Interploid crosses display a common approach in plant breeding to vary ploidy level in crops. This research included three trials to determine ploidy purity and genomic stability of diploid, triploid ...and auto-tetraploid varieties of German chamomile during life-time and across generations after interploid crosses. Impacts of auxin application were evaluated for seed set, germination rate and progeny ploidy. Ploidy was assessed by flow cytometry and chromosome counting. Ploidy purity in cultivars ranged from 64% (‘Lutea’, 4x) to 100% (‘Bona’, 2x), the share of ploidy-deviants was in 4x-cultivars higher (8%) than in 2x (1%). Auxin application resulted in higher seed set in tetraploids only, while the number of progeny did neither depend on cross direction nor on auxin application. Life time genome stability applied for all ploidy levels. Ploidy level of progeny from 2x × 4x crosses was mostly linked to the maternal level. 3x plants bore progeny with diverse ploidy forms, but not with triploidy. However, cultivars should regularly be monitored for conformance to declared ploidy also in awareness of possible unintended contamination.
Abstract
We extend results first announced by Franz et al., that identified vA 351 = H346 in the Hyades as a multiple star system containing a white dwarf. With Hubble Space Telescope Fine Guidance ...Sensor fringe tracking and scanning, and more recent speckle observations, all spanning 20.7 years, we establish a parallax, relative orbit, and mass fraction for two components, with a period,
and total mass 2.1
. With ground-based radial velocities from the McDonald Observatory Otto Struve 2.1 m Telescope Sandiford Spectrograph, and Center for Astrophysics Digital Speedometers, spanning 37 years, we find that component B consists of BC, two M dwarf stars orbiting with a very short period (
days), having a mass ratio
/
= 0.95. We confirm that the total mass of the system can only be reconciled with the distance and component photometry by including a fainter, higher-mass component. The quadruple system consists of three M dwarfs (A, B, C) and one white dwarf (D). We determine individual M dwarf masses
= 0.53 ± 0.10
,
= 0.43 ± 0.04
, and
= 0.41 ± 0.04
. The white dwarf mass, 0.54 ± 0.04
, comes from cooling models, an assumed Hyades age of 670 Myr, and consistency with all previous and derived astrometric, photometric, and radial velocity results. Velocities from H
α
and He
i
emission lines confirm the BC period derived from absorption lines, with similar (He
i
) and higher (H
α
) velocity amplitudes. We ascribe the larger H
α
amplitude to emission from a region each component shadows from the other, depending on the line of sight.
We report on Keck Interferometer observations of the double-lined binary (B) component of the quadruple pre-main-sequence (PMS) system HD 98800. With these interferometric observations, combined with ...astrometric measurements made by the Hubble Space Telescope (HST) Fine Guidance Sensors (FGS) and published radial velocity observations, we have estimated preliminary visual and physical orbits of the HD 98800 B subsystem. Our orbit model calls for an inclination of 66.8 c 3.2 and allows us to infer the masses and luminosities of the individual components. In particular we find component masses of 0.699 c 0.064 and 0.582 c 0.051 M sub( )for the Ba (primary) and Bb (secondary) components, respectively. Spectral energy distribution (SED) modeling of the B subsystem suggests that the B circumstellar material is a source of extinction along the line of sight to the B components. This seems to corroborate a conjecture by Tokovinin that the B subsystem is viewed through circumbinary material, but it raises important questions about the morphology of that circumbinary material. Our modeling of the subsystem component SEDs finds temperatures and luminosities in agreement with previous studies, and coupled with the component mass estimates allows for comparison with PMS models in the low-mass regime with few empirical constraints. Solar abundance models seem to underpredict the inferred component temperatures and luminosities, while assuming slightly subsolar abundances brings the models and observations into better agreement. The current preliminary orbit does not yet place significant constraints on existing PMS stellar models, but prospects for additional observations improving the orbit model and component parameters are very good.
The purpose of this study was to correlate histopathological with CT findings in patients suffering from hepatocellular carcinoma (HCC) eligible for orthotopic liver transplantation (OLT), with a ...special focus on the antitumoral effect of transarterial chemoembolization (TACE) therapy. A total of 42 consecutive patients suffering from HCC had been treated prior to OLT by means of TACE. TACE was carried out with a mixture of Lipiodol (10–20 ml) and mitomycin C (max. dosage, 10 mg). TACE was performed at 6- to 8-week intervals. Follow-up investigation included contrast-enhanced multislice CT controls and laboratory control. Liver explants were evaluated macroscopically and microscopically to determine the number and size of the tumor lesions as well as the degree of tumor necrosis. Necrosis was investigated in H&E-stained sections. The degree of necrosis was classified as follows: 0–25%, 26–50%, 51–75%, 75–99%, and complete necrosis. Two hundred thirty-one TACE procedures (5.5 ± 2.9; range, 1–14) were performed. Mean tumor size in CT before and after TACE was 4.1 ± 2.4 (range, 1.0–12.0 cm) and 2.7 ± 1.2 (range, 1.0–6.0 cm;
p
< 0.001). Mean tumor number before and after TACE in CT was 2.5 ± 1.5 (
n
= 105; range, 1–8) and 2.4 ± 2.0 (
n
= 103; range, 1–6;
p
= 0.99). In the surgical specimen tumor size and tumor number were 2.8 ± 1.6 (range, 1.0–7.0 cm;
p
= 0.78) and 1.9 ± 1.2 (range, 1–7;
p
= 0.003). Mean tumor necrosis was 67.8% ± 28.1%. Tumor necrosis was subtotal or complete in 17 of 42 (40.5%) patients. Tumor necrosis correlated significantly with the degree of arterial devascularization in CT (
p
= 0.001), the amount of Lipiodol washout (
p
= 0.002), and the number of tumor lesions (i.e., unifocal vs. multifocal). Furthermore, elevated serum levels of bilirubin (
p
= 0.005) and decreased albumin (
p
= 0.004) affected the local antitumoral effect. A poor necrosis rate (< 25%) significantly correlated with the number of TACE procedures accomplished (
p
= 0.023). In conclusion, TACE provided an acceptable local antitumoral effect in patients scheduled for liver transplantation. Tumor necrosis depended significantly on the degree of arterial devascularization and the accumulation of Lipiodol within the HCC lesions. Unifocal tumors and preserved liver function were positive predictors for a more favorable local antitumoral effect. Poor necrosis rates were found in patients with significant Lipiodol washout and who received a limited number of TACE procedures.
An analysis of 15 speckle observations taken at the Lowell-Tololo Telescope at Cerro Tololo Inter-American Observatory and 6 speckle observations taken at the WIYN Telescope at Kitt Peak National ...Observatory indicates that it is possible to characterize the separations, position angles, and magnitude differences of binary stars down to at least one quarter of the diffraction limit with CCD-based speckle imaging. This is made possible by the fact that CCD-based speckle imaging permits the retrieval of reliable photometric information from speckle data, and therefore the elongation of the speckles due to a blended companion may be reliably measured. When observations in two colors are obtained, atmospheric dispersion, which also affects the speckle shape, can be distinguished from binarity in a large number of cases. A regimen for observing sub-diffraction-limited speckle binaries is proposed that could lead to efficient surveys of small-separation binary stars.
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