Landscape changes in agrarian landscapes in the 1990s: the interaction between farmers and the farmed landscape. A case study from Jutland, Denmark

Recent landscape changes in a farmed landscape are analysed and related to farm and farmer characteristics. It is assumed that farm and farmer characteristics serve as mediators of large scale or macro driving forces of change-in the present case, a changing farming context including demands for a more environmentally friendly farming practise and a reduced output. The results are based on multivariate analyses of data collected from structured interviews of 160 farmers in a case study area, in central Jutland, measuring 5000 ha. The analysis shows that farmers are highly involved in landscape changes. The investigated landscape changes include creation and removal of landscape elements as well as certain management changes. The most common activity was creation of elements: hedgerows, small woodlands and conversion of rotational arable land to permanent grassland, whereas removal of elements, mainly hedgerows and semi-natural grasslands, were seen less frequently. Management changes like abandonment of permanent grassland were widespread. The results indicate a general extensification of the land use and the authors interpret the results partly as an indication of a change from productivism to a more multifunctional agricultural regime. The observed landscape changes at the farm level show a low, but structured relationship with the current farm and farmer characteristics, meaning that landscape changes were undertaken by various farmers and on various farms. On a general level, however, the age of the farmer and the duration of farm ownership seem to have a major influence on the landscape changes.     

Declining extent of open-water refugia for top predators in Baffin Bay and adjacent waters

Global climate change is expected to severely impact Arctic ecosystems, yet predictions of impacts are complicated by region-specific patterns and nonuniform trends. Twentyfour open-water overwintering areas (or "microhabitats") were identified to be of particular importance for eight seabird and marine mammal species in the eastern Canadian High Arctic and Baffin Bay. Localized trends in the available fraction of open-water were examined in March during 1979--2001, derived from approximate sea ice concentrations from satellite-based microwave telemetry. Declines in the fraction of open-water were identified at microhabitats in Baffin Bay, Davis Strait, coastal West Greenland, and Lancaster Sound. Increases in open-water were observed in Hudson Bay, Hudson Strait, and Foxe Basin. The biological importance of each microhabitat was examined based on species distribution and abundance. Potential consequences of reduced open-water for top marine predators include impacts on foraging efficiency and oxygen and prey availability.     

Protective effect of different types of bicycle helmets

The effectiveness of bicycle helmets in preventing head injuries is well documented. There are different opinions about the effectiveness of helmets in preventing face injuries, and few studies have analyzed the effect of different types of helmets. This study was performed to examine the effect of different helmet types to head and face injuries. The use of helmets was analyzed in cyclists with head or face injuries and compared with two control groups. The main control group was cyclists that had injuries not including the head or neck, and another control group was cyclists that had been involved in an accident, regardless of whether they had sustained any injury. Cross-table and logistic regression analyses were applied to analyze the protective effect of helmets. A total of 991 injured patients served as a basis for this study. Most of the accidents, (82%) were single accidents with no other persons involved. Of patients with injuries to the head, excluding face, 11.4% had been using hard shell helmets, and 9.6% had been using foam helmets at the time of the accident. Among the emergency room controls, the proportion of hard shell helmet users and foam helmet users was 26.4% and 11.4%, respectively. Compared to non-helmet users, this gave an odds ratio of 0.36 (CI = 0.21-0.60) for getting head injuries if the cyclists had been using hard shell helmets at the time of the injury, and 0.83 (CI = 0.41-1.67) for users of foam helmets. The odds ratio for getting face injuries was 0.90 (CI = 0.58-1.41) among users of hard shell helmets, and 1.87 (CI = 1.03-3.40) for users of foam helmets. The use of hard shell helmets reduced the risk of getting injuries to the head. Children less than nine years old that used foam helmets had an increased risk of getting face injuries. All bicyclists should be recommended to use hard shell bicycle helmets while cycling.     

Transport and degradation of toluene and o-xylene in an unsaturated soil with dipping sedimentary layers

A lysimeter trench was established at the Gardermoen delta (50 km north of Oslo, Norway) to study the flow of water and transport and degradation of aromatic jet fuel components (toluene and o-xylene) in the undisturbed unsaturated zone. Site investigations with ground-penetrating radar revealed the presence of dipping sedimentary layers within the foreset unit. This study has shown that the foreset bed of the Gardermoen delta structure provided a preferential flow path for the transport of the solute plumes, but did not have dramatic effects on the degradation potential under the current conditions. The degradation potential for toluene and o-xylene in the unsaturated zone at Gardermoen was very high and almost all of the injected hydrocarbons were biodegraded before reaching the saturated zone. However, the horizontal displacement of the plume showed that knowledge about sedimentary structures in the unsaturated zone is important for a sufficient monitoring of contaminant transport and for remediation purposes. Carbon dioxide and O2 were measured in situ simultaneously with extraction of water samples, and indicated aerobic biodegradation of toluene and o-xylene. Overall, first-order degradation coefficients were calculated to be in the range of 0.19 to 0.21 d(-1) and 0.10 to 0.11 d(-1) for toluene and o-xylene, respectively.     

Sorption of polycyclic aromatic compounds to humic and fulvic acid HPLC column materials

Two different humic acids (HA) and a fulvic acid (FA) were chemically immobilized to a high performance liquid chromatography (HPLC) silica column material. The immobilization was performed by binding amino groups in HA/FA to the free aldehyde group in glutardialdehyde attached to the silica gel. The HPLC column materials were compared with a blank column material made by applying the same procedure but without immobilizing HA or FA. Also, a column was made by binding carbonyl groups in HA to amino groups attached to the silica gel. The humic substances were selected to secure appropriate variation of their structural features. The retention factors of 45 polycyclic aromatic compounds (PAC) to the four columns were determined by HPLC. The advantage of the technique is a large number of compounds can easily be studied. The binding procedure does not appear to cause a drastic selection between the HA molecules. The k' values obtained for the two Aldrich HA columns agree in general reasonably. The retention or sorption of the compounds increased with the size of the PAC and the number of lipophilic substituents, but decreased when polar substituents were present. The PAC retention was much stronger to the two HA columns than to the FA and blank column, both for hydrophobic polycyclic aromatic hydrocarbons (PAH) and the polar PAC. Other factors impacting the PAC binding may be specific interactions with HA and the ionic strength of the aqueous phase. The technique has been applied to do direct determinations of Koc.     

The influence on partial order ranking from input parameter uncertainty. Definition of a robustness parameter

The method of partial order ranking has been used within the environmental area for a variety of purposes as an attractive way of handling complex information. However, the environmental data are often associated with a significant degree of uncertainty. In this investigation the general nature of the influence from data uncertainty on the partial order ranking is analyzed. A Monte Carlo type analysis is performed in which a series of randomly formed data are used to test the influence of data uncertainty. The partial order ranking is interpreted, where the results are transferred to a one-dimensional ranking scale taking into account that not all elements are ranked with the same certainty. A simple general robustness parameter (E) in form of the expected number of comparisons for each ranking element is defined and correlated to the uncertainty analysis results. A simple equation relates E to the number of elements and the number of parameters, respectively. The magnitude of the ranking uncertainty is shown to increase rapidly when the E value decreases below 4-5 comparisons per element. When the E value exceeds 5 the ranking uncertainty becomes nearly constant and independent on the actual E value.     

考虑应变速率影响的混凝土重力坝非线性地震响应分析

通过引入应变速率、损伤变量以及刚度退化指标等参数,建立了应变率相关的混凝土弹塑性损伤模型。运用该模型对某重力坝厂房坝段分别就率相关及率无关两种情况进行了三维非线性地震响应时程分析。深入研究了混凝土应变速率等相关特性对结构动力响应的影响。结果表明,应变速率对混凝土的力学性能有一定的影响,随着应变速率的增加,坝体结构的变形减小,主拉应力有所提高,应变能有所减小以及开裂损伤有一定的降低。所得结论对混凝土重力坝的震害研究有一定的参考价值。     

Democracy at its Best? The Consensus Conference in a Cross-national Perspective

Over recent decades, public participation in technology assessment has spread internationally as an attempt to overcome or prevent societal conflicts over controversial technologies. One outcome of this new surge in public consultation initiatives has been the increased use of participatory consensus conferences in a number of countries. Existing evaluations of consensus conferences tend to focus on the modes of organization, as well as the outcomes, both procedural and substantial, of the conferences they examine. Such evaluations seem to rest on the assumption that this type of procedure has universally agreed goals and meanings, and that therefore consensus conferences can readily be interpreted and applied across national boundaries. This article challenges this approach to consensus conferences. The core of the article is a study of national differences in ideas about what constitutes legitimate goals for participatory arrangements. The study looks at three consensus conferences on GMOs, which took place in France, Norway, and Denmark. Drawing on this study, the article discusses the ways in which interpretations of the concept of participation; the value attributed to lay knowledge vs. technical expertise; as well as ideas about the role of the layperson, are all questions that prompt entirely different answers from country to country. Further, the article analyses these national differences within a theoretical framework of notions of democratic legitimacy.     

Levels and risk assessment of chemical contaminants in byproducts for animal feed in Denmark

With aim to provide information on chemical contaminants in byproducts in animal feed, the data from an official control by the Danish Plant Directorate during 1998–2009, were reviewed and several samples of citrus pulp and dried distillers grains with solubles (DDGS) were additionally collected for analysis and risk assessment. The levels of contaminants in the samples from the official control were below maximum limits from EU regulations with only a few exceptions in the following groups; dioxins and dioxin-like polychlorobiphenyls (PCBs) in fish-containing byproducts and dioxins in vegetable and animal fat, hydrogen cyanide in linseed, and cadmium in sunflowers. The levels of pesticides and mycotoxins in the additionally collected samples were below maximum limits. Enniatin B (ENN B) was present in all DDGS samples. The hypothetical cases of carry-over of contamination from these byproducts were designed assuming total absorption and accumulation of the ingested contaminant in meat and milk and high exposure (a byproduct formed 15–20% of the feed ration depending on the species). The risk assessment was refined based on literature data on metabolism in relevant animal species. Risk assessment of contaminants in byproducts is generally based on a worst-case approach, as data on carry-over of a contaminant are sparse. This may lead to erroneous estimation of health hazards. The presence of ENN B in all samples of DDGS indicates that potential impact of this emerging mycotoxin on feed and food safety deserves attention. A challenge for the future is to fill up gaps in toxicological databases and improve models for carry-over of contaminants.