Discolored1 (DSC1) is an ADP-Ribosylation Factor-GTPase Activating Protein Required to Maintain Differentiation of Maize Kernel Structures

The embryo and endosperm are the products of double fertilization and comprise the clonally distinct products of angiosperm seed development. Recessive mutations in the maize gene discolored1 (dsc1) condition inviable seed that are defective in both embryo and endosperm development. Here, detailed phenotypic analyses illustrate that discolored mutant kernels are able to establish, but fail to maintain, differentiated embryo, and endosperm structures. Development of the discolored mutant embryo and endosperm is normal albeit delayed, prior to the abortion and subsequent degeneration of all differentiated kernel structures. Using a genomic fragment that was previously isolated by transposon tagging, the full length dsc1 transcript is identified and shown to encode an ADP-ribosylation factor-GTPase activating protein (ARF-GAP) that co-localizes with the trans-Golgi network/early endosomes and the plasma membrane during transient expression assays in N. benthamiana leaves. DSC1 function during endomembrane trafficking and the maintenance of maize kernel differentiation is discussed

Near-Ultraviolet and Visible Spectroscopy of HAYABUSA Spacecraft Re-entry

HAYABUSA is the first spacecraft ever to land on and lift off from any celestial body other than the moon. The mission, which returned asteroid samples to the Earth while overcoming various technical hurdles, ended on June 13, 2010, with the planned atmospheric re-entry. In order to safely deliver the sample return capsule, the HAYABUSA spacecraft ended its 7-year journey in a brilliant "artificial fireball" over the Australian desert. Spectroscopic observation was carried out in the near-ultraviolet and visible wavelengths between 3000 and 7500 \AA at 3 - 20 \AA resolution. Approximately 100 atomic lines such as Fe I, Mg I, Na I, Al I, Cr I, Mn I, Ni I, Ti I, Li I, Zn I, O I, and N I were identified from the spacecraft. Exotic atoms such as Cu I, Mo I, Xe I and Hg I were also detected. A strong Li I line (6708 \AA) at a height of ~55 km originated from the onboard Li-Ion batteries. The FeO molecule bands at a height of ~63 km were probably formed in the wake of the spacecraft. The effective excitation temperature as determined from the atomic lines varied from 4500 K to 6000 K. The observed number density of Fe I was about 10 times more abundant than Mg I after the spacecraft explosion. N2+(1-) bands from a shock layer and CN violet bands from the sample return capsule's ablating heat shield were dominant molecular bands in the near-ultraviolet region of 3000 - 4000 \AA. OH(A-X) band was likely to exist around 3092 \AA. A strong shock layer from the HAYABUSA spacecraft was rapidly formed at heights between 93 km and 83 km, which was confirmed by detection of N2+(1-) bands with a vibration temperature of ~13000 K. Gray-body temperature of the capsule at a height of ~42 km was estimated to be ~2437 K which is matched to a theoretical prediction. The final message of the HAYABUSA spacecraft and its sample return capsule are discussed through our spectroscopy.Comment: Accepted for publication in PASJ, 22 pages, 7 figures, 6 table

Stable Iodine Distribution among Children after the 2011 Fukushima Nuclear Disaster in Japan: An Observational Study

福島第一原発事故後の安定ヨウ素剤配布後の実態調査を実施 --安定ヨウ素剤の情報提供・内服指示に関する課題が浮き彫りに--. 京都大学プレスリリース. 2019-01-10.Context: Intake of stable iodine helps prevent childhood thyroid cancer in nuclear emergencies but there is limited case information. Objective: We identified the intake rate and the factors associated with no intake among children who did not take stable iodine after the Fukushima disaster. Design: Retrospective observational study. Setting: Data were obtained from thyroid cancer screening performed in August–November 2017. Participants: Children in Miharu Town, Fukushima, Japan. Intervention: No intervention. Main Outcome Measures: We performed multilevel logistic regression analysis at the regional and individual levels. We qualitatively examined the reasons for no intake of stable iodine based on closed- and open-ended questions. Results: The rate of distribution was 94.9%, but the intake rate was only 63.5%. Intake was lower in those aged 0–2 years compared with those aged ≥3 years: odds ratio (OR), 0.21 [95% confidence interval (CI), 0.11–0.36]. Parents’ intake was positively associated with their children’s intake [OR, 61.0 (95% CI, 37.9–102.9)]. The variance partition coefficient for regions was 0.021, suggesting that the intake of stable iodine was more likely affected by individual than by regional factors. The main reasons for avoiding intake were concern about safety, issues related to distribution, drug information sharing, and instructions for intake. There were no claimed adverse effects. Conclusions: The distribution and consumption of stable iodine occurred without claims of adverse effects after the Fukushima disaster. To prepare for future nuclear emergencies, it is important to explain to both children and parents the need for intake of stable iodine, particularly among young children