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Liquid cloud droplets supercooled to temperatures approaching -40 degrees C have been detected at the base of a cirrostratus cloud through a combination of ground-based, polarization laser radar (lidar) and in situ aircraft measurements, Solar and thermal infrared radiative budget calculations based on these observatoins indicate that significant changes in the atmospheric heating distribution and the surface radiative budget may be attributed to liquid layers in cirrus clouds.

A liver microsomal protein, previously referred to as preneoplastic antigen, from hyperplastic nodules of rats fed a diet containing 2-acetylaminofluorene has been identified as the enzyme epoxide hydrase [glycol hydro-lyase (epoxideforming), EC 4.2.1.631. Purified preneoplastic antigen from hyperp astic nodules and purified rat liver microsomal epoxide hydrase are immunochemically identical on the basis of Ouchterlony double-diffusion analysis. In addition, the purified proteins have identical minimum molecular weights in sodium dodecyl Su crylamide gels, and both proteins catalyze the hydration o arene oxides to dihydrodiols. Chronic feeding of 2-acetylaminofluorene to rats results in a 5-to 7-fold increase in epoxide hydrase activity in rat liver. The induced level of the enzyme is maintained in developing hyperplastic nodules and hepatomas but not in the nontumor tissue after removal of the carcinogen from the diet. (9) showed by immunodiffusion and immunoelectrophoresis in the presence of deoxycholate that PN antigen was present in normal rat liver at approximately one-fourth the concentration found in hyperplastic nodules. The PN antigen has been purified (9) and the present report identifies the protein as the microsomal enzyme epoxide hydrase [glycol hydro-lyase (epoxide-forming), EC 4.2.1.63].MATERIALS AND METHODS Animals. Male Holtzman rats (150-170 g) were fed a basal diet (10) with or without 0.05% AAF for a period of 13-16 weeks according to the following protocol as originally described by Epstein et al. (3): 3 weeks on basal diet containing AAF, 1 week on basal diet, 2 weeks on diet containing AAF, 2 weeks on basal diet, and 3 weeks on diet containing AAF followed by removal of the carcinogen from the diet until termination of the experiments. Intermittent feeding of AAF produces a high incidence of large hyperplastic nodules in rat liver (3). Control rats received only the basal diet.Enzymes. Animals were killed by cervical dislocation and the livers were perfused with ice-cold isotonic saline. Hyperplastic nodules were dissected out of the liver, leaving behind a rim of nodular tissue to ensure a clean separation of nodular tissue from the surrounding liver. Microsomes were prepared from hyperplastic nodules and control liver as described (8). Purification of PN antigen from hyperplastic nodule microsomes was performed by the method of Griffin and Kizer (9). Liver microsomal epoxide hydrase was purified from immature male Long-Evans rats as described by Lu et al. (11). The method for the production of antibodies against PN antigen has been described (4, 9) and that for purified liver microsomal epoxide hydrase will be described elsewhere.Assay Procedures. Ten substrates for epoxide hydrase activity were used in the present study. The synthesis and specific activity of these 3H-labeled substrates and the assay for epoxide hydrase activity have been described (12

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The first demonstration of rocket exhaust driven amplification (REDA) of whistler mode waves occurred on May 26, 2020 by transferring energy from pickup ions in a rocket exhaust plume to EM waves. The source of coherent VLF waves was the Navy NML Transmitter at 25.2 kHz located in LaMoure, North Dakota. The topside ionosphere at 480 km altitude became an amplifying medium with a 60 s firing of the Cygnus BT‐4 engine. The rocket engine injected exhaust as a neutral cloud moving perpendicular to field lines that connected the NML transmitter to the VLF Radio Receiver Instrument (RRI) on e‐POP/SWARM‐E. Charge exchange between the ambient O+ ions and the hypersonic water molecules in the exhaust produced H2O+ ions in a ring‐beam velocity distribution. The 25.2 kHz VLF signal from NML was amplified by 30 dB for a period 77 s as observed by the RRI. Simultaneously, preexisting coherent ELF waves at 300 Hz were amplified by 50 dB during and after the Cygnus burn. Extremely strong coherent emissions and quasiperiodic bursts in the 300–310 Hz frequency range lasted for 200 s after the release. The excitation of an ELF whistler cavity may have lasted even longer, but the orbit of the SWARM‐E/e‐POP moved the RRI sensor away from the wave emission region. The amplified 300 Hz ELF waves may have gained even more energy by cyclotron resonance with radiation belt electrons as they were ducted between geomagnetic‐conjugate hemispheres.