bluuebunny/crossref_metadata_2025 huggingface dataset:
Primordial Black Holes Formation and Secondary Gravitational Waves in Nonminimal Derivative Coupling Inflation
Authors: Teimoori Zeinab , Rezazadeh Kazem , Karami Kayoomars
Published: July 2021

We study the possibility of the primordial black holes (PBHs) formation with the aim of finding a considerable fraction of dark matter (DM), using the gravitationally enhanced friction mechanism which arises from a nonminimal derivative coupling between the scalar field and the gravity. Assuming the nonminimal coupling parameter as a special function of the scalar field and considering the potential of natural inflation, we find three parameter sets that produce a period of ultra slow-roll inflation. This leads to sufficiently large enhancement in the curvature power spectra to form PBHs. We show that under the gravitationally enhanced friction mechanism, PBHs with a mass around



10

−
12

M

⊙

can constitute around 96% of the total DM and so this class of PBHs can be taken as a great candidate for DM. We further study the secondary gravitational waves (GWs) in our setting and show that our model predicts the peak of the present fractional energy density as ΩGW0 ∼ 10−8 at different frequencies for all the three parameter sets. This value lies well inside the sensitivity region of some GWs detectors at some frequencies, and therefore the observational compatibility of our model can be appraised by the data from these detectors.
The Power Spectrum and Structure Function of the Gamma-Ray Emission from the Large Magellanic Cloud
Authors: Besserglik Daniel , Goldman Itzhak
Published: July 2021

The Fermi-LAT observational data of the diffuse γ ray emission from the Large Magellanic Cloud (LMC) were examined to test for the existence of underlying long-range correlations. A statistical test applied to the data indicated that the probability that data are random is extremely small. Thus we proceeded and have used the counts-number data to compute 2D spatial autocorrelation, power spectrum, and structure function. The most important result of the present study is a clear indication for large-scale spatial underlying correlations. This is evident in all the functions mentioned above. The 2D power spectrum has a logarithmic slope of −3 on large spatial scales and a logarithmic slope of −4 on small spatial scales. The structure function has logarithmic slopes equaling 1 and 2 for the large and small scales, respectively. The logarithmic slopes of the structure function and the power spectrum are consistent. A plausible interpretation of these results is the existence of a large-scale supersonic compressible turbulence with a 3D logarithmic slope of −4 extending over scales comparable to the size of the LMC. Both the power spectrum and structure function exhibit steeper logarithmic slopes for smaller spatial scales. This is interpreted as an indication that the turbulent region has an effective depth of about 1.5 kpc.
Huffing and Puffing and Blowing Your House In: Strong Stellar Wind Interaction with a Supermassive Black Hole
Authors: Lora V. , Raga A. C. , Cantó J. , Esquivel A.
Published: July 2021

We present analytical and numerical models of a cluster wind flow resulting from the interaction of stellar winds of massive stars with a supermassive black hole (SMBH). We consider the motion of the stars as well as the gravitational force of the SMBH. In the numerical simulations we consider two cases: the first one with the stars in circular orbits around the SMBH, and the second one with the stars in eccentric orbits. We found that after the system reaches an equilibrium, the circular and elliptical cases are very similar. We found a very good agreement between the analytical and numerical results, not only from our numerical simulations but also from other high-resolution numerical calculations. The analytical models are very interesting, since the properties of such complex systems involving strong winds and a massive compact object can be rapidly inferred without the need of a numerical calculation.
On the Origin of Stochastic, Low-Frequency Photometric Variability in Massive Stars
Authors: Cantiello Matteo , Lecoanet Daniel , Jermyn Adam S. , Grassitelli Luca
Published: July 2021

High-precision photometric observations have revealed ubiquitous stochastic low-frequency photometric variability in early-type stars. It has been suggested that this variability arises due to either subsurface convection or internal gravity waves launched by the convective core. Here we show that relevant properties of convection in subsurface convective layers correlate very well with the timescale and amplitude of stochastic low-frequency photometric variability, as well as with the amplitude of macroturbulence. We suggest that low-frequency, stochastic photometric variability and surface turbulence in massive stars are caused by the presence of subsurface convection. We show that an explanation for the observed surface photometric variability and macroturbulence relying on convective core driven internal gravity waves encounters a number of difficulties and seems unlikely to be able to explain the observed trends.
Asteroid 16 Psyche: Shape, Features, and Global Map
Authors: Shepard Michael K. , de Kleer Katherine , Cambioni Saverio , Taylor Patrick A. , Virkki Anne K. , Rívera-Valentin Edgard G. , Rodriguez Sanchez-Vahamonde Carolina , Fernanda Zambrano-Marin Luisa , Magri Christopher , Dunham David , Moore John , Camarca Maria
Published: July 2021

We develop a shape model of asteroid 16 Psyche using observations acquired in a wide range of wavelengths: Arecibo S-band delay-Doppler imaging, Atacama Large Millimeter Array (ALMA) plane-of-sky imaging, adaptive optics (AO) images from Keck and the Very Large Telescope (VLT), and a recent stellar occultation. Our shape model has dimensions 278 (−4/+8 km) × 238(−4/+6 km) × 171 km (−1/+5 km), an effective spherical diameter D
eff = 222-1/+4 km, and a spin axis (ecliptic lon, lat) of (36°, −8°) ± 2°. We survey all the features previously reported to exist, tentatively identify several new features, and produce a global map of Psyche. Using 30 calibrated radar echoes, we find Psyche’s overall radar albedo to be 0.34 ± 0.08 suggesting that the upper meter of regolith has a significant metal (i.e., Fe–Ni) content. We find four regions of enhanced or complex radar albedo, one of which correlates well with a previously identified feature on Psyche, and all of which appear to correlate with patches of relatively high optical albedo. Based on these findings, we cannot rule out a model of Psyche as a remnant core, but our preferred interpretation is that Psyche is a differentiated world with a regolith composition analogous to enstatite or CH/CB chondrites and peppered with localized regions of high metal concentrations. The most credible formation mechanism for these regions is ferrovolcanism as proposed by Johnson et al. (2020).
The Association of Psoriatic Arthritis With All-cause Mortality and Leading Causes of Death in Psoriatic Arthritis
Authors: Haddad Amir , Saliba Walid , Lavi Idit , Batheesh Amin , Kasem Samir , Gazitt Tal , Feldhamer Ilan , Cohen Arnon Dov , Zisman Devy
Published: July 2021

Objective

To examine the association between psoriatic arthritis (PsA) and all-cause mortality from a large population-based database.

Methods

Patients with PsA from the Clalit Health Services database were identified between 2003–2018 and matched to 4 controls by age, sex, ethnicity, and index date. Patient demographics, comorbidities, and treatments were extracted. Mortality data were obtained from the Israeli Notification of Death certificate. The proportionate mortality rate (PMR) of the leading causes of death was calculated and compared to that of the general population. Cox proportional hazard regression models were used to estimate the crude and the multivariate adjusted HR for the association between PsA and all-cause mortality and for factors associated with mortality within the PsA group.

Results

There were 5275 patients with PsA and 21,011 controls included and followed for 7.2 ± 4.4 years. The mean age was 51.7 ± 15.4 years, and 53% were females. Among patients with PsA, 38.2% were on biologics. Four hundred seventy-one (8.9%) patients died in the PsA group compared to 1668 (7.9%) in the control group. The crude HR for the association of PsA and all-cause mortality was 1.16 (95% CI 1.04–1.29) and 1.02 (95% CI 0.90–1.15) on multivariate analysis. Malignancy was the leading cause of death (26%), followed by ischemic heart disease (15.8%); this is in keeping with the leading causes of death in the general population. Older age, male sex, lower socioeconomic status, increased BMI, increased Charlson comorbidity index scores, and history of psoriasis or hospitalization in 1 year prior to entry were positive predictors for mortality.

Conclusion

No clinically relevant increase in mortality rate was observed in patients with PsA, and specific PMRs were similar to those of the general population.
Esophageal Dilation and Other Clinical Factors Associated With Pulmonary Function Decline in Patients With Systemic Sclerosis
Authors: Showalter Kimberly , Hoffmann Aileen , Richardson Carrie , Aaby David , Lee Jungwha , Dematte Jane , Agrawal Rishi , Savas Hatice , Wu Xiaoping , Chang Rowland W. , Hinchcliff Monique
Published: July 2021

Objective

To identify clinical factors, including esophageal dilation on chest high-resolution computed tomography (HRCT), that are associated with pulmonary function decline in patients with systemic sclerosis (SSc).

Methods

Patients fulfilled 2013 SSc criteria and had ≥ 1 HRCT and ≥ 2 pulmonary function tests (PFTs). According to published methods, widest esophageal diameter (WED) and radiographic interstitial lung disease (ILD) were assessed, and WED was dichotomized as dilated (≥ 19 mm) vs not dilated (< 19 mm). Clinically meaningful PFT decline was defined as % predicted change in forced vital capacity (FVC) ≥ 5 and/or diffusion capacity for carbon monoxide (DLCO) ≥ 15. Linear mixed effects models were used to model PFT change over time.

Results

One hundred thirty-eight patients with SSc met the study criteria: 100 (72%) had radiographic ILD; 49 (35%) demonstrated FVC decline (median follow-up 2.9 yrs). Patients with antitopoisomerase I (Scl-70) autoantibodies had 5-year FVC% predicted decline (–6.33, 95% CI –9.87 to –2.79), whereas patients without Scl-70 demonstrated 5-year FVC stability (+1.78, 95% CI –0.59 to 4.15). Esophageal diameter did not distinguish between those with vs without FVC decline. Patients with esophageal dilation had statistically significant 5-year DLCO% predicted decline (–5.58, 95% CI –10.00 to –1.15), but this decline was unlikely clinically significant. Similar results were observed in the subanalysis of patients with radiographic ILD.

Conclusion

In patients with SSc, Scl-70 positivity is a risk factor for FVC% predicted decline at 5 years. Esophageal dilation on HRCT was associated with a minimal, nonclinically significant decline in DLCO and no change in FVC during the 5-year follow-up. These results have prognostic implications for SSc-ILD patients with esophageal dilation.
Signifié du suicide et de l’infanticide chez les Africains asservis
Authors: Tardieu Jean-Pierre
Published: July 2021

Pour l’Africain réduit à l’esclavage outre-mer le suicide et l’infanticide relevaient bien souvent de l’exigence du culte des ancêtres. Car il était « mnémon », « celui qui se souvient, qui doit emmagasiner dans sa tête tout le savoir permettant que chacun connaisse son identité » (J.-P. Vernant). Le suicide ou l’infanticide lui donnaient ainsi accès au monde des ancêtres et permettaient de participer de nouveau à la vie de la communauté dont il avait été arraché.
Vers un monde digitalisé de la formation ?
Authors: Jacquot Thierry , Hoffmann Steve
Published: July 2021

La digitalisation est au cœur des enjeux de la formation. Le présent article reprend les principales formes de digitalisation et d’animation des dispositifs numériques en comparant leurs conditions préalables d’utilisation. Les formations combinant les cours en présentiel et à distance l’emportent en termes d’efficacité sur le seul enseignement à distance. À titre de démonstration, un classement des dispositifs numériques selon les quatre critères suivants est proposé : le niveau d’interactivité, l’efficience, l’étendue des compétences développées et la capacité des apprenants à utiliser les connaissances acquises dans un contexte pratique. Cette typologie permet de soutenir que, malgré la diversité des outils technologiques, un apprentissage en blended learning ou encore le game based learning sont privilégiés pour leurs caractéristiques telles que l’expérimentation ou encore la mise en situation collaborative. Mais l’efficacité des outils digitalisés dépend beaucoup du respect de quelques principes fondamentaux à intégrer dans leur conception et surtout dans l’animation de la formation. De manière générale un apprentissage, sous forme traditionnelle ou en ligne, est efficace sous condition d’être adapté à son public cible et de miser sur une formation humanisée associant qualité d’animation, interactivité et démarche réflexive.
Continuité pédagogique, innovation en formation et e-learning : le cas de l’École Supérieure de l’Immobilier
Authors: Cheminant Thierry , Rasolofo-Distler Fana , Husson Julien
Published: July 2021

Face au premier confinement dû à la crise sanitaire du Covid 19, l’Ecole Supérieure de l’Immobilier (ESI) s’est trouvée dans l’obligation d’assurer la continuité pédagogique pour tous ses programmes : diplômants ou de formation continue. Pour faire face à ce défi pédagogique et technologique, elle s’est appuyée sur son expérience du e-learning pour déployer un projet ambitieux visant à organiser l’essentiel de ses programmes en distanciel. Cette recherche-intervention décrit le processus appliqué et mobilise les retours d’expériences recueillis auprès des acteurs impliqués : enseignants, formateurs, étudiants et professionnels. Il en résulte que le déploiement de cette innovation pédagogique a démontré sa pertinence, son efficacité et la capacité d’appropriation du e-learning par les apprenants et les enseignants, démontrant ainsi la capacité entrepreneuriale de l’ESI.
Le théâtre, un support pédagogique innovant pour développer le capital culturel des étudiants
Authors: Kuhn Antony , Moulin Yves
Published: July 2021

L’université française, au cours des deux dernières décennies, a connu un double mouvement : un accroissement du nombre de ses diplômés et une standardisation des intitulés des formations délivrées dans le cadre de l’harmonisation européenne des systèmes universitaires. Dans ce nouveau contexte, comment les composantes universitaires peuvent-elles différencier leur offre de formation ? Comment peuvent-elles aider leurs étudiants à se singulariser sur un marché du travail qui compte deux fois moins d’emplois de cadres que de diplômés du supérieur ? Une réponse réside dans le développement d’innovations pédagogiques visant à faciliter l’apprentissages de compétences comportementales et relationnelles des étudiants. Après avoir approfondi le rôle du capital culturel et des soft skills dans l’insertion professionnelle des étudiants, cette communication présente trois projets pédagogiques qui ont mis en relation des enseignements académiques et des représentations théâtrales.
La mondialisation des entreprises françaises à partir des années 1980, un changement global d’échelle et de logique
Authors: Torres Félix
Published: July 2021

Des années 1980 aux années 2000, la première phase de la 2 e mondialisation a été l’un des phénomènes majeurs de la fin du XX e et du début du XXI e  siècle. L’une de ses caractéristiques est l’essor de Firmes multinationales (FMN) agissant de manière globale et intégrée au-delà de la simple internationalisation des décennies d’après-guerre. Si l’économie française a subi plutôt qu’endossé ce mouvement, la mondialisation poussée qui a été celle des grandes entreprises françaises a pour l’instant été peu étudiée. Le mouvement d’externalisation des FMN hexagonales procède de l’imbrication de plusieurs phénomènes, dans un contexte de retrait de l’État : nécessité de trouver des relais de croissance hors d’un marché domestique mature, mais aussi une émancipation des carcans étatistes et fiscaux de celui-ci dans le cadre d’une planète économique globalisée, marquée notamment par la financiarisation, l’intégration des marchés et des processus de production. Dans cette perspective, la globalisation a signifié pour les FMN françaises, anciennes, nouvelles ou «  born again  » une véritable métamorphose qui a radicalement modifié leurs stratégies, leurs domaines d’activité, leur financement, capital et gouvernance. Deux autres caractéristiques de la mondialisation des grandes entreprises françaises méritent d’être signalées : un large spectre d’activités, analogue à celui des FMN américaines ; une stratégie active de conquête de parts de marché mondiales grâce à une politique plus ou moins agressive d’acquisitions externes plutôt qu’une croissance organique « à l’allemande » autour de grandes chaines de valeur.
Polycystic Ovarian Syndrome in Adolescents: Keys to Diagnosis and Management
Authors: Khan Leah
Published: July 2021

Polycystic ovarian syndrome (PCOS) is the most common endocrine condition in women, affecting anywhere from 3% to 13% depending on the population being studied. PCOS often begins in adolescence, but diagnosis is difficult due to the overlap of symptoms with normal puberty. It is also necessary to rule out other potential causes of these symptoms before diagnosis. Once diagnostic criteria have been met, there are many treatment options to consider including lifestyle changes, combined oral contraceptive pills, metformin, and in some cases, antiandrogens.

[
Pediatr Ann
. 2021;50(7):e272–e275.]
Pediatric Unilateral Vocal Fold Immobility
Authors: DeHart Austin N. , Curtis Stuart , Mancuso David L. , Gnagi Sharon H.
Published: July 2021

Vocal fold immobility in children can affect breathing, swallowing, and speech function. Although sometimes idiopathic, it is often caused by injury to the recurrent laryngeal nerve during cardiac surgery. A detailed history and physical examination can identify risk factors, which affect the rate of resolution and overall prognosis. Fiberoptic laryngoscopy can be used to confirm the diagnosis and evaluate laryngeal anatomy. Many treatment options exist to improve function and quality of life, including vocal fold injection and laryngeal innervation.

[
Pediatr Ann
. 2021;50(7):e286–e291.]
Dynamic behavior of transport fuel demand and regional environmental policy: The case of Portugal
Authors: Silva Susana ,   CEFUP and Faculdade de Economia da Universidade do Porto (FEP), R. Roberto Frias, 4200-464 Porto, Portugal, Soares Isabel , Pinho Carlos ,   GOVCOPP—Unidade de Investigação em Governança, Competitividade e Políticas Públicas DEGEIT—Departamento de Economia, Gestão, Engenharia Industrial e Turismo, Universidade de Aveiro
Published: July 2021

Despite the increase in electric mobility, fossil fuels still dominate the transport sector. For a sustainable management of these fuels, environmental policy plays a significant role. It is key to know if higher taxes are effective to moderate demand, which will depend on demand elasticities. While price elasticities determine the effectiveness of higher taxes, income elasticities are important for macroeconomic policy considerations. Furthermore, in dynamic societies and economies, it is possible that elasticities change over time or as a response to certain events, determining the need to adjust policies. We study the case of a small, open economy, highly dependent on fuel imports: Portugal. Our estimation of price and income elasticities for gasoline and diesel demand control for breakpoints and uses a dynamic perspective. The period covered (1995–2015) includes important macroeconomic events, such as the fuel market liberalization and a severe economic crisis. Results for the whole period show that long-run price elasticities are −0.368 for diesel and −0.911 for gasoline. Hence, taxes are more effective to moderate gasoline demand than diesel demand. Long-run income elasticities are 2.338 for diesel and 0.877 for gasoline, demonstrating the strong dependence of diesel consumption on the level of economic activity. The breakpoint analysis indicates that contrarily to the fuel market liberalization process, the economic crisis impacted elasticities. Furthermore, we find variability in elasticities around the period of the economic crisis, which justifies the need for a flexible policy. Dynamic policies can use specific periods as opportunities to promote technical and behavioral desirable changes.
Unleashing the Sounds of Silence: Hong Kong’s Story in Troubled Times
Authors: Riemenschnitter Andrea
Published: July 2021

Hong Kong’s story is difficult to tell, commented Leung Ping-kwan (1949–2013) in consideration of the city’s complicated historical configuration as well as of the aesthetic reflection on the same by the writers and artists that have come to shape and promote the colonial city’s unique culture. Confronting the post-handover government’s suppression of democratic decision-making with massive street protests, the next generation of cultural producers continues to critically interrogate, contest, and subvert the official genealogy and nationalist master narrative. In response to the various factors contributing to the ongoing silencing of the city’s critical voices, many artists, directors, and writers have turned to (absent) sound as the aesthetic signifier of the sociopolitical turn from hope and reconciliation to despair. Their performative silence simultaneously protests and mourns the denunciation, suppression, and erasure of oppositional groups. In this paper, I apply a methodological cluster comprising concepts from ecocriticism, microhistorical-discourse analysis, social anthropology, and other disciplinary fields to address the ramifications of Hong Kong’s story as inscribed within protest-related literary, visual and multimedia art productions. Street art performance, handover-themed art exhibitions, Wong King Fai’s video “Umbrella Dance for Hong Kong,” and Samson Young’s sonic multimedia installations appositely illustrate the conundrum addressed.
Implementing Universal Design for Learning in the Virtual Learning Environment
Authors: Parrish Andrea Harkins , Kouo Jennifer Lee , Carey Lisa Beth , Swanson Christopher
Published: July 2021

This chapter presents an overview of learner variability and addresses how the Universal Design for Learning framework can be applied to meet the diverse needs of all students in a virtual learning environment. Emphasis is placed on how educational professionals at multiple levels can apply their current knowledge to design and implement effective and universally designed instruction through multiple means of engagement, representation, and action and expression. It also addresses the importance of providing specialized instruction, including how educators can provide federally protected educational supports in virtual learning environments. The authors provide directions for further examination of virtual learning and the implications of this instructional delivery model for meeting the needs of all learners in light of recent trends.
Choosing Culturally, Linguistically, and Cognitively Distance Learning Platforms
Authors: Terlop Rachel E. , Vargas-Ewing James
Published: July 2021

Upon completion of their educator preparation program, a study done by Archambault found that teachers felt most prepared in the areas of pedagogy, content, and pedagogical content. However, the same teachers reported feeling least prepared in the areas of technology and technology integration. With instruction shifting to an online space during COVID-19, the consideration of how to teach virtually was no longer abstract. This chapter highlights the journey of a teacher working to find supportive technology for their class, evaluating existing resources, connecting the tools to teaching standards, and ensuring platforms are inclusive and relevant for the culturally, linguistically, and cognitively diverse (CLCD) learners who utilize augmentative and alternative communication (AAC) devices. This chapter is rooted in early childhood education, social constructivism, and disability critical race theory (DisCrit) and seeks to serve as a critical guide, or model, for intentional and inclusive educators, researchers, practitioners, and learners.
Pedagogical Challenges During COVID
Authors: Meier Ellen B. , Mineo Caron
Published: July 2021

Educators could not have predicted the degree of disruption that COVID-19 could cause until schools closed and forced teachers to move to online teaching. This chapter describes the use of a research-based model, Innovating Instruction, to support teachers in their transition to remote learning. Grounded in a concern for greater equity and social justice for all students, the model prepares teachers to design inquiry-based, culturally relevant projects. The development of the model is based on a critique that technology has largely failed to impact pedagogical change because of a limited sense of the scope of the change needed. Instructional Innovation brings together key aspects of a systems change effort, thus contributing to an emerging educational theory for the catalytic use of technology to promote pedagogical practices that are culturally responsive, rigorous, and engaging.
Four Steps to Promote Teacher Creativity When Making the Transition to Virtual Learning Experiences
Authors: Worwood Matthew
Published: July 2021

This chapter presents four steps for teacher creativity as part of a design-based approach to problem-solving pedagogical challenges using virtual learning environments. Building on existing practices found in creative problem-solving and design thinking methodology, these steps explore change as a journey that begins with an intent to produce an outcome that improves a specific aspect of the learning experience. Glaveanu's five-A framework provides a sociocultural perspective to support the concept of teacher creativity in the classroom, while Kaufman and Beghetto's 4-C model serves as a developmental approach to evaluating outcomes based on the impact they have in the environment. Future opportunities for study, including integrating learning analytics and situating the different stages of creative problem-solving in education, are also discussed.
Teaching Strategies During a Pandemic
Authors: Medellin Kelly , Gupta Dittika , Acuña Kym
Published: July 2021

Due to the COVID-19 pandemic, teachers were faced with the insurmountable task of changing teaching methods to virtual online pedagogy, practically overnight, that continued to provide students with quality instruction using best practices. Action research was employed to help seek the answers to the question: During a pandemic with school online and students socially distanced in person simultaneously, how could teachers still provide cooperative learning experiences that give students opportunities to collaborate in class while continuing to use best practices like the 4Cs (communication, collaboration, critical thinking, and creativity)? Through completely online and synchronous (online and face-to-face) instruction, Jamboard, Padlet, Mentimeter, Flipgrid, and Bitmoji Classroom were implemented to support student learning through the 4Cs of 21st century learning. In this chapter, the rationale, implementation, successes, and challenges will be revealed from self-examined action research.
The 4Cs of Academic Language and Literacy
Authors: Lawrence Salika A. , Labissiere Tiffany , Stone Monique C.
Published: July 2021

This chapter describes how teachers have used structured discussions and digital tools to transition from traditional classrooms to remote, online instruction during the COVID-19 pandemic. With emphasis on culturally and linguistically diverse students, the chapter includes examples of how teachers reinforce literacy while supporting 21st century skills such as collaboration, communication, critical thinking, and creativity. Tools and strategies are presented along with examples teachers can use to facilitate student learning across content areas in virtual classrooms.
Computational Thinking and Making in Virtual Elementary Classrooms
Authors: Jocius Robin , Blanton Melanie , Albert Jennifer , Joshi Deepti , Andrews Ashley Ray
Published: July 2021

This chapter documents findings from the Making CT (Computational Thinking) project, a collaborative effort between project team members and elementary teachers that aims to reimagine interdisciplinary, computational thinking-infused making lessons for a virtual format. Virtual making CT lessons were grounded in four design principles: standards-based practices, clear and explicit expectations, multiple means of engagement, and opportunities for collaboration. Drawing on data from virtual teacher professional development sessions, lesson implementation, and teacher interviews, this chapter illustrates how teachers were able to engage in the difficult work of reconceptualizing CT-infused making lessons for the virtual classroom. These principles can be used to support the design of other interdisciplinary activities to support P-5 students' development of creative and authentic problem-solving in virtual learning environments.
Mathematics, Social Structure, and Technology
Authors: Bengtson Douglas W. , Golden John , Kasmer Lisa A. , Thomas Sarah M. , Yu Paul Woo Dong
Published: July 2021

This chapter provides insights gained from a collaborative action research project with university and middle school mathematics faculty. A categorical framework that considers the relationship between technology, mathematics content, and social interaction was used by the researchers to more deeply examine the varied uses and types of technology related to online teaching. In particular was the use of a relatively new category of software, Interactive Mathematics Classroom Builders, which integrates powerful mathematics tools with highly interactive classroom management features. The teachers found opportunities to try several novel uses of technology in their online lessons, advancing their teaching and the student experience, while learning lessons about teaching with technology that may apply to both remote teaching and the face-to-face classroom.
Cloud Computing Virtual Machine Workload Prediction Method Based on Variational Autoencoder
Authors: Abdullayeva Fargana J.
Published: July 2021

The paper proposes a method for predicting the workload of virtual machines in the cloud infrastructure. Reconstruction probabilities of variational autoencoders were used to provide the prediction. Reconstruction probability is a probability criterion that considers the variability in the distribution of variables. In the proposed approach, the values of the reconstruction probabilities of the variational autoencoder show the workload level of the virtual machines. The results of the experiments showed that variational autoencoders gave better results in predicting the workload of virtual machines compared to simple deep neural networks. The generative characteristics of the variational autoencoders determine the workload level by the data reconstruction.
PNTRS
Authors: Tiwari Sunita , Kumar Sushil , Jethwani Vikas , Kumar Deepak , Dadhich Vyoma
Published: July 2021

A news recommendation system not only must recommend the latest, trending, and personalized news to the users but also give opportunity to know about the people's opinion on trending news. Most of the existing news recommendation systems focus on recommending news articles based on user-specific tweets. In contrast to these recommendation systems, the proposed Personalized News and Tweet Recommendation System (PNTRS) recommends tweets based on the recommended article. It firstly generates news recommendation based on user's interest and twitter profile using the Multinomial Naïve Bayes (MNB) classifier. Further, the system uses these recommended articles to recommend various trending tweets using fuzzy inference system. Additionally, feedback-based learning is applied to improve the efficiency of the proposed recommendation system. The user feedback rating is taken to evaluate the satisfaction level, and it is 7.9 on the scale of 10.
Characteristics Shifting of Heart Disease in Pregnancy: A Report from Low Middle-Income Country
Authors: Puspa Pitaloka Cyntia , Secka Absa , Ernawati Ernawati , Sulistyono Agus , Juwono Hermanto Tri , Gumilar Dachlan Erry , Aditiawarman
Published: July 2021

Background

Heart disease in pregnancy is one of the leading causes of maternal mortality and morbidity in developing countries. However, the characteristics of the disease vary between countries and regions. This study aimed to present the characteristics of pregnant women with heart disease in an economically advantageous region of a developing country.

Design and methods

A cross-sectional study was conducted using data from the Weekly Report of Obstetrics and Gynaecology Department to assess pregnant women with heart disease characteristics and pregnancy outcomes. A total sample of 69 pregnant women with heart disease regarding theirgestational age was included in the study. Variables observed were maternal characteristics, heart disease's clinical parameter, and maternal and neonatal outcomes. Chi-square test was used to examine the different characteristics of congenital and acquired heart disease groups.

Results

The prevalence of cardiac disease in pregnancy was 5.19%. Fifty-three point six percent of pregnant women with heart disease were suffered from congenital heart disease (CHD), while 46.4% were acquired heart disease (AHD). Most labor methods were Cesarean delivery, and 69.6% of women experienced cardiac complications. Maternal death was reported in 8.69% of cases. Four cases were CHD complicated by pulmonary hypertension, which leads to Eisenmenger syndrome. Two other cases were AHD complicated by Peripartum Cardiomyopathies. Although statistically insignificant, complications are more common in the AHD group than CHD.

Conclusion

Cardiac disease prevalence in pregnancy is considered high, with CHD as the most common case, which significantly differs from other developing countries.
Sequential Presentation of Bilateral Brown Syndrome
Authors: Bagheri Abbas , Abbasnia Ehsan , Abrishami Alireza , Tavakoli Mehdi
Published: July 2021

Purpose:

To present a case of bilateral Brown syndrome who presented as a unilateral disease and then showed the disease in the fellow eye in an older age.

Methods:

A 4-year-old girl presented with congenital Brown syndrome of the left eye and underwent a superior oblique weakening procedure in that eye, but then developed Brown syndrome in the right eye which required two more surgeries on the right eye to attain an acceptable alignment.

Results:

Her orbital computed tomography scan revealed that the distance between the annulus of Zinn and trochlea (Z-T distance) was 41.2 mm in both sides, which was comparatively longer than her age- and sex-matched cases. This finding can suggest a possible mechanism of Brown syndrome development in some patients.

Conclusion:

Bilateral Brown syndrome can present as a sequential disease, and its radiologic finding may be associated with increased Z-T distance.
Perioperative Management of Antithrombotic Medications
Authors: Garcia Giancarlo A , Bair Henry , Kossler Andrea L
Published: July 2021

Purpose:

To investigate the availability and content of educational statements or recommendations disseminated by U. S. ophthalmologic organizations regarding perioperative management of antithrombotic agents for ophthalmic and orbital surgery, given the highly variable management of these agents by U. S. ophthalmologists and limited consensus recommendations in the literature.

Methods:

National U. S. ophthalmic surgical organization websites were systematically examined for educational statements, which were reviewed for discussion of perioperative management of antithrombotic agents including antiplatelet and anticoagulant medications. A “statement” was defined as either: (a) a guideline directed toward ophthalmologists or (b) a surgical/clinical educational posting directed toward ophthalmologists or patients.

Results:

Fourteen surgical organizations were identified, with eight of these publishing clinical/surgical educational statements. A total of 3408 organizational statements were identified, with 252 (7.4%) and 3156 (92.6%) statements directed toward physicians and patients, respectively. In total, 0.3% (9/3408) of statements discussed perioperative management of antithrombotics. These accounted for 0.8% (2/252) of ophthalmologist-directed statements and 0.2% (7/3156) of patient-directed statements. The majority of patient-directed statements (57.1%, 4/7) recommended that patients discuss antithrombotic cessation with their ophthalmologists, though ophthalmologist-directed information regarding these medications was scant or absent.

Conclusions:

Educational material from U. S. ophthalmologic organizations regarding perioperative management of antithrombotics is notably lacking despite the fact that ophthalmic and orbital surgeries carry unique vision-threatening hemorrhagic risks. Given these risks, as well as the medicolegal consequences of hemorrhagic complications in ophthalmic surgery, increased dissemination of educational material, and consensus statements by ophthalmic surgical organizations on the perioperative management of antithrombotics may be justified.
Effect of omega-3 fatty acids on dry eye following phacoemulsification
Authors: Kesba Mahmoud M. , Saif Mohamed Y.S. , Saeed Moustafa A.
Published: July 2021

Purpose

The aim of this study was to evaluate the efficacy of omega-3 fatty acids on dry eye after phacoemulsification.

Patients and methods

This is a randomized controlled clinical trial which included 50 patients who developed dry eye symptoms following phacoemulsification. They were randomly allocated into two groups, with 25 patients each. The first group received an omega-3 dietary supplementation of 1000 mg in addition to the conventional treatment (artificial tears and anti-inflammatory eye drops) for 3 months. The second group received only artificial tears and anti-inflammatory eye drops. Both groups received treatment from September 2019 to March 2020, and they were followed up for 3 months. All patients had the same diagnostic tests (Schirmer test, ocular surface disease index, and tear break-up time), postoperatively.

Results

There was no statistically significant difference between the two groups in the demographic data. However, a significant difference was noted in the tear break-up time test scores (11.08±3.29 and 9.20±1.87 s) in the treatment and control groups, respectively. In addition, the ocular surface disease index showed a statistically significant difference between the treatment and control groups (19.41±9.69 and 31.23±11.66, respectively) after 3 months. No significant difference (P=0.186) was noted in the Schirmer test between the treatment and the control groups (9.16±2.72 and 8.12±2.76 mm, respectively).

Conclusions

The study showed that the addition of omega-3 fatty acid supplements after phacoemulsification can reduce the incidence of dry eye and improve both the objective and subjective measurements of dry eye.
Role of optical coherence tomography angiography in detecting possible retinal vascular complications of sofosbuvir and daclatasvir in patients with hepatitis C virus infection
Authors: Elmekkawy Hany E. , Emam Mohamed S. , Abdelaziz Magda S. , Mehrez Mai I. , Alahmadawy Yomna A.
Published: July 2021

Purpose

The aim of this study was to evaluate the value of optical coherence tomography angiography (OCTA) in the detection of any suspected retinal complications associated with the use of combined therapy (sofosbuvir ‘Sovaldi’ and daclatasvir ‘Daklinza’) in patients with hepatitis C virus infection.

Patients and methods

This is a prospective cohort study that enrolled patients with chronic hepatitis C who did not receive any previous antiviral treatment and who were candidates for the dual therapy. During a 3-month duration (the treatment course duration), OCTA was performed for documented chronic hepatitis C-infected patients before and after receiving the dual therapy (daclatasvir–sofosbuvir). The minimum outcome measures were best-corrected visual acuity and vascular density by OCTA macula.

Results

There was a statistically significant reduction in the deep capillary plexus (P≤0.05). The whole macular vessel density was reduced from 51.56 to 47.68% after the treatment course (P=0.04). These vascular density changes were associated with statistically insignificant increase in thickness. In addition, the choriocapillaris had a statistically significant reduction in flow area from 2.145 to 2.063 mm2 (P=0.0001). The superficial capillary plexus changes in vessel density were statistically insignificant except at the temporal parafoveal area. There was also a statistically significant reduction in the foveal avascular zone flow density from 54.42% before starting the dual therapy course to 51.85% after finishing it (P=0.022). These changes were associated with a statistically significant reduction in best-corrected visual acuity from 0.83 to 0.63 (P<0.001) and a statistically significant development of macular drusen (P=0.004).

Conclusions

Hepatitis C virus dual treatment (sofosbuvir and daclatasvir) may result in significant changes affecting the retinal microvasculature.
Clinical outcome of femtosecond laser flap formation versus mechanical microkeratome in laser in situ keratomileusis for treatment of myopia
Authors: Rashad Dina F. , Khallaf Magdy E. , Khalil Adel M.A. , Aly Mona M.
Published: July 2021

Purpose

The aim of this study was to evaluate and to compare the thickness and morphology of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and mechanical microkeratome flaps using anterior segment optical coherence tomography (AS-OCT).

Patients and methods

This prospective, interventional, comparative clinical study was performed on 60 eyes of 30 patients. Flaps were created in 30 eyes using the WaveLight FS200 FS laser and in 30 eyes using the Moria M2 microkeratome. AS-OCT was used at 1 month postoperatively to evaluate the thickness of each flap at four points, which were 1 and 2 mm from the corneal vertex on the horizontal meridian.

Results

At the sixth month postoperatively, the uncorrected visual acuity was 0.98±0.10 in the FS-LASIK group and 0.98±0.11 in the microkeratome group, which denotes the efficacy of both procedures. No vision-threatening complications occurred in either group. The average flap thickness at 1 mm was 114.93±3.04 µm in the FS-LASIK group compared with 128.57±3.98 µm in the microkeratome group, with a statistically significant difference (P=0.000). The difference between the achieved and intended flap thickness at 1 mm (accuracy) was 4.93±3.04 µm in the FS-LASIK group compared with 18.57±3.98 µm in the microkeratome group, with a statistically significant difference (P=0.000). At 2 mm, the average flap thickness was 115.22±3.34 µm in the FS-LASIK group compared with 139.00±4.75 µm in the microkeratome group (P=0.000). The flap accuracy at 2 mm was 5.22±3.34 µm and 29.00±4.75 µm in the FS-LASIK group and the microkeratome group, respectively (P=0.000). Flap morphology showed a planar shape (uniform) in the FS-LASIK group and a meniscus shape in the microkeratome group.

Conclusion

Both FS-LASIK and microkeratome techniques were safe and efficient in correcting myopia and myopic astigmatism, achieving good visual outcome. AS-OCT showed that flaps created by the FS laser were more accurate and uniform than those created by the Moria M2 microkeratome.
Photo-activated chromophore for keratitis (PACK-CXL) window absorption (WA) alone versus combined PACK-CXL window absorption and standard anti-microbial therapy (SAT) for treatment of infectious keratitis
Authors: Tawfeek Mohammed M.M.
Published: July 2021

Objective

The aim of this study was to compare the outcome of photo-activated chromophore for keratitis cross-linking (PACK-CXL) window absorption (WA) alone with combined PACK-CXL WA and standard antimicrobial therapy (SAT) for treatment of infectious keratitis.

Patients and methods

This is a randomized prospective comparative clinical trial that enrolled 30 eyes with clinically suspected infectious keratitis. They were randomly assigned into 2 equal groups of 15 eyes each: Group A was treated by PACK-CXL WA alone and group B was treated by PACK-CXL WA combined with SAT. Identification of organisms was done by laboratory study before treatment. Corneal healing was evaluated by corneal examination and anterior segment OCT (AS-OCT).

Results

Complete healing and resolution (successful treatment) was observed in 10 eyes (66.7%) of group A and in 14 eyes (93.3%) of group B, a statistically significant difference (P=0.042). Complications were absent in 12 eyes (80%) in group A and in 14 eyes (93.3%) of group B. However, perforation and impending perforation were found in 3 patients of group A and in only 1 patient of group B, a statistically insignificant difference (P=0.123).

Conclusion

PACK-CXL is a promising, non-invasive treatment option for superficial infectious keratitis, especially when performed with WA technique, either alone or combined with SAT. However, combined PACK-CXL WA with SAT was more effective for treatment of infectious keratitis than PACK-CXL WA alone with shorter resolution period.
Effect of parity on the serum calcium in the pregnancy
Authors: Wu Nan-Nan , Cao Bin , Lang Jia-Nan , Zhao Dong
Published: July 2021

Background:

Maternal hypocalcaemia has adverse outcomes on pregnant women and offspring development. The objective of this study is to test whether parity number is associated with maternal calcium level.

Materials and Methods:

According to parity numbers, the pregnant women were divided into never parturition group (NPG) and previous parturition group (PPG). Association between parity number and serum calcium was tested in multivariate linear regression models controlling for age, body mass index (BMI), Vitamin D, and Homeostasis model assessment for insulin resistance (HOMA-IR). The subjects were also subgrouped by recruitment in four seasons and their development of gestational hypertension (GH) and diabetes.

Results:

Mean serum calcium was lower in the PPG than that in the NPG (2.15 vs. 2.20 mmol/L, P < 0.001). After adjusted for albumin, adjusted serum calcium was still lower in PPG than that in NPG (2.20 vs. 2.23 mmol/L, P < 0.001). Interestingly, adjusted serum calcium level is consistently lower in the PPG in both the diabetic and hypertension subgroups compared to NPG (2.20 vs. 2.23 mmol/L, P < 0.001). In different seasons, the serum calcium level and adjusted serum calcium level in the PPG were significantly lower than the NPG (P < 0.001). Importantly, adjusted calcium correlated negatively with the parity number (r = −0.044, P < 0.001), when adjusting for age, BMI, Vitamin D, and HOMA-IR. In addition, there was a significant increase in the PPG compared to the NPG including age (29.61 vs. 33.39 years old), BMI (22.80 vs. 23.55), triglyceride (2.27 vs. 2.43 mmol/L), and fasting basal blood glucose (4.73 vs. 4.81 mmol/L), and a significant decrease regarding the albumin (38.72 vs. 37.65 g/L) and Vitamin D (20.98 vs. 18.62 ng/ml). There was no difference in the onset of GH and gestational diabetes mellitus (GDM) between the two groups.

Conclusion:

Parity negatively correlated with the serum calcium level. The small but significant difference in the calcium levels indicated that parity may play an intricate role in calcium homeostasis. Timely monitoring of maternal calcium could be clinically beneficial to the multiparous women.