bluuebunny/crossref_metadata_2025 huggingface dataset:
Infrared light sensors permit rapid recording of wingbeat frequency and bioacoustic species identification of mosquitoes
Authors: Kim Dongmin , DeBriere Terry J. , Cherukumalli Satish , White Gregory S. , Burkett-Cadena Nathan D.
Published: May 2021

Recognition and classification of mosquitoes is a critical component of vector-borne disease management. Vector surveillance, based on wingbeat frequency and other parameters, is becoming increasingly important in the development of automated identification systems, but inconsistent data quality and results frequently emerge from different techniques and data processing methods which have not been standardized on wingbeat collection of numerous species. We developed a simple method to detect and record mosquito wingbeat by multi-dimensional optical sensors and collected 21,825 wingbeat files from 29 North American mosquito species. In pairwise comparisons, wingbeat frequency of twenty six species overlapped with at least one other species. No significant differences were observed in wingbeat frequencies between and within individuals of Culex quinquefasciatus over time. This work demonstrates the potential utility of quantifying mosquito wingbeat frequency by infrared light sensors as a component of an automated mosquito identification system. Due to species overlap, wingbeat frequency will need to integrate with other parameters to accurately delineate species in support of efficient mosquito surveillance, an important component of disease intervention.
Inhibition of a nutritional endosymbiont by glyphosate abolishes mutualistic benefit on cuticle synthesis in Oryzaephilus surinamensis
Authors: Kiefer Julian Simon Thilo , Batsukh Suvdanselengee , Bauer Eugen , Hirota Bin , Weiss Benjamin , Wierz Jürgen C. , Fukatsu Takema , Kaltenpoth Martin , Engl Tobias
Published: May 2021

Glyphosate is widely used as a herbicide, but recent studies begin to reveal its detrimental side effects on animals by targeting the shikimate pathway of associated gut microorganisms. However, its impact on nutritional endosymbionts in insects remains poorly understood. Here, we sequenced the tiny, shikimate pathway encoding symbiont genome of the sawtoothed grain beetleOryzaephilus surinamensis. Decreased titers of the aromatic amino acid tyrosine in symbiont-depleted beetles underscore the symbionts’ ability to synthesize prephenate as the precursor for host tyrosine synthesis and its importance for cuticle sclerotization and melanization. Glyphosate exposure inhibited symbiont establishment during host development and abolished the mutualistic benefit on cuticle synthesis in adults, which could be partially rescued by dietary tyrosine supplementation. Furthermore, phylogenetic analyses indicate that the shikimate pathways of many nutritional endosymbionts likewise contain a glyphosate sensitive 5-enolpyruvylshikimate-3-phosphate synthase. These findings highlight the importance of symbiont-mediated tyrosine supplementation for cuticle biosynthesis in insects, but also paint an alarming scenario regarding the use of glyphosate in light of recent declines in insect populations.
Coupled oscillations enable rapid temporal recalibration to audiovisual asynchrony
Authors: Lennert Therese , Samiee Soheila , Baillet Sylvain
Published: May 2021

The brain naturally resolves the challenge of integrating auditory and visual signals produced by the same event despite different physical propagation speeds and neural processing latencies. Temporal recalibration manifests in human perception to realign incoming signals across the senses. Recent behavioral studies show it is a fast-acting phenomenon, relying on the most recent exposure to audiovisual asynchrony. Here we show that the physiological mechanism of rapid, context-dependent recalibration builds on interdependent pre-stimulus cortical rhythms in sensory brain regions. Using magnetoencephalography, we demonstrate that individual recalibration behavior is related to subject-specific properties of fast oscillations (>35 Hz) nested within a slower alpha rhythm (8–12 Hz) in auditory cortex. We also show that the asynchrony of a previously presented audiovisual stimulus pair alters the preferred coupling phase of these fast oscillations along the alpha cycle, with a resulting phase-shift amounting to the temporal recalibration observed behaviorally. These findings suggest that cross-frequency coupled oscillations contribute to forming unified percepts across senses.
Accurate absolute free energies for ligand–protein binding based on non-equilibrium approaches
Authors: Gapsys Vytautas , Yildirim Ahmet , Aldeghi Matteo , Khalak Yuriy , van der Spoel David , de Groot Bert L.
Published: May 2021

The accurate calculation of the binding free energy for arbitrary ligand–protein pairs is a considerable challenge in computer-aided drug discovery. Recently, it has been demonstrated that current state-of-the-art molecular dynamics (MD) based methods are capable of making highly accurate predictions. Conventional MD-based approaches rely on the first principles of statistical mechanics and assume equilibrium sampling of the phase space. In the current work we demonstrate that accurate absolute binding free energies (ABFE) can also be obtained via theoretically rigorous non-equilibrium approaches. Our investigation of ligands binding to bromodomains and T4 lysozyme reveals that both equilibrium and non-equilibrium approaches converge to the same results. The non-equilibrium approach achieves the same level of accuracy and convergence as an equilibrium free energy perturbation (FEP) method enhanced by Hamiltonian replica exchange. We also compare uni- and bi-directional non-equilibrium approaches and demonstrate that considering the work distributions from both forward and reverse directions provides substantial accuracy gains. In summary, non-equilibrium ABFE calculations are shown to yield reliable and well-converged estimates of protein–ligand binding affinity.
Structure of a seeded palladium nanoparticle and its dynamics during the hydride phase transformation
Authors: Suzana Ana F. , Wu Longlong , Assefa Tadesse A. , Williams Benjamin P. , Harder Ross , Cha Wonsuk , Kuo Chun-Hong , Tsung Chia-Kuang , Robinson Ian K.
Published: May 2021

Palladium absorbs large volumetric quantities of hydrogen at room temperature and ambient pressure, making the palladium hydride system a promising candidate for hydrogen storage. Here, we use Bragg coherent diffraction imaging to map the strain associated with defects in three dimensions before and during the hydride phase transformation of an individual octahedral palladium nanoparticle, synthesized using a seed-mediated approach. The displacement distribution imaging unveils the location of the seed nanoparticle in the final nanocrystal. By comparing our experimental results with a finite-element model, we verify that the seed nanoparticle causes a characteristic displacement distribution of the larger nanocrystal. During the hydrogen exposure, the hydride phase is predominantly formed on one tip of the octahedra, where there is a high number of lower coordinated Pd atoms. Our experimental and theoretical results provide an unambiguous method for future structure optimization of seed-mediated nanoparticle growth and in the design of palladium-based hydrogen storage systems.
Naturally occurring prenylated chalcones from plants: structural diversity, distribution, activities and biosynthesis
Authors: Zhou Kang , Yang Song , Li Shu-Ming
Published: May 2021

This review covers the literature until July 2020 on structures, biological activities, distribution and biosynthesis of prenylated chalcones in plants.
Dual-emission ratio fluorescence for selective and sensitive detection of ferric ions and ascorbic acid based on one-pot synthesis of glutathione protected gold nanoclusters
Authors: Zhang Shuai , Zhang Cong , Shao Xiaodong , Guan Rentian , Hu Yingying , Zhang Keying , Liu Wenjing , Hong Min , Yue Qiaoli
Published: May 2021

A fluorometric method was proposed for the determination of Fe3+ and ascorbic acid (AA) based on blue and red dual fluorescence emissions of glutathione (GSH) stabilized-gold nanoclusters (AuNCs).
Cryogenic activity and stability of benzaldehyde lyase enzyme in lipidic mesophases-nanoconfined water
Authors: Zhou Tao , Yao Yang , Zhang Qin , Mezzenga Raffaele
Published: May 2021

Cryogenic activity and stability of benzaldehyde lyase enzyme are achieved in lipidic mesophases, relying on the existence of liquid water at subzero temperatures.
The electrochemistry of size dependent graphene via liquid phase exfoliation: capacitance and ionic transport
Authors: Deerattrakul Varisara , Hirunpinyopas Wisit , Pisitpipathsin Nuttapon , Saisopa Thanit , Sawangphruk Montree , Nualchimplee Chakrit , Iamprasertkun Pawin
Published: May 2021

This work explores the capacitance and ionic transport properties of size dependent graphene (from 100 nm to 1 μm) prepared through the liquid phase exfoliation of graphite in which the size of graphene was finely selected using a multi-step centrifugation technique.
The effect of graphene oxide cross-linking and ionization on the crystallization behavior, and the electrical and thermal conductivity of a nylon-66 nanocomposite
Authors: Guo Junyi , Ye Yuxing , Du Zhongjie , Zhang Chen , Zou Wei
Published: May 2021

A GO–PPD/NAAK/PA-66 composite with excellent electrical and thermal conductivity was obtained through a step-by-step chemical surface modification method involving GO.
Recent updates on the bioactive compounds of the marine-derived genusAspergillus
Authors: Orfali Raha , Aboseada Mahmoud A. , Abdel-Wahab Nada M. , Hassan Hossam M. , Perveen Shagufta , Ameen Fuad , Alturki Eman , Abdelmohsen Usama Ramadan
Published: May 2021

The genusAspergillusis widely distributed in terrestrial and marine environments.
Potential role for pyruvate kinase M2 in the regulation of murine cardiac glycolytic flux during in vivo chronic hypoxia
Authors: Handzlik Michal K. , Tooth David J. , Constantin-Teodosiu Dumitru , Greenhaff Paul L. , Cole Mark A.
Published: May 2021

Carbohydrate metabolism in heart failure shares similarities to that following hypoxic exposure, and is thought to maintain energy homoeostasis in the face of reduced O2 availability. As part of these in vivo adaptations during sustained hypoxia, the heart up-regulates and maintains a high glycolytic flux, but the underlying mechanism is still elusive. We followed the cardiac glycolytic responses to a chronic hypoxic (CH) intervention using [5-3H]-glucose labelling in combination with detailed and extensive enzymatic and metabolomic approaches to provide evidence of the underlying mechanism that allows heart survivability. Following 3 weeks of in vivo hypoxia (11% oxygen), murine hearts were isolated and perfused in a retrograde mode with function measured via an intraventricular balloon and glycolytic flux quantified using [5-3H]-glucose labelling. At the end of perfusion, hearts were flash-frozen and central carbon intermediates determined via liquid chromatography tandem mass spectrometry (LC-MS/MS). The maximal activity of glycolytic enzymes considered rate-limiting was assessed enzymatically, and protein abundance was determined using Western blotting. Relative to normoxic hearts, CH increased ex vivo cardiac glycolytic flux 1.7-fold with no effect on cardiac function. CH up-regulated cardiac pyruvate kinase (PK) flux 3.1-fold and cardiac pyruvate kinase muscle isoenzyme M2 (PKM2) protein content 1.4-fold compared with normoxic hearts. CH also augmented cardiac pentose phosphate pathway (PPP) flux, reflected by higher ribose-5-phosphate (R5P) content. These findings support an increase in the covalent (protein expression) and allosteric (flux) control of PKM2 as being central to the sustained up-regulation of the glycolytic flux in the chronically hypoxic heart.
Mode recognition and coordinated magnetisation control method for variable flux memory machine
Authors: Wang Wei , Lin Heyun , Yang Hui , Lyv Shukang , Liu Wei , Fang Shuhua
Published: May 2021

The hybrid permanent magnet (PM) variable flux memory machine employs high‐ and low‐coercive‐force hybrid PMs to simultaneously obtain a high torque density and regulable PM flux property. The operating trajectories and steady working‐points of this type of machine switch back and forth in multiple regions. To identify operating modes under various PM magnetisation states and speed ranges, this paper proposes a mode recognition and coordinated control method based on probabilistic neural networks (PNNs). A PNN algorithm is trained offline and executed in real‐time to obtain a certain operating mode with the maximum probability of current state. According to the mode recognition result, a coordinated control scheme for applying short‐time pulses or continuous flux‐weakening current in a reasonable manner is presented. The proposed method exhibits an excellent capability in real‐time operating modes identification, hence achieving magnetisation current control of multiple modes easily. Its feasibility and effectiveness are validated by experimental results on a hybrid PM VFMM prototype.
Affine projection sign algorithm based control for mitigation of distribution side power quality problems
Authors: Sharma Archana , Rajpurohit Bharat Singh , Agnihotri Samar
Published: May 2021

This paper proposes the implementation of Affine Projection Sign Algorithm (APSA) based control for DSTATCOM to mitigate distribution side power quality issues like harmonic elimination, reactive power compensation, load balancing, power factor compensation, voltage regulation, etc. Affine projection algorithms have already finds application in power quality mitigation, but they suffer from high complexity and degraded performance due to impulsive interference. Whereas, sign algorithms are known to be robust against the impulsive noise and converges faster. Hence, sign algorithm with affine projection is proposed for mitigation of power quality problems in this work. APSA is used to estimate the reference active and reactive power component of polluted load current, which is further used to generate the reference signal for DSTATCOM. The performance of the algorithm is investigated for some real operating conditions of power system network in MATLAB/SIMULINK environment. The algorithm is tested in real‐time simulator for validation. The result shows that the control algorithm is able to resolve distribution side power quality problems with fast convergence.
How the formation of Neptune shapes the Kuiper belt
Authors: Pirani Simona , Johansen Anders , Mustill Alexander J.
Published: May 2021

Hydrodynamical simulations predict the inward migration of giant planets during the gas phase of the protoplanetary disc. This phenomenon is also invoked to explain resonant and near-resonant exoplanetary system structures. The early inward migration may also have affected our Solar System and sculpted its different minor planet reservoirs. In this study we explore how the early inward migration of the giant planets shapes the Kuiper belt. We test different scenarios with only Neptune and Uranus and with all the four giant planets, also including some models with the subsequent outward planetesimal-driven migration of Neptune after the gas dispersal. We find objects populating mean motion resonances even when Neptune and Uranus do not migrate at all or only migrate inwards. When the planets are fixed, planetesimals stick only temporarily to the mean motion resonances, while inwards migration yields a new channel to populate the resonances without invoking convergent migration. However, in these cases, it is hard to populate mean motion resonances that do not cross the planetesimal disc (such as 2:1 and 5:2) and there is a lack of resonant Kuiper belt objects (KBOs) crossing Neptune’s orbit. These Neptune crossers are an unambiguous signature of the outward migration of Neptune. The starting position and the growth rate of Neptune have consequences for the contamination of the classical Kuiper belt region from neighbouring regions. The eccentricity and inclination space of the hot classical Kuiper belt objects and the scattered disc region become much more populated when all the giant planets are included. The 5:2 resonance with Neptune becomes increasingly populated with deeper inward migrations of Neptune. However, the overall inclination distribution is still narrower than suggested by observations, as is generally the case for Kuiper belt population models.
The ART-XC telescope on board the SRG observatory
Authors: Pavlinsky M. , Tkachenko A. , Levin V. , Alexandrovich N. , Arefiev V. , Babyshkin V. , Batanov O. , Bodnar Yu. , Bogomolov A. , Bubnov A. , Buntov M. , Burenin R. , Chelovekov I. , Chen C.-T. , Drozdova T. , Ehlert S. , Filippova E. , Frolov S. , Gamkov D. , Garanin S. , Garin M. , Glushenko A. , Gorelov A. , Grebenev S. , Grigorovich S. , Gureev P. , Gurova E. , Ilkaev R. , Katasonov I. , Krivchenko A. , Krivonos R. , Korotkov F. , Kudelin M. , Kuznetsova M. , Lazarchuk V. , Lomakin I. , Lapshov I. , Lipilin V. , Lutovinov A. , Mereminskiy I. , Molkov S. , Nazarov V. , Oleinikov V. , Pikalov E. , Ramsey B. D. , Roiz I. , Rotin A. , Ryadov A. , Sankin E. , Sazonov S. , Sedov D. , Semena A. , Semena N. , Serbinov D. , Shirshakov A. , Shtykovsky A. , Shvetsov A. , Sunyaev R. , Swartz D. A. , Tambov V. , Voron V. , Yaskovich A.
Published: May 2021

Astronomical Roentgen Telescope – X-ray Concentrator (ART-XC) is the hard X-ray instrument with grazing incidence imaging optics on board the Spektr-Roentgen-Gamma (SRG) observatory. The SRG observatory is the flagship astrophysical mission of the Russian Federal Space Program, which was successively launched into orbit around the second Lagrangian point (L2) of the Earth-Sun system with a Proton rocket from the Baikonur cosmodrome on 13 July 2019. The ART-XC telescope will provide the first ever true imaging all-sky survey performed with grazing incidence optics in the 4–30 keV energy band and will obtain the deepest and sharpest map of the sky in the energy range of 4–12 keV. Observations performed during the early calibration and performance verification phase as well as during the ongoing all-sky survey that started on 12 December 2019 have demonstrated that the in-flight characteristics of the ART-XC telescope are very close to expectations based on the results of ground calibrations. Upon completion of its four-year all-sky survey, ART-XC is expected to detect approximately 5000 sources (~3000 active galactic nuclei, including heavily obscured ones, several hundred clusters of galaxies, ~1000 cataclysmic variables and other Galactic sources), and to provide a high-quality map of the Galactic background emission in the 4–12 keV energy band. ART-XC is also well suited for discovering transient X-ray sources. In this paper, we describe the telescope, the results of its ground calibrations, the major aspects of the mission, the in-flight performance of ART-XC, and the first scientific results.
The Gaia RVS benchmark stars
Authors: Caffau E. , Bonifacio P. , Korotin S. A. , François P. , Lallement R. , Matas Pinto A. M. , Di Matteo P. , Steffen M. , Mucciarelli A. , Katz D. , Haywood M. , Chemin L. , Sartoretti P. , Sbordone L. , Andrievsky S. M. , Kovtyukh V. V. , Spite M. , Spite F. , Panuzzo P. , Royer F. , Thévenin F. , Ludwig H.-G. , Marchal O. , Plum G.
Published: May 2021

Context. The Radial Velocity Spectrometer (RVS) on board the Gaia satellite is not provided with a wavelength calibration lamp. It uses its observations of stars with known radial velocity to derive the dispersion relation. To derive an accurate radial velocity calibration, a precise knowledge of the line spread function (LSF) of the RVS is necessary. Good-quality ground-based observations in the wavelength range of the RVS are highly desired to determine the LSF.

Aims. Several radial velocity standard stars are available to the Gaia community. The highest possible number of calibrators will surely allow us to improve the accuracy of the radial velocity. Because the LSF may vary across the focal plane of the RVS, a large number of high-quality spectra for the LSF calibration may allow us to better sample the properties of the focal plane.

Methods. We selected a sample of stars to be observed with UVES at the Very Large Telescope, in a setting including the wavelength range of RVS, that are bright enough to allow obtaining high-quality spectra in a short time. We also selected stars that lack chemical investigation in order to increase the sample of bright, close by stars with a complete chemical inventory.

Results. We here present the chemical analysis of the first sample of 80 evolved stars. The quality of the spectra is very good, therefore we were able to derive abundances for 20 elements. The metallicity range spanned by the sample is about 1 dex, from slightly metal-poor to solar metallicity. We derived the Rb abundance for all stars and investigated departures from local thermodynamical equilibrium (NLTE) in the formation of its lines.

Conclusions. The sample of spectra is of good quality, which is useful for a Gaia radial velocity calibration. The Rb NLTE effects in this stellar parameters range are small but sometimes non-negligible, especially for spectra of this good quality.
Evaluation des apprentissages au sein d’un environnement de type MOOC adaptatif
Authors: Hamida Soufiane , Cherradi Bouchaib , Raihani Abdelhadi , Ouajji Hassan
Published: May 2021

La problématique de l’évaluation des apprentissages au sein d’un MOOC suscite un grand débat. Ce type d’environnements d’apprentissage offre des cours limités dans le temps, organisés en ligne et ouverts à tous. L’apprentissage au sein des MOOC consiste en l’échange du savoir entre les participants et l’interaction avec les concepteurs (forum, chat, etc.) en se libérant des contraintes de temps et d’espace. En effet, le MOOC est un outil d’apprentissage en ligne et rythmés. L’évaluation des apprentissages au sein des MOOC représente un pilier essentiel pour la favorisation d’un apprentissage rythmé. Cet apprentissage libère les apprenants dans le temps et dans l’espace. Les concepteurs des MOOC ont largement investi sur des modalités d’évaluation automatisées, tels que des modes de la correction automatique (les quiz ou les questionnaires à choix multiples). Pourtant, ces modalités restent très limitées face au développement d’une pensée critique au cours d’une séquence d’apprentissage. Dans ce papier nous allons aborder les techniques et les méthodes d’évaluation qui permettent de mesurer l’atteinte des objectifs d’apprentissage dans un MOOC. Ensuite, nous présentons l’architecture d’un modèle d’apprentissage basé sur les agents susceptibles de fournir une évaluation formative et personnalisé de cours en ligne massifs.
Les interactions en ligne et la construction du savoir dans les dispositifs de formation complètement à distance: Quels rapports?
Authors: Mouni Meryem , Boumalek Abdallah
Published: May 2021

Cette contribution se propose d’étudier la relation entre les interactions en ligne et la construction collaborative du savoir dans trois MOOC. Son objectif principal est l’examen, dans l’ingénierie pédagogique adoptée, du rôle envisagé pour les interactions en ligne dans le processus d’apprentissage. Elle tentera également de comprendre comment les forums de discussion contribuent à une co-construction des savoirs entre les participants. Le modèle d’analyse des interactions adopté dans ce travail est l’analyse conversationnelle d’inspiration ethnométhodologique qui renvoie aux actions. Elle étudie les conversations dans un espace écologique et tâche de comprendre leur organisation séquentielle. Ce modèle est foncièrement centré sur les interactions, en vue de décrire les stratégies adoptées par les participants présents lors des tours de paroles. Dans cette perspective, ce travail n’ambitionne pas l’étude des aspects iconographiques que véhiculent les interactions en ligne. Le corpus d’étude est composé de forums de discussion enregistrés sur des MOOC dans le but de répondre à notre objectif de recherche.
Pratique de fraude aux examens scolaires et sa relation avec l’évolution des TIC et les modes d’évaluation
Authors: Cherradi Bouchaib , Atmani Rachid , Boumilk Fouad
Published: May 2021

La fraude aux examens scolaire a fait l’objet ces dernières années l’objet d’une forte médiatisation, en particulier à l’approche des examens. Par ailleurs, les enseignants se plaignent de plus en plus des apprenants et des étudiants qui utilisent leur téléphone pendant les épreuves. Avec l’arrivée de la technologie dans les classes et l’utilisation courante d’Internet dans les activités scolaires, les apprenants et les étudiants ont davantage d’opportunités de plagier des documents ou de frauder lors des épreuves sur table. L’intégration des nouvelles technologies de l’information et de la communication dans l’ensemble de corps scolaire nous a amené à poser la question du mode d’évaluation. À travers ce travail, nous avons procédé à une recherche exploratoire, à travers un questionnaire élaboré par le logiciel Sphinx. L’analyse des données par Sphinx et par le test de confiance khideux, nous a permis de déterminer un aperçu sur l’ampleur de ce phénomène dans le milieu scolaire. Nous avons constaté d’une part, que la plupart des étudiants trichent lors des examens et d’autre part les deux facteurs qui contribuer à la fraude sont: les méthodes d’évaluation adoptées et les moyens technologiques.
Apprendre à enseigner à l’ère numérique : Perception de compétences et intégration pédagogique des TIC
Authors: El Khalfi Nadia
Published: May 2021

La valeur pédagogique du numérique a été, dernièrement, l’objet de beaucoup d’espoirs et de spéculations dans les différentes sphères de notre société voire celle de l’éducation n’y faisant pas exception. En effet, l’évolution des TICE a alimenté les attentes autour du numérique pour l’apprentissage, eu égard au niveau des performances des élèves en recul. Toutefois, à l'heure où se dessinent de nouveaux plans numériques pour l'éducation, l’on constate un décalage entre les innovations technologiques et leur intégration pédagogique par les enseignants dans le cadre scolaire. Faut-il rappeler que la seule distribution de supports numériques ne peut suffire à faire des TIC un levier d’amélioration de l’éducation au Maroc. L’article traite de l’impact de la formation aux TICE sur le sentiment de compétence professionnelle des futurs enseignants en matière de compétence numérique. Une enquête a été menée auprès de 248 futurs enseignants en formation initiale au CRMEF Casa-Settat ; et nous a permis de constater un sentiment d’auto-efficacité assez faible des compétences techno-pédagogiques. L’article suggère aussi des recommandations concernant la formation initiale des enseignants futurs.
La communication engageante au service de l’éducation inclusive : Etude expérimentale
Authors: Seddik Lahcen
Published: May 2021

L’éducation inclusive des enfants en situation d’handicap implique la remise en question du paradigme éducationnel traditionnel. Ceci nécessite la transformation radicale du système scolaire en place de façon à ce que tous les enfants aient une place au sein de l’école de leur quartier de résidence. Ainsi la révision des curricula et des dispositifs de formation initiale et qualifiante s’impose d’emblée. Par ailleurs, l’implication et l’engagement des enseignants constituent-ils un des défis majeurs face à l’implantation de ce nouveau paradigme. Leurs résistances à un tel changement constituent un facteur de risque d’échec de l’éducation inclusive. D’où la nécessité de mener une campagne d’information et de communication au sein des écoles pour amener les enseignants à s’y engager librement et sans aucune contrainte. Cet article a pour objet la présentation des résultats d’une recherche expérimentale sur l’incidence de la communication engageante sur l’intention comportementale des enseignants au regard de l’éducation inclusive. L’objectif en est de comparer l’efficacité d’une démarche de communication engageante à celle d’engagement et à celle de communication persuasive. Les résultats de cette expérimentation montrent que les participants, ayant été soumis à une démarche de communication engageante, ont exprimé une intention plus forte d’intégrer les élèves en situation de handicap dans leur classe, en comparaison avec ceux qui ont été soumis à une démarche d’engagement ou de persuasion.
Qu'en est-il de la pédagogie de l’étonnement ?: Cas de l'enseignement des Mathématiques au primaire
Authors: abbou Nada Ait si
Published: May 2021

Le but premier de l'école n'est ni de transmettre des connaissances, ni de dresser l'enfant à l'objectivité en restant passif, mais de favoriser son développement et son intelligence en lui fournissant les moyens de penser, de réfléchir, bref de s'étonner en classe. La pédagogie de l'étonnement est parmi les pédagogies actives dont le pionnier est Louis Legrand. Etonner l'apprenant, c'est le déstabiliser et le mettre dans une situation dans laquelle ses connaissances et croyances seront mises en cause, l'engageant ainsi dans la recherche de nouvelles connaissances. Notre étude est de nature descriptive qui porte sur l'enseignement des mathématiques à des élèves de CM1 et CM2 au Maroc. Les résultats montrent que les problèmes proposés aux apprenants représentent plutôt des exercices d'application des règles « apprises » et d'une imitation stricto sensu de l'enseignant sans faire appel à une recherche de sens dû au manque de sollicitation de toute curiosité et de stimulation de leur intelligence.
Valorization of glass powder waste, crushed and dune sands in the mix design of ultra-high performance fiber reinforced concrete: Assessing effect of waste variability
Authors: Belkadi Mourad , Chaid Rabah , Perrot Arnaud
Published: May 2021

This work deals with the valorization of industrial glass waste as supplementary cementitious materials in Ultra High Performance Fiber-Reinforced Concrete (UHPFRC). It aims to take advantage of this type of by-product in order to improve both fresh and hardened performances of conventional cementitious materials. This study concerns the use of glass powder originating from different locations with slight variation in their chemical composition (named transparent, smoked, and opaque) as a supplementary cementitious material (substitution ratio: 20% of the cement weight). Series of standardized tests were performed to characterize the influence of these glass powders on both fresh state properties (slump flow) and hardened state properties of tested UHPFRC. Mechanical properties are measured after cure periods lasting from 2 to 28 days. The study on the microstructure of hardened concrete was made using scanning electron microscopy and water penetration. Obtained results show the beneficial effect brought by the addition of a significant dosage of glass powder (here 20% of the cement weight) on the behavior of concrete in its fresh and hardened state.
Roboterassistierte Harnblasendivertikelresektion (RAHDR)
Authors: Kajaia David , Hager Benjamin , Kliebisch Stefan , Weingärtner Karl , Seggewiss-Bernhardt Ruth , Zugor Vahudin
Published: May 2021

Ziele Seit Oktober 2018 werden Harnblasendivertikelresektionen in der Klinik für Urologie, Kinderurologie und roboterassistierte minimalinvasive Urologie der Sozialstiftung Bamberg roboterassistiert und minimalinvasiv, mit dem DaVinci-Operationssystem®, durchgeführt. Das Ziel dieser Arbeit ist die operativen Ergebnisse unserer Patienten zu objektivieren und mit anderen Daten zu vergleichen, um ggf. die Diagnostik und Therapie zu optimieren.

Methoden In dieser retrospektiven Analyse haben wir alle Patienten, die zwischen Oktober 2018 und Mai 2020 eine RAHDR erhalten haben, eingeschlossen. Die primären Endpunkte waren: der intraoperative bzw. postoperative Blutverlust (Hämoglobin-Abfall postoperativ), die Operationszeit (min), die Hospitationsdauer (Tage), der postoperative Restharn, das Auftreten von Anastomoseninsuffizienzen, die postoperative Lebensqualität und die postoperative Zufriedenheit mit den Miktionsverhältnissen.

Ergebnisse Es konnten insgesamt 11 Patienten eingeschlossen werden. Das mittlere Alter betrug 64,8 Jahre (52–82) und alle Patienten waren männlich. Der durchschnittliche BMI war 26,5 kg/m² (19–37). 3 Patienten wurden mit ASA-Score III eigestuft, 5 mit II und 3 mit I. Der durchschnittliche Restharnwert präoperativ lag bei 183 ml (90–240). 7 von 11 Patienten bekamen simultan eine oder 2 weitere Operationen. Ein Zystogramm zum Ausschluss einer Extravasation erfolgte am fünften bzw. sechsten postoperativen Tag. Die mittlere Operationszeit war 212 min (148–294) und die mittlere Hospitationsdauer betrug 7,6 Tage (6–10). Der durchschnittliche postoperative Restharnwert war 25 ml (10–60). Die durchschnittliche postoperative maximale Harnflussrate (max. Flow) wurde mit 27,7 ml/s (11–55) gemessen. Bei keinem der Patienten wurde eine Kontrastmittelextravasation im Zystogramm nachgewiesen. Die Komplikationen nach Clavien waren nicht objektivierbar. Der mittlere postoperative Hb-Abfall betrug 1,61 g/dl (0–3,2).

Schlussfolgerungen In den meisten Fällen ist die Entfernung eines oder mehrerer Blasendivertikel über die minimalinvasive roboterassistierte Technik möglich. Dabei ist die Möglichkeit gegeben verschiedene Operationen wie YV-Blasenhalsplastik, Prostataadenomenukleation, Blasensteinsanierung, Leistenherniotomie u. a. simultan durchzuführen. Eine roboterassistierte Harnblasendivertikelresektion ist ein effektives und schonendes Verfahren, welches aber, durch fehlende DRG-Abbildung, finanzielle Nachteile für den Leistungserbringer verursachen kann.
Skin Diseases in Elite Athletes
Authors: Liebich Christoph , Wegin V. Vanessa , Marquart Christine , Schubert Irene , von Bruehl Marie-Luise , Halle Martin , Oberhoffer Renate , Wolfarth Bernd
Published: May 2021

An athlete’s skin has to cope with various stressors that influence skin integrity. This study investigated the effect of intense sporting activity at a competitive level on skin health, independent of the type of sport. The prevalence of dermatoses in elite athletes who exercise 8 or more hours per week was compared to recreational athletes. By applying a questionnaire, we acquired data from n=492 recruited athletes and recreational athletes regarding the prevalence of dermatoses, the extent of physical activity, and sports discipline practiced. Compared to the reference group, elite athletes showed less inflammatory, traumatic, infectious, and sebaceous skin diseases and especially neurodermitis, pruritus, bullae, tinea pedis, acne, and herpes were less common. Women suffered from skin diseases more often than men. With advanced age, the incidence of dermatoses increased, but less so among elite athletes. The discipline practiced and the duration of training, especially when performed outdoors, strongly influenced the development of dermatoses. Even though the skin of athletes is exposed to higher stress levels and physical strain, we can state that intensive physical activity seems to act as a protecting factor against skin diseases and significantly promotes skin health.
Silica Gel-mediated Oxidation of Prenyl Motifs Generates Natural Product-Like Artifacts
Authors: Tang Yu , Friesen J. Brent , Nikolić Dejan S. , Lankin David C. , McAlpine James B. , Chen Shao-Nong , Pauli Guido F.
Published: May 2021

Prenyl moieties are commonly encountered in the natural products of terpenoid and mixed biosynthetic origin. The reactivity of unsaturated prenyl motifs is less recognized and shown here to affect the acyclic Rhodiola rosea monoterpene glycoside, kenposide A (8), which oxidizes readily on silica gel when exposed to air. The major degradation product mediated under these conditions was a new aldehyde, 9. Exhibiting a shortened carbon skeleton formed through the breakdown of the terminal isopropenyl group, 9 is prone to acetalization in protic solvents. Further investigation of minor degradation products of both 8 and 8-prenylapigenin (8-PA, 12), a flavonoid with an ortho-prenyl substituent, revealed that the aldehyde formation was likely realized through epoxidation and subsequent cleavage at the prenyl olefinic bond. Employment of 1H NMR full spin analysis (HiFSA) achieved the assignment of all chemical shifts
and coupling constants of the investigated terpenoids and facilitated the structural validation of the degradation product, 9. This study indicates that prenylated compounds are generally susceptible to oxidative degradation, particularly in the presence of catalytic mediators, but also under physiological conditions. Such oxidative artifact/metabolite formation leads to a series of compounds with prenyl-derived (cyclic) partial structures that are analogous to species formed during Phase I metabolism in vivo. Phytochemical and pharmacological studies should take precautions or at least consider the impact of (unavoidable) exposure of prenyl-containing compounds to catalytic and/or oxidative conditions.
Endovenöse Therapie chronisch venöser Obstruktionen
Authors: Jalaie Houman , Barbati Mohammad E. , Gombert Alexander , Kotelis Drosos , Jacobs Michael J. , Schleimer Karina
Published: May 2021

Bei der chronisch venösen Obstruktion (CVO) liegt ein Abstromhindernis vor, welches eine venöse Hypertension im betroffenen Bein verursacht. Die CVO tritt vornehmlich auf dem Boden eines postthrombotischen Syndroms (PTS) oder eines May-Thurner-Syndroms (MTS) auf. Die CVO kann zu einer deutlichen Einschränkung des täglichen Lebens führen und hat erhebliche sozioökonomische Konsequenzen. Bei der endovenösen Rekanalisation zur Behandlung einer symptomatischen CVO handelt es sich um eine relativ neue therapeutische Option, die mittlerweile generell als Behandlung der ersten Wahl akzeptiert ist. Seit Verwendung spezieller venöser Stents können auch ausgedehntere Befunde, die eine anspruchsvollere Rekonstruktion erforderlich machen, erfolgreich therapiert werden.

Damit nach einer venösen Rekanalisation keine Stase des Blutstroms und ein Primärverschluss auftreten, müssen ein suffizienter Ein- und Ausstrom gewährleistet sein. Zur Verbesserung des Einstroms werden Hybrideingriffe mit Endophlebektomie der Vena femoralis communis und AV-Fistel-Anlage, zur Ausstromverbesserung werden spezielle Rekonstruktionen der Vena-cava-inferior-Konfluenz, z. B. die Skipped-Technik, empfohlen.
Bedeutung nicht-invasiver Verfahren in der Therapie des akuten hypoxämischen Versagens bei COVID-19
Authors: Windisch Wolfram , Schönhofer Bernd , Majorski Daniel Sebastian , Wollsching-Strobel Maximilian , Criée Carl-Peter , Schwarz Sarah Bettina , Westhoff Michael
Published: May 2021

In der Corona-Pandemie werden zunehmend nicht-invasive Verfahren zur Behandlung des akuten hypoxämischen Versagens bei COVID-19 eingesetzt. Hier stehen mit der HFOT (high-flow oxygen therapy), CPAP (continuous positive airway pressure) und der NIV (non-invasive ventilation) unterschiedliche Verfahren zur Verfügung, die das Ziel einer Intubationsvermeidung verfolgen. Der aktuelle Übersichtsartikel fasst die heterogene Studienlage zusammen. Wesentlich ist die Erkenntnis, dass diese nicht-invasiven Verfahren durchaus auch bei einem schweren, akuten hypoxämischen Versagen erfolgreich sein können und damit die Intubation wie auch Tubus-assoziierte Komplikationen vermeiden können. Demgegenüber bleibt aber ebenso zu betonen, dass die prolongierte unterstützte Spontanatmung ebenfalls zu Komplikationen führt und dass demzufolge insbesondere ein spätes NIV-Versagen mit erheblich verschlechterter Prognose einhergeht, was vor dem Hintergrund weiterhin hoher NIV-Versagensraten in Deutschland bedeutsam ist. Der aktuelle Artikel verweist schließlich auch auf einen Parallelartikel in dieser Ausgabe, der die medial in der Öffentlichkeit in Deutschland geführte Debatte zu diesem Thema aufgreift und deren inhaltliche Fragwürdigkeit, aber auch die negativen Auswirkungen auf die Gesellschaft und die Fachwelt adressiert. Gleichzeitig wird die Bedeutung von regelmäßig zu überarbeitenden Leitlinien untermauert.
Modern Organoselenium Catalysis: Opportunities and Challenges
Authors: Zhao Xiaodan , Liao Lihao
Published: May 2021

Organoselenium catalysis has attracted increasing interest in recent years. This Cluster highlights recent key advances in this area regarding the functionalization of alkenes, alkynes, and arenes by electrophilic selenium catalysis, selenonium salt catalysis, selenium-based chalcogen-bonding catalysis, and Lewis basic selenium catalysis. These achievements might inspire and help future research.

1 Introduction

2 Electrophilic Selenium Catalysis

3 Selenonium Salt Catalysis

4 Selenium-Based Chalcogen-Bond Catalysis

5 Lewis Basic Selenide Catalysis

6 Conclusion
Transinfratemporal Fossa Transposition of the Temporalis Muscle Flap for Skull Base Reconstruction after Endoscopic Expanded Nasopharyngectomy: Anatomical Study and Clinical Application
Authors: Sun Xicai , Liu Quan , Yu Hongmeng , Wang Huan , Zhao Weidong , Gu Yurong , Li Houyong , Zhao Keqing , Song Xiaole , Wang Dehui , Miranda Juan C. Fernandez , Snyderman Carl H.
Published: May 2021

Objective Temporalis muscle flap (TMF) is widely used in traditional skull base surgery, but its application in endoscopic skull base surgery remains rarely reported. We aimed to investigate the surgical anatomy and clinical application of TMF for reconstruction of skull base defects after expanded endoscopic nasopharyngectomy.

Methods Nine fresh cadaver heads (18 sides) were used for endoscopic dissection at the University of Pittsburgh School of Medicine in the United States. TMF was harvested using a traditional open approach and then transposed into the maxillary sinus and nasal cavity through the infratemporal fossa using an endoscopic transnasal transmaxillary approach. TMF length was then measured. Moreover, TMF was used for the reconstruction of skull base defects of six patients with recurrent nasopharyngeal carcinoma after expanded endoscopic nasopharyngectomy.

Results The length of TMF harvested from the temporal line to the tip of the coronoid process of the mandible was 11.8 ± 0.9 cm. The widest part of the flap was 9.0 ± 0.4 cm. When TMF was dislocated from the coronoid process of the mandible, approximately another 2 cm of reach could be obtained. When the superficial layer of the temporalis muscle was split from the deep layer, the pedicle length could be extended 1.9 ± 0.2 cm. TMF could cover skull base defects in the anterior skull base, sellar, and clivus regions.

Conclusion TMF can be used to reconstruct skull base defects after endoscopic expanded nasopharyngectomy and can effectively prevent the occurrence of serious complications in patients with recurrent nasopharyngeal carcinoma.
l-Arginine Can Enhance the Beneficial Effect of Losartan in Patients with Chronic Aortic Regurgitation and Isolated Systolic Hypertension
Authors: Lin Shoa-Lin , Lin Mike , Wang Kuei-Liang , Kuo Hsien-Wen , Tak Tahir
Published: May 2021

Information about the effects of angiotensin II receptor blocker (ARB) therapy on the hemodynamic and cardiac structure in patients with chronic aortic regurgitation (CAR) and isolated systolic hypertension (ISH) is limited.

This study planned to test the hypothesis that l-arginine could further enhance the beneficial effect of an ARB, losartan, and provide a favorable effect on the natural history of CAR and ISH.

Sixty patients with CAR and ISH were enrolled in a randomized, double-blind trial comparing hemodynamic and ultrasonic change in two treatment arms: losartan + l-arginine and losartan-only treated groups. Serial echocardiographic and hemodynamic studies were evaluated before and after treatment.

Both groups had a significant reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP), left ventricular end-diastolic volume index (LVEDVI), LV end-systolic volume index (LVESVI), LV mass index (LVMI), and LV mean wall stress after 6- and 12-month treatment (p <0.01 in all comparisons). Both groups had a significant increase in LV ejection fraction and exercise duration after 6- and 12-month treatment (p < 0.01 in all comparisons). Using multivariate linear regression analysis, only losartan + l-arginine therapy achieved a significantly lower LVESVI (38.89 ± 0.23 mL/m2), LVEDVI (102.3 ± 0.3 mL/m2), LVMI (107.6 ± 0.3 g/m2), SBP (123.5 ± 1.0 mm Hg), and greater exercise duration (7.38 ± 0.02 minutes) than those of the losartan-only treated groups (p <0.01 in all comparisons).

These findings suggest that early co-administrative strategy provides a beneficial approach to favorably influence the natural history of CAR.
Recurrent Acute Pancreatitis following Colonoscopic Fecal Microbiota Transplantation for Ulcerative Colitis
Authors: Seth Avnish Kumar , Gupta Mahesh Kumar , Verma Radha Krishan
Published: May 2021

A 37-year-old man with corticosteroid-dependent ulcerative pancolitis was taken up for colonoscopic fecal microbiota transplant (FMT). Preparation for colonoscopy was done with 118 g polyethylene glycol (PEG) in 2 L water ingested over 2 hours, followed by clear fluids. 200 g of screened donor stool, blended with water was instilled into terminal ileum; cecum; and ascending, transverse, and descending colon. Eighteen hours following ingestion of PEG and 2 hours following FMT, he complained of severe epigastric pain with radiation to back. Serum lipase was 6,756 U/L. He was managed with intravenous (IV) fluids and symptomatic treatment with discontinuation of corticosteroids and 6-MP. Ultrasound did not reveal gall bladder stones or sludge. There was no history of alcohol intake. Contrast-enhanced computed tomography scan at 48 hours showed bulky pancreas with peripancreatic stranding. He recovered over a week with normalization of lipase. Three weeks later he again reported severe epigastric pain 14 hours following ingestion of PEG, this time prior to colonoscopic FMT. Serum lipase was 1,140 U/L; the procedure was deferred and he recovered with symptomatic treatment over 3 days. Maintenance colonoscopic FMT was performed 4 times over the following 2 years with sodium phosphate preparation with no recurrence of pain. MRCP showed no evidence of chronic pancreatitis. He remains in clinical and endoscopic steroid-free, thiopurine-free remission. PEG is a rare cause of acute pancreatitis and merits consideration in appropriate clinical setting.
Risk Factors and Clinical Characteristics of Metabolic Bone Disease of Prematurity
Authors: Mutlu Mehmet , Aktürk-Acar Filiz , Kader Şebnem , Aslan Yakup , Karagüzel Gülay
Published: May 2021

Objective The study aimed to analyze the risk factors and clinical features of metabolic bone disease of prematurity (MBDP) in premature infants compared with infants of similar gestational age and birth weight without MBDP.

Study Design This retrospective case–control study was performed by comparing 81 cases of MBDP with 63 controls to identify potential risk factors. Premature infants with a gestational age ≤33 weeks and birth weight <1,500 g were included. Medical records were examined in terms of maternal conditions, potential risk factors, and clinical characteristics.

Results Bone fractures and invasive ventilator dependence were the most common clinical features of MBDP. Duration of invasive ventilation and total mechanical ventilation days, necrotizing enterocolitis, corticosteroid use, anticonvulsive drug use, duration of dexamethasone and caffeine use, total parenteral nutrition, and length of hospitalization were significantly higher in neonates with MBDP (p < 0.05). Breastfed neonates and those receiving human milk fortifier had a lower incidence of MBDP than those premature formula or mixed feeding (p < 0.05). Anticonvulsive drug use (odds ratio: 2.935; 95% confidence interval: 1.265–6.810) was identified as a risk factor for MBDP at multiple regression analysis.

Conclusion Our results show that anticonvulsive drug use is a significant risk factor for the development of MBDP. If long-term use is not required, anticonvulsive drugs should be stopped as soon as possible. Further studies involving patients with MBDP are required to determine the risk factors and clinical features.

Key Points