97 research outputs found
Excitation sources of oscillations in solar coronal loops : a multi-wavelength analysis
An investigation into the excitation sources of oscillations detected in a coronal loop structure is carried out using the images obtained with Interface Region Imaging Spectrometer (IRIS) and the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory (SDO). A loop structure in the active region AR 11967 on 2014 January 28, oscillating in the vicinity of a strong eruption and an M3.6 class flare site, is clearly noticeable in SDO/AIA 171 Å images. We study in detail, the oscillations with detected periods between 4 and 13 minutes and their connection in IRIS SJI 1330 Å and SDO/AIA 1700 Å images; both of these wavelengths sample the lower parts of the solar atmosphere. The simultaneous presence of many oscillations in the region of interest in all three wavelength passbands suggest that these oscillations were excited in the lower-chromosphere–photosphere plasma connected to the loop structure and then propagated at higher heights. We further investigate the Doppler velocity measurements from the spectrograph snapshots in IRIS C II 1336 Å, Si IV 1403 Å and Mg II k 2796 Å. These show signatures of upflows in the vicinity of the loop structure’s endpoints estimated from 171 Å images. We suggest that some of the oscillations observed in AIA 171 Å have been triggered by plasma ejections and perturbations seen in the lower layers of the solar atmosphere. Based on the estimated phase speeds, the oscillations are likely to be slow magnetoacoustic in nature
Analysis of prescription pattern of antihypertensive medication and adherence to Beers criteria in geriatric department of a tertiary care hospital in Mysuru
Background: The objective of the present study was to evaluate the prescription pattern of anti-hypertensive drugs and adherence to Beers’ criteria in geriatric department of JSS Hospital, Mysuru.Methods: An observational, prospective, cross-sectional study was carried out in geriatric department. The basic demographic information and prescriptions of geriatric patients were studied. Descriptive analysis was used to present the results, prescriptions were analysed and checked for adherence to Beers’ criteria.Results: Out of 485 patients, 82.68% received monotherapy, 15.87% received 2-drug combination therapy and 1.4% received 3-drug combination therapy. Among patients receiving monotherapy, angiotensin receptor blockers (49.06%) was the commonest antihypertensive class of drug prescribed. Telmisartan (38.96%) was the commonest drug prescribed. Among 2-drug combination therapy angiotensin converting enzyme inhibitor and Calcium channel blockers were combined commonly. In 3-drug combination therapy angiotensin converting enzyme inhibitor, beta blockers and diuretics were combined commonly. 99.3% of prescriptions were adhered to 2015 American Geriatrics Society Beers criteria.Conclusions: Almost 82% of the patients were treated with monotherapy. The trends in prescribing of anti-hypertensives were in favor of conventional ones such as Angiotensin receptor blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, diuretics, beta blockers and centrally acting alpha agonists. 99.3% of prescriptions were in accordance with the American Geriatrics Society 2015 Updated Beers criteria
Sources and Rates of Phosphorus in Improving Degraded Pasture in Brazilian West Amazon
The effects of phosphorus sources (triple superphosphate – TSP, single superphosphate – SSP and partially acidulated rock phosphate – PARP) and rates (0, 50 and 100 kg/ha of P2O5 on dry matter (DM) yields and chemical composition of a degraded Brachiaria brizantha cv. Marandu pasture were evaluated in a cutting trial. Phosphorus fertilization, irrespective of sources and rates, showed an effective agronomic technique for pasture recuperation. The grass DM yields and potassium contents were significantly improved by phosphorus application, while weed DM yields were depressed. Irrespective of sources and rates, crude protein, phosphorus, and calcium contents were not affected by phosphorus fertilization. The application of 100 kg of P2O5 /ha, as TSP, provided the highest grass yields, while for PARP it was observed the least effect of phosphorus fertilization
On isotropic cylindrically symmetric stellar models
We attempt to match the most general cylindrically symmetric vacuum
space-time with a Robertson-Walker interior. The matching conditions show that
the interior must be dust filled and that the boundary must be comoving.
Further, we show that the vacuum region must be polarized. Imposing the
condition that there are no trapped cylinders on an initial time slice, we can
apply a result of Thorne's and show that trapped cylinders never evolve. This
results in a simplified line element which we prove to be incompatible with the
dust interior. This result demonstrates the impossibility of the existence of
an isotropic cylindrically symmetric star (or even a star which has a
cylindrically symmetric portion). We investigate the problem from a different
perspective by looking at the expansion scalars of invariant null geodesic
congruences and, applying to the cylindrical case, the result that the product
of the signs of the expansion scalars must be continuous across the boundary.
The result may also be understood in relation to recent results about the
impossibility of the static axially symmetric analogue of the Einstein-Straus
model.Comment: 13 pages. To appear in Classical and Quantum Gravit
LOTIS, Super-LOTIS, SDSS and Tautenburg Observations of GRB 010921
We present multi-instrument optical observations of the High Energy Transient
Explorer (HETE-2)/Interplanetary Network (IPN) error box of GRB 010921. This
event was the first gamma ray burst (GRB) localized by HETE-2 which has
resulted in the detection of an optical afterglow. In this paper we report the
earliest known observations of the GRB010921 field, taken with the 0.11-m
Livermore Optical Transient Imaging System (LOTIS) telescope, and the earliest
known detection of the GRB010921 optical afterglow, using the 0.5-m Sloan
Digital Sky Survey Photometric Telescope (SDSS PT). Observations with the LOTIS
telescope began during a routine sky patrol 52 minutes after the burst.
Observations were made with the SDSS PT, the 0.6-m Super-LOTIS telescope, and
the 1.34-m Tautenburg Schmidt telescope at 21.3, 21.8, and 37.5 hours after the
GRB, respectively. In addition, the host galaxy was observed with the USNOFS
1.0-m telescope 56 days after the burst. We find that at later times (t > 1 day
after the burst), the optical afterglow exhibited a power-law decline with a
slope of . However, our earliest observations show that
this power-law decline can not have extended to early times (t < 0.035 day).Comment: AASTeX v5.x LaTeX 2e, 6 pages with 2 postscript figures, will be
submitted to ApJ Letter
Chapter 5: Food Security
The current food system (production, transport, processing, packaging, storage, retail, consumption, loss and waste) feeds the great majority of world population and supports the livelihoods of over 1 billion people. Since 1961, food supply per capita has increased more than 30%, accompanied by greater use of nitrogen fertilisers (increase of about 800%) and water resources for irrigation (increase of more than 100%). However, an estimated 821 million people are currently undernourished, 151 million children under five are stunted, 613 million women and girls aged 15 to 49 suffer from iron deficiency, and 2 billion adults are overweight or obese. The food system is under pressure from non-climate stressors (e.g., population and income growth, demand for animal-sourced products), and from climate change. These climate and non-climate stresses are impacting the four pillars of food security (availability, access, utilisation, and stability)
Latent tuberculosis infection, tuberculin skin test and vitamin D status in contacts of tuberculosis patients: a cross-sectional and case-control study
<p>Abstract</p> <p>Background</p> <p>Deficient serum vitamin D levels have been associated with incidence of tuberculosis (TB), and latent tuberculosis infection (LTBI). However, to our knowledge, no studies on vitamin D status and tuberculin skin test (TST) conversion have been published to date. The aim of this study was to estimate the associations of serum 25-hydroxyvitamin D<sub>3 </sub>(25[OH]D) status with LTBI prevalence and TST conversion in contacts of active TB in Castellon (Spain).</p> <p>Methods</p> <p>The study was designed in two phases: cross-sectional and case-control. From November 2009 to October 2010, contacts of 42 TB patients (36 pulmonary, and 6 extra-pulmonary) were studied in order to screen for TB. LTBI and TST conversion cases were defined following TST, clinical, analytic and radiographic examinations. Serum 25(OH)D levels were measured by electrochemiluminescence immunoassay (ECLIA) on a COBAS<sup>® </sup>410 ROCHE<sup>® </sup>analyzer. Logistic regression models were used in the statistical analysis.</p> <p>Results</p> <p>The study comprised 202 people with a participation rate of 60.1%. Only 20.3% of the participants had a sufficient serum 25(OH)D (≥ 30 ng/ml) level. In the cross-sectional phase, 50 participants had LTBI and no association between LTBI status and serum 25(OH)D was found. After 2 months, 11 out of 93 negative LTBI participants, without primary prophylaxis, presented TST conversion with initial serum 25(OH)D levels: a:19.4% (7/36): < 20 ng/ml, b:12.5% (4/32):20-29 ng/ml, and c:0%(0/25) ≥ 30 ng/ml. A sufficient serum 25(OH)D level was a protector against TST conversion a: Odds Ratio (OR) = 1.00; b: OR = 0.49 (95% confidence interval (CI) 0.07-2.66); and c: OR = 0.10 (95% CI 0.00-0.76), trends p = 0.019, adjusted for high exposure and sputum acid-fast bacilli positive index cases. The mean of serum level 25(OH)D in TST conversion cases was lower than controls,17.5 ± 5.6 ng/ml versus 25.9 ± 13.7 ng/ml (p = 0.041).</p> <p>Conclusions</p> <p>The results suggest that sufficient serum 25(OH)D levels protect against TST conversion.</p
Design and Simulated Performance of Calorimetry Systems for the ECCE Detector at the Electron Ion Collider
We describe the design and performance the calorimeter systems used in the
ECCE detector design to achieve the overall performance specifications
cost-effectively with careful consideration of appropriate technical and
schedule risks. The calorimeter systems consist of three electromagnetic
calorimeters, covering the combined pseudorapdity range from -3.7 to 3.8 and
two hadronic calorimeters. Key calorimeter performances which include energy
and position resolutions, reconstruction efficiency, and particle
identification will be presented.Comment: 19 pages, 22 figures, 5 table
ECCE Sensitivity Studies for Single Hadron Transverse Single Spin Asymmetry Measurements
We performed feasibility studies for various single transverse spin
measurements that are related to the Sivers effect, transversity and the tensor
charge, and the Collins fragmentation function. The processes studied include
semi-inclusive deep inelastic scattering (SIDIS) where single hadrons (pions
and kaons) were detected in addition to the scattered DIS lepton. The data were
obtained in {\sc pythia}6 and {\sc geant}4 simulated e+p collisions at 18 GeV
on 275 GeV, 18 on 100, 10 on 100, and 5 on 41 that use the ECCE detector
configuration. Typical DIS kinematics were selected, most notably
GeV, and cover the range from to . The single spin
asymmetries were extracted as a function of and , as well as the
semi-inclusive variables , and . They are obtained in azimuthal moments
in combinations of the azimuthal angles of the hadron transverse momentum and
transverse spin of the nucleon relative to the lepton scattering plane. The
initially unpolarized MonteCarlo was re-weighted in the true kinematic
variables, hadron types and parton flavors based on global fits of fixed target
SIDIS experiments and annihilation data. The expected statistical
precision of such measurements is extrapolated to 10 fb and potential
systematic uncertainties are approximated given the deviations between true and
reconstructed yields. The impact on the knowledge of the Sivers functions,
transversity and tensor charges, and the Collins function has then been
evaluated in the same phenomenological extractions as in the Yellow Report. The
impact is found to be comparable to that obtained with the parameterized Yellow
Report detector and shows that the ECCE detector configuration can fulfill the
physics goals on these quantities.Comment: 22 pages, 22 figures, to be submitted to joint ECCE proposal NIM-A
volum
Open Heavy Flavor Studies for the ECCE Detector at the Electron Ion Collider
The ECCE detector has been recommended as the selected reference detector for
the future Electron-Ion Collider (EIC). A series of simulation studies have
been carried out to validate the physics feasibility of the ECCE detector. In
this paper, detailed studies of heavy flavor hadron and jet reconstruction and
physics projections with the ECCE detector performance and different magnet
options will be presented. The ECCE detector has enabled precise EIC heavy
flavor hadron and jet measurements with a broad kinematic coverage. These
proposed heavy flavor measurements will help systematically study the
hadronization process in vacuum and nuclear medium especially in the
underexplored kinematic region.Comment: Open heavy flavor studies with the EIC reference detector design by
the ECCE consortium. 11 pages, 11 figures, to be submitted to the Nuclear
Instruments and Methods
- …