| 1. |
- Appelberg, Jonas, 1985-, et al.
(författare)
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Social media in the professional work of Polish, Russian and Swedish journalists
- 2014
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Ingår i: Journal of Print and Media Technology Research. - Darmstadt : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; 3:2, s. 107-118
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Tidskriftsartikel (refereegranskat)abstract
- Professional journalistic culture is a complex of journalistic values, practices, norms and media products. On the one hand it tends to unification across the globe, but on the other hand these cultures varies according to cultural diversities. Technological development leads to a media convergence, increasing interactivity and plenty of opportunities for individualization of media content influence audience’s demands and consequently challenge of traditional routine of journalists’ work, affect professional practices and even undermine traditional role of a journalist in society. Social media creates new conditions for both actors: readers/viewers/listeners and for media professionals who use it as a tool for media work. Journalists in the different countries, however, use social media for professional needs not equally. This paper is discussing differences and similarities in the patterns of social media use by Polish, Russian and Swedish journalists. The research is based on a survey of 500 journalists in each country.
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| 2. |
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| 3. |
- Gambarato, Renira R.
(författare)
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Transmedia storytelling in analyisis : The case of Final punishment
- 2014
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Ingår i: Journal of Print and Media Technology Research. - : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; 3:2, s. 95-106
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Tidskriftsartikel (refereegranskat)abstract
- Transmedia storytelling refers to both fictional and non-fictional narratives that are expanded across different media platforms, inviting the audience to engage and migrate from one medium to another in order to undergo an enriched experience. As a relatively new and elusive subject, it does not have its own specific methods and methodology of analysis. This was my main motivation in proposing a transmedia project design analytical model, aimed at outlining relevant aspects that could contribute to understanding the process of the development of transmedia projects. First, this article succinctly presents the original analytical model to approach cases of transmedia projects and later applies it to Final Punishment, an award-winning multiplatform series produced in Brazil in 2009 by the Portuguese company BeActive – one of the pioneering transmedia production companies. The transmedia project focuses on eight women imprisoned in a fictitious high-security prison in Rio de Janeiro. It was possible to conclude that Final Punishment contributed to the development and dissemination of transmedia storytelling in Brazil, because in 2009 the country was just crawling in terms of multiplatform media production. Final Punishment gained notoriety not because of its rather limited range in terms of audience reach (a million viewers per episode and 115000 alternate reality game (ARG) players is not a great amount in such a large country as Brazil), but for its integrated and well-designed content which unfolded across multiple media platforms in a mixture of portmanteau and franchise transmedia type. The inconsistencies generated by the courageous initiative to produce a mockumentary in a country accustomed to mostly trusting everything that appears in the media, did not reduce the impact of Final Punishment.
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| 4. |
- Gooran, Sasan, 1965-, et al.
(författare)
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A novel spectral trapping model for color halftones
- 2018
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Ingår i: Journal of Print and Media Technology Research. - : INT ASSOC RESEARCH ORGANIZATIONS INFORM, MEDIA & GRAPHIC ARTS IND. - 2223-8905 .- 2414-6250. ; 7:3, s. 107-113
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Tidskriftsartikel (refereegranskat)abstract
- The amount of trapping has a great impact on the gray balance and color reproduction of printed products. The conventional trapping models are print density based and give percentage values to estimate the effect of trapping. In an earlier paper (Hauck and Gooran, 2011), a spectral trapping model was proposed, that defines the trapping effect as the DE* ab colorimetric differences between the real ink overlap (measurements) and the ideal ink overlap. All the trapping models proposed so far, however, only calculate the trapping value for full-tone (solid) ink overlap. As the trapping value for full-tone ink overlap could be overestimating the actual ink trapping effect for halftones, it is important to be able to also approximate the trapping value of color halftones. Furthermore, for a detailed gray balance shift analysis, there is a need to estimate the trapping effect for specific color halftones.In the present paper, we propose a novel spectral trapping model that delivers the trapping value as DE* ab color difference for color halftones taking into account secondary and tertiary ink overlap.The results of the experiments show that the trapping value for color halftones are much smaller than their corresponding trapping value at full-tone, but trapping value of halftones, besides other common quality parameters, should still be considered if some quality inaccuracy, such as gray balance shift, occurs in a print production.
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| 5. |
- Gooran, Sasan, et al.
(författare)
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Multi-channel dot-off-dot halftoning compensating for slightly chromatic gray inks
- 2015
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Ingår i: Journal of Print and Media Technology Research. - 2223-8905 .- 2414-6250. ; 4:2, s. 119-127
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Tidskriftsartikel (refereegranskat)abstract
- Printing using more than four ink channels visually improves the reproduction but causes challenges with the ink layer thickness that could lead to ink bleeding and color inaccuracy. A color image is commonly prepared for print by first being separated into the colorant channels the intended print device utilizes. The separations are usually halftoned independently, resulting in random dot overlap with possible spots where all colorants are printed. A multilevel halftoning algorithm that processes each channel so that it is printed with multiple inks of the same hue value has already been applied to three achromatic inks – photo gray, gray, black – in a real paper–ink setup. Results proved a successful multilevel halftone implementation workflow using multiple inks while avoiding dot-on-dot placement. However, in this approach, the gray inks were assumed to be neutral and lighter versions of black, an assumption that may cause a ΔE*ab color difference as high as 5. In the present paper an alternative approach, based on dot-off-dot halftoning avoiding dot overlap, is proposed andapplied to the same three inks. A look-up table driven separation procedure of the original image into the three channels is also proposed, which, combined with dot-off-dot halftoning, results in a ΔE*ab color difference not larger than 1.8. Results show that the dot-off-dot halftoned images are visually pleasant without any artifacts in tone transitions. The proposed approach has three main advantages to the commonly used independent halftoning. One being that dot overlap between different inks is completely avoided, i.e. photo gray, gray and black in the present work. The other one is that the results are less grainy compared to independent channel halftoning. The third one is that dot-off-dot halftoning consumes less ink than independent halftoning when reproducing the same color.
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| 6. |
- Hauck, Shahram, et al.
(författare)
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A novel method to determine register variation of a press by a densitometry tool
- 2015
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Ingår i: Journal of Print and Media Technology Research. - 2223-8905 .- 2414-6250. ; 4:2, s. 95-102
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Tidskriftsartikel (refereegranskat)abstract
- The print quality of a printing machine highly depends on good register variation values. The measuring of register variation is very important for putting a multicolor press in operation or for its repair and service. The manufacturers of print presses also need the evaluation of register variation to develop new products. The current industry standard method for measuring the register variation is based on image processing, which is a very expensive method. It was a great demand to determine the register variation by an alternative and affordable technique. In the present paper we introduce a new method to determine the register variation based on densitometry. In order to create a new method, a special color test target has been designed. The input of the method is the densitometric measurement values, and its output is the register variation value. The results of the method have been compared with those of an image processing method and the correlation coefficient between the results is almost 0.9. Since in the proposed method only a densitometer is needed, it can be considered as a very inexpensive alternative to the image processing methods. The results were also demonstrated to different specialists of a manufacturer of print press and received very positive feedback.
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| 7. |
- Hauck, Shahram, et al.
(författare)
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Automated CtP calibration system in an offset printing workflow
- 2018
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Ingår i: Journal of Print and Media Technology Research. - 2223-8905 .- 2414-6250. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Although offset printing has been and still is the most common printing technology for color print productions, its print productions are subject to variations due to environmental and process parameters. Therefore, it is very important to frequently control the print production quality criteria in order to make the process predictable, reproducible and stable. One of the most important parts in a modern industrial offset printing is Computer to Plate (CtP), which makes the printing plate.One of the most important quality criteria for printing is to control the dot gain level. It is crucial to have the dot gain level within an acceptable range, defined by ISO 12647-2/13. This is done by dot gain compensation methods in the Raster Image Processor (RIP). Dot gain compensation, which is also referred to as CtP calibration, is however a complicated task in offset printing because of the huge number of parameters affecting dot gain. The conventional CtP calibration methods for an offset printing process, which are very time and resource demanding and hence expensive, mostly uses one to five dot gain correction curves as maximum. The proposed CtP calibration method in this paper, calibrates the dot gain according to ISO 12647-2/13 recommendations fully automatically parallel to the print production.Besides that, there is no limitation of the number of the needed dot gain correction curves. This method, which is much more efficient and economically beneficial compared to conventional CtP calibration methods, also makes the printing production very accurate in terms of dot gain value. This automated CtP calibration system for offset printing workflow is introduced and described in this paper.
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| 8. |
- Hauck, Shahram, et al.
(författare)
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Investigation of the effect of ink penetration and gloss on a proposed spectral trapping model for high quality glossy coated paper
- 2013
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Ingår i: Journal of Print and Media Technology Research. - : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; 2:4, s. 235-244
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Tidskriftsartikel (refereegranskat)abstract
- The amount of trapping has a great impact on the gray balance and color reproduction of printed products. Therefore, conventional print density based models to estimate the effect of trapping have been created, which only give percentage values. In an earlier paper (Hauck and Gooran, 2011) we have proposed a trapping model based on reflectance spectra, which defines the trapping effect as the DE*ab colorimetric differences between the measurements and the calculated values. Therefore, this model is more useful and meaningful for the press machine operators than the conventional trapping models. The surface (gloss) and ground (ink penetration) effect may have an impact on the print results depending on the substrate and inks but these effects have mainly been ignored in all previous trapping models. In the present paper, we extend our earlier model to investigate the impact of both effects for high quality glossy coated paper and a set of sheet-fed offset inks. An ink mileage test was carried out to find the surface and ink penetration effects. The results of our investigation demonstrates that these two effects compensate each other and their total impact is almost negligible for the tested materials. This means that our previously proposed model can successfully be used for high quality glossy coated papers to determine the trapping value.
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| 9. |
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| 10. |
- Kamal Alm, Hajer, et al.
(författare)
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Ink adhesion failure during full scale offset printing : causes and impact on print mottle
- 2015
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Ingår i: Journal of Print and Media Technology Research. - 2223-8905 .- 2414-6250. ; 4:4, s. 257-284
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Tidskriftsartikel (refereegranskat)abstract
- The printing plate used in offset lithography is designed to accept ink on image areas and reject ink on non-image areas. In order to reject ink in conventional offset, fountain solution is needed to form a weak boundary layer between the plate and the ink. Paper and coated paper in particular are designed to accept ink and absorb ink oil and fountain solution. The latter is often transferred to the paper surface through the rubber blanket and its absorption or subsequent displacement is essential for final ink transfer to the surface. There are strong demands on the uniformity of the paper surface, including in respect to absorptivity, both in structure and chemistry, in order to gain a print of high quality. If this is not the case, the ink film thickness may be non-uniform; subsequently, ink adhesion may even fail completely, leaving white spots on the paper surface in the print. This gives rise to print mottle, a severe print quality defect. The aim of this paper was to study the quality of prints from a full scale offset printing trial made on pilot coated paper, with attention given to ink-surface adhesion. Seven calcium carbonate pigment based coatings with different contents of pigment dispersing agent were included in this study. The work showed that a moderate over-dosage of dispersant significantly increased the ink adhesion failure and print mottle, mainly on prints from the later print units and especially at high fountain feed levels. These findings demonstrate the fundamental impact of fount level, surface chemistry and coating formulation on ink adhesion and thus also print mottle.
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| 11. |
- Picha Edwardsson, Malin, 1970-, et al.
(författare)
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Explorative scenarios of emerging media trends
- 2014
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Ingår i: Journal of Print and Media Technology Research. - Zagreb : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; 3:3, s. 195-206
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Tidskriftsartikel (refereegranskat)abstract
- Dealing with the on-going structural changes in the media landscape is one of the most urgent challenges in today's society, both for people working in the media industry and for consumers trying to adapt to a large and increasing number of new media technologies and services. In this article, we present and discuss a number of current media trends, outline possible future scenarios and evaluate and discuss these scenarios in terms of future media consumption, mainly focusing on the Nordic media market. The research questions are: What are the main media consumption trends today, and what could be the most important characteristics of media consumption in different future scenarios? We have used a combination of a future studies approach, semi-structured expert interviews and design fiction methodology. We have organized two reference group workshops and then interviewed 11 media experts, both from the media industry and the academic world, and combined the results of these interviews and workshops with the significant media trends generated through design fiction methodology in the project course "The Future of Media" at the KTH Royal Institute of Technology in Stockholm.One of the conclusions drawn is that the mobile phone (smartphone) and other mobile devices such as tablets, etc., are playing an increasingly important role in current media consumption trends. We can see this through an increased number of mobile devices, an increased use of multiple devices (often used simultaneously) and in the fact that users tend to be "always connected and always synchronized". Another conclusion drawn is that there is an increased focus on personalized and individualized news with more co-creation and sharing of media content. The amount of non-text formats for news, e.g., video, is increasing, as well as the need for a high-speed, high-quality infrastructure/network. The news consumers are increasingly time-pressed, and commute more, which creates new and different demands on the media content, such as being easily accessible at all times and places. Finally, more data is collected by media companies about the consumption habits of media users and more surveillance is performed on citizens by governments and corporations. When interviewed about the scenarios and trends in this study, the experts considered the most desirable future society to have a balanced mix of governmental control and commercial powers. As an example, public service media was considered an important counterbalance to commercially oriented media companies. According to the experts that were interviewed, aspects of all four proposed scenarios could however become true in the future, depending on choices made both on an individual level and on a societal level.
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| 12. |
- Picha Edwardsson, Malin, et al.
(författare)
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Local Television Content Production : Process Structures and Climate Impacts – a Case Study
- 2012
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Ingår i: Journal of Print and Media Technology Research. - 2223-8905 .- 2414-6250. ; 1:4, s. 215-232
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Tidskriftsartikel (refereegranskat)abstract
- The business environment in which media companies exist today is rapidly changing. If they have not done so already, media companies need to position themselves to this ongoing change and find their place in the new media landscape. However, this could also mean a good opportunity to optimize work processes on different levels. In order to meet these opportunities, as well as being proactive when it comes to environmental performance, we first need to understand the current structure of media companies, for example when it comes to work processes.The aim of this study is to identify and analyze the process structure and the potential climate impact of the content production of the local television station TV4 Gävle/Dalarna in Sweden. The study objectives are:to identify the major editorial and marketing processes and to visualize the two workflows in order to discover how the processes could be optimized and how this in turn may affect the environmental impact.to assess the carbon footprint of the content production of the local television station and to identify the major reasons for this climate change impact.Two main methods were used – semi-structured interviews and carbon footprint assessment.The editorial part of the workflow is centered on broadcasting news at certain times. A total of nine process steps were identified in the editorial workflow. The largest amount of person hours can be found in the process steps of content production and content editing. Work is done in order to meet the deadlines which come every time there is a broadcast. This fact puts special demands on the personnel, such as an ability to manage stress and short deadlines, and an ability to handle the technical equipment in one-person teams. There is a total of seven process steps on the marketing side, two of which are located outside of the local television station.A large part of the carbon footprint from the TV4 Gävle/Dalarna content production is caused by business trips by car. The editorial department makes most of the business trips, but the marketing department is also responsible for some of the trips. The total carbon footprint from the television production is estimated to 52 tons of CO2 eq/year, including the employees’ trips to andfrom the workplace. The trips to and from work is the second largest contributor to the carbon footprint. When considering the impact per viewer, the result is 0.35 kg of CO2 eq/viewer and year.Judging from today’s situation, the efficiency on the editorial side is very good. However, it might still be fruitful to consider the travelling practices in order to improve the overall environmental performance.
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| 13. |
- Qu, Yuanyuan, et al.
(författare)
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A simple color separation model based on colorimetric and spectral data
- 2013
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Ingår i: Journal of Print and Media Technology Research. - : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; II:2, s. 77-86
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Tidskriftsartikel (refereegranskat)abstract
- A color separation model which separates a target color inside the gamut of a printing system into the combination of process inks used in the system is a crucial part of the printing procedure. A simple color separation model for CMY printing is presented in this paper. It is based on a color prediction model proposed in our previous papers. This color prediction model, which was based on CIEXYZ (CIELAB) values, is extended in this paper to work also for spectral data. Therefore, the color separation model is executable for target colors represented by both CIELAB and spectral data. Two experiments are designed and carried out to evaluate the accuracy of the proposed models. The first experiment proves the accuracy and stability of the forward (color prediction) model. The second experiment shows that our simple inverse model (color separation) has a satisfying accuracy for different target colors in terms of giving less ink consumption and small CIELAB (ΔE94) or small spectrum difference (ΔRMS). The proposed color separation model has the potential to be applied to practical printing systems due to its simplicity and accuracy.
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| 14. |
- Rehberger, Marcus, et al.
(författare)
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VDP Quality aspects on fibre based packaging : An elementary print quality study on corrugated board
- 2024
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Ingår i: Journal of Print and Media Technology Research. - Darmstadt. - 2223-8905 .- 2414-6250.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Variable data printing (VDP) is a technique whereby certain information can be altered in an otherwise static layout with the help of a digital printing system, and in the packaging industry a wide range of applications are possible. Inkjet printing, due to its non-impact printing (NIP) principle, is the most suitable technique to be implemented in packaging production (van Daele, 2005). Only when printing high volumes is inkjet printing much more expensive than conventional printing (Viström, et al., 2006). However, the advantages of inkjet printing could still be adopted by another approach.At Innventia AB, the “HybSpeed Printing” project was initiated to study the combination of a conventional printing process with inkjet printing. The aim of the project is to assess the practicability of attaining high quality VDP at high speed on a variety of packaging papers for corrugated board production. The exploratory trials were conducted on a Kodak Versamark DP5240 in Örnsköldsvik, Sweden, in cooperation with the Mid-Sweden University - Digital Printing Centre (DPC). Nine different substrates, white top and pure white liner, single-coated, double-coated, kraftliner and testliner were printed at a speed of 2 m/s.Rehberger et al. (2010) described in the first part of the study that high-speed inkjet printing at 5 m/s has only an insignificant influence on the print quality. In this article, the influence of paper properties is discussed and it is shown that the paper quality has a considerable influence on the print quality. All paper qualities led to an acceptable print result at a medium print resolution. Speed is the most important factor for inline implementation of inkjet, but the tests revealed that the paper properties are most decisive for good print quality.
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| 15. |
- Teljas, Cecilia, 1980-
(författare)
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Interactive and social - A study of Swedish online newspapers
- 2013
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Ingår i: Journal of Print and Media Technology Research. - Darmstadt : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; :2-13, s. 63-123
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Tidskriftsartikel (refereegranskat)abstract
- This study explores how established media services such as online newspapers meet the increasing popularity of social media. A case study of Aftonbladet.se was conducted in order to understand how one of the leading Swedish online newspapers uses social media and relates to this new media form. The most important evidence of the influence of social media on Aftonbladet is apparent in the way its role as an online newspaper is expressed: "Aftonbladet wants to be a meeting place (……). The whole experience builds on interactivity and community". The case study results of Aftonbladet's social media use are interesting because they offer indications of Sweden's leading online newspaper's take on new media developmentand more specifically of the reasoning within the newspaper organization around the changing user relations.
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| 16. |
- Thorman, Sofia, et al.
(författare)
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The impact of non-uniform ink absorptionon flexographic print mottle
- 2018
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Ingår i: Journal of Print and Media Technology Research. - Darmstadt, Germany : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; 7:1, s. 7-18
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Tidskriftsartikel (refereegranskat)abstract
- Absorption non-uniformity and surface roughness of coated packaging boards are believed to have an impact on flexographic print mottle. Yet, their respective contributions are not well recognised due to their co-existence. Therefore, we propose a method that can solely study the effects of absorption non-uniformity on print mottle. This is achieved by artificially introducing uneven absorption, through well-controlled barrier patterns. The barrier patterns were added onto board surfaces using flexographic printing. By applying barrier patterns of several area coverages on board substrates of different intrinsic surface roughness it is possible to create a property-matrix, absorption non-uniformity versus for example surface roughness. With this matrix, the impact on print mottle from either of the properties can be studied independently. The results showed that surface roughness had a dominant effect on the print mottle, but mainly when comparing samples that spanned a broad roughness range. On the other hand, within a limited range of surface roughness, uneven ink absorption governed print mottle instead. This may explain why printing problems are sometimes encountered despite smooth board surfaces. Although the impact of absorption non-uniformity on print mottle differed from one board to another, the results indicated that a change towards more uneven absorption will have a negative impact on the print quality for most of the coated boards. The results give a better understanding of flexographic print quality and thereby can enable more reliable print mottle predictions.
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| 17. |
- Willfahrt, Andreas, 1977-, et al.
(författare)
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Model for calculation of design and electrical parameters of thermoelectric generators
- 2012
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Ingår i: Journal of Print and Media Technology Research. - : International Association of Research Organizations for the Information, Media and Graphic Arts Industrie (IARIGAI). - 2223-8905 .- 2414-6250. ; 1:4, s. 247-257
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Tidskriftsartikel (refereegranskat)abstract
- Energy harvesting - the conversion of ambient energy into electrical energy - is a frequently used term nowadays. Several conversion principles are available, e.g., photovoltaics, wind power and water power. Lesser-known are thermoelectric generators (TEG) although they were already studied actively during and after the world wars in the 20th century (Caltech Material Science, n. d.). In this work, the authors present a mathematical model for the calculation of input or output parameters of printed thermoelectric generators. The model is strongly related to existing models (Freunek et al., 2009; Rowe, 1995; Glatz et al., 2006) for conventionally produced TEGs as well as for printed TEGs. Thermal effects as investtigated by Freunek et al. (2009; 2010) could be included. In order to demonstrate the benefit of the model, two examples of calculations are presented. The parameters of the materials are derived from existing printing inks reported elsewhere (Chen et al., 2011; Wuesten and Potje-Kamloth, 2008; Zhang et al., 2010; Liu et al., 2011; Bubnova et al., 2011). The printing settings are chosen based on feasibility and convenience.
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| 18. |
- Willfahrt, Andreas, et al.
(författare)
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Model for calculation of design and electrical parametersof thermoelectric generators
- 2012
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Ingår i: Journal of Print and Media Technology Research. - 2223-8905 .- 2414-6250. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Energy harvesting - the conversion of ambient energy into electrical energy - is a frequently used term nowadays. Severalconversion principles are available, e. g., photovoltaics, wind power and water power. Less known are thermoelectricgenerators (TEG) although they were already studied actively during and after the world wars in the 20th century (CaltechMaterial Science, n. d.). In this work, the authors present a mathematical model for the calculation of input or outputparameters of printed thermoelectric generators. The model is strongly related to existing models (Freunek et al., 2009;Rowe, 1995; Glatz et al., 2006) for conventionally produced TEGs as well as for printed TEGs. Thermal effects asinvestigated by Freunek et al. (2009; 2010) could be included. In order to demonstrate the benefit of the model, twoexamples of calculations are presented. The parameters of the materials are derived from existing printing inks reportedelsewhere (Chen et al., 2011; Wuesten and Potje-Kamloth, 2008; Zhang et al., 2010; Liu et al., 2011; Bubnova et al., 2011).The printing settings are chosen based on feasibility and convenience.
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| 19. |
- Finotello, Simone, et al.
(författare)
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Repeated pulse exposures to lambda-cyhalothrin affect the behavior, physiology, and survival of the damselfly larvae Ischnura graellsii (Insecta; Odonata)
- 2017
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Ingår i: Ecotoxicology and Environmental Safety. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0147-6513 .- 1090-2414. ; 144, s. 107-114
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Tidskriftsartikel (refereegranskat)abstract
- Damselflies form an essential part of the aquatic and terrestrial food web. Pesticides may, however, negatively affect their behavior, physiology, and survival. To assess this, a 42-day-lasting bioassay was conducted, during which damselfly larvae (Ischnura graellsii; n = 20) were repeatedly exposed to lambda-cyhalothrin (3 days at; 0, 10, 50, 250, 1250, and 6250 ng LCH L-1), followed by recovery phases (4 days) in pesticide-free medium for six weeks. This exposure design was used to simulate frequent runoff events in the field. Variables related to the behavior (strikes against prey and capture success), growth, physiology (lipid content and fatty acid composition), as well as mortality were assessed throughout the experiment. The two highest LCH concentrations induced 100% mortality within the first 48 h, whereas 85% of the test organisms survived 28 days under control conditions. The number of strikes against prey was not affected by LCH. In contrast, prey capture success decreased significantly (up to similar to 50% at 250 ng LCH L-1, for instance, after the third pulse exposure) following LCH-exposures compared to the control. This difference was not observed after recovery phases, however, which did not counteract the enhanced energy demand for detoxification and defense mechanisms indicated by a lower growth rate (up to similar to 20%) and lipid content (up to similar to 30%) of damselflies at 50 and 250 ng LCH L-1. In addition, two essential fatty acids (eicosapentaenoic acid and arachidonic acid) and two precursors (linolenic acid and alinolenic acid) decreased in their concentrations upon exposure towards 250 ng LCH L-1. Thus the results of this study indicate that long-term exposure towards LCH pulses can affect damselfly behavior, physiology and survival. Given the essential role of damselflies in food web dynamics, these effects may potentially translate into local population impairments with subsequent bottom-up directed effects within and across ecosystem boundaries.
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