Conditioned suppression tests of the context-blocking hypothesis: Testing in the absence of the preconditioned context.

A conditioned-suppression procedure was used in 2 studies, with 96 male albino rats, to test the context-blocking hypothesis, the proposition that static apparatus cues, or conditioning contexts, can block conditioning to discrete CSs. Exp I tested for conditioning to the target CS in the same context that had been preconditioned and in which target conditioning had occurred. A context-blockinglike effect was demonstrated. Exp II tested for conditioning not only in the preconditioned context but also in a nonpreconditioned context. Exp II results are consistent with the idea that associative conditioning to a discrete target CS is not independent of the conditioned strength of the context in which target conditioning occurs. Evidence for context blocking was similar in the 2 studies, suggesting that conditioned contexts block the acquisition of associative strength by discrete CSs at the time of target conditioning and not through performance factors at the time of testing. (45 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Model Intervals

This paper summarizes the most important results and features of Modal Interval Analysis. The ground idea of Interval mathematics is that ordinary set-theoretical intervals are the consistent context for numerical computing. However, this interval context presents basic structural and semantic rigidity arising from its set-theoretical foundation. To correct this situation, Modal Interval Analysis defines intervals starting from the identification of real numbers with the sets of predicates they accept or reject. A modal interval is defined as a pair formed by a classical interval (i.e. a set of numbers) and a quantifier, following a similar method to that in which real numbers are associated in pairs having the same absolute value but opposite signs. Two different extensions for a continuous function (called semantic extensions, since both will have a meaning thanks to the important semantic theorems) are defined and their properties are established. The definition of the rational extension, and its relationships with the semantic extensions, it make possible to compute the semantic extensions and to give a logical meaning to the interval results of a rational computations.For some functions the semantic extensions are equal, for instance, for the arithmetic operators, which can be obtained through computations with the intervals' bounds, obtaining the definitions of the well-known Kaucher's completed interval arithmetic. It is important to remark that the process of the construction of the Modal Interval Analysis is absolutely different from the process followed by Kaucher.Similarly to the Kaucher's completed interval arithmetic, with modal intervals it is possible to solve the equations A + X = B or A * X = B but with a very important difference. To find the algebraic solution for the equation A + X = B or A * X = B when A, X and B are classical intervals is a single problem: a) to find and interval X which substituted in the corresponding equation, satisfies the equality. Modal Interval Analysis not only solves that problem but also it gives a logical meaning to the solution.As a conclusion, the most important difference between Modal Interval Analysis versus Classical Intervals + Kaucher's Completed Arithmetic is the logical-semantic ground of the modal intervals and the meaning for the interval results in the functional computations or in the solution of a linear equation, provided by the semantic theorems.     

Learning hand manipulative tasks: When instructional animations are superior to equivalent static representations

Cognitive load theory was used to argue why instructional animations are more effective in teaching human motor skills than static representations. A key aspect to this argument is the role played by the transitory nature of animation and the newly discovered human mirror-neuron system. In two experiments students were taught to tie knots or complete puzzle rings either through an animated presentation or an equivalent sequence of static diagrams. In both experiments students learnt more from the animation mode than the static one, thus supporting the general thesis of the paper.     

Low cost multimedia sensor networks for obtaining lighting maps

In many applications, video streams, images, audio streams and scalar data are commonly used. In these fields, one of the most important magnitudes to be collected and controlled is the light intensity in different spots. So, it is extremely important to be able to deploy a network of light sensors which are usually integrated in a more general Wireless Multimedia Sensor Network (WMSN). Light control systems have increasing applications in many places like streets, roads, buildings, theaters, etc. In these situations having a dense grid of sensing spots significantly enhances measuring precision and control performance. When a great number of measuring spots are required, the cost of the sensor becomes a very important concern. In this paper the use of very low cost light sensors is proposed and it is shown how to overcome its limited performance by directionally correcting its results. A correction factor is derived for several lighting conditions. The proposed method is firstly applied to measure light in a single spot. Additionally a prototype of a sensor network is employed to draw the lighting map of a surface. Finally the sensor grid is employed to estimate the position and power of a set of light sources in a certain region of interest (street, building, …). These three applications have shown that using low cost sensors instead of luxmeters is a feasible approach to estimate illuminance levels in a room and to derive light sources maps. The obtained error measuring spots illuminance or estimating lamp emittances are quite acceptable in many practical applications.     

Evaluating hardening laws at large tensile strains in sheet specimens

In the finite element modeling of sheet metal formability, the strains in the sheet are calculated from a hardening law which is normally derived from a tensile test. These laws are known to be accurate only up to the maximum uniform strain in tension. However, they are extrapolated during modeling to strains three to five times greater than the uniform strain. In assessing the applicability of these hardening laws at large strains, tensile specimens of 1008 AK steel and commercial purity titanium and zinc were gridded with a fine mesh and slowly pulled to failure. During the test, photographs were taken of the deforming grid in order to develop a complete strain and strain-rate history for each element across the minimum cross section. These data were combined with a hardening law for each material to calculate the total axial load on the specimen. Good agreement between the calculated and measured loads suggests that hardening laws for these materials can be extrapolated to large strains.     

The Functional Data Model as the Basis for an Enriched Database Query Language

Conventional database languages rely on the user specifying what relations are to be used when evaluating a query. Consequently they preclude queries which involve searching for unspecified connections or associations in the database. In this paper we present Hydra, a functional language with all the facilities to define, update and query a database, which also enables users to carry out associational queries. Hydra uses a graph-based data model in which nodes represent values or entities and arcs the relationships between them. Associational facilities are made possible by the provision of built-in functions which find paths through the database graph. The mappings between sets of nodes in the database graph are represented as functions at the Hydra language level and it is as lists of such functions that associational results are returned. The use of a functional language is important since such languages allow functions to be returned as results; such an approach could not be adopted in a logic-based language which would not permit predicates to be returned as answers. Hydra also allows users to define general computational functions which are not considered to form part of the database. This use of two sets of functions achieves a computationally complete system which extends the query power of previous database systems without compromising their expressive or query power.     

Unbridled Development of Urban Space and its Implications for the Preservation of Landmarks: The Morro da Queimada Archaeological Site, Ouro Preto, Brazil

The process of expansion of urban centers in Brazil has been distinguished by the complete absence of planning. As a result, urban environments lead to land uses encroaching on, defacing and destroying landmarks. Attention is given to the Morro da Queimada Archaelogical Site. This represents an important cultural heritage of the 1720 movement of secession during the gold rush. Several ruins of mining equipments such as houses, wells, shafts and galleries have been gradually destroyed. The process of the site's loss of distinct character has been monitored since 1950 using aerial photographs and cartography. Collected data indicate a conservative annual land-use change rate of about 1.5%. This rate points to the complete destruction of the site in 2008. This paper proposes the creation of the Morro da Queimada Historical Park, within the limits of the remaining set of ruins.     

The 1.7 kilogram microchip: energy and material use in the production of semiconductor devices

The scale of environmental impacts associated with the manufacture of microchips is characterized through analysis of material and energy inputs into processes in the production chain. The total weight of secondary fossil fuel and chemical inputs to produce and use a single 2-gram 32MB DRAM chip are estimated at 1600 g and 72 g, respectively. Use of water and elemental gases (mainly N2) in the fabrication stage are 32,000 and 700 g per chip, respectively. The production chain yielding silicon wafers from quartz uses 160 times the energy required for typical silicon, indicating that purification to semiconductor grade materials is energy intensive. Due to its extremely low-entropy, organized structure, the materials intensity of a microchip is orders of magnitude higher than that of "traditional" goods. Future analysis of semiconductor and other low entropy high-tech goods needs to include the use of secondary materials, especially for purification.     

Itraconazole formation using supercritical carbon dioxide

A new method of preparing Itraconazole (C₃₅H₃₈Cl₂N₈O₄), a synthetic triazole antifungal agent, was developed using supercritical carbon dioxide (SC CO₂) while eliminating the use of toxic solvents. Dissolution amounts of the product were measured in gastric fluid and compared to those of conventional drug formulations. Different operating conditions (five levels of treatment temperature ranging between 110-140°C, four levels of treatment pressure ranging between 30-400 atm, and four different treatment times ranging from 10-60 minutes) were tested in order to produce a desired Itraconazole product, which does not degrade during the product formation and has the highest extent of dissolution in gastric fluid after one hour. Itraconazole dissolution of 100% at one-hour was achieved for the drug produced at the optimum treatment condition: 135°C, 300 atm, and 30 minutes. Extent of dissolution obtained from this solvent and detergent-free process is 10% higher than that of the conventional method involving toxic organic solvents. Itraconazole produced using SC CO₂ should provide minimal side effects in human body.