• Title/Summary/Keyword: HI

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HI gas kinematics of galaxy pairs in the Hydra cluster from ASKAP pilot observations

  • Kim, Shin-Jeong;Oh, Se-Heon
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.61.1-61.1
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    • 2020
  • We examine the HI gas kinematics and distribution of galaxy pairs in group or cluster environment from high-resolution Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot observations. We use 22 well-resolved galaxies in the Hydra cluster of which 4 galaxies are visually identified as pairs and others are isolated ones. We perform profile decomposition of HI velocity profiles of the galaxies using a new tool, BAYGAUD which enables us to separate a line-of-sight velocity profile into an optimal number of Gaussian components based on Bayesian MCMC techniques. All the HI velocity profiles of the galaxies are decomposed into kinematically cold or warm gas components with their velocity dispersion, 4~8 km/s or > 8 km/s, respectively. We derive the mass fraction of the kinematically cold gas with respect to the total HI gas mass, f = log10(M_cold / M_HI), of the galaxies and correlate them with their dynamical mass. The cold gas reservoir of the paired galaxies in the Hydra cluster is found to be relatively higher than that of the isolated ones which show a negative correlation with the dynamical mass in general.

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HI gas properties of BAT-BASS AGN host galaxies

  • Kim, Jeein;Chung, Aeree;Baek, Junhyun;Oh, Kyuseok;Wong, O. Ivy;Koss, Michael J.
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.69.1-69.1
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    • 2021
  • We present preliminary results of the VLA archival HI data of local AGN hosts. The sample consists of the galaxies selected from the Swift-BAT hard X-ray survey. The main goal is to probe the gas environment of the sample in order to verify the role of gas accretion as one of the major AGN triggering mechanisms. HI, as a mostly diffuse and extended gas component in many galaxies, is a sensitive tracer to explore the impact of the surroundings on galaxies. In this work, we therefore probe the HI imaging data of a subsample of BAT-BASS AGN hosts, starting with the cases for which relatively high HI fluxes have been reported from the past single-dish observations. Based on their resolved HI properties, we will discuss the possibility of gas accretion and its role in powering AGNs in these examples.

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Study on Scale-up of Electro-Electrodialysis [EED] Cell for HI Concentration (HI 농축을 위한 전해-전기투석 셀의 스케일-업에 관한 연구)

  • Lee, Sang-Ho;Hong, Seong-Dae;Kim, Jeong-Keun;Hwang, Gab-Jin;Moon, Il-Sik
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.4
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    • pp.458-463
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    • 2007
  • An experimental study on scale-up of Electro-electrodialysis(EED) to increase the efficiency of HI decomposition section in the IS(Iodine-Sulfur) process was carried out. The EED stack extends the effective area of the membrane to 20 times of that formerly used in a single EED unit cell. The experiment was carried out using HIx solution($HI:H_2O:I_2=1:8.4{\sim}9:1.85{\sim}1.9$) at $100^{\circ}C$ and various solution flow rates of 20, 30, 40 and 50 cc/min. The increased HI molality in catholyte after one-pass throughout from the EED stack was 3 mol/kg-$H_2O$, 2.2 mol/kg-$H_2O$, 2 mol/kg-$H_2O$ and 1.37 mol/kg-$H_2O$ at 20, 30, 40 and 50 cc/min, respectively. These values satisfied the target of HI molality(the increase of HI molality: 2 mol/kg-$H_2O$) in the IS process for hydrogen production of 20 L/hr.

A role of Sodium Bicarbonate Cotransporter(NBC) in $HCO_3^-$ Formation in Human Salivary Gland Acinar Cells

  • Jin, Mee-Hyun;Koo, Na-Youn;Jin, Mei-Hong;Hwang, Sung-Min;Park, Kyung-Pyo
    • International Journal of Oral Biology
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    • v.33 no.4
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    • pp.143-147
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    • 2008
  • The sodium bicarbonate cotransporter (NBC) protein is functionally expressed in salivary glands. In this experiment, we examined the role of NBC in $HCO_3^-$ formation in human parotid gland acinar cells. Intracellular pH (pHi) was measured in 2'-7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-loaded cells. Acetazolamide (0.1 mM) and 4,4'-diisothio cyanatostilbene-2,2'-disulphonic acid (DIDS, 0.5 mM) were used as specific inhibitors of carbonic anhydrase and NBC, respectively. The degree of inhibition was assessed by measuring the pHi recovery rate (${\Delta}pHi$/min) after cell acidification using an ammonium prepulse technique. In control experiments, ${\Delta}pHi$/min was $1.40{\pm}0.06$. Treatment of cells with 0.5 mM DIDS or 0.1 mM acetazolamide significantly reduced ${\Delta}pHi$/min to $1.14{\pm}0.14$ and $0.74{\pm}0.15$, respectively. Simultaneous application of DIDS and acetazolamide further reduced ${\Delta}pHi$/min to $0.47{\pm}0.10$. Therefore, DIDS and acetazolamide reduced ${\Delta}pHi$/min by 19% and 47%, respectively, while simultaneous application of both DIDS and acetazolamide caused a reduction in ${\Delta}pHi$/min of 67%. These results suggest that in addition to carbonic anhydrase, NBC also partially contributes to $HCO_3^-$ formation in human parotid gland acinar cells.

Frankia sp. strain SNU 014201의 nif-H, D, K, 유전자 클로닝

  • 권석윤;강명수;안정선
    • Korean Journal of Microbiology
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    • v.30 no.1
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    • pp.30-36
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    • 1992
  • nif (nitrogen fixation)-H.D, K genes of Frankia sp. SNU 014201. a symbiotic strain isolated from root nodule of Alnus hirsura, were found to be located in the genome on 13.5 kb of EcoRI, 18.0 kb of BamHI, 10.5 kb of BglII and 4.5 kb of KpnI fragments. Using EMBL-3 BamHI arms of bacteriophage lambda. the genomic library was constructed. from which fourteen recombinant phage nif-clones were selected. Among them, Ahnif-I2 had insert DNA of 18 kb, in which 7.9 kb of BamHl fragment contained nif-H, D, K and 3.6 kb of HindlIl/KpnI had nif-H and partial -D. Therefore, the 7.9 kb and 3.6 kb fragments were subcloned and partial restriction maps were constructed. As the results, nif-F1, D.K genes were found to be located continuously on the 6.5 kb of HindII/BamHI and 5.2 kb of SalIIBamHI fragment in the genome of Frankia sp. SNU 014201.

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The comparative study on Newcastle disease virus antibody titer by hemagglutination inhibition test and enzyme-linked immunosorbent assay (혈구응집억제반응과 효소면역측정법을 이용한 닭 뉴캣슬병 바이러스에 대한 혈중항체가 비교)

  • Han, Sung-Tae;Lee, Cheong-San;Kwak, Hak-Koo;Song, Jong-Han;Lee, Jong-In
    • Korean Journal of Veterinary Service
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    • v.26 no.3
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    • pp.215-219
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    • 2003
  • This study was conducted to investigate the similarity between hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay(ELISA) titers and sample to positive ratio (S/P ratio) of Newcastle disease(ND) virus. To perform this study, the 372 sera of broiler chicks and 120 sera of layers and breed chicks were collected from slaughter house and farms, respectively. As a result of HI test out of different chicks, the positive percentage of ND antibody titer of broiler, layer and breeder, when a standard positive HI titer were '2', was 84.4%, 100% and 100%, respectively. The positive percentage of ND antibody titer by ELISA was shown 38.4%, 100% and 100% and S/P ratio were also shown 81.5%, 98.2% and 99.2%, respectively. The results of comparative survey with same sera by two experimental methods were as follows; In low HI titer, ELISA titer was not similar to HI titer, but S/P ratio was similar to it. In high HI titer, ELISA titer was not similar to HI titer. Therefore, HI titer was more similar to S/P ratio than ELISA titer.

Comparison of ELISA and HI titers in broiler chicks vaccinated with infectious bronchitis virus and Newcastle disease virus (전염성기관지염 및 뉴캣슬병 백신을 접종한육계에서 ELISA 및 HI 항체가 비교)

  • 고원석;이정원;곽길한;권정택;송희종
    • Korean Journal of Veterinary Service
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    • v.24 no.1
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    • pp.21-29
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    • 2001
  • To compare of serum antibody titers using ELISA and HI, serum samples were collected from 100 breeders and their progeny 550 broilers. The breeders and broilers were vaccinated with infectious bronchitis(IB)- and Newcastle disease(ND)-viruses according to general vaccination program. The antibodies in serum samples against IB and ND viruses were detected by enzyme-linked immunosorbent assay(ELISA) using commercial ELISA kit and hemagglutination inhibition(HI) test. Geometric mean titer(GMT) of ELISA and In titers were monitored from 1-day-old to 35-day-old broilers and compared to those of breeder chickens. The antibody titers of breeders vaccinated with ]B virus showed 47,800, ELISA and 7.2, HI, respectively. Progeny chicks, 1-day-old, vaccinated with IBV showed high antibody titers than those of breed chickens. Those chicks were maintained protective antibody levels until 11-day-old. From 14-day-old, the antibody level decreased below protective levels. In ND, breeders serum antibody titers ELISA and Eiu were 30,200 GMT and 8.7 HI titer, respectively. On 1-day-old chicks, antibody levels was decreased to half in ELISA(16,270) compared with those of breeders, but In titers was 7.4. Progeny broilers, protective antibody level was maintained until 14- day-old by ELISA, but at 11-day-old by HI titers. After then, ND antibody titer was continuously decreased underdefense level. These result indicated that the ELISA method be more sensitive than HI titration to detect serum antibody level for IBV and NDV.

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HI Shells and Supershells in the I-GALFA HI 21-cm Line Survey

  • Park, Geum-Sook;Koo, Bon-Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.112.2-112.2
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    • 2011
  • We carry out a systematic study of HI shells and supershells in the first Galactic quadrant (l = $32^{\circ}$ to $77^{\circ}$, b = $-10^{\circ}$ to $10^{\circ}$) using the "Inner-Galaxy Arecibo L-band Feed Array (I-GALFA)" HI 21-cm survey data. The high-resolution (3.'4) and high sensitivity (0.2 K) of the survey provide us an opportunity to exploit the true nature of the sources detected in previous low-resolution studies and also to detect faint and/or small shells that were not detectable before. Our work is composed of three parts: (1) confirm the objects in the low-resolution (about 30') catalog of Heiles (1979), (2) search for fast-expanding HI shells associated with Galactic supernova remnants (SNRs), and (3) search for new shell structures. Among the 21 Heiles' supershells in the I-GALFA survey area, we confirm fourteen. The high resolution data reveal their complex morphology, and provide direct evidence for expansion in some sources. Among the 39 Galactic SNRs in the survey area, we find five with associated fast expanding HI shells, which is consistent with previous results. A remarkable result from the SNR study is the detection of HI gas at very high negative velocities in the SNR W44 that should be from the approaching part of the HI expanding shell. This is the first time to detect both the approaching and receding sides of an expanding shell in HI 21-cm emission line in SNRs. We have found 33 new shell candidates of angular sizes ranging from 0.5 to 6.5 degrees, half of which appear to be expanding. We summarize these results and discuss some individual interesting objects in detail.

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Effects of carnosine and hypothermia combination therapy on hypoxic-ischemic brain injury in neonatal rats

  • Byun, Jun Chul;Lee, Seong Ryong;Kim, Chun Soo
    • Clinical and Experimental Pediatrics
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    • v.64 no.8
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    • pp.422-429
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    • 2021
  • Background: Carnosine has antioxidative and neuroprotective properties against hypoxic-ischemic (HI) brain injury. Hypothermia is used as a therapeutic tool for HI encephalopathy in newborn infants with perinatal asphyxia. However, the combined effects of these therapies are unknown. Purpose: Here we investigated the effects of combined carnosine and hypothermia therapy on HI brain injury in neonatal rats. Methods: Postnatal day 7 (P7) rats were subjected to HI brain injury and randomly assigned to 4 groups: vehicle; carnosine alone; vehicle and hypothermia; and carnosine and hypothermia. Carnosine (250 mg/kg) was intraperitoneally administered at 3 points: immediately following HI injury, 24 hours later, and 48 hours later. Hypothermia was performed by placing the rats in a chamber maintained at 27℃ for 3 hours to induce whole-body cooling. Sham-treated rats were also included as a normal control. The rats were euthanized for experiments at P10, P14, and P35. Histological and morphological analyses, in situ zymography, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assays, and immunofluorescence studies were conducted to investigate the neuroprotective effects of the various interventional treatments. Results: Vehicle-treated P10 rats with HI injury showed an increased infarct volume compared to sham-treated rats during the triphenyltetrazolium chloride staining study. Hematoxylin and eosin staining revealed that vehicle-treated P35 rats with HI injury had decreased brain volume in the affected hemisphere. Compared to the vehicle group, carnosine and hypothermia alone did not result in any protective effects against HI brain injury. However, a combination of carnosine and hypothermia effectively reduced the extent of brain damage. The results of in situ zymography, TUNEL assays, and immunofluorescence studies showed that neuroprotective effects were achieved with combination therapy only. Conclusion: Carnosine and hypothermia may have synergistic neuroprotective effects against brain damage following HI injury.