A ambivalência da opinião pública em Georg WF Hegel

A concepção hegeliana da Opinião Pública é um dos mais interessantes entendimentos estando reservado ao conceito um papel determinante dentro das mediações lógico-políticas. Hegel concedelhe inclusivamente uma força transformadora enquanto agente histórico e social. Nesta reflexão, apresentamos o modo como Georg WF Hegel descreve a Opinião Pública no quadro da sua Filosofia Política. Concentrando-nos nos Princípios da Filosofia do Direito, discutiremos a centralidade do princípio de publicidade e da comunicação nas relações políticas. No pensamento de Hegel, a publicidade não é tanto condição moral e política quanto um princípio inabalável da consciência do sujeito livre. É indissociável da liberdade formal e da liberdade subjectiva de opinar. O sujeito livre da modernidade resulta do processo do Espírito onde a contradição comanda o movimento de consciência. Na génese do espírito público, encontramos a oposição entre a consciência privada e a consciência pública. A Opinião Pública vive, pois, por entre esta dualidade de responder a exigências éticas e simultaneamente emanar de interesses particulares privados. A ambivalência da Opinião Pública decorre, então, do seu carácter eminentemente contraditório. Eis uma Opinião Pública em movimento perpétuo atravessada pelo particular e pelo universal. Verdade e erro compõemna. Esta é a inerente contradição que resume o estatuto ambivalente que Hegel concede à Opinião Pública. E esta é, talvez, a maior contribuição de Hegel para reflectirmos sobre o conceito na contemporaneidade.

A ambivalência da opinião pública em Georg WF Hegel

A concepção hegeliana da Opinião Pública é um dos mais interessantes entendimentos estando reservado ao conceito um papel determinante dentro das mediações lógico-políticas. Hegel concedelhe inclusivamente uma força transformadora enquanto agente histórico e social. Nesta reflexão, apresentamos o modo como Georg WF Hegel descreve a Opinião Pública no quadro da sua Filosofia Política. Concentrando-nos nos Princípios da Filosofia do Direito, discutiremos a centralidade do princípio de publicidade e da comunicação nas relações políticas. No pensamento de Hegel, a publicidade não é tanto condição moral e política quanto um princípio inabalável da consciência do sujeito livre. É indissociável da liberdade formal e da liberdade subjectiva de opinar. O sujeito livre da modernidade resulta do processo do Espírito onde a contradição comanda o movimento de consciência. Na génese do espírito público, encontramos a oposição entre a consciência privada e a consciência pública. A Opinião Pública vive, pois, por entre esta dualidade de responder a exigências éticas e simultaneamente emanar de interesses particulares privados. A ambivalência da Opinião Pública decorre, então, do seu carácter eminentemente contraditório. Eis uma Opinião Pública em movimento perpétuo atravessada pelo particular e pelo universal. Verdade e erro compõemna. Esta é a inerente contradição que resume o estatuto ambivalente que Hegel concede à Opinião Pública. E esta é, talvez, a maior contribuição de Hegel para reflectirmos sobre o conceito na contemporaneidade.

Elevated uric acid correlates with wound severity

Chronic venous leg ulcers are a major health issue and represent an often overlooked area of biomedical research. Nevertheless, it is becoming increasingly evident that new approaches to enhance healing outcomes may arise through better understanding the processes involved in the formation of chronic wounds. We have for the first time shown that the terminal purine catabolite uric acid (UA) is elevated in wound fluid (WF) from chronic venous leg ulcers with relative concentrations correlating with wound chronicity. We have also shown a corresponding depletion in UA precursors, including adenosine, with increased wound severity. Further, we have shown that xanthine oxidase, the only enzyme in humans that catalyses the production of UA in conjunction with a burst of free radicals, is active in chronic WF. Taken together, this provides compelling evidence that xanthine oxidase may play a critical role in the formation of chronic wounds by prolonging the inflammatory process.

fMRI evidence of word frequency and strength effects during episodic memory encoding

Word frequency (WF) and strength effects are two important phenomena associated with episodic memory. The former refers to the superior hit-rate (HR) for low (LF) compared to high frequency (HF) words in recognition memory, while the latter describes the incremental effect(s) upon HRs associated with repeating an item at study. Using the "subsequent memory" method with event-related fMRI, we tested the attention-at-encoding (AE) [M. Glanzer, J.K. Adams, The mirror effect in recognition memory: data and theory, J. Exp. Psychol.: Learn Mem. Cogn. 16 (1990) 5-16] explanation of the WF effect. In addition to investigating encoding strength, we addressed if study involves accessing prior representations of repeated items via the same mechanism as that at test [J.L. McClelland, M. Chappell, Familiarity breeds differentiation: a subjective-likelihood approach to the effects of experience in recognition memory, Psychol. Rev. 105 (1998) 724-760], entailing recollection [K.J. Malmberg, J.E. Holden, R.M. Shiffrin, Modeling the effects of repetitions, similarity, and normative word frequency on judgments of frequency and recognition memory, J. Exp. Psychol.: Learn Mem. Cogn. 30 (2004) 319-331] and whether less processing effort is entailed for encoding each repetition [M. Cary, L.M. Reder, A dual-process account of the list-length and strength-based mirror effects in recognition, J. Mem. Lang. 49 (2003) 231-248]. The increased BOLD responses observed in the left inferior prefrontal cortex (LIPC) for the WF effect provide support for an AE account. Less effort does appear to be required for encoding each repetition of an item, as reduced BOLD responses were observed in the LIPC and left lateral temporal cortex; both regions demonstrated increased responses in the conventional subsequent memory analysis. At test, a left lateral parietal BOLD response was observed for studied versus unstudied items, while only medial parietal activity was observed for repeated items at study, indicating that accessing prior representations at encoding does not necessarily occur via the same mechanism as that at test, and is unlikely to involve a conscious recall-like process such as recollection. This information may prove useful for constraining cognitive theories of episodic memory.

Wheeler-Feynman absorber revisited: a useful technique to calculate decay rates and lifetimes in small scale optical systems

The Wheeler-Feynman (WF) absorber theory of radiation though no more of interest in explaining self interaction of an electron, can be very useful in today's research in small scale optical systems. The significance of the WF absorber is the use of time-symmetrical solution of Maxwell's equations as opposed to only the retarded solution. The radiative coupling of emitters to nano wires in the near field and change in their lifetimes due to small mode volume enclosures have been elucidated with the retarded solutions before. These solutions have also been shown to agree with quantum electrodynamics, thus allowing for classical electromagnetic approaches in such problems. It is here assumed that the radiative coupling of the emitter with a body is in proportion to its contribution to the classical force of radiative reaction as derived in the WF absorber theory. Representing such nano structures as a partial WF absorber acting on the emitter makes the computations considerably easier than conventional electromagnetic solutions for full boundary conditions.

Valence band electronic structure of Nd1-xYxMnO3 using X-ray absorption, photoemission and GGA plus U calculations

The electronic structures of Nd1-xYxMnO3 (x=0-0.5) were studied using X-ray absorption near-edge structure (XANES) at the Mn L-3,L-2- and O K-edge along with valence-band photoemission spectroscopy (VB-PES). The systematic increase in white-line intensity of the Mn L-3,L-2-edge with doping, suggests a decrease in the occupancy of Mn 3d orbitals. The O K-edge XANES shows a depletion of unoccupied states above the Fermi energy. The changes in the O K-edge spectra due to doping reflects an increase in the Jahn-Teller distortion. The VB-PES shows broadening of the features associated with Mn 3d and O 2p hybridized states and the shift of these features to a slightly higher binding energy in agreement with our GGA + U calculations. The system shows a net shift of the occupied and unoccupied states away from the Fermi energy with doping. The shift in theoretical site-projected density of states of x=0.5 composition with respect to x=0 suggest a subtle change from a charge transfer to Mott-Hubbard type insulator. (C) 2013 Elsevier B.V. All rights reserved.

Electronic structure of Nd1-xYxMnO3 from Mn K edge absorption spectroscopy and DFT methods

The electronic structure of Nd1-xYxMnO3 (x-0-0.5) is studied using x-ray absorption near-edge structure (XANES) spectroscopy at the Mn K-edge along with the DFT-based LSDA+U and real space cluster calculations. The main edge of the spectra does not show any variation with doping. The pre-edge shows two distinct features which appear well-separated with doping. The intensity of the pre-edge decreases with doping. The theoretical XANES were calculated using real space multiple scattering methods which reproduces the entire experimental spectra at the main edge as well as the pre-edge. Density functional theory calculations are used to obtain the Mn 4p, Mn 3d and O 2p density of states. For x=0, the site-projected density of states at 1.7 eV above Fermi energy shows a singular peak of unoccupied e(g) (spin-up) states which is hybridized Mn 4p and O 2p states. For x=0.5, this feature develops at a higher energy and is highly delocalized and overlaps with the 3d spin-down states which changes the pre-edge intensity. The Mn 4p DOS for both compositions, show considerable difference between the individual p(x), p(y) and p(z)), states. For x=0.5, there is a considerable change in the 4p orbital polarization suggesting changes in the Jahn-Teller effect with doping. (C) 2013 Elsevier Ltd. All rights reserved.

Enhancement of four-wave mixing induced by interacting dark resonances

We analyse a four-wave mixing (FWM) scheme in a five-level atomic system in which double-dark resonances are present. It is found that the enhancement of FWM in both electromagnetically induced transparency (EIT) windows can be obtained even without the condition of multiphoton resonance. Moreover, the conversion efficiency of FWM in one EIT window can be much larger than that in the other due to the presence of interacting dark resonances.