Science & Mathematics

In the context of global warming and ice melting in the Arctic Ocean, maritime activities have significantly increased over recent years. However, the Arctic remains a wild and risky region where marine accidents regularly occur. Despite the difficulty in compiling relevant data on Arctic shipping casualties, we have identified 156 accidents along the NorthEast Passage (NEP) over the last twenty years. Following a data-driven approach, we combine multiple sources and use the standardized International Maritime Organization (IMO) taxonomy on casualty investigation. We disclose and classify the concerned cases by severity level, cause, age, and type of vessels. We draw the profile of the vessels with the highest accidentology level, ascertain the high-risk areas and the seasons with the highest accident rate. Our results stress that serious casualties represent the largest part of the accidents occurring in this area. Fishing vessels show the highest accident rate, and machinery issues are one of the most common accident types. Furthermore, the NEP accidentology during the last two decades does not seem to decline unlike the downward trend elsewhere around the globe. Finally, we call for greater reporting of marine accidents and compliance with the IMO risk classification to better understand accidentology in this growing shipping zone. A plea in favor of stricter enforcement of the Polar Code and a holistic risk-based policy combining mandatory and non-mandatory measures are notably suggested to prevent casualties in the near future.

La poesia di Mas-Felipe Delavouët (1920-1990), ignota a molti, forse perché scritta in provenzale, largamente disprezzato in Francia in quanto « lingua regionale », fu riconosciuta come una delle maggiori voci poetiche del Novecento, da autori fra i più rilevanti del momento: Jules Supervielle o Lawrence Durrell (quest’ultimo riteneva perfino che Delavouët avrebbe meritato il Nobel di letteratura). Delavouët, che fu anche autore di teatro, artista grafico, incisore, editore e persino tipografo, era contadino di professione. Scrittore autodidatta dalla cultura vastissima, bastì un’opera ampia, il cui edificio maggiore è l’impressionante Pouèmo. Questo vasto poema, e i suoi cinque tomi (la cui stesura si estende lungo la seconda metà nel Novecento), costituisce un affresco potente dell’esistenza umana. Radicato nella Provenza rurale dove vive il poeta, s'innalza a una dimensione universale, interrogando in modo intenso il posto dell’uomo tra terra e cielo, in un vivissimo intreccio di evocazioni mitiche. Ci proponiamo di percorrere quest’opera, seguendo l’io poetico che si esprime in Pouèmo con sembianze diverse. Fra loro domina quella di un misterioso personaggio chiamato “Il Principe”, che, di volta in volta si pone in posizione dialogica con l’io poetico o si rivela forse un alter ego del poeta stesso.

The reversibility of a moderate thermal treatment (TT) at 120 °C on modern and historical oak wood samples was investigated by 1H nuclear magnetic resonance (NMR) relaxometry, equilibrium moisture content (EMC) determination, and measurements of volumetric deformations. The EMC values showed full reversibility after conditioning the samples at 65% relative humidity (RH) for one week, in agreement with previous research that utilized moderate TTs. However, 1H NMR relaxometry evidenced an irreversible effect on water mobility (i.e., molecular tumbling) for both wood samples. This result is compared to volumetric deformations that are determined by considering two reference states. When using, as a reference, the dry volume at each state, volumetric deformations are consistent with EMC values. However, when using the dry volume of the sample before TT, the volumetric deformations are found to be higher than the ones before TT for modern wood but remain lower for historical wood. The irreversible changes in water dynamics suggest that some modifications of the wood structure have not been completely recovered but are not linked to the changes in volumetric deformations. In addition, 13C solid-state NMR spectroscopy allowed the comparison of the composition between both wood samples, suggesting that their different behavior concerning volumetric deformations could be explained by a lower proportion of acetyl groups from hemicelluloses for historical wood due to its natural aging. We showed that combining macroscopic observations with molecular-level information gained from 1H and 13C NMR leads to a deeper understanding of the effects of thermal treatments and reversibility tests.

In this paper, we introduce a prototype-based clustering algorithm dealing with graphs. We propose a hypergraph-based model for graph data sets by allowing clusters overlapping. More precisely, in this representation one graph can be assigned to more than one cluster. Using the concept of the graph median and a given threshold, the proposed algorithm detects automatically the number of classes in the graph database. We consider clusters as hyperedges in our hypergraph model and we define a retrieval technique indexing the database with hyperedge centroids. This model is interesting to travel the data set and efficient to cluster and retrieve graphs.

Introduction : le portage physiologique est utilisé par les parents pour son côté pratique et ses avantages (dans la relation mère-enfant, l’allaitement maternel, les pleurs, etc…). Méthode : nous souhaitions comprendre comment les sages-femmes élaboraient et pratiquaient les ateliers de portage avec les futures et/ou jeunes mères (ou parents). Une étude qualitative menée par des entretiens semi-dirigés a été conduite. Six sages-femmes, recrutées via les réseaux sociaux ou par courriel, ont été interrogées. Résultats : les sages-femmes ont pu exprimer comment elles procédaient quant à l’organisation et au déroulement de leurs ateliers de portage. Elles ont expliqué leur méthode d’observation du lien parent-enfant et elles ont mis en avant l’importance de leur accompagnement à la parentalité, tant en anténatal qu’en post-natal, grâce aux ateliers de portage. Discussion : très peu de données de la littérature ont été retrouvées pour discuter nos résultats. Cependant, les pratiques retrouvées sont très semblables entre toutes les participantes et plusieurs hypothèses ont pu ressortir afin d’expliquer ces différentes pratiques. Des nouvelles perspectives quant au suivi post-natal pourrait être bénéfiques au développement des ateliers de portage menés par une sage-femme. Conclusion : le portage physiologique permet de favoriser l’installation et la pérennité du lien mère-enfant grâce à la proximité qu’il procure et les ateliers de portage permettent sa pérennité. Lorsqu’une mère décide d’elle-même d’assister à un atelier de portage, alors le lien mère-enfant est déjà créé. La sage-femme est alors là pour accompagner au mieux les couples sur le chemin de la parentalité.

Indica rice starch and japonica rice starch were used in the study. The protein contents of the two rice variety were respectively 0.43%, 0.62%, 0.84%, 1.08%, 1.25%. The pasting and rheological properties of samples were determined with Rapid Visco Analyzer and dynamic rheometer. The results indicated that, with the increase of protein content, the peak viscosity, breakdown viscosity and final viscosity of rice starch paste decreased, the setback viscosity increased and the pasting temperature did not change significantly. With the increase of protein content, the consistency coefficient of starch decreased, the corresponding yield stress also decreased, however, the flow behavior index increased with the decrease of consistency coefficient. At same temperature, the storage modulus G' was greater when the protein content was higher.

Cet article présente et discute les apports des approches sémiotiques à l’analyse de la présence de l’environnement dans la communication, pour montrer les contributions de la sémiotique aux sciences de l’information et de la communication (SIC). En premier lieu, il s’agit de résumer certains apports de type plus théorique d’auteurs qui pratiquent la sémiotique concernant les enjeux de l’environnement et de la relation entre humain et « nature ». Ensuite, l’article présente des contributions plus empiriques, souvent plus internes aux SIC, qui utilisent la sémiotique comme « boite à outils » analytique pour analyser des objets signifiants et des formes de communication concernant les enjeux de l’environnement. Le texte est clôturé par une discussion sur les perspectives, en termes de manques et d’éléments à développer.

Rethinking urban life in a world of massive disruptions (climate change, air pollution, nature, water biodiversity and now Covid-19) has become one of the greatest challenges of the 21st century. To face these crises we must urgently address lifestyles and mobility, move away from the omnipresent car and the petroleum era and question what kind of city we really want to live in. The proposition of Professor Carlos Moreno is the "15-Minute City" concept, in a compact zone (or the "30-Minute Territory" in a semi-dense or sparse zone), where inhabitants can access all their essential needs of life: living, working, supplying, caring, educating, enjoying. The 15-Minute City addresses the key components required for a sustainable world (ecological, social, economic) and integrates the concepts of chrono-urbanism, chronotopia, and topophilia. This reinvention of proximities utilizes the convergence of open data, digital mapping, geolocation and the massification of new services. Nevertheless, citizens and their quality of life are always at the heart of the 15-Minute City. It is thus a polycentric city which combines urban intelligence, social inclusion and technological innovation and ultimately defines itself as an urban life planning. Paris is among the world's first cities to have implemented the 15-Minute City, where it is famously quoted as the "big-bang of proximities". It has recognized this innovative approach based on a global and systemic vision of the city in order to meet the fundamental needs of its inhabitants and to urgently address the unprecedented challenges it is facing today. This concept has now become a global movement.

Introduction. Durant l’épidémie de Zika qui a touché la Guadeloupe et les Antilles françaises en 2016, une émergence de microcéphalies et d’anomalies cérébrales a été observée chez les fœtus exposés au virus in utero. L’objectif principal de cette étude était de déterminer le devenir neurodéveloppemental à moyen terme des enfants atteints d’une microcéphalie associée ou non à une anomalie cérébrale dans un contexte d’infection maternelle au Zika pendant la grossesse. Nous avons également décrit les comorbidités associées sur le plan staturo-pondéral et neurosensoriel. Matériel et méthode. Il s’agissait d’une étude de cas, observationnelle, descriptive, prospective, monocentrique, réalisée au CHU de Pointe-à-Pitre/Abymes en Guadeloupe entre novembre 2016 et août 2018. Nous avons réalisé un questionnaire standardisé intitulé « Inventaire du Développement de l’Enfant » permettant d’obtenir un quotient de développement pour chaque enfant inclus. Résultats. Nous avons suivi 11 enfants sur une durée moyenne de 16,8 mois. L’âge moyen au moment de l’évaluation était de 18,9 mois. Les cas de microcéphalie isolée avaient un examen neurologique et un développement neuro-psychomoteur normaux avec un quotient de développement moyen de 122,25%. À l’inverse, les enfants atteints de malformations cérébrales associées présentaient une quadriparésie spastique prédominante aux membres supérieurs avec un très haut risque de retard et un quotient de développement inférieur à 63,6%. Conclusion. En accord avec les données de la littérature, les enfants atteints d’un syndrome de Zika congénital présentaient un retard global du développement à moyen terme. Ils avaient également un retard staturo-pondéral sans étiologie hormonale ou carentielle identifiée. Contrairement aux autres études, nous n’avons pas retrouvé de déficit neurosensoriel. Un des défis majeurs sera de dépister précocement les troubles neurologiques à plus long terme chez les enfants exposés in utero au Zika et asymptomatiques à la naissance. Ceci passe par la mise en place d’un réseau de suivi dédié associant les Centres d’Action Médico-Sociale Précoce et les pédiatres libéraux. .

The frequent and excessive fluctuation of agricultural and livestock products price is not only harmful to residents' living, but also affects CPI (Consumer Price Index) values, and even leads to social crisis, which influences social stability. Therefore it is important to forecast the price of agriculture and livestock products. As a result, we make a research on the factors affecting agricultural and livestock products price, establish a forecasted model of agricultural and livestock products price, and develop its early-warning system which is suitable to China. Considering the direct relationship between the price and the output, multiple linear regression method is adopted to study this problem. The model is composed of three sub-models. This paper puts forward the concept of price equilibrium coefficient C0, which describes the degree to which people accepting the forecasted price. With the establishment of the standard for the influence of price fluctuation, the influence of price fluctuation is measured. Each range of the C0 value corresponds with a specific result, which may informs the government with the danger of price fluctuation. As a result, the model can early-warn the price rising caused by crop reduction due to sudden natural disaster, which may induce social turmoil and crisis. If the forecasted price rises heavily, the government should take measures to avoid crisis. This paper offers the method to control future price. At last, a forecasted model of pork price is calculated with simulated data. The forecasted result is in good agreement with actual situation.

Hydrogen is emerging as a promising solution for reducing greenhouse gas emissions in key industrial sectors. However, its deployment faces significant uncertainties related to technological progress, economic viability, political decisions, and geopolitical dynamics. This study adopts a scenario-based approach to assess the resilience of a hydrogen ecosystem in an industrial hub. A two-step methodology is developed to explore how an optimised multi-energy system would respond to unanticipated disruptions such as fuel price shocks, policy changes, or slower-than-expected technological advancements. First, an integrated capacity expansion and operation model determines optimal system capacities assuming perfect foresight. Second, the resulting energy system is evaluated under an alternative context, where only operational decisions are optimised. Special attention is given to electricity price modelling, due to its crucial impact on electrolytic hydrogen production. Nine scenarios are investigated, reflecting major categories of deep uncertainty relevant to long-term energy planning, including policy directions, technological innovation, and resource availability. Results show that the most pessimistic scenarios in terms of hydrogen cost are also the most robust. Scenarios with more electrolysis capacities are generally more expensive but less sensitive to disruptions. In contrast, scenarios relying on early development of a European hydrogen transportation infrastructure are cheaper but less resilient. For policymakers, these findings highlight the need for coherent strategies integrating electricity and hydrogen systems to balance cost-efficiency, resilience, and environmental goals. Clear strategic direction, combined with support for local hydrogen industries, will be vital to securing Europe’s energy sovereignty and long-term sustainability in the face of evolving uncertainties.

We present new magnetostratigraphic results obtained for the Drumian stage (504.5-500.5 Ma; Epoch 3/Middle Cambrian) from the Khorbusuonka sedimentary section in northeastern Siberia. They complement previous data that did not allow the determination of a reliable estimate of the geomagnetic reversal frequency during this time. Magnetization of the samples is carried by a mixture of magnetite and hematite in various proportions. Thermal demagnetization makes it possible to distinguish two magnetization components. The low unblocking temperature (20 reversals per Myr during the Drumian to similar to 1.5 reversals per Myr during the Furongian/Upper Cambrian. Such a sharp decrease is consistent with a transition at a similar to 1-Myr timescale, probably caused by threshold effects in core processes, between two geodynamo modes, one characterized by reversals occurring at frequencies ranging from 1 to 5 reversals per Myr, and the other marked by hyperactivity of the reversing process, with reversal rates >15 reversals per Myr. (C) 2019

On considère l'interaction en liaisons fortes d'une bande d'électrons "s" avec une surface (100). On admet que ce modèle décrit grossièrement la bande "d" du tungstène et on l'applique à l'étude de l'adsorption d'atomes de la 3e série de transition. Le potentiel d'interaction entre l'atome et le cristal, limité aux premiers voisins de l'atome adsorbé, est traité par la méthode des fonctions de Green compte tenu de la règle de Friedel.