414 research outputs found
Management Strategies for the Control of Soybean Rust
The identification of Asian soybean rust in Paraguay in 2001(Morel and Yorinori, 2002) and its spread to over 90% of the soybean production in Brazil through the 2003 season has heightened the awareness that this disease will soon be a threat to production on the continental USA. With the yield losses this disease can cause it will have a big impact on the profitability of soybean production
Investigations into the possible regulation of negative gravitropic curvature in intact Avena sativa plants and in isolated stem segments by ethylene and gibberellins
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72965/1/j.1399-3054.1985.tb02389.x.pd
The Nature of Associated Absorption and the UV-X-ray Connection in 3C 288.1
We discuss new Hubble Space Telescope spectroscopy of the radio-loud quasar,
3C 288.1. The data cover ~590 A to ~1610 A in the quasar rest frame. They
reveal a wealth of associated absorption lines (AALs) with no accompanying
Lyman-limit absorption. The metallic AALs range in ionization from C III and N
III to Ne VIII and Mg X. We use these data and photoionization models to derive
the following properties of the AAL gas: 1) There are multiple ionization zones
within the AAL region, spanning a factor of at least ~50 in ionization
parameter. 2) The overall ionization is consistent with the ``warm'' X-ray
continuum absorbers measured in Seyfert 1 nuclei and other QSOs. However, 3)
the column densities implied by the AALs in 3C 288.1 are too low to produce
significant bound-free absorption at any UV-X-ray wavelengths. Substantial
X-ray absorption would require yet another zone, having a much higher
ionization or a much lower velocity dispersion than the main AAL region. 4) The
total hydrogen column density in the AAL gas is log N_H (cm-2)= 20.2. 5) The
metallicity is roughly half solar. 6) The AALs have deconvolved widths of ~900
km/s and their centroids are consistent with no shift from the quasar systemic
velocity (conservatively within +/-1000 km/s). 7) There are no direct
indicators of the absorber's location in our data, but the high ionization and
high metallicity both suggest a close physical relationship to the quasar/host
galaxy environment. Finally, the UV continuum shape gives no indication of a
``blue bump'' at higher energies. There is a distinct break of unknown origin
at ~1030 A, and the decline toward higher energies (with spectral index alpha =
-1.73, for f_nu ~ nu^alpha) is even steeper than a single power-law
interpolation from 1030 A to soft X-rays.Comment: 27 pages with figures and tables, in press with Ap
The USNO-B Catalog
USNO-B is an all-sky catalog that presents positions, proper motions,
magnitudes in various optical passbands, and star/galaxy estimators for
1,042,618,261 objects derived from 3,643,201,733 separate observations. The
data were obtained from scans of 7,435 Schmidt plates taken for the various sky
surveys during the last 50 years. USNO-B1.0 is believed to provide all-sky
coverage, completeness down to V = 21, 0.2 arcsecond astrometric accuracy at
J2000, 0.3 magnitude photometric accuracy in up to five colors, and 85%
accuracy for distinguishing stars from non-stellar objects. A brief discussion
of various issues is given here, but the actual data are available from
http://www.nofs.navy.mil and other sites.Comment: Accepted by Astronomical Journa
Active vitamin D (1,25-dihydroxyvitamin D) and bone health in middle-aged and elderly men: the European male aging study (EMAS)
<p>Context: There is little information on the potential impact of serum 1,25-dihydroxyvitamin D [1,25(OH)2D] on bone health including turnover.</p>
<p>Objective: The objective of the study was to determine the influence of 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] on bone health in middle-aged and older European men.</p>
<p>Design, Setting, and Participants: Men aged 40–79 years were recruited from population registers in 8 European centers. Subjects completed questionnaires that included questions concerning lifestyle and were invited to attend for quantitative ultrasound (QUS) of the heel, assessment of height and weight, and a fasting blood sample from which 1,25(OH)2D, 25(OH)D, and PTH were measured. 1,25(OH)2D was measured using liquid chromatography tandem mass spectrometry. Bone markers serum N-terminal propeptide of type 1 procollagen (P1NP) and crosslinks (β-cTX) were also measured. Dual-energy x-ray absorptiometry (DXA) of the hip and lumbar spine was performed in 2 centers.</p>
<p>Main Outcome Measure(s): QUS of the heel, bone markers P1NP and β-cTX, and DXA of the hip and lumbar spine were measured.</p>
<p>Results: A total of 2783 men, mean age 60.0 years (SD 11.0) were included in the analysis. After adjustment for age and center, 1,25(OH)2D was positively associated with 25(OH)D but not with PTH. 25(OH)D was negatively associated with PTH. After adjustment for age, center, height, weight, lifestyle factors, and season, 1,25(OH)2D was associated negatively with QUS and DXA parameters and associated positively with β-cTX. 1,25(OH)2D was not correlated with P1NP. 25(OH)D was positively associated with the QUS and DXA parameters but not related to either bone turnover marker. Subjects with both high 1,25(OH)2D (upper tertile) and low 25(OH)D (lower tertile) had the lowest QUS and DXA parameters and the highest β-cTX levels.</p>
<p>Conclusions: Serum 1,25(OH)2D is associated with higher bone turnover and poorer bone health despite being positively related to 25(OH)D. A combination of high 1,25(OH)2D and low 25(OH)D is associated with the poorest bone health.</p>
Active vitamin D (1,25-dihydroxyvitamin D) and bone health in middle-aged and elderly men: the European male aging study (EMAS)
<p>Context: There is little information on the potential impact of serum 1,25-dihydroxyvitamin D [1,25(OH)2D] on bone health including turnover.</p>
<p>Objective: The objective of the study was to determine the influence of 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] on bone health in middle-aged and older European men.</p>
<p>Design, Setting, and Participants: Men aged 40–79 years were recruited from population registers in 8 European centers. Subjects completed questionnaires that included questions concerning lifestyle and were invited to attend for quantitative ultrasound (QUS) of the heel, assessment of height and weight, and a fasting blood sample from which 1,25(OH)2D, 25(OH)D, and PTH were measured. 1,25(OH)2D was measured using liquid chromatography tandem mass spectrometry. Bone markers serum N-terminal propeptide of type 1 procollagen (P1NP) and crosslinks (β-cTX) were also measured. Dual-energy x-ray absorptiometry (DXA) of the hip and lumbar spine was performed in 2 centers.</p>
<p>Main Outcome Measure(s): QUS of the heel, bone markers P1NP and β-cTX, and DXA of the hip and lumbar spine were measured.</p>
<p>Results: A total of 2783 men, mean age 60.0 years (SD 11.0) were included in the analysis. After adjustment for age and center, 1,25(OH)2D was positively associated with 25(OH)D but not with PTH. 25(OH)D was negatively associated with PTH. After adjustment for age, center, height, weight, lifestyle factors, and season, 1,25(OH)2D was associated negatively with QUS and DXA parameters and associated positively with β-cTX. 1,25(OH)2D was not correlated with P1NP. 25(OH)D was positively associated with the QUS and DXA parameters but not related to either bone turnover marker. Subjects with both high 1,25(OH)2D (upper tertile) and low 25(OH)D (lower tertile) had the lowest QUS and DXA parameters and the highest β-cTX levels.</p>
<p>Conclusions: Serum 1,25(OH)2D is associated with higher bone turnover and poorer bone health despite being positively related to 25(OH)D. A combination of high 1,25(OH)2D and low 25(OH)D is associated with the poorest bone health.</p>
Scientific Objectives of Einstein Telescope
The advanced interferometer network will herald a new era in observational
astronomy. There is a very strong science case to go beyond the advanced
detector network and build detectors that operate in a frequency range from 1
Hz-10 kHz, with sensitivity a factor ten better in amplitude. Such detectors
will be able to probe a range of topics in nuclear physics, astronomy,
cosmology and fundamental physics, providing insights into many unsolved
problems in these areas.Comment: 18 pages, 4 figures, Plenary talk given at Amaldi Meeting, July 201
Discovery of an Unusually Red L-type Brown Dwarf
We report the discovery of an unusually red brown dwarf found in a search for
high proper motion objects using WISE and 2MASS data. WISEP J004701.06+680352.1
is moving at 0.44$ arcsec/yr and lies relatively close to the Galactic Plane
(b=5.2 degrees). Near-infrared photometry and spectroscopy reveals that this is
one of the reddest (2MASS J-K_s = 2.55 +/- 0.08 mag) field L dwarfs yet
detected, making this object an important member of the class of unusually red
L dwarfs. We discuss evidence for thick condensate clouds and speculate on the
age of the object. Although models by different research groups agree that
thick clouds can explain the red spectrum, they predict dramatically different
effective temperatures, ranging from 1100K to 1600K. This brown dwarf is well
suited for additional studies of extremely dusty substellar atmospheres because
it is relatively bright (K_s = 13.05 +/- 0.03 mag), which should also
contribute to an improved understanding of young gas-giant planets and the
transition between L and T brown dwarfs.Comment: Accepted to Astronomical Journal (AJ
Astrometry and Photometry for Cool Dwarfs and Brown Dwarfs
Trigonometric parallax determinations are presented for 28 late type dwarfs
and brown dwarfs, including eight M dwarfs with spectral types between M7 and
M9.5, 17 L dwarfs with spectral types between L0 and L8, and three T dwarfs.
Broadband photometry at CCD wavelengths (VRIz) and/or near-IR wavelengths (JHK)
are presented for these objects and for 24 additional late-type dwarfs.
Supplemented with astrometry and photometry from the literature, including ten
L and two T dwarfs with parallaxes established by association with bright,
usually HIPPARCOS primaries, this material forms the basis for studying various
color-color and color-absolute magnitude relations. The I-J color is a good
predictor of absolute magnitude for late-M and L dwarfs. M_J becomes
monotonically fainter with I-J color and with spectral type through late-L
dwarfs, then brightens for early-T dwarfs. The combination of zJK colors alone
can be used to classify late-M, early-L, and T dwarfs accurately, and to
predict their absolute magnitudes, but is less effective at untangling the
scatter among mid- and late-L dwarfs. The mean tangential velocity of these
objects is found to be slightly less than that for dM stars in the solar
neighborhood, consistent with a sample with a mean age of several Gyr. Using
colors to estimate bolometric corrections, and models to estimate stellar
radii, effective temperatures are derived. The latest L dwarfs are found to
have T_eff ~ 1360 K.Comment: 48 pages, including 7 figures and 6 tables. Accepted for A
Identification of GSK3186899/DDD853651 as a Preclinical Development Candidate for the Treatment of Visceral Leishmaniasis
The leishmaniases are diseases that
affect millions of people across
the world, in particular visceral leishmaniasis (VL) which is fatal
unless treated. Current standard of care for VL suffers from multiple
issues and there is a limited pipeline of new candidate drugs. As
such, there is a clear unmet medical need to identify new treatments.
This paper describes the optimization of a phenotypic hit against Leishmania donovani, the major causative organism
of VL. The key challenges were to balance solubility and metabolic
stability while maintaining potency. Herein, strategies to address
these shortcomings and enhance efficacy are discussed, culminating
in the discovery of preclinical development candidate GSK3186899/DDD853651
(<b>1</b>) for VL
- …