THE BORON ISOTOPE GEOCHEMISTRY OF THE KIRKA BORATE DEPOSIT, WESTERN TURKEY

We have measured the boron isotope composition of seventeen samples of borate minerals (colemanite, ulexite, and borax) and the Sr-87/Sr-86 ratio in thirteen borate samples from the Kirka borate deposit in western Anatolia, Turkey. These Neogene deposits were formed by evaporation of playa lakes fed by geothermal springs. The delta(11)B values range from - 14.9 parts per thousand in colemanite to -1.6 parts per thousand in borax. To a first approximation the relative differences in the delta(11)B values of the borate minerals are consistent With their basic boron atomic configuration, but the magnitude of the boron isotope fractionation between the three minerals precludes their simultaneous precipitation from a brine with the same boron isotope composition and pH. Rather the data are consistent with precipitation of colemanite from a brine with lower pH than that required for ulexite precipitation, which in turn requires a lower pH than is needed for borax precipitation. The boron isotope data also suggest that the borate minerals did not maintain boron isotopic equilibrium with the brine after they precipitated. Rayleigh fractionation models indicate that during borax precipitation the delta(11)B value of the brine was slightly heavier than during precipitation of ulexite and colemanite

The boron isotope geochemistry of the neogene borate deposits of western Turkey

We have analyzed the boron isotope composition of 80 borate minerals (major minerals: borax, colemanite, and ulexite; minor minerals: veatchite-A, tunellite, kernite, terrugite, probertite, meyerhofferite, inderite, inyoite, hydroboracite, howlite, and pandermite) from the main deposits (Kirka, Bigadic, and Emet) and two smaller deposits (Kestelek and Sultancayir) in the western Turkish borate deposits. Forty-three samples were also analysed for their Sr isotope composition. The data span a wide range in delta(11)B values from -1.6 parts per thousand to to -25.3 parts per thousand. The delta(11)B values of the main borate minerals are largely controlled by their mineralogy and the pH of the brines from which they precipitated. An inverse correlation between the average delta(11)B and Sr-87/Sr-86 ratios of colemanite in the different deposits suggests there is some variation in the sources of boron and Sr to the deposits. Emet has the highest contribution from aluminosilicates and Kirka the highest contribution from Eocene carbonates, with Bigadic occupying an intermediate position. The delta(11)B values of the minor borate minerals distinguish between those which are primary precipitates from the original brines (or formed from primary berates without boron loss from the system) and those which formed from alteration of preexisting borate minerals with substantial loss of boron from the system. Copyright (C) 1997 Elsevier Science Ltd

Diagnosis of Hashimoto's thyroiditis in ultrasound using tissue characterization and pixel classification

Hashimoto's thyroiditis is the most common type of inflammation of the thyroid gland, and accurate diagnosis of Hashimoto's thyroiditis would be helpful to better manage the disease process and predict thyroid failure. Most of the published computer-based techniques that use ultrasound thyroid images for Hashimoto's thyroiditis diagnosis are limited by lack of procedure standardization because individual investigators use various initial ultrasound settings. This article presents a computer-aided diagnostic technique that uses grayscale features and classifiers to provide a more objective and reproducible classification of normal and Hashimoto's thyroiditis-affected cases. In this paradigm, we extracted grayscale features based on entropy, Gabor wavelet, moments, image texture, and higher order spectra from the 100 normal and 100 Hashimoto's thyroiditis-affected ultrasound thyroid images. Significant features were selected using t-test. The resulting feature vectors were used to build the following three classifiers using tenfold stratified cross validation technique: support vector machine, k-nearest neighbor, and radial basis probabilistic neural network. Our results show that a combination of 12 features coupled with support vector machine classifier with the polynomial kernel of order 1 and linear kernel gives the highest accuracy of 80%, sensitivity of 76%, specificity of 84%, and positive predictive value of 83.3% for the detection of Hashimoto's thyroiditis. The proposed computer-aided diagnostic system uses novel features that have not yet been explored for Hashimoto's thyroiditis diagnosis. Even though the accuracy is only 80%, the presented preliminary results are encouraging to warrant analysis of more such powerful features on larger database

Prevalence and treatment of hypertensive patients with multiple concomitant cardiovascular risk factors in The Netherlands and Italy

The Anglo-Scandinavian Cardiac Outcomes Trial-Lipid-Lowering Arm (ASCOT-LLA) trial demonstrated the benefits of combined antihypertensive/ lipid-lowering treatment over antihypertensive treatment alone in hypertensive patients with ≥3 additional cardiovascular (CV) risk factors. We assessed the prevalence and treatment of patients with hypertension and ≥3 additional CV risk factors in The Netherlands and Italy in a retrospective cohort study using the Integrated Primary Care Information (IPCI) database in The Netherlands and the Health Search/ Thales Database (HSD) in Italy. Patients aged ≥16 years, with 1 year of valid database history, diagnosed and/or treated for hypertension (>140/90 mmHg) during 2000-2002 were included in the study. The IPCI and HSD populations consisted of ∼175 000 and ∼325 000 patients, respectively. The prevalence of hypertension increased from 20.3 to 22.3% in the IPCI, and from 19.0 to 21.8% in the HSD during 2000-2002. The prevalence of ≥3 concomitant risk factors among hypertensive patients increased from 31.2 and 31.1% in 2000 to 34.2 and 39.3% in 2002 in the IPCI and HSD, respectively. From 2000 to 2002, among hypertensive patients with ≥3 CV risk factors and no prior symptomatic CV disease (CVD) approximately 54-57% in the IPCI and 80-83% in the HSD received antihypertensive treatment. In these patients, the use of combined antihypertensive and lipid-lowering treatment increased from 14.2 to 17.6% in the IPCI and from 15.5 to 17.4% in the HSD from 2000 to 2002. This study shows that primary prevention of CVD in hypertensive patients in The Netherlands and Italy could be improved