1,085 research outputs found
Finding RR Lyrae Stars with SkyMapper: an Observational Test
One of the major science goals of the SkyMapper Survey of the Southern
Hemisphere sky is the determination of the shape and extent of the halo of the
Galaxy. In this paper we quantify the likely efficiency and completeness of the
survey as regards the detection of RR Lyrae variable stars, which are excellent
tracers of the halo stellar population. We have accomplished this via
observations of the RR Lyrae-rich globular cluster NGC 3201. We find that for
single epoch uvgri observations followed by two further epochs of g, r imaging,
as per the intended three-epoch survey strategy, we recover known RR Lyraes
with a completeness exceeding 90%. We also investigate boundaries in the
gravity-sensitive single-epoch two-color diagram that yield high completeness
and high efficiency (i.e., minimal contamination by non-RR Lyraes) and the
general usefulness of this diagram in separating populations.Comment: 10 pages, 5 figures, to appear in the Publications of the
Astronomical Society of Australia (PASA), published by Cambridge University
Pres
Exploring the perceptions of Patients with Chronic Respiratory Diseases and their insights into Pulmonary Rehabilitation in Bangladesh
Background: Chronic respiratory diseases (CRDs) require holistic management reflecting patient preferences, appropriate pharmacotherapy, pulmonary rehabilitation, and integrated care. We aimed to understand the perceptions of people with CRDs about their condition and pulmonary rehabilitation in Bangladesh.Methods: We conducted semi-structured interviews with a maximum variation sample of people with CRD who had participated in a feasibility study of pulmonary rehabilitation in 2021/ 2022. Interviews were transcribed verbatim, analysed in Bengali using a grounded theory approach and interpreted by a multidisciplinary team.Results: We interviewed 15 participants with COPD, asthma, or post-tuberculosis. Analysis revealed three themes. 1) Understanding CRD: patients characterised their condition by the symptoms (e.g., ‘Hapani’ meaning ‘breathlessness’) rather than describing a disease entity. Some identified occupation, previous infection or family history that they believed was the cause. 2) Perceptions of pulmonary rehabilitation: Exercise was counterintuitive as it exacerbated the breathlessness symptom that defined their disease. Views varied, though many acknowledged the benefits after a few sessions. Even with home-based programmes, participants described practical barriers to finding time for the sessions and adopted strategies to overcome the challenges. 3) Implementation: Participants highlighted the need for raising awareness of CRD and the potential of pulmonary rehabilitation in the community, adapting to the local context, and establishing an accessible resourced service. Conclusion: Understanding how patients and their communities perceive their condition and the barriers (both conceptual and logistical) to acceptance is the first step to embedding this highly effective intervention into routine healthcare services in Bangladesh with potential benefits for the increasing number of people living with CRDs in LMICs.<br/
Nanomedicines as cancer therapeutics: Current status
As of 21st century, cancer is arguably the most complex and challenging disease known to mankind and an inevitable public health concern of this millennium. Nanotechnology, suitably amalgamated with cancer research, has ushered an era of highly personalized and safer medicines which can improve cancer diagnosis and therapy. A wide variety of nanomedicines are currently under investigation, including polymeric/non-polymeric nanoparticles, dendrimers, quantum dots, carbon nanotubes, lipid- and micelle-based nanoparticles. The bases of these nanomedicines in reducing toxicity associated with cancer therapy are their ability to carry a large payload and multivalent-ligand targeting. This imparts specificity for targeting the tissues as well as bypass resistance mechanisms. The major hurdles on these future medicines are potential toxicity of nanoparticles, which imposes the need of extensive regulatory evaluation before nanomedicines could be utilized as cancer therapeutics. This review highlights nanopharmaceuticals that have been investigated in oncology for various applications (diagnosis, therapeutic delivery and theranostics). It also discusses the effects of nano-sized materials on tissues/organ functions, the possibility of overcoming multi-drug resistance by using nanomedicines and their current clinical status
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Consolidation of Geologic Studies of Geopressured Geothermal Resources in Texas
The objective of the current studies at the Pleasant Bayou geopressured geothermal reservoir in Brazoria County, Texas, was to evaluate the resource base and long-term performance. The approach was to develop an integrated understanding of the hydrogeology of the reservoir and the hydrochemistry of the produced brine. Such an understanding would allow determination of the extent of lateral and vertical hydrologic continuity of the target zone and to identify the sources of brine being produced from the geopressured reservoir.
The current phase of long-term production testing of the Frio C-zone at Pleasant Bayou Well No. 2 began in May 1988. During the past 16 months of production, nearly 6.8 million barrels of brine and 162.2 million cubic feet of gas have been produced, and a relatively small (less than 300 psi) drop in bottom-hole pressure has been observed at sustained producing rates of between 15,000 and 20,000 barrels per day. Earlier geologic studies have estimated the effective pore volume of the C-zone in the neighborhood of 6.2 to 6.6 billion barrels. Analysis of pressure and production data from current testing indicates that the limits of the geopressured reservoir at Pleasant Bayou have not been reached; that is, either the size of the reservoir could be larger than anticipated, or there could be a continuous influx of waters from other geopressured sources that sustains the reservoir energy at Pleasant Bayou. Geochemical testing has proved inconclusive in identifying other sources of water partly because of the variability of chemical composition within the produced zone.
Evaluation of reservoir performance at active oil and gas fields in the immediate vicinity of the Pleasant Bayou fault block has not provided evidence of direct hydrologic communication between the geopressured aquifer and the overlying hydrocarbon reservoirs. The pattern of depletion in these oil and gas fields reflects some characteristic features that may become evident in Pleasant Bayou over a long period of production. Moreover, additional refinement of the integrated hydrogeologic-hydrochemical model is possible either through prolonged testing at Pleasant Bayou No. 2 well or through drilling and testing of additional wells in the Pleasant Bayou fault block. Determining the nature of bounding faults around the test well will require additional seismic data as well as multiwell testing of the reservoir.Bureau of Economic Geolog
Microstructure and Magnetic Properties of Very Thin CoCr Films Deposited on Different Underlayers by rf-Sputtering
Very thin CoCr films deposited on different underlayers on glass disk substrates were studied by the magneto-optic Kerr effect, VSM, torque magnetometry and TEM selected area diffraction. Square or near square perpendicular loops were obtained from Co/Ti, CoCr/Au, CoCr/Al, CoCr/C and CoCr/Si films. TEM SAD study revealed that the crystalline structure is a key factor determining the magnetic anisotropy of the very thin CoCr films. In particular, the c-axis of the hep CoCr films which exhibit square perpendicular loops is perpendicular to the film plane whilst that of the CoCr films which exhibit a thin and flat perpendicular loop lies in the film plane. The texture of the very thin CoCr films deposited on different underlayers is mainly dependent on the structure and texture of underlayers. The relation between the structure of CoCr and its underlayers is discussed
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Development of Artificial Geochemical Filter to Treat Acid Mine Drainage for Safe Disposal of Mine Water in Salt Range Portion of Indus Basin—A Lab to Pilot Scale Study
Data Availability Statement:
Not applicable.Copyright © 2022 by the authors. Several passive and active treatment approaches are available for dealing with Acid Mine Drainage (AMD). Despite a range of newly emergent techniques for the treatment of AMD, pH control using low-cost neutralizing reagents has been the most common and economical technique for the treatment of AMD. Thereby, owing to their widespread availability, ease of use, and cost effectiveness, active treatment techniques utilizing calcium-based reagents (particularly limestone) are considered the prime choice for treating AMD. Limestone is a well-known option worldwide for AMD neutralization thanks to its easy availability, low cost, and excellent efficiency. Generally, acidity is reduced by the presence of CaCO3 and alkalinity (i.e., HCO−3) is increased. pH can be increased from 2.5 to 7.5 by using limestone as a treating agent, resulting in the precipitation of heavy metals, which can then be removed by precipitation and sorption. Wargal limestone, a well-known limestone from the Salt Range, Indus basin, Pakistan, has high potential for neutralization and treatment of PTEs present in mine water or AMD. After selecting a suitable neutralization material at pilot scale, two different filters were designed using selected Wargal limestone: Filter 1 A (Oxic-based, Vertical bed-type Wargal Limestone Filter) and Filter 1 B (Anoxic-based Vertical bed-type Wargal Limestone Filter with Compost). The pH of the AMD under study was elevated from 2.5 to 7.65 and 7.60, respectively, in uncoated and coated media of limestone. Although the neutralization potential decreased over time, as an overall phenomenon the Ca concentration and net alkalinity (280–360 mg/L) were increased with the removal of metals such as Fe, Cu, Pb and Mn. The respective removal efficiency of these metals was 98%, 99%, 99% and 60%, with a threshold residence time of 5 h. in all columns of the developed filters.Chinese Academy of Sciences President’s International Fellowship Initiative (Grant No. 2021VCA0010); International Science and Technology Cooperation Program of China (2018YFE0100100)
4,4′-Dibromo-2-nitrobiphenyl
The title compound, C12H7Br2NO2, a biphenyl derivative, displays a twisted conformation with the two benzene rings making a dihedral angle of 55.34 (14)°. The dihedral angle between the nitro group and its parent benzene ring is 26.8 (2)°. The crystal structure is stabilized by intermolecular C—H⋯Br and C—H⋯O interactions, which lead to the formation of chains propagating along the c-axis direction
Rice diversity and the joy of eid
This brief presents the results of research on the conservation and sustainable use of rice diversity in Bangladesh and how the rice varieties used and planted are intrinsically linked to religious festivals, food culture, land morphology and the climate that shape rice farming/cropping in this region. It highlights the important roles played by Community Seed Wealth Centers (community seed banks) and the Nayakrishi farmers, who manage them, in ensuring the conservation of rice varieties that are in danger of disappearing, and in supplying farmers with diverse, good quality seed. It also demonstrates the key roles played by women farmers as seed custodians and the strategic research and capacity building activities carried out by the Community Seed Wealth Centers
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