A Condition‐Based Deterioration Model for the Stochastic Dependency of Corrosion Rate and Crack Propagation in Corroded Concrete Structures

Physics‐based models are intensively studied in mechanical and civil engineering but their constant increase in complexity makes them harder to use in a maintenance context, especially when degradation model can/should be updated from new inspection data. On the other hand, Markovian cumulative damage approaches such as Gamma processes seem promising; however, they suffer from lack of acceptability by the civil engineering community due to poor physics considerations. In this article, we want to promote an approach for modeling the degradation of structures and infrastructures for maintenance purposes which can be seen as an intermediate approach between physical models and probabilistic models. A new statistical, data‐driven state‐dependent model is proposed. The construction of the degradation model will be discussed within an application to the cracking of concrete due to chloride‐induced corrosion. Numerical experiments will later be conducted to identify preliminary properties of the model in terms of statistical inferences. An estimation algorithm is proposed to estimate the parameters of the model in cases where databases suffer from irregularities.     

Enzymatic characteristics of blood lymphocytes during postnatal rabbit ontogenesis

Studies have been made on ontogenetic changes in the activity of succinic dehydrogenase, alpha-glycerophosphate dehydrogenase and acid phosphatase from the lymphocytes of rabbit blood. It was found that maturation of alpha-glycerophosphate dehydrogenase takes place at later stages as compared to other enzymes. The activity of succinic dehydrogenase gradually decreases. Acid phosphatase activity, being rather high in very young animals, also decreases with ageing.     

Concurrent mapping of brain sites for sensitivity to the direct application of morphine and focal electrical stimulation in the production of antinociception in the rat

The effect of morphine microinjection (5 microgram/0.5 microliter) and focal electrical stimulation on the animal's response to radiant heat and noxious pinch was studied concurrently at 117 brain loci extending from the medial thalamus caudally to the periaqueductal gray area (PAG). Three populations of brain sites were discernible based on their responsiveness to focal electrical stimulation and morphine microinjection in the production of antinociception: (a) sites which support stimulation-produced analgesia (SPA, n = 24), (b) sites which were sensitive to the direct application of morphine (n = 8), (c) sites responsive to both manipulations (n = 8). With a few exceptions, all morphine sensitive sites were located within the anatomical boundaries of the PAG while sites supporting SPA were located not only within the PAG but also in the brain regions peripheral to this structure. Sites responsive to both manipulations were generally distributed throughout thf lateral aspect of the posteroventral PAG. Stimulation strength-effect curves for sites subserving SPA were also obtained. No differences were discovered between curves obtained from morphine-sensitive and -insensitive brain loci.     

Cyanogen bromide treatment of methionine-containing compounds

The preparation of a series of X-Met-Gly-OEt and X-Met-Phe-OMe and their treatment with CNBr in either 70% or 97-100% formic acid at 25 degrees C are described where X is methanesulfonyl (mesyl), p-nitrobenzyloxycarbonyl, phthaloyl, trifluoroacetyl, acetyl, formyl, or tert-butyloxycarbonyl. Total cleavage of the peptide esters was found with mesyl-, p-nitrobenzyloxycarbonyl-, phthaloyl-, and trifluoroacetylmethionyl derivatives which indicated the suitability of these derivatives as amino protecting groups in peptide synthesis. Treatment of the acetylmethionyl peptide esters with CNBr in 70 and 97-100% formic acid resulted in 92 and 98% cleavage, respectively. With formylmethionyl peptide esters, about 85-95% cleavage was estimated when either 70 or 97-100% formic acid was used as the solvent. With the tert-butyloxycarbonylmethionyl derivatives, CNBr treatment in 70% formic acid resulted in about 93% cleavage of peptides, while treatment in 97-100% formic acid led to only 30-33% release of C-terminal amino acid esters. Quantitative cleavage of the carbonylbis(methionyl peptide esters) was observed. The reaction of CNBr with N-terminal methionyl derivatives containing free alpha-amino groups revealed that free methionine was quantitatively converted to homoserine lactone, whereas methionine ethyl ester and methionyl peptides (Met-Gly and Met-Phe) disappeared from the reaction mixture in 70% formic acid with only partial splitting of the ester (16%) or peptide bond (45%).     

One-step concentration of analytes based on dynamic change in pH in capillary zone electrophoresis

A novel strategy for one-step concentration of analytes during capillary electrophoresis (CE) is presented. A short platinum wire was inserted into the 75-microm-i.d. separation capillary. When a high voltage was applied for CE separation, a sharp pH gradient along the capillary was created dynamically by the electrolysis of water in the running buffer. Concentration of a large volume of injected analytes was accomplished by the change in analyte charge due to the dynamic pH gradient. Depending on the polarity of the applied potential and the direction of electroosmotic flow, either anions or cations can be concentrated. Several hundredfold concentration factors were achieved. Fluorescence imaging by a CCD camera was used to monitor 10 cm of the capillary near the platinum wire during the concentration process. The observations are consistent with a sweeping mechanism.     

Bidirectional deformable matching with application to handwritten character extraction

To achieve integrated segmentation and recognition in complex scenes, the model-based approach has widely been accepted as a promising paradigm. However, the performance is still far from satisfactory when the target object is highly deformed and the level of outlier contamination is high. In this paper, we first describe two Bayesian frameworks, one for classifying input patterns and another for detecting target patterns in complex scenes using deformable models. Then, we show that the two frameworks are similar to the forward-reverse setting of Hausdorff matching and that their matching and discriminating properties are complementary to each other. By properly combining the two frameworks, we propose a new matching scheme called bidirectional matching. This combined approach inherits the advantages of the two Bayesian frameworks. In particular, we have obtained encouraging empirical results on shape-based pattern extraction, using a subset of the CEDAR handwriting database containing handwritten words of highly varying shape.     

Combinatorial screening of enzyme activity by using multiplexed capillary electrophoresis

Efficient and comprehensive screening of enzyme activity was accomplished in a combinatorial array of 96 reaction microvials. Quantitation of the extent of the reaction at well-defined time intervals was achieved by using 96-capillary array electrophoresis coupled with a multiplexed absorption detector. Capillary electrophoresis provides high separation resolution to isolate the product from the reactants. Absorption detection provides universal applicability to combinatorial screening. For the conversion of NADH to NAD+, the catalytic activity of LDH was confirmed to be the highest at pH 7. This scheme should be useful for high-throughput drug discovery, clinical diagnosis, substrate binding, as well as combinatorial synthesis.     

Meniere's disease. A neuropsychological study

A neuro-psychological study is described comprising 19 patients with Meniere's Disease who were participating in an experimental lithium therapy programme. The patients evidenced an organic dysfunction which is not entirely periphearl. The interpretation of the results are not incompatible with an attempt to reconcile neuro-psychological and psycho-somatic viewpoints regarding etiological aspects of Meniere's Disease. An evaluation of the lithium effect was performed.