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This study characterized cremated bone to better understand isotope exchanges during burial, using archeological samples. The cremated bones of Jokei, a Buddhist monk (AD 1155–1213), found in an urn from the Jisho-in Temple, Nara Prefecture, Japan, were used for the analysis. 14C dates were determined for eight of Jokei bone fragments of different colors (black, gray, and white). The white fragments had the highest x-ray diffractometry (XRD) crystallinity index (CI) values (0.89–1.05), Fourier-transform infrared spectroscopy (FTIR) splitting factor values (IRSF) of 5.3–7.1, and the lowest Ba concentrations. The calibrated date of the white bone fragments is 1152–1216 cal AD, consistent with Jokei’s lifespan, showing these fragments yield reliable 14C ages. Meanwhile, the black and gray fragments, which probably experienced lower temperatures during cremation, had lower CI and IRSF values of 0.25–0.46 and 4.2–4.9, respectively, and higher Ba concentrations. The black and gray fragments tended to show unreliable younger 14C dates and higher 87Sr/86Sr values close to the soil value due to soil contamination. The results in this study indicate that it is important to check crystallinity of apatite and soil contamination using chemical indexing methods such as Ba capture, to clarify the reliability of 14C dates for cremated bone samples.
Transnasal inferior meatal antrostomy is increasingly used for the treatment of post-Caldwell–Luc mucoceles in maxillary sinus. This study aimed to report the outcomes after inferior meatal antrostomy with a mucosal flap for recurrent mucoceles.
The records of patients who had undergone transnasal inferior meatal antrostomy with or without a mucosal flap were reviewed.
Transnasal endoscopic inferior meatal antrostomy with or without a mucosal flap was performed in 21 and 49 patients, respectively. No complications were observed. A closing of the antrostomy was found in 9 (18.4 per cent) of the 49 patients who underwent antrostomy without a mucosal flap. No closings were observed in the 21 patients who underwent antrostomy with a mucosal flap. There was a significant difference in the rate of closing for surgery with and without the mucosal flap.
Transnasal endoscopic inferior meatal antrostomy with a mucosal flap is a safe method for the treatment of post-Caldwell–Luc maxillary mucoceles that effectively prevents recurrence.
Structural variation of LiMn1.5Ni0.5O4 spinel cathode during the Li+ extraction/insertion reaction was studied using operando X-ray diffraction. It was found that the reaction in the voltage range from 3.5 to 4.9 V consisted of two consecutive two-phase reactions, where three spinel phases of LiMn1.5Ni0.5O4, Li0.5Mn1.5Ni0.5O4 and Mn1.5Ni0.5O4 were identified and the lattice volume change in the whole reaction was evaluated as 6%. The reactions were symmetric and reversible under low-current conditions, but some asymmetries were detected during high current operation. Furthermore, a two-phase reaction between cubic and tetragonal phases was observed in the low-voltage reaction at 2.1–3.5 V, where the lattice volume change was approximately 4.9%. The rate-determining step was discussed based on these operando results.
An outbreak of enterohaemorrhagic Escherichia coli O157 occurred in multiple prefectures of Japan in November 2009. We conducted two case–control studies with trace-back and trace-forward investigations to determine the source. The case definition was met by 21 individuals; 14 (66.7%) were hospitalised, but no haemolytic uraemic syndrome, acute encephalopathy or deaths occurred. Median age was 23 (range 12–48) years and 14 cases were male (66.7%). No significant associations with food were found in a case–control study by local public health centres, but our matched case–control study using Internet surveys found that beef hanging tender (or hanger steak), derived from the diaphragm of the cattle, was significantly associated with illness (odds ratio = 15.77; 95% confidence interval, 2.00–124.11). Pulsed-field gel electrophoresis analysis of isolates from patients and the suspected food showed five different patterns: two in faecal and food samples, and another three in patient faecal samples only, although there were epidemiological links to the meat consumed at the restaurants. Trace-back investigation implicated a common food processing company from outside Japan. Examination of the logistics of the meat processing company suggested that contamination did not occur in Japan. We concluded that the source of the outbreak was imported hanging tender. This investigation revealed that Internet surveys could be useful for outbreak investigations.
Tensile fracture strengths of fine-grained compressed high-density snow, of compressed and metamorphosed high-density snow-ice, of fine-grained naturally settled snow, and of snow-ice artificially made from the settled snow by freezing with absorbed water, were obtained at constant deformation speeds (constant strain-rates) in a temperature range of 264 to 270K. No remarkable temperature dependence of fracture stresses was observed in this temperature range. A critical deformation speed in a tensile test above which all the snow samples, except settled snow, fractured, was 4.2 × 10–7 m s–1. The fracture strength ρ (in N m–2) varied with snow density ρ (kg m–3) as σ = 2.5 × 104 × 1.004 6ρ. In a power-law relationship between strain-rate and maximum stress, ∝ σn, the constant n obtained was 5.3 for all the unfractured snow samples.
In 1987 an ice core to the bedrock at a depth of 85.6 m was drilled at the top of Høghetta ice dome in northern Spitsbergen. Chronology of the ice core was examined by tritium and 14C methods showing time gap at about 50 m depth. The age of three bottom ice samples was determined as 4150–5670 year B.P. by 14C method done for frozen bacteria colonies and a frozen petal. This chronology and negative bottom temperature of −9.4°C suggest that glaciers in Spitsbergen shrank considerably during the hypsithermal. The pH of melt-water samples lower than 5.0 corresponds well to large northern hemispheric volcanic eruptions during the last 300 years. Increase of acidity from 30 m depth to the surface may reflect the spread of air pollution to the Arctic during the past 200 years. On the basis of ice-core analyses on electrical conductivity, pH, chemical composition and air bubble pattern, climate and environment in Spitsbergen during the last 6000 years are discussed.
The Universe is permeated by hot, turbulent, magnetized plasmas. Turbulent plasma is a major constituent of active galactic nuclei, supernova remnants, the intergalactic and interstellar medium, the solar corona, the solar wind and the Earth’s magnetosphere, just to mention a few examples. Energy dissipation of turbulent fluctuations plays a key role in plasma heating and energization, yet we still do not understand the underlying physical mechanisms involved. THOR is a mission designed to answer the questions of how turbulent plasma is heated and particles accelerated, how the dissipated energy is partitioned and how dissipation operates in different regimes of turbulence. THOR is a single-spacecraft mission with an orbit tuned to maximize data return from regions in near-Earth space – magnetosheath, shock, foreshock and pristine solar wind – featuring different kinds of turbulence. Here we summarize the THOR proposal submitted on 15 January 2015 to the ‘Call for a Medium-size mission opportunity in ESAs Science Programme for a launch in 2025 (M4)’. THOR has been selected by European Space Agency (ESA) for the study phase.
Reference archaeomagnetic secular variation (SV) curves recently have been proposed for the Iberian Peninsula and may now be used for archaeomagnetic dating. Archaeomagnetic dating is a relative dating technique that is strongly dependent on the age control of the data used to construct the reference curves. In order to test the method, an archaeological structure from central Spain has been studied. Samples have been taken for both archaeomagnetic and radiocarbon dating, and the results are compared. Close agreement is observed between both techniques, with the archaeomagnetic age of AD 603–999 overlapping the calibrated age of AD 770–890. These results demonstrate the reliability of the proposed reference curves as a dating tool within the Iberian Peninsula during this archaeological period.
We have constructed a system to extract carbon from meteorites using a vacuum-tight RF melting method in order to study radiocarbon activities in meteorites. The extraction system was examined using iron standards of known carbon content. The carbon extraction efficiencies and 14C ages of the iron standards by this method were compared with the results obtained previously by our older melting system and a wet oxidation method. Higher collection efficiencies of about 90% for the iron samples of relatively high carbon content were achieved by the new system. The efficiency of extracting a small amount of carbon is also near 90% after improving the extraction procedure. The 14C ages of the iron standards were compared to the ages by the wet method. The results indicate that contamination by modern carbon is negligible in the system. Furthermore, terrestrial 14C ages of two Antarctic meteorites, Y-75102 and ALH-77294, from the Yamato and Allan Hills ice fields, respectively, were determined. The age of Y-75102 is estimated 4.0 ± 1.0 ka, and the age of ALH-77294 is 19.5 ± 1.2 ka. The 14C ages on the meteorites roughly agree with the literature value. However, further study is needed in improvement on reducing a background value and of complete fusion of a meteorite in the extraction system.
We investigated the radiocarbon ages and carbon and nitrogen isotope ratios of human skeletal remains from burials at the Yuigahama-minami and Chusei-Shudan-Bochi sites in the Yuigahama area (Kamakura, Japan), which we believe are associated with the great attack on Kamakura by Nitta Yoshisada in AD 1333. The human bones produced enriched δ13C and δ15N values that could be affected by consumption of protein from marine fish and/or mammals with high δ13C and δ15N, and therefore older apparent 14C ages. We thus estimated the marine reservoir effect on human skeletons to determine their true ages. The IsoSource isotope mixing model was employed for reconstructing percentages of marine protein in the human diet, and calibrated calendar dates for the 14C ages were calculated using the marine percentages. At the Yuigahama-minami site, most skeletons from individual burials now date to the last phase of the Kamakura period or the early part of the Muromachi period, while skeletons from mixed human-animal multiple burials date to the latter part of the Kamakura period. The humans from the individual burials, consisting of normal ratios of adult males, could have died a natural death, though the site could also have been used to inter victims of the battle of 1333. The humans from mixed human-animal burials, consisting of a high proportion of infants, were not victims of the 1333 battle, but the site may have been used to inter victims of the Kamakura earthquake in 1293, which resulted in a catastrophic tsunami. On the other hand, the skeletons from multiple burials in the Chusei-Shudan-Bochi site all date to the middle Kamakura period. Coupled with the fact that most humans in the site are male but show no evidence of injuries by sword cuts, it is likely that burials of the Chusei-Shudan-Bochi site could have been a collective interment following the Jinji earthquake in 1241, the Shoka earthquake in 1257, or the Shoka famine in 1258 in the middle Kamakura period. The results of this study indicate that humans from burials in the Yuigahama region were not necessarily victims of the attack by Nitta Yoshisada on Kamakura, but instead were likely victims of natural disasters such as large earthquakes and severe famines, which often occurred in the middle Kamakura period.
We discuss the fragmentation of primordial gas clouds in the universe after decoupling. Comparing the timescale of collapse (tdyn) with that of fragmentation (tfrag), we obtained the minimum mass of a fragment analytically as following way.
We discuss the properties of the very energetic Type Ic supernovae (SNe Ic) 1998bw and 1997ef, and of Type IIn supernova (SN IIn) 1997cy. SNe Ic 1998bw and 1997ef are characterized by their large luminosity and very broad spectral features. Their observed properties can be explained if they are very energetic SN explosions (EK ≳ 1 × 1052 erg), originating probably from the core collapse of the bare C+O cores of massive stars (~ 30–40M⊙). At late times, both the light curve and the spectra suggest that the explosion may have been asymmetric; this may help us understand the claimed connection with GRBs. Type IIn SN 1997cy is even more luminous than SN 998bw, and the light curve declines more slowly than the 56Co decay. We model such a light curve with circumstellar interaction, which requires the explosion energy of ~ 5 × 1052 erg. Because these kinetic energies of explosion are much larger than in normal core-collapse SNe, we call objects like these SNe “hypernovae”.
In the present paper, we stress the importance of the magnetic field in the problem of acceleration and collimation of astrophysical jets, and discuss our proposed generic picture for such “central gravitator + jets + lobes” systems and inherent interpretations of the various observational characteristics of such systems: Mechanisms are proposed for (1) the enhanced liberation of gravitational energy at the central object, (2) the transfer of a part of the liberated energy along the large-scale magnetic field by large-amplitude, torsional Alfvén wave trains that form collimated jets (we call this a sweeping pinch process), (3) the dumping of the transferred energy at the end of the jets when they impinge on the denser region outside the border of the “cavity” from which the mass contracted to the central condensation (central gravitator + accretion disk, as well as the larger-scale condensation surrounding them), and (4) the formation of wiggled jets and lobes as helical kinks and the tucked-up magnetic field produced in the sweeping pinch process, respectively.
During the period from July 1996 to Dec 1998, 189 photographic positions of the galilean satellites were obtained with the zonal astrograph (D=120 mm, F=2044mm). In the year 1998 the close approach of the satellite system with the star N 117881 from the HIPPARCOS catalogue was observed. The observations of 1996 were processed using PPM catalogue and the observations of 1997, 1998 in the ICRS using HIPPARCOS and ACTRC star catalogues. The results are not yet published, but are available upon request. Observations made since 1962 up to 1996 with the zonal astrograph were reprocessed and results are in preparation for publication. During the period from 1996 to 1998, 69 positions of the Galilean satellites were determined by photoelectric meridian observations with the Repsold meridian circle equipped by CCD-microscopes (F=2150 mm, D=150 mm).