2,382 research outputs found
Sugar Maple Borer (Coleoptera: Cerambycidae) Activity Associated With Periods of Severe Defoliation
A perusal of previous research on sugar maple borer, Glycobius speciosus, in northern New York State strongly associates severe early and late season defoliation with increased borer damage. This re-examination of earlier work suggests foliage protection may be necessary when forest management objectives are concerned with wood volume and quality
Initial agro-economic performance of the crop-forest integration system in the Xingu Valley - MT.
To validate the agro-economically integrated rubber with annual crops (soybeans and corn) on the Xingu Valley (MT), Embrapa in partnership with Certeza Farm, implemented and is leading the five years an area of nine hectares, called Unit Technological Reference, to validate agroeconomically this integration model Crop-Forest
The Nature of Optical Features in the Inner Region of the 3C48 Host Galaxy
The well-known quasar 3C48 is the most powerful compact steep-spectrum
radio-loud QSO at low redshifts. It also has two unusual optical features
within the radius of the radio jet (~1"): (1) an anomalous, high-velocity
narrow-line component, having several times as much flux as does the
narrow-line component coinciding with the broad-line redshift; and (2) a bright
continuum peak (3C48A) ~1" northeast of the quasar. Both of these optical
features have been conjectured to be related to the radio jet. Here we explore
these suggestions. We have obtained Gemini North GMOS integral-field-unit (IFU)
spectroscopy of the central region around 3C48. We use the unique features of
the IFU data to remove unresolved emission at the position of the quasar. The
resolved emission at the wavelength of the high-velocity component is peaked
<~0.25" north of the quasar, at virtually the same position angle as the base
of the radio jet. These observations appear to confirm that this high-velocity
gas is connected with the radio jet. However, most of the emission comes from a
region where the jet is still well collimated, rather than from the regions
where the radio maps indicate strong interaction with an external medium. We
also present the results of HST STIS spectroscopy of 3C48A. We show that 3C48A
is dominated by stars with a luminosity-weighted age of ~1.4 X 10^8 years,
substantially older than any reasonable estimate for the age of the radio
source. Our IFU data indicate a similar age. Thus, 3C48A almost certainly
cannot be attributed to jet-induced star formation. The host galaxy of 3C48 is
clearly the result of a merger, and 3C48A seems much more likely to be the
distorted nucleus of the merging partner, in which star formation was induced
during the previous close passage.Comment: 10 pages, accepted by The Astrophysical Journa
3C 48: Stellar Populations and the Kinematics of Stars and Gas in the Host Galaxy
We present deep Keck LRIS spectroscopy of the host galaxy of 3C 48. Our
observations at various slit positions sample the different luminous components
near the quasar, including the apparent tidal tail to the NW and several strong
emission line regions.
By fitting Bruzual & Charlot (1996) population synthesis models to our
spectra, we obtain ages for the most recent major episodes of star formation in
various parts of the host galaxy covered by our slits. There is vigorous
current star formation in regions just NE and SE of the quasar and
post-starburst regions with ages up to ~10^8 years in other parts of the host
galaxy, but most of the NW tidal tail shows no sign of significant recent star
formation. We use these model fits, together with the kinematics of the stars
and gas, to outline a plausible evolutionary history for the host galaxy, its
recent starburst activity, the triggering of the quasar, and the interaction of
the radio jet with the ambient gas.
There is strong evidence that the 3C 48 host is an ongoing merger, and that
it is probably near the peak of its starburst activity. Nevertheless, the
quasar itself seems to suffer little extinction, perhaps because we are viewing
it along a particularly favorable line-of-sight.Comment: 27 pages plus 11 figures (7 postscript, 4 gif). Postscript version
including figures (1840 kb) available at
http://www.ifa.hawaii.edu/~canaguby/preprints.html . Accepted for publication
in Ap
Radio Supernova SN 1998bw and Its Relation to GRB 980425
SN 1998bw is an unusual Type Ic supernova that may be associated with the
-ray burst GRB 980425. We use a synchrotron self-absorption model for
its radio emission to deduce that the synchrotron-emitting gas is expanding
into a circumstellar medium of approximately density profile, at a
speed comparable to the speed of light. We assume that the efficiencies of
production of relativistic electrons and magnetic field are constant through
the evolution. The circumstellar density is consistent with that expected
around the massive star core thought to be the progenitor of SN 1998bw. The
explosion energy in material moving with velocity is ergs, with some preference for the high values. The rise in
the radio light curves observed at days 20-40 is inferred to be the result of a
rise in the energy of the blast wave by a factor . Interaction with a
jump in the ambient density is not consistent with the observed evolution. We
infer that the boost in energy is from a shell of matter from the explosion
that catches up with the decelerating shock front. Both the high explosion
energy and the nature of the energy input to the blast wave are difficult to
reconcile with energy input from the shock-accelerated high velocity ejecta
from a supernova. The implication is that there is irregular energy input from
a central engine, which is the type of model invoked for normal -ray
bursts. The link between SN 1998bw and GRB 980425 is thus strengthened.Comment: 21 pages, 9 figures, revised version to appear in Ap
Smell you later - the repelling effect of secondary plant compounds against water voles and common voles
Fischer, D., Prokop, A., Wink, M., Mattes, H., Jacob, J
Hot gas and dust in a protostellar cluster near W3(OH
We used the IRAM Interferometer to obtain sub-arcsecond resolution
observations of the high-mass star-forming region W3(OH) and its surroundings
at a frequency of 220 GHz. With the improved angular resolution, we distinguish
3 peaks in the thermal dust continuum emission originating from the hot core
region about 6 arcsec (0.06 pc) east of W3(OH). The dust emission peaks are
coincident with known radio continuum sources, one of which is of non-thermal
nature. The latter source is also at the center of expansion of a powerful
bipolar outflow observed in water maser emission. We determine the hot core
mass to be 15 solar masses based on the integrated dust continuum emission.
Simultaneously many molecular lines are detected allowing the analysis of the
temperature structure and the distribution of complex organic molecules in the
hot core. From HNCO lines, spanning a wide range of excitation, two 200 K
temperature peaks are found coincident with dust continuum emission peaks
suggesting embedded heating sources within them.Comment: 12 pages, 3 figure
Neutron-induced background in the CONUS experiment
CONUS is a novel experiment aiming at detecting elastic neutrino nucleus
scattering in the fully coherent regime using high-purity Germanium (Ge)
detectors and a reactor as antineutrino () source. The detector setup
is installed at the commercial nuclear power plant in Brokdorf, Germany, at a
very small distance to the reactor core in order to guarantee a high flux of
more than 10/(scm). For the experiment, a good
understanding of neutron-induced background events is required, as the neutron
recoil signals can mimic the predicted neutrino interactions. Especially
neutron-induced events correlated with the thermal power generation are
troublesome for CONUS. On-site measurements revealed the presence of a thermal
power correlated, highly thermalized neutron field with a fluence rate of
(74530)cmd. These neutrons that are produced by nuclear
fission inside the reactor core, are reduced by a factor of 10 on
their way to the CONUS shield. With a high-purity Ge detector without shield
the -ray background was examined including highly thermal power
correlated N decay products as well as -lines from neutron
capture. Using the measured neutron spectrum as input, it was shown, with the
help of Monte Carlo simulations, that the thermal power correlated field is
successfully mitigated by the installed CONUS shield. The reactor-induced
background contribution in the region of interest is exceeded by the expected
signal by at least one order of magnitude assuming a realistic ionization
quenching factor of 0.2.Comment: 28 pages, 28 figure
Psychopharmacologic Treatment of Children Prenatally Exposed to Drugs of Abuse
Objective
This pilot study compared the pharmacologic treatment history and clinical outcomes observed in pediatric outpatients with psychiatric disorders exposed to drugs of abuse in utero to those of an age-matched, sex-matched and psychiatric disorder-matched, non-drug-exposed group.
Methods
In this matched cohort study, medical records of children treated at an academic, child and adolescent psychiatry outpatient clinic were reviewed. Children with caregiver-reported history of prenatal drug exposure were compared with a non-drug-exposed control group being cared for by the same providers. Patients were rated with the Clinical Global Impressions—Severity scale (CGI-S) throughout treatment. The changes in pre-treatment and post-treatment CGI-S scores and the total number of medication trials were determined between groups.
Results
The drug-exposed group (n = 30) had a higher total number of lifetime medication trials compared with the non-drug-exposed group (n = 28) and were taking significantly more total medications, at their final assessment. Unlike the non-drug-exposed group, the drug-exposed group demonstrated a lack of clinical improvement.
Conclusions
These results suggest that in utero drug-exposed children may be more treatment-refractory to or experience greater side effects from the pharmacologic treatment of psychiatric disorders than controls, although we cannot determine if early environment or drugs exposure drives these findings
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