90 research outputs found

    The extent of metal enrichment from galactic winds during the Cosmic Dawn

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    One of the key processes driving galaxy evolution during the Cosmic Dawn is supernova feedback. This likely helps regulate star formation inside of galaxies, but it can also drive winds that influence the large-scale intergalactic medium. Here, we present a simple semi-analytic model of supernova-driven galactic winds and explore the contributions of different phases of galaxy evolution to metal enrichment in the high-redshift (z > 6) Universe. We show that models calibrated to the observed galaxy luminosity function at z~6-8 have filling factors ~1% at z~6 and ~0.1% at z~12, with different star formation prescriptions providing about an order of magnitude uncertainty. Despite the small fraction of space filled by winds, these scenarios still provide more than enough enriched volume to explain the observed abundance of metal-line absorbers in quasar spectra at z > 5. We also consider enrichment through winds driven by Pop III star formation in minihaloes. We find that these can dominate the total filling factor at z > 10 and even compete with winds from normal galaxies at z~6, at least in terms of the total enriched volume. But these regions have much lower overall metallicities, because each one is generated by a small burst of star formation. Finally, we show that Compton cooling of these supernova-driven winds at z > 6 has only a small effect on the cosmic microwave background.Comment: 12 pages, 8 figures, submitted to MNRA

    Simultaneous Screening of 24 Target Genes of Foodborne Pathogens in 35 Foodborne Outbreaks Using Multiplex Real-Time SYBR Green PCR Analysis

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    A set of 8 multiplex real-time SYBR Green PCR (SG-PCR) assays including 3 target primers and an internal amplification control (IAC) primer was simultaneously evaluated in 3 h or less with regard to detection of 24 target genes of 23 foodborne pathogens in 7 stool specimens of foodborne outbreak using a 96-well reaction plate. This assay, combined with DNA extraction (QIAamp DNA Stool Mini kit), offered detection of greater than 103-104 foodborne pathogens per g in stool specimens. The products formed were identified using melting point temperature (Tm) curve analysis. This assay was evaluated for the detection of foodborne pathogens in 33 out of 35 cases of foodborne outbreak, using 4 different PCR instruments in 5 different laboratories. No interference from the multiplex real-time SG-PCR assay, including IAC, was observed in stool specimens in any analysis. We found multiplex real-time SG-PCR assay for simultaneous detection of 24 target genes of foodborne pathogens to be comprehensive, rapid, inexpensive, accurate, of high selectivity, and good for screening probability

    A CASE OF CORONAVIRUS DISEASE 2019 COMPLICATED BY VENTILATORASSOCIATED PNEUMONIA, LUNG ABSCESS, AND STAPHYLOCOCCUS AUREUS BACTEREMIA

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    Complications of healthcare-associated infections have been reported in patients with coronavirus disease 2019 (COVID-19). We encountered a case of ventilator-associated pneumonia and lung abscess, complicated with Staphylococcus aureus bacteremia and multiple abscesses, in a patient with COVID-19. Streptococci and anaerobes were cultured from the sputum, which was considered to be the causative organism of the lung abscess. In the management of severe COVID-19, care should be taken to prevent complications of healthcare-associated infections; when secondary respiratory tract infections are suspected, the presence of lung abscess and anaerobic culture should be considered

    High Excitation Molecular Gas in the Galactic Center Loops; 12CO(J =2-1 and J =3-2) Observations

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    We have carried out 12CO(J =2-1) and 12CO(J =3-2) observations at spatial resolutions of 1.0-3.8 pc toward the entirety of loops 1 and 2 and part of loop 3 in the Galactic center with NANTEN2 and ASTE. These new results revealed detailed distributions of the molecular gas and the line intensity ratio of the two transitions, R3-2/2-1. In the three loops, R3-2/2-1 is in a range from 0.1 to 2.5 with a peak at ~ 0.7 while that in the disk molecular gas is in a range from 0.1 to 1.2 with a peak at 0.4. This supports that the loops are more highly excited than the disk molecular gas. An LVG analysis of three transitions, 12CO J =3-2 and 2-1 and 13CO J =2-1, toward six positions in loops 1 and 2 shows density and temperature are in a range 102.2 - 104.7 cm-3 and 15-100 K or higher, respectively. Three regions extended by 50-100 pc in the loops tend to have higher excitation conditions as characterized by R3-2/2-1 greater than 1.2. The highest ratio of 2.5 is found in the most developed foot points between loops 1 and 2. This is interpreted that the foot points indicate strongly shocked conditions as inferred from their large linewidths of 50-100 km s-1, confirming the suggestion by Torii et al. (2010b). The other two regions outside the foot points suggest that the molecular gas is heated up by some additional heating mechanisms possibly including magnetic reconnection. A detailed analysis of four foot points have shown a U shape, an L shape or a mirrored-L shape in the b-v distribution. It is shown that a simple kinematical model which incorporates global rotation and expansion of the loops is able to explain these characteristic shapes.Comment: 59 pages, accepted to PAS

    Temperature and Density in the Foot Points of the Molecular Loops in the Galactic Center; Analysis of Multi-J Transitions of 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) and C18O(J=1-0)

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    Fukui et al. (2006) discovered two molecular loops in the Galactic center and argued that the foot points of the molecular loops, two bright spots at both loops ends, represent the gas accumulated by the falling motion along the loops, subsequent to magnetic flotation by the Parker instability. We have carried out sensitive CO observations of the foot points toward l=356 deg at a few pc resolution in the six rotational transitions of CO; 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) and C18O(J=1-0). The high resolution image of 12CO (J=3-2) has revealed the detailed distribution of the high excitation gas including U shapes, the outer boundary of which shows sharp intensity jumps accompanying strong velocity gradients. An analysis of the multi-J CO transitions shows that the temperature is in a range from 30-100 K and density is around 10^3-10^4 cm^-3, confirming that the foot points have high temperature and density although there is no prominent radiative heating source such as high mass stars in or around the loops. We argue that the high temperature is likely due to the shock heating under C-shock condition caused by the magnetic flotation. We made a comparison of the gas distribution with theoretical numerical simulations and note that the U shape is consistent with numerical simulations. We also find that the region of highest temperature of ~100 K or higher inside the U shape corresponds to the spur having an upward flow, additionally heated up either by magnetic reconnection or bouncing in the interaction with the narrow neck at the bottom of the U shape. We note these new findings further reinforce the magnetic floatation interpretation.Comment: 40 pages, 23 figures, accepted by PASJ on Vol.62 No.

    Calaxin is required for cilia-driven determination of vertebrate laterality

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    Sasaki, K., Shiba, K., Nakamura, A. et al. Calaxin is required for cilia-driven determination of vertebrate laterality. Commun Biol 2, 226 (2019). https://doi.org/10.1038/s42003-019-0462-

    The fastest stars in the Galaxy

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    We report a spectroscopic search for hypervelocity white dwarfs (WDs) that are runaways from Type Ia supernovae (SNe Ia) and related thermonuclear explosions. Candidates are selected from Gaia data with high tangential velocities and blue colors. We find six new runaways, including four stars with radial velocities (RVs) >1000kms1>1000\,\rm km\,s^{-1} and total space velocities 1300kms1\gtrsim 1300\,\rm km\,s^{-1}. These are most likely the surviving donors from double-degenerate binaries in which the other WD exploded. The other two objects have lower minimum velocities, 600kms1\gtrsim 600\,\rm km\,s^{-1}, and may have formed through a different mechanism, such as pure deflagration of a WD in a Type Iax supernova. The four fastest stars are hotter and smaller than the previously known "D6^6 stars," with effective temperatures ranging from \sim20,000 to \sim130,000 K and radii of 0.020.10R\sim 0.02-0.10\,R_{\odot}. Three of these have carbon-dominated atmospheres, and one has a helium-dominated atmosphere. Two stars have RVs of 1694-1694 and 2285kms1-2285\rm \,km\,s^{-1} -- the fastest systemic stellar RVs ever measured. Their inferred birth velocities, 22002500kms1\sim 2200-2500\,\rm km\,s^{-1}, imply that both WDs in the progenitor binary had masses >1.0M>1.0\,M_{\odot}. The high observed velocities suggest that a dominant fraction of the observed hypervelocity WD population comes from double-degenerate binaries whose total mass significantly exceeds the Chandrasekhar limit. However, the two nearest and faintest D6^6 stars have the lowest velocities and masses, suggesting that observational selection effects favor rarer, higher-mass stars. A significant population of fainter low-mass runaways may still await discovery. We infer a birth rate of D6^6 stars that is consistent with the SN Ia rate. The birth rate is poorly constrained, however, because the luminosities and lifetimes of D6\rm D^6 stars are uncertain.Comment: 26 pages, 17 figures. Accepted to OJ

    Genetic variants in mannose receptor gene (MRC1) confer susceptibility to increased risk of sarcoidosis

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    <p>Abstract</p> <p>Background</p> <p>Mannose receptor (MR) is a member of the C-type lectin receptor family involved in pathogen molecular-pattern recognition and thought to be critical in shaping host immune response. The aim of this study was to investigate potential associations of genetic variants in the <it>MRC1 </it>gene with sarcoidosis.</p> <p>Methods</p> <p>Nine single nucleotide polymorphisms (SNPs), encompassing the <it>MRC1 </it>gene, were genotyped in a total of 605 Japanese consisting of 181 sarcoidosis patients and 424 healthy controls.</p> <p>Results</p> <p>Suggestive evidence of association between rs691005 SNP and risk of sarcoidosis was observed independent of sex and age in a recessive model (<it>P </it>= 0.001).</p> <p>Conclusions</p> <p>These results suggest that <it>MRC1 </it>is an important candidate gene for sarcoidosis. This is the first study to imply that genetic variants in <it>MRC1</it>, a major member of the C-type lectin, contribute to the development of sarcoidosis.</p

    いい音・悪い音 : 音を目で見ると

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    When young, one of the authors heard someone say \u27In fact there\u27s little difference between the refreshing waterfall sound and the traffic noise on roads.\u27 So-called good sounds include insects\u27 chirping, tinkles of the wind-bell and piano tunes. Bad ones include noises of trams or machinery. What makes the difference between a \u27good sound\u27 and a \u27bad sound\u27? This paper intended to visually compare the frequencies of various sounds using Windows Media Player. The results obtained were as follows. 1. So-called good sounds generally had sharp fluctuations in their frequency ranges as shown on attached graphs. 2. So-called bad sounds had less sharp fluctuations in their frequency ranges, hence did not show a clear sound. 3. However, the fluctuations of the waterfall sound and the fluctuations of the traffic noise of the road were not very different, which suggests for some sounds the existence of other factors such as listeners\u27 psychology; memories of the past, the milieu and connotations

    Prevention of hypoglycemia by intermittent-scanning continuous glucose monitoring device combined with structured education in patients with type 1 diabetes mellitus : A randomized, crossover trial

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    Aims: We conducted a randomized, crossover trial to compare intermittent-scanning continuous glucose monitoring (isCGM) device with structured education (Intervention) to self-monitoring of blood glucose (SMBG) (Control) in the reduction of time below range. Methods: This crossover trial involved 104 adults with type 1 diabetes mellitus (T1DM) using multiple daily injections. Participants were randomly allocated to either sequence Intervention/Control or sequence Control/Intervention. During the Intervention period which lasted 84 days, participants used the first-generation FreeStyle Libre (Abbott Diabetes Care, Alameda, CA, USA) and received structured education on how to prevent hypoglycemia based on the trend arrow and by frequent sensor scanning (≥10 times a day). Confirmatory SMBG was conducted before dosing insulin. The Control period lasted 84 days. The primary endpoint was the decrease in the time below range (TBR; <70 mg/dL). Results: The time below range was significantly reduced in the Intervention arm compared to the Control arm (2.42 ± 1.68 h/day [10.1 %±7.0 %] vs 3.10 ± 2.28 h/day [12.9 %±9.5 %], P = 0.012). The ratio of high-risk participants with low blood glucose index >5 was significantly reduced (8.6 % vs 23.7 %, P < 0.001). Conclusions: The use of isCGM combined with structured education significantly reduced the time below range in patients with T1DM
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