913 resultados para Tests diagnostiques
Resumo:
Test-based assessment tools are mostly focused on the use of computers. However, advanced Information and Communication Technologies, such as handheld devices, opens up the possibilities of creating new assessment scenarios, increasing the teachers’ choices to design more appropriate tests for their subject areas. In this paper we use the term Computing-Based Testing (CBT) instead of Computer-Based Testing, as it captures better the emerging trends. Within the CBT context, the paper is centred on proposing an approach for “Assessment in situ” activities, where questions have to be answered in front of a real space/location (situ). In particular, we present the QuesTInSitu software implementation that includes both an editor and a player based on the IMS Question and Test Interoperability specification and GoogleMaps. With QuesTInSitu teachers can create geolocated questions and tests (routes), and students can answer the tests using mobile devices with GPS when following a route. Three illustrating scenarios and the results from the implementation of one of them in a real educational situation show that QuesTInSitu enables the creation of innovative, enriched and context-aware assessment activities. The results also indicate that the use of mobile devices and location-based systems in assessment activities facilitates students to put explorative and spatial skills into practice and fosters their motivation, reflection and personal observation.
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This study tests the theory of rationing, examining changes in household consumption behavior during the transition to a market economy in Poland, 1987–92. A model of consumption under rationing is developed and fitted to prereform quarterly data from the Polish Household Budget Survey. Virtual prices, prices at which consumers would have voluntarily chosen the rationed levels of goods, are derived for food and housing. The prereform Almost Ideal Demand System (AIDS) model with rationing is estimated. Estimates from the virtual AIDS yield plausible values for price and income elasticities. The AIDS model (without rationing) is also fitted to postreform quarterly household survey data for comparison and evaluation. When the two sets of results are compared, the impacts of rationing are consistent with the theory. Own-price elasticities for nonrationed goods are larger after the reform, and there is increased complementarity and decreased substitutability for the nonrationed goods. The results for Poland show a 75 percent decline in real household welfare over the transition and this welfare loss is one-third the value obtained using reported prices.
Resumo:
The McIsaac scoring system is a tool designed to predict the probability of streptococcal pharyngitis in children aged 3 to 17 years with a sore throat. Although it does not allow the physician to make the diagnosis of streptococcal pharyngitis, it enables to identify those children with a sore throat in whom rapid antigen detection tests have a good predictive value.
Resumo:
Recent progresses in genetics have opened new avenues to further our understanding of the pathophysiological mechanisms underlying cardiovascular disease, raising, new expectations in the field of personalized medicine. Genetic tests may have a high predictive value for rare monogenic diseases. The situation is very different for common polygenic diseases, such as myocardial infarction, type 2 diabetes or stroke. The results from recent genome-wide association studies have provided useful information for research, but have not yet been proven to be clinically useful. It is therefore currently not recommended to conducted genetic testing to guide cardiovascular prevention neither in clinical nor in public health settings.
Resumo:
Testosterone abuse is conventionally assessed by the urinary testosterone/epitestosterone (T/E) ratio, levels above 4.0 being considered suspicious. A deletion polymorphism in the gene coding for UGT2B17 is strongly associated with reduced testosterone glucuronide (TG) levels in urine. Many of the individuals devoid of the gene would not reach a T/E ratio of 4.0 after testosterone intake. Future test programs will most likely shift from population based- to individual-based T/E cut-off ratios using Bayesian inference. A longitudinal analysis is dependent on an individual's true negative baseline T/E ratio. The aim was to investigate whether it is possible to increase the sensitivity and specificity of the T/E test by addition of UGT2B17 genotype information in a Bayesian framework. A single intramuscular dose of 500mg testosterone enanthate was given to 55 healthy male volunteers with either two, one or no allele (ins/ins, ins/del or del/del) of the UGT2B17 gene. Urinary excretion of TG and the T/E ratio was measured during 15 days. The Bayesian analysis was conducted to calculate the individual T/E cut-off ratio. When adding the genotype information, the program returned lower individual cut-off ratios in all del/del subjects increasing the sensitivity of the test considerably. It will be difficult, if not impossible, to discriminate between a true negative baseline T/E value and a false negative one without knowledge of the UGT2B17 genotype. UGT2B17 genotype information is crucial, both to decide which initial cut-off ratio to use for an individual, and for increasing the sensitivity of the Bayesian analysis.
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While it is now well accepted that radiolabeled antibodies can be useful for tumour detection by immunoscintigraphy, the use of larger doses of more aggressive radioisotopes coupled to antibodies for radioimmunotherapy is still in its infancy. At the experimental level, our group has shown that the intravenous injection of large doses of 131I labeled F(ab')2 fragments from monoclonal anti-carcinoembryonic antigen (CEA) antibodies can eradicate well established human colon carcinoma xenografts in nude mice. At the clinical level, in a dosimetry study performed at the Institut Gustave Roussy, the same anti-CEA monoclonal antibodies and fragments, labeled with subtherapeutic doses of 131I, were injected in patients with liver metastases from colorectal carcinomas. Direct measurement of radioactivity in surgically resected liver metastases and normal liver confirmed the specificity of tumour localization of the antibodies, but also showed that the calculated radiation doses which could be delivered by injections of 200 to 300 mCi of 131I labeled antibodies or fragments, remained fairly low, in the range of 1,500 to 3,000 rads. This is obviously insufficient for a single modality treatment. An alternative approach is to inject radiolabeled antibodies intra peritoneally to treat peritoneal carcinomatosis. Several clinical studies using this strategy are presently under evaluation and suggest that positive results can be obtained when the tumour diameters are very small. In systemic radioimmunotherapy, positive results have been obtained in more radiosensitive types of malignancies such as B cell lymphomas by intravenous injection of antibodies directed against B cell differentiation markers or against idiotypic antigens from each lymphoma, and labeled with 131I or 90Y. The major directions of research for improvement of radioimmunotherapy include the design of genetically engineered new forms of humanized antibodies, the synthesis of original chelates for coupling new radioisotopes to antibodies and the development of two step strategies for immunolocalization of radioisotopes.
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Great effort is put into developing reliable, predictive, high-throughput, and low-cost screening approaches for the toxicity evaluation of ambient and manufactured nanoparticles (NP). These tests often consider oxidative reactivity, as oxidative stress is a well-documented pathway in particle toxicology. Based on a panel of six carbonaceous and five metal/metal oxide (Me/MeOx) nanoparticles, we: (i) compared the specifications (linearity, detection limits, repeatability) of three acellular reactivity tests using either dithiothreitol (DTT assay), dichlorofluorescein (DCFH assay), or ascorbic acid (AA-assay) as the reducing agent; and (ii) evaluated which physicochemical properties were important for explaining the observed reactivity. The selected AA assay was found to be neither sensitive nor robust enough to be retained. For the other tests, the surface properties of carbonaceous NP were of utmost importance for explaining their reactivity. In particular, the presence of "strongly reducing" surface functions explained most of its DCFH reactivity and a large part of its DTT reactivity. For the selected Me/MeOx, a different picture emerged. Whereas all particles were able to oxidize DCFH, dissolution and complexation processes could additionally influence the measured reactivity, as observed using the DTT assay. This study suggests that a combination of the DTT and DCFH assays provides complementary information relative to the quantification of the oxidative capacity of NP.
Resumo:
Sobriety checkpoints are not usually randomly located by traffic authorities. As such, information provided by non-random alcohol tests cannot be used to infer the characteristics of the general driving population. In this paper a case study is presented in which the prevalence of alcohol-impaired driving is estimated for the general population of drivers. A stratified probabilistic sample was designed to represent vehicles circulating in non-urban areas of Catalonia (Spain), a region characterized by its complex transportation network and dense traffic around the metropolis of Barcelona. Random breath alcohol concentration tests were performed during spring 2012 on 7,596 drivers. The estimated prevalence of alcohol-impaired drivers was 1.29%, which is roughly a third of the rate obtained in non-random tests. Higher rates were found on weekends (1.90% on Saturdays, 4.29% on Sundays) and especially at night. The rate is higher for men (1.45%) than for women (0.64%) and the percentage of positive outcomes shows an increasing pattern with age. In vehicles with two occupants, the proportion of alcohol-impaired drivers is estimated at 2.62%, but when the driver was alone the rate drops to 0.84%, which might reflect the socialization of drinking habits. The results are compared with outcomes in previous surveys, showing a decreasing trend in the prevalence of alcohol-impaired drivers over time.
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PURPOSE: To investigate the effect of intraocular straylight (IOS) induced by white opacity filters (WOF) on threshold measurements for stimuli employed in three perimeters: standard automated perimetry (SAP), pulsar perimetry (PP) and the Moorfields motion displacement test (MDT).¦METHODS: Four healthy young (24-28 years old) observers were tested six times with each perimeter, each time with one of five different WOFs and once without, inducing various levels of IOS (from 10% to 200%). An increase in IOS was measured with a straylight meter. The change in sensitivity from baseline was normalized, allowing comparison of standardized (z) scores (change divided by the SD of normative values) for each instrument.¦RESULTS: SAP and PP thresholds were significantly affected (P < 0.001) by moderate to large increases in IOS (50%-200%). The drop in motion displacement (MD) from baseline with WOF 5, was approximately 5 dB, in both SAP and PP which represents a clinically significant loss; in contrast the change in MD with MDT was on average 1 minute of arc, which is not likely to indicate a clinically significant loss.¦CONCLUSIONS: The Moorfields MDT is more robust to the effects of additional straylight in comparison with SAP or PP.