A pseudo-neural system for hypothesis selection

The article describes a system for hypothesis elicitation and ranking formed by a net of computational elements obtained by modifying the classical neural model of Caianiello. This neural structure was chosen on the basis both of knowledge representation and of parallel processing considerations. the two fundamental components of the system are an elaboration layer and, in case the available evidences are insufficient to trigger explanatory hypotheses, a query layer that enables the system to gather additional information. Algorithms that help setting the crucial variable parameters of the net are described in the Appendix. © 1992 John Wiley & Sons, Inc.     

Care for the Cuban child born to an HIV-seropositive mother

Up to this moment, 25 children have been born from mothers seropositive to HIV. Of these, only 12 who are seropositive have been studied. Four of these children had developed the disease (33.3%), and the route of transmission was a blood transfusion. From the moment they were born, these children had been followed up monthly at the out-patient service and the polymerase chain reaction test, as well as ELISA and western blot is performed at 3, 6, and 9 months of age. Also, the same test are performed at 18 and 36 months of age for diagnostic confirmation in order to know whether they are virus carriers.     

Retention of the high optical absorptance in thermally aged black chrome on variably sensitized Cu

The chemical composition, morphology, selective absorber characteristics, and degradation of selective absorber characteristics at high temperatures of black chrome solar selective coating are influenced by various substrate pre-treatments like mechanical polishing, chemical etching, and electropolishing prior to film deposition. The major oxide content in the deposit is formed as Cu₂(OH)₂CrO₄ (JCPDS 38-0230), which on high temperature annealing decomposes to CuCrO₄ (JCPDS 34-0507), CuO (JCPDS 41-0254), and Cu₂O (JCPDS 5-0667). Formation of the oxides of Cu at high temperatures retains the high optical absorption characteristics of the coating even after high temperature degradation.     

HIV infection and isosporiasis. Presentation of a case

Tear lactoferrin concentration was measured by ELISA technique and followed in 30 patients undergoing cataract surgery. On the first day following surgery, there was a significant decrease in tear lactoferrin concentration followed by a gradual return to the initial values during the postoperative observation period of 7 days. There was an inverse linear relationship between tear lactoferrin concentration and the tear secretion rate measured by a modified Schirmer I test (1 min) suggesting a constant lactoferrin secretion by the tear glands. Since lactoferrin has known antibacterial and anti-inflammatory effects, the results may contribute to further understanding of the microbial vulnerability or resistance of the eye following surgical procedures.     

Dynamic Contextual Adaptation

When developing systems based on COTS, components need to be adapted in most of the occasions to work under certain conditions which were not initially predicted by their developers. Thus, it is very important to provide systems with the skill to dynamically alter their behaviour while running, depending on the changing conditions of the environment. In this work we describe a context-dependent, dynamic mapping between the interfaces of the components being adapted, overcoming some of the limitations of the static mappings presented in previous works. This is achieved by means of contextual environments, which define flexible adaptation policies. We also present a case study, illustrating the proposal, and discuss the improvements these mappings represent in comparison with previous works, as well as some open issues.     

Improving the moisture resistance of adobe structures

Mud plasters or soil stuccos are commonly used to protect adobe walls from water erosion. Due to drying shrinkage cracks and high permeability, the commonly used soil stuccos are not durable. Stucco stabilizers such as Portland cement, lime and asphalt are expensive. An experimental study undertaken to evaluate some of the locally available, inexpensive, stucco stabilizers is reported here. Crack-resistant stucco compositions made with a cactus solution are described and techniques to make the stucco surface impervious to water are discussed. The results of durability tests involving simulated rainfall on stucco panels, and stucco applied to adobe walls, are presented. Recommendations for field practice are also given.     

Electron effective mass in InuGa1−uPvAs1−v for 0 ≤ v ≤ 1

The electron effective mass in In_uGa_1−uP_vAs_1−v has been measured on seven samples lattice-matched to InP and evenly spaced in values of v between 0 and 1, using the temperature dependence of the amplitude of the Shubnikov-de Haas oscillations at high magnetic fields. Values of the carrier concentrations, Hall mobilities and Dingle temperatures measured on these samples are also reported. Work sponsored in part by the National Science Foundation, Grant No. ENG 76-09586, and in part by International Telephone and Telegraph Electro-Optical Products Division. Work done in part at the M.I.T. Francis Bitter National Magnet Laboratory. Funded in part by the National Science Foundation under Grant No. DMR-76-80895.     

A contribution to the study of the electrochemical oxidation of p-aminophenol on a mercury electrode

The reversibility of the oxidation process of p-aminophenol on a mercury electrode in buffered aqueous solutions is studied. Differential capacity curves are recorded and the number of electrons is determined by chronoamperometry. Kinetic parameters are determined at the foot of the wave.The results obtained are in agreement with the hypothesis that quinoneimine hydrolysis is slower than its diffusion, therefore the former takes place in a homogeneous medium and not in the interphase.