A new architecture to support efficient web browsing in a wireless mobile computing environment

Mobile computing environments present several challenges arising from the limitations inherent in wireless networks and the inability of current network protocols to cope with these limitations. As the popularity of untethered access to the Internet increases, conventional network applications such as web browsing must overcome these challenges to support the needs of mobile users. Recent work in the mobile computing research community has attempted to increase the efficiency of web browsing in a mobile computing environment by employing a client/intercept/server architecture which enables the optimization of application layer data transmitted across the wireless portion of the network. Although effective, this strategy relies on the existence of a wired side agent, which introduces a new problem with respect to mobility across different heterogeneous networks where the agent may or may not be available). This thesis presents a new architecture to support the optimization of web browsing in a wireless mobile computing environment. The architecture uses mobile agents to dynamically deploy a client/intercept/server architecture on foreign networks that provide a certain mobility framework. The new architecture offers the following specific advantages: (1) A framework is identified that enables mobile units to discover and use mobile agent systems on foreign networks; (2) The benefits of a client/intercept/server architecture are translated to any network that supports this framework; (3) The architecture works with existing Internet protocols; (4) Mobile agent systems on foreign networks are modeled as a service that the foreign network provides, similar to other services such as printers. Finally, a prototype system is described that is implemented using the architecture to demonstrate the feasibility of the approach

Cardiobacterium hominis Endocarditis: A Case Report and Review of the Literature

The present case report describes the clinical course of a patient who presented with Cardiobacterium hominis endocarditis. A review of the literature follows the case presentation. C hominis, a fastidious Gram-negative bacillus, is a member of the HACEK group of microorganisms (Haemophilus species, Actinobacillus actinomycetemcomitans, C hominis, Eikenella corrodens and Kingella kingae). Endocarditis caused by C hominis is uncommon and generally follows a subacute course. Patients may present with constitutional symptoms, symptoms related to valvular destruction or symptoms secondary to embolic events. Diagnosis requires identification of the pathogen from blood or vegetation by either culture or molecular techniques. Blood cultures may require prolonged incubation, highlighting the importance of incubating blood cultures for at least two to three weeks in patients with suspected endocarditis. In the past, C hominis was generally sensitive to penicillin. However, reports of beta-lactamase-producing C hominis have appeared in the literature over the past decade. The current recommendation for first-line treatment is a third-generation cephalosporin (ceftriaxone) for four weeks (six weeks if a prosthetic valve is in place).Peer Reviewe

SCISAT-1 ACE Mission C&DH Unit Development

The SCISAT-1 Atmospheric Chemistry Experiment (ACE) Mission is a part of the Canadian Space Agency’s (CSA’s) space science program, to support ongoing research in the areas of solarterrestrial relations, atmospheric sciences and space astronomy. Bristol Aerospace Limited is the CSA’s Spacecraft Prime Contractor for the ACE Mission. The ACE spacecraft will be launched on a Pegasus XL vehicle in mid-2002, co-manifested with a NASA spacecraft. A Control and Data Handling (C&DH) Unit is being developed by Bristol for the ACE Mission. This C&DH Unit will be responsible for all onboard command, control, monitoring and science data recording. This unit is being developed to support a range of Canadian small science missions, from Smallsats to Microsats. The unit is low power and light weight, and features a rad-tolerant core to assure reliable operation in a single string architecture. The C&DH Unit is comprised of a Controller Card (CC), Data Handling Card (DHC), Input/Output Card (IOC) and a Power Supply Card (PSC). Each card is housed in its own aluminum frame, and the frames are integrated into a vertical stack. The unit is expected to operate with 7 Watts orbit average power and uses a UTMC 80C196 16-bit processor running at 16 MHz to manage the satellite operations and perform attitude control. Mass storage of 1.5 Gbytes and CCSDS variable-rate telemetry up to 5 Mbits/sec are provided. This paper will present an overview of the ACE Mission and a description of the C&DH Unit, describing its architecture, hardware/software partitioning, FPGA functionality and key performance specifications

<i>Caulobacter</i>Species as a Cause of Postneurosurgical Bacterial Meningitis in a Pediatric Patient

Caulobacterspecies have been rarely found to be a cause of human infection. A case of probableCaulobacterspecies meningitis occurring postneurosurgery in a pediatric patient is reported in the present article. Gram stain and colony morphology of the isolate were not consistent with the identification provided by commercial phenotypic identification systems. The present case illustrates the need to reconcile conflicting phenotypic test results using 16S ribosomal DNA sequencing.</jats:p

Osteomyelitis Due to Multiple Carbapenemase-Producing Gram-Negative Bacteria: The First Case Report of a GES-13-Producing Pseudomonas aeruginosa

A case of osteomyelitis in an infant following a burn injury sustained in Pakistan caused by a GES-13-producing Pseudomonas aeruginosa (the first reported in Canada) and an OXA-48 producing Klebsiella pneumoniae is described. The present case serves to highlight the importance of international travel as a risk factor for infection with carbapenemase-producing bacteria and the challenges in the laboratory detection of these organisms

Opening Pandora's box:High-level resistance to antibiotics of last resort in Gram-negative bacteria from Nigeria

OBJECTIVES: The aim of this study was to determine the percentage of antimicrobial-resistant isolates and the associated resistance mechanisms in Gram-negative bacteria from South Western Nigeria. METHODS: A total of 306 non-duplicate unbiased Gram-negative isolates were recovered from patients admitted to three teaching hospitals in South Western Nigeria in 2011 and 2013. Isolates were from clinical samples as well as from stool samples of inpatients without infection to assess antimicrobial resistance patterns in carriage isolates. Antimicrobial susceptibility testing was performed, and PCR and sequencing were used to identify genes encoding various known β-lactamases. Based on phenotypic and genotypic results, 10 isolates representing the diversity of phenotypes present were selected for whole-genome sequencing (WGS). RESULTS: Antimicrobial susceptibility testing revealed the following resistance rates: fluoroquinolones, 78.1%; third-generation cephalosporins, 92.2%; and carbapenems, 52.6%. More resistant isolates were isolated from stools of uninfected patients compared with clinical infection specimens. Klebsiella (10%) and Escherichia coli (7%) isolates produced a carbapenemase. WGS of selected isolates identified the presence of globally disseminated clones. CONCLUSION: This study illustrates a crisis for the use of first-line antimicrobial therapy in Nigerian patients. It is likely that Nigeria is playing a significant role in the spread of antimicrobial resistance owing to its large population with considerable global mobility

Multicentre study of the in vitro activity of ceftolozane/tazobactam and other commonly used antibiotics against Pseudomonas aeruginosa isolates from patients in the UK.

Objectives: To evaluate the in vitro activity of ceftolozane/tazobactam and other commonly used antipseudomonal antibiotics against geographically spread Pseudomonas aeruginosa isolates in the UK using disc susceptibility testing. Methods: The in vitro activity of ceftolozane/tazobactam and nine other commonly used antipseudomonal antibiotics was evaluated. Isolates were collected between January 2015 and April 2018. Susceptibility results were interpreted using EUCAST 2018 criteria. Results: Overall, 1326 clinical isolates from 14 centres in the UK were tested. The majority of the isolates were collected from non-cystic fibrosis (non-CF) patients (n = 1123, 85.0%). In addition, 199 cystic fibrosis (CF) isolates were collected from 10 centres. Overall susceptibility to ceftolozane/tazobactam was 89.3% (n = 1181), which included 128 CF and 1053 non-CF isolates. The other antibacterial agents with the highest susceptibility were tobramycin (92.4%, n = 1221) and piperacillin/tazobactam (90.7%, n = 1199). Susceptibility to all antibacterial agents was lower for CF isolates. Piperacillin/tazobactam was the most active of the antibacterial agents tested, followed by ceftolozane/tazobactam (70.4% and 64.3%, respectively), and <60% of CF isolates were susceptible to ceftazidime and the carbapenems. The reason for the higher rates of susceptibility to piperacillin/tazobactam and lower susceptibility to ceftazidime compared with other studies is unclear. Conclusions: The data presented here support the need to investigate the place of ceftolozane/tazobactam as a treatment option in the management of pseudomonal infections, particularly in patients with CF. The results highlight the importance of routine testing of new antibacterial agents and of making the data available to clinicians to make appropriate and informed treatment choices