A Revised Look at Relativistic Electrons in the Earth's Inner Radiation Zone and Slot Region.

We describe a new, more accurate procedure for estimating and removing inner zone background contamination from Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) radiation belt measurements. This new procedure is based on the underlying assumption that the primary source of background contamination in the electron measurements at L shells less than three, energetic inner belt protons, is relatively stable. Since a magnetic spectrometer can readily distinguish between foreground electrons and background signals, we are able to exploit the proton stability to construct a model of the background contamination in each MagEIS detector by only considering times when the measurements are known to be background dominated. We demonstrate, for relativistic electron measurements in the inner zone, that the new technique is a significant improvement upon the routine background corrections that are used in the standard MagEIS data processing, which can "overcorrect" and therefore remove real (but small) electron fluxes. As an example, we show that the previously reported 1-MeV injection into the inner zone that occurred in June of 2015 was distributed more broadly in L and persisted in the inner zone longer than suggested by previous estimates. Such differences can have important implications for both scientific studies and spacecraft engineering applications that make use of MagEIS electron data in the inner zone at relativistic energies. We compare these new results with prior work and present more recent observations that also show a 1-MeV electron injection into the inner zone following the September 2017 interplanetary shock passage.

Prognostic implication of the primary tumor location in early-stage breast cancer: focus on lower inner zone.

BACKGROUND: The aim of this study was to investigate the prognostic significance of tumor location of lower inner zone (LIZ) on the survival of patients with early-stage breast cancer. METHODS: We retrospectively identified 961 breast cancer patients from Jan 2000 to Apr 2016 from hospital database. We evaluated overall survival (OS) and disease-free survival (DFS) in patients with tumors in and outside LIZ. Subgroup analyses were performed according to clinicopathological characteristics and treatment strategies. RESULTS: A total of 838 cases were finally included. Patients with tumor location of LIZ showed significantly lower survival rates than tumors in other sites in terms of DFS (p = 0.028) but not OS (p = 0.106). When stratified into subgroups, tumors in LIZ retained a significant worse prognosis in DFS in patients with HER-2-negative, high ki-67 expression breast cancers, those who received neoadjuvant chemotherapy, axillary nodal negative patients, and patients with lymphovascular invasion. Univariate and multivariate analyses suggested that tumor location of LIZ was an independent prognostic factor for DFS (p = 0.022). CONCLUSIONS: Our results suggested that tumor location of LIZ was an independent adverse prognostic factor for DFS in patients with early-stage breast cancer. Multicenter studies with larger sample size are needed to confirm the conclusion and anatomical experiments are desired to elaborate the mechanism.

Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions.

We present observations of the radiation belts from the Helium Oxygen Proton Electron and Magnetic Electron Ion Spectrometer particle detectors on the Van Allen Probes satellites that illustrate the energy dependence and L shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on 1 March in more detail. The observations show the following: (a) at all L shells, lower energy electrons are enhanced more often than higher energies; (b) events that fill the slot region are more common at lower energies; (c) enhancements of electrons in the inner zone are more common at lower energies; and (d) even when events do not fully fill the slot region, enhancements at lower energies tend to extend to lower L shells than higher energies. During enhancement events the outer zone extends to lower L shells at lower energies while being confined to higher L shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L shells for lower energies. Both boundaries are nearly straight in log(energy) versus L shell space. At energies below a few 100 keV, radiation belt electron penetration through the slot region into the inner zone is commonplace, but the number and frequency of "slot filling" events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy- and L shell-dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.