376 research outputs found
An Overview of Electronic Publishing and Extensible Markup Language (XML)
Many knowledge-based organizations are expanding their publishing efforts to include electronic publishing. This article gives evidence of this move and discusses the factors that have been instrumental in promoting electronic publishing. The importance of information stucture and adherence to open standards are emphasized as critical components of digital document management systems. The development and use of Standard Generalized Markup Language (SGML) and Hypertext Markup Language (HTML) are discussed along with their strengths and weaknesses as tools of electronic publishing. An emerging alternative, Extensible Markup Language (XML), is described as having features that may reduce some of the impediments to producing and managing documents digitally
Computer Applications in Extension Water Quality Programs
Cooperative Extension was established as an educational and problem-solving institution in 1914
A microstructure-sensitive electro-chemo-mechanical phase-field model of pitting and stress corrosion cracking
An electro-chemo-mechanical phase-field formulation is developed to simulate pitting and stress corrosion in polycrystalline materials. The formulation incorporates dependencies of mechanical properties and corrosion potential on crystallographic orientation. The model considers the formation and charging dynamics of an electric double layer through a new general boundary condition for the solution potential. The potential of the model is demonstrated by simulating corrosion in polycrystalline materials with various grain morphology distributions. The results show that incorporating the underlying microstructure yields more extensive defects, faster defect kinetics, and irregular pit and crack shapes relative to a microstructurally-insensitive homogeneous material scenario
Droplet-based digital antibiotic susceptibility screen reveals single-cell clonal heteroresistance in an isogenic bacterial population
Since antibiotic resistance is a major threat to global health, recent observations that the traditional test of minimum inhibitory concentration (MIC) is not informative enough to guide effective antibiotic treatment are alarming. Bacterial heteroresistance, in which seemingly susceptible isogenic bacterial populations contain resistant sub-populations, underlies much of this challenge. To close this gap, here we developed a droplet-based digital MIC screen that constitutes a practical analytical platform for quantifying the single-cell distribution of phenotypic responses to antibiotics, as well as for measuring inoculum effect with high accuracy. We found that antibiotic efficacy is determined by the amount of antibiotic used per bacterial colony forming unit (CFU), not by the absolute antibiotic concentration, as shown by the treatment of beta-lactamase-carrying Escherichia coli with cefotaxime. We also noted that cells exhibited a pronounced clustering phenotype when exposed to near-inhibitory amounts of cefotaxime. Overall, our method facilitates research into the interplay between heteroresistance and antibiotic efficacy, as well as research into the origin and stimulation of heterogeneity by exposure to antibiotics. Due to the absolute bacteria quantification in this digital assay, our method provides a platform for developing reference MIC assays that are robust against inoculum-density variations
A microstructure-sensitive electro-chemo-mechanical phase-field model of pitting and stress corrosion cracking
An electro-chemo-mechanical phase-field formulation is developed to simulate
pitting and stress corrosion in polycrystalline materials. The formulation
incorporates dependencies of mechanical properties and corrosion potential on
crystallographic orientation. The model considers the formation and charging
dynamics of an electric double layer through a new general boundary condition
for the solution potential. The potential of the model is demonstrated by
simulating corrosion in polycrystalline materials with various grain morphology
distributions. The results show that incorporating the underlying
microstructure yields more extensive defects, faster defect kinetics, and
irregular pit and crack shapes relative to a microstructurally-insensitive
homogeneous material scenario
Automated Global Feature Analyzer - A Driver for Tier-Scalable Reconnaissance
For the purposes of space flight, reconnaissance field geologists have trained to become astronauts. However, the initial forays to Mars and other planetary bodies have been done by purely robotic craft. Therefore, training and equipping a robotic craft with the sensory and cognitive capabilities of a field geologist to form a science craft is a necessary prerequisite. Numerous steps are necessary in order for a science craft to be able to map, analyze, and characterize a geologic field site, as well as effectively formulate working hypotheses. We report on the continued development of the integrated software system AGFA: automated global feature analyzerreg, originated by Fink at Caltech and his collaborators in 2001. AGFA is an automatic and feature-driven target characterization system that operates in an imaged operational area, such as a geologic field site on a remote planetary surface. AGFA performs automated target identification and detection through segmentation, providing for feature extraction, classification, and prioritization within mapped or imaged operational areas at different length scales and resolutions, depending on the vantage point (e.g., spaceborne, airborne, or ground). AGFA extracts features such as target size, color, albedo, vesicularity, and angularity. Based on the extracted features, AGFA summarizes the mapped operational area numerically and flags targets of "interest", i.e., targets that exhibit sufficient anomaly within the feature space. AGFA enables automated science analysis aboard robotic spacecraft, and, embedded in tier-scalable reconnaissance mission architectures, is a driver of future intelligent and autonomous robotic planetary exploration
Anticipatory regulation: lessons from fracking and insights for Greenhouse Gas Removal innovation and governance
The UK has incorporated a net-zero emissions target into national legislation. A range of Greenhouse Gas Removal (GGR) options will likely play a key role in the government's strategy toward meeting this goal. Governance frameworks will need to be developed to support GGR development and manage the potential impacts, particularly those on the diverse local communities where the various options will be deployed. This research examines the UK's experience with development and regulation of shale gas - using the technologies of hydraulic fracturing combined with horizontal drilling - with a focus on governance and the implications for the development and widespread deployment of GGR. We evaluate the approach used against the principles of good governance, which emphasizes the critical role that local communities and publics play in deployment. The UK's top-down governance of shale gas highlights the risk of regulation driven by assumptions about national and local need, value and a lack of transparency or meaningful stakeholder participation in decision-making. The use of existing legislative frameworks for conventional fossil fuel extraction proved inadequate to address unanticipated consequences such as induced seismicity. Moreover, the support for unconventional hydrocarbons in UK energy policy appeared inconsistent with the goal of meeting greenhouse gas targets and passing significant legislation in 2019 to bring carbon emissions to net-zero. To gain social acceptance at the local level, deployment of new technologies needs to be evaluated from a variety of framings and viewpoints. Where new technologies or practices are deployed, such as fracking and GGR, the knowledge and understanding of the impacts - a fundamental principle of good governance - may be less certain or more contested. Early inclusion and participation of local communities would allow issues of concern to inform how trials are undertaken and regulation designed. This anticipatory and participatory approach fits with the principles of good governance and procedural justice, which can help build the trust needed to ensure social legitimacy leading to development and implementation of technological innovations
Beta-blockers to prevent gastroesophageal varices in patients with cirrhosis.
BACKGROUND: Nonselective beta-adrenergic blockers decrease portal pressure and prevent variceal hemorrhage. Their effectiveness in preventing varices is unknown. METHODS: We randomly assigned 213 patients with cirrhosis and portal hypertension (minimal hepatic venous pressure gradient [HVPG] of 6 mm Hg) to receive timolol, a nonselective beta-blocker (108 patients), or placebo (105 patients). The primary end point was the development of gastroesophageal varices or variceal hemorrhage. Endoscopy and HVPG measurements were repeated yearly. RESULTS: During a median follow-up of 54.9 months, the rate of the primary end point did not differ significantly between the timolol group and the placebo group (39 percent and 40 percent, respectively; P=0.89), nor were there significant differences in the rates of ascites, encephalopathy, liver transplantation, or death. Serious adverse events were more common among patients in the timolol group than among those in the placebo group (18 percent vs. 6 percent, P=0.006). Varices developed less frequently among patients with a baseline HVPG of less than 10 mm Hg and among those in whom the HVPG decreased by more than 10 percent at one year and more frequently among those in whom the HVPG increased by more than 10 percent at one year. CONCLUSIONS: Nonselective beta-blockers are ineffective in preventing varices in unselected patients with cirrhosis and portal hypertension and are associated with an increased number of adverse events. (ClinicalTrials.gov number, NCT00006398.
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