7,619 research outputs found

    Physical Multi-Layer Phantoms for Intra-Body Communications

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    This paper presents approaches to creating tissue mimicking materials that can be used as phantoms for evaluating the performance of Body Area Networks (BAN). The main goal of the paper is to describe a methodology to create a repeatable experimental BAN platform that can be customized depending on the BAN scenario under test. Comparisons between different material compositions and percentages are shown, along with the resulting electrical properties of each mixture over the frequency range of interest for intra-body communications; 100 KHz to 100 MHz. Test results on a composite multi-layer sample are presented confirming the efficacy of the proposed methodology. To date, this is the first paper that provides guidance on how to decide on concentration levels of ingredients, depending on the exact frequency range of operation, and the desired matched electrical characteristics (conductivity vs. permittivity), to create multi-layer phantoms for intra-body communication applications

    Neuro-Protection and Neuro-Therapy Effects of Acalypha Indica Linn. Water Extract Ex Vivo on Musculus Gastrocnemius Frog

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    The studies of neuro-protection and neuro-therapy effects of Acalypha indica Linn. water extract ex vivo on Musculus gastrocnemius frog have already done at three Departments in Faculty of Medicine, University of Indonesia. The experimental studies were done on 2 groups of frog for neuro-protection and neuro-therapy effects. Each group of frog was divided into 7 subgroups of application, 4 samples each. There were 5 subgroups of doses: 5; 10; 15; 20; 25 mg and 2 subgroups as control. Pancuronium bromide 0.2%, 4 mg, was used for a positive control as muscle relaxant. Neuro-protection study was done as follow: ringer – extract – pancuronium bromide, and neuro-therapy study was ringer – pancuronium bromide – extract, respectively. The parameters measured in these studies were the electrical activities such as amount and duration (second) of re-polarization; depolarization, resting potential, and the height of spike after electrical stimulation at 5 mV. Neuro-protection effect of extract was determined by the ability of muscle to show the electrical response after incubating with pancuronium bromide for 10 minutes, and after incubating with extract for 10 minutes for neuro-therapy effect. In the dose of 15 mg and 20 mg/mL of A. indica Linn. extract showed better activities than the dose of 25 mg of extract, both as neuro-protection and neuro-therapy effects, but statistically its have not a significant difference. This study should be followed by an in vivo experiment on frog and it would be done in pharmacokinetic and pharmacodynamic studies on other animal models

    Large evolution of the bilinear Higgs coupling parameter in SUSY models and reduction of phase sensitivity

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    The phases in a generic low-energy supersymmetric model are severely constrained by the experimental upper bounds on the electric dipole moments of the electron and the neutron. Coupled with the requirement of radiative electroweak symmetry breaking, this results in a large degree of fine tuning of the phase parameters at the unification scale. In supergravity type models, this corresponds to very highly tuned values for the phases of the bilinear Higgs coupling parameter BB and the universal trilinear coupling A0A_0. We identify a cancellation/enhancement mechanism associated with the renormalization group evolution of BB, which, in turn, reduces such fine-tuning quite appreciably without taking recourse to very large masses for the supersymmetric partners. We find a significant amount of reduction of this fine-tuning in nonuniversal gaugino mass models that do not introduce any new phases.Comment: Version to appear in Phys.Rev.D. Insignificant changes like a few typos corrected. 26 pages, 7 figures, LaTe

    Gamma Ray Assessment of Subsurface water-Rock interaction in Abuja from Geologic Background and Its Effect in Groundwater, Nigeria (Review Article)

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    The radiometric interpretation of geologic data is aimed at mapping the concentration of Uranium, Thorium and Potassium and its effect in groundwater in subsurface rock formations. The water has been consumed without treatment and during drilling, the process cut across so many rock formations. The Uranium and Thorium exist in this rock formation like granite to some extent which could contaminate the groundwater system through leaching and weathering process. This study is to address the issue by determining the concentration of uranium, Thorium and potassium in the water-rock interface. The mean dose equivalent for rock samples will be obtained and determine the health implications or adverse effect on the populace and the environment. The methodology will include drilling of boreholes measuring 40m, 50m, 60m and 70m in depth using 30ton capacity Rig machine. Samples obtained during cutting and coring will be analyzed using High Resolution Gamma Spectroscopy. From the 3D model, it indicates the linear relationship in water-rock lithologic structure. The linear relationship between unit volume of granite, hydraulic gradient and hydraulic conductivity is inferred to be the effect of tectonic activity during Pan African Orogeny in Nigeria. Keywords: Geologic Map of Abuja, 3D Model of (hydraulic conductivity; Unit Volume of Granite and hydraulic gradient

    Assessing the prevalence of refractive errors and accuracy of vision screening by schoolteachers in Liberia

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    Background Evidence indicates that school-based vision screening by trained teachers is an effective way of identifying and addressing potential vision problems in schoolchildren. However, inconsistencies have been reported in both the testing methods and accuracy of the screeners. This study assessed the prevalence of refractive errors and accuracy of screening by teachers in Grand Kru County, Liberia. Methods We conducted a retrospective analysis of data from four schools where, in February 2019, children were screened for refractive errors by trained teachers and then re-examined by ophthalmic technicians. One row of five optotypes of the Snellen 6/9 (0.2 logMar) scale (tumbling E chart) was used at a distance of 3 m. The prevalence of visual impairment and associations with sex, age and school were explored. Sensitivity, specificity and predictive values were calculated. Results Data were available for 823 of 1095 eligible children with a mean age of 13.7 y (range 5–18) and male:female ratio of 1:0.8. Poor vision was identified in 24 (2.9%) children with no differences by either sex or age but small differences by school. Screening by teachers had a sensitivity of 0.25 (95% confidence interval [CI] 0.077 to 0.423) and a specificity of 0.996 (95% CI 0.992 to 1.000). Positive and negative predictive values were 0.667 (95% CI 0.359 to 0.975) and 0.978 (95% CI 0.968 to 0.988), respectively. The results were influenced by a high number of misclassifications in one of the four schools. Conclusions Teachers can be trained to conduct vision screening tests on schoolchildren to an acceptable level of accuracy, but strong monitoring and quality assurance systems should be built into screening programmes from the onset. In settings like Liberia, where many children do not attend school regularly, screening programmes should extend to community platforms to reach children out of school

    Tyrosine kinase inhibitors for the therapy of anaplastic thyroid cancer

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    Anaplastic thyroid cancer (ATC) is often incurable so new therapeutic approaches are needed. Tyrosine kinases inhibitors (such as imanitib, sunitinib or sorafenib) are under evaluation for the treatment of ATC. Other vascular disrupting agents, such as combretastatin A4 phosphate, and antiangiogenic agents, such as aplidin, PTK787/ZK222584 and human VEGF monoclonal antibodies (bevacizumab, cetuximab), have been evaluated. Small-molecule adenosine triphosphate competitive inhibitors directed intracellularly at EGFRs tyrosine kinase, such as erlotinib or gefitinib, are also studied. Furthermore, new molecules have been shown to be active against ATC, such as CLM94 and CLM3. However, more research is needed to finally identify therapies able to control and to cure this disease

    Design of a Wastewater Treatment Oxidation Pond

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    The proposed site of the wastewater treatment pond is located in a terrain inside the Polytechnic Campus and the New Staff Quarters where the storm-runoff flow has on effect. The site possesses good soil characteristics which include a particle size distribution of sandy soil with little fine particles of gravel, a specific gravity of 2.77 and a soil moisture content of 7.26% indicating a high degree of permeability. The output of geotechnical analysis indicated that the proposed site has soil particle density (ρs) and dry bulk density (ρb) of 1.76 g/cm3 and 1.64g/cm3 respectively. Void ratio (e), porosity (ȵ) values of 0.87 and 0.46 (46%) were determined. The atterbergs limits of 19.0%, 14.96% and 19.6% for shrinkage limit (SL), plastic limit (PL) and liquid limit (LL) were estimated with a computed plastic index (PI) of 3.04. The soil profile formation is highly sandy with a good lateritic layer to support the pond foundation. The proposed pond design volume (V) is 898.5 m3 and land areas of 718.8 m2 were estimated for the project
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