143 research outputs found

    E-Commerce Adoption and Acceptance by Firms: Exploratory Study

    Get PDF
    This study attempts to explore the internal and external factors affecting the adoption and acceptance of e-commerce by businesses in developing countries. It provides an exploratory analysis of surveying 524 firms in Abu Dhabi. In an attempt to specify the factors that encourage/deter e-commerce adoption by businesses, 14 factors (8 internal and 6 external) were surveyed. The results indicated that most of the firms were either at the first or second stage on the e-commerce 5-stage adoption ladder. This indicated that the e-commerce adoption is not matching and far less than the IT readiness of both the firms and the country

    Latent effect of gamma irradiation on reproductive potential and ultrastructure of males' testes of Culex pipiens (Diptera; Culicidae)

    Get PDF
    AbstractLaboratory male pupae of Culex pipiens were exposed to 23, 41, 74 and 128 Gy doses of gamma radiation according to the LD25, LD50, LD75 and LD90 calculation, respectively. The inherited deleterious effects of gamma radiation were observed in the F1, F2 and F3 generations. Levels of sterility index in the F1 and F2 were higher than those of untreated control but in the F3 generation there was a semi-sterility compared with the control. Ultrastructure of normal males' testes of C. pipiens was studied using transmission electron microscopy. Histopathological responses were observed in the irradiated testes of C. pipiens. Gamma radiation had greatly affected the testes, such as (i) rupture, necrosis, degeneration and small vacuoles were reported in the testicular wall (ii) an abnormal distribution of the developmental stages of spermatogonia and spermatocytes leading to a general decrease in the rate of spermatogenesis; and (iii) deformity of sperm inhibitting the movements and the fertility of the sperm led to the decrease in the reproductive potential of C. pipiens. Consequently, these radiation doses are consistent with those used in the already established Sterile Insect Technique (SIT) programmes against Culex pipiens

    BIOPROCESIRANJE PRIRODNE FOSFATNE RUDE BAKTERIJOM STAPHYLOCOCCUS AUREUS

    Get PDF
    Phosphate ores are in high demand around the world because they are the primary raw materials used in the manufacturing of phosphatic fertilizers and other chemicals. Since the grade of the ore is gradually declining, it is becoming economically viable to mine and beneficiate numerous lower-grade deposits, and a significant number of precious minerals are discarded due to the inadequacy of new technological advances. Thus, biological processes are becoming more appealing in mineral processing due to their lower operating costs and potential applications to beneficiate low-grade complex ores through the interaction of bacteria and mineral surfaces, resulting in surface modification and mineral separation via bio-flotation. Staphylococcus aureus was supplied by the mineral bioprocessing lab, CMRDI. Bacterial adhesion measurements revealed a higher affinity for apatite than quartz. A binary mixture containing 12.5% P2O5 and 42.5% SiO2 yielded a concentrate containing 20.15% P2O5 and 33.5% SiO2. Using the bio-flotation process with Staphylococcus aureus and the optimal conditions on natural phosphate ore, a concentrate with 30.25% P2O5 was obtained from a feed containing 21.89% P2O5.Diljem svijeta velika je potražnja za fosfatnom rudom s obzirom na to da je riječ o primarnoj sirovini koja se koristi u proizvodnji fosfatnih gnojiva i drugih kemikalija. Budući da se koncentracija rude postupno smanjuje, ekonomski je sve isplativije eksploatirati i oplemenjivati brojna ležišta niže koncentracije s obzirom na to da se znatne količine korisne mineralne sirovine nedovoljno iskorištavaju zbog neadekvatnosti novih tehnologija. Stoga biološki procesi postaju sve zanimljiviji u oplemenjivanju SiO2 mineralnih sirovina zbog nižih operativnih troškova i potencijalne primjene za obogaćivanje kompleksnih ruda niskoga stupnja koncentracije, i to interakcijom bakterija i površine minerala, što rezultira površinskom modifikacijom i odvajanjem minerala putem bioflotacije. Bakteriju Staphylococcus aureus isporučio je laboratorij za bioprocesiranje minerala, CMRDI. Mjerenja bakterijske adhezije pokazala su veći afinitet za apatit nego za kvarc. Binarna smjesa koja je sadržavala 12,5 % P2O5 i 42,5 % SiO2 dala je koncentrat koji je sadržavao 20,15 % P2O5 i 33,5 % SiO2. Postupkom bioflotacije bakterijom Staphylococcus aureus pri optimalnim uvjetima na prirodnoj fosfatnoj rudi dobiven je koncentrat s 30,25 % P2O5 iz sirovine koja je sadržavala 21,89 % P2O5

    Bioassay-guided isolation, metabolic profiling, and docking studies of hyaluronidase inhibitors from Ravenala madagascariensis

    Get PDF
    Hyaluronidase enzyme (HAase) has a role in the dissolution or disintegration of hyaluronic acid (HA) and in maintaining the heathy state of skin. Bioassay-guided fractionation of Ravenala madagascariensis (Sonn.) organ extracts (leaf, flower, stem, and root) testing for hyaluronidase inhibition was performed followed by metabolic profiling using LC–HRMS. Additionally, a hyaluronidase docking study was achieved using Molecular Operating Environment (MOE). Results showed that the crude hydroalcoholic (70% EtOH) extract of the leaves as well as its n-butanol (n-BuOH) partition showed higher HAase activity with 64.3% inhibition. Metabolic analysis of R. madagascariensis resulted in the identification of 19 phenolic compounds ranging from different chemical classes (flavone glycosides, flavonol glycosides, and flavanol aglycones). Bioassay-guided purification of the leaf n-BuOH partition led to the isolation of seven compounds that were identified as narcissin, rutin, epiafzelechin, epicatechin, isorhamnetin 7-O-glucoside, kaempferol, and isorhamnetin-7-O-rutinoside. The docking study showed that narcissin, rutin, and quercetin 3-O-glucoside all interact with HAase through hydrogen bonding with the Asp111, Gln271, and/or Glu113 residues. Our results highlight Ravenala madagascariensis and its flavonoids as promising hyaluronidase inhibitors in natural cosmetology preparations for skin care

    Association between Macronutrients Intake, Visceral Obesity and Blood Pressure in a Sample of Obese Egyptian Women

    Get PDF
    AIM: Study the association between the total caloric intake, protein, lipid, and some classes of fatty acids of the diet, and their effects on blood pressure in a sample of Egyptian obese women with and without visceral obesity.METHODS: Five hundred forty-nine obese women were included in the study with mean age of 38.1 ± 11.56 years and mean Body mass index [BMI] of 36.17 ± 7.23. They enrolled in a program for losing weight. Visceral fat was determined using ultrasound. Blood pressure was measured 3 times and the mean was recorded. Twenty four hours dietary recall was reported.RESULTS: Thirty point four percentages of samples has visceral obesity ≥ 7cm; they were the older, showed higher values of BMI, visceral obesity and blood pressure. Significant difference was found between groups regarding mean value of BMI, visceral obesity, both systolic blood pressure SBP and diastolic blood pressure DBP and most of the daily macronutrients intake. In groups (2&3) positive significant correlation was recorded between (SBP) & (DBP) and total daily intake of total calories, carbohydrate, total fat, saturated fatty acids and cholesterol, and negative significant correlation with total daily intake of total protein, animal and vegetable protein, linolenic and linoleic fatty acids, while oleic fatty acid showed negative correlation with SBP&DBP in all groups.CONCLUSION: This study emphasizes the hypothesis that the macronutrients composition of diet influences blood pressure in different ways, in obese patients with visceral obesity

    Vermicompost Supply Modifies Chemical Composition and Improves Nutritive and Medicinal Properties of Date Palm Fruits From Saudi Arabia

    Get PDF
    To meet the increased demand for phytochemicals, plant cultivation in soil amended with biofertilizers has been developed. Here, we aimed to use vermicompost as an environmentally safe biofertilizer to enhance the nutritive and medicinal value of five common cultivars of Saudi date palm; namely Phoenix dactylifera L. var. Ajwa, Hulwa, Ruthana, Sefri, and Luban. To determine changes in the fruit nutritive composition, primary metabolites, antioxidants, phenolic compounds and mineral profiles were analyzed in the fruits from non-fertilized and vermicompost-fertilized date palms. We also tested how changes in the fruit chemical compositions due to vermicompost fertilization affected their medicinal potentials. Applying vermicomposts generally increased primary metabolites, vitamins, and mineral content as well as the medicinal potential of the date palm fruits. This positive effect is possibly explained by the role of vermicomposts in improving soil health and fertility. Furthermore, clustering analyses and principal component analysis (PCA) indicated cultivar-specific responses. PCA analysis also revealed that the bioactivities of the date palm fruit extracts and their antioxidants tended to display correlated output values. One of the highly accumulated phenolic compounds, β-D-glucogallin, was extracted and purified from P. dactylifera L. var. Ajwa fruits and showed significant antioxidant, anticancer, antibacterial, antimutagenic, and antiprotozoal activities. Overall, applying vermicompost is an innovative approach to increase the nutritive quality and medicinal potential of date palm fruits

    Surveillance on A/H5N1 virus in domestic poultry and wild birds in Egypt

    Get PDF
    The endemic H5N1 high pathogenicity avian influenza virus (A/H5N1) in poultry in Egypt continues to cause heavy losses in poultry and poses a significant threat to human health. Here we describe results of A/H5N1 surveillance in domestic poultry in 2009 and wild birds in 2009-2010. Tracheal and cloacal swabs were collected from domestic poultry from 22024 commercial farms, 1435 backyards and 944 live bird markets (LBMs) as well as from 1297 wild birds representing 28 different types of migratory birds. Viral RNA was extracted from a mix of tracheal and cloacal swabs media. Matrix gene of avian influenza type A virus was detected using specific real-time reverse-transcription polymerase chain reaction (RT-qPCR) and positive samples were tested by RT- qPCR for simultaneous detection of the H5 and N1 genes. In this surveillance, A/H5N1 was detected from 0.1% (n = 23/) of examined commercial poultry farms, 10.5% (n = 151) of backyard birds and 11.4% (n = 108) of LBMs but no wild bird tested positive for A/H5N1. The virus was detected from domestic poultry year- round with higher incidence in the warmer months of summer and spring particularly in backyard birds. Outbreaks were recorded mostly in Lower Egypt where 95.7% (n = 22), 68.9% (n = 104) and 52.8% (n = 57) of positive commercial farms, backyards and LBMs were detected, respectively. Higher prevalence (56%, n = 85) was reported in backyards that had mixed chickens and waterfowl together in the same vicinity and LBMs that had waterfowl (76%, n = 82). Our findings indicated broad circulation of the endemic A/H5N1 among poultry in 2009 in Egypt. In addition, the epidemiology of A/H5N1 has changed over time with outbreaks occurring in the warmer months of the year. Backyard waterfowl may play a role as a reservoir and/or source of A/H5N1 particularly in LBMs. The virus has been established in poultry in the Nile Delta where major metropolitan areas, dense human population and poultry stocks are concentrated. Continuous surveillance, tracing the source of live birds in the markets and integration of multifaceted strategies and global collaboration are needed to control the spread of the virus in Egypt

    A Comparative Study of Efficient Initialization Methods for the K-Means Clustering Algorithm

    Full text link
    K-means is undoubtedly the most widely used partitional clustering algorithm. Unfortunately, due to its gradient descent nature, this algorithm is highly sensitive to the initial placement of the cluster centers. Numerous initialization methods have been proposed to address this problem. In this paper, we first present an overview of these methods with an emphasis on their computational efficiency. We then compare eight commonly used linear time complexity initialization methods on a large and diverse collection of data sets using various performance criteria. Finally, we analyze the experimental results using non-parametric statistical tests and provide recommendations for practitioners. We demonstrate that popular initialization methods often perform poorly and that there are in fact strong alternatives to these methods.Comment: 17 pages, 1 figure, 7 table
    corecore