428 research outputs found
Dwarf mistletoe-pandora moth interaction and its contribution to ponderosa pine mortality in Arizona
The interaction between Southwestern dwarf mistletoe, Arceuthobtum vaginalum subspecies cryptopodum, infestation and defoliation by the pandora moth, Coloradia pandora pandora , on the Kaibab Plateau in Arizona was evaluated. Heavy defoliation of ponderosa pine, Pinus ponderosa, in 1979 and 1981 resulted in mortality of individual trees in areas of heavy dwarf mistletoe infestation. Postmortem evaluation of ponderosa pines indicated that dead trees had a significantly higher dwarf mistletoe rating than did nearby paired live trees. Of 25 tree pairs evaluated, only two live trees had higher dwarf mistletoe ratings than the paired dead tree. Mean dwarf mistletoe ratings were:live trees 2.9, dead trees 4.6 (6 class dwarf mistletoe rating system). Implications for management of the pandora moth are discussed
Validation of real-time PCR and bacteriological culture for identification of Streptococcus agalactiae and Staphylococcus aureus in milk and on teat skin in herds with automatic milking system
OGLE-2009-BLG-092/MOA-2009-BLG-137: A Dramatic Repeating Event With the Second Perturbation Predicted by Real-Time Analysis
We report the result of the analysis of a dramatic repeating gravitational
microlensing event OGLE-2009-BLG-092/MOA-2009-BLG-137, for which the light
curve is characterized by two distinct peaks with perturbations near both
peaks. We find that the event is produced by the passage of the source
trajectory over the central perturbation regions associated with the individual
components of a wide-separation binary. The event is special in the sense that
the second perturbation, occurring days after the first, was
predicted by the real-time analysis conducted after the first peak,
demonstrating that real-time modeling can be routinely done for binary and
planetary events. With the data obtained from follow-up observations covering
the second peak, we are able to uniquely determine the physical parameters of
the lens system. We find that the event occurred on a bulge clump giant and it
was produced by a binary lens composed of a K and M-type main-sequence stars.
The estimated masses of the binary components are
and , respectively, and they are separated in
projection by . The measured distance to the
lens is . We also detect the orbital motion
of the lens system.Comment: 18 pages, 5 figures, 1 tabl
MOA-2009-BLG-387Lb: A massive planet orbiting an M dwarf
We report the discovery of a planet with a high planet-to-star mass ratio in
the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations
over a 12-day interval, one of the longest for any planetary event. The host is
an M dwarf, with a mass in the range 0.07 M_sun < M_host < 0.49M_sun at 90%
confidence. The planet-star mass ratio q = 0.0132 +- 0.003 has been measured
extremely well, so at the best-estimated host mass, the planet mass is m_p =
2.6 Jupiter masses for the median host mass, M = 0.19 M_sun. The host mass is
determined from two "higher order" microlensing parameters. One of these, the
angular Einstein radius \theta_E = 0.31 +- 0.03 mas, is very well measured, but
the other (the microlens parallax \pi_E, which is due to the Earth's orbital
motion) is highly degenate with the orbital motion of the planet. We
statistically resolve the degeneracy between Earth and planet orbital effects
by imposing priors from a Galactic model that specifies the positions and
velocities of lenses and sources and a Kepler model of orbits. The 90%
confidence intervals for the distance, semi-major axis, and period of the
planet are 3.5 kpc < D_L < 7.9 kpc, 1.1 AU < a < 2.7AU, and 3.8 yr < P < 7.6
yr, respectively.Comment: 20 pages including 8 figures. A&A 529 102 (2011
High-precision photometry by telescope defocussing - VI. WASP-24, WASP-25 and WASP-26
The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013/) under grant agreement nos. 229517 and 268421. This publication was supported by grants NPRP 09-476-1-078 and NPRP X-019-1-006 from Qatar National Research Fund (a member of Qatar Foundation). TCH acknowledges financial support from the Korea Research Council for Fundamental Science and Technology (KRCF) through the Young Research Scientist Fellowship Programme and is supported by the KASI (Korea Astronomy and Space Science Institute) grant 2012-1-410-02/2013-9-400-00. SG, XW and XF acknowledge the support from NSFC under the grant no. 10873031. The research is supported by the ASTERISK project (ASTERoseismic Investigations with SONG and Kepler) funded by the European Research Council (grant agreement no. 267864). DR, YD, AE, FF (ARC), OW (FNRS research fellow) and J Surdej acknowledge support from the Communauté française de Belgique – Actions de recherche concertées – Académie Wallonie-Europe.We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 and WASP-26 have been observed with Spitzer, and WASP-25 was previously comparatively neglected. Our light curves were obtained using the telescope-defocussing method and have scatters of 0.5–1.2 mmag relative to their best-fitting geometric models. We use these data to measure the physical properties and orbital ephemerides of the systems to high precision, finding that our improved measurements are in good agreement with previous studies. High-resolution Lucky Imaging observations of all three targets show no evidence for faint stars close enough to contaminate our photometry. We confirm the eclipsing nature of the star closest to WASP-24 and present the detection of a detached eclipsing binary within 4.25 arcmin of WASP-26.Publisher PDFPeer reviewe
MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light
Microlensing detections of cool planets are important for the construction of
an unbiased sample to estimate the frequency of planets beyond the snow line,
which is where giant planets are thought to form according to the core
accretion theory of planet formation. In this paper, we report the discovery of
a giant planet detected from the analysis of the light curve of a
high-magnification microlensing event MOA-2010-BLG-477. The measured
planet-star mass ratio is and the projected
separation is in units of the Einstein radius. The angular
Einstein radius is unusually large mas. Combining
this measurement with constraints on the "microlens parallax" and the lens
flux, we can only limit the host mass to the range . In
this particular case, the strong degeneracy between microlensing parallax and
planet orbital motion prevents us from measuring more accurate host and planet
masses. However, we find that adding Bayesian priors from two effects (Galactic
model and Keplerian orbit) each independently favors the upper end of this mass
range, yielding star and planet masses of
and at a distance of kpc,
and with a semi-major axis of AU. Finally, we show that the
lens mass can be determined from future high-resolution near-IR adaptive optics
observations independently from two effects, photometric and astrometric.Comment: 3 Tables, 12 Figures, accepted in Ap
Faint source star planetary microlensing : the discovery of the cold gas giant planet OGLE-2014-BLG-0676Lb
We report the discovery of a planet — OGLE-2014-BLG-0676Lb— via gravitational microlensing. Observations for the lensing event were made by the MOA, OGLE, Wise, RoboNET/LCOGT, MiNDSTEp and μFUN groups. All analyses of the light curve data favour a lens system comprising a planetary mass orbiting a host star. The most favoured binary lens model has a mass ratio between the two lens masses of (4.78 ± 0.13) × 10−3. Subject to some important assumptions, a Bayesian probability density analysis suggests the lens system comprises a 3.09 (+1.02/−1.12) MJ planet orbiting a 0.62(+0.20/−0.22) M⊙ host star at a deprojected orbital separation of 4.40 (+2.16/−1.46) AU. The distance to the lens system is 2.22 (+0.96/−0.83) kpc. Planet OGLE-2014-BLG-0676Lb provides additional data to the growing number of cool planets discovered using gravitational microlensing against which planetary formation theories may be tested. Most of the light in the baseline of this event is expected to come from the lens and thus high-resolution imaging observations could confirm our planetary model interpretation.PostprintPeer reviewe
MOA-2010-BLG-523: "Failed Planet" = RS CVn Star
peer reviewedThe Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing light curve near the peak of an A [SUB]max[/SUB] ~ 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spectrum taken near peak to demonstrate that this is an RS CVn variable, so that planetary microlensing is not required to explain the light-curve deviations. This is the first spectroscopically confirmed RS CVn star discovered in the Galactic bulge. Based on observations made with the European Southern Observatory telescopes, Program ID 85.B-0399(I)
A giant planet beyond the snow line in microlensing event OGLE-2011-BLG-0251
Aims: We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic bulge. Methods: Based on detailed modelling of the observed light curve, we find that the lens is composed of two masses with a mass ratio q = 1.9 × 10[SUP]-3[/SUP]. Thanks to our detection of higher-order effects on the light curve due to the Earth's orbital motion and the finite size of source, we are able to measure the mass and distance to the lens unambiguously. Results: We find that the lens is made up of a planet of mass 0.53 ± 0.21 M[SUB]J[/SUB] orbiting an M dwarf host star with a mass of 0.26 ± 0.11 M[SUB]⊙[/SUB]. The planetary system is located at a distance of 2.57 ± 0.61 kpc towards the Galactic centre. The projected separation of the planet from its host star is d = 1.408 ± 0.019, in units of the Einstein radius, which corresponds to 2.72 ± 0.75 AU in physical units. We also identified a competitive model with similar planet and host star masses, but with a smaller orbital radius of 1.50 ± 0.50 AU. The planet is therefore located beyond the snow line of its host star, which we estimate to be around ~1-1.5 AU
Hippocampal - diencephalic - cingulate networks for memory and emotion: An anatomical guide
This review brings together current knowledge from tract tracing studies to update and reconsider those limbic connections initially highlighted by Papez for their presumed role in emotion. These connections link hippocampal and parahippocampal regions with the mammillary bodies, the anterior thalamic nuclei, and the cingulate gyrus, all structures now strongly implicated in memory functions. An additional goal of this review is to describe the routes taken by the various connections within this network. The original descriptions of these limbic connections saw their interconnecting pathways forming a serial circuit that began and finished in the hippocampal formation. It is now clear that with the exception of the mammillary bodies, these various sites are multiply interconnected with each other, including many reciprocal connections. In addition, these same connections are topographically organised, creating further subsystems. This complex pattern of connectivity helps explain the difficulty of interpreting the functional outcome of damage to any individual site within the network. For these same reasons, Papez’s initial concept of a loop beginning and ending in the hippocampal formation needs to be seen as a much more complex system of hippocampal–diencephalic–cingulate connections. The functions of these multiple interactions might be better viewed as principally providing efferent information from the posterior medial temporal lobe. Both a subcortical diencephalic route (via the fornix) and a cortical cingulate route (via retrosplenial cortex) can be distinguished. These routes provide indirect pathways for hippocampal interactions with prefrontal cortex, with the preponderance of both sets of connections arising from the more posterior hippocampal regions. These multi-stage connections complement the direct hippocampal projections to prefrontal cortex, which principally arise from the anterior hippocampus, thereby creating longitudinal functional differences along the anterior–posterior plane of the hippocampus
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