4,485 research outputs found
First experiences in the application of biopreparations against the cherry fruit fly in Southern Russia in 2007
On the Russian market there are no currently registered biological preparations for the
control of Rhagoletis cerasi (cherry fruit fly, CFF), and therefore the effects of natural
products against this pest were studied. In laboratory, semi-field and field experiments a
range of botanicals (NeemAzal-T/S and Quassia-MD) were tested alone and in
combination with comparison product Phytoverm and chemical standard insecticides for
their effectiveness against R. cerasi in commercial orchards. These products showed a
high biological effectiveness against R. cerasi comparable with chemical insecticides
VLT observations of the magnetar CXO J164710.2-455216 and the detection of a candidate infrared counterpart
We present deep observations of the field of the magnetar CXOJ164710.2-455216
in the star cluster Westerlund 1, obtained in the near-infrared with the
adaptive optics camera NACO@VLT. We detected a possible candidate counterpart
at the {\em Chandra} position of the magnetar, of magnitudes , , and . The K-band measurements available for two epochs (2006 and
2013) do not show significant signs of variability but only a marginal
indication that the flux varied (at the 2 level), consistent with the
fact that the observations were taken when CXOJ164710.2-455216 was in
quiescence. At the same time, we also present colour--magnitude and
colour--colour diagrams in the J, H, and K bands from the 2006 epoch
only, the only one with observations in all three bands, showing that the
candidate counterpart lies in the main bulk of objects describing a relatively
well--defined sequence. Therefore, based on its colours and lack of
variability, we cannot yet associate the candidate counterpart to
CXOJ164710.2-455216. Future near-infrared observations of the field,
following-up a source outburst, would be crucial to confirm the association
from the detection of near-infrared variability and colour evolution.Comment: 5 pages, 3 figures, accepted for publication in MNRA
A purely geometric distance to the binary star Atlas, a member of the Pleiades
We present radial velocity and new interferometric measurements of the double
star Atlas, which permit, with the addition of published interferometric data,
to precisely derive the orbital parameters of the binary system and the masses
of the components. The derived semi-major axis, compared with its measured
angular size, allows to determine a distance to Atlas of 132+-4 pc in a purely
geometrical way. Under the assumption that the location of Atlas is
representative of the average distance of the cluster, we confirm the distance
value generally obtained through main sequence fitting, in contradiction with
the early Hipparcos result (118.3+-3.5 pc).Comment: 5 pages, 3 figures, accepted for publication in A&A Letter
Some Observations of Wake Behavior in Laminar and Turbulence Free Stream Flow
Visual observations of the sphere wake have been obtained using the flash photolysis technique. Free stream turbulence of 7 and 10% was found to progressively reduce the size of the wake but no turbulence was found in the attached shear layer nor was the position of the separation point affected. A separation bubble was identified as predicted by Son and Hanratty (1969). Evidence is presented to show that drag reduction in turbulent free streams is not due to turbulence in the attached boundary layer but to enhanced momentum transfer in the wake
Cicrumnuclear Supernova Remnants and HII Regions in NGC 253
Archival VLA data has been used to produce arcsecond-resolution 6- and 20-cm
images of the region surrounding the nuclear 200-pc (~15") starburst in NGC
253. Twenty-two discrete sources stronger than 0.4 mJy have been detected
within ~2 kpc (~3') of the galaxy nucleus; almost all these sources must be
associated with the galaxy. None of the radio sources coincides with a detected
X-ray binary, so they appear to be due to supernova remnants and H II regions.
The region outside the central starburst has a derived radio supernova rate of
<~0.1/yr, and may account for at least 20% of the recent star formation in NGC
253. Most of the newly identified sources have steep, nonthermal radio spectra,
but several relatively strong thermal sources also exist, containing the
equivalent of tens of O5 stars. These stars are spread over tens of parsecs,
and are embedded in regions having average ionized gas densities of
20-200/cm^3, much lower than in the most active nuclear star-forming regions in
NGC 253 or in the super star clusters seen in other galaxies. The strongest
region of thermal emission coincides with a highly reddened area seen at
near-infrared wavelengths, possibly containing optically obscured H II regions.Comment: 17 pages, 3 postscript figures, AASTeX format, in press for
Astronomical Journal, July 200
The Shade of a Criminal Record: Colorism, Incarceration, and External Racial Classification
Recent high-profile research suggests that social indicators like incarceration influence racial categorization. Yet, this research has largely ignored colorism—intraracial differences in skin tone that matter for stratification outcomes. In two experiments, we address how skin tone interacts with criminal background to produce external racial classification and skin tone attributions. We find no evidence that criminal history affects external racial classification or skin tone attribution. However, we find that skin tone is a strong and consistent predictor of external racial classification and skin tone attribution
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