1,658 research outputs found

    Curie Temperature of Diluted Magnetic Semiconductors: the Influence of the Antiferromagnetic Exchange Interaction

    Get PDF
    The coherent potential approximation and mean field approximation are used to calculate the free energy of the coupled carrier – localized spin system in III-V diluted magnetic semiconductors. Thus the magnetic transition temperature Tc can be determined and its dependence on important model parameters. We show that the strong antiferromagnetic superexchange interaction between nearest neighbour sites considerably reduces the Curie temperature

    ofw: An R package to select continuous variables for multiclass classification with a stochastic wrapper method

    Get PDF
    When dealing with high dimensional and low sample size data, feature selection is often needed to help reduce the dimension of the variable space while optimizing the classification task. Few tools exist for selecting variables in such data sets, especially when classes are numerous ( > 2). We have developed ofw, an R package that implements, in the context of classification, the meta algorithm "optimal feature weighting". We focus on microarray data, although the method can be applied to any p >> n problems with continuous variables. The aim is to select relevant variables and to numerically evaluate the resulting variable selection. Two versions are proposed with the application of supervised multiclass classifiers such as classification and regression trees and support vector machines. Furthermore, a weighted approach can be chosen to deal with unbalanced multiclasses, a common characteristic in microarray data sets

    Medium Resolution Near-Infrared Spectra of the Host Galaxies of Nearby Quasars

    Full text link
    We present medium resolution near-infrared host galaxy spectra of low redshift quasars, PG 0844 + 349 (z=0.064), PG 1226 + 023 (z=0.158), and PG 1426+015 (z=0.086). The observations were done by using the Infrared Camera and Spectrograph (IRCS) at the Subaru 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by operations of an adaptive optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. We spent up to several hours per target and developed data reduction methods to reduce the systematic noises of the telluric emissions and absorptions. From the obtained spectra, we identified absorption features of Mg I (1.503 um), Si I (1.589 um) and CO (6-3) (1.619 um), and measured the velocity dispersions of PG 0844 + 349 to be 132+/-110 km s-1 and PG 1426 + 015 to be 264+/-215 km s-1. By using an M_BH-sigma relation of elliptical galaxies, we derived the black hole (BH) mass of PG 0844+349, log(M_BH/M_SUN) = 7.7+/-5.5 and PG 1426+015, log(M_BH/M_SUN) = 9.0+/-7.5. These values are consistent with the BH mass values from broad emission lines with an assumption of a virial factor of 5.5.Comment: 16 pages, 5 figure

    Determination of the Administration Routes, Doses and Appropriate Age to Vaccinate With Ornitin Triple Vaccine For Cross-breed Colored Broilers in Vietnam

    Get PDF
    The study was to determine the appropriate dose and administration route of Ornitin Triple vaccine in cross-breed coloured broilers in Vietnam by evaluating the antibody titer against Ornithobacterium rhinotracheale (ORT) and local reactions at injection sites on chickens after vaccination. The study was divided into 2 trials. Both trials were designed with 3 vaccine dose groups: 0.0ml (control group), 0.25ml and 0.5ml and 2 different administration routes: subcutaneous at neck (SC) and intramuscular at breast (IM) injection. The result showed that, no statistically significant difference was found between antibody titer of two administration routes as well as 2 vaccine doses until 13-week-old. Local reactions at the injection sites of IM route was less severe than SC at neck and in higher dose would produce a more severe swelling reaction. Daily weight gain was found to have a slight decrease in the vaccinated groups within 2 weeks after vaccination, however, no statistically significant difference was found in later stage (P > 0.05). In conclusion, Ornitin Triple can be used to vaccinate by IM with the dose of 0.25ml for coloured broilers at early age (3-week-old), or 0.5ml for older birds and should be careful for some reactions at the injection sites

    First workshop of the Asian Network for Environment and Energy: Event report

    Get PDF
    Asia is one of the most densely populated areas in the world. Many Asian countries experienced strong economic growth and rapid urbanization in the last decade. However, Asia is also faced with the challenge of environmental protection, energy security and CO2 emissions. The purpose of establishment of the Asian Network for Environment and Energy (ANEE) is to connect the re-search and training institutions, facilitate the exchange of experience and know-how, and initiating joint projects on environmental protection and renewable energy. The network organizes annual scientific conferences, develops projects addressing environmental problems of the region, and builds personnel training programs for renewable energy and environment. The first ANEE workshop held in Ho Chi Minh City is the launching event the network addressing air pollution, water management, solid waste and energy.Châu Á là một trong những khu vực đông dân nhất trên thế giới. Nhiều quốc gia tại châu Á đã có sự phát triển kinh tế mạnh mẽ và đô thị hóa rất nhanh trong thập kỷ vừa qua. Tuy nhiên, khu vực châu Á cũng đối mặt với các thách thức về bảo vệ môi trường, phát thải CO2 và an ninh năng lượng. Mục đích thành lập Mạng lưới châu Á về Môi trường và Năng lượng (ANEE) nhằm kết nối các tổ chức nghiên cứu và đào tạo, tạo điều kiện cho trao đổi kinh nghiệm và know-how, xây dựng các dự án tổng thể về bảo vệ môi trường và năng lượng tái tạo. Mạng lưới tổ chức các Hội thảo khoa học hàng năm, phát triển các dự án giải quyết các vấn đề môi trường thời sự của khu vực, xây dựng các chương trình đào tạo nhân lực ngành môi trường và năng lượng tái tạo. Hội thảo lần thứ nhất của ANEE được tổ chức tại Tp.Hồ Chí Minh là sự kiện khởi động Mạng lưới với các chuyên đề về Ô nhiễm không khí, Quản lý nguồn nước, chất thải rắn và năng lượng

    ERRATUM

    Get PDF
    ERRATU

    Biosynthesis of silver nanoparticles using curcumin against the bovine mastitis bacteria

    Get PDF
    Bovine mastitis is the most common disease and has greatly affected economies around the world. This study aimed to determine the antibacterial ability of bovine mastitis by curcumin - silver nanoparticles (Cur-AgNPs). The study included experiments on presenting a new process for synthesizing silver nanoparticles using curcumin from fresh turmeric as a reducing agent and stabilizer. UV visible spectroscopy of the samples revealed the localized surface plasmon resonance absorbance of the dispersion of silver nanoparticles at 430 nm. The prepared Cur-AgNPs has a spherical shape with an average size of 30 nm and a size distribution of 15–47 nm. FT-IR (Fourier transform infrared spectroscopy) measurements of the samples showed that silver nanopartilces has been encapsulated well by curcumin. Cur-AgNPs with a concentration of 50-200 μg/mL has very effect to Staphylococcus aureus, Pseudomonas aeruginosa causing bovine mastitis in vitro. The maximum inhibition zone formed was 15 ± 0.85 mm for Staphylococcus aureus and 14 ± 0.56 mm for Pseudomonas aeruginosa. Plant materials mediating for the synthesis of silver nanoparticles have relatively rapid, less expensive, and widespread applications for antimicrobial therapy in the livestock sector

    A Novel Magnetic Actuation Scheme to Disaggregate Nanoparticles and Enhance Passage across the Blood–Brain Barrier

    Get PDF
    The blood–brain barrier (BBB) hinders drug delivery to the brain. Despite various efforts to develop preprogramed actuation schemes for magnetic drug delivery, the unmodeled aggregation phenomenon limits drug delivery performance. This paper proposes a novel scheme with an aggregation model for a feed-forward magnetic actuation design. A simulation platform for aggregated particle delivery is developed and an actuation scheme is proposed to deliver aggregated magnetic nanoparticles (MNPs) using a discontinuous asymmetrical magnetic actuation. The experimental results with a Y-shaped channel indicated the success of the proposed scheme in steering and disaggregation. The delivery performance of the developed scheme was examined using a realistic, three-dimensional (3D) vessel simulation. Furthermore, the proposed scheme enhanced the transport and uptake of MNPs across the BBB in mice. The scheme presented here facilitates the passage of particles across the BBB to the brain using an electromagnetic actuation scheme

    China's Angel Investment Policy

    Get PDF
    Purpose: This paper summarized and systematized the case of China's policies applied to attract angel investment which turned this country into a global highlight in angel investment.   Theoretical framework: The authors conducted a literature review on start-up and angel investment to introduce angel investment in China, analyze the role of angel investments in developing start-ups, and factor determinants and policy of angel investment in China.   Design/Methodology/Approach: This paper uses qualitative method to provide overviews on the case of China in attracting angel investment for their start-ups with an updated analysis on their relevant factor determinants and policies that contributed to the success of China.   Findings: It is found that the Chinese Government has actively carried out packages, including tax incentives, built programs, investment cooperation funds, developed networks, and angel investment education systems to boost funding readiness for firms. They also focus on promoting the start-up ecosystem and providing financial support to implement an innovation-driven development strategy to raise the nation's competitiveness.   Research, practical & social implications: This paper provides some suggestions for Chinese government in making policies to enhance the role of angel investments in developing start-ups.   Originality/Value: This paper contributes to the evolvement of research about start- up and angel investment, particularly in China, in the context of high-tech  production and breakthrough technologies, by providing a policy perspective to imply lessons for other countries
    corecore