616 research outputs found
Determination of 3D Trajectories of Knots in Solar Prominences Using MSDP Data
In this paper we present a new method of restoration of the true
thee-dimensional trajectories of the prominence knots based on ground-based
observations taken with a single telescope, which is equipped with a
Multi-Channel Subtractive Double Pass imaging spectrograph. Our method allows
to evaluate true three-dimensional trajectories of the prominence knots without
any assumptions concerning the shape of the trajectories or dynamics of the
motion. The reconstructed trajectories of several knots observed in three
prominences are presented.Comment: 14 pages, 9 figures, accepted for publication in Solar Physic
Analysis and interpretation of a fast limb CME with eruptive prominence, C-flare and EUV dimming
Coronal Mass ejections or CMEs are large dynamical solar-corona events. The
mass balance and kinematics of a fast limb CME, including its prominence
progenitor and the associated flare, will be compared with computed magnetic
structures to look for their origin and effect.
Multi-wavelength ground-based and space-borne observations are used to study
a fast W-limb CME event of December 2, 2003, taking into account both on and
off disk observations. Its erupting prominence is measured at high cadence with
the Pic du Midi full H-alpha line-flux imaging coronagraph. EUV images from
space instruments are processed including difference imaging. SOHO/LASCO images
are used to study the mass excess and motions. A fast bright expanding coronal
loop is identified in the region recorded slightly later by GOES as a C7.2
flare, followed by a brightening and an acceleration phase of the erupting
material with both cool and hot components. The total coronal radiative flux
dropped by 5 percent in the EUV channels, revealing a large dimming effect at
and above the limb. The typical 3-part structure observed 1 hour later shows a
core shaped similarly to the eruptive filament/prominence. The total measured
mass of the escaping CME (1.5x10to16 g from C2 LASCO observations) definitely
exceeds the estimated mass of the escaping cool prominence material although
assumptions made to analyse the Ha erupting prominence, as well as the
corresponding EUV darkening of the filament observed several days before, made
this evaluation uncertain by a factor of 2. From the current free extrapolation
we discuss the shape of the magnetic neutral surface and a possible scenario
leading to an instability, including the small scale dynamics inside and around
the filament.Comment: 11 pages, 9 figure
Genotype-independent association between vitamin D deficiency and polycystic ovarian syndrome in Lahore, Pakistan.
Both vitamin D deficiency and single nucleotide polymorphisms (SNPs) in the gene encoding the vitamin D receptor (VDR) have been widely reported to associate with susceptibility to polycystic ovarian syndrome (PCOS). A case-control study was conducted to study the influence of vitamin D status and genotpye for 24 SNPs in four genes in the vitamin D pathway (VDR, DBP, CYP27B1, CYP24A1) on PCOS. Statistical analyses were conducted to identify phenotypic and genotypic factors associated with risk of PCOS and to test for interactions between genotype and vitamin D status. PCOS was independently associated with lower age, higher body mass index, lower waist-hip ratio, vitamin D deficiency (serum 25-hydroxyvitamin D concentration <10 ng/mL), lack of outdoor exercise, increased fasting glucose and a family history of PCOS in at least one first degree relative. No statistically significant association was observed between the genotype of any SNP investigated and risk of PCOS, either as a main effect or in interaction with vitamin D status. We report a strong and independent association between vitamin D deficiency and risk of PCOS in Pakistan, that was not modified by genetic variation in the vitamin D pathway
Development and benchmarking of a dose rate engine for raster-scanned FLASH helium ions
Background: Radiotherapy with charged particles at high dose and ultra-high dose rate (uHDR) is a promising technique to further increase the therapeutic index of patient treatments. Dose rate is a key quantity to predict the so-called FLASH effect at uHDR settings. However, recent works introduced varying calculation models to report dose rate, which is susceptible to the delivery method, scanning path (in active beam delivery) and beam intensity. Purpose: This work introduces an analytical dose rate calculation engine for raster scanned charged particle beams that is able to predict dose rate from the irradiation plan and recorded beam intensity. The importance of standardized dose rate calculation methods is explored here. Methods: Dose is obtained with an analytical pencil beam algorithm, using pre-calculated databases for integrated depth dose distributions and lateral penumbra. Dose rate is then calculated by combining dose information with the respective particle fluence (i.e., time information) using three dose-rate-calculation models (mean, instantaneous, and threshold-based). Dose rate predictions for all three models are compared to uHDR helium ion beam (145.7 MeV/u, range in water of approximatively 14.6 cm) measurements performed at the Heidelberg Ion Beam Therapy Center (HIT) with a diamond-detector prototype. Three scanning patterns (scanned or snake-like) and four field sizes are used to investigate the dose rate differences. Results: Dose rate measurements were in good agreement with in-silico generated distributions using the here introduced engine. Relative differences in dose rate were below 10% for varying depths in water, from 2.3 to 14.8 cm, as well as laterally in a near Bragg peak area. In the entrance channel of the helium ion beam, dose rates were predicted within 7% on average for varying irradiated field sizes and scanning patterns. Large differences in absolute dose rate values were observed for varying calculation methods. For raster-scanned irradiations, the deviation between mean and threshold-based dose rate at the investigated point was found to increase with the field size up to 63% for a 10 mm × 10 mm field, while no significant differences were observed for snake-like scanning paths. Conclusions: This work introduces the first dose rate calculation engine benchmarked to instantaneous dose rate, enabling dose rate predictions for physical and biophysical experiments. Dose rate is greatly affected by varying particle fluence, scanning path, and calculation method, highlighting the need for a consensus among the FLASH community on how to calculate and report dose rate in the future. The here introduced engine could help provide the necessary details for the analysis of the sparing effect and uHDR conditions
3D evolution of a filament disappearance event observed by STEREO
A filament disappearance event was observed on 22 May 2008 during our recent
campaign JOP 178. The filament, situated in the southern hemisphere, showed
sinistral chirality consistent with the hemispheric rule. The event was well
observed by several observatories in particular by THEMIS. One day before the
disappearance, H observations showed up and down flows in adjacent
locations along the filament, which suggest plasma motions along twisted flux
rope. THEMIS and GONG observations show shearing photospheric motions leading
to magnetic flux canceling around barbs. STEREO A, B spacecraft with separation
angle 52.4 degrees, showed quite different views of this untwisting flux rope
in He II 304 \AA\ images. Here, we reconstruct the 3D geometry of the filament
during its eruption phase using STEREO EUV He II 304 \AA\ images and find that
the filament was highly inclined to the solar normal. The He II 304 \AA\ movies
show individual threads, which oscillate and rise to an altitude of about 120
Mm with apparent velocities of about 100 km s, during the rapid
evolution phase. Finally, as the flux rope expands into the corona, the
filament disappears by becoming optically thin to undetectable levels. No CME
was detected by STEREO, only a faint CME was recorded by LASCO at the beginning
of the disappearance phase at 02:00 UT, which could be due to partial filament
eruption. Further, STEREO Fe XII 195 \AA\ images showed bright loops beneath
the filament prior to the disappearance phase, suggesting magnetic reconnection
below the flux rope
Integrated transcriptomics and metabolomics reveal signatures of lipid metabolism dysregulation in HepaRG liver cells exposed to PCB 126.
Chemical pollutant exposure is a risk factor contributing to the growing epidemic of non-alcoholic fatty liver disease (NAFLD) affecting human populations that consume a western diet. Although it is recognized that intoxication by chemical pollutants can lead to NAFLD, there is limited information available regarding the mechanism by which typical environmental levels of exposure can contribute to the onset of this disease. Here, we describe the alterations in gene expression profiles and metabolite levels in the human HepaRG liver cell line, a validated model for cellular steatosis, exposed to the polychlorinated biphenyl (PCB) 126, one of the most potent chemical pollutants that can induce NAFLD. Sparse partial least squares classification of the molecular profiles revealed that exposure to PCB 126 provoked a decrease in polyunsaturated fatty acids as well as an increase in sphingolipid levels, concomitant with a decrease in the activity of genes involved in lipid metabolism. This was associated with an increased oxidative stress reflected by marked disturbances in taurine metabolism. A gene ontology analysis showed hallmarks of an activation of the AhR receptor by dioxin-like compounds. These changes in metabolome and transcriptome profiles were observed even at the lowest concentration (100 pM) of PCB 126 tested. A decrease in docosatrienoate levels was the most sensitive biomarker. Overall, our integrated multi-omics analysis provides mechanistic insight into how this class of chemical pollutant can cause NAFLD. Our study lays the foundation for the development of molecular signatures of toxic effects of chemicals causing fatty liver diseases to move away from a chemical risk assessment based on in vivo animal experiments
Prevention and management of chronic disease in Aboriginal and Islander Community Controlled Health Services in Queensland: a quality improvement study assessing change in selected clinical performance indicators over time in a cohort of services
OBJECTIVE To evaluate clinical healthcare performance in Aboriginal Medical Services in Queensland and to consider future directions in supporting improvement through measurement, target setting and standards development. DESIGN Longitudinal study assessing baseline performance and improvements in service delivery, clinical care and selected outcomes against key performance indicators 2009-2010. SETTING 27 Aboriginal and Islander Community Controlled Health Services (AICCHSs) in Queensland, who are members of the Queensland Aboriginal and Islander Health Council (QAIHC). PARTICIPANTS 22 AICCHS with medical clinics. INTERVENTION Implementation and use of an electronic clinical information system that integrates with electronic health records supported by the QAIHC quality improvement programme-the Close the Gap Collaborative. MAIN OUTCOME MEASURES Proportion of patients with current recording of key healthcare activities and the prevalence of risk factors and chronic disease. RESULTS Aggregated performance was high on a number of key risk factors and healthcare activities including assessment of tobacco use and management of hypertension but low for others. Performance between services showed greatest variation for care planning and health check activity. CONCLUSIONS Data collected by the QAIHC health information system highlight the risk factor workload facing the AICCHS in Queensland, demonstrating the need for ongoing support and workforce planning. Development of targets and weighting models is necessary to enable robust between-service comparisons of performance, which has implications for health reform initiatives in Australia. The limited information available suggests that although performance on key activities in the AICCHS sector has potential for improvement in some areas, it is nonetheless at a higher level than for mainstream providers. IMPLICATIONS The work demonstrates the role that the Community Controlled sector can play in closing the gap in Aboriginal and Torres Strait Islander health outcomes by leading the use of clinical data to record and assess the quality of services and health outcome.Office of Aboriginal and Torres Strait Islander Health, Department of
Health and Ageing, Canberra, ACT, Australia
Magnetic Field Structures in a Facular Region Observed by THEMIS and Hinode
The main objective of this paper is to build and compare vector magnetic maps
obtained by two spectral polarimeters, i.e. THEMIS/MTR and Hinode SOT/SP, using
two inversion codes (UNNOFIT and MELANIE) based on the Milne-Eddington solar
atmosphere model. To this end, we used observations of a facular region within
active region NOAA 10996 on 23 May 2008, and found consistent results
concerning the field strength, azimuth and inclination distributions. Because
SOT/SP is free from the seeing effect and has better spatial resolution, we
were able to resolve small magnetic polarities with sizes of 1" to 2", and we
could detect strong horizontal magnetic fields, which converge or diverge in
negative or positive facular polarities. These findings support models which
suggest the existence of small vertical flux tube bundles in faculae. A new
method is proposed to get the relative formation heights of the multi-lines
observed by MTR assuming the validity of a flux tube model for the faculae. We
found that the Fe 1 6302.5 \AA line forms at a greater atmospheric height than
the Fe 1 5250.2 \AA line.Comment: 20 pages, 9 figures, 3 tables, accepted for publication in Solar
Physic
A cross-sectional exploratory analysis between pet ownership and sleep, exercise, health and neighborhood perceptions : The Whitehall II cohort study
A cross-sectional exploratory analysis between pet ownership and sleep, exercise, health and neighbourhood perceptions: The Whitehall II cohort study
Gill Mein (corresponding author), Robert Grant. Faculty of Health, Social Care and Education. Kingston University and St George’s University of London
Background: To explore associations between pets, and specifically dog ownership and sleep, health, exercise and neighbourhood.
Methods: Cross sectional examination of 6575 participants of the Whitehall II study aged between 59-79 years. We used self-assessed measurement scales of the Short Form (SF36), General Health Questionnaire (GHQ), Control, Autonomy, Self-realisation and Pleasure (CASP), Centre for Epidemiologic Studies Depression Scale (CES-D), sleep, exercise, and perceptions of local neighbourhood. In addition the Mini Mental State Examination which is administered to test global cognitive status (MMSE)
Results: We found 2/7 people owned a pet and of those 64% were “very” attached to their pet. Mild exercise in metabolic equivalents (MET-hours) was significantly higher in pet owners than non-owners (median 27.8 (IQR 18.1 to 41.8) vs 25.7 (IQR 16.8 to 38.7), p=0.0001), and in dog owners than other pets (median 32.3 (IQR 20.8 to 46.1) vs 25.6 (IQR 16.8 to 38.5), p<0.0001). Moderate exercise was also significantly higher in pet owners than non pet owners (median 11.8 (IQR 4.2 to 21.9) vs 9.8 (IQR 2.8 to 19.5), p<0.0001), and dog owners than owners of other pets (median 12.3 (IQR 4.2 to 22.2) vs 10.1 (3.1 to 20.0), p=0.0002) but there were no significant differences with vigorous exercise. We found that pet owners were significantly more positive about their neighbourhood than non-owners on 8/9 questions, while dog owners were (significantly) even more positive than owners of other pets on 8/9 questions. Associations with sleep were mixed, although dog owners had less trouble falling asleep than non-dog owners, with borderline statistical significance.
Conclusion: Dog owners feel more positive about their neighbourhood, do more exercise, and fall asleep more easily than non-dog owners. These results suggest that dog owners could be more likely to exercise by walking their dogs and therefore may be more familiar and positive about the area in which they walk their dog
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