[1] We have obtained a state-of-the-art picture of substorm-associated evolution of the near-Earth magnetotail and the inner magnetosphere for understanding the substorm triggering mechanism. We performed superposed epoch analysis of Geotail, Polar, and GOES data with 2-min resolution, utilizing a total of 3787 substorms for each of which auroral breakup was determined from Polar UVI or IMAGE FUV auroral imager data. The decrease of the north-south magnetic field associated with plasmoids and the initial total pressure decrease suggest that the magnetic reconnection first occurs in the premidnight tail, on average, at X $ À16 to À20 R E at least 2 min before auroral onset. The magnetic reconnection site is located near the tailward edge of a region of considerably taillike magnetic field lines and intense cross-tail current, which extends from X $ À5 to À20 R E in the premidnight sector. Then the plasmoid substantially evolves tailward of X $ À20 R E immediately after onset. Almost simultaneously with the magnetic reconnection, the dipolarization begins first at X $ À7 to À10 R E 2 min before onset. The dipolarization region then expands tailward as well as in the dawn-dusk directions and earthward. We find that the total pressure generally enhances in association with the dipolarization, with the contribution of high-energy particles. Also, energy release is more significant between the regions of the magnetic reconnection and the initial dipolarization. The present results will be helpful as a reference guide to developing the overall picture of magnetotail evolution and studying the causal relationship between the magnetic reconnection and the dipolarization as well as detailed mechanisms of each of the two processes on the basis of multispacecraft observations.

[1] We present in situ observations consistent with the ballooning mode in the vicinity of the magnetic equator at X GSM = À10 to À13 R E prior to substorm-associated dipolarization onsets. The ballooning instability is expected to have a wavevector along the Y direction and to give variation to the curvature of the ambient magnetic field lines. The magnetic field fluctuations appearing in the B x component are transported by the ambient plasma drift in the Y direction. A discrete frequency band would be identified in time series data if the mode has a discrete wavelength. The ballooning mode of this property was identified at the magnetic equator a few min before dipolarization onsets only when the plasma b was large (20 to 70). Using low-energy ion velocity data, we show that the mode has almost zero frequency in the plasma rest frame so that w sc $ k y Á v y , where w sc is the frequency in the spacecraft frame, and k y and v y are the wavenumber and the ambient plasma flow in the Y direction, respectively. This enables us to estimate the wavelengths of the ballooning mode, which were found to be of the order of the ion Larmor radius.

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Background-Cardiac-directed expression of adenylyl cyclase type VI (AC VI ) in mice results in structurally normal hearts with normal basal heart rate and function but increased responses to catecholamine stimulation. We tested the hypothesis that increased left ventricular (LV) AC VI content would increase mortality after acute myocardial infarction (MI

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Activation of cardiac AC(VI) expression in mice with ischemic cardiomyopathy and severe CHF improves function of the failing heart.

[1] We present THEMIS observations of the near-Earth plasma sheet that permit us to assess the geometrical structure of the magnetotail prior to dipolarization. Latitudinal profiles of the magnetic field were obtained by five spacecraft simultaneously around the magnetic equator at a distance of X GSM ∼ −10 R E in the premidnight for two events. It is found that the strength of normal magnetic field B z was increased with a distance from the magnetic equator, which differs considerably from the standard magnetic field model. Instead, the observation can be explained by a magnetic field model that has a minimum in the equatorial field strength (minimum B), as required from the force-balanced magnetotail model with steady earthward convection. Moreover, the analyses showed that the feature of minimum B sustained continuously for ∼20 min before dipolarization onsets.

We applied the Grad-Shafranov reconstruction (GSR) technique to Martian magnetic flux ropes observed downstream from strong crustal magnetic fields in the southern hemisphere. The GSR technique can provide a two-dimensional axial magnetic field map as well as the axial orientation of flux ropes from single-spacecraft data under assumptions that the structure is magnetohydrostatic and time independent. The reconstructed structures, including their orientation, allowed us to evaluate possible formation processes for the flux ropes. We reconstructed 297 magnetic flux ropes observed by Mars Global Surveyor between April 1999 and November 2006. Based on characteristics of their geometrical axial orientation and transverse magnetic field topology, we found that they can be mainly distinguished according to whether draped interplanetary magnetic fields overlaying the crustal magnetic fields are involved or not. Approximately two thirds of the flux ropes can be formed by magnetic reconnection between neighboring crustal magnetic fields attached to the surface. The remaining events seem to require magnetic reconnection between crustal and overlaid draped magnetic fields. The latter scenario should allow planetary ions to be transferred from closed magnetic flux tube to flux tubes connected to interplanetary space, allowing atmospheric ions to escape from Mars. We quantitatively evaluate lower limits on potential ion escape rates from Mars owing to magnetic flux ropes.