Effect of ascorbic acid on serum cholesterol levels and on die-away curves of 14C-4-cholesterol in baboons

Fourteen young male baboons (Papio ursinus) were divided into two groups. All the animals received the same dietary regimen during a 2%-month adaptation period. During the next 3 months one group received 250 mg and the other 20 mg vitamin C daily. For the last 2% months of the experiment no vitamin C was given to the first group, and that of the second group was increased to 350 mg daily. Simultaneously with the switchover, 14C-4-cholesterol was administered. A classical twopool system for the kinetic behaviour of cholesterol in the body was confirmed. Vitamin C treatment did not alter the serum cholesterol levels significantly, but the production rate was repressed. It was also shown that vitamin C was depleted from the body in a typical two-pool fashion.S. Afr. Med. J., 48, 1182 (1974)

Seasonal variation in serum ascorbic acid and serum lipid composition of free-living baboons (Papio ursinus)

Two surveys were conducted in the Kruger National Park in which 205 baboons were captured. The first survey was done during late summer and the second during late winter. Serum ascorbic acid, serum cholesterol and serum phospholipids were determined. Baboons of both sexes and various ages were captured. This work was undertaken to establish serum ascorbic acid, serum cholesterol and serum phospholipid values for baboons under free-living conditions. A seasonal variation was found, and the serum ascorbic acid serum cholesterol and serum phospholipid values were significantly higher during winter than during summer.S. Afr. Med. J., 48, 1700 (1974

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 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 $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) 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 $\,{M}_{\odot }$. 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 $\sim 40\,{\rm{Mpc}}$) 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 $\sim 9$ and $\sim 16$ 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 NGC 4993 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