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Clear Demarcation (clear + demarcation)
Selected AbstractsMutual-information-based approach for neural connectivity during self-paced finger lifting taskHUMAN BRAIN MAPPING, Issue 3 2008Chun-Chuan Chen Abstract Frequency-dependent modulation between neuronal assemblies may provide insightful mechanisms of functional organization in the context of neural connectivity. We present a conjoined time-frequency cross mutual information (TFCMI) method to explore the subtle brain neural connectivity by magnetoencephalography (MEG) during a self-paced finger lifting task. Surface electromyogram (sEMG) was obtained from the extensor digitorum communis. Both within-modality (MEG-MEG) and between-modality studies (sEMG-MEG) were conducted. The TFCMI method measures both the linear and nonlinear dependencies of the temporal dynamics of signal power within a pre-specified frequency band. Each single trial of MEG across channels and sEMG signals was transformed into time-frequency domain with use of the Morlet wavelet to obtain better temporal spectral (power) information. As compared to coherence approach (linear dependency only) in broadband analysis, the TFCMI method demonstrated advantages in encompassing detection for the mesial frontocentral cortex and bilateral primary sensorimotor areas, clear demarcation of event- and non-event-related regions, and robustness for sEMG - MEG between-modality study, i.e., corticomuscular communication. We conclude that this novel TFCMI method promises a possibility to better unravel the intricate functional organizations of brain in the context of oscillation-coded communication. Hum Brain Mapp, 2008. © 2007 Wiley-Liss, Inc. [source] Fluorescent imaging in a glioma model in vivoLASERS IN SURGERY AND MEDICINE, Issue 1 2001Dimitrios C. Nikas MD Abstract Background and Objective Nile blue dyes have been shown to have affinity for tumor tissue as compared to surrounding normal tissue and to be relatively non-toxic. We have employed EtNBA, a lipophilic, fluorescent benzophenoxazine dye, in a murine model to image subcutaneous and intracranial U-87 glioma implants. Study Design/Materials and Methods The imaging system used to detect fluorescence consists of a SIT video camera fitted with a zoom microscope-magnifying lens. The tumor was illuminated with a 632.8-nm diffuse beam from a helium,neon laser. The video image was processed using a Sony image processor to give real-time pseudocolor and enhanced black and white images. Results Following subcutaneous injection of the dye at doses of 2.5,5.0 mg/kg bw, we observed a gradual increase of the fluorescent signal from the tumor which peaked 1,3 hours post-injection with variable selectivity (typically 4:1) for tumor to normal surrounding tissues permitting the clear demarcation of the tumor. Conclusions The present in vivo study demonstrates that EtNBA is a safe and effective photodiagnostic agent, able to demarcate U87-MG solid tumors in mice on a real-time basis at a concentration of 2.5,5.0 mg/kg 1,3 hours after administration. Lasers Surg. Med. 29:11,17, 2001. © 2001 Wiley-Liss, Inc. [source] Teaching and Learning Guide for: Locutionary, Illocutionary, PerlocutionaryLINGUISTICS & LANGUAGE COMPASS (ELECTRONIC), Issue 9 2010Mikhail Kissine This guide accompanies the following article: Mikhail Kissine, ,Locutionary, Illocutionary, Perlocutionary', Language and Linguistics Compass 2/6 (2008) pp. 1189,1202. DOI: 10.1111/j.1749-818x.2008.00093.x. The terms locutionary act, illocutionary act and perlocutionary act originate from Austin's classical How to do with words. The corresponding notions, however, prove difficult to define. Yet, lack of careful delineating of each level can lead to important theoretical confusions. This Teaching and Learning Guide explains why proper understanding of Austin's trichotomy is crucial for semantics and pragmatics. Author's Introduction Most contemporary discussions in semantics and pragmatics employ , implicitly or explicitly , some or all of the concepts of locutionary,illocutionary or perlocutionary acts. These notions originate from Austin's posthumous and notoriously intricate book, How to do things with words. The point of interest for the linguist, however, is not so much the exegesis of Austin's ideas, as the precise delimitation of these levels of meaning. First, it is important to characterise the locutionary level , which falls short of any illocutionary force , to avoid contaminating analyses of utterance meanings with matters relative to the illocutionary level, viz. to the speech act performed. Second, the precise definition of illocutionary acts is an extremely difficult matter. However, the first, imperative step must be a clear demarcation between perlocutionary acts , relative to causal effects of the utterances , and the utterance's illocutionary force. Third, to assess theories of illocutionary forces, one must take into account the requirements for psychological and empirical plausibility. For instance, classical Gricean theories of illocutionary force attribution link it with the cognitive capacity to perform complex multi-layered mental state attributions, which is incompatible with the data available on the pragmatic and cognitive functioning of young children. In sum, gaining better understanding of the tripartite distinction between the locutionary, illocutionary and perlocutionary levels is not a taxonomical exercise, but a prerequisite for anyone willing to tackle semantic and/or pragmatic issues with the right tools. Suggested Reading Austin, J.L. (1975) How to do things with words, Second edition, Oxford, Oxford University Press. Lecture VIII. Difficult reading, but essential to understand Austin's intuitions and the origin of the debate. Strawson, P.F. (1964) "Intention and convention in speech acts", Philosophical Review, 73, 439,60. Classical criticism of Austin's claim abut the conventionality of illocutionary acts and first formulation of a Gricean theory of speech acts. Strawson, P.F. (1973) "Austin and ,Locutionary meaning'", in I. Berlin et al. (eds.) Essays on J.L. Austin, Oxford, Clarendon Press, 46,68. This equally classical paper sheds light onto the difficult notions of rhetic and locutionary acts; it paves the way for using these concepts interchangeably. Recanati, F. (1987) Meaning and Force. The pragmatics of performative utterances, Cambridge, Cambridge University Press. Chapter 9. This is a lucid discussion and elaboration of Strawson's conception of the locuitonary act as a potential for the illocutionary level. Wilson, D. and Sperber, D. (1988) "Mood and the analysis of non-declarative sentences", in J. Dancy et al. (eds.) Human Agency, Language, Duty and Value. Philosophical essayes in honour of J.O. Urmson, Stanford, Stanford University Press, 77,101. This paper gives important reasons for not confusing the analysis of mood , of the locutionary level , with the analysis of speech acts. Kissine, M. (2009) "Illocutionary forces and what is said", Mind and Language, 24, 122,38. Provides a definition of locutionary acts as linguistic representations of mental states, and lays grounds for a theory of speech acts as reasons to believe or to act. Bach, K. (1994) "Conversational impliciture", Mind and Language, 9, 124,62. An important defence of the distinction between illocutionary and locutionary acts. However, the reader should be warned that Bach conceives of locutionary acts as context-independent propositional radicals, which is not a self-evident position. Alston (2000) Illocutionary Acts and Sentence Meaning, Ithaca, Cornell University Press, Chapter 2. Contains a clear and lucid criticism of theories that confuse illocutionary and perlocutionary levels. Dominicy, M. (2008) "Epideictic rhetoric and the representation of human decision and choice", in K. Korta and J. Garmendia (eds.) Meaning, Intentions, and Argumentation, Stanford, CSLI, 179,207. This paper contains a useful test for distinguishing verbs that describe illocutionary acts form those that describe perlocutionary acts. It is also the first proposal to formulate the illocutionary/perlocutionary divide in Davidsonian terms. Focus Questions 1,What kind of philosophy of action is called for by the distinction between locutions, perlocutions and illocutions? 2,Should the locutionary level be always fully propositional? 3,Can illocutionary acts be characterised in terms of prototypical perlocutional effects? 4,Should illocutionary acts be divided in conventional (institutional) and non-conventional (non-insitutional) ones? 5,Are there good reasons for singling out a locutionary level? 6,,Does the attribution of illocutionary forces presuppose a complex mindreading process? Connexion with to Related Material in Lectures or Discussions 1,The distinction between the locutionary and illocutionary levels is crucial for any discussion about the semantics/pragmatics interface. Many scholars hastily characterise semantics as related to sentence-meaning and pragmatics as concerning the speech act performed. However, one should not take for granted that any level where the meaning is context-dependant is necessarily that of the illocutionary act performed. 2,This distinction can also be relevant for the discussions about the meaning of moods. For instance, the imperative mood is often analysed in terms of the directive illocutionary force. However, there are cases where utterances of imperative sentences do not correspond to a directive speech act. 3,The distinction between perlocutionary and illocutionary acts remains central for any attempt to classify or to define illocutionary forces. 4,Different conceptions of illocutionary acts are important for discussions about the ontogeny and phylogeny of the pragmatic dimension(s) of linguistic competence. [source] Photocatalytic Coatings for Environmental Applications,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Norman S. Allen ABSTRACT A series of nano- and micronparticle-grade anatase and rutile titanium dioxide pigments have been prepared with various densities of surface treatments, particle size and surface area. Their photocatalytic activities have been determined in a series of paint films by FTIR, chalking, color, gloss change and weight loss after artificial weathering. The pigments have also been examined by rapid assessment methodologies using photodielectric microwave spectroscopy, 2-propanol oxidation and hydroxyl analysis. The microwave response under light and dark cycles provides an extended timescale probe of chargecarrier dynamics in the pigments. Pigment particle size, surface area and properties clearly play an important role in dispersion and any polymer-pigment interactions. Photooxidation studies on several types of paint films show a clear demarcation between nanoparticle- and pigmentary-grade titanium dioxide, with the former being more active because of their greater degree of catalytic surface activity. The photosensitivity of titanium dioxide is considered to arise from localized sites on the crystal surface (i.e. acidic OH), and occupation of these sites by surface treatments inhibits photoreduction of the pigment by ultraviolet radiation; hence, the destructive oxidation of the binder is inhibited. Coatings containing 2,5% by weight alumina or alumina and silica are satisfactory for generalpurpose paints. If greater resistance to weathering is desired, the pigments are coated more heavily to about 7,10% weight. The coating can consist of a combination of several materials, e.g. alumina, silica, zirconia, aluminum phosphates of other metals. For example, the presence of hydrous alumina particles lowers van der Waals forces between pigments particles by several orders of magnitude, decreasing particle-particle attractions. Hydrous aluminum oxide phases appear to improve dispersibility more effectively than most of the other hydroxides and oxides. Coated nanoparticles are shown to exhibit effective light stabilization in various water- and oilbased paint media in comparison with conventional organic stabilizers. Hindered piperidine stabilizers are shown to provide no additional benefits in this regard, often exhibiting strong antagonism. The use of photocatalytic titania nanoparticles in the development of self-cleaning paints and microbiological surfaces is also demonstrated in this study. In the former case, surface erosion is shown to be controlled by varying the ratio of admixture of durable pigmentary-grade rutile (heavily coated) and a catalytic-grade anatase nanoparticle. For environmental applications in the development of coatings for destroying atmospheric pollutants such as nitrogen oxide gases (NOX), stable substrates are developed with photocatalytic nanoparticle-grade anatase. In this study, porosity of the coatings through calcium carbonate doping is shown to be crucial in the control of the effective destruction of atmospheric NOx gases. For the development of microbiological substrates for the destruction of harmful bacteria, effective nanoparticle anatase titania is shown to be important, with hydrated high surface area particles giving the greatest activity. [source] | ||||||||||