TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

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Contagion émotionnelle chez l'humain : étude de la transmission des émotions positives via les odeurs endogènes et exogènes véhiculées par le corps

Chez l’être humain l’odeur du corps d’un individu semble être porteuse d’informations de nature très variée à son sujet, et ces molécules une fois captées par d’autres individus semblent causer des effets à la fois cognitifs et physiologiques chez ces derniers. La littérature montre que les individus sont capables de collecter des informations sur des traits constants ainsi que sur des états transitoires d’une personne, en étant exposés à son odeur uniquement, et ceci de manière non consciente. Parmi les états internes transitoires étant communiqués via le sens olfactif, un facteur a récemment été l’objet d’études prometteuses : les odeurs corporelles semblent également être porteuses d'informations sur les émotions ressenties par la personne qui les émet. Ces études se sont concentrées sur le cas des émotions négatives, mettant de côté les états positifs pourtant porteurs de bénéfices majeurs pour les individus, les groupes, et la société. Outre ces lacunes, une autre zone d’ombre prend forme lorsque l’on s’intéresse à un facteur allant souvent de pair avec nos odeurs corporelles naturelles : les odeurs exogènes. L’être humain se parfume depuis l’antiquité et ces odeurs rajoutées par-dessus notre odeur endogène peuvent, logiquement, interagir avec celle-ci. Le but de cette thèse a été de tenter d’éclaircir ces zones d’ombres multiples pour comprendre si une transmission des états émotionnels positifs via le sens olfactif existait chez l’humain, et quelle potentielle modulation le parfum pouvait avoir sur celle-ci. Pour cela, nous avons mis en place dans une première étude un paradigme expérimental chez des « donneurs », de qui nous avons collecté les odeurs corporelles pendant qu’ils ressentaient des émotions positives ou non, puis les avons fait sentir dans un deuxième temps à des « receveurs », chez qui nous avons effectué des mesures physiologiques, verbales, et comportementales. Nos résultats montrent que cette transmission semble être possible et qu’il s’agirait même non seulement d’une transmission mais d’une « contagion », des indices de l’affect positif des donneurs étant retrouvés chez les receveurs après exposition aux odeurs des premiers. Dans une deuxième étude, nous avons testé cette fois-ci une méthode potentiellement plus efficace et écologique d’induire des émotions : via réalité virtuelle. Les résultats de l’étude 1 n’ont pas été répliqués, ce qui nous a fait prendre conscience de la nature subtile et hautement dépendante du contexte de ces signaux chimiques. Nous avons alors décidé d’augmenter encore le niveau de « réalisme » en menant une troisième étude faite à domicile. Dans cette étude les donneurs et receveurs vivaient sous le même toit en tant que colocataires ou couples, ce qui nous a permis d’explorer l’impact de la nature de la relation liant les deux partenaires communicants, ainsi que des niveaux de sociabilité de ceux-ci. La dernière étude est une preuve de concept et rend compte du développement méthodologique d’un outil pour mieux étudier les bases chimiques liées à ce type de communication, via la captation par des polymères des molécules odorantes au niveau du cou et des aisselles de participants, par la suite analysés en GC-MS. Dans les trois premières études le faisceau d’évidences pointe vers un effet non perturbateur du parfum sur la communication chimique des émotions positives, avec même pour certaines mesures verbales un potentiel synergique du parfum et de l’odeur corporelle positive qui mettrait en avant des caractéristiques de cette dernière. Finalement, un papier hybride mêlant opinion, revue de la littérature et présentant également quelques données expérimentales, s’intéresse aux multiples défis et obstacles que doit surmonter le domaine de la communication chimique chez l’humain, dont tous ont été rencontrés au cours de cette thèse, et certaines pistes de réflexion ainsi que des perspectives sont abordées.In humans, the smell of an individual's body seems to carry a wide variety of information about them, and these molecules once caught by other individuals, whether relatives or strangers, seem to cause both cognitive and physiological effects in them. The scientific literature shows that individuals are able to gather information about another person's persistent traits as well as transient states by being exposed to their scent alone, and this in a non-conscious way. Among the transient internal states that can be communicated via the olfactory sense, one factor has recently been the subject of promising studies: body odors also seem to carry information about the emotions felt by the person emitting them. Inappropriately, these studies have been focused on negative emotions, leaving aside positive states, despite the fact that they carry major benefits for individuals, groups, as well as for society at large. In addition to these shortcomings, another literature gap is found when one looks at a factor that often goes hand in hand with our natural body odors: exogenous odors. Humans have been perfuming themselves directly (on the skin) and indirectly (via clothing or ambient scents) since antiquity and these odors added on top of our endogenous odor can, logically, interact with it. The aim of this thesis was to try to clarify these multiple gaps in the literature, in order to understand if a transmission of positive emotional states via the olfactory sense existed in humans, and what potential modulation perfume could have on it. To this end, in a first study, we set up an experimental paradigm with "donors", from whom we collected body odors while they were feeling positive emotions or not, and then in a second step we exposed “receivers” to these odors, in whom we carried out physiological, verbal, and behavioral measurements. Our results show that this transmission of positive states seems possible in humans and that it is not only a transmission but rather a "contagion", because indices of the positive affect of the donors are found in the receivers when the latter are exposed to the odors of the former. In a second study, we repeated the same experimental design, this time testing a potentially more effective and ecologically valid method to induce emotions: via virtual reality. The results of the first study were not replicated, which made us even more aware of the subtle and highly context-dependent nature of these chemical signals. To better understand this, we decided to further increase the level of "realism" by conducting a third study which participants did at-home. In this study the donors and receivers both lived under the same roof, as either roommates or couples, which allowed us to better understand the impact of the nature of the relationship between the two communicating partners, as well as of their level of sociability. The last study is a proof of concept and reports on the methodological development of a device to better study the chemical bases underlying this type of communication, via the polymer capture of odorant molecules on the necks and armpits of participants, subsequently analyzed in GC-MS. In the first three studies, the sum of results points to a non-disruptive effect of perfume on the chemical communication of positive emotions, with even for some verbal measures, a synergistic potential of perfume and positive body odor that would highlight characteristics of the latter. Finally, a hybrid paper mixing opinion, literature review, and also presenting some experimental data, focuses on the multiple challenges and obstacles that the field of chemical communication in humans has to overcome, all of which have been encountered during this thesis, as well as gives some insights and perspectives for the future

Mallarmé's children: symbolism and the renewal of experience

In a narrative gracefully combining intellectual and cultural history, Richard Cándida Smith unfolds the legacy of Stéphane Mallarmé (1842-1898), the poet who fathered the symbolist movement in poetry and art. The symbolists found themselves in the midst of the transition to a world in which new media devoured cultural products and delivered them to an ever-growing public. Their goal was to create and oversee a new elite culture, one that elevated poetry by removing it from a direct relationship to experience. Instead, symbolist poetry was dedicated to exploring discourse itself, and its practitioners to understanding how language shapes consciousness.Cándida Smith investigates the intellectual context in which symbolists came to view artistic practice as a form of knowledge. He relates their work to psychology, especially the ideas of William James, and to language and the emergence of semantics. Through the lens of symbolism, he focuses on a variety of subjects: sexual liberation and the erotic, anarchism, utopianism, labor, and women's creative role. Paradoxically, the symbolists' reconfiguration of elite culture fit effectively into the modern commercial media. After Mallarmé was rescued from obscurity, symbolism became a valuable commodity, exported by France to America and elsewhere in the market-driven turn-of-the-century world. Mallarmé's Children traces not only how poets regarded their poetry and artists their art but also how the public learned to think in new ways about cultural work and to behave differently as a result

Asymmetric Mannich Synthesis of α‑Amino Esters by Anion-Binding Catalysis

We report a scalable, one-pot Mannich route to enantioenriched α-amino esters by direct reaction of α-chloroglycine ester as a practical imino ester surrogate. The reaction is promoted by a chiral aminothiourea, which is proposed to operate cooperatively by generating an iminium ion by chloride abstraction and an enolate by deprotonation, followed by highly stereoselective C–C bond formation between both reactive intermediates associated non-covalently within the catalyst framework

Molecular and physiological logics of the pyruvate-induced response of a novel transporter in Bacillus subtilis

At the heart of central carbon metabolism, pyruvate is a pivotal metabolite in all living cells. Bacillus subtilis is able to excrete pyruvate as well as to use it as the sole carbon source. We herein reveal that ysbAB (renamed pftAB), the only operon specifically induced in pyruvate-grown B. subtilis cells, encodes a heterooligomeric membrane complex which operates as a facilitated transport system specific for pyruvate, thereby defining a novel class of transporter. We demonstrate that the LytST two-component system is responsible for the induction of pftAB in the presence of pyruvate by binding of the LytT response regulator to a palindromic region upstream of pftAB. We show that both glucose and malate, the preferred carbon sources for B. subtilis, trigger the binding of CcpA upstream of pftAB, which results in its catabolite repression. However, an additional CcpA-independent mechanism represses pftAB in the presence of malate. Screening a genome-wide transposon mutant library, we find that an active malic enzyme replenishing the pyruvate pool is required for this repression. We next reveal that the higher the influx of pyruvate, the stronger the CcpA-independent repression of pftAB, which suggests that intracellular pyruvate retroinhibits pftAB induction via LytST. Such a retroinhibition challenges the rational design of novel nature-inspired sensors and synthetic switches but undoubtedly offers new possibilities for the development of integrated sensor/controller circuitry. Overall, we provide evidence for a complete system of sensors, feed-forward and feedback controllers that play a major role in environmental growth of B. subtilis. [br/] IMPORTANCE Pyruvate is a small-molecule metabolite ubiquitous in living cells. Several species also use it as a carbon source as well as excrete it into the environment. The bacterial systems for pyruvate import/export have yet to be discovered. Here, we identified in the model bacterium Bacillus subtilis the first import/export system specific for pyruvate, PftAB, which defines a novel class of transporter. In this bacterium, extracellular pyruvate acts as the signal molecule for the LytST two-component system (TCS), which in turn induces expression of PftAB. However, when the pyruvate influx is high, LytST activity is drastically retroinhibited. Such a retroinhibition challenges the rational design of novel nature-inspired sensors and synthetic switches but undoubtedly offers new possibilities for the development of integrated sensor/controller circuitry

Crystal Growth and First Crystallographic Characterization of Mixed Uranium(IV)–Plutonium(III) Oxalates

The mixed-actinide uranium­(IV)–plutonium­(III) oxalate single crystals (NH₄)_0.5[Pu^III_0.5U^IV_0.5(C₂O₄)₂·H₂O]·<i>n</i>H₂O (<b>1</b>) and (NH₄)_2.7Pu^III_0.7U^IV_1.3(C₂O₄)₅·<i>n</i>H₂O (<b>2</b>) have been prepared by the diffusion of different ions through membranes separating compartments of a triple cell. UV–vis, Raman, and thermal ionization mass spectrometry analyses demonstrate the presence of both uranium and plutonium metal cations with conservation of the initial oxidation state, U^IV and Pu^III, and the formation of mixed-valence, mixed-actinide oxalate compounds. The structure of <b>1</b> and an average structure of <b>2</b> were determined by single-crystal X-ray diffraction and were solved by direct methods and Fourier difference techniques. Compounds <b>1</b> and <b>2</b> are the first mixed uranium­(IV)–plutonium­(III) compounds to be structurally characterized by single-crystal X-ray diffraction. The structure of <b>1</b>, space group <i>P</i>4/<i>n</i>, <i>a</i> = 8.8558(3) Å, <i>b</i> = 7.8963(2) Å, <i>Z</i> = 2, consists of layers formed by four-membered rings of the two actinide metals occupying the same crystallographic site connected through oxalate ions. The actinide atoms are nine-coordinated by oxygen atoms from four bidentate oxalate ligands and one water molecule, which alternates up and down the layer. The single-charged cations and nonbonded water molecules are disordered in the same crystallographic site. For compound <b>2</b>, an average structure has been determined in space group <i>P</i>6/<i>mmm</i> with <i>a</i> = 11.158(2) Å and <i>c</i> = 6.400(1) Å. The honeycomb-like framework [Pu^III_0.7U^IV_1.3(C₂O₄)₅]^2.7‑ results from a three-dimensional arrangement of mixed (U_0.65Pu_0.35)­O₁₀ polyhedra connected by five bis-bidentate μ²-oxalate ions in a trigonal-bipyramidal configuration

Crystal Growth and First Crystallographic Characterization of Mixed Uranium(IV)–Plutonium(III) Oxalates

The mixed-actinide uranium­(IV)–plutonium­(III) oxalate single crystals (NH₄)_0.5[Pu^III_0.5U^IV_0.5(C₂O₄)₂·H₂O]·<i>n</i>H₂O (<b>1</b>) and (NH₄)_2.7Pu^III_0.7U^IV_1.3(C₂O₄)₅·<i>n</i>H₂O (<b>2</b>) have been prepared by the diffusion of different ions through membranes separating compartments of a triple cell. UV–vis, Raman, and thermal ionization mass spectrometry analyses demonstrate the presence of both uranium and plutonium metal cations with conservation of the initial oxidation state, U^IV and Pu^III, and the formation of mixed-valence, mixed-actinide oxalate compounds. The structure of <b>1</b> and an average structure of <b>2</b> were determined by single-crystal X-ray diffraction and were solved by direct methods and Fourier difference techniques. Compounds <b>1</b> and <b>2</b> are the first mixed uranium­(IV)–plutonium­(III) compounds to be structurally characterized by single-crystal X-ray diffraction. The structure of <b>1</b>, space group <i>P</i>4/<i>n</i>, <i>a</i> = 8.8558(3) Å, <i>b</i> = 7.8963(2) Å, <i>Z</i> = 2, consists of layers formed by four-membered rings of the two actinide metals occupying the same crystallographic site connected through oxalate ions. The actinide atoms are nine-coordinated by oxygen atoms from four bidentate oxalate ligands and one water molecule, which alternates up and down the layer. The single-charged cations and nonbonded water molecules are disordered in the same crystallographic site. For compound <b>2</b>, an average structure has been determined in space group <i>P</i>6/<i>mmm</i> with <i>a</i> = 11.158(2) Å and <i>c</i> = 6.400(1) Å. The honeycomb-like framework [Pu^III_0.7U^IV_1.3(C₂O₄)₅]^2.7‑ results from a three-dimensional arrangement of mixed (U_0.65Pu_0.35)­O₁₀ polyhedra connected by five bis-bidentate μ²-oxalate ions in a trigonal-bipyramidal configuration

Crystal Growth and First Crystallographic Characterization of Mixed Uranium(IV)–Plutonium(III) Oxalates

The mixed-actinide uranium­(IV)–plutonium­(III) oxalate single crystals (NH₄)_0.5[Pu^III_0.5U^IV_0.5(C₂O₄)₂·H₂O]·<i>n</i>H₂O (<b>1</b>) and (NH₄)_2.7Pu^III_0.7U^IV_1.3(C₂O₄)₅·<i>n</i>H₂O (<b>2</b>) have been prepared by the diffusion of different ions through membranes separating compartments of a triple cell. UV–vis, Raman, and thermal ionization mass spectrometry analyses demonstrate the presence of both uranium and plutonium metal cations with conservation of the initial oxidation state, U^IV and Pu^III, and the formation of mixed-valence, mixed-actinide oxalate compounds. The structure of <b>1</b> and an average structure of <b>2</b> were determined by single-crystal X-ray diffraction and were solved by direct methods and Fourier difference techniques. Compounds <b>1</b> and <b>2</b> are the first mixed uranium­(IV)–plutonium­(III) compounds to be structurally characterized by single-crystal X-ray diffraction. The structure of <b>1</b>, space group <i>P</i>4/<i>n</i>, <i>a</i> = 8.8558(3) Å, <i>b</i> = 7.8963(2) Å, <i>Z</i> = 2, consists of layers formed by four-membered rings of the two actinide metals occupying the same crystallographic site connected through oxalate ions. The actinide atoms are nine-coordinated by oxygen atoms from four bidentate oxalate ligands and one water molecule, which alternates up and down the layer. The single-charged cations and nonbonded water molecules are disordered in the same crystallographic site. For compound <b>2</b>, an average structure has been determined in space group <i>P</i>6/<i>mmm</i> with <i>a</i> = 11.158(2) Å and <i>c</i> = 6.400(1) Å. The honeycomb-like framework [Pu^III_0.7U^IV_1.3(C₂O₄)₅]^2.7‑ results from a three-dimensional arrangement of mixed (U_0.65Pu_0.35)­O₁₀ polyhedra connected by five bis-bidentate μ²-oxalate ions in a trigonal-bipyramidal configuration

Local Structure, Dynamics, and the Mechanisms of Oxide Ionic Conduction in Bi₂₆Mo₁₀O₆₉

We report the results of a computational and experimental study into the stabilized fluorite-type δ-Bi₂O₃-related phase Bi₂₆Mo₁₀O₆₉ aimed at clarifying the local and average structure, for which two distinct models have previously been proposed, and the oxide ionic diffusion mechanism, for which three distinct models have previously been proposed. Concerning the structure, we propose a new model in which some molybdenum atoms have higher coordination numbers than 4; that is, some MoO₅ trigonal bipyramids coexist with MoO₄ tetrahedra. This accounts for the additional oxygen required to achieve the nominal composition (a tetrahedron-only model gives Bi₂₆Mo₁₀O₆₈) without invoking a previously proposed unbonded interstitial site, which we found to be energetically unfavorable. All these MoO_<i>x</i> units are rotationally disordered above a first-order transition at 310 °C, corresponding to a first-order increase in conductivity. Concerning oxide ionic diffusion above that transition temperature, we found excellent agreement between the results of ab initio molecular dynamics simulations and quasielastic neutron scattering experiments. Our results indicate a mechanism related to that proposed by Holmes et al. (<i>Chem. Mater.</i> <b>2008</b>, <i>20</i>, 3638), with the role previously assigned to partially occupied interstitial oxygen sites played instead by transient but stable MoO₅ trigonal bipyramids and with more relaxed requirements in terms of the orientation and timing of the diffusive jumps