89 research outputs found
The MeerKAT Fornax Survey -- II. The rapid removal of HI from dwarf galaxies in the Fornax cluster
We present MeerKAT Fornax Survey atomic hydrogen (HI) observations of the
dwarf galaxies located in the central ~2.5 x 4 deg of the Fornax galaxy
cluster. The HI images presented in this work have a column density
sensitivity between 2.7 and 50 x 10 cm over 25 km s for
spatial resolution between 4 and 1 kpc. We are able to detect an impressive MHI
= 5 x 10 Msun 3 point source with a line width of 50 km s
at a distance of 20 Mpc. We detect HI in 17 out of the 304 dwarfs in our field
-- 14 out of the 36 late type dwarfs (LTDs), and 3 of the 268 early type dwarfs
(ETDs). The HI-detected LTDs have likely just joined the cluster and are on
their first infall as they are located at large clustocentric radii, with
comparable MHI and mean stellar surface brightness at fixed luminosity as blue,
star-forming LTDs in the field. The HI-detected ETDs have likely been in the
cluster longer than the LTDs and acquired their HI through a recent merger or
accretion from nearby HI. Eight of the HI-detected LTDs host irregular or
asymmetric HI emission and disturbed or lopsided stellar emission. There are
two clear cases of ram-pressure shaping the HI, with the LTDs displaying
compressed HI on the side closest to the cluster centre and a one-sided,
starless tail pointing away from the cluster centre. The HI-detected dwarfs
avoid the most massive potentials, consistent with massive galaxies playing an
active role in the removal of HI. We create a simple toy model to quantify the
timescale of HI stripping in the cluster. We find that a MHI = 10 Msun
dwarf will be stripped in ~ 240 Myr. The model is consistent with our
observations, where low mass LTDs are directly stripped of their HI from a
single encounter and more massive LTDs can harbour a disturbed HI morphology
due to longer times or multiple encounters being required to fully strip their
HI.Comment: Accepted in Astronomy & Astrophysics. 21 pages, 10 figures. Data
available at the MeerKAT Fornax Survey website
https://sites.google.com/inaf.it/meerkatfornaxsurve
MeerKAT-16 H I observation of the dIrr galaxy WLM
We present observations and models of the kinematics and the distribution of
the neutral hydrogen (HI) in the isolated dwarf irregular galaxy,
Wolf-Lundmark-Melotte (WLM). We observed WLM with the Green Bank Telescope
(GBT) and as part of the MeerKAT Early Science Programme, where 16 dishes were
available. The HI disc of WLM extends out to a major axis diameter of 30 arcmin
(8.5 kpc), and a minor axis diameter of 20 arcmin (5.6 kpc) as measured by the
GBT. We use the MeerKAT data to model WLM using the TiRiFiC software suite,
allowing us to fit different tilted-ring models and select the one that best
matches the observation. Our final best-fitting model is a flat disc with a
vertical thickness, a constant inclination and dispersion, and a
radially-varying surface brightness with harmonic distortions. To simulate
bar-like motions, we include second-order harmonic distortions in velocity in
the tangential and the vertical directions. We present a model with only
circular motions included and a model with non-circular motions. The latter
describes the data better. Overall, the models reproduce the global
distribution and the kinematics of the gas, except for some faint emission at
the 2-sigma level. We model the mass distribution of WLM with a
pseudo-isothermal (ISO) and a Navarro-Frenk-White (NFW) dark matter halo
models. The NFW and the ISO models fit the derived rotation curves within the
formal errors, but with the ISO model giving better reduced chi-square values.
The mass distribution in WLM is dominated by dark matter at all radii.Comment: Accepted for publication in MNRAS, 25 pages, 21 figures, 5 table
Multi-omics integration identifies key upstream regulators of pathomechanisms in hypertrophic cardiomyopathy due to truncating MYBPC3 mutations
BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the cardiac muscle, frequently caused by mutations in MYBPC3. However, little is known about the upstream pathways and key regulators causing the disease. Therefore, we employed a multi-omics approach to study the pathomechanisms underlying HCM comparing patient hearts harboring MYBPC3 mutations to control hearts. RESULTS: Using H3K27ac ChIP-seq and RNA-seq we obtained 9310 differentially acetylated regions and 2033 differentially expressed genes, respectively, between 13 HCM and 10 control hearts. We obtained 441 differentially expressed proteins between 11 HCM and 8 control hearts using proteomics. By integrating multi-omics datasets, we identified a set of DNA regions and genes that differentiate HCM from control hearts and 53 protein-coding genes as the major contributors. This comprehensive analysis consistently points toward altered extracellular matrix formation, muscle contraction, and metabolism. Therefore, we studied enriched transcription factor (TF) binding motifs and identified 9 motif-encoded TFs, including KLF15, ETV4, AR, CLOCK, ETS2, GATA5, MEIS1, RXRA, and ZFX. Selected candidates were examined in stem cell-derived cardiomyocytes with and without mutated MYBPC3. Furthermore, we observed an abundance of acetylation signals and transcripts derived from cardiomyocytes compared to non-myocyte populations. CONCLUSIONS: By integrating histone acetylome, transcriptome, and proteome profiles, we identified major effector genes and protein networks that drive the pathological changes in HCM with mutated MYBPC3. Our work identifies 38 highly affected protein-coding genes as potential plasma HCM biomarkers and 9 TFs as potential upstream regulators of these pathomechanisms that may serve as possible therapeutic targets
MeerKAT-64 discovers wide-spread tidal debris in the nearby NGC 7232 galaxy group
We report the discovery of large amounts of previously undetected cold neutral atomic hydrogen (H I) around the core triplet galaxies in the nearby NGC 7232 galaxy group with MeerKAT. With a physical resolution of ∼1 kpc, we detect a complex web of low-surface-brightness HI emission down to a 4σ column density level of ∼1 × 1019 cm-2 (over 44 km s-1). The newly discovered HI streams extend over ∼20 arcmin corresponding to 140 kpc in projection. This is approximately three times the HI extent of the galaxy triplet (52 kpc). The HI debris has an HI mass of ∼6.6 × 109 M⊙, more than 50 per cent of the total HI mass of the triplet. Within the galaxy triplet, NGC 7233 and NGC 7232 have lost a significant amount of HI while NGC 7232B appears to have an excess of HI. TheHI deficiency in NGC 7232 and NGC 7233 indicates that galaxÿCgalaxy interaction in the group concentrates on this galaxy pair while the other disc galaxies have visited them over time. In comparison to the AMIGA sample of isolated galaxies, we find that with regards to its total HI mass the NGC 7232/3 galaxy triplet is not HI-deficient. Despite the many interactions associated to the triplet galaxies, no HI seems to have been lost from the group (yet)
Service Interaction Flow Analysis Technique for Service Personalization
Abstract
Service interaction flows are difficult to capture, analyze, outline, and represent for research and design purposes. We examine how variation of personalized service flows in technology-mediated service interaction can be modeled and analyzed to provide information on how service personalization could support interaction. We have analyzed service interaction cases in a context of technology-mediated car rental service. With the analysis technique we propose, inspired by Interaction Analysis method, we were able to capture and model the situational service interaction. Our contribution regarding technology-mediated service interaction design is twofold: First, with the increased understanding on the role of personalization in managing variation in technology-mediated service interaction, our study contributes to designing service management information systems and human-computer interfaces that support personalized service interaction flows. Second, we provide a new analysis technique for situated interaction analysis, particularly when the aim is to understand personalization in service interaction flows
Antibacterial resistance and their genetic location in MRSA isolated in Kuwait hospitals, 1994-2004
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major cause of serious infections in hospitals and in the community worldwide. In this study, MRSA isolated from patients in Kuwait hospitals were analyzed for resistance trends and the genetic location of their resistance determinants. METHODS: Between April 1994 and December 2004, 5644 MRSA isolates obtained from different clinical samples were studied for resistance to antibacterial agents according to guidelines from the National Committee for Clinical Laboratory Standards and the British Society for Antimicrobial Chemotherapy. The genetic location of their resistance determinants was determined by curing and transfer experiments. RESULTS: They were resistant to aminoglycosides, erythromycin, tetracycline, trimethoprim, fusidic acid, ciprofloxacin, chloramphenicol, rifampicin, mupirocin, cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide but susceptible to vancomycin, teicoplanin and linezolid. The proportion of the isolates resistant to erythromycin, ciprofloxacin and fusidic acid increased during the study period. In contrast, the proportion of isolates resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim declined. High-level mupirocin resistance increased rapidly from 1996 to 1999 and then declined. They contained plasmids of 1.9, 2.8, 3.0, 4.4, 27 and 38 kilobases. Genetic studies revealed that they carried plasmid-borne resistance to high-level mupirocin resistance (38 kb), chloramphenicol (2.8 – 4.4 kb), erythromycin (2.8–3.0 kb) and cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide (27 kb) and chromosomal location for methicillin, the aminoglycosides, tetracycline, fusidic acid, ciprofloxacin and trimethoprim resistance. Thus, the 27 kb plasmids had resistance phenotypes similar to plasmids reported in MRSA isolates in South East Asia. CONCLUSION: The prevalence of resistance to erythromycin, ciprofloxacin, high-level mupirocin and fusidic acid increased whereas the proportion of isolates resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim declined during the study period. They contained 27-kb plasmids encoding resistance to cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide similar to plasmids isolated in MRSA from South East Asia. Molecular typing of these isolates will clarify their relationship to MRSA from South East Asia
MeerKAT-16 HI observation of the dIrr galaxy WLM
We present observations and models of the kinematics and the distribution of the
neutral hydrogen (Hi) in the isolated dwarf irregular galaxy, Wolf-Lundmark-Melotte
(WLM). We observed WLM with the Green Bank Telescope (GBT) and as part of
the MeerKAT Early Science Programme, where 16 dishes were available. The Hi disc
of WLM extends out to a major axis diameter of 300 (8.5 kpc), and a minor axis
diameter of 200 (5.6 kpc) as measured by the GBT. We use the MeerKAT data to
model WLM using the TiRiFiC software suite, allowing us to t di erent tilted-ring
models and select the one that best matches the observation. Our nal best- tting
model is a
at disc with a vertical thickness, a constant inclination and dispersion,
and a radially-varying surface brightness with harmonic distortions. To simulate bar-
like motions, we include second-order harmonic distortions in velocity in the tangential
and the vertical directions. We present a model with only circular motions included
and a model with non-circular motions. The latter describes the data better. Overall,
the models reproduce the global distribution and the kinematics of the gas, except for
some faint emission at the 2 level. We model the mass distribution of WLM with a
pseudo-isothermal (ISO) and a Navarro-Frenk-White (NFW) dark matter halo models.
The NFW and the ISO models t the derived rotation curves within the formal errors,
but with the ISO model giving better reduced chi-square values. The mass distribution
in WLM is dominated by dark matter at all radii.The MeerKAT telescope is operated by the South African
Radio Astronomy Observatory, which is a facility of the Na-
tional Research Foundation, an agency of the Department
of Science and Innovation.
This work is based upon research supported by the South
African Research Chairs Initiative of the Department of Sci-
ence and Technology and National Research Foundation.
The nancial assistance of the South African Radio Astron-
omy Observatory (SARAO) towards this research is hereby
acknowledged (www.sarao.ac.za).
PK is partially supported by the BMBF project 05A17PC2
for D-MeerKAT.
AS acknowledges the Russian Science Foundation grant
19-12-00281 and the Program of development of M.V.http://mnras.oxfordjournals.orgam2021Physic
Highway increases concentrations of toxic metals in giant panda habitat
The Qinling panda subspecies (Ailuropoda melanoleuca qinlingensis) is highly endangered with fewer than 350 individuals inhabiting the Qinling Mountains. Previous studies have indicated that giant pandas are exposed to heavy metals, and a possible source is vehicle emission. The concentrations of Cu, Zn, Mn, Pb, Cr, Ni, Cd, Hg, and As in soil samples collected from sites along a major highway bisecting the panda's habitat were analyzed to investigate whether the highway was an important source of metal contamination. There were 11 sites along a 30-km stretch of the 108th National Highway, and at each site, soil samples were taken at four distances from the highway (0, 50, 100, and 300 m) and at three soil depths (0, 5, 10 cm). Concentrations of all metals except As exceeded background levels, and concentrations of Cu, Zn, Mn, Pb, and Cd decreased significantly with increasing distance from the highway. Geo-accumulation index indicated that topsoil next to the highway was moderately contaminated with Pb and Zn, whereas topsoil up to 300 m away from the highway was extremely contaminated with Cd. The potential ecological risk index demonstrated that this area was in a high degree of ecological hazards, which were also due to serious Cd contamination. And, the hazard quotient indicated that Cd, Pb, and Mn especially Cd could pose the health risk to giant pandas. Multivariate analyses demonstrated that the highway was the main source of Cd, Pb, and Zn and also put some influence on Mn. The study has confirmed that traffic does contaminate roadside soils and poses a potential threat to the health of pandas. This should not be ignored when the conservation and management of pandas is considered
GASP XXVI. HI gas in jellyfish galaxies : the case of JO201 and JO206
Please read abstract in the article.European
Research Council (ERC) under the European Union’s Horizon 2020 research
and innovation programme grant agreement no. 679627 and no.833824,
project name FORNAX and GASP, respectively. We acknowledge funding from
the agreement ASI-INAF n.2017-14-H.0, as well as from the INAF main-stream
funding programme. M. R’s research is supported by the SARAO HCD programme
via the "New Scientific Frontiers with Precision Radio Interferometry"
research group grant. M. R. acknowledges support from the Italian Ministry
of Foreign A airs and International Cooperation (MAECI Grant Number
ZA18GR02) and the South African Department of Science and Technology’s
National Research Foundation (DST-NRF Grant Number 113121) as
part of the ISARP RADIOSKY2020 Joint Research Scheme. B. V. and M. G.
also acknowledge the Italian PRIN-Miur 2017 (PI A. Cimatti). Y. J. acknowledges
financial support from CONICYT PAI (Concurso Nacional de Insercion
en la Academia 2017), No. 79170132 and FONDECYT Iniciación 2018 No.
11180558. M. V. acknowledges support by the Netherlands Foundation for Scientific
Research (NWO) through VICI grant 016.130.338.http://www.aanda.orgam2020Physic
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