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Author (up) Figura, J.; Haughwout, C.; Cahoy, K.; Welle, R.; Hardy, B.; Pack, D.; Bosh, A. url  openurl
  Title Initial Demonstration of an Uplink LED Beacon to a Low Earth Orbiting CubeSat Type Journal Article
  Year 2018 Publication Journal of Small Satellites Abbreviated Journal  
  Volume 7 Issue 2 Pages 719-732  
  Keywords Remote Sensing  
  Abstract In this study, an uplink light-emitting diode (LED) beacon that can enable a CubeSat to locate a laser communication ground station was designed, constructed, and tested, and detection of the beacon from low Earth orbit (LEO) with a CMOS camera on the AeroCube-5 CubeSat was demonstrated. The LED beacon described is an alternative to the near-infrared laser beacons commonly used in laser communication systems, and has the potential to be cheaper, easier to point, and to require less regulatory coordination than a laser beacon, while performing the same function. An optical design is detailed, consisting of an array of 80 green LEDs with a center wavelength of 528 nm, producing 15.9 watts of free-space optical power, focused to a beamwidth of 8.12 degrees full-widthhalf-max (FWHM). A link budget is presented that shows the beacon is detectable by a CubeSat-mounted camera with a 7.9 mm diameter aperture and a silicon CMOS detector. A prototype beacon comprised of an LED array, focusing optics, thermal control, and tracking mechanisms was designed and constructed, and laboratory measurements of the beam profile and optical power of the prototype beacon using an optical power meter are presented herein. A field test is also described, in which the beacon was deployed at Wallace Astrophysical Observatory in the early morning of May 15, 2017 and imaged with a camera on AeroCube-5. The array is successfully identified in a sequence of five images taken by the CubeSat, demonstrating the viability of LED uplink beacons with CubeSat imagers.  
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  Call Number NC @ ehyde3 @ Serial 2108  
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Author (up) Firebaugh, A.; Haynes, K.J. url  doi
openurl 
  Title Light pollution may create demographic traps for nocturnal insects Type Journal Article
  Year 2018 Publication Basic and Applied Ecology Abbreviated Journal Basic and Applied Ecology  
  Volume 34 Issue Pages 118-125  
  Keywords Animals  
  Abstract Light pollution impacts both intra- and inter-specific interactions, such as interactions between mates and predator–prey interactions. In mobile organisms attracted to artificial lights, the effect of light pollution on these interactions may be intensified. If organisms are repelled by artificial lights, effects of light pollution on intra- and inter-specific interactions may be diminished as organisms move away. However, organisms repelled by artificial lights would likely lose suitable habitat as light pollution expands. Thus, we investigated how light pollution affects both net attraction or repulsion of organisms and effects on intra- and inter-specific interactions. In manipulative field studies using fireflies, we found that Photuris versicolor and Photinus pyralis fireflies were lured to artificial (LED) light at night and that both species were less likely to engage in courtship dialogues (bioluminescent flashing) in light-polluted field plots. Light pollution also lowered the mating success of P. pyralis. P. versicolor is known to prey upon P. pyralis by mimicking the flash patterns of P. pyralis, but we did not find an effect of light pollution on Photuris–Photinus predator–prey interactions. Our study suggests, that for some nocturnal insects, light-polluted areas may act as demographic traps, i.e., areas where immigration exceeds emigration and inhibition of courtship dialogues and mating reduces reproduction. Examining multiple factors affecting population growth in concert is needed to understand and mitigate impacts of light pollution on wildlife.  
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  ISSN 1439-1791 ISBN Medium  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1978  
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Author (up) Flores, D.E.F.L.; Oda, G.A. url  doi
openurl 
  Title Novel Light/Dark Regimens with Minimum Light Promote Circadian Disruption: Simulations with a Model Oscillator Type Journal Article
  Year 2018 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms  
  Volume in press Issue Pages  
  Keywords Animals  
  Abstract Artificial lab manipulation of LD cycles has enabled simulations of the disruptive conditions found in modern human societies, such as jet-lag, night-work and light at night. New techniques using animal models have been developed, and these can greatly improve our understanding of circadian disruption. Some of these techniques, such as in vivo bioluminescence assays, require minimum external light. This requirement is challenging because the usual lighting protocols applied in circadian desynchronization experiments rely on considerable light input. Here, we present a novel LD regimen that can disrupt circadian rhythms with little light per day, based on computer simulations of a model limit-cycle oscillator. The model predicts that a single light pulse per day has the potential to disturb rhythmicity when pulse times are randomly distributed within an interval. Counterintuitively, the rhythm still preserves an underlying 24-h periodicity when this interval is as large as 14 h, indicating that day/night cues are still detectable. Only when pulses are spread throughout the whole 24-h day does the rhythm lose any day-to-day period correlation. In addition, the model also reveals that stronger pulses of brighter light should exacerbate the disrupting effects. We propose the use of this LD schedule-which would be compatible with the requirements of in vivo bioluminescence assays-to help understand circadian disruption and associated illnesses.  
  Address Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0748-7304 ISBN Medium  
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  Notes PMID:30595077 Approved no  
  Call Number GFZ @ kyba @ Serial 2146  
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Author (up) Flowers, N.D.; Gibson, D.J. url  doi
openurl 
  Title Quantified effects of artificial versus natural nighttime lighting on the Eurasian grassesBothriochloa bladhii(Poaceae) andBothriochloa ischaemum(Poaceae) and the North American grassesPanicum virgatum(Poaceae) andSorghastrum nutans(Poaceae) Type Journal Article
  Year 2018 Publication The Journal of the Torrey Botanical Society Abbreviated Journal The Journal of the Torrey Botanical Society  
  Volume 145 Issue 2 Pages 147-155  
  Keywords Plants  
  Abstract Artificial nighttime lighting (light pollution) is increasing worldwide and may have undocumented consequences. In this study, we asked if artificial nighttime lighting affects the performance in monoculture of four grass species: the Eurasian Bothriochloa bladhii (Retz.) S.T. Blake (Poaceae), and Bothriochloa ischaemum (L.) Keng (Poaceae); and the North American Panicum virgatum (L.) (Poaceae), and Sorghastrum nutans (L.) Nash (Poaceae). We conducted a field pot experiment to test for the effects of artificial nighttime lighting and plant density on height, biomass, and leaf number. Height of the tallest individual per population was affected by separate interactions between species and density, light, and time. Final total biomass per individual biomass was increased under nighttime lighting, but more so at low density. Leaf number was increased by artificial nighttime lighting irrespective of species. These results suggest that artificial nighttime lighting may have previously undocumented influences on plant height, biomass, and leaf number within certain species. These findings warrant more in-depth studies into the role that artificial nighttime lighting can have on various plant species.  
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  ISSN 1095-5674 ISBN Medium  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1902  
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Author (up) Foster, J.J.; Smolka, J.; Nilsson, D.-E.; Dacke, M. url  doi
openurl 
  Title How animals follow the stars Type Journal Article
  Year 2018 Publication Proceedings. Biological Sciences Abbreviated Journal Proc Biol Sci  
  Volume 285 Issue 1871 Pages  
  Keywords Vision; Animals  
  Abstract Throughout history, the stars have provided humans with ever more information about our world, enabling increasingly accurate systems of navigation in addition to fuelling some of the greatest scientific controversies. What information animals have evolved to extract from a starry sky and how they do so, is a topic of study that combines the practical and theoretical challenges faced by both astronomers and field biologists. While a number of animal species have been demonstrated to use the stars as a source of directional information, the strategies that these animals use to convert this complex and variable pattern of dim-light points into a reliable 'stellar orientation' cue have been more difficult to ascertain. In this review, we assess the stars as a visual stimulus that conveys directional information, and compare the bodies of evidence available for the different stellar orientation strategies proposed to date. In this context, we also introduce new technologies that may aid in the study of stellar orientation, and suggest how field experiments may be used to characterize the mechanisms underlying stellar orientation.  
  Address Department of Biology, Lund University, Solvegatan 35, Lund 223 62, Sweden  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29367394 Approved no  
  Call Number LoNNe @ kyba @ Serial 1802  
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