Voluntary action and causality in temporal binding

Previous studies have documented temporal attraction in perceived times of actions and their effects. While some authors argue that voluntary action is a necessary condition for this phenomenon, others claim that the causal relationship between action and effect is the crucial ingredient. In the present study, we investigate voluntary action and causality as the necessary and sufficient conditions for temporal binding. We used a variation of the launching effect proposed by Michotte, in which participants controlled the launch stimulus in some blocks. Volunteers reported causality ratings and estimated the interval between the two events. Our results show dissociations between causality ratings and temporal estimation. While causality ratings are not affected by voluntary action, temporal bindings were only found in the presence of both voluntary action and high causality. Our results indicate that voluntary action and causality are both necessary for the emergence of temporal binding.

Probing the dependence of the properties of cellulose acetates and their films on the degree of biopolymer substitution: use of solvatochromic indicators and thermal analysis

Although cellulose acetates, CAs, are extensively employed there is scant information about the systematic dependence of their properties on their degree of substitution, DS; this is the subject of the present work. Nine CAs samples, DS from 0.83 to 3.0 were synthesized; their films were prepared. The following solvatochromic probes have been employed in order to determine the empirical polarity, E (T)(33); ""acidity, alpha""; ""basicity, beta"", and ""dipolarity/polarizability, pi*"" of the casted films: 2,6-dichloro-4-(2,4,6-triphenyl-pyridinium-1-yl) phenolate, WB; 4-nitroaniline; 4-nitroanisole; 4-nitro-N,N-dimethylaniline; 2,6-diphenyl-4-(2,4,6-triphenyl-pyridinium-1-yl)phenolate, RB. Additionally, two systems, ethanol plus ethyl acetate (EtOH-EtAc), and cellulose plus cellulose triacetate, CTA, were employed as models for CAs of different DS. Regarding the model systems, the following was observed: (i) For EtOH-EtAc, the dependence of all solvatochromic parameters on the ""equivalent-DS"" of the binary mixture was non-linear because of preferential solvation; (ii) The dependence of E (T)(33) on equivalent DS of the cellulose-CTA films is linear, but the slope is smaller than that of the corresponding plot for CAs. This is attributed to the more efficient hydrogen bonding in the model system, a conclusion corroborated by IR measurements. The dependence of solvatochromic parameters of CAs on their DS is described by the simple equations; a consequence of the substitution of the OH by the ester group. The thermal properties of bulk CAs samples were investigated by DSC and TGA; their dependence on DS is described by simple equations. The relevance of these data to the processing and applications of CAs is briefly discussed.

Comparison of SERS performances of Co and Ni ultrathin films over silver to electrochemically activated Co and Ni electrodes

In this work, the surface-enhanced Raman scattering (SERS) spectra of pyridine (py) on thin films of Co and Ni electrodeposited on an Ag electrode activated by oxidation-reduction cycles (ORC) are presented. The SERS spectra from the thin films were compared to those of py on activated bare transition metal electrodes. It was verified that the SERS spectra of py on 3 monolayers (ML)-thick films of Ni and Co presented only bands assignable to the py adsorbed on transition metal surfaces. It was also observed that even for 50 ML-thick transition metal films, the py SERS intensity was ca. 40% of the intensity from the 3 ML-thick films. The relative intensities of the SERS bands depended on the thickness of the films, and for films thicker than 7 ML for Co and 9 ML for Ni they were very similar to those of the bare transition metal electrodes. The transition metal thin films over Ag activated electrodes presented SERS intensities 3 orders of magnitude higher than the ones from bare transition metal electrodes. These films are more suitable to study the adsorption of low Raman cross-section molecules than are ORC-activated transition metal electrodes.

The relation between action, predictability and temporal contiguity in temporal binding

Previous studies have documented a subjective temporal attraction between actions and their effects. This finding, named intentional binding, is thought to be the result of a cognitive function that links actions to their consequences. Although several studies have tried to outline the necessary and sufficient conditions for intentional binding, a quantitative comparison between the roles of temporal contiguity, predictability and voluntary action and the evaluation of their interactions is difficult due to the high variability of the temporal binding measurements. In the present study, we used a novel methodology to investigate the properties of intentional binding. Subjects judged whether an auditory stimulus, which could either be triggered by a voluntary finger lift or be presented after a visual temporal marker unrelated to any action, was presented synchronously with a reference stimulus. In three experiments, the predictability, the interval between action and consequence and the presence of action itself were manipulated. The results indicate that (1) action is a necessary condition for temporal binding; (2) a fixed interval between the two events is not sufficient to cause the effect and (3) only in the presence of voluntary action do temporal predictability and contiguity play a significant role in modulating the effect.These findings are discussed in the context of the relationship between intentional binding and temporal expectation. (C) 2010 Elsevier B.V. All rights reserved.

Stability and interface properties of thin cellulose ester films adsorbed from acetone and ethyl acetate solutions

Stability and interface properties of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) films adsorbed from acetone or ethyl acetate onto Si wafers have been investigated by means of contact angle measurements and atomic force microscopy (AFM). Surface energy (gamma(total)(S)) values determined for CAP adsorbed from acetone are larger than those from ethyl acetate. In the case of CAB films adsorbed from ethyl acetate and acetone were similar. Dewetting was observed by AFM only for CAP films prepared from ethyl acetate. Positive values of effective Hamaker constant (A(eff)) were found only for CAP prepared from ethyl acetate, corroborating with dewetting phenomena observed by AFM. Oil the contrary, negative values of A(eff) were determined for CAP and CAB prepared from acetone and for CAB prepared from ethyl acetate, Corroborating with experimental observations. Sum frequency generation (SFG) vibrational spectra indicated that CAP and CAB films prepared from ethyl acetate present more alkyl groups oriented perpendicularly to the polymer-air interface than those films prepared from acetone. Such preferential orientation corroborates with macroscopic contact angle measurements. Moreover, SFG spectra showed that acetone hinds strongly to Si wafers, creating a new surface for CAP and CAB films. (C) 2008 Elsevier Inc. All rights reserved.

SURFACE-ENHANCED RAMAN SCATTERING: METAL NANOSTRUCTURES COATED WITH LANGMUIR-BLODGETT FILMS

This review deals with surface-enhancved Raman scattering (SERS) employing Langmuir-Blodgett (LB) films, which serve as model systems for developing theoretical and experimental studies to elucidate the SERS effect. In addition, LB films have be used as integral parts of molecular architectures for SERS-active substrates. On the other hand, SERS and surface-enhaced resonant Raman scattering (SERRS) have allowed various properties of LB films to be investigated, especially those associated with molecular-level interactions. In the paper, emphasis is placed on single molecule detection (SMD), where the target molecule is diluted on an LB matrix of spectral silent material (low Raman cross section). The perspectives and challenges for combining SERS and LB films are also discussed.

Prolonged Physical Training Decreases mRNA Levels of Glucocorticoid Receptor and Inflammatory Genes

Background/Aims: Prolonged physical exercise induces adaptive alterations in the hypothalamic-pituitary axis, increasing cortisol metabolism, and reducing cortisol synthesis and glucocorticoid sensitivity. The mechanisms responsible for this relative glucocorticoid resistance remain unknown but may involve expression of genes encoding glucocorticoid receptor (GR) and/or inflammatory molecules of nuclear factor kappa B1 (NFkB1) signaling pathway and cytokines. This study aimed to determine the impact of prolonged physical training on the expression of genes involved in glucocorticoid action and inflammatory response. Methods: Normal sedentary male cadets of the Brazilian Air Force Academy were submitted to 6 weeks of standardized physical training. Eighteen of 29 initially selected cadets were able to fully complete the training program. Fasting glucose, insulin and cortisol levels, cytokine concentration and the expression of genes encoding GR, NFkB1, inhibitor of NFkB1 and IkB kinase A were determined before and after the training period. Results: Prolonged physical exercise reduced the basal cortisol levels and the percent cortisol reduction after dexamethasone. These findings were associated with a significant reduction in the mRNA levels of GR (6.3%), NFkB1 (63%), inhibitor of NFkB1 (25%) and IkB kinase A (46%) with concomitant reduction in cytokine concentrations (ELISA). Conclusions: Prolonged physical training decreases the glucocorticoid sensitivity and the mRNA levels of the GR gene combined with decreased mRNA of genes related to the NFkB pathway. Copyright (C) 2010 S. Karger AG, Basel

Nanostructured europium oxide thin films deposited by pulsed laser ablation of a metallic target in a He buffer atmosphere

Nanostrucured europium oxide and hydroxide films were obtained by pulsed Nd:YAG (532 nm) laser ablation of a europium metallic target, in the presence of a 1 mbar helium buffer atmosphere. Both the produced film and the ambient plasma were characterized. The plasma was monitored by an electrostatic probe, for plume expansion in vacuum or in the presence of the buffer atmosphere. The time evolution of the ion saturation current was obtained for several probe to substrate distances. The results show the splitting of the plume into two velocity groups, being the lower velocity profile associated with metal cluster formation within the plume. The films were obtained in the presence of helium atmosphere, for several target-to-substrate distances. They were analyzed by Rutherford backscattering spectrometry, x-ray diffraction, and atomic force microscopy, for as-deposited and 600 degrees C treated-in-air samples. The results show that the as-deposited samples are amorphous and have chemical composition compatible with europium hydroxide. The thermally treated samples show x-ray diffraction peaks of Eu(2)O(3), with chemical composition showing excess oxygen. Film nanostructuring was shown to be strongly correlated with cluster formation, as shown by velocity splitting in probe current versus time plots. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3457784]

Photoluminescent behavior of SrZrO(3)/SrTiO(3) multilayer thin films

A detailed investigation was made into the origin of photoluminescence in an alternate multilayer system of SrZrO(3) (SZO) and SrTiO(3) (STO) thin films. XRD and room-temperature PL studies revealed a high consistency with respect to improved crystallization at elevated temperatures. The photoluminescence behaviour of SZO/STO multilayered system consists in the superposition of independent photoluminescence emissions of both STO and SZO films. Based on the present results and on previous experimental and theoretical data, we propose that the origin of the photoluminescence emission results from structural disorder generated by the presence of distortions in the ideal constituent clusters of these materials. (c) 2009 Elsevier B.V. All rights reserved.

Structural basis for selective inhibition of purine nucleoside phosphorylase from Schistosoma mansoni: Kinetic and structural studies

Selectivity plays a crucial role in the design of enzyme inhibitors as novel antiparasitic agents, particularly in cases where the target enzyme is also present in the human host. Purine nucleoside phosphorylase from Schistosoma mansoni (SmPNP) is an attractive target for the discovery of potential antischistosomal agents. In the present work, kinetic studies were carried out in order to determine the inhibitory potency, mode of action and enzyme selectivity of a series of inhibitors of SmPNP. In addition, crystallographic studies provided important structural insights for rational inhibitor design, revealing consistent structural differences in the binding mode of the inhibitors in the active sites of the SmPNP and human PNP (HsPNP) structures. The molecular information gathered in this work should be useful for future medicinal chemistry efforts in the design of new inhibitors of SmPNP having increased affinity and selectivity. (C) 2010 Elsevier Ltd. All rights reserved.

Spectroscopic investigation of the interactions between emeraldine base polyaniline and Eu(III) ions

The interactions of emeraldine base form of polyaniline (EB-PANI) and Eu(III) ions in 1-methyl-2-pyrrolidinone (NMP) solution and in films have been investigated by UV-vis-NIR, resonance Raman. luminescence and electron paramagnetic resonance (EPR) spectroscopies. These spectroscopic techniques allowed to characterize quinone and semiquinone segments in the polymeric chains. and the oxidation state of europium ions in Eu-PANI samples. For high values of Eu(III)/N molar ratio (24/1) the presence of a weak polaronic absorption band at 980 nm in UV-vis-NIR spectrum and the observation of bands at 1330 and 1378 (nu(center dot)(C-N+)) cm(-1) due to emeraldine salt in the Raman spectrum at 1064 nm indicate a low doping degree. Oxidation of EB-PANI to pernigraniline base (PB-PANI) occurs in diluted solutions. The experimental data showed that the solvent plays an important role on the nature of formed species. The narrow EPR signal at g = 2.006 (line width 8G) confirms the presence of PANI radical cations in Eu-PANI film. The absence of broad signal characteristic of Eu(II) in EPR spectrum suggested that europium ions are primarily at Eu(III) oxidation state. The luminescence spectra of Eu-PANI film presented emission bands at 405 and 418 nm assigned to PANI moieties and bands at 594,615 and 701 nm assigned to (5)D(0) -> (7)F(J) (J = 1, 2 and 4, respectively) transitions of Eu(III). EPR and photoluminescence data confirm that europium ions are mainly in Eu(III) oxidation state in Eu(III)/PANI films. (C) 2008 Elsevier B.V. All rights reserved.

Effects of starch gelatinization and oxidation on the rheological behavior of chitosan/starch blends

Chitosan/starchblends represent an interesting alternative for the preparation of biocompatible drug delivery systems, packing materials and edible films. This paper reports on the effects of starch gelatinization and oxidation on the rheological behavior of chitosan/starch blends. The results show that the modifications in the starch structure cause changes in G` (storage modulus) and G `` (lossmodulus) as a function of frequency. For chitosan/starch, G `` is higher than G`, showing a viscous behavior. However, for chitosan/gelatinized starch and chitosan/oxidized starch, an increase in the angular frequency promotes a modulus crossover at omega = 0.02 and 0.04 rad s(-1), respectively. The viscosity curves as a function of shear rate show that both modifications cause an increase in viscosity, and all blends show a non-Newtonian behavior. (C) 2011 Society of Chemical Industry