Before-Commit Client State Management Services for AJAX Applications

Heavily script-based browser applications change the manner in which users interact with Web browsers. Instead of downloading a succession of HTML pages, users download a single application and use that application for a long period of time. The application is not a set of HTML pages, but rather a single page that can possible modify its own presentation based on data exchanged with a server. In such an environment, it is necessary to provide some means for the client to manage its own state. We describe the initial results of our work in providing client-side state management services for these script-based applications. We focus on browser-based services that can help the user before any data is committed on the server. Our services include state checkpointing, property binding, operation logging, operational replay, ATOM/RSS data updates, and application-controlled persistence

Kinetic physico-chemical model for cell culture processes – applications and opportunities

Cell culture processes for production of recombinant proteins can be modeled to provide critical insights into the interrelationship between several parameters that impact the process performance and control. For the first time, we describe a model that incorporates pH control in combination with gas transfer to provide a more complete description of the physicochemical processes that occur during the entire course of the cell culture process. The model includes multi-component chemical equilibria involving carbonate, lactate and sodium hydroxide coupled with electroneutrality for calculation of pH. Further, the pH feedback control has been incorporated depending on levels of carbonate and lactate in the culture. Additionally, pH ramp, and pH dead-band controls have been included to facilitate simulation of real process conditions. For oxygen transfer, cascaded control including agitation, air flow and oxygen flow are implemented. Very limited actual data from at-scale or small scale studies are required for the model, essentially requiring only cell density profiles and lactate profiles. Other specific rates are readily calculated based on measurements. Simulations based on these models provide key relationships that provide a clear basis for designing control strategies for the entire process. Several scenarios, including the choice of base, the impact of lactate consumption and production, the impact of cascaded controls for oxygen transfer, as well as the buffer composition of the media have been simultaneously evaluated through simulations, resulting in valuable approaches to scale-up and scale-down design of cell culture processes. Case studies will be presented demonstrating some of the applications. Potential improvements and opportunities will also be presented

The development of effective behaviour change interventions to support the use of malaria rapid diagnostic tests by Tanzanian clinicians.

BACKGROUND: Parasitological confirmation is now recommended for all cases of suspected malaria. The roll-out of rapid diagnostic tests (RDTs) is hoped to enable this goal in low resource settings through point of care testing. However, simply making RDTs available has not led to high uptake of the tests or adherence to results by clinicians, with malaria continuing to be overdiagnosed in many settings. We undertook to design an evidence-based intervention package that would be sufficient to support the introduction of RDTs at dispensaries in Tanzania, to be evaluated through the Targeting Artemisinin Combination Therapy (TACT) cluster randomised controlled trial. METHODS: We describe five steps in our intervention design: formative research, review of existing evidence and theory, a workshop to define the intervention approach and content and results of formative research, engagement with behaviour change theory and literature, detailed design of intervention materials and piloting and pretesting of intervention materials. This involved fieldwork with a total of 19 health workers and 212 community members in northeast Tanzania. RESULTS: The formative research suggested that RDTs were a potential source of conflict in the health worker-patient interaction, but that health workers used various techniques to resolve this, including provision of antimalarial drugs for RDT-negative patients. Our reviews showed that evidence was mixed regarding the effectiveness of different methods and theories to support change in prescribing practice. Our design process is presented, drawing from this collective evidence. We describe the final TACT intervention package (including interactive small group workshops, feedback text messages, motivational text messages and patient information leaflets and posters) in terms of its programme theory and implementation theory. CONCLUSIONS: Our study suggests that evidence-based design of complex interventions is possible. The use of formative research to understand malaria overdiagnosis in context was central to the design of the intervention as well as empirical research to test materials and methods prior to implementation. The TACT interventions may be appropriate for other settings where clinicians face similar challenges with malaria diagnostics. TRIAL REGISTRATION: NCT01292707

Severe upper airway obstruction due to delayed retropharyngeal hematoma formation following blunt cervical trauma

BACKGROUND: We report a case of severe upper airway obstruction due to a retropharyngeal hematoma that presented nearly one day after a precipitating traumatic injury. Retropharyngeal hematomas are rare, but may cause life-threatening airway compromise. CASE PRESENTATION: A 50 year-old man developed severe dyspnea with oropharyngeal airway compression due to retropharyngeal hematoma 20 hours after presenting to the emergency department. The patient also had a fractured first cervical vertebra and was diagnosed with a left brachial plexopathy. The patient underwent emergent awake fiberoptic endotracheal intubation to provide a definitive airway. CONCLUSION: Retropharyngeal hematoma with life-threatening airway compromise can develop hours or days after a precipitating injury. Clinicians should be alert to the potential for this delayed airway collapse, and should also be prepared to rapidly secure the airway in this patient population likely to have concomitant cervical spinal or head injuries