Speed limits: Orientation and semantic context interactions constrain natural scene discrimination dynamics.

The visual system rapidly extracts information about objects from the cluttered natural environment. In 5 experiments, the authors quantified the influence of orientation and semantics on the classification speed of objects in natural scenes, particularly with regard to object-context interactions. Natural scene photographs were presented in an object-discrimination task and pattern masked with various scene-to-mask stimulus-onset asynchronies (SOAs). Full psychometric functions and reaction times (RTs) were measured. The authors found that (a) rotating the full scenes increased threshold SOA at intermediate rotation angles but not for inversion; (b) rotating object or context degraded classification performance in a similar manner; (c) semantically congruent contexts had negligible facilitatory effects on object classification compared with meaningless baseline contexts with a matching contrast structure, but incongruent contexts severely degraded performance; (d) any object-context incongruence (orientation or semantic) increased RTs at longer SOAs, indicating dependent processing of object and context; and (e) facilitatory effects of context emerged only when the context shortly preceded the object. The authors conclude that the effects of natural scene context on object classification are primarily inhibitory and discuss possible reasons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in Fatty Acid, Tocopherol and Xanthophyll Contents During the Development of Tunisian-Grown Pecan Nuts

Among oil compounds, fatty acids, tocopherols and xanthophylls (lutein and zeaxanthin) are of special interest due to their nutritional properties. The identification and quantification of these compounds in pecan nuts (Carya illinoinensis) could therefore be very useful to produce functional foods rich in compounds of this type. This paper reports studies on their accumulation and the effect of ripening on the content of these high value-added compounds. The total lipid content increased during the ripening. Saturated and polyunsaturated fatty acids decreased significantly, whereas, monounsaturated fatty acids increased during the ripening of pecan nut fruit. Maximum levels of total tocopherol (279.53 mg/kg oil) and xanthophyll (6.18 mg/kg oil) were detected at 20th weeks after the flowering date. These amounts decreased gradually as ripening advances. The early stages of pecan ripening seem to have nutritional and pharmaceutical interests. These results may be useful for evaluating the pecan nut quality and determining the optimal period when the pecans accumulated the maximum of these nutritional and healthy compounds.     

Detection of polyunsaturated omega-6 fatty acid in human malignant prostate tissue by 1D and 2D high-resolution magic angle spinning NMR spectroscopy

Object  

Polyunsaturated omega-6 fatty acids (PUFAs) have been shown to promote prostate cancer. Here, we describe the use of HRMAS NMR spectroscopy to detect omega-6 PUFA species in prostate tissues.     

Enthalpy of formation of B2-Fe1−x Al x and B2-(Ni,Fe)1−x Al x

The enthalpy of formation of the ordered B2 phases in the Fe-Al and Fe-Ni-Al systems was measured with very good accuracy using a special, laboratory-built differential-solution calorimeter. The measurements were performed at 1073 K as a function of composition, with an accuracy of about 1 pct. The enthalpy of formation of B2-FeAl is most negative for the composition Fe_0.50Al_0.50 (−36.29 kJ/mol). Compounds with Al contents less than about 40 at. pct show a deviation from the linear dependence of the enthalpy of formation with composition which prevails for Al contents larger than 40 at. pct. Upon replacing Fe by Ni while maintaining a constant Al content, the enthalpy of formation of B2-(Fe,Ni)Al compounds becomes more negative. With decreasing Al content and for a constant Fe/Ni ratio, the enthalpy of formation of the ternary phase becomes less negative.     

The Use of Infrared Thermography as a Novel Approach for Real-Time Validation of PCR Thermocyclers

Validation of PCR thermocycler performance is crucial to obtain reliable results. In this study, infrared (IR) thermography was evaluated as a novel validation tool. After stabilisation, no significant difference in the temperatures recorded using thermography and a reference block-based system was found. By employing IR thermography, information about the length of the time until temperature stabilisation in the sample could be obtained. This study shows the potential of using IR thermography for validation of thermocyclers.     

An overdeterrnined two-dimensional transient inverse heat conduction problem

The method of solving the two-dimensional nonlinear inverse heat conduction problems is presented. The time- and space temperature distribution inside a solid and heat transfer coefficient distribution on the boundary of the solid is determined based on the temperature histories measured in several selected inside locations. The problem is overdetermined because the number of measuring points is higher than the number of calculated parameters (components of heat transfer coefficient).     

Monitoring and Origin of Polycyclic Aromatic Hydrocarbons (PAHs) in Effluents from a Surface Treatment Industry

ABSTRACT

In Europe, polycyclic aromatic hydrocarbons (PAHs) are a source of concern due to their toxic effects and are considered as priority pollutants by water authorities. In this study, we reported the results of qualitative and quantitative monitoring of 16 PAHs in effluents from a surface treatment industry to determine their origin. The results indicated that PAHs were present in the discharge waters at a concentration of 500 ng L^?1 (in average for the PAH sum). However, the further we returned to the start of the industrial process, the more the PAH concentrations increased. Indeed, the highest concentrations (>20,000 ng L^?1 for the PAH sum) were found in the degreasing baths – the first step in the part treatment. The final analyses showed that the PAHs came from the oils left on the metal parts by the suppliers. The important difference in concentrations between the upstream (first baths in the production line) and the downstream (discharge water) of the effluent showed that phenomena including dilution or potentially degradation occurred but that the major part of the PAHs tended to adsorb to sludge during the settling step in the effluent treatment plant.