13,199 research outputs found

    Photoelectrochemical Detection of Dengue-Related Oligonucleotide Sequence Using Anthocyanin as an Intercalating Agent and Electrochromic Material

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    World Health Organization (WHO) presupposes a confirmation of dengue virus infection diagnosis with two criteria, i.e. clinical and laboratory criteria. One of the basic methods used by most laboratories to diagnose dengue virus is to detect oligonucleotide sequence using a DNA amplification technique. In this research, the measurement of denguerelated oligonucleotide was conducted by photoelectrochemical method. The presence of oligonucleotide sequence in target DNA can be detected by DNA probe that is immobilized on TiO2 electrode. The DNA hybrid is then bound to electrochromic substance like anthocyanin that generates current when it is subjected to light. The photocurrent is directly proportional to the number of target DNA. The aim of this research is to obtain photoelectrochemical system that has sensitivity and high responsiveness toward the change in oligonucleotide concentration, especially the applicability of anthocyanin as a electrochromic substance and intercalating agent. Linearity (R2) generated from the change of current in response to concentration changes of target DNA (in the concentration range of 0.75–3.00 nM) is 0.9611. Thus, this method has the potential to be developed to detect the presence of dengue virus in biological sample

    One-loop contributions of charginos and neutralinos to W-pair production in E+ E- collisions

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    We study the one-loop effects of charginos and neutralinos on the helicity amplitudes for \eeww in the minimal supersymmetric standard model. The calculation is tested by using two methods. First, the sum rule for the form factors between \eeww and the process where the external W±W^\pm bosons are replaced by the corresponding Goldstone bosons ω±\omega^\pm is employed to test the analytic expression and the accuracy of the numerical program. Second, the decoupling property in the large mass limit is used to test the overall normalization of the amplitudes. These two tests are most effectively carried out when the amplitudes are expanded in terms of the modified minimal subtraction (MSˉ\bar{\rm MS}) couplings of the standard model. The resulting perturbation expansion is valid at collider energies below and around the threshold of the light supersymmetric particles. We find that the corrections to the cross section of the longitudinally polarized WW-pair production can be as large as -1.4% at the threshold of the light chargino-pair production for large scattering angles. We also study the effects of the CP-violating phase in the chargino and neutralino sectors on the helicity amplitudes. We find that the resulting CP-violating asymmetries can be at most 0.1%.Comment: 30 pages, 25 figures, Final verision, To appear in Physical Review D, Several sentences are improve

    Detecting informal buildings from high resolution quickbird satellite image, an application for insitu [sic.] upgrading of informal setellement [sic.] for Manzese area - Dar es Salaam, Tanzania.

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    Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.Documentation and formalization of informal settlements ("insitu" i.e. while people continue to live in the settlement) needs appropriate mapping and registration system of real property that can finally lead into integrating an informal city to the formal city. For many years extraction of geospatial data for informal settlement upgrading have been through the use of conventional mapping, which included manual plotting from aerial photographs and the use of classical surveying methods that has proved to be slow because of manual operation, very expensive, and requires well-trained personnel. The use of high-resolution satellite image like QuickBird and GIS tools has recently been gaining popularity to various aspects of urban mapping and planning, thereby opening-up new opportunities for efficient management of rapidly changing environment of informal settlements. This study was based on Manzese informal area in the city of Dar es salaam, Tanzania for which the Ministry of Lands and Human Settlement Development is committed at developing strategic information and decision making tools for upgrading informal areas using digital database, Orthophotos and Quickbird satellite image. A simple prototype approach developed in this study, that is, 'automatic detection and extraction of informal buildings and other urban features', is envisaged to simplify and speedup the process of land cover mapping that can be used by various governmental and private segments in our society. The proposed method, first tests the utility of high resolution QuickBird satellite image to classify the detailed 11 classes of informal buildings and other urban features using different image classification methods like the Box, maximum likelihood and minimum distance classifier, followed by segmentation and finally editing of feature outlines. The overall mapping accuracy achieved for detailed classification of urban land cover was 83%. The output demonstrates the potential application of the proposed approach for urban feature extraction and updating. The study constrains and recommendations for future work are also discussed

    Classification of Several Skin Cancer Types Based on Autofluorescence Intensity of Visible Light to Near Infrared Ratio

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    Skin cancer is a Malignant growth on the skin caused by many factors. The most common skin cancers are Basal Cell Cancer (BCC) and Squamous Cell Cancer (SCC). This research uses a discriminant analysis to classify some tissues of skin cancer based on criterion number of independent variables. An independent variable is variation of excitation light sources (LED lamp), filters, and sensors to measure autofluorescence intensity (IAF) of visible light to near infrared (VIS/NIR) ratio of paraffin embedded tissue biopsy from BCC, SCC, and Lipoma. From the result of discriminant analysis, it is known that the discriminant function is determined by 4 (four) independent variables i.e., blue LED-red filter, blue LED-yellow filter, UV LED-blue filter, and UV LED-yellow filter. The accuracy of discriminant in classifying the analysis of three skin cancer tissues is 100%

    Bitcoin Price Prediction Using Machine Learning Techniques

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    This paper discusses, trying to accurately assess the price of Bitcoin by looking at differ-ent parameters affects the value of Bitcoin. In our work, we focus on understanding and seeing the evolution of Bitcoin daily market, a1 and gaining intuition in the most rele-vant aspects surrounding the Bitcoin price. In the meantime, market capitalization of publicly traded cryptocurrencies exceeds $ 230 billion. The most important cryptocur-rency, Bitcoin, is used primarily as a digital value store, and its pricing opportunities have been extensively considered. These features are described in more detail in the fol-lowing paragraph: details of the main Bitcoin, as described in the paper. Bitcoin is the most expensive digital currency in the market. However, Bitcoin prices have been highly volatile, making it difficult to forecast. As a result, the goal of this research is to find the most efficient and accurate model for predicting Bitcoin prices using various machine learning algorithms. Several regression models with scikit-learn and Keras libraries were tested using 1-minute interval trading data from the Bitcoin exchange website bit stamp from January 1. 2012 to January 8, 2018. The best results showed a Mean Squared Error (MSE) as low as 0.00002 and an R- Square (R2) as high as 99.2 percent

    On the EDM Cancellations in D-brane models

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    We analyze the possibility of simultaneous electron, neutron, and mercury electric dipole moment (EDM) cancellations in the mSUGRA and D--brane models. We find that the mercury EDM constraint practically rules out the cancellation scenario in D-brane models whereas in the context of mSUGRA it is still allowed with some fine-tuning.Comment: 10 pages, to appear in Phys. Rev. Let

    The Electric Dipole Moment and CP Violation in B→Xsl+l−B \to X_s l^+ l^- in SUGRA Models with Nonuniversal Gaugino Masses

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    The constraints of electric dipole moments (EDMs) of electron and neutron on the parameter space in supergravity (SUGRA) models with nonuniversal gaugino masses are analyzed. It is shown that with a light sparticle spectrum, the sufficient cancellations in the calculation of EDMs can happen for all phases being order of one in the small tanβ\beta case and all phases but ϕμ\phi_{\mu} (∣ϕμ∣<∼π/6|\phi_{\mu}| <\sim \pi/6) order of one in the large tanβ\beta case. This is in contrast to the case of mSUGRA in which in the parameter space where cancellations among various SUSY contributions to EDMs happen ∣ϕμ∣|\phi_{\mu}| must be less than π/10\pi/10 for small tanβtan\beta and O(10−2){\cal{O}}(10^{-2}) for large tanβtan\beta. Direct CP asymmetries and the T-odd polarization of lepton in B→Xsl+l−B\to X_s l^+l^- are investigated in the models. In the large tanβ\beta case, ACP2A_{CP}^2 and PNP_N for l=μ\mu (τ\tau) can be enhanced by about a factor of ten (ten) and ten (three) respectively compared to those of mSUGRA.Comment: 12 pages, latex, 4 figures, a few change

    Performance of metakaolin based geopolymer concrete at elevated temperature

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    Due to the carbon dioxide emission arising from the production of cement, alternative concrete that is environmentally friendly such as metakaolin geopolymer concrete have been developed. However, the performance of metakaolin based geopolymer concrete (MKGC) when exposed to aggressive environment particularly elevated temperature has not been investigated. Therefore, this paper assessed the performance of MKGC exposed to elevated temperatures. MKGC cube specimens of grade 25 were produced using a mix ratio of 1:1.58:3.71.After preparing the specimens, they were placed in an electric oven at a temperature of 60oC for 24 hours. Thereafter, the specimens were stored in the laboratory at ambient temperature for 28 days. The specimens were then exposed to elevated temperatures of 200, 400, 600 and 800oC. After exposure to elevated temperatures, the MKGC specimens were subjected to compressive strength, water absorption and abrasion resistance tests. Results show that at 600 and 800oC, the MKGC lost a compressive strength of 59.69% and 71.71% respectively. Higher water absorption and lower abrasion resistance were also observed. Keywords: Cement, Compressive Strength, Metakaolin Concrete, Elevated Temperature
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