Graph Neural Networks for an Accurate and Interpretable Prediction of the Properties of Polycrystalline Materials

Various machine learning models have been used to predict the properties of polycrystalline materials, but none of them directly consider the physical interactions among neighboring grains despite such microscopic interactions critically determining macroscopic material properties. Here, we develop a graph neural network (GNN) model for obtaining an embedding of polycrystalline microstructure which incorporates not only the physical features of individual grains but also their interactions. The embedding is then linked to the target property using a feed-forward neural network. Using the magnetostriction of polycrystalline Tb0.3Dy0.7Fe2 alloys as an example, we show that a single GNN model with fixed network architecture and hyperparameters allows for a low prediction error of ~10% over a group of remarkably different microstructures as well as quantifying the importance of each feature in each grain of a microstructure to its magnetostriction. Such microstructure-graph-based GNN model therefore enables an accurate and interpretable prediction of the properties of polycrystalline materials.Comment: 28 pages, 6 figures

Évaluation de l'approche neurolinguistique (ANL) auprès d'apprenants chinois de français en première et en deuxième année d'université

Dans cet article, nous présentons les résultats d’une expérimentation de l’ANL pendant deux ans. Nous comparons les résultats en production orale et en production écrite de deux classes expérimentales après un an puis deux ans d’utilisation de l’ANL (an I : n=28; an II : n= 26) aux résultats de deux classes (an I : n= 27; an II : n=28) d’une autre université chinoise ayant plutôt recours à la ‘méthode traditionnelle chinoise’. En dépit de quelques variantes portant sur des critères spécifiques à l’écrit, les résultats des tests montrent que les résultats sont supérieurs dans le groupe expérimental. Ces résultats sont semblables à ceux obtenus auprès de jeunes élèves anglophones et allophones (âgés de 11 et 12 ans) lors de l’application antérieure de l’ANL au Canada, désignée comme ‘le français intensif’. Contrairement à nos attentes, pareils résultats semblent suggérer une grande ouverture des étudiants chinois à des manières plus interactives d’apprendre une langue étrangère.A two-year experiment of the NLA is presented. Results in oral and written production for two experimental classes after one and two years of instruction (1 year: n=28; 2 years: n=26) are compared with those of two classes (1 year: n=27; 2 years: n=28) at another Chinese university using the ‘traditional Chinese method’. Despite some variations on specific criteria for writing, test results indicate superior performance for the experimental group. These findings tend to replicate those for young anglophone and allophone students (11 or 12 years old) in Intensive French, the application of NLA in Canada. Contrary to expectations, these results suggest a tendency for chinese students to be open to more interactive ways of learning a foreign language

Graph Neural Network for Predicting the Effective Properties of Polycrystalline Materials: A Comprehensive Analysis

We develop a polycrystal graph neural network (PGNN) model for predicting the effective properties of polycrystalline materials, using the Li7La3Zr2O12 ceramic as an example. A large-scale dataset with >5000 different three-dimensional polycrystalline microstructures of finite-width grain boundary is generated by Voronoi tessellation and processing of the electron backscatter diffraction images. The effective ion conductivities and elastic stiffness coefficients of these microstructures are calculated by high-throughput physics-based simulations. The optimized PGNN model achieves a low error of <1.4% in predicting all three diagonal components of the effective Li-ion conductivity matrix, outperforming a linear regression model and two baseline convolutional neural network models. Sequential forward selection method is used to quantify the relative importance of selecting individual grain (boundary) features to improving the property prediction accuracy, through which both the critical and unwanted node (edge) feature can be determined. The extrapolation performance of the trained PGNN model is also investigated. The transfer learning performance is evaluated by using the PGNN model pretrained for predicting conductivities to predict the elastic properties of the same set of microstructures.Comment: 23 pages, 6 figures; added testing results on a new dataset and sequential feature selectio

Characterization of the Toxicities of Cd-Ni and Cd-Cr Binary Mixtures Using Combination Index Method

Direct equipartition ray design was used to construct Cd-Ni and Cd-Cr binary mixtures. Microplate toxicity analysis was used to evaluate the toxicity of individual substance and the Cd-Ni and Cd-Cr mixtures on Chlorella pyrenoidosa and Selenastrum capricornutum. The interacting toxicity of the mixture was analyzed with concentration addition (CA) model. In addition, combination index method (CI) was proposed and used to quantitatively characterize the toxicity of the binary mixtures of CdNi and Cd-Cr observed in experiment and find the degree of deviation from the predicted outcome of the CA model, that is, the intensity of interacting toxicity. Results indicate that most of the 20 binary mixtures exhibit enhancing and synergistic effect, and only Cd-Cr-R4 and Cd-Cr-R5 mixtures have relatively high antagonistic effects against C. pyrenoidosa. Based on confidence interval, CI can compare the intensities of interaction of the mixtures under varying levels of effect. The characterization methods are applicable for analyzing binary mixture with complex interaction

Development and evaluation of a new luciferase immunosorbent assay to detect GII.6 norovirus-specific IgG in different domestic and wild animals

Noroviruses (NoVs) are the leading viral pathogens globally causing acute gastroenteritis (AGE) in humans, posing a significant global health threat and economic burden. Recent investigations revealed that human NoVs had been detected in different animals, which raises concerns about whether NoVs are potential zoonotic diseases. This study developed a novel luciferase immunosorbent assay (LISA) to detect GII.6 NoV IgG based on P protein of VP1. The LISA showed high specificity (99.20%) and sensitivity (92.00%) with 4–16 times more sensitivity compared with an ELISA. NoV-LISA was reproducible with human serum regarding the inter- and intra-assay coefficient of variance values. Potential cross-reactivity was also evaluated using mice serum immunized by other antigens, which showed that NoV-LISA could differentiate GII.6 NoV from rotavirus and various genotypes of NoV. Specific GII.6 NoV IgG was widely detected in different domestic and wild animals, including dogs, pigs, bats, rats, and home shrews, with various IgG-positive rates ranging from 2.5 to 74.4%. In conclusion, our newly developed NoV-LISA assay is suitable for NoV-specific IgG detection in humans and animals. The wide distribution of IgG antibodies against human NoV indicates potential zoonotic transmission between humans and animals

Poleward energy transport: is the standard definition physically relevant at all time scales?

Poleward energy transport in the atmosphere and oceans constitutes an important branch of the global energy budget, and its role in the climate system has been the subject of many studies. In the atmosphere, the transport is affected by “eddies” and large scale meridional cells, both with zero net mass transport across latitude circles, but also partly by processes associated with a net transport of mass across latitude circles. The latter must cease to operate in steady state, but they may be significant when time variability of the heat budget is considered. Indeed, examination of reanalysis data on short (daily to monthly) timescales shows that mass variations on these timescales result in surprisingly large fluctuations (in excess of 10^15 W = 1 PW) in the poleward heat transport. These fluctuations are referred to as “extensive”, for they primarily alter the mass integrated energy of the region considered, but not its averaged value. It is suggested that extensive fluctuations mask more meaningful climate signals present in the heat transport variability on monthly and interannual timescales, and a new formulation is proposed to isolate the latter. This new formulation is applied successfully to reanalysis data and climate model simulations

The atmospheric heating patterns: a new heat transport perspective

The standard definition of poleward heat transport was found to lead to surprisingly large fluctuations (in excess of $10^{15}$W = 1PW) on timescales shorter than a few years. We have argued in this thesis the standard definition masks more meaningful climate signals present in the heat transport variability, and a new definition is proposed to isolate the latter. Utilising the new definition of heat transport, large/weak heat transport events are identified. The atmospheric heating patterns by the mean flow and eddies under these enhanced heat transport events are also discussed. It is found that for every 1PW increase in heat transport across $45^\circ$ latitude, a surface heating and cooling dipole at the rate of about 0.3 K/day is observed. This is largely attributed to stationary (transient) eddies in the NH (SH). The same dipole structure is noticeable in the upper troposphere but tilted towards the pole when analysing the heating patterns by eddies (but is partially compensated by the mean flow). This tilted dipole might be linked to poleward energy propagation. For the sub-tropics, when the atmosphere carries more heat across $10^\circ$ latitude, a vertically coherent heating/cooling, extending from the surface to the upper troposphere, is observed, with values being about $\pm$ 0.5K/day. This heating pattern is closely linked to the strengthening of the Hadley circulation. Using the standard definition of heat transport, similar heating patterns are also found, although the magnitude is much smaller. This further confirms our hypothesis that the new definition may shed further light on the intuitive link between energy transport and climate variability. The above analysis is carried out under the Eulerian mean framework. Next, we analyse the cancellation effect between the mean flow and eddies using the three most popular frameworks under pressure coordinates: the Eulerian mean, the conventional transformed Eulerian mean, and the modified transformed Eulerian mean. It is found that the choice of framework largely depends on the domain one is interested in, and there is no one framework that is more favourable than the others. We further conclude that Eulerian mean framework is adequate for the analysis of the heating patterns under enhanced heat transport events as discussed in this thesis.Open Acces

The meaning of the experience of being cared for by elderly Chinese immigrants in Sweden

Background: The elderly Chinese group is growing in Sweden but no studies about their experiences of being cared for were found. In order to meet the elderly Chinese need for care, it is necessary to understand their perspectives of being cared for. Aim: To describe the meaning of the experiences of being cared for by elderly Chinese immigrants in a Swedish context. Method: For this phenomenological study, open-end interviews were carried out with 7 informants originally from Mainland China and Hong Kong. Result and Conclusion: For the elderly Chinese in Sweden, ‘being cared for’ means being involved in a caring community, to have a mutual relationship with someone who can see and understand their needs. In such a relationship, they felt that they were included and respected. They were being treated as valuable with a genuine manner. They had a feeling of satisfaction, happiness, peacefulness, closeness, togetherness, and wholeness when ‘being cared for’. For these elderly Chinese immigrants, informal care was indispensable even when they were receiving formal care. They wished that their family could show concern and formal caregivers could understand and give space to the informal caregivers on caregiving

Revendications didactiques des enseignants de FLE en Chine, mobilité et construction professionnelle : en finir avec ‘lenseignant-chinois-type » ? – Regards franco-chinois

ACTES PUBLIES DE CONFERENCES INTERNATIONALES, CONGRES ET COLLOQUES..

Nurses' experiences with working during the COVID-19 pandemic within emergency care : An interview study

Bakgrund: Sedan COVID-19 pandemins början har sjuksköterskor mött utmaningar som hög stress och psykiska besvär. Det finns en brist på forskning om sjuksköterskors upplevelser av att arbeta och vårda COVID-19 patienter på akutkliniker i Sverige. En djupare förståelse om hur vården ser ut från sjuksköterskors perspektiv behövs för att förbättra och förbereda vården för framtidens pandemier.Syfte:Var att beskriva sjuksköterskors upplevelser av att arbeta under COVID-19 pandemin på akutkliniker. Metod: En kvalitativ intervjustudie användes. Totalt genomfördes tio semistrukturerade intervjuer med sjuksköterskor från två sjukhus i södra Sverige. Data analyserades med hjälp av kvalitativ innehållsanalys. Resultat: Tre kategorier framkom: att kämpa mot svårigheter, att anpassa sig till nya omständigheter, ochatt vara beskyddaren inom vården. Sjuksköterskor på akutkliniker har upplevt frustration och känslor av otillräcklighet när de vårdat patienter under pandemin. De ansåg att kunskap och resurser behövde utökas för att klara av stressen och den höga arbetsbelastningen. Det fanns ett behov av anpassning till nya arbetssätt för de nya omständigheterna. Sjuksköterskornas yrkesplikt motiverade dem att arbeta även om de led av olika psykiska besvär. Slutsats: Sjuksköterskor har blivit sårbara i sitt vårdande beroende på utmaningarna som hög arbetsbelastning och brist på resurser och skyddsmaterial. Ett tillräckligt stöd och förberedelser från akutkliniker och hälso- och sjukvårdsorganisations sida behövs för att klara framtidens pandemier. Genom att ta lärdom av sjuksköterskornas upplevelser kan den evidensbaserade omvårdnaden utvecklas ytterligare. Det kan i sin tur skapa möjligheter att hantera svårigheter och utmaningar i vårdandet på akutkliniker på ett bättre sätt vid framtida pandemier.Background: Since the COVID-19 pandemic began nurses have encountered different challenges such as working under high pressure and suffering from psychological distress. However there is a lack of research about nurses’ working and caring experiences for COVID-19 patients in the emergency clinics in Sweden. In order to provide better care and better preparation for the future pandemics, it is necessary to understand nurses’ perspectives of caring during the pandemic. Aim: Was to describe the nurses’ experiences with working during COVID-19 pandemic in the emergency clinics.  Method: A qualitative interview study was conducted for this study. Ten semi-structured interviews were carried out in two hospitals that were located in the south of Sweden. A qualitative content analysis method was applied for the analysis. Results: Three categories were described: Struggling against difficulties, adapting to new circumstancesand being a protector in the context of caring. Nurses experienced frustration and feelings of inadequacy when caring for patients during the pandemic in the emergency clinics. They mentioned that knowledge and resources should be enhanced in order to cope with the pressure and heavy workload. It required them to adjust and adapt the new ways of working under new circumstances. The nurses' professional duty motivated them to work even if they suffered from various psychological distresses. Conclusion: Nurses became vulnerable while working under the challenges such as heavy workload, lack of human resources and shortage of protection materials under pandemic. It is required that emergency clinics and healthcare organizations be sufficiently prepared and provide necessary support in order to overcome the future pandemics. The evidence-based nursing can be developed through learning the nurses’ experiences. It can provide opportunities for them to handle difficulties and challenges in the emergency care in a better way in the future pandemics. By providing opportunities to practice evidence-based nursing, nurses can retain their physical and psychological health and increase coping abilities towards the difficulties during the pandemic.