244 research outputs found
On duality theory and pseudodifferential techniques for Colombeau algebras: generalized delta functionals, kernels and wave front sets
Summarizing basic facts from abstract topological modules over Colombeau
generalized complex numbers we discuss duality of Colombeau algebras. In
particular, we focus on generalized delta functionals and operator kernels as
elements of dual spaces. A large class of examples is provided by
pseudodifferential operators acting on Colombeau algebras. By a refinement of
symbol calculus we review a new characterization of the wave front set for
generalized functions with applications to microlocal analysis
Microlocal analysis of generalized functions: pseudodifferential techniques and propagation of singularities
We characterize microlocal regularity of Colombeau generalized functions by
an appropriate extension of the classical notion of micro-ellipticity to
pseudodifferential operators with slow scale generalized symbols. Thus we
obtain an alternative, yet equivalent, way to determine generalized wave front
sets, which is analogous to the original definition of the wave front set of
distributions via intersections over characteristic sets. The new methods are
then applied to regularity theory of generalized solutions of
(pseudo-)differential equations, where we extend the general noncharacteristic
regularity result for distributional solutions and consider propagation of
generalized singularities for homogeneous first-order hyperbolic equations
Age‐dependent retinal neuroaxonal degeneration in children and adolescents with Leber hereditary optic neuropathy under idebenone therapy
Background
The aim of this study was to investigate the neuroretinal structure of young patients with Leber hereditary optic neuropathy (LHON).
Methods
For this retrospective cross-sectional analysis, the peripapillary retinal nerve fiber layer (pRNFL) thickness and the macular retinal layer volumes were measured by optical coherence tomography. Patients aged 12 years or younger at disease onset were assigned to the childhood-onset (ChO) group and those aged 13–16 years to the early teenage-onset (eTO) group. All patients received treatment with idebenone. The same measurements were repeated in age-matched control groups with healthy subjects.
Results
The ChO group included 11 patients (21 eyes) and the eTO group 14 patients (27 eyes). Mean age at onset was 8.6 ± 2.7 years in the ChO group and 14.8 ± 1.0 years in the eTO group. Mean best-corrected visual acuity was 0.65 ± 0.52 logMAR in the ChO group and 1.60 ± 0. 51 logMAR in the eTO group (p < 0.001). Reduced pRNFL was evident in the eTO group compared to the ChO group (46.0 ± 12.7 μm vs. 56.0 ± 14.5 μm, p = 0.015). Additionally, a significantly lower combined ganglion cell and inner plexiform layer volume was found in the eTO compared to the ChO group (0.266 ± 0.0027 mm3 vs. 0.294 ± 0.033 mm3, p = 0.003). No difference in these parameters was evident between the age-matched control groups.
Conclusion
Less neuroaxonal tissue degeneration was observed in ChO LHON than in eTO LHON, a finding that may explain the better functional outcome of ChO LHON
Suppression subtractive hybridization identifies an autotransporter adhesin gene of E. coli IMT5155 specifically associated with avian pathogenic Escherichia coli (APEC)
<p>Abstract</p> <p>Background</p> <p>Extraintestinal pathogenic <it>E. coli </it>(ExPEC) represent a phylogenetically diverse group of bacteria which are implicated in a large range of infections in humans and animals. Although subgroups of different ExPEC pathotypes, including uropathogenic, newborn meningitis causing, and avian pathogenic <it>E. coli </it>(APEC) share a number of virulence features, there still might be factors specifically contributing to the pathogenesis of a certain subset of strains or a distinct pathotype. Thus, we made use of suppression subtractive hybridization and compared APEC strain IMT5155 (O2:K1:H5; sequence type complex 95) with human uropathogenic <it>E. coli </it>strain CFT073 (O6:K2:H5; sequence type complex 73) to identify factors which may complete the currently existing model of APEC pathogenicity and further elucidate the position of this avian pathoype within the whole ExPEC group.</p> <p>Results</p> <p>Twenty-eight different genomic loci were identified, which are present in IMT5155 but not in CFT073. One of these loci contained a gene encoding a putative autotransporter adhesin. The open reading frame of the gene spans a 3,498 bp region leading to a putative 124-kDa adhesive protein. A specific antibody was raised against this protein and expression of the adhesin was shown under laboratory conditions. Adherence and adherence inhibition assays demonstrated a role for the corresponding protein in adhesion to DF-1 chicken fibroblasts. Sequence analyses revealed that the flanking regions of the chromosomally located gene contained sequences of mobile genetic elements, indicating a probable spread among different strains by horizontal gene transfer. In accordance with this hypothesis, the adhesin was found to be present not only in different phylogenetic groups of extraintestinal pathogenic but also of commensal <it>E. coli </it>strains, yielding a significant association with strains of avian origin.</p> <p>Conclusions</p> <p>We identified a chromosomally located autotransporter gene in a highly virulent APEC strain which confers increased adherence of a non-fimbriated <it>E. coli </it>K-12 strain to a chicken fibroblast cell line. Even though flanked by mobile genetic elements and three different genetic regions upstream of the gene, most probably indicating horizontal gene transfer events, the adhesin gene was significantly linked with strains of avian origin. Due to the nucleotide sequence similarity of 98% to a recently published adhesin-related gene, located on plasmid pAPEC-O1-ColBM, the name <it>aatA </it>(APEC autotransporter adhesin A) was adopted from that study.</p> <p>Our data substantiate that AatA might not only be of relevance in APEC pathogenicity but also in facilitating their reservoir life style in the chicken intestine, which might pave the way for future intestinal preventive strategies.</p
Long-term safety and efficacy of apomorphine infusion in Parkinson's disease patients with persistent motor fluctuations:Results of the open-label phase of the TOLEDO study
Introduction: The randomized, double-blind phase (DBP) of the TOLEDO study confirmed the efficacy of apomorphine infusion (APO) in reducing OFF time in PD patients with persistent motor fluctuations despite optimized oral/transdermal therapy. Here we report safety and efficacy results including the 52-week open-label phase (OLP). Methods: All patients completing the 12-week DBP (including those switching early to open-label treatment) were offered OLP entry. The primary objective was the evaluation of long-term safety of APO. Results: Eighty-four patients entered the OLP (40 previously on APO, 44 on placebo) and 59 patients (70.2%) completed the study. The safety profile of APO was consistent with experience from extensive clinical use. Common treatment-related adverse events (AEs) were mild or moderate infusion site nodules, somnolence and nausea. Fourteen (16.7%) patients discontinued the OLP due to AEs, those involving >1 patient were infusion site reactions (n = 4) and fatigue (n = 2); hemolytic anemia occurred in one case. Reduction in daily OFF time and improvement in ON time without troublesome dyskinesia were sustained for up to 64 weeks. Pooled data for week 64 (n = 55) showed a mean (SD) change from DBP baseline in daily OFF time of-3.66 (2.72) hours and in ON time without troublesome dyskinesia of 3.31 (3.12) hours. Mean (+/- SD) daily levodopa-equivalent dose decreased from DBP baseline to week 64 by 543 mg (+/- 674) and levodopa dose by 273 mg (+/- 515). Conclusions: The safety and efficacy of APO infusion were demonstrated with long-term use for persistent motor fluctuations, allowing substantial reductions in oral PD medication
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High temperature sensitivity of Arctic isoprene emissions explained by sedges.
It has been widely reported that isoprene emissions from the Arctic ecosystem have a strong temperature response. Here we identify sedges (Carex spp. and Eriophorum spp.) as key contributors to this high sensitivity using plant chamber experiments. We observe that sedges exhibit a markedly stronger temperature response compared to that of other isoprene emitters and predictions by the widely accepted isoprene emission model, the Model of Emissions of Gases and Aerosols from Nature (MEGAN). MEGAN is able to reproduce eddy-covariance flux observations at three high-latitude sites by integrating our findings. Furthermore, the omission of the strong temperature responses of Arctic isoprene emitters causes a 20% underestimation of isoprene emissions for the high-latitude regions of the Northern Hemisphere during 2000-2009 in the Community Land Model with the MEGAN scheme. We also find that the existing model had underestimated the long-term trend of isoprene emissions from 1960 to 2009 by 55% for the high-latitude regions
Resummed lattice QCD equation of state at finite baryon density: Strangeness neutrality and beyond
We calculate a resummed equation of state with lattice QCD simulations at
imaginary chemical potentials. This work presents a generalization of the
scheme introduced in 2102.06660 to the case of non-zero , focusing on
the line of strangeness neutrality. We present results up to
on the strangeness neutral line in the
temperature range . We also extrapolate
the finite baryon density equation of state to small non-zero values of the
strangeness-to-baryon ratio . We perform a continuum extrapolation using lattice simulations
of the 4stout-improved staggered action with 8, 10, 12 and 16 timeslices.Comment: 15 pages, 12 figures; v2: contains ancillary files with tabulated
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PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
We present the updated version of the code used to compute stellar
evolutionary tracks in Padova. It is the result of a thorough revision of the
major input physics, together with the inclusion of the pre-main sequence
phase, not present in our previous releases of stellar models. Another
innovative aspect is the possibility of promptly generating accurate opacity
tables fully consistent with any selected initial chemical composition, by
coupling the OPAL opacity data at high temperatures to the molecular opacities
computed with our AESOPUS code (Marigo & Aringer 2009). In this work we present
extended sets of stellar evolutionary models for various initial chemical
compositions, while other sets with different metallicities and/or different
distributions of heavy elements are being computed. For the present release of
models we adopt the solar distribution of heavy elements from the recent
revision by Caffau et al. (2011), corresponding to a Sun's metallicity
Z=0.0152. From all computed sets of stellar tracks, we also derive isochrones
in several photometric systems. The aim is to provide the community with the
basic tools to model star clusters and galaxies by means of population
synthesis techniques.Comment: To appear on MNRAS. While the full database is still being prepared,
the first isochrones can be retrieved via http://stev.oapd.inaf.it/cm
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