Identifying the driver of pulsating aurora

Pulsating aurora, a spectacular emission that appears as blinking of the upper atmosphere in the polar regions, is known to be excited by modulated, downward-streaming electrons. Despite its distinctive feature, identifying the driver of the electron precipitation has been a long-standing problem. Using coordinated satellite and ground-based all-sky imager observations from the THEMIS mission, we provide direct evidence that a naturally occurring electromagnetic wave, lower-band chorus, can drive pulsating aurora. Because the waves at a given equatorial location in space correlate with a single pulsating auroral patch in the upper atmosphere, our findings can also be used to constrain magnetic field models with much higher accuracy than has previously been possible.     

A vital stain for the Golgi apparatus

The Golgi complex, a membranous organelle with important functions in membrane traffic and macromolecular synthesis, has been stained in living cells with a fluorescent sphingolipid. Cells were first incubated with liposomes containing N-[7-(4-nitrobenzo-2-oxa-1,3-diazole)]-6-aminocaproyl sphingosine (C6-NBD-ceramide), or with a bovine serum albumin complex of the fluorescent lipid, and then examined by fluorescence microscopy. An intensely fluorescent perinuclear structure was identified as the Golgi apparatus by its colocalization with known Golgi markers in fixed cells. C6-NBD-ceramide was used to observe the morphology of the Golgi apparatus in living cells in the presence or absence of monensin or Colcemid, and during mitosis. In all cases, C6-NBD-ceramide revealed a Golgi apparatus in the living cell that was identical to that obtained with conventional procedures that require fixation.     

Hemolysis near an ultrasonically pulsating gas bubble

A small volume of an erythrocyte suspension was subjected to the action of a manipulated gas bubble set into stable oscillation at 20 kilohertz. Release of hemoglobin occurred when the oscillation amplitude exceeded a critical threshold. Hydrodynamic stresses resulting from acoustically induced small-scale eddying motion near the bubble may be the mechanism of hemolysis.     

Pulse structure of the pulsating radio source in vulpecula

The pulses from the pulsating radio source at right ascension 19 hours 19 minutes, declination +22 degrees have the following characteristics: (i) they begin with a sharp leading edge; (ii) they terminate after 37 milliseconds; and (iii) they consist of three subpulses, the first of which is both the strongest and the best defined.     

Vitamin A: concentration in the rat liver Golgi apparatus

Vitamin A compounds (principally as retinyl esters) are concentrated in Golgi apparatus fractions from rat liver. The amounts vary with the vitamin A status of the liver and show an inverse relation to the concentration of ubiubinone. The results suggest a specific role of the Golgi apparatus in the mobilization or action, or both, of vitamin A compounds.     

高温产氢菌的一种简单筛选法

在实验中常采用改良Hungate技术、斜面法和平板培养瓶法来进行产氢菌的分离与纯化,但如果事先对所用的样品(材料)进行一些必要的预处理,达到一定的前期选择性培养的效果,就能减少随后的工作量。通过利用简单的酸处理与热处理相结合的方法,并结合平面厌氧操作技术与培养瓶厌氧技术,成功的分离得到了一株高温产氢菌。此菌在45～50℃范围内具有较强的产氢能力。电镜观察表明:此菌为长杆状,无鞭毛。在对此菌进行热处理时,实验结果显示:85℃下处理10min是适宜的。