Crystallization of Fe-Si-B metallic glasses studied by X-ray synchrotron radiation

We have studied the crystallization kinetics of Fe_90-x Si _x B₁₀ amorphous alloys withx ranging from 7 to 21, by synchrotron X-ray radiation. Using energy- dispersive X-ray diffraction, the kinetics of the different crystalline phases evolving during isothermal annealing were followed. These crystalline phases were identified as precipitation of-Fe(Si) and/or Fe₃Si in the amorphous matrix. At a later time or at a higher temperature, Fe₂B starts to crystallize (x < 21 ). Only at low iron concentration (x = 21) was the second phase different, namely Fe₅SiB₂ The hypo- and hyper-eutectic Fe-Si-B glasses were found to crystallize differently. The crystallization processes are discussed in some detail.     

Concentration of enteric viruses in wastewater and effluent: a two year survey

A 2 year survey has been carried out on the wastewater and effluent of the Haifa treatment plant in order to gather information on the concentration and composition of the enteric viral population. The results obtained showed (a) the enteric viruses are present in wastewater and effluent all year round. (b) Their numbers fluctuate and are usually lower during the winter. (c) The highest numbers have been recorded between April and September with peaks occurring in wastewater during the month of July (106,000 PFU 100 ml⁻¹) and in effluent in August (94,000 PFU 100 ml⁻¹). During the months January through March the most prevalent viruses isolated were Polio I and ECHO₄.     

Carcinoma of the stomach following the Chernobyl nuclear accident

Medical consequences of many nuclear accidents on humans are well studied, but the results pertaining to gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident have not been analysed. In this study, the outcome of the surgical treatment of 68 gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident was compared with that of 117 consecutive gastric cancer patients from uncontaminated areas of the Ukraine. Patients in the study group was significantly younger than that of the control group. Comparative analysis showed the same frequency of regional metastases (65.7% versus 71.1%, P > 0.05), but a smaller number of distant metastases (23.8% versus 38.1%, P < 0.05) in the study group. 41.2% of patients in the study group underwent total gastrectomy compared to 19.6% of patients in the control group (P = 0.002). Postoperative complications developed in 13.2% of patients in the study group, while postoperative mortality in the study group was 7.3% compared to 1.7% in the control group. A significant decrease in CD16 cells was noted in patients from the study group following the operative procedure. Young age, invasive tumours with smaller number of distant metastases, frequent necessity for total gastrectomy and combined operations with adjacent organs, a higher level of postoperative morbidity and mortality and low levels of natural killer cells (CD16+) with a tendency to decrease after surgery are characteristic of patients with carcinoma of the stomach affected by the Chernobyl accident.     

A simple test for differentiation between E. coli and A. aerogenes

An important problem in water quality control is the ability to differentiate between E. coli (faecal) and A. aerogenes (non-faecal) coliforms. To perform this differentiation, a simple test, based on a modification of the selective mFC medium and optimal incubation temperature (37°C) is proposed. Under these specific conditions E. coli bacteria develop into dark blue colonies, whereas A. aerogenes into pink ones. The intermediate coliform bacteria appear greenish-blue or pink, depending on their relation (closeness) to E. coli or A. aerogenes.     

1,25-Dihydroxyvitamin D3 receptor as a marker of human colon carcinoma cell line differentiation and growth inhibition

The antiproliferative action of 1,25-dihydroxyvitamin D3 in osteosarcoma, breast carcinoma, and colon carcinoma cell lines has been described. In this study, the level of vitamin D receptor was analyzed in a panel of colon adenoma and adenocarcinoma cell lines and the receptor level was correlated with the response to treatment with 1,25-dihydroxyvitamin D3. Ribonuclease protection and ligand-binding assays quantitated the level of vitamin D receptor mRNA expression and the level of functional receptors, respectively. The more well-differentiated cell lines, such as VACO 330, showed higher levels of vitamin D receptor than less-differentiated cell lines, such as SW620. Proliferation assay, clonogenic assay, and growth curve study in HT29 and SW620 cell lines assessed the antiproliferative effect of 1,25-dihydroxyvitamin D3 at concentrations ranging from 10(-11) to 10(-6) M. HT29 showed significant (P < 0.05) growth inhibition at 10(-9) to 10(-6) M concentrations, but growth of SW620 remained unchanged. The amount of vitamin D receptor in 12 malignant colonic tumors was compared with that of adjacent normal tissue, and in 9 cases, the tumor expressed a lower vitamin D receptor level. Our results suggest that the level of vitamin D receptor correlates with the degree of differentiation in human colon cancer cell lines and may serve as a useful biological marker in predicting clinical outcome in patients.     

Building New Water Resources Projects or Managing Existing Systems?

Abstract

The planning of regional water resources systems and their subsequent management has to rest firmly on three foundations: availability of water of adequate quality, demand for water expressed quantitatively for specific periods of time, and direct, indirect, and externality costs. Mathematical models of hydrosystems represent only a segment of the real world. The basic science of hydrology is an empirical discipline, and its basic law is the continuity equation. Optimization of operating rules based on this law of conservation of matter may face difficulties when the objective function is expressed in economic terms. Overcoming this obstacle requires the use of targets (for water releases and stored volumes) expressible in physical units. The optimization objective can then be expressed as the sum of the squares of the differences between the results of the analysis and the targets. An additional complexity is created by parties who are interested in regional hydrosystems for purposes other than the traditional water supply and flood control. They may require certain elevations of water levels in streams and reservoirs for wildlife or recreational purposes or minimal flows needed for fishing and fisheries. All these complexities lead to an expansion of regional water resources models so as to enable the manager to investigate factors and decision alternatives not included in the model. A regional water resources system is relevant only in so far as it advances the solution of socio-economic and political issues and promotes development rather than growth. Management of existing systems should take precedence over building new water resources projects