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Author Clark, G.F.; Stark, J.S.; Johnston, E.L.; Runcie, J.W.; Goldsworthy, P.M.; Raymond, B.; Riddle, M.J.
Title (up) Light-driven tipping points in polar ecosystems Type Journal Article
Year 2013 Publication Global Change Biology Abbreviated Journal Glob Chang Biol
Volume 19 Issue 12 Pages 3749-3761
Keywords Ecology; benthic; biodiversity; irradiance; macroalgae; marine ecology; polar; regime shift
Abstract Some ecosystems can undergo abrupt transformation in response to relatively small environmental change. Identifying imminent 'tipping points' is crucial for biodiversity conservation, particularly in the face of climate change. Here, we describe a tipping point mechanism likely to induce widespread regime shifts in polar ecosystems. Seasonal snow and ice-cover periodically block sunlight reaching polar ecosystems, but the effect of this on annual light depends critically on the timing of cover within the annual solar cycle. At high latitudes, sunlight is strongly seasonal, and ice-free days around the summer solstice receive orders of magnitude more light than those in winter. Early melt that brings the date of ice-loss closer to midsummer will cause an exponential increase in the amount of sunlight reaching some ecosystems per year. This is likely to drive ecological tipping points in which primary producers (plants and algae) flourish and out-compete dark-adapted communities. We demonstrate this principle on Antarctic shallow seabed ecosystems, which our data suggest are sensitive to small changes in the timing of sea-ice loss. Algae respond to light thresholds that are easily exceeded by a slight reduction in sea-ice duration. Earlier sea-ice loss is likely to cause extensive regime shifts in which endemic shallow-water invertebrate communities are replaced by algae, reducing coastal biodiversity and fundamentally changing ecosystem functioning. Modeling shows that recent changes in ice and snow cover have already transformed annual light budgets in large areas of the Arctic and Antarctic, and both aquatic and terrestrial ecosystems are likely to experience further significant change in light. The interaction between ice-loss and solar irradiance renders polar ecosystems acutely vulnerable to abrupt ecosystem change, as light-driven tipping points are readily breached by relatively slight shifts in the timing of snow and ice-loss.
Address School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, NSW, 2052, Australia
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1354-1013 ISBN Medium
Area Expedition Conference
Notes PMID:23893603 Approved no
Call Number LoNNe @ kagoburian @ Serial 850
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Author Kostic, A.; Kremic, M.; Djokic, L.; Kostic, M.
Title (up) Light-emitting diodes in street and roadway lighting – a case study involving mesopic effects Type Journal Article
Year 2013 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology
Volume 45 Issue 2 Pages 217-229
Keywords LED; LED lighting; mesopic; street lighting; outdoor lighting; roadway lighting
Abstract The paper considers the justification for the application of light-emitting diode (LED) technology to urban lighting. The results suggest that LEDs are convenient for architectural lighting and deserve to be considered for use in ambient lighting. The recently developed Commission Internationale de l’Eclairage (CIE) mesopic system enabled the inclusion of mesopic effects into a comprehensive techno-economic analysis, which dealt with efficiency, maintenance and financial aspects of the use of LEDs in street and roadway lighting. It is concluded that the average energy savings when using LED instead of high-pressure sodium (HPS) luminaires amount to 19–26% for single-sided, staggered and opposite layouts, although they are frequently negligible if mesopic effects are not included. The total costs of the LED lighting solutions, even including mesopic effects, are 1.36 to 6.44 times higher than those of the comparable HPS lighting solutions. Therefore, LEDs are questionable for street and roadway lighting.
Address Faculty of Architecture, University of Belgrade, Belgrade, Serbia
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 339
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Author Femia, N.; Fortunato, M.; Vitelli, M.
Title (up) Light-to-Light: PV-Fed LED Lighting Systems Type Journal Article
Year 2013 Publication IEEE Transactions on Power Electronics Abbreviated Journal IEEE Trans. Power Electron.
Volume 28 Issue 8 Pages 4063-4073
Keywords light-to-light systems; outdoor lighting; lighting technology; LED; LED lighting; photovoltaics; PV
Abstract This paper discusses the principle of operation, dynamic modeling, and control design for light-to-light (LtL) systems, whose aim is to directly convert the sun irradiation into artificial light. The system discussed in this paper is composed by a photovoltaic (PV) panel, an LED array, a dc-dc converter dedicated to the maximum power point tracking of the PV panel and a dc-dc converter dedicated to drive the LEDs array. A system controller is also included, whose goal is to ensure the matching between the maximum available PV power and the LED power by means of a low-frequency LEDs dimming. An experimental design example is discussed to illustrate the functionalities of the LtL system.
Address Dipt. di Ing. Elettron. e Ing. Inf., Univ. of Salerno, Salerno, Italy
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0885-8993 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 331
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Author Nowinszky, L.
Title (up) Light-trap Catch of Harmful Microlepidoptera Species in Connection with Polarized Moonlight and Collecting Distance Type Journal Article
Year 2013 Publication Journal of Advanced Laboratory Research in Biology Abbreviated Journal
Volume 4 Issue 4 Pages 108-117
Keywords Animals
Abstract The paper deals with light-trap catch of 25 Microlepidoptera species depending on the polarized moonlight and

collecting distance. The catching data were chosen from the 27 stations of the Hungarian National Light-trap Network and

from the years between 1959 and 1961. Relative catch values were calculated from the catching data per stations and

swarming. They are ranged and averaged in the phase angle divisions. The catching peak of ten species is in First Quarter,

another ten species have the peak in the First Quarter and Last one, and only in two cases the peak is in Last Quarter. Then

there is the maximum ratio of polarized moonlight. Catching peak of only three species is in connection with the collecting

distance when is the greatest of collection distance.

Keywords: Microlepidoptera, light-trap moon phases, polarized moonlight, catching distance.
Address
Corporate Author Thesis
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Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 381
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Author Dominoni, D.M.; Quetting, M.; Partecke, J.
Title (up) Long-term effects of chronic light pollution on seasonal functions of European blackbirds (Turdus merula) Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume 8 Issue 12 Pages e85069
Keywords Turdus merula; European blackbird; birds; animals; Reproduction
Abstract Light pollution is known to affect important biological functions of wild animals, including daily and annual cycles. However, knowledge about long-term effects of chronic exposure to artificial light at night is still very limited. Here we present data on reproductive physiology, molt and locomotor activity during two-year cycles of European blackbirds (Turdus merula) exposed to either dark nights or 0.3 lux at night. As expected, control birds kept under dark nights exhibited two regular testicular and testosterone cycles during the two-year experiment. Control urban birds developed testes faster than their control rural conspecifics. Conversely, while in the first year blackbirds exposed to light at night showed a normal but earlier gonadal cycle compared to control birds, during the second year the reproductive system did not develop at all: both testicular size and testosterone concentration were at baseline levels in all birds. In addition, molt sequence in light-treated birds was more irregular than in control birds in both years. Analysis of locomotor activity showed that birds were still synchronized to the underlying light-dark cycle. We suggest that the lack of reproductive activity and irregular molt progression were possibly the results of i) birds being stuck in a photorefractory state and/or ii) chronic stress. Our data show that chronic low intensities of light at night can dramatically affect the reproductive system. Future studies are needed in order to investigate if and how urban animals avoid such negative impact and to elucidate the physiological mechanisms behind these profound long-term effects of artificial light at night. Finally we call for collaboration between scientists and policy makers to limit the impact of light pollution on animals and ecosystems.
Address Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany ; Department of Biology, University of Konstanz, Konstanz, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:24376865; PMCID:PMC3869906 Approved no
Call Number IDA @ john @ Serial 49
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