Search

On 10 January 2001, Cassini briefly entered into the magnetosphere of Jupiter, en route to Saturn. During this excursion into the Jovian magnetosphere, the Cassini Magnetosphere Imaging Instrument/Charge‐Energy‐Mass Spectrometer detected oxygen and sulfur ions. While Charge‐Energy‐Mass Spectrometer can distinguish between oxygen and sulfur charge states directly, only 95.9 ± 2.9 keV/e ions were sampled during this interval, allowing for a long time integration of the tenuous outer magnetospheric (~200 RJ) plasma at one energy. For this brief interval for the 95.9 keV/e ions, 96% of oxygen ions were O+, with the other 4% as O2+, while 25% of the energetic sulfur ions were S+, 42% S2+, and 33% S3+. The S2+/O+ flux ratio was observed to be 0.35 (±0.06 Poisson error)., Key Points Cassini measured the relative charge state abundances of 95.9 keV/e oxygen and sulfur in the outer magnetosphere (~200 RJ) of JupiterThe flux of 95.9 keV/e O+ was higher than that of S2+, with S2+ being the most abundant charge state among sulfur ionsThe relative abundances of 95.9 keV/e heavy ions are compared to thermal ions in the inner to middle magnetosphere

The Magnetospheric Imaging Instrument (MIMI) onboard the Cassini spacecraft observed the saturnian magnetosphere from January 2004 until Saturn orbit insertion (SOI) on 1 July 2004. The MIMI sensors observed frequent energetic particle activity in interplanetary space for several months before SOI. When the imaging sensor was switched to its energetic neutral atom (ENA) operating mode on 20 February 2004, at ∼10 3 times Saturn's radius R S (0.43 astronomical units), a weak but persistent signal was observed from the magnetosphere. About 10 days before SOI, the magnetosphere exhibited a day-night asymmetry that varied with an ∼11-hour periodicity. Once Cassini entered the magnetosphere, in situ measurements showed high concentrations of H + , H 2 + , O + , OH + , and H 2 O + and low concentrations of N + . The radial dependence of ion intensity profiles implies neutral gas densities sufficient to produce high loss rates of trapped ions from the middle and inner magnetosphere. ENA imaging has revealed a radiation belt that resides inward of the D ring and is probably the result of double charge exchange between the main radiation belt and the upper layers of Saturn's exosphere.

[1] The Magnetospheric Imaging Instrument (MIMI) Ion and Neutral Camera (INCA) on the Cassini spacecraft has recorded abrupt increases in energetic neutral atom flux coming from the general direction of Saturn's magnetotail. These bursts of ion activity in the tail are well correlated with enhancements in the Saturn kilometric radiation. Given the similarities between these events and substorm activity on Earth, including their dependence on interplanetary conditions, we conclude that Earth-like substorms occur within Saturn's magnetosphere.

One-week-old Large White piglets were weaned and allocated to 14 experimental groups, each composed of five animals. Each group was housed in a separate Rochester exposure chamber and exposed continuously to gaseous ammonia at either 0, 5, 10, 15, 25, 35, or 50 ppm (two groups per exposure level). One week after ammonia exposure commenced, the pigs from one group at each exposure level were inoculated intranasally with 9 x 10(7) CFU of Pasteurella multocida type D. After a further 4 weeks of exposure, all the pigs were euthanized and the extent of turbinate degeneration was assessed by using a morphometric index (J.T. Done, D. H. Upcott, D. C. Frewin, and C. N. Hebert, Vet. Rec. 114:33-35, 1984) and a subjective scoring system (Ministry of Agriculture, Fisheries and Food, Atrophic Rhinitis: a System of Snout Grading, 1978). Exposure to ammonia at a concentration of 5 ppm or greater resulted in a significant increase in the severity of turbinate atrophy induced by P. multocida compared with that occurring in pigs kept in 0 ppm of ammonia. This effect was maximal at 10 ppm but decreased progressively at concentrations above 25 ppm. Regression analysis revealed a significant relationship between the severity of turbinate degeneration and the number of P. multocida organisms isolated from the nasal epithelium at the end of the experiment (R2 = 0.86). These findings suggest that exposure to ammonia facilitates the growth and/or survival of P. multocida within the upper respiratory tract of the pig, thereby contributing to the severity of the clinical disease atrophic rhinitis. Furthermore, exposure of pigs to ammonia at 10 ppm or greater, in the absence of either P. multocida or Bordetella bronchiseptica, induced a mild but statistically significant degree of turbinate atrophy. The findings of this study demonstrate that exposure to ammonia, at concentrations within the range encountered commonly in commercial piggeries, contributes to the severity of clinical lesions associated with atrophic rhinitis.