Farms In Denmark Research Articles

Photobacterium damselae subsp. damselae, an emerging pathogen in Danish rainbow trout, Oncorhynchus mykiss (Walbaum), mariculture

A selection of 16 field isolates of Photobacterium damselae from marine rainbow trout farms in Denmark was subjected to phenotypic and genotypic characterization and pathogenicity to fish. All isolates belonged to the subspecies damselae, being positive for haemolysis, motility and urease. There were considerable differences in haemolytic properties, some isolates presenting a broad zone of haemolysis and others only a narrow zone. Pulsed-field gel electrophoresis revealed a high diversity indicating that P. damselae subsp. damselae is an opportunistic, not clonal pathogen in Danish marine rainbow trout. Virulence of the strains to rainbow trout was highly variable with LD(50) values ranging from 3.9 x 10(3) to 1.5 x 10(8) cfu at 20 degrees C. The virulence was significantly higher at 20 degrees C than at 13 degrees C. The strains with the strongest haemolytic properties were the most virulent suggesting a strong involvement of haemolysin in the pathogenesis. The pathological changes were consistent with a bacterial septicaemia and the haemorrhages were more pronounced than for most other bacterial infections.

Avian sensitivity to mortality: Prioritising migratory bird species for assessment at proposed wind farms

Wind power generation is likely to constitute one of the most extensive human physical exploitation activities of European marine areas in the near future. The many millions of migrating birds that pass these man-made obstacles are protected by international obligations and the subject of public concerns. Yet some bird species are more sensitive to bird–wind turbine mortality than others. This study developed a simple and logical framework for ranking bird species with regard to their relative sensitivity to bird–wind turbine-collisions, and applied it to a data set comprising 38 avian migrant species at the Nysted offshore wind farm in Denmark. Two indicators were selected to characterize the sensitivity of each individual species: 1) relative abundance and 2) demographic sensitivity (elasticity of population growth rate to changes in adult survival). In the case-study from the Nysted offshore wind farm, birds of prey and waterbirds dominated the group of high priority species and only passerines showed a low risk of being impacted by the wind farm. Even where passerines might be present in very high numbers, they often represent insignificant segments of huge reference populations that, from a demographic point of view, are relatively insensitive to wind farm-related adult mortality. It will always be important to focus attention and direct the resources towards the most sensitive species to ensure cost-effective environmental assessments in the future, and in general, this novel index seems capable of identifying the species that are at high risk of being adversely affected by wind farms.

Surveillance of health status on eight marine rainbow trout, Oncorhynchus mykiss (Walbaum), farms in Denmark in 2006

The health status of eight marine rainbow trout farms was followed from mid-June to mid-September 2006 by sampling both dead and healthy fish approximately every 2 weeks for bacteriological and virological investigation. No fish pathogenic viruses were detected, but all farms experienced disease and mortality as a result of various bacterial infections. Yersinia ruckeri was found on four and Renibacterium salmoninarum on five of the farms, but only during the first part of the surveillance period. This indicates that the fish carried the infection from fresh water, and cleared the infection in salt water. Aeromonas salmonicida subsp. salmonicida caused mortality on five farms, but persisted throughout the sampling period. Although A. salmonicida was probably carried from fresh water, the fish were not able to clear the infection in the sea. Vibrio anguillarum caused mortality on six of the farms throughout the sampling period, O1 being the dominant serovar, and Photobacterium damselae subsp. damselae was found on seven farms as a cause of disease. During the period of highest water temperatures Vibrio parahaemolyticus and Vibrio vulnificus were detected in dead fish in five and two farms, respectively, although their significance as causative pathogens is questionable. Vibrio vulnificus has not previously been found in rainbow trout in Denmark. Both mortality and number of antimicrobial treatments during the period were considerably higher in unvaccinated compared with vaccinated fish. Resistance to commonly used antimicrobials was low or absent.

Regime-switching modelling of the fluctuations of offshore wind generation

The magnitude of power fluctuations at large offshore wind farms has a significant impact on the control and management strategies of their power output. If focusing on the minute scale, it looks like different regimes yield different behaviours of the wind power output. The use of statistical regime-switching models is thus investigated. Regime-switching approaches relying on observable (i.e. based on recent wind power production) or non-observable (i.e. a hidden Markov chain) regime sequences are considered. The former approach is based on either self-exciting threshold autoregressive (SETAR) or smooth transition autoregressive (STAR) models, while Markov-switching autoregressive (MSAR) models comprise the kernel of the latter one. The particularities of these models are presented, as well as methods for the estimation of their parameters. The competing approaches are evaluated on a one-step ahead forecasting exercise with time-series of power production averaged at a 1, 5, and 10-min rate, at the Horns Rev and Nysted offshore wind farms in Denmark. For the former wind farm, the one-step ahead root mean square error (RMSE) is contained between 0.8% and 5% of installed capacity, while it goes from 0.6% to 3.9% of installed capacity for the case of Nysted. It is shown that the regime-switching approach based on MSAR models significantly outperforms those based on observable regime sequences. The reduction in one-step ahead RMSE ranges from 19% to 32% depending on the wind farm and time resolution considered. The presented results clearly demonstrate that the magnitude of fluctuations of offshore wind power cannot be considered as simply influenced by the generation level only.

Offshore Coastal Wind Speed Gradients: Issues for the Design and Development of Large Offshore Windfarms

Simulations, from mesoscale numerical models, and analyses of in-situ and remote sensing data from offshore wind farms in Denmark, are used to examine both horizontal and vertical gradients of wind speeds in the coastal zone. Results suggest that the distance from the coastline over which wind speed vertical profiles are not at equilibrium with the sea surface (which defines the coastal zone) extends to 20 km and possibly 70 km from the coast. Using this operational definition of the coastal zone, these results thus imply the typical width of the coastal zone in northern Europe is between 20 and 70 km. The width of the coastal zone, and the wind's vertical (shear) and horizontal gradients within the coastal zone, depend on atmospheric stability. Although vertical wind speed profiles above 50 m are likely responding to additional factors such as the height of the boundary-layer, using a stability correction improves predictions of wind speed compared with the logarithmic profile. Modelling indicates that within the coastal zone, wind speeds at typical turbine hub-heights can change by 2 m/s over the horizontal extent of a large wind farm, depending on stability. However, if the fetch is sufficiently long (or the windfarm is further from the coast) both horizontal and vertical wind speed gradients over the area of the wind farm appear to be small and negligible.

Modelling of power fluctuations from large offshore wind farms

AbstractThis paper deals with modelling of power fluctuations from large wind farms. The modelling is supported and validated using wind speed and power measurements from the two large offshore wind farms in Denmark. The time scale in focus is from 1min to a couple of hours, where significant power fluctuations have been observed from these wind farms. Power and wind speed are measured with 1s sampling time in all individual wind turbines in almost 1 year, which provides a substantial database for the analyses. The paper deals with diversified models representing each wind turbine individually and with aggregation of a wind farm to be represented by a single large wind turbine model. Copyright © 2007 John Wiley & Sons, Ltd.

Socio-cultural processes behind the differential distribution of organic farming in Denmark: a case study

Conversion to organic farming, along with its associated driving forces and barriers, has been explored intensively over the past decade, while studies on the distribution and impacts of local socio-cultural processes in relation to conversion to and diffusion of organic farming have been scarce. The concentration of organic farms in Denmark differs according to county and, moreover, there appears to be large within-county variation in the density of organic farms. The present study explores local aspects of conversion to organic farming and the factors that may help explain variation in density and concentration of organic farms within smaller areas. The study is based on nine qualitative interviews with organic farmers from two neighboring areas, referred to as “mainland” and “island,” respectively. Three farms were situated in the high-density area (mainland) and the remaining six in the low-density area (island). Furthermore, five advisors with connections to the area provided information with regard to their local experience and perceptions. Three main, and to some extent interacting, issues are discussed. The first is the price of land related to local scarcity of land, in the context of structural development and the effects of agricultural policies. The second is distance – both physical and social. Cooperation and exchange of experience among organic farmers was frequent on the mainland side, while isolation and lack of interaction was more common for the island farmers. Third, the role of the agricultural advisory service and the existence of champion farmers are important: pioneer farmers on the mainland have been supported by committed agricultural advisors, while lack of organic champion farmers and low priority granted to organic farming among agricultural advisors were found on the island.

In memoriam: Oluf L. Gamborg, 1924–2007

Oluf was born on a farm in Denmark and attended school there. His teenage years were influenced by the Second World War and the occupation by the German military forces. It was during that period that he got the inspiration to move to North America, which he did in 1949. He had attended a horticultural college in Denmark, but after arriving in Chauvin, Alberta, the home of a distant cousin, he entered the University of Alberta in Edmonton in 1952 where he obtained a B.Sc. in Agriculture with distinction in 1956 and a M.Sc. in Plant Biochemistry in 1958. He then worked at the Prairie Regional Laboratory (PRL) of the National Research Council of Canada in Saskatoon. The job also allowed him to study, and he registered as a Ph.D. student at the University of Saskatchewan in Fall 1958. He worked on the synthesis of phenolic compounds in plants. He obtained his Ph.D. in Biochemistry in 1962 and continued to work at PRL. Oluf began working with plant cell suspension cultures in the 1960s and made some seminal findings relating to the nutritional requirements for such cultures. During his career, he energetically worked to establish plant tissue culture as a viable and essential agricultural tool in many parts of the developing world, particularly Asia. Through his travels and his training activities, the technology spread rapidly. As a result, tissue culture techniques—such as micropropagation of elite genotypes and in vitro germplasm storage—now play a key role in the agricultural selfsufficiency of many countries. Indeed, one paper outlined a medium now referred to as Gamborg’s B5 medium, which is still one of the most widely used media for plant tissue and cell cultures at present. In the early 1970s, he began working on protoplasts and discovered inter alia, the value of polyethleneglycol as an aid to protoplast fusion. This method is still widely used. His work in the 1960s and 1970s made the Prairie Regional Lab, Saskatoon (now Plant Biotechnology Institute) of the National Research Council of Canada a highly recognized center worldwide for in vitro technology. The second phase of his career took Oluf to the USA where he was a Senior Scientist/Research Director/Scientific Consultant for different biotechnology companies in California between 1979 and 1985 and where he exploited in vitro technology for applied purposes. He then moved on to Colorado State University (1985–1991) where he was Associate Director and Research Coordinator of the “Plant Tissue Culture for Crops” project of the US Aid for International Development Agency. This involved various areas of in vitro research for salt tolerance and also included organizing training courses, networking, and consultancies in several developing countries. Some of this research resulted in publications, but more importantly, it led to the establishment of tissue culture-based research activities in several of these countries. From 1991 to 1998, he was a full time consultant to private companies and had major projects in Indonesia and Viet Nam. Oluf also played a role in the personal development of numerous scientists with whom he interacted in the early phases of their careers. My first working relationship with him was as a member of the Tissue Culture Association Committee that he chaired on “Chemically Defined Media” in 1972, which also included Toshio Murashige and Indra Vasil. The report “Plant Tissue Culture Media” was published in In Vitro in 1976 and is still widely quoted. The International Association for Plant Tissue Culture was headquartered in Canada in 1974–1978, mainly because of In Vitro Cell.Dev.Biol.—Plant (2007) 43:281–282 DOI 10.1007/s11627-007-9070-5

Willingness to pay for reduced visual disamenities from offshore wind farms in Denmark

Expansion of offshore wind power plays a significant role in the energy policies of many EU countries. However, offshore wind farms create visual disamenities. These disamenities can be reduced by siting wind farms at larger distances from the coast—and accepting higher costs per kWh produced. In this paper willingness to pay for reducing the visual disamenities from future offshore wind farms is elicited using the economic valuation method Choice Experiments. The valuation scenario comprises the location of 720 offshore wind turbines (equivalent to 3600 MW) in farms at distances equal to: 12, 18 or 50 km from the shore, relative to an 8 km baseline. Using a fixed effect logit model average willingness to pay amounts were estimated as: 46, 96 and 122 Euros/household/year for having the wind farms located at 12, 18 and 50 km from the coast as opposed to 8 km. The results also reveal that WTP deviates significantly depending on the age of respondents and their experiences with offshore wind farms.

Estimated N leaching losses for organic and conventional farming in Denmark

The impact of organic, compared with conventional, farming practices on N leaching loss was studied for Danish mixed dairy and arable farms using an N balance approach based on representative data. On mixed dairy farms, a simple N balance method was used to estimate N surplus and N leaching loss. On arable farms, the simple N balance method was unreliable due to changes in the soil N pool. Consequently, the Farm ASSEssment Tool (FASSET) simulation model was used to estimate N surplus, N leaching loss and the changes in the soil N pool.The study found a lower N leaching loss from organic than conventional mixed dairy farms, primarily due to lower N inputs. On organic arable farms, the soil N pool increased over time but the N leaching loss was comparable with conventional arable farms. The soil N pool was increased primarily by organic farming practices and incorporation of straw. The highest increase in the soil N pool was seen on soils with a low initial level of organic matter. The N leaching loss was dependent on soil type, the use of catch crops and the level of soil organic matter, whereas incorporation of straw had a minor effect. N leaching was highest on sandy soils with a high level of soil organic matter and no catch crops. The present results stress the importance of using representative data from organic and conventional farming practices in comparative studies of N leaching loss. Lack of representative data has been a major weakness of previous comparisons on N leaching losses on organic and conventional farms.

Search Efficiency of Spalangia cameroni and Muscidifurax raptor on Musca domestica Pupae in Dairy Cattle Farms in Denmark

Indoor releases of Spalangia cameroni Perkins and Muscidifurax raptor Girauelt & Sanders (Hymenoptera: Pteromalidae) were conducted in five organic dairy cattle farms to evaluate the overall effect on parasitism and efficiency at different pupal depths of Musca domestica L. (Diptera: Muscidae). Overall, parasitism increased significantly from 5.3 to 28.8–28.7% of the exposed house fly pupae due to the release of pupal parasitoids. Spalangia cameroni was by far the most dominant species, contributing approximately 71.5–72.3% of the parasitism in the release and post-release period, whereas 20.9–24.4% could be attributed to Muscidifurax raptor. A naturally occurring ichneumonid, Phygadeuon fumator Gravenhorst (Hymenoptera: Ichneumonidae) parasitized 4.1–6.8% of the exposed fly pupae. The placement of house fly pupae at two depths of the bedding, 5–10 and 15–20 cm had no significant effect on overall parasitism whereas M. raptor attacked the house fly pupae significantly more when placed in the 5–10 cm stratum (10.0%) compared to the 15–20 cm stratum (3.2%). The two pupal depths had no significant effect on parasitism by S. cameroni and P. fumator. Albeit S. cameroni contributed significantly to overall parasitism, M. raptor had a significantly higher attack rate when first a female had located bags with sentinel pupae. Based on the above results, however, S. cameroni seems the most appropriate species for managing house flies in straw bedded dairy cattle farms in Denmark. A biological control strategy of simultaneous releases of S. cameroni and M. raptor is discussed.

Vancomycin-resistantEnterococcus faeciumClone in Swine, Europe

To the Editor: The use of antimicrobial agents for growth promotion (AGP) in food-producing animals has been extensively debated because of the risk of establishing a reservoir of antimicrobial resistance genes or antimicrobial-resistant organisms of potential relevance for human health. This concern has motivated the progressive ban of the use of different AGP in the European Union, which began in 1997 with avoparcin and will end in 2006 (1). Worldwide trade of living animals for food production or breeding and of meat products enables multidrug-resistant pathogens to spread across national borders. Intercontinental dissemination of antimicrobial-resistant bacteria associated with food animals has been described for particular clones such as Salmonella enterica Typhimurium DT104 or Escherichia coli O157:H7 and for transferable genetic elements such as the genomic island SG1 or the streptococcal plasmid pRE25 (2). Vancomycin-resistant enterococci (VRE) in European farms were initially associated with the intensive use of avoparcin; however, the persistence of VRE in food animal environments after years of avoparcin withdrawal indicates that coselection by further antimicrobial or other agents, increased fitness of strains, and mobile genetic elements cannot be ruled out (1–3). A specific clone was recently detected among vancomycin-resistant E. faecium (VREF) isolated from different swine farms in Denmark and Switzerland and from a healthy Danish woman without antimicrobial drug exposure who ate pork, chicken, and beef (4,5). Since Portugal and Spain maintain commercial trade of food-producing swine (living or meat products) between them and with other European countries, including Denmark (http://www.dgv.min-agricultura.pt/dgv.nsf), we investigated a possible relationship among VREF swine fecal isolates from Portugal and Spain and compared these isolates with the Swiss/Danish clone. We studied 3 VREF from a Figueira da Foz slaughterhouse in central Portugal (1997–1998) and 3 VREF isolates from 3 Spanish slaughterhouses in Valencia, Lugo, and Murcia in eastern, northern, and southern Spain, respectively (1998–2000). These isolates were recovered in the course of previous surveillance studies (C. Novais/I. Herrero, unpub data). Antimicrobial susceptibility was tested for 13 antimicrobial agents by using the agar dilution method (6). Clonal relationships were analyzed by pulsed-field gel electrophoresis (PFGE) and characterization of pur-K alleles by amplification and further sequencing (6,7; http://efaecium.mlst.net). Species identification, genes coding for antimicrobial resistance genes or for putative virulence traits, and the backbone structure of Tn1546 were analyzed by polymerase chain reaction followed by sequencing when necessary (6,8). Broth and filter mating were performed by using E. faecium GE1 as recipient strain (6). Following criteria published elsewhere (6), the VREF isolates studied were considered a single clone (0–4 bands difference by PFGE). Some vancomycin-susceptible E. faecium swine isolates (VSEF) from Spain and Switzerland showed an SmaI-PFGE pattern closely related to that of VREF isolates (data not shown [4]; ). Representative VREF of each country harbored the allele 9 of the housekeeping gene purK, previously found among E. faecium isolates from swine and healthy persons (7). All VREF isolates were resistant to glycopeptides (vanA), erythromycin [erm(B)], and tetracycline. Two Spanish isolates were also highly resistant to streptomycin and kanamycin [aph(3´)-IIIa] (Table). All VREF isolates tested carried a Tn1546 type D, previously found in isolates from food-producing animals (8). This element showed alterations in orf1 and a G-T point mutation in the position 8234 at vanX. Transfer of vancomycin resistance was detected for the Swiss (4), Spanish, and Portuguese isolates and was associated with erythromycin resistance in all cases. Tetracycline resistance was also transferable in the Spanish strains. No virulence traits were detected. Table Features of vancomycin-resistant Enterococcus faecium swine isolates from European countries* We describe the simultaneous occurrence of a VREF strain among swine in 4 distant European countries for at least a 4-year period. Tn1546 type D has been largely described in European swine isolates, which indicates stability of this particular type among the high diversity of Tn1546 described to date (8). The finding of a group of genetically closely related strains, which include both VSEF and VREF isolates and which harbor a particular purK allele previously associated with E. faecium swine strains, might mirror wide dissemination of a host-specific clone more prone than others to acquire and spread different antimicrobial resistance, as reported for human clinical E. faecium isolates (9). Since enterococci from swine are able to colonize in the human gut (5,7) and isolates harboring purK-9 can be recovered from hospitalized patients with severe infections (10), specific swine enterococcal strains might represent a risk for antimicrobial resistance spread in the clinical setting. Further analyses need to be performed to understand the role of international animal movements, animal feed, and colonized farmers in the spread of this particular strain and to assess whether this clone shows an increased fitness in the porcine intestine when compared to other E. faecium strains.

Temporal and spatial analysis of the 1999 outbreak of acute clinical infectious bursal disease in broiler flocks in Denmark

The objective of this study was to describe the spatial and temporal dynamics of the 1999 outbreak of acute clinical infectious bursal disease (IBD) in broiler chicken farms in Denmark. The analysis was performed using data from all broiler farms located in the Jutland peninsula and the island of Funen (168 municipalities). The Moran's index I, K-functions and scan statistics were used to describe the dynamics of the epidemic. In addition, spatially correlated survival analyses were performed and the posterior frailties were mapped to identify areas with high or low survival times. From January to October 1999, a total of 43 farms (81 flocks) out of a total of 299 farms (2970 flocks) in 110 municipalities were infected with IBD. The outbreak developed more or less simultaneously in two regions, one in the north and the other in the center of the study area. The space–time descriptive methods suggested that the cases were more likely to occur during a short period of time and over relatively short distances, indicating that local factors facilitated the spread of the virus. For instance, the highest risk, as estimated by the K-function, was within 20 km and 20 days. The risk of transmission peaked in July and remained high until the end of the study. The spatially correlated survival analysis identified municipalities with low survival times that roughly corresponded to the clusters found using scan statistics. The analysis for the full hierarchical structure of the dataset identified variation (i.e. clustering) at the farm and municipality levels.

Wake effects of large offshore wind farms identified from satellite SAR

The effect of large offshore wind farms on the local wind climate is studied using satellite synthetic aperture radar (SAR). Wind maps are derived from a total of 30 ERS-2 SAR scenes and 11 Envisat ASAR scenes over two large offshore wind farms in Denmark: Horns Rev in the North Sea (80 turbines) and Nysted in the Baltic Sea (78 turbines). The wind farms are the world's largest to date. For the first time, high-resolution SAR-derived wind speed images are utilized to identify regions of reduced wind speed and high turbulence intensity (i.e. wind wakes) downstream of wind turbine arrays. After quality control, 19 SAR scenes are available for the study of wake effects. A decrease of the mean wind speed is found as the wind flows through the wind farms, leaving a velocity deficit of 8–9% on average, immediately downstream of the wind turbine arrays. From this point, wind speed recovers to within 2% of the free stream velocity over a distance of 5–20 km depending on the ambient wind speed, the atmospheric stability and the number of turbines in operation. The wake magnitude and extent found from SAR wind maps is consistent with in situ measurements and results from wake models. The standard deviation of SAR-derived wind speeds is an indicator of turbulence intensity. Added turbulence intensity downstream of a wind farm is found for 7 of the 19 cases. Turbulence intensity is not as easily identified from SAR images as changes in the mean wind speed. This may be due to a low impact of wind turbine generated turbulence on the sea surface where SAR measurements are obtained.

Major and trace elements in organically or conventionally produced milk

A total of 480 samples of milk from 10 organically and 10 conventionally producing dairy farms in Denmark and covering 8 sampling periods over 1 year (triplicate samplings) were analysed for 45 trace elements and 6 major elements by high-resolution inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. Sampling, sample preparation, and analysis of the samples were performed under carefully controlled contamination-free conditions. The dairy cattle breeds were Danish-Holstein or Jersey. Sources of variance were quantified, and differences between production systems and breeds were tested. The major source of variation for most elements was week of sampling. Concentrations of Al, Cu, Fe, Mo, Rb, Se, and Zn were within published ranges. Concentrations of As, Cd, Cr, Mn and Pb were lower, and concentrations of Co and Sr were higher than published ranges. Compared with Holsteins, Jerseys produced milk with higher concentrations of Ba, Ca, Cu, Fe, Mg, Mn, Mo, P, Rh, and Zn and with a lower concentration of Bi. The organically produced milk, compared with conventionally produced milk, contained a significantly higher concentration of Mo (48 v. 37 ng/g) and a lower concentration of Ba (43 v. 62 ng/g), Eu (4 v. 7 ng/g), Mn (16 v. 20 ng/g) and Zn (4400 v. 5150 ng/g respectively). The investigation yielded typical concentrations for the following trace elements in milk, for which no or very few data are available: Ba, Bi, Ce, Cs, Eu, Ga, Gd, In, La, Nb, Nd, Pd, Pr, Rh, Sb, Sm, Tb, Te, Th, Ti, Tl, U, V, Y, and Zr.

A model of decision-making and information flows for information-intensive agriculture

This paper describes the development of a systems based model to characterise farmers’ decision-making process in information-intensive practices, and its evaluation in the context of Precision Agriculture (PA). A participative methodology was developed in which farm managers decomposed their process of decision-making into brief decision statements along with associated information requirements. The methodology was first developed on a university research farm in Denmark and further revised during testing on a number of research and commercial farms in Indiana, USA. Twenty-one decision-analysis factors were identified to characterise a farm manager’s decision-making process. Then, a general data flow diagram (DFD) was constructed that describes the information flows “from data to decision”. Illustrative examples of the model in the form of DFDs are presented for a strategic, a tactical and an operational decision. The model was validated for a range of decisions related to operations by three university farm managers and by five commercial farmers practicing PA for cereal, corn and soybean production in Denmark and in Indiana, USA.

The impact of R&D on innovation for wind energy in Denmark, Germany and the United Kingdom

This paper examines the impact of public research and development (R&D) support on cost reducing innovation for wind turbine farms in Denmark, Germany and the United Kingdom (UK). First we survey the literature in this field. The literature indicates that in Denmark R&D policy has been more successful than in Germany or the UK in promoting innovation of wind turbines. Furthermore, such studies point out that (subsidy-induced) capacity expansions were more effective in the UK and Denmark in promoting cost-reducing innovation than in Germany. The second part of the paper describes the quantitative analysis of the impact of R&D and capacity expansion on innovation. This is calculated using the two-factor learning curve (2FLC) model, in which investment cost reductions are explained by cumulative capacity and the R&D based knowledge stock. Time-series data were collected for the three countries and organized as a panel data set. The parameters of the 2FLC model were estimated, focusing on the homogeneity and heterogeneity of the parameters across countries. We arrived at robust estimations of a learning-by-doing rate of 5.4% and a learning-by-searching rate of 12.6%. The analysis underlines the homogeneity of the learning parameters, enhancing the validity of the 2FLC formulation.

Regulation of the erm(C) Gene in Staphylococci from Reservoir with Different Usage of Macrolides

Regulation of the erm(C) Gene in Staphylococci from Reservoir with Different Usage of Macrolides

LOCALISATION AND CONCENTRATION OF ORGANIC FARMING IN THE 1990s – THE DANISH CASE

ABSTRACT This paper explores the localisation of organic farms in Denmark for the three years 1994, 1997 and 2001, on a county and parish level. Spatial concentration is found in counties with a high share of milk producers, but also in the counties, which contain the two largest urban centres. General regional specialisation of the agricultural sector in Denmark contributes to the explanation of concentration patterns of organic conversion, but other factors such as a regional favourable policy climate and support also appear to play a role. Major variations in concentration within regions are found, suggesting that local factors play an important role for the explanation of spatial patterns of organic conversion and diffusion.

Ice loading on Danish wind turbines: Part 2. Analyses of dynamic model test results

The present paper deals with ice loads on wind turbine foundations from large floating ice floes. Some newly developed procedures to estimate the extreme ice load and combined loads from wind with loads from ice are described. The procedures have been developed as a part of the design basis for two of the first large offshore wind farms in Denmark, and they have been further developed in a research project including ice model tests with cones and vertical cylinders at the National Research Council (NRC), Canada. The principles are included in the new “Danish Recommendation to Technical Approval of Offshore Wind Turbines”. The design procedures are an integrated part of a selected design philosophy, which also includes a procedure for defining a consistent set of partial safety factors for the various extreme load cases. For a partial safety factor for wind loads of 1.4 to 1.5 (as defined in the Danish standards), the partial coefficients for ice load should be 2.0 to 2.5, depending on the determining ice load case.