Science & Mathematics

We describe an efficient palladium‐catalyzed selective C–H ortho ‐monohalogenation (X=I, Br, Cl, F) of various functionalized (2‐pyridyl)arylsulfones. ortho‐ , meta‐ and para ‐functionalization is tolerated at the arene group which undergoes C–H halogenation. Some modifications are also possible on the 2‐(arylsulfonyl)heteroaryl directing groups. A comparison of the halogenation efficiency suggests that bromination is the practical method of choice, while chlorination and fluorination are possible but more challenging. Under forcing conditions ortho ‐dihalogenation can also be achieved. magnified image

In spite of the biological importance of the binding of Zn2+ , Ca2+ , and Mg2+ to the carboxylate group, cation-acetate binding affinities and binding modes remain actively debated. Here, we report the first use of Raman multivariate curve resolution (Raman-MCR) vibrational spectroscopy to obtain self-consistent free and bound metal acetate spectra and one-to-one binding constants, without the need to invoke any a priori assumptions regarding the shapes of the corresponding vibrational bands. The experimental results, combined with classical molecular dynamics simulations with a force field effectively accounting for electronic polarization via charge scaling and ab initio simulations, indicate that the measured binding constants pertain to direct (as opposed to water separated) ion pairing. The resulting binding constants do not scale with cation size, as the binding constant to Zn2+ is significantly larger than that to either Mg2+ or Ca2+, although Zn2+ and Mg2+ have similar radii that are about 25% smaller than Ca2+. Remaining uncertainties in the metal acetate binding free energies are linked to fundamental ambiguities associated with identifying the range of structures pertaining to non-covalently bound species.

We explore the role of contextual versus lexical alternatives in pragmatic strengthening using a novel training-with-feedback paradigm. In two experiments, we investigate whether training with inferences over contextual alternatives affects pragmatic strengthening with lexical alternatives, and the other way around. In both Experiments, we find that training that encouraged (or discouraged) pragmatic strengthening of simple disjunctions carried over to complex disjunctions of an unfamiliar kind to our experimental participants. This shows that our novel methodology is effective in training general mechanisms for activating alternatives. In Experiment 2, we showed that this methodology can be made to work across different kinds of alternatives, if certain salience conditions are met.

La littérature scientifique en histoire et philosophie de la médecine est ici convoquée afin d'examiner les spécificités de l'auto-expérimentation comme mode d'investigation des phénomènes biologiques humains normaux ou pathologiques. Il aborde tout d'abord l'histoire de l'auto-expérimentation médicale depuis les origines jusqu'à nos jours en accordant un intérêt particulier au XVIIIe et XIXe siècle, durant lesquels les médecins auto-expérimentateurs jouèrent un rôle important dans le développement de la médecine pour l'identification des maladies, la connaissance de leurs modes de propagation, le développement de l’anesthésie ou de la vaccination. La seconde partie s'attache à déterminer les enjeux moraux de l'auto-expérimentation en les mettant notamment en regard de l'éthique de l'expérimentation humaine. Il s'agit ensuite d'examiner, dans une dernière partie, quels peuvent être les avantages et inconvénients de l'auto-expérimentation d'un point de vue épistémologique. Tout en faisant le constat que la méthode est défaillante sur le plan scientifique par rapport aux essais randomisés contrôlés, puisqu'il n'y a pas de groupe témoin ni d'observateur extérieur, cette étude souhaite suggérer que l'auto-expérimentation permet de poser de façon plus aiguë la question de la responsabilité par rapport au progrès de la connaissance médicale en la replaçant au niveau du choix individuel.

Le monde rural a été le terrain, depuis les années 1970 en France, de beaucoup de luttes sociales. Que ce soit au Larzac, à Sivens, ou encore à Notre-Dame-des-Landes, les résistances et militances alternatives ont pour origine les campagnes. Mathieu Gervais revient sur l'histoire de ces paysans militants et montre en quoi ces paysans peuvent être appréhendés en tant que figures décoloniales.

Des hétérojonctions (p) ZnTe/(n) Ga1-xAl xSb ont été obtenues par épitaxie en phase liquide de Ga1- xAlxSb dopé au tellure sur substrat ZnTe dopé au phosphore, la concentration en AlSb des couches épitaxiées variant de 0 à 0,60. La présence, à l'interface substrat-dépôt, d'un alliage quinaire (Ga1-xAlx)1- yZnySb1-zTe z a été mise en évidence par analyse des structures à l'aide d'une microsonde électronique de Castaing. Les couches épitaxiées, de type n, sont fortement dopées au tellure (de l'ordre de 1 % atomique). Une diffusion des éléments Ga, Al et Sb du dépôt dans le substrat de ZnTe a été détectée par S.I.M.S. sur une profondeur d'environ 10 μ. Cette diffusion rend le ZnTe semi-isolant, et luminescent dans le rouge. L'analyse des caractéristiques courant-tension à diverses températures laisse supposer que le courant direct est un courant de recombinaison de trous excités thermiquement dans la bande de valence. L'étude de la réponse spectrale montre que seuls les porteurs minoritaires du côté de ZnTe participent à la conduction sous éclairement. Une structure de bandes d'énergie est proposée pour une hétérojonction (p) ZnTe/(n) Ga0,40Al0,60Sb.

3D diffraction imaging techniques like X-ray diffraction contrast tomography and Topotomography enable the observation of slip bands at the onset of plastic deformation in polycrystalline materials. Using the previously introduced 6D DCT reconstruction framework local changes in crystal orientation adjacent to these bands can be detected. The combination of both scanning modalities into a joint reconstruction problem with potentially superior spatial resolution and increased angular sensitivity is under investigation.

Carbonate platforms developed in the southwestern Provence area during the late Cretaceous on the rims of a narrow deep E-W oriented basin. The upper Cenomanian lower Member Fontblanche 1 of the Fontblanche limestones Formation is exceptionally rich in rudists. This member is well exposed in two quarries with flat outcrop surfaces, thanks to sawn surfaces, that allow 3D investigation of its litho- and biofades and sedimentary structures. The paper describes the sedimentary sequences of each quarry from a quantitative study of both sedimentary and palaeontological data, both macroscopic and microscopic, derived from quadra counts in the field and thin section analyses. The sequences are one to several metres thick and each of them shows a basal drowning and a final emersion surface with evidence of reworking and dissolution. The microfacies are dominated by floatstone texture, most common grains being bioclasts derived from biocorrosion of rudist shells and benthic foraminifers. The matrix is made mostly of microbioclasts and micrite, resulting from a strong microborers activity. Fossil organisms are regarded as autochthonous or parautochthonous. The overall depositional environment was shallow marine with a maximum depth of a few metres in an inner, peritidal, sheltered and quiet platform. We found a link between the sedimentary fades and rudist ecotypes. The statistical analysis of the fossil counts, using multivariate statistics and clustering, differentiates four fossil assemblages, namely the Chondrodonta assemblage, the Apricardia-Sauyagesiinae assemblage, the Caproana assemblage, and the Nerinea assemblage, which are considered to represent biotic communities. The replacement of communities through Fontblanche 1 and within the elementary sequences illustrates a relationship between the benthic communities, the degree of biocorrosion, the sedimentary texture, and the sedimentation rate so that ecological processes affect the sedimentary dynamics which in turn affects communities through feedback mechanism. Such an intimate link between the sedimentary facies and ecosystems provides evidence that biotic parameters played an important role in the rudist-rich fades succession.

This article analyzes the different phases the Information Systems--Sociology relationship has gone through and points out some specific features of sociologists and Information Systems scientists in their conceptualization of Information Technology (IT). It shows that both academic fields develop more and more convergent theorizations. The first part is centered on an historical analysis of sociology itself. It shows the great comeback of the Object within the sociological field at the beginning of the 80s. Different models have been developed from the generalized kinds of sociology to those that have been focused on the social construction of the Object. These make up sociological groups, which we call "autonomous". The second part presents the sociological approaches used and worked out in the domain of Information Systems (IS). These are presented by means of three historical moments (causalist, actor-based and processual). For each of these stages the influence of sociologies, notably those that deal with the Object, is obvious and models are more or less "illuminated" by means of broader perspectives. In the third part, there is a discussion of ontological differences between the work of sociologists studying IS objects and the work of IS researchers drawing on sociologists' conceptual contributions. Lastly, it seems that if sociology and Information Systems sometimes diverge in the way they study sociotechnical systems, they converge gradually in their conceptualization of the IT artifact.

La détermination des besoins énergétiques par la méthode des essais d’alimentation présente des limites, notamment pour extrapoler les résultats obtenus à d’autres situations. A partir de résultats de travaux personnels et des données bibliographiques disponibles sur le métabolisme énergétique de la truie allaitante, nous présentons les bases permettant de déterminer ses besoins en énergie par une méthode factorielle. La démarche repose sur les données relatives aux besoins d’entretien (110 kcal d’énergie métabolisable (EM) par kg P0.75) et aux rendements d’utilisation de l’EM (kl = 72 %) et des réserves corporelles (krl = 88 %) pour la synthèse du lait. L’énergie exportée dans le lait est estimée à partir de la croissance de la portée (R’ > 0,87). Les calculs mettent en évidence que les besoins en EM varient avec le poids vif de la truie et surtout avec le gain de poids de la portée. En moyenne, ils sont de 18 à 20 Mcal par jour, valeurs supérieures à la capacité d’ingestion moyenne des truies allaitantes. L’inadéquation entre les besoins et la consommation d’énergie pendant la phase de lactation est alors à prendre en considération pour moduler le niveau alimentaire pendant la gestation.

An auto-tuning system for the microwave cavity of hydrogen masers is considered. It is shown that it can be applied to oscillating masers. A tight control of the cavity resonant frequency is insured, with a short time constant. This is favourable to the improvement of the long term frequency stability of this frequency standard. Operating conditions exist which do not perturb the ultimately achievable long term frequency stability of the standard. It is shown that the microwave cavity resonant frequency can be easily adjusted so that the spin exchange frequency shift is eliminated as well as with known other cavity tuning methods.

24x36 mm, gélatine plan-film.

This review paper examines the development and application of climate predictions, primarily at seasonal timescales, as actionable information for decision‐making, with a specific focus on the Mediterranean region. It illustrates and analyses the steps required to transform climate model probabilistic forecasts into user‐defined information, emphasising the iterative nature of climate service development. By leveraging tools such as bias adjustment, downscaling, probabilistic calibration and impact models, these services provide tailored solutions to key sectors including energy, water supply, transport and agriculture. The paper discusses the contributions of global initiatives, such as the Global Framework for Climate Services (GFCS), and EU‐funded projects like EUPORIAS, MEDSCOPE and MED‐GOLD, which have advanced sector‐specific applications of climate predictions in the region. These initiatives illustrate how tailored climate services can address critical challenges ranging from renewable energy planning to drought risk mitigation and agricultural yield forecasting. The review highlights persistent challenges, including limited forecasting skill in the Mediterranean area, data accessibility issues and the need for robust impact‐based verification. To enhance the uptake and effectiveness of climate services, the review recommends fostering interdisciplinary collaboration, promoting iterative co‐production with users, improving the communication of uncertainty and forecast skill, and ensuring the sustainability of services beyond project lifetimes. This work underscores the potential of climate services to enhance resilience in the Mediterranean region, bridging the gap between scientific advances and practical applications.