787 research outputs found

    Three-Body Halo States in Effective Field Theory: Renormalization and Three-Body Interactions in the Helium-6 System

    Get PDF
    In this paper we study the renormalization of Halo effective field theory applied to the Helium-6 halo nucleus seen as an alpha-neutron-neutron three-body state. We include the 0(+) dineutron channel together with both the 3/2(-) and 1/2(-) neutron-alpha channels into the field theory and study all of the six lowest-order three-body interactions that are present. Furthermore, we discuss three different prescriptions to handle the unphysical poles in the P-wave two-body sector. In the simpler field theory without the 1/2(-) channel present we find that the bound-state spectrum of the field theory is renormalized by the inclusion of a single three-body interaction. However, in the field theory with both the 3/2(-) and 1/2(-) included, the system can not be renormalized by only one three-body operator

    Incorporating molecular data in fungal systematics: a guide for aspiring researchers

    Full text link
    The last twenty years have witnessed molecular data emerge as a primary research instrument in most branches of mycology. Fungal systematics, taxonomy, and ecology have all seen tremendous progress and have undergone rapid, far-reaching changes as disciplines in the wake of continual improvement in DNA sequencing technology. A taxonomic study that draws from molecular data involves a long series of steps, ranging from taxon sampling through the various laboratory procedures and data analysis to the publication process. All steps are important and influence the results and the way they are perceived by the scientific community. The present paper provides a reflective overview of all major steps in such a project with the purpose to assist research students about to begin their first study using DNA-based methods. We also take the opportunity to discuss the role of taxonomy in biology and the life sciences in general in the light of molecular data. While the best way to learn molecular methods is to work side by side with someone experienced, we hope that the present paper will serve to lower the learning threshold for the reader.Comment: Submitted to Current Research in Environmental and Applied Mycology - comments most welcom

    l-α-Lysophosphatidylinositol (LPI) aggravates myocardial ischemia/reperfusion injury via a GPR55/ROCK-dependent pathway

    Get PDF
    The phospholipid l-α-lysophosphatidylinositol (LPI), an endogenous ligand for GPR55, is elevated in patients with acute coronary syndrome, and a GPR55 antagonist cannabidiol (CBD) reduces experimental ischemia/reperfusion (I/R) injury. While LPI activates multiple signaling pathways, little is known about which ones are important in cardiomyocytes. In this study we explored whether activation of the Rho kinase/ROCK/p38 MAPK pathway is responsible for LPI-induced extension of I/R injury. Using a high-throughput screening method (dynamic mass redistribution; DMR), mouse- and human-induced pluripotent stem cell (iPSC) cardiomyocytes exposed to LPI were shown to exhibit a rapid, sustained, and concentration‐dependent (1 nmol L−1‐30 ÎŒmol L−1) cellular response. Y‐27632 (ROCK inhibitor; 10 & 50 ÎŒmol L−1) and CBD (1 ÎŒmol L−1) both abolished the DMR response to LPI (10 ÎŒmol L−1). In murine iPSC cardiomyocytes, LPI-induced ROCK and p38 MAPK phosphorylation, both of which were prevented by Y-27632 and CBD, but did not induce JNK activation or cleavage of caspase-3. In hearts isolated from wild type (WT) mice subjected to 30 minutes global I/R, LPI (10 ÎŒmol L−1) administered via the coronary circulation increased infarct size when applied prior to ischemia onset, but not when given at the time of reperfusion. The exacerbation of tissue injury by LPI was not seen in hearts from GPR55−/− mice or in the presence of Y-27632, confirming that injury is mediated via the GPR55/ROCK/p38 MAPK pathway. These findings suggest that raised levels of LPI in the vicinity of a developing infarct may worsen the outcome of AMI

    Pharmacological profiling of the hemodynamic effects of cannabinoid ligands: a combined in vitro and in vivo approach.

    Get PDF
    The receptors mediating the hemodynamic responses to cannabinoids are not clearly defined due to the multifarious pharmacology of many commonly used cannabinoid ligands. While both CB1 and TRPV1 receptors are implicated, G protein-coupled receptor 55 (GPR55) may also mediate some of the hemodynamic effects of several atypical cannabinoid ligands. The present studies attempted to unravel the pharmacology underlying the in vivo hemodynamic responses to ACEA (CB1 agonist), O-1602 (GPR55 agonist), AM251 (CB1 antagonist), and cannabidiol (CBD; GPR55 antagonist). Agonist and antagonist profiles of each ligand were determined by ligand-induced GTPcS binding in membrane preparations expressing rat and mouse CB1 and GPR55 receptors. Blood pressure responses to ACEA and O-1602 were recorded in anesthetized and conscious mice (wild type, CB1 / and GPR55 / ) and rats in the absence and presence of AM251 and CBD. ACEA demonstrated GTPcS activation at both receptors, while O-1602 only activated GPR55. AM251 exhibited antagonist activity at CB1 and agonist activity at GPR55, while CBD demonstrated selective antagonist activity at GPR55. The depressor response to ACEA was blocked by AM251 and attenuated by CBD, while O-1602 did not induce a depressor response. AM251 caused a depressor response that was absent in GPR55 / mice but enhanced by CBD, while CBD caused a small vasodepressor response that persisted in GPR55 / mice. Our findings show that assessment of the pharmacological profile of receptor activation by cannabinoid ligands in in vitro studies alongside in vivo functional studies is essential to understand the role of cannabinoids in hemodynamic control

    Succinate receptor GPR91, a Gαi coupled receptor that increases intracellular calcium concentrations through PLCÎČ

    Get PDF
    AbstractSuccinate has been reported as the endogenous ligand for GPR91. In this study, succinate was confirmed to activate GPR91 resulting in both 3â€Č–5â€Č-cyclic adenosine monophosphate (cAMP) inhibition and inositol phosphate formation in a pertussis toxin (PTX)-sensitive manner. GPR91 agonist-mediated effects detected using dynamic mass redistribution (DMR) were inhibited with PTX, edelfosine and U73122 demonstrating the importance of not only the Gαi pathway but also PLCÎČ. These results show that GPR91 when expressed in HEK293s cells couples exclusively through the Gαi pathway and acts through Gαi not only to inhibit cAMP production but also to increase intracellular Ca2+ in an inositol phosphate dependent mechanism via PLCÎČ activation

    On the socio-technical potential for onshore wind in Europe : a response to Enevoldsen et al. (2019), Energy Policy, 132, 1092-1100

    Get PDF
    Acknoweldgements: S.W. and J.S. received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (reFUEL, grant agreement No. 758149). J.L. and T.T. received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 715132).Peer reviewedPostprin

    Topical and Systemic Cannabidiol Improves Trinitrobenzene Sulfonic Acid Colitis in Mice

    Get PDF
    Background/Aims: Compounds of Cannabis sativa are known to exert anti-inflammatory properties, some of them without inducing psychotropic side effects. Cannabidiol (CBD) is such a side effect-free phytocannabinoid that improves chemically induced colitis in rodents when given intraperitoneally. Here, we tested the possibility whether rectal and oral application of CBD would also ameliorate colonic inflammation, as these routes of application may represent a more appropriate way for delivering drugs in human colitis. Methods: Colitis was induced in CD1 mice by trinitrobenzene sulfonic acid. Individual groups were either treated with CBD intraperitoneally (10 mg/kg), orally (20 mg/kg) or intrarectally (20 mg/kg). Colitis was evaluated by macroscopic scoring, histopathology and the myeloperoxidase (MPO) assay. Results: Intraperitoneal treatment of mice with CBD led to improvement of colonic inflammation. Intrarectal treatment with CBD also led to a significant improvement of disease parameters and to a decrease in MPO activity while oral treatment, using the same dose as per rectum, had no ameliorating effect on colitis. Conclusion: The data of this study indicate that in addition to intraperitoneal application, intrarectal delivery of cannabinoids may represent a useful therapeutic administration route for the treatment of colonic inflammation. Copyright (C) 2012 S. Karger AG, Base

    Food-web structure in relation to environmental gradients and predator-prey ratios in tank-bromeliad ecosystems

    Get PDF
    Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators: prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests
    • 

    corecore