Review: Role of tubal environment in preimplantation embryogenesis: application to co-culture assays

The culture of early preimplantation stage embryo is still delicate and the metabolic pathways of embryos are not completely understood. Embryo needs are evolutionary during the preimplantation development, consequently it is difficult to meet embryo needs in vitro. Culture conditions have to respect several physical and chemical equilibria: such as redox potential, pH, osmotic pressure, metabolic flux of energetic compounds, endogenous pools of amino acids and transcripts, etc. Embryo culture media are generally supplemented with amino acids, glucose, other energetic metabolites and antioxidant compounds, vitamin, and growth factors etc. Furthermore autocrine and paracrine regulation of embryo development probably exist. In fact embryo culture conditions have to be as non-toxic as possible. Various types of co-culture systems have been devised to overcome these problems. Complex interrelations exist between embryos and co-cultured cells. The beneficial effects of co-cultured cells may be due to continuous modifications of the culture medium, i.e. the elimination of toxic compounds and/or the supply of embryotrophic factor

Founding territorial sciences

International audienceThe “Founding Territorial Sciences” conference marked the birth of the International College of Territorial Sciences (CIST), a new research body devoted to the study of space and territory. The purpose of the conference was to answer the following question: Although the concept of territory is central to recent social changes, are we justified in seeking to establish the “territorial sciences” as a new academic field or discipline?To answer this question, we need to address a number of other issues. These include:– the issues raised by interdisciplinary research in other countries; if we want to develop an international network, we will need to ensure that similar initiatives are underway in other countries and that they are compatible with the research projects of the CIST;– the issues surrounding the questions addressed by researchers in the territorial sciences; though it has defined an initial set of research questions, the GIS may need to explore other avenues;– the issues surrounding the nature of the “territorial sciences”: should the territorial sciences be defined as an interdisciplinary field, i.e. as a set of disciplines brought together to understand the territorial dimension of their objects of study? Or should they be defined as an emerging discipline, the key concepts, principles and methods of which will need to be defined?The new field covers a wide range of disciplines extending well beyond the humanities and social sciences. The main theoretical and methodological challenges are to foster links between the humanities and social sciences and the life and earth sciences, the health sciences and the engineering sciences (modeling, complex systems, etc.). For example, the lack of collaboration between physicists and mathematicians working on climate change models and humanities and social science researchers concerned with the territorial impact of climate change has created a gap between global and local approaches.Finally, beyond the confines of academia, what is the proper relationship between the territorial sciences and territorial development strategies and practices?Le colloque « Fonder les sciences du territoire » a constitué le lancement scientifique du GIS CIST. Il devait répondre à cette question : nous savons que le territoire est au cœur d’un grand nombre des transformations des sociétés contemporaines, mais pour autant avons-nous raison de vouloir fonder les « sciences du territoire » ? Cela supposait de répondre à d’autres questions préalables :– sur la confrontation aux expériences interdisciplinaires étrangères dans le domaine. Si l’on veut constituer un réseau international, encore faut-il s’assurer de l’existence d’initiatives similaires à l’étranger et du degré de compatibilité avec elles ;– sur les thématiques des sciences du territoire, le GIS ayant lancé de premiers axes de travail mais devant rester ouvert à d’autres axes possibles ;– sur la nature de ces « sciences du territoire » : doivent-elles être conçues comme un champ multidisciplinaire c’est-à-dire comme un ensemble de disciplines scientifiques que l’on confronterait pour comprendre, de manière minimalement harmonisée, la dimension territoriale de leurs objets propres ? Ou doit-on aller jusqu’à considérer qu’il s’agirait d’une discipline scientifique émergente, dont il faudra alors définir les concepts, les lois et les méthodes d’analyse ?Le spectre des disciplines concernées est large, très au-delà des SHS. Car c’est dans la confrontation des SHS avec les sciences de la vie et de la terre, les sciences de santé et les sciences de l’ingénieur (modélisation, systèmes complexes…) que les enjeux théoriques et méthodologiques sont les plus grands. Par exemple le manque d’échanges entre les physiciens ou mathématiciens qui conçoivent les modèles du changement climatique, et les SHS dédiées à l’impact territorial de ce changement climatique, se traduit par une insuffisante interaction entre les analyses globales et locales.Enfin, au-delà des disciplines scientifiques, comment les sciences du territoire devraient-elles se situer par rapport aux pratiques du développement territorial

L’intervention publique paysagère comme processus normatif

Notre analyse interroge la production sociale de normes concomitante à la définition et à la mise en place d’interventions publiques paysagères à l’échelle locale. Elle montre que cette production normative s’accompagne d’une évolution dans la façon de nommer certains objets matériels. Cette nouvelle dénomination, souvent instable, témoigne de conflits normatifs, tant certaines normes peuvent être difficiles pour certains acteurs à concilier avec celles appliquées jusque-là. Notre étude montre également que ces conflits de normes autour des objets matériels sont autant de signes des usages alternatifs ou combinés de ces objets. On voit de la sorte que les politiques paysagères ont pour effet de reconnaître le « multi-usages » de l’espace rural en renforçant les pratiques liées aux loisirs (randonnées, visites). Elles légitiment en cela l’appropriation de l’espace par le regard, appropriation spécifique qui accompagne ces pratiques.landscape, local public action, norm, rural area

Les attitudes du public canadien envers les politiques criminelles

Etude sur les images, les perceptions et les représentations que se font les citoyens du phénomène criminel et analyse des attitudes du public à l'égard des mesures prises, par les autorités gouvernementales, pour prévenir le crime et pour neutraliser ou réhabiliter les criminels.Solliciteur général du Canad

Symmetry of the Fermi surface and evolution of the electronic structure across the paramagnetic-helimagnetic transition in MnSi/Si(111)

MnSi has been extensively studied for five decades, nonetheless detailed information on the Fermi surface (FS) symmetry is still lacking. This missed information prevented from a comprehensive understanding the nature of the magnetic interaction in this material. Here, by performing angle-resolved photoemission spectroscopy on high-quality MnSi films epitaxially grown on Si(111), we unveil the FS symmetry and the evolution of the electronic structure across the paramagnetic-helimagnetic transition at T$_C$ $\sim$ 40 K, along with the appearance of sharp quasiparticle emission below T$_C$. The shape of the resulting FS is found to fulfill robust nesting effects. These effects can be at the origin of strong magnetic fluctuations not accounted for by state-of-art quasiparticle self-consistent GW approximation. From this perspective, the unforeseen quasiparticle damping detected in the paramagnetic phase and relaxing only below T$_C$, along with the persistence of the d-bands splitting well above T$_C$, at odds with a simple Stoner model for itinerant magnetism, open the search for exotic magnetic interactions favored by FS nesting and affecting the quasiparticles lifetime

Use of the 3D radon transform to examine the properties of oceanic Rossby waves

One of the most successful applications of satellite-borne radar altimeter data over the oceans in recent years has been the extraction of information about long-wavelength baroclinic Rossby (or planetary) waves, which play a significant role in ocean circulation and climate dynamics. These waves cross ocean basins from east to west at speeds of few centimetres per second at mid-latitudes. The cross-basin propagation time may therefore be several months or even years and an accurate estimation of the speed of the waves is important. We review the methods for obtaining information on Rossby wave velocity from altimetry data, particularly the two-dimensional Radon transform. Unfortunately the use of longitude-time plots, although it allows the estimation of the zonal phase speeds, does not give any information on the speed vector when the propagation of the waves is not purely zonal (east-west). We show how the two-dimensional Radon Transform can be generalised to three dimensions, enabling not only the true propagation velocity component to be determined, but also the direction of the waves and thus any deviation from the pure-westward case. As examples of the application of this extended technique, we show maps of direction, speed and energy of Rossby waves in the North Atlantic Ocean

Communication from Learned to Innate Olfactory Processing Centers Is Required for Memory Retrieval in Drosophila.

The behavioral response to a sensory stimulus may depend on both learned and innate neuronal representations. How these circuits interact to produce appropriate behavior is unknown. In Drosophila, the lateral horn (LH) and mushroom body (MB) are thought to mediate innate and learned olfactory behavior, respectively, although LH function has not been tested directly. Here we identify two LH cell types (PD2a1 and PD2b1) that receive input from an MB output neuron required for recall of aversive olfactory memories. These neurons are required for aversive memory retrieval and modulated by training. Connectomics data demonstrate that PD2a1 and PD2b1 neurons also receive direct input from food odor-encoding neurons. Consistent with this, PD2a1 and PD2b1 are also necessary for unlearned attraction to some odors, indicating that these neurons have a dual behavioral role. This provides a circuit mechanism by which learned and innate olfactory information can interact in identified neurons to produce appropriate behavior. VIDEO ABSTRACT.This work was supported by MRC LMB graduate studentships and Boehringer Ingelheim Fonds PhD fellowships (to M.-J.D. and A.S.B.) and a Janelia graduate research fellowship (to M.-J.D.), ERC starting (211089) and consolidator (649111) grants and core support from the MRC (MC-U105188491) (to G.S.X.E.J.), Agence Nationale de la Recherche funding of the MemoNetworks and MemoMap projects (to P.-Y.P. and T.P.) and the Labex Memolife PhD fellowship (to G.B.-G.), the Howard Hughes Medical Institute (to A.W. and G.M.R.), a Wellcome Trust collaborative award (203261/Z/16/Z to G.S.X.E.J., D.B., and G.M.R.), and a Cambridge Neuroscience-PSL collaborative grant supported by the Embassy of France in London (to G.S.X.E.J.). This work was also supported by the HHMI Janelia Visiting Scientist Program

Net greenhouse gas balance of fibre wood plantation on peat in Indonesia

Tropical peatlands cycle and store large amounts of carbon in their soil and biomass1,2,3,4,5. Climate and land-use change alters greenhouse gas (GHG) fluxes of tropical peatlands, but the magnitude of these changes remains highly uncertain6,7,8,9,10,11,12,13,14,15,16,17,18,19. Here we measure net ecosystem exchanges of carbon dioxide, methane and soil nitrous oxide fluxes between October 2016 and May 2022 from Acacia crassicarpa plantation, degraded forest and intact forest within the same peat landscape, representing land-cover-change trajectories in Sumatra, Indonesia. This allows us to present a full plantation rotation GHG flux balance in a fibre wood plantation on peatland. We find that the Acacia plantation has lower GHG emissions than the degraded site with a similar average groundwater level (GWL), despite more intensive land use. The GHG emissions from the Acacia plantation over a full plantation rotation (35.2 ± 4.7 tCO2-eq ha−1 year−1, average ± standard deviation) were around two times higher than those from the intact forest (20.3 ± 3.7 tCO2-eq ha−1 year−1), but only half of the current Intergovernmental Panel on Climate Change (IPCC) Tier 1 emission factor (EF)20 for this land use. Our results can help to reduce the uncertainty in GHG emissions estimates, provide an estimate of the impact of land-use change on tropical peat and develop science-based peatland management practices as nature-based climate solutions