bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategic competence for multistep fraction word problems: an overlooked aspect of mathematical knowledge for teaching
Authors: Copur-Gencturk Yasemin , Doleck Tenzin
Published: March 2021

Prior work on teachers’ mathematical knowledge has contributed to our understanding of the important role of teachers’ knowledge in teaching and learning. However, one aspect of teachers’ mathematical knowledge has received little attention:strategic competence for word problems.Adapting from one of the most comprehensive characterizations of mathematics learning (NRC, 2001), we argue that teachers’ mathematical knowledge also includes strategic competence, which consists ofdevising a valid solution strategy,mathematizing the problem(i.e., choosing particular strategies and presentations to translate the word problem into mathematical expressions), andarriving at a correct answer(executing a solution) for a word problem. By examining the responses of 350 fourth- and fifth-grade teachers in the USA to four multistep fraction word problems, we were able to explore manifestations of teachers’ strategic competence for word problems. Findings indicate that teachers’ strategic competence was closely related to whether they devised a valid strategy. Further, how teachers dealt with known and unknown quantities in their mathematization of word problems was an important indicator of their strategic competence. Teachers with strong strategic competence used algebraic notations or pictorial representations and dealt with unknown quantities more frequently in their solution methods than did teachers with weak strategic competence. The results of this study provide evidence for the critical nature of strategic competence as another dimension needed to understand and describe teachers’ mathematical knowledge.
Bog plant/lichen tissue nitrogen and sulfur concentrations as indicators of emissions from oil sands development in Alberta, Canada
Authors: Wieder R. Kelman , Vile Melanie A. , Scott Kimberli D. , Albright Cara M. , Quinn James C. , Vitt Dale H.
Published: March 2021

Increasing gaseous emissions of nitrogen (N) and sulfur (S) associated with oil sands development in northern Alberta (Canada) has led to changing regional wet and dry N and S deposition regimes. We assessed the potential for using bog plant/lichen tissue chemistry (N and S concentrations, C:N and C:S ratios, in 10 plant/lichen species) to monitor changing atmospheric N and S deposition through sampling at five bog sites, 3–6 times per growing season from 2009 to 2016. During this 8-year period, oil sands N emissions steadily increased, while S emissions steadily decreased. We examined the following: (1) whether each species showed changes in tissue chemistry with increasing distance from the Syncrude and Suncor upgrader stacks (the two largest point sources of N and S emissions); (2) whether tissue chemistry changed over the 8 year period in ways that were consistent with increasing N and decreasing S emissions from oil sands facilities; and (3) whether tissue chemistry was correlated with growing season wet deposition of NH4+-N, NO3−-N, or SO42−-S. Based on these criteria, the best biomonitors of a changing N deposition regime were Evernia mesomorpha, Sphagnum fuscum, and Vaccinium oxycoccos. The best biomonitors of a changing S deposition regime were Evernia mesomorpha, Cladonia mitis, Sphagnum fuscum, Sphagnum capillifolium, Vaccinium oxycoccos, and Picea mariana. Changing N and S deposition regimes in the oil sands region appear to be influencing N and S cycling in what once were pristine ombrotrophic bogs, to the extent that these bogs may effectively monitor future spatial and temporal patterns of deposition.
Ethical implications of digital infrastructures for pluralistic perspectives
Authors: Israel Maria Joseph , Amer Ahmed
Published: March 2021

It is important to design digital infrastructure that can better accommodate multicultural and pluralistic views from its foundations. It is insufficient to look at only the responses and influences of culture on technology without considering how the technology can be adapted in anticipation of, and to support, pluralistic multicultural perspectives in its original design. This goes beyond the simple act of supporting multiple languages and interfaces, but should include the ability of digital and data infrastructure to capture and accommodate pluralistic views, supporting multiple perspectives in the representation and processing of the data itself. In this work, we look at how rethinking the representation of data can allow us to more directly tackle domains that are typically hampered due to intercultural differences, and their inevitable losses in translation, particularly losses of valuable information like context and intention. When we refer to a loss of context and intention, we are referring to the loss of semantic information when practices such as referencing and citation are hard-coded to a particular set of cultural norms. We show that it is possible to expand the way in which we track referential data to capture richer semantic information regarding the contexts and intentions of the creators of this data, and thereby better serve the varied needs of those who consume, study, and refer to such data. We demonstrate this concept through a prototype system for a multicultural digital infrastructure, which we have namedMultiVerse, and discuss its ethical implications from the perspectives of ‘multistability’, Intercultural Information Ethics framework, and poststructuralism.
Academics’ perceptions of what it means to be both a parent and an academic: perspectives from an English university
Authors: Rosewell Kayleigh
Published: March 2021

This article explores male and female academics’ perceptions of what it means to be both a parent and an academic and the relations between them. Based on an Interpretative Phenomenological Analysis of interviews with 35 academics from a university in England, findings suggest that the way in which academics experience being both a parent and an academic depends upon how they understand the meaning of each of these two roles and what they are trying to achieve within them. These meanings and experiences also appear to differ by gender. Ways in which higher education can offer more targeted and specific support to academic mothers in particular are discussed.
Back to the future? Reflections on three phases of education policy reform in Wales and their implications for teachers
Authors: Evans Gareth
Published: March 2021

Wales’ education system is part-way through an extensive journey of reform. This contextual paper explores the evolution of that journey, from the establishment of the Welsh Parliament in 1999 to late 2020, as Wales readies itself for the launch of a radical, new national curriculum. Drawing from a range of international literature and experience, it provides an overview of key policy developments and insight into the rationale for decisions taken by the Welsh Government to effect change. To do this, it separates reform into three core phases, each with its own characteristics borne out of landmark events that helped shape contemporary political and public discourse. In particular, the paper examines the impact of Wales’ shifting approach to policy development on the teaching workforce and considers implications for those at the site of practice. Ahead of forthcoming parliamentary elections, the paper resolves that a new, long-term approach to policy reform and teacher development is needed if Wales is to realise its ambitious vision for education.
Metamorphic graphite from Szendrőlád (Szendrő Mts., NE-Hungary) detected by simultaneous DTA-TG
Authors: Majoros Lívia , Fintor Krisztián , Koós Tamás , Szakáll Sándor , Kristály Ferenc
Published: March 2021

Graphite, one of the polymorphic forms of carbon, has become a versatile industrial material of nowadays due to its particular attributes. It is used mainly in the automobile industry, metal extractive industry and in the high-tech industry. Moreover, it is also included in the list of critical raw materials for the EU. Our aim was to prove the presence of graphite by thermal analysis beyond X-ray powder diffraction (XRD) and Raman spectroscopy. Thermogravimetry yields comparable results with quantitative XRD. The formation conditions are described by Raman spectrometry and microscopy examinations of drill core samples from Szendrőlád (Szendrő Mts, NE-Hungary; (Szendrőlád Limestone Formation, middle-late Devonian, shelf-basin facies). Polished rock slabs were made for optical microscopy, scanning electron microscopy with energy dispersive spectrometry (SEM–EDS) and Raman spectroscopy. X-ray powder diffraction (XRD) and thermal analysis (DTA-TG) measurements were made on powders. Based on our results, the graphite is epigenetic; its quantity varies between 1.5–3 mass% in the samples. It was developed in 20–50 μm sized flakes, which are often arranged in > 300 μm sized aggregates. Graphite was formed during regional metamorphism from the organic matter-rich shales. The average formation temperature, calculated from the results of Raman spectroscopy, is around 410 °C (± 30 °C). The Raman measurements also indicated the presence of a partially graphitized (disordered graphite) material beside graphite.
Moral Judgments, Cognitivism and the Dispositional Nature of Belief: Why Moral Peer Intransigence is Intelligible
Authors: Eriksson John , Tiozzo Marco
Published: March 2021

Richard Rowland has recently argued that considerations based on moral disagreement between epistemic peers give us reason to think that cognitivism about moral judgments, i.e., the thesis that moral judgments are beliefs, is false. The novelty of Rowland’s argument is to tweak the problem descriptively, i.e., not focusing on what one ought to do, but on what disputants actually do in the light of peer disagreement. The basic idea is that moral peer disagreement is intelligible. However, if moral judgments were beliefs, and beliefs track perceived evidence, then moral peer disagreement would not be intelligible. Hence, moral judgments are not beliefs. The argument is both novel and interesting, but this paper argues that it fails to establish the conclusion. Beliefs are plausibly analyzed as constituted by dispositions to respond to what is perceived as evidence, but dispositions can always be interfered with. Provided a background explanation of why the disposition is not manifested, peer intransigence is quite intelligible.
Development of Thermomechanical Processes as an Alternative to Grain Refiners in 18 Carat Gold Alloys
Authors: Pigato Mirko , Pezzato Luca , Cason Claudio , Dabalà Manuele
Published: March 2021

The use of grain refiners, such as iridium, in 18 kt gold alloys is a common practice in jewelry industrial applications. The use of these elements leads, however, to an increase in the costs of raw materials and greater attention during the solidification phases and during the refining and recycling of alloys is required. This work aims to demonstrate that through the optimization of thermo-mechanical processes, it is possible to obtain a result comparable to that obtained with refiner in terms of workability, mechanical and aesthetic properties and corrosion behavior. The study focused on evaluating the grain growth in annealing processes after plastic deformation, also examining the casting phase and the effect of the different cooling rates. The samples, after the different thermo-mechanical treatments, were characterized in terms of microstructure, grain size and micro-hardness comparing the results with the ones of an iridium-containing alloy. The results showed that with proper optimization of annealing time is possible to obtain, without grain refiners, gold alloys with properties similar to ones obtained with Iridium as a grain refiner.
Cognitive Enhancement: Unanswered Questions About Human Psychology and Social Behavior
Authors: Racine Eric , Sattler Sebastian , Boehlen Wren
Published: March 2021

Stimulant drugs, transcranial magnetic stimulation, brain-computer interfaces, and even genetic modifications are all discussed as forms of potential cognitive enhancement. Cognitive enhancement can be conceived as a benefit-seeking strategy used by healthy individuals to enhance cognitive abilities such as learning, memory, attention, or vigilance. This phenomenon is hotly debated in the public, professional, and scientific literature. Many of the statements favoring cognitive enhancement (e.g., related to greater productivity and autonomy) or opposing it (e.g., related to health-risks and social expectations) rely on claims about human welfare and human flourishing. But with real-world evidence from the social and psychological sciences often missing to support (or invalidate) these claims, the debate about cognitive enhancement is stalled. In this paper, we describe a set of crucial debated questions about psychological and social aspects of cognitive enhancement (e.g., intrinsic motivation, well-being) and explain why they are of fundamental importance to address in the cognitive enhancement debate and in future research. We propose studies targeting social and psychological outcomes associated with cognitive enhancers (e.g., stigmatization, burnout, mental well-being, work motivation). We also voice a call for scientific evidence, inclusive of but not limited to biological health outcomes, to thoroughly assess the impact of enhancement. This evidence is needed to engage in empirically informed policymaking, as well as to promote the mental and physical health of users and non-users of enhancement.
Backbone chemical shift spectral assignments of SARS coronavirus-2 non-structural protein nsp9
Authors: F. Dudás Erika , Puglisi Rita , Korn Sophie Marianne , Alfano Caterina , Bellone Maria Laura , Piaz Fabrizio Dal , Kelly Geoff , Monaca Elisa , Schlundt Andreas , Schwalbe Harald , Pastore Annalisa
Published: March 2021

As part of an International consortium aiming at the characterization by NMR of the proteins of the SARS-CoV-2 virus, we have obtained the virtually complete assignment of the backbone atoms of the non-structural protein nsp9. This small (12 kDa) protein is encoded by ORF1a, binds to RNA and seems to be essential for viral RNA synthesis. The crystal structures of the SARS-CoV-2 protein and other homologues suggest that the protein is dimeric as also confirmed by analytical ultracentrifugation and dynamic light scattering. Our data constitute the prerequisite for further NMR-based characterization, and provide the starting point for the identification of small molecule lead compounds that could interfere with RNA binding and prevent viral replication.
Gross values: Investigating the role of disgust in bioethics
Authors: Sanyal Mohima , McAuliffe William H. B. , Curry Oliver Scott
Published: March 2021

What is the role of disgust in moral judgements? Previous research found that disgust increases the severity of judgments; but other more recent work has cast doubt on these findings. Here we investigate roles of induced and trait disgust on moral judgments of controversial biological and medical technologies – bioethics – an area rife with proto-typical disgust cues. Participants (N = 600) viewed disgusting, frightening, or neutral pictures, rated the moral acceptability of biotechnologies, and completed questionnaire measures of trait disgust. We found a small negative effect of induced disgust (but not fear) on the acceptability of ‘existing’ biotechnology, but not ‘future’, ‘agricultural’, or ‘termination’ biotechnologies. But this effect was too small to change pre-existing opinions and would not have survived a correction for multiple tests. Although trait disgust had mostly negative relationships with the moral acceptability of biotechnologies, it did not moderate the effect of observing disgusting photos on biotechnology judgments. The larger, more consistent effects for trait disgust suggest that either (a) measures of trait disgust and moral attitudes share a source of method variance or (b) incidental, visual manipulations are too weak to capture the true effect of disgust on moral judgments.
Innenarchitektur der Zellkraftwerke — Membranfalten in Hochauflösung
Authors: Stephan Till , Ilgen Peter , Jakobs Stefan
Published: March 2021

Mitochondria are essential cellular organelles, which supply eukaryotic cells with the universal energy carrier adenosine triphosphate. These organelles feature a unique double-membrane architecture, which is formed by a smooth outer membrane and a highly folded inner membrane. Harnessing super-resolution light and electron microscopy, we investigate the role of MICOS, a large mitochondrial protein complex, in determining the complex folding of the inner membrane.
Fluorimetrische Bestimmung von intrazellulären Polyhydroxyalkanoaten
Authors: Griehl Carola , Kettner Alexander , Noll Matthias , Bieler Simone
Published: March 2021

Polyhydroxyalkanoates (PHA) are synthesized as intracellular carbon and energy storage compounds by many bacteria and are accumulated as granules in the cytoplasm of cells. Quantification of enriched PHA is of great importance for industrial production processes. Fluorescence measurements are particularly suitable for rapid determination of PHA during fermentation. With LipidGreen2 as fluorescent marker a fast and reliable assay for PHA monitoring in bioreactors was developed.
Sphincter preservation in patients with low rectal cancer: striking the right oncological balance
Authors: Luvisetto Federico , Shamali Awad , Rutgers Marieke L. W. , Flashman Karen , Khan Jim S.
Published: March 2021

Background

The surgical treatment options for low rectal cancer patients include the Abdominoperineal Resection and the sphincter saving Low Anterior Resection. There is growing evidence towards better outcomes for patients being treated with a Low Anterior Resection compared to an Abdominoperineal Resection.

Objective

The aim of this study was to evaluate the short term and oncological outcomes in low rectal cancer treatment.

Design

This is a retrospective cohort study of prospectively collected data.

Setting

Rectal cancer patients from a single center in the United Kingdom.

Patients

Patients included all low rectal cancer patients (≤ 6 cm from the anal verge) undergoing Low Anterior Resection or Abdominoperineal Resection between 2006 and 2016.

Outcome measures

To identify differences in postoperative complications and disease free and overall survival.

Results

A total of 262 patients were included for analysis (Low Anterior Resection n = 170, Abdominoperineal Resection n = 92). Abdominoperineal Resection patients were significantly older (69 versus 66 years), had lower tumours (3 versus 5 cm), received more neo-adjuvant radiation, had longer hospital stay and more complications (wound infections and wound dehiscence). Low Anterior Resections had a significantly higher number of harvested lymph nodes (17 versus 12) however there was no difference in nodal involvement and R0 resection rate. No significant difference was found for recurrence, overall survival and disease free survival.

Limitation

Retrospective review of cancer database and single center data.

Conclusion

In the treatment of low rectal cancer Abdominoperineal Resection is associated with higher rates of postoperative complications and longer hospital stay compared to the Low Anterior Resection, with similar oncological outcomes.
Status and trends of mercury pollution of the atmosphere and terrestrial ecosystems in Poland
Authors: Jędruch Agnieszka , Falkowska Lucyna , Saniewska Dominika , Durkalec Maciej , Nawrocka Agnieszka , Kalisińska Elżbieta , Kowalski Artur , Pacyna Józef M.
Published: March 2021

The goal of this paper is to assess the current status and trends of total mercury (THg) contamination of the atmosphere and terrestrial ecosystems in Poland. The study shows that the reduced domestic and worldwide atmospheric emission of Hg resulted in decreased THg level in the terrestrial biotope and biosphere. Considering that Poland is one of the main Hg emitters in Europe, the THg concentrations in its abiotic environment are still elevated. However, the THg level in terrestrial organisms is relatively low, which is because a large proportion of Hg deposited on land is accumulated in organic-rich soils. Regarding the THg concentration, consumption of wildlife and livestock from Poland is safe for humans. Nevertheless, the authors indicate the need for effective environmental monitoring, based on selected bioindicators, which is crucial considering the slowing reduction of Hg emission combined with the consequences of the changing climate.
An Extended Doctrine of Implied Consent – A Digital Mediator?
Authors: Jenkins Georgia
Published: March 2021

This article explores whether an extended doctrine of implied consent can better balance copyright interests in the digital environment, particularly users’ access to digital content. Implied licences are analysed from a variety of jurisdictions including the United Kingdom, the European Union, Germany, the United States and Australia to submit that the role of implied consent emerges as a fundamental legal principle in both common and civil law jurisdictions. Given the significance of consent within the doctrine of exhaustion, the article also evaluates its application in the digital environment and the extent to which this could impact the proposal for an extended doctrine of implied consent. The boundaries of the extended doctrine along with its practical impact will be assessed through an example illustrating users’ access and interaction with digital content. It then becomes clear from the discussion that follows, that an extended doctrine of implied consent has the potential to balance copyright interests in the digital environment due to its status as a fundamental legal principle and inherent flexibility to consider a range of factors regarding users’ subsequent use of digital content.
Unpacking the Quantifying and Qualifying Potential of Semi-Open Job Satisfaction Questions through Computer-Aided Sentiment Analysis
Authors: Wijngaards Indy , Burger Martijn , van Exel Job
Published: March 2021

Despite their suitability for mitigating survey biases and their potential for enhancing information richness, open and semi-open job satisfaction questions are rarely used in surveys. This is mostly due to the high costs associated with manual coding and difficulties that arise when validating text measures. Recently, advances in computer-aided text analysis have enabled researchers to rely less on manual coding to construct text measures. Yet, little is known about the validity of text measures generated by computer-aided text analysis software and only a handful of studies have attempted to demonstrate their added value. In light of this gap, drawing on a sample of 395 employees, we showed that the responses to a semi-open job satisfaction question can reliably and conveniently be converted into a text measure using two types of computer-aided sentiment analysis: SentimentR, and Linguistic Inquiry and Word Count (LIWC) 2015. Furthermore, the substantial convergence between the LIWC2015 and, in particular, SentimentR measure with a closed question measure of job satisfaction and logical associations with closed question measures of constructs that fall within and outside job satisfaction’s nomological network, suggest that a semi-open question has adequate convergent and discriminant validity. Finally, we illustrated that the responses to our semi-open question can be used to fine-tune the computer-aided sentiment analysis dictionaries and unravel antecedents of job satisfaction.
A Systematic Risk Assessment Framework of Automotive Cybersecurity
Authors: Wang Yunpeng , Wang Yinghui , Qin Hongmao , Ji Haojie , Zhang Yanan , Wang Jian
Published: March 2021

The increasingly intelligent and connected vehicles have brought many unprecedented automotive cybersecurity threats, which may cause privacy breaches, personal injuries, and even national security issues. Before providing effective security solutions, a comprehensive risk assessment of the automotive cybersecurity must be carried out. A systematic cybersecurity risk assessment framework for automobiles is proposed in this study. It consists of an assessment process and systematic assessment methods considering the changes of threat environment, evaluation target, and available information in vehicle lifecycle. In the process of risk identification and risk analysis, the impact level and attack feasibility level are assessed based on the STRIDE model and attack tree method. An automotive cybersecurity risk matrix using a global rating algorithm is then constructed to create a quantitative risk metric. Finally, the applicability and feasibility of the proposed risk assessment framework are demonstrated through a use case, and the results prove that the proposed framework is effective. The proposed assessment framework helps to systematically derive automotive cybersecurity requirements.
A CFD study on hydrocarbon mean residence time in a horizontal oil–water separator
Authors: Acharya Tathagata , Potter Terry
Published: March 2021

This study presents computational fluid dynamics analyses on oil–water flow characteristics in a horizontal separator. The performance of these vessels are inferred from mean residence time and cumulative residence time distribution of the hydrocarbon phase inside the separator. The authors model a separator used by previous researchers and evaluate mean residence time of the hydrocarbon phase in a two-phase mixture of oil and water. Three different water-cuts of 21%, 32%, and 57% are used. Additional analyses are done to assess how certain geometric features of the separator influence hydrocarbon mean residence time. The results show that the addition of a second perforated baffle plate does not improve the hydrocarbon mean residence time significantly. However, introducing a downward slanting throat section between the primary zone and the gravity separation zone improves the hydrocarbon mean residence time at 21% and 32% water-cuts. The results suggest oil–water separators with a throat section may be more efficient than regular horizontal separators without the throat section at low water-cuts.
Resumption of sport after spinal fusion for adolescent idiopathic scoliosis: a review of the current literature
Authors: Barile Francesca , Ruffilli Alberto , Manzetti Marco , Fiore Michele , Panciera Alessandro , Viroli Giovanni , Faldini Cesare
Published: March 2021

Background

Adolescent idiopathic scoliosis (AIS) is a frequent disorder. Since patients with AIS are typically as active as age-matched controls and post-operative reduction in physical activity has detrimental effects on their well-being, return to sport (RTS) is an important perioperative concern. Aim of the present study is to review the literature concerning return to sport after spinal fusion for AIS.

Methods

This work was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search was carried out in December 2020. Only peer-reviewed randomized controlled trials (RCTs), retrospective studies (RS), retrospective case series (RCS) and perspective cohort studies (PCS) were considered for inclusion.

Results

Six studies were included; only one of them was prospective. All the authors reported a time to RTS ranging between 6 and 18 months. Between 28 and 36.6% of all patients changed sport, choosing lower impact activities, mostly due to loss of flexibility of the spine. No complications due to return to play were noted.

Conclusion

According to current evidence, patients who received spinal arthrodesis for AIS can safely return to any sport, even those that require extreme levels of spinal and pelvic movements such as gymnastics and golf. As there is little evidence, however, of the spinal loading that occurs during such movements, there is a lack of scientific evidence-based recommendations or guidelines surgeons and other health care providers can follow. Prospective comparative studies are needed to investigate these biomechanical and clinical issues.

Level of evidence

Level III.
Contemporary Experience of Posterior Retroperitoneoscopic Adrenalectomy in the US
Authors: Chiu Alexander , Vargas-Pinto Susana , Abou-Azar Sara , Maduka Richard , Man Jianling , Peters Nicholas , Carling Tobias , Gibson Courtney
Published: March 2021

BACKGROUND:

As the incidence of adrenalectomy increases steadily, so does the use of minimally invasive approaches like posterior retroperitoneoscopic adrenalectomy (PRA). To date, the largest studies of PRA have been from abroad, and we sought to provide a contemporary US update on the outcomes after PRA.

METHODS:

A retrospective chart review was conducted on all PRAs performed at a single tertiary care institution between 2013 and 2020. Patient demographic characteristics, indication for operation, operative details, and postoperative course were abstracted. Outcomes of interest included 30-day mortality, conversion to open or transabdominal approach, postoperative complication, and 30-day readmission.

RESULTS:

A total of 249 PRAs were performed between 2013 and 2020. The population was 54.2% women and mean (SD) age was 54.1 (14.1) years. Most lesions (60.6%) were left-sided, and the most common diagnosis was nonfunctioning adenoma (39.4%), followed by pheochromocytoma (21.3%) and aldosteronoma (16.6%). Mean (SD) tumor size was 3.2 cm (range 0.5 to 9.4 cm). Median operative length was 110 minutes (range 30 to 319 minutes).

Overall, the complication rate was 6.4%. Nine patients (3.6%) had a minor postoperative complication (Clavien-Dindo I to III) and 5 patients (2.0%) had a major postoperative complication (Clavien-Dindo IV to V), including 1 mortality (0.4%). There were 2 conversions of approach (0.8%). The majority of patients (58.2%) were discharged on postoperative day 1, and 92.0% were discharged by postoperative day 3. The 30-day readmission rate was 1.6%.

CONCLUSIONS:

Current practice demonstrates that PRA is an extremely safe approach, with a complication rate < 7% and mortality rate < 1%. In addition, the vast majority of patients are able to return home in an expedient manner.
Seal failure in aerospace applications – creating a global open-source database
Authors: Shabbir Sarah , Garvey Seamus D. , Dakka Sam M. , Rothwell Benjamin C.
Published: March 2021

Seals are important components in aerospace applications because they restrict leakage of fluids and prevent debris from entering systems. However, the failure of these components is detrimental and it is essential to understand how, why and where they fail in service, and how often. There have been numerous reports where seal failure has led to aircraft incidents – jeopardising the safety of passengers and crew alike. However, it is often difficult to find these reports because of the varying reporting systems and databases that are in use in different countries. In this article we propose a plan to create a designated open-source data-set for reports that involve seal failure, which is accessible to everyone and enables user interaction. In addition, interested individuals can add to the data set easily, enabling it to grow and adding statistical power to its value.
Bernstein and Robbins
Authors: Redfern Sophie
Published: March 2021

The formative early ballets of West Side Story creators Leonard Bernstein and Jerome Robbins explored in detail for the very first time.
Healthcare and Terrorism: The Lebanese Experience
Authors: Iskandar Nooreddine , Rahbany Tatiana , Shokor Ali
Published: March 2021

Background:

Due to the common instability caused by political and security issues, Lebanese hospitals have experienced acts of terrorism multiple times. The most recent Beirut Explosion even forced several hospitals to cease operations for the first time in decades—but studies show the preparedness levels for such attacks in similar countries are low.

Objective:

The aim of this study is to explore the experience of Lebanese hospitals with terrorist attacks.

Methods:

This qualitative study used semi-structured interviews with various stakeholders to assess their experience with terrorist bombings. Data was analyzed using the thematic analysis method.

Results:

The researchers found that Lebanese hospitals vary greatly in their structures and procedures. Those differences are a function of 3 contextual factors: location, culture, and accreditation status. Hospitals found near ‘dangerous zones’ were more likely to be aware and to have better response to such events. A severe lack of communication, unity of command, and collaboration between stakeholders has made the process fragmented.

Conclusion:

The researchers recommend a larger role for the Ministry of Public Health (MOPH) in this process, and the creation of a platform where Lebanese organizations can share their experiences to improve preparedness and resilience of the Lebanese healthcare system in the face of terrorism.
Local limit theorems in relatively hyperbolic groups I: rough estimates
Authors: DUSSAULE MATTHIEU
Published: March 2021

This is the first of a series of two papers dealing with local limit theorems in relatively hyperbolic groups. In this first paper, we prove rough estimates for the Green function. Along the way, we introduce the notion of relative automaticity which will be useful in both papers and we show that relatively hyperbolic groups are relatively automatic. We also define the notion of spectral positive recurrence for random walks on relatively hyperbolic groups. We then use our estimates for the Green function to prove that$p_n\asymp R^{-n}n^{-3/2}$for spectrally positive-recurrent random walks, where$p_n$is the probability of going back to the origin at timenand whereRis the inverse of the spectral radius of the random walk.
The effects of diffusion on the principal eigenvalue for age-structured models with random diffusion
Authors: Kang Hao
Published: March 2021

In this paper, we study the principal spectral theory of age-structured models with random diffusion. First, we provide an equivalent characteristic for the principal eigenvalue, the strong maximum principle and a positive strict super-solution. Then, we use the result to investigate the effects of diffusion rate on the principal eigenvalue. Finally, we study how the principal eigenvalue affects the global dynamics of the KPP model and verify that the principal eigenvalue being zero is a critical value.
A virtual environment for evaluation of computer vision algorithms under general airborne camera imperfections
Authors: Mahmoudi Arshiya , Sabzehparvar Mehdi , Mortazavi Mahdi
Published: March 2021

This paper describes a camera simulation framework for validating machine vision algorithms under general airborne camera imperfections. Lens distortion, image delay, rolling shutter, motion blur, interlacing, vignetting, image noise, and light level are modelled. This is the first simulation that considers all temporal distortions jointly, along with static lens distortions in an online manner. Several innovations are proposed including a motion tracking system allowing the camera to follow the flight log with eligible derivatives. A reverse pipeline, relating each pixel in the output image to pixels in the ideal input image, is developed. It is shown that the inverse lens distortion model and the inverse temporal distortion models are decoupled in this way. A short-time pixel displacement model is proposed to solve for temporal distortions (i.e. delay, rolling shutter, motion blur, and interlacing). Evaluation is done by several means including regenerating an airborne dataset, regenerating the camera path on a calibration pattern, and evaluating the ability of the time displacement model to predict other frames. Qualitative evaluations are also made.
Vulnerability and resiliency implications of human capital and linked inequality presence denial perspectives: Acknowledging Zigler's contributions to child well-being
Authors: Nichols Lodato Bronwyn , Hall Jennifer , Spencer Margaret Beale
Published: March 2021

Edward Zigler's groundbreaking research on child development resulted in the historic Head Start program. It is useful to examine the theoretical implications of his work by applying a human development theoretical perspective. Phenomenological variant of ecological systems theory (PVEST) is a strengths-based theoretical framework that engages the variability of resource access and coping strategies that promote positive identity development for diverse children. While skill acquisition is a key focus of human capital theory's engagement of early childhood needs, this article highlights the on-going status of human vulnerability that undergirds identity development over the life course. The authors note that “inequality presence denial” combines with high-risk contexts, framed by geography and psychohistoric moments (e.g., The Great Recession, COVID-19), to alter diverse children's developmental pathways. The acknowledgement of “morbid risk” motivates the urgency for research that builds upon Zigler's innovations and privileges human development imperatives. The case study explores these concepts by examining the challenges and assets available to mothers in a low-income community. The article's closing notes developments in the field of economics that ameliorate human capital theory's conceptual limitations, underscoring human development's theoretical strength in motivating research and policies that are maximally responsive to children's positive identity development.
Grammar instruction through multinational telecollaboration for pre-service teachers
Authors: Wach Aleksandra , Zhang De , Nichols-Besel Kristen
Published: March 2021

Recognizing the importance of multinational telecollaboration and form-focused instruction in computer-assisted language learning teacher education, this article investigates teaching English grammar through a seven-week-long telecollaborative project with 41 pre-service language teachers from the United States (US), Poland, and China. The telecollaboration was a pedagogical intervention in which the US participants taught grammar to their non-native-speaker peers. Specifically, the study aimed to trace pre-service teachers’ grammar instruction techniques applied in the communication-oriented context of online exchanges and responses to this instruction, the grammar forms attended to in the exchanges, and the participants’ evaluations of the usefulness of telecollaboration for teaching and learning grammar. Utilizing data from the participants’ emails and results of a post-project survey, this mixed methods study reveals that (1) the implicit technique of modeling was the most frequently applied; (2) the grammatical forms used in both implicit and explicit teaching reflected the communicative orientation of the exchanges; (3) the levels of uptake (i.e. attempts to follow the models provided in the input), and the forms attended to by the learners, reflected their proficiency levels and linguistic background; and (4) participants reported positive opinions about the value of telecollaboration in grammar instruction and in teacher training. The data thus underscore the benefits of online exchanges in giving prospective teachers hands-on experience with communicative grammar teaching.
Echinococcosis in both heart and lungs, the first case reported in Albania
Authors: Maliqari Numila , Teneqexhi Loreta , Koja Albert , Veshti Altin , Baboci Arben , Haxhiu Albana , Kuci Saimir , Ibrahimi Alfred , Cela Durim , Vanini Vittorio
Published: March 2021

An 11-year-old male was admitted with cough and fever for the last 4 days and also complained of pain in the right lung for some weeks. The boy did not show any other symptoms and his past medical history was unremarkable as well. The radiologist findings showed an aspect that suggested for echinococcosis.

At first, it was realised the heart intervention. About a 2-month period later, the child underwent another cyst removal in lung. He had begun taking albendazole 5 days before the heart intervention. The therapy was continued until the lung intervention and for 12 weeks post-operatively. The patient had an uneventful recovery and after about 4 years.
The utility of ISSRs for the identification of interspecific hybrids between pearl millet (Pennisetum glaucum [L.] R.Br.) × napier grass (Pennisetum purpureum Schumach)
Authors: Jade S. S. , Takawale P. S. , Bahulikar R. A.
Published: March 2021

Interspecific hybrids between pearl millet (Pennisetum glaucum) and napier grass (Pennisetum purpureum) give rise to perennial fodder crops characterized by high biomass, broad clumps and good palatability. These hybrids are triploid and developed by hand pollination of napier grass pollen on pearl millet panicles. The progeny shows a high percentage of pearl millet genotype due to self-pollination in the female parent. Identification of hybrids at a young stage based on morphological characters is difficult. DNA-based molecular markers have high discriminating power and were used to assess genetic differences between hybrids and their parents. Genetic diversity was studied in 18 pearl millet × napier grass hybrids along with their parents and two released national checks using inter simple sequence repeat (ISSR) markers. Eight ISSR primers gave rise to 125 bands, of which 120 bands were polymorphic. Polymorphic information content and ISSR primer index ranged from 0.40 to 0.49 and 8.88 to 11.14, respectively. The hybrids showed the presence of unique bands, besides those shared with male and female parents. Female (pearl millet) parents formed a separate group in the dendrogram constructed based on ISSR polymorphism. The male (napier grass) parents formed a separate group along with hybrids, indicating a higher similarity of hybrids with the male parents. Principal component analysis and STRUCTURE analyses showed a similar grouping. The close resemblance of hybrids to the male parents confirmed their interspecific origin. The study revealed that ISSR marker analysis could be a quick and reliable method to identify interspecific hybrids at an early stage of growth.
Intergenerationale Transmission psychischer Auffälligkeiten unter Berücksichtigung von Geschlechtereffekten
Authors: Alsmeier Nina , Schulz Wolfgang
Published: March 2021

Zusammenfassung. Hintergrund: Kinder psychisch kranker Eltern sind eine Hochrisikogruppe. Eine mütterliche Erkrankung scheint sich stärker negativ auf die Nachkommen auszuwirken als eine väterliche Erkrankung. Ob sich die Auswirkungen auf Mädchen und Jungen unterscheiden, ist unklar. Fragestellung: Ziel der Studie ist die Klärung von Geschlechtereffekten bei der intergenerationalen Transmission psychischer Auffälligkeiten. Methode: Es wurden N = 267 Familien untersucht, indem die Depressions- und Angstsymptome von Müttern und Vätern mit einem latenten Wachstumskurvenmodell über vier Messzeitpunkte (zehn Jahre) modelliert wurden. Die Überprüfung erfolgt mittels Strukturgleichungsmodellen. Ergebnisse: Es wurden Zusammenhänge zwischen elterlichen und kindlichen Auffälligkeiten gefunden. Dabei steht eine väterliche depressive Symptomatik stärker mit jugendlichen externalisierenden Auffälligkeiten in Verbindung als eine mütterliche depressive Symptomatik. Mädchen entwickeln tendenziell mehr als Jungen internalisierende Auffälligkeiten bei psychisch belasteten Eltern. Schlussfolgerung: Zukünftige Studien sollten Mütter und Väter gleichermaßen einbeziehen. Weiterhin sollten verstärkt Transmissionsmechanismen inklusive möglicher Mediatoren mit Berücksichtigung des elterlichen und kindlichen Geschlechtes untersucht werden.
Engineered Continental‐Scale Rivers Can Drive Changes in the Carbon Cycle
Authors: Shen Zhixiong , Rosenheim Brad E. , Törnqvist Torbjörn E. , Lang Andreas
Published: March 2021

Floodplains of large alluvial rivers modulate the composition of riverine organic carbon (OC) and control OC oxidative loss, constituting a critical component in the global river‐atmosphere‐ocean carbon cycle. Therefore, anthropogenic management disconnecting rivers from their floodplains is expected to reduce the oxidative loss and to change the quality and quantity of riverine OC exported to the ocean. Here, we test this idea by combining two chronometers—14C age spectra of OC and optically stimulated luminescence ages of quartz—to interrogate sediments of the Lower Mississippi River (LMR) system to constrain the anthropogenic effects on carbon cycling in a continental‐scale sediment routing system. The 14C age of the LMR OC has been reduced from >5,000 yr in prehistoric sediments to <3,000 yr in historic and modern sediments with significantly narrowed age spectrum width, following centuries of embanking the LMR. Bank stabilization reduced the river‐floodplain sediment exchange by ∼90%, effectively cutting off older floodplain OC from the river and reducing OC residence time in the severely truncated floodplain system, and expedited the downstream transmission of OC. The reduced residence time will have decreased riverine OC loss and enhanced younger OC delivery to marine sediments. We estimate that the oxidative loss of the LMR OC has been reduced by ≥ 1.1 Tg C/yr or 40%. Extrapolation to other large rivers that have undergone anthropogenic changes similar to the LMR illustrates that this process likely represents a carbon sink that can significantly increase if currently free‐flowing large tropical rivers are embanked in the future.
Earth's Magnetic Field Strength and the Cretaceous Normal Superchron: New Data From Costa Rica
Authors: Di Chiara A. , Tauxe L. , Staudigel H. , Florindo F. , Protti M. , Yu Y. , Wartho J.‐A. , van den Bogaard P. , Hoernle K.
Published: March 2021

Constraining the long‐term variability and average of the Earth's magnetic field strength is fundamental to understanding the characteristics and behavior of the geomagnetic field. Questions remain about the strength of the average field, and the relationship between strength and reversal frequency, due to the dispersion of data from key time intervals. Here, we focus on the Cretaceous Normal Superchron (CNS; 121‐84 Ma), during which there were no reversals. We present new intensity results from 41 submarine basaltic glass (SBG) sites collected on the Nicoya Peninsula and Murcièlago Islands, Costa Rica. New and revised40Ar/39Ar and biostratigraphic age constraints from previous studies indicate ages from 141 to 65 Ma. One site with an age of 135.1 ± 1.5 Ma (2σ) gave a reliable intensity result of 34 ± 8 µT (equivalent to a virtual axial dipole moment, VADM, value of 88 ± 20 ZAm2), three sites from 121 to 112 Ma, spanning the onset of the CNS, vary from 21 ± 1 to 34 ± 4 µT (53 ± 3 to 87 ± 10 ZAm2). These results from the CNS are all higher than the long‐term average of ∼42 ZAm2and data from Suhongtu, Mongolia (46–53 ZAm2) and are similar to the Troodos Ophiolite, Cyprus (81 ZAm2, reinterpreted in this study). Together with the reinterpreted data, the new Costa Rica results suggest that the strength of the geomagnetic field was approximately the same both before and after the onset of the CNS. Therefore, the data do not support a strict correlation between polarity interval length and the strength of the magnetic field.