3,764 research outputs found
It Takes a Village: Using Network Science to Identify the Effect of Individual Differences in Bilingual Experience for Theory of Mind
An increasing amount of research has examined the effects of bilingualism on performance
in theory of mind (ToM) tasks. Bilinguals outperform monolinguals in ToM when comparing groups.
However, it is unclear what aspects of the bilingual experience contribute to this effect in a dynamic
construct like ToM. To date, bilingualism has been conceptualized as a dichotic skill that is distinct
from monolingualism, obscuring nuances in the degree that different bilingual experience affects
cognition. The current study used a combination of network science, cognitive, and linguistic
behavioral measurements to explore the factors that influence perspective-taking ToM based on
participants’ current and previous experience with language, as well as their family networks’
experience with language. The results suggest that some aspects of the bilingual experience predict
task performance, but not others, and these predictors align with the two-system theory of ToM.
Overall, the findings provide evidence for the extent to which individual differences in bilingualism
are related to different cognitive outcomes
Simulations of galaxy formation in a Λ cold dark matter universe : I : dynamical and photometric properties of a simulated disk galaxy.
We present a detailed analysis of the dynamical and photometric properties of a disk galaxy simulated in the cold dark matter (CDM) cosmogony. The galaxy is assembled through a number of high-redshift mergers followed by a period of quiescent accretion after z1 that lead to the formation of two distinct dynamical components: a spheroid of mostly old stars and a rotationally supported disk of younger stars. The surface brightness profile is very well approximated by the superposition of an R1/4 spheroid and an exponential disk. Each photometric component contributes a similar fraction of the total luminosity of the system, although less than a quarter of the stars form after the last merger episode at z1. In the optical bands the surface brightness profile is remarkably similar to that of Sab galaxy UGC 615, but the simulated galaxy rotates significantly faster and has a declining rotation curve dominated by the spheroid near the center. The decline in circular velocity is at odds with observation and results from the high concentration of the dark matter and baryonic components, as well as from the relatively high mass-to-light ratio of the stars in the simulation. The simulated galaxy lies 1 mag off the I-band Tully-Fisher relation of late-type spirals but seems to be in reasonable agreement with Tully-Fisher data on S0 galaxies. In agreement with previous simulation work, the angular momentum of the luminous component is an order of magnitude lower than that of late-type spirals of similar rotation speed. This again reflects the dominance of the slowly rotating, dense spheroidal component, to which most discrepancies with observation may be traced. On its own, the disk component has properties rather similar to those of late-type spirals: its luminosity, its exponential scale length, and its colors are all comparable to those of galaxy disks of similar rotation speed. This suggests that a different form of feedback than adopted here is required to inhibit the efficient collapse and cooling of gas at high redshift that leads to the formation of the spheroid. Reconciling, without fine-tuning, the properties of disk galaxies with the early collapse and high merging rates characteristic of hierarchical scenarios such as CDM remains a challenging, yet so far elusive, proposition
The type-material of Arctiinae (Lepidoptera, Erebidae) described by Burmeister and Berg in the collection of the Museo Argentino de Ciencias Naturales Bernardino Rivadavia (Buenos Aires, Argentina)
Carlos G. Burmeister and Carlos Berg were among the most important and influential naturalists and zoologists in Argentina and South America and described 241 species and 34 genera of Lepidoptera. The Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN) housed some of the Lepidoptera type specimens of these authors. In this study we present a catalogue with complete information and photographs of 11 Burmeister type specimens and 10 Berg type specimens of Phaegopterina, Arctiina and Pericopina (Lepidoptera, Erebidae, Arctiinae, Arctiini) housed in the MACN. Lectotypes or holotypes were designated where primary type specimens could be recognized; in some cases we were not able to recognize types. The catalogue also proposes nomenclatural changes and new synonymies: Opharus picturata (Burmeister, 1878), comb. n.; Opharus brunnea Gaede, 1923: 7, syn. n.; Hypocrisias jonesi (Schaus, 1894), syn. n.; Leucanopsis infucata (Berg, 1882), stat. rev.; Paracles argentina (Berg, 1877), sp. rev.; Paracles uruguayensis (Berg, 1886), sp. rev.Fil: Beccacece, Hernán Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Vincent, Benoit. Muséum National d'Histoire Naturelle; FranciaFil: Navarro, Fernando Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentin
The Cores of Dwarf Galaxy Halos
We use N-body simulations to examine the effects of mass outflows on the
density profiles of cold dark matter (CDM) halos surrounding dwarf galaxies. In
particular, we investigate the consequences of supernova-driven winds that
expel a large fraction of the baryonic component from a dwarf galaxy disk after
a vigorous episode of star formation. We show that this sudden loss of mass
leads to the formation of a core in the dark matter density profile, although
the original halo is modeled by a coreless (Hernquist) profile. The core radius
thus created is a sensitive function of the mass and radius of the baryonic
disk being blown up. The loss of a disk with mass and size consistent with
primordial nucleosynthesis constraints and angular momentum considerations
imprints a core radius which is only a small fraction of the original
scale-length of the halo. These small perturbations are, however, enough to
reconcile the rotation curves of dwarf irregulars with the density profiles of
haloes formed in the standard CDM scenario.Comment: PS file. 6 figures included. 531072 bytes. Accepted for publication
in MNRAS Letters. Also available from
http://penedes.as.arizona.edu/~jfn/preprints . (File name: rcore.ps.gz
Locking Solar Tracking Bushing
The contents of this final design review (FDR) outline the progress made by a team of four mechanical engineering students at California Polytechnic State University, San Luis Obispo to solve the problem of torsional galloping in solar tracker panels since the preliminary design review. The project proposed by the sponsor, Christian Friedrich, on behalf of ARaymond is a design for a friction based braking system integrated into a redesigned bushing.
The CDR contains details about the system design, the design justification, the manufacturing plan, and design verification plan. In the system design section, the four manufacturing subsystems (bushing mount, actuation, power screw, and braking system) will be analyzed. This analysis will be expanded upon in the manufacturing plan where the current manufacturing plan for the project deliverable will be explained. The CDR will also detail any changes that have been made since the preliminary design review (PDR). Since the PDR, the frictional force that is needed to dampen the system has been adjusted to emulate the system more accurately. The project objectives are to dampen oscillation through frictional means, withstand gravitational and wind static loads of 7.5 metric tons, and endure wearing for 30 years.
The overall structure of the bushing has been altered in a variety of different ways. First, the outer journal has been completely separated into two parts to increase the available contact area for the band brake which permits multiple different band orientations to test. As a result, the inner journal has increased in axial length in accordance with the outer journal separation. The lever arm system has also been altered to allow the power screw to interface with the lever arm system. The lever arm system also straddles the I-beam support for ease of rotation and proper power screw engagement. In order to accommodate the separation between the outer journals, an additional mounting plate has been incorporated to mount both halves of the outer journal. Finally, the power screw has been re-oriented to be perpendicular with the I-beam to increase support and adjustability
5GNOW: Challenging the LTE Design Paradigms of Orthogonality and Synchronicity
LTE and LTE-Advanced have been optimized to deliver high bandwidth pipes to
wireless users. The transport mechanisms have been tailored to maximize single
cell performance by enforcing strict synchronism and orthogonality within a
single cell and within a single contiguous frequency band. Various emerging
trends reveal major shortcomings of those design criteria: 1) The fraction of
machine-type-communications (MTC) is growing fast. Transmissions of this kind
are suffering from the bulky procedures necessary to ensure strict synchronism.
2) Collaborative schemes have been introduced to boost capacity and coverage
(CoMP), and wireless networks are becoming more and more heterogeneous
following the non-uniform distribution of users. Tremendous efforts must be
spent to collect the gains and to manage such systems under the premise of
strict synchronism and orthogonality. 3) The advent of the Digital Agenda and
the introduction of carrier aggregation are forcing the transmission systems to
deal with fragmented spectrum. 5GNOW is an European research project supported
by the European Commission within FP7 ICT Call 8. It will question the design
targets of LTE and LTE-Advanced having these shortcomings in mind and the
obedience to strict synchronism and orthogonality will be challenged. It will
develop new PHY and MAC layer concepts being better suited to meet the upcoming
needs with respect to service variety and heterogeneous transmission setups.
Wireless transmission networks following the outcomes of 5GNOW will be better
suited to meet the manifoldness of services, device classes and transmission
setups present in envisioned future scenarios like smart cities. The
integration of systems relying heavily on MTC into the communication network
will be eased. The per-user experience will be more uniform and satisfying. To
ensure this 5GNOW will contribute to upcoming 5G standardization.Comment: Submitted to Workshop on Mobile and Wireless Communication Systems
for 2020 and beyond (at IEEE VTC 2013, Spring
Quantitative full-colour transmitted light microscopy and dyes for concentration mapping and measurement of diffusion coefficients in microfluidic architectures
International audienceA simple and versatile methodology has been developed for the simultaneous measurement of multiple concentration profiles of colourants in transparent microfluidic systems, using a conventional transmitted light microscope, a digital colour (RGB) camera and numerical image processing combined with multicomponent analysis. Rigorous application of the Beer-Lambert law would require monochromatic probe conditions, but in spite of the broad spectral bandwidths of the three colour channels of the camera, a linear relation between the measured optical density and dye concentration is established under certain conditions. An optimised collection of dye solutions for the quantitative optical microscopic characterisation of microfluidic devices is proposed. Using the methodology for optical concentration measurement we then implement and validate a simplified and robust method for the microfluidic measurement of diffusion coefficients using an H-filter architecture. It consists of measuring the ratio of the concentrations of the two output channels of the H-filter. It enables facile determination of the diffusion coefficient, even for non-fluorescent molecules and nanoparticles, and is compatible with non-optical detection of the analyte
Application of electric fields to clean ultrafiltration membranes fouled with whey model solutions
In this work, the effectiveness of electric fields to clean two ZrO2 TiO2 ultrafiltration (UF) membranes
fouled with three types of whey model solutions was investigated. Membranes tested had different
molecular weight cut-offs (MWCOs) (15 and 50 kDa). Whey model solutions consisted of aqueous
solutions of bovine serum albumin (BSA) at 10 g/L, a mixture of BSA (10 g/L) and CaCl2 (1.65 g/L) and whey protein concentrate (WPC) (total protein content 45%) solutions at different concentrations (22.2, 33.3 and 150.0 g/L). The hydraulic cleaning efficiency (HCE) achieved by means of the application of the electric fields was evaluated as a function of the membrane MWCO and the operating conditions of the cleaning technique (applied potential, temperature of the cleaning solution and concentration of NaCl). The results demonstrated that the presence of NaCl favoured the removal of protein deposits on the membrane layer. On the other hand, the higher the temperature of the cleaning solution and the applied potential were, the higher HCE was achieved. Regarding the membrane MWCO, the permselective properties of the 15 kDa membrane were completely recovered after the cleaning procedure by electric field for all the feed fouling solutions tested, whereas this technique could not completely remove the protein deposits on the 50 kDa membrane when BSA solutions were used as feed.The authors of this work wish to gratefully acknowledge the financial support from the Spanish Ministry of Science and Innovation through the project CTM2010-20186 and the company MAGNETO Special Anodes B.V. for supplying the Ti-Ir electrode.Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC.; Ortega Navarro, EM.; Pérez-Herranz, V. (2016). Application of electric fields to clean ultrafiltration membranes fouled with whey model solutions. Separation and Purification Technology. 159:92-99. https://doi.org/10.1016/j.seppur.2015.12.039S929915
Intrinsic Shape of Star-Forming BzK Galaxies at z~2 in GOODS-N
We study structure of star-forming galaxies at z~2 in GOODS-N field selected
as sBzK galaxies down to K_{AB} <24.0 mag. Among 1029 sBzK galaxies, 551
galaxies (54%) show a single component in ACS/F850LP image obtained with the
Hubble Space Telescope; the rest show multiple components. We fit the
single-component sBzK galaxies with the single S\'ersic profile using the
ACS/F850LP image and find that a majority of them (64%) show S\'ersic index of
n=0.5-2.5, indicating that they have a disk-like structure. The resulting
effective radii typically range from 1.0 to 3.0 kpc in the rest-frame UV
wavelength. After correcting the effective radii to those in the rest-frame
optical wavelength, we find that the single-component sBzK galaxies locate in
the region where the local and z~1 disk galaxies distribute in the stellar
mass-size diagram, suggesting comparable surface stellar mass density between
the sBzK and z~0-1 disk galaxies. All these properties suggest that the
single-component sBzK galaxies are progenitors of the present-day disk
galaxies. However, by studying their intrinsic shape through comparison between
the observed distribution of apparent axial ratios and the distribution for
triaxial models with axes (A>B>C), we find that the mean B/A ratio is
0.61^{+0.05}_{-0.08} and disk thickness C/A is 0.28^{+0.03}_{-0.04}. This
indicates that the single-component sBzK galaxies at z~2 have a bar-like or
oval shape rather than a round disk shape. The shape seems to resemble to a
bar/oval structure that form through bar instability; if it is the case, the
intrinsic shape may give us a clue to understand dynamical evolution of
baryonic matter in a dark matter halo.Comment: 14 pages, 13 figure, 2 tables, Accepted for publication in Ap
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