Postgraduale Weiterbildung, Nachwuchsf?rderpreis 2005, Jahrestagung 2006 in Landau

Ohne Zusammenfassung     

The relationship between surface dust lead loadings on carpets and the blood lead of young children

The final clean-up of residential lead abatement projects in federally-supported housing, as well as in other housing in a number of states, must meet surface dust lead clearance levels expressed as g of lead per square foot. These clearance levels were established because hand-to-mouth ingestion of lead-contaminated dust is recognised as a major pathway through which many children are exposed. A dilemma exists because many floors in housing undergoing abatement are carpeted and the established clearance levels are generally not recommended for use on carpets. These clearance levels are also used as 'action levels' to determine whether exposure reduction activities are needed. The US Environmental Protection Agency is currently in the process of issuing standards for hazardous levels of lead in interior dust and bare soil under Title X of the Housing and Community Development Act of 1992, The Residential Lead-Based Paint Hazard Reduction Act of 1992. An effort to develop a potential surface dust lead clearance level for carpets was made using an existing vacuum dust collection method that has previously been shown to be a reliable indicator of childhood lead exposure. This method was designed for use on carpeted and non-carpeted surfaces. Using data from the Cincinnati Soil Lead Abatement Demonstration Project, the suggested floor-dust lead level where an estimated 95% of the population of children would be expected to have blood lead values below the national goal of 10 g dL^–1, was more than an order of magnitude lower than the current floor-dust lead clearance level of 1080 g m^–2 (100 g ft^–2). Further comparisons of blood lead and carpet lead levels in other parts of the country should be performed before a risk-based lead loading clearance level is established.     

Behavioral diversification in a young species flock of pupfish (<Emphasis Type="Italic">Cyprionodon</Emphasis> spp.): shoaling and aggressive behavior

Increasing empirical and theoretical evidence supports the idea that sympatric speciation is operating, for example, in species flocks comprising several closely related fish species within one lake. Divergent natural selection (promoting spatial and food niche partitioning) and sexual selection (assortative mating) have been identified as key selection factors in intralacustric adaptive radiations. However, the evolution of social behaviors accompanying such adaptive radiations is less well understood. Using a phylogenetically young species flock of pupfish (Cyprinodon spp.) as a model, we examined differences among six sympatric species and compared their shoaling, aggressive, and territorial behaviors with that of a sister species (C. artifrons). Despite an estimated age of the species flock of less than 8,000 years, pronounced behavioral differentiation was found. C. simus, the smallest species in the flock, shoaled more than the other species and was less aggressive and less territorial than C. beltrani. F₁-hybrids between C. simus males and C. beltrani females showed an intermediate expression of shoaling and aggressive behavior. Niche partitioning among the members of this species flock appears to be accompanied by rapid divergent evolution of social behaviors. We discuss the potential role of phenotypic plasticity and within-species variation of social behaviors for such rapid behavioral diversifications in sympatric speciation processes.     

Ecosystem services in mountain regions: experts’ perceptions and research intensity

Facing the challenges of global and regional changes, society urgently needs applicable and broadly accepted tools to effectively manage and protect ecosystem services (ES). This requires knowing which ES are perceived as important. We asked decision-makers from different thematic backgrounds to rank 25 ES on the basis of their importance for society. To test whether perceptions are varying across regions, we surveyed three Alpine regions in Austria and Italy. The ranking of importance showed a high variability amongst experts but was not influenced by region or thematic background. ES that satisfy physiological needs (‘fresh water’, ‘food’, ‘air quality regulation’) were indicated as most important. ES that relate to safety and security needs were ranked in the middle field, whereas cultural ES were perceived as less important. We used principal component analysis (PCA) to identify ES bundles based on perception of importance. In order to investigate whether research intensity follows the perceived importance, we related the interviews with a comprehensive literature review. ‘Global climate regulation’, ‘food’, ‘biodiversity’, ‘fresh water’ and ‘water quality’ were studied most often. Although ‘habitat’, ‘energy’, ‘primary production’, ‘tourism’, ‘water cycle’, and ‘local climate regulation’ were ranked as important by decision-makers, they did not receive corresponding research attention. We conclude that more interaction between research and stakeholders is needed to promote a broader application and understanding of the ES concept in practice. The use of ES bundles could help to manage its inherent complexity and facilitate its application.     

Impact of soil water regime on degradation and plant uptake behaviour of the herbicide isoproturon in different soil types

The environmental fate of the worldwide used herbicide isoproturon was studied in four different, undisturbed lysimeters in the temperate zone of Middle Europe. To exclude climatic effects due to location, soils were collected at different regions in southern Germany and analyzed at a lysimeter station under identical environmental conditions. ¹⁴C-isoproturon mineralization varied between 2.59% and 57.95% in the different soils. Barley plants grown on these lysimeters accumulated ¹⁴C-pesticide residues from soil in partially high amounts and emitted ¹⁴CO₂ in an extent between 2.01% and 13.65% of the applied ¹⁴C-pesticide. Plant uptake and ¹⁴CO₂ emissions from plants were inversely linked to the mineralization of the pesticide in the various soils: High isoproturon mineralization in soil resulted in low plant uptake whereas low isoproturon mineralization in soil resulted in high uptake of isoproturon residues in crop plants and high ¹⁴CO₂ emission from plant surfaces. The soil water regime was identified as an essential factor that regulates degradation and plant uptake of isoproturon whereby the intensity of the impact of this factor is strongly dependent on the soil type.     

How career orientation shapes the job satisfaction–turnover intention link

This study examined the impact of career orientation on the static and dynamic relationships between job satisfaction and turnover intention. Longitudinal data of 255 employees were collected at three waves of measurement 1 year apart. Results for career orientations as a moderator differed between the static and dynamic job satisfaction–turnover links. The static relationship was found to be similar and less negative for employees with independent and loyalty‐focused career orientations than for promotion‐focused and disengaged employees. Regarding the dynamic relationship between job satisfaction change and turnover intention change, however, independent and loyalty‐focused employees differed: An increase (decline) in job satisfaction was more strongly related to a decline (increase) in turnover intention for independent employees than for loyalty‐focused employees. These findings provide new insights into the differential dynamics involved in assessing work situations and responding to them based on different career aspirations and interests. Consequences for research and practice regarding more effective human resource management are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Characteristic Properties of Novel Organosolv Lignin/Polylactide/Delta-Valerolactone Terpolymers

Compostable terpolymers of l-lactide (LLA), delta-valerolactone (DVL), and switchgrass organosolv lignin (OSL) were synthesized via ring-opening polymerization to improve on polylactide homopolymer properties for commercial applications. OSL has properties that improve some of the deficiencies of polylactide, including polylactide’s limitations for use in food, beverage and medical applications due to its high water permeability and low ultraviolet light (UV) blocking capabilities. DVL was incorporated into these polymers to add flexibility. The addition of DVL to the polymer had a positive effect on the tensile strain properties of the resultant terpolymer, resulting in a more flexible polymer with a reduced Young’s modulus. Water vapor transmission rate calculations confirmed that water vapor was transported more slowly through terpolymer films than through the PLLA homopolymer under varying hygrostatic conditions. While the addition of DVL increased UV permeability, the addition of even a small amount of lignin can effectively counteract this effect.     

Characteristics of Coastal Dune Topography and Vegetation in Environments Recently Modified Using Beach Fill and Vegetation Plantings,Veneto, Italy

Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation. Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush.