Identification of a non-thermal X-ray burst with the Galactic magnetar SGR J1935+2154 and a fast radio burst using

Plant uptake of antibiotic oxytetracycline is energy-dependent. AbstractA series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by MichaeliseMenten equation with V max of 2.25 mmol g À1 fresh weight h À1 , and K m of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag þ . OTC uptake, however, was significantly inhibited by Hg 2þ , suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg 2þ on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process.

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A B S T R A C TA pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing de-dispersion of the pulsar signals is provided by a 2 Â 128 Â 2:5 MHz filterbank/digitizer system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period derivatives, as well as improved positions. Comparison with previous measurements showed that the changes in period and period derivative tend to have the same sign and to be correlated in amplitude. A model based on unseen glitches gives a good explanation of the observed changes, suggesting that long-term fluctuations in period and period derivatives are dominated by glitches. In 2000 July, we detected a glitch of relative amplitude Dn/ n , 24 Â 10 29 in the Crab pulsar. The post-glitch decay appears similar to other large Crab glitches.