Advanced solutions for quality-oriented multimedia broadcasting

Multimedia content is increasingly being delivered via different types of networks to viewers in a variety of locations and contexts using a variety of devices. The ubiquitous nature of multimedia services comes at a cost, however. The successful delivery of multimedia services will require overcoming numerous technological challenges many of which have a direct effect on the quality of the multimedia experience. For example, due to dynamically changing requirements and networking conditions, the delivery of multimedia content has traditionally adopted a best effort approach. However, this approach has often led to the end-user perceived quality of multimedia-based services being negatively affected. Yet the quality of multimedia content is a vital issue for the continued acceptance and proliferation of these services. Indeed, end-users are becoming increasingly quality-aware in their expectations of multimedia experience and demand an ever-widening spectrum of rich multimedia-based services. As a consequence, there is a continuous and extensive research effort, by both industry and academia, to find solutions for improving the quality of multimedia content delivered to the users; as well, international standards bodies, such as the International Telecommunication Union (ITU), are renewing their effort on the standardization of multimedia technologies. There are very different directions in which research has attempted to find solutions in order to improve the quality of the rich media content delivered over various network types. It is in this context that this special issue on broadcast multimedia quality of the IEEE Transactions on Broadcasting illustrates some of these avenues and presents some of the most significant research results obtained by various teams of researchers from many countries. This special issue provides an example, albeit inevitably limited, of the richness and breath of the current research on multimedia broadcasting services. The research i- - ssues addressed in this special issue include, among others, factors that influence user perceived quality, encoding-related quality assessment and control, transmission and coverage-based solutions and objective quality measurements

Evaluation of the Potency of Commercial and Locally Prepared Antibiotic Discs on Clinical Bacterial Isolates in Calabar, Nigeria

Antibiotic susceptibility discs are used for vitro susceptibility testing of antimicrobial agents to fast growing bacteria and fastidious species by agar diffusion method. It is a semi quantitative method. This study was designed to assess the efficacy of commercial antibiotic discs over in-house prepared discs. Identified clinical isolates were obtained in house in the Department of Medical Microbiology/Parasitology, University of Calabar Teaching Hospital, Nigeria. Staphylococcus aureus (ATCC 7553) and Escherichia Coli (ATCC 25922) were obtained and used as controls. The antibiotics tested includes; Ciprofloxacin, Erythromycin, Amoxicillin, Gentamicin, Zinacef. These were obtained commercially from Pharmacy shops. The local antibiotic dics were prepared with Whatman filter paper number 3. The antibiotic susceptibility testing was done using Kirby-Bauer method. Out of the 40 clinical isolates tested, 15(37.5%) were Staphylococcus aureus while 10(12.5%) each were Escherichia coli and Pseudomonas aeruginosa respectively. Only 5 isolates of Proteus vulgaris were used. The susceptibility profile of isolates to the commonly used local antibiotic discs ranged between 66.7% to 100%, while the range for commercial discs was 53.3% to 86.7%. Locally prepared discs were found to be more effective than commercial discs. The high resistance rates (0.0% to 33.3%) of clinical isolates to the commercial discs may be attributed to prolong exposure to environmental factors such as heat, moisture, sunlight as well as humidity when transported to retailers and the final users. There is need for constant monitoring and quality controls of susceptibility testing in our laboratories for the production of quality results and efficient patient care. Antibiotic susceptibility discs can be prepared locally for routine laboratory use; this may indirectly reduce importation of commercial discs and the burden on foreign exchange

Brans-Dicke model constrained from Big Bang nucleosynthesis and magnitude redshift relations of Supernovae

The Brans-Dicke model with a variable cosmological term ($BD\Lambda$) has been investigated with use of the coupling constant of $\omega=10^4$. Parameters inherent in this model are constrained from comparison between Big Bang nucleosynthesis and the observed abundances. Furthermore, the magnitude redshift ($m-z$) relations are studied for $BD\Lambda$ with and without another constant cosmological term in a flat universe. Observational data of Type Ia Supernovae are used in the redshift range of $0.01<z<2$. It is found that our model with energy density of the constant cosmological term with the value of 0.7 can explain the SNIa observations, though the model parameters are insensitive to the $m-z$ relation.Comment: Submitted to A&A, 4 pages, 3 figure