishment. Future research is needed into whether MBPs can improve student–teacher relationships, and how some schools have successfully implemented MBPs.
Lunar Seismology: A Data and Instrumentation Review
Authors: Nunn Ceri , Garcia Raphael F. , Nakamura Yosio , Marusiak Angela G. , Kawamura Taichi , Sun Daoyuan , Margerin Ludovic , Weber Renee , Drilleau Mélanie , Wieczorek Mark A. , Khan Amir , Rivoldini Attilio , Lognonné Philippe , Zhu Peimin 
Published: July 2020

AbstractSeveral seismic experiments were deployed on the Moon by the astronauts during the Apollo missions. The experiments began in 1969 with Apollo 11, and continued with Apollo 12, 14, 15, 16 and 17. Instruments at Apollo 12, 14, 15, 16 and 17 remained operational until the final transmission in 1977. These remarkable experiments provide a valuable resource. Now is a good time to review this resource, since the InSight mission is returning seismic data from Mars, and seismic missions to the Moon and Europa are in development from different space agencies. We present an overview of the seismic data available from four sets of experiments on the Moon: the Passive Seismic Experiments, the Active Seismic Experiments, the Lunar Seismic Profiling Experiment and the Lunar Surface Gravimeter. For each of these, we outline the instrumentation and the data availability.We show examples of the different types of moonquakes, which are: artificial impacts, meteoroid strikes, shallow quakes (less than 200 km depth) and deep quakes (around 900 km depth). Deep quakes often occur in tight spatial clusters, and their seismic signals can therefore be stacked to improve the signal-to-noise ratio. We provide stacked deep moonquake signals from three independent sources in miniSEED format. We provide an arrival-time catalog compiled from six independent sources, as well as estimates of event time and location where available. We show statistics on the consistency between arrival-time picks from different operators. Moonquakes have a characteristic shape, where the energy rises slowly to a maximum, followed by an even longer decay time. We include a table of the times of arrival of the maximum energy $t_{\max}$

t
max

and the coda quality factor $Q_{c}$

Q
c

.Finally, we outline minimum requirements for future lunar missions to the Moon. These requirements are particularly relevant to future missions which intend to share data with other agencies, and set out a path for an International Lunar Network, which can provide simultaneous multi-station observations on the Moon.
The influence of inorganic components and carbon-oxygen surface functionalities in activated hydrothermally carbonized waste materials for water treatment
Authors: Niinipuu Mirva , Latham Kenneth G. , Jansson Stina 
Published: July 2020

AbstractIn this study, we have examined how the activation of hydrothermally carbonized sewage sludge and horse manure influences the inorganic component of these materials and surface chemistry. This was examined through statistical correlations between kinetic tests using trimethoprim, fluconazole, perfluorooctanoic acid, and copper, zinc, and arsenic and physicochemical properties. Yield and inorganic content varied considerably, with potassium hydroxide–activated materials producing lower yields with higher inorganic content. Phosphoric acid activation incorporated inorganically bound phosphorus into the material, although this showed no statistically relevant benefit. A maximum surface area of 1363 m2g−1 and 343 m2g−1 was achieved for the horse manure and sewage sludge. Statistical analysis found positive correlations between carbon-oxygen functionalities and trimethoprim, fluconazole, perfluorooctanoic acid, and copper removal, while inorganic content was negatively correlated. Conversely, arsenic removal was positively correlated with inorganic content. This research provides insight into the interactions with the organic/inorganic fraction of activated waste materials for water treatment.
Gewaltsoziologie im Wandel
Authors: Braun Andreas 
Published: July 2020

ZusammenfassungIn den gegenwärtigen gewaltsoziologischen Debatten und Diskursen lassen sich im deutschsprachigen Kontext aktuell drei Ansätze identifizieren, die der Frage nach gehenwiegewalthafte Ereignisse, Handlungen, Erfahrungen etc. künftig (oder weiterhin?) adäquat erklärt werden können. Unter den Schlagworten Situation, Prozess sowie Reflexivität und variierende Ordnung widmet sich dieser Beitrag einer kurzen bestandsaufnehmenden Sichtung jener (mehr oder weniger) konträr gelagerten Perspektiven.