The large carpenter bee Xylocopa augusti (Hymenoptera: Apidae): new record for Chile

The large carpenter bee Xylocopa (Neoxylocopa) augusti Lepeletier de Saint Fargeau, 1841, is here recorded for the first time in Chile. This new record increases to four the number of carpenter bees known for the country. Host plant associations for X. augusti in Chile are provided. A key to the species of Xylocopa Latreille in Chile as well as comments on the presence of X. (N.) bruesi Cockerell in the country are also presented.Fil: Montalva, José.Fil: Allendes, Juan L..Fil: Lucia, Mariano. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dynamic heterogeneity in the glass-like monoclinic phases of some halogen methane compounds

In this work we study the heterogeneity of the dynamics on the low-temperature monoclinic phases of the simple molecular glassy systems CBrnCl4−nCBrnCl4−n, n = 0, 1, 2. In these systems the disorder comes exclusively from reorientational jumps mainly around the C3 molecular axes. The different time scales are determined by means of the analysis of the spin-lattice relaxation time obtained through Nuclear Quadrupole Resonance (NQR) technique. Results are compared with those obtained from dielectric spectroscopy, from which two α- and β-relaxation times appear. NQR results enable us to ascribe with no doubt that the existence of two relaxations is due to dynamical heterogeneities which are the consequence of the different molecular surroundings of the molecules in the asymmetric unit cell of systems here studied.Fil: Zuriaga, Mariano Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Perez, S. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Pardo, L. C.. Universidad Politecnica de Catalunya; EspañaFil: Tamarit, J. L.. Universidad Politecnica de Catalunya; Españ

Quantum pump effect in one-dimensional systems of Dirac fermions

We investigate the behavior of the directed current in one-dimensional systems of Dirac fermions driven by local periodic potentials in the forward as well in backscattering channels. We treat the problem with Keldysh non-equilibrium Green's function formalism. We present the exact solution for the case of an infinite wire and show that in this case the dc current vanishes identically. We also investigate a confined system consistent in an annular arrangement coupled to a particle reservoir. We present a perturbative treatment that allows for the analytical expressions of the dc current in the lowest order of the amplitudes of the potential. We also present results obtained from the exact numerical solution of the problem.Comment: 8 pages, 5 figure

Eco-Anthropic Compatibility - a Multidisciplinary Model in Urban Ecology

In this paper I propose a multidisciplinary model of urban development which goes beyond the notion of ecological sustainability, by building on the concept of eco-anthropic compatibility. First of all I will sketch the historical development of human aggregations and I will underline the difference between ancient and modern aggregations. On the basis of this analysis, I will take into consideration the notion of sustainability and its possible application to present conurbations. I will underline several limits of the notion of sustainable development and I will propose a multidisciplinary model grounded on a broader and new notion: the eco-anthropic compatibility. Using this notion, which includes the idea of sustainability, it is possible to handle, within the model, the human factors and human living conditions inside an urban aggregation. Finally, I will state that the actual urban model is decaying and therefore, sooner or later, we will have to face the end of urban civilization; for this reason we can start imagining new future ways for human aggregations on the planet based on the notion of eco-anthropic compatibility

Larval description and phylogenetic placement of the Australian endemic genus Barretthydrus Lea, 1927 (Coleoptera: Dytiscidae: Hydroporinae: Hydroporini: Sternopriscina)

The larvae of the Australian endemic species Barretthydrus tibialis Lea, 1927 and Barretthydrus geminatus Lea, 1927 are described and illustrated for the first time, with detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi. A parsimony analysis based on 118 informative larval characteristics of 34 species in all 10 tribes of the subfamily Hydroporinae was conducted using the program TNT. No clear larval morphological synapomorphies support the monophyletic origin of the tribe Hydroporini. Compared to other known larvae of Hydroporini, Barretthydrus Lea is postulated to share a closer phylogenetic relationship with Antiporus Sharp, which reinforces their inclusion in the subtribe Sternopriscina.Fil: Alarie, Yves. Laurentian University. Department of Biology; CanadáFil: Michat, Mariano Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Entomología; ArgentinaFil: Hendrich, L.. Zoologische Staatssammlung Munchen; AlemaniaFil: Watts, Chris H. S.. South Australian Museum; Australi

Conocimiento y verdad en el pragmatismo de William James

Among the pragmatic philosophers, James is the only one to develop a theory of truth in the empirical tradition, projecting it, however, far beyond the limits of positivism. His theory of meaning as the capacity of an idea's producing clearly perceptible effects does not easily fit into the setting given by the bounds of natural sciences, a definitely limited area beyond which empirical logic does not admit any meaning at all. James bases his conception of truth in its concrete historica1 and changing form on a model which is situated halfway between the theory of truth as conformity with- and as transformation of reality. Truth is the fruit of the collaboration between malleable reality, not given as an absolute entity, and man. However, facing transcendentalist prejudices, it is necessary to see experience not as a conglomerate of separate, isolated items, but as specific relations between items, these relations being just as real as the items themselves. Pragmatism values cognition as a function of the living subject situated in his natural historical and social environment and whose mission it is to create effective habits of conduct

Effect of nonadiabatic switching of dynamic perturbations in 1d Fermi systems

We study a two-dimensional fermionic QFT used to model 1D strongly correlated electrons in the presence of a time-dependent impurity that drives the system out of equilibrium. In contrast to previous investigations, we consider a dynamic barrier switched on at a finite time. We compute the total energy density (TED) of the system and establish two well defined regimes in terms of the relationship between the frequency of the time-dependent perturbation $\Omega$ and the electron energy $\omega$. Finally, we derive a relaxation time $t_{R}$ such that for times shorter than $t_{R}$ the finite-time switching process is relevant.Comment: 9 pages, 4 figures. Changed title. Added comments on backscattering. Added result for electrical current. Version accepted in PR

Left Ventricular Trabeculations Decrease the Wall Shear Stress and Increase the Intra-Ventricular Pressure Drop in CFD Simulations

The aim of the present study is to characterize the hemodynamics of left ventricular (LV) geometries to examine the impact of trabeculae and papillary muscles (PMs) on blood flow using high performance computing (HPC). Five pairs of detailed and smoothed LV endocardium models were reconstructed from high-resolution magnetic resonance images (MRI) of ex-vivo human hearts. The detailed model of one LV pair is characterized only by the PMs and few big trabeculae, to represent state of art level of endocardial detail. The other four detailed models obtained include instead endocardial structures measuring ≥1 mm2 in cross-sectional area. The geometrical characterizations were done using computational fluid dynamics (CFD) simulations with rigid walls and both constant and transient flow inputs on the detailed and smoothed models for comparison. These simulations do not represent a clinical or physiological scenario, but a characterization of the interaction of endocardial structures with blood flow. Steady flow simulations were employed to quantify the pressure drop between the inlet and the outlet of the LVs and the wall shear stress (WSS). Coherent structures were analyzed using the Q-criterion for both constant and transient flow inputs. Our results show that trabeculae and PMs increase the intra-ventricular pressure drop, reduce the WSS and disrupt the dominant single vortex, usually present in the smoothed-endocardium models, generating secondary small vortices. Given that obtaining high resolution anatomical detail is challenging in-vivo, we propose that the effect of trabeculations can be incorporated into smoothed ventricular geometries by adding a porous layer along the LV endocardial wall. Results show that a porous layer of a thickness of 1.2·10−2 m with a porosity of 20 kg/m2 on the smoothed-endocardium ventricle models approximates the pressure drops, vorticities and WSS observed in the detailed models.This paper has been partially funded by CompBioMed project, under H2020-EU.1.4.1.3 European Union’s Horizon 2020 research and innovation programme, grant agreement n◦ 675451. FS is supported by a grant from Severo Ochoa (n◦ SEV-2015-0493-16-4), Spain. CB is supported by a grant from the Fundació LaMarató de TV3 (n◦ 20154031), Spain. TI and PI are supported by the Institute of Engineering in Medicine, USA, and the Lillehei Heart Institute, USA.Peer ReviewedPostprint (published version