4,335 research outputs found
Sobre la presència de Melogramma campylosporum a Catalunya
Sobre la presència de Melogramma campylosporum a Catalunya. Es menciona per
primera vegada la presència per a la micoflora de Catalunya de Melogramma campylosporum Fr., un
fong que creix en el nostre cas sobre branques de Corylus avellana. Donat el seu interès corològic,
aportem una descripció detallada de l'espècie, acompanyada d'iconografia.About the presence of Melogramma campylosporum in Catalonia. Melogramma
campylosporum Fr. is a corticicolous fungus first mentioned for the mycoflora of Catalonia. In our
case, it grows on branches of Corylus avellana and given its chorological interest, we provide a
detailed description of the species, accompanied by iconography.Sobre la presencia de Melogramma campylosporum en Cataluña. Se menciona por
primera vez, la presencia para la micoflora de Cataluña de Melogramma campylosporum Fr., un hongo
que crece en nuestro caso sobre ramas de Corylus avellana. Dado su interés corológico, aportamos una
descripción detallada de la especie, acompañada de iconografía
Factorization invariants in half-factorial affine semigroups
Let be the monoid generated by We introduce the
homogeneous catenary degree of as the smallest with the following property: for each and any two factorizations of
, there exists factorizations of such that, for every where is the
usual distance between factorizations, and the length of is less than or equal to
We prove that the homogeneous catenary degree of
improves the monotone catenary degree as upper bound for the ordinary catenary
degree, and we show that it can be effectively computed. We also prove that for
half-factorial monoids, the tame degree and the -primality coincide,
and that all possible catenary degrees of the elements of an affine semigroup
of this kind occur as the catenary degree of one of its Betti elements.Comment: 8 pages, 1 figur
Thing Complex Fuzzy Systems by Supervised Learning Algorithms
Tuning a fuzzy system to meet a given set of inpuffoutput
patterns is usually a difficult task that involves many parameters.
This paper presents an study of different approaches
that can be applied to perform this tuning process automatically,
and describes a CAD tool, named xfsl, which allows
applying a wide set of these approaches: (a) a large number
of supervised learning algorithms; (b) different processes to
simplify the learned system; (c) tuning only specific parameters
of the system; (d) the ability to tune hierarchical fuzzy
systems, systems with continuous output (like fuzzy controller)
as well as with categorical output (like fuzzy classifiers),
and even systems that employ user-defined fuzzy
functions; and, finally, (e) the ability to employ this tuning
within the design flow of a fuzzy system, because xfsl is integrated
into the fuzzy system development environment
Xfuzzy 3.0.Comisión Interministerial de Ciencia y Tecnología TIC2001-1726-C02-0
The landscape of fear: Why some free-ranging rodents choose repeated live-trapping over predation risk and how it is associated with the physiological stress response
Live trapping is an essential element of field ecological studies. However, the act of trapping provides two types of conditional benefits (food from the bait when hungry, and refuge from a predator when threatened) against one type of drawback (confinement). Our understanding of how animals assess the two benefits against the lone risk determines how we interpret classic field studies in chemical ecology and wildlife management. Here, we studied wood mice responses to these risks and rewards of field trapping by examining experience through recapture and faecal corticosterone metabolites (FCM) as a physiological response indicator. Wood mice were live-trapped in two different plots subjected to two distinct phases: phase 1, absence of predator cues, and phase 2, in which traps were treated with red fox faeces. During phase 1, the recapture percentage was lower indicating that mice avoided traps while FCM levels in recaptured mice were higher. On the contrary, during phase 2, despite the total number of captures was lower we found an increase in the recapture percentage and FCM levels did not increase in recaptured mice. Our results suggest that under increased risk perception traps could be likely considered as a suitable shelter and thus, for some individuals the benefits of traps may outweigh their risks. In addition, we discovered that the effects of combining two stressors do not result in the addition of the response originated by each factor separatelyThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
Evidence of strong antiferromagnetic coupling between localized and itinerant electrons in ferromagnetic Sr2FeMoO6
Magnetic dc susceptibility () and electron spin resonance (ESR)
measurements in the paramagnetic regime, are presented. We found a Curie-Weiss
(CW) behavior for (T) with a ferromagnetic K and
, this being lower than that expected for
either or ions. The ESR g-factor , is associated with . We obtained an excellent description
of the experiments in terms of two interacting sublattices: the localized
() cores and the delocalized electrons. The coupled equations
were solved in a mean-field approximation, assuming for the itinerant electrons
a bare susceptibility independent on . We obtained
emu/mol. We show that the reduction of for
arises from the strong antiferromagnetic (AFM) interaction between the two
sublattices. At variance with classical ferrimagnets, we found that is
ferromagnetic. Within the same model, we show that the ESR spectrum can be
described by Bloch-Hasegawa type equations. Bottleneck is evidenced by the
absence of a -shift. Surprisingly, as observed in CMR manganites, no
narrowing effects of the ESR linewidth is detected in spite of the presence of
the strong magnetic coupling. These results provide evidence that the magnetic
order in does not originates in superexchange interactions,
but from a novel mechanism recently proposed for double perovskites
Engineered microenvironments for synergistic VEGF - integrin signalling during vascularization
We have engineered polymer-based microenvironments that promote vasculogenesis both in vitro and in vivo through synergistic integrin-growth factor receptor signalling. Poly(ethyl acrylate) (PEA) triggers spontaneous organization of fibronectin (FN) into nanonetworks which provide availability of critical binding domains. Importantly, the growth factor binding (FNIII12-14) and integrin binding (FNIII9-10) regions are simultaneously available on FN fibrils assembled on PEA. This material platform promotes synergistic integrin/VEGF signalling which is highly effective for vascularization events in vitro with low concentrations of VEGF. VEGF specifically binds to FN fibrils on PEA compared to control polymers (poly(methyl acrylate), PMA) where FN remains in a globular conformation and integrin/GF binding domains are not simultaneously available. The vasculogenic response of human endothelial cells seeded on these synergistic interfaces (VEGF bound to FN assembled on PEA) was significantly improved compared to soluble administration of VEGF at higher doses. Early onset of VEGF signalling (PLCγ1 phosphorylation) and both integrin and VEGF signalling (ERK1/2 phosphorylation) were increased only when VEGF was bound to FN nanonetworks on PEA, while soluble VEGF did not influence early signalling. Experiments with mutant FN molecules with impaired integrin binding site (FN-RGE) confirmed the role of the integrin binding site of FN on the vasculogenic response via combined integrin/VEGF signalling. In vivo experiments using 3D scaffolds coated with FN and VEGF implanted in the murine fat pad demonstrated pro-vascularization signalling by enhanced formation of new tissue inside scaffold pores. PEA-driven organization of FN promotes efficient presentation of VEGF to promote vascularization in regenerative medicine applications
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