Circadian clock-dependent and -independent rhythmic proteomes implement distinct diurnal functions in mouse liver.

Diurnal oscillations of gene expression controlled by the circadian clock underlie rhythmic physiology across most living organisms. Although such rhythms have been extensively studied at the level of transcription and mRNA accumulation, little is known about the accumulation patterns of proteins. Here, we quantified temporal profiles in the murine hepatic proteome under physiological light-dark conditions using stable isotope labeling by amino acids quantitative MS. Our analysis identified over 5,000 proteins, of which several hundred showed robust diurnal oscillations with peak phases enriched in the morning and during the night and related to core hepatic physiological functions. Combined mathematical modeling of temporal protein and mRNA profiles indicated that proteins accumulate with reduced amplitudes and significant delays, consistent with protein half-life data. Moreover, a group comprising about one-half of the rhythmic proteins showed no corresponding rhythmic mRNAs, indicating significant translational or posttranslational diurnal control. Such rhythms were highly enriched in secreted proteins accumulating tightly during the night. Also, these rhythms persisted in clock-deficient animals subjected to rhythmic feeding, suggesting that food-related entrainment signals influence rhythms in circulating plasma factors.

An evaluation of the inorganic and organic geochemistry of the San Vicente Mississippi Valley-type zinc-lead district, central Peru: Implications for ore fluid composition, mixing processes, and sulfate reduction

Mississippi Tialley-type zinc-lead deposits and ore occurrences in the San Vicente belt are hosted in dolostones of the eastern Upper Triassic to Lower Jurassic Pucara basin, central Peru. Combined inorganic and organic geochemical data from 22 sites, including the main San Vicente deposit, minor ore occurrences, and barren localities, provide better understanding of fluid pathways and composition, ore precipitation mechanisms, Eh-pH changes during mineralization, and relationships between organic matter and ore formation. Ore-stage dark replacement dolomite and white sparry dolomite are Fe and rare earth element (REE) depleted, and Mn enriched, compared to the host dolomite. In the main deposit, they display significant negative Ce and probably Eu anomalies. Mixing of an incoming hot, slightly oxidizing, acidic brine (H2CO3 being the dominant dissolved carbon species), probably poor in REE and Fe, with local intraformational, alkaline, reducing waters explains the overall carbon and oxygen isotope variation and the distributions of REE and other trace elements in the different hydrothermal carbonate generations. The incoming ore fluid flowed through major aquifers, probably basal basin detrital units, with limited interaction with the carbonate host rocks. The hydrothermal carbonates show a strong regional chemical homogeneity, indicating access of the ore fluids by interconnected channelways near the ore occurrences. Negative Ce anomalies in the main deposit, that are absent at the district scale, indicate local ore-fluid chemical differences. Oxidation of both migrated and indigenous hydrocarbons by the incoming fluid provided the local reducing conditions necessary for sulfate reduction to H2S, pyrobitumen precipitation, and reduction of Eu3+ to Eu2+. Fe-Mn covariations, combined with the REE contents of the hydrothermal carbonates, are consistent with the mineralizing system shifting from reducing/rock-dominated to oxidizing/fluid-dominated conditions following ore deposition. Sulfate and sulfide sulfur isotopes support sulfide origin from evaporite-derived sulfate by thermochemical organic reduction; further evidence includes the presence of C-13-depleted calcite cements (similar to-12 parts per thousand delta(13)C) as sulfate pseudomorphs, elemental sulfur, altered organic matter in the host dolomite, and isotopically heavier, late, solid bitumen. Significant alteration of the indigenous and extrinsic hydrocarbons, with absent bacterial membrane biomarkers (hopanes) is observed. The light delta(34)S of sulfides from small mines and occurrences compared to the main deposit reflect a local contribution of isotopically light sulfur, evidence of local differences in the ore-fluid chemistry.

Blue light activates a specific protein kinase in higher plants.

Blue light mediates the phosphorylation of a membrane protein in seedlings from several plant species. When crude microsomal membrane proteins from dark-grown pea (Pisum sativum L.), sunflower (Helianthus annuus L.), zucchini (Cucurbita pepo L.), Arabidopsis (Arabidopsis thaliana L.), or tomato (Lycopersicon esculentum L.) stem segments, or from maize (Zea mays L.), barley (Hordeum vulgare L.), oat (Avena sativa L.), wheat (Triticum aestivum L.), or sorghum (Sorghum bicolor L.) coleoptiles are illuminated and incubated in vitro with [gamma-(32)P]ATP, a protein of apparent molecular mass from 114 to 130 kD is rapidly phosphorylated. Hence, this system is probably ubiquitous in higher plants. Solubilized maize membranes exposed to blue light and added to unirradiated solubilized maize membranes show a higher level of phosphorylation of the light-affected protein than irradiated membrane proteins alone, suggesting that an unirradiated substrate is phosphorylated by a light-activated kinase. This finding is further demonstrated with membrane proteins from two different species, where the phosphorylated proteins are of different sizes and, hence, unambiguously distinguishable on gel electrophoresis. When solubilized membrane proteins from one species are irradiated and added to unirradiated membrane proteins from another species, the unirradiated protein becomes phosphorylated. These experiments indicate that the irradiated fraction can store the light signal for subsequent phosphorylation in the dark. They also support the hypothesis that light activates a specific kinase and that the systems share a close functional homology among different higher plants.

Workplace Aggressive Behaviors: Three Essays

Abstract¦This thesis examines through three essays the role of the social context and of people concern for justice in explaining workplace aggressive behaviors.¦In the first essay, I argue that a work group instrumental climate - a climate emphasizing respect of organizational procedures -deters employees to manifest counterproductive work behaviors through informal sanctions (i.e., socio-emotional disapproval) they anticipate from it for misbehaving. A contrario, a work group affective climate - a climate concerned about others' well-being - leads employees to infer less informal sanctions and thus indirectly facilitates counterproductive work behaviors. I additionally expect these indirect effects to be conditional on employees' level of conscientiousness and agreeableness. Cross-level structural equations on cross-sectional data obtained from 158 employees in 26 work groups supported my expectations. By promoting collective responsibility for the respect of organizational rules and by knowing what their work group considers threatening their well-being, leaders may be able to prevent counterproductive work behaviors.¦Adopting an organizational justice perspective, the second essay provides a theoretical explanation of why and how collective deviance can emerge in a collective. In interdependent situations, employees use justice perceptions to infer others' cooperative intent. Even if moral transgressions (e.g., injustice) are ambiguous, their repetition and configuration within a team can lead employees to assign blame and develop collective cynicism toward the transgressor. Over time, collective cynicism - a shared belief about the transgressor's intentional lack of integrity - progressively constrains the diversity of employees' response to blame and leads collective deviance to emerge. This essay contributes to workplace deviance research by offering a theoretical framework for investigations of the phenomenon at the collective level. It organizations effort to manage and prevent deviance should consider.¦In the third essay, I solve an apparent contradiction in the literature showing that justice concerns sometimes lead employees to react aggressively to injustice and sometimes to refrain from it. Drawing from just-world theory, a cross-sectional field study and an experiment provide evidence that retaliatory tendencies following injustice are moderated by personal and general just-world beliefs. Whereas a high personal just-world belief facilitates retaliatory reactions to injustice, a high general just-world belief attenuates such reactions. This essay uncovers a dark side of personal just-world belief and a bright one of general just-world belief, and participates to extend just-world theory to the working context.

Comparison of Fundus Autofluorescence Between Fundus Camera (Topcon) and Confocal Scanning Laser Ophthalmoscope (HRA) in Various Pathologies

Purpose: To investigate the differences between the Fundus Camera (Topcon TRC-50X) and Confocal Scanning Laser Ophthalmoscope (Heidelberg retina angiogram (HRA)) on the fundus autofluorescence (FAF) imaging (resolution and FAF characteristics). Methods: Eighty nine eyes of 46 patients with various retinal diseases underwent FAF imaging with HRA (488nm exciter / 500nm barrier filter) before fluorescein angiography (FFA) and Topcon Fundus Camera (580nm exciter / 695nm barrier filter) before and after FFA. The quality of the FAF images was estimated, compared for their resolution and analysed for the influence of fixation stability and cataracts. Hypo- and hyper-FAF behaviour was analysed for the healthy disc, healthy fovea, and a variety of pathological features. Results: HRA images were found to be of superior quality in 18 eyes, while Topcon images were estimated superior in 21 eyes. No difference was found in 50 eyes. Both poor fixation (p=0.009) and more advanced cataract (p=0.013) were found to strongly increase the likelihood of better image quality by Topcon. Images acquired by Topcon before and after FFA were identical (100%). The healthy disc was usually dark on HRA (71%), but showed mild autofluorescence on Topcon (88%). The healthy fovea showed in 100% Hypo-FAF on HRA, while Topcon showed in 52% Iso-FAF, in 43% mild Hypo-FAF, and in 5% Hypo-FAF as on HRA. No difference of FAF was found for geographic atrophy, pigment changes, and drusen, although Topcon images were often more detailed. Hyper-FAF due to exudation showed better on HRA. Pigment epithelium detachment showed identical FAF behaviour on the border, but reduced FAF with Topcon in the center. Cystic edema was visible only on HRA in a petaloid pattern. Hard exsudates caused Hypo-FAF only on HRA, hardly visible on Topcon. Blocage phenomenon by blood however was identical. Conclusions: The filter set of Topcon and the single image acquisition appear to be an advantage for patients with cataract or poor fixation. Preceding FFA does not alter the Topcon FAF image. Regarding the FAF behaviour, there are differences between the two systems which need to be taken into account when interpreting the images.

Pheomelanin-based coloration and the ability to cope with variation in food supply and parasitism.

Although gene by environment interactions may play a key role in the maintenance of genetic polymorphisms, little is known about the ecological factors involved in these interactions. We investigated whether food supply and parasites can mediate covariation between the degree of adult pheomelanin-based coloration, a heritable trait, and offspring body mass in the tawny owl (Strix aluco). We swapped clutches between nests to allocate genotypes randomly among environments. Three weeks after hatching, we challenged the immune system of 80 unrelated nestlings with either a phytohemagglutinin (PHA) or a lipopolysaccharide, surrogates of alternative parasites, and then fed them ad lib. or food-restricted them during the following 6 days in the laboratory. Whatever the immune challenge, nestlings fed ad lib. converted food more efficiently into body mass when their biological mother was dark pheomelanic. In contrast, food-restricted nestlings challenged with PHA lost less body mass when their biological mother was pale pheomelanic. Nestling tawny owls born from differently melanic mothers thus show differing reaction norms relative to food availability and parasitism. This suggests that dark and pale pheomelanic owls reflect alternative adaptations to food availability and parasites, factors known to vary in space and time.

Melanin-specific life-history strategies.

Abstract The maintenance of genetic variation is a long-standing issue because the adaptive value of life-history strategies associated with each genetic variant is usually unknown. However, evidence for the coexistence of alternative evolutionary fixed strategies at the population level remains scarce. Because in the tawny owl (Strix aluco) heritable melanin-based coloration shows different physiological and behavioral norms of reaction, we investigated whether coloration is associated with investment in maintenance and reproduction. Light melanic owls had lower adult survival compared to dark melanic conspecifics, and color variation was related to the trade-off between offspring number and quality. When we experimentally enlarged brood size, light melanic males produced more fledglings but in poorer condition, and they were less often recruited in the local breeding population than those of darker melanic conspecifics. Our results also suggest that dark melanic males allocate a constant effort to raise their brood independently of environmental conditions, whereas lighter melanic males finely adjust reproductive effort in relation to changes in environmental conditions. Color traits can therefore be associated with life-history strategies, and stochastic environmental perturbation can temporarily favor one phenotype over others. The existence of fixed strategies implies that some phenotypes can sometimes display a "maladapted" strategy. Long-term population monitoring is therefore vital for a full understanding of how different genotypes deal with trade-offs.

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This chapter looks at the place of the Gothic in Batman's history and current revival via the Nolan films. It examines the specificity of comic book characters, which exist in a wide variety of texts, forms and media, and focuses on the way that Batman has oscillated between light and dark versions while always returning to the Gothic as a means of commercial reanimation when the franchise seems to wane.

Etude clinique et angiographique lors de la syphilis oculaire

UNIVERSITE DE LAUSANNE - FACULTE DE BIOLOGIE ET DE MEDECINE Médecine Ophtalmologie Etude clinique et angiographique lors de la Syphilis Oculaire THESE préparée sous la direction du Docteur Yan Guex-Crosier et présentée à la Faculté de biologie et de médecine de l'Université de Lausanne pour l'obtention du grade de DOCTEUR EN MEDECINE par Konstantinos BALASKAS Médecin diplômé de la Grèce Originaire d'Athènes (Grèce) ι Lausanne 2012  Une recrudescence des cas de syphilis a été observée ces dernières années. Son diagnostic clinique reste particulièrement difficile en l'absence de signe pathognomonique. Sur le plan oculaire elle présente un vaste spectre de manifestations diverses lui ayant valu le surnom de « la grande imitatrice ». Sa rareté et son hétérogénéité ont empêché l'identification et la vérification statistique des facteurs liés à un pronostic défavorable. Le but de cette étude a été d'explorer les paramètres cliniques et para-cliniques déterminant la sévérité et influençant l'évolution de la maladie. Ce travail comprend deux volets, la première partie intitulée : «Analysis of significant factors influencing visual acuity in ocular syphilis» publiée dans le British Journal of Ophthalmology a démontré qu'une mauvaise acuité visuelle initiale est associée de façon statistiquement significative à la sévérité de l'amputation du champ visuel, à la présence d'un oedème maculaire ou d'une neuropathie optique. Une amélioration de l'acuité visuelle grâce au traitement antibiotique est associée à la présence d'une vasculite (visible à l'angiographie fluorescéinique), d'une neurosyphilis ou d'une uvéite antérieure. Une récidive inflammatoire est fortement associée à une durée prolongée des symptômes avant l'introduction du traitement et à la présence de douleur comme signe d'appel. L'utilité clinique principale de ces résultats statistiques permet de conclure que les formes inflammatoires sévères associées à la triade (vasculite, neurosyphilis et uvéite antérieure) constituent un phénomène réversible pour autant qu'un traitement précoce et adéquat ait été introduit. Le deuxième volet de l'étude analyse les manifestations angiographiques (à la fluorescéine (AF) et au vert d'indocyanine (AICG)) de la syphilis oculaire et a été publié dans le journal du Graefes Archives of Clinical and Experimental Ophthalmology sous le titre suivant : "Fluorescein and indocyanine-green angiography in ocular syphilis: an exploratory study". Des associations faibles ont été démontrées entre la présence d'une vasculite lors de AF et d'une uvéite antérieure, d'une hyalite et d'un âge plus jeune. Une association forte est identifiée entre la présence des «dark dots» sur l'AICG et d'une uvéite antérieure ainsi qu'entre la présence des «hot spots» sur l'AICG et d'une durée prolongée des symptômes. Les conclusions d'importance clinique significative lors de la syphilis oculaire sont que les « dark dots » ou hypofluorescences en AICG évoquent la présence d'une atteinte inflammatoire oculaire sévère et que les « hot spots » ou hyperfluorescences en AICG sont significatifs d'une atteinte chronique. Cette étude contribue à modifier les attitudes cliniques lors de la syphilis oculaire surtout en ce qui concerne l'urgence à traiter afin d'assurer une récupération optimale. Elle aide aussi à redéfinir le rôle de l'angiographie dans la syphilis oculaire pour déterminer la sévérité, la durée de la maladie ainsi que le pronostic visuel.

Rhythmic growth explained by coincidence between internal and external cues.

Most organisms use circadian oscillators to coordinate physiological and developmental processes such as growth with predictable daily environmental changes like sunrise and sunset. The importance of such coordination is highlighted by studies showing that circadian dysfunction causes reduced fitness in bacteria and plants, as well as sleep and psychological disorders in humans. Plant cell growth requires energy and water-factors that oscillate owing to diurnal environmental changes. Indeed, two important factors controlling stem growth are the internal circadian oscillator and external light levels. However, most circadian studies have been performed in constant conditions, precluding mechanistic study of interactions between the clock and diurnal variation in the environment. Studies of stem elongation in diurnal conditions have revealed complex growth patterns, but no mechanism has been described. Here we show that the growth phase of Arabidopsis seedlings in diurnal light conditions is shifted 8-12 h relative to plants in continuous light, and we describe a mechanism underlying this environmental response. We find that the clock regulates transcript levels of two basic helix-loop-helix genes, phytochrome-interacting factor 4 (PIF4) and PIF5, whereas light regulates their protein abundance. These genes function as positive growth regulators; the coincidence of high transcript levels (by the clock) and protein accumulation (in the dark) allows them to promote plant growth at the end of the night. Thus, these two genes integrate clock and light signalling, and their coordinated regulation explains the observed diurnal growth rhythms. This interaction may serve as a paradigm for understanding how endogenous and environmental signals cooperate to control other processes.

Melanin-based colour polymorphism signals aggressive personality in nest and territory defence in the tawny owl (Strix aluco)

Nest and territory defence are risky and potentially dangerous behaviours. If the resolution of life history trade-offs differs between individuals, the level of defence may also vary among individuals. Because melanin-based colour traits can be associated with life history strategies, differently coloured individuals may display different nest and territory defence strategies. We investigated this issue in the colour polymorphic tawny owl (Strix aluco) for which plumage varies from dark to light reddish melanic. Accordingly, we found that (1) our presence induced a greater response (flying around) from dark-coloured than light-coloured females and (2) dark reddish males suffered lower nest predation rates than light-coloured males. In experimentally enlarged broods, the probability that females reacted after we played back the hoot calls of a stranger male was higher if these females were lighter reddish; the opposite pattern was found in experimentally reduced broods with dark parents being more reactive than light parents. Finally, darker females alarmed more frequently when paired with a light than with a dark male, suggesting that partners adjust their behaviour to each other. We also tested whether colouration is used as a signal by conspecifics to adjust the level of their defensive behaviour. Accordingly, breeding females responded more vigorously to a dark than a light reddish stuffed tawny owl placed beside their nest. We conclude that melanin-based colouration is a signal of alternative nest and territory defence behaviour that depends on ecological factors.

Étude des mécanismes de transfert des fibres en sciences forensiques

RESUME Les fibres textiles sont des produits de masse utilisés dans la fabrication de nombreux objets de notre quotidien. Le transfert de fibres lors d'une action délictueuse est dès lors extrêmement courant. Du fait de leur omniprésence dans notre environnement, il est capital que l'expert forensique évalue la valeur de l'indice fibres. L'interprétation de l'indice fibres passe par la connaissance d'un certain nombre de paramètres, comme la rareté des fibres, la probabilité de leur présence par hasard sur un certain support, ainsi que les mécanismes de transfert et de persistance des fibres. Les lacunes les plus importantes concernent les mécanismes de transfert des fibres. A ce jour, les nombreux auteurs qui se sont penchés sur le transfert de fibres ne sont pas parvenus à créer un modèle permettant de prédire le nombre de fibres que l'on s'attend à retrouver dans des circonstances de contact données, en fonction des différents paramètres caractérisant ce contact et les textiles mis en jeu. Le but principal de cette recherche est de démontrer que la création d'un modèle prédictif du nombre de fibres transférées lors d'un contact donné est possible. Dans le cadre de ce travail, le cas particulier du transfert de fibres d'un tricot en laine ou en acrylique d'un conducteur vers le dossier du siège de son véhicule a été étudié. Plusieurs caractéristiques des textiles mis en jeu lors de ces expériences ont été mesurées. Des outils statistiques (régression linéaire multiple) ont ensuite été utilisés sur ces données afin d'évaluer l'influence des caractéristiques des textiles donneurs sur le nombre de fibres transférées et d'élaborer un modèle permettant de prédire le nombre de fibres qui vont être transférées à l'aide des caractéristiques influençant significativement le transfert. Afin de faciliter la recherche et le comptage des fibres transférées lors des expériences de transfert, un appareil de recherche automatique des fibres (liber finder) a été utilisé dans le cadre de cette recherche. Les tests d'évaluation de l'efficacité de cet appareil pour la recherche de fibres montrent que la recherche automatique est globalement aussi efficace qu'une recherche visuelle pour les fibres fortement colorées. Par contre la recherche automatique perd de son efficacité pour les fibres très pâles ou très foncées. Une des caractéristiques des textiles donneurs à étudier est la longueur des fibres. Afin de pouvoir évaluer ce paramètre, une séquence d'algorithmes de traitement d'image a été implémentée. Cet outil permet la mesure de la longueur d'une fibre à partir de son image numérique à haute résolution (2'540 dpi). Les tests effectués montrent que les mesures ainsi obtenues présentent une erreur de l'ordre du dixième de millimètre, ce qui est largement suffisant pour son utilisation dans le cadre de cette recherche. Les résultats obtenus suite au traitement statistique des résultats des expériences de transfert ont permis d'aboutir à une modélisation du phénomène du transfert. Deux paramètres sont retenus dans le modèle: l'état de la surface du tissu donneur et la longueur des fibres composant le tissu donneur. L'état de la surface du tissu est un paramètre tenant compte de la quantité de fibres qui se sont détachées de la structure du tissu ou qui sont encore faiblement rattachées à celle-ci. En effet, ces fibres sont les premières à se transférer lors d'un contact, et plus la quantité de ces fibres par unité de surface est importante, plus le nombre de fibres transférées sera élevé. La longueur des fibres du tissu donneur est également un paramètre important : plus les fibres sont longues, mieux elles sont retenues dans la structure du tissu et moins elles se transféreront. SUMMARY Fibres are mass products used to produce numerous objects encountered everyday. The transfer of fibres during a criminal action is then very common. Because fibres are omnipresent in our environment, the forensic expert has to evaluate the value of the fibre evidence. To interpret fibre evidence, the expert has to know some parameters as frequency of fibres,' probability of finding extraneous fibres by chance on a given support, and transfer and persistence mechanisms. Fibre transfer is one of the most complex parameter. Many authors studied fibre transfer mechanisms but no model has been created to predict the number of fibres transferred expected in a given type of contact according to parameters as characteristics of the contact and characteristics of textiles. The main purpose of this research is to demonstrate that it is possible to create a model to predict the number of fibres transferred during a contact. In this work, the particular case of the transfer of fibres from a knitted textile in wool or in acrylic of a driver to the back of a carseat has been studied. Several characteristics of the textiles used for the experiments were measured. The data obtained were then treated with statistical tools (multiple linear regression) to evaluate the influence of the donor textile characteristics on the number of úbers transferred, and to create a model to predict this number of fibres transferred by an equation containing the characteristics having a significant influence on the transfer. To make easier the searching and the counting of fibres, an apparatus of automatic search. of fibers (fiber finder) was used. The tests realised to evaluate the efficiency of the fiber finder shows that the results obtained are generally as efficient as for visual search for well-coloured fibres. However, the efficiency of automatic search decreases for pales and dark fibres. One characteristic of the donor textile studied was the length of the fibres. To measure this parameter, a sequence of image processing algorithms was implemented. This tool allows to measure the length of a fibre from it high-resolution (2'540 dpi) numerical image. The tests done shows that the error of the measures obtained are about some tenths of millimetres. This precision is sufficient for this research. The statistical methods applied on the transfer experiment data allow to create a model of the transfer phenomenon. Two parameters are included in the model: the shedding capacity of the donor textile surface and the length of donor textile fibres. The shedding capacity of the donor textile surface is a parameter estimating the quantity of fibres that are not or slightly attached to the structure of the textile. These fibres are easily transferred during a contact, and the more this quantity of fibres is high, the more the number of fibres transferred during the contact is important. The length of fibres is also an important parameter: the more the fibres are long, the more they are attached in the structure of the textile and the less they are transferred during the contact.

Carbon-isotope stratigraphy of the Liesberg Beds Member (Oxfordian, Swiss Jura) using echinoids and crinoids

The Liesberg Beds form the transition between the lower Oxfordian dark coloured marls (Renggeri Member and the Terrain a Chailles Member) and the middle Oxfordian reefal limestones (St-Ursanne Formation). Both lithofacies and biofacies are diverse and evolve rapidly up-section. Stable isotope studies of whole-rock samples are therefore excluded. In search for a convenient isotopic marker, we measured carbon isotope compositions of several fossil groups and chose crinoid stems of Millericrinus spp and echinoid spines of Paracidaris spp because of their abundance throughout the section and the small variations of delta(13)C within one fossil and between fossils from the same stratigraphic level. The delta(13)C values of echinoderms largely reflect earliest diagenetic conditions at the seawatersediment interface. The porous stereome structure secreted of high Mg-calcite by echinoderms has a high reactive surface/volume ratio, which triggers the precipitation of very early syntaxial cements. In the four studied sections reproducible carbon isotope shifts were observed both for Millericrinus spp stems and Paracidaris spp spines. A negative delta(13)C shift of 1-1.5 parts per thousand was observed near the base of the section, just above the transition from Terrain a Chailles Member, where the first corals occur. In the middle and upper part of the four sections, characterised by a stepwise increase of corals and the macrofossils, a positive delta(13)C Shift of about 2 parts per thousand was observed. Despite the highly variable lithologic composition of the Liesberg Beds;Member, carbon isotope shifts seem to be consistent and warrant an interpretation as an original signal, controlled by the isotopic composition of dissolved carbonic acid in seawater. We explain the heavy delta(13)C values (approximate to 2-2.3 parts per thousand) in the lower Liesberg Beds as a transition from an oxygen-limited environment (Terrain a Chailles Member) to the Liesberg Beds Member. The lowest delta(13)C values (approximate to 1-1.5 parts per thousand) correspond to a large input of dissolved nutrients to the platform under oxidizing conditions. The ensuing positive shift (between 2.5 and 3.5 parts per thousand), however, seems to correspond to a general trend of opening up of the platform and connection to open marine waters. Positive delta(13)C values in the upper Liesberg Beds is interpreted as a result of important accelareted extraction of organic carbon from the ocean reservoir, that occurred possibly during periods of warm and humid climate.

Owl melanin-based plumage redness is more frequent near than away from the equator: implications on the effect of climate change on biodiversity

Climate change acts as a major new selective agent on many organisms, particularly at high latitudes where climate change is more pronounced than at lower latitudes. Studies are required to predict which species are at a high risk of extinction and whether certain phenotypes may be more affected by climate change than others. The identification of susceptible phenotypes is important for evaluating the potential negative effect of climate change on biodiversity at the inter- and intraspecific levels. Melanin-based coloration is an interesting and easily accessible candidate trait because, within certain species, reddish pheomelanin-based coloration is associated with adaptations to warm climates. However, it is unclear whether the same holds among species. We tested one prediction of this hypothesis in four owl genera (wood, scops, screech, and pygmy owls), namely that darker reddish species are more prevalent near the equator than polewards. Our comparative analysis is consistent with this prediction for the northern hemisphere, suggesting that pale reddish species may be adapted to cold climates and dark reddish species to warmer climates. Thus, climate change may have a larger negative impact on pale pheomelanic owls and favour dark pheomelanic species.

Synergistic and antagonistic interaction between different branches of the immune system is related to melanin-based coloration in nestling tawny owls.

When exposed to parasites, hosts often mount energetically expensive immune responses, and this may alter resource allocation between competing life history traits including other components of the immune system. Here, we investigated whether a humoral immune challenge towards a vaccine reduces or enhances the cutaneous immune responses towards an injection of lipopolysaccharid (LPS, innate immunity) and phytohaemagglutinin (PHA, T-cell immunity) in nestling tawny owls in interaction with the degree of plumage melanin-based coloration. The humoral immune challenge enhanced the response to LPS similarly in differently coloured nestlings. In contrast, the same humoral immune challenge enhanced immune response to PHA in dark reddish melanic nestlings while reducing it in pale reddish melanic nestlings. Our results highlight that both antagonistic and synergistic interactions can take place among branches of immune system, and that the sign and magnitude of these interactions can vary with immune responses involved and the degree of melanin-based coloration.