Ulysses radio and plasma wave observations in the jupiter environment

A Preliminary Study of Magnetosphere-Ionosphere-Thermosphere Coupling at Jupiter: Juno Multi-Instrument Measurements and Modeling Tools

The dynamics of the Jovian magnetosphere are controlled by the interplay of the planet's fast rotation, its main iogenic plasma source and its interaction with the solar wind. Magnetosphere-Ionosphere-Thermosphere (MIT) coupling processes controlling this interplay are significantly different from their Earth and Saturn counterparts. At the ionospheric level, they can be characterized by a set of key parameters: ionospheric conductances, electric currents and fields, exchanges of particles along field lines, Joule heating and particle energy deposition. From these parameters, one can determine (a) how magnetospheric currents close into the ionosphere, and (b) the net deposition/extraction of energy into/out of the upper atmosphere associated to MIT coupling. We present a new method combining Juno multi-instrument data (MAG, JADE, JEDI, UVS, JIRAM and Waves) and modeling tools to estimate these key parameters along Juno's trajectories. We first apply this method to two southern hemisphere main auroral oval crossings to illustrate how the coupling parameters are derived. We then present a preliminary statistical analysis of the morphology and amplitudes of these key parameters for eight among the first nine southern perijoves. We aim to extend our method to more Juno orbits to progressively build a comprehensive view of Jovian MIT coupling at the level of the main auroral oval.

miR-214 down-regulates Sema4D expression in colon cancer LoVo cells

AIM: To observe the effect of miR-214 on Sema4D expression in human colon cancer cell line LoVo.

METHODS: miR-214 mimic, miR-214 inhibitor, and two control sequences (mi-control, in-control) were designed, synthesized and transfected into LoVo cells, respectively. RT-PCR was used to detect the expression changes of miR-214 and Sema4D mRNA in transfected cells, and the expression change of Sema4D protein was detected by Western blot.

RESULTS: The relative expression levels of miR-214 in LoVo cells transfected with miR-214 mimic, mi-control, miR-214 inhibitor, and in-control were 8.003 ± 0.651, 3.464 ± 0.332, 0.740 ± 0.088, and 2.620 ± 0.166, respectively. The expression of miR-214 increased significantly in the mimic group compared with the control group, but was significantly lower in the inhibitor group than in the control group (P < 0.05). The relative expression levels of Sema4D mRNA in LoVo cells transfected with miR-214 mimic, mi-control, miR-214 inhibitor, and in-control were 0.420 ± 0.027, 0.851 ± 0.062, 1.243 ± 0.087, and 0.660 ± 0.042, respectively, and the relative expression levels of Sema4D protein were 0.163 ± 0.037, 0.550 ± 0.038, 1.137 ± 0.112, and 0.457 ± 0.046, respectively. Sema4D mRNA and protein expression in the mimic group was decreased significantly compared with the control group, but was significantly increased in the inhibitor group compared with the control group (P < 0.05).

CONCLUSION: Sema4D expression is regulated by miR-214 in human colon cancer cell line LoVo, and miR-214 can down-regulate the expression of Sema4D mRNA and thereby influence the protein expression. miR-214 could be used as a new target for treatment of colon carcinoma.

Energetic Charged-Particle Phenomena in the Jovian Magnetosphere: First Results from the Ulysses COSPIN Collaboration

The Ulysses spacecraft made the first exploration of the region of Jupiter's magnetosphere at high Jovigraphic latitudes ( approximately 37 degrees south) on the dusk side and reached higher magnetic latitudes ( approximately 49 degrees north) on the day side than any previous mission to Jupiter. The cosmic and solar particle investigations (COSPIN) instrumentation achieved a remarkably well integrated set of observations of energetic charged particles in the energy ranges of approximately 1 to 170 megaelectron volts for electrons and 0.3 to 20 megaelectron volts for protons and heavier nuclei. The new findings include (i) an apparent polar cap region in the northern hemisphere in which energetic charged particles following Jovian magnetic field lines may have direct access to the interplanetary medium, (ii) high-energy electron bursts (rise times </= 1 minute and energies extending to > approximately 17 megaelectron volts) on the dusk side that are apparently associated with field-aligned currents and radio burst emissions, (iii) persistence of the global 10-hour relativistic electron "clock" phenomenon throughout Jupiter's magnetosphere, (iv) on the basis of charged-particle measurements, apparent dragging of magnetic field lines at large radii in the dusk sector toward the tail, and (v) consistent outflow of megaelectron volt electrons and large-scale departures from corotation for nucleons.

Ulysses Radio Occultation Observations of the Io Plasma Torus During the Jupiter Encounter

Radio signals from Ulysses were used to probe the lo plasma torus (IPT) shortly after the spacecraft's closest approach to Jupiter. The frequencies of the two downlinks at S-band (2.3 gigahertz) and X-band (8.4 gigahertz) were recorded, differenced, and integrated in order to derive the columnar electron density of the IPT. The measurements agree qualitatively with contemporary models of the IPT based on Voyager data, but significant differences are apparent as well. The overall level of the IPT electron density is approximately the same as the prediction, implying that the amount of gas (or plasma) injected from lo is similar to that observed during the Voyager era. On the other hand, the IPT seems to be less extended out of the centrifugal equator, implying a smaller plasma temperature than predicted.