Alongside good governance, technology is considered among the greatest enablers for improved quality of life. However, the majority of its benefits have been concentrated in industrialized nations ...and therefore limited to a fraction of the world's population. We believe that technology has a large role to play in developing regions, that "First World" technology to date has been a poor fit in these areas, and that there is thus a need for technology research for developing regions. Despite the relative infancy of technology studies in developing regions, anecdotal evidence suggests that access to technology has a beneficial economic impact. Cellular telephony is probably the most visible application, but there are many others, some of which we cover in this article. The World Bank's infoDev site catalogs hundreds of information and communications technologies (ICT) projects, albeit not all successful. Most of these projects use existing off-the-shelf technology designed for the industrialized world. Although it is clear that there are large differences in assumptions related to cost, power, and usage, there has been little work on how technology needs in developing regions differ from those of industrialized nations. We argue that Western market forces continue to meet the needs of developing regions accidentally at best.
The Micra transcatheter pacemaker was designed to have similar functionality to conventional transvenous VVIR pacing systems. It provides rate adaptive pacing using a programmable 3-axis ...accelerometer designed to detect patient activity in the presence of cardiac motion.
The purpose of this study was to evaluate the system's performance during treadmill tests to maximum exertion in a subset of patients within the Micra Transcatheter Pacing Study.
Patients underwent treadmill testing at 3 or 6 months postimplant with algorithm programming at physician discretion. Normalized sensor rate (SenR) relative to the programmed upper sensor rate was modeled as a function of normalized workload in metabolic equivalents (METS) relative to maximum METS achieved during the test. A normalized METS and SenR were determined at the end of each 1-minute treadmill stage. The proportionality of SenR to workload was evaluated by comparing the slope from this relationship to the prospectively defined tolerance margin (0.65-1.35).
A total of 69 treadmill tests were attempted by 42 patients at 3 and 6 months postimplant. Thirty tests from 20 patients who completed ≥4 stages with an average slope of 0.86 (90% confidence interval 0.77-0.96) confirmed proportionality to workload. On an individual test basis, 25 of 30 point estimates (83.3%) had a normalized slope within the defined tolerance range (range 0.46-1.08).
Accelerometer-based rate adaptive pacing was proportional to workload, thus confirming rate adaptive pacing commensurate to workload is achievable with an entirely intracardiac pacing system.
The work we've done in the world's developing regions has been immensely rewarding and helped make us all strong advocates for technology. The first reward is simply the experience of these ...countries, their surprising happiness, and the technology insights that come from being there. The deeper reward is of course actually helping people by creating new options through technology. However, we encountered a wide range of technical, environmental, and cultural challenges that are outside the scope of typical computer science research. In this article, we share some of our experiences with the hope of increasing understanding of these issues. We also hope to help others, particularly researchers from outside these regions, to avoid our mistakes. We document real challenges, try to generalize them, and suggest steps that might at least mitigate the problems.
In vacuum salt production sulfate is an important impurity, but it is also used to remove other cationic impurities from the raw brine. Removal of excess sulfate is currently done by purging salt ...crystallizer mother liquor from the brine plant, or crystallizing sodium sulfate through evaporative or cooling crystallization. The use of nanofiltration for the production of brines supersaturated in sodium sulfate is a technically feasible and attractive alternative. Crystallization of sodium sulfate in the membrane modules can be avoided by the presence of a primary nucleation inhibitor in the feed to the nanofiltration unit. Sodium sulfate crystallization can be induced in a separate crystallizer outside of the membrane unit by addition of crystal seeds. NF270 is a suitable membrane for this application and is preferred over Desal DK, Desal DL, TS-80 and MPF-34. Chloride and bromide retentions are negative and they are a function of the difference in sulfate concentration between concentrate and permeate. Carbonate retentions are linearly dependent on sulfate retentions. Calcium retention for NF270 is in excess of 95% and proven to be stable during 1200 h of continuous on-site pilot plant operation. The same applies for the potassium retention albeit at a lower level of 10%.
Children attending a primary school showed symptoms such as headache, cough, rhinitis and epistaxis. Assessment of specific IgE to formaldehyde gave positive results in some children.
Was ...IgE-mediated sensitization as well as symptoms in children associated with formaldehyde exposure at school?
Sixty-two 8-year-old children attending three forms at a primary school were investigated. Indoor formaldehyde concentrations were measured in classrooms of both schools (one frame construction with particleboard used extensively as panelling vs a brick building) which were consecutively attended. Assessment of specific IgE to formaldehyde was done in all children. Children were transferred to a brick building and 3 months later specific IgE to formaldehyde in pupils showing initially elevated radioallergosorbent test (RAST) values reassessed. In all children symptoms were evaluated by questionnaire before and 3 months after changing school.
In the school panelled with particleboard the World Health Organization (WHO) threshold for formaldehyde of 0.050 ppm was crossed in two classrooms (0.075 ppm and 0.069 ppm) whereas in one classroom 0.043 ppm was found. RAST classes of > or = 2 were found in three children, two of them attending the classroom with 0.075 ppm formaldehyde. Elevated RAST classes of > or = 1.3 were found in another 21 pupils. Thirty-eight pupils as well as 19 control children showed RAST classes in the normal range of < or = 1.2. Headache, nose bleeding, rhinitis, fatigue, cough, dry nasal mucosa and burning eyes were found in the affected children. There was a good correlation between symptoms and the formaldehyde concentrations in the classrooms. However, elevated IgE levels to formaldehyde did not correlate with symptoms. Formaldehyde concentrations in the classrooms of the brick built school were 0.029 ppm, 0.023 ppm and 0.026 ppm. After transferral specific IgE to formaldehyde decreased significantly from 1.7 +/- 0.5 to 1.2 +/- 0.2 (P < 0.002) as did the incidence of symptoms.
Gaseous formaldehyde, besides its irritant action, leads to IgE-mediated sensitization. As children are more sensitive to toxic substances than adults, threshold levels for indoor formaldehyde should be reduced for children.
The DTN architecture is based around sender-initiated unicast communication that is insufficient or inconvenient to meet the needs of many applications. To address these limitations, we define a DTN ...session layer and associated extensions to the DTN bundle protocol that more naturally support receiver-driven applications and multicast communication. Within a session, we provide mechanisms allowing applications to convey ordering relationships between successive transmissions that can be used by the network to help ensure a distributed application’s delivery ordering expectations are met. We also extend the bundle protocol’s expiration procedures to support more efficient network utilization by allowing in-network deletion of obsolete messages. We present the design rationale and describe our implementation of these mechanisms and discuss their advantages in meeting the needs of several popular types of applications.
Summary
Background
Children attending a primary school showed symptoms such as headache, cough, rhinitis and epistaxis. Assessment of specific IgE to formaldehyde gave positive results in some ...children.
Objective
Was IgE‐mediated sensitization as well as symptoms in children associated with formaldehyde exposure at school?
Methods
Sixty‐two 8‐year‐old children attending three forms at a primary school were investigated. Indoor formaldehyde concentrations were measured in classrooms of both schools (one frame construction with particleboard used extensively as panelling vs a brick building) which were consecutively attended. Assessment of specific IgE to formaldehyde was done in all children. Children were transferred to a brick building and 3 months later specific IgE to formaldehyde in pupils showing initially elevated radioallergosorbent test (RAST) values reassessed. In all children symptoms were evaluated by questionnaire before and 3 months after changing school.
Results
In the school panelled with particleboard the World Health Organization (WHO) threshold for formaldehyde of 0.050 ppm was crossed in two classrooms (0.075 ppm and 0.069 ppm) whereas in one classroom 0.043 ppm was found. RAST classes of >2 were found in three children, two of them attending the classroom with 0.075 ppm formaldehyde. Elevated RAST classes of ≥1.3 were found in another 21 pupils. Thirty‐eight pupils as well as 19 control children showed RAST classes in the normal range of ≤1.2. Headache, nose bleeding, rhinitis, fatigue, cough, dry nasal mucosa and burning eyes were found in the affected children. There was a good correlation between symptoms and the formaldehyde concentrations in the classrooms. However, elevated IgE levels to formaldehyde did not correlate with symptoms. Formaldehyde concentrations in the classrooms of the brick built school were 0.029 ppm, 0.023 ppm and 0.026 ppm. After transferral specific IgE to formaldehyde decreased significantly from 1.7 ± 0.5 to 1.2 ± 0.2 (P> 0.002) as did the incidence of symptoms.
Conclusion
Gaseous formaldehyde, besides its irritant action, leads to IgE‐mediated sensitization. As children are more sensitive to toxic substances than adults, threshold levels for indoor formaldehyde should be reduced for children.
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