Laser induced fluorescence emission (L.I.F.E.): in situ and remote detection of life in Antarctic and Alaskan ice

2009 ◽  
Author(s):  
Michael C. Storrie-Lombardi ◽  
Birgit Sattler
Keyword(s):  
Fluorescence Emission ◽  
Laser Induced Fluorescence ◽  
Remote Detection

scholarly journals Laser-Induced Fluorescence Emission (L.I.F.E.) as Novel Non-Invasive Tool for In-Situ Measurements of Biomarkers in Cryospheric Habitats

10.3791/60447 ◽  
2019 ◽  
Author(s):  
Klemens Weisleitner ◽  
Lars Hunger ◽  
Christoph Kohstall ◽  
Albert Frisch ◽  
Michael C. Storrie-Lombardi ◽  
...  
Keyword(s):  
Fluorescence Emission ◽  
Laser Induced Fluorescence ◽  
In Situ Measurements ◽  
Non Invasive

scholarly journals Improvements to a laser-induced fluorescence instrument for measuring SO<sub>2</sub>: impact on accuracy and precision

2020 ◽  
Author(s):  
Pamela S. Rickly ◽  
Lu Xu ◽  
John D. Crounse ◽  
Paul O. Wennberg ◽  
Andrew W. Rollins
Keyword(s):  
Limit Of Detection ◽  
Fluorescence Emission ◽  
Laser Induced Fluorescence ◽  
Fluorescence Signal ◽  
Fluorescence Emission Spectrum ◽  
Signal Ratio ◽  
Accuracy And Precision ◽  
Aromatic Species

Abstract. This work describes improvements made to the in-situ laser induced fluorescence SO2 instrument as originally described in Rollins et al. (2016). We report measurements of the SO2 fluorescence emission spectrum. These measurements allow for the determination of the most appropriate bandpass filters to optimize the fluorescence signal while reducing the instrumental background. Because many aromatic species fluoresce in the same spectral region as SO2, fluorescence spectra were also measured for naphthalene and anisole to determine if ambient SO2 measurements may be biased in the presence of such species. In addition, the 216.9 nm laser linewidth was decreased in order to increase the online/offline signal ratio which in-turn increases the precision of the measurement. The effects of these improvements on the instrumental sensitivity were determined by analyzing the signal and background of the instrument using varying optical bandpass filter ranges and cell pressures and calculating the resulting limit of detection. As a result, we report an improvement to the instrumental sensitivity by as much as 50 %.

scholarly journals Laser-induced fluorescence emission (LIFE) from Lake Fryxell (Antarctica) cryoconites

2010 ◽  
Vol 51 (56) ◽  
pp. 145-152 ◽  
Author(s):  
Birgit Sattler ◽  
Michael C. Storrie-Lombardi ◽  
Christine M. Foreman ◽  
Markus Tilg ◽  
Roland Psenner
Keyword(s):  
Ice Core ◽  
Fluorescence Emission ◽  
Digital Camera ◽  
Laser Induced Fluorescence ◽  
Green Laser ◽  
Fluorescence Response ◽  
Total Pigment ◽  
Reflection And Refraction ◽  
Lake Fryxell

AbstractLaser-induced fluorescence emission (LIFE) images were obtained in situ from a 27 cm long ice core at Lake Fryxell, Antarctica. The excitation was accomplished with a simple 532 nm green laser pen light, and the fluorescence images were captured with a small compact digital camera. The targets for the experiment were mm-scale cryoconite assemblages found in the ice covers of this perennially frozen Antarctic lake. The fluorescence response originates from photo-pigments in cyanobacteria-dominated cryoconite assemblages with phycoerythrin (PE) exhibiting the optimal target cross section. This inexpensive, low-mass, low-energy method avoids manipulation of the in situ habitat and individual target organisms and does not disturb the microbial community or the surrounding ice matrix. We establish the correlation between fluorescence intensity and PE concentration. We show that cryoconite fluorescence response does not appear to decrease with depth in the ice cover, in agreement with similar findings at Lake Untersee, a perennially ice-covered lake in Dronning Maud Land, Antarctica. Optical reflection and refraction events at the air/ice interface can complicate quantitative estimates of total pigment concentrations. Laser targeting of a single mm-scale cryoconite can result in multiple neighboring excitation events secondary to reflection and refraction phenomena in the multiple air/ice interface of the bubbles surrounding the primary target.

In situ study of photoinhibition of photosynthesis and xanthophyll cycle activity in plants growing in natural gaps of the tropical forest

1998 ◽  
Vol 25 (2) ◽  
pp. 189 ◽  
Author(s):  
A. Thiele ◽  
G.H. Krause ◽  
K. Winter
Keyword(s):  
Chlorophyll A ◽  
Xanthophyll Cycle ◽  
Fluorescence Emission ◽  
D1 Protein ◽  
Barro Colorado Island ◽  
Slow Phase ◽  
Photoinhibition Of Photosynthesis ◽  
Total Carotenoids ◽  
Lowland Forest

Photoinhibition of photosynthesis was studied in situ in leaves of several species of plants growing in natural treefall gaps of a tropical lowland forest (Barro Colorado Island, Panama). Leaves showed several features typical of sun-acclimation: relatively high pools of total carotenoids and xanthophyll cycle pigments and high ratios of chlorophyll a to b. During 1–2 h periods of exposure to direct mid-day sun, all leaves experienced substantial photoinhibition as indicated by a marked decline in the ratio of variable to maximum chlorophyll a fluorescence emission, FV/FM, detected after 10 min of dark adaptation. After return to shade, these ‘dark-adapted’ FV/FM ratios increased with biphasic kinetics, similar to previous findings under controlled conditions in the laboratory. A phase lasting about 1 h accounted for most of the recovery of FV/FM and was followed by a slow phase which proceeded until sunset. The decline in FV/FM during photoinhibition and the fast phase of recovery correlated closely with the amounts of zeaxanthin in the leaves. Given the small portion of the second recovery phase which has previously been attributed to turnover of the D1 protein in Photosystem II, high xanthophyll cycle activity in these gap leaves is probably responsible for the major part of photoinhibition, providing an efficient energy dissipation pathway during periods of high sunlight exposure.

Prototype for In Situ Detection of Atmospheric NO3and N2O5via Laser-Induced Fluorescence

2003 ◽  
Vol 37 (24) ◽  
pp. 5732-5738 ◽  
Author(s):  
Ezra C. Wood ◽  
Paul J. Wooldridge ◽  
Jens H. Freese ◽  
Tim Albrecht ◽  
Ronald C. Cohen
Keyword(s):  
Laser Induced Fluorescence ◽  
In Situ Detection

In situ classification of rocks using stand-off laser-induced breakdown spectroscopy with a compact spectrometer

2018 ◽  
Vol 33 (3) ◽  
pp. 461-467 ◽  
Author(s):  
W. T. Li ◽  
Y. N. Zhu ◽  
X. Li ◽  
Z. Q. Hao ◽  
L. B. Guo ◽  
...  
Keyword(s):  
High Accuracy ◽  
Remote Detection ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

The ASPI-LDA algorithm combined with a compact spectrometer to achieve high accuracy classification, which has a great potential for field in situ remote detection.

scholarly journals Using Scuba for In Situ Determination of Chlorophyll Distributions in Corals by Underwater Near Infrared Fluorescence Imaging

2020 ◽  
Vol 8 (1) ◽  
pp. 53
Author(s):  
Thomas Oh ◽  
Jittiwat Sermsripong ◽  
Barry W. Hicks
Keyword(s):  
Fluorescence Imaging ◽  
Large Scale ◽  
Near Infrared ◽  
Fluorescent Proteins ◽  
Fluorescence Emission ◽  
Florida Keys ◽  
Nir Fluorescence ◽  
Novel Method ◽  
Near Infrared Fluorescence Imaging

Studies reporting quantitation and imaging of chlorophyll in corals using visible fluorescent emission in the red near 680 nm can suffer from competing emission from other red-emitting pigments. Here, we report a novel method of selectively imaging chlorophyll distributions in coral in situ using only the near infrared (NIR) fluorescence emission from chlorophyll. Commercially available equipment was assembled that allowed the sequential imaging of visible, visible-fluorescent, and NIR-fluorescent pigments on the same corals. The relative distributions of chlorophyll and fluorescent proteins (GFPs) were examined in numerous corals in the Caribbean Sea, the Egyptian Red Sea, the Indonesian Dampier Strait, and the Florida Keys. Below 2 m depth, solar induced NIR chlorophyll fluorescence can be imaged in daylight without external lighting, thus, it is much easier to do than visible fluorescence imaging done at night. The distributions of chlorophyll and GFPs are unique in every species examined, and while there are some tissues where both fluorophores are co-resident, often tissues are selectively enriched in only one of these fluorescent pigments. Although laboratory studies have clearly shown that GFPs can be photo-protective, their inability to prevent large scale bleaching events in situ may be due to their limited tissue distribution.

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