The influence of Atlantic High on seasonal rainfall in Argentina

The objective of this work is to quantify the influence of the position and intensity of the Atlantic High (AH) on seasonal rainfall in Argentina. Monthly precipitation data in 68 stations from the National Meteorological Service of Argentina, the Secretariat of Water Resource and the Territorial Authority of the Limay, Neuquén, and Negro rivers basins (AIC) were used. Correlation was the methodology used to identify the link between seasonal rainfall and some indices especially defined to detect the position and intensity of the anticyclone. Precipitation composites of the years when the value of these indices was extremely high (greater than their second tercile) and extremely low (lower than their first tercile) were built for every season. They were analyzed and compared with humidity anomaly transport composites for the same sets of years in order to study circulation patterns associated with seasonal rainfall anomalies. Results indicate that when the AH is intensified, winter rainfall increases in central Argentina and spring rainfall increases in northern Cuyo region. When the AH is displaced towards the north of its mean position, autumn rainfall is favored in the northeast and central and south Patagonia, meanwhile winter and spring rainfall decreases in central Argentina. When the AH is displaced towards the east of its mean position, summer rainfall decreases in Central Andes. Finally, AH indices were used to detect the influence on rainfall in advance. Correlations between seasonal rainfall and the defined indices that characterize the anticyclone in the previous month suggest that there is some rainfall predictability, especially during spring in almost every region in Argentina.Fil: Garbarini, Eugenia María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: González, Marcela Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Rolla, Alfredo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentin

Strain-rate-dependent properties of short carbon fiber-reinforced acrylonitrile-butadiene-styrene using material extrusion additive manufacturing

Purpose – The purpose of the present paper is to quantify and analyze the strain-rate dependence of the yield stress for both unfilled acrylonitrilebutadiene- styrene (ABS) and short carbon fiber-reinforced ABS (CF-ABS) materials, fabricated via material extrusion additive manufacturing (MEAM). Two distinct and opposite infill orientation angles were used to attain anisotropy effects. Design/methodology/approach – Tensile test samples were printed with two different infill orientation angles. Uniaxial tensile tests were performed at five different constant linear strain rates. Apparent densities were measured to compensate for the voided structure. Scanning electron microscope fractography images were analyzed. An Eyring-type flow rule was evaluated for predicting the strain-rate-dependent yield stress. Findings – Anisotropy was detected not only for the yield stresses but also for its strain-rate dependence. The short carbon fiber-filled material exhibited higher anisotropy than neat ABS material using the same ME-AM processing parameters. It seems that fiber and molecular orientation influence the strain-rate dependence. The Eyring-type flow rule can adequately describe the yield kinetics of ME-AM components, showing thermorheologically simple behavior. Originality/value – A polymer’s viscoelastic behavior is paramount to be able to predict a component’s ultimate failure behavior. The results in this manuscript are important initial findings that can help to further develop predictive numerical tools for ME-AM technology. This is especially relevant because of the inherent anisotropy that ME-AM polymer components show. Furthermore, short carbon fiber-filled ABS enhanced anisotropy effects during ME-AM, which have not been measured previously

Hydrothermal thresholds for seed germination in winter annual forbs from old-field Mediterranean landscapes

Under Mediterranean climates with dry‐hot summers and cool‐wet winters, many forbs with potential for habitat restoration are winter annuals, but there is little information about their germination. We performed laboratory germination experiments on 13 ruderal dicots native to Andalusia (southern Spain). We measured the germination of recently harvested seeds from natural populations across nine temperature treatments (from 5 to 35 °C, constant and alternate); two storage periods; and eight water stress treatments (from 0 to −1.0 MPa). We then calculated the hydrothermal thresholds for seed germination. Final germination ranged from 0–100% and results were mixed in response to temperature. Base temperature was below 6 °C, optimal temperature was around 14 °C and the ceiling temperature around 23 °C. For five species, 10 months of storage improved total germination, indicating a dormancy‐breaking effect, but the other species did not respond or had their germination reduced. All species were relatively tolerant to water stress, with base water potential ranging from −0.8 to −1.8 MPa. Our results suggest that hydrothermal germination thresholds, rather than physiological dormancy, are the main drivers of germination phenology in annual forbs from Mediterranean semi‐dry environments. The variation in germination responses of these forb species differs from winter annual grasses, but their seeds are all suitable for being stored before restoration.European Union's Seventh Framework Programme FP7/2007‐2013/. Grant Number: n°607785 Government of Asturias European Commission. Grant Number: ACA14‐1

Tensile properties and failure behavior of chopped and continuous carbon fiber composites produced by additive manufacturing

The use of additive manufacturing (AM) is rapidly expanding in many industries mostly because of the flexibility to manufacture complex geometries. Recently, a family of technologies that produce fiber reinforced components has been introduced, widening the options available to designers. AM fiber reinforced composites are characterized by the fact that process related parameters such as the amount of reinforcement fiber, or printing architecture, significantly affect the tensile properties of final parts. To find optimal structures using new AM technologies, guidelines for the design of 3D printed composite parts are needed. This paper presents an evaluation of the effects that different geometric parameters have on the tensile properties of 3D printed composites manufactured by fused filament fabrication (FFF) out of continuous and chopped carbon fiber reinforcement. Parameters such as infill density and infill patterns of chopped composite material, as well as fiber volume fraction and printing architecture of continuous fiber reinforcement (CFR) composites are varied. The effect of the location of the initial deposit point of reinforcement fibers on the tensile properties of the test specimens is studied. Also, the effect that the fiber deposition pattern has on tensile performance is quantified. Considering the geometric parameters that were studied, a variation of the Rule of Mixtures (ROM) that provides a way to estimate the elastic modulus of a 3D printed composite is proposed. Findings may be used by designers to define the best construction parameters for 3D printed composite parts

Nephrops discards, size composition, recruitment and directed effort of the Spanish fleets in Porcupine Bank (FU 16)

Spanish fleets have been fishing Norway lobster (Nephrops norvegicus) in Porcupine Bank for more than 45 years. Despite a huge Spanish effort descent in the area during this period, nowadays Spain is after Ireland the second country in Nephrops landings from this functional unit (12%). Nephrops discards in the Spanish fleets were traditionally considered negligible, but a revision about the issue is necessary. On the other hand, there are problems since 2005 to carry out length sampling from the fishery on the ports, since retained catch is now frozen on board. This lack of information can be addressed by length information collected by the observers on board. Concerning effort, Spain has been providing in the last decades effort data of the hake directed fleet (that collects almost all Nephrops catch) for the successive ICES working groups related to FU 16 Nephrops. New effort information more accurate and directed to Nephrops is needed. Taking into account this demands, discards rates and estimations, catch length information and Nephrops directed effort are presented on this document

Transcription factor FOXP2 is a flow-induced regulator of collecting lymphatic vessels.

The lymphatic system is composed of a hierarchical network of fluid absorbing lymphatic capillaries and transporting collecting vessels. Despite distinct functions and morphologies, molecular mechanisms that regulate the identity of the different vessel types are poorly understood. Through transcriptional analysis of murine dermal lymphatic endothelial cells (LECs), we identified Foxp2, a member of the FOXP family of transcription factors implicated in speech development, as a collecting vessel signature gene. FOXP2 expression was induced after initiation of lymph flow in vivo and upon shear stress on primary LECs in vitro. Loss of FOXC2, the major flow-responsive transcriptional regulator of lymphatic valve formation, abolished FOXP2 induction in vitro and in vivo. Genetic deletion of Foxp2 in mice using the endothelial-specific Tie2-Cre or the tamoxifen-inducible LEC-specific Prox1-CreER <sup>T2</sup> line resulted in enlarged collecting vessels and defective valves characterized by loss of NFATc1 activity. Our results identify FOXP2 as a new flow-induced transcriptional regulator of collecting lymphatic vessel morphogenesis and highlight the existence of unique transcription factor codes in the establishment of vessel-type-specific endothelial cell identities

Modulated Amplitude Waves in Bose-Einstein Condensates

We analyze spatio-temporal structures in the Gross-Pitaevskii equation to study the dynamics of quasi-one-dimensional Bose-Einstein condensates (BECs) with mean-field interactions. A coherent structure ansatz yields a parametrically forced nonlinear oscillator, to which we apply Lindstedt's method and multiple-scale perturbation theory to determine the dependence of the intensity of periodic orbits (``modulated amplitude waves'') on their wave number. We explore BEC band structure in detail using Hamiltonian perturbation theory and supporting numerical simulations.Comment: 5 pages, 4 figs, revtex, final form of paper, to appear in PRE (forgot to include \bibliography command in last update, so this is a correction of that; the bibliography is hence present again

Hyperbolicity of the Kidder-Scheel-Teukolsky formulation of Einstein's equations coupled to a modified Bona-Masso slicing condition

We show that the Kidder-Scheel-Teukolsky family of hyperbolic formulations of the 3+1 evolution equations of general relativity remains hyperbolic when coupled to a recently proposed modified version of the Bona-Masso slicing condition.Comment: 4 pages. Several changes. Main corrections are in eqs. 4.9 and 4.1

On the role of the magnetic dipolar interaction in cold and ultracold collisions: Numerical and analytical results for NH(3Σ−^3\Sigma^-) + NH(3Σ−^3\Sigma^-)

We present a detailed analysis of the role of the magnetic dipole-dipole interaction in cold and ultracold collisions. We focus on collisions between magnetically trapped NH molecules, but the theory is general for any two paramagnetic species for which the electronic spin and its space-fixed projection are (approximately) good quantum numbers. It is shown that dipolar spin relaxation is directly associated with magnetic-dipole induced avoided crossings that occur between different adiabatic potential curves. For a given collision energy and magnetic field strength, the cross-section contributions from different scattering channels depend strongly on whether or not the corresponding avoided crossings are energetically accessible. We find that the crossings become lower in energy as the magnetic field decreases, so that higher partial-wave scattering becomes increasingly important \textit{below} a certain magnetic field strength. In addition, we derive analytical cross-section expressions for dipolar spin relaxation based on the Born approximation and distorted-wave Born approximation. The validity regions of these analytical expressions are determined by comparison with the NH + NH cross sections obtained from full coupled-channel calculations. We find that the Born approximation is accurate over a wide range of energies and field strengths, but breaks down at high energies and high magnetic fields. The analytical distorted-wave Born approximation gives more accurate results in the case of s-wave scattering, but shows some significant discrepancies for the higher partial-wave channels. We thus conclude that the Born approximation gives generally more meaningful results than the distorted-wave Born approximation at the collision energies and fields considered in this work.Comment: Accepted by Eur. Phys. J. D for publication in Special Issue on Cold Quantum Matter - Achievements and Prospects (2011

A new Mean Dynamic Topography of the Mediterranean Sea based on model outputs, drifter data, hydrological profiles and altimeter measurements

Trabajo presentado en la EGU General Assemby 2013, celebrada del 7 al 12 de abril de 2013 en Viena (Austria)Peer Reviewe