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Pasteurella multocida is one of the major causes of mass mortalities in wild birds. Here, we report the complete genome sequences of two P. multocida isolates from wild populations of two endangered seabird species, the Indian yellow-nosed albatrosses (Thalassarche carteri) and the northern rockhopper penguins (Eudyptes moseleyi).

Climate change is most strongly felt in the polar regions of the world, with significant impacts on the species that live there. The arrival of parasites and pathogens from more temperate areas may become a significant problem for these populations, but current observations of parasite presence often lack a historical reference of prior absence. Observations in the high Arctic of the seabird tick Ixodes uriae suggested that this species expanded poleward in the last two decades in relation to climate change. As this tick can have a direct impact on the breeding success of its seabird hosts and vectors several pathogens, including Lyme disease spirochaetes, understanding its invasion dynamics is essential for predicting its impact on polar seabird populations. Here, we use population genetic data and host serology to test the hypothesis that I. uriae recently expanded into Svalbard. Both black-legged kittiwakes (Rissa tridactyla) and thick-billed murres (Uria lomvia) were sampled for ticks and blood in Kongsfjorden, Spitsbergen. Ticks were genotyped using microsatellite markers and population genetic analyses were performed using data from 14 reference populations from across the tick's northern distribution. In contrast to predictions, the Spitsbergen population showed high genetic diversity and significant differentiation from reference populations, suggesting long-term isolation. Host serology also demonstrated a high exposure rate to Lyme disease spirochaetes (Bbsl). Targeted PCR and sequencing confirmed the presence of Borrelia garinii in a Spitsbergen tick, demonstrating the presence of Lyme disease bacteria in the high Arctic for the first time. Taken together, results contradict the notion that I. uriae has recently expanded into the high Arctic. Rather, this tick has likely been present for some time, maintaining relatively high population sizes and an endemic transmission cycle of Bbsl. Close future observations of population infestation/infection rates will now be necessary to relate epidemiological changes to ongoing climate modifications., (© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

The reduced species richness typical of oceanic islands provides an interesting environmental setup to examine in natura the epidemiological dynamics of infectious agents with potential implications for public health and/or conservation. On Amsterdam Island (Indian Ocean), recurrent die-offs of Indian yellow-nosed albatross (Thalassarche carteri) nestlings have been attributed to avian cholera, caused by the bacterium Pasteurella multocida. In order to help implementing efficient measures for the control of this disease, it is critical to better understand the local epidemiology of P. multocida and to examine its inter- and intra-annual infection dynamics. We evaluated the infection status of 264 yellow-nosed albatrosses over four successive breeding seasons using a real-time PCR targeting P. multocida DNA from cloacal swabs. Infection prevalence patterns revealed an intense circulation of P. multocida throughout the survey, with a steady but variable increase in infection prevalence within each breeding season. These epizootics were associated with massive nestling dies-offs, inducing very low fledging successes (≤ 20%). These results suggest important variations in the transmission dynamics of this pathogen. These findings and the developed PCR protocol have direct applications to guide future research and refine conservation plans aiming at controlling the disease.

Despite critical implications for disease dynamics and surveillance in wild long-lived species, the immune response after exposure to potentially highly pathogenic bacterial disease agents is still poorly known. Among infectious diseases threatening wild populations, avian cholera, caused by the bacterium Pasteurella multocida, is a major concern. It frequently causes massive mortality events in wild populations, notably affecting nestlings of Indian yellow-nosed albatrosses (Thalassarche carteri) in the Indian Ocean. If adults are able to mount a long-term immune response, this could have important consequences regarding the dynamics of the pathogen in the local host community and the potential interest of vaccinating breeding females to transfer immunity to their offspring. By tracking the dynamics of antibodies against P. multocida during 4 years and implementing a vaccination experiment in a population of yellow-nosed albatrosses, we show that a significant proportion of adults were naturally exposed despite high annual survival for both vaccinated and non-vaccinated individuals. Adult-specific antibody levels were thus maintained long enough to inform about recent exposure. However, only low levels of maternal antibodies could be detected in nestlings the year following a vaccination of their mothers. A modification of the vaccine formulation and the possibility to re-vaccinate females 2 years after the first vaccination revealed that vaccines have the potential to elicit a stronger and more persistent response. Such results highlight the value of long-term observational and experimental studies of host exposure to infectious agents in the wild, where ecological and evolutionary processes are likely critical for driving disease dynamics.

Spatio-temporally stable prey distributions coupled with individual foraging site fidelity are predicted to favour individual resource specialisation. Conversely, predators coping with dynamic prey distributions should diversify their individual diet and/or shift foraging areas to increase net intake. We studied individual specialisation in Scopoli's shearwaters (Calonectris diomedea) from the highly dynamic Western Mediterranean, using daily prey distributions together with resource selection, site fidelity and trophic-level analyses. As hypothesised, we found dietary diversification, low foraging site fidelity and almost no individual specialisation in resource selection. Crucially, shearwaters switched daily foraging tactics, selecting areas with contrasting prey of varying trophic levels. Overall, information use and plastic resource selection of individuals with reduced short-term foraging site fidelity allow predators to overcome prey field lability. Our study is an essential step towards a better understanding of individual responses to enhanced environmental stochasticity driven by global changes, and of pathways favouring population persistence., (© 2018 John Wiley & Sons Ltd/CNRS.)

The peculiar features of domain walls observed in ferroelectrics make them promising active elements for next-generation non-volatile memories, logic gates and energy-harvesting devices. Although extensive research activity has been devoted recently to making full use of this technological potential, concrete realizations of working nanodevices exploiting these functional properties are yet to be demonstrated. Here, we fabricate a multiferroic tunnel junction based on ferromagnetic La 0.7 Sr 0.3 MnO 3 electrodes separated by an ultrathin ferroelectric BaTiO 3 tunnel barrier, where a head-to-head domain wall is constrained. An electron gas stabilized by oxygen vacancies is confined within the domain wall, displaying discrete quantum-well energy levels. These states assist resonant electron tunnelling processes across the barrier, leading to strong quantum oscillations of the electrical conductance.

Spatial disease ecology is emerging as a new field that requires the integration of complementary approaches to address how the distribution and movements of hosts and parasites may condition the dynamics of their interactions. In this context, migration, the seasonal movement of animals to different zones of their distribution, is assumed to play a key role in the broad scale circulation of parasites and pathogens. Nevertheless, migration is not the only type of host movement that can influence the spatial ecology, evolution, and epidemiology of infectious diseases. Dispersal, the movement of individuals between the location where they were born or bred to a location where they breed, has attracted attention as another important type of movement for the spatial dynamics of infectious diseases. Host dispersal has notably been identified as a key factor for the evolution of host-parasite interactions as it implies gene flow among local host populations and thus can alter patterns of coevolution with infectious agents across spatial scales. However, not all movements between host populations lead to dispersal per se. One type of host movement that has been neglected, but that may also play a role in parasite spread is prospecting, i.e., movements targeted at selecting and securing new habitat for future breeding. Prospecting movements, which have been studied in detail in certain social species, could result in the dispersal of infectious agents among different host populations without necessarily involving host dispersal. In this article, we outline how these various types of host movements might influence the circulation of infectious disease agents and discuss methodological approaches that could be used to assess their importance. We specifically focus on examples from work on colonial seabirds, ticks, and tick-borne infectious agents. These are convenient biological models because they are strongly spatially structured and involve relatively simple communities of interacting species. Overall, this review emphasizes that explicit consideration of the behavioral and population ecology of hosts and parasites is required to disentangle the relative roles of different types of movement for the spread of infectious diseases., (© The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.)

Repeated deep dives are highly pro-oxidative events for air-breathing aquatic foragers such as penguins. At fledging, the transition from a strictly terrestrial to a marine lifestyle may therefore trigger a complex set of anti-oxidant responses to prevent chronic oxidative stress in immature penguins but these processes are still undefined. By combining in vivo and in vitro approaches with transcriptome analysis, we investigated the adaptive responses of sea-acclimatized (SA) immature king penguins (Aptenodytes patagonicus) compared with pre-fledging never-immersed (NI) birds. In vivo, experimental immersion into cold water stimulated a higher thermogenic response in SA penguins than in NI birds, but both groups exhibited hypothermia, a condition favouring oxidative stress. In vitro, the pectoralis muscles of SA birds displayed increased oxidative capacity and mitochondrial protein abundance but unchanged reactive oxygen species (ROS) generation per g tissue because ROS production per mitochondria was reduced. The genes encoding oxidant-generating proteins were down-regulated in SA birds while mRNA abundance and activity of the main antioxidant enzymes were up-regulated. Genes encoding proteins involved in repair mechanisms of oxidized DNA or proteins and in degradation processes were also up-regulated in SA birds. Sea life also increased the degree of fatty acid unsaturation in muscle mitochondrial membranes resulting in higher intrinsic susceptibility to ROS. Oxidative damages to protein or DNA were reduced in SA birds. Repeated experimental immersions of NI penguins in cold-water partially mimicked the effects of acclimatization to marine life, modified the expression of fewer genes related to oxidative stress but in a similar way as in SA birds and increased oxidative damages to DNA. It is concluded that the multifaceted plasticity observed after marine life may be crucial to maintain redox homeostasis in active tissues subjected to high pro-oxidative pressure in diving birds. Initial immersions in cold-water may initiate an hormetic response triggering essential changes in the adaptive antioxidant response to marine life., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The passage from shore to marine life is a critical step in the development of juvenile penguins and is characterized by a fuel selection towards lipid oxidation concomitant to an enhancement of lipid-induced thermogenesis. However, mechanisms of such thermogenic improvement at fledging remain undefined. We used two different groups of pre-fledging king penguins (Aptenodytes patagonicus) to investigate the specific contribution of cold exposure during water immersion to lipid metabolism. Terrestrial penguins that had never been immersed in cold water were compared with experimentally cold-water immersed juveniles. Experimentally immersed penguins underwent ten successive immersions at approximately 9-10 °C for 5 h over 3 weeks. We evaluated adaptive thermogenesis by measuring body temperature, metabolic rate and shivering activity in fully immersed penguins exposed to water temperatures ranging from 12 to 29 °C. Both never-immersed and experimentally immersed penguins were able to maintain their homeothermy in cold water, exhibiting similar thermogenic activity. In vivo, perfusion of lipid emulsion at thermoneutrality induced a twofold larger calorigenic response in experimentally immersed than in never-immersed birds. In vitro, the respiratory rates and the oxidative phosphorylation efficiency of isolated muscle mitochondria were not improved with cold-water immersions. The present study shows that acclimation to cold water only partially reproduced the fuel selection towards lipid oxidation that characterizes penguin acclimatization to marine life.

The borrowing hydrogen methodology allows for the use of alcohols as alkylating agents for CC bond forming processes offering significant environmental benefits over traditional approaches. Iridium(I)-cyclooctadiene complexes having a NHC ligand with a O- or N-functionalised wingtip efficiently catalysed the oxidation and β-alkylation of secondary alcohols with primary alcohols in the presence of a base. The cationic complex [Ir(NCCH3 )(cod)(MeIm(2- methoxybenzyl))][BF4 ] (cod=1,5-cyclooctadiene, MeIm=1-methylimidazolyl) having a rigid O-functionalised wingtip, shows the best catalyst performance in the dehydrogenation of benzyl alcohol in acetone, with an initial turnover frequency (TOF0 ) of 1283 h(-1) , and also in the β-alkylation of 2-propanol with butan-1-ol, which gives a conversion of 94 % in 10 h with a selectivity of 99 % for heptan-2-ol. We have investigated the full reaction mechanism including the dehydrogenation, the cross-aldol condensation and the hydrogenation step by DFT calculations. Interestingly, these studies revealed the participation of the iridium catalyst in the key step leading to the formation of the new CC bond that involves the reaction of an O-bound enolate generated in the basic medium with the electrophilic aldehyde., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Here we study the electronic properties of cuprate-manganite interfaces. By means of atomic resolution electron microscopy and spectroscopy, we produce a subnanometer scale map of the transition metal oxidation state profile across the interface between the high Tc superconductor YBa2Cu3O7-δ and the colossal magnetoresistance compound (La,Ca)MnO3. A net transfer of electrons from manganite to cuprate with a peculiar nonmonotonic charge profile is observed. Model calculations rationalize the profile in terms of the competition between standard charge transfer tendencies (due to band mismatch), strong chemical bonding effects across the interface, and Cu substitution into the Mn lattice, with different characteristic length scales.

During the cold austral winter, king penguin chicks are infrequently fed by their parents and thus experience severe nutritional deprivation under harsh environmental conditions. These energetic constraints lead to a range of energy sparing mechanisms balanced by the maintenance of efficient thermogenic processes. The present work investigated whether the high thermogenic capacities exhibited by winter-acclimatized king penguin chicks could be related to an increase in lipid substrate supply and oxidation in skeletal muscle, the main site of thermogenesis in birds. To test this hypothesis, we examined i) the effect of an experimental rise in plasma triglyceride on the whole metabolic rate in winter-acclimatized (WA) and de-acclimatized king penguin chicks kept at thermoneutrality (TN), and ii) investigated the fuel preference of muscle mitochondria. In vivo, a perfusion of a lipid emulsion induced a small 10% increase of metabolic rate in WA chicks but not in TN group. In vitro, the oxidation rate of muscle mitochondria respiring on lipid-derived substrate was +40% higher in WA chicks than in TN, while no differences were found between groups when mitochondria oxidized carbohydrate-derived substrate or succinate. Despite an enhanced fuel selection towards lipid oxidation in skeletal muscle, a rise of circulating lipids per se was not sufficient to fully unravel the thermogenic capacity of winter-acclimatized king penguin chicks., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The passage from shore to marine life of juvenile penguins represents a major energetic challenge to fuel intense and prolonged demands for thermoregulation and locomotion. Some functional changes developed at this crucial step were investigated by comparing pre-fledging king penguins with sea-acclimatized (SA) juveniles (Aptenodytes patagonicus). Transcriptomic analysis of pectoralis muscle biopsies revealed that most genes encoding proteins involved in lipid transport or catabolism were upregulated, while genes involved in carbohydrate metabolism were mostly downregulated in SA birds. Determination of muscle enzymatic activities showed no changes in enzymes involved in the glycolytic pathway, but increased 3-hydroxyacyl-CoA dehydrogenase, an enzyme of the β-oxidation pathway. The respiratory rates of isolated muscle mitochondria were much higher with a substrate arising from lipid metabolism (palmitoyl-L-carnitine) in SA juveniles than in terrestrial controls, while no difference emerged with a substrate arising from carbohydrate metabolism (pyruvate). In vivo, perfusion of a lipid emulsion induced a fourfold larger thermogenic effect in SA than in control juveniles. The present integrative study shows that fuel selection towards lipid oxidation characterizes penguin acclimatization to marine life. Such acclimatization may involve thyroid hormones through their nuclear beta receptor and nuclear coactivators.

The efficiency and aberration of partitioned-field uniaxial volume holographic compound lenses are theoretically and experimentally studied. These systems increase the image fields of holographic volume lenses, limited by the angular selectivity that is typical of these elements. At the same time, working with uniaxial systems has led to a decrease in aberration because two recording points (that behave as aberration-free points) are used. The extension of the image field is experimentally proved.

Cryoglobulins are immunoglobulins characterized by precipitating when serum is cooled and redissolving when serum is heated. There is strong evidence to consider mixed cryoglobulins as circulating immunocomplexes, and various investigators have applied the precipitating physical property as a method to isolate immunocomplexes. In the recent years some authors have reported the presence of cryoglobulins in acute and chronic liver diseases of diverse etiology. This study investigates the presence of cryoglobulins in 34 patients with different liver diseases. Mixed cryoglobulins were detected in eight patients (23.5 percent), but only three of them had clinical symptoms attributable to the existence of cryoglobulins. In relation to the etiology of the liver disease, the highest frequency has been found among patients with hepatopathies of undetermined origin.

Cryoglobulins are serum immunoglobulins which precipitate in the cold and redissolve on warming at 37 degrees C. According to its immunochemical composition three different types have been described. Cryoglobulins have been reported associated with hematologic disorders, systemic diseases, infectious conditions, and diseases of the liver and kidneys. There is also an idiopathic variant called essential cryoglobulinemia. Five patients (four males) with mixed essential cryoglobulinemia are reported. Common clinical manifestations included fever, articular symptoms, purpura, glomerulonephritis, Raynaud's phenomenon, erythematomacular cutaneous eruption, polyneuritis and abdominal pain. Serum activity of rheumatoid factor has been detected in three cases; in other three decreased levels of serum complement have been found. Serum HBsAg was negative in four cases (passive hemagglutination technique). It is possible that all cases of mixed essential cryoglobulinemia may correspond to bacterial, viral or fungal occult infections.

Cryoglobulins are immunoglobulins characterized by precipitating when serum is cooled and redissolving when serum is heated. There is strong evidence to consider mixed cryoglobulins as circulating immunocomplexes. Cryoglobulins have been demonstrated in association to hematologic, hepatic, lymphoproliferative, autoimmune and infectious conditions. There is also an essential or idiopathic variant. The present report studies a series of 70 patients with several rheumatic and systemic diseases, and a group of ten patients with cutaneous vasculitis. Significant levels of cryoglobulins have been detected in nine cases (overall incidence 12.8 percent). The diagnoses corresponding to these patients were as follows: systemic lupus erythematosus in three cases, dermatopolymyositis in three cases, Sjögren's syndrome in two cases, and Wegener's granulomatosis in one case. Cryoglobulins could not be demonstrated in patients with rheumatoid artritis, sclerodermia, periarteritis nodosa, cutaneous vasculitis, Reiter's syndrome, ankylosing spondilitis and acute articular rheumatism. Among patients with systemic lupus erythematosus a good correlation has been observed between the presence of serum cryoglobulins, the activity and severity of the diseases and the decrease of serum complement levels.