Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Study of Pickling Methods for Burdock (Arctium lappa L.)

近年由於牛蒡產量大增，開發新的牛蒡加工途徑遂為刻不容緩之事。因此，本研究嘗試以醃漬方法加工牛莠根，以保持或提高其風味、脆度及儲存期限，以增加牛蒡之出路及商品價值。醃漬條件有常法醃漬、低鹽漬、含酒精之低鹽漬及半固態醃漬，包括糠漬、醬油粕漬及味噌漬。結果顯示0.1％檸檬酸溶液即對牛蒡根之黑變有明顯抑制作用，15％食鹽水、7％食靈水及含酒精之7％食鹽水醃漬者，其總氮、甲酵態氮及還原糖含量均被溶出而下降，而且褐變情形嚴重。以半固體醃漬者，所得成品之色澤風味以味噌漬最好。味噌漬成品之切斷強度與切斷能量則於醃漬期間穩定下降，從生牛蒡根之4100g及3000erg下降至成品之1400g及900erg左右，雖以粗老牛蒡製備，但其咬感甚佳。 The browning of burdock root was significantly inhibited in 10% brine containing 0.l%(w/w) citric acid. The addition of citric acid from 0.1 to 1.0% to 10% brine, would keep the color of burdock root in its fresh white state in the first week. Severe browning accurred when burdock root was pickled in 1 5% brine or 7% brine added with or without alcohol, due to the reducing sugar. The nitrogen containing compounds were extracted from burdock root into the pickling medium. Burdock root pickled with miso had better color than that were pickled with rice bran, wine cake, or soy sauce cake. The burdock root pickled with rice bran or soy sauce got higher salt content due to higher amount of salt used in rice bran or soy sauce. Burdock root pickled with miso, wine cake, rice bran, or soy sauce showed lower value of cutting strength (1200-1700g) and cutting energy (about 1100erg), than that pickled with brine-citric acid ( cutting strength 3400g, cutting energy 2400erg)

Bizonplast, a unique chloroplast in the epidermal cells of microphylls in the shade plant Selaginella erythropus (Selaginellaceae)

Study of the unique leaf anatomy and chloroplast structure in shade-adapted plants will aid our understanding of how plants use light efficiently in low light environments. Unusual chloroplasts in terms of size and thylakoid membrane stacking have been described previously in several deep-shade plants. In this study, a single giant cup-shaped chloroplast, termed a bizonoplast, was found in the abaxial epidermal cells of the dorsal microphylls and the adaxial epidermal cells of the ventral microphylls in the deep-shade spike moss Selaginella erythropus. Bizonoplasts are dimorphic in ultrastructure: the upper zone is occupied by numerous layers of 2–4 stacked thylakoid membranes while the lower zone contains both unstacked stromal thylakoids and thylakoid lamellae stacked in normal grana structure oriented in different directions. In contrast, other cell types in the microphylls contain chloroplasts with typical structure. This unique chloroplast has not been reported from any other species. The enlargement of epidermal cells into funnel-shaped, photosynthetic cells coupled with specific localization of a large bizonoplast in the lower part of the cells and differential modification in ultrastructure within the chloroplast may allow the plant to better adapt to low light. Further experiments are required to determine whether this shade-adapted organism derives any evolutionary or ecophysiological fitness from these unique chloroplasts

Bizonoplast a unique chloroplast in the epidermal cells of microphylls in the shade plant Selaginella Erythropus (Selaginellaceae)

Copyright © 2007 Botanical Society of America, Inc.Chiou-Rong Sheue, Vassilios Sarafis, Ruth Kiew, Ho-Yih Liu, Alexandre Salino, Ling-Long Kuo-Huang, Yuen-Po Yang, Chi-Chu Tsai, Chun-Hung Lin, Jean W. H. Yong and Maurice S. B. K