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Qualitative Shift (qualitative + shift)
Selected AbstractsModeling Infant Speech Sound Discrimination Using Simple Associative NetworksINFANCY, Issue 1 2001Graham Schafer Infants' responses in speech sound discrimination tasks can be nonmonotonic over time. Stager and Werker (1997) reported such data in a bimodal habituation task. In this task, 8-month-old infants were capable of discriminations that involved minimal contrast pairs, whereas 14-month-old infants were not It was argued that the older infants' attenuated performance was linked to their processing of the stimuli for meaning. The authors suggested that these data are diagnostic of a qualitative shift in infant cognition. We describe an associative connectionist model showing a similar decrement in discrimination without any qualitative shift in processing. The model suggests that responses to phonemic contrasts may be a nonmonotonic function of experience with language. The implications of this idea are discussed. The model also provides a formal framework fer studying habituation-dishabituation behaviors in infancy. [source] IDENTIFYING CAUSALITY IN PUBLIC INSTITUTIONAL CHANGE: THE ADAPTATION OF THE NATIONAL ASSEMBLY FOR WALES TO THE EUROPEAN UNIONPUBLIC ADMINISTRATION, Issue 2 2008CAITRÍONA A. CARTER The aim of this article is to identify causes and effects of public institutional change. Analysis is centred on those endogenous, not exogenous, sources of political change that account for the institutional metamorphosis of the Welsh Assembly in its engagement with UK-EU processes since 1999. The central research question addressed is to explain a qualitative shift in the logic of action of Assembly engagement, resulting in the conduct of a territorially sensitive ,parliamentary' EU scrutiny, but within a model of executive devolution. To capture agency and change, and to engage with sociological institutionalist debates, the article develops analytical tools of ,framing' and ,operationalizing' institutions to study the interplay between informal and formal processes of institution building since devolution. In so doing, we place refined sociological conceptions of institutions at the heart of analyses of political discontinuity and theorization of public institutional change. [source] Bacterial vaginosis , a microbiological and immunological enigma,APMIS, Issue 2 2005Review article The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria. [source] Game Vertebrate Densities in Hunted and Nonhunted Forest Sites in Manu National Park, PeruBIOTROPICA, Issue 2 2010Whaldener Endo ABSTRACT Manu National Park of southern Peru is one of the most renowned protected areas in the world, yet large-bodied vertebrate surveys conducted to date have been restricted to Cocha Cashu Biological Station, a research station covering <0.06 percent of the 1.7 Mha park. Manu Park is occupied by >460 settled Matsigenka Amerindians, 300,400 isolated Matsigenka, and several, little-known groups of isolated hunter,gatherers, yet the impact of these native Amazonians on game vertebrate populations within the park remains poorly understood. On the basis of 1495 km of standardized line-transect censuses, we present density and biomass estimates for 23 mammal, bird, and reptile species for seven lowland and upland forest sites in Manu Park, including Cocha Cashu. We compare these estimates between hunted and nonhunted sites within Manu Park, and with other Neotropical forest sites. Manu Park safeguards some of the most species-rich and highest biomass assemblages of arboreal and terrestrial mammals ever recorded in Neotropical forests, most likely because of its direct Andean influence and high levels of soil fertility. Relative to Barro Colorado Island, seed predators and arboreal folivores in Manu are rare, and generalist frugivores specializing on mature fruit pulp are abundant. The impact of such a qualitative shift in the vertebrate community on the dynamics of plant regeneration, and therefore, on our understanding of tropical plant ecology, must be profound. Despite a number of external threats, Manu Park continues to serve as a baseline against which other Neotropical forests can be gauged. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp. [source] The influence of synthetic sheep urine on ammonia oxidizing bacterial communities in grassland soilFEMS MICROBIOLOGY ECOLOGY, Issue 3 2006Shahid Mahmood Abstract In grazed, grassland soils, sheep urine generates heterogeneity in ammonia concentrations, with potential impact on ammonia oxidizer community structure and soil N cycling. The influence of different levels of synthetic sheep urine on ammonia oxidizers was studied in grassland soil microcosms. ,Total' and active ammonia oxidizers were distinguished by comparing denaturing gradient gel electrophoresis (DGGE) profiles following PCR and RT-PCR amplification of 16S rRNA gene fragments, targeting DNA and RNA, respectively. The RNA-based approach indicated earlier, more reproducible and finer scale qualitative shifts in ammonia oxidizing communities than DNA-based analysis, but led to amplification of a small number of nonammonia oxidizer sequences. Qualitative changes in RNA-derived DGGE profiles were related to changes in nitrate accumulation. Sequence analysis of excised DGGE bands revealed that ammonia oxidizing communities in synthetic sheep urine-treated soils consisted mainly of Nitrosospira clusters 2, 3 and 4. Nitrosospira cluster 2 increased in relative abundance in microcosms treated with all levels of synthetic sheep urine. Low levels additionally led to increased relative abundance of Nitrosospira cluster 4 and medium and high levels increased relative abundance of cluster 3. Synthetic sheep urine is therefore likely to influence the spatial distribution and composition of ammonia oxidizer communities, with consequent effects on nitrate accumulation. [source] Modeling Age Differences in Infant Category LearningINFANCY, Issue 2 2004Thomas R. Shultz We used an encoder version of cascade correlation to simulate Younger and Cohen's (1983, 1986) finding that 10-month-olds recover attention on the basis of correlations among stimulus features, but 4- and 7-month-olds recover attention on the basis of stimulus features. We captured these effects by varying the score threshold parameter in cascade correlation, which controls how deeply training patterns are learned. When networks learned deeply, they showed more error to uncorrelated than to correlated test patterns, indicating that they abstracted correlations during familiarization. When prevented from learning deeply, networks decreased error during familiarization and showed as much error to correlated as to uncorrelated tests but less than to test items with novel features, indicating that they learned features but not correlations among features. Our explanation is that older infants learn more from the same exposure than do younger infants. Unlike previous explanations that postulate unspecified qualitative shifts in processing with age, our explanation focuses on quantitatively deeper learning with increasing age. Finally, we provide some new empirical evidence to support this explanation. [source] Funds of knowledge and discourses and hybrid spaceJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 1 2009Angela Calabrese Barton Abstract The findings reported on in this manuscript emerged from a design experiment conducted at a low-income urban middle school intended to support the teacher in incorporating pedagogical practices supportive of students' everyday knowledge and practices during a 6th grade unit on food and nutrition from the LiFE curriculum. In studying the impact of the design experiment we noticed qualitative shifts in classroom Discourse marked by a changing role and understandings of the funds of knowledge students brought to science learning. Using qualitative data and grounded theory we present an analysis of the different types of funds of knowledge and Discourse that students brought into science class. We focus on how the students' strategic use of these funds augmented the learning experience of the students and the learning community as well as the learning outcomes. We discuss the implications these funds of knowledge and Discourses had on the development of three related third space transformations: physical, political, and pedagogical. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 46: 50,73, 2009 [source] | |||||||||||||