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SO2/H2SO3can damage plants. However, its toxic mechanism has still been controversial. Two models have been proposed, cytosolic acidification model and cellular oxidation model. Here, we assessed the toxic mechanism of H2SO3in three cell types of Arabidopsis thaliana, mesophyll cells, guard cells (GCs), and petal cells. The sensitivity of GCs of Chloride channel a(CLCa)-knockout mutants to H2SO3was significantly lower than those of wildtype plants. Expression of other CLC genes in mesophyll cells and petal cells were different from GCs. Treatment with antioxidant, disodium 4,5-dihydroxy-1,3-benzenedisulfonate (tiron), increased the median lethal concentration (LC50) of H2SO3in GCs indicating the involvement of cellular oxidation, while the effect was negligible in mesophyll cells and petal cells. These results indicate that there are two toxic mechanisms of SO2to Arabidopsis cells: cytosolic acidification and cellular oxidation, and the toxic mechanism may vary among cell types.Graphical AbstractThere are two toxic mechanisms of SO2to plant cells: cytosolic acidification and cellular oxidation.

The well-established oxidative addition–reductive elimination pathway is the most followed one in transition metal-catalysed cross-coupling reactions. While readily occurring with a series of transition metals, gold(i) complexes have shown some reluctance to undergo oxidative addition unless special sets of ligands on gold(i), reagents or reaction conditions are used. Here we show that under visible-light irradiation, an iridium photocatalyst triggers—via triplet sensitization—the oxidative addition of an alkynyl iodide onto a vinylgold(i) intermediate to deliver C(sp)2–C(sp) coupling products after reductive elimination. Mechanistic and modelling studies support that an energy-transfer event takes place, rather than a redox pathway. This particular mode of activation in gold homogenous catalysis was applied in several dual catalytic processes. Alkynylbenzofuran derivatives were obtained from o-alkynylphenols and iodoalkynes in the presence of catalytic gold(i) and iridium(iii) complexes under blue light-emitting diode irradiation. Studies into gold-catalysed cross-coupling reactions have expanded over recent decades; however, oxidative addition to gold(i) complexes remains challenging. Now it has been shown that a dual catalytic transformation involving iridium photosensitization to trigger oxidative addition to organogold intermediates enables C(sp2)–C(sp) cross-coupling reactions that are useful for the alkynylation of benzofurans.

The animal-like cryptochrome of Chlamydomonas reinhardtii(CraCRY) is a recently discovered photoreceptor that controls the transcriptional profile and sexual life cycle of this alga by both blue and red light. CraCRY has the uncommon feature of efficient formation and longevity of the semireduced neutral form of its FAD cofactor upon blue light illumination. Tyrosine Y373plays a crucial role by elongating , as fourth member, the electron transfer (ET) chain found in most other cryptochromes and DNA photolyases, which comprises a conserved tryptophan triad. Here, we report the full mechanism of light-induced FADH•formation in CraCRY using transient absorption spectroscopy from hundreds of femtoseconds to seconds. Electron transfer starts from ultrafast reduction of excited FAD to FAD•–by the proximal tryptophan (0.4 ps) and is followed by delocalized migration of the produced WH•+radical along the tryptophan triad (∼4 and ∼50 ps). Oxidation of Y373by coupled ET to WH•+and deprotonation then proceeds in ∼800 ps, without any significant kinetic isotope effect, nor a pH effect between pH 6.5 and 9.0. The FAD•–/Y373•pair is formed with high quantum yield (∼60%); its intrinsic decay by recombination is slow (∼50 ms), favoring reduction of Y373•by extrinsic agents and protonation of FAD•–to form the long-lived, red-light absorbing FADH•species. Possible mechanisms of tyrosine oxidation by ultrafast proton-coupled ET in CraCRY, a process about 40 times faster than the archetypal tyrosine-Z oxidation in photosystem II, are discussed in detail.

In the Decision accompanying the Paris Agreement, the Conference of the Parties “recog-nizes the social, economic and environmental value of voluntary mitigation actions and their co-benefits to adaptation, health and sustainable development”. This paper argues that this Social Value of Mitigation Activities (SVMA) can lay the ground to a new set of tools in climate policies, complementary to more traditional carbon pricing strategies. It first proposes a summary of the economic and political reasons which lead to this article 108 of the Paris Agreement, and the follow-up that emerged since December 2015. It then gives a theoretical back-up to this necessity of SVMA as a climate policy tool by deriving it from the more usual concepts of Social Cost of Carbon (SCC) and Shadow Price of Carbon (SPC). The use of such a value to help fund projects at the micro-level is proposed in a specific institutional arrangement, especially when carbon pricing strategies fail to be implemented at the optimal level. Its potential to bridge the macro-level funding gap between developed and developing or emerging countries is also developed. The last section concludes on the perspectives opened by the recent Stern-Stiglitz report and its corridor of carbon prices to the local and global implementation of SVMAs.

This paper argues that integrated assessment models (IAMs) are useful tools to build corridors of social costs of carbon (SCC) reflecting divergent worldviews. Instead of pursuing the elusive quest for the right SCC, IAMs could indeed be useful tools to rationalize the different beliefs on climate related parameters (or worldviews) in the climate debate and help build politically coherent corridors of SCCs. We first take the example of the Stern-Nordhaus controversy as an illustration of the impossible quest for the right SCC. Disentangling the drivers of this controversy, we show that the main differences in results come from a mix of ethical choices of the representative agent (pure time preference), long-term assumptions on technical parameters (abatement cost dynamics) and climate related unknowns (climate sensitivity). We then argue that these sources of disagreement can be best understood as differing worldviews rather than pure scientific uncertainties. This implies that IAMs are of limited help in determining the right SCC, in line with Pindyck (2017). But contrary to him, we consider it necessary to separate the wheat from the chaff, and argue for a middle way between the blind confidence in IAMs' outputs and their full rejection with respect to the SCC debate. Instead, we show how they could help rationalize the climate debates around a corridor of SCCs. We thus analyze the drivers of such corridors of values, or how the sources of divergent worldviews differently impact the SCC-abatement space with time. All in all, the climate policy debate around carbon pricing can benefit from a renewed understanding of the role of IAMs, less divinatory and more institutionally centered.

The worldwide growing demand for energy drives oil and gas companies to drill deeper and hotter wells. The exploration and the development of Deeply Buried Reservoirs (DBR) generate major technical challenges due to the extremely high pressures and temperatures met (1 400 bar, 300°C). Currently, several drilling fluids are emerging. They are briefly reviewed at the beginning of the paper. The technical difficulty related to HP-HT mud is so significant that standard mud formulation technologies are irrelevant and alternative systems have to be considered. New formulations based on perfluorochemicals have been jointly developed by IFP Energies nouvelles (IFPEN), SolvaySpecialty Polymers Italy and Total. Their lab characterizations are presented and reveal their promising benefits.

The article focuses on Austrian art historian Rudolf Eitelberger von Edelberg. Although forgotten today, Eitelberger is considered the founder of the Vienna School of Art History, due to his development of art pedagogy. In 1852, the historian became a professor at the University of Vienna and started a series of education reforms, helping Vienna reach the level of Great-Britain or France, in terms of art pedagogy.

The article discusses the issue of national identity in European countries in a historical context and in modern times. Topics mentioned in the article include cultural relations between France and Germany, French and German national formation during the 19th century, and culture diffusion between Germany and Russia.

Drosophila melanogaster resistance against the parasitoid wasp Leptopilina boulardi is under the control of a single gene (Rlb), with two alleles, the resistant one being dominant. Using strains bearing deletions, we previously demonstrated that the 55E2–E6; 55F3 region on chromosome 2R is involved in the resistance phenomenon. In this paper, we first restricted the Rlb containing region by mapping at the molecular level the breakpoints of the Df(2R)Pc66, Df(2R)P34 and Df(2R)Pc4 deficiencies, using both chromosomal in situ hybridization and Southern analyses. The resistance gene was localized in a 100 kb fragment, predicted to contain about 10 different genes. Male recombination genetic experiments were then performed, leading to identification of two possible candidates for the Rlb gene. Potential involvement of one of this genes, edl/mae, is discussed.

PYP, the Photoactive Yellow Protein, is a small water-soluble protein extracted from the cytosol of the halophilic purple bacterium Halorhodospira halophila. PYP is thought to mediate the phototactic response of the bacterium against blue light. Its chromophore is the deprotonated trans-p-hydroxycinnamic acid covalently linked, viaa thioester bond, to the unique cysteine residue of the protein. Upon blue-light irradiation, PYP undergoes a photocycle. As for rhodopsins, the transto cisisomerization of the chromophore was shown to be the first overall step of this photocycle. From time-resolved spectroscopy measurements on native PYP in solution, it emerged that the reaction involves a series of fast events on the subpicosecond and picosecond timescales, but the reaction path that leads to the formation of the cisisomer is not clear yet. A few years ago, we initiated a comparative study of native PYP and several chromophore analogues in solution in order to try to further clarify the early steps of the photocycle. Our experimental approach consists in probing, in real-time, the ultrafast photoinduced events by transient absorption and gain spectroscopy using the pump–probe technique. In the present paper, we review our experimental results and discuss them within the context of the recent literature.

We report a comparative study of the isomerization reaction in native and denatured photoactive yellow protein (PYP) and in various chromophore analogues in their transdeprotonated form. The excited-state relaxation dynamics was followed by subpicosecond transient absorption and gain spectroscopy. The free p-hydroxycinnamate (pCA2-) and its amide analogue (pCM-) are found to display a quite different transient spectroscopy from that of PYP. The excited-state deactivation leads to the formation of the ground-state cisisomer without any detectable intermediate with a mechanism comparable to trans-stilbene photoisomerization. On the contrary, the early stage of the excited-state deactivation of the free thiophenyl-p-hydroxycinnamate (pCT-) and of the denatured PYP is similar to that of the native protein. It involves the formation of an intermediate absorbing in the spectral region located between the bleaching and gain bands in less than 2 ps. However, in these two cases, the formation of the cisisomer has not been proved yet. This difference with pCA-and pCM-might result from the fact that, in the thioester substituted chromophore, simultaneous population of two quasi-degenerate excited states occurs upon excitation. This comparative study highlights the determining role of the chromophore structure and of its intrinsic properties in the primary molecular events in native PYP.

We report a comparative study of the isomerization reaction in native and denatured photoactive yellow protein (PYP) and in various chromophore analogues in their trans deprotonated form. The excited-state relaxation dynamics was followed by subpicosecond transient absorption and gain spectroscopy. The free p-hydroxycinnamate (pCA2−) and its amide analogue (pCM−) are found to display a quite different transient spectroscopy from that of PYP. The excited-state deactivation leads to the formation of the ground-state cis isomer without any detectable intermediate with a mechanism comparable to trans-stilbene photoisomerization. On the contrary, the early stage of the excited-state deactivation of the free thiophenyl-p-hydroxycinnamate (pCT−) and of the denatured PYP is similar to that of the native protein. It involves the formation of an intermediate absorbing in the spectral region located between the bleaching and gain bands in less than 2 ps. However, in these two cases, the formation of the cis isomer has not been proved yet. This difference with pCA− and pCM− might result from the fact that, in the thioester substituted chromophore, simultaneous population of two quasi-degenerate excited states occurs upon excitation. This comparative study highlights the determining role of the chromophore structure and of its intrinsic properties in the primary molecular events in native PYP.

We report a comparative study of the isomerization reaction in native and denatured photoactive yellow protein PYP and in various chromophore analogues in their transdeprotonated form. The excited-state relaxation dynamics was followed by subpicosecond transient absorption and gain spectroscopy. The free p-hydroxycinnamate pCA2− and its amide analogue pCM− are found to display a quite different transient spectroscopy from that of PYP. The excited-state deactivation leads to the formation of the ground-state cisisomer without any detectable intermediate with a mechanism comparable to trans-stilbene photoisomerization. On the contrary, the early stage of the excited-state deactivation of the free thiophenyl-p-hydroxycinnamate pCT− and of the denatured PYP is similar to that of the native protein. It involves the formation of an intermediate absorbing in the spectral region located between the bleaching and gain bands in less than 2 ps. However, in these two cases, the formation of the cisisomer has not been proved yet. This difference with pCA−and pCM−might result from the fact that, in the thioester substituted chromophore, simultaneous population of two quasi-degenerate excited states occurs upon excitation. This comparative study highlights the determining role of the chromophore structure and of its intrinsic properties in the primary molecular events in native PYP.

Yeasts lacking cytoplasmic superoxide dismutase (Cu,Zn-SOD) activity are permanently subjected to oxidative stress. We used two-dimensional PAGE to examine the proteome pattern of Saccharomyces cerevisiae strains lacking Cu,Zn-SOD. We found a new stable form of alkyl hydroperoxide reductase 1 (Ahp1) with a lower isoelectric point. This form was also present in wild type strains after treatment with tert-butyl hydroperoxide. In vitro enzyme assays showed that Ahp1p had lower specific activity in strains lacking Cu,Zn-SOD. We studied three mutants presenting a reduced production of the low pI variant under oxidative stress conditions. Two of the mutants (C62S and S59D) were totally inactive, thus suggesting that the acidic form of Ahp1p may only appear when the enzyme is functional. The other mutant (S59A) was active in vitro and was more resistant to inactivation by tert-butyl hydroperoxide than the wild type enzyme. Furthermore, the inactivation of Ahp1p in vitro is correlated with its conversion to the low pI form. These results suggest that in vivo during some particular oxidative stress (alkyl hydroperoxide treatment or lack of Cu,Zn-SOD activity but not hydrogen peroxide treatment), the catalytic cysteine of Ahp1p is more oxidized than cysteine-sulfenic acid (a natural occurring intermediate of the enzymatic reaction) and that cysteine-sulfinic acid or cysteine-sulfonic acid variant may be inactive.

Die neu aufgefundenen Pariser Handschriften zum Spätwerk W. Benjamins belegen u. a., daß Benjamins Anspruch, mit einem vollständigen Buch über Baudelaire ein “Miniaturmodell” des Passagenwerks zu liefern, ernst zu nehmen ist, und beleuchten die theoretischen und praktischen Schwierigkeiten, auf die Benjamins Versuch einer Synthese seiner Arbeiten über das 19. Jahrhundert stieß. The rediscovery of Walter Benjamin’s late Paris manuscripts proves the validity of his claim that his intended book on Baudelaire would on completion have provided a ‘miniature model’ of his ‘Passagenwerk’. Light is also thrown on the difficulties he encountered, both theoretical and practical, in his attempt at a synthesis of his research on the 19th century.

Abstract: Objective:To investigate plasma and skin suction-blister-fluid pharmacokinetics of oral mizolastine in order to determine whether the drug concentration in the fluid of suction-induced skin blisters could better predict the antihistamine activity than the plasma concentration. Setting:Department of Internal Medicine, Université Paris 6.Subjects:Ten healthy male volunteers.Methods:The volunteers (mean age 26.8 years, mean weight 75.8 kg) received a single 10-mg oral dose of mizolastine at 1000 hours. The pharmacokinetic study included 11 plasma and 9 blister fluid samples and blister epidermal-roof specimens. Mizolastine was assayed by high-performance liquid chromatography (HPLC). Each volunteer also received nine intradermal injections of 5 μg histamine. Antihistamine activity was assessed as the post-treatment percentages of changes in the histamine-induced relative wheal and flare areas versus baseline. Results:Mizolastine mean Cmax (SD) and median tmax were, respectively, 380 ng ⋅ ml−1and 0.8 h in plasma, and 21.8 ng ⋅ ml−1 and 10 h in blister fluid. Mizolastine could not be quantified in the epidermis. The maximal histamine-induced relative flare inhibition was 72.5% and was attained at the median time of 3 h post-dosing and therefore was delayed by 2.2 h with respect to the plasma tmax. Mean relative wheal inhibition, although lower, showed the same time profile. A direct relationship could not be found between drug concentrations in blister fluid and antihistamine activity. Simulated concentrations in the peripheral compartment better explain the maximum inhibition effect on flare, observed 3 h post-dosing, with a flatter hysteresis loop obtained when plotting relative flare inhibition versus plasma or blister-fluid drug concentrations. Conclusion:The mizolastine concentrations in the skin suction-blister fluid were not predictive of the antihistamine activity.

In Heines Handschriften zu der “Reise von München nach Genua” entwickelt sich an der Figur der toten Maria eine untergründige Theorie der Natursubstanz, die den Heineschen Pantheismus in den 1820er Jahren weitgehend beleuchtet. An den vielen Überarbeitungen der Handschriften läßt sich außerdem das unablässige Spiel des Dichters mit diesem Ungesagten ablesen, das zum Fundament der Heineschen “Poiesis” gehört. The manuscripts of “Reise von München nach Genua” by H. Heine pertaining to the figure “tote Maria” constitute a subliminal theoretical consideration of the natural elements which elucidates the author’s pantheism circa 1820. Through the changes in the manuscripts, we can see how the care taken to reveal, hide or reformulate this secret illustrates the Heinian “poiesis” principles.

Zu den Leitfäden von Heines schriftstellerischem Werk gehört seine ständige Auseinandersetzung mit dem Begriffspaar Sensualismus/Asketismus. Von den Frühschriften bis zur „Matratzengruft“ durchzieht die Apologie der Sinnlichkeit die meisten Texte. Es wäre falsch zu behaupten, daß dieses obsessive Bekenntnis zu den Rechten der Materie den Germanisten bislang entgangen ist, und die meisten Untersuchungen von Heines Beziehung zum Hegelianismus, zum jungen Deutschland, zum Saint-Simonismus, zur Pantheismusdebatte unterstreichen gewöhnlich die Bedeutung des Sensualismus-Begriffs für Heine. Allerdings setzen sie sich nur selten so gründlich mit dem Wortlaut der Reisebilderauseinander, wo die ganze Problematik entstanden ist. Deshalb muß man der umfassenden interpretatorischen Arbeit von Olaf Hildebrand dankbar sein, die dem Leser zur genauen Einsicht in die frühen Varianten des Sensualismus-Motivs verhilft und eine Linie durchzieht, die von den Reisebildernzu den späten Gedichten kontinuierlich führt.

Jean Pauls Romanästhetik hat die neuere Forschung immer wieder beschäftigt. Auch Götz Müller nahm den Dichter in seiner Studie über die Verschränkung von Naturphilosophie und Ästhetik in der Vorschuleals Theoretiker ernst. In der vorliegenden Monographie soll er nun auch als Geschichtsphilosoph in den Vordergrund rücken, und dadurch soll zugleich das Bild des Ästhetikers erneuert werden. Denn Ralf Berhorst knüpft nicht nur an jene früheren Interpretationen wieder an, die vor allem daran interessiert waren, die politische Aussage des Werks zu erschließen. Angeregt von Gadamers und Ricœurs hermeneutischem Ansatz spürt er den vielfältigen Analogien zwischen Dichtung und Geschichte im Jean Paulschen Œuvre nach.

L’association entre migraine et signes otologiques (acouphènes et otalgies) est bien établie mais la physiopathologie en est mal connue [1,2].