The role of parasites in the invasion success of the exotic brine shrimp Artemia Franciscana in the Meditarranean region

Trabajo presentado en el Symposium for European Freshwater Science, celebardo en Girona del 27 de junio al 1 de julio de 2011.Biological invasions are main threats to biodiversity at global scale and increasing numbers of studies suggest that parasites may have a role. However, the mechanism through which parasites may influence the outcome of the invasion is poorly understood. Here we provide evidence supporting the role of parasites as potential agents mediating the competitive exclusion of Mediterranean brine shrimps Artemia (A. parthenogenetica and A. salina) by the exotic American A. franciscana, using different native and invasive populations from South Spain and South France. Our results revealed high rates of infection by cestodes in native brine shrimps, sometimes with extreme prevalences of up to 100%. In contrast, A. franciscana populations showed very low diversity, prevalence and burden of cestodes. The effect of parasites in native populations was multiple, ranging from reproduction and survival, to life history traits, microhabitat selection and diet. Infection strongly reduced host fitness by both, reducing fecundity (parasite castration) and indirectly increasing predation by birds final hosts as revealed by prey choice experiments. We found evidence that high rate of parasitism (particularly the castrating parasite Flamingolepis liguloides, the most prevalent cestode in natives but nearly absent in the exotic Artemia), indirectly affected the life-history strategy of non infected individuals, inducing for example earlier maturation. Moreover cestodes influenced spatial (vertical and horizontal) distribution of the host, altering the diet as revealed by isotopic analysis. Contrasting with the strong impact of parasites in native populations, we have never observed any pathology (castration, behavioural alteration, etc) associated with infection in the exotic species. Overall, the results of this study suggest that the large impact of cestode on the native, but not the invading species, is likely to confer a decisive competitive advantage to the invader, contributing to explain the demographic success of A. franciscana in the Mediterranean region.Peer reviewe

Nutrition and Inflammatory Biomarkers in Chronic Pancreatitis Patients

BackgroundChronic pancreatitis (CP) patients frequently experience malabsorption and maldigestion, leading to micronutrient and macronutrient deficiencies. Comorbid diabetes and lifestyle habits, such as alcohol consumption, may impact nutrition status.MethodsWe compared micronutrient antioxidant, bone metabolism, serum protein, and inflammatory marker levels in 301 CP patients and 266 controls with no known pancreatic disease. We analyzed serum prealbumin and retinol binding protein; vitamins A, D, E, and B12; osteocalcin; tumor necrosis factor‐α; and C‐reactive protein (CRP). We also evaluated biomarkers among subsets of patients, examining factors including time since diagnosis, body mass index, alcohol as primary etiology, diabetes mellitus, vitamin supplementation, and pancreatic enzyme replacement.ResultsAfter correcting for multiple comparisons, CP patients had significantly lower levels than controls of the following: vitamin A (40.9 vs 45.4 μg/dL) and vitamin E (α‐tocopherol [8.7 vs 10.3 mg/L] and γ‐tocopherol [1.8 vs 2.2 mg/L]), as well as osteocalcin (7.9 vs 10 ng/mL) and serum prealbumin (23 vs 27 mg/dL). Both patients and controls who took vitamin supplements had higher serum levels of vitamins than those not taking supplements. Compared with controls, in controlled analyses, CP patients had significantly lower levels of vitamins A, D, and E (both α‐tocopherol and γ‐tocopherol). CP patients also had significantly lower levels of osteocalcin, serum prealbumin, and retinol binding protein, and higher CRP.ConclusionsCP patients demonstrated lower levels of selected nutrition and bone metabolism biomarkers than controls. Diabetes and alcohol did not impact biomarkers. Vitamin supplements and pancreatic enzyme replacement therapy improved nutrition biomarkers in CP patients.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149272/1/ncp10186-sup-0001-TableS1-S4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149272/2/ncp10186.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149272/3/ncp10186_am.pd

Diverse values of nature for sustainability

Twenty-five years since foundational publications on valuing ecosystem services for human well-being(1,2), addressing the global biodiversity crisis(3) still implies confronting barriers to incorporating nature's diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever(4). Notwithstanding agreements to incorporate nature's values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)(5) and the UN Sustainable Development Goals(6), predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature(7). Arguably, a 'values crisis' underpins the intertwined crises of biodiversity loss and climate change(8), pandemic emergence(9) and socio-environmental injustices(10). On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature's diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions(7,11). Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures

Diverse values of nature for sustainability

Twenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures

ϒ production in p–Pb collisions at √sNN=8.16 TeV

ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio

Diverse values of nature for sustainability

Twenty-five years since foundational publications on valuing ecosystem services for human well-being, addressing the global biodiversity crisis still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF) and the UN Sustainable Development Goals, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change, pandemic emergence and socio-environmental injustices. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures

Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels

Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels

Towards an assessment of the potential risks associated with population control using gene drive

International audienc

Microevolution in action : a quantitative case study on natural populations of Artemia spp.

La compréhension des processus microévolutifs ayant lieu dans la nature nécessite la quantification des principales forces sélectives s'exerçant sur les populations sauvages. Ces 10 dernières années, les études à long terme et l'écologie de la résurrection (qui fait revivre des stades en dormance) ont été les principales approches pour étudier l'évolution des traits d'histoire de vie sur plusieurs générations dans les populations sauvages. Mon travail consiste à comprendre comment des facteurs écologies simples (p. ex. la température) et des interactions interspécifiques ou intraspécifiques plus complexes (p. ex. les interactions antagonistes hôte-parasite ou mâle-femelle) façonnent le processus évolutif des populations sauvages. Dans cette optique, j'ai utilisé l'Artémia comme un organisme modèle, en combinant des études sur le terrain et en laboratoire. Premièrement, j'ai étudié l'évolution de la niche thermique avec une approche d'écologie de la résurrection, en utilisant une série temporelle d'œufs de dormance d'une population d' introduite à partir de marais salants de régions tempérées dans des marais salants tropicaux dans les années 80. Cette étude montre que la survie aux températures élevées (caractéristiques du nouvel environnement) a augmenté linéairement au cours du temps à partir de l'introduction, suggérant un taux d'adaptation constant sur plus de 100 générations. Deuxièmement, j'ai utilisé une approche similaire pour étudier l'adaptation entre males et femelles dans une autre population d'Artémia. Cette étude suggère que les conflits sexuels provoquent une dynamique de coévolution fluctuante dans la nature sur une échelle d'environ 100 générations. Troisièmement, j'ai étudié les impacts respectifs de différents parasites (une espèce de cestode et deux espèces de microsporidie) sur la compétition entre une espèce d'hôte autochtone asexuée et une espèce d'hôte invasive sexuée. Chacun des trois parasites étaient soit spécialiste d'une espèce ou de certains génotypes d'hôte. De plus, l'espèce de cestode dont l'effet castrateur chez l'hôte est bien connu infectait uniquement l'espèce autochtone, suggérant que ce parasite joue un rôle majeur dans la compétition entre les espèces d'hôte autochtones et invasives. Par ailleurs, les trois espèces de parasite semblaient manipuler le comportement d'agrégation de leur hôte, très probablement pour augmenter leur transmission à de nouveaux hôtes. Enfin, j'ai réalisé des études de génétiques des populations d'espèces asexuées diploïdes et polyploïdes d'Artemia et d'espèces sexuées asiatiques proches. Les espèces asexuées diploïdes produisent des mâles rares et il semblerait que ceux-ci permettent une faible fréquence de reproduction sexuée. De plus, l'hybridation d'espèces d'Artémia éloignée phylogénétiquement a donné naissance à au moins trois lignées polyploïdes indépendantes.Getting a comprehensive understanding of microevolution in natural populations requires proper quantification of the important selective forces exerted on these populations. Over the last decade, long-term studies and resurrection-ecology (revival of resting stages) have been the main approaches to study life history trait evolution over many generations in the wild. My work aims at understanding how simple ecological factors (e.g. temperature) and complex interactions between and within species (host-parasite and male-females antagonistic interactions) shape evolutionary processes in natural populations. To this end, I used the brine shrimp Artemia as a model system and combined laboratory and field studies. First, I investigated thermal niche evolution with a resurrection ecology approach, using dormant-egg time series from an Artemia population introduced from temperate to tropical salterns in the mid-80's. This experiment shows that survival at the high temperatures typical of the new environment increased linearly through time after the introduction, suggesting a sustained rate of adaptation over more than 100 generations. Second, I used the same approach to study adaptation between sexes in another Artemia population. I found that sexual conflicts result in fluctuating male-female coevolutionary dynamics in natura, over a time scale of ~100 generations. Third, I studied the relative role of one cestode and two microsporidian parasites in mediating the competition between a native asexual host and an invasive bisexual host. I found that all three parasites were either host- or genotype-specific and that the castrating cestode parasite specifically infected the native species, suggesting that this parasite actually played a major role in the competition between native and invasive hosts. Interestingly, all three parasites manipulated the swarming behavior of their host, most likely to increase their transmission. Fourth, I performed population genetic studies of diploid and polyploid Artemia parthenogenetica and their Asian bisexual close relatives. Diploid asexual Artemia produce rare males and I found indication that these males allow some rare sex in this otherwise parthenogenetic species. In addition, hybridization between divergent Artemia species has led to the origin of at least three independent polyploid lineages