59 research outputs found
Records of sunspot and aurora during CE 960-1279 in the Chinese chronicle of the Song dynasty
Records of sunspots and aurora observations in pre-telescopic historical
documents can provide useful information about solar activity in the past. This
is also true for extreme space weather events, as they may have been recorded
as large sunspots observed by the naked eye or as low-latitude auroras. In this
paper, we present the results of a comprehensive survey of records of sunspots
and auroras in the Songshi, a Chinese formal chronicle spanning the tenth to
the thirteenth century. This chronicle contains a record of continuous
observations with well-formatted reports conducted as a policy of the
government. A brief comparison of the frequency of observations of sunspots and
auroras and the observations of radioisotopes as an indicator of the solar
activity during corresponding periods is provided. This paper is the first step
of our project in which we survey and compile the records of sunspots and
aurora in historical documents from various locations and languages, ultimately
providing it to the science community as online data.Comment: Accepted for for publication in Earth, Planets and Space. This
manuscript includes the original texts in Chinese, which is omitted in the
version published in EP
Archaeal Phospholipid Biosynthetic Pathway Reconstructed in Escherichia coli
A part of the biosynthetic pathway of archaeal membrane lipids, comprised of 4 archaeal enzymes, was reconstructed in the cells of Escherichia coli. The genes of the enzymes were cloned from a mesophilic methanogen, Methanosarcina acetivorans, and the activity of each enzyme was confirmed using recombinant proteins. In vitro radioassay showed that the 4 enzymes are sufficient to synthesize an intermediate of archaeal membrane lipid biosynthesis, that is, 2,3-di-O-geranylgeranyl-sn-glycerol-1-phosphate, from precursors that can be produced endogenously in E. coli. Introduction of the 4 genes into E. coli resulted in the production of archaeal-type lipids. Detailed liquid chromatography/electron spray ionization-mass spectrometry analyses showed that they are metabolites from the expected intermediate, that is, 2,3-di-O-geranylgeranyl-sn-glycerol and 2,3-di-O-geranylgeranyl-sn-glycerol-1-phosphoglycerol. The metabolic processes, that is, dephosphorylation and glycerol modification, are likely catalyzed by endogenous enzymes of E. coli
A Great Space Weather Event in February 1730
Aims. Historical records provide evidence of extreme magnetic storms with
equatorward auroral extensions before the epoch of systematic magnetic
observations. One significant magnetic storm occurred on February 15, 1730. We
scale this magnetic storm with auroral extension and contextualise it based on
contemporary solar activity. Methods. We examined historical records in East
Asia and computed the magnetic latitude (MLAT) of observational sites to scale
magnetic storms. We also compared them with auroral records in Southern Europe.
We examined contemporary sunspot observations to reconstruct detailed solar
activity between 1729 and 1731. Results. We show 29 auroral records in East
Asian historical documents and 37 sunspot observations. Conclusions. These
records show that the auroral displays were visible at least down to 25.8{\deg}
MLAT throughout East Asia. In comparison with contemporary European records, we
show that the boundary of the auroral display closest to the equator surpassed
45.1{\deg} MLAT and possibly came down to 31.5{\deg} MLAT in its maximum phase,
with considerable brightness. Contemporary sunspot records show an active phase
in the first half of 1730 during the declining phase of the solar cycle. This
magnetic storm was at least as intense as the magnetic storm in 1989, but less
intense than the Carrington event.Comment: 30 pages, 5 figures, and 2 tables, accepted for publication in
Astronomy & Astrophysics on 25 April 2018. The figures and
transcriptions/translations of historical documents are partially omitted in
this manuscript due to the condition of reproduction. They are available in
the publisher versio
A new auroral candidate in 775 in Japanese historical source
第6回極域科学シンポジウム[OS] 宙空圏11月16日(月) 国立極地研究所 2階 大会議
Three novel NY-ESO-1 epitopes bound to DRB1*0803, DQB1*0401 and DRB1*0901 recognized by CD4 T cells from CHP-NY-ESO-1-vaccinated patients
Three novel NY-ESO-1 CD4 T cell epitopes were identified using PBMC obtained from patients who were vaccinated with a complex of cholesterol-bearing hydrophobized pullulan (CHP) and NY-ESO-1 protein (CHP-NY-ESO-1). The restriction molecules were determined by antibody blocking and using various EBV-B cells with different HLA alleles as APC to present peptides to CD4 T cells. The minimal epitope peptides were determined using various N- and C-termini truncated peptides deduced from 18-mer overlapping peptides originally identified for recognition. Those epitopes were DRB1*0901-restricted NY-ESO-1 87-100. DQB1*0401-restricted NY-ESO-1 95-107 and DRB1*0803-restricted NY-ESO-1 124-134. CD4 T cells used to determine those epitope peptides recognized EBV-B cells or DC that were treated with recombinant NY-ESO-1 protein or NY-ESO-1-expressing tumor cell lysate, suggesting that the epitope peptides are naturally processed. These CD4 T cells showed a cytokine profile with Th1 characteristics. Furthermore, NY-ESO-1 87-100 peptide/HLA-DRB1*0901 tetramer staining was observed. Multiple Th1-type CD4 T cell responses are beneficial for inducing effective anti-tumor responses after NY-ESO-1 protein vaccination
- …