Search results for "clone"

Trace gas composition in the Asian summer monsoon anticyclone: a case study based on aircraft observations and model simulations

2017

We present in situ measurements of the trace gas composition of the upper tropospheric (UT) Asian summer monsoon anticyclone (ASMA) performed with the High Altitude and Long Range Research Aircraft (HALO) in the frame of the Earth System Model Validation (ESMVal) campaign. Air masses with enhanced O3 mixing ratios were encountered after entering the ASMA at its southern edge at about 150 hPa on 18 September 2012. This is in contrast to the presumption that the anticyclone's interior is dominated by recently uplifted air with low O3 in the monsoon season. We also observed enhanced CO and HCl in the ASMA, which are tracers for boundary layer pollution and tropopause layer (TL) air or stratosp…

2018

Abstract. This study places HALO research aircraft observations in the upper-tropospheric Asian summer monsoon anticyclone (ASMA) into the context of regional, intra-annual variability by hindcasts with the ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The observations were obtained during the Earth System Model Validation (ESMVal) campaign in September 2012. Observed and simulated tracer–tracer relations reflect photochemical O3 production as well as in-mixing from the lower troposphere and the tropopause layer. The simulations demonstrate that tropospheric trace gas profiles in the monsoon season are distinct from those in the rest of the year, and the measurements reflect the main proc…

Modeling the aerosol chemical composition of the tropopause over the Tibetan Plateau during the Asian summer monsoon

2019

Enhanced aerosol abundance in the upper troposphere and lower stratosphere (UTLS) associated with the Asian summer monsoon (ASM) is referred to as the Asian Tropopause Aerosol Layer (ATAL). The chemical composition, microphysical properties, and climate effects of aerosols in the ATAL have been the subject of discussion over the past decade. In this work, we use the ECHAM/MESSy Atmospheric Chemistry (EMAC) general circulation model at a relatively fine grid resolution (about 1.1×1.1∘) to numerically simulate the emissions, chemistry, and transport of aerosols and their precursors in the UTLS within the ASM anticyclone during the years 2010–2012. We find a pronounced maximum of aerosol extin…

Persistent inflammation alters the function of the endogenous brain stem cell compartment

2008

Endogenous neural stem/precursor cells (NPCs) are considered a functional reservoir for promoting tissue homeostasis and repair after injury, therefore regenerative strategies that mobilize these cells have recently been proposed. Despite evidence of increased neurogenesis upon acute inflammatory insults (e.g. ischaemic stroke), the plasticity of the endogenous brain stem cell compartment in chronic CNS inflammatory disorders remains poorly characterized. Here we show that persistent brain inflammation, induced by immune cells targeting myelin, extensively alters the proliferative and migratory properties of subventricular zone (SVZ)-resident NPCs in vivo leading to significant accumulation…

Replication of HSV-1 in murine peritoneal macrophages: comparison of various virus strains with different properties.

1984

The in vitro replication of eleven different strains of herpes simplex virus type 1 was studied in resident or thioglycollate-stimulated mouse macrophages. The strains of herpes simplex virus differed in the type of cytopathic effect, induction capacity for herpes simplex virus coded thymidine kinase and pathogenicity in the mouse. Herpes simplex virus replicated better in thioglycollate-stimulated macrophages than in resident macrophages. In vitro ageing of macrophages increased their replicative potency. Herpes simplex virus replicated better in macrophages from homozygous bg/bg C57/BL6J mice than in macrophages from their heterozygous littermates. Separation of macrophages on discontinuo…

EST sequencing of Onychophora and phylogenomic analysis of Metazoa

2007

Onychophora (velvet worms) represent a small animal taxon considered to be related to Euarthropoda. We have obtained 1873 5' cDNA sequences (expressed sequence tags, ESTs) from the velvet worm Epiperipatus sp., which were assembled into 833 contigs. BLAST similarity searches revealed that 51.9% of the contigs had matches in the protein databases with expectation values lower than 10(-4). Most ESTs had the best hit with proteins from either Chordata or Arthropoda (approximately 40% respectively). The ESTs included sequences of 27 ribosomal proteins. The orthologous sequences from 28 other species of a broad range of phyla were obtained from the databases, including other EST projects. A conc…

Oxidative stress induces the expression of the major histocompatibility complex in murine tumor cells.

2001

The effect of t-butyl hydroperoxide (t-BOOH) on the induction of the Major Histocompatibility Complex (MHC) class I genes has been studied in two cell clones (B9 and G2) of the methylcholanthrene-induced murine fibrosarcoma GR9. These two clones were selected based on their different biological and biochemical behavior specially related to their tumor induction capability when injected into a BALB/c mouse. t-BOOH (0.125 mM) induced the expression of H-2 molecules in both cell clones. In B9 cell clone, in which MHC basal expression is very low or absent, t-BOOH significantly induced H-2Kd, H-2Dd and H-2Ld molecules. In G2 cell clone the expression of MHC class I genes was also enhanced by th…

Analysis of a severe pollution episode in Valencia (Spain) and its effect on ground level particulate matter

2013

Abstract This study analyzes the atmospheric particles concentration at ground level during a severe pollution event that took place in Valencia (Spain) from 7 to 12 February 2011. The episode was related to a subtropical anticyclone system that affected the Iberian Peninsula and western Europe. The dominant anticyclone imposed an extended low gradient pressure system and a low mixing layer height in the region that caused the accumulation of pollutants over the western Mediterranean. Moreover, the stagnant conditions led to the formation of the local sea breeze, accompanied by an increase of relative humidity and the decrease of ambient temperature. Our study is mainly focused on the analy…

Predominance of the fimH30 Subclone Among Multidrug-Resistant Escherichia coli Strains Belonging to Sequence Type 131 in Italy

2013

Genotypic study of Citrobacter koseri , an emergent platelet contaminant since 2012 in France

2019

International audience; Background: Transfusion-transmitted bacterial infection is a rare occurrence but the most feared complication in transfusion practices. Between 2012 and 2017, five cases of platelet concentrates (PCs) contaminated with the bacterial pathogen Citrobacter koseri (PC-Ck) have been reported in France, with two leading to the death of the recipients. We tested the possibilities of the emergence of a PC-specific clone of C. koseri (Ck) and of specific bacterial genes associated with PC contamination.Study design and methods: The phylogenetic network, based on a homemade Ck core genome scheme, inferred from the genomes of 20 worldwide Ck isolates unrelated to PC contaminati…