Distinction morale entre animaux sauvages et non‐sauvages : une critique de l’approche contextuelle de Clare Palmer

Dans deux articles récents, Clare Palmer défend la portée morale de la distinction entre animaux non humains domestiqués et animaux non humains sauvages suivant une approche « contextuelle ». Suivant cette approche, Palmer considère que les liens historiques qui unissent les animaux domestiqués aux êtres humains, à l'origine causale d'un état de dépendance et de vulnérabilité subi par les premiers, génèrent des obligations morales spéciales à leur égard (devoir de protection, notamment) non partagées par les animaux non-domestiqués (« sauvages »). Considérant tout d'abord les limites de la distinction sauvage/domestique et de l'approche contextuelle proposées par Palmer, cet article questionne la capacité de l'approche contextuelle de Palmer à pouvoir faire sens néanmoins d'une autre idée de sauvage, à savoir un sauvage « localisé » ou environnemental

Les limites du principe de neutralité libérale en termes de politiques environnementales

Le principe de neutralité libéral (PNL) est l’idée selon laquelle l’autorité publique d’une société libérale doit permettre à tous ses membres politiques de suivre leur conception personnelle, individuelle de la vie bonne. Cet article vise à démontrer la non neutralité morale du PNL et les limites politiques que celle-ci implique – considérée dans le cadre du PNL – au niveau environnemental. Dans cet objectif, les trois aspects de neutralité engagés par le PNL seront exposés, puis critiqués. Cette analyse en trois temps visera à défendre la thèse selon laquelle le PNL ne permet pas au libéralisme politique de mettre en place des politiques environnementales qui seraient satisfaisantes d’un point de vue non- anthropocentré ni pour le moins « viables » écologiquement

Les limites du principe de neutralité libérale en termes de politiques environnementales

Le principe de neutralité libéral (PNL) est l’idée selon laquelle l’autorité publique d’une société libérale doit permettre à tous ses membres politiques de suivre leur conception personnelle, individuelle de la vie bonne. Cet article vise à démontrer la non neutralité morale du PNL et les limites politiques que celle-ci implique – considérée dans le cadre du PNL – au niveau environnemental. Dans cet objectif, les trois aspects de neutralité engagés par le PNL seront exposés, puis critiqués. Cette analyse en trois temps visera à défendre la thèse selon laquelle le PNL ne permet pas au libéralisme politique de mettre en place des politiques environnementales qui seraient satisfaisantes d’un point de vue non- anthropocentré ni pour le moins « viables » écologiquement

Resistance risk assessment of the novel complex II inhibitor pyflubumide in the polyphagous pest Tetranychus urticae

Pyflubumide is a novel selective carboxanilide acaricide that inhibits mitochondrial complex II of spider mite species such as Tetranychus urticae. We explored the baseline toxicity and potential cross-resistance risk of pyflubumide in a reference panel of T. urticae strains resistant to various acaricides with different modes of action. A cyenopyrafen-resistant strain (JPR) was identified as the only strain with low-to-moderate level of cross-resistance to pyflubumide (LC50 = 49.07 mg/L). In a resistance risk assessment approach, JPR was subsequently selected which led to two highly resistant strains JPR-R1 (RR = 466.7) and JPR-R2 (RR = 614.8). Interestingly, compared to adult females, resistance was much less pronounced in adult males and eggs of the two JPR-R strains. In order to elucidate resistance mechanisms, we first sequenced the complex II subunits in susceptible and resistant strains, but target-site insensitivity could not be detected. In contrast, synergism/antagonism experiments strongly suggested that cytochrome P450 monooxygenases are involved in pyflubumide resistance. We therefore conducted genome-wide gene expression experiments to investigate constitutive and induced expression patterns and documented the overexpression of five cytochrome P450 and four carboxyl/choline esterase genes in the JPR-R strains after pyflubumide exposure. Together, we provide a first resistance risk assessment of a novel complex II inhibitor and provide first evidence for metabolic resistance mediated by cytochrome P450s in T. urticae

Quality control of substrate conformation in the Escherichia coli Twin Arginine protein-targeting pathway

In Escherichia coli, the twin arginine translocase (Tat) is one of the major protein translocation mechanisms. The Tat system has the ability to transport folded proteins across the inner membrane. Therefore, it has the ability to discriminate between folding states. However, it is not well understood how the Tat system senses the folding state of a substrate. In this study we probed the Tat proofreading mechanism and we investigated whether Tat substrates in E. coli are translocated by the Tat system due to their rapid folding kinetics. We demonstrate that the E. coli Tat machinery can process a de-novo designed substrate (BT6 maquette). Moreover the Tat proofreading mechanism can discriminated between different folding states of this substrate. This data and the fact that this simple four helix artificial substrate offers a lot of engineering freedom, suggests that BT6 is an ideal candidate to study the Tat proofreading mechanism (chapter 3). In chapter 4, we focussed on the Tat system’s proofreading ability by substituting substrate surfaces of BT6 maquette. Mutants with substituted surface properties were expressed in order to understand what Tat senses as folded. Expression assays showed whether the mutants were accepted or rejected by Tat. We propose that the proofreading system does not sense a global unfolded state of the substrate but has the ability to sense localised unfolded regions. Finally, we tested whether Tat substrates fold co- or post-translationally to determine the speed of the folding kinetics by using an arrest peptide-mediated force measurements assay (chapter 5). This study was to increase our understanding about the rationale for using the Tat system

Nonsteroidal anti-inflammatory drugs as therapeutic allies of the gut microbiome on chronic inflammation

Our gut harbours around 1014bacteria of more than 1000 species, accounting for approximately 2 kg of biomass. Thegut microbiome plays several vital functions in processes such as the development of the immune system, food digestion and protection against pathogens. For these functions to be beneficial for both host and microbiome, interactions are tightly regulated.Gut and immune cells continuously interact to distinguish among commensal microbiota, harmless foodstuff, and pathogens. A fine balance between inflammatory and anti-inflammatory state is fundamental to protect intestinal homeostasis. Nonsteroidal anti-inflammatories (NSAIDs) are a class of drugs used for management of pain and inflammation. These compounds have heterologous structures but similar therapeutic activities. The target of all NSAIDs are the isoforms of cyclooxygenase enzymes (COX): the primarily constitutive form COX-1, and the inducible from COX-2. Both isoforms catalyse the conversion of arachidonic acid to PGH2, the immediate substrate for specific prostaglandin and thromboxane synthesis. The gut microbiota plays a role in drug metabolism, resulting in altered bioavailability of these compounds. Additionally, complex host-microbiome interactions lead to modified xenobiotic metabolism and altered expression of genes involved in drug metabolism. These effects can be at gut tissue-level, or distant, including in the liver. Besides the gut microbiome influencing drug metabolism, drugs also impact the microbial communities in the gut. As different drugs exert selective pressures on the gut microbiome, understanding this bidirectional relationshipis crucial for developing effective therapies for managing chronic inflammation

L’art et la nature

À propos de : Catherine et Raphaël Larrère, Penser et agir avec la nature : Une enquête philosophique, Paris, La Découverte, 2015. L’idée d’une nature sauvage à protéger des avancées techniques ne prend en compte ni la complexité des artefacts, ni ce qu’implique aujourd’hui la protection de la nature. En mettant l’accent sur la notion de biodiversité, C. et R. Larrère cherchent à donner un nouveau fondement à l’écologie politique

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS AS THERAPEUTIC ALLIES OF THE GUT MICROBIOME ON CHRONIC INFLAMMATION

Our gut harbours around 1014 bacteria of more than 1000 species, accounting for approximately 2 kg of biomass. The gut microbiome plays several vital functions in processes such as the development of the immune system, food digestion and protection against pathogens. For these functions to be beneficial for both host and microbiome, interactions are tightly regulated. Gut and immune cells continuously interact to distinguish among commensal microbiota, harmless foodstuff, and pathogens. A fine balance between inflammatory and anti-inflammatory state is fundamental to protect intestinal homeostasis. Nonsteroidal anti-inflammatories (NSAIDs) are a class of drugs used for management of pain and inflammation. These compounds have heterologous structures but similar therapeutic activities. The target of all NSAIDs are the isoforms of cyclooxygenase enzymes (COX): the primarily constitutive form COX-1, and the inducible from COX-2. Both isoforms catalyse the conversion of arachidonic acid to PGH2, the immediate substrate for specific prostaglandin and thromboxane synthesis. The gut microbiota plays a role in drug metabolism,  resulting in altered bioavailability of these compounds. Additionally, complex host-microbiome interactions lead to modified xenobiotic metabolism and altered expression of genes involved in drug metabolism. These effects can be at gut tissue-level, or distant, including in the liver. Besides the gut microbiome influencing drug metabolism, drugs also impact the microbial communities in the gut. As different drugs exert selective pressures on the gut microbiome,  understanding this bidirectional relationship is crucial for developing effective therapies for managing chronic inflammation