5,988 research outputs found
Financial Soundness Prediction Using a Multi-classification Model: Evidence from Current Financial Crisis in OECD Banks
The paper aims to develop an early warning model that separates previously
rated banks (337 Fitch-rated banks from OECD) into three classes, based on their
financial health and using a one-year window. The early warning system is based
on a classification model which estimates the Fitch ratings using Bankscope bankspecific data, regulatory and macroeconomic data as input variables. The authors
propose a “hybridization technique” that combines the Extreme learning machine
and the Synthetic Minority Over-sampling Technique. Due to the imbalanced nature
of the problem, the authors apply an oversampling technique on the data aiming to
improve the classification results on the minority groups. The methodology proposed
outperforms other existing classification techniques used to predict bank solvency. It
proved essential in improving average accuracy and especially the performance of the
minority groups
The multicomponent 2D Toda hierarchy: Discrete flows and string equations
The multicomponent 2D Toda hierarchy is analyzed through a factorization
problem associated to an infinite-dimensional group. A new set of discrete
flows is considered and the corresponding Lax and Zakharov--Shabat equations
are characterized. Reductions of block Toeplitz and Hankel bi-infinite matrix
types are proposed and studied. Orlov--Schulman operators, string equations and
additional symmetries (discrete and continuous) are considered. The
continuous-discrete Lax equations are shown to be equivalent to a factorization
problem as well as to a set of string equations. A congruence method to derive
site independent equations is presented and used to derive equations in the
discrete multicomponent KP sector (and also for its modification) of the theory
as well as dispersive Whitham equations.Comment: 27 pages. In the revised paper we improved the presentatio
Rapid colour changes in Euglena sanguinea (Euglenophyceae) caused by internal lipid globule migration
The accumulation of red pigments under chronic stress is a response observed in most
groups of oxygenic photoautotrophs. It is thought that the red pigments in the cell shield
the chlorophyll located underneath from the light. Among these red pigments, the
accumulation of carotenoids is one of the most frequent cases. However, the synthesis
or degradation of carotenoids is a slow process and this response is usually only
observed when the stress is maintained over a period of time. In the Euglenophyte
Euglena sanguinea, this is due to the accumulation of a large amount of free and
esterified astaxanthin (representing 80% of the carotenoid pool). While reddening is a
slow and sometimes irreversible process in other phototrophs, reducing the efficiency of
light harvesting by chlorophyll, in E. sanguinea it is highly dynamic, capable of shifting
from red to green (and vice-versa) in 10-20 min. This change is not due to de novo
carotenogenesis, but to the relocation of cytoplasmic lipid globules where astaxanthin
accumulates. Thus, red globules migrate from the centre of the cell to peripheral
locations when photoprotection is demanded. This protective system seems to be so
efficient that other classical mechanisms are not operative in this species. For example,
despite the presence and operation of the diadino-diatoxanthin cycle, nonphotochemical
quenching (NPQ) is almost undetectable. Since E. sanguinea forms
extensive floating colonies, reddening can be observed at much greater scale than at a
cellular level, the mechanism described here being one of the fastest and most dramatic
colour changes attributable to photosynthetic organisms at cell and landscape level. In
sum, these data indicate an extremely dynamic and efficient photoprotective mechanism
based on organelle migration more than on carotenoid biosynthesis that prevents excess
light absorption by chlorophylls reducing the need for other protective processes related
to energy dissipation.This work was supported by the Basque Government [UPV/EHU-GV IT-1018-16] [UPV/EHU PPG17/67 – GV IT-1040-16], and by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Research and Development Foundation (FEDER) through (i) [CTM2014-53902-C2-2-P] national grant and (ii) a “Juan de la Cierva-Incorporación” postdoctoral grant [IJCI-2014-22489] to BFM
Unprecedented magnetoresistance in Cd-substituted Tl2Mn2O7 pyrochlores
3 pages, 3 figures.Moderate pressure techniques (P = 20 kbar) have been used to prepare Tl2–xCdxMn2O7 (0x0.4) pyrochlore-like materials. The x = 0.2 compound has been characterized by neutron powder diffraction, magnetic, magnetotransport, and Hall measurements. This material is ferromagnetic below TC = 110 K. Both electrical resistance and magnetoresistance (MR) are enhanced with respect to stoichiometric Tl2Mn2O7, due to the drastic reduction in the number of carriers (electrons) induced by hole doping. MR(0.5 T) is higher than 106% at 120 K, and MR(9 T) is 30% at room temperature. We show that hole doped derivatives of Tl2Mn2O7 are promising candidates in which to search for large bulk magnetoresistance.The author are grateful for the financial support of
CICyT (Project Nos. PB97-1181 and MAT99-1045).Peer reviewe
Preservation of Quercus robur germplasm by cryostorage of embryogenic cultures derived from mature trees and rapd analysis of genetic stability
This study reports on the cryostorage of embryogenic lines derived from selected mature Quercus robur trees, following application of the PVS2-vitrification based procedure. In seven oak genotypes, embryo recovery levels ranging from 57-92% were obtained when 4-6 mg embryo clumps were precultured for 3 days on 0.3 M sucrose basal medium, treated with PVS2 solution for 60 min at 24ºC, and then immersed in liquid nitrogen (LN). Embryos of six out of seven lines were cryostored for one week and one year and used to evaluate cryopreservation tolerance, germination ability and to assess genetic fidelity by random amplified polymorphic DNA (RAPD) markers. There were no significant differences between the recovery frequencies of samples retrieved from LN after 1 week and 1 year of cryostorage. In five out of six lines, RAPD profiles of cryopreserved somatic embryos and regenerated plantlets were identical to those of the controls. Although polymorphisms were detected in only one cryostored embryo of one genotype, no genetic instability was found in the regenerated plantlets. This methodology appears to be suitable for long-term storage of this valuable germplasm, as the recovered plantlets were found to be genetically stable.Xunta de Galicia project: PGIDIT03RFO40001PR
MEC (Spain) project: AGL2006-01387/FORPeer reviewe
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Ectomycorrhizal fungal communities and their functional traits mediate plant–soil interactions in trace element contaminated soils
There is an increasing consensus that microbial communities have an important role in mediating ecosystem processes. Trait-based ecology predicts that the impact of the microbial communities on ecosystem functions will be mediated by the expression of their traits at community level. The link between the response of microbial community traits to environmental conditions and its effect on plant functioning is a gap in most current microbial ecology studies. In this study, we analyzed functional traits of ectomycorrhizal fungal species in order to understand the importance of their community assembly for the soil–plant relationships in holm oak trees (Quercus ilex subsp. ballota) growing in a gradient of exposure to anthropogenic trace element (TE) contamination after a metalliferous tailings spill. Particularly, we addressed how the ectomycorrhizal composition and morphological traits at community level mediate plant response to TE contamination and its capacity for phytoremediation. Ectomycorrhizal fungal taxonomy and functional diversity explained a high proportion of variance of tree functional traits, both in roots and leaves. Trees where ectomycorrhizal fungal communities were dominated by the abundant taxa Hebeloma cavipes and Thelephora terrestris showed a conservative root economics spectrum, while trees colonized by rare taxa presented a resource acquisition strategy. Conservative roots presented ectomycorrhizal functional traits characterized by high rhizomorphs formation and low melanization which may be driven by resource limitation. Soil-to-root transfer of TEs was explained substantially by the ectomycorrhizal fungal species composition, with the highest transfer found in trees whose roots were colonized by Hebeloma cavipes. Leaf phosphorus was related to ectomycorrhizal species composition, specifically higher leaf phosphorus was related to the root colonization by Thelephora terrestris. These findings support that ectomycorrhizal fungal community composition and their functional traits mediate plant performance in metal-contaminated soils, and have a high influence on plant capacity for phytoremediation of contaminants. The study also corroborates the overall effects of ectomycorrhizal fungi on ecosystem functioning through their mediation over the plant economics spectrum
Evaluación de la producción de carne de ganado criollo patagónico
Objetivo. Evaluar la producción de carne del ganado Criollo Patagónico respecto al Angus y cruzas entre ambas razas. Materiales y métodos. Se dispuso de una muestra de 42 animales de los genotipos Criollo Patagónico, Angus y cruza entre ambos, clasificados en novillitos o vaquillonas, terminados en feed lot durante un período de 114 y 156 días, a partir de los cuales se conformaron ocho grupos de análisis desbalanceados. Para la parte exploratoria se empleó análisis factorial. Se usaron modelos lineales mixtos para contemplar las correlaciones entre las mediciones sobre un mismo animal. Resultados. Se pudo constatar diferencias entre las medias de los pesos a faena de los dos períodos de engorde y que esta ganancia de peso se depositó en los cortes de menor valor comercial. Con relación al rendimiento de los cortes de alto valor económico, se detectó interacción entre éstos y los grupos, identificándose diferencias entre grupos para algunos de los cortes. Conclusiones. En virtud de los resultados obtenidos, se considera promisoria la producción de carne del ganado Criollo Patagónico con relación al rendimiento de los cortes de alto valor económico, pues sus rendimientos medios sólo se vieron superados en bife ancho por su cruza con Angus
Characterization of α-amilasa activity in five Mediterranean sparids
Alpha-amylase activity was measured and described in five species of Mediterranean sparids: Pagrus pagrus (Linnaeus, 1758), Pagellus erytrhinus (Linnaeus, 1758), Pagellus bogaraveo (Brünnich, 1768), Boops boops (Linnaeus, 1758), and Diplodus annularis (Linnaeus, 1758). Major differences were found regarding the optimum pH and thermal sensitivity of this activity. B. boops showed low resistance at high temperatures, compared with D. annularis, which showed a higher thermal tolerance. Electrophoretic separation under native conditions (PAGE) and isoelectrofocus (IEF) revealed the existence of several α-amylase isoforms, ranging from 1-3 active fractions in the species studied. These differences are probably related to differences in their feeding habits, and having a variety of amylases can be considered an ecological advantage for those animals with this characteristic.La actividad α-amilasa intestinal fue medida y caracterizada en cinco especies de espáridos que habitan en el mar Mediterráneo: Pagrus pagrus (Linnaeus, 1758), Pagellus erytrhinus (Linnaeus, 1758), Pagellus bogaraveo (Brünnich, 1768), Boops boops (Linnaeus, 1758) y Diplodus annularis (Linnaeus, 1758). Las principales diferencias fueron observadas en el pH óptimo y en la sensibilidad a la temperatura. La actividad amilasa en B. boops demostró ser poco resistente a altas temperaturas, a diferencia de la de D. annularis, que resultó ser muy resistente. La separación electroforética en condiciones nativas (PAGE) e isoelectroenfoque (IEF) revelaron la existencia de un número de isoformas de la α-amilasa que osciló entre una y tres fracciones activas en las especies estudiadas. Estas diferencias posiblemente estén relacionadas con los distintos hábitos alimentarios de las especies estudiadas. Esta variedad de amilasas mostrada representa una ventaja ecológica para los animales que la poseen.Instituto Español de Oceanografí
Injuries in Traditional Wrestling: The Leonese Wrestling Case Study (2005-2015)
El objetivo de este estudio fue describir la localización anatómica, el tipo y la gravedad de las lesiones ocurridas en las competiciones oficiales de las ligas de verano masculinas (2005-2015) de Lucha Leonesa. Al objeto de realizar un análisis más profundo, se tuvo en cuenta, el perfil del luchador. Se produjeron un total de 401 lesiones, siendo los luchadores de mayor nivel los que menos número de lesiones sufrieron. Las contusiones fueron las lesiones más frecuentes (41,4%) pero entre las graves fueron los esguinces (42,3%). Los miembros inferiores fueron la localización más frecuente en el total de lesiones (38,2%) y entre las graves (45,4%). La rodilla, el tórax y el hombro acumulaban casi la mitad de las lesiones y el 68% de las lesiones graves. Los resultados obtenidos sugieren que las características de las lesiones que se pueden observar en la lucha leonesa son similares a las de otros deportes de combateThis study aimed at describing the anatomical location, type and severity of the sport injuries observed during the Leonese Wrestling “masculine summer leagues” official tournaments (2005-2015). The wrestler’s profile was taken into account as a way to achieve a deep analysis. A total of 401 injuries were registered. The best wrestlers were the ones that suffered the least number of injuries. Contusions were the type of injuries more frequently registered (41.4%), while sprains were the most common cause of severe injury (42.3%). The most frequent anatomical location affected and the one in which a great number of severe injuries occurred were the lower limbs (38.2% and 45.4%). The knee, thorax, and shoulder accounted for almost half of the total injuries and represented 68% of the severe injuries. The obtained results suggest that Leonese Wrestling show a similar injury pattern to the one observed in other combat sportsEste trabajo contó con financiación parcial de la Diputación de León, la Federación Territorial de Castilla y León de Lucha y CIBERESP (MTM2015-64465-C2-1-R; MINECO / FEDER
Aging impairs the hepatic subcellular distribution of ChREBP in response to fasting/feeding in rats: Implications on hepatic steatosis
© 2015 Elsevier Inc. All rights reserved. Aging is associated with alterations of lipid metabolism and increased prevalence of non alcoholic hepatic steatosis.Nevertheless, themechanisms bywhich fat is accumulated in the liver during aging remain incompletely understood. In the present study, we investigated potential alterations that might contribute to the development of hepatic steatosis with aging. To this end, we analyzed the expression and the subcellular localization
of key transcriptional factors involved in lipid metabolism such as ChREBP, Foxo1, Foxa2 and SREBP-1c in the liver of 3- and 24-month oldWistar rats. In addition, we studied the intracellular redistribution of ChREBP in response to fasting/refeeding transition. Old rats were characterized by hepatic steatosis, low serum ketone body levels and postprandial hyperinsulinemia. These observations were paralleled by the cytoplasmic localization and decreased expression of Foxa2, while ChREBP expression was markedly up-regulated and mainly localized in the nucleus. Consequently, the expression of lipogenic and β-oxidation genes was up-regulated or downregulated, respectively. Besides, the intracellular redistribution of ChREBP in response to fasting/refeeding transition was also impaired in old animals. Additionally, a negative correlation between serum ketone body levels and the nuclear localization of ChREBP was observed only in adult but not in old rats. Taken together, these data suggest that an age-related dysfunctional adaptation of ChREBP, in response to changes in the nutritional state, might contribute to the development of liver steatosis with aging.Junta de Comunidades de Castilla-La Mancha (JCCM), BFU2012- 39705-C03-01 from Ministerio de Ciencia e Innovación, and S2010/BMC2423 from Comunidad de Madrid, Spain. A.S. was supported by FPU predoctoral fellowship from Ministerio de Educación y Ciencia (MEC), Spain, and B.B. was supported by CONACyT predoctoral fellowship from México. The Centre of Molecular Biology “Severo Ochoa” is the recipient of institutional aid from the Ramón Areces FoundationPeer Reviewe
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