2,154 research outputs found
Biologic effects of oil fly ash.
Epidemiologic studies have demonstrated increased human morbidity and mortality with elevations in the concentration of ambient air particulate matter (PM). Fugitive fly ash from the combustion of oil and residual fuel oil significantly contributes to the ambient air particle burden. Residual oil fly ash (ROFA) is remarkable in the capacity to provoke injury in experimental systems. The unique composition of this emission source particle makes it particularly useful as a surrogate for ambient air PM in studies of biologic effects testing the hypothesis that metals mediate the biologic effects of air pollution particles. A majority of the in vitro and animal model investigations support the postulate that transition metals present in ROFA (especially vanadium) participate in Fenton-like chemical reactions to produce reactive oxygen species. This is associated with tyrosine phosphorylation, nuclear factor kappa B and other transcription factor activation, induction of inflammatory mediator expression, and inflammatory lung injury. It is also evident that vanadium accounts for a significant portion of the biologic activity of ROFA. The extrapolation of this body of investigation on ROFA to the field of ambient air PM is difficult, as particles in numerous environments have such small amounts of vanadium
‘It's like the bad guy in a movie who just doesn't die’ : a qualitative exploration of young people's adaptation to eczema and implications for self‐care
Background
Eczema is a common childhood inflammatory skin condition, affecting more than one in five children. A popular perception is that children ‘outgrow eczema’, although epidemiological studies have shown that, for many, eczema follows a lifelong episodic course.
Objectives
To explore the perceptions of young people about the nature of their eczema and how these perceptions relate to their self‐care and adapting to living with eczema.
Methods
This is a secondary inductive thematic analysis of interviews conducted for Healthtalk.org. In total 23 interviews with young people with eczema were included. Of the 23 participants, 17 were female and six male, ranging from 17 to 25 years old.
Results
Participants generally experienced eczema as an episodic long‐term condition and reported a mismatch between information received about eczema and their experiences. The experience of eczema as long term and episodic had implications for self‐care, challenging the process of identifying triggers of eczema flare‐ups and evaluating the success of treatment regimens. Participants’ experiences of eczema over time also had implications for adaptation and finding a balance between accepting eczema as long term and hoping it would go away. This linked to a gradual shift in treatment expectations from ‘cure’ to ‘control’ of eczema.
Conclusions
For young people who continue to experience eczema beyond childhood, a greater focus on self‐care for a long‐term condition may be helpful. Greater awareness of the impact of early messages around ‘growing out of’ eczema and provision of high‐quality information may help patients to manage expectations and support adaptation to treatment regimens
The GRAAL high resolution BGO calorimeter and its energy calibration and monitoring system
We describe the electromagnetic calorimeter built for the GRAAL apparatus at
the ESRF. Its monitoring system is presented in detail. Results from tests and
the performance obtained during the first GRAAL experiments are given. The
energy calibration accuracy and stability reached is a small fraction of the
intrinsic detector resolution.Comment: 19 pages, 14 figures, submitted to Nuclear Instruments and Method
Evidence for narrow resonant structures at and GeV in real Compton scattering off the proton
First measurement of the beam asymmetry for Compton scattering off
the proton in the energy range GeV is presented. The
data reveals two narrow structures at and
GeV. They may signal narrow resonances with masses near
and GeV, or they may be generated by the sub-threshold
and production. Their decisive identification requires additional
theoretical and experimental efforts.Comment: Published versio
Deuteron photo-disintegration with polarised photons in the energy range 30 - 50 MeV
The reaction d(\vec\gamma,np) has been studied using the tagged and polarised
LADON gamma ray beam at an energy 30 - 50 MeV to investigate the existence of
narrow dibaryonic resonances recently suggested from the experimental
measurements in a different laboratory. The beam was obtained by Compton
back-scattering of laser light on the electrons of the storage ring ADONE.
Photo-neutron yields were measured at five neutron angle \vartheta_n = 22,
55.5, 90, 125 and 157 degrees in the center of mass system.Our results do not
support the existence of such resonances.Comment: 16 pages, Latex, 22 figures, 1 table. Nucl. Phys. A to appea
Shedding New Light on Kaon-Nucleon/Nuclei Interaction and Its Astrophysical Implications with the AMADEUS Experiment at DAFNE
The AMADEUS experiment deals with the investigation of the low-energy
kaon-nuclei hadronic interaction at the DA{\Phi}NE collider at LNF-INFN, which
is fundamental to respond longstanding questions in the non-perturbative QCD
strangeness sector. The antikaon-nucleon potential is investigated searching
for signals from possible bound kaonic clusters, which would open the
possibility for the formation of cold dense baryonic matter. The confirmation
of this scenario may imply a fundamental role of strangeness in astrophysics.
AMADEUS step 0 consisted in the reanalysis of 2004/2005 KLOE dataset,
exploiting K- absorptions in H, 4He, 9Be and 12C in the setup materials. In
this paper, together with a review on the multi-nucleon K- absorption and the
particle identification procedure, the first results on the {\Sigma}0-p channel
will be presented including a statistical analysis on the possible accomodation
of a deeply bound stateComment: 6 pages, 2 figure, 1 table, HADRON 2015 conferenc
Eta photoproduction off the neutron at GRAAL: Evidence for a resonant structure at W=1.67 GeV
New (preliminary) data on eta photoproduction off the neutron are presented.
These data reveal a resonant structure at W=1.67 GeV.Comment: 8 pages, 4 figures. Published in Proceedings of Workshop on the
Physics of Excited Nucleons NSTAR2004, Grenoble, France, March 24 - 27,
pg.19
Unprecedented studies of the low-energy negatively charged kaons interactions in nuclear matter by AMADEUS
The AMADEUS experiment aims to provide unique quality data of hadronic
interactions in light nuclear targets, in order to solve fundamental open
questions in the non-perturbative strangeness QCD sector, like the
controversial nature of the state, the yield of hyperon
formation below threshold, the yield and shape of multi-nucleon
absorption, processes which are intimately connected to the possible existence
of exotic antikaon multi-nucleon clusters. AMADEUS takes advantage of the
DANE collider, which provides a unique source of monochromatic
low-momentum kaons and exploits the KLOE detector as an active target, in order
to obtain excellent acceptance and resolution data for nuclear capture on
H, He, Be and C, both at-rest and in-flight. During the
second half of 2012 a successful data taking was performed with a dedicated
pure carbon target implemented in the central region of KLOE, providing a high
statistic sample of pure at-rest nuclear interactions. For the future
dedicated setups involving cryogenic gaseous targets are under preparation.Comment: 14 pages, 6 figure
Perception de la parole et IRM : réalisation, évaluation et validation d'un système permettant une stimulation sonore de qualité en cours de séquence IRM
International audienceThis study describes the design and the assessment of a MRI-compatible sound production hardware. This system was developed to permit auditory studies with Magnetic Resonance Imaging (MRI) techniques. An important disadvantage caused by the MR imager is the acoustic noise generated during data acquisition, due to the fast gradient switching interacting with the main magnetic field. Several solutions were explored to reduce noise and to provide audio stimuli with a reasonable quality. The sound production system was first tested by instrumental methods (sound level, spectral analysis). Finally, perceptual tests consisting in intelligibility, semantic decision and prosodic judgement were achieved to validate the installation.Cette étude décrit la réalisation d'un dispositif de stimulation auditive pour un imageur à résonnance magnétique fonctionelle de 3 Tesla. Le plus important probléme de ces systémes réside dans l'émission d'un niveau de bruit considérable au cours de son fonctionnement qui les rend quasi impossible à utiliser pour des études en stimulation auditive.Plusieurs solutions de stimulation de réalisation locale sont proposées pour permettre de gérérer au tympan des sujet une stimulation de qualité raisonnable. Les stimulus ainsi générés sont d'abord testés au moyen de méthodes physiques classiques (analyses acoustiques). Ils sont ensuite testés au moyen de tests d'intelligibilité de décision sémantique et de jugement prosodique afin de les valider pour des études de psycho linguistique et psycho acoustique
-series X-ray yield measurement of kaonic hydrogen atoms in a gaseous target
We measured the -series X-rays of the exotic atom in the
SIDDHARTA experiment with a gaseous hydrogen target of 1.3 g/l, which is about
15 times the of hydrogen gas. At this density, the absolute
yields of kaonic X-rays, when a negatively charged kaon stopped inside the
target, were determined to be 0.012 for and
0.043 for all the -series transitions . These
results, together with the KEK E228 experiment results, confirm for the first
time a target density dependence of the yield predicted by the cascade models,
and provide valuable information to refine the parameters used in the cascade
models for the kaonic atoms.Comment: 9 pages, 5 figures. Submitted to Nuclear Physics A, Special Issue on
Strangeness and Char
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