978 resultados para Short-text clustering
Resumo:
Warming of the world's oceans is predicted to have many negative effects on organisms as they have optimal thermal windows. In coastal waters, however, both temperatures and pCO2 (pH) exhibit diel variations, and biological performances are likely to be modulated by physical and chemical environmental changes. To understand how coastal zooplankton respond to the combined impacts of heat shock and increased pCO2, the benthic copepod Tigriopus japonicus were treated at temperatures of 24, 28, 32 and 36 °C to simulate natural coastal temperatures experienced in warming events, when acclimated in the short term to either ambient (LC, 390 µatm) or future CO2 (HC, 1000 µatm). HC and heat shock did not induce any mortality of T. japonicus, though respiration increased up to 32 °C before being depressed at 36 °C. Feeding rate peaked at 28 °C but did not differ between CO2 treatments. Expression of heat shock proteins (hsps mRNA) was positively related to temperature, with no significant differences between the CO2 concentrations. Nauplii production was not affected across all treatments. Our results demonstrate that T. japonicus responds more sensitively to heat shocks rather than to seawater acidification; however, ocean acidification may synergistically act with ocean warming to mediate the energy allocation of copepods.
Resumo:
Ocean acidification and greenhouse warming will interactively influence competitive success of key phytoplankton groups such as diatoms, but how long-term responses to global change will affect community structure is unknown. We incubated a mixed natural diatom community from coastal New Zealand waters in a short-term (two-week) incubation experiment using a factorial matrix of warming and/or elevated pCO2 and measured effects on community structure. We then isolated the dominant diatoms in clonal cultures and conditioned them for 1 year under the same temperature and pCO2 conditions from which they were isolated, in order to allow for extended selection or acclimation by these abiotic environmental change factors in the absence of interspecific interactions. These conditioned isolates were then recombined into 'artificial' communities modelled after the original natural assemblage and allowed to compete under conditions identical to those in the short-term natural community experiment. In general, the resulting structure of both the unconditioned natural community and conditioned 'artificial' community experiments was similar, despite differences such as the loss of two species in the latter. pCO2 and temperature had both individual and interactive effects on community structure, but temperature was more influential, as warming significantly reduced species richness. In this case, our short-term manipulative experiment with a mixed natural assemblage spanning weeks served as a reasonable proxy to predict the effects of global change forcing on diatom community structure after the component species were conditioned in isolation over an extended timescale. Future studies will be required to assess whether or not this is also the case for other types of algal communities from other marine regimes.
Resumo:
In this paper we investigate whether conventional text categorization methods may suffice to infer different verbal intelligence levels. This research goal relies on the hypothesis that the vocabulary that speakers make use of reflects their verbal intelligence levels. Automatic verbal intelligence estimation of users in a spoken language dialog system may be useful when defining an optimal dialog strategy by improving its adaptation capabilities. The work is based on a corpus containing descriptions (i.e. monologs) of a short film by test persons yielding different educational backgrounds and the verbal intelligence scores of the speakers. First, a one-way analysis of variance was performed to compare the monologs with the film transcription and to demonstrate that there are differences in the vocabulary used by the test persons yielding different verbal intelligence levels. Then, for the classification task, the monologs were represented as feature vectors using the classical TF–IDF weighting scheme. The Naive Bayes, k-nearest neighbors and Rocchio classifiers were tested. In this paper we describe and compare these classification approaches, define the optimal classification parameters and discuss the classification results obtained.
Resumo:
Course Title: HERSTORIES – Women Writers of Missouri Course Instructor: kYmberly Keeton, M.L.S. Course Focus: Introduce students and community members to women writers in the state of Missouri. Dates for Course: March 22nd, April 12th, April 26th, and May 3rd Meeting Times: 11:00 AM -12:30 PM Course Info: All materials are provided by the library. Course Website: www.herstories365.wordpress.com
Resumo:
As a result of alternative splicing, the D2 gene of the dopamine receptor family exists in two isoforms. The D2 long is characterized by the insertion of 29 amino acids in the third cytoplasmic loop, which is absent in the short isoform. We have produced subtype-specific antibodies against both the D2 short and D2 long isoforms and found a unique compartmentalization between these two isoforms in the primate brain. The D2 short predominates in the cell bodies and projection axons of the dopaminergic cell groups of the mesencephalon and hypothalamus, whereas the D2 long is more strongly expressed by neurons in the striatum and nucleus accumbens, structures targeted by dopaminergic fibers. These results show that the splice variants of the dopamine D2 receptor are differentially distributed and possess distinct functions. The strategic localization of the D2 short isoform in dopaminergic cell bodies and axons strongly suggests that this isoform is the likely dopamine autoreceptor, whereas the D2 long isoform is primarily a postsynaptic receptor.