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Vortex Motions in the Solar Atmosphere
Vortex flows, related to solar convective turbulent dynamics at granular scales and their interplay with magnetic fields within intergranular lanes, occur abundantly on the solar surface and in the atmosphere above. Their presence is revealed in high-resolution and high-cadence solar observations from the ground and from space and with state-of-the-art magnetoconvection simulations. Vortical flows exhibit complex characteristics and dynamics, excite a wide range of different waves, and couple different layers of the solar atmosphere, which facilitates the channeling and transfer of mass, momentum and energy from the solar surface up to the low corona. Here we provide a comprehensive review of documented research and new developments in theory, observations, and modelling of vortices over the past couple of decades after their observational discovery, including recent observations in Hα, innovative detection techniques, diverse hydrostatic modelling of waves and forefront magnetohydrodynamic simulations incorporating effects of a non-ideal plasma. It is the first systematic overview of solar vortex flows at granular scales, a field with a plethora of names for phenomena that exhibit similarities and differences and often interconnect and rely on the same physics. With the advent of the 4-m Daniel K. Inouye Solar Telescope and the forthcoming European Solar Telescope, the ongoing Solar Orbiter mission, and the development of cutting-edge simulations, this review timely addresses the state-of-the-art on vortex flows and outlines both theoretical and observational future research directions.
Journal Article
Vortex Motions in the Solar Atmosphere
Vortex flows, related to solar convective turbulent dynamics at granular scales and their interplay with magnetic fields within intergranular lanes, occur abundantly on the solar surface and in the atmosphere above. Their presence is revealed in high-resolution and high-cadence solar observations from the ground and from space and with state-of-the-art magnetoconvection simulations. Vortical flows exhibit complex characteristics and dynamics, excite a wide range of different waves, and couple different layers of the solar atmosphere, which facilitates the channeling and transfer of mass, momentum and energy from the solar surface up to the low corona. Here we provide a comprehensive review of documented research and new developments in theory, observations, and modelling of vortices over the past couple of decades after their observational discovery, including recent observations in
H
α
, innovative detection techniques, diverse hydrostatic modelling of waves and forefront magnetohydrodynamic simulations incorporating effects of a non-ideal plasma. It is the first systematic overview of solar vortex flows at granular scales, a field with a plethora of names for phenomena that exhibit similarities and differences and often interconnect and rely on the same physics. With the advent of the 4-m Daniel K. Inouye Solar Telescope and the forthcoming European Solar Telescope, the ongoing Solar Orbiter mission, and the development of cutting-edge simulations, this review timely addresses the state-of-the-art on vortex flows and outlines both theoretical and observational future research directions.
Journal Article
When to use single-inhaler triple therapy in COPD: a practical approach for primary care health care professionals
While single-inhaler triple therapy (SITT) devices were not available when the Global Initiative for Chronic Obstructive Lung Disease strategy and National Institute for Health and Care Excellence guidelines were developed, two devices are now available in the UK. This paper offers practical, patient-focused advice to optimize placement of SITT in the management of COPD. A survey of UK health care professionals (HCPs) identified issues around, and attitudes toward, SITT, which informed a multidisciplinary expert panel's discussions. The survey confirmed the need to clarify the place of SITT in COPD management. The panel suggested three criteria, any one of which identifies a high-risk patient where escalation to triple therapy from monotherapy or double combination treatment is appropriate: 1) at least two exacerbations treated with oral corticosteroids, antibiotics, or both in the previous year; 2) at least one severe exacerbation that required hospital admission in the previous year; 3) one exacerbation a year on a repeated basis for 2 consecutive years. Appropriate non-pharmacological management is essential for all patients and should be considered before stepping up treatment. Regular review is essential. During each review, HCPs should consider stepping treatment up or down. If patients exacerbate despite adhering to triple therapy, an individualized approach should be considered if the inhaled corticosteroid (ICS) confers benefit or causes side effects. In this situation, the blood eosinophil count could aid decision making. ICSs should be continued when the history suggests that asthma overlaps with COPD. Training, counseling, and education should be individualized. HCPs should consider referral: 1) when there is limited response to treatment and persistent exacerbations; 2) where there is diagnostic uncertainty or suspected comorbidity; 3) whenever they feel \"out of their depth.\" Overall, the panel concurred that when used correctly, SITT has the potential to improve adherence, symptom control, and quality of life, and reduce exacerbations. Studies using real-world evidence need to confirm these benefits.
Journal Article
Solar Science with the Atacama Large Millimeter/Submillimeter Array—A New View of Our Sun
The Atacama Large Millimeter/submillimeter Array (ALMA) is a new powerful tool for observing the Sun at high spatial, temporal, and spectral resolution. These capabilities can address a broad range of fundamental scientific questions in solar physics. The radiation observed by ALMA originates mostly from the chromosphere—a complex and dynamic region between the photosphere and corona, which plays a crucial role in the transport of energy and matter and, ultimately, the heating of the outer layers of the solar atmosphere. Based on first solar test observations, strategies for regular solar campaigns are currently being developed. State-of-the-art numerical simulations of the solar atmosphere and modeling of instrumental effects can help constrain and optimize future observing modes for ALMA. Here we present a short technical description of ALMA and an overview of past efforts and future possibilities for solar observations at submillimeter and millimeter wavelengths. In addition, selected numerical simulations and observations at other wavelengths demonstrate ALMA’s scientific potential for studying the Sun for a large range of science cases.
Journal Article
Muscarinic Receptor-Dependent Long Term Depression in the Perirhinal Cortex and Recognition Memory are Impaired in the rTg4510 Mouse Model of Tauopathy
Neurodegenerative diseases affecting cognitive dysfunction, such as Alzheimer’s disease and fronto-temporal dementia, are often associated impairments in the visual recognition memory system. Recent evidence suggests that synaptic plasticity, in particular long term depression (LTD), in the perirhinal cortex (PRh) is a critical cellular mechanism underlying recognition memory. In this study, we have examined novel object recognition and PRh LTD in rTg4510 mice, which transgenically overexpress tauP301L. We found that 8–9 month old rTg4510 mice had significant deficits in long- but not short-term novel object recognition memory. Furthermore, we also established that PRh slices prepared from rTg4510 mice, unlike those prepared from wildtype littermates, could not support a muscarinic acetylcholine receptor-dependent form of LTD, induced by a 5 Hz stimulation protocol. In contrast, bath application of the muscarinic agonist carbachol induced a form of chemical LTD in both WT and rTg4510 slices. Finally, when rTg4510 slices were preincubated with the acetylcholinesterase inhibitor donepezil, the 5 Hz stimulation protocol was capable of inducing significant levels of LTD. These data suggest that dysfunctional cholinergic innervation of the PRh of rTg4510 mice, results in deficits in synaptic LTD which may contribute to aberrant recognition memory in this rodent model of tauopathy.
Journal Article
Off-limb (Spicule) DEM Distribution from SoHO/SUMER Observations
In the present work we derive a Differential Emission Measure (DEM) distribution from a region dominated by spicules. We use spectral data from the
Solar Ultraviolet Measurements of Emitted Radiation
(SUMER) spectrometer on-board the
Solar Heliospheric Observatory
(SoHO) covering the entire SUMER wavelength range taken off-limb in the Northern polar coronal hole to construct this DEM distribution using the CHIANTI atomic database. This distribution is then used to study the thermal properties of the emission contributing to the 171 Å channel in the
Atmospheric Imaging Assembly
(AIA) on-board the
Solar Dynamics Observatory
(SDO). From our off-limb DEM we found that the radiance in the AIA 171 Å channel is dominated by emission from the Fe
ix
171.07 Å line and has sparingly little contribution from other lines. The product of the Fe
ix
171.07 Å line contribution function with the off-limb DEM was found to have a maximum at log
T
max
(K)=5.8 indicating that during spicule observations the emission in this line comes from plasma at transition region temperatures rather than coronal. For comparison, the same product with a quiet Sun and prominence DEM were found to have a maximum at log
T
max
(K)=5.9 and log
T
max
(K)=5.7, respectively. We point out that the interpretation of data obtained from the AIA 171 Å filter should be done with foreknowledge of the thermal nature of the observed phenomenon. For example, with an off-limb DEM we find that only 3.6 % of the plasma is above a million degrees, whereas using a quiet Sun DEM, this contribution rises to 15 %.
Journal Article
Predicting fracture risk in patients with chronic obstructive pulmonary disease: a UK-based population-based cohort study
ObjectiveTo assess the incidence of hip fracture and all major osteoporotic fractures (MOF) in patients with chronic obstructive pulmonary disease (COPD) compared with non-COPD patients and to evaluate the use and performance of fracture risk prediction tools in patients with COPD. To assess the prevalence and incidence of osteoporosis.DesignPopulation-based cohort study.SettingUK General Practice health records from The Health Improvement Network database.ParticipantsPatients with an incident COPD diagnosis from 2004 to 2015 and non-COPD patients matched by age, sex and general practice were studied.OutcomesIncidence of fracture (hip alone and all MOF); accuracy of fracture risk prediction tools in COPD; and prevalence and incidence of coded osteoporosis.MethodsCox proportional hazards models were used to assess the incidence rates of osteoporosis, hip fracture and MOF (hip, proximal humerus, forearm and clinical vertebral fractures). The discriminatory accuracies (area under the receiver operating characteristic [ROC] curve) of fracture risk prediction tools (FRAX and QFracture) in COPD were assessed.ResultsPatients with COPD (n=80 874) were at an increased risk of fracture (both hip alone and all MOF) compared with non-COPD patients (n=308 999), but this was largely mediated through oral corticosteroid use, body mass index and smoking. Retrospectively calculated ROC values for MOF in COPD were as follows: FRAX: 71.4% (95% CI 70.6% to 72.2%), QFracture: 61.4% (95% CI 60.5% to 62.3%) and for hip fracture alone, both 76.1% (95% CI 74.9% to 77.2%). Prevalence of coded osteoporosis was greater for patients (5.7%) compared with non-COPD patients (3.9%), p<0.001. The incidence of osteoporosis was increased in patients with COPD (n=73 084) compared with non-COPD patients (n=264 544) (adjusted hazard ratio, 1.13, 95% CI 1.05 to 1.22).ConclusionPatients with COPD are at an increased risk of fractures and osteoporosis. Despite this, there is no systematic assessment of fracture risk in clinical practice. Fracture risk tools identify those at high risk of fracture in patients with COPD.
Journal Article
Exploring Flaring Behaviour on Low Mass Stars, Solar-type Stars and the Sun
We report on our project to study the activity in both the Sun and low mass stars. Utilising high cadence, Hα observations of a filament eruption made using the CRISP spectropolarimeter mounted on the Swedish Solar Telescope has allowed us to determine 3D velocity maps of the event. To gain insight into the physical mechanism which drives the event we have qualitatively compared our observation to a 3D MHD reconnection model. Solar-type and low mass stars can be highly active producing flares with energies exceeding erg. Using K2 and TESS data we find no correlation between the number of flares and the rotation phase which is surprising. Our solar flare model can be used to aid our understanding of the origin of flares in other stars. By scaling up our solar model to replicate observed stellar flare energies, we investigate the conditions needed for such high energy flares.
Journal Article