bluuebunny/crossref_metadata_2025 huggingface dataset:
REXPACO: An algorithm for high contrast reconstruction of the circumstellar environment by angular differential imaging
Authors: Flasseur Olivier , Thé Samuel , Denis Loïc , Thiébaut Éric , Langlois Maud
Published: May 2021

Context.Direct imaging is a method of choice for probing the close environment of young stars. Even with the coupling of adaptive optics and coronagraphy, the direct detection of off-axis sources such as circumstellar disks and exoplanets remains challenging due to the required high contrast and small angular resolution. Angular differential imaging (ADI) is an observational technique that introduces an angular diversity to help disentangle the signal of off-axis sources from the residual signal of the star in a post-processing step.

Aims.While various detection algorithms have been proposed in the last decade to process ADI sequences and reach high contrast for the detection of point-like sources, very few methods are available to reconstruct meaningful images of extended features such as circumstellar disks. The purpose of this paper is to describe a new post-processing algorithm dedicated to the reconstruction of the spatial distribution of light (total intensity) received from off-axis sources, in particular from circumstellar disks.

Methods.Built on the recentPACOalgorithm dedicated to the detection of point-like sources, the proposed method is based on the local learning of patch covariances capturing the spatial fluctuations of the stellar leakages. From this statistical modeling, we develop a regularized image reconstruction algorithm (REXPACO) following an inverse problems approach based on a forward image formation model of the off-axis sources in the ADI sequences.

Results.Injections of fake circumstellar disks in ADI sequences from the VLT/SPHERE-IRDIS instrument show that both the morphology and the photometry of the disks are better preserved byREXPACOcompared to standard post-processing methods such as cADI. In particular, the modeling of the spatial covariances proves useful in reducing typical ADI artifacts and in better disentangling the signal of these sources from the residual stellar contamination. The application to stars hosting circumstellar disks with various morphologies confirms the ability ofREXPACOto produce images of the light distribution with reduced artifacts. Finally, we show howREXPACOcan be combined withPACOto disentangle the signal of circumstellar disks from the signal of candidate point-like sources.

Conclusions.REXPACOis a novel post-processing algorithm for reconstructing images of the circumstellar environment from high contrast ADI sequences. It produces numerically deblurred images and exploits the spatial covariances of the stellar leakages and of the noise to efficiently eliminate this nuisance term. The processing is fully unsupervised, all tuning parameters being directly estimated from the data themselves.
Transition primaire-collège au Bénin, Maroc et Tunisie: Pour un état des lieux, comparaison et perspectives de l’enseignement de l’arithmétique et de l’algèbre
Authors: Najar Ridha , Squalli Hassane , Adihou Adolphe , Abouhanifa Said
Published: May 2021

Dans cet article nous présentons un projet de recherche interuniversitaire auquel participent quatre pays: le Canada, le Maroc, le Bénin et la Tunisie. Le projet vise à dresser un état de la situation de la transition entre l’enseignement de l’arithmétique au primaire et l’enseignement de l’algèbre au collège au Maroc, au Bénin et en Tunisie. Il envisage d’identifier et de caractériser les difficultés des élèves de la dernière année du primaire et de la première année du collège dans ces trois pays en algèbre et d’étudier le potentiel du développement de la pensée algébrique dans les programmes et manuels officiels du primaire et du collège, ainsi que dans les pratiques des enseignants.
Le changement d’axiomatique dans l’enseignement de la géométrie
Authors: Mrabet Slim
Published: May 2021

Dans l’enseignement tunisien, la transition collège-lycée en géométrie est marquée par un changement de point de vue dans la résolution des problèmes: les outils traditionnels de la géométrie rencontrés au collège seront accompagnés par le nouvel outil vectoriel. Pour contribuer à la question des difficultés éventuelles qui accompagnent cette transition, nous faisons un retour sur l’histoire de la géométrie et de son enseignement pour fixer des axiomatiques différentes qui nous servent de référence pour analyser l’enseignement actuel. Nous nous servons du théorème de Thalès qui, avec ses différentes approches, se place au coeur de cette transition, et analysons sa vie dans le système tunisien. Une expérimentation menée auprès d’élèves tunisiens et français montre que dans les deux pays, le passage de la géométrie classique à la géométrie vectorielle leur pose des difficultés différentes. L’analyse de ces difficultés et des avis des enseignants des classes visitées, montre que cette problématique est une piste qui mérite d’être explorée.
Utilisation du modèle de classe inversée pour l’introduction des Séries de Fourier en première année universitaire
Authors: Khalloufi-Mouha Faten
Published: May 2021

Dans ce papier, nous décrivons la mise en place d’une expérience de classe inversée pour l’introduction de la notion de série de Fourier à des étudiants de première année universitaire en sciences de l’informatique de la faculté des sciences de Bizerte en Tunisie. Dans l’objectif d’explorer l’impact de ce dispositif pédagogique sur l’apprentissage des mathématiques et en se plaçant dans le cadre de la théorie commognitive, nous avons cherché à étudier l’appropriation par les étudiants, des routines identifiées dans les capsules vidéos qui introduisent le contenu mathématique visé. Sur le plan pédagogique, les premiers résultats font apparaitre une hétérogénéité importante chez les étudiants qui a amené l’enseignante que nous sommes à mettre en place une méthode hybride qui consiste à introduire une séance de synthèse qui a suivi la visualisation des capsules vidéos. Sur le plan didactique, nous avons étudié l’individualisation par les étudiants des trois types de routines associées aux séries de Fourier: les routines de traitement graphique, les routines de traitement calculatoire et les routines de justification et de preuve.
Le concept de modèle scientifique: Vision des étudiants universitaires algériens
Authors: Houatis Djamel
Published: May 2021

La notion du “modèle” est devenue un outil indispensable dans le processus d’acquisition des connaissances et l’usage du terme “modèle” est devenu très fréquent dans les discours et les écrits en classe. Dans cet article, nous allons porter notre attention sur l’interaction des étudiants universitaires algériens avec le concept “modèle”, nous identifierons les trais distinctifs de leurs points de vue épistémologiques sur la notion de “modèle” en sollicitant par questionnaire des étudiants de trois établissements universitaires algériens (deux universités et une école supérieure). Nous avons choisi de poser des questions fermées avec justification des réponses. La grille d’analyse de nos résultats est basée sur des thèmes centraux préalablement sélectionnés. Sur le plan théorique, nous nous sommes placés dans le cadre du schéma de Jean-Louis Martinand qui décrit l’activité de la modélisation dans la classe. Les résultats de cette étude pourraient, il nous semble, être pris en compte dans la conception des programmes afin de mettre les étudiants dans des conditions favorables lors de l’intégration des modèles dans l’enseignement de la physique.
Proposition et évaluation d’un programme d’enseignement de l’informatique basé sur le modèle STEAM pour les élèves du primaire
Authors: Elmahni Lahoussine , Baribi Soufiane , Kitane Hassan , Ambri Badr , Douslimane Farid , Elkhalifi Hicham
Published: May 2021

Le développement de l’intelligence numérique va profondément modifier aussi bien notre marché du travail que notre enseignement. Pour s’adapter à une telle situation, la généralisation d’un modèle d’enseignement basé sur la théorie STEAM (Sciences, Technologies, Engineering, Arts et Mathématiques), s’avère une solution attrayante. Cette approche interdisciplinaire qui combine la créativité (art et design) et les sciences (technologie, ingénierie et mathématiques), permet aux élèves de développer des solutions innovantes à des problèmes réels, en développant l’hémisphère gauche et l’hémisphère droit du cerveau. L’objectif de cette approche est de développer chez les apprenants un certain nombre de compétences comportementales et techniques essentielles dans un futur proche, par le biais de la robotique et du codage. Ceux-ci permettent d’introduire de nouveaux modes d’apprentissage à travers des expériences, en mode projet, par essai-erreur et résolution de problèmes. Le but de cet article est de développer un programme de robotique et de programmation destiné aux écoles primaires Marocaines et de favoriser le processus de transfert didactique des apprentissages. L’étude a montré que l’introduction des robots dans l’apprentissage au primaire est une approche concrète pour construire les nouveaux concepts informatiques.
Formation des enseignants d’informatique au Maroc : Un regard critique
Authors: Iqdour Radouane , Serrar Ouafae , Abra Oum El kheir
Published: May 2021

L’introduction de l’enseignement de l’informatique en tant que science reste un sujet d’actualité dans plusieurs pays. Les principales questions qui surgissent à chaque fois concernent le curricula de l’informatique, c’est-à-dire définir le contenu du programme, sa répartition et sa progression didactique, ainsi que la formation des enseignants. Au Maroc, comme dans beaucoup d’autres pays, l’enseignement de l’informatique comme une discipline scolaire au même niveau que les mathématiques, les sciences de la vie et de la terre, la chimie et la physique peine à s’installer et cela malgré la volonté affichée et les efforts déployés par les différents intervenants dans l’éducation nationale. L’instauration d’un enseignement de l’informatique de qualité nécessite une véritable formation des enseignants. Le présent article a comme objectif de présenter un regard critique sur la formation qualifiante des enseignants d’informatique, programme, contenu pédagogique, etc., et de formuler quelques réflexions et préconisations de réforme.
Patterns of numerical relations in goal-scoring possessions of the 2014 FIFA World Cup Winner
Authors: Santos Rodrigo , Duarte Ricardo , de Andrade Ricardo Leão , Garganta Júlio , Teoldo Israel
Published: May 2021

Goal scoring has been regarded as the ultimate indicator of offensive success in soccer. Research on patterns that characterize goal-scoring possessions have frequently employed reductionist approaches. This paper aimed to examine the patterns of numerical relations of open-play goal-scoring possessions of the 2014 FIFA™ World Cup winner team. We hypothesized that a more unstable distribution of players in goal-scoring possessions Germany would be generated in sub-areas of the effective play-space closer to opponents’ goal. We analysed 11 video sequences from 6 matches of the German team in this tournament. The uncertainty of teams’ numerical advantage within sub-areas of play was calculated for each offensive sequence through Shannon’s entropy. We observed higher entropy within Germany’s Central Offensive (opponents’ Central Defensive) sub-area in comparison with the other sub-areas of play. There is a tendency of the German team to generate numerical instability within locations closer to the opponents’ goal, possibly due to the shifting of positions, drawing of opposing defenders towards peripheral areas and the creation of spaces for teammates to exploit within this risky zone to the opposition.
Operative Knorpeltherapie aktuell
Authors: Hinz Maximilian , Imhoff Andreas B. , Schmitt Andreas
Published: May 2021

Fokale Knorpelschäden gehen mit Schwellung, Funktionsverlust der betroffenen Gelenke und starker Schmerzsymptomatik einher. Zudem werden sie mit der Entstehung einer späteren Arthrose in Verbindung gebracht. Oftmals betroffen sind hierbei junge, sportlich aktive Patienten, die einen hohen funktionellen Anspruch haben. Die Behandlungsmöglichkeiten des Orthopäden in Bezug auf knorpelregenerative Therapiemöglichkeiten an Knie, Hüfte, Schulter, Ellenbogen und Sprunggelenk sind mannigfaltig.
Metastatische pulmonale Kalzifikation – eine selten diagnostizierte Entität in der differenzialdiagnostischen Abklärung interstitieller Lungenerkrankungen
Authors: Groß T. , Woziwodski A. , Simka S.
Published: May 2021

Eine 70-jährige Patientin, die vor ca. 20 Jahren aufgrund einer Anti-Neutrophile cytoplasmatische Antikörper (ANCA)-positiven, rapid-progressiven Glomerulonephritis eine Nierentransplantation erhielt, wurde uns zur Abklärung einer fibrosierenden interstitiellen Lungenerkrankung mit Computertomografie (CT)-radiologischen Veränderungen im Sinne (i. S.) einer akuten Alveolitis zugewiesen. Sie beklagte eine bereits seit Längerem bestehende Belastungsdyspnoe. Lungenfunktionell zeigte sich eine leichte Restriktion (FVC 78 % d. Soll), ausgeprägt eine schwere Diffusionsstörung (DLCO 41 % d. Soll). Sowohl anamnestisch als auch serologisch ergab sich kein Hinweis auf eine exogen-allergische Alveolitis. In den bronchoskopisch gewonnenen Proben wurden initial Veränderungen i. S. einer nichtspezifischen interstitiellen Lungenerkrankung vom fibrotischen Typ, z. B. zu einer Reaktion im Rahmen der immunsuppressiven Therapie passend, gefunden. Mikrobiologisch wurde in der bronchoalveolären Lavage (BAL)-Flüssigkeit Herpes-simplex-Virus mittels Polymerase-Kettenreaktion (PCR) nachgewiesen. Unter der Arbeitsdiagnose einer Herpes-Pneumonitis wurde eine antivirale Therapie durchgeführt. Die immunsuppressive Therapie wurde fortgesetzt. In einer Kontrolle konnte der Herpesvirus nicht mehr nachgewiesen werden. Nach initialer subjektiver Verbesserung der Luftnot und wiederholter Kontroll-CT-Bildgebung stellten sich die initialen radiologischen Veränderung nach ca. einem Jahr als unverändert dar und die Belastungsluftnot als persistierend. In der neuerlichen transbronchialen Lungenbiopsie konnte eine metastatische pulmonale Kalzifikation nachgewiesen werden. Eine Aktivität der Erkrankung konnte erfreulicherweise ausgeschlossen werden.

Fazit In der differenzialdiagnostischen Abklärung interstitieller Lungenerkrankungen muss v. a. bei Patient*innen mit vulnerablem Kalzium-Phosphat-Haushalt und Säure-Basen-Gleichgewicht, wie es z. B. im Rahmen chronischer Nierenerkrankungen auftritt, auch an die Möglichkeit einer metastatischen pulmonalen Kalzifikation (MPC) gedacht werden, v. a. wenn das radiologische Bild persistierende, oberlappenbetonte Milchglasveränderungen aufzeigt. Die Diagnosestellung erfordert hierbei eine multidisziplinäre Zusammenarbeit zwischen Pneumologen, Radiologen und Pathologen.
The Efficacy of Adjuvant Chloroquine for Glioblastoma: A Meta-Analysis of Randomized Controlled Studies
Authors: Wei Hong , Jiang Zhenfu
Published: May 2021

Introduction The efficacy of adjuvant chloroquine for glioblastoma remains controversial. We conduct a systematic review and meta-analysis to explore the influence of adjuvant chloroquine on treatment efficacy for recurrent glioblastoma.

Methods We search PubMed, Embase, Web of science, EBSCO, and Cochrane library databases through January 2020 for randomized controlled trials (RCTs) assessing the efficacy of adjuvant chloroquine for glioblastoma. This meta-analysis is performed using the random-effect model.

Results Three RCTs are included in the meta-analysis. Overall, compared with control group for glioblastoma, adjuvant chloroquine is associated with significantly reduced mortality (risk ratio [RR] = 0.59; 95% confidence interval [CI] = 0.47–0.72; p < 0.00001), improved remission (RR = 11.53; 95% CI = 1.53–86.57; p = 0.02), and prolonged survival time (Std.MD = 11.53; 95% CI = 1.53–86.57; p = 0.02), but has no substantial effect on recurrence (RR = 0.42; 95% CI = 0.12–1.49; p = 0.18).

Conclusion Adjuvant chloroquine may provide additional benefits for the treatment of glioblastoma.
Brain Abscess in the Current Decade (2010–2019) in India—A Review
Authors: Ravikumar R. , John Daisy Vanitha
Published: May 2021

Brain abscess outcomes have improved in recent years due to advancements in cranial imaging, microbiological techniques, minimally invasive neurosurgical procedures, and effective antibiotic treatments. However, the incidence of brain abscess remains unchanged in developing countries. We searched PubMed and Google Scholar for references using the key words “brain abscess” and “India” and reviewed both retrospective and prospective studies published in peer-reviewed journals in the current decade to understand the present status. The review shows that the patients’ ages, the predominance of male patients, the symptoms and locations of brain abscesses, and the types of bacteria associated with them have remained unchanged over the past decade. The most common predisposing condition in recent years has been chronic suppurative otitis media with a mortality rate of 7 to 10%. Middle ear infection is often neglected and not treated aggressively in Asian countries. It requires multidisciplinary treatment strategies to address the primary source of infection and better health awareness to prevent the development of brain abscess.
Extraction of an Impacted Foreign Body Bronchus in an Adult Using Flexible Bronchoscopy
Authors: T. Chandramouli M. , Baikunje Nandakishore , Venkataram Rajesh , Hosmane Giridhar
Published: May 2021

Foreign body aspiration (FBA) can be potentially fatal if the object is large enough to cause nearly complete obstruction of the upper airway. The object causing obstruction beyond the carina can result in less severe clinical presentation. FBA is rare in adults than in children. If the clinical history is not suggestive of FBA, then a high index of suspicion and flexible bronchoscopy can ensure proper diagnosis and prompt intervention. We present a case of an adult with aspirated betel nut in the left main bronchus, removed using flexible bronchoscopy with the aid of a Fogarty balloon catheter following the failure of rigid bronchoscopy.
Perceptions of Surgical and Other Medical Specialties about Medical Oncologists: A Survey among Physicians in a Filipino Tertiary Hospital
Authors: De Veyra Jamila Marie J. , Calma Clevelinda S.
Published: May 2021

Introduction There are unverified negative perceptions about medical oncologists. Identifying how they are perceived may provide guidance on how to strengthen the positive and correct the negative impressions.

Methods Questionnaires were distributed to 528 physicians. They were asked to answer a Likert scale of opposing descriptors.

Results Two hundred and fifty-nine of 528 physicians completed the questionnaire, yielding a 49% response rate. Medical oncologists were perceived to have a medical rather than social focus to their work, render holistic care, have a multifaceted role, communicate with many other professionals, work more effectively in a team, have deep relationships with patients, and care for their general well-being. They are considered to be the nonsporty, intellectual type, who do not consider themselves superior, but rather treat other physicians as colleagues. They are perceived to not only have the skills to deal with a psychiatric problem and a wide spectrum of patients, have a health education role, require a high level of intellectual skills, collaborate more with others, possess good interpersonal skills with an individual patient, but are also adept within a group. They are autonomous workers, but usually refer patients to other professionals as well. Lack of finances hinders referral to medical oncologists.

Conclusion Perceptions were generally positive in terms of breadth of professional outlook, degree of patient interaction, projected professional image, perception of own professional status, possession of skills for a wide professional scope of responsibility, level of rapport with patient and colleagues, and degree of professional interdependence. Mainly financial factors are the barriers to referral to medical oncologists.
Signatures of self-interstitials in laser-melted and regrown silicon
Authors: Menold T. , Ametowobla M. , Werner J. H.
Published: May 2021

Photoluminescence spectroscopy investigates epitaxially regrown silicon single crystals after pulsed laser melting for atomic-level lattice defects. The measurements identify a transition from a regime free of defect-related spectral lines to a regime in which spectral lines appear originating from small self-interstitial clusters. This finding of self-interstitial clusters indicates supersaturated concentrations of self-interstitials within the regrown volume. Molecular dynamics simulations confirm that recrystallization velocities vre ≈ 1 m/s after laser melting lead to supersaturation of both self-interstitials and vacancies. Their concentrations ci and cv in the regrown volumes are ci ≈ cv ≈ 1017 cm−3. An analytical model based on time-dependent nucleation theory shows a very strong dependence of self-interstitial aggregation to clusters on the cooling rate after solidification. This model explains the transition identified by photoluminescence spectroscopy.
Probing the local emission of CaAlSiN3:Eu2+ via X-ray nanoprobe
Authors: Huang Shu-Chi , Wu Yu-Hao , Fu Shih-Yu , Lee Chien-Yu , Chen Bo-Yi , Yin Gung-Chian , Chung Shyan-Lung , Lin Bi-Hsuan , Tang Mau-Tsu
Published: May 2021

A synchrotron source offers the advantage of continuous and tunable x rays. Therefore, not only an X-ray nanoprobe can provide the desired spatial resolution to measure the elemental distribution of CaAlSiN3:Eu2+ via X-ray fluorescence mapping but X-ray absorption spectroscopy can also be used to unambiguously analyze the valence states of europium ions (Eu2+ or Eu3+) in different local areas. X-ray excited optical luminescence spectra exhibit only one red emission peak (∼650 nm) corresponding to the 4f65d1 to 4f7 transition of Eu2+, which reveals the fact that Eu2+ ions substitute perfectly for Ca2+ ions at the same site. Through detailed analysis, we demonstrated that the main contribution to the luminescence intensity of CASIN:Eu2+ comes from the Eu2+ activator in the product. We anticipate that X-ray nanoprobes will open new avenues with great characterization ability for studying the emission properties of CASIN:Eu2+.
Optimization of key power loss for LLC circuits with planar transformer in high-frequency and high-power scenarios
Authors: Ji Ziyi , Min Fuhong , Dou Yiping , Cao Ziqing , Li Xinya
Published: May 2021

An accurate power loss model, for the design of high-efficiency switching power supplies, is difficult to establish due to the complicated magnetic components where the power loss is hard to calculate. This paper proposed a multi-level power loss model of LLC circuits with a planar transformer of high frequency, high power, and low voltage output. The key loss items can be optimized by using this loss model, the accuracy of which and the feasibility of the optimization method are validated by extensive prototype experiments. The experimental results show that the average accuracy of the loss calculation is about 93.6%, and the high efficiency at high-power conversion (95.9% @ 3 kW, 224–16 V) has been realized using an optimized prototype converter.
Multi-layer optical Fourier neural network based on the convolution theorem
Authors: Wu Qiuhao , Sui Xiubao , Fei Yuhang , Xu Chen , Liu Jia , Gu Guohua , Chen Qian
Published: May 2021

To take full advantage of the application of neural networks to optical systems, we design an optical neural network based on the principle of free-space optical convolution. In this article, considering the need for a high-power light source to excite the nonlinearity of an optical material, we describe how to reduce the power consumption of the system by quantifying the output of each layer after the softmax operation as an 8-bit value and loading these values into amplitude-only spatial light modulators (SLMs). In addition, we describe how to load the matrix with positive and negative values in the amplitude-only SLM by utilizing Fourier properties of the odd-order square matrix. We apply our six-layer optical network to the classification of Mixed National Institute of Standards and Technology database (MNIST) and Fashion-MNIST and find that the accuracy reaches 92.51% and 80.67%, respectively. Finally, we consider the error analysis, power consumption, and response time of our framework.
Can sampling for vegetation characterisation surrogate for species richness? Case studies from the wet–dry tropics of northern Australia
Authors: Patykowski John , Cowie Ian , Cuff Nick , Chong Caroline , Nano Catherine , Jobson Peter , Lewis Donna
Published: May 2021

Understanding the distribution of plant species and vegetation communities is important for effective conservation planning and ecosystem management, but many parts of the world remain under-surveyed. The Top End of Australia’s Northern Territory is vast, remote, and sparsely populated; knowledge of the flora, in many areas, is limited to common or dominant species. Here, we describe and contrast the benefits and trade-offs between two approaches to botanical survey – vegetation sampling (assessment of structural attributes and species composition, fundamentally for mapping purposes) and hybrid floristic survey (an intensive, inventory approach considering seasonality) – as applied in each of four remote areas of the Australian wet–dry monsoonal tropics. Hybrid floristic survey effectively doubled the species richness recorded within each study area, largely due to improved detections of forbs and sedges. Species-sampling effort relationships predicted hybrid floristic survey to consistently out-perform vegetation sampling in maximum species richness and rate of species accumulation. Although vegetation sampling offers an efficient means of circumscribing vegetation communities over large areas, hybrid floristic survey improved detection of seasonal species and, potentially, those of conservation concern. Strategic, proactive investment in hybrid floristic surveys may offer improved conservation outcomes and potential efficiency dividends in biodiversity conservation planning.
Leichhardt’s ethnobotany for the eucalypts of south-east Queensland
Authors: Fensham Roderick J.
Published: May 2021

The explorer Ludwig Leichhardt travelled with Aboriginal people in south-east Queensland during 1843–44. Leichhardt’s record of Aboriginal taxonomy in Yagara, Wakka, Kabi, and other languages was related to the current taxonomy of the eucalypts of south-east Queensland. Most of the taxonomic entities could be associated across cultures and verifies the intimate understanding of Aboriginal peoples with tree species that are difficult to distinguish in the field. Leichhardt’s record together with that of Gairabau, a Dungidau man from south-east Queensland verifies a broad array of uses for eucalypts including as gum for chewing, dying, and medicine; ash rubbed into the skin for soothing young mothers, where bees, honey and wax can be found, hollow logs for fish-traps, hard timber for weapons and utensils, bark for shelter, canoes, embalming, and containers – some species contained water, others were used to create smoke for sending signals, some species indicated an unsuitable camp-site, and others indicated the likelihood of finding koalas and possum as game. Flowering and the shedding of bark are signs for the bush calendar.Warning: Aboriginal and Torres Strait Islander readers are advised that this article contains the names and images of deceased persons.
Degradation kinetics of alkali-activated mortar in aggressive citric acid environment
Authors: Nidhu M S , Sniktha V R , Benny Libin , Thomas Jerin , Ajay Athira , Ramaswamy K P
Published: May 2021

Acid attack is a complex phenomenon arising in construction industries worldwide as it is responsible for the deterioration of concrete in acidic environments resulting in premature degradation with regard to mass changes, weakening of mechanical properties, and increase in porosity due to calcium leaching. This paper investigates the citric acid resistance of geopolymer composites (GP) and its comparison with conventional concrete system (OPC) in lower and higher concentrations of acid medium. The GP samples displayed increased resistance to citric acid attack than OPC system in terms of mass and strength loss. It was also found that geopolymer mortar made with a blend of ground granulated blast furnace slag (GGBS) and red mud (RM) offered increased acid resistance based on the parameters studied in the degradation kinetics
Degradation kinetics of alkali-activated pastes in acetic acid
Authors: Ajay Athira , Ramaswamy K P , Thomas Anu V
Published: May 2021

Growing urban and industrial activities globally are found to be the sources of rising acidic environment. These acidic environments ensue early degradation of concrete in terms of microstructural alteration of phases formulating to mass changes, weakening of mechanical properties, and increase in porosity due to calcium leaching. This paper probes into the acetic acid resistance of geopolymer composites (GP) and its comparison with conventional concrete system (OPC) in 0.125M and 0.25M concentrations of acetic acid medium. The GP samples displayed increased resistance to acetic acid attack in terms of mass and thickness loss. It was also found that blends of ground granulated blast furnace slag (GGBS) and fly ash (class F) (FA) with red mud (RM) offered increased acid resistance due to the nature of the main binder gel produced in GP systems.
Earthquake data analysis and data visualization of Maharashtra state, India from 1912 to 2009 using R programming
Authors: Battul Vaishnavi , Helen Santhi M , Malathi G
Published: May 2021

This paper presents the seismic data analysis and visualization using R programming for the state of Maharashtra, India. Maharashtra has witnessed a significant number of earthquakes ranging from low to high in magnitude. The past earthquake data of a particular location are useful to the civil and structural engineers for the safe and efficient planning, designing and construction of seismic resistant buildings in that locality. In this paper the past earthquake data of Maharashtra from the year 1912 to 2009 are collected and analyzed. There are 53 earthquake data with magnitudes ranging from 3.6 to 7.2. This analysis shows the relationship between magnitude and depth, intensity and PGA, visualization of classification of earthquakes depends on magnitude and intensity.
Seismic performance assessment of a typified school building damaged during the 2019 Albanian earthquakes
Authors: Hysenlliu Marjo , Bilgin Hüseyin
Published: May 2021

This study presents the seismic performance evaluation of a typified masonry school building, Shkolla 9-Vjeçare “26 Nëntori”, which was damaged by the recent earthquakes which hit Albanian territory on November 26, 2019. This building was constructed in 1985 by following the template school projects in Albanian construction practice. The current situation of the building was evaluated by considering the provisions of modern codes i.e. Eurocode 6, Eurocode 8 and Turkish building Code. Analytical model of the school building was developed using the experimental test results conducted on the brick units and mortar. Nonlinear static pushover analyses were executed to estimate the seismic capacity, the performance point, and the damage limit state levels. The performance based assessment rules were used for this objective. Deficiencies and weak points were identified by the detailed examination of the pushover curves. Results showed that selected school designed per pre-modern code is far from satisfying the desired criteria, suggesting that urgent response and necessary measures should be put into action.
Classification of certain vertebral degenerations using MRI image features
Authors: Athertya Jiyo S , Saravana Kumar G
Published: May 2021

Background and Objective: This article describes a fully automatic system for classifying various spinal degenerative phenotypes namely Modic changes, endplate defects and focal changes which are associated with lower back pain. These are obtained from T1/T2 Magnetic Resonance Imaging (MRI) scans. Lower back pain is a predominantly occurring ailment, which is prone to have various roots including the anatomical and pathophysciological aspects. Clinicians and radiologist use MRI to assess and evaluate the extent of damage, cause, and to decide on the future course of treatment. In large healthcare systems, to circumvent the manual reading of various image slices, we describe a system to automate the classification of various vertebral degeneracies that cause lower back pain. Methods: We implement a combination of feature extraction, image analysis based on geometry and classification using machine learning techniques for identifying vertebral degeneracies. Image features like local binary pattern, Hu’s moments and gray level co-occurrence matrix (GLCM) based features are extracted to identify Modic changes, endplate defects, and presence of any focal changes. A combination of feature set is used for describing the extent of Modic change on the end plate. Feature sensitivity studies towards efficient classification is presented. A STIR based acute/chronic classification is also attempted in the current work. Results: The implemented method is tested and validated over a dataset containing 100 patients. The proposed framework for detecting the extent of Modic change achieves an accuracy of 85.91%. From the feature sensitivity analysis, it is revealed that entropy based measure obtained from gray level co-occurrence matrix alone is sufficient for detection of focal changes. The classification performance for detecting endplate defect is highly sensitive to the first 2 Hu’s moments. Conclusion: A novel approach to identify the allied vertebral degenerations and extent of Modic changes in vertebrae by exploiting image features and classification through machine learning is proposed. This shall assist radiologists in detecting abnormalities and in treatment planning.
Apical oxygen vibrations dominant role in d-wave cuprate superconductivity and its interplay with spin fluctuations
Authors: Rosenstein B , Shapiro B Ya
Published: May 2021

Microscopic theory of a high T

c
cuprate Bi
2
Sr
2
CaCu
2
O
8+x
based on main pairing channel of electrons in CuO planes due to 40mev lateral vibrations of the apical oxygen atoms in adjacent the SrO ionic insulator layer is proposed. The separation between the vibrating charged atoms and the 2D electron gas creates the forward scattering peak leading in turn to the d -wave pairing within Eliashberg formalism. The phonon mode naturally explain the kink in dispersion relation observed by ARPES and the and effect of the O
16 → O
18 isotope substitution in the normal state. To describe the pseudogap physics a single band fourfold symmetric

t
−

t

′

Hubbard model, with the hopping parameters

t

′

∼
−
0.17
t

and the on site repulsion e U ∼ 6t. It described the Mott insulator at low doping, while at higher dopping the pseudogap physics (still strongly correlated) can be be approximated by the symmetrized mean field model and with renormalized U incorporating screening. The location of the transition line T
*between the locally antiferromagnetic pseudogap and the paramagnetic overdoped phases and susceptibility (describing spin fluctuations coupling to 2DEG) are also obtained within this approximation. The superconducting d - wave gap mainly due to the phonon channel but is assisted by the spin fluctuations (15%–20%). The dependence of the gap and T

c
on doping and effect of the isotope substitution are obtained and is consistent with experiments.
The condition for the conservation of momentum at the interface under phase transitions of solutions
Authors: Guskov Alex
Published: May 2021

The present work considers a change in the momentum under the transfer of a solution through the interface. It is shown that pressure related to the partial volumes of the components arises as a result of the kinetics of the addition of particles to a new phase in the solution. In contrast to the description of one-dimensional interphase mass transfer using the convective diffusion problem, the proposed model provides the stationary exponential distributions of components in both phases. It is shown that generalized Fick’s law provides the condition for the conservation of the momentum of a component at the interface. The model describes component segregation by the interface.
Existence theory for the EED inpainting problem
Authors: Bildhauer M. , Cárdenas M. , Fuchs M. , Weickert J.
Published: May 2021

An existence theory is developed for an elliptic boundary value problem in image analysis known as edge-enhancing diffusion (EED) inpainting. The EED inpainting problem aims at restoration of missing data in an image as the steady state of a nonlinear anisotropic diffusion process where the known data provide Dirichlet boundary conditions. The existence of a weak solution is established by applying the Leray–Schauder fixed point theorem, and it is shown that the set of all possible weak solutions is bounded. Moreover, it is demonstrated that under certain conditions the sequences resulting from iterative application of the operator from the existence theory contain convergent subsequences.
On Silence and History
Authors: Topouzova Lilia
Published: May 2021

How to write a silenced history is the broad question that frames this essay. It explores the methodological challenges of working with a purged archive and fragmented oral histories while telling the little-known story of the Bulgarian gulag and its aftermath. Weaving together the personal and the historical, the essay unfolds the silences that constitute the experience of state repression during the Communist era and the trauma that lingers to this day in the lives of survivors and society. To write a history of the Communist camp past in the capitalist present requires scholars to overcome intellectual frameworks deeply mired in triumphalist Cold War rhetoric. The historical methodology laid out here suggests that doing so demands of us to embrace the imperfect evidence that we have at our disposal: disjointed testimonies and purged documents. Instead of trying to make them cohere into a linear historical narrative, the essay proposes that we leave the gaps open and let the silences speak. In grappling with the limit of the archival record and faded memories, the essay also reflects on the multiplicity of the lived experience of twentieth-century Eastern European Communism and its contradicting realities, emancipatory and repressive at once.
Methods for the Analysis of 26 Million VOC Area Measurements during the Deepwater Horizon Oil Spill Clean-up
Authors: Groth Caroline P , Banerjee Sudipto , Ramachandran Gurumurthy , Stewart Patricia A , Sandler Dale P , Blair Aaron , Engel Lawrence S , Kwok Richard K , Stenzel Mark R
Published: May 2021

The NIEHS GuLF STUDY is an epidemiologic study of the health of workers who participated in the 2010 Deepwater Horizon oil spill response and clean-up effort. Even with a large database of approximately 28 000 personal samples that were analyzed for total hydrocarbons (THCs) and other oil-related chemicals, resulting in nearly 160 000 full-shift personal measurements, there were still exposure scenarios where the number of measurements was too limited to rigorously assess exposures. Also available were over 26 million volatile organic compounds (VOCs) area air measurements of approximately 1-min duration, collected from direct-reading instruments on 38 large vessels generally located near the leaking well. This paper presents a strategy for converting the VOC database into hourly average air concentrations by vessel as the first step of a larger process designed to use these data to supplement full-shift THC personal exposure measurements. We applied a Bayesian method to account for measurements with values below the analytic instrument’s limit of detection while processing the large database into average instrument-hour concentrations and then hourly concentrations across instruments on each day of measurement on each of the vessels. To illustrate this process, we present results on the drilling rig ship, the Discoverer Enterprise. The methods reduced the 26 million measurements to 21 900 hourly averages, which later contributed to the development of additional full-shift THC observations. The approach used here can be applied by occupational health professionals with large datasets of direct-reading instruments to better understand workplace exposures.
Combination of ablative fractional carbon dioxide laser and platelet-rich plasma treatment to improve hypertrophic scars: a retrospective clinical observational study
Authors: Dai Zhanzhan , Lou Xiaozhen , Shen Tuo , Sun Yu , Xiao Yongqiang , Zheng Xingfeng , Wang Xuexin , Peng Yu , Guo Yukun , Guo Yibin , Wen Jiannan , Fang He , Ma Bing , Xia Zhaofan
Published: May 2021

Background

Hypertrophic scars are one of the main complications that affect the quality of life of patients after burns. Many methods have been shown to be effective in the treatment of hypertrophic scars, such as ablative fractional CO2 laser (AFCL) and platelet-rich plasma (PRP). However, there are few studies on the effect of the combined application of these measures. The purpose of this study was to explore the therapeutic effect of AFCL combined with PRP on hypertrophic burn scars.

Methods

A retrospective clinical observation study was conducted on 50 patients with hypertrophic burn scars. The AFCL+PRP group included 31 patients who received AFCL combined with PRP treatment; the AFCL group included 19 patients who received AFCL treatment only. The University of North Carolina 4P Scar Scale (UNC4P) and the Vancouver Scar Scale (VSS) scores that were collected before each treatment were used as indicators of the effectiveness of the previous treatment. The scores recorded at the second, fourth and seventh months were analysed.

Results

The demographic data of the 2 groups were not significantly different. Before treatment, there was no difference in the UNC4P and VSS scores between the 2 groups. There was a significant decline in the UNC4P and VSS total scores over 6 months in both groups (p < 0.05) and scores in the 2 groups were comparable after 3 and 6 months (p < 0.05). UNC4P scores in the AFCL+PRP group decreased from a mean of 8.26 to 2.61 (p < 0.05) with a concomitant drop in VSS scores from a mean of 11.74 to 6.06 (p < 0.01). In the AFCL group UNC4P and VSS scores decreased from 7.68 to 4.63 (p < 0.05) and from 10.89 to 8.16 (p < 0.05), respectively. The sub-items of these 2 assessments were analysed and the results suggest that AFCL combined with PRP can comprehensively improve scarring.

Conclusions

This study shows that PRP is an effective adjunct for AFCL in the treatment of hypertrophic burn scars and that the combination of PRP and AFCL proved to be more useful than AFCL alone. This combination may be a new and effective clinical practice for the treatment of scars. However, larger and higher-level clinical studies are still needed to determine its efficacy and possible mechanisms.
First Case of Lethal Encephalitis in Western Europe Due to European Bat Lyssavirus Type 1
Authors: Regnault Béatrice , Evrard Bruno , Plu Isabelle , Dacheux Laurent , Troadec Eric , Cozette Pascal , Chrétien Delphine , Duchesne Mathilde , Vallat Jean-Michel , Jamet Anne , Leruez Marianne , Pérot Philippe , Bourhy Hervé , Eloit Marc , Seilhean Danielle
Published: May 2021

Background

Inaccurate diagnosis of encephalitis is a major issue as immunosuppressive treatments can be deleterious in case of viral infection. The European bat lyssavirus type 1 (EBLV-1), a virus related to rabies virus, is endemic in European bats. No human case has yet been reported in Western Europe. A 59-year-old patient without specific past medical history died from encephalitis. A colony of bats lived in an outbuilding of his house. No diagnosis was made using standard procedures.

Methods

We used a next generation sequencing (NGS) based transcriptomic protocol to search for pathogens in autopsy samples (meninges and brain frontal lobe). Results were confirmed by polymerase chain reaction (PCR) and by antibody testing in serum. Immunochemistry was used to characterize inflammatory cells and viral antigens in brain lesions. Cells and mice were inoculated with brain extracts for virus isolation.

Results

The patient’s brain lesions were severe and diffuse in white and gray matter. Perivascular inflammatory infiltrates were abundant and rich in plasma cells. NGS identified European bat lyssavirus type 1a in brain, which was confirmed by PCR. A high titer of neutralizing antibodies was found in serum. No viral antigen was detected, and the virus could not be isolated by cell culture or by mouse inoculation.

Conclusions

The patient died from European bat lyssavirus type 1a infection. NGS was key to identifying this unexpected viral etiology in an epidemiological context that did not suggest rabies. People exposed to bats should be strongly advised to be vaccinated with rabies vaccines, which are effective against EBLV-1.
Burden of dementia in atrial fibrillation hospitalizations- analysis of national inpatient sample 2016-2018
Authors: Thyagaturu H , Shah K , Li S , Thangjui S , Shrestha B
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial fibrillation is a common disorder in the elderly population and a known risk factor for stroke and dementia.

Purpose

 To study the burden of dementia in Afib hospitalizations and identify the predictors of in-hospital mortality in Afib with dementia hospitalizations.

Methods

We queried January 2016 to December 2018 National Inpatient Sample (NIS) to identify adult (≥18 yrs) hospitalizations with a primary diagnosis of Afib. Hospitalizations of Afib with dementia was compared with Afib without dementia. We used the Chi-square test for differences between categorical variables, and Student’s t-test for continuous variables. Multivariate logistic regression was used in outcomes analysis to adjust for potential hospital and patient-level confounders.

Results

 We identified 1,236,540 weighted Afib hospitalizations across three years. Of which, 79,405 (6.4%) of them were associated with dementia. Afib with dementia hospitalizations were associated with older age (mean age 83.2 vs 70.0 yrs; P < 0.01), higher rate of chronic Afib (15.3% vs 7.5%; P < 0.01), higher rate of comorbidity (% of >3 Elixhauser comorbidity score 91.8% vs 83.6%; P < 0.01). After adjusting for patient and hospital-level characteristics, we observed that Afib with dementia hospitalizations was associated with higher odds of in-hospital mortality compared to Afib without dementia [Odds Ratio (OR): 1.6 (1.4 – 1.9); P < 0.01]. We also observed statistically significant association with increased LOS [4.7 vs 3.2 days; P < 0.01], repeated falls [OR: 2.8 (2.5 – 3.1); P < 0.01] and protein calorie malnutrition [OR: 1.9 (1.7 – 2.0); P < 0.01] in Afib with dementia group.

Conclusion

Afib with dementia hospitalizations are not only associated with higher mortality, but they are also associated with higher repeated fall rates, and skilled nursing facility discharge dispositions. Co-morbidities like hypertension, CKD, obesity, HFrEF, HFpEF, OSA are associated with higher in-hospital mortality. Our study findings emphasize the burden of dementia in Afib hospitalizations and the need for prevention of poor outcomes in this population.