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Do penguins care about on-paper boundaries? Conservation implications of spatio-temporal winter consistency in an Antarctic sentinel species
No full textInternational audienceUnderstanding the spatial and temporal at-sea distribution of marine predators throughout their annual cycle is crucial for identifying priority areas for conservation in the Southern Ocean. However, the delimitation of boundaries of the proposed East Antarctic Marine Protected Area (EAMPA) is largely based on species' breeding distributions, overlooking seasonal and annual shifts driven by sea ice variability. We studied the non-breeding distribution and space use of a key Antarctic eco-indicator species, the Adélie penguin, by tracking 62 individuals from Terre Adélie over five years using geolocators. Moulting occurred in areas of low sea ice concentration (SIC), whereas during winter, penguins migrated on average 1550 km westward from the colony to areas along the sea ice edge with high SIC (75 %). The inter-annual overlap of wintering grounds revealed high spatiotemporal consistency, indicating productive regions. Despite variability across years, tracked individuals moulted predominantly outside the proposed EAMPA, and only 16.3 % of winter locations fell within its boundaries. These findings provide new insights into the non-breeding ecology of Adélie penguins, and highlight a relevant gap in spatial coverage of critical moulting and wintering areas of this highly mobile species in the current EAMPA proposal
Hybrid antioxidant based on exfoliated layered double hydroxides nanosheets with improved thermal stabilizing effects for polypropylene
No full textInternational audienceAn antioxidant (AO) agent, 3-(3,5-ditertbutyl-4-hydroxyphenyl) propionate anions (DBHP), intercalated between layered double hydroxides (DBHP-LDH) was prepared by coprecipitation method and then a part was delaminated in toluene to form exfoliated DBHP-LDH nanosheets. Both types of DBHP-LDH compositions, powder and exfoliated nanosheets were characterized by XRD, SEM and TEM, and subsequently incorporated into polypropylene (PP) as AO filler to improve the thermal stability of PP. The addition of DBHP-LDH affected the crystallization and melting behaviour as well as transmittance of PP, giving rise to its crystallinity improved but its transparency reduced. It was found that by incorporating either DBHP-LDH powder or exfoliated DBHP-LDH nanosheets the thermal decomposition temperatures and thermal aging resistance of PP were enhanced. Interestingly, between the two hybrid systems, it is however the exfoliated DBHP-LDH nanosheets that showed a better stabilizing effect for PP. This is attributed to the better dispersion regarding the exfoliated DBHP-LDH nanosheets, thus providing a more efficient radical scavenging capability. Even with its pronounced interface between PP chains and highly exposed nanosheets, about 30 % of DBHP was released from the exfoliated DBHP-LDH/PP compared to about 20 % DBHP migrated out of the conventional DBHP-LDH/PP films after 132 h test. This shows that the organic AO agent is well tethered to hydroxyl-bearing LDH nanosheets, thus opening new route to design functionalized filler for polymer from exfoliated LDH hybrid layers
Ribosomal protein L5 (RPL5/uL18) I60V mutation is associated to increased translation and modulates drug sensitivity in T-cell acute lymphoblastic leukemia cells
No full textInternational audienc
Les économistes libéraux français et l'amélioration du sort des ouvriers (1870-1914)
No full textInternational audienceThis article examines how French liberal economists addressed the issue of improving workers’ conditions between 1870 and 1914. Drawing on contributions from authors who participated in the debates of the Société d’économie politique and published in the Journal des économistes, it highlights the diversity of positions within the liberal camp, thereby challenging the idea of a homogeneous liberal doctrine. While some, such as Guyot and Passy, rejected any intervention, a first group of economists, represented by Molinari and Royer, sought to improve the functioning of the labour market by enhancing information flows and worker mobility. A second group, illustrated by Colson and Cheysson, accepted limited state intervention, particularly in the form of assistance to the poorest in exchange for work, and the implementation of social insurance system.Cet article examine comment les économistes libéraux français ont abordé la question de l’amélioration du sort des ouvriers entre 1870 et 1914. En s’appuyant sur les contributions d’auteurs ayant participé aux débats de la Société d’économie politique et ayant publié dans le Journal des économistes, il met en lumière la diversité des positions en présence, remettant ainsi en cause l’idée d’un libéralisme homogène. Alors que certains, comme Guyot ou Passy, rejettent toute intervention, une première série d’économistes, représentée par Molinari ou Royer, proposent d’améliorer le fonctionnement du marché du travail en facilitant la circulation de l’information et la mobilité des ouvriers. Une seconde série, illustrée par les développements de Colson et Cheysson, admet une intervention de l’État limitée, notamment sous la forme d’une assistance accordée aux plus démunis en échange d’un travail et de la mise en place d’un système d’assurances sociales
Experimental investigation and multi-scale Mori–Tanaka modeling of viscoelastic asphalt mastic with imperfect interfaces
No full textInternational audienceAsphalt mastics, comprising asphalt binder and mineral filler, play a critical role in determining the performance of asphalt mixtures. This study examines the viscoelastic behavior of mastics composed of two asphalt binders and three fillers (gabbro, quartz, and hydrated lime) with varying particle sizes. Repeated Creep and Recovery Tests (RCRT) were conducted to evaluate the influence of filler type and concentration on mastic strain response. Then, a modified multi-scale Mori-Tanaka model was successfully employed to predict the viscoelastic properties of the mastics. The model parameters were found to be influenced by the filler type and size, as well as by imperfections at the binder-filler interface. Results show that mastics containing hydrated lime exhibit higher moduli, particularly at high filler content (40% by volume), with significantly lower final strain in RCRT compared to those with gabbro or quartz. This enhanced performance is attributed to the high surface area of hydrated lime and its chemical interactions with the asphalt binder, which promote the formation of a network structure within the mastic. While the proposed model effectively captures the physical interactions in asphalt mastics, it requires further refinement to account for the additional influence of chemical reactions between fillers, such as hydrated lime, and the asphalt binder.</div
Economic policy uncertainty, ESG practices, and investment inefficiency in U.S. firms
No full textInternational audienceThis study examines how economic policy uncertainty (EPU) influences the efficiency of corporate investments and whether strong environmental, social, and governance (ESG) practices impact this relationship. Using data on U.S. firms from 2010 to 2022, we find that higher EPU leads to greater investment inefficiency, including both under- and overinvestment. When faced with uncertainty, firms tend to favor R&D over capital expenditures, reflecting a preference for flexibility. We also show that information asymmetry intensifies the negative impact of uncertainty on investment decisions. Importantly, robust ESG practices help mitigate the adverse impact of EPU by easing financial constraints and reducing information asymmetry. These results highlight the value of ESG as a stabilizing force in uncertain environments. More broadly, the study underscores the importance of integrating ESG considerations into corporate strategies to foster stability and sustainable growth amid evolving economic conditions
Investigation of lubricant flow in a planetary bearing cavity under stationary carrier condition
No full textPlanetary bearings are critical components in planetary transmission systems. As transmission systems evolve toward higher speeds, the lubrication of planetary bearings faces significant challenges. In this study, a specialized test rig was developed to visualize the oil flow in a planetary bearing cavity under a stationary carrier condition, a configuration featuring outer ring rotation and central oil supply. The experimental results reveal the oil flow patterns and distribution characteristics within the bearing cavity. Additionally, a dynamic-static fluid domain coupled numerical model was established to simulate the oil-air two-phase flow field in the rotating bearing domain. This model was used to analyze the variations in oil distribution inside the bearing cavity and the oil volume fraction(OVF) on component surfaces under different speeds. The research results indicate that the bearing cavity is fully filled with oil at low speeds. As the speed increases, the oil near the roller end faces on the inner ring side begins to decrease, and an arc-shaped oil film forms along the inner side of the cage. With further speed increase, this oil film expands radially outward. At 9000 r/min, only a small amount of oil remains distributed near the outer ring. Increasing the oil flow rate further enhances the OVF on these surfaces, which can alleviate oil starvation in the lubrication zone between the rollers and the inner ring under highspeed conditions. However, higher flow rates also lead to increased churning losses in the planetary bearing. The research results provide theoretical guidance for the lubrication design of planetary bearings in transmission systems
Free-range versus conventional: A comparison of microbial composition and Campylobacter contamination in broiler carcasses after chilling
No full textInternational audienc
Exploring the colloidal stability of curcumin nanoparticles formed by nanoprecipitation
No full textInternational audiencePure curcumin nanoparticles were prepared by antisolvent precipitation using acetone as the solvent and water as the antisolvent, offering a simple and food-compatible strategy to enhance curcumin dispersibility in aqueous environments. The colloidal stability of the aqueous dispersions was assessed by static multiple light scattering. Progressive particle size growth led to sedimentation. This study then focused on the stability of nanoprecipitated curcumin prior to sedimentation, in order to unambiguously determine the mechanisms responsible for destabilization. Particle size evolution over time was monitored by dynamic light scattering. The physical state of curcumin was determined by 1 H NMR and XRD analyses, confirming that neither coalescence nor crystallization occurred. Ostwald ripening was successfully confirmed by modeling the particle growth kinetics using the Lifshitz-Slyozov-Wagner (LSW) theory. Nevertheless, it is known that the LSW model remains superficial. That is why an original approach is used in this study to validate the destabilization mechanism. This involves varying the composition of the solvent in order to modify the solubility of curcumin in the continuous phase, a key parameter in the context of Ostwald ripening. Thus, varying the acetone content demonstrated the role of curcumin solubility in governing dispersion stability, confirming that Ostwald ripening occurred, as faster particle growth was observed at higher acetone levels. Moreover, curcumin solubility in the continuous phase derived from the LSW model was consistent with measurements performed by HPLC. These findings demonstrated that amorphous curcumin nanoparticles undergo Ostwald ripening in stabilizer-free aqueous systems, with ripening rates controlled by solvent-induced solubility changes
"Not retrograde, but still capable of great improvement”: exploring Alpine modernisation through the life of an Italian Travelling Chair for Agriculture (1869-1929)
No full textInternational audienceThis talk explores the role of a Travelling Chair for Agriculture, an agrarian institution tasked with modernizing agricultural practices in the Italian Western Alps through scientific experimentation and dissemination. Using archival research, the lecture examines how expert knowledge about Alpine farming was produced within a complex socio-technical interplay between formal science and local, informal forms of knowledge. Aligning with recent perspectives in critical development studies, it inquires into the emotional and idealistic dimensions of development interventions, showing that agricultural experts were driven by a genuine desire to improve local livelihoods rather than governmentalizing motives. These findings invite us to reframe current narratives about modernization processes as an inevitable erasure of local cultures and offer a nuanced, decentered perspective on Alpine agricultural modernization as a multifaceted movement shaped by historical and political dynamics