Osler and neurology.
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Bibliographies as Topic↗
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Results for “Maps as Topic”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
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Evaluation of the meningitis epidemics risk model in Africa.
Meningitis epidemics have a strong environmental component in Africa with the most severe epidemics occurring in the Sahelian region known as the Meningitis Belt. The objective of this study is to evaluate an ecological model based on absolute humidity and land cover type to predict the location of these epidemics. The risk model is evaluated prospectively based on epidemics occurring in Africa from January 2000 to April 2004. Seventy-one epidemics occurred during this time period affecting 22% of continental African districts. The model predicted their location with a sensitivity of 88%. The evaluation also suggests that epidemics may be extending south of the Sahel, which is consistent with environmental changes in the region. This model could be used to select priority areas for the introduction of the newly developed conjugate meningococcal vaccines. Further studies are needed to enhance our understanding of the complex relationship between meningitis epidemics and the environment.
Africa↗
Mapping residents' perceptions of neighborhood boundaries: a methodological note.
Neighborhood influences on children and youth are the subjects of increasing numbers of studies, but there is concern that these investigations may be biased, because they typically rely on census-based units as proxies for neighborhoods. This pilot study tested several methods of defining neighborhood units based on maps drawn by residents, and compared the results with census definitions of neighborhoods. When residents' maps were used to create neighborhood boundary definitions, the resulting units covered different space and produced different social indicator values than did census-defined units. Residents' agreement about their neighborhoods' boundaries differed among the neighborhoods studied. This pilot study suggests that discrepancies between researcher and resident-defined neighborhoods are a possible source of bias in studies of neighborhood effects.
Adult↗
Microsatellites in the sand lizard (Lacerta agilis): description, variation, inheritance, and applicability.
We developed microsatellite markers for the sand lizard (Lacerta agilis) to enable investigations of the genetic variability within and among populations with a heterogeneous spatial distribution in Sweden. The populations, which could not be characterized by variation in allozymes or mitochondrial DNA, had a substantial level of variability in microsatellite loci. However, the variability in Swedish populations was limited compared to a large, outbred Hungarian population. In the sand lizard, the number of (GT/CA)n repeats was approximately three times higher than that for (CT/GA)n. The number of repeats and the frequency of microsatellites were within the range reported for other species. Three of nine microsatellite loci showed alleles that could not be amplified, which is in agreement with recent reports describing microsatellite "null alleles" as a common occurrence. We discuss the caution which this calls for when calculating paternity probabilities and when estimating between-population allelic differentiation. A potential problem with different mutation rates for alleles within the same locus is discussed.
Alleles↗
Using hierarchical spatial models for cancer control planning in Minnesota (United States).
OBJECTIVE: Region-specific maps of cancer incidence, mortality, late detection rates, and screening rates can be very helpful in the planning, targeting, and coordination of cancer control activities. Unfortunately, past efforts in this area have been few, and have not used appropriate statistical models that account for the correlation of rates across both neighboring regions and different cancer types. In this article we develop such models, and apply them to the problem of cancer control in the counties of Minnesota during the period 1993-1997. METHODS: We use hierarchical Bayesian spatial statistical methods, implemented using modern Markov chain Monte Carlo computing techniques and software. RESULTS: Our approach results in spatially smoothed maps emphasizing either cancer prevention or cancer outcome for breast, colorectal, and lung cancer, as well as an overall map which combines results from these three individual cancers. CONCLUSIONS: Our methods enable us to produce a more statistically accurate picture of the geographic distribution of important cancer prevention and outcome variables in Minnesota, and appear useful for making decisions regarding targeting cancer control resources within the state.
Bayes Theorem↗
Comparison of ordinary and lognormal kriging on skewed data of total cadmium in forest soils of Sweden.
Spatial statistical analysis of georeferenced data of total cadmium (TCd) in forest soils of Sweden was assumed to provide more advantageous maps than traditional interpolated maps. However, 264 measurements of TCd in O-horizon of forest soils displayed skewed frequency distribution. Since atypical observations affect badly the variogram, outliers were identified, different data transformations were tested and ordinary (OK) and lognormal kriging (LK) scenarios were compared based on cross-validation. Results were compared using overall measures of predictors, e.g. traditional mean squared prediction error (MSPE), mean of kriging variances, variance ratio, median of internally standardised residuals, and assessments of classification accuracy, such as percentage of correctly predicted samples and within-class MSPE. One outlier was identified based on the absolute value of skewness of value differences less or equal to one in data pairs separated at certain lag classes. Mapping categories characterised by percentage of correct classification and within-class MSPE were found to be essential in comparison of kriging results additionally to the overall measures. In comparison of kriging methods, OK predicted high values more accurately and LK was more effective to predict low and medium values. Thus, OK was suggested for mapping high concentration of TCd and other pollutants. Percentage of correctly predicted samples and within-class MSPE were found to be dependent on kriging method, as well as on the number and limits of categories.
Cadmium↗
Concept mapping in pulmonary physiology using pathfinder scaling.
This three-part article begins with a brief presentation of a framework that describes different approaches to conduct and report research on expert knowledge. The framework contrasts direct vs. indirect approaches and provides examples of each. Second, the article gives a detailed description of the methods and results of three concept mapping studies in pulmonary physiology that employ Pathfinder scaling, an indirect approach. The studies derive concepts maps for a variety of faculty experts individually and in groups. Two of the studies focus on changes in students' concept maps of the pulmonary physiology concepts as a result of instruction. Changes are gauged in terms of the degree to which students' concept maps approximate instructors' concept maps due to educational interventions. An index of student-instructor concept map similarity is also correlated with student performance on final examinations. The article concludes by articulating several "next steps" in the Feinberg Northwestern and Wisconsin program of health sciences education research on concept mapping using Pathfinder scaling.
Adult↗
Alternative approaches to concept mapping and implications for medical education: commentary on reliability, validity and future research directions.
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Concept Formation↗
Connecting the dots: children's use of a systematic figure to facilitate mapping and search.
Organizing locations into a systematic figure was predicted to facilitate children's use of spatial relations in a mapping task. In Study 1, 3-, 4-, and 5-year-olds used a map to find a sticker hidden under 1 of 27 locations. The search locations formed a systematic figure, the outline of a dog. Half of the children were shown that the locations formed a dog. Seeing the dog pattern facilitated the performance of 5-year-olds but not that of the younger children. Study 2 indicated that children had to see a systematic figure to gain an advantage; adding lines to an unsystematic figure did not convey an advantage. Study 3 indicated that a verbal label alone could not convey an advantage. Study 4 revealed that seeing the dog pattern could also facilitate performance when the map was rotated relative to the represented space. The importance of organizing spatial information to facilitate relational thinking and mapping is discussed.
Child↗
The mental representation of knowledge acquired from maps.
Recognition priming and distance estimation were used to investigate the mental representation of knowledge acquired from maps. In Experiment 1, recognition priming showed that cities close in route distance primed each other more than cities far in route distance, even when Euclidean distance was equated. Experiment 2 showed that this finding was robust and not an artifact of the way subjects learned the maps. Distance estimations in Experiment 1 supported the priming results. These results indicated that psychological distance in cognitive maps is primarily dependent on route distance rather than Euclidean distance.
Cognition↗
Updating geographical knowledge: principles of coherence and inertia.
In 2 experiments, the authors investigated how representations of global geography are updated when people learn new location information about individual cities. Participants estimated the latitude of cities in North America (Experiment 1) and in the Old and New Worlds (Experiment 2). After making their first estimates, participants were given information about the latitudes of 2 cities and asked to make a second set of estimates. Both the first and second estimates revealed evidence for psychologically distinct geographical subregions that were coordinated, in an ordinal sense, across the Atlantic Ocean. Further, the second estimates were affected by the nature of the physical adjacency between regions (e.g., the southern U.S. and Mexico) and by accurate location information about distant, but coordinated, subregions (e.g., the southern U.S. and Mediterranean Europe). The data provide support for a framework for making geographical estimates in which people strike a balance between 2 principles: the need to keep their knowledge base coherent, and the inertial tendency to resist changing the knowledge base unless it is necessary to maintain coherence.
Cognition↗
The emergence of spatial rotation deficits in dementia and normal aging.
The mental rotation required in the Road Map Test of Direction Sense (the "Road Map Test"; J. Money, 1976; J. Money, D. Alexander, & H. T. Walker, 1965) has been thought to be impaired as a function of age, but not dementia. However, spatial rotation in dementia has not been investigated in reference to spatial coordinate systems. Patients with dementia (Alzheimer's and ischemic vascular dementias) and elderly control participants were administered the Road Map Test. The authors analyzed whether the geocentric or egocentric coordinate system determined rotation of Road Map Test turns and predicted impairment in dementia patients. They found equivalent impairment in both types of dementia, greater angulation effect in the geocentric system in patients relative to normal controls, and no egocentric effect. Results also suggest early emergence of spatial rotation deficit in dementia. Spatial rotation is most often associated with working memory, which predicts the correlations found.
Age Factors↗
Early development of scaling ability.
The map is a small-scaled version of the space it represents. It has been argued that children have difficulty interpreting maps because they do not understand scale relations. Recent research has shown that even preschoolers can solve problems that involve scaling in one dimension. This study examined whether early scaling ability extends to tasks involving two-dimensional maps and referent spaces of different sizes. Results showed that about 60% of the 4-year-olds and 90% of the 5-year-olds tested used distance information presented on a map to locate an object in a two-dimensional spatial layout. Children had more difficulties in solving mapping tasks with a larger referent space. This decrease in accuracy as a function of space size on the mapping task was greater than would have been expected on the basis of performance on a parallel nonmapping task. The results are discussed in terms of their implications for the mechanisms underlying early scaling ability.
Aptitude↗
What's in a name? In the Middle East, everything.
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Animals↗
Sound thinking.
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Environmental Monitoring↗
Noise management: sound and vision.
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Acoustic Stimulation↗