The Solling roof revisited--slow recovery from acidification observed and modeled despite a decade of "clean-rain" treatment

Soil chemistry under the Solling clean-rain roof was simulated using the dynamic multi-layer soil chemistry model SAFE, including sulfate adsorption. Soil was sampled in order to parameterize the pH and sulfate concentration dependent sulfate adsorption isotherm used in SAFE. Modeled soil solution chemistry was compared to the 14 year long time-series of monthly measurements of soil solution data at 10 and 100cm depth. The deposition of N and S under the roof has been reduced by 68% and 53%, respectively, compared to the surrounding area. Despite this the soil solution concentrations of sulfate are still high (a median of 420mumol(c)/L at 100cm depth between 2000 and 2002) and the soil base saturation low (approximately 3% in the whole profile in 1998). Sulfate adsorption is an important process in Solling. The soil capacity to adsorb sulfate is large, the modeled adsorbed pool in 2003 down to 100cm was 1030kg S/ha, and the measured sulfate concentration is high, due to release of adsorbed sulfate. The addition of sulfate adsorption improved the modeled sulfate dynamics although the model still slightly underestimated the sulfate concentration at 100cm. Model predictions show no recovery, based on the criteria of Bc/Al ratio above 1 in the rooting zone, before the year 2050, independent of future deposition cuts.     

LAND USE AND ENVIRONMENTAL PLANNING: AN APPLICATION IN THE SOUTH CAROLINA COASTAL ZONE1

ABSTRACT: The purpose of this paper is to describe a land use and environmental planning model. Map overlays were used for analyzing and aggregating economic, social, and environmental data. Various land use categories were evaluated using a numerical scoring system. These scores were then used to assist in the development of land use regulations in a coastal county in South Carolina.     

Vergleichende Neurobiologie der Organisation von blickstabilisierenden Reflexsystemen bei Wirbeltieren

During locomotion gaze is stabilized against passive head movements by compensatory eye movements. The efficacy and the neuronal organization of optokinetic and vestibular reflexes of different vertebrate species is compared. Besides many similarities between species a number of differences can be found as well. Increase in the efficacy of compensatory reflexes is not correlated with an increase in the efficacy of basic neuronal circuits but with the appearance of functionally new connections and of new network properties. This increasingly higher complexity allows to maintain gaze stability at increasingly higher speeds of locomotion or to suppress these reflexes during visual pursuit of a moving object.     

Grenzüberschreitender Seeuferschutz im Spannungsfeld von Nutzungsinteressen am Beispiel Bodensee (Teil 1)

The shores of many Central European lakes located in the hinterland of large conurbations are heavily endangered by intensive settlement, traffic, sewage input, manipulation of the water level, tourism and recreation. This increasing impact has negatively affected the function of the lake shore in respect to conservation and species protection, to water protection and its importance for recreation. This paper describes the overlap of the multiple uses and the precautions planned since 1981 on the national and international level to guarantee the essential multiple functionality, e.g. as drinking water reservoir for the conurbations in the northern part of Baden-Württemberg, as supraregional centre for water sports and tourism, and as an important environment for endangered plant and animal species. Management measures include regional planning as well as the international water protection and preservation with many contributions from non governmental international organisations. Given a high agreement concerning these aims, many indispensable actions could successfully be realised on the political and administrative level. On the basis of 14 topics we follow the development since 1981, most recently also driven by the EU (FFH Natura 2000, Water framework directive). Backlogs became obvious for four topics: 1. The lack of efficient reviews on completed measures, 2. gaps in basic understanding, 3. The dragging harmonisation of an integrated shore protection program across the borders, and 4. the lack of concepts for a sustainable development including plans for monitoring.     

First-trimester maternal serum biochemical indicators in Down syndrome

A set of 21 early maternal serum samples (19 first-trimester and two at 14 weeks) from pregnancies resulting in a child with Down syndrome was matched for gestation and length of storage with 63 samples from unaffected pregnancies. The concentrations of alpha-fetoprotein (AFP), unconjugated oestriol (uE₃), human chorionic gonadotrophin (hCG), pregnancy-specific β₁–glycoprotein (SP₁), and placental alkaline phosphatase (PALP) were measured. The ratios of the medians for Down syndrome pregnancies compared with the medians for controls were AFP 0·71, uE₃ 0·67, hCG 1·43, SP₁ 0·79, and PALP 0·92. Although the differences between the medians for affected and unaffected pregnancies were not significant, the trends for AFP, uE₃, and hCG confirm earlier findings on first-trimester samples.     

First-trimester prenatal diagnosis of hypophosphatasia: Experience with 16 cases

We have carried out first-trimester prenatal diagnosis of hypophosphatasia in 1 6 pregnancies with a 1 in 4 risk of this condition. The liver/bone/kidney isoenzyme of alkaline phosphatase was measured in chorionic villus samples using a specific monoclonal antibody and an enzymatic amplification system. Fifteen of the 16 pregnancies were correctly predicted, while one has been lost to follow up. We suggest that this assay system is likely to be superior to DNA-base methods for the first-trimester prenatal diagnosis of hypophosphatasia.     

Evaluation of a novel structural model to describe the endogenous release of lead from bone

The aim of this paper was to assess the endogenous release of lead from bone to blood, in 204 exposed subjects. resuming their duties after a 10-month strike in a primary lead smelter in 1991. In vivo 109Cd K X-ray Fluorescence (109Cd K XRF) was used to measure the bone lead concentration in tibia and calcaneus in the smelter, in 1994 and five years later. The 1994 data were used to derive the post-strike bone lead concentrations retrospectively from the significant association between bone lead and the cumulative blood lead index (CBLI). When a linear model was used to predict the current blood lead upon the level of lead in bone, structural analysis of the data produced slopes for tibia (2.0, 95% CI 1.66-2.54) and calcaneus (0.19, 95% CI 0.16-0.23) that were significantly higher than those predicted by the commonly used simple linear regression method, for tibia (0.73, 95%, CI 0.58-0.88) and calcaneus (0.08, 95% CI 0.06-0.09). This suggests that more lead than previously predicted by regression is released from bone to blood. Furthermore, the structural analysis of the data produced an estimation of the contribution of the bone lead stores to the bloodstream that was more consistent with the 1999 epidemiological data than did the regression estimation. Moreover, a non-linear relationship between tibia lead and blood lead was suggested from the assumption checking procedures for regression. When a non-linear regression model was fit to the data, the method produced estimates of important parameters in human lead kinetics, namely the blood lead saturation constant, showing a good agreement with current knowledge of lead metabolism. Finally, the likelihood of a non-linear bone lead release seems to be supported by the recently described dependence of the half-life of lead in bone on age and intensity of occupational exposure.     

Bioaccessibility testing of cobalt compounds

Testing of metal compounds for solubility in artificial fluids has been used for many years to assist determining human health risk from exposure to specific compounds of concern. In lieu of obtaining bioavailability data from samples of urine, blood, or other tissues, these studies measured solubility of compounds in various artificial fluids as a surrogate for bioavailability. In this context, the measurement of metal "bioaccessibility" can be used as an in vitro substitute for measuring metal bioavailability. Bioaccessibility can be defined as a value representing the availability of metal for absorption when dissolved in in vitro surrogates of body fluids or juices. The aim of this study was to measure and compare the bioaccessibility of selected cobalt compounds in artificial human tissue fluids and human serum. A second aim was to initiate studies to experimentally validate an in vitro methodology that would provide a conservative estimate of cobalt bioavailability in the assessment of dose from human exposure to various species of cobalt compounds. This study evaluated the bioaccessibility of cobalt(II) from 11 selected cobalt compounds and an alloy in 2 physical forms in 5 surrogate human tissue fluids and human serum. Four (4) separate extraction times were used up to 72 hours. The effect of variables such as pH, dissolution time, and mass-ion effect on cobalt bioaccessibility were assessed as well. We found that the species of cobalt compound as well as the physico-chemical properties of the surrogate fluids, especially pH, had a major impact on cobalt solubility. Cobalt salts such as cobalt(II) sulfate heptahydrate were highly soluble, whereas cobalt alloys used in medical implants and cobalt aluminate spinels used as pigments, showed minimal dissolution over the period of the assay.