4,783 research outputs found
Implementation of liquid culture for tuberculosis diagnosis in a remote setting: lessons learned.
Although sputum smear microscopy is the primary method for tuberculosis (TB) diagnosis in low-resource settings, it has low sensitivity. The World Health Organization recommends the use of liquid culture techniques for TB diagnosis and drug susceptibility testing in low- and middle-income countries. An evaluation of samples from southern Sudan found that culture was able to detect cases of active pulmonary TB and extra-pulmonary TB missed by conventional smear microscopy. However, the long delays involved in obtaining culture results meant that they were usually not clinically useful, and high rates of non-tuberculous mycobacteria isolation made interpretation of results difficult. Improvements in diagnostic capacity and rapid speciation facilities, either on-site or through a local reference laboratory, are crucial
Proposal for a Universal Particle Detector Experiment
The Universal Particle Detector Experiment (UPDE), which consists of parallel planes of two diode laser beams of different wavelengths and a large surface metal oxide semiconductor (MOS) impact detector, is proposed. It will be used to perform real-time monitoring of contamination particles and meteoroids impacting the spacecraft surface with high resolution of time, position, direction, and velocity. The UPDE will discriminate between contaminants and meteoroids, and will determine their velocity and size distribution around the spacecraft environment. With two different color diode lasers, the contaminant and meteroid composition will also be determined based on laboratory calibration with different materials. Secondary particles dislodged from the top aluminum surface of the MOS detector will also be measured to determine the kinetic energy losses during energetic meteoroid impacts. The velocity range of this instrument is 0.1 m/s to more than 14 km/s, while its size sensitivity is from 0.2 microns to millimeter-sized particles. The particulate measurements in space of the kind proposed will be the first simultaneous multipurpose particulate experiment that includes velocities from very slow to hypervelocities, sizes from submicrometer- to pellet-sized diameters, chemical analysis of the particulate composition, and measurements of the kinetic energy losses after energetic impacts of meteroids. The experiment will provide contamination particles and orbital debris data that are critically needed for our present understanding of the space environment. The data will also be used to validate contamination and orbital debris models for predicting optimal configuration of future space sensors and for understanding their effects on sensitive surfaces such as mirrors, lenses, paints, and thermal blankets
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The Participatory Process: Producing Photoliterature
This note describes a step-by-step process for involving learners in the development, production and evaluation of various types of photoliterature including fotonovellas. Technical information on photographic techniques is presented to assist educators in the participatory process.
In this manual, we have given suggestions on how to combine participation and the development of photo-literature. First, we consider the rationales for learner-produced materials. In the second section we discuss the participatory process and focus on the relationship of the facilitator (probably you) to the participants and how the facilitator can enhance or inhibit the process. The third section is designed to answer the technical questions a facilitator may have regarding how to put a fotonovela together. The technical aspects are about the same for all types of photo-literature. Participation is difficult to discuss and understand in a vacuum, and, therefore, we have integrated participatory process boxes throughout the technical section to give specific suggestions on how to increase participation in the context of specific technical problems. In the fourth section we discuss some considerations in summative evaluation, following in the last section with an examination of some of the pros and cons of various photo-literature formats
The Ranger 4 Flight Path and Its Determination from Tracking Data
The ranger iv flight path and its determination from tracking dat
Fluctuating Hall resistance defeats the quantized Hall insulator
Using the Chalker-Coddington network model as a drastically simplified, but
universal model of integer quantum Hall physics, we investigate the
plateau-to-insulator transition at strong magnetic field by means of a
real-space renormalization approach. Our results suggest that for a fully
quantum coherent situation, the quantized Hall insulator with R_H approx. h/e^2
is observed up to R_L ~25 h/e^2 when studying the most probable value of the
distribution function P(R_H). Upon further increasing R_L ->\infty the Hall
insulator with diverging Hall resistance R_H \propto R_L^kappa is seen. The
crossover between these two regimes depends on the precise nature of the
averaging procedure.Comment: major revision, discussion of averaging improved; 8 pages, 7 figures;
accepted for publication in EP
Garside and quadratic normalisation: a survey
Starting from the seminal example of the greedy normal norm in braid monoids,
we analyse the mechanism of the normal form in a Garside monoid and explain how
it extends to the more general framework of Garside families. Extending the
viewpoint even more, we then consider general quadratic normalisation
procedures and characterise Garside normalisation among them.Comment: 30 page
On the informational content of wage offers
This article investigates signaling and screening roles of wage offers in a single-play matching model with two-sided unobservable characteristics. It generates the following predictions as matching equilibrium outcomes: (i) “good” jobs offer premia if “high-quality” worker population is large; (ii) “bad” jobs pay compensating differentials if the proportion of “good” jobs to “low-quality” workers is large; (iii) all firms may offer a pooling wage in markets dominated by “high-quality” workers and firms; or (iv) Gresham’s Law prevails: “good” types withdraw if “bad” types dominate the population. The screening/signaling motive thus has the potential of explaining a variety of wage patterns
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