Brick production with dredged harbour sediments. An industrial-scale experiment

A volume of 600.000 m3 harbour sediments is annually dredged out of the harbour basin of Bremen to maintain a certain water depth. Because of its perpetual availability, homogeneity and mineralogical, petrographic and chemical composition, the sediment is regarded as a suitable raw material for brick production. A pilot experiment was conducted at a full-scale industrial brickworks. During production, the environmental standards concerning waste-water treatment and the quality of exhausted gas were sufficiently fulfilled. Bricks specified as "building bricks" were produced according to German industrial standards. The parameters pH-value and grain size were varied in leaching tests performed on the bricks as both parameters are likely to change in the course of the brick's life cycle. The leaching data showed that As was stabilised and heavy metals were immobilised in a way that the bricks were not (hazardous to soil or groundwater) neither by their use, for example, in masonry, nor afterwards, when they will be deposited as mineral demolition mass.     

Proposing an information criterion for individual-based models developed in a pattern-oriented modelling framework

Individual-based models (IBMs) have been improved in quality and reliability in recent years with an approach called pattern-oriented modelling (POM). POM proposes guidelines to develop models reproducing multiple patterns observed on the field and to test systematically how well the IBMs reproduce them. POM studies used generally traditional methods of goodness of fit such as the sum of squares evaluation or ad hoc comparisons of fitting errors and variations. Model selection, however, can be a rigorous statistical approach based on information theory and information criteria such as the Akaike's information criterion (AIC) or the deviance information criterion (DIC). So far, it has not been tried to link POM to these rigorous techniques. The main problems to achieve that are: (a) the difficulty to have likelihood functions for IBMs’ parameters and (b) the possibility to obtain posterior distributions of IBMs’ parameters given the patterns to reproduce. In a first part, this paper answers problem (a) by proposing and explaining how to calculate a deviance measure (POMDEV) for models developed in a context of POM. And while answering the second problem, a second part of the paper proposes an information criterion for model selection in a POM context (the pattern-oriented modelling information criterion: POMIC). This criterion does not yet have the same theoretical foundation as, e.g., AIC, but uses formal analogies to the DIC. In a third part POMIC is tested with a modelling exercise. This exercise shows the potential of POMIC to use multiple patterns for selecting among multiple potential submodels and eventually select the most parsimonious and well fitting model version. We conclude that POMIC, although being a heuristically derived approach, can greatly improve the POM framework.     

INTEGRATING DEMOGRAPHIC AND LANDSAT (TM) DATA AT A WATERSHED SCALE1

ABSTRACT: Recurrent calls for integrated resource management urge that an understanding of human activities and populations be incorporated into natural resource research, management, and protection efforts. In this paper, we hypothesize that watersheds can be a valuable geography for organizing an inquiry into the relationship between humans and the environment, and we present a framework for conducting such efforts. The framework is grounded in the emerging field of landscape ecology and incorporates demographic theory and data. Demography has been advanced by technological capabilities associated with the 1990 Census. Employing Geographic Information System (GIS) tools, we couple Landsat Thematic Mapper (TM) land cover data with census‐derived housing density data to demonstrate the operation of our framework and its utility for better understanding human‐landscape interactions. In our investigation of the Kickapoo Watershed and two sub‐ watersheds, located in southwestern Wisconsin, we identify relationships between landscape composition and the distribution and social structure of human populations. Our findings offer insight into the interplay between people and biophysical systems.     

Trends in airborne particulates in Stuttgart, Germany: 1972-2005

Since 1972, at the University of Hohenheim in Stuttgart, Germany, airborne particulate matter (PM12 and then PM10) was continuously collected on filters and analyzed for environmentally relevant elements by X-ray fluorescence analysis. The resulting long-term time series are suitable for the investigation of trends and of seasonal variation. For the period 1972-2005, monthly and annual concentration mean values of 13 elements (Br, Ca, Cr, Cu, Fe, K, Mn, Ni, Pb, S, Ti, V, and Zn) in the air are presented. Trend curves were fitted and the mean yearly variation of the concentration for these elements was calculated and represented graphically. All trend curves show a diminution of the air pollution during this period, but to different extents. Mean trends in percent per year were calculated for each element both for the entire investigation period and for three data subsets of 10-11 years. Possible explanations are discussed in detail.     

Relativistische Astrophysik — zum Einstein-Jahr 1979

The 9th Texas Symposium on Relativistic Astrophysics took place in Munich on the eve of the Einstein year 1979. An outstanding tribute to Einstein was the announcement by J. Taylor that gravitational radiation has finally been shown to exist. We report in some detail on the history of this event: the progress in timing accuracy of the binary pulsar PSR 1913 + 16 and the chain of conclusions which lead to the present result. The binary pulsar appears as ‘Einstein's dream’. We also emphasize that tests of gravitational theories in the solar system have left Einstein's General Relativity as the lone survivor. In context with Einstein's basic ideas we also discuss the puzzling fact that a “new aether drift” has appeared in measurements against photons of the 3-K cosmic background radiation. We finally report on spectacular progress in X-ray astronomy.     

A chemical view of the most ancient metazoa--biomarker chemotaxonomy of hexactinellid sponges

Hexactinellid sponges are often considered to be the most ancient metazoans. Lipid biomarkers from 23 species were studied for information on their phylogenetic properties, particularly their disputed relation to the two other sponge classes (Demospongiae, Calcarea). The most prominent lipid compounds in the Hexactinellida comprise C28 to C32 polyenoic fatty acids. Their structures parallel the unique patterns found in demosponge membrane fatty acids ('demospongic acids') and strongly support a close phylogenetic association of the Demospongiae and the Hexactinellida. Both taxa also show unusual mid-chain methylated fatty acids (C15-C25) and irregular C25- and C40-isoprenoid hydrocarbons, tracers for specific eubacteria and Archaea, respectively. These biomarkers indicate a similar, highly conservative symbiont community, although some shift in the abundance of the associated microbiota was observed. The lack of these features in calcareous sponges further contradicts the still common view that Calcarea and Demospongiae are more closely related to each other than either is to the Hexactinellida.     

The steroids of hexactinellid sponges

The Hexactinellida ('glass sponges') are commonly considered to be the most basic metazoans. Steroids of 20 species from different taxa were studied for chemotaxonomy and biosynthetic implications. All Hexactinellida contain cholest-5-en-3#-ol (cholesterol) and/or its saturated derivative 5!(H)-cholestan-3#-ol, along with their C-24-alkylated homologues. Where 5!(H)-stanols are present, they regularly co-occur with their 3-keto analogues. The steroid concentrations generally decrease with increasing carbon numbers, similar to sterol distributions typically found in marine sediments. These features argue against de novo sterol biosynthesis operating in hexactinellid sponges. Rather, we suggest a dietary uptake of (⁵-stenols and their stereoselective transformation via 3-keto intermediates to 5!(H)-stanols.     

Stopover behaviour and departure decision of northern wheatears, Oenanthe oenanthe, facing different onward non-stop flight distances

On the small North Sea island Helgoland (54°11' N, 07°55' E) we studied the stopover ecology of two subspecies of northern wheatear, Oenanthe oenanthe, during spring migration. Birds heading for Scandinavia (O. o. oenanthe) face only short flights across an ecological barrier (50-500 km) whereas those originating from Greenland and Iceland (O. o. leucorhoa) have to cover between 1,000 and 2,500 km in the impending flight. Colour-ringed individuals showed that 90% of Scandinavian birds left on the day of ringing while 40% (males) and 30% (females) of Greenland/Icelandic birds stayed at least 1 night. The birds who remained were thus mostly O. o. leucorhoa. They often established desirable feeding territories on the beach and had a high rate of body mass increase (1.7 g/day). However, subspecies did not differ in habitat choice and in foraging effort, but O. o. leucorhoa had a higher success rate in pecking. Departure decisions were analysed by comparing (a) conditions on the day of ringing between departing and staying birds and (b) for birds staying between the day of departure and the preceding day. The factors that were probably important in the decision to depart differed between subspecies. In O. o. leucorhoa, few birds departed with bad or deteriorating weather conditions (tailwind component, cloud cover), whereas departures of O. o. oenanthe seemed to be little affected by those factors. A few O. o. oenanthe stayed early in the spring migration season and/or had low fat reserves. Interference during foraging seemed to play a role because both subspecies tended to leave when the densities of northern wheatears were high. Other factors related to refuelling conditions (food supply, foraging effort, predation risk) failed to show differences between staying and departing individuals. In summary, almost all Scandinavian birds departed quickly and irrespective of refuelling and weather conditions, whereas many (but not all) Greenland/Icelandic birds seemed to prepare for a long-distance flight and carefully adjusted departure to weather conditions. The observed differences in stopover behaviour and departure decisions in the two subspecies of northern wheatear indicate that the distance to the next stopover site or to the goal area has to be considered when applying optimal migration models.