462 research outputs found
Study of polytropes with Generalized polytropic Equation of State
The aim of this paper is to discuss the theory of Newtonian and relativistic
polytropes with generalized polytropic equation of state. For this purpose, we
formulated the general framework to discuss the physical properties of
polytrops with anisotropic inner fluid distribution under conformally flat
condition in the presence of charge. We investigate the stability of these
polytrops in the vicinity of generalized polytropic equation through
Tolman-mass. It is concluded that one of the derived models is physically
acceptable.Comment: 21 pages, 3 figure
Surface energy measurements of coated titanium dioxide pigment
In this study surface energy measurements have been carried out on titanium
dioxide pigments coated with different types of organic compound. The organic
coatings investigated were polymethylsiloxane and octyl triethoxy-silane. The level of
coating applied was increased from 0.2 up to 1.5 weight %. Contact angles were
measured using an advancing sessile drop method. To allow for the fact that
measurements were made on pressed discs of particles rather than on a perfectly flat
surface, a correction was applied to convert each measured contact angle to the true
Young’s contact angle. Surface energies were calculated from the corrected contact
angles using the Owens and Wendt equation. From the values of surface energy it was
possible to determine at what coating level the surface characteristics changed from
hydrophilic to hydrophobic and hence when complete coverage had taken place. For
both the siloxane and the silane coatings it was found that complete coating coverage
occurred at an addition level of around 0.8 weight %. The surface energies of all the
coated pigments were found to correlate well with their dispersion behaviour in liquid
paraffin.
Keywords: In this study surface energy measurements have been carried out on titanium
dioxide pigments coated with different types of organic compound. The organic
coatings investigated were polymethylsiloxane and octyl triethoxy-silane. The level of
coating applied was increased from 0.2 up to 1.5 weight %. Contact angles were
measured using an advancing sessile drop method. To allow for the fact that
measurements were made on pressed discs of particles rather than on a perfectly flat
surface, a correction was applied to convert each measured contact angle to the true
Young’s contact angle. Surface energies were calculated from the corrected contact
angles using the Owens and Wendt equation. From the values of surface energy it was
possible to determine at what coating level the surface characteristics changed from
hydrophilic to hydrophobic and hence when complete coverage had taken place. For
both the siloxane and the silane coatings it was found that complete coating coverage
occurred at an addition level of around 0.8 weight %. The surface energies of all the
coated pigments were found to correlate well with their dispersion behaviour in liquid
paraffin.
Keywords: Titanium dioxide; surface energy; contact angle; organic coating; surface energy; contact angle; organic coatin
Survival of ancient landforms in a collisional setting as revealed by combined fission track and (U-Th)/He thermochronometry: A case study from Corsica (France)
The age of high-elevation planation surfaces in Corsica is constrained using new apatite (U-Th)/He data, field observations, and published work (zircon fission track, apatite fission track [AFT] data and landform/stratigraphical analysis). Thermal modeling results based on AFT and (U-Th)/He data, and the Eocene sediments uncomformably overlapping the Variscan crystalline basement indicate that present-day elevated planation surfaces in Corsica are the remnants of an erosion surface formed on the basement between ∼120 and ∼60 Ma. During the Alpine collision in the Paleocene-Eocene, the Variscan crystalline basement was buried beneath a westward-thinning wedge of flysch, and the eastern portion was overridden by the Alpine nappes. Resetting of the apatite fission track thermochronometer suggests an overburden thickness of >4 km covering Variscan Corsica. Protected by soft sediment, the planation surface was preserved. In the latest Oligocene to Miocene times, the surface was re-exposed and offset by reactivated faults, with individual basement blocks differentially uplifted in several phases to elevations of, in some cases, >2 km.Currently the planation surface remnants occur at different altitudes and with variable tilt. This Corsican example demonstrates that under favorable conditions, paleolandforms typical of tectonically inactive areas can survive in tectonically active settings such as at collisional plate margins. The results of some samples also reveal some discrepancies in thermal histories modeled from combined AFT and (U-Th)/He data. In some cases, models could not find a cooling path that fit both data sets, while in other instances, the modeled cooling paths suggest isothermal holding at temperature levels just below the apatite partial annealing zone followed by final late Neogene cooling. This result appears to be an artifact of the modeling algorithm as it is in conflict with independent geological constraints. Caution should be used when cross-validating the AFT and (U-Th)/He systems both in the case extremely old terrains and in the case of rocks with a relatively simple, young cooling history
Comparison of various oxidative treatments for removal of reactive black CNN
Decolorization of reactive black CNN by chemical oxidation and reduction using KMnO4, H2O2 and Ferrioxalate as oxidizing agents and Na2SO3 as reducing agent individually as well as in combination was studied on batch scale using UV-visible spectroscopy. Degradation of dye occurred in acidic medium with KMnO4 and in alkaline medium with H2O2 and ferrioxalate. The most efficient methods for decolorization of reactive black CNN is oxidation using KMnO4 as an oxidizing agent which removed 97.64% of dye. Maximum decolorization was obtained at 60 min of treatment under static conditions. H2O2 and ferrioxalate could remove only 50.71 and 44.21% dye, respectively. Sequential treatment was more successful with H2O2 and ferrioxalate when compared with KMnO4. Chemical oxygen demand (COD) and total organic carbon (TOC) contents of treated wastewater decreased appreciably from 83.6 to 63.7 mg/L and 86.8 to 72.8 mg/L, respectively. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) study revealed the degradation of reactive black CNN after treatment into non toxic products.Keywords: Reactive black CNN, KMnO4, ferrioxalate, sodium sulphite, chemical oxygen demand (COD)
Association of tumor necrosis factor alpha gene polymorphism G-308A with pseudoexfoliative glaucoma in the Pakistani population
Contains fulltext :
80274.pdf (publisher's version ) (Open Access)PURPOSE: The purpose of the present study was to determine the role of the tumor necrosis factor alpha (TNF-alpha) gene polymorphism G-308A and total serum immunoglobulin E (TsIgE) levels in the onset of pseudoexfoliation glaucoma (PEXG) in Pakistani patients. METHODS: The TNF-alpha polymorphism G-308A was analyzed in 122 patients with PEXG and 126 healthy unrelated controls by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). TsIgE levels were determined by solid-phase enzyme-linked immunosorbent assay (ELISA). RESULTS: The AA and GA genotypes were strongly associated with PEXG (p<0.001), with an odds ratio (OR) of 0.07 (95% confidence interval [CI]=0.02-0.27) and 0.24 (95% CI=0.12-0.51), respectively, while the GG genotype was found at a higher frequency in controls as compared to patients (p<0.001) OR=8.95 (95% CI=4.55-17.81). No significant difference was found in TsIgE levels of both patients and controls (p=0.86). CONCLUSION: The present study concludes that the TNF-alpha polymorphism G-308A is strongly associated with PEXG. To our knowledge this is the first study in southeast Asia which demonstrates a strong association of a TNF-alpha polymorphism with PEXG
Performance measurement - A balanced score card approach
This paper suggests a framework of performance
measurement through a balanced scorecard and
to provide an objective indicator for evaluating the achievement of the strategic goals of the corporate.This paper uses the concepts of balanced score card and adopts an
analytical hierarchical process model to measure an organizational performance. The
balanced score card is a widely used management framework for the measurement of organizational performance.Preference theory is used to calculate the relative weightage for each factor, using the pair wise comparison.This framework may be used to
calculate the effectiveness score for balanced score card as a final value of performance for any organization.The variations between targeted performance and actual performance were analyzed
Stakeholder narratives on trypanosomiasis, their effect on policy and the scope for One Health
Background
This paper explores the framings of trypanosomiasis, a widespread and potentially fatal zoonotic disease transmitted by tsetse flies (Glossina species) affecting both humans and livestock. This is a country case study focusing on the political economy of knowledge in Zambia. It is a pertinent time to examine this issue as human population growth and other factors have led to migration into tsetse-inhabited areas with little historical influence from livestock. Disease transmission in new human-wildlife interfaces such as these is a greater risk, and opinions on the best way to manage this are deeply divided.
Methods
A qualitative case study method was used to examine the narratives on trypanosomiasis in the Zambian policy context through a series of key informant interviews. Interviewees included key actors from international organisations, research organisations and local activists from a variety of perspectives acknowledging the need to explore the relationships between the human, animal and environmental sectors.
Principal Findings
Diverse framings are held by key actors looking from, variously, the perspectives of wildlife and environmental protection, agricultural development, poverty alleviation, and veterinary and public health. From these viewpoints, four narratives about trypanosomiasis policy were identified, focused around four different beliefs: that trypanosomiasis is protecting the environment, is causing poverty, is not a major problem, and finally, that it is a Zambian rather than international issue to contend with. Within these narratives there are also conflicting views on the best control methods to use and different reasoning behind the pathways of response. These are based on apparently incompatible priorities of people, land, animals, the economy and the environment. The extent to which a One Health approach has been embraced and the potential usefulness of this as a way of reconciling the aims of these framings and narratives is considered throughout the paper.
Conclusions/Significance
While there has historically been a lack of One Health working in this context, the complex, interacting factors that impact the disease show the need for cross-sector, interdisciplinary decision making to stop rival narratives leading to competing actions. Additional recommendations include implementing: surveillance to assess under-reporting of disease and consequential under-estimation of disease risk; evidence-based decision making; increased and structurally managed funding across countries; and focus on interactions between disease drivers, disease incidence at the community level, and poverty and equity impacts
Comparison of greenhouse gas fluxes from tropical forests and oil palm plantations on mineral soil
In Southeast Asia, oil palm (OP) plantations have largely replaced tropical forests. The impact of this shift in land use on greenhouse gas (GHG) fluxes remains highly uncertain, mainly due to a relatively small pool of available data. The aim of this study is to quantify differences of nitrous oxide (N2O) and methane (CH4) fluxes as well as soil carbon dioxide (CO2) respiration rates from logged forests, oil palm plantations of different ages, and an adjacent small riparian area. Nitrous oxide fluxes are the focus of this study, as these emissions are expected to increase significantly due to the nitrogen (N) fertilizer application in the plantations. This study was conducted in the SAFE (Stability of Altered Forest Ecosystems) landscape in Malaysian Borneo (Sabah) with measurements every 2 months over a 2-year period. GHG fluxes were measured by static chambers together with key soil physicochemical parameters and microbial biodiversity. At all sites, N2O fluxes were spatially and temporally highly variable. On average the largest fluxes (incl. 95 % CI) were measured from OP plantations (45.1 (24.0–78.5) µg m−2 h−1 N2O-N), slightly smaller fluxes from the riparian area (29.4 (2.8–84.7) µg m−2 h−1 N2O-N), and the smallest fluxes from logged forests (16.0 (4.0–36.3) µg m−2 h−1 N2O-N). Methane fluxes were generally small (mean ± SD): −2.6 ± 17.2 µg CH4-C m−2 h−1 for OP and 1.3 ± 12.6 µg CH4-C m−2 h−1 for riparian, with the range of measured CH4 fluxes being largest in logged forests (2.2 ± 48.3 µg CH4-C m−2 h−1). Soil respiration rates were larger from riparian areas (157.7 ± 106 mg m−2 h−1 CO2-C) and logged forests (137.4 ± 95 mg m−2 h−1 CO2-C) than OP plantations (93.3 ± 70 mg m−2 h−1 CO2-C) as a result of larger amounts of decomposing leaf litter. Microbial communities were distinctly different between the different land-use types and sites. Bacterial communities were linked to soil pH, and fungal and eukaryotic communities were linked to land use. Despite measuring a large number of environmental parameters, mixed models could only explain up to 17 % of the variance of measured fluxes for N2O, 3 % of CH4, and 25 % of soil respiration. Scaling up measured N2O fluxes to Sabah using land areas for forest and OP resulted in emissions increasing from 7.6 Mt (95 % confidence interval, −3.0–22.3 Mt) yr−1 in 1973 to 11.4 Mt (0.2–28.6 Mt) yr−1 in 2015 due to the increasing area of forest converted to OP plantations over the last ∼ 40 years
Multiple Sterile Withdrawals from Iohexol Bottles Does Not Increase Contamination Risk
BACKGROUND: There is a global shortage of iohexol contrast media, commonly used in epidural injections, as a result of lockdown and decreased production due to COVID-19. Iohexol bottles are designated for single use, which, depending on the vials available, often leads to wasting up to 95% of this limited resource. However, avoiding multiple withdrawals may be unnecessary if withdrawing multiple times using sterile technique does not increase the risk for contamination.
OBJECTIVES: The purpose of our study is to determine whether multiple withdrawals from iohexol injection bottles using a sterile technique poses a greater risk of introducing contaminants than a single withdrawal. Furthermore, we wish to determine the extent to which bacteria can survive and grow in the contrast media.
STUDY DESIGN: Experimental.
SETTING: Outpatient fluoroscopic suite and laboratory.
METHODS: Twenty-one 100 mL 300 mg(iodine)/mL iohexol injection bottles, after one clinical use, were tested after the first and last withdrawals (withdrawal one and withdrawal 9 or 10) for bacterial and fungal specimens using culture media and 3Mâ„¢ Petrifilmsâ„¢. To determine the ability of methicillin-susceptible Staphylococcus aureus (MSSA) to survive or grow in the media, MSSA was added to different concentrations (0, 25, 50, 75, and 100%) of iohexol contrast media.
RESULTS: There was no growth observed in cultures or on Petrifilms among the first and last draws of any of the samples. When bacteria were grown in different dilutions of the media, there was a significant, approximately one log decrease in counts from 0% contrast media to 100% contrast media (8.4 x 108 vs 5.6 x 107, P \u3c 0.01).
LIMITATIONS: Our study is limited in the number of samples tested and would benefit from additional investigation before consideration of clinical application.
CONCLUSIONS: Our results suggest that single-use 300 iohexol bottles may be reusable and that the contrast media is mildly antimicrobial, but not enough to retard contamination. In setting of shortages, contrast media bottles can safely be reused. This is valuable for conserving resources and limiting unnecessary health care-associated costs
Regional zircon U-Pb geochronology for the Maniitsoq region, southwest Greenland
The Ministry of Mineral Resources, Government of Greenland, funded this project. Analyses in the JdLC GeoHistory Facility were enabled by instrumentation supported by AuScope (auscope.org.au) and the Australian Government via the National Collaborative Research Infrastructure Strategy. The Tescan Mira3 FEG-SEM was funded through the Australian Research Council LIEF program.Zircon U-Pb geochronology places high-temperature geological events into temporal context. Here, we present a comprehensive zircon U-Pb geochronology dataset for the Meso- to Neoarchean Maniitsoq region in southwest Greenland, which includes the Akia Terrane, Tuno Terrane, and the intervening Alanngua Complex. The magmatic and metamorphic processes recorded in these terranes straddle a key change-point in early Earth geodynamics. This dataset comprises zircon U-Pb ages for 121 samples, including 46 that are newly dated. A principal crystallization peak occurs across all three terranes at ca. 3000 Ma, with subordinate crystallization age peaks at 3200 Ma (Akia Terrane and Alanngua Complex only), 2720 Ma and 2540 Ma. Metamorphic age peaks occur at 2990 Ma, 2820-2700 Ma, 2670-2600 Ma and 2540 Ma. Except for one sample, all dated metamorphic zircon growth after the Neoarchean occurred in the Alanngua Complex or within 20 km of its boundaries. This U-Pb dataset provides an important resource for addressing Earth Science topics as diverse as crustal evolution, fluid-rock interaction and mineral deposit genesis.Publisher PDFPeer reviewe
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