Nonparametric Estimation of Convergence of Interest Rates: Effects on Bond Pricing

We present and estimate a model of short term interest rate dynamics where we incorporate the convergent behavior of interest rates implied by the transition to EMU. We apply this model to data of two EMU countries -Spain and Italy- and compare the performance, in terms of accuracy of bond pricing, of this two-factor convergence model with alternative specifications. Nonparametric techniques are used for the estimation of the processes. The two-factor model which accounts for the convergence with Europe of the domestic economies, obtains better results than alternative models mainly for short-term assets. The results of the nonparametric specifications are shown to be significantly better than those of parametric alternatives.

New Eunicellin-Type Diterpenes from the Panamanian Octocoral Briareum Asbestinum

Gorgonian octocorals are considered a prolific source of secondary metabolites with a wide range of biological activities, including anti-inflammatory activity. In particular, the genus Briareum is known for producing a wealth of diterpenes with complex chemical structures. The chemical study of the methanolic extract of Briareum asbestinum collected in Bocas del Toro, on the Caribbean side of Panama, led to the isolation of three new eunicellin-type diterpenes: briarellin T (1), asbestinin 27 (2), asbestinin 28 (3) and the previously described asbestinin 17 (4). The structures of the new compounds were determined by extensive NMR analyses and HRMS. Anti-inflammatory activity assays showed a significant reduction of the pro-inflammatory cytokines TNF-α, IL-6, IL-1β and IL-8 as well as a downregulation of COX-2 expression in LPS-stimulated THP-1 macrophages. These findings support the potential use of these marine compounds as therapeutic agents in the treatment of inflammatory diseases

On the study of train-track dynamic interactions caused by rail welds on discrete supported rails

The paper studies the influence of rail weld dip on wheel-rail contact dynamics, with particular reference to freight trains where it is important to increase the operating speed and also the load transported. This has produced a very precise model, albeit simple and cost-effective, which has enabled train-track dynamic interactions over rail welds to be studied to make it possible to quantify the influence on dynamic forces and displacements of the welding geometry; of the position of the weld relative to the sleeper; of the vehicle's speed; and of the axle load and wheelset unsprung mass. It is a vertical model on the spatial domain and is drawn up in a simple fashion from vertical track receptances. For the type of track and vehicle used, the results obtained enable the quantification of increases in wheel-rail contact forces due to the new speed and load conditions.Spanish Research Ministry MICINN/Economy and Competitiveness Ministry MINECO through contract TRA2010-18386, including funding by the FEDER-ERDF European Regional Development Fund. Basque Government for financial assistance through IT-453-10 and IT-691-13 as well as for Research Grant BFI08.172. UPV/EHU through the training and research unit UFI11/29

Declarative and procedural learning in children and adolescents with posterior fossa tumours

BACKGROUND: This quasi-experimental study was designed to assess two important learning types – procedural and declarative – in children and adolescents affected by posterior fossa tumours (astrocytoma vs. medulloblastoma), given that memory has an important impact on the child's academic achievement and personal development. METHODS: We had three groups: two clinical (eighteen subjects) and one control (twelve subjects). The learning types in these groups were assessed by two experimental tasks evaluating procedural-implicit and declarative memory. A Serial Reaction-Time Task was used to measure procedural sequence learning, and the Spanish version [1] of the California Verbal Learning Test-Children's Version- CVLT- [2] to measure declarative-explicit learning. The learning capacity was assessed considering only the blocks that represent learning, and were compared with MANOVA in clinical and normal subjects. The Raven, simple reaction-time, finger-tapping test, and grooved pegboard tests were used to assess the overall functioning of subjects. The results were compared with those from a control group of the same age, and with Spanish norm-referenced tools where available RESULTS: The results indicate the absence of procedural-implicit learning in both clinical groups, whereas declarative-explicit learning is maintained in both groups. CONCLUSION: The clinical groups showed a conservation of declarative learning and a clear impairment of procedural learning. The results support the role of the cerebellum in the early phase of procedural learning

Characterization of the response to zinc deficiency in the cyanobacterium Anabaena sp. strain PCC 7120

Zur regulators control zinc homeostasis by repressing target genes under zinc-sufficient conditions in a wide variety of bacteria. This paper describes how part of a survey of duplicated genes led to the identification of the open reading frame all2473 as the gene encoding the Zur regulator of the cyanobacterium Anabaena sp. strain PCC 7120. All2473 binds to DNA in a zinc-dependent manner, and its DNA-binding sequence was characterized, which allowed us to determine the relative contribution of particular nucleotides to Zur binding. A zur mutant was found to be impaired in the regulation of zinc homeostasis, showing sensitivity to elevated concentrations of zinc but not other metals. In an effort to characterize the Zur regulon in Anabaena, 23 genes containing upstream putative Zur-binding sequences were identified and found to be regulated by Zur. These genes are organized in six single transcriptional units and six operons, some of them containing multiple Zur-regulated promoters. The identities of genes of the Zur regulon indicate that Anabaena adapts to conditions of zinc deficiency by replacing zinc metalloproteins with paralogues that fulfill the same function but presumably with a lower zinc demand, and with inducing putative metallochaperones and membrane transport systems likely being involved in the scavenging of extracellular zinc, including plasma membrane ABC transport systems and outer membrane TonB-dependent receptors. Among the Zur-regulated genes, the ones showing the highest induction level encode proteins of the outer membrane, suggesting a primary role for components of this cell compartment in the capture of zinc cations from the extracellular medium.Ministerio de Ciencia e Innovación y Fondo Social Europeo BFU2007-66589/BMC BFU2010-19544Junta de Andalucía y FEDER P07-CVI-0316

Effect of Perioperative Blood Transfusions and Infectious Complications on Inflammatory Activation and Long-Term Survival Following Gastric Cancer Resection.

Gastric cancer; Infectious complications; Perioperative transfusionCáncer gástrico; Complicaciones infecciosas; Transfusión perioperatoriaCàncer gàstric; Complicacions infeccioses; Transfusió perioperatòriaBackground: The aim of this study was to evaluate the impact of perioperative blood transfusion and infectious complications on postoperative changes of inflammatory markers, as well as on disease-free survival (DFS) in patients undergoing curative gastric cancer resection. Methods: Multicenter cohort study in all patients undergoing gastric cancer resection with curative intent. Patients were classified into four groups based on their perioperative course: one, no blood transfusion and no infectious complication; two, blood transfusion; three, infectious complication; four, both transfusion and infectious complication. Neutrophil-to-lymphocyte ratio (NLR) was determined at diagnosis, immediately before surgery, and 10 days after surgery. A multivariate Cox regression model was used to analyze the relationship of perioperative group and dynamic changes of NLR with disease-free survival. Results: 282 patients were included, 181 in group one, 23 in group two, 55 in group three, and 23 in group four. Postoperative NLR changes showed progressive increase in the four groups. Univariate analysis showed that NLR change > 2.6 had a significant association with DFS (HR 1.55; 95% CI 1.06-2.26; p = 0.025), which was maintained in multivariate analysis (HR 1.67; 95% CI 1.14-2.46; p = 0.009). Perioperative classification was an independent predictor of DFS, with a progressive difference from group one: group two, HR 0.80 (95% CI: 0.40-1.61; p = 0.540); group three, HR 1.42 (95% CI: 0.88-2.30; p = 0.148), group four, HR 2.85 (95% CI: 1.64-4.95; p = 0.046). Conclusions: Combination of perioperative blood transfusion and infectious complications following gastric cancer surgery was related to greater NLR increase and poorer DFS. These findings suggest that perioperative blood transfusion and infectious complications may have a synergic effect creating a pro-inflammatory activation that favors tumor recurrence

Genetic analysis of pre-Columbian human remains from Lower Magdalena suggests a migratory route and matrilineal genetic continuity in Northern South America

El análisis del ADN en restos de poblaciones prehispánicas ha permitido aproximarse al origen genético de una proporción importante de los habitantes de la actual Colombia. Los resultados arqueológicos de la tradición de Malambo, cuyo origen se remonta a 3.000 años A.P. en el bajo Magdalena, se complementaron con estudios genéticos de cuatro individuos asociados con esta población. Para ello se extrajo ADN de muestras de dientes y huesos. El ADN extraído se purificó y se amplificó por PCR para su posterior secuenciación y análisis filogenético. El haplogroupo B2j se identificó y se caracterizó mediante la mutación G16361A, así como la deleción de 9pb y las mutaciones diagnósticas del haplogrupo B. Este mismo haplogrupo fue descrito recientemente en un individuo en Venezuela, lo que sugiere la filiación genética matrilineal y su continuidad en el norte de SuraméricaDNA analysis in pre-Hispanic populations remains has allowed approaching the genetic origins of inhabitants in present-day Colombia. In this work, we complemented the archaeological results on the Malambo tradition, originated 3000 years B.P. in Lower Magdalena, with genetic studies of bone remains of four individuals associated with this population. We extracted DNA from bone samples and purified and amplified them by PCR for further sequencing and phylogenetic analysis. We identified the B2j haplogroup in all individuals as characterized by a G16361A mutation, as well as a 9-pb deletion and diagnostic mutations of haplogroup B. This same haplogroup was recently described in an individual in Venezuela suggesting genetic maternal filiation and continuity in northern South AmericaN/

Trans-oligomerization of duplicated aminoacyl-tRNA synthetases maintains genetic code fidelity under stress

Aminoacyl-tRNA synthetases (aaRSs) play a key role in deciphering the genetic message by producing charged tRNAs and are equipped with proofreading mechanisms to ensure correct pairing of tRNAs with their cognate amino acid. Duplicated aaRSs are very frequent in Nature, with 25,913 cases observed in 26,837 genomes. The oligomeric nature of many aaRSs raises the question of how the functioning and oligomerization of duplicated enzymes is organized. We characterized this issue in a model prokaryotic organism that expresses two different threonyl-tRNA synthetases, responsible for Thr-tRNAThr synthesis: one accurate and constitutively expressed (T1) and another (T2) with impaired proofreading activity that also generates mischarged Ser-tRNAThr. Low zinc promotes dissociation of dimeric T1 into monomers deprived of aminoacylation activity and simultaneous induction of T2, which is active for aminoacylation under low zinc. T2 either forms homodimers or heterodimerizes with T1 subunits that provide essential proofreading activity in trans. These findings evidence that in organisms with duplicated genes, cells can orchestrate the assemblage of aaRSs oligomers that meet the necessities of the cell in each situation. We propose that controlled oligomerization of duplicated aaRSs is an adaptive mechanism that can potentially be expanded to the plethora of organisms with duplicated oligomeric aaRSs.Ministerio de Economía y Competitividad BFU2010–19544, BFU2013–44686-