203 research outputs found
Tricritical behavior of the frustrated XY antiferromagnet
Extensive histogram Monte-Carlo simulations of the XY antiferromagnet on a
stacked triangular lattice reveal exponent estimates which strongly favor a
scenario of mean-field tricritical behavior for the spin-order transition. The
corresponding chiral-order transition occurs at the same temperature but
appears to be decoupled from the spin-order. These results are relevant to a
wide class of frustrated systems with planar-type order and serve to resolve a
long-standing controversy regarding their criticality.Comment: J1K 2R1 4 pages (RevTex 3.0), 4 figures available upon request,
Report# CRPS-94-0
Annual cycle of zooplankton biomass, abundance and species composition in the neritic area of the Balearic Sea, western Mediterranean
Publicado
Complexity in Spanish optical fiber and SDH transport networks
Complex networks are important instances of technology-related complex systems. In this work we apply tools from complexity science to characterise two Telefónica España transport network systems: the optical fiber network and the SDH transport network. We compare both cases and derive its most important properties. Remarkably, our results show that in both cases several features of heterogeneous, hierarchical complex networks arise
ARE SETS ON YFT NOT ASSOCIATED WITH FLOATING OBJECTS REALLY FREE SCHOOLS SETS? IMPLICATIONS ON FISHING EFFORT
Updating the statistics reported for the EU-Spain purse seine fishing fleet in the Indian Ocean (period 1984-2019) and the effects of the COVID-19 pandemic on the port sampling activity in Victoria (Seychelles)
This document provides an update on the statistics reported for the Spanish purse seine fleet fisheries in the Indian Ocean for the period 1984 to 2019. Data include catch and effort statistics, as well as some fishery indicators by species and fishing mode. Information about the coverage of the sampling, together with maps and diagrams illustrating the spatial-temporal fishing patterns of this fleet are also provided
Data Provision for Science-Based FAD Fishery Management: Spanish FAD Management Plan as a Case Study
The use of fish aggregating devices (FADs) in tropical tuna fisheries has increased significantly during recent decades. Concurrently, concern about juvenile tuna mortality, bycatch, and marine debris associated with FAD fisheries increased, and this led to the implementation of FAD management measures and more sustainable designs (e.g., non-entangling or biodegradable FADs, limits on active FADs, etc.). This document reviews data collection and reporting requirements of tuna-Regional Fisheries Management Organizations (t-RFMOs) on drifting FADs and summarizes the work carried out since 2010 under the Spanish FAD management plan to create an adequate standard data collection aimed at improving science-based decision making. The aim of this study is to assist in the strengthening of data collection systems through: (1) a review of the existing data requirements, (2) a review of the status of FAD data collection worldwide and identification of data gaps, and (3) recommendations aimed at improving FAD management through the strengthening of FAD data requirements. Due to the complexities of data collection, we summarize the difficulties faced when processing the data and propose concrete and practical solutions to improve both the data collection system and information quality.Postprin
Immunomodulation induced by synthetic peptides derived from Staphylococcus aureus protein A
Peptides from 10 to 22 amino acids containing sequences encompassed by Staphylococcus aureus protein A were synthesized. Some of these peptides, when present in cultures of lymphomononuclear cells from healthy donors or from cancer patients (melanoma, breast carcinoma, non-Hodgkin lymphoma and renal cell carcinoma) promoted: (i) changes in the phenotype of the lymphomononuclear population, (ii) stimulation of monocytes (release of IL-1 and TNF-alpha), and (iii) an increase in cytotoxicity against K562, Daudi and HT-29 cells. Isolated monocytes responded also to those peptides with a release of IL-1 and TNF alpha and an increase of cytotoxicity against HT-29 cells. It was found that the active peptides had the following structural pattern: a length of at least 15 amino-acid residues with a proline at position 6, valine, leucine, isoleucine, glycine, alanine or lysine at position 2, and glutamic or aspartic acid at position 11. Replacement of Pro at position 6 with any other residue turned the peptide inactive. Replacement of residues at positions 2 and 11 with amino-acid residues other than those required for activity resulted in compounds with a marked decrease in the immunomodulating properties described, or lacking these properties altogether
Triple configuration coexistence in 44 S
The neutron-rich N=28 nucleus S44 was studied using the two-proton knockout reaction from Ar46 at intermediate beam energy. We report the observation of four new excited states, one of which is a strongly prolate deformed 4 + state, as indicated by a shell-model calculation. Its deformation originates in a neutron configuration which is fundamentally different from the "intruder" configuration responsible for the ground-state deformation. Consequently, we do not have three coexisting shapes in S44, but three coexisting configurations, corresponding to zero-, one-, and two-neutron particle-hole excitations. � 2011 American Physical Society
Co-expression of inducible nitric oxide synthase and arginases in different human monocyte subsets. Apoptosis regulated by endogenous NO
Human monocyte subsets, isolated from cultures of mononuclear cells, or freshly obtained from patients with multiple sclerosis, Graves' disease or pemphigus vulgaris, differed in phenotype, apoptotic features, mRNA levels of arginase II (A-II) and the inducible form of nitric oxide synthase (iNOS). Liver-type arginase I mRNA was present in all subsets. Apoptosis was followed by the expression of T cell intracellular antigen (TIA) and the simultaneous detection of DNA stainability by propidium iodine and annexin V binding. Apoptosis was practically absent both in activated CD14(++)CD33(++)DR(++)CD25(++)CD69(++)CD71(++/+) CD16(-) cells, expressing A-II mRNA and having arginase activity, but not iNOS mRNA, and in not fully mature large CD14(++)CD16(+)CD23(+)DR(++) monocytes, expressing simultaneously both mRNAs and having both enzyme activities. However, differentiated small CD14(+/++)CD16(+)CD69(+)CD25(+/-)CD71(++)CD23(+) DR(++) monocytes, expressing high levels of iNOS mRNA, exhibited apoptotic signs. Amounts of NO synthesised by monocytes co-expressing iNOS and arginase changed with the addition of arginine or an iNOS inhibitor; in that case a correlation of NO production and apoptotic features was observed. Data suggest a regulatory role for endogenous NO in apoptosis of stimulated and differentiated monocytes, and also that iNOS and A-II, when simultaneously present, could control the production of NO as a consequence of their competition for arginine
Vertical biogeographical overview of the Zooplankton community across the Atlantic, Pacific and Indian ocean (35ºN-40ºS)
From December 2010 to June 2011 the mesozooplankton has been sampled at the deep Atlantic, Indian and Pacific Ocean (*). From surface to 3000 m depth a HYDROBIOSS multinet was used distinguishing the epipelagic (77%), mesopelagic (11%) and bathypelagic zones (11%), where five layers were usually sampled (0-200, 200-500, 500-1000, 1000-2000 and 2000-3000 m depth). Among the three oceans, no large differences on abundance were found when taxonomic groups were considered, being always depth the most important factor affecting the vertical zooplankton distribution. The zooplankton abundance strongly decreased with depth and very low abundance was found at deeper waters. Very irregular spatial distribution was observed all across the three oceans, finding the lowest abundance in the south and western Pacific region. Copepods were always the most abundant contributors of the zooplankton community (84%) and more than 260 species identified. They were followed by chaetognaths (5%), siphonophores (3%), ostracods (2%) and euphausiids (1%). In a biogeographical overview, the vertical distribution of the most abundant copepods is analyzed, finding the largest copepods at deeper stratum, where small cosmopolitan copepods were also found
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