1,805 research outputs found
There is a short gamma-ray burst prompt phase at the beginning of each long one
We compare the prompt intrinsic spectral properties of a sample of short
Gamma--ray Burst (GRB) with the first 0.3 seconds (rest frame) of long GRBs
observed by Fermi/GBM. We find that short GRBs and the first part of long GRBs
lie on the same E_p--E_iso correlation, that is parallel to the relation for
the time averaged spectra of long GRBs. Moreover, they are indistinguishable in
the E_p--L_iso plane. This suggests that the emission mechanism is the same for
short and for the beginning of long events, and both short and long GRBs are
very similar phenomena, occurring on different timescales. If the central
engine of a long GRB would stop after ~0.3 * (1+z) seconds the resulting event
would be spectrally indistinguishable from a short GRB.Comment: 14 pages, 6 figures, MNRAS accepte
DBATE: database of alternative transcripts expression
The use of high-throughput RNA sequencing technology (RNA-seq) allows whole transcriptome analysis, providing an unbiased and unabridged view of alternative transcript expression. Coupling splicing variant-specific expression with its functional inference is still an open and difficult issue for which we created the DataBase of Alternative Transcripts Expression (DBATE), a web-based repository storing expression values and functional annotation of alternative splicing variants. We processed 13 large RNA-seq panels from human healthy tissues and in disease conditions, reporting expression levels and functional annotations gathered and integrated from different sources for each splicing variant, using a variant-specific annotation transfer pipeline. The possibility to perform complex queries by cross-referencing different functional annotations permits the retrieval of desired subsets of splicing variant expression values that can be visualized in several ways, from simple to more informative. DBATE is intended as a novel tool to help appreciate how, and possibly why, the transcriptome expression is shaped. DATABASE URL: http://bioinformatica.uniroma2.it/DBATE/
The role of Isocitrate Lyase (ICL1) in the metabolic adaptation of Candida albicans biofilms
Background
A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility.
Objectives
This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components.
Methods
Growth, adhesion, biofilm formation, and cell wall carbohydrate composition were quantified for isogenic Candida albicans ICL1/ICL1, ICL1/icl1, and icl1/icl1 strains. The morphology and topography of these strains were compared by light microscopy and scanning electron microscopy. FKS1 (glucan synthase), ERG11 (14-α-demethylase), and CDR2 (efflux pump) mRNA levels were quantified using qRT-PCR.
Results
The ICL1/icl1 and icl1/icl1 strains formed similar biofilms and exhibited analogous drug-tolerance levels to the control ICL1/ICL1 strains. Furthermore, the drug sequestration ability of β-1, 3-glucan, a major carbohydrate component of the extracellular matrix, was not impaired. However, the inactivation of ICL1 did impair morphogenesis. ICL1 deletion also had a considerable effect on the expression of the FKS1, ERG11, and CDR2 genes. FKS1 and ERG11 were upregulated in ICL1/icl1 and icl1/icl1 cells throughout the biofilm developmental stages, and CDR2 was upregulated at the early phase. However, their expression was downregulated compared to the control ICL1/ICL1 strain.
Conclusions
We conclude that the glyoxylate cycle is not a specific determinant of biofilm drug resistance
The epidemiology of Candida species isolated from urinary tract infections
Candida spp. are members of a genus, including closely related fungal species that cause a variety of infections. Objectives: The aim of this study was the isolation of various Candida species from vulvovaginitis and urethra of patients in Neyshabur, Northeast Iran from 2013 to 2015. Methods: This descriptive-analytical and cross-sectional study was performed to identify Candida spp. causing vulvovaginitis and Urinary Tract Infection (UTI) at a referral laboratory in Neyshabur district, Khorasan Razavi Province. A total of 451 vaginal and midstream urine samples were collected. Ten micro-liters of each specimen was cultured on CHROM agar plates and then incubated at 37°C for 24 to 48 hours, aerobically. Candida species were identified based on colony morphology, germ tube production and micro-morphology on corn meal agar including 1% Tween 80. Results: The mean age of the patients was 34.7_16.3. Candida albicans was the predominant species isolated. Moreover, age groups of 21 to 30 and 0 to 1 years were the most and the least infected individuals. Moreover, Candida spp. were significantly morecommon in females compared to males (P value 103. Conclusions: In this study, C. albicans was the most common species isolated from patients with vulvovaginitis and UTI, and significantly more common amongst females compared to males. The prevalence of candida spp. had significantly declined from 2013 to 2015. Moreover, the candida spp. counts were mostly higher than 103cfu/mL
Choreography, controversy and child sex abuse: Theoretical reflections on a cultural criminological analysis of dance in a pop music video
This article was inspired by the controversy over claims of ‘pedophilia!!!!’ undertones and the ‘triggering’ of memories of childhood sexual abuse in some viewers by the dance performance featured in the music video for Sia’s ‘Elastic Heart’ (2015). The case is presented for acknowledging the hidden and/or overlooked presence of dance in social scientific theory and cultural studies and how these can enhance and advance cultural criminological research. Examples of how these insights have been used within other disciplinary frameworks to analyse and address child sex crime and sexual trauma are provided, and the argument is made that popular cultural texts such as dance in pop music videos should be regarded as significant in analysing and tracing public perceptions and epistemologies of crimes such as child sex abuse
A four-helix bundle stores copper for methane oxidation
Methane-oxidising bacteria (methanotrophs) require large quantities of copper for the membrane-bound (particulate) methane monooxygenase (pMMO). Certain methanotrophs are also able to switch to using the iron-containing soluble MMO (sMMO) to catalyse methane oxidation, with this switchover regulated by copper. MMOs are Nature’s primary biological mechanism for suppressing atmospheric levels of methane, a potent greenhouse gas. Furthermore, methanotrophs and MMOs have enormous potential in bioremediation and for biotransformations producing bulk and fine chemicals, and in bioenergy, particularly considering increased methane availability from renewable sources and hydraulic fracturing of shale rock. We have discovered and characterised a novel copper storage protein (Csp1) from the methanotroph Methylosinus trichosporium OB3b that is exported from the cytosol, and stores copper for pMMO. Csp1 is a tetramer of 4-helix bundles with each monomer binding up to 13 Cu(I) ions in a previously unseen manner via mainly Cys residues that point into the core of the bundle. Csp1 is the first example of a protein that stores a metal within an established protein-folding motif. This work provides a detailed insight into how methanotrophs accumulate copper for the oxidation of methane. Understanding this process is essential if the wide-ranging biotechnological applications of methanotrophs are to be realised. Cytosolic homologues of Csp1 are present in diverse bacteria thus challenging the dogma that such organisms do not use copper in this location
Improving the solubility of a new class of antiinflammatory pharmacodynamic hybrids, that release nitric oxide and inhibit cycloxygenase-2 isoenzyme
The development of a novel class of pharmacodynamic hybrids that inhibits COX-2 isoform is reported. These molecules display enhanced nitric oxide releasing properties due to the presence of an ionisable moiety. The in vivo analgesic/anti-inflammatory activity was maintained in relation to the parent compounds
Cellular responses of Candida albicans to phagocytosis and the extracellular activities of neutrophils are critical to counteract carbohydrate starvation, oxidative and nitrosative stress
Acknowledgments We thank Alexander Johnson (yhb1D/D), Karl Kuchler (sodD/D mutants), Janet Quinn (hog1D/D, hog1/cap1D/D, trx1D/D) and Peter Staib (ssu1D/D) for providing mutant strains. We acknowledge helpful discussions with our colleagues from the Microbial Pathogenicity Mechanisms Department, Fungal Septomics and the Microbial Biochemistry and Physiology Research Group at the Hans Kno¨ll Institute (HKI), specially Ilse D. Jacobsen, Duncan Wilson, Sascha Brunke, Lydia Kasper, Franziska Gerwien, Sea´na Duggan, Katrin Haupt, Kerstin Hu¨nniger, and Matthias Brock, as well as from our partners in the FINSysB Network. Author Contributions Conceived and designed the experiments: PM HW IMB AJPB OK BH. Performed the experiments: PM CD HW. Analyzed the data: PM HW IMB AJPB OK BH. Wrote the paper: PM HW OK AJPB BH.Peer reviewedPublisher PD
The Rewiring of Ubiquitination Targets in a Pathogenic Yeast Promotes Metabolic Flexibility, Host Colonization and Virulence
Funding: This work was funded by the European Research Council [http://erc.europa.eu/], AJPB (STRIFE Advanced Grant; C-2009-AdG-249793). The work was also supported by: the Wellcome Trust [www.wellcome.ac.uk], AJPB (080088, 097377); the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk], AJPB (BB/F00513X/1, BB/K017365/1); the CNPq-Brazil [http://cnpq.br], GMA (Science without Borders fellowship 202976/2014-9); and the National Centre for the Replacement, Refinement and Reduction of Animals in Research [www.nc3rs.org.uk], DMM (NC/K000306/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We thank Dr. Elizabeth Johnson (Mycology Reference Laboratory, Bristol) for providing strains, and the Aberdeen Proteomics facility for the biotyping of S. cerevisiae clinical isolates, and to Euroscarf for providing S. cerevisiae strains and plasmids. We are grateful to our Microscopy Facility in the Institute of Medical Sciences for their expert help with the electron microscopy, and to our friends in the Aberdeen Fungal Group for insightful discussions.Peer reviewedPublisher PD
A Variable-Density Absorption Event in NGC 3227 mapped with Suzaku and Swift
The morphology of the circumnuclear gas accreting onto supermassive black
holes in Seyfert galaxies remains a topic of much debate. As the innermost
regions of Active Galactic Nuclei (AGN) are spatially unresolved, X-ray
spectroscopy, and in particular line-of-sight absorption variability, is a key
diagnostic to map out the distribution of gas. Observations of variable X-ray
absorption in multiple Seyferts and over a wide range of timescales indicate
the presence of clumps/clouds of gas within the circumnuclear material. Eclipse
events by clumps transiting the line of sight allow us to explore the
properties of the clumps over a wide range of radial distances from the
optical/UV Broad Line Region (BLR) to beyond the dust sublimation radius.
Time-resolved absorption events have been extremely rare so far, but suggest a
range of density profiles across Seyferts. We resolve a weeks-long absorption
event in the Seyfert NGC 3227. We examine six Suzaku and twelve Swift
observations from a 2008 campaign spanning 5 weeks. We use a model accounting
for the complex spectral interplay of three differently-ionized absorbers. We
perform time-resolved spectroscopy to discern the absorption variability
behavior. We also examine the IR-to-X-ray spectral energy distribution (SED) to
test for reddening by dust. The 2008 absorption event is due to
moderately-ionized () gas covering 90% of the line of
sight. We resolve the density profile to be highly irregular, in contrast to a
previous symmetric and centrally-peaked event mapped with RXTE in the same
object. The UV data do not show significant reddening, suggesting that the
cloud is dust-free. The 2008 campaign has revealed a transit by a filamentary,
moderately-ionized cloud of variable density that is likely located in the BLR,
and possibly part of a disk wind.Comment: Accepted for publication by A&
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