Abstract. On the basis of S4max data retrieved from COSMIC GPS radio occultation measurements, the long-term climatology of the intensity of Es layers is investigated for the period from December 2006 to January 2014. Global maps of Es intensity show the high-spatial-resolution geographical distribution and strong seasonal dependence of Es layers. The maximum intensity of Es occurs over the mid-latitudes, and its value in summer is 2–3 times larger than that in winter. A relatively strong Es layer is observed at the North Pole and South Pole, with a distinct boundary dividing the mid-latitudes and high latitudes along the 60–80∘ geomagnetic latitude band. The simulation results show that the convergence of vertical ion velocity could partially explain the seasonal dependence of Es intensity. Furthermore, some disagreements between the distributions of the calculated divergence of vertical ion velocity and the observed Es intensity indicate that other processes, such as the vertical motions of gravity waves, magnetic-field effects, meteoric mass influx into Earth's atmosphere, and the chemical processes of metallic ions, should also be considered as they may also play an important role in the spatial and seasonal variations in Es layers.

Double neutron star (DNS) merger events are promising candidates of short gamma-ray burst (sGRB) progenitors as well as high-frequency gravitational wave (GW) emitters. On August 17, 2017, such a coinciding event was detected by both the LIGO-Virgo gravitational wave detector network as GW170817 and Gamma-Ray Monitor on board NASA’s Fermi Space Telescope as GRB 170817A. Here, we show that the fluence and spectral peak energy of this sGRB fall into the lower portion of the distributions of known sGRBs. Its peak isotropic luminosity is abnormally low. The estimated event rate density above this luminosity is at least  Gpc−3 yr−1, which is close to but still below the DNS merger event rate density. This event likely originates from a structured jet viewed from a large viewing angle. There are similar faint soft GRBs in the Fermi archival data, a small fraction of which might belong to this new population of nearby, low-luminosity sGRBs.

The ionospheric sporadic E (Es) layer has a significant impact on the global positioning system (GPS)/global navigation satellite system (GNSS) signals. These influences on the GPS/GNSS signals can also be used to study the occurrence and characteristics of the Es layer on a global scale. In this paper, 5.8 million radio occultation (RO) profiles from the FORMOSAT-3/COSMIC satellite mission and ground-based observations of Es layers recorded by 25 ionospheric monitoring stations and held at the UK Solar System Data Centre at the Rutherford Appleton Laboratory and the Chinese Meridian Project were used to derive the hourly Es critical frequency ( f o Es) data. The global distribution of f o Es with a high spatial resolution shows a strong seasonal variation in f o Es with a summer maximum exceeding 4.0 MHz and a winter minimum between 2.0 and 2.5 MHz. The GPS/GNSS RO technique is an important tool that can provide global estimates of Es layers, augmenting the limited coverage and low-frequency detection threshold of ground-based instruments. Attention should be paid to small f o Es values from ionosondes near the instrumental detection limits corresponding to minimum frequencies in the range 1.28–1.60 MHz.

On the basis of S4max data retrieved from COSMIC GPS radio occultation measurements, the long-term climatology of the intensity of E s layers is investigated for the period from December 2006 to January 2014. The global maps of E s intensity shows a high spatial resolution geographical distributions and strong seasonal dependence of E s layers.The maximum intensity of E s occurs in the midlatitudes, and its value in summer is 2-3 times larger than that in winter. A relatively strong E s layer is observed at the North and South Poles with a distinct boundary dividing the middle latitudes and high latitudes along 60 • -5 80 • geomagnetic latitude bands. Besides, simulation results shows that the convergence of vertical ion velocity could partially explain the seasonal dependence of E s intensity. Furthermore, some disagreements between the distributions of calculated divergence of vertical ion velocity and observed E s intensity indicate that other processes such as magnetic field effects, meteoric mass influx into the earth's atmosphere and chemical processes of metallic ions should also be considered, which play an important role in the spatial and seasonal variations of E s layers. 10 1 IntroductionThe ionospheric sporadic E (E s ) layers are known as thin-layered structures of intense high electron density at 90-130 km altitudes. Rocket-borne mass spectrometric measurements proved that the E s layer is mostly the ionization of metal atoms such as Fe + , Mg + , and Na + (Kopp, 1997;Grebowsky and Aikin, 2002). The E s layer is mainly at midlatitudes and relatively absent at geomagnetic equator and high latitudes (Whitehead, 1989). It is widely accepted that the mechanism responsible for the E s 15 layer formation at midlatitudes is the windshear theory, in which the zonal and meridional winds provide the vertical windshear convergence nodes. As a result, the long-lived metallic ions are forced to converge towards the wind shear null to form a thin layer of intense metallic ionization (Whitehead, 1961;Macleod, 1966;Whitehead, 1970;Nygren et al., 1984;Whitehead, 1989;Haldoupis, 2012). In the equatoral region, the physical process of E s irregularities is attributed to the gradient-drift instabilities associated with the equatorial electrojet (Tsunoda, 2008). The E s layer generally has a vertical scale of 1 km or less, but its 20 1 Atmos. Chem. Phys. Discuss., https://doi.

Compound 6 isolated from the leaves of Gynura nepalensis potently protects H9c2 cardiomyoblasts against HO-induced apoptosis, possibly by inhibiting intrinsic apoptosis and the ERK/JNK pathway.

Aim: Cinnamon extracts rich in procyanidin oligomers have shown to improve pancreatic β-cell function in diabetic db/db mice. The aim of this study was to identify the active compounds in extracts from two species of cinnamon responsible for the pancreatic β-cell protection in vitro. Methods: Cinnamon extracts were prepared from Cinnamomum tamala (CT-E) and Cinnamomum cassia (CC-E). Six compounds procyanidin B2 (cpd1), (-)-epicatechin (cpd2), cinnamtannin B1 (cpd3), procyanidin C1 (cpd4), parameritannin A1 (cpd5) and cinnamtannin D1 (cpd6) were isolated from the extracts. INS-1 pancreatic β-cells were exposed to palmitic acid (PA) or H 2 O 2 to induce lipotoxicity and oxidative stress. Cell viability and apoptosis as well as ROS levels were assessed. Glucose-stimulated insulin secretion was examined in PA-treated β-cells and murine islets. Results: CT-E, CC-E as well as the compounds, except cpd5, did not cause cytotoxicity in the β-cells up to the maximum dosage using in this experiment. CT-E and CC-E (12.5-50 μg/mL) dose-dependently increased cell viability in both PA-and H 2 O 2 -treated β-cells, and decreased ROS accumulation in H 2 O 2 -treated β-cells. CT-E caused more prominent β-cell protection than CC-E. Furthermore, CT-E (25 and 50 μg/mL) dose-dependently increased glucose-stimulated insulin secretion in PA-treated β-cells and murine islets, but CC-E had little effect. Among the 6 compounds, trimer procyanidins cpd3, cpd4 and cpd6 (12.5-50 μmol/L) dose-dependently increased the cell viability and decreased ROS accumulation in H 2 O 2 -treated β-cells. The trimer procyanidins also increased glucose-stimulated insulin secretion in PA-treated β-cells. Conclusion: Trimer procyanidins in the cinnamon extracts contribute to the pancreatic β-cell protection, thus to the anti-diabetic activity.

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