ANALYZING SOLAR, COSMIC, AND GEOPHYSICAL EVENTS IN SEPTEMBER 2017, USING SHICRA SB RAS COMPLEX OBSERVATIONS
SOLAR-TERRESTRIAL PHYSICS
Authors: Starodubtsev, S. A.; Kozlov, V., I; Baishev, D. G.; Korsakov, A. A.; Grigoryev, V. G.; Makarov, G. A.; Karimov, Rr; Moiseev, A., V
Abstract
We report the results of monitoring of cosmic rays and geomagnetic field along 210 magnetic meridians in Yakutia in the first half of September 2017. The energy spectrum of solar cosmic rays during Ground Level Enhancement in September 10, 2017 is estimated as J=3027E(-1.99)exp(-E/729 MeV). We present the results of the forecast and complex analysis of the magnetic storm on September 7-9, 2017 with Dst=-124 nT. The forecast lead time is about one day. We examine how the storm affected the electric potential and VLF signal propagation from RSDN-20 radio navigation stations. Irregular Pi3-Pi1 pulsations occurred during the September 8, 2017 magnetic storm from 12 to 20 UT. The pulsations were accompanied by variations in electrotelluric potentials and geomagnetic fields with the correlation coefficient between them rho(E, H)=0.5 divided by 0.9. The effects of the magnetic storm manifested themselves as an increase in the attenuation and a decrease in the phase delay of VLF radio signals.
SMG1 heterozygosity exacerbates haematopoietic cancer development in Atm null mice by increasing persistent DNA damage and oxidative stress
JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
Authors: Ho, Uda; Luff, John; James, Alexander; Lee, Cheok Soon; Quek, Hazel; Lai, Hui-Chi; Apte, Simon; Lim, Yi Chieh; Lavin, Martin F.; Roberts, Tara L.
Abstract
Suppressor of morphogenesis in genitalia 1 (SMG1) and ataxia telangiectasia mutated (ATM) are members of the PI3-kinase like-kinase (PIKK) family of proteins. ATM is a well-established tumour suppressor. Loss of one or both alleles of ATM results in an increased risk of cancer development, particularly haematopoietic cancer and breast cancer in both humans and mouse models. In mice, total loss of SMG1 is embryonic lethal and loss of a single allele results in an increased rate of cancer development, particularly haematopoietic cancers and lung cancer. In this study, we generated mice deficient in Atm and lacking one allele of Smg1, Atm(-/-)Smg1(gt/+) mice. These mice developed cancers more rapidly than either of the parental genotypes, and all cancers were haematopoietic in origin. The combined loss of Smg1 and Atm resulted in a higher level of basal DNA damage and oxidative stress in tissues than loss of either gene alone. Furthermore, Atm(-/-)Smg1(gt/+) mice displayed increased cytokine levels in haematopoietic tissues compared with wild-type animals indicating the development of low-level inflammation and a pro-tumour microenvironment. Overall, our data demonstrated that combined loss of Atm expression and decreased Smg1 expression increases haematopoietic cancer development.