7,352 research outputs found
The Mass-Concentration Relation and the Stellar-to-Halo Mass Ratio in the CFHT Stripe 82 Survey
We present a new measurement of the mass-concentration relation and the
stellar-to-halo mass ratio over the halo mass range to
. To achieve this, we use weak lensing measurements
from the CFHT Stripe 82 Survey (CS82), combined with the central galaxies from
the redMaPPer cluster catalogue and the LOWZ/CMASS galaxy sample of the Sloan
Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey Tenth Data
Release. The stacked lensing signals around these samples are modelled as a sum
of contributions from the central galaxy, its dark matter halo, and the
neighboring halos, as well as a term for possible centering errors. We measure
the mass-concentration relation: with
for and for . These amplitudes and slopes are completely
consistent with predictions from recent simulations. We also measure the
stellar-to-halo mass ratio for our samples, and find results consistent with
previous measurements from lensing and other techniques.Comment: 10 pages, 3 figures, 3 table
Effect of particle size upon the extent of extraction of antioxidant power from the plants Agrimonia eupatoria, Salvia sp. and Satureja montana
The dependence of the extent of aqueous extraction of antioxidant compounds on particle size and contact
time was studied for three important medicinal plants, that are commonly used in infusions: agrimony,
sage and savoury. The effect of extraction time was dependent on the plant considered;
however, ca. 5 min can be taken as the minimum period required to assure an acceptable degree of
extraction of those compounds. As expected, a smaller particle size led to a higher extraction extents;
a typical value of 0.2 mmis accordingly recommended. Chlorogenic acid was the dominant phenolic compound
extracted from agrimony, whereas caffeic acid dominated in the case of sage or savoury. A mathematical
model based on Fick’s law was developed from first principles, and its two parameters were
suitably fitted to the experimental data generated – in attempts to predict the evolution of antioxidant
capacity extracted during contact time, for each plant and each particle size
Weak-lensing calibration of a stellar mass-based mass proxy for redMaPPer and Voronoi Tessellation clusters in SDSS Stripe 82
We present the first weak lensing calibration of , a new galaxy
cluster mass proxy corresponding to the total stellar mass of red and blue
members, in two cluster samples selected from the SDSS Stripe 82 data: 230
redMaPPer clusters at redshift and 136 Voronoi Tessellation
(VT) clusters at . We use the CS82 shear catalog and stack
the clusters in bins to measure a mass-observable power law
relation. For redMaPPer clusters we obtain , . For VT clusters, we find
, and , for a low and a high redshift bin, respectively. Our results are
consistent, internally and with the literature, indicating that our method can
be applied to any cluster finding algorithm. In particular, we recommend that
be used as the mass proxy for VT clusters. Catalogs including
measurements will enable its use in studies of galaxy evolution
in clusters and cluster cosmology.Comment: Updated to be consistent with the published versio
Stellar-to-halo mass relation of cluster galaxies
In the hierarchical formation model, galaxy clusters grow by accretion of
smaller groups or isolated galaxies. During the infall into the centre of a
cluster, the properties of accreted galaxies change. In particular, both
observations and numerical simulations suggest that its dark matter halo is
stripped by the tidal forces of the host.
We use galaxy-galaxy weak lensing to measure the average mass of dark matter
haloes of satellite galaxies as a function of projected distance to the centre
of the host, for different stellar mass bins. Assuming that the stellar
component of the galaxy is less disrupted by tidal stripping, stellar mass can
be used as a proxy of the infall mass. We study the stellar to halo mass
relation of satellites as a function of the cluster-centric distance to measure
tidal stripping.
We use the shear catalogues of the DES science verification archive, the
CFHTLenS and the CFHT Stripe 82 (CS82) surveys, and we select satellites from
the redMaPPer catalogue of clusters. For galaxies located in the outskirts of
clusters, we find a stellar to halo mass relation in good agreement with the
theoretical expectations from \citet{moster2013} for central galaxies. In the
centre of the cluster, we find that this relation is shifted to smaller halo
mass for a given stellar mass. We interpret this finding as further evidence
for tidal stripping of dark matter haloes in high density environments.Comment: 15 pages, 14 figure
Effects of zinc against mercury toxicity in female rats 12 and 48 hours after HgCl2 exposure
This work investigated the toxicity of inorganic mercury and zinc preventive effects in female rats sacrificed 12 or 48 h after HgCl2 exposure. Female Wistar rats were subcutaneously injected with ZnCl2 (27 mg/kg) or saline (0.9 %), and 24 h later they were exposed to HgCl2 (5 mg/kg) or saline (0.9 %). Rats sacrificed 12 hours after Hg administration presented an increase in kidney weight and a decrease in renal ascorbic acid levels. Zinc pretreatment prevented the renal weight increase. Rats sacrificed 48 h after Hg exposure presented a decrease in body weight gain, an increase in renal weight, a decrease in renal δ-aminolevulinic acid dehydratase activity, an increase in serum creatinine and urea levels, and a decrease in kidney total thiol levels. Zinc pretreatment partly prevented the decrease in body weight gain and increase in creatinine levels, in addition to totally preventing renal δ-aminolevulinic acid dehydratase inhibition. Mercury accumulation in the kidney and liver in both periods was observed after Hg administration. These results show the different Hg effects along the time of intoxication, and a considerably preventive effect of zinc against Hg toxicity
Weak-lensing analysis of galaxy pairs using CS82 data
Here we analyze a sample of close galaxy pairs (relative projected separation < 25 h -1 kpc and relative radial velocities < 350 km s -1 ) using a weak-lensing analysis based on the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). We determine halo masses for the total sample of pairs as well as for interacting, red, and higher-luminosity pair subsamples with ∼3σ confidence. The derived lensing signal for the total sample can be fitted either by a Singular Isothermal Sphere (SIS) with σ V = 223 ± 24 km s -1 or a Navarro-Frenk-White (NFW) profile with R 200 = 0.30 ± 0.03 h -1 Mpc. The pair total masses and total r band luminosities imply an average mass-to-light ratio of ∼200 h M ⊙ /L ⊙ . On the other hand, red pairs which include a larger fraction of elliptical galaxies, show a larger mass-to-light ratio of ∼345 h M ⊙ /L ⊙ . Derived lensing masses were compared to a proxy of the dynamical mass, obtaining a good correlation. However, there is a large discrepancy between lensing masses and the dynamical mass estimates, which could be accounted for by astrophysical processes such as dynamical friction, by the inclusion of unbound pairs, and by significant deviations of the density distribution from SIS and NFW profiles in the inner regions. We also compared lensing masses with group mass estimates, finding very good agreement with the sample of groups with two members. Red and blue pairs show large differences between group and lensing masses, which is likely due to the single mass-to-light ratio adopted to compute the group masses.Fil: Gonzalez, Elizabeth Johana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Rodriguez, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Makler, Martín. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Mesa, Valeria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Alonso, Sol. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; ArgentinaFil: Duplancic Videla, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; ArgentinaFil: Pereira, Maria E. S.. Brandeis University; Estados UnidosFil: Shan, HuanYuan. Shanghai Astronomical Observatory; República de Chin
Blood Group Antigen Studies Using Cdte Quantum Dots And Flow Cytometry.
New methods of analysis involving semiconductor nanocrystals (quantum dots [QDs]) as fluorescent probes have been highlighted in life science. QDs present some advantages when compared to organic dyes, such as size-tunable emission spectra, broad absorption bands, and principally exceptional resistance to photobleaching. Methods applying QDs can be simple, not laborious, and can present high sensibility, allowing biomolecule identification and quantification with high specificity. In this context, the aim of this work was to apply dual-color CdTe QDs to quantify red blood cell (RBC) antigen expression on cell surface by flow cytometric analysis. QDs were conjugated to anti-A or anti-B monoclonal antibodies, as well as to the anti-H (Ulex europaeus I) lectin, to investigate RBCs of A1, B, A1B, O, A2, and Aweak donors. Bioconjugates were capable of distinguishing the different expressions of RBC antigens, both by labeling efficiency and by flow cytometry histogram profile. Furthermore, results showed that RBCs from Aweak donors present fewer amounts of A antigens and higher amounts of H, when compared to A1 RBCs. In the A group, the amount of A antigens decreased as A1 > A3 > AX = Ael, while H antigens were AX = Ael > A1. Bioconjugates presented stability and remained active for at least 6 months. In conclusion, this methodology with high sensibility and specificity can be applied to study a variety of RBC antigens, and, as a quantitative tool, can help in achieving a better comprehension of the antigen expression patterns on RBC membranes.104393-440
Knitted textile KTPs for instrumented underwater building systems
[Excerpt] The main scope of this study was to assess the potential of knitted textiles for underwater instrumented underwater building
systems, using textile knitted preforms (multi-shape; multimaterial; etc…), using natural fibres (Hemp, Linen and Cotton)
Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)
Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade
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