572 research outputs found

    M-ary Coded Mouldation Assisted Genetic Algorithm Based Multiuser Detection for CDMA Systems

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    In this contribution we propose a novel M-ary Coded Modulation assisted Genetic Algorithm based Multiuser Detection (CM-GA-MUD) scheme for synchronous CDMA systems. The performance of the proposed scheme was investigated using Quadrature-Phase-Shift-Keying (QPSK), 8-level PSK (8PSK) and 16-level Quadrature Amplitude Modulation (16QAM) when communicating over AWGN and narrowband Rayleigh fading channels. When compared with the optimum MUD scheme, the GAMUD subsystem is capable of reducing the computational complexity significantly. On the other hand, the CM subsystem is capable of obtaining considerable coding gains despite being fed with sub-optimal information provided by the GA-MUD output

    Virtual objects in electronic catalogs: A human-computer interface issue

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    Web interface design is an important aspect of electronic commerce (EC). However, apart from design frameworks and guidelines for Web-based EC, not much has been done by researchers or practitioners on how electronic catalogs (e-catalogs) influence the users' desirability and satisfaction as purchasers. In this correspondence, we investigate the form of media that represented the most efficient mode to present products to Web users by summarizing and evaluating various existing forms of e-catalogs and their respective responses from Web users. We conclude that a 3-D virtual object (VO) is the most efficient mode of electronic cataloging for Web interface due to a better sense of presence of users, a more attractive and enjoyable media of delivery of useful information to users, and a higher level of engagement of user's memory. A 3-D VO, as a result, generates the highest users' satisfaction, which leads to increased propensity to purchase. Further, we discuss the practical and theoretical research implications of these findings to e-catalogs. © 2007 IEEE.published_or_final_versio

    Gracilaria changii (Rhodophyta) alleviates bisphenol A-induced adverse reproductive abnormalities in mice

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    Objective: To evaluate the potential of Gracilaria changii extract in ameliorating the potential adverse effects of bisphenol A. Methods: The antioxidant capacity of Gracilaria changii extracted using different solvents (methanol, ethanol, and aqueous) was studied. The mice were administered by oral gavage with bisphenol A (60 mg/kg body weight) for 6 weeks with or without Gracilaria changii aqueous extract. Thereafter, the mice were either euthanized for histology and immunohistochemistry studies or mated to evaluate the pregnancy rate. Results: Gracilaria changii aqueous extract showed the highest antioxidant properties compared with extract using methanol and ethanol. The aqueous extract of Gracilaria changii improved the uterus index and uterine lipid peroxidation after bisphenol A exposure, although the uterine expressions of estrogen receptors and complement C3 were not improved. Histological evaluation of the uterus during the estrus stage has revealed that the extract could mitigate bisphenol A-induced adverse effects in the uterus as there was a lower percentage of mice showing abnormalities like decreased eosin staining in the myometrium, and decrease in the number of eosinophil and endometrial glands in the endometrium. Besides, Gracilaria changii aqueous extract improved the pregnancy rate of mice administered with bisphenol A. Conclusions: Gracilaria changii extract protects against bisphenol A-induced female reproductive abnormalities in mice which may be mediated via modulation of eosinophil migration, endometrial gland formation, and protein expressions associated with prostaglandins in the myometrium

    Influence of Salinity of Mixing Water Towards Physical and Mechanical Properties of High Strength Concrete

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    Dramatic population and economic growth result in increasing demand for concrete infrastructure, which leads to an increment of freshwater demand and a reduction of freshwater resources. however, freshwater is a finite resource, which means that freshwater will be used up someday in the future when freshwater demand keeps increasing while freshwater resources are limited. therefore, replacing freshwater with seawater in concrete blending seems potentially beneficial for maintaining the freshwater resources as well as advantageous alternatives to the construction work near the sea. there have been few experimental research on the effect of blending water salt content on the mechanical and physical characteristics of concrete, particularly high-strength concrete. therefore, a research study on the influence of salt concentration of blending water on the physical and mechanical properties of high-strength concrete is necessary. this study covered the blending water salinity, which varied from 17.5 g/l to 52.5 g/l and was determined on the physical and mechanical properties, including workability, density, compressive strength, and flexural strength. the test results indicate that the use of sea salt in blending water had a slight negative influence on both the workability and the density of high strength concrete. it also indicates that the use of sea salt in blending water had a positive influence on both the compressive strength and the flexural strength of high-strength concrete in an earlystage

    First detection of a Vssc allele V1016G conferring a high level of insecticide resistance in Aedes albopictus collected from Europe (Italy) and Asia (Vietnam), 2016. A new emerging threat to controlling arboviral diseases

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    Introduction Aedes albopictus (Skuse) is an important vector of arboviral diseases, including dengue, chikungunya and Zika virus disease. Monitoring insecticide resistance and mechanisms by which the mosquito develops resistance is crucial to minimise disease transmission. Aim To determine insecticide resistance status and mechanisms in Ae. albopictus from different geographical regions. Methods We sampled 33 populations of Ae. albopictus from Asia, Europe and South America, and tested these for susceptibility to permethrin, a pyrethroid insecticide. In resistant populations, the target site for pyrethroids, a voltage-sensitive sodium channel (Vssc) was genotyped. Three resistant sub-strains, each harbouring a resistance allele homozygously, were established and susceptibilities to three different pyrethroids (with and without a cytochrome P450 inhibitor) were assayed. Results Most populations of Ae. albopictus tested were highly susceptible to permethrin but a few from Italy and Vietnam (4/33), exhibited high-level resistance. Genotyping studies detected a knockdown resistance (kdr) allele V1016G in Vssc for the first time in Ae. albopictus. Two previously reported kdr alleles, F1534C and F1534S, were also detected. The bioassays indicated that the strain homozygous for the V1016G allele showed much greater levels of pyrethroid resistance than other strains harbouring F1534C or F1534S. Conclusion The V1016G allele was detected in bothAsian and Italian Ae. albopictus populations, thus a spread of this allele beyond Italy in Europe cannot be ruled out. This study emphasises the necessity to frequently and regularly monitor the V1016G allele in Ae. albopictus, particularly where this mosquito species is the main vector of arboviruses

    Broad Surveys of DNA Viral Diversity Obtained through Viral Metagenomics of Mosquitoes

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    Viruses are the most abundant and diverse genetic entities on Earth; however, broad surveys of viral diversity are hindered by the lack of a universal assay for viruses and the inability to sample a sufficient number of individual hosts. This study utilized vector-enabled metagenomics (VEM) to provide a snapshot of the diversity of DNA viruses present in three mosquito samples from San Diego, California. The majority of the sequences were novel, suggesting that the viral community in mosquitoes, as well as the animal and plant hosts they feed on, is highly diverse and largely uncharacterized. Each mosquito sample contained a distinct viral community. The mosquito viromes contained sequences related to a broad range of animal, plant, insect and bacterial viruses. Animal viruses identified included anelloviruses, circoviruses, herpesviruses, poxviruses, and papillomaviruses, which mosquitoes may have obtained from vertebrate hosts during blood feeding. Notably, sequences related to human papillomaviruses were identified in one of the mosquito samples. Sequences similar to plant viruses were identified in all mosquito viromes, which were potentially acquired through feeding on plant nectar. Numerous bacteriophages and insect viruses were also detected, including a novel densovirus likely infecting Culex erythrothorax. Through sampling insect vectors, VEM enables broad survey of viral diversity and has significantly increased our knowledge of the DNA viruses present in mosquitoes

    Socio-demographic and health-related factors associated with cognitive impairment in the elderly in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Cognitive impairment is an age-related condition as the rate of cognitive decline rapidly increases with aging. It is especially important to better understand factors involving in cognitive decline for the countries where the older population is growing rapidly. The aim of this study was to examine the association between socio-demographic and health-related factors and cognitive impairment in the elderly in Taiwan.</p> <p>Methods</p> <p>We analysed data from 2119 persons aged 65 years and over who participated in the 2005 National Health Interview Survey. Cognitive impairment was defined as having the score of the Mini Mental State Examination lower than 24. The χ<sup>2 </sup>test and multiple logistic regression models were used to evaluate the association between cognitive impairment and variables of socio-demography, chronic diseases, geriatric conditions, lifestyle, and dietary factors.</p> <p>Results</p> <p>The prevalence of cognitive impairment was 22.2%. Results of multivariate analysis indicated that low education, being single, low social support, lower lipid level, history of stroke, physical inactivity, non-coffee drinking and poor physical function were associated with a higher risk of cognitive impairment.</p> <p>Conclusion</p> <p>Most of the characteristics in relation to cognitive impairment identified in our analysis are potentially modifiable. These results suggest that improving lifestyle behaviours such as regular exercise and increased social participation could help prevent or decrease the risk of cognitive impairment. Further investigations using longitudinal data are needed to clarify our findings.</p
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