Situated in the so-called “island of inversion,” the nucleus 32Mg is considered as an archetypal example of the disappearance of magicity at N=20. We report on high statistics in-beam spectroscopy of ...32Mg with a unique approach, in that two direct reaction probes with different sensitivities to the underlying nuclear structure are employed at the same time. More specifically, states in 32Mg were populated by knockout reactions starting from 33Mg and 34Si, lying inside and outside the island of inversion, respectively. The momentum distributions of the reaction residues and the cross sections leading to the individual final states were confronted with eikonal-based reaction calculations, yielding a significantly updated level scheme for 32Mg and spin-parity assignments. By fully exploiting observables obtained in this measurement, a variety of structures coexisting in 32Mg was unraveled. Comparisons with theoretical predictions based on shell-model overlaps allowed for clear discrimination between different structural models, revealing that the complete theoretical description of this key nucleus is yet to be achieved.
At 02:13 UT on 18 November 2015 when the geomagnetic dipole was tilted by -27deg, the MMS spacecraft observed southward reconnection jets near the subsolar magnetopause under southward and dawnward ...interplanetary magnetic field conditions. Based on four-spacecraft estimations of the magnetic field direction near the separatrix and the motion and direction of the current sheet, the location of the reconnection line was estimated to be approx.1.8 R(sub E) or further northward of MMS. The Geotail spacecraft at GSM Z approx. 1.4 R(sub E) also observed southward reconnection jets at the dawnside magnetopause 30-40 min later. The estimated reconnection line location was northward of GSM Z approx.2 R(sub E). This crossing occurred when MMS observed purely southward magnetic fields in the magnetosheath. The simultaneous observations are thus consistent with the hypothesis that the dayside magnetopause reconnection line shifts from the subsolar point toward the northem (winter) hemisphere due to the effect of geomagnetic dipole tilt.
We investigated characteristics of slow‐mode shocks in the dayside magnetopause based on Magnetospheric Multiscale observations from September 2015 to February 2017. We analyzed 99 magnetopause ...crossings with reconnection jets and high time resolution data, out of which 20 crossings showed slow‐mode shock signatures. Out of these crossings, one crossing showed slow‐mode shock signature on both sides, and the rest had slow‐mode shock signatures on one side, six (13) on magnetosphere (magnetosheath). The detection probability of slow‐mode shocks in the magnetopause is ~20%, which is greater than that reported in the magnetotail. We also found 12 rotational discontinuities in these slow‐mode shock events. The results also show that the observation of magnetosphere side slow‐mode shock is favored when the number density ratio of magnetosheath to magnetosphere is small. No clear dependence of the existence of slow‐mode shocks on other parameters such as, plasma beta, temperature anisotropy, and jet velocity, was found.
Plain Language Summary
When two oppositely directed magnetic field lines come in contact, they break and reconnect releasing large amounts of energy and accelerating particles. This process is called magnetic reconnection. At the dayside interface of the magnetic barrier formed by Earth's intrinsic magnetic field against the plasma flow from the Sun (magnetopause), terrestrial magnetic fields interact with solar magnetic fields through this process. One theory of magnetic reconnection proposes the presence of a structure, called the slow‐mode shock, which helps in fast release of energy and acceleration of particles. However, the magnetopause is known to have asymmetric magnetic configuration and only a few observational studies have reported the presence of the slow‐mode shock in the magnetopause. Based on observations by the Magnetospheric Multiscale spacecraft in the magnetopause, we found that 20% of the magnetopause crossings with reconnection jets had the slow‐mode shock structure. The occurrence frequency is comparable to or a little higher than the symmetric reconnection cases. Their dependence on the number of particles is consistent with previous simulation studies. This study provides substantial evidence that the slow‐mode shocks are as common in the asymmetric magnetic reconnection as in the symmetric cases.
Key Points
Seven (14) slow shocks were found on the magnetosphere (magnetosheath) side out of 99 magnetopause crossings with reconnection jets studied
In the slow shock events, nine rotational discontinuities were observed on the magnetosheath side whereas three were not clearly toward any side
The smaller the number density ratio of magnetosheath to magnetosphere, the greater the chance to observe magnetosphere slow‐mode shocks
Cholesterol crystals embolise when an aortic atherosclerotic lesion ruptures and cholesterol crystals are scattered and obstruct small peripheral arterioles. Risk factors include both iatrogenic ...factors such as intravascular catheterisation, and spontaneous factors for atherosclerosis such as aging, hypertension, dyslipidaemia, and smoking. We describe the case of an 83-year-old Japanese man who developed unilateral, superficial necrosis of the tongue as a result of spontaneous embolisation of cholesterol crystals.
Background: While tumour necrosis factor α (TNF-α) appears to be associated with the development of non-alcoholic steatohepatitis (NASH), its precise role in the pathogenesis of NASH is not well ...understood. Methods: Male mice deficient in both TNF receptors 1 (TNFR1) and 2 (TNFR2) (TNFRDKO mice) and wild-type mice were fed a methionine and choline deficient (MCD) diet or a control diet for eight weeks, maintaining isoenergetic intake. Results: MCD dietary feeding of TNFRDKO mice for eight weeks resulted in attenuated liver steatosis and fibrosis compared with control wild-type mice. In the liver, the number of activated hepatic Kupffer cells recruited was significantly decreased in TNFRDKO mice after MCD dietary feeding. In addition, hepatic induction of TNF-α, vascular cell adhesion molecule 1, and intracellular adhesion molecule 1 was significantly suppressed in TNFRDKO mice. While in control animals MCD dietary feeding dramatically increased mRNA expression of tissue inhibitor of metalloproteinase 1 (TIMP-1) in both whole liver and hepatic stellate cells, concomitant with enhanced activation of hepatic stellate cells, both factors were significantly lower in TNFRDKO mice. In primary cultures, TNF-α administration enhanced TIMP-1 mRNA expression in activated hepatic stellate cells and suppressed apoptotic induction in activated hepatic stellate cells. Inhibition of TNF induced TIMP-1 upregulation by TIMP-1 specific siRNA reversed the apoptotic suppression seen in hepatic stellate cells. Conclusions: Enhancement of the TNF-α/TNFR mediated signalling pathway via activation of Kupffer cells in an autocrine or paracrine manner may be critically involved in the pathogenesis of liver fibrosis in this NASH animal model.
Excited states in 56Zn were populated following one-neutron removal from a 57Zn beam impinging on a Be target at intermediate energies in an experiment conducted at the Radioactive Isotope Beam ...Factory at RIKEN. Three γ rays were observed and tentatively assigned to the 6+→4+→2+→0+ yrast sequence. This turns 56Zn into the heaviest Tz=−2 nucleus in which excited states are known. The excitation-energy differences between these levels and the isobaric analogue states in the Tz=+2 mirror partner, 56Fe, are compared with large-scale shell-model calculations considering the full pf valence space and various isospin-breaking contributions. This comparison, together with an analysis of the mirror energy differences in the A=58, Tz=±1 pair 58Zn and 58Ni, provides valuable information with respect to the size of the monopole radial and the isovector multipole isospin-breaking terms in the region above doubly-magic 56Ni.
The Magnetospheric Multiscale (MMS) spacecraft observed many enhancements of electromagnetic ion cyclotron (EMIC) waves in an event in the late afternoon outer magnetosphere. These enhancements ...occurred mainly in the troughs of magnetic field intensity associated with a compressional ultralow frequency (ULF) wave. The ULF wave had a period of ∼2–5 min (Pc5 frequency range) and was almost static in the plasma rest frame. The magnetic and ion pressures were in antiphase. They are consistent with mirror‐mode type structures. We apply the Wave‐Particle Interaction Analyzer method, which can quantitatively investigate the energy transfer between hot anisotropic protons and EMIC waves, to burst‐mode data obtained by the four MMS spacecraft. The energy transfer near the cyclotron resonance velocity was identified in the vicinity of the center of troughs of magnetic field intensity, which corresponds to the maxima of ion pressure in the compressional ULF wave. This result is consistent with the idea that the EMIC wave generation is modulated by ULF waves, and preferential locations for the cyclotron resonant energy transfer are the troughs of magnetic field intensity. In these troughs, relatively low resonance velocity due to the lower magnetic field intensity and the enhanced hot proton flux likely contribute to the enhanced energy transfer from hot protons to the EMIC waves by cyclotron resonance. Due to the compressional ULF wave, regions of the cyclotron resonant energy transfer can be narrow (only a few times of the gyroradii of hot resonant protons) in magnetic local time.
Key Points
Electromagnetic ion cyclotron wave enhancements were detected in a compressional ultralow frequency (ULF) wave
Troughs of magnetic field intensity of the ULF wave are preferential locations for the cyclotron resonant energy transfer
Due to compressional ULF wave, regions of the cyclotron resonant energy transfer can be narrow in magnetic local time
Characteristics of photoelectron flows and presence of a field‐aligned potential drop on the open magnetic field lines in the polar cap are systematically investigated using the data obtained by the ...FAST satellite during geomagnetically quiet periods in July 2002. We found high occurrence frequencies of the potential drop larger than ∼10 V, reaching ∼90% (small field‐aligned current (FAC) case) and ∼83% (all data). A typical magnitude of the potential drop above ∼3800 km altitude is ∼20 V. This value is significantly larger than the potential drop below ∼3800 km altitude (probably ∼1–3 V), although the typical potential drop is smaller by a factor of ∼2–3 in comparison to the modeling results that suggested presence of a field‐aligned potential jump at several earth radii. The net escaping electron number flux negatively correlates with the upward electron number flux and with the magnitude of the potential drop. This relation is contrary to expectation from photoelectron‐driven polar wind models that an increase in the photoelectrons drives the larger polar wind flux, since the net escaping electron number flux balances the flux of polar wind ions under zero net FAC conditions. An increase in the upward backscatter of reflected electrons with an increasing potential drop may explain the negative correlations. A potential drop at high altitudes would provide a polar wind system regulated by a negative feedback, and the most appropriate balance for polar wind ions would be achieved near the median of the reflection potential.
Key Points
A field‐aligned potential drop exists in the polar cap almost permanently
The net electron number flux negatively correlates with the potential drop
The polar wind system is regulated by a negative feedback by the potential drop
Objective: To prospectively investigate the effect of tocilizumab (TCZ) on the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), as a predictor of congestive heart failure (CHF) in ...patients with active rheumatoid arthritis (RA).
Method: Seventy patients with RA (median age 59 years, 86% female) free of cardiovascular disease were treated with TCZ and followed for 24 weeks. The NT-proBNP levels were measured at baseline and week 24. Thirty healthy controls were included for comparison of normal NT-proBNP levels with those of RA patients.
Results: The NT-proBNP level was significantly higher in patients with RA than in controls (median 42.5 pg/mL vs 109.0 pg/mL, p < 0.001). NT-proBNP levels decreased by 63% over the 24 weeks of TCZ treatment. Multiple linear regression analysis indicated that the percentage change in the NT-proBNP level was significantly associated with that of the Simplified Disease Activity Index (β = 0.356, p = 0.014), even after adjusting for the levels of rheumatoid factor, duration of RA, age, and anti-cyclic citrullinated peptide antibody.
Conclusion: TCZ decreased the NT-proBNP level in patients with RA without preceding cardiovascular disease and CHF. TCZ may have a cardioprotective effect in those with active RA.
We constructed an empirical model of the electron density profile with solar zenith angle (SZA) dependence in the polar cap during geomagnetically quiet periods using 63 months of Akebono satellite ...observations at solar maximum. The electron density profile exhibits a transition at ∼2000 km altitude only under dark conditions. The electron density and scale height at low altitudes change drastically, by factors of 25 (at 2300 km altitude) and 2.0, respectively, as the SZA increases from 90° to 120°. The SZA dependence of the ion and electron temperatures is also investigated statistically on the basis of data obtained by the Intercosmos satellites and European Incoherent Scatter (EISCAT) Svalbard radar (ESR). A drastic change in the electron temperature occurs near the terminator, similarly to that in the electron density profile obtained by the Akebono satellite. The sum of the ion and electron temperatures obtained by the ESR (∼6500 K at ∼1050 km altitude under sunlit conditions and ∼3000 K at ∼750 km altitude under dark conditions) agrees well with the scale height at low altitudes obtained from the Akebono observations, assuming that the temperature is constant and that O+ ions are dominant. Comparisons between the present statistical results (SZA dependence of the electron density and ion and electron temperatures) and modeling studies of the polar wind indicate that the plasma density profile (especially of the O+ ion density) in the polar cap is strongly controlled by solar radiation onto the ionosphere by changing ion and electron temperatures in the ionosphere during geomagnetically quiet periods.
Key Points
Empirical model of the electron density profile with SZA dependence
Drastic change in the electron density and temperature near the terminator
Comparison between the scale height and the ion and electron temperatures
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