Ultraviolet Radiation Effects On Rotifers

The purpose of this investigation was to study ultraviolet radiation effects on rotifers. The rotifer studied was Philodina acuticornis odiosa Milne. Isolation cultures were used to grow the rotifers individually in separate U-plate depressions. The source of ultraviolet radiation consisted of four mercury germicidal lamps used in combination to deliver a uniform flux of 315 uW/cm2 over the sample. Five groups of rotifers, one control and four experimental groups of 96 each, were used. The rotifers used were 2-10 hours of age at the beginning of the experiment. The experimental groups were exposed to uv radiation for 3 minutes, 5 minutes, 7 minutes, 9 minutes. The mean lifetime of each of the control, 3 minutes, 5 minutes, 7 minutes, and 9 minutes irradiated groups was 20.4 days, 19.1 days, 17.1 days, 11.5 days, and 6.3 days respectively. No specific theory, nor the mechanism involved is given to explain these uv radiation effects on rotifers. From the data, it is concluded that some radiation shortens the mean lifetimes of rotifers and that there is a threshold exposure after which the survival of the rotifer changes drastically

Content-aware power saving multimedia adaptation for mobile learning

Due to the tremendous enhancements in the capabilities of mobile devices in recent years and accessibility to higher bandwidth mobile internet, the use of online multimedia learning resources on mobile devices is increasingly becoming popular. Improvements in battery capacity have not matched the same advancements compared to other features of mobile devices. Limited Battery power is introducing a significant challenge in making better use of online educational multimedia resources. Online Multimedia Resources drains more battery power as a result of higher amount of wireless data transfer and therefore limiting learning opportunities on the move. Many power saving multimedia adaptation techniques have been suggested. Majority of these techniques achieve battery efficiency while reducing multimedia quality. So far, however, to the best of our knowledge no previous effort has considered the factor of learning efficacy in multimedia adaptation process. Existing adaptation techniques are susceptible to information loss as a result of quality of reduction. Such loss affects the learning content efficacy and jeopardizes the learning process. In this paper, we recommend a novel power save educational multimedia adaptation approach that considers the learning aspect of multimedia in the adaptation process. Our technique enables learning for extended duration by battery power saving without putting the learning process at risk. Efficacy of entire learning resources is managed by not allowing any part of the learning multimedia to be delivered in a quality that will negatively affect the learning outcome. We also present a framework that guides the implementation of our approach followed by description of our prototype application that uses educational multimedia metadata implemented in semantic web technologies

Energy-Aware Streaming Multimedia Adaptation: An Educational Perspective

As mobile devices are getting more powerful and more affordable the use of online educational multimedia is also getting very prevalent. Limited battery power is nevertheless, a major restricting factor as streaming multimedia drains battery power quickly. Many battery efficient multimedia adaptation techniques have been proposed that achieve battery efficiency by lowering presentation quality of entire multimedia. Adaptation is usually done without considering any impact on the information contents of multimedia. In this paper, based on the results of an experimental study, we argue that without considering any negative impact on information contents of multimedia the adaptation may negatively impact the learning process. Some portions of the multimedia that require a higher visual quality for conveying learning information may lose their learning effectiveness in the adapted lowered quality. We report results of our experimental study that indicate that different parts of the same learning multimedia do not have same minimum acceptable quality. This strengthens the position that power-saving adaptation techniques for educational multimedia must be developed that lower the quality of multimedia based on the needs of its individual fragments for successfully conveying learning informatio

Initial Assessment of Environmental Microbial Hazards in Doha Restaurants

This study was carried out to assess hygiene conditions, food handling practices, food safety knowledge of food service providers (FSPs), and the microbial quality of food served in different food service establishments in Doha. Fifty-three FSPs were randomly selected among 200 FSPs. Face-to-face interviews with the food safety managers at each participating FSP were conducted using a survey consisting of 40-questions (demographic data on workers, HACCP training, knowledge on personal hygiene, and safe-food handling practices) in October-December 2015. In addition to survey questionnaire, a checklist was used to determine the implementation of international food safety standards by observing actual practices applied at each FSP. The microbial quality of food samples (n=105) served and swabs collected from food preparation surfaces (n=58) were also assessed using select media (APC, MCA, XLT4, and LSA). The identification of positive samples was carried out using VITEK-2 system. The survey results indicated that average service years of FSPs was 11, the average age of food safety managers interviewed was 33, most managers (66%) had college degree, and 68% of them were trained on HACCP. It was demonstrated that casual-sit-in and fine-dine-in restaurants are the only FSP types which consistently kept records (100%), followed by fast-food (36%), and catering (14%) FSPs. The microbial analysis indicated that the average APC in food samples collected from all FSPs met the international standards, while the APC counts of swab samples were considered unsatisfactory since the levels were above 106 Log10 CFU/cm2. The highest bacterial count was reported in swab samples (7.26 Log10 CFU/cm2) collected from preparation area in takeaway restaurants. Concerning the target organisms (Escherichia coli, Salmonella spp., and Listeria monocytogenes), among 105 food samples and 58 swab samples collected, 13 samples (8%) exhibited positive results for possible target pathogens. Positive samples were identified as Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas aeruginosa, and Pantoea spp. Results obtained in this study might help food safety managers in these select FSPs to better understand the need for implementing effective control measures in order to prevent contamination and eventually protect the public health

Recent advances in the synthesis of triazole derivatives

Triazole ring system has attracted a continuously growing interest of synthetic organic chemists and those dealing with the medicinal compounds due to its versatile potential to interact with biological systems. The triazole compounds possess a wide range of biological activities and are especially focused for antifungal behavior. In thisreview article, we have summarized the recent developmentsin the synthetic methodologies of this ring system. The main focus was on the methodologies which deal with the facile and convenient synthesis

Three Essays on the Gender Differentials in Mortality and Undernutrition in Pakistan

Kindersterblichkeit und Unterernährung sind die zwei Hauptprobleme der öffentlichen Gesundheitsversorgung in Entwicklungsländern. Ein damit verbundenes Phänomen ist die geschlechtsspezifische Diskriminierung von Mädchen. Besonders in Südasien leiden Mädchen unter schlimmsten Formen der geschlechtsspezifischen Diskriminierung bezüglich des Zugangs zu medizinischer Versorgung und Ernährung. Diese Dissertation untersucht diese beiden Probleme in Pakistan und erforscht empirisch die Determinanten geschlechtsspezifischer Unterschiede von Sterblichkeit und Unterernährung. Die erst kürzlich entwickelten Bayesianischen Verfahren zur Schätzung strukturierter additiver Modelle werden anhand zweier Mikrodatensätze aus Pakistan verwendet