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Patterns Underlying (pattern + underlying)
Selected AbstractsThe mouse MPTP model: gene expression changes in dopaminergic neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2003Kati Kühn Abstract Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Although valuable animal models have been developed, our knowledge of the aetiology and pathogenic factors implicated in PD is still insufficient to develop causal therapeutic strategies aimed at halting its progression. The neurotoxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is one of the most valuable models for analysing pathological aspects of PD. In this paper we studied the gene expression patterns underlying the pathogenesis of MPTP-induced neurodegeneration. We treated young and old C57BL/6 mice with different schedules of MPTP to induce degenerative processes that vary in intensity and time-course. During the first week after intoxication we used nonradioactive in situ -hybridization to investigate the expression patterns of genes associated with (i) dopamine metabolism and signalling; (ii) familial forms of PD; (iii) protein folding and (iv) energy metabolism. MPTP injections induced different severities of neuronal injury depending on the age of the animals and the schedule of administration as well as a significant degeneration in the striatum. In situ hybridization showed that MPTP intoxication initiated a number of gene expression changes that (i) were restricted to the neurons of the substantia nigra pars compacta; (ii) were correlated in intensity and number of changes with the age of the animals and the severity of histopathological disturbances; (iii) displayed in each a significant down-regulation by the end of one week after the last MPTP injection, but (iv) varied within one MPTP regimen in expression levels during the observation period. The subacute injection of MPTP into one-year-old mice induced the most severe changes in gene expression. All genes investigated were affected. However, ,-synuclein was the only gene that was exclusively up-regulated in MPTP-treated animals displaying cell death. [source] Applying Conceptual Grammar to Advanced-Level Language Teaching: The Case of Two Completive Constructions in KoreanMODERN LANGUAGE JOURNAL, Issue 2 2006SUSAN STRAUSS This article introduces conceptual grammar as an approach to the analysis and teaching of grammar in foreign and second language contexts through a combination of paradigms: corpus, discourse analysis, and cognitive linguistics. Although the approach is applicable to virtually any language and any construction within that language at various levels of study, we provide a detailed demonstration using Korean as a model. In particular, we focus on constructions expressing the completive aspect. The Korean system of marking aspect can be quite complex; what renders the Korean completive even more perplexing is the fact that it is expressed through two seemingly similar auxiliary forms, each of which signals different elements in the speaker's or writer's stance vis-à-vis the described event. By combining the paradigms of corpus, discourse analysis, and cognitive linguistics, the article demonstrates how a conceptual grammatical approach can render salient the particular discursive and conceptual patterns underlying the target forms. It is designed as a pedagogical tool to guide users to discern both inductively and deductively how native speakers conceptualize these differences and express them morphosyntactically,a perspective that is absent from most existing reference grammars and textbooks. In this article, we present samples of pedagogical materials developed using this model in addition to results of an experiment in which a version of those materials was administered to teachers and students of advanced Korean. [source] Energetic costs, underlying resource allocation patterns, and adaptive value of predator-induced life-history shiftsOIKOS, Issue 2 2008Karsten Rinke We studied costs and benefits of life history shifts of water fleas (genus Daphnia) in response to infochemicals from planktivorous fish. We applied a dynamic energy budget model to investigate the resource allocation patterns underlying the observed life history shifts and their adaptive value under size selective predation in one coherent analysis. Using a published data set of life history shifts in response to fish infochemicals we show that Daphnia invests less energy in somatic growth in the fish treatment. This observation complies with theoretical predictions on optimal resource allocation. However, the observed patterns of phenotypic plasticity cannot be explained by changes in resource allocation patterns alone because our model-based analysis of the empirical data clearly identified additional bioenergetic costs in the fish treatments. Consequently, the response to fish kairomone only becomes adaptive if the intensity of size selective predation surpasses a certain critical level. We believe that this is the first study that puts resource allocation, energetic costs, and adaptive value of predator induced life-history shifts , using empirical data , into one theoretical framework. [source] Ecogeographic size variation in small-bodied subfossil primates from Ankilitelo, Southwestern MadagascarAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2007Kathleen M. Muldoon Abstract Variation in body size is well documented for both extant and extinct Malagasy primates, and appears to be correlated with geographic patterns of resource seasonality. Less attention has been paid to extant lemurs in subfossil collections, although it has been suggested that subfossil forms of extant species are characterized by greater size than their modern counterpart. This trend of phyletic size change has been related to climate change, habitat fragmentation, or human hunting. However, space- and time-averaging in the subfossil samples of previous studies may have obscured more general ecogeographic patterns underlying these size differences. Our objective is to examine size variation in subfossil still-extant primates within a regional comparative context to determine if subfossil and living forms conform to similar ecogeographic patterns. We report on the subfossil still-extant primate assemblage from Ankilitelo, southwestern Madagascar (,500 yr BP) to test this hypothesis. The Ankilitelo primates were compared with museum specimens of known locality. Extant taxa were assigned to one of five distinct ecogeographic regions, including spiny thicket, dry deciduous forest, succulent woodland, lowland and subhumid rainforest. Comparisons of tooth size in extant lemurs reveal significant geographical patterns of variation within genera. In general, the primates from Ankilitelo are indeed larger than their modern counterpart. However, these differences fit an ecoregional model of size variation, whereby Ankilitelo species are comparable in size to living forms inhabiting ecoregions present near the cave today. This suggests that Malagasy primates have been subjected to similar patterns of resource seasonality for at least 500 years. Am J Phys Anthropol, 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||