Analysis of enterococci using portable testing equipment for developing countries--variance of Azide NutriDisk medium under variable time and temperature.

This report compares the enterococci count on samples obtained with Azide NutriDisk (AND) (sterile, dehydrated culture medium) and Slanetz and Bartley (SB) medium when exposed to a variable in incubation time and temperature. Three experiments were performed to examine the recovery of enterococci on AND and SB media using membrane filtration with respect to: (a) incubation time; (b) incubation temperature; and (c) a combination of the two. Presumptive counts were observed at 37, 41, 46 and 47 degrees C and at 20, 24, 28 and 48 h. These were compared to AWWA standard method 9230 C (44 degrees C, 44 h). Samples were confirmed using Kanamycin Aesculin Azide (KAA) agar. Friedman's ANOVA and Students t-test analysis indicated higher enumeration of enterococci when grown on AND (p = 0.45) than SB (p = < 0.001) at all temperatures with a survival threshold at 47 degrees C. Significant results for AND medium were noted at 20 h (p = 0.021), 24 h (p = 0.278) and 28 h (p = 0.543). The study concluded that the accuracy of the AND medium at a greater time and temperature range provided flexibility in incubator technology making it an appropriate alternative to SB medium for monitoring drinking water using field testing kits in developing countries.     

EBSP study of the annealing behavior of aluminum deformed by equal channel angular processing

Commercial purity aluminum (99.5%) was fabricated by equal channel angular pressing (ECAP) up to total accumulated strains of approx. 10. The annealing behavior of material deformed to total strains of approx. 1 and 10 was investigated, using heat treatments of 2 h at various temperatures from 100 to 500 °C. The microstructure of the annealed materials was characterized using the electron back-scatter pattern technique. A number of parameters were determined including the distribution and average values of both the boundary spacings and misorientations. For samples deformed to a total strain of 1, annealing resulted in discontinuous recrystallization. For samples deformed to a total strain of 10, annealing resulted in microstructures exhibiting characteristics of both uniform coarsening and, in a number of places, of discontinuous recrystallization. An attempt was made, based on the boundary spacing distributions, to separate these two components. The grain size after annealing was still however small, being just 6.4 μm after 2 h at 300 °C.     

Construction of recombination-deficient strains of Streptococcus gordonii by disruption of the recA gene

Degenerate oligonucleotide primers were used in a polymerase chain reaction (PCR) to amplify a region of the recA sequence of Streptococcus gordonii Challis. The resulting PCR fragment was cloned into the suicide vector pAM6199 and introduced into strain Challis, giving rise to recombination-deficient strains in which the recA gene was specifically inactivated.     

Modeling tool wear in end-milling using enhanced GMDH learning networks

This paper presents an enhanced approach to predictive modeling for determining tool-wear in end-milling operations based on enhanced-group method of data handling (e-GMDH). Using milling input parameters (speed, feed, and depth-of-cut) and response (tool wear), the data for the model is partitioned into training and testing datasets, and the training dataset is used to realize a predictive model that is a function of the input parameters and the coefficients determined. In our approach, we first present a methodology for modeling, and then develop predictive model(s) of the problem being solved in the form of second-order equations based on the input data and coefficients realized. This approach leads to some generalization because it becomes possible to predict not only the test data obtained during experimentation, but other test data outside the experimental results can also be used. Moreover, this approach makes it easy to present the realized solution in a form that can be further optimized for the input parameters using some optimization techniques. The results realized using our e-GMDH method are promising, and the comparative study presented shows that the e-GMDH outperforms polynomial neural network (PNN); moreover, it is more flexible than the conventional GMDH, which tends to produce nonlinear solutions even for simple problems. In the investigation, the extended particle swarm optimization (PSO) technique was applied to obtain the optimal parameters. Consequently, the modeling approach is extremely useful in realizing a computer-aided process-planning system in an advanced manufacturing environment.     

The sleeping dragon: Wind energy in the Asia-Pacific region

The Asia-Pacific region is one of the fastest growing regional economies in the world today. The region is home to over half of the global population and is one of the most important markets for multinational corporations to penetrate. The wind power sector is no exception. Wind resources remain untapped and the demand for electricity continues to grow as a result of expanding and modernizing economies. Godfrey Chua, Emerging Energy Research USA reports on the current status and development of the wind industry in the region.     

Metastatic parathyroid carcinoma in the MEN2A syndrome

We report a patient with a metastatic parathyroid carcinoma and medullary carcinoma of the thyroid. This patient represents a variation of the multiple endocrine neoplasia syndrome (MEN) type 2A. There was no evidence of a phaeochromocytoma. The case illustrates the difficulties that may be encountered in localising the source of PTH secretion; the patient underwent four unsuccessful exploratory operations of the neck and mediastinum before further investigations revealed a single metastatic deposit of parathyroid carcinoma involving the first thoracic vertebra. PCR amplification and sequencing of the RET oncogene from the metastatic parathyroid carcinoma and genomic DNA revealed a heterozygous mutation (Cys634Tyr) in exon 11, as has previously been described to occur in MEN 2A. In addition, loss of tumour heterozygosity was demonstrated at loci from chromosomes 1, 2, 3p, 13q and 16p. This represents the first report of a parathyroid carcinoma in a MEN2A patient, in which the multiple allelic deletions are consistent with the generalised losses observed in aggressive tumours.     

Analysis of immunoglobulin-synthesizing cells in human dental periapical lesions by in situ hybridization and immunohistochemistry

The iron status of 22 children and adolescents with Crohn's disease (mean age: 13 years) was evaluated. Eleven patients were suffering from active disease with inflammation, identified by at least one abnormal value for serum orosomucoid, C-reactive protein or sedimentation rate (group I). Eleven patients were in clinical remission and showed no biological evidence of inflammation (group II). Hemoglobin and red cell indices, erythrocyte protoporphyrin, serum iron, transferrin, serum ferritin and basic red cell ferritin were determined in all patients. The usual indicators of iron status, particularly serum ferritin, were affected by the inflammatory processes, but basic red cell ferritin appeared to be independent of inflammation. Basic red cell ferritin can therefore be considered to be a reliable indicator of iron status in children and adolescents with Crohn's disease.