Background/Objectives: Relational databases are a commonly utilized technology that allows for the storage, administration, and retrieval of various data schemas. However, for certain big databases, executing queries can become a time-consuming and inefficient procedure. Furthermore, storing enormous volumes of data necessitates servers with greater capacity and scalability. Relational databases have limits when it comes to dealing with scalability for big amounts of data. On the other hand, non-relational database systems, often known as NoSQL, were created to better fulfill the demands of key-value storing of enormous volumes of records. However, there are several NoSQL options, and the majority have not yet been extensively compared. The goal of this research is to examine different NoSQL databases and evaluate their performance in terms of typical data storage and retrieval. Methods: In this study, we use the YCSB tool to measure the performance of three NoSQL databases: MongoDB, Cassandra, and Redis. We test six different workloads with 100000, 250000, 500000, 750000, and 1000000 operations. Our test was designed with five different operations, i.e., 100000, 250000, 500000, 750000, and 1000000, with six different workloads to see which database is most suitable for applications which use a large amount of data to process. Findings: MongoDB is a superior performing NoSQL database among Cassandra and Redis. The numerous optimizations used by the designers of NoSQL solutions to improve performance, such as good cache memory operation, have a direct impact on the execution time. In all workloads except workload D, MongoDB has significantly reduced latency across all operation counts. Novelty: We also measure the average latency of different workload scenarios that include a mix of read, write, and update activities.

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Background: Pneumonia acquired outside the hospital by an immune-competent individual is defined as community acquired pneumonia (CAP). It is to be distinguished, on the basis of a wider spectrum of pathogens, from nosocomial pneumonia from pneumonia in an immune-compromised host. Community-acquired pneumonia is associated with a significant mortality and morbidity. Etiology of CAP varies geographically and the understanding of local epidemiology plays an important role in decision making for empirical treatment before test results are available. Primary decisions about empirical antimicrobial treatment required knowledge of predominant microbial patterns and their sensitivities. Objectives: The aim of this study was to identify the bacterial etiology of CAP, their sensitivity towards empirical therapy and to observe the clinical course as well as short term outcome in hospitalized adult patients. Methodology: It was one year-long observational prospective study on 87 patients diagnosed with CAP admitted in Chattogram Medical College Hospital, second largest tertiary care hospital during August 2018 to July 2019. Sputum for Gram and Z-N staining, culture and sensitivity, blood for culture, sensitivity and PCR for Streptococcus pneumonia, Mycoplasma pneumoniae, Legionella pneumophila and Chlamydophila pneumonia were done. Patients were followed up for in-hospital outcome and 30-day mortality. Results: The mean age was 49.59 years and male - female ratio was 1.56: 1. Fever, chest pain and cough were the most common clinical findings. Klebsiella pneumoniae was identified (39.1%) in the majority of the patients, followed by Pseudomonas aeruginosa (10.3%), Staphylococcus aureus and Escherichia coli (5.7%). Staphylococcus aureus was positive in blood culture of one patient. Four samples were positive in PCR and identified Streptococcus pneumoniae. The sensitivity to meropenem, levofloxacin and amikacin was highest. The mean duration of hospital stay was 6.34 ± 2.37 days along with in-hospital mortality and 30-day mortality was 6.9% and 16.1% respectively. Conclusion: The bacteriologic profile of community acquired pneumonia revealed Gram-negative bacteria as pre-dominant organism by conventional sputum and blood culture. But need for further serologic tests for atypical and viral pathogens and development of institutional antibiogram to facilitate the choice for empirical therapy is required.

Abstract— The emerging corona virus (Covid-19) has become at the forefront of the scene around us around the world, after the disease has swept all over the earth, causing high numbers of deaths and infections, and it continues to expand terribly across countries without stopping or finding a drug that can stop it finally in an effective form yet. For sure the emergence and spread of the virus in this rapid way has effectively and strongly affected people, commerce and industries. Many researchers who were interested in the field of e-commerce around the world are more intensive to learn about the impact that the emergence of the emerging corona virus (Covid-19) has on the economic around the world, and economics of Oman in depth and whether this effect was negative or positive, and what are the aspects of Impact. The main objective of this research paper is to investigate in deep through reviewing several studies, the effect of corona virus in economics of Oman and Omani consumer’s behavior as well as the aspects of the change that occurred in the behavior of Omani consumers as a result of this virus.