1,722 research outputs found

    Antibacterial And Antifungal Effect Of Some Natural Extracts And Their Potential Use As Photosensitizers

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    One of the threats on the health sector is the appearance of multi antibiotic resistant microorganisms. Thus, this occurs because of using natural and synthetic antimicrobial agents in excessive doses. Now, many scientists all around the world are performing research on natural extracts that have antimicrobial activity using photodynamic therapy (PDT) which involves light activation. The aim of this study, however, is to evaluate the effect of photodynamic antimicrobial chemotherapy using extracts from Pomegranate (Punica granatum), Cinnamon (Cinnamomum verum), Roselle (Hibiscus sabdariffa), Carob (Ceratonia siliqua), and Nigella or black cumin oil (Nigella sativa) against two gram-positive and two gram-negative bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) respectively; and three different fungi (Aspergillus niger, Mucor sp., and Rhizopus sp.), using agar well diffusion method. The prepared methanolic extracts presented absorption between 300 and –900 nm wavelengths. The maximum activity of Roselle (Hibiscus sabdariffa) was against Staphylococcus aureus in total darkness with 52.5 ± 2.5 mm inhibition zone diameter. Also, the most sensitive fungi was Mucor sp. Cinnamon (Cinnamomum verum) extract was with 31.0 ± 1.0 mm inhibition zone diameters. The results showed that there was an inhibitory effect of Cinnamon (Cinnamomum verum) and Roselle (Hibiscus sabdariffa) extracts against most of the tested species

    The Effect of Static Magnetic Field on E. coli, S. aureus and B. subtilis Viability

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    This study investigated the effects of low static magnetic field on the growth of three bacterial strains (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) that plays a versatile role in infecting wounded tissues. The viability of these bacteria was measured with and without different magnetic fields (30, 50, and 80) mT after 24 hours. Results illustrate that magnetic field decreased the growth rate of Escherichia coli and Staphylococcus aureus bacteria, while increased the growth rate of Bacillus subtilis after 24 hours of exposure. Keywords: Magnetic field, Bacillus subtilis, Escherichia coli, Staphylococcus aureus

    Prevalence of Rabies in Various Species in Yemen and Risk Factors Contributing to the Spread of the Disease

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    Objectives: This study aimed to describe for the first time the prevalence of the passively-reported rabies virus among different domestic and wild animals submitted to the Central Veterinary Laboratory from various areas in Yemen, and to study prevalence proportion ratios (PPR) that contributed to the spread of rabies among animals, and its transmission to humans. Methods: A brain sample was obtained from each of the 180 animals and tested for rabies virus by a direct fluorescent antibody test. Results: Out of the total number of animals involved in attacks on humans, 63.3 % were positive for rabies. Of these, dogs were the main animal involved in attacks with a percentage of 92%, of which 62.7% were positive for rabies. Of animals involved in attacks, 70.6% were males of which 60.6% were positive, and 29.4% were females of which 69.8% were positive. Males comprised 68.9% of the total human individuals attacked, of whom 62.9% were attacked by rabies-positive animals. The significant risk factors that contributed to the spread of rabies in general included the presence of poultry carcasses and other waste in the vicinity of the attacks (PPR = 9.5) with a percentage of 84.8%, followed by the time of year, in particular school vacations (PPR = 3.8) with a percentage of 78%. Conclusion: Rabies is endemic in Yemen with a very high rabies-positive rate for animals involved in attacks, particularly for stray male dogs. Male children were most often involved in attacks by rabies-positive animals. The presence of food waste (particularly poultry carcasses) and school vacation periods were found to correlate significantly with increased risk for human exposure to rabies

    "Toxic pleasures”: A study of eating out behavior in Arab female university students and its associations with psychological distress and disordered eating

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    University years are a critical period in which young people establish independence and adopt lasting health behaviors. The aim of this study was to estimate the associations between eating out, psychological distress, and disordered eating behaviors among young Arab females in Qatar a rapidly developing small nation. A cross-sectional probability-based survey of 1615 Qatar University's female students assessed the frequency of eating out (main independent variable) and other eating behaviors in relation to two main dependent variables, disordered eating and psychological distress, which were measured using the Eating Attitudes Test and the Kessler Psychological Distress Scale, respectively. Multivariable logistic-regression analyses were used to estimate these two main associations with and without adjustment for other potential confounding variables, including the main effects of psychological distress and disordered eating on each other. Of the students, 45% reported eating out 3 times or more a week. Furthermore, approximately 18% screened positive for disordered eating and 33% reported high levels of psychological distress in the past 30 days. After adjustment for other variables, eating out 5 times or more a week was not significantly associated with the odds of disordered eating (OR 1.21, p=0.32). However, eating out 5 times or more per week was significantly associated with odds of having psychological distress (OR 1.46, p=0.03). Both psychological distress and disordered eating were strongly associated with each other (OR 2.58, p < 0.001)

    A Study of Faculty Members’ Perceptions of the Effect of the Globalization on Higher Education: The Case of Jordan

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    The purpose of study was to investigate Jordanian higher education faculty members’ perceptions of the phenomenon of globalization and its effect on higher education. The participants in this study were 6 faculty members from a Jordanian university. Four of the participants have leadership positions at the university. Two of them were deans, one of them was vice dean, and the fourth one was a head of department.  Semi-structured interviews were used as research method. The researchers formulated the interview questions based on the purpose of the research. Qualitative data analysis techniques were used to analyze participants’ responses.  Participants’ responses to the interview questions were organized, coded, interpreted, and represented. The findings showed that the Jordanian faculty members are aware of the effects of globalization on the fields of higher education. All the participants believed that globalization have positive effect on higher education. Most of the participants believed that the institutions of higher education should work on facing the negative impact of globalization on the national identity, culture, and heritage. Mixed results were found regarding the challenge of applying the principle of free market on the fields of higher education due to the globalization. Based on the findings, some of recommendations were presented. Keywords: Globalization, Faculty Perceptions, Jordanian Higher educatio

    Value Relevance of Voluntary Risk Disclosure Levels: Evidence from Saudi Banks

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    This study seeks to examine whether the levels of voluntary risk disclosure in Saudi listed banks are valuerelevant or not. The sample of this investigation consists of all banks listed on the Saudi Stock Market Exchange (Tadawul). All data was collected from the annual reports of the sample banks from 2009 to 2013 using manual content analysis. Other variables were collected using DataStream and Bloomberg. Ordinary least squares regressions analysis was used. The findings of the multivariate analysis demonstrated that there is no association between the levels of voluntary risk disclosure and firm value as measured by the market to book value at the end of the year (MTBV). But, the results generate from the accounting based measure (ROA) show that there is a positively significant association between the levels of voluntary risk disclosure and firm value. This study contributes to the literature on general accounting disclosure and in particular advances and contributes to the literature on risk disclosure in developing economies. It also contributes to the understanding of the role of accounting information in relation to the market valuation of a firm. The empirical findings of this study have several implications for banks’ investors, regulatory bodies and any other interested group as they report the importance of corporate risk disclosure and its economic consequences. This can be used to increase the value relevance in the banking sector. This study also informs regulators about the current level of risk disclosure in all Saudi listed banks. To the best of the researcher’s knowledge, no prior research has been conducted on the relationship between firm value and levels of risk disclosure in general nor especially in emerging markets, such as Saudi Arabia, the focus of this study

    Optimization of chloroxylenol degradation by Aspergillus niger using Plackett-Burman design and response surface methodology

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    Chloroxylenol is a very toxic phenolic derivative and it represents potential hazard towards human health and to the environment. Aspergillus niger, local isolate, is an efficient fungus to degrade 99.72% of 2 mg/L of chloroxylenol after 7 days of fermentation. It also has a high capacity to degrade 91.83% of higher chloroxylenol concentration of 20 mg/L after 6 days of incubation on mineral medium amended with 2 g/L of glucose. Statistical experimental designs were used to optimize the process of chloroxylenol degradation by the fungus. The most important factors influencing chloroxylenol degradation, as identified by a two-level Plackett-Burman design with 11 variables, were NaCl, (NH4)2SO4, and inoculums size. Response surface analysis was adopted to further investigate the mutual interactions between these variables and to identify their optimal values that would generate maximum chloroxylenol degradation. Under the optimized medium compositions and culture conditions, A. niger was able to degrade completely (100%) chloroxylenol (20 mg/L) after 134.6 h of fermentation. The predicted values of Plackett-Burman conditions and response surface methodology were further verified by validation experiments. The excellent correlation between predicted and experimental values confirmed the validity and practicability of this statistical optimum strategy. Optimal conditions obtained in this work laid to a solid foundation for further use of A. niger in treatment of high strength chloroxylenol polluted effluents. So, the optimized conditions were applied to bioremediate crude sewage containing 27.8 mg/L of chloroxylenol by A. niger. The fungus efficiently degraded chloroxylenol after 8 days of fermentation.Key words: Chloroxylenol degradation, Aspergillus niger, Plackett-Burman design, Response surface methodology
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