1,060 research outputs found
Biomassa, morfologia e curva de crescimento de cinco genótipos de Pfaffia glomerata em condição de estufa
Monografia (graduação)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2012.As raízes de Pfaffia glomerata (Spreng.) Pedersen, espécie perene, de porte arbustivo pertencente à família Amaranthaceae, são de grande interesse comercial, tanto na forma de fito-medicamentos, quanto de suplementos alimentares. É uma espécie nativa da América do Sul e de ocorrência comum nos Estados do Paraná, Mato Grosso do Sul e Goiás. O objetivo do presente trabalho foi obter a curva de crescimento de cinco genótipos de Pfaffia glomerata obtidos a partir da autosemeadura ocorrida na coleção de acessos da UnB, determinar a produção de biomassa da parte aérea e da raiz e descrever sua morfologia externa. O ensaio foi feito em estufa do tipo Glasshouse. As temperaturas médias das mínimas e das máximas durante os meses de ensaio foram respectivamente 20.1º C e 35,5 ºC. A partir das cinco plântulas oriundas da autosemeadura foram obtidas estacas uninodais que foram crescidas em miniestufa e ao enraizarem e atingirem em média 10 cm de altura, foram transplantadas para vasos de 2L de capacidade contendo mistura de solo adubado e dispostos sobre bancadas de cimento na estufa do tipo Glasshouse. Durante oito semanas após o transplante, foi medida semanalmente a altura da planta, desde o nível do coleto até o broto mais elevado e, ao final do ensaio foi obtida a massa fresca das raízes e a massa fresca da parte aérea. Foram anotadas as características morfológicas das plantas para acessar a diversidade neste item, compreendendo a morfologia do limbo foliar, a cor do talo e a pilosidade e a emissão floral. O crescimento das plantas de P. glomerata em condição de estufa apresentou-se compatível com o padrão da cultura. As plantas oriundas da auto-semeadura apresentaram elevada segregação de caracteres morfológicos
Confirmation detection in human-agent interaction using non-lexical speech cues
Brandt M, Wrede B, Kummert F, Schillingmann L. Confirmation detection in human-agent interaction using non-lexical speech cues. Presented at the AAAI Symposium on Natural Communication for Human-Robot Collaboration, Arlington, VA.Even if only the acoustic channel is considered, human communication is
highly multi-modal. Non-lexical cues provide a variety of information such as
emotion or agreement. The ability to process such cues is highly relevant for
spoken dialog systems, especially in assistance systems. In this paper we focus
on the recognition of non-lexical confirmations such as "mhm", as they enhance
the system's ability to accurately interpret human intent in natural
communication. The architecture uses a Support Vector Machine to detect
confirmations based on acoustic features. In a systematic comparison, several
feature sets were evaluated for their performance on a corpus of human-agent
interaction in a setting with naive users including elderly and cognitively
impaired people. Our results show that using stacked formants as features yield
an accuracy of 84% outperforming regular formants and MFCC or pitch based
features for online classification
The lack of star formation gradients in galaxy groups up to z~1.6
In the local Universe, galaxy properties show a strong dependence on
environment. In cluster cores, early type galaxies dominate, whereas
star-forming galaxies are more and more common in the outskirts. At higher
redshifts and in somewhat less dense environments (e.g. galaxy groups), the
situation is less clear. One open issue is that of whether and how the star
formation rate (SFR) of galaxies in groups depends on the distance from the
centre of mass. To shed light on this topic, we have built a sample of X-ray
selected galaxy groups at 0<z<1.6 in various blank fields (ECDFS, COSMOS,
GOODS). We use a sample of spectroscopically confirmed group members with
stellar mass M >10^10.3 M_sun in order to have a high spectroscopic
completeness. As we use only spectroscopic redshifts, our results are not
affected by uncertainties due to projection effects. We use several SFR
indicators to link the star formation (SF) activity to the galaxy environment.
Taking advantage of the extremely deep mid-infrared Spitzer MIPS and
far-infrared Herschel PACS observations, we have an accurate, broad-band
measure of the SFR for the bulk of the star-forming galaxies. We use
multi-wavelength SED fitting techniques to estimate the stellar masses of all
objects and the SFR of the MIPS and PACS undetected galaxies. We analyse the
dependence of the SF activity, stellar mass and specific SFR on the
group-centric distance, up to z~1.6, for the first time. We do not find any
correlation between the mean SFR and group-centric distance at any redshift. We
do not observe any strong mass segregation either, in agreement with
predictions from simulations. Our results suggest that either groups have a
much smaller spread in accretion times with respect to the clusters and that
the relaxation time is longer than the group crossing time.Comment: Accepted for publication in MNRA
The Sloan Digital Sky Survey Reverberation Mapping Project: the XMM-Newton X-ray source catalog and multi-band counterparts
The XMM-RM project was designed to provide X-ray coverage of the Sloan
Digital Sky Survey Reverberation Mapping (SDSS-RM) field. 41 XMM-Newton
exposures, placed surrounding the Chandra AEGIS field, were taken, covering an
area of 6.13 deg^2 and reaching a nominal exposure depth of ~15 ks. We present
an X-ray catalog of 3553 sources detected in these data, using a PSF-fitting
algorithm and a sample selection threshold that produces a ~5% fraction of
spurious sources. In addition to the PSF-fitting likelihood, we calculate a
second source reliability measure based on Poisson theory using source and
background counts within an aperture. Using the Poissonian likelihood, we
select a sub-sample with a high purity and find that it has similar number
count profiles to previous X-ray surveys. The Bayesian method "NWAY" was
employed to identify counterparts of the X-ray sources from the optical Legacy
and the IR unWISE catalogs, using a 2-dimensional unWISE magnitude-color prior
created from optical/IR counterparts of Chandra X-ray sources. A significant
number of the optical/IR counterparts correspond to sources with low detection
likelihoods, proving the value of retaining the low-likelihood detections in
the catalog. 932 of the XMM-RM sources are covered by SDSS spectroscopic
observations. 89% of them are classified as AGN, and 71% of these AGN are in
the SDSS-RM quasar catalog. Among the SDSS-RM quasars, 80% are detectable at
the depth of the XMM observations.Comment: ApJS accepted. 20 pages, 16 figure
The COSMOS AGN Spectroscopic Survey I: XMM Counterparts
We present optical spectroscopy for an X-ray and optical flux-limited sample
of 677 XMM-Newton selected targets covering the 2 deg^2 COSMOS field, with a
yield of 485 high-confidence redshifts. The majority of the spectra were
obtained over three seasons (2005-2007) with the IMACS instrument on the
Magellan (Baade) telescope. We also include in the sample previously published
Sloan Digital Sky Survey spectra and supplemental observations with
MMT/Hectospec. We detail the observations and classification analyses. The
survey is 90% complete to flux limits of f_{0.5-10 keV}>8 x 10^-16 erg cm^-2
s^-1 and i_AB+<22, where over 90% of targets have high-confidence redshifts.
Making simple corrections for incompleteness due to redshift and spectral type
allows for a description of the complete population to $i_AB+<23. The corrected
sample includes 57% broad emission line (Type 1, unobscured) AGN at
0.13<z<4.26, 25% narrow emission line (Type 2, obscured) AGN at 0.07<z<1.29,
and 18% absorption line (host-dominated, obscured) AGN at 0<z<1.22 (excluding
the stars that made up 4% of the X-ray targets). We show that the survey's
limits in X-ray and optical flux include nearly all X-ray AGN (defined by
L_{0.5-10 keV}>3 x 10^42 erg s^-1) to z<1, of both optically obscured and
unobscured types. We find statistically significant evidence that the obscured
to unobscured AGN ratio at z<1 increases with redshift and decreases with
luminosity.Comment: Accepted for publication in the ApJ. 31 pages, 17 figures. Table 2 is
available on reques
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