Observations of wild hunting behaviour and bioluminescence of a large deep-sea, eight-armed squid, Taningia danae

Our newly developed underwater high definition video camera system took the first live images of adults of the mesopelagic large squid, Taningia danae, between 240 and 940 m deep off Ogasawara Islands, western North Pacific. The resulting footage includes attacking and bioluminescence behaviours, and reveals that T. danae is far from the sluggish neutrally buoyant deep-sea squid previously suspected. It can actively swim both forward and backward freely by flapping its large muscular triangular fins and changes direction quickly through bending its flexible body. It can attain speeds of 2–2.5 m s−1 (7.2–9 km h−1) when attacking bait rigs. They emitted short bright light flashes from their large arm-tip photophores before final assault, which might act as a blinding flash for prey as well as a means of measuring target distance in a dark deep-sea environment. They also emitted long and short glows separated by intervals while wandering around the double torch lights attached to the bait rig, suggestive of potential courtship behaviours during mating

On the Nature of AX J2049.6+2939 and AX J2050.0+2914

AX J2049.6+2939 is a compact X-ray source in the vicinity of the southern blow-up region of the Cygnus Loop supernova remnant (Miyata et al. 1998a). This source was the brightest X-ray source inside the Cygnus Loop observed during the ASCA survey project. The X-ray spectrum was well fitted by a power-law function with a photon index of $-2.1 \pm 0.1$. Short-term timing analysis was performed and no coherent pulsation was found. Follow-up observations with ASCA have revealed a large variation in X-ray intensity by a factor of $\simeq$ 50, whereas the spectral shape did not change within the statistical uncertainties. In the second ASCA observation, we found another X-ray source, AX J2050.0+2941, at the north east of AX J2049.6+2939. During the three ASCA observations, the X-ray intensity of AX J2050.0+2941 varied by a factor of $\simeq$4. No coherent pulsations could be found for AX J2050.0+2941. We have performed optical photometric and spectroscopic observations in the vicinity of AX J2049.6+2939 at the Kitt Peak National Observatory (KPNO). As a result, all objects brighter than $B$-band magnitude of 22 in the error box can be identified with normal stars. Combined with the X-ray results and the fact that there are no radio counterparts, AX J2049.6+2939 is not likely to be either an ordinary rotation-powered pulsar or an AGN. The nature of AX J2049.6+2939 is still unclear and further observations over a wide energy band are strongly required. As to AX J2050.0+2941, the long-term X-ray variability and the radio counterpart suggests that it is an AGN.Comment: 23 pages, 4 figures, Accepted for publication by Astrophysical Journa

発症早期ALS患者に対する超高用量メチルコバラミンの有効性・安全性について : ランダム化比較試験

Importance: Post hoc analysis in a phase 2/3 trial indicated ultra-high dose methylcobalamin slowed decline of the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score at week 16 as well as at week 182, without increase of adverse events, in patients with amyotrophic lateral sclerosis (ALS) who were enrolled within 1 year from onset. Objective: To validate the efficacy and safety of ultra-high dose methylcobalamin for patients with ALS enrolled within 1 year of onset. Design: A multicenter, placebo-controlled, double-blind, randomized phase 3 trial with 12-week observation and 16-week randomized period, conducted from October 2017 to September 2019. Setting: Twenty-five neurology centers in Japan. Participants: Patients with ALS diagnosed within 1 year of onset by the updated Awaji criteria were initially enrolled. Of those, patients fulfilling the following criteria after 12-week observation were eligible for randomization: 1- or 2-point decrease in ALSFRS-R total score, a percent forced vital capacity over 60%, no history of noninvasive respiratory support and tracheostomy, and being ambulant. The target number was 64 in both methylcobalamin and placebo groups. Of 203 patients enrolled in the observation, 130 patients (age, 61.0 ± 11.7 years; female, 56) met the criteria and were randomly assigned through an electronic web-response system to methylcobalamin or placebo (65 for each). Of these, 129 patients were eligible for the full analysis set, and 126 completed the double-blind stage. Interventions: Intramuscular injection of methylcobalamin 50 mg or placebo twice weekly for 16 weeks. Main outcomes and measures: The primary endpoint was change in ALSFRS-R total score from baseline to week 16 in the full analysis set. Results: The least-squares mean difference in ALSFRS-R total score at week 16 of the randomized period was 1.97 points greater with methylcobalamin than placebo (−2.66 versus −4.63; 95% CI, 0.44–3.50; P = 0.012). The incidence of adverse events was similar between the two groups. Conclusions and relevance: Ultra-high dose methylcobalamin was efficacious in slowing functional decline and safe in the 16-week treatment period in ALS patients in the early stage and with moderate progression rate. Trial registration: UMIN-CTR Identifier: UMIN000029588 (umin.ac.jp/ctr); ClinicalTrials.gov Identifier: NCT03548311 (clinicaltrials.gov