648 research outputs found
Particle-structure interaction using cad-based boundary descriptions and isogeometric B-REP analysis (IBRA)
The procedure and the properties with the use of NURBS-described CAD models in particle-structure interaction are presented within this contribution. This implies the needed entities of those models and the description of trimmed multipatches to discretize analysis suitable numerical models. Finally, the properties will be shown with some test cases in comparison to analytical benchmarks and simulations with FEM as
boundary description
Results from Bottom Trawl Survey on Flemish Cap of June-July 2017
A stratified random bottom trawl survey on Flemish Cap was carried out from June 16th to July 15th 2017. The area surveyed was extended up to depths of 800 fathoms (1460 meters) following the same procedures as in previous years and 181 fishing stations planned. The survey was carried out by the R/V Vizconde de Eza with the usual survey gear (Lofoten). A total of 181 valid hauls were made by the vessel R/V Vizconde de Eza, 120 up to 730 meters depth and 61 up to 1460 meters. Survey results including abundance indices of the main commercial species and age distributions for American plaice, Greenland halibut, roughhead grenadier and shrimp are presented. Cod and redfish age distributions are not available for 2017 due to administrative problems. The general indexes for this year are estimated taken into account the traditional swept area (strata 1-19, up to depths of 730 m.) and the total area surveyed (strata 1-34, up to depths of 1460 m.).Versión del editor
Hematologic and biochemical values for spanish ibex (Capra Pyrenaica) captured via drive-net and box-trap
Between October 2002 and September 2004, 70 free-ranging Spanish ibex (Capra pyrenaica) were captured in Catalonia, northeastern Spain, using two different physical methods, drive-net (n=26) and box-trap (n=44). Blood samples were taken to determine 20 hematologic and 23 biochemical variables. Values obtained fell within already published reference intervals, with the following exceptions: higher values for red blood cells (RBC), packed cell volume (PCV), white blood cells (WBC), eosinophil count, triglyceride concentration, creatine kinase (CK; in box-trap), chloride, sodium, alpha-1, alpha-2, and gamma electrophoretic fractions of serum proteins; and lower values for hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), urea concentration, CK (in drive-net), albumin, and albumin:globulins ratio (A:G). Published values for aspartate aminotransferase (AST) concentration are both higher and lower than observed in this study. In our study, monocyte and eosinophil counts, as well as triglyceride and potassium concentrations, were lower in animals captured via box-trap than those captured via drive-net. Conversely, MCHC, neutrophil count, total bilirubin concentration, urea, and AST were higher in animals captured via box-trap. Hematologic and biochemical values obtained from Spanish ibexes show that the drive-net is a newer, less-stressful method of capture than the box-trap
Haloperidol and Azaperone in Drive-net Captured Southern Chamois (Rupicapra pyrenaica)
We investigated the effect of haloperidol and azaperone in drive-net captured Southern chamois (Rupicapra pyrenaica). Both tranquilizers have been successfully used in a wide range of wild species for reducing postcapture stress response. During 2005, 39 free-ranging chamois were captured, randomly injected intramuscularly with haloperidol (0.29 +/- 0.12 mg/kg; n=24), azaperone (1.1 +/- 0.82 mg/kg; n=6), or saline (0.5 ml; n=9), and restrained for 3 hr. Heart rate was higher in the treated chamois; erythrocyte parameters and total protein concentration decreased over time owing to splenic sequestration, hemodilution, vasodilation, and reflex tachycardia. Creatinine, sodium, and chloride remained stable only in the haloperidol-treated group, suggesting an improvement in renal perfusion. Nevertheless, the azaperone-treated chamois displayed higher body temperature, and both treated groups had higher serum muscular enzymes than the control group, suggesting higher muscle stress. These results lead us not to recommend the use of these tranquilizers-especially azaperone-as first-choice neuroleptics in chamois
Enlarging the window for radiative leptogenesis
We investigate the scenario of resonant thermal leptogenesis, in which the
leptonic asymmetries are generated through renormalization group corrections
induced at the leptogenesis scale. In the framework of the standard model
extended by three right-handed heavy Majorana neutrinos with masses M1 = M2 <<
M3 at some high scale, we show that the mass splitting and CP-violating effects
induced by renormalization group corrections can lead to values of the CP
asymmetries large enough for a successful leptogenesis. In this scenario, the
low-energy neutrino oscillation data can also be easily accommodated. The
possibility of having an underlying symmetry behind the degeneracy in the
right-handed neutrino mass spectrum is also discussed.Comment: 20 pages, 2 figures, final version to appear in Phys. Lett.
Chemical Modification of a Dehydratase Enzyme Involved in Bacterial Virulence by an Ammonium Derivative: Evidence of its Active Site Covalent Adduct
The first example of an ammonium derivative that causes a specific modification of the active site of type I dehydroquinase (DHQ1), a dehydratase enzyme that is a promising target for antivirulence drug discovery, is described. The resolution at 1.35 Å of the crystal structure of DHQ1 from Salmonella typhi chemically modified by this ammonium derivative revealed that the ligand is covalently attached to the essential Lys170 through the formation of an amine. The detection by mass spectroscopy of the reaction intermediates, in conjunction with the results of molecular dynamics simulations, allowed us to explain the inhibition mechanism and the experimentally observed differences between S. typhi and Staphylococcus aureus enzymes. The results presented here reveal that the replacement of Phe225 in St-DHQ1 by Tyr214 in Sa-DHQ1 and its hydrogen bonding interaction with the conserved water molecule observed in several crystal structures protects the amino adduct against further dehydration/aromatization reactions. In contrast, for the St-DHQ1 enzyme, the carboxylate group of Asp114, with the assistance of this water molecule, would trigger the formation of a Schiff base that can undergo further dehydration reactions until full aromatization of the cyclohexane ring is achieved. Moreover, in vitro antivirulence studies showed that the reported compound is able to reduce the ability of Salmonella Enteritidis to kill A459 respiratory cells. These studies have identified a good scaffold for the design of irreversible inhibitors that can be used as drugs and has opened up new opportunities for the development of novel antivirulence agents by targeting the DHQ1 enzymeFinancial support from the Spanish Ministry of Science and
Innovation (SAF2013-42899-R), Xunta de Galicia (GRC2013-041), and the European Regional Development Fund (ERDF)
is gratefully acknowledged. E.L. thanks the Xunta de Galicia for
his postdoctoral fellowship. A.B. thanks the Miguel Servet
Programme ISCIII-FEDER (CP13/00226) and the ISCIIIGeneral
Subdirection of Assesment and Promotion of the
Research (PI14/00059) for financial supportS
Marine copepods shift in seasonal amplitude and synchronicity in the northwest Iberian shelf driven by meteo-hydrographic forcing
An Assessment of Beaked Redfish (S. mentella and S. fasciatus) in NAFO Division 3M (at times when natural mortality is driven stock dynamics and fishing mortality reference points are useless to scientific advice)
The 3M redfish assessment is focused on the beaked redfish, regarded as a management unit composed of two populations from two very similar species: the Flemish Cap S. mentella and S. fasciatus. The reason for this approach is the historical dominance of this group in the 3M redfish commercial catch until 2005. However a new golden redfish fishery (S. marinus) started on September 2005 on shallower depths of the Flemish Cap bank above 300m, and the Flemish Cap cod fishery reopened in 2010. These new realities implied a revision of catch estimates, in order to split recent redfish commercial catch and by-catch from the major fleets on Div. 3M into golden (S. marinus) and beaked (S. mentella and S. fasciatus) redfish catches.
The Extended Survivor Analysis assessment used as tuning file the 1989-2014 EU survey abundance at age matrix included in a revised input framework. Continuing pressure over Flemish Cap redfish stocks by cod predation, at levels higher, or much higher, than the levels prior to 2006 lead to higher natural mortalities since then. Natural mortality have been tuned to survey at age data 2006 onwards by the sensitivity analysis preceding each assessment, and on 2013-2104 has a best estimate at slightly higher level from previous years. A 2015-2011 retrospective XSA was carried out, confirming that the present assessment is very much in line with their immediate predecessors
Study of the Phosphoryl‐Transfer Mechanism of Shikimate Kinase by NMR Spectroscopy
This is the peer-reviewed version of the following article: Prado, V., Lence, E., Vallejo, J., Beceiro, A., Thompson, P., Hawkins, A., & González-Bello, C. (2016). Study of the Phosphoryl-Transfer Mechanism of Shikimate Kinase by NMR Spectroscopy. Chemistry - A European Journal, 22(8), 2758-2768, which has been published in final form at https://doi.org/10.1002/chem.201504438. This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-ArchivingThe phosphoryl‐transfer mechanism of shikimate kinase from Mycobacterium tuberculosis and Helicobacter pylori, which is an attractive target for antibiotic drug discovery, has been studied by 1D 1H and 31P NMR spectroscopy. Metaphosphoric acid proved to be a good mimetic of the metaphosphate intermediate and facilitated the ready and rapid evaluation by NMR spectroscopic analysis of a dissociative mechanism. The required closed form of the active site for catalysis was achieved by the use of ADP (product) or two synthetic ADP analogues (AMPNP, AMPCP). Molecular dynamics simulation studies reported here also revealed that the essential arginine (Arg116/Arg117 in H. pylori and M. tuberculosis, respectively), which activates the γ‐phosphate group of ATP for catalysis and triggers the release of the product for turnover, would also be involved in the stabilisation of the metaphosphate intermediate during catalysis. We believe that the studies reported here will be helpful for future structure‐based design of inhibitors of this attractive target. The approach is also expected be useful for studies on the possible dissociative mechanism of other kinase enzymesSpanish Ministry of Economy and Competiveness. Grant Number: SAF2013-42899-R
Xunta de Galicia. Grant Number: GRC2013-041
European Regional Development Fund
Sara Borrell Programme. Grant Number: CD13/00373
ISCIII General Subdirection of Assesment and Promotion of the Research. Grant Number: PI14/00059S
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