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We conducted batch studies to investigate the effect of phosphate and dominant cations present in tannery waste on desorption of chromium (Cr) from surface and subsurface soil horizons from a contaminated tannery waste site at Mount Barker, South Australia. The surface horizon (0-15 cm) of the soil profile was alkaline (pH 7.9) and the subsurface horizon (50-90 cm) was acidic (pH 3.9). Aqua-regia extractable Cr concentration ranged from 62 g/kg in the surface to 0.26 g/kg in the subsurface soils. X-ray diffraction and scanning electron microscopic studies revealed the predominance of carbonate and kaolin minerals in the surface soils, and highly weathered framboidal particles, with morphology similar to that of pyrites, in the subsurface soils. The amount of Cr desorbed from the contaminated soils varied considerably with both the electrolyte's cationic charge and soil properties. The effect of cations, [Ca.sup.2+] and [Na.sup.+] (Ca[Cl.sub.2], NaCl), and phosphate on desorption of Cr was investigated. While the ionic strength of the solutions was standardised at approximately 0.03 mol/L, the concentration of phosphate (as [KH.sub.2][PO.sub.4]) was varied from 0 to 3.2 mmol/L. On the basis of studies on solution to soil ratio and desorption kinetics we chose a 20:1 solution to soil ratio and 2 h equilibration time. In the surface alkaline soil, the amount of Cr released decreased in the order [Na.sub.+] (286 µg/L) [is greater than or equal to] water (256 µg/L) [is greater than] [Ca.sup.2+] (156 µg/L). In contrast subsurface acidic soil showed a reverse trend, i.e. [Ca.sup.2+] (52 µg/L) [is greater than] [Na.sup.+] (29 µg/L) [is greater than] water (20 µg/ L). Speciation of Cr in the extracts showed predominantly Cr(VI) in the alkaline surface soil and Cr(III) in the subsurface acidic soil. A strong effect of phosphate on the cumulative amount of chromate desorbed was observed. The study shows that the presence of high concentrations of [Na.sup.+] (0.03 mol/L) and phosphate (3.2 mmol/L) in soil solution enhances Cr(VI) mobility. In contrast, [Ca.sup.2+] may induce retention of Cr(VI) in Cr-contaminated alkaline soils. Additional keywords: hexavalent chromium, chromate, leaching, contaminated site., Introduction Tanning industries worldwide generate approximately 40 million [m.sup.3] of waste containing chromium (Cr) every year (Macchi et al. 1991). With inadequate regulatory guidelines, wastes were largely disposed on land [...]

The suitability of several extractants was tested for assessing the plant-available cadmium (Cd) in a few selected soils of South Australia. The amount of Cd extracted by 7 extractants (0.01 and 0.05 M Ca[Cl.sub.2], [Na.sub.2]EDTA, DTPA-TEA, M [NH.sub.4][NO.sub.3], AAAC-EDTA, and M [NH.sub.4]Cl) was related to the Cd concentration in the stem and leaves of durum wheat (Triticum aestivum L. var. Excalibur) grown in the greenhouse for 5 weeks. Soil extraction with M [NH.sub.4]Cl gave the best overall prediction of extractable Cd with plant Cd concentration (r = 0.928, P [is less than] 0.001) compared with the other extractants. Multivariate models were derived to predict both the total and plant-available Cd from the soil factors. The aqua-regia-extractable Cd was on an average 45.3% of the total Cd content, as determined by HF-HCl[O.sub.4] digestion, and at best could represent the easily extractable fraction of soil Cd. Around 77% of the variation in total Cd content of the soils could be explained using selected soil properties, such as free Fe, organic C, and pH. The accumulation of Cd by wheat plants from the soils studied could be assessed using the multivariate model, log leaf Cd = -0.2107 + 1.2281 log Cd [NH.sub.4]Cl, with high correlation ([R.sup.2] = 0.93). The coefficient of determination could be improved further ([R.sup.2] = 0.99) with the inclusion of the soil variables free Fe, pH, organic C, and clay contents: log leaf Cd = 0.2095 + 1.2556 log Cd [NH.sub.4]Cl + 0.0219 Fe + 0.0149 clay - 0.2633 org. C - 0.0577 pH. Additional keywords: soil extractants, cadmium, availability, wheat., Introduction The complex nature of soil processes and soil-plant relations is probably one of the major reasons for the existence of a large number of methods to assess the `plant-available' [...]

Yttrium tetraboride was synthesized by reactions of Y2O3 with B4C or with a B4C/C mixture. Fully dense YB4 ceramics were prepared by hot-pressing at 1800°C and 20 MPa in He. The flexural strength and microhardness of the YB4 were about 300 MPa and 27 GPa, respectively. Pure YB4 showed considerable oxidation above 1200°C. The effect of SiC, AlN, and AlN/SiC on the properties of YB4 ceramics was characterized. No chemical interactions were identified in the YB4-SiC and YB4-AlN pseudo binaries. The addition of SiC improved the oxidation resistance below 1200°C. At higher temperatures, the low viscosity of a surface melt caused its continuous runoff and the loss of the oxidation-protection capability of the scale. The addition of AlN/SiC improved the oxidation resistance compared to the ceramics containing only SiC, which was attributed to the presence of Al2O3 in the Y2O3-SiO2-B2O3 glass leading to an increase in its viscosity and preventing glass runoff. A significant improvement in the oxidation resistance of the YB4 ceramics and extension of their oxidation stability to 1400°C was accomplished by the introduction of AlN only. [ABSTRACT FROM AUTHOR]

The UK has experienced various animal health events that have had national impact in recent years. In response, a ‘Veterinary Surveillance Strategy’ (VSS) was published in 2003, with the objective of enhancing and coordinating national veterinary surveillance practice in a way that would enable important animal health events to be detected and assessed more rapidly and reliably. The VSS adopts an integrated UK-wide approach, which includes widespread engagement with interested parties both within government and beyond. It proposes enhancing surveillance through improved collaboration; transparent and defensible prioritisation of government resources to surveillance; deriving better value from existing resources, and assuring quality of the surveillance reports and source data. This article describes progress with implementing the VSS, in particular the methodology for developing a functional network and creating an effective, quality-assured, information management system, RADAR. [ABSTRACT FROM AUTHOR]

We show that the transmission of light through metallic hole arrays supported by a glass substrate can be tuned by depositing a controlled number of Langmuir–Blodgett layers on top of the hole array. Enhanced transmission is achieved when the number of overlayers is such that the surface plasmon-polariton modes on the two sides of the metal hole array have matched wavevectors. Dye molecules introduced into some of these overlayers allow us to explore the relationship between molecular fluorescence and the transmission properties of the structure, through measurement of the fluorescence lifetime of the molecules. We find there to be little change in the fluorescence lifetime between enhanced and non-enhanced transmission regimes and offer an explanation of our findings in terms of changes in the photonic mode density. [ABSTRACT FROM AUTHOR]

Objective: This study aims to characterize the rate of occurrence and nature of outcomes associated with obstetrical deliveries in women with malignant neoplasms among 3,168,911 women who delivered in California in 1992 through 1997.Design: The study is a population-based retrospective review of infant birth and death certificates and maternal and neonatal discharge records. Cases of malignant neoplasms associated with obstetrical delivery were attributed to 1 of 3 categories, depending on the earliest documented hospital discharge diagnosis, as follows: "prenatal" if the diagnosis was first documented by hospitalization within 9 months preceding delivery, "at delivery" if the diagnosis was established from the delivery hospitalization, or "postpartum" if the diagnosis was first documented by hospitalization within 12 months after delivery.Methods: Computer-linked infant birth and death certificates and maternal and neonatal discharge records were used to identify cases and outcomes. Cases of malignant neoplasms were identified by using International Classification of Diseases, Ninth Revision codes (140-208). Noninvasive neoplasms and carcinoma in situ neoplasms were excluded. In analysis of outcomes, the Mantel-Haenszel estimate for adjusted odds ratios was used.Results: Among 3,168,911 obstetrical deliveries over the 6-year span, a total of 2247 cases of primary malignancy were identified. The observed rate of occurrence for primary malignant neoplasms was 0.71 per 1000 live singleton births. Most cases (53.3%) were first documented in the postpartum period as follows: prenatal, 587 cases (0.18 per 1000); at delivery, 462 cases (0.15 per 1000); and postpartum, 1198 cases (0.38 per 1000). The most frequently documented primary malignant neoplasms associated with obstetrical delivery were breast cancer (423 cases, 0.13 per 1000), thyroid cancer (389 cases, 0.12 per 1000), cervical cancer (266 cases, 0.08 per 1000), Hodgkin's disease (172 cases, 0.05 per 1000), and ovarian cancer (123 cases, 0.04 per 1000). Odds ratios for a variety of demographic factors identified maternal age as the most significant risk factor for development of malignant neoplasms (age greater than 40 vs 20-25, odds ratio 5.7, CI 4.6-6.9). Age-adjusted odds ratios for maternal cancer of any type suggested significantly elevated risks for cesarean delivery (odds ratio 1.4, CI 1.3-1.6), blood transfusion (odds ratio 6.2, CI 4.5-8.5), hysterectomy (odds ratio 27.4, CI 20.8-36.1), and maternal postpartum hospital stay greater than 5 days (odds ratio 30.6, CI 27.9-33.6), but not for postpartum maternal death (odds ratio 0.8, CI 0.6-1.0). Odds ratios also suggested significantly elevated risks for premature newborn (odds ratio 2.0, CI 1.8-2.2), very low birth weight (odds ratio 2.9, CI 2.2-3.8), and newborn hospital stay longer than 5 days (odds ratio 2.6, CI 2.4-3.0), but not for neonatal death (odds ratio 1.6, CI 0.8-3.1) or infant death (odds ratio 1.2, CI 0.5-3.3). However, several types of malignant neoplasms did confer significant elevations in risk for neonatal death. Hospital charges for both maternal and neonatal care were significantly elevated in the maternal malignant neoplasm group.Conclusion: A lower than expected occurrence rate of obstetrical delivery associated with maternal malignancy was seen when compared with previously published hospital-based reports. Malignant neoplasms associated with obstetrical delivery were most frequently first documented in the postpartum period. Maternal and neonatal morbidity were significantly increased, yet the risk of in-hospital maternal death was not significantly elevated. A significant increase in risk of neonatal death for infants of mothers with cervical cancer was found. [ABSTRACT FROM AUTHOR]

This decade has witnessed dramatic advances in the surgical management of urinary calculi. Today, most stones can be removed by minimally invasive means. In fact, the treatment of choice in 60% to 90% of patients with renal and ureteral calculi that need to be surgically removed is extracorporeal shock wave lithotripsy (ESWL). This article reviews indications for ESWL and discusses deleterious effects of ESWL. [ABSTRACT FROM AUTHOR]