Aims. We analyze OGLE-2007-BLG-050, a high magnification microlensing event ($A\sim 432$) whose peak occurred on 2 May, 2007, with pronounced finite-source and parallax effects. We compute planet ...detection efficiencies for this event in order to determine its sensitivity to the presence of planets around the lens star. Methods. Both finite-source and parallax effects permit a measurement of the angular Einstein radius $\theta_{\rm E}=0.48\pm 0.01$ mas and the parallax $\pi_{\rm E}=0.12\pm 0.03$, leading to an estimate of the lens mass $M=0.50\pm0.14\,M_{\odot}$ and its distance to the observer $D_L=5.5\pm0.4$ kpc. This is only the second determination of a reasonably precise (<$30\%$) mass estimate for an isolated unseen object, using any method. This allows us to calculate the planetary detection efficiency in physical units $(r_\perp,m_{\rm p})$, where $r_\perp$ is the projected planet-star separation and mp is the planet mass. Results. When computing planet detection efficiency, we did not find any planetary signature, i.e. none of the planetary configurations provides a $\Delta\chi^2$ improvement higher than 60, and our detection efficiency results reveal significant sensitivity to Neptune-mass planets, and to a lesser extent Earth-mass planets in some configurations. Indeed, Jupiter and Neptune-mass planets are excluded with a high confidence for a large projected separation range between the planet and the lens star, respectively 0.6–10 and 1.4–4 AU, and Earth-mass planets are excluded with a 10% confidence in the lensing zone, i.e. 1.8–3.1 AU.
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FMFMET, NUK, UL, UM, UPUK
We present the first microlensing candidate for a free-floating exoplanet-exomoon system, MOA-2011-BLG-262, with a primary lens mass of M sub(host) ~ 4 Jupiter masses hosting a sub-Earth mass moon. ...The argument for an exomoon hinges on the system being relatively close to the Sun. The data constrain the product M sub(L)pi sub(rel) where M sub(L) is the lens system mass and pi sub(rel) is the lens-source relative parallax. If the lens system is nearby (large pi sub(rel)), then M sub(L) is small (a few Jupiter masses) and the companion is a sub-Earth-mass exomoon. The best-fit solution has a large lens-source relative proper motion, mu sub(rel) = 19.6 + or - 1.6 mas yr super(-1), which would rule out a distant lens system unless the source star has an unusually high proper motion. However, data from the OGLE collaboration nearly rule out a high source proper motion, so the exoplanet+exomoon model is the favored interpretation for the best fit model. However, there is an alternate solution that has a lower proper motion and fits the data almost as well. This solution is compatible with a distant (so stellar) host. A Bayesian analysis does not favor the exoplanet+exomoon interpretation, so Occam's razor favors a lens system in the bulge with host and companion masses of M sub(host) = 0.12 super(+0.19) sub(-0.06) M sub(middot in circle) and m sub(comp) = 18 super(+28) sub(-10) M sub(+ in circle), at a projected separation of a sub(perpendicular) = 0.84 super(+0.25) sub(-0.14) AU. The existence of this degeneracy is an unlucky accident, so current microlensing experiments are in principle sensitive to exomoons. In some circumstances, it will be possible to definitively establish the mass of such lens systems through the microlensing parallax effect. Future experiments will be sensitive to less extreme exomoons.
•Our offline adaptive clinical workflow for proton radiotherapy in oesophageal cancer assured adequate target dose coverage.•Target dose coverage was mainly affected by diaphragm displacements in ...VMAT, and target displacements in IMPT.•Most clinically relevant replanning was performed in the first treatment week.•The difference of organ-at-risk dose between IMPT and VMAT remained unchanged during treatment, ensuring adequate model-based patient selection.
In the Netherlands, oesophageal cancer (EC) patients are selected for intensity modulated proton therapy (IMPT) using the expected normal tissue complication probability reduction (ΔNTCP) when treating with IMPT compared to volumetric modulated arc therapy (VMAT). In this study, we evaluate the robustness of the first EC patients treated with IMPT in our clinic in terms of target and organs-at-risk (OAR) dose with corresponding NTCP, as compared to VMAT.
For 20 consecutive EC patients, clinical IMPT and VMAT plans were created on the average planning 4DCT. Both plans were robustly evaluated on weekly repeated 4DCTs and if target coverage degraded, replanning was performed. Target coverage was evaluated for complete treatment trajectories with and without replanning. The planned and accumulated mean lung dose (MLD) and mean heart dose (MHD) were additionally evaluated and translated into NTCP.
Replanning in the clinic was performed more often for IMPT (15x) than would have been needed for VMAT (8x) (p = 0.11). Both adaptive treatments would have resulted in adequate accumulated target dose coverage. Replanning in the first week of treatment had most clinical impact, as anatomical changes resulting in insufficient accumulated target coverage were already observed at this stage. No differences were found in MLD between the planned dose and the accumulated dose. Accumulated MHD differed from the planned dose (p < 0.001), but since these differences were similar for VMAT and IMPT (1.0 and 1.5 Gy, respectively), the ΔNTCP remained unchanged.
Following an adaptive clinical workflow, adequate target dose coverage and stable OAR doses with corresponding NTCPs was assured for both IMPT and VMAT.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A doubled haploid (DH) barley (
Hordeum vulgare
L.) population of 334 lines (ND24260 × Flagship) genotyped with DArT markers was used to map genes for adult plant resistance (APR) to leaf rust (
...Puccinia hordei
Otth) under field conditions in Australia and Uruguay. The Australian barley cultivar Flagship carries an APR gene (
qRphFlag
) derived from the cultivar Vada. Association analysis and composite interval mapping identified two genes conferring APR in this DH population.
qRphFlag
was mapped to the short arm of chromosome 5H (5HS), accounting for 64–85% of the phenotypic variation across four field environments and 56% under controlled environmental conditions (CEC). A second quantitative trait locus (QTL) from ND24260 (
qRphND
) with smaller effect was mapped to chromosome 6HL. In the absence of
qRphFlag
,
qRphND
conferred only a low level of resistance. DH lines displaying the highest level of APR carried both genes. Sequence information for the critical DArT marker bPb-0837 (positioned at 21.2 cM on chromosome 5HS) was used to develop
bPb
-
0837
-
PCR
, a simple PCR-based marker for
qRphFlag
. The 245 bp fragment for
bPb
-
0837
-
PCR
was detected in a range of barley cultivars known to possess APR, which was consistent with previous tests of allelism, demonstrating that the
qRphFlag
resistant allele is common in leaf rust resistant cultivars derived from Vada and Emir.
qRphFlag
has been designated
Rph20
, the first gene conferring APR to
P. hordei
to be characterised in barley. The PCR marker will likely be effective in marker-assisted selection for
Rph20
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•IMPT accomplishes a significant and consistent dose reduction to OARs.•IMPT has comparable robustness compared to VMAT for oesophageal cancer.•Re-planning was required more often for IMPT compared ...to VMAT.
Intensity-modulated proton therapy (IMPT) is expected to result in clinical benefits by lowering radiation dose to organs-at-risk (OARs). However, there are concerns about plan robustness due to motion. To address this uncertainty we evaluated the robustness of IMPT compared to the widely clinically used volumetric modulated arc therapy (VMAT) on weekly repeated computed tomographies (CT).
19 patients with oesophageal cancer were evaluated. IMPT and VMAT plans were created on a planning 4-Dimensional CT (p4DCT) and evaluated on weekly repeated 4DCTs (r4DCT). In case of inadequate target coverage or unacceptable high dose to normal tissue, re-planning was performed. Dose distributions of the r4DCTs were warped to p4DCT, resulting in an estimated actual given dose (EAGD).
Compared to VMAT, IMPT resulted in significantly lowered dose to heart, lungs, spleen, liver and kidneys. For IMPT, target coverage was adequate (after max 1 replanning) in 17/19 cases. In two cases target coverage remained insufficient. However, in one of these patients the summed dose was insufficient (due to tumor shrinkage) while weekly coverage was adequate. For the other patient the target coverage was also insufficient by VMAT, due to large anatomical changes during treatment. For VMAT, adequate target coverage was achieved in 18/19 cases without re-planning. However, for reasons of high OAR dose re-planning was required in two cases.
IMPT reduces the dose to OARs significantly, while achieving adequate target coverage in the majority of patients. Re-planning was necessary for both IMPT and VMAT due to anatomical changes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The mass function and statistics of binaries provide important diagnostics of the star formation process. Despite this importance, the mass function at low masses remains poorly known due to ...observational difficulties caused by the faintness of the objects. Here we report the microlensing discovery and characterization of a binary lens composed of very low mass stars just above the hydrogen-burning limit. From the combined measurements of the Einstein radius and microlens parallax, we measure the masses of the binary components of 0.10 ? 0.01 M and 0.09 ? 0.01 M . This discovery demonstrates that microlensing will provide a method to measure the mass function of all Galactic populations of very low mass binaries that is independent of the biases caused by the luminosity of the population.
We report the discovery of a several-Jupiter mass planetary companion to the
primary lens star in microlensing event OGLE-2005-BLG-071. Precise (<1%)
photometry at the peak of the event yields an ...extremely high signal-to-noise
ratio detection of a deviation from the light curve expected from an isolated
lens. The planetary character of this deviation is easily and unambiguously
discernible from the gross features of the light curve. Detailed modeling
yields a tightly-constrained planet-star mass ratio of q=m_p/M=0.0071+/-0.0003.
This is the second robust detection of a planet with microlensing,
demonstrating that the technique itself is viable and that planets are not rare
in the systems probed by microlensing, which typically lie several kpc toward
the Galactic center.
Period Changes in the X-ray Pulsar GX 1 + 4 Greenhill, J. G.; Giles, A. B.; Sharma, D. P. ...
Publications of the Astronomical Society of Australia,
1989, Volume:
8, Issue:
2
Journal Article
Peer reviewed
The binary X-ray source GX 1 + 4 was observed during a balloon flight in 1986, November. The source was in a relatively high intensity state. Time analysis of the data shows that the pulsation period ...was 111.8 ± 1.0 s indicating that one or more episodes of spin-down occurred between 1980 and 1986. Folded pulse profiles are very broad with an indication of a notch at the peak. Evidence has been found for a correlation between hard X-ray intensity and phase of the proposed 304 day orbital period. The time averaged intensity since 1980 is an order of magnitude lower than during the 1970’s. A survey of the post 1980 data shows that several reversals of the period derivative have occurred. Spin-up at the rates typical of the 1970’s has been followed by a dramatic spin-down episode with dP/dt>2.4 × 10−7 s/s.
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