179 research outputs found
Politiques du marchĂ© du travail et nĂ©gociations par branches dâactivitĂ© dans un modĂšle dâappariement
Dans la plupart des pays europĂ©ens, la redĂ©finition du contrat de travail et de ses modalitĂ©s de rupture est au coeur des dĂ©bats contemporains de politique Ă©conomique du marchĂ© du travail. Ces dĂ©bats sâappuient sur lâimposante littĂ©rature consacrĂ©e aux liens entre protection de lâemploi et performance du marchĂ© du travail dĂ©veloppĂ©e au cours des dix derniĂšres annĂ©es. Toutefois, une source de divergence importante entre les marchĂ©s du travail europĂ©ens, le degrĂ© de centralisation des nĂ©gociations salariales, a Ă©tĂ© curieusement Ă©ludĂ©e dans la plupart de ces Ă©tudes. Lâobjet de cet article est prĂ©cisĂ©ment dâenvisager dâun point de vue thĂ©orique la nature des interactions entre politiques du marchĂ© du travail et niveaux de nĂ©gociation. Dans cette perspective, nous dĂ©veloppons un modĂšle dynamique du marchĂ© du travail dans la lignĂ©e des travaux de Pissarides (2000) intĂ©grant diffĂ©rentes branches dâactivitĂ©. Notre analyse montre que dans ce cadre de rĂ©fĂ©rence, les nĂ©gociations de branche conduisent systĂ©matiquement Ă une allocation inefficace des ressources. Il existe alors une justification explicite Ă lâintroduction des politiques de lâemploi. Nous montrons alors quâun ensemble de politiques, notamment fiscales et de protection de lâemploi, est susceptible dâassurer lâÂŽequivalence entre Ă©quilibre de branches et optimum.ModĂšle dâappariement, Niveau des nĂ©gociations salariales, Politiques de lâemploi
Point de rĂ©fĂ©rence et aversion aux pertes : quel intĂ©rĂȘt pour les gestionnaires ?
Les notions de point de rĂ©fĂ©rence et dâaversion aux pertes sont deux Ă©lĂ©ments essentiels de la prospect theory, qui constitue Ă ce jour la thĂ©orie la plus reconnue concernant la reprĂ©sentation de la prise de dĂ©cision individuelle dans le risque. Lâobjectif de cet article est de montrer comment ces notions peuvent ĂȘtre utilisĂ©es par les gestionnaires pour amĂ©liorer leur comprĂ©hension du comportement des managers et des consommateurs. Trois contextes de dĂ©cision sont Ă©tudiĂ©s Ă savoir les marchĂ©s financiers, les Ă©changes commerciaux et la politique de fixation du prix. Dans chaque contexte, des pistes de rĂ©flexion pour la recherche future sont proposĂ©es.Prospect theory; Point de rĂ©fĂ©rence; Aversion aux pertes; Comportement du consommateur; Finance comportementale; Marketing
Quoting the Confucian Analects in Defense of Indian Buddhism: An Exegetical Study of Confuciusâ Utterances in the Mouzi li huo lun
I first encountered the Mouzi çć while working on a Confucian text attributed to Lu Jia éžèł (d. c. 170 BCE), the New Discourses (Xinyu æ°èȘ), and more particularly on the problems raised by its authenticity. Lu Jia, as an ambassador for two emperors of the Han dynasty, Gaozu é«ç„ (r. 202-195 BCE) and Wendi æćž (r. 179-157 BCE), led two expeditions to the remote area of Jiaozhi äș€è¶Ÿ, then an independent kingdom (Nan Yue ćè¶) at the extreme south of the Chinese space. The New Discourses, despite the imp..
Relationship Between IFN-t Production by Bovines Embryos Derived Ex Vivo and Completely Produced In Vitro
Reactive oxygen species and plant resistance to fungal pathogens
Reactive oxygen species (ROS) have been studied for their role in plant development as well as in plant immunity. ROS were consistently observed to accumulate in the plant after the perception of pathogens and microbes and over the years, ROS were postulated to be an integral part of the defence response of the plant. In this article we will focus on recent findings about ROS involved in the interaction of plants with pathogenic fungi. We will describe the ways to detect ROS, their modes of action and their importance in relation to resistance to fungal pathogens. In addition we include some results from works focussing on the fungal interactor and from studies investigating roots during pathogen attack
Politiques du marchĂ© du travail et nĂ©gociations par branches dâactivitĂ© dans un modĂšle dâappariement
Dans la plupart des pays europĂ©ens, la redĂ©finition du contrat de travail et de ses modalitĂ©s de rupture est au cĆur des dĂ©bats contemporains de politique Ă©conomique de marchĂ© du travail. Ces dĂ©bats sâappuient sur lâimposante littĂ©rature consacrĂ©e aux liens entre protection de lâemploi et performance du marchĂ© du travail dĂ©veloppĂ©e au cours des dix derniĂšres annĂ©es. Toutefois, une source de divergence importante entre les marchĂ©s du travail europĂ©ens, le degrĂ© de centralisation des nĂ©gociations salariales, a Ă©tĂ© curieusement Ă©ludĂ©e dans la plupart de ces Ă©tudes. Lâobjet de cet article, est prĂ©cisĂ©ment dâenvisager dâun point de vue thĂ©orique la nature des interactions entre politiques du marchĂ© du travail et niveaux de nĂ©gociation. Dans cette perspective, nous dĂ©veloppons un modĂšle dynamique du marchĂ© du travail dans la lignĂ©e des travaux Pissarides (2000) intĂ©grant diffĂ©rentes branches dâactivitĂ©. Notre analyse montre que dans ce cadre de rĂ©fĂ©rence, les nĂ©gociations de branche conduisent systĂ©matiquement Ă une allocation inefficace des ressources. Il existe alors une justification explicite Ă lâintroduction des politiques dâemploi. Nous montrons alors quâun ensemble de politiques, notamment fiscales et de protection de lâemploi est susceptible dâassurer lâĂ©quivalence entre Ă©quilibre de branches et optimum.modĂšle dâappariement, niveau des nĂ©gociations salariales, politiques de lâemploi
The innate immune signaling system as a regulator of disease resistance and induced systemic resistance activity against Verticillium dahliae
In the last decades, the plant innate immune responses against pathogens have been extensively studied, while biocontrol interactions between soilborne fungal pathogens and their hosts have received much less attention. Treatment of Arabidopsis thaliana with the nonpathogenic bacterium Paenibacillus alvei K165 was shown previously to protect against Verticillium dahliae by triggering induced systemic resistance (ISR). In the present study, we evaluated the involvement of the innate immune response in the K165-mediated protection of Arabidopsis against V. dahliae. Tests with Arabidopsis mutants impaired in several regulators of the early steps of the innate immune responses, including fls2, efr-1, bak1-4, mpk3, mpk6, wrky22, and wrky29 showed that FLS2 and WRKY22 have a central role in the K165-triggered ISR, while EFR1, MPK3, and MPK6 are possible susceptibility factors for V. dahliae and bak1 shows a tolerance phenomenon. The resistance induced by strain K165 is dependent on both salicylate and jasmonate-dependent defense pathways, as evidenced by an increased transient accumulation of PR1 and PDF1.2 transcripts in the aerial parts of infected plants treated with strain K165
The formation of physician altruism
We study how patient-regarding altruism is formed by medical education. We elicit and structurally estimate altruistic preferences using experimental data from a large sample of medical students ( = 733) in Germany at different progress stages in their studies. The estimates reveal substantial heterogeneity in altruistic preferences of medical students. Patient-regarding altruism is highest for freshmen, significantly declines for students in the course of medical studies, and tends to increase again for last year students, who assist in clinical practice. Also, patient-regarding altruism is higher for females and positively associated to general altruism. Altruistic medical students have gained prior practical experience in healthcare, have lower income expectations, and are more likely to choose surgery and pediatrics as their preferred specialty
Endophytes and epiphytes from the grapevine leaf microbiome as potential biocontrol agents against phytopathogens
Plants harbor diverse microbial communities that colonize both below-ground and above-ground organs. Some bacterial members of these rhizosphere and phyllosphere microbial communities have been shown to contribute to plant defenses against pathogens. In this study, we characterize the pathogen-inhibiting potential of 78 bacterial isolates retrieved from endophytic and epiphytic communities living in the leaves of three grapevine cultivars. We selected two economically relevant pathogens, the fungus Botrytis cinerea causing gray mold and the oomycete Phytophthora infestans, which we used as a surrogate for Plasmopara viticola causing downy mildew. Our results showed that epiphytic isolates were phylogenetically more diverse than endophytic isolates, the latter mostly consisting of Bacillus and Staphylococcus strains, but that mycelial inhibition of both pathogens through bacterial diffusible metabolites was more widespread among endophytes than among epiphytes. Six closely related Bacillus strains induced strong inhibition (<60%) of Botrytis cinerea mycelial growth. Among these, five led to significant perturbation in spore germination, ranging from full inhibition to reduction in germination rate and germ tube length. Different types of spore developmental anomalies were observed for different strains, suggesting multiple active compounds with different modes of action on this pathogen. Compared with B. cinerea, the oomycete P. infestans was inhibited in its mycelial growth by a higher number and more diverse group of isolates, including many Bacillus but also Variovorax, Pantoea, Staphylococcus, Herbaspirillum, or Sphingomonas strains. Beyond mycelial growth, both zoospore and sporangia germination were strongly perturbed upon exposure to cells or cell-free filtrates of selected isolates. Moreover, three strains (all epiphytes) inhibited the pathogenâs growth via the emission of volatile compounds. The comparison of the volatile profiles of two of these active strains with those of two phylogenetically closely related, inactive strains led to the identification of molecules possibly involved in the observed volatile-mediated pathogen growth inhibition, including trimethylpyrazine, dihydrochalcone, and L-dihydroxanthurenic acid. This work demonstrates that grapevine leaves are a rich source of bacterial antagonists with strong inhibition potential against two pathogens of high economical relevance. It further suggests that combining diffusible metabolite-secreting endophytes with volatile-emitting epiphytes might be a promising multi-layer strategy for biological control of above-ground pathogens
Microbial life in the grapevine: what can we expect from the leaf microbiome?
Recent studies have shown that plants harbor complex bacterial communities, the so- called âmicrobiomeâ. We are only beginning to unravel the origin of these bacterial plant inhabitants, their community structure and their roles, which, in analogy to the gut microbiome, are likely to be of essential nature. The aim of this work was to analyze the abundance and diversity of the cultivable members of the bacterial microbiome living in and on the leaves of grapevine, and to identify microbiome members with putative plant-protective activities against phytopathogenic organisms.Methods and results: Grapevine leaves were sampled three times during the growing season at one location and used to quantify the abundance and isolate representative members of the epiphytic and endophytic bacterial communities. Results were compared for three grapevine cultivars: Pinot noir, Chasselas and Solaris. Greater bacterial abundance and diversity was observed among epiphytes than among endophytes. Leaf imprints revealed a higher colonization density for the upper than for the lower surface of leaves. A high relative frequency of strains belonging to the genera Staphylococcus and Bacillus was observed, especially in the endophytic communities.Conclusions: The first results of this ongoing study led to the conclusion that epiphytic bacteria of the cultivable grapevine microbiome were more abundant and diverse than endophytic bacteria. A tendency towards more abundant bacteria in the resistant variety Solaris than in the susceptible varieties Chasselas and Pinot noir contrasted with a higher diversity of epiphytic bacteria in the Pinot noir variety. A trend for higher frequency of strains showing antagonistic activity towards the grapevine pathogen Botrytis cinerea among isolates from the resistant variety Solaris could indicate a putative contribution of microbiome bacteria to this resistant phenotype, even though this remains to be confirmed.Significance and impact of the study: This study constitutes a first step in characterizing the endo- and epiphytic cultivable bacterial communities of three grapevine varieties grown at the same location. Further, presently ongoing studies shall reveal i) the true complexity of these leaf-associated communities through cultivation-independent, next generation sequencing techniques, and ii) their potential as a source of biofungicidal agents. In this last point, the contribution of the emission of volatile organic compounds (VOCs) as a newly discovered type of bacterial weapon against fungal and oomycetal pathogens shall be quantified
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