Efecto de la fase fenológica de verano sobre algunas características del ensamble de Diptera registrado en una vega altoandina del desierto transicional de Chile

Diptera are one of the dominant taxonomic groups of animal invertebrates to be found in the highland wet pastures of the transitional desert of Chile. In wetlands, these insects play important roles as pollinators, decomposers and trophic resources for aquatic vertebrates. Additionally, Diptera are recognized to have the potentiality to be used as indicators of the health condition of wet terrestrial environments, important attribute in the case of Andean highland wet pastures given the water stress under which they are presently subjected. By using Barber and Malaise traps, the Diptera-assemblage associated to a highland wet pasture located in a transitional desert basin was investigated. This study was conducted during the growing season for the area. Its aims were to a) document the taxonomic structure of the assemblage in terms of the composition of Diptera-families and the relative abundance of its members, and b) evaluate the effect of the summer phenological phase on F-richness, relative abundance relationships, F-diversity and evenness. The PERMANOVA and t-pairwise tests were used to evaluate the effect of the summer phenological phase on the numerical relationships among families. The Simpsons D, Brillouin D, Berger-Parker dominance, and Fisher indices were used to estimate the F-diversity; in turn, the Simpson E, Camargo, Smith-Wilson B, and NHC indices estimated the F-evenness. Similarity between assemblages was compared by ANOSIM. The percent contribution by family to the observed differences between assemblages was computed by the SIMPER-routine. All analyses were done on the log-transformed data (x+1; log 10). 44524 Diptera-representatives were collected throughout the study, with a record of 27 families. The tests and the indices support the idea that the middle-summer phase provided the best environmental conditions for the diptero-fauna of the wet pasture. Apparently, this effect would be more related to the thermal pattern of the area than to the micro-habitat availabilityEsta publicación fue financiada por la Dirección de Investigación de la Universidad de La Seren

Relación entre las concentraciones de polen aéreo de Artemisia, Chenopodiaceae, Plantago y Taraxacum y la prevalencia de polinosis en estudiantes universitarios de León

XV lnternational A.P.L.E. Symposium of Palynolog

Nonorientable spacetime tunneling

Misner space is generalized to have the nonorientable topology of a Klein bottle, and it is shown that in a classical spacetime with multiply connected space slices having such a topology, closed timelike curves are formed. Different regions on the Klein bottle surface can be distinguished which are separated by apparent horizons fixed at particular values of the two angular variables that eneter the metric. Around the throat of this tunnel (which we denote a Klein bottlehole), the position of these horizons dictates an ordinary and exotic matter distribution such that, in addition to the known diverging lensing action of wormholes, a converging lensing action is also present at the mouths. Associated with this matter distribution, the accelerating version of this Klein bottlehole shows four distinct chronology horizons, each with its own nonchronal region. A calculation of the quantum vacuum fluctuations performed by using the regularized two-point Hadamard function shows that each chronology horizon nests a set of polarized hypersurfaces where the renormalized momentum-energy tensor diverges. This quantum instability can be prevented if we take the accelerating Klein bottlehole to be a generalization of a modified Misner space in which the period of the closed spatial direction is time-dependent. In this case, the nonchronal regions and closed timelike curves cannot exceed a minimum size of the order the Planck scale.Comment: 11 pages, RevTex, Accepted in Phys. Rev.

Uniqueness and Nondegeneracy of Ground States for (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1} = 0 in R\mathbb{R}

We prove uniqueness of ground state solutions $Q = Q(|x|) \geq 0$ for the nonlinear equation $(-\Delta)^s Q + Q - Q^{\alpha+1}= 0$ in $\mathbb{R}$, where $0 < s < 1$ and $0 < \alpha < \frac{4s}{1-2s}$ for $s < 1/2$ and $0 < \alpha < \infty$ for $s \geq 1/2$. Here $(-\Delta)^s$ denotes the fractional Laplacian in one dimension. In particular, we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for $s=1/2$ and $\alpha=1$ in [Acta Math., \textbf{167} (1991), 107--126]. As a technical key result in this paper, we show that the associated linearized operator $L_+ = (-\Delta)^s + 1 - (\alpha+1) Q^\alpha$ is nondegenerate; i.\,e., its kernel satisfies $\mathrm{ker}\, L_+ = \mathrm{span}\, \{Q'\}$. This result about $L_+$ proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for nonlinear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page

Scale dependence of the quark masses and mixings: leading order

We consider the Renormalization Group Equations (RGE) for the couplings of the Standard Model and its extensions. Using the hierarchy of the quark masses and of the Cabibbo-Kobayashi-Maskawa (CKM) matrix our argument is that a consistent approximation for the RGE should be based on the parameter $\lambda= |\hat{V}_{ud}| \approx0.22$. We consider the RGE in the approximation where we neglect all the relative terms of the order $\sim\lambda^{4}$ and higher. Within this approximation we find the exact solution of the evolution equations of the quark Yukawa couplings and of the vacuum expectation value of the Higgs field. Then we derive the evolution of the observables: quark masses, CKM matrix, Jarlskog invariant, Wolfenstein parameters of the CKM matrix and the unitarity triangle. We show that the angles of the unitarity triangle remain constant. This property may restrict the possibility of new symmetries or textures at the grand unification scale.Comment: 15 pages, 4 figures, author of one reference adde

Sharp constants in weighted trace inequalities on Riemannian manifolds

We establish some sharp weighted trace inequalities W^{1,2}(\rho^{1-2\sigma}, M)\hookrightarrow L^{\frac{2n}{n-2\sigma}}(\pa M) on $n+1$ dimensional compact smooth manifolds with smooth boundaries, where $\rho$ is a defining function of $M$ and $\sigma\in (0,1)$. This is stimulated by some recent work on fractional (conformal) Laplacians and related problems in conformal geometry, and also motivated by a conjecture of Aubin.Comment: 34 page

Desarrollo de la Red Aerobiológica de Castilla y León (RACYL)

XV lnternational A.P.L.E. Symposium of Palynolog

NL mind-best: aweb server for ligands and proteins discovery; theoretic experimental study of proteins of giardia lamblia

Comunicaciones a congreso

The three-nucleon bound state using realistic potential models

The bound states of $^3$H and $^3$He have been calculated using the Argonne $v_{18}$ plus the Urbana three-nucleon potential. The isospin $T=3/2$ state have been included in the calculations as well as the $n$-$p$ mass difference. The $^3$H-$^3$He mass difference has been evaluated through the charge dependent terms explicitly included in the two-body potential. The calculations have been performed using two different methods: the solution of the Faddeev equations in momentum space and the expansion on the correlated hyperspherical harmonic basis. The results are in agreement within 0.1% and can be used as benchmark tests. Results for the CD-Bonn interaction are also presented. It is shown that the $^3$H and $^3$He binding energy difference can be predicted model independently.Comment: 5 pages REVTeX 4, 1 figures, 6 table