bluuebunny/crossref_metadata_2025_split huggingface dataset:
Teaching and learning discrete mathematics
Authors: Sandefur James , Lockwood Elise , Hart Eric , Greefrath Gilbert 
Published: July 2022

AbstractIn this paper, we provide an overall perspective on the teaching and learning of discrete mathematics. Our aim is to highlight what research has been conducted in this area and to connect it to existing research ideas for future work. We begin by characterizing discrete mathematics and its role in the school curriculum, highlighting themes, topics, and mathematical practices that distinguish discrete mathematics. We then present potential benefits of focusing on discrete mathematics topics for mathematics education; in particular, we discuss the accessibility of topics in discrete mathematics, the connection to mathematical processes and affect, and the relevance of discrete mathematics in our current society. We also emphasize discrete mathematics from an international perspective, highlighting studies from the US, Italy, France, Chile, and Germany, which are across all school levels–primary, middle, and secondary school, and with some implications for post-secondary education. We particularly discuss discrete topics including number theory, combinatorics, iteration and recursion, graph theory, and discrete games and puzzles; we describe and situate these topics within literature. We also suggest the additional topics of game theory and the mathematics of fairness that we hope to see addressed in future studies.
Unraveling the Contribution of Serotonergic Polymorphisms, Prefrontal Alpha Asymmetry, and Individual Alpha Peak Frequency to the Emotion-Related Impulsivity Endophenotype
Authors: Javelle Florian , Löw Andreas , Bloch Wilhelm , Hosang Thomas , Jacobsen Thomas , Johnson Sheri L. , Schenk Alexander , Zimmer Philipp 
Published: July 2022

AbstractThe unique contribution of the serotonin transporter-linked polymorphic region (5-HTTLPR), intronic region 2 (STin2), and monoamine oxidase A (MAO-A) genes to individual differences in personality traits has been widely explored, and research has shown that certain forms of these polymorphisms relate to impulsivity and impulsivity-related disorders. Humans showing these traits are also described as having an asymmetrical prefrontal cortical activity when compared to others. In this explorative study, we examine the relationship between serotonergic neurotransmission polymorphisms, cortical activity features (prefrontal alpha asymmetry, individual alpha peak frequency [iAPF]), emotion-related and non-emotion-related impulsivity in humans. 5-HTTLPR, MAO-A, and STin2 polymorphisms were assessed in blood taken from 91 participants with high emotion-related impulsivity levels. Sixty-seven participants completed resting electroencephalography and a more comprehensive impulsivity index. In univariate analyses, iAPF correlated with both forms of emotion-related impulsivity. In multiple linear regression models, 5-HTTLPR polymorphism (model 1, adj. R2 = 15.2%) and iAPF were significant interacting predictors of emotion-related impulsivity, explaining a large share of the results’ variance (model 2, adj. R2 = 21.2%). Carriers of the low transcriptional activity 5-HTTPLR and MAO-A phenotypes obtained higher emotion-related impulsivity scores than others did. No significant results were detected for non-emotion-related impulsivity or for a form of emotion-related impulsivity involving cognitive/motivational reactivity to emotion. Our findings support an endophenotypic approach to impulsivity, showing that tri-allelic 5-HTTLPR polymorphism, iAPF, and their interaction are relevant predictors of one form of emotion-related impulsivity.
Linking academic buoyancy and math achievement in secondary school students: Does academic self-efficacy play a role?
Authors: Weißenfels Marie , Hoffmann Dana , Dörrenbächer-Ulrich Laura , Perels Franziska 
Published: July 2022

AbstractAcademic buoyancy describes the ability to successfully overcome and recover from setbacks in an academic context (e.g., a poor grade, motivational dips, stress due to upcoming performance exams). This day-to-day form of academic resilience has recently been defined in the context of positive psychology. The present study aimed to gain insights into the mechanisms of academic buoyancy by predicting math achievement. Since there is already evidence that this relationship is rather indirect than direct, we were particularly interested in investigating a potential actor of an indirect effect, namely academic self-efficacy. For this purpose, n = 974 students at eleven secondary schools in southwestern Germany were surveyed through a questionnaire. The data were analyzed using a latent variable approach. The results of the study show that academic buoyancy is a significant predictor of math achievement and that this relation is explained through academic self-efficacy, even when controlling for gender. Implications for practice and further research are also discussed.
Model-based design of crop diversification through new field arrangements in spatially heterogeneous landscapes. A review
Authors: Hernández-Ochoa Ixchel M. , Gaiser Thomas , Kersebaum Kurt-Christian , Webber Heidi , Seidel Sabine Julia , Grahmann Kathrin , Ewert Frank 
Published: July 2022

AbstractIntensive agriculture in Germany is not only highly productive but has also led to detrimental effects in the environment. Crop diversification together with new field arrangements considering soil heterogeneities can be an alternative to improve resource use efficiency (RUE), ecosystem services (ESS), and biodiversity. Agroecosystem models are tools that help us to understand and design diversified new field arrangements. The main goal of this study was to review the extent to which agroecosystem models have been used for crop diversification design at field and landscape scale by considering soil heterogeneities and to understand the model requirements for this purpose. We found several agroecosystem models available for simulating spatiotemporal crop diversification at the field scale. For spatial crop diversification, simplified modelling approaches consider crop interactions for light, water, and nutrients, but they offer restricted crop combinations. For temporal crop diversification, agroecosystem models include the major crops (e.g., cereals, legumes, and tuber crops). However, crop parameterization is limited for marginal crops and soil carbon and nitrogen (N). At the landscape scale, decision-making frameworks are commonly used to design diversified cropping systems. Within-field soil heterogeneities are rarely considered in field or landscape design studies. Combining static frameworks with dynamic agroecosystems models can be useful for the design and evaluation of trade-offs for ESS delivery and biodiversity. To enhance modeling capabilities to simulate diversified cropping systems in new field arrangements, it will be necessary to improve the representation of crop interactions, the inclusion of more crop species options, soil legacy effects, and biodiversity estimations. Newly diversified field arrangement design also requires higher data resolution, which can be generated via remote sensing and field sensors. We propose the implementation of a framework that combines static approaches and process-based models for new optimized field arrangement design and propose respective experiments for testing the combined framework.
Enhanced High-Temperature Mechanical Behavior of an in Situ TiAl Matrix Composite Reinforced With Alumina
Authors: Pilone D. , Mondal A. , Pulci G. , Paglia L. , Brotzu A. , Marra F. , Felli F. 
Published: July 2022

AbstractA Ti-45Al-3Cr-2.5Nb alloy reinforced with in situ formed alumina has been produced by means of centrifugal casting by adding zirconium oxide in the crucible. The dispersion-strengthened alloy has been characterized to verify its microstructure and particle distribution. Mechanical tests carried out over the temperature range 850–950 °C highlighted that in situ formed alumina allows to increase the alloy yield stress by 21% at 850 °C and by 35% at 900 °C. Moreover, the in situ formed oxide particles produced an increase of the Young’s modulus of about 10% at 850 °C and of about 8% at 900 °C. Considering that the tested alloy has a density that is about a half of nickel superalloys, obtaining high specific mechanical properties over the temperature range 850–950 °C can boost its application in the production of turbine blades.
Graphical abstract
An open-set framework for underwater image classification using autoencoders
Authors: Akhtarshenas Azim , Toosi Ramin 
Published: July 2022

AbstractIn this paper, we mainly intend to address the underwater image classification problem in an open-set scenario. Image classification algorithms have been mostly provided with a small set of species, while there exist lots of species not available to the algorithms or even unknown to ourselves. Thus, we deal with an open-set problem and extremely high false alarm rate in real scenarios, especially in the case of unseen species. Motivated by these challenges, our proposed scheme aims to prevent the unseen species from going to the classifier section. To this end, we introduce a new framework based on convolutional neural networks (CNNs) that automatically identifies various species of fishes and then classifies them into certain classes using a novel technique. In the proposed method, an autoencoder is employed to distinguish between seen and unseen species. To clarify, the autoencoder is trained to reconstruct the available species with high accuracy and filter out species that are not in our training set. In the following, a classifier based on EfficientNet is trained to classify the samples that are accepted by the autoencoder (AE), i.e. the samples that have small reconstruction error. Our proposed method is evaluated in terms of precision, recall, and accuracy and compared to the state-of-the-art methods utilizing WildFish dataset. Simulation results reveal the supremacy of the proposed method.
Necroptosis-Related LncRNA Signatures for Prognostic Prediction in Uterine Corpora Endometrial Cancer
Authors: Lin Zhiheng , Fan Weisen , Sui Xiaohui , Wang Juntao , Zhao Junde 
Published: July 2022

Abstract
Necroptosis is one of the common modes of apoptosis, and it has an intrinsic association with cancer prognosis. However, the role of the necroptosis-related long non-coding RNA LncRNA (NRLncRNAs) in uterine corpora endometrial cancer (UCEC) has not yet been fully elucidated at present. Therefore, the present study is designed to investigate the potential prognostic value of necroptosis-related LncRNAs in UCEC. In the present study, the expression profiles and clinical data of UCEC patients were downloaded from TCGA database to identify the differentially expressed NRLncRNAs associated with overall survival. A LncRNA risk model was constructed via Cox regression analysis, and its prognostic value was evaluated. We have also further evaluated the relationships between the LncRNA features and the related cellular function, related pathways, immune status, and immune checkpoints m6A-related genes. Seven signatures, including PCAT19, CDKN2B-AS1, LINC01936, LINC02178, BMPR1B-DT, LINC00237, and TRPM2-AS, were established to assess the overall survival (OS) of the UCEC in the present study. Survival analysis and ROC curves indicated that the correlated signature has good predictable performance. The normogram could accurately predict the overall survival of the patients with an excellent clinical practical value. Enrichment analysis of gene sets indicated that risk signals were enriched in several immune-related pathways. In addition, the risk characteristics were significantly correlated with immune cells, immune function, immune cell infiltration, immune checkpoints, and some m6A-related genes. This study has identified seven necroptosis-related LncRNA signatures for the first time, providing a valuable basis for a more accurate prognostic prediction of UCEC.
Precarious ageing in a global pandemic – older adults' experiences of being at risk due to COVID-19
Authors: Gallistl Vera , Richter Lukas , Heidinger Theresa , Schütz Teresa , Rohner Rebekka , Hengl Lisa , Kolland Franz 
Published: July 2022

AbstractHealth authorities worldwide address older adults as a risk group for more serious illness and health complications associated with COVID-19, while social gerontologists have warned that addressing older adults as a risk group of COVID-19 bears the risk of reinforcing ageism. This paper empirically explores to what extent older adults perceive themselves as part of a COVID-19 risk group and how these perceptions influence their everyday lives and experiences of age and ageing. This paper draws upon data from a mixed-methods study on older adults' risk perceptions during COVID-19 in Lower Austria, including a representative survey on 521 adults (60+ years) and data from 20 semi-structured interviews. Approximately two-thirds of the respondents consider themselves at risk of COVID-19 and name age, in addition to pre-existing illness, as a contributing factor in this risk perception. Older adults with health constraints, and especially older men, have a higher probability of perceiving risk due to COVID-19. Additionally, older adults report that they experience being ‘suddenly seen as old’ or ‘being put into a box’ during the pandemic, which influenced their experiences and images of ageing. Our study provides insights into how perceived COVID-19 risk affects the everyday lives of older adults. Age-based categorisations of risk contribute to a shift in images of age and ageing, drawing on insecurity and risk, rather than successful and active ageing, to conceptualise later life.
Age, ethnicity, life events and wellbeing among New Zealand women
Authors: Newton Nicky J. , Howard Chloe , Houkamau Carla A. , Sibley Chris G. 
Published: July 2022

AbstractBy the year 2030, 19–21 per cent of the population of New Zealand (NZ) is projected to be aged 65 and over. Like many countries, life expectancy in NZ differs by gender but also ethnicity: in 2019, life expectancy for Māori (indigenous) women was 77.1 years compared with 84.4 years for non-Māori women. If Māori and NZ European women are to flourish in later life, examining the factors associated with their wellbeing is paramount. The current study draws on the Life Course Perspective to explore how wellbeing is associated with age-related life events among mid- to later-life NZ women. The women in this study (N = 19,624) are participants in the 2018 wave of the New Zealand Attitudes and Values Study, a national probabilistic 20-year longitudinal study (mean age = 55.62; Māori = 10.8%, NZ European = 89.2%). We found that stressful life events were negatively associated with life satisfaction but positively associated with meaning in life. Māori women exhibited lower levels of life satisfaction but there were no ethnic differences for meaning in life; however, Māori and NZ European women showed different patterns of significant correlates associated with meaning in life. Findings highlight the necessity of an intersectional approach to the study of mid- to later-life wellbeing and the utility of measuring wellbeing in more than one way within NZ's unique cultural-historical context.
Explicit and implicit knowledge and learning of an additional language: A research agenda
Authors: Roehr-Brackin Karen 
Published: July 2022

AbstractThis paper puts forward a research agenda in the area of explicit and implicit knowledge and learning of second or additional languages. Based on a brief overview of reliable findings as well as open questions in the field, three agenda items are highlighted. First, valid and reliable measures of explicit and, in particular, implicit knowledge and learning need to be identified and their suitability for participants of different ages established. Second, and closely related to the previous point, explicit and implicit knowledge and learning should be investigated across the human lifespan. Therefore, studies need to include to a greater extent hitherto under-represented groups such as children and older adults in order to pinpoint the benefits or otherwise of implicit and, in particular, explicit knowledge and learning in these age ranges. Third, researchers should aim to capture with their designs the complex and dynamic interplay of the multiple cognitive, affective, biographical and contextual factors that influence the development of explicit and implicit knowledge over time. Concrete tasks for future research are proposed under these three agenda items, with a view to assisting interested investigators in formulating research questions and specifying research designs.
Baroclinic Blocking
Authors: Martineau P. , Nakamura H. , Yamamoto A. , Kosaka Y. 
Published: July 2022

AbstractAtmospheric blocking events, which cause abnormal weather conditions, have been studied from a viewpoint of quasi‐stationary barotropic circulation systems because of their apparent lack of vertical tilt. However, this work demonstrates that blocking events often have such structure that anomalies in geopotential height and temperature are horizontally out‐of‐phase, allowing blocking anomalies to produce fluxes of heat against the climatological‐mean gradients for amplifying and maintaining blocking‐related temperature anomalies. This process, which represents the baroclinic conversion of energy from the climatological‐mean flow to the blocking‐related anomalies, is shown to be one of the leading energy sources through an analysis of blocking energetics. In winter, the contribution of the baroclinic energy conversion, especially for North Pacific and Greenland blocks, is substantially larger than the contributions from barotropic energy conversion and feedback forcing by high‐frequency eddies. In summer, the baroclinic energy conversion and feedback from high‐frequency eddies are more comparable in magnitude.
Mechanisms of Landslide Destabilization Induced by Glacier‐Retreat on Tungnakvíslarjökull Area, Iceland
Authors: Lacroix Pascal , Belart Joaquin M. C. , Berthier Etienne , Sæmundsson Þorsteinn , Jónsdóttir Kristín 
Published: July 2022

AbstractThe massive worldwide deglaciation leads to more frequent slope instabilities in mountainous terrains. The physical processes leading to such destabilizations are poorly constrained due to little monitoring of dynamic parameters at the local scale. Here we study a very large slow‐moving landslide (∼0.8 km2), on the flank of Tungnakvíslarjökull glacier in Iceland. Based on a combination of remote sensing images, we monitor the landslide and glacier kinematics over 75 years, with a focus over the period 1999–2019 when rapid glacier wastage has been observed. The landslide accelerates from 2 to 45 m/yr in the 6 years following a sudden increase in glacier mass loss. This acceleration coincides with intense quake activity (Mℓ < 2.8), recorded by a regional seismic network. We show that this seismicity is caused by the landslide sliding on a rough surface. The evolution of the quake magnitudes suggests a progressive segmentation of the landslide mass during its acceleration.
Drought Legacy in Sub‐Seasonal Vegetation State and Sensitivity to Climate Over the Northern Hemisphere
Authors: Wu Minchao , Manzoni Stefano , Vico Giulia , Bastos Ana , de Vries Franciska T. , Messori Gabriele 
Published: July 2022

AbstractDroughts affect ecosystems at multiple time scales, but their sub‐seasonal legacy effects on vegetation activity remain unclear. Combining the satellite‐based enhanced vegetation index MODIS EVI with a novel location‐specific definition of the growing season, we quantify drought impacts on sub‐seasonal vegetation activity and the subsequent recovery in the Northern Hemisphere. Drought legacy effects are quantified as changes in post‐drought greenness and sensitivity to climate. We find that greenness losses under severe drought are partially compensated by a ∼+5% greening within 2–6 growing‐season months following the droughts, both in woody and herbaceous vegetation but at different timings. In addition, post‐drought sensitivity of herbaceous vegetation to hydrological conditions increases noticeably at high latitudes compared with the local normal conditions, regardless of the choice of drought time scales. In general, the legacy effects on sensitivity are larger in herbaceous vegetation than in woody vegetation.
Impact of Three Solar Eclipses of 2019–2020 on the D‐Region Ionosphere Observed From a Subtropical Low‐Latitude VLF Radio Station
Authors: Das B. , Barman K. , Pal S. , Haldar P. K. 
Published: July 2022

AbstractIonospheric impact of three solar eclipses (January 2019, December 2019, and June 2020) observed by Very Low Frequency (VLF) radio signals from a single receiver at a subtropical low‐latitude station in India is presented here. Perturbations in signal amplitudes of VLF transmitters such as the VTX (18.2 kHz), NWC (19.8 kHz), JJI (22.2 kHz), and DHO (23.4 kHz) are analyzed. Both positive, negative, and also mixed‐type of amplitude deviations are observed which are explained based on the solar eclipse obscuration profiles over the entire propagation paths. The difference in observed amplitude deviations for a VLF signal during the different solar eclipses are reproduced using the Long Wave Propagation Capability code and solar obscuration profile. Particularly, the effects of two solar eclipses on the VLF signal propagation characteristics have been analyzed. The modal attenuation coefficients of the VTX signal in the earth‐ionosphere waveguide are decreased with the increase of solar obscuration. A negative linear relationship of VLF signal attenuation with solar obscuration has been found for the first time during the solar eclipse. The relations are almost similar for the two solar eclipses of December 2019 and June 2020. Further, the percentage reduction of the D‐region electron density profiles as a function of altitude and solar obscuration during the two solar eclipses is presented.
An Empirical Model of the Ionospheric Sporadic E Layer Based on GNSS Radio Occultation Data
Authors: Yu Bingkun , Xue Xianghui , Scott Christopher J. , Yue Xinan , Dou Xiankang 
Published: July 2022

AbstractThe intense plasma irregularities within the ionospheric sporadic E (Es) layers at 90–130 km altitude have a significant impact on radio communications and navigation systems. As a result, the modeling of the Es layer is very important for the accuracy, reliability, and further applications of modern real‐time global navigation satellite system precise point positioning. In this study, we have constructed an empirical model of the Es layer using the multivariable nonlinear least‐squares‐fitting method, based on the S4max from Constellation Observing System for Meteorology, Ionosphere, and Climate satellite radio occultation measurements in the period 2006–2014. The model can describe the climatology of the intensity of Es layers as a function of altitude, latitude, longitude, universal time, and day of year. To validate the model, the outputs of the model were compared with ionosonde data. The correlation coefficients of the hourly foEs and the daily maximum foEs between the ground‐based ionosonde observations and model outputs at Beijing are 0.52 and 0.68, respectively. The model can give a global climatology of the intensity of Es layers and the seasonal variations of Es layers, although the Es layers during the summer are highly variable and difficult to accurately predict. The outputs of the model can be implemented in comprehensive models for a description of the climatology of Es layers and provide relatively accurate information about the global variation of Es layers.