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result(s) for
"Kitazaki, K"
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Cytoplasmic genome diversity in the cultivated apple - Short Communication
by
Yuji Kishima
,
Kazuyoshi Kitazaki
,
Tetsuo Mikami
in
Agriculture (General)
,
Apples
,
Chloroplasts
2015
The cultivated apple is one of the most common and important fruit crops in temperate regions. Phylogenetic analysis using a wide array of apple genotypes could give insights into the origin and domestication history of this crop. Maternally inherited mitochondrial and chloroplast DNAs have been utilised to characterise the cytoplasmic diversity within the apple germplasm collection and to elucidate the relationships between the cytoplasm types defined. This review focuses on the molecular basis of changes in the mitochondrial genome giving rise to diverse cytoplasm types. The possible maternal lineage of the cultivated apple is also discussed.
Journal Article
Scaling slowly rotating asteroids by stellar occultations
2023
As evidenced by recent survey results, majority of asteroids are slow rotators (P>12 h), but lack spin and shape models due to selection bias. This bias is skewing our overall understanding of the spins, shapes, and sizes of asteroids, as well as of their other properties. Also, diameter determinations for large (>60km) and medium-sized asteroids (between 30 and 60 km) often vary by over 30% for multiple reasons. Our long-term project is focused on a few tens of slow rotators with periods of up to 60 hours. We aim to obtain their full light curves and reconstruct their spins and shapes. We also precisely scale the models, typically with an accuracy of a few percent. We used wide sets of dense light curves for spin and shape reconstructions via light-curve inversion. Precisely scaling them with thermal data was not possible here because of poor infrared data: large bodies are too bright for WISE mission. Therefore, we recently launched a campaign among stellar occultation observers, to scale these models and to verify the shape solutions, often allowing us to break the mirror pole ambiguity. The presented scheme resulted in shape models for 16 slow rotators, most of them for the first time. Fitting them to stellar occultations resolved previous inconsistencies in size determinations. For around half of the targets, this fitting also allowed us to identify a clearly preferred pole solution, thus removing the ambiguity inherent to light-curve inversion. We also address the influence of the uncertainty of the shape models on the derived diameters. Overall, our project has already provided reliable models for around 50 slow rotators. Such well-determined and scaled asteroid shapes will, e.g. constitute a solid basis for density determinations when coupled with mass information. Spin and shape models continue to fill the gaps caused by various biases.
Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs
2020
Trans-Neptunian objects (TNOs) and Centaurs are remnants of our planetary system formation, and their physical properties have invaluable information for evolutionary theories. Stellar occultation is a ground-based method for studying these small bodies and has presented exciting results. These observations can provide precise profiles of the involved body, allowing an accurate determination of its size and shape. The goal is to show that even single-chord detections of TNOs allow us to measure their milliarcsecond astrometric positions in the reference frame of the Gaia second data release (DR2). Accurated ephemerides can then be generated, allowing predictions of stellar occultations with much higher reliability. We analyzed data from stellar occultations to obtain astrometric positions of the involved bodies. The events published before the Gaia era were updated so that the Gaia DR2 catalog is the reference. Previously determined sizes were used to calculate the position of the object center and its corresponding error with respect to the detected chord and the International Celestial Reference System (ICRS) propagated Gaia DR2 star position. We derive 37 precise astrometric positions for 19 TNOs and 4 Centaurs. Twenty-one of these events are presented here for the first time. Although about 68\\% of our results are based on single-chord detection, most have intrinsic precision at the submilliarcsecond level. Lower limits on the diameter and shape constraints for a few bodies are also presented as valuable byproducts. Using the Gaia DR2 catalog, we show that even a single detection of a stellar occultation allows improving the object ephemeris significantly, which in turn enables predicting a future stellar occultation with high accuracy. Observational campaigns can be efficiently organized with this help, and may provide a full physical characterization of the involved object.
Physical properties of Centaur (60558) 174P/Echeclus from stellar occultations
by
Assafin, M
,
Sebastian, D
,
Ortiz, J L
in
Internal friction
,
Optical thickness
,
Physical properties
2023
The Centaur (60558) Echeclus was discovered on March 03, 2000, orbiting between the orbits of Jupiter and Uranus. After exhibiting frequent outbursts, it also received a comet designation, 174P. If the ejected material can be a source of debris to form additional structures, studying the surroundings of an active body like Echeclus can provide clues about the formation scenarios of rings, jets, or dusty shells around small bodies. Stellar occultation is a handy technique for this kind of investigation, as it can, from Earth-based observations, detect small structures with low opacity around these objects. Stellar occultation by Echeclus was predicted and observed in 2019, 2020, and 2021. We obtain upper detection limits of rings with widths larger than 0.5 km and optical depth of \\(\\tau\\) = 0.02. These values are smaller than those of Chariklo's main ring; in other words, a Chariklo-like ring would have been detected. The occultation observed in 2020 provided two positive chords used to derive the triaxial dimensions of Echeclus based on a 3D model and pole orientation available in the literature. We obtained \\(a = 37.0\\pm0.6\\) km, \\(b = 28.4 \\pm 0.5\\) km, and \\(c= 24.9 \\pm 0.4\\) km, resulting in an area-equivalent radius of \\(30.0 \\pm 0.5\\) km. Using the projected limb at the occultation epoch and the available absolute magnitude (\\(\\rm{H}_{\\rm{v}} = 9.971 \\pm 0.031\\)), we calculate an albedo of \\(p_{\\rm{v}} = 0.050 \\pm 0.003\\). Constraints on the object's density and internal friction are also proposed.
Growth enhancement effects of radish sprouts: atmospheric pressure plasma irradiation vs. heat shock
by
Amano, T
,
Hayashi, N
,
Uchida, G
in
Barometric pressure
,
Dielectric barrier discharge
,
Heat shock
2014
We compare growth enhancement effects due to atmospheric air dielectric barrier discharge plasma irradiation and heat shock to seeds of radish sprouts (Raphanus sativus L.). Interactions between radicals and seeds in a short duration of 3 min. lead to the growth enhancement of radish sprouts in a long term of 7 days and the maximum average length is 3.7 times as long as that of control. The growth enhancement effects become gradually weak with time, and hence the ratio of the average length for plasma irradiation to that for control decreases from 3.7 for the first day to 1.3 for 7 day. The average length for heat shock of 60°C for 10 min. and 100°C for 3 min. is longer than that for control, and the maximum average length is 1.3 times as long as that of control. Heat shock has little contribution to the growth enhancement due to plasma irradiation, because the maximum temperature due to plasma irradiation is less than 60°C.
Journal Article
Usefulness of antiemetic therapy with aprepitant, palonosetron, and dexamethasone for lung cancer patients on cisplatin-based or carboplatin-based chemotherapy
by
Fukahori, Susumu
,
Kohno, Shigeru
,
Soda, Hiroshi
in
Aged
,
Antiemetics - therapeutic use
,
Antineoplastic Agents - adverse effects
2015
Purpose
The purpose of the study is to investigate the usefulness of the triplet regimen comprising aprepitant, palonosetron, and dexamethasone in patients treated with highly emetogenic chemotherapy (HEC) and moderately emetogenic chemotherapy (MEC).
Methods
Patients with lung cancer (aged 65.8 ± 8.4 years) who received carboplatin-based MEC and those treated with cisplatin-based HEC were enrolled. The antiemetic regimen for both types of chemotherapy consisted of aprepitant, palonosetron, and dexamethasone based on the May 2010 guidelines prepared by the Japan Society of Clinical Oncology. The incidence of chemotherapy-induced nausea and vomiting (CINV) and the use of salvage treatment were assessed. The primary endpoints were the percentage of patients with a complete response (CR: no nausea and no salvage treatment) during the entire study period (5 days) after chemotherapy, during the acute phase (day 1), and during the delayed phase (days 2–5).
Results
CR rates for the entire period were 86 and 71 % in patients receiving carboplatin-based and cisplatin-based chemotherapy, respectively. CR rates were respectively 98 and 100 % in the acute phase versus 87 and 71 % in the delayed phase. Most of the patients could ingest food throughout the entire period after chemotherapy. Assessment of various risk factors for acute and delayed CINV (gender, age, prior vomiting due to antineoplastic therapy, prior experience of motion sickness, and history of drinking) revealed no significant influence of these factors on the CR rate for the entire period in patients receiving either carboplatin-based or cisplatin-based chemotherapy.
Conclusion
The present triple therapy can be recommended for supporting both carboplatin-based and cisplatin-based chemotherapy regimens.
Journal Article