What is coded into memory in the absence of outcome feedback?

Although people often have to learn from environments with scarce and highly selective outcome feedback, the question of how nonfeedback trials are represented in memory and affect later performance has received little attention in models of learning and decision making. In this article, the authors use the generalized context model (Nosofsky, 1986) as a vehicle to test contrasting hypotheses about the coding of nonfeedback trials. Data across 3 experiments with selective decision-contingent and selective outcome-contingent feedback provide support for the hypothesis of constructivist coding (Elwin, Juslin, Olsson, & Enkvist, 2007), according to which the outcomes on nonfeedback trials are coded with the most likely outcome, as inferred by the individual. The relation to sampling-based approaches to judgment, and the adaptive significance of constructivist coding, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nondestructive evaluation of the depth of surface-breaking cracks in concrete pipes

Surface-breaking cracks affect the material and structural properties of concrete pipes. Therefore, the nondestructive evaluation of the crack depth is important to assess the serviceability of these pipes, which are commonly used in underground infrastructure and trenchless installations (micro-tunneling). This paper presents theoretical, numerical and experimental results for the depth evaluation of surface-breaking cracks. The wall of a concrete pipe is represented as a plate in the numerical and the analytical studies. In the experiments, an ultrasonic piezoelectric transmitter is used as a source. The propagation of the ultrasonic pulse is analyzed using the wavelet transform. A newly proposed wavelet transmission coefficient (WTC) is measured using an equal spacing configuration for the crack depth evaluation in concrete pipes and concrete plates. The results from laboratory and in situ tests show good potential for the practical application of the WTC for the depth evaluation of surface-breaking cracks.     

The rapid synthesis of nanostructured orthorhombic KNbO3 particles by a microwave-assisted hydrothermal method and their characterization

We studied the molar ratio effects of niobium and potassium precursors on the structure and morphology of potassium niobate powders prepared via microwave-assisted hydrothermal synthesis (MaHS). KNbO₃ nanostructures in the form of nanotowers and nanocubes were obtained at reduced synthesis times (30–240 min). The products were characterized via XRD, Raman spectroscopy, SEM, and TEM; band gap calculations used diffuse reflectance data. The results indicate that KNbO₃ nanostructures were obtained with crystallite sizes ranging from 33 to 52 nm. An orthorhombic crystalline structure was formed from the increase of KOH at a molar ratio Nb₂O₅:KOH (1:8 to 1:16 M). The band-gap of 3.1–3.3 eV has potential use in photodegradation applications.     

Use of coffee by‐products for the cultivation of Pleurotus citrinopileatus and Pleurotus salmoneo‐stramineus and its impact on biological properties of extracts thereof

Incorporating spent coffee grounds (SCGs), a by‐product from coffee brewing, in growth substrate of beneficial edible mushrooms is an approach that has to be further studied due to its potential positive outcomes: environmental impact mitigation, production costs reduction and beneficial impact on consumer health. Hence, cultivation of Pleurotus citrinopileatus and Pleurotus salmoneo‐stramineus was tested using SCG which enabled maximum production yield of P. citrinopileatus which was of 25.1% (w/w). Variable antidiabetic potential was observed between aqueous and enzymatic extracts (3.8%–29% inhibition) regardless species and substrates, whereas aqueous extract of P. citrinopileatus grown in substrate without SCG stood out presenting the highest antioxidant activity and inhibition activity of angiotensin I‐converting enzyme (IC₅₀ = 123 μg mL^?1). Ethanolic and aqueous extracts of both Pleurotus species grown in the presence or absence of SGC proved to be an interesting prebiotic source for growth of Bifidobacterium animalis Bo in comparison with fructooligosaccharides (FOS).     

Effect of addition of Agaricus blazei mushroom residue to milk enriched with Omega‐3 on the prevention of lipid oxidation and bioavailability of bioactive compounds after in vitro gastrointestinal digestion

The residue from a hydroalcoholic extract of the mushroom Agaricus blazei (MAR) was evaluated for phenolic compounds, flavonoids and antioxidant activity. The ability of MAR to slow the oxidation of Omega‐3 resulting from light exposure in milk matrix, and its bioavailability after in vitro digestion was investigated. MAR presented phenolic compounds and flavonoids and showed antioxidant activity. At each concentration, addition of MAR to Omega‐3‐supplemented milk inhibited the production of conjugated dienes and malonaldehyde compared with samples without MAR. The bioavailability assay showed that polyphenols were still present after in vitro digestion and had antioxidant activity.     

Multitemporal thermal analysis to detect moisture on a building façade

It is well known that the content of water does affect materials behaviour and may cause important damages to buildings, including structural deterioration. Thermography is a non-intrusive imaging technique that allows the inspection of different materials based on their surface temperatures. Within an appropriate thermal analysis, moisture and other structural damages can be detected. The present research work deals with multitemporal thermal analysis to detect moisture on buildings, as well as other alterations. Two different approaches are tested to determine the effectiveness on the moisture surveys, one simple based on image differences, and another more sophisticated based on principal components analysis (PCA). The results are tested at the front door of the Arenberg Castle (Leuven, Belgium). Some moisture maps are derived and used to determine the reliability of either the computation of image differences or the PCA to carry out semi-automatically moisture surveys on architectural façades. The latter method is proven to be superior when using thermal imagery acquired at different times.     

Modulation of the action control system by social intention: Unexpected social requests override preplanned action.

Four experiments investigated the influence of a sudden social request on the kinematics of a preplanned action. In Experiment 1, participants were requested to grasp an object and then locate it within a container (unperturbed trials). On 20% of trials, a human agent seated nearby the participant unexpectedly stretched out her arm and unfolded her hand as if to ask for the object (perturbed trials). In the remaining 3 experiments, similar procedures were adopted except that (a) the human was replaced by a robotic agent, (b) the gesture performed by the human agent did not imply a social request, and (c) the gaze of the human agent was not available. Only when the perturbation was characterized by a social request involving a human agent were there kinematic changes to the action directed toward the target. Conversely, no effects on kinematics were evident when the perturbation was caused by the robotic agent or by a human agent performing a nonsocial gesture. These findings are discussed in the light of current theories proposed to explain the effects of social context on the control of action. (PsycINFO Database Record (c) 2010 APA, all rights reserved)