WorldWideScience

Sample records for meghdar-e chlorophyll dar

  1. Fast and nondestructive method for leaf level chlorophyll estimation using hyperspectral LiDAR

    NARCIS (Netherlands)

    Nevalainen, O.; Hakala, T.; Suomalainen, J.M.; Mäkipää, R.; Peltoniemi, M.; Krooks, A.; Kaasalainen, S.

    2014-01-01

    We propose an empirical method for nondestructive estimation of chlorophyll in tree canopies. The first prototype of a full waveform hyperspectral LiDAR instrument has been developed by the Finnish Geodetic Institute (FGI). The instrument efficiently combines the benefits of passive and active

  2. Phytoplankton chlorophyll

    NARCIS (Netherlands)

    van de Poll, W.H.; Kulk, G.; Timmermans, K.R.; Brussaard, C.P.D.; van der Woerd, H.J.; Kehoe, M.J.; Mojica, K.D.A.; Visser, R.J.W.; Rozema, P.D.; Buma, A.G.J.

    2013-01-01

    Relationships between sea surface temperature (SST, > 10 m) and vertical density stratification, nutrient concentrations, and phytoplankton biomass, composition, and chlorophyll a (Chl a) specific absorption were assessed in spring and summer from latitudes 29 to 63 degrees N in the northeast

  3. Indicators: Chlorophyll a

    Science.gov (United States)

    Chlorophyll allows plants (including algae) to photosynthesize, i.e., use sunlight to convert simple molecules into organic compounds. Chlorophyll a is the predominant type of chlorophyll found in green plants and algae.

  4. Chlorophyll: The wonder pigment

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.R.

    Chlorophyll, the green plant pigment, a 'real life force' of living beings, besides synthesizing food, is a great source of vitamins, minerals and other phytochemicals. Adding chlorophyll rich food to our diet fortifies our body against health...

  5. Chlorophyll and starch assays

    OpenAIRE

    sprotocols

    2015-01-01

    Chlorophyll, starch, and sugar contents are good indicators of growth vigor in plants. To measure the chlorophyll content, we used a modified protocol (1,2). The starch content was determined using iodine staining (3) and enzymatic reactions (4-6).

  6. Chlorophyll_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included chlorophyll for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...

  7. (DArT) markers

    Indian Academy of Sciences (India)

    wilt and sterility mosaic disease, etc.) stresses. Despite past. ∗For correspondence. E-mail: r.k.varshney@cgiar.org .... Shi Ying Yang et al. Table 2. Details on 466 polymorphic DArT markers. Female specific. Male specific. Total. 198. 268. Class I. 142. 203. Class II. 27. 16. Others. 29. 49. Mapped. 122. 172. Linkage mapping.

  8. (DArT) markers

    Indian Academy of Sciences (India)

    age groups of both maternal and paternal maps. The segre- gating markers were classified into two classes; for DArT class 1 consensus marker the selection criterion were of very high stringency parameters with clustering settings; Q >. 70; P > 75; call rate > 90, 100% reproducibility, no dis- cordance, and probability > 0.001 ...

  9. Chlorophyll formation and phytochrome

    NARCIS (Netherlands)

    Raven, C.W.

    1973-01-01

    The rôle of phytochrome in the regeneration of protochlorophyll (Pchl) in darkness following short exposures to light, as well as in the accumulation of chlorophyll- a (Chl- a ) in continuous light in previously dark-grown seedlings of pea, bean,

  10. Chlorophyll d: the puzzle resolved

    DEFF Research Database (Denmark)

    Larkum, Anthony W D; Kühl, Michael

    2005-01-01

    Chlorophyll a (Chl a) has always been regarded as the sole chlorophyll with a role in photochemical conversion in oxygen-evolving phototrophs, whereas chlorophyll d (Chl d), discovered in small quantities in red algae in 1943, was often regarded as an artefact of isolation. Now, as a result...... replace Chl a in the special pair of chlorophylls in both reactions centers of photosynthesis. Udgivelsesdato: 2005-Aug...

  11. Chlorophyll breakdown in higher plants.

    OpenAIRE

    Hörtensteiner Stefan; Kräutler Bernhard

    2011-01-01

    Chlorophyll breakdown is an important catabolic process of leaf senescence and fruit ripening. Structure elucidation of colorless linear tetrapyrroles as (final) breakdown products of chlorophyll was crucial for the recent delineation of a chlorophyll breakdown pathway which is highly conserved in land plants. Pheophorbide a oxygenase is the key enzyme responsible for opening of the chlorin macrocycle of pheophorbide a characteristic to all further breakdown products. Degradation of chlorophy...

  12. Evaluation of Chlorophyll Content and Chlorophyll Fluorescence Parameters and Relationships between Chlorophyll a, b and Chlorophyll Content Index under Water Stress in Olea europaea cv. Dezful

    OpenAIRE

    E. Khaleghi; K. Arzani; N. Moallemi; M. Barzegar

    2012-01-01

    This study was conducted to determine effect of water stress on chlorophyll content and chlorophyll fluorescence parameter in young `Dezful- olive trees. Three irrigation regimes (40% ETcrop, 65% ETcrop and 100% ETcrop) were used. After irrigation treatments were applied, some of biochemical parameters including chlorophyll a, b, total chlorophyll, chlorophyll fluorescence and also chlorophyll content index (C.C.I) were measured. Results of Analysis of variance showed that irrigation treatmen...

  13. LiDAR for data efficiency.

    Science.gov (United States)

    2011-09-30

    This report documents the AHMCT research project: LiDAR for Data Efficiency for the Washington State Department of Transportation (WSDOT). The research objective was to evaluate mobile LiDAR technology to enhance safety, determine efficiency ga...

  14. Dynamics of chlorophyll b in the photosystems of Arabidopsis thaliana

    OpenAIRE

    贾, 婷

    2016-01-01

    In the chlorophyll cycle, chlorophyll b is synthesized from chlorophyll a (forward reaction) by chlorophyllide a oxygenase (CAO) and chlorophyll b is reconverted to chlorophyll a (backward reaction) by chlorophyll b reductase (NOL, NYC1) and 7-hydroxyl chlorophyll a reductase (HCAR). Activity of the forward and backward reactions alters the levels of chlorophyll a and chlorophyll b which is associated with the changes of chlorophyll a/b ratio. The level of light harvesting complexes, which fo...

  15. Photosynthetic bark : use of chlorophyll absorption continuum index to estimate Boswellia papyrifera bark chlorophyll content

    NARCIS (Netherlands)

    Girma Gebrekidan, A.; Skidmore, A.K.; de Bie, C.A.J.M.; Bongers, Frans; Schlerf, Martin; Schlerf, M.

    2013-01-01

    Quantification of chlorophyll content provides useful insight into the physiological performance of plants. Several leaf chlorophyll estimation techniques, using hyperspectral instruments, are available. However, to our knowledge, a non-destructive bark chlorophyll estimation technique is not

  16. Photosynthetic bark: use of chlorophyll absorption continuum index to estimate Boswellia papyrifera bark chlorophyll content

    NARCIS (Netherlands)

    Girma, A.; Skidmore, A.K.; Bie, de C.A.J.M.; Bongers, F.; Schlerf, M.

    2013-01-01

    Quantification of chlorophyll content provides useful insight into the physiological performance of plants. Several leaf chlorophyll estimation techniques, using hyperspectral instruments, are available. However, to our knowledge, a non-destructive bark chlorophyll estimation technique is not

  17. The Total Synthesis of Chlorophyll

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 7. The Total Synthesis of Chlorophyll. Setty Mallikarjuna Babu Subramania Ranganathan. General Article Volume 19 Issue 7 July 2014 pp 645-648. Fulltext. Click here to view fulltext PDF. Permanent link:

  18. The Total Synthesis of Chlorophyll

    Indian Academy of Sciences (India)

    IAS Admin

    Fresh from his dramatic conquest of the blood pigment, Fischer hurdled his legions in the attack on chlorophyll, and during a period of approxi- mately 15 years, built a monumental corpus of fact. As this chemical record, almost unique in the scope and depth, was constructed, the mol- ecule was transformed and rent ...

  19. Chlorophyll catabolism in Prunus serrulata autumnal leaves

    OpenAIRE

    Đapić Nina

    2012-01-01

    Chlorophyll catabolism in Prunus serrulata autumnal leaves was investigated. The amount of chlorophyll catabolites accumulated within the same plant species varies with the time of the leaf collection, seasonal climate and developmental stage of the plant. The chlorophyll catabolites found in P. serrulata autumnal leaves presented the tendency of the organism to decrease the level of photodynamically active chlorophyll before the programmed cell death. In the methanol extract several ch...

  20. 2015 Puget Sound LiDAR Consortium (PSLC) LiDAR: WA DNR Lands (P2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 2014, WSI, a Quantum Spatial Inc. (QSI) company, was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  1. 2014 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Willapa Valley (Delivery 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In January, 2014 WSI, a Quantum Spatial (QSI) company, was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR) data...

  2. 2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Saddle Mountain

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In October 2013, WSI, a Quantum Spatial Company (QSI), was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR) data...

  3. 2015 Puget Sound LiDAR Consortium (PSLC) LiDAR: WA DNR Lands (P1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 2014, WSI, a Quantum Spatial Inc. (QSI) company, was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  4. 2011 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Quinault River Basin

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data on the Quinault River Basin survey area for the Puget Sound LiDAR Consortium and...

  5. 2009 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data for the Lewis County survey area for the Puget Sound LiDAR Consortium. This data...

  6. Pigment Composition of a Novel Oxygenic Photosynthetic Prokaryote Containing Chlorophyll d as the Major Chlorophyll

    OpenAIRE

    Hideaki, Miyashita; Kyoko, Adachi; Norihide, Kurano; Hisato, Ikemoto; Mitsuo, Chihara; Shigetoh, Miyachi; Marine Biotechnology Institute, Kamaishi Laboratories; Marine Biotechnology Institute, Shimizu Laboratories; Marine Biotechnology Institute, Kamaishi Laboratories; Marine Biotechnology Institute, Kamaishi Laboratories; Marine Biotechnology Institute, Kamaishi Laboratories:Japanese Red Cross college of Nursing; Marine Biotechnology Institute

    1997-01-01

    The principal pigment found in the majority of oxygenic photosynthetic organisms is known to be chlorophyll a. However, we isolated a new oxygenic photosynthetic prokaryote that contained chlorophyll d as a predominant pigment with chlorophyll a being a minor pigment. Chlorophyll d had previously been noted but its natural occurrence and function remained unclear. Cells of the new prokaryote had an absorption maximum at red region of 714-718 nm due to chlorophyll d absorption, but no characte...

  7. Chlorophyll b degradation by chlorophyll b reductase under high-light conditions

    OpenAIRE

    Sato, Rei; Ito, Hisashi; Tanaka, Ayumi

    2015-01-01

    The light-harvesting chlorophyll a/b binding protein complex of photosystem II (LHCII) is the main antenna complex of photosystem II (PSII). Plants change their LHCII content depending on the light environment. Under high-light conditions, the content of LHCII should decrease because over-excitation damages the photosystem. Chlorophyll b is indispensable for accumulating LHCII, and chlorophyll b degradation induces LHCII degradation. Chlorophyll b degradation is initiated by chlorophyll b red...

  8. Infrastructure Investment Protection with LiDAR

    Science.gov (United States)

    2012-10-15

    The primary goal of this research effort was to explore the wide variety of uses of LiDAR technology and to evaluate their : applicability to NCDOT practices. NCDOT can use this information about LiDAR in determining how and when the : technology can...

  9. Iowa LiDAR Mapping Project

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This is collection level metadata for LAS and ASCII data files from the statewide Iowa Lidar Project. The Iowa Light Detection and Ranging (LiDAR) Project collects...

  10. Hawaii DAR Dealer Reporting System Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2000 January, the Hawaii Division of Aquatic Resources (DAR) implemented a computerized data processing system for fish dealer data collected state-wide. Hawaii...

  11. USGS Atchafalaya 2 LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the Atchafalaya Basin project area. The entire survey area for Atchafalaya encompasses approximately...

  12. The spontaneous chlorophyll mutation frequency in barley

    DEFF Research Database (Denmark)

    Jørgensen, Jørgen Helms; Jensen, Hans Peter

    1986-01-01

    materials and the resulting estimate of the chlorophyll mutant frequency is 1.6 .times. 10-4 in about 1.43 million seedlings. The estimate of the chlorophyll mutation rate per generation is close to 67.3 .times. 10-4 per diploid genome or in the order of 6 .times. 10-7 per locus and haploid genome....

  13. Quantifying mangrove chlorophyll from high spatial resolution imagery

    NARCIS (Netherlands)

    Heenkenda, M.K.; Joyce, K.E.; Maier, S.W.; Bruin, de S.

    2015-01-01

    Lower than expected chlorophyll concentration of a plant can directly limit photosynthetic activity, and resultant primary production. Low chlorophyll concentration may also indicate plant physiological stress. Compared to other terrestrial vegetation, mangrove chlorophyll variations are poorly

  14. Chlorophyll regulates accumulation of the plastid-encoded chlorophyll apoproteins CP43 and D1 by increasing apoprotein stability.

    OpenAIRE

    Mullet, J E; Klein, P G; Klein, R R

    1990-01-01

    Chlorophyll apoprotein accumulation in higher plant chloroplasts is controlled by light-dependent chlorophyll formation. Dark-grown plants lack chlorophyll and chlorophyll apoproteins. However, the plastid genes encoding the chlorophyll apoproteins are transcribed; chlorophyll apoprotein mRNA accumulates and associates with polysomes in plastids of dark-grown plants. Pulse-labeling assays revealed a population of short-lived proteins in plastids of dark-grown plants. One of these transiently ...

  15. Seasonal Composite Chlorophyll Concentrations - Gulf of Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This personal geodatabase contains raster images of chlorophyll concentrations in the Gulf of Maine. These raster images are seasonal composites, and were calculated...

  16. Localisation of chlorophyll within the chloroplast

    NARCIS (Netherlands)

    Thomas, J.B.; Post, L.C.; Vertregt, N.

    1954-01-01

    Silver nitrate reduction was shown to occur in illuminated suspensions of Hibiscus grana. The action spectrum of this reduction, the reaction, proved to coincide satisfactorily with the chlorophyll absorption spectrum. Electron micrographs reveal that this reaction occurs in single lamellae.

  17. EmpiricalValues_Chlorophyll_GrandComposite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This personal geodatabase contains raster images of chlorophyll concentrations in the Gulf of Maine. These raster images are a composite of several years (1997-2005)...

  18. Effect of Salinity on Chlorophyll Fluorescence and Chlorophyll Content of the Desert Shrub Calotropis procera

    OpenAIRE

    , A. Akhkha; , T. Boutraa

    2010-01-01

    The effect of salinity stress on the efficiency of the photosynthetic apparatus in the desert shrub Calotropis procera Aiton (family: Asclepiadaceae) was investigated using chlorophyll fluorescence technique. This technique allowed the determination of a number of chlorophyll fluorescence parameters such as initial fluorescence Fo, maximum fluorescence Fm and variable fluorescence Fv. Furthermore, the effect of salinity stress on other chlorophyll fluorescence parameters (Fv / Fo and Fv / Fm ...

  19. Mediterranean Ocean Colour Chlorophyll Trends.

    Directory of Open Access Journals (Sweden)

    Simone Colella

    Full Text Available In being at the base of the marine food web, phytoplankton is particularly important for marine ecosystem functioning (e.g., biodiversity. Strong anthropization, over-exploitation of natural resources, and climate change affect the natural amount of phytoplankton and, therefore, represent a continuous threat to the biodiversity in marine waters. In particular, a concerning risks for coastal waters is the increase in nutrient inputs of terrestrial/anthropogenic origin that can lead to undesirable modifications of phytoplankton concentration (i.e., eutrophication. Monitoring chlorophyll (Chl concentration, which is a proxy of phytoplankton biomass, is an efficient tool for recording and understanding the response of the marine ecosystem to human pressures and thus for detecting eutrophication. Here, we compute Chl trends over the Mediterranean Sea by using satellite data, also highlighting the fact that remote sensing may represent an efficient and reliable solution to synoptically control the "good environmental status" (i.e., the Marine Directive to achieve Good Environmental Status of EU marine waters by 2020 and to assess the application of international regulations and environmental directives. Our methodology includes the use of an ad hoc regional (i.e., Mediterranean algorithm for Chl concentration retrieval, also accounting for the difference between offshore (i.e., Case I and coastal (i.e., Case II waters. We apply the Mann-Kendall test and the Sens's method for trend estimation to the Chl concentration de-seasonalized monthly time series, as obtained from the X-11 technique. We also provide a preliminary analysis of some particular trends by evaluating their associated inter-annual variability. The high spatial resolution of our approach allows a clear identification of intense trends in those coastal waters that are affected by river outflows. We do not attempt to attribute the observed trends to specific anthropogenic events. However

  20. Mediterranean Ocean Colour Chlorophyll Trends.

    Science.gov (United States)

    Colella, Simone; Falcini, Federico; Rinaldi, Eleonora; Sammartino, Michela; Santoleri, Rosalia

    2016-01-01

    In being at the base of the marine food web, phytoplankton is particularly important for marine ecosystem functioning (e.g., biodiversity). Strong anthropization, over-exploitation of natural resources, and climate change affect the natural amount of phytoplankton and, therefore, represent a continuous threat to the biodiversity in marine waters. In particular, a concerning risks for coastal waters is the increase in nutrient inputs of terrestrial/anthropogenic origin that can lead to undesirable modifications of phytoplankton concentration (i.e., eutrophication). Monitoring chlorophyll (Chl) concentration, which is a proxy of phytoplankton biomass, is an efficient tool for recording and understanding the response of the marine ecosystem to human pressures and thus for detecting eutrophication. Here, we compute Chl trends over the Mediterranean Sea by using satellite data, also highlighting the fact that remote sensing may represent an efficient and reliable solution to synoptically control the "good environmental status" (i.e., the Marine Directive to achieve Good Environmental Status of EU marine waters by 2020) and to assess the application of international regulations and environmental directives. Our methodology includes the use of an ad hoc regional (i.e., Mediterranean) algorithm for Chl concentration retrieval, also accounting for the difference between offshore (i.e., Case I) and coastal (i.e., Case II) waters. We apply the Mann-Kendall test and the Sens's method for trend estimation to the Chl concentration de-seasonalized monthly time series, as obtained from the X-11 technique. We also provide a preliminary analysis of some particular trends by evaluating their associated inter-annual variability. The high spatial resolution of our approach allows a clear identification of intense trends in those coastal waters that are affected by river outflows. We do not attempt to attribute the observed trends to specific anthropogenic events. However, the trends

  1. LiDAR data for the Delta Area of California

    Data.gov (United States)

    California Natural Resource Agency — LiDAR data for the Delta Area of California from the California Department of Water Resources. Bare earth grids from LiDAR.This data is in ESRI Grid format with 2...

  2. LiDAR data for the Delta Area of California

    Data.gov (United States)

    California Department of Resources — LiDAR data for the Delta Area of California from the California Department of Water Resources. Bare earth grids from LiDAR.This data is in ESRI Grid format with 2...

  3. Green vegetable supply in Dar es Salaam

    NARCIS (Netherlands)

    Wegerif, M.C.A.

    2015-01-01

    This article constructs a picture of green vegetable growing and supply in Dar es Salaam by looking at the lives and work of a small trader and an urban farmer. It reveals the importance of a range of distribution and trade networks and the integration of a wider city region, alongside urban and

  4. University of Dar es Salaam Library Journal

    African Journals Online (AJOL)

    The University of Dar es Salaam Library Journal publishes articles on all aspects of library and information science. These include organization and dissemination of information, library education and training, information technology and its application in libraries, book reviews and short communications. Journal Homepage ...

  5. municipal solid waste of dar es salaam

    African Journals Online (AJOL)

    methane yields decreased by 30-50%. The mixed waste category constituting a substrate concentration of 6 g VS [-1. F V was degraded by 65% and gave a yield of 428 ml CH4 per gram VS added. This study concludes that individual fractions of MSW of Dar es salaam city are suitable as feedstocks for biogas digesters.

  6. Excreta Disposal in Dar-es-salaam

    NARCIS (Netherlands)

    Chaggu, E.; Mashouri, D.; Buuren, van J.C.L.; Sanders, W.T.M.; Lettinga, G.

    2002-01-01

    The sociocultural and socioeconomic situation of sanitation in Dar-es-Salaam (Dsm), Tanzania, was studied with explicit emphasis on pit-latrines. Without considering the sociocultural conditions, the so-called best solution might not be the right one. Therefore, in order to achieve the intended

  7. Orienteerumiskaart vs. LiDAR / Marek Karm

    Index Scriptorium Estoniae

    Karm, Marek

    2012-01-01

    Bakalaureusetööst, mille eesmärk oli võrrelda orienteerumiskaardi reljeefi LiDAR-i andmete põhjal saadava reljeefimudeliga ning leida vastus küsimusele, kas o-kaart võib olla kasulik kooste- või kontrollmaterjal mistahes reljeefimudelile

  8. University of Dar es Salaam Library Journal

    African Journals Online (AJOL)

    The University of Dar es Salaam Library Journal publishes articles on all aspects of Library and Information Science. These include organization and dissemination of information, library education and training, information technology and its application in libraries, book reviews and short communications. Authors are in ...

  9. LiDAR utility for natural resource managers

    Science.gov (United States)

    Andrew Thomas Hudak; Jeffrey Scott Evans; Alistair Mattthew Stuart. Smith

    2009-01-01

    Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR across a suite of...

  10. 2000 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Kitsap Peninsula, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 1,146 square miles and covers part...

  11. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Lewis County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data for the Lewis County project of 2005. The project site covered approximately 223 square miles, divided...

  12. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Olympic Peninsula

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data for the Olympic Peninsula project of 2005, totaling approximately 114.59 sq mi: 24.5 for Clallam...

  13. 2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Nooksack

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In July 2012, WSI (Watershed Sciences, Inc.) was contracted by the Puget Sound LiDARConsortium (PSLC) to collect Light Detection and Ranging (LiDAR) data on a...

  14. 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: North Puget Sound Lowlands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Terrapoint collected Light Detection and Ranging (LiDAR) data contributing to the Puget Sound Lowlands project of 2005. Arlington, City of Snohomish, Snohomish...

  15. 2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Upper Naches River, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data of the Upper Naches River Valley and Nile Slide area of interest on September 30th,...

  16. 2003 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Snohomish County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 167 square miles and covers a...

  17. 2009 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Snohomish River Estuary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) co-acquired Light Detection and Ranging (LiDAR) data and Truecolor Orthophotographs of the Snohomish River Estuary, WA on July 20 &...

  18. 2009 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Douglas Co.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data of the Douglas County PUD area of interest (AOI) east of Wenatchee, WA on May 2nd -...

  19. 2014 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Cedar River Watershed (Delivery 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In September 2013, WSI, a Quantum Spatial company (QSI), was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  20. 2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Quinault River Watershed, Washington (Delivery 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data on the Quinault watershed survey area for the Puget Sound LiDAR Consortium. This...

  1. 2014 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Cedar River Watershed (Delivery 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In September 2013, WSI, a Quantum Spatial company (QSI), was contracted by the Puget Sound LiDAR Consortium (PSLC) to collect Light Detection and Ranging (LiDAR)...

  2. Novel Methods for Measuring LiDAR

    Science.gov (United States)

    Ayrey, E.; Hayes, D. J.; Fraver, S.; Weiskittel, A.; Cook, B.; Kershaw, J.

    2017-12-01

    The estimation of forest biometrics from airborne LiDAR data has become invaluable for quantifying forest carbon stocks, forest and wildlife ecology research, and sustainable forest management. The area-based approach is arguably the most common method for developing enhanced forest inventories from LiDAR. It involves taking a series of vertical height measurements of the point cloud, then using those measurements with field measured data to develop predictive models. Unfortunately, there is considerable variation in methodology for collecting point cloud data, which can vary in pulse density, seasonality, canopy penetrability, and instrument specifications. Today there exists a wealth of public LiDAR data, however the variation in acquisition parameters makes forest inventory prediction by traditional means unreliable across the different datasets. The goal of this project is to test a series of novel point cloud measurements developed along a conceptual spectrum of human interpretability, and then to use the best measurements to develop regional enhanced forest inventories on Northern New England's and Atlantic Canada's public LiDAR. Similarly to a field-based inventory, individual tree crowns are being segmented, and summary statistics are being used as covariates. Established competition and structural indices are being generated using each tree's relationship to one another, whilst existing allometric equations are being used to estimate diameter and biomass of each tree measured in the LiDAR. Novel metrics measuring light interception, clusteredness, and rugosity are also being measured as predictors. On the other end of the human interpretability spectrum, convolutional neural networks are being employed to directly measure both the canopy height model, and the point clouds by scanning each using two and three dimensional kernals trained to identify features useful for predicting biological attributes such as biomass. Predictive models will be trained and

  3. SHORT COMMUNICATION ISOLATION OF CHLOROPHYLL A ...

    African Journals Online (AJOL)

    a

    KEY WORDS: Chlorophyll a, Spinach leaves, Separation, Column chromatography, Solvent extraction,. Pheophytin a ... 0.65 L min-1; auxiliary gas flow rate, 0.06 L min-1; ion spray voltage, 3.5 kV; capillary temperature, 200 ºC; .... This work presents a successful application of column chromatography coupled with solvent.

  4. Afterglow of chlorophyll in vivo and photosynthesis

    NARCIS (Netherlands)

    Goedheer, J.C.

    1962-01-01

    Two pigment systems are involved in the afterglow of chlorophyll a-containing cells. Absorption in only one of these systems (promoting or “p” system) is effective in producing luminescence. If light is absorbed simultaneously by the other (quenching or “q” system), a decrease in luminescence

  5. Thin Layer Chromatography (TLC) of Chlorophyll Pigments.

    Science.gov (United States)

    Foote, Jerry

    1984-01-01

    Background information, list of materials needed, procedures used, and discussion of typical results are provided for an experiment on the thin layer chromatography of chlorophyll pigments. The experiment works well in high school, since the chemicals used are the same as those used in paper chromatography of plant pigments. (JN)

  6. Nutrient and Phytoplankton Dynamics along the Ocean Road Sewage Discharge Channel, Dar es Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    Mariam I. Hamisi

    2014-01-01

    Full Text Available Ocean Road shoreline is situated close to Dar es Salaam largest fish market and is subjected to sewage discharge. In this study, temporal and spatial variations of physicochemical parameters and phytoplankton were studied in five stations along the Ocean Road Coast. Phytoplankton composition, temperature, dissolved oxygen (DO, salinity, water clarity, pH, and dissolved inorganic nutrients (DIN including nitrite, nitrate, and phosphate were measured. Results revealed that DIN were significantly higher in the station close to the discharge point than other stations (P<0.0001. There were no significant temporal variations in DIN except nitrate that was significantly higher during Northeast Monsoon than Southeast Monsoon (P<0.001. Other environmental parameters showed no significant differences except clarity, conductivity, and DO. Occurrence of potential harmful species such as Trichodesmium, Microcystis, and Pseudo-nitzschia was observed. The phytoplankton biomass (chlorophyll a ranged from 3.2 to 56.5 mg m−3 and 18 to 113 mg m−3 for Mjimwema (MJ and Ocean Road (OR stations, respectively. There was significant difference (P=0.0033 in chlorophyll a among the stations being higher in OR II. The phytoplankton biomass was positively correlated with nutrient concentration in all stations except OR I. This study suggests an alarming level of DIN at OR that may alter phytoplankton biomass, abundance, and composition.

  7. The preparation, identification and properties of chlorophyll derivatives

    Science.gov (United States)

    Katz, J. J.; Pennington, F. C.; Strain, H. H.; Svec, W. A.

    1968-01-01

    In the investigation of 10-hydroxy chlorophylls a and b novel techniques included modification of chromatography and the use of fully-deuterated compounds isolated from fully-deuterated autotropic algae to determine the molecular structure of the chlorophylls.

  8. Comprehensive chlorophyll composition in the main edible seaweeds.

    Science.gov (United States)

    Chen, Kewei; Ríos, José Julián; Pérez-Gálvez, Antonio; Roca, María

    2017-08-01

    Natural chlorophylls present in seaweeds have been studied regarding their biological activities and health benefit effects. However, detailed studies regarding characterization of the complete chlorophyll profile either qualitatively and quantitatively are scarce. This work deals with the comprehensive spectrometric study of the chlorophyll derivatives present in the five main coloured edible seaweeds. The novel complete MS 2 characterization of five chlorophyll derivatives: chlorophyll c 2 , chlorophyll c 1 , purpurin-18 a, pheophytin d and phytyl-purpurin-18 a has allowed to obtain fragmentation patterns associated with their different structural features. New chlorophyll derivatives have been identified and quantified by first time in red, green and brown seaweeds, including some oxidative structures. Quantitative data of the chlorophyll content comes to achieve significant information for food composition databases in bioactive compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Determination of Fluorescence Chlorophyll a Concentration in Kumanonada bays

    OpenAIRE

    表, 寿一; 畑中, 伉

    2011-01-01

    This paper investigated, how climate change impacts the fluorescence chlorophyll a of phytoplankton on Kumanonada bays and reports on the variation of fluorescence chlorophyll a in seasons in the coastal seas. The biological scale (as the varying fluorescence chlorophyll a concentration) was determined by the Uranine concentration using the fluorescence intensity.

  10. Identification and classification of vertical chlorophyll patterns in the ...

    African Journals Online (AJOL)

    Information on the vertical chlorophyll structure in the ocean is important for estimating integrated chlorophyll a and primary production from satellite. For this study, vertical chlorophyll profiles from the Benguela upwelling system and the Angola-Benguela front were collected in winter to identify characteristic profiles.

  11. LiDAR Application for WInd Energy Efficiency : Final report

    NARCIS (Netherlands)

    Boorsma, K; Wagenaar, J.W.; Savenije, F.J.; Boquet, M.; Bierbooms, W.A.A.M.; Giyanani, A.H.; Rutteman, R.

    2016-01-01

    ECN with its partners TU DelŌ, Avent LiDAR Technologies and XEMC Darwind executed the four-year TKI Wind op Zee project LAWINE (LiDAR ApplicaƟon for WInd Energy Efficiency). In this project the applica Ɵon of LiDAR technology has been developed and validated so that it can be used to improve the

  12. 2004 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Portland, Oregon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The all returns ASCII files contain the X,Y,Z values of all the LiDAR returns collected during the survey mission. In addition each return also has a time stamp,...

  13. Reflectance variation within the in-chlorophyll centre waveband for robust retrieval of leaf chlorophyll content.

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    Full Text Available The in-chlorophyll centre waveband (ICCW (640-680 nm is the specific chlorophyll (Chl absorption band, but the reflectance in this band has not been used as an optimal index for non-destructive determination of plant Chl content in recent decades. This study develops a new spectral index based solely on the ICCW for robust retrieval of leaf Chl content for the first time. A glasshouse experiment for solution-culture of one chlorophyll-deficient rice mutant and six wild types of rice genotypes was conducted, and the leaf reflectance (400-900 nm was measured with a high spectral resolution (1 nm spectrophotometer and the contents of chlorophyll a (Chla, chlorophyll b (Chlb and chlorophyll a+b (Chlt of the rice leaves were determined. It was found that the reflectance curves from 640 nm to 674 nm and from 675 nm to 680 nm of the low-chlorophyll mutant leaf were drastically steeper than that of the wild types in the ICCW. The new index based on the reflectance variation within ICCW, the difference of the first derivative sum within the ICCW (DFDS_ICCW, was highly sensitive (r = -0.77, n = 93, P0.05 to Chlt when the leaf Chlt was higher than 200 mg/m(2. The best equations of R-ICCW and DFDS_ICCW yielded an RMSE of 78.7, 32.9 and 107.3 mg/m(2, and an RMSE of 37.4, 16.0 and 45.3 mg/m(-2, respectively, for predicting Chla, Chlb and Chlt. The new index could rank in the top 10 for prediction of Chla and Chlt as compared with the 55 existing indices. Additionally, most of the 55 existing Chl-related VIs performed robustly or strongly in simultaneous prediction of leaf Chla, Chlb and Chlt.

  14. Genetic analysis of sunflower chlorophyll mutants

    International Nuclear Information System (INIS)

    Mashkina, E.V.; Guskov, E.P.

    2001-01-01

    The method of getting the chlorophyll mutations in sunflower was developed by Y.D. Beletskii in 1969 with the use of N-nitroso-N-methylurea (NMH). Certain concentrations of NMH are known to induce plastid mutations in growing seeds, and their yield depends on the duration of the exposure. The given work presented studies on the influence of rifampicin (R) and 2,4-dinitrophenol (DNP) on the genetic activity NMH, as an inductor of plastid and nuclear mutations

  15. 'Dar' + gerund in Ecuadorian Highland Spanish: contact-induced grammaticalization?

    NARCIS (Netherlands)

    Olbertz, H.

    2008-01-01

    The benefactive construction dar + gerund is used in the North Andean region only and is unknown elsewhere in the Spanish-speaking world. Based on the analysis of spontaneous data from Ecuadorian Highland Spanish, this paper provides a linguististic description of dar + gerund and of the social and

  16. of Sediment Deposition into the Dar es Salaam Harbour

    African Journals Online (AJOL)

    The University of Dar es Salaam, Institute of Marine Sciences, P. O. Box 668 Zanzibar, Tanzania. Key words: Dar es Salaam harbour, sediment deposition, entrance channel. Abstract: The ..... Harbour Transportation, Fishing Ports, Sediment. Transport, Geomorphology, Inlets, and Dredging. Gulf Publishing Company, Book ...

  17. Liquid waste management: The case of Bahir Dar, Ethiopia ...

    African Journals Online (AJOL)

    Background: Human beings pollute the environment with their industrial and domestic wastes. In Bahir Dar Town there is no conventional municipal waste water collection and treatment system. Objective: The aim of this study was to describe the liquid waste disposal practices of the residents of Bahir Dar Town and to ...

  18. 2006 OSIP OGRIP: Upland Counties LiDAR Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2006 OSIP digital LiDAR data was collected during the months of March and May (leaf-off conditions). The LiDAR covers the entire land area of the northern tier...

  19. Liquid waste management: The case of Bahir Dar, Ethiopia

    African Journals Online (AJOL)

    admin

    Abstract. Background: Human beings pollute the environment with their industrial and domestic wastes. In Bahir Dar Town there is no conventional municipal waste water collection and treatment system. Objective: The aim of this study was to describe the liquid waste disposal practices of the residents of Bahir Dar Town.

  20. Assessing LiDAR elevation data for KDOT applications.

    Science.gov (United States)

    2013-02-01

    LiDAR-based elevation surveys are a cost-effective means for mapping topography over large areas. LiDAR : surveys use an airplane-mounted or ground-based laser radar unit to scan terrain. Post-processing techniques are : applied to remove vegetation ...

  1. Analysis of inflow parameters using LiDARs

    NARCIS (Netherlands)

    Giyanani, A.H.; Bierbooms, W.A.A.M.; Van Bussel, G.J.W.

    2014-01-01

    Remote sensing of the atmospheric variables with the use of LiDAR is a relatively new technique for wind resource assessment and oncoming wind prediction in wind energy. The validation of LiDAR measurements and comparisons with other sensing elements thus, is of high importance for further

  2. Salt stress change chlorophyll fluorescence in mango

    Directory of Open Access Journals (Sweden)

    Cicero Cartaxo de Lucena

    2012-12-01

    Full Text Available This study evaluated the tolerance of mango cultivars 'Haden', 'Palmer', 'Tommy Atkins' and 'Uba' grafted on rootstock 'Imbú' to salt stress using chlorophyll fluorescence. Plants were grown in modified Hoagland solution containing 0, 15, 30, and 45 mmol L-1 NaCl. At 97 days the parameters of the chlorophyll fluorescence (F0, Fm, Fv, F0/Fm, Fv/Fm, Fv'/Fm', ΦPSII = [(Fm'-Fs/(Fm'], D = (1- Fv'/Fm' and ETR = (ΦPSII×PPF×0,84×0,5 were determined. At 100 days, the leaf emission and leaf area, toxicity and leaf abscission indexes were determined. In all cultivars evaluated, in different degree, there were decreases in photochemical efficiency of photosystem II, enhanced concentrations from 15 mmol L-1 NaCl. The decreases in the potential quantum yield of photosystem II (Fv/Fm were 27.9, 18.7, 20.5, and 27.4%, for cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba', respectively, when grown in 45 mmol L-1 NaCl. It was found decreases in leaf emission and mean leaf area in all cultivars from 15 mmol L-1 NaCl. There were increases in leaf toxicity of 33.0, 67.5, 41.6 and 80.8% and in leaf abscission of 71.8, 29.2, 32.5, and 67.9% for the cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba' respectively, when grown in 45 mmol L-1 NaCl. Leaf toxicity and leaf abscission were not observed in 15 mmol L-1 NaCl. The decrease in Fv/Fm ratio were accompanied by decreasing in leaf emission and increased leaf toxicity index, showing, therefore, the potential of chlorophyll fluorescence in the early detection of salt stress in mango tree.

  3. The Use of a Chlorophyll Meter (SPAD-502) for Field Determinations of Red Mangrove (Rhizophora Mangle L.) Leaf Chlorophyll Amount

    Science.gov (United States)

    Connelly, Xana M.

    1997-01-01

    The red mangrove Rhizophora mangle L., is a halophytic woody spermatophyte common to the land-sea interface of tropical and subtropical intertidal zones. It has been reported that 60 to 75% of the coastline of the earth's tropical regions are lined with mangroves. Mangroves help prevent shoreline erosion, provide breeding, nesting and feeding areas for many marine animals and birds. Mangroves are important contributors of primary production in the coastal environment, and this is largely proportional to the standing crop of leaf chlorophylls. Higher intensities of ultraviolet radiation, resulting from stratospheric ozone depletion, can lead to a reduction of chlorophyll in terrestrial plants. Since the most common method for determining chlorophyll concentration is by extraction and this is labor intensive and time consuming, few studies on photosynthetic pigments of mangroves have been reported. Chlorophyll meter readings have been related to leaf chlorophyll content in apples and maples. It has also been correlated to nitrogen status in corn and cotton. Peterson et al., (1993) used a chlorophyll meter to detect nitrogen deficiency in crops and in determining the need for additional nitrogen fertilizer. Efforts to correlate chlorophyll meter measurements to chlorophyll content of mangroves have not been reported. This paper describes the use of a hand-held chlorophyll meter (Minolta SPAD-502) to determine the amount of red mangrove foliar chlorophyll present in the field.

  4. The Magnesium Chelation Step in Chlorophyll Biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gregory L. Dilworth, Ph.D Chemical Sciences, Geosciences and Biosciences Division Office of Basis Energy Sciences, greg.dilworth@science.doe.gov

    2001-01-17

    The progress described in this report encompasses work supported by DOE grant DE-FG09-89ER13989 for the period 2/15/92 to the present 6/14/94. The goals of the project were to continue investigating the enzymology of Mg-chelatase and to investigate the co-regulation of heme and chlorophyll formation in intact plastids. During this period the laboratory had additional support (two years) from USDA to investigate heme metabolism in chloroplasts. This report is arranged so that the progress is described by reference to manuscripts which are published, under review or in preparation.

  5. Relationship of intertidal surface sediment chlorophyll concentration to hyper-spectral reflectance and chlorophyll fluorescence

    NARCIS (Netherlands)

    Kromkamp, J.C.; Morris, E.P.; Forster, R.M.; Honeywill, C.; Hagerthey, S.; Paterson, D.M.

    2006-01-01

    Estimating biomass of microphytobenthos (MPB) on intertidal mud flats is extremely difficult due to their patchy occurrence, especially at the scale of an entire mud flat. We tested two optical approaches that can be applied in situ: spectral reflectance and chlorophyll fluorescence. These two

  6. Object Classification Using Airborne Multispectral LiDAR Data

    Directory of Open Access Journals (Sweden)

    PAN Suoyan

    2018-02-01

    Full Text Available Airborne multispectral LiDAR system,which obtains surface geometry and spectral data of objects,simultaneously,has become a fast effective,large-scale spatial data acquisition method.Multispectral LiDAR data are characteristics of completeness and consistency of spectrum and spatial geometric information.Support vector machine (SVM,a machine learning method,is capable of classifying objects based on small samples.Therefore,by means of SVM,this paper performs land cover classification using multispectral LiDAR data. First,all independent point cloud with different wavelengths are merged into a single point cloud,where each pixel contains the three-wavelength spectral information.Next,the merged point cloud is converted into range and intensity images.Finally,land-cover classification is performed by means of SVM.All experiments were conducted on the Optech Titan multispectral LiDAR data,containing three individual point cloud collected by 532 nm,1024 nm,and 1550 nm laser beams.Experimental results demonstrate that ①compared to traditional single-wavelength LiDAR data,multispectral LiDAR data provide a promising solution to land use and land cover applications;②SVM is a feasible method for land cover classification of multispectral LiDAR data.

  7. Stereoelectronic properties of aggregated chlorophyll systems

    Energy Technology Data Exchange (ETDEWEB)

    Christoffersen, R. E.; Maggiora, G. M.

    1979-09-01

    During the first nine months of the current contract, significant progress has occurred in several areas. All SCF CI studies of the singlet and triplet states of the neutral molecules Et-Chl a, Et-Pheo a, Et-BChl a, and Et-BPheo a, and the doublet states of the ..pi..-cation radicals Et-Chl a/sup +/. and Et-BChl a/sup +/. have now been completed. In addition, SCF CI calculations on BPheo a/sup -/. indicate that ..pi..-anion radicals can also be studied using the present approach. Similar work on a number of other ..pi..-cation and ..pi..-anion radicals is currently underway. Preliminary SCF CI studies have also been completed for benzoquinone and dihydroquinone, and studies on benzoquinone/sup -/. should be completed by the end of this year. The development and characterization of an empirical potential function is nearly complete, and data from selected systems is summarized. Implementation of a more efficient, quadratically convergent energy minimization procedure is also being carried out. This procedure should make it possible to study the geometry and properties of dimeric chlorophyll systems as well as various ligand-chlorophyll systems. Developmental work is continuing on the direct calculation of optical rotatory strengths.

  8. The magnesium chelation step in chlorophyll biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, J.D.

    1991-01-01

    The biogenesis of energy transducing membranes requires the coordinate synthesis of prosthetic groups, proteins and lipids. Two of the major prosthetic groups, chlorophyll and heme, share a common biosynthetic pathway that diverges at the point of metal insertion into protoporphyrin IX. Insertion of iron leads to heme, while insertion of magnesium leads to chlorophyll. The Mg-chelatase from intact cucumber chloroplasts has been characterized with regard to substrate specificity, regulation, ATP requirement, and a requirement for intact chloroplasts. Mg-chelatase was isolated from maize, barley and peas and characterized in order to circumvent the intact chloroplast requirement of cucumber Mg-chelatase. Pea Mg-chelatase activity is higher than cucumber Mg-chelatase activity, and lacks the requirement for intact chloroplasts. Studies on isolated pea Mg-chelatase have shown more cofactors are required for the reaction than are seen with ferrochelatase, indicating a greater opportunity for regulatory control of this pathway. Two of the cofactors are proteins, and there appears to be a requirement for a protease-sensitive component which is outside the outer envelope. We are developing a continuous spectrophotometric assay for Mg-chelatase activity, and an assay for free heme which has shown heme efflux from intact chloroplasts. 18 refs. (MHB)

  9. TENSOR MODELING BASED FOR AIRBORNE LiDAR DATA CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    N. Li

    2016-06-01

    Full Text Available Feature selection and description is a key factor in classification of Earth observation data. In this paper a classification method based on tensor decomposition is proposed. First, multiple features are extracted from raw LiDAR point cloud, and raster LiDAR images are derived by accumulating features or the “raw” data attributes. Then, the feature rasters of LiDAR data are stored as a tensor, and tensor decomposition is used to select component features. This tensor representation could keep the initial spatial structure and insure the consideration of the neighborhood. Based on a small number of component features a k nearest neighborhood classification is applied.

  10. No sólo dar, sino darse

    OpenAIRE

    Rodríguez, Pedro

    2012-01-01

    El amor es darse, decimos. El que ama «no se conforma con dar: se da». ¿Pero se puede dar sin recibir? ¿Por qué languidece el amor, o incluso muere, cuando se da sin recibir o cuando se recibe sin dar? ¿No es necesario que el amor sea correspondido? Haremos aquí una consideración teológica sobre esta triple cuestión, en referencia particular al amor matrimonial.

  11. Revisiting chlorophyll extraction methods in biological soil crusts – methodology for determination of chlorophyll a and chlorophyll a + b as compared to previous methods

    Directory of Open Access Journals (Sweden)

    J. Caesar

    2018-03-01

    Full Text Available Chlorophyll concentrations of biological soil crust (biocrust samples are commonly determined to quantify the relevance of photosynthetically active organisms within these surface soil communities. Whereas chlorophyll extraction methods for freshwater algae and leaf tissues of vascular plants are well established, there is still some uncertainty regarding the optimal extraction method for biocrusts, where organism composition is highly variable and samples comprise major amounts of soil. In this study we analyzed the efficiency of two different chlorophyll extraction solvents, the effect of grinding the soil samples prior to the extraction procedure, and the impact of shaking as an intermediate step during extraction. The analyses were conducted on four different types of biocrusts. Our results show that for all biocrust types chlorophyll contents obtained with ethanol were significantly lower than those obtained using dimethyl sulfoxide (DMSO as a solvent. Grinding of biocrust samples prior to analysis caused a highly significant decrease in chlorophyll content for green algal lichen- and cyanolichen-dominated biocrusts, and a tendency towards lower values for moss- and algae-dominated biocrusts. Shaking of the samples after each extraction step had a significant positive effect on the chlorophyll content of green algal lichen- and cyanolichen-dominated biocrusts. Based on our results we confirm a DMSO-based chlorophyll extraction method without grinding pretreatment and suggest the addition of an intermediate shaking step for complete chlorophyll extraction (see Supplement S6 for detailed manual. Determination of a universal chlorophyll extraction method for biocrusts is essential for the inter-comparability of publications conducted across all continents.

  12. 47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Satellite DARS applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401 Satellite DARS applications subject to competitive bidding. Mutually exclusive initial applications for DARS...

  13. Elevation - LiDAR Survey Minnehaha Creek, MN Watershed

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — LiDAR Bare-Earth Grid - Minnehaha Creek Watershed District. The Minnehaha Creek watershed is located primarily in Hennepin County, Minnesota. The watershed covers...

  14. Dar es Salaam Land Use and Informal Settlement Data Set

    Data.gov (United States)

    National Aeronautics and Space Administration — The Dar es Salaam Land Use and Informal Settlement Data Set represents urban land use and consolidation of informal settlements for the years 1982, 1992, 1998, and...

  15. 2009 PSLC-USGS Topographic LiDAR: Wenatchee

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data of the Wenatchee USGS area of interest (AOI) east of Wenatchee, WA on May 1nd - May...

  16. Connecticut Statewide LiDAR 2016 - Blocks 1-7

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata record describes the Classified Point Cloud (LAS) for the 2016 Connecticut LiDAR project covering approximately 5240 square miles in seven blocks. The...

  17. LiDAR (Terrain), THURSTON COUNTY, WASHINGTON, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Fugro EarthData Company furnished the collection, processing, and development of LiDAR for 825 square miles in Washington (805 square miles of Thurston County and 20...

  18. LiDAR error estimation with WAsP engineering

    DEFF Research Database (Denmark)

    Bingöl, Ferhat; Mann, Jakob; Foussekis, D.

    2008-01-01

    The LiDAR measurements, vertical wind profile in any height between 10 to 150m, are based on assumption that the measured wind is a product of a homogenous wind. In reality there are many factors affecting the wind on each measurement point which the terrain plays the main role. To model LiDAR me...... data is compared with the model results. The model results are acceptable and very close for one site while the more complex one is returning higher errors at higher positions and in some wind directions.......DAR measurements and predict possible error in different wind directions for a certain terrain we have analyzed two experiment data sets from Greece. In both sites LiDAR and met. mast data have been collected and the same conditions are simulated with Riso/DTU software, WAsP Engineering 2.0. Finally measurement...

  19. Shipborne LiDAR system for coastal change monitoring

    Science.gov (United States)

    Kim, chang hwan; Park, chang hong; Kim, hyun wook; hyuck Kim, won; Lee, myoung hoon; Park, hyeon yeong

    2016-04-01

    Coastal areas, used as human utilization areas like leisure space, medical care, ports and power plants, etc., are regions that are continuously changing and interconnected with oceans and land and the sea level has risen by about 8cm (1.9mm / yr) due to global warming from 1964 year to 2006 year in Korea. Coastal erosion due to sea-level rise has caused the problem of marine ecosystems and loss of tourism resources, etc. Regular monitoring of coastal erosion is essential at key locations with such volatility. But the survey method of land mobile LiDAR (light detection and ranging) system has much time consuming and many restrictions. For effective monitoring beach erosion, KIOST (Korea Institute of Ocean Science & Technology) has constructed a shipborne mobile LiDAR system. The shipborne mobile LiDAR system comprised a land mobile LiDAR (RIEGL LMS-420i), an INS (inertial navigation system, MAGUS Inertial+), a RTKGPS (LEICA GS15 GS25), and a fixed platform. The shipborne mobile LiDAR system is much more effective than a land mobile LiDAR system in the measuring of fore shore areas without shadow zone. Because the vessel with the shipborne mobile LiDAR system is continuously moved along the shoreline, it is possible to efficiently survey a large area in a relatively short time. Effective monitoring of the changes using the constructed shipborne mobile LiDAR system for seriously eroded coastal areas will be able to contribute to coastal erosion management and response.

  20. Extraction of Rooftops from LiDAR and Multispectral Imagery

    OpenAIRE

    Kim, Angela M.; Kruse, Fred A.; Olsen, Richard C.; Clasen, Chris C.

    2012-01-01

    Imaging and Applied Optics Technical Digest, 2012 A rooftop extraction scheme based on statistical analysis of the LiDAR point cloud is presented. Spectral data are incorporated to reduce false alarms due to vegetation and to provide spectral discrimination of rooftop materials. This research was partially supported by the Science and Technology Directorate, USA Department of Homeland Security (DHS). The LiDAR data were provided by the Association of Monterey Bay Area Governments (AM...

  1. Photoinduced electron transfer of chlorophyll in lipid bilayer system

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Photoinduced electron transfer from chlorophyll-athrough the interface of dipalmitoylphosphatidylcholine (DPPC) headgroup of the lipid bilayers was studied with electron magnetic resonance (EMR). The photoproduced radicals were identified with electron spin resonance (ESR) and radical yields of chlorophyll- ...

  2. Oxidation-reduction potentials of different chlorophylls in methanol

    NARCIS (Netherlands)

    Goedheer, J.C.; Horreus de Haas, G.H.; Schuller, P.

    1958-01-01

    It was found that the reversible decolorisation of some chlorophylls upon the subsequent addition of ferric and ferrous salts, as originally measured by Rabinowtich and Weiss for chlorophyll a, proceeded at a reproducible oxidation-reduction potential. A marked difference was found to occur

  3. A model for chlorophyll fluorescence and photosynthesis at leaf scale

    NARCIS (Netherlands)

    Tol, van der C.; Verhoef, W.; Rosema, A.

    2009-01-01

    This paper presents a leaf biochemical model for steady-state chlorophyll fluorescence and photosynthesis of C3 and C4 vegetation. The model is a tool to study the relationship between passively measured steady-state chlorophyll fluorescence and actual photosynthesis, and its evolution during the

  4. Chlorophyll modulation of mixed layer thermodynamics in a mixed ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    ing solar radiation is trapped due to phytoplankton at upper layers (from surface to 35m), while the lower layers (from 65m to 80m) does not receive the same solar energy as before the chlorophyll blooming in the previous month. In the equatorial Pacific where horizontal advec- tion effect is important, the effect of chlorophyll.

  5. Chlorophyll meter reading and total nitrogen content applied as ...

    African Journals Online (AJOL)

    Ana Mascarello

    The present study was aimed to assess the relationship between the reading of the chlorophyll meter and the total nitrogen (N) content ... devices to measure chlorophyll index (SPAD) and N content in the leaf. The nitrogen levels were found ... absorption of other nutrients and the production of carbohydrates. The methods ...

  6. An optimal thermal condition for maximal chlorophyll extraction

    Directory of Open Access Journals (Sweden)

    Fu Jia-Jia

    2017-01-01

    Full Text Available This work describes an environmentally friendly process for chlorophyll extraction from bamboo leaves. Shaking water bath and ultrasound cleaner are adopted in this technology, and the influence of temperature of the water bath and ultrasonic cleaner is evaluated. Results indicated that there is an optimal condition for maximal yield of chlorophyll.

  7. Influence of selected abiotic factors on the decomposition of chlorophylls

    Directory of Open Access Journals (Sweden)

    Gra¿yna Kowalewska

    2001-09-01

    Full Text Available The paper presents the results of experiments to determine the influence of selected physico-chemical factors - oxygen, visible light and temperature - on the decomposition of (1 chlorophylls a, b and c, chlorophyll a derivatives and beta-carotene in acetone solution, and (2 chlorophyll a and beta-carotene in axenic cultures of the blue-green algae Anabaena variabilis. The results indicate that both in acetone extracts and in blue-green algae cultures these pigments were most sensitive to light and oxygen; temperatures of up to 25oC had no marked influence on these compounds. Under anoxia in acetone solution, the stability towards light decreased in the order chlorophyll a, chlorophyll b, chlorophylls c. Chlorophyll a, moreover, was less stable than its derivatives - phaeophorbides, phaeophytins, pyrophaeophytins and steryl chlorins - but more stable than beta-carotene, in the last case also in the blue-green algae cultures. Decomposition of all the pigments proceeded mainly via the breakdown of the porphyrin macrocycle, since the decomposition products were not detected in the VIS range. On the basis of these experiments one can state that while light and oxygen may have a decisive direct influence on the distribution of chlorophylls and beta-carotene in sediments, in the natural environment, temperatures of up to 25oC may have very little immediate effect.

  8. Effect of preservation on the chlorophyll content, phytochemicals ...

    African Journals Online (AJOL)

    The results of the study show that in both broad and slender leaves pumpkin varieties investigated, refrigeration and freezing for two weeks led to a significant decrease (p<0.05) in their chlorophyll contents. Total chlorophyll a and b content in the preserved broad leaf pumpkin variety (BLP) decreased by an average of ...

  9. Chlorophyll in tomato seeds: marker for seed performance?

    NARCIS (Netherlands)

    Suhartanto, M.R.

    2002-01-01

    Using Xe-PAM, laser induced fluorometry and high performance liquid chromatography we found that chlorophyll was present in young tomato (cv. Moneymaker) seeds and was degraded during maturation. Fluorescence microscopy and imaging showed that the majority of chlorophyll is located in the

  10. Genetic dissection of chlorophyll content at different growth stages in ...

    Indian Academy of Sciences (India)

    [Zhang K., Fang Z., Liang Y. and Tian J. 2009 Genetic dissection of chlorophyll content at different growth stages in common wheat. J. Genet. 88, 183–189]. Introduction. Chlorophyll a and b contained in leaves of higher plants are the main pigments of photosynthesis in the chloroplasts, and have important functions in the ...

  11. Overview of remote sensing of chlorophyll flourescene in ocean waters

    African Journals Online (AJOL)

    This study reviews the history of initial cognitions, investigations and detailed approaches towards chlorophyll fluorescence, and then introduces the biological mechanism of fluorescence remote sensing and main spectral characteristics such as the positive correlation between fluorescence and chlorophyll concentration ...

  12. The magnesium chelation step in chlorophyll biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, J.

    1990-11-01

    In photosynthetic organisms, the biogenesis of energy transducing membranes requires the coordinate synthesis of prosthetic groups, proteins, and various lipids. Two of the major prosthetic groups, chlorophyll and heme, share a common biosynthetic pathway that diverges at the point of metal insertion into protoporphyrin IX (Proto). Insertion of iron leads to the formation of hemes, while insertion of magnesium is the first step unique to chlorophyll formation. This project is directed toward identifying the enzyme(s) responsible for magnesium chelation and elucidating the mechanism which regulates the flux of precursors through the branch point enzymes in isolated chloroplasts. Using intact chloroplasts from greening cucumber cotyledons, we have confirmed the ATP requirement for Mg-Proto formation. Use of non-hydrolyzable ATP analogs, uncouplers and ionophores has led to the conclusions that ATP hydrolysis is necessary, but that this hydrolysis is not linked to the requirement for membrane intactness by transmembrane ion gradients or electrical potentials. The enzyme(s) are flexible with respect to the porphyrin substrate specificity, accepting porphyrins with -vinyl, -ethyl, or -H substituents at the 2 and 4 positions. The activity increases approximately four-fold during greening. Possible physiological feedback inhibitors such as heme, protochlorophyllide, and chlorophyllide had no specific effect on the activity. The activity has now been assayed in barely, corn and peas, with the system from peas almost ten-fold more active than the cucumber system. Work is continuing in pea chloroplasts with the development of a continuous assay and investigation of the feasibility of characterizing an active, organelle-free preparation. 6 figs.

  13. The biogeochemistry of tetrapyrrole pigments, emphasizing chlorophyll

    Energy Technology Data Exchange (ETDEWEB)

    Louda, J.W.

    1993-01-01

    Electronic absorption spectra recorded on native geopigments and on in vitro derivatives, obtained with combinations of copper insertion and borohydride reduction reactions, allowed a sensitive chromophore identification' scheme to be developed. Quantitation of the Ni and VO geoporphyrins, as well as the benzo-forms of each, was tested and precisions at the level of 100 [+-] 5% found. An overall methodology for obtaining repeatable low-voltage mass spectra on geoporphyrin arrays is presented. Repeatabilities for the various mass spectral-derived indices were; %DPEP ([+-]2%), X ([+-]2%), A.I.([+-]5%) and % BENZ ([+-]10%). Quantitation of the metallobenzoporphyrins was much better ([+-]2%) with UV/VIS techniques. Tetrapyrrole geochemistry was investigated at all stages of organic evolution. Thus, viable and senescent/dead uni-algal cultures, sediment trap material, surface (<1m) sediments, deep ocean long cores (DSDP), oil shales and petroleum crudes were investigated. Results indicate that the chlorophylls can serve as sources for a variety of geoporphyrins. Early in diagenesis two competing reactions dictate further fossilization.' First is the loss of the carbomethoxy group. This produces pyropheophorbides which can either lead to the true DPEP series, via a sequence of defunctionaliation reactions or, via intramolecular cyclization (dehydration), to certain 13[sup 2], 17[sup 3]-cyclopheophorbide enols. The latter, following defunctionalization, give rise to DiDPEP and/or DPEP-type pigments with a 7-membered exocyclic ring. Second, chlorophyll nuclei which have undergone oxidative scission of the isocyclic ring can, through purpurins and chlorins, theoretically yield C28-C30 ETIO-series porphyrins. Bacteriochlorophyll-a was found to be a dominant pigment in several anoxic sediments and is suggested as an important and highly specific precursor for certain geoporphyrins (i.e 3-methyl-desethyl-DPEP).

  14. Ultraviolet Fluorescence LiDAR (UFL as a Measurement Tool for Water Quality Parameters in Turbid Lake Conditions

    Directory of Open Access Journals (Sweden)

    Heiko Balzter

    2013-09-01

    Full Text Available Despite longstanding contributions to oceanography, similar use of fluorescence light detection and ranging (LiDAR in lake settings is not routine. The potential for ship-mounted, multispectral Ultraviolet Fluorescence LiDAR (UFL to provide rapid, high-resolution data in variably turbid and productive lake conditions are investigated here through a series of laboratory tank and field measurements carried out on Lake Balaton, Hungary. UFL data, calibrated empirically to a set of coinciding conventionally-analyzed samples, provide simultaneous estimates of three important parameters-chlorophyll a(chla, total suspended matter (TSM and colored dissolved organic matter (CDOM. Successful UFL retrievals from both laboratory and field measurements were achieved for chla (0.01–378 mg∙m−3; R = 0.83–0.92, TSM (0.1–130 g∙m−3; R = 0.90–0.96 and CDOM (0.003–0.125 aCDOM(440; R = 0.80–0.97. Fluorescence emission at 685 nm is shown through tank measurements to display robust but distinct relationships with chla concentration for the two cultured algae species investigated (cyanobacteria, Cylindrospermopsis raciborskii, and chlorophyta, Scenedesmus armatus. The ratio between fluorescence emissions measured at 650 nm, related to the phycocyanin fluorescence maximum, to that at 685 nm is demonstrated to effectively distinguish these two species. Validation through both laboratory measurements and field measurements confirmed that site specific calibration is necessary. This study presents the first known assessment and application of ship-mounted fluorescence LiDAR in freshwater lake conditions and demonstrates the use of UFL in measuring important water quality parameters despite the more complicated hydro-optic conditions of inland waters.

  15. 2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Chehalis River Watershed Area, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data for the Chehalis River Watershed study area on January 28th, February 2nd-7th,...

  16. 2002 Puget Sound LiDAR Consortium (PSLC) Unclassified Topographic LiDAR: Puget Sound Lowlands Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 730 square miles and covers the...

  17. 2006 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Eastern Washington and River Corridors

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data in eastern Washington, eastern Oregon, and southern Canada in October and November,...

  18. 2012-2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Hoh River Watershed, Washington (Deliveries 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data on the Hoh River watershed survey area for the Puget Sound LiDAR Consortium and the...

  19. Chlorophyll as an indicator of green tea quality

    Directory of Open Access Journals (Sweden)

    Martina Ošťádalová

    2014-01-01

    Full Text Available The objective of this work was to study the changes in chlorophyll contents in green teas stored under different conditions and to suggest the most suitable way and length of green tea storage. A secondary aim was to evaluate the possibility of using the chlorophyll content as an indicator of tea freshness. Samples for analysis were obtained from a range of tea-growing regions. Chlorophyll contents were measured using UV-vis spectrophotometry. Chlorophyll absorbance was measured at 642.5 and 660 nm. Prior to storage, chlorophyll concentration in teas ranged from 1.12 to 1.89 mg per 1 g of tea, which corresponded to data given by other authors. Storage was found to lead to a decline in chlorophyll concentration. From the 6th month of storage onwards, a significant decrease (P < 0.05 was observed in all samples, irrespective of storage conditions. Based on the findings of this study, original and metal packaging can be considered the most chlorophyll-friendly. On the other hand, glass and paper packaging stored in direct daylight were found to have the strongest impact on chlorophyll concentration. Overall, it can be concluded that the storage time can have a strong influence on oolong green tea colour as an important qualitative variable. Thus, the shelf-life of tea should be shorter than the 12 months claimed by most manufacturers. Once the relationship between changes in chlorophyll concentration and length of the storage period had been established, the chlorophyll content was suggested as an indicator of the storage time (freshness of a tea substance.

  20. THE CHLOROPHYLL-PROTEIN COMPOUND OF THE GREEN LEAF.

    Science.gov (United States)

    Smith, E L

    1941-05-20

    1. Aqueous extracts of spinach and Aspidistra leaves yield highly opalescent preparations which are not in true solution. Such extracts differ markedly from colloidal chlorophyll in their spectrum and fluorescence. The differences between the green leaf pigment and chlorophyll in organic solvents are shown to be due to combination of chlorophyll with protein in the leaf. 2. The effect of some agents on extracts of the chlorophyll-protein compound has been investigated. Both strong acid and alkali modify the absorption spectrum, acid converting the compound to the phaeophytin derivative and alkali saponifying the esterified groups of chlorophyll. Even weakly acid solutions (pH 4.5) denature the protein. Heating denatures the protein and modifies the absorption spectrum and fluorescence as earlier described for the intact leaf. The protein is denatured by drying. Low concentrations of alcohol or acetone precipitate and denature the protein; higher concentrations cause dissociation liberating the pigments. 3. Detergents such as digitonin, bile salts, and sodium desoxycholate clarify the leaf extracts but denature the protein changing the spectrum and other properties. 4. Inhibiting agents of photosynthesis are without effect on the absorption spectrum of the chlorophyll-protein compound. 5. The red absorption band of chlorophyll possesses the same extinction value in organic solvents such as ether or petroleum ether, and in aqueous leaf extracts clarified by digitonin although the band positions are different. Using previously determined values of the extinction coefficients of purified chlorophylls a and b, the chlorophyll content of the leaf extracts may be estimated spectrophotometrically. 6. It was found that the average chlorophyll content of the purified chloroplasts was 7.86 per cent. The protein content was 46.5 per cent yielding an average value of 16.1 parts per 100 parts of protein. This corresponds to a chlorophyll content of three molecules of chlorophyll

  1. Agrotóxico: que nome dar?

    Directory of Open Access Journals (Sweden)

    Márcia Gomide

    Full Text Available Os trabalhadores, de um modo geral, estão sempre expostos a maiores ou menores intensidades de risco. Os agricultores, em particular, também estão expostos e de forma bastante estabelecida. Contudo, trabalhos têm mostrado que existe um código coletivo de proteção para lhes permitir dar continuidade às suas atividades, uma vez que, em sua maioria, os próprios donos do cultivo fazem parte do processo produtivo e, portanto, precisam garantir a sua safra aplicando os agrotóxicos. Este trabalho apresenta uma pesquisa desenvolvida com agricultores de dois municípios do sudeste do Piauí, utilizando uma abordagem qualitativa, com o intuito de compreender os mecanismos de proteção destes agricultores com a sua atividade. Os resultados apontaram para práticas defensivas tais como consumo de bebida alcoólica, a sublocação do serviço aos mais jovens e a existência de um certo grau de compreensão do risco à saúde com a utilização dos agrotóxicos. A partir daí, se discute a importância da denominação dada ao agrotóxico, como um fator de proteção que deveria ser mais valorizado para maximizar a proteção do agricultor, em vez de se manter a estratégia de aumento de informação e controle de EPI (Equipamento de Proteção Individual.

  2. LiDAR Vegetation Investigation and Signature Analysis System (LVISA)

    Science.gov (United States)

    Höfle, Bernhard; Koenig, Kristina; Griesbaum, Luisa; Kiefer, Andreas; Hämmerle, Martin; Eitel, Jan; Koma, Zsófia

    2015-04-01

    Our physical environment undergoes constant changes in space and time with strongly varying triggers, frequencies, and magnitudes. Monitoring these environmental changes is crucial to improve our scientific understanding of complex human-environmental interactions and helps us to respond to environmental change by adaptation or mitigation. The three-dimensional (3D) description of the Earth surface features and the detailed monitoring of surface processes using 3D spatial data have gained increasing attention within the last decades, such as in climate change research (e.g., glacier retreat), carbon sequestration (e.g., forest biomass monitoring), precision agriculture and natural hazard management. In all those areas, 3D data have helped to improve our process understanding by allowing quantifying the structural properties of earth surface features and their changes over time. This advancement has been fostered by technological developments and increased availability of 3D sensing systems. In particular, LiDAR (light detection and ranging) technology, also referred to as laser scanning, has made significant progress and has evolved into an operational tool in environmental research and geosciences. The main result of LiDAR measurements is a highly spatially resolved 3D point cloud. Each point within the LiDAR point cloud has a XYZ coordinate associated with it and often additional information such as the strength of the returned backscatter. The point cloud provided by LiDAR contains rich geospatial, structural, and potentially biochemical information about the surveyed objects. To deal with the inherently unorganized datasets and the large data volume (frequently millions of XYZ coordinates) of LiDAR datasets, a multitude of algorithms for automatic 3D object detection (e.g., of single trees) and physical surface description (e.g., biomass) have been developed. However, so far the exchange of datasets and approaches (i.e., extraction algorithms) among LiDAR users

  3. LBA-ECO LC-07 Amazon Floodplain Lake Chlorophyll from MODIS, Para, Brazil: 2002-2003

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains chlorophyll concentration maps of the Amazon River floodplain region from Parintins (Amazonas) to Almeirim (Para). These chlorophyll fraction...

  4. LBA-ECO LC-07 Amazon Floodplain Lake Chlorophyll from MODIS, Para, Brazil: 2002-2003

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains chlorophyll concentration maps of the Amazon River floodplain region from Parintins (Amazonas) to Almeirim (Para). These chlorophyll...

  5. Visual-LiDAR Odometry Aided by Reduced IMU

    Directory of Open Access Journals (Sweden)

    Yashar Balazadegan Sarvrood

    2016-01-01

    Full Text Available This paper proposes a method for combining stereo visual odometry, Light Detection And Ranging (LiDAR odometry and reduced Inertial Measurement Unit (IMU including two horizontal accelerometers and one vertical gyro. The proposed method starts with stereo visual odometry to estimate six Degree of Freedom (DoF ego motion to register the point clouds from previous epoch to the current epoch. Then, Generalized Iterative Closest Point (GICP algorithm refines the motion estimation. Afterwards, forward velocity and Azimuth obtained by visual-LiDAR odometer are integrated with reduced IMU outputs in an Extended Kalman Filter (EKF to provide final navigation solution. In this paper, datasets from KITTI (Karlsruhe Institute of Technology and Toyota technological Institute were used to compare stereo visual odometry, integrated stereo visual odometry and reduced IMU, stereo visual-LiDAR odometry and integrated stereo visual-LiDAR odometry and reduced IMU. Integrated stereo visual-LiDAR odometry and reduced IMU outperforms other methods in urban areas with buildings around. Moreover, this method outperforms simulated Reduced Inertial Sensor System (RISS, which uses simulated wheel odometer and reduced IMU. KITTI datasets do not include wheel odometry data. Integrated RTK (Real Time Kinematic GPS (Global Positioning System and IMU was replaced by wheel odometer to simulate the response of RISS method. Visual Odometry (VO-LiDAR is not only more accurate than wheel odometer, but it also provides azimuth aiding to vertical gyro resulting in a more reliable and accurate system. To develop low-cost systems, it would be a good option to use two cameras plus reduced IMU. The cost of such a system will be reduced than using full tactical MEMS (Micro-Electro-Mechanical Sensor based IMUs because two cameras are cheaper than full tactical MEMS based IMUs. The results indicate that integrated stereo visual-LiDAR odometry and reduced IMU can achieve accuracy at the

  6. UAS TOPOGRAPHIC MAPPING WITH VELODYNE LiDAR SENSOR

    Directory of Open Access Journals (Sweden)

    G. Jozkow

    2016-06-01

    Full Text Available Unmanned Aerial System (UAS technology is nowadays willingly used in small area topographic mapping due to low costs and good quality of derived products. Since cameras typically used with UAS have some limitations, e.g. cannot penetrate the vegetation, LiDAR sensors are increasingly getting attention in UAS mapping. Sensor developments reached the point when their costs and size suit the UAS platform, though, LiDAR UAS is still an emerging technology. One issue related to using LiDAR sensors on UAS is the limited performance of the navigation sensors used on UAS platforms. Therefore, various hardware and software solutions are investigated to increase the quality of UAS LiDAR point clouds. This work analyses several aspects of the UAS LiDAR point cloud generation performance based on UAS flights conducted with the Velodyne laser scanner and cameras. The attention was primarily paid to the trajectory reconstruction performance that is essential for accurate point cloud georeferencing. Since the navigation sensors, especially Inertial Measurement Units (IMUs, may not be of sufficient performance, the estimated camera poses could allow to increase the robustness of the estimated trajectory, and subsequently, the accuracy of the point cloud. The accuracy of the final UAS LiDAR point cloud was evaluated on the basis of the generated DSM, including comparison with point clouds obtained from dense image matching. The results showed the need for more investigation on MEMS IMU sensors used for UAS trajectory reconstruction. The accuracy of the UAS LiDAR point cloud, though lower than for point cloud obtained from images, may be still sufficient for certain mapping applications where the optical imagery is not useful.

  7. Regional ocean-colour chlorophyll algorithms for the Red Sea

    KAUST Repository

    Brewin, Robert J.W.

    2015-05-18

    The Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making use of a new merged ocean-colour product, from the European Space Agency (ESA) Climate Change Initiative, and in situ data in the region, we test the performance of a series of ocean-colour chlorophyll algorithms. We find that standard algorithms systematically overestimate chlorophyll when compared with the in situ data. To investigate this bias we develop an ocean-colour model for the Red Sea, parameterised to data collected during the Tara Oceans expedition, that estimates remote-sensing reflectance as a function of chlorophyll concentration. We used the Red Sea model to tune the standard chlorophyll algorithms and the overestimation in chlorophyll originally observed was corrected. Results suggest that the overestimation was likely due to an excess of CDOM absorption per unit chlorophyll in the Red Sea when compared with average global conditions. However, we recognise that additional information is required to test the influence of other potential sources of the overestimation, such as aeolian dust, and we discuss uncertainties in the datasets used. We present a series of regional chlorophyll algorithms for the Red Sea, designed for a suite of ocean-colour sensors, that may be used for further testing.

  8. DART: Recent Advances in Remote Sensing Data Modeling With Atmosphere, Polarization, and Chlorophyll Fluorescence

    Science.gov (United States)

    Gastellu-Etchegorry, Jean-Phil; Lauret, Nicolas; Yin, Tiangang; Landier, Lucas; Kallel, Abdelaziz; Malenovsky, Zbynek; Bitar, Ahmad Al; Aval, Josselin; Benhmida, Sahar; Qi, Jianbo; hide

    2017-01-01

    To better understand the life-essential cycles and processes of our planet and to further develop remote sensing (RS) technology, there is an increasing need for models that simulate the radiative budget (RB) and RS acquisitions of urban and natural landscapes using physical approaches and considering the three-dimensional (3-D) architecture of Earth surfaces. Discrete anisotropic radiative transfer (DART) is one of the most comprehensive physically based 3-D models of Earth-atmosphere radiative transfer, covering the spectral domain from ultraviolet to thermal infrared wavelengths. It simulates the optical 3-DRB and optical signals of proximal, aerial, and satellite imaging spectrometers and laser scanners, for any urban and/or natural landscapes and for any experimental and instrumental configurations. It is freely available for research and teaching activities. In this paper, we briefly introduce DART theory and present recent advances in simulated sensors (LiDAR and cameras with finite field of view) and modeling mechanisms (atmosphere, specular reflectance with polarization and chlorophyll fluorescence). A case study demonstrating a novel application of DART to investigate urban landscapes is also presented.

  9. Chlorophyll derivatives for pest and disease control: Are they safe?

    International Nuclear Information System (INIS)

    Azizullah, Azizullah; Murad, Waheed

    2015-01-01

    Chlorophyll derivatives are getting widespread acceptance among the researchers as natural photosensitizers for photodynamic control of pests and disease vectors; however, rare attention has been given to evaluation of their toxicity to non-target organisms in the environment. This perspective article highlights that chlorophyll derivatives may not be as safe as believed and can possibly pose risk to non-target organisms in the environment. We invite the attention of environmental biologists, particularly ecotoxicologists, to contribute their role in making the application of chlorophyll derivatives more environmentally friendly and publicly acceptable

  10. A Study on Factors Affecting Airborne LiDAR Penetration

    Directory of Open Access Journals (Sweden)

    Wei-Chen Hsu

    2015-01-01

    Full Text Available This study uses data from different periods, areas and parameters of airborne LiDAR (light detection and ranging surveys to understand the factors that influence airborne LiDAR penetration rate. A discussion is presented on the relationships between these factors and LiDAR penetration rate. The results show that the flight height above ground level (AGL does not have any relationship with the penetration rate. There are some factors that should have larger influence. For example, the laser is affected by a wet ground surface by reducing the number of return echoes. The field of view (FOV has a slightly negative correlation with the penetration rate, which indicates that the laser incidence angle close to zero should achieve the best penetration. The vegetation cover rate also shows a negative correlation with the penetration rate, thus bare ground and reduced vegetation in the aftermath of a typhoon also cause high penetration rate. More return echoes could be extracted from the full-waveform system, thereby effectively improving the penetration rate. This study shows that full-waveform LiDAR is an effective method for increasing the number of surface reflected echoes. This study suggests avoiding LiDAR survey employment directly following precipitation to prevent laser echo reduction.

  11. Chlorophyll assembled electrode for photovoltaic conversion device

    Energy Technology Data Exchange (ETDEWEB)

    Amao, Yutaka; Kato, Koichi [Department of Applied Chemistry, Oita University, 700 Dannoharu, Oita 870-1192 (Japan)

    2007-11-20

    Chlorophyll-a (Chl-a) assembled in hydrophobic domain by fatty acid with long alkyl hydrocarbon chain such as myristic acid (Myr), stearic acid (Ste) and cholic acid (Cho) modified onto nanocrystalline TiO{sub 2} electrode is prepared and the photovoltaic properties of the nanocrystalline TiO{sub 2} film by Chl-a are studied. Incident photon to current efficiency (IPCE) value at 660 nm in photocurrent action spectrum of Chl-a/Ste-TiO{sub 2}, Chl-a/Myr-TiO{sub 2} and Chl-a/Cho-TiO{sub 2} electrodes are 5.0%, 4.1% and 4.1%, respectively. Thus, the IPCE is maximum using Chl-a/Ste-TiO{sub 2} electrode. From the results of photocurrent responses with light intensity of 100 mW cm{sup -2} irradiation or monochromatic light with 660 nm, generated photocurrent increases using Chl-a/Ste-TiO{sub 2} electrode compared with the other Chl-a assembled TiO{sub 2} electrodes. These results show that the hydrophobic domain formed by stearic acid with long alkyl hydrocarbon chain is suitable for fixation of Chl-a onto TiO{sub 2} film electrodes and photovoltaic performance is improved using Chl-a onto Ste-TiO{sub 2} film electrode. (author)

  12. Automated Probabilistic LiDAR Swath Registration

    Science.gov (United States)

    Jalobeanu, A.; Gonçalves, G. R.

    2014-12-01

    We recently developed a new point cloud registration algorithm. Compared to Iterated Closest Point (ICP) techniques, it is robust to noise and outliers, and easier to use, as it is less sensitive to initial conditions. It minimizes the entropy of the joint point cloud (including intensity attributes to help register areas with poor relief), uses a voxel space and B-Spline interpolation to accelerate computation. A natural application of registration is swath alignment in airborne light detection and ranging (LiDAR). Indeed, due to uncertainty in the inertial navigation system (INS), attitude angles are subject to time-dependent errors. Such errors can be understood as a sum of three terms: 1) a global term, or boresight error, which can be addressed using several existing techniques; 2) a low-frequency term, which is modeled as a constant attitude error for regions several hundred meters along-track; 3) a high-frequency term, responsible for corduroy artifacts (not addressed here). We propose to use the new registration algorithm to correct the low-frequency attitude variations. Relative geometric errors are significantly reduced, as pairs of swaths are registered onto each other local corrections. Absolute geometric errors are reduced during a second step, by applying all the corrections together to the entire dataset. We used a test area of 200 km2 in Portugal, with a density of 3-4 pts/m2. The point clouds were derived from waveform data, and include predictive range uncertainties estimated within a Bayesian framework. The data collection was supported by FCT and FEDER as part of the AutoProbaDTM research project (2009-2012). Modeling and reducing geometric error helps build consistent uncertainty maps. After correction, residual errors are taken into account in the final 3D error budget. For gridded elevation models a vertical uncertainty map is computed. Finally, it is possible to use the inter-swath registration parameters to estimate the distribution of

  13. A database of chlorophyll a in Australian waters

    Science.gov (United States)

    Davies, Claire H.; Ajani, Penelope; Armbrecht, Linda; Atkins, Natalia; Baird, Mark E.; Beard, Jason; Bonham, Pru; Burford, Michele; Clementson, Lesley; Coad, Peter; Crawford, Christine; Dela-Cruz, Jocelyn; Doblin, Martina A.; Edgar, Steven; Eriksen, Ruth; Everett, Jason D.; Furnas, Miles; Harrison, Daniel P.; Hassler, Christel; Henschke, Natasha; Hoenner, Xavier; Ingleton, Tim; Jameson, Ian; Keesing, John; Leterme, Sophie C.; James McLaughlin, M; Miller, Margaret; Moffatt, David; Moss, Andrew; Nayar, Sasi; Patten, Nicole L.; Patten, Renee; Pausina, Sarah A.; Proctor, Roger; Raes, Eric; Robb, Malcolm; Rothlisberg, Peter; Saeck, Emily A.; Scanes, Peter; Suthers, Iain M.; Swadling, Kerrie M.; Talbot, Samantha; Thompson, Peter; Thomson, Paul G.; Uribe-Palomino, Julian; van Ruth, Paul; Waite, Anya M.; Wright, Simon; Richardson, Anthony J.

    2018-01-01

    Chlorophyll a is the most commonly used indicator of phytoplankton biomass in the marine environment. It is relatively simple and cost effective to measure when compared to phytoplankton abundance and is thus routinely included in many surveys. Here we collate 173, 333 records of chlorophyll a collected since 1965 from Australian waters gathered from researchers on regular coastal monitoring surveys and ocean voyages into a single repository. This dataset includes the chlorophyll a values as measured from samples analysed using spectrophotometry, fluorometry and high performance liquid chromatography (HPLC). The Australian Chlorophyll a database is freely available through the Australian Ocean Data Network portal (https://portal.aodn.org.au/). These data can be used in isolation as an index of phytoplankton biomass or in combination with other data to provide insight into water quality, ecosystem state, and relationships with other trophic levels such as zooplankton or fish. PMID:29461516

  14. A database of chlorophyll a in Australian waters

    Science.gov (United States)

    Davies, Claire H.; Ajani, Penelope; Armbrecht, Linda; Atkins, Natalia; Baird, Mark E.; Beard, Jason; Bonham, Pru; Burford, Michele; Clementson, Lesley; Coad, Peter; Crawford, Christine; Dela-Cruz, Jocelyn; Doblin, Martina A.; Edgar, Steven; Eriksen, Ruth; Everett, Jason D.; Furnas, Miles; Harrison, Daniel P.; Hassler, Christel; Henschke, Natasha; Hoenner, Xavier; Ingleton, Tim; Jameson, Ian; Keesing, John; Leterme, Sophie C.; James McLaughlin, M.; Miller, Margaret; Moffatt, David; Moss, Andrew; Nayar, Sasi; Patten, Nicole L.; Patten, Renee; Pausina, Sarah A.; Proctor, Roger; Raes, Eric; Robb, Malcolm; Rothlisberg, Peter; Saeck, Emily A.; Scanes, Peter; Suthers, Iain M.; Swadling, Kerrie M.; Talbot, Samantha; Thompson, Peter; Thomson, Paul G.; Uribe-Palomino, Julian; van Ruth, Paul; Waite, Anya M.; Wright, Simon; Richardson, Anthony J.

    2018-02-01

    Chlorophyll a is the most commonly used indicator of phytoplankton biomass in the marine environment. It is relatively simple and cost effective to measure when compared to phytoplankton abundance and is thus routinely included in many surveys. Here we collate 173, 333 records of chlorophyll a collected since 1965 from Australian waters gathered from researchers on regular coastal monitoring surveys and ocean voyages into a single repository. This dataset includes the chlorophyll a values as measured from samples analysed using spectrophotometry, fluorometry and high performance liquid chromatography (HPLC). The Australian Chlorophyll a database is freely available through the Australian Ocean Data Network portal (https://portal.aodn.org.au/). These data can be used in isolation as an index of phytoplankton biomass or in combination with other data to provide insight into water quality, ecosystem state, and relationships with other trophic levels such as zooplankton or fish.

  15. Assessment of water pollution by airborne measurement of chlorophyll

    Science.gov (United States)

    Arvesen, J. C.; Weaver, E. C.; Millard, J. P.

    1972-01-01

    Remote measurement of chlorophyll concentrations to determine extent of water pollution is discussed. Construction and operation of radiometer to provide measurement capability are explained. Diagram of equipment is provided.

  16. Relationship between chlorophyll-a and column primary production

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Bhargava, R.M.S.

    Relationship between surface chlorophyll a and column primary production has been established to help in estimating the latter more quickly and accurately. The equation derived is Primary Production, y = 0.54 Ln Chl a - 0.6. The relationship...

  17. Effect of immersion systems on chlorophyll contents in micro ...

    African Journals Online (AJOL)

    Basrai variety) an efficient micro-propagation protocol was developed by using micro-stem cutting, as an explant. The maximum numbers of plantlets with higher chlorophyll and lower carotenoid contents were observed, which developed through ...

  18. Remotely sensed variability of temperature and chlorophyll in the ...

    African Journals Online (AJOL)

    series of daily sea surface temperature (SST) and chlorophyll a ... Most notable is the rapidly pulsating nature of the upwelling, with intense warm/cold events clearly distinguished. The phytoplankton response to this physical forcing is described.

  19. Peregrinaciones parisinas: Rubén Darío

    OpenAIRE

    Colombi, Beatriz

    1997-01-01

    Hacia 1900 se nuclea en París un grupo de corresponsales latinoamericanos conformando una suerte de enclave que reúne a figuras como Rubén Darío, Manuel Ugarte, Amado Nervo o Enrique Gómez Carrillo. Desde sus respectivas columnas estos cronistas construyen imágenes del mundo moderno atravesadas por el conflicto de pertenencia y marginalidad respecto al mismo. Este trabajo analiza las entregas que Rubén Darío escribe para La Nación de Buenos Aires durante la Feria Internacional de Paris de 190...

  20. Adolescent Girls with illegally Induced Abortion in Dar es Salaam

    DEFF Research Database (Denmark)

    Rasch, V; Silberschmidt, Margrethe; Mchumvu, Y

    2000-01-01

    This article reports on a study of induced abortion among adolescent girls in Dar es Salaam, Tanzania, who were admitted to a district hospital in Dar es Salaam because of an illegally induced abortion in 1997. In the quantitative part of the study, 197 teenage girls (aged 14-19) were asked...... contraception or condoms though they were also at risk of STDs and HIV. These girls were getting pregnant expecting their boyfriends to marry them, or because they did not think they could become pregnant or failed to use contraception correctly. Most adolescent girls are not aware of the 1994 Tanzanian policy...... adolescent girls....

  1. Tomato seeds maturity detection system based on chlorophyll fluorescence

    Science.gov (United States)

    Li, Cuiling; Wang, Xiu; Meng, Zhijun

    2016-10-01

    Chlorophyll fluorescence intensity can be used as seed maturity and quality evaluation indicator. Chlorophyll fluorescence intensity of seed coats is tested to judge the level of chlorophyll content in seeds, and further to judge the maturity and quality of seeds. This research developed a detection system of tomato seeds maturity based on chlorophyll fluorescence spectrum technology, the system included an excitation light source unit, a fluorescent signal acquisition unit and a data processing unit. The excitation light source unit consisted of two high power LEDs, two radiators and two constant current power supplies, and it was designed to excite chlorophyll fluorescence of tomato seeds. The fluorescent signal acquisition unit was made up of a fluorescence spectrometer, an optical fiber, an optical fiber scaffolds and a narrowband filter. The data processing unit mainly included a computer. Tomato fruits of green ripe stage, discoloration stage, firm ripe stage and full ripe stage were harvested, and their seeds were collected directly. In this research, the developed tomato seeds maturity testing system was used to collect fluorescence spectrums of tomato seeds of different maturities. Principal component analysis (PCA) method was utilized to reduce the dimension of spectral data and extract principal components, and PCA was combined with linear discriminant analysis (LDA) to establish discriminant model of tomato seeds maturity, the discriminant accuracy was greater than 90%. Research results show that using chlorophyll fluorescence spectrum technology is feasible for seeds maturity detection, and the developed tomato seeds maturity testing system has high detection accuracy.

  2. Estimating chlorophyll content from Eucalyptus dunnii leaves by reflectance values

    Directory of Open Access Journals (Sweden)

    João Alexandre Lopes Dranski

    2016-06-01

    Full Text Available This study aimed to estimate photosynthetic pigments contents from leaves of Eucalyptus dunni Maiden based on values of reflectance spectra of red, green and blue colors obtained with a digital color analyzer. We collected fifty leaves from the lower third of the crown of twenty trees including young as well as mature leaves. From each leaf an area of 14 cm2 of the leaf blade was cut in which we measured reflectance values on the red, green and blue spectra with a portable digital colorimeter, obtained relative index of chlorophyll with a SPAD – 502 and determined the content of the chlorophyll a, b, and a + b by classic method of solvent extraction. We submitted the data to multiple linear regression and nonlinear analysis at 5% of error probability. It was evaluated the occurrence of multicollinearity. The negative exponential model resulted in good fit when data from red spectrum was used for chlorophyll a, green spectrum for chlorophyll b and a + b, making possible correlation coefficients between the estimated values and the extracted above 0.85. Except for the chlorophyll a content, the accuracy in estimates of photosynthetic pigments were higher than estimated by the chlorophyll meter, even with linearity between methods. Therefore, it is possible to estimate photosynthetic pigments on E. dunni leaves through values of red and green wavelengths from a digital color analyser.

  3. Structures of chlorophyll catabolites in bananas (Musa acuminata) reveal a split path of chlorophyll breakdown in a ripening fruit.

    Science.gov (United States)

    Moser, Simone; Müller, Thomas; Holzinger, Andreas; Lütz, Cornelius; Kräutler, Bernhard

    2012-08-27

    The disappearance of chlorophyll is a visual sign of fruit ripening. Yet, chlorophyll breakdown in fruit has hardly been explored; its non-green degradation products are largely unknown. Here we report the analysis and structure elucidation of colorless tetrapyrrolic chlorophyll breakdown products in commercially available, ripening bananas (Musa acuminata, Cavendish cultivar). In banana peels, chlorophyll catabolites were found in an unprecedented structural richness: a variety of new fluorescent chlorophyll catabolites (FCCs) and nonfluorescent chlorophyll catabolites (NCCs) were detected. As a rule, FCCs exist only "fleetingly" and are hard to observe. However, in bananas several of the FCCs (named Mc-FCCs) were persistent and carried an ester function at the propionate side-chain. NCCs were less abundant, and exhibited a free propionic acid group, but functional modifications elsewhere. The modifications of NCCs in banana peels were similar to those found in NCCs from senescent leaves. They are presumed to be introduced by enzymatic transformations at the stage of the mostly unobserved, direct FCC-precursors. The observed divergent functional group characteristics of the Mc-FCCs versus those of the Mc-NCCs indicated two major "late" processing lines of chlorophyll breakdown in ripening bananas. The "last common precursor" at the branching point to either the persistent FCCs, or towards the NCCs, was identified as a temporarily abundant "secondary" FCC. The existence of two "downstream" branches of chlorophyll breakdown in banana peels, and the striking accumulation of persistent Mc-FCCs call for attention as to the still-elusive biological roles of the resulting colorless linear tetrapyrroles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Structures of Chlorophyll Catabolites in Bananas (Musa acuminata) Reveal a Split Path of Chlorophyll Breakdown in a Ripening Fruit

    Science.gov (United States)

    Moser, Simone; Müller, Thomas; Holzinger, Andreas; Lütz, Cornelius; Kräutler, Bernhard

    2012-01-01

    Abstract The disappearance of chlorophyll is a visual sign of fruit ripening. Yet, chlorophyll breakdown in fruit has hardly been explored; its non-green degradation products are largely unknown. Here we report the analysis and structure elucidation of colorless tetrapyrrolic chlorophyll breakdown products in commercially available, ripening bananas (Musa acuminata, Cavendish cultivar). In banana peels, chlorophyll catabolites were found in an unprecedented structural richness: a variety of new fluorescent chlorophyll catabolites (FCCs) and nonfluorescent chlorophyll catabolites (NCCs) were detected. As a rule, FCCs exist only "fleetingly" and are hard to observe. However, in bananas several of the FCCs (named Mc-FCCs) were persistent and carried an ester function at the propionate side-chain. NCCs were less abundant, and exhibited a free propionic acid group, but functional modifications elsewhere. The modifications of NCCs in banana peels were similar to those found in NCCs from senescent leaves. They are presumed to be introduced by enzymatic transformations at the stage of the mostly unobserved, direct FCC-precursors. The observed divergent functional group characteristics of the Mc-FCCs versus those of the Mc-NCCs indicated two major "late" processing lines of chlorophyll breakdown in ripening bananas. The "last common precursor" at the branching point to either the persistent FCCs, or towards the NCCs, was identified as a temporarily abundant "secondary" FCC. The existence of two "downstream" branches of chlorophyll breakdown in banana peels, and the striking accumulation of persistent Mc-FCCs call for attention as to the still-elusive biological roles of the resulting colorless linear tetrapyrroles. PMID:22807397

  5. Evaluation of nitrogen status and total chlorophyll in longkong (Aglaia dookkoo Griff. leaves under water stress using a chlorophyll meter

    Directory of Open Access Journals (Sweden)

    Sdoodee, S.

    2005-07-01

    Full Text Available A chlorophyll meter (SPAD-502 was used to assess nitrogen status and total chlorophyll in longkong leaves, leaves from twelve of 10-year-old trees grown in the experimental plot at Prince of Songkla University, Songkhla province. The relationship between SPAD-502 meter reading and nitrogen status and total chlorophyll content analyzed in the laboratory was evaluated during 8 months (May-December 2003. It was found that the trend of the relationships in each month was similar. There was no significant differenceamong regression linears of all months. The data of 8 months showed that SPAD-reading and nitrogen content, and SPAD-reading and total chlorophyll content were related in a positive manner. They were Y = 0.19X+10.10, r = 0.76** (n = 240, and Y = 0.43X-7.89, r = 0.79** (n = 400, respectively. The SPAD-502 was then used to assess total nitrogen and total chlorophyll content during imposed water stress. Fifteen 4-yearold plants were grown in pots (each pot containing 50 kg soil volume. The experiment was arranged in acompletely randomized design with 3 treatments: (1 daily watering (2 once watering on day 7 (3 no watering with 5 replications during 14 days of the experimental period. Measurements showed a continuous decrease of SPAD-reading in the treatment of no watering. On day 14, a significant difference of SPAD- reading values between the treatment of daily watering and no watering was found. Then, the values of nitrogen content and total chlorophyll were assessed by using the linear regression equations. From the result, it is suggested that the measurement by chlorophyll meter is a rapid technique for the evaluation of total chlorophyll and nitrogen status in longkong leaves during water stress.

  6. 2011 U.S. Geological Survey (USGS) Topographic LiDAR: Louisiana Region 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Louisiana Region 1 LiDAR ARRA Task Order LiDAR Data Acquisition and Processing Production Task- Vermillion, Iberia, St. Mary, Terrebonne, and Lafourche...

  7. 2011 U.S. Geological Survey (USGS) Topographic LiDAR: Louisiana Region 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Louisiana Region 2 LiDAR ARRA Task Order LiDAR Data Acquisition and Processing Production Task- Orleans, Plaquemines, St. Bernard, St. Tammany Parishes,...

  8. 2007 US Army Corps of Engineers (USACE), Jacksonville District US Virgin Islands LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Light Detection and Ranging (LiDAR) bare-earth classified LAS dataset is a topographic survey conducted for the USACE USVI LiDAR Project. These data were...

  9. 2004 Federal Emergency Management Agency (FEMA) Bare Earth Topographic LiDAR: Connecticut River

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. The LiDAR files were converted from .PTS format to LAS...

  10. Study on environmental test technology of LiDAR used for vehicle

    Science.gov (United States)

    Wang, Yi; Yang, Jianfeng; Ou, Yong

    2018-03-01

    With the development of intelligent driving, the LiDAR used for vehicle plays an important role in it, in some extent LiDAR is the key factor of intelligent driving. And environmental adaptability is one critical factor of quality, it relates success or failure of LiDAR. This article discusses about the environment and its effects on LiDAR used for vehicle, it includes analysis of any possible environment that vehicle experiences, and environmental test design.

  11. A correlation analysis on chlorophyll content and SPAD value in tomato leaves

    OpenAIRE

    JIANG, Chengyao; JOHKAN, Masahumi; HOHJO, Masaaki; TSUKAGOSHI, Satoru; MATURO, Toru

    2017-01-01

    [Abstract] To investigate relationship between tomato (Solanum lycopersicum) leaf chlorophyll content and Minolta SPAD-502 plus chlorophyll meter, we studied leaves at plant vegetative growth stage and reproductive growth stage, and conducted correlation analysis to establish most optimal function model. The results showed that the correlation of SPAD value and the content of chlorophyll a, chlorophyll b and total chlorophyll content were significantly correlated in tomato leaves. At plant ve...

  12. Chlorophyll b can serve as the major pigment in functional photosystem II complexes of cyanobacteria

    OpenAIRE

    Xu, Hong; Vavilin, Dmitrii; Vermaas, Wim

    2001-01-01

    An Arabidopsis thaliana chlorophyll(ide) a oxygenase gene (cao), which is responsible for chlorophyll b synthesis from chlorophyll a, was introduced and expressed in a photosystem I-less strain of the cyanobacterium Synechocystis sp. PCC 6803. In this strain, most chlorophyll is associated with the photosystem II complex. In line with observations by Satoh et al. [Satoh, S., Ikeuchi, M., Mimuro, M. & Tanaka, A. (2001) J. Biol. Chem. 276, 4293–4297], chlorophyll b was made but accounted for le...

  13. CHLOROPHYLL a FLUORESCENCE ANALYSIS IN FORESTS

    Directory of Open Access Journals (Sweden)

    M. Pollastrini

    2016-03-01

    Full Text Available A European-wide assessment of chlorophyll a fluorescence (ChlF, prompt fluorescence on dark-adapted samples parameters in forest ecosystems was carried out in the years 2012-2013, within the 7FP FunDivEUROPE project. A total of 1596 trees growing in 209 stands distributed in six countries, from Mediterranean to boreal sites, were sampled. This paper shows the applicability of the ChlF in forest ecology surveys, the protocols adopted for leaf sampling and ChlF measurements, the variability of the ChlF parameters within and between trees, their dependence to environmental factors and the relationships with other functional leaf traits. The most relevant findings were as follows: (i The least variable ChlF parameter within and between the trees was the maximum quantum yield of primary photochemistry (FV/FM, whereas the performance indices (PIABS and PITOT showed the highest variability; (ii for a given tree, the ChlF parameters measured at two heights of the crown (top and bottom leaves were correlated and, in coniferous species, the ChlF parameters were correlated between different needle age classes (from the current year and previous year; (iii the ChlF parameters showed a geographical pattern, and the photochemical performance of the forest trees was higher in central Europe than in the edge sites (northernmost and southernmost; and (iv ChlF parameters showed different sensitivity to specific environmental factors: FV/FM increased with the increase of the leaf area index of stands and soil fertility; ΔVIP was reduced under high temperature and drought. The photochemical responses of forest tree species, analyzed with ChlF parameters, were influenced by the ecology of the trees (i.e. their functional groups, continental distribution, successional status, etc., tree species’ richness and composition of the stands. Our results support the applicability and usefulness of the ChlF in forest monitoring investigations on a large spatial scale and

  14. Presentation and management of maxillofacial trauma in Dar es ...

    African Journals Online (AJOL)

    Setting: Department of Oral and Maxillofacial Surgery, Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. ... age, gender, length of interval between injury and presentation to the hospital, aetiology, pattern of soft tissue injury and fractures, therapy, co-morbidity, complications and number of hospitalisation days.

  15. Feeding Dar es Salaam: a symbiotic food system perspective

    NARCIS (Netherlands)

    Wegerif, Marc C.A.

    2017-01-01

    This thesis is a sociological analysis of the agri-food system that feeds most of the over four and a half million residents of the fast-growing city of Dar es Salaam in Tanzania. It is based on qualitative research that has generated a picture of the food system that supplies the important foods

  16. SURVEY OF WOODY FLORA AND FAUNA OF THE BAHIR DAR ...

    African Journals Online (AJOL)

    Abstract: The aim of this project was to survey the flora and fauna of the main campus of. Bahir Dar Vniversity. It was necessary because the university campus is relatively well rehabilitated and it is very important that the composition of the vegetation, the regeneration capacity of the vegetation and the importance of the tree ...

  17. Suicidal ideation among school-attending adolescents in Dar es ...

    African Journals Online (AJOL)

    Background: Suicidal ideation is an understudied risk factor for suicidal intent. The present study investigates the patterns and risk factors for suicidal ideation among a sample of school-attending adolescents in Dar es Salaam, Tanzania. Methods: This study examined secondary data collected in 2006 through the Global ...

  18. Aloe; Beyond use as cosmetics | Pili | Dar Es Salaam Medical ...

    African Journals Online (AJOL)

    Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Aloe; Beyond use as cosmetics. K Pili. Abstract.

  19. Nitrogen concentration estimation with hyperspectral LiDAR

    Directory of Open Access Journals (Sweden)

    O. Nevalainen

    2013-10-01

    Full Text Available Agricultural lands have strong impact on global carbon dynamics and nitrogen availability. Monitoring changes in agricultural lands require more efficient and accurate methods. The first prototype of a full waveform hyperspectral Light Detection and Ranging (LiDAR instrument has been developed at the Finnish Geodetic Institute (FGI. The instrument efficiently combines the benefits of passive and active remote sensing sensors. It is able to produce 3D point clouds with spectral information included for every point which offers great potential in the field of remote sensing of environment. This study investigates the performance of the hyperspectral LiDAR instrument in nitrogen estimation. The investigation was conducted by finding vegetation indices sensitive to nitrogen concentration using hyperspectral LiDAR data and validating their performance in nitrogen estimation. The nitrogen estimation was performed by calculating 28 published vegetation indices to ten oat samples grown in different fertilization conditions. Reference data was acquired by laboratory nitrogen concentration analysis. The performance of the indices in nitrogen estimation was determined by linear regression and leave-one-out cross-validation. The results indicate that the hyperspectral LiDAR instrument holds a good capability to estimate plant biochemical parameters such as nitrogen concentration. The instrument holds much potential in various environmental applications and provides a significant improvement to the remote sensing of environment.

  20. Aggression; a Paradoxical pathology of the mind | Kitapondya | Dar ...

    African Journals Online (AJOL)

    Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Aggression; a Paradoxical pathology of the mind.

  1. Knowledge, attitudes and practice of Bahir Dar University ...

    African Journals Online (AJOL)

    Nowadays environmental problems have become issues of great concern to many parties. However, many people in Ethiopia seem to have low level of environmental knowledge. This study examined environmental awareness and attitudes of Bahir Dar University students. Data were collected from 523 respondents using ...

  2. Assessment on Vulnerable Youths Integration to Dar es Salaam ...

    African Journals Online (AJOL)

    The present study assessed the possibility of integrating vulnerable youths to complement government and community based efforts in improving the existing municipal solid waste management crisis facing Dar es Salaam City using a case study of Kinondoni Municipality. The study was motivated by the fact that, many ...

  3. Dar es Salaam City and Challenges in Solid Waste Management ...

    African Journals Online (AJOL)

    The focus of this paper is on challenges facing solid waste management in. Manzese and Sinza wards, in Dar es Salaam city. In this paper different ways of generating, disposing waste and the associated problems are surveyed. About 102 people were interviewed. Different methods were employed in data collection which ...

  4. Accessibility, Congestion and Travel Delays in Dar es Salaam

    DEFF Research Database (Denmark)

    Melbye, Dea Christine; Møller-Jensen, Lasse; Andreasen, Manja Hoppe

    2015-01-01

    on to present a review of research into travel speed levels and congestion in Dar es Salaam. A set of city-wide maps of accessibility and delay levels are constructed based on available speed data and road network data obtained from the OpenStreetMap project and the findings are discussed with respect...

  5. Heavy Metals and Organic Pollutants in Sediments of Dar es ...

    African Journals Online (AJOL)

    The Florida criteria (MacDonald 1993) for assessment of pollution of tropical marine sediments was adopted in oredr to evaluate the extent of pollution in Dar es Salaam harbour sediments. The Florida criteria is one of the established references for sediment quality assessment. Heavy metals that had concentrations above ...

  6. Engineering geological mapping of Dar es Salaam city, Tanzania ...

    African Journals Online (AJOL)

    Two basic maps were prepared, namely, geomorphological and geological map depicts the spatial extent of the Neogene geological formations. Three distinct sandstone terraces could be distinguished in Dar es Salaam region at 0-15 m and 30 – 40 m above sea level. The terraces comprised sandstones fringed by coral ...

  7. Charcoal Supply In Dar Es Salaam City, Tanzania | Malimbwi ...

    African Journals Online (AJOL)

    In Tanzania, charcoal is the primary source of energy particularly in urban areas. Dar es Salaam, being the largest urban center in the country, is also the largest consumer of charcoal. Assuming that all charcoal transported in the city is consumed, an investigation to estimate the amount of charcoal supplied daily was ...

  8. International Journal of Science and Technology (STECH) Bahir Dar ...

    African Journals Online (AJOL)

    Nneka Umera-Okeke

    International Journal of Science and Technology. (STECH). Bahir Dar- Ethiopia. Vol. 6 (1) ... Logic studies the relation of propositions in order to ascertain the relation of entailment, which ultimately leads to the relation of truth ...... Filosofika: University of. Port Harcourt Journal of Philosophy and Public Affairs. 1.1 (2014): 96 –.

  9. Community violence in Dar es Salaam, Tanzania: A mixed methods ...

    African Journals Online (AJOL)

    Most homicide deaths in Dar es Salaam, Tanzania (DSM) are a result of violence arising from within the community. This type of violence is commonly called, by perpetrators and victims, “mob justice”. Unilateral non-state collective violence can take four forms: lynching, vigilantism, rioting, and terrorism. The purpose of this ...

  10. Knowledge, Attitude and Practice of Commercial Drivers in Dar es ...

    African Journals Online (AJOL)

    Purpose: The objective of this study was, first, to assess the knowledge, attitude and practice of commercial drivers in Dar es Salaam with regard to medicines that impair driving, and second, to evaluate the adequacy of antihistamine label information. Methods: Drivers were interviewed using a questionnaire after obtaining ...

  11. Aloe; Beyond use as cosmetics | Pili | Dar Es Salaam Medical ...

    African Journals Online (AJOL)

    Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

  12. Performance Analysis of Throughput at Bahir Dar University LAN ...

    African Journals Online (AJOL)

    Computer scientists and network users have discovered that standard TCP does not perform well in high bandwidth delay environments. As a model, the Local Area Network of Bahir Dar University Engineering Faculty was tested and reported. . In this paper, we explore the challenges of achieving high throughput over real ...

  13. Coastal Marine Pollution in Dar es Salaam (Tanzania) relative to ...

    African Journals Online (AJOL)

    Abstract—Pollution surveys were undertaken during 2007 and 2008 in the coastal marine environment of Dar es Salaam and the remote Ras Dege. Creek. The objective was to determine the levels of microbial contamination, heavy metals and persistent organic pollutants and compare these with the recommended ...

  14. Case Report: Congenital Biliary Atresia | Gulamabbas | Dar Es ...

    African Journals Online (AJOL)

    Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Case Report: Congenital Biliary Atresia.

  15. Case Report: Congenital Biliary Atresia | Gulamabbas | Dar Es ...

    African Journals Online (AJOL)

    Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

  16. Modeling low-height vegetation with airborne LiDAR

    Science.gov (United States)

    Low-height vegetation, common in semiarid regions, is difficult to characterize with LiDAR (Light Detection and Ranging) due to similarities, in time and space, of the point returns of vegetation and ground. Other complications may occur due to the low-height vegetation structural characteristics a...

  17. Coastal Marine Pollution in Dar es Salaam (Tanzania) relative to ...

    African Journals Online (AJOL)

    Pollution surveys were undertaken during 2007 and 2008 in the coastal marine environment of Dar es Salaam and the remote Ras Dege Creek. The objective was to determine the levels of microbial contamination, heavy metals and persistent organic pollutants and compare these with the recommended environmental ...

  18. Quantifying Ladder Fuels: A New Approach Using LiDAR

    Science.gov (United States)

    Heather Kramer; Brandon Collins; Maggi Kelly; Scott Stephens

    2014-01-01

    We investigated the relationship between LiDAR and ladder fuels in the northern Sierra Nevada, California USA. Ladder fuels are often targeted in hazardous fuel reduction treatments due to their role in propagating fire from the forest floor to tree crowns. Despite their importance, ladder fuels are difficult to quantify. One common approach is to calculate canopy base...

  19. 2011 USGS Topographic LiDAR: Suwannee River Expansion

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — USGS Task Order No. G10PD00236 USGS Contract No. G10PC00093 The Light Detection and Ranging (LiDAR) dataset is a survey of the Suwannee River Expansion in...

  20. History of diagnosis of cardiovascular diseases | Lubinza | Dar Es ...

    African Journals Online (AJOL)

    Dar Es Salaam Medical Students' Journal. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 2 (2012) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

  1. Relationship between LiDAR-derived forest canopy height and Landsat images

    Science.gov (United States)

    Cristina Pascual; Antonio Garcia-Abril; Warren B. Cohen; Susana. Martin-Fernandez

    2010-01-01

    The mean and standard deviation (SD) of light detection and ranging (LiDAR)-derived canopy height are related to forest structure. However, LiDAR data typically cover a limited area and have a high economic cost compared with satellite optical imagery. Optical images may be required to extrapolate LiDAR height measurements across a broad landscape. Different spectral...

  2. Demystifying LiDAR technologies for temperate rainforest in the Pacific Northwest

    Science.gov (United States)

    Rhonda Mazza; Demetrios Gatziolis

    2013-01-01

    Light detection and ranging (LiDAR), also known as airborne laser scanning, is a rapidly emerging technology for remote sensing. Used to help map, monitor, and assess natural resources, LiDAR data were first embraced by forestry professionals in Scandinavia as a tool for conducting forest inventories in the mid to late 1990s. Thus early LiDAR theory and applications...

  3. Three-dimensional canopy fuel loading predicted using upward and downward sensing LiDAR systems

    Science.gov (United States)

    Nicholas S. Skowronski; Kenneth L. Clark; Matthew Duveneck; John. Hom

    2011-01-01

    We calibrated upward sensing profiling and downward sensing scanning LiDAR systems to estimates of canopy fuel loading developed from field plots and allometric equations, and then used the LiDAR datasets to predict canopy bulk density (CBD) and crown fuel weight (CFW) in wildfire prone stands in the New Jersey Pinelands. LiDAR-derived height profiles were also...

  4. A multiscale curvature algorithm for classifying discrete return LiDAR in forested environments

    Science.gov (United States)

    Jeffrey S. Evans; Andrew T. Hudak

    2007-01-01

    One prerequisite to the use of light detection and ranging (LiDAR) across disciplines is differentiating ground from nonground returns. The objective was to automatically and objectively classify points within unclassified LiDAR point clouds, with few model parameters and minimal postprocessing. Presented is an automated method for classifying LiDAR returns as ground...

  5. Chlorophyll biosynthesis and assembly into chlorophyll-protein complexes in isolated developing chloroplasts

    International Nuclear Information System (INIS)

    Bhaya, D.; Castelfranco, P.A.

    1985-01-01

    Isolated developing plastids from greening cucumber cotyledons or from photoperiodically grown pea seedlings incorporated 14 C-labeled 5-aminolevulinic acid (ALA) into chlorophyll (Chl). Incorporation was light dependent, enhanced by S-adenosylmethionine, and linear for 1 hr. The in vitro rate of Chl synthesis from ALA was comparable to the in vivo rate of Chl accumulation. Levulinic acid and dioxoheptanoic acid strongly inhibited Chl synthesis but not plastid protein synthesis. Neither chloramphenicol nor spectinomycin affected Chl synthesis, although protein synthesis was strongly inhibited. Components of thylakoid membranes from plastids incubated with [ 14 C]ALA were resolved by electrophoresis and then subjected to autoradiography. This work showed that (i) newly synthesized Chl was assembled into Chl-protein complexes and (ii) the inhibition of protein synthesis during the incubation did not alter the labeling pattern. Thus, there was no observable short-term coregulation between Chl synthesis (from ALA) and the synthesis of membrane proteins in isolated plastids

  6. APPLICATION OF MODULATED CHLOROPHYLL FLUORESCENCE AND MODULATED CHLOROPHYLL FLUORESCENCE IMAGING IN STUDYING ENVIRONMENTAL STRESSES EFFECT

    Directory of Open Access Journals (Sweden)

    L. Guidi

    2016-03-01

    Full Text Available Chlorophyll (Chl a fluorescence is a widely used tool to monitor the photosynthetic process in plants subjected to environmental stresses.this review reports the theoretical bases of Chl fluorescence, and the significance of the most important Chl fluorescence parameters. it also reportshow these parameters can be utilised to estimate changes in photosystem ii (PSII photochemistry, linear electron flux and energy dissipationmechanisms. the relation between actual PSII photochemistry and CO2 assimilation is discussed, as is the role of photochemical andnon-photochemical quenching in inducing changes in PSII activity. the application of Chl fluorescence imaging to study heterogeneity on leaflamina is also considered. this review summarises only some of the results obtained by this methodology to study the effects of differentenvironmental stresses, namely water and nutrients availability, pollutants, temperature and salinity.

  7. Participation of Chlorophyll b Reductase in the Initial Step of the Degradation of Light-harvesting Chlorophyll a/b-Protein Complexes in Arabidopsis*

    Science.gov (United States)

    Horie, Yukiko; Ito, Hisashi; Kusaba, Makoto; Tanaka, Ryouichi; Tanaka, Ayumi

    2009-01-01

    The light-harvesting chlorophyll a/b-protein complex of photosystem II (LHCII) is the most abundant membrane protein in green plants, and its degradation is a crucial process for the acclimation to high light conditions and for the recovery of nitrogen (N) and carbon (C) during senescence. However, the molecular mechanism of LHCII degradation is largely unknown. Here, we report that chlorophyll b reductase, which catalyzes the first step of chlorophyll b degradation, plays a central role in LHCII degradation. When the genes for chlorophyll b reductases NOL and NYC1 were disrupted in Arabidopsis thaliana, chlorophyll b and LHCII were not degraded during senescence, whereas other pigment complexes completely disappeared. When purified trimeric LHCII was incubated with recombinant chlorophyll b reductase (NOL), expressed in Escherichia coli, the chlorophyll b in LHCII was converted to 7-hydroxymethyl chlorophyll a. Accompanying this conversion, chlorophylls were released from LHCII apoproteins until all the chlorophyll molecules in LHCII dissociated from the complexes. Chlorophyll-depleted LHCII apoproteins did not dissociate into monomeric forms but remained in the trimeric form. Based on these results, we propose the novel hypothesis that chlorophyll b reductase catalyzes the initial step of LHCII degradation, and that trimeric LHCII is a substrate of LHCII degradation. PMID:19403948

  8. The Effect of Terbacil on Chlorophyll Content of Strawberry (Fragaria × ananassa cv. ‘Honeoye’) Leaves

    OpenAIRE

    A. Z. Makaraci; J. A. Flore

    2006-01-01

    In this research terbacil was used as a tool to study chlorophyll regeneration in strawberry (Fragaria × ananassa cv. ‘Honeoye’) leaves. Strawberry plants which are in two different growth stages (During fruit set and after harvest) were applied with 50, 100 and 200 ppm terbacil. Chlorophyll a, chlorophyll b, proto-chlorophyll and total chlorophyll contents were measured with 4 days of intervals up to 16 days. Chlorophyll a and total chlorophyll content decreased within 4 days of terbacil app...

  9. Modelling ocean-colour-derived chlorophyll a

    Science.gov (United States)

    Dutkiewicz, Stephanie; Hickman, Anna E.; Jahn, Oliver

    2018-01-01

    This article provides a proof of concept for using a biogeochemical/ecosystem/optical model with a radiative transfer component as a laboratory to explore aspects of ocean colour. We focus here on the satellite ocean colour chlorophyll a (Chl a) product provided by the often-used blue/green reflectance ratio algorithm. The model produces output that can be compared directly to the real-world ocean colour remotely sensed reflectance. This model output can then be used to produce an ocean colour satellite-like Chl a product using an algorithm linking the blue versus green reflectance similar to that used for the real world. Given that the model includes complete knowledge of the (model) water constituents, optics and reflectance, we can explore uncertainties and their causes in this proxy for Chl a (called derived Chl a in this paper). We compare the derived Chl a to the actual model Chl a field. In the model we find that the mean absolute bias due to the algorithm is 22 % between derived and actual Chl a. The real-world algorithm is found using concurrent in situ measurement of Chl a and radiometry. We ask whether increased in situ measurements to train the algorithm would improve the algorithm, and find a mixed result. There is a global overall improvement, but at the expense of some regions, especially in lower latitudes where the biases increase. Not surprisingly, we find that region-specific algorithms provide a significant improvement, at least in the annual mean. However, in the model, we find that no matter how the algorithm coefficients are found there can be a temporal mismatch between the derived Chl a and the actual Chl a. These mismatches stem from temporal decoupling between Chl a and other optically important water constituents (such as coloured dissolved organic matter and detrital matter). The degree of decoupling differs regionally and over time. For example, in many highly seasonal regions, the timing of initiation and peak of the spring bloom in

  10. 2005 Mississippi Merged LiDAR Data (2005 LiDAR data merged with 2005 Post-Katrina LiDAR data to create a bare-earth product for flood plain mapping in coastal Mississippi).

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pre- and post-hurricane Katrina LiDAR datasets of Hancock, Harrison, and Jackson Counties, MS, were merged into a seamless coverage by URS. The pre-Katrina LiDAR...

  11. Optimal leaf positions for chlorophyll meter measurement in rice

    Directory of Open Access Journals (Sweden)

    Zhaofeng eYuan

    2016-05-01

    Full Text Available The Soil Plant Analysis Development (SPAD chlorophyll meter is one of the most commonly used diagnostic tools to measure crop nitrogen status. However, the measurement method of the meter could significantly affect the accuracy of the final estimation. Thus, this research was undertaken to develop a new methodology to optimize SPAD meter measurements in rice (Oryza sativa L.. A flatbed color scanner was used to map the dynamic chlorophyll distribution and irregular leaf shapes. Calculus algorithm was adopted to estimate the potential positions for SPAD meter measurement along the leaf blade. Data generated by the flatbed color scanner and SPAD meter were analysed simultaneously. The results suggested that a position 2/3 of the distance from the leaf base to the apex (2/3 position could represent the chlorophyll content of the entire leaf blade, as indicated by the relatively low variance of measurements at that positon. SPAD values based on di-positional leaves and the extracted chlorophyll a and b contents were compared. This comparison showed that the 2/3 position on the lower leaves tended to be more sensitive to changes in chlorophyll content. Finally, the 2/3 position and average SPAD values of the fourth fully expanded leaf from the top were compared with leaf nitrogen concentration. The results showed the 2/3 position on that leaf was most suitable for predicting the nitrogen status of rice. Based on these results, we recommend making SPAD measurements at the 2/3 position on the fourth fully expanded leaf from the top. The coupling of dynamic chlorophyll distribution and irregular leaf shapes information can provide a promising approach for the calibration of SPAD meter measurement, which can further benefit the in situ nitrogen management by providing reliable estimation of crops nitrogen nutrition status.

  12. Investigation into robust spectral indices for leaf chlorophyll estimation

    CSIR Research Space (South Africa)

    Main, R

    2011-11-01

    Full Text Available were extracted in 100% acetone. The extract was then spun in a micro centrifuge to precipitate the cell debris. The absorbance (A) of the samples was measured at 661.2 nm (for chlorophyll a) and 644.8 nm (for chlorophyll b) by the Ultra Violet...-1198 Ustin, S.L. Gitelson, A. A., Jacquemoud, S., Schaepman, M., Asner, G.P., Gamon, J. A., Zarco- Tejada, P. J., 2009. Retrieval of foliar information about plant pigment systems from high resolution spectroscopy. Remote Sensing of Environment 113 (1...

  13. Ecology: a niche for cyanobacteria containing chlorophyll d

    DEFF Research Database (Denmark)

    Kühl, Michael; Chen, Min; Ralph, Peter J

    2005-01-01

    The cyanobacterium known as Acaryochloris marina is a unique phototroph that uses chlorophyll d as its principal light-harvesting pigment instead of chlorophyll a, the form commonly found in plants, algae and other cyanobacteria; this means that it depends on far-red light for photosynthesis. Here...... we demonstrate photosynthetic activity in Acaryochloris-like phototrophs that live underneath minute coral-reef invertebrates (didemnid ascidians) in a shaded niche enriched in near-infrared light. This discovery clarifies how these cyanobacteria are able to thrive as free-living organisms...

  14. PHOTODEGRADATION AND ANTIOXIDANT ACTIVITY OF CHLOROPHYLL a FROM SPIRULINA (Spirulina sp. POWDER

    Directory of Open Access Journals (Sweden)

    Rebecca Christiana

    2010-06-01

    Full Text Available Research on chlorophyll a from Spirulina (Spirulina sp. powder has been done in order to determine chlorophyll a content, to compare degradation pattern and kinetics degradation of chlorophyll a and crude extract as well as to investigate the difference of antioxidant activity of chlorophyll a with or without irradiation. Chlorophyll a content in spirulina powder was calculated by using Porra's equation. Irradiation and recovery ability of chlorophyll a were measured by using volpi light (Intralux 6100 equipped with daylight filter. The antioxidant activity of chlorophyll a was determined by using DPPH method. The results showed that chlorophyll a content was 2.886 μg/g dry weight. Chlorophyll a has the higher stability than crude extract against 60 minutes irradiation at room temperature. Kinetics degradation of chlorophyll a was based on second order while crude extract based on first order. Chlorophyll a and crude extract have recovery ability. The results also showed that antioxidant activity of chlorophyll a was increased after 60 minutes of irradiation.   Keywords: antioxidant activity, chlorophyll a, photodegradation, spirulina powder

  15. Rockfall hazard analysis using LiDAR and spatial modeling

    Science.gov (United States)

    Lan, Hengxing; Martin, C. Derek; Zhou, Chenghu; Lim, Chang Ho

    2010-05-01

    Rockfalls have been significant geohazards along the Canadian Class 1 Railways (CN Rail and CP Rail) since their construction in the late 1800s. These rockfalls cause damage to infrastructure, interruption of business, and environmental impacts, and their occurrence varies both spatially and temporally. The proactive management of these rockfall hazards requires enabling technologies. This paper discusses a hazard assessment strategy for rockfalls along a section of a Canadian railway using LiDAR and spatial modeling. LiDAR provides accurate topographical information of the source area of rockfalls and along their paths. Spatial modeling was conducted using Rockfall Analyst, a three dimensional extension to GIS, to determine the characteristics of the rockfalls in terms of travel distance, velocity and energy. Historical rockfall records were used to calibrate the physical characteristics of the rockfall processes. The results based on a high-resolution digital elevation model from a LiDAR dataset were compared with those based on a coarse digital elevation model. A comprehensive methodology for rockfall hazard assessment is proposed which takes into account the characteristics of source areas, the physical processes of rockfalls and the spatial attribution of their frequency and energy.

  16. LIF LiDAR high resolution ground truth data, suitable to validate medium-resolution bands of MODIS/Terra radiometer in case of inner waterbody ecological monitoring

    Science.gov (United States)

    Pelevin, Vadim; Zavialov, Peter; Zlinszky, Andras; Khimchenko, Elizaveta; Toth, Viktor; Kremenetskiy, Vyacheslav

    2017-04-01

    The report is based on field measurements on the lake Balaton (Hungary) in September 2008 as obtained by Light Induced Fluorescence (LIF) portable LiDAR UFL-8. It was tested in natural lake waters and validated by contact conventional measurements. We had opportunity to compare our results with the MODIS/Terra spectroradiometer satellite images received at the satellite monitoring station of the Eötvös Loránd University (Budapest, Hungary) to make an attempt of lidar calibration of satellite medium-resolution bands data. Water quality parameters were surveyed with the help of UFL-8 in a time interval very close to the satellite overpass. High resolution maps of the chlorophyll-a, chromophoric dissolved organic matter and total suspended sediments spatial distributions were obtained. Our results show that the resolution provided by laboratory measurements on a few water samples does not resemble actual conditions in the lake, and it would be more efficient to measure these parameters less accurately but in a better spatial distribution with the LiDAR. The UFL instrument has a great potential for being used for collecting ground truth data for satellite remote sensing of these parameters. Its measurement accuracy is comparable to classic water sample measurements, the measurement speed is high and large areas can be surveyed in a time interval very close to the satellite overpass.

  17. Chlorophyll as a measure of plant health: Agroecological aspects

    Directory of Open Access Journals (Sweden)

    Danijela Pavlović

    2014-03-01

    Full Text Available As photosynthesis is the basic process during which light energy is absorbed and converted into organic matter, the importance of the plant pigment chlorophyll (a and b forms as an intermediary in transformation of the absorbed solar energy and its activity in the process of photosynthesis and synthesis of organic substances in plants are crucial. Therefore, this paper provides an overview of methods for monitoring the optical activity of chlorophyll molecules and methods (non-destructive and destructive for quantification of chlorophyll in plants. These methods are used to estimate the effects of different stress factors (abiotic, biotic and xenobiotic on the efficiency of photosynthesis and bioproductivity, aiming to assess the impact that these limiting factors have on the yield of various cultivars. Also, those methods for analysis of chlorophyll optical activity and/or content are appropriate for assessing the reaction of weed species to different agricultural practices (mineral nutrition, treatment by herbicides, etc. and studies of different aspects of weed ecophysiology and their influence on crop harvest.

  18. Chlorophyll, nitrogen and antioxidant activities in Cumaru ( Dipteryx ...

    African Journals Online (AJOL)

    ... by traditional populations and industries using timber and non-timber forest products. This study aimed to analyze the levels of chlorophyll A, B, total ammonia levels, nitrate, proline, electrolyte leakage and activity of oxidative enzymes in evaluation to tolerance of cumaru plants subjected to drought for 21 days of stress.

  19. Using chlorophyll fluorescence to determine stress in Eucalyptus ...

    African Journals Online (AJOL)

    Using chlorophyll fluorescence to determine stress in Eucalyptus grandis seedlings: scientific paper. ... Southern Forests: a Journal of Forest Science ... factors affect the functioning of the photosynthetic system, the status of the photosynthetic apparatus is a good indicator of the plant in terms of stress and stress adaptation.

  20. Endolithic chlorophyll d-containing phototrophs

    DEFF Research Database (Denmark)

    Behrendt, Lars; Larkum, Anthony W D; Norman, Anders

    2011-01-01

    Cyanobacteria in the genus Acaryochloris are the only known oxyphototrophs that have exchanged chlorophyll a (Chl a) with Chl d as their primary photopigment, facilitating oxygenic photosynthesis with near infrared (NIR) light. Yet their ecology and natural habitats are largely unknown. We used h...

  1. Boron, zinc and microtone effects on growth, chlorophyll contents ...

    African Journals Online (AJOL)

    The micronutrient required in minute quantity and their deficiency leads to diminished growth and yield of crops. The effect of soil application of Zinc (Zn), Boron (B) and Microtone (MT) on growth, chlorophyll contents, mineral profile and yield components were investigated in rice at Chakkanwali Reclamation Research ...

  2. Effects of copper stress on antioxidative enzymes, chlorophyll and ...

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... Our study showed the effect of Cu on Atriplex halimus grown in hydroponics conditions. The aim of this work was to investigate some enzymatic systems response of this plant to copper stress. Analysis was carried on enzymatic profiles, protein tenor and chlorophyll content of A. halimus leaves. Two.

  3. The magnesium chelation step in chlorophyll biosynthesis. Progress report 1993

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, J.D.

    1993-12-31

    Progress is reported on the identification and fractionation of Magnesium chealatase, an enzyme involved in addition of Mg to chlorophyll during the later`s biosynthesis. Progress is documented as a series of synopsis of published and unpublished papers by the author.

  4. Antioxidants and chlorophyll content of blanched vegetables stored ...

    African Journals Online (AJOL)

    The fresh leaves of 'Tete' (Amaranthus hybridus) and 'Soko' (Celosia argentea) were blanched and stored in the freezer at the temperature of -10oC±2oC where there was 8hours (day) and 5hours (night) electric power supply to the freezer. The antioxidant (Vitamin C, total phenol and reducing power) and chlorophyll a and ...

  5. Effects of storage conditions on chlorophyll content in diploid black ...

    African Journals Online (AJOL)

    Within this research it is critical to have reliable and affordable methods to identify the polyploids from the normal diploid material, one such method identified is using chlorophyll content. A practical limitation of this method is that many of the samples being tested are in the field and away from the laboratory and thus ...

  6. TEMPERATURE EFFECTS ON CHLOROPHYLL FLUORESCENCE INDUCTION IN TOMATO

    NARCIS (Netherlands)

    JANSSEN, LHJ; VANHASSELT, PR

    Chlorophyll fluorescence induction of tomato leaf discs was measured at a low actinic light intensity of 10 mu mol.m(-2).s(-1) and at decreasing temperatures from 30 degrees to 0 degrees C. F-o remained constant within the temperature range assessed. In contrast, the peak of fluorescence induction,

  7. Photoinduced electron transfer of chlorophyll in lipid bilayer system

    Indian Academy of Sciences (India)

    Unknown

    Chlorophyll-a was extracted from fresh spinach leaves by the conventional method. Its purity was determined to be 96% from its extinction coefficient in diethyl ether at 660 nm vs the literature value of 8⋅6 × 104 M–1 cm–1.10 Dipalmitoylphosphatidylcholine (DPPC) was purchased from Sigma Chemical Co. and was used ...

  8. Covalently stabilized self-assembled chlorophyll nanorods by olefin metathesis.

    Science.gov (United States)

    Sengupta, Sanchita; Würthner, Frank

    2012-06-11

    A new chlorophyll derivative with peripheral olefinic chains has been synthesised and its self-assembly properties have been studied, revealing formation of well-defined nanorods. These nanorods were stabilized and rigidified by olefin metathesis reaction as confirmed by spectroscopic and microscopic methods.

  9. Chlorophyll meter reading and total nitrogen content applied as ...

    African Journals Online (AJOL)

    The present study was aimed to assess the relationship between the reading of the chlorophyll meter and the total nitrogen (N) content in the leaf in different parts of the crambe plant, depending on the doses of nitrogen applied to the canopy. Randomized block design in a split plot experimental design was used. The plots ...

  10. Improved ocean chlorophyll estimate from remote sensed data: The ...

    African Journals Online (AJOL)

    0000

    ocean chlorophyll, expressed the need for further work to be done in order to obtain improved results. One problem ... Key words: Satellite, in-situ, sea-WiFS, blending, corrector factor, pseudozeroes, noisy data, kernel smoothing. INTRODUCTION ...... is one of the most important components in the formation of the ocean life ...

  11. Effects of copper stress on antioxidative enzymes, chlorophyll and ...

    African Journals Online (AJOL)

    Our study showed the effect of Cu on Atriplex halimus grown in hydroponics conditions. The aim of this work was to investigate some enzymatic systems response of this plant to copper stress. Analysis was carried on enzymatic profiles, protein tenor and chlorophyll content of A. halimus leaves. Two months after sowing, ...

  12. Chlorophyll Fluorescence Imaging Uncovers Photosynthetic Fingerprint of Citrus Huanglongbing

    Directory of Open Access Journals (Sweden)

    Haiyan Cen

    2017-08-01

    Full Text Available Huanglongbing (HLB is one of the most destructive diseases of citrus, which has posed a serious threat to the global citrus production. This research was aimed to explore the use of chlorophyll fluorescence imaging combined with feature selection to characterize and detect the HLB disease. Chlorophyll fluorescence images of citrus leaf samples were measured by an in-house chlorophyll fluorescence imaging system. The commonly used chlorophyll fluorescence parameters provided the first screening of HLB disease. To further explore the photosynthetic fingerprint of HLB infected leaves, three feature selection methods combined with the supervised classifiers were employed to identify the unique fluorescence signature of HLB and perform the three-class classification (i.e., healthy, HLB infected, and nutrient deficient leaves. Unlike the commonly used fluorescence parameters, this novel data-driven approach by using the combination of the mean fluorescence parameters and image features gave the best classification performance with the accuracy of 97%, and presented a better interpretation for the spatial heterogeneity of photochemical and non-photochemical components in HLB infected citrus leaves. These results imply the potential of the proposed approach for the citrus HLB disease diagnosis, and also provide a valuable insight for the photosynthetic response to the HLB disease.

  13. Nodulation, chlorophyll content and nitrogen yield of two woody ...

    African Journals Online (AJOL)

    Two field studies were conducted at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife, Nigeria between 2000 and 2002 to compare the growth, nodulation, chlorophyll content and nitrogen accumulation of Leucaena leucocephala (Lam) de Wit cv. 28 and Gliricidia sepium (Jacq.) Walp cv. ILG50 at the ...

  14. Application of a chlorophyll index derived from satellite data to ...

    African Journals Online (AJOL)

    Application of a chlorophyll index derived from satellite data to investigate the variability of phytoplankton in the Benguela ecosystem. H Demarcq, R Barlow, L Hutchings. Abstract. No Abstract. African Journal of Marine Science Vol.29(2) 2007: pp. 271-282. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD ...

  15. Effect of temperature on accumulation of chlorophylls and leaf ...

    African Journals Online (AJOL)

    White young shoots from albino tea cultivars have high level of amino acids and are rare and valuable materials for processing green tea. The effects of temperature on leaf colour, accumulation of chlorophylls and leaf ultrastructures of an albino tea cultivar 'Xiaxueya' were investigated. The study showed that the shoot ...

  16. Chlorophyll modulation of mixed layer thermodynamics in a mixed ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 111; Issue 3. Chlorophyll modulation of mixed layer thermodynamics in a mixed-layer isopycnal General Circulation Model - An example from Arabian Sea and equatorial Pacific. S Nakamoto S Prasanna Kumar J M Oberhuber H Saito K Muneyama R Frouin.

  17. Effects of bisphenol A on chlorophyll fluorescence in five plants.

    Science.gov (United States)

    Zhang, Jiazhi; Wang, Lihong; Li, Man; Jiao, Liya; Zhou, Qing; Huang, Xiaohua

    2015-11-01

    The aim of this study was to evaluate the effects of bisphenol A (BPA) on plant photosynthesis and determine whether the photosynthetic response to BPA exposure varies in different plants. Chlorophyll fluorescence techniques were used to investigate the effects of BPA on chlorophyll fluorescence parameters in tomato (Lycopersicum esculentum), lettuce (Lactuca sativa), soybean (Glycine max), maize (Zea mays), and rice (Oryza sativa) seedlings. Low-dose (1.5 or 3.0 mg L(-1)) BPA exposure improved photosystem II efficiency, increased the absorption and conversion efficiency of primary light energy, and accelerated photosynthetic electron transport in each plant, all of which increased photosynthesis. These effects weakened or disappeared after the withdrawal of BPA. High-dose (10.0 mg L(-1)) BPA exposure damaged the photosystem II reaction center, inhibited the photochemical reaction, and caused excess energy to be released as heat. These effects were more evident after the highest BPA dose (17.2 mg L(-1)), but they weakened after the withdrawal of BPA. The magnitude of BPA exposure effects on the chlorophyll fluorescence parameters in the five plants followed the order: lettuce > tomato > soybean > maize > rice. The opposite order was observed following the removal of BPA. In conclusion, the chlorophyll fluorescence response in plants exposed to BPA depended on BPA dose and plant species.

  18. Validation of OCM-2 sensor performance in retrieving chlorophyll ...

    Indian Academy of Sciences (India)

    The Chlorophyll and Total Suspended Matter (TSM) data retrieved from Ocean Colour Monitor (OCM-2) onboard Oceansat-2 were tested for the accuracy using in-situ measurements made along the southwest Bay of Bengal coast during cruises and monthly samplings synchronized with satellite overpass from January ...

  19. Laser-Induced Breakdown Spectroscopy and Chlorophyll a Flourescence Transients

    DEFF Research Database (Denmark)

    Frydenvang, Jens

    of a sufficient quality; something that remains a problem for many in-situ methods. In my PhD, I present my work with two such in-situ methods, Laser-Induced Breakdown Spectroscopy (LIBS) and OJIP transients, the rising part of chlorophyll a fluorescence transients from dark-adapted leaves....

  20. Leaf Chlorophyll Content and Tuberous Root Yield of Cassava in ...

    African Journals Online (AJOL)

    Two field trials were established in 1996 and 1997 to assess genotypic variability of four cassava (Manihot esculanta) cultivars for adaptability in the inland valley in terms of leaf chlorophyll content and tuberous root yield, using a 4 x 4 Latin square design with four replications arranged along the toposequence.

  1. Chlorophyll a fluorescence and herbicide efficacy, metabolism and selectivity

    DEFF Research Database (Denmark)

    Abbas Poor, Majid

    Analysis of chlorophyll fluorescence induction curve (Kautsky curve) parameters was used for the study of the efficacy, metabolism and selectivity of ACCase, PSII and EPSPS inhibitors. Fv/Fm, Fvj and area above Kautsky curve and maximum fluorescence were selected among numerous fluorescence...

  2. Mahalanobis distance screening of Arabidopsis mutants with chlorophyll fluorescence

    Czech Academy of Sciences Publication Activity Database

    Codrea, C. C.; Hakala-Yatkin, M.; Karlund-Marttila, A.; Nedbal, Ladislav; Aittokallio, T.; Nevalainen, O. S.; Tyystjärvi, E.

    2010-01-01

    Roč. 105, č. 3 (2010), s. 273-283 ISSN 0166-8595 Institutional research plan: CEZ:AV0Z60870520 Keywords : arabidopsis thaliana * chlorophyll fluorescence * fluorescence imaging * mutant detection * outlier detection Subject RIV: EH - Ecology, Behaviour Impact factor: 2.410, year: 2010 http://www.springerlink.com/content/x3586512462pn006/

  3. Measurement of Sun Induced Chlorophyll Fluorescence Using Hyperspectral Satellite Imagery

    Science.gov (United States)

    Irteza, S. M.; Nichol, J. E.

    2016-06-01

    Solar Induced Chlorophyll Fluorescence (SIF), can be used as an indicator of stress in vegetation. Several scientific approaches have been made and there is considerable evidence that steady state Chlorophyll fluorescence is an accurate indicator of plant stress hence a reliable tool to monitor vegetation health status. Retrieval of Chlorophyll fluorescence provides an insight into photochemical and carbon sequestration processes within vegetation. Detection of Chlorophyll fluorescence has been well understood in the laboratory and field measurement. Fluorescence retrieval methods were applied in and around the atmospheric absorption bands 02B (Red wavelength) approximately 690 nm and 02A (Far red wavelengths) 740 nm. Hyperion satellite images were acquired for the years 2012 to 2015 in different seasons. Atmospheric corrections were applied using the 6S Model. The Fraunhofer Line Discrimanator (FLD) method was applied for retrieval of SIF from the Hyperion images by measuring the signal around the absorption bands in both vegetated and non vegetated land cover types. Absorption values were extracted in all the selected bands and the fluorescence signal was detected. The relationships between NDVI and Fluorescence derived from the satellite images are investigated to understand vegetation response within the absorption bands.

  4. Effect of organic and inorganic fertilizer on yield and chlorophyll ...

    African Journals Online (AJOL)

    The effects of amending soil with organic (poultry manure) and inorganic fertilizer on yield and chlorophyll content of maize (Zea mays L.) and sorghum (Sorghum bicolour (L.) Moench) was carried out at the Teaching and Research (T&R) Farm of the Obafemi Awolowo University, (O.A.U.) Ile - Ife, Nigeria. The experiment ...

  5. Optically induced thermal response of Chlorophyll for biomedical applications

    Science.gov (United States)

    Tu, Chiawei; Md Ehsan, Sadat; Zhao, Yuan; Shi, Donglu; Mast, David

    The heating behavior of Chlorophyll was investigated for possible use in hyperthermia cancer treatments. One measure of hyperthermia effectiveness is the Specific Absorption Rate (SAR) defined as the initial slope of the sample heating behavior, however, for nanoparticle (NP) loaded samples, this initial heating rate is often limited by heat transfer mechanisms from the NPs to the surrounding material and not the initial NP heating. This is especially true for water-based, NP loaded tissue surrogates. Organic solvent dispersed NP loaded samples face the additional problem of heating rate variations due to solvent evaporation effects. We report on measurements of the initial optical heating rates of Chlorophyll and deposited directly on small, Pt thin film resistance temperature detectors (RTDs). Solid state lasers (638 nm and 655 nm) were used to illuminate these samples at different intensities and at specific wavelengths associated with peaks (662 nm) in Chlorophyll's UV-VIS optical absorption spectra while recording the RTD resistance at 0.1 second intervals. This technique significantly reduce evaporation errors we had experienced and has the potential to directly measure the heating behavior of Chlorophyll based NP materials.

  6. Photoinduced electron transfer of chlorophyll in lipid bilayer system

    Indian Academy of Sciences (India)

    The formation of vesicles was identified by changes in measured max values from diethyl ether solutions to vesicles solutions indirectly, and observed directly with SEM and TEM images. The efficiency of photosynthesis in model system was determined by measuring the amount of chlorophyll-a radical yields which were ...

  7. Genome-wide examination of chlorophyll metabolic genes in maize ...

    African Journals Online (AJOL)

    Chlorophyll (Chl) is the key pigment involved in photosynthesis. Analysis of the expression pattern of Chl metabolic genes will contribute to our understanding of photosynthesis. Also, the genes coding for Chl metabolism are ideal targets for revealing the evolution relationships of photosynthetic organisms. In this study, we ...

  8. Genome-wide examination of chlorophyll metabolic genes in maize ...

    African Journals Online (AJOL)

    Jane

    2011-06-22

    Jun 22, 2011 ... Chlorophyll (Chl) is the key pigment involved in photosynthesis. Analysis of the expression pattern of. Chl metabolic genes will contribute to our understanding of photosynthesis. Also, the genes coding for. Chl metabolism are ideal targets for revealing the evolution relationships of photosynthetic organisms ...

  9. Improved ocean chlorophyll estimate from remote sensed data: The ...

    African Journals Online (AJOL)

    Gregg and Conkright (2001) who pioneered the use of the blending technique in an attempt to calibrate ocean chlorophyll, expressed the need for further work to be done in order to obtain improved results. One problem faced when using this technique with spatially sparse data, is distortion of the resulting blended field ...

  10. Validation of OCM-2 sensor performance in retrieving chlorophyll ...

    Indian Academy of Sciences (India)

    wide area coverage has revolutionized the oceano- graphic observations in the past decades and made easy to map ocean geophysical parameters and their inter-linkages. Remote sensing of water quality parameter has involved mainly estimation of chlorophyll and total suspended matter (TSM) from sensor derived radi-.

  11. Chlorophyll a interference in phycocyanin and allophycocyanin spectrophotometric quantification

    Directory of Open Access Journals (Sweden)

    Rosaria Lauceri

    2017-09-01

    Full Text Available The accurate quantification of cyanobacteria phycobiliproteins is an important aspect in various research topics, such as cyanobacteria ecology and physiology studies, and especially to calibrate algorithms used in remote sensing of cyanobacterial blooms. Here we present a spectroscopic approach, exploiting spectrophotometric equations, aimed at improving the phycocyanin and allophycocyanin quantification when chlorophyll a is present in the phycobiliprotein aqueous extract.

  12. Indicators of Coastal Water Quality: Annual Chlorophyll-a Concentration 1998-2007

    Data.gov (United States)

    National Aeronautics and Space Administration — The Annual Chlorophyll-a Concentrations component of the Indicators of Coastal Water Quality Collection consists of gridded satellite measurements of chlorophyll-a...

  13. Ocean Chlorophyll as a Precursor of ENSO: An Earth System Modeling Study

    Science.gov (United States)

    Park, Jong-Yeon; Dunne, John P.; Stock, Charles A.

    2018-02-01

    Ocean chlorophyll concentration, a proxy for phytoplankton, is strongly influenced by internal ocean dynamics such as those associated with El Niño-Southern Oscillation (ENSO). Observations show that ocean chlorophyll responses to ENSO generally lead sea surface temperature (SST) responses in the equatorial Pacific. A long-term global Earth system model simulation incorporating marine biogeochemical processes also exhibits a preceding chlorophyll response. In contrast to simulated SST anomalies, which significantly lag the wind-driven subsurface heat response to ENSO, chlorophyll anomalies respond rapidly. Iron was found to be the key factor connecting the simulated surface chlorophyll anomalies to the subsurface ocean response. Westerly wind bursts decrease central Pacific chlorophyll by reducing iron supply through wind-driven thermocline deepening but increase western Pacific chlorophyll by enhancing the influx of coastal iron from the maritime continent. Our results mechanistically support the potential for chlorophyll-based indices to inform seasonal ENSO forecasts beyond previously identified SST-based indices.

  14. The regulatory role of reversible phosphorylation in the chlorophyll degradation pathway

    Science.gov (United States)

    Senescence represents the final stage of plant development and is characterized by several processes including the systematic degradation of the photosynthetic apparatus and chlorophyll molecules inside chloroplasts. Normally, chlorophyll is catabolized to colorless compounds through a series of enz...

  15. The effect of acid rain stress on chlorophyll, peroxidase of the conservation of rare earth elements

    International Nuclear Information System (INIS)

    Chongling, Y.; Yetang, H.; Xianke, Y.; Shunzhen, F.; Shanql, W.

    1998-01-01

    Full text: Based on pot experiment, the effect of acid rain stress on chlorophyll, peroxidase of wheat, the relationship of them and the conservation of rare earth elements has been studied. The result showed: stress of acid rain resulted in decrease of chlorophyll content and a/b values, chlorophyll a/b value and chlorophyll content is positive correlation with pH value of acid rain: peroxidase activity was gradually rise with pH value decrease, which indirectly increased decomposition intensity of chlorophyll. Decreased content and a/b value of chlorophyll further speeded blade decay affected the transport and transformation of light energy and metabolism of carbohydrates. After being treated by rare earth elements content and pH value of chlorophyll and peroxidase activity could be relatively stable. Therefore, under lower acidity condition, rare earth elements can influence the effect of acid rain on chlorophyll and peroxidase activity of wheat

  16. Global NOAA CoastWatch Chlorophyll Frontal Product from MODIS/Aqua (NCEI Accession 0110333)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MODIS/Aqua chlorophyll frontal products: the NOAA Okeanos operational production system produces near real-time chlorophyll frontal products (magnitude and...

  17. Atmospheric deposition and surface stratification as controls of contrasting chlorophyll abundance in the North Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Patra, P.K.; DileepKumar, M.; Mahowald, N.; Sarma, V.V.S.S.

    -averages (1997-2004) revealed chlorophyll abundances in northwestern regions are larger than in other regions of the respective basins. The NW regions of the Arabian Sea and the Bay of Bengal have exhibited contrasting chlorophyll distribution patterns during El...

  18. Subsurface chlorophyll maxima in the north-western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.; Aswanikumar, V.

    The depth profiles of phytoplankton pigments in the north-western Bay of Bengal are generally characterizEd. by a subsurface chlorophyll maximum. The occurrence of subsurface chlorophyll maxima is discussed in relation to other information on water...

  19. LBA-ECO LC-07 Amazon Floodplain Lake Chlorophyll from MODIS, Para, Brazil: 2002-2003

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set, LBA-ECO LC-07 Amazon Floodplain Lake Chlorophyll from MODIS, Para, Brazil: 2002-2003, contains chlorophyll concentration maps of the Amazon River...

  20. Measuring Leaf Chlorophyll Concentration from Its Color: A Way in Monitoring Environment Change to Plantations

    OpenAIRE

    Shibghatallah, Muhammad Abdul Hakim; Khotimah, Siti Nurul; Suhandono, Sony; Viridi, Sparisoma; Kesuma, Teja

    2013-01-01

    Leaf colors of a plant can be used to identify stress level due to its adaptation to environmental change. For most leaves green-related colors are sourced from chlorophyll a and b. Chlorophyll concentration is normally measured using a spectrophotometer in laboratory. In some remote observation places, it is impossible to collect the leaves, preserve them, and bring them to laboratory to measure their chlorophyll content. Based on this need, measurement of chlorophyll content is observed thr...

  1. Portable chlorophyll meter (PCM-502) values are related to total chlorophyll concentration and photosynthetic capacity in papaya (Carica papaya L.)

    Science.gov (United States)

    This study was carried out to verify the practical use of the portable chlorophyll meter-PCM502 (PCM) in two papaya cultivars with contrasting green coloring of the leaf blade (‘Golden’: yellowish-green; ‘Solo’: dark green). The relationship was studied between the photosynthetic process and leaf n...

  2. Modeling the relationship between extractable chlorophyll and SPAD-502 readings for endangered plant species research

    Science.gov (United States)

    Tracy S. Hawkins; Emile S. Gardiner; Greg S. Comer

    2009-01-01

    Handheld chlorophyll meters have proven to be useful tools for rapid, nondestructive assessment of chlorophyll and nutrient status in various agricultural and arborescent plant species. We proposed that a SPAD-502 chlorophyll meter would provide valuable information when monitoring life cycle changes and intraspecific variation in...

  3. Decreasing the chlorophyll a/b ratio in reconstituted LHCII: Structural and functional consequences

    NARCIS (Netherlands)

    Kleima, F.J.; Hobe, S.; Calkoen, F.; Urbanus, M.L.; Peterman, E.J.G.; van Grondelle, R.; Paulsen, H.; van Amerongen, H.

    1999-01-01

    Trimeric (bT) and monomeric (bM) light-harvesting complex II (LHCII) with a chlorophyll a/b ratio of 0.03 were reconstituted from the apoprotein overexpressed in Escherichia coli. Chlorophyll/xanthophyll and chlorophyll/protein ratios of bT complexes and 'native' LHCII are rather similar, namely,

  4. Integrating Biology into the General Chemistry Laboratory: Fluorometric Analysis of Chlorophyll "a"

    Science.gov (United States)

    Wesolowski, Meredith C.

    2014-01-01

    A laboratory experiment that introduces fluorometry of chlorophyll "a" at the general chemistry level is described. The use of thin-layer chromatography to isolate chlorophyll "a" from spirulina and leaf matter enables quantification of small amounts of chlorophyll "a" via fluorometry. Student results were reasonably…

  5. Effect of automobile pollution on chlorophyll content of roadside urban trees

    Directory of Open Access Journals (Sweden)

    M. Iqbal

    2015-09-01

    Full Text Available The effect of automobile pollution was determined on chlorophyll content of four different tree species viz. Azadirachta indica L., Conocarpus erectus L., Guiacum officinale L.and Eucalyptus sp. growing along the roads of the city.  Significant changes in the level of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” were found in the leaves of four tree species (A. indica, C. erectus, G.officinale and Eucalyptus sp. collected from polluted sites (Airport, Malir Halt, Quaidabad as compared to control site (Karachi University Campus. Lowest concentration of chlorophyll “a”, chlorophyll “b” and chlorophyll “a+b” was recorded in the leaf samples of all tree species collected from Quaidabad site when compared with the leaf samples collected from control site. The highest levels of chlorophyll pigment were recorded in all tree species leave samples collected from Karachi University Campus.  Similarly, better levels of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” was observed in all tree species growing at Airport site as compared to plants growing at Malir Halt and Quaidabad sites.  This study clearly indicated that the vehicular activities induced air pollution problem and affected on the level of chlorophyll pigments in trees which were exposed to road side pollution.

  6. Two-photon excited fluorescence from higher electronic states of chlorophylls in photosynthetic antenna complexes a new approach to detect strong excitonic chlorophyll a/b coupling

    CERN Document Server

    Leupold, D; Ehlert, J; Irrgang, K D; Renger, G; Lokstein, H

    2002-01-01

    Stepwise two-photon excitation of chlorophyll a and b in the higher plant main light-harvesting complex (LHC II) and the minor complex CP29 (as well as in organic solution) with 100-fs pulses in the Q/sub y/ region results in a weak blue fluorescence. The dependence of the spectral shape of the blue fluorescence on excitation wavelength offers a new approach to elucidate the long-standing problem of the origin of spectral "chlorophyll forms" in pigment-protein complexes, in particular the characterization of chlorophyll a/b-heterodimers. As a first result we present evidence for the existence of strong chlorophyll a/b-interactions (excitonically coupled transitions at 650 and 680 nm) in LHC II at ambient temperature. In comparison with LHC II, the experiments with CP29 provide further evidence that the lowest energy chlorophyll a transition (at ~680 nm) is not excitonically coupled to chlorophyll b. (22 refs).

  7. Development of a regional LiDAR field plot strategy for Oregon and Washington

    Science.gov (United States)

    Arvind Bhuta; Leah. Rathbun

    2015-01-01

    The National Forest System (NFS) Pacific Northwest Region (R6) has been flying LiDAR on a per project basis. Additional field data was also collected in situ to many of these LiDAR projects to aid in the development of predictive models and estimate values which are unattainable through LiDAR data alone (e.g. species composition, tree volume, and downed woody material...

  8. Participation of Chlorophyll b Reductase in the Initial Step of the Degradation of Light-harvesting Chlorophyll a/b-Protein Complexes in Arabidopsis

    OpenAIRE

    Horie, Yukiko; Ito, Hisashi; Kusaba, Makoto; Tanaka, Ryouichi; Tanaka, Ayumi

    2009-01-01

    The light-harvesting chlorophyll a/b-protein complex of photosystem II (LHCII) is the most abundant membrane protein in green plants, and its degradation is a crucial process for the acclimation to high light conditions and for the recovery of nitrogen (N) and carbon (C) during senescence. However, the molecular mechanism of LHCII degradation is largely unknown. Here, we report that chlorophyll b reductase, which catalyzes the first step of chlorophyll b degradation, plays a central role in L...

  9. Peregrinaciones parisinas: Rubén Darío

    Directory of Open Access Journals (Sweden)

    Beatriz Colombi

    1996-11-01

    Full Text Available Hacia 1900 se nuclea en París un grupo de corresponsales latinoamericanos conformando una suerte de enclave que reúne a figuras como Rubén Darío, Manuel Ugarte, Amado Nervo o Enrique Gómez Carrillo. Desde sus respectivas columnas estos cronistas construyen imágenes del mundo moderno atravesadas por el conflicto de pertenencia y marginalidad respecto al mismo. Este trabajo analiza las entregas que Rubén Darío escribe para La Nación de Buenos Aires durante la Feria Internacional de Paris de 1900, en relación con su contexto discursivo. En la enunciación de estas crónicas se alternan pasajes donde prima la superficialidad de la crónica elegante parisina con otras secciones argumentativas que dan cuenta de los desplazamientos de este sujeto entre el 'chroniqueur' y el intelectual que interviene -con la autoridad que le otorga su liderazgo estético- en el campo de los sucesos políticos, desmoronando cualquier 'fetichización' del espectáculo. Darío trama en su crónica la línea 'ondulante' de su prosa de artista con la línea 'informativa' de su tarea de diarista, imponiendo una marca 'modern style' a su escritura, que privilegia imágenes donde se fusionan elementos de ámbitos dispares; también se contamina de la retórica del acontecimiento moderno, en una hibridez propia del efecto sumativo de ese vasto mercado. Las crónicas, reunidas luego en Peregrinaciones de 1901, señalan también el pasaje entre el gran mercado cultural y el pequeño mercado estético, en una posición anfibia propia de esta textualidad

  10. LiDAR remote sensing applied to forest resources assessment

    OpenAIRE

    Fernández-Landa, Alfredo

    2016-01-01

    Disponer de información precisa y actualizada de inventario forestal es una pieza clave para mejorar la gestión forestal sostenible y para proponer y evaluar políticas de conservación de bosques que permitan la reducción de emisiones de carbono debidas a la deforestación y degradación forestal (REDD). En este sentido, la tecnología LiDAR ha demostrado ser una herramienta perfecta para caracterizar y estimar de forma continua y en áreas extensas la estructura del bosque y las principales vari...

  11. Bovine Pulmonary Tuberculosis At Bahir Dar Municipality Abattoir ...

    African Journals Online (AJOL)

    Une étude transversale a été menée de décembre 2005 à juin 2006 pour déterminer la prévalence de la tuberculose bovine chez 1441 bovins abattus et aussi pour valider la qualité de diagnostic de l'inspection de routine à l'abattoir de la municipalité de Bahir Dar, dans le nord-ouest de l'Ethiopie. On a aussi comparé la ...

  12. Plant Chlorophyll Content Imager with Reference Detection Signals

    Science.gov (United States)

    Spiering, Bruce A. (Inventor); Carter, Gregory A. (Inventor)

    2000-01-01

    A portable plant chlorophyll imaging system is described which collects light reflected from a target plant and separates the collected light into two different wavelength bands. These wavelength bands, or channels, are described as having center wavelengths of 700 nm and 840 nm. The light collected in these two channels is processed using synchronized video cameras. A controller provided in the system compares the level of light of video images reflected from a target plant with a reference level of light from a source illuminating the plant. The percent of reflection in the two separate wavelength bands from a target plant are compared to provide a ratio video image which indicates a relative level of plant chlorophyll content and physiological stress. Multiple display modes are described for viewing the video images.

  13. The biochemistry and molecular biology of chlorophyll breakdown.

    Science.gov (United States)

    Kuai, Benke; Chen, Junyi; Hörtensteiner, Stefan

    2018-02-12

    Chlorophyll breakdown is one of the most obvious signs of leaf senescence and fruit ripening. The resulting yellowing of leaves can be observed every autumn, and the color change of fruits indicates their ripening state. During these processes, chlorophyll is broken down in a multistep pathway, now termed the 'PAO/phyllobilin' pathway, acknowledging the core enzymatic breakdown step catalysed by pheophorbide a oxygenase, which determines the basic linear tetrapyrrole structure of the products of breakdown that are now called 'phyllobilins'. This review provides an update on the PAO/phyllobilin pathway, and focuses on recent biochemical and molecular progress in understanding phyllobilin-modifying reactions as the basis for phyllobilin diversity, on the evolutionary diversity of the pathway, and on the transcriptional regulation of the pathway genes. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  14. [Vegetation index estimation by chlorophyll content of grassland based on spectral analysis].

    Science.gov (United States)

    Xiao, Han; Chen, Xiu-Wan; Yang, Zhen-Yu; Li, Huai-Yu; Zhu, Han

    2014-11-01

    Comparing the methods of existing remote sensing research on the estimation of chlorophyll content, the present paper confirms that the vegetation index is one of the most practical and popular research methods. In recent years, the increasingly serious problem of grassland degradation. This paper, firstly, analyzes the measured reflectance spectral curve and its first derivative curve in the grasslands of Songpan, Sichuan and Gongger, Inner Mongolia, conducts correlation analysis between these two spectral curves and chlorophyll content, and finds out the regulation between REP (red edge position) and grassland chlorophyll content, that is, the higher the chlorophyll content is, the higher the REIP (red-edge inflection point) value would be. Then, this paper constructs GCI (grassland chlorophyll index) and selects the most suitable band for retrieval. Finally, this paper calculates the GCI by the use of satellite hyperspectral image, conducts the verification and accuracy analysis of the calculation results compared with chlorophyll content data collected from field of twice experiments. The result shows that for grassland chlorophyll content, GCI has stronger sensitivity than other indices of chlorophyll, and has higher estimation accuracy. GCI is the first proposed to estimate the grassland chlorophyll content, and has wide application potential for the remote sensing retrieval of grassland chlorophyll content. In addition, the grassland chlorophyll content estimation method based on remote sensing retrieval in this paper provides new research ideas for other vegetation biochemical parameters' estimation, vegetation growth status' evaluation and grassland ecological environment change's monitoring.

  15. Estimate of Leaf Chlorophyll and Nitrogen Content in Asian Pear (Pyrus serotina Rehd. by CCM-200

    Directory of Open Access Journals (Sweden)

    Mostafa GHASEMI

    2011-03-01

    Full Text Available In many cases evaluation of chlorophyll and nitrogen content in plants need to destructive methods, more time and organic solvents. Application of chlorophyll meters save time and resources. The aim of this study was estimating of chlorophyll and nitrogen content in Asian pear leaves using non-destructive method and rapid quantification of chlorophyll by chlorophyll content meter (CCM-200. This study was conducted on 8 years old Asian pear trees during June 2008 in Tehran, Iran. To develop our regression model, the chlorophyll meter data were correlated with extracted chlorophyll and nitrogen content data obtained from DMSO and Kejeldal methods, respectively. The results showed that, there was positive and linear correlation between CCM-200 data and chlorophyll a (R�=0.7183, chlorophyll b (R�=0.8523, total chlorophyll (R�=0.90, and total nitrogen content (R�=0.76 in Asian pear leaves. Thus, it can be concluded that, CCM-200 can be used in order to predict both chlorophyll and nitrogen content in Asian pear leaves.

  16. SPAD-502 readings in response to photon fluence in leaves with different chlorophyll content

    Directory of Open Access Journals (Sweden)

    Helena Cristina Santos Nascimento

    2010-10-01

    Full Text Available The chlorophyll meter (SPAD-502 is widely used to estimate chlorophyll content, but non-uniform chloroplast distribution can affect its accuracy. This study aimed to assess the effect of photon fluence (F, irradiance x time of illumination in leaves with different chlorophyll content and determine the effect of chlorophyll a/b on SPAD values of four tropical tree species (Croton draconoides Müll. Arg., Hevea guianensis Aubl., Hymenaea courbaril L. and Matisia cordata H.B.K.. There were also determined calibration equations for the chlorophyll meter and assessed the effect of F on SPAD values between 07:00 h and 17:00 h. Calibration equations were obtained after determining leaf chlorophyll content in the laboratory. Increases in F with time caused a reduction in SPAD values in species with a high chlorophyll content, with reductions of 20% in M. cordata and 10% in H. guianensis. Leaves of C. draconoides and H. courbaril had lower chlorophyll content and showed no changes in SPAD values with increase in F. The chlorophyll a/b ratio increased with SPAD values and the SPAD/chlorophyll relationship was best described by an exponential equation. It seems that F may affect SPAD values in leaves with high chlorophyll content, probably due to non-uniform chloroplast distribution at high irradiance. This indicates that SPAD values tend to be more accurate if recorded early in morning when irradiance is low.

  17. Gas exchange and chlorophyll a fluorescence parameters of ornamental bromeliads

    Directory of Open Access Journals (Sweden)

    Karina Gonçalves da Silva

    2017-10-01

    Full Text Available Gas exchange and chlorophyll a fluorescence are widely used in physiological and ecological studies; however, few studies have used these techniques with ornamental plants. This study tested the potential contribution of gas exchange and chlorophyll a fluorescence to evaluate the water and nutrients uptake by the tank and root system of epiphyte bromeliad Guzmania lingulata. For this purpose, we conducted an experiment with different water regime and another with different concentrations of nitrogen. The experiments were: 1 - Watering: Control (application of water into Tank and Root, Tank (watering into Tank, Root (watering Root and Drought (water suspension during the 90 days of experimentation and 2 - Nitrogen: Plants fertilized with Hoagland and Arnon nutrient solution exclusively into Tank or Root with nitrogen concentrations of control and 2.62 or 5.34 mM N applied as urea. The Fv /Fm ratio allowed comparing the treatments between experiments, demonstrating that Root and Tank both have the capacity to maintain G. lingulata photosynthetic activity and growth, while Drought treatment (water suspension was the limiting factor for energy conversion efficiency of PSII. However, gas exchange was more permissive as a parameter for comparing treatments in the nitrogen experiment, providing important information about the general aspects of the photosynthetic process in the watering experiment. Both gas exchange and chlorophyll a fluorescence can support the evaluation of G. lingulata physiological status and can be useful tools in ornamental horticultural studies.

  18. Automatic building extraction using LiDAR and aerial photographs

    Directory of Open Access Journals (Sweden)

    Melis Uzar

    Full Text Available This paper presents an automatic building extraction approach using LiDAR data and aerial photographs from a multi-sensor system positioned at the same platform. The automatic building extraction approach consists of segmentation, analysis and classification steps based on object-based image analysis. The chessboard, contrast split and multi-resolution segmentation methods were used in the segmentation step. The determined object primitives in segmentation, such as scale parameter, shape, completeness, brightness, and statistical parameters, were used to determine threshold values for classification in the analysis step. The rule-based classification was carried out with defined decision rules based on determined object primitives and fuzzy rules. In this study, hierarchical classification was preferred. First, the vegetation and ground classes were generated; the building class was then extracted. The NDVI, slope and Hough images were generated and used to avoid confusing the building class with other classes. The intensity images generated from the LiDAR data and morphological operations were utilized to improve the accuracy of the building class. The proposed approach achieved an overall accuracy of approximately 93% for the target class in a suburban neighborhood, which was the study area. Moreover, completeness (96.73% and correctness (95.02% analyses were performed by comparing the automatically extracted buildings and reference data.

  19. Performance testing of LiDAR exploitation software

    Science.gov (United States)

    Varela-González, M.; González-Jorge, H.; Riveiro, B.; Arias, P.

    2013-04-01

    Mobile LiDAR systems are being used widely in recent years for many applications in the field of geoscience. One of most important limitations of this technology is the large computational requirements involved in data processing. Several software solutions for data processing are available in the market, but users are often unknown about the methodologies to verify their performance accurately. In this work a methodology for LiDAR software performance testing is presented and six different suites are studied: QT Modeler, AutoCAD Civil 3D, Mars 7, Fledermaus, Carlson and TopoDOT (all of them in x64). Results depict as QTModeler, TopoDOT and AutoCAD Civil 3D allow the loading of large datasets, while Fledermaus, Mars7 and Carlson do not achieve these powerful performance. AutoCAD Civil 3D needs large loading time in comparison with the most powerful softwares such as QTModeler and TopoDOT. Carlson suite depicts the poorest results among all the softwares under study, where point clouds larger than 5 million points cannot be loaded and loading time is very large in comparison with the other suites even for the smaller datasets. AutoCAD Civil 3D, Carlson and TopoDOT show more threads than other softwares like QTModeler, Mars7 and Fledermaus.

  20. 2001-2002 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Island County and Northeast Jefferson County, Washington

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TerraPoint surveyed and created this data for the Puget Sound LiDAR Consortium under contract. The area surveyed is approximately 525 square miles and covers all of...

  1. The Typology of Female Sex Workers in Dar-es-Salaam ...

    African Journals Online (AJOL)

    Objective: To establish the categories of female sex workers in Dar es Salaam. Methods: We conducted in depth-interviews with 32 female sex workers (FSWs) in five geographic areas of Dar-es-Salaam known to be the primary residential and working places, three local government leaders in three of the five areas known ...

  2. Anti-diabetic drugs in the private and public sector in Dar es Salaam ...

    African Journals Online (AJOL)

    Objectives: To compare availability, cost, affordability and sources of anti-diabetic drugs between private and public health facilities in Dar es Salaam, Tanzania. Design: Cross sectional descriptive study. Setting: Diabetic clinics in private and public health facilities in Dar es Salaam, Tanzania. Subjects: Eighty patients ...

  3. Wayne and Washtenaw Counties 1.0 PPSM LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Wayne and Washtenaw Counties 1.0 PPSM LiDAR LiDAR Data Acquisition and Processing Production Task USGS CONTRACT: 07CRCN0006 TASK ORDER NUMBER: G09PD00300...

  4. The growth of population and employment in the Dar es Salaam city region, Tanzania.

    Science.gov (United States)

    Hayuma, A M

    1983-01-01

    The problems of rapid population growth and unemployment in the Dar es Salaam urban region, Tanzania, are discussed. Efforts to deal with these problems through the 1968 Dar es Salaam master plan are reviewed, and the ineffectiveness of the plan to date is noted.

  5. Layer stacking: A novel algorithm for individual forest tree segmentation from LiDAR point clouds

    Science.gov (United States)

    Elias Ayrey; Shawn Fraver; John A. Kershaw; Laura S. Kenefic; Daniel Hayes; Aaron R. Weiskittel; Brian E. Roth

    2017-01-01

    As light detection and ranging (LiDAR) technology advances, it has become common for datasets to be acquired at a point density high enough to capture structural information from individual trees. To process these data, an automatic method of isolating individual trees from a LiDAR point cloud is required. Traditional methods for segmenting trees attempt to isolate...

  6. Using LiDAR surveys to document floods: A case study of the 2008 Iowa flood

    Science.gov (United States)

    Chen, Bo; Krajewski, Witold F.; Goska, Radek; Young, Nathan

    2017-10-01

    Can we use Light Detection and Ranging (LiDAR), an emergent remote sensing technology with wide applications, to document floods with high accuracy? To explore the feasibility of this application, we propose a method to extract distributed inundation depths from a LiDAR survey conducted during flooding. This method consists of three steps: (1) collecting LiDAR data during flooding; (2) classifying the LiDAR observational points as flooded water surface points and non-flooded points, and generating a floodwater surface elevation model; and (3) subtracting the bare earth Digital Terrain Model (DTM) from the flood surface elevation model to obtain a flood depth map. We applied this method to the 2008 Iowa flood in the United States and evaluated the results using the high-water mark measurements, flood extent extracted from SPOT (Small Programmable Object Technology) imagery, and the near-simultaneously acquired aerial photography. The root mean squared error of the LiDAR-derived floodwater surface profile to high-water marks was 30 cm, the consistency between the two flooded areas derived from LiDAR and SPOT imagery was 72% (81% if suspicious isolated ponds in the SPOT-derived extent were removed), and LiDAR-derived flood extent had a horizontal resolution of ∼3 m. This work demonstrates that LiDAR technology has the potential to provide calibration and validation reference data with appreciable accuracy for improved flood inundation modeling.

  7. 2011-2013 Indiana Statewide Imagery and LiDAR Program: Lake Michigan Watershed Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Indiana's Statewide LiDAR data is produced at 1.5-meter average post spacing for all 92 Indiana Counties covering more than 36,420 square miles. New LiDAR data was...

  8. Effect of slope on treetop detection using a LiDAR Canopy Height Model

    NARCIS (Netherlands)

    Khosravipour, A.; Skidmore, A.K.; Wang, Tiejun; Isenburg, M.; Khoshelham, K.

    2015-01-01

    Canopy Height Models (CHMs) or normalized Digital Surface Models (nDSM) derived from LiDAR data have been applied to extract relevant forest inventory information. However, generating a CHM by height normalizing the raw LiDAR points is challenging if trees are located on complex terrain. On steep

  9. Mapping of landslides under dense vegetation cover using object - oriented analysis and LiDAR derivatives

    NARCIS (Netherlands)

    Van Den Eeckhout, Miet; Kerle, N.; Hervas, Javier; Supper, Robert; Margottini, C.; Canuti, P.; Sassa, K.

    2013-01-01

    Light Detection and Ranging (LiDAR) and its wide range of derivative products have become a powerful tool in landslide research, particularly for landslide identification and landslide inventory mapping. In contrast to the many studies that use expert-based analysis of LiDAR derivatives to identify

  10. Utility of LiDAR for large area forest inventory applications

    Science.gov (United States)

    Nicholas S. Skowronski; Andrew J. Lister

    2012-01-01

    Multi-resource inventory data are used in conjunction with Light Detection and Ranging (LiDAR) data from the Pennsylvania Department of Natural Resource's PAMAP Program to assess the utility of extensive LiDAR acquisitions for large area forest assessments. Background, justification, and initial study designs are presented. The proposed study will involve three...

  11. Wetland inundation mapping and change monitoring using landsat and airborne LiDAR data

    Science.gov (United States)

    This paper presents a new approach for mapping wetland inundation change using Landsat and LiDAR intensity data. In this approach, LiDAR data were used to derive highly accurate reference subpixel inundation percentage (SIP) maps at the 30-m resolution. The reference SIP maps were then used to est...

  12. Stationary LiDAR for traffic and safety applications - vehicles interpretation and tracking.

    Science.gov (United States)

    2014-01-01

    The goal of the T-Scan project is to develop a data processing module for a novel LiDAR-based traffic scanner to collect highly accurate microscopic traffic data at road intersections. : T-Scan uses Light Detection and Ranging (LiDAR) technology that...

  13. Quantifying aboveground forest carbon pools and fluxes from repeat LiDAR surveys

    Science.gov (United States)

    Andrew T. Hudak; Eva K. Strand; Lee A. Vierling; John C. Byrne; Jan U. H. Eitel; Sebastian Martinuzzi; Michael J. Falkowski

    2012-01-01

    Sound forest policy and management decisions to mitigate rising atmospheric CO2 depend upon accurate methodologies to quantify forest carbon pools and fluxes over large tracts of land. LiDAR remote sensing is a rapidly evolving technology for quantifying aboveground biomass and thereby carbon pools; however, little work has evaluated the efficacy of repeat LiDAR...

  14. Assessing LiDAR elevation data for KDOT applications : [technical summary].

    Science.gov (United States)

    2013-02-01

    LiDAR-based elevation surveys : are a cost-effective means for : mapping topography over large : areas. LiDAR surveys use an : airplane-mounted or ground-based : laser radar unit to scan terrain. : Post-processing techniques are : applied to remove v...

  15. Investigating assumptions of crown archetypes for modelling LiDAR returns

    NARCIS (Netherlands)

    Calders, K.; Lewis, P.; Disney, M.; Verbesselt, J.; Herold, M.

    2013-01-01

    LiDAR has the potential to derive canopy structural information such as tree height and leaf area index (LAI), via models of the LiDAR signal. Such models often make assumptions regarding crown shape to simplify parameter retrieval and crown archetypes are typically assumed to contain a turbid

  16. Airborne LiDAR reflective linear feature extraction for strip adjustment and horizontal accuracy determination.

    Science.gov (United States)

    2009-02-01

    ODOT's Office of Aerial Engineering (OAE) has been using an Opetch 30/70 ALTM airborne LiDAR system for about four years. The introduction of LiDAR technology was a major development towards improving the mapping operations. The overall experiences a...

  17. University of Dar es Salaam Library Journal - Vol 9, No 1 (2007)

    African Journals Online (AJOL)

    Gender Analysis Of Electronic Information Resource Use: The Case Of The University Of Dar Es Salaam, Tanzania · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL ... A Bibliometric Study Of Research On Dar Es Salaam Region: 1980 To 2003 · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  18. FY12 St Johns River Water Management LiDAR Survey: Putnam (FL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the FY12 St Johns River Water Management LiDAR Survey, project area in north-central Florida and...

  19. Epidemiological Studies on Bovine Mastitis in Smallholder Dairy Herds in the Dar es Salaam Region, Tanzania

    NARCIS (Netherlands)

    Kivaria, F.M.

    2006-01-01

    Recently the number of milking cows has increased substantially in the Dar es Salaam region due to an increasing demand for fresh milk in this densely populated urban centre. It is estimated that there are 1,765 smallholder dairy herds with 8,233 improved dairy animals in and around the Dar es

  20. Status and prospects for LiDAR remote sensing of forested ecosystems

    Science.gov (United States)

    M. A. Wulder; N. C. Coops; A. T. Hudak; F. Morsdorf; R. Nelson; G. Newnham; M. Vastaranta

    2013-01-01

    The science associated with the use of airborne and satellite Light Detection and Ranging (LiDAR) to remotely sense forest structure has rapidly progressed over the past decade. LiDAR has evolved from being a poorly understood, potentially useful tool to an operational technology in a little over a decade, and these instruments have become a major success story in...

  1. 2007 South Carolina LiDAR: Charleston (partial), Jasper, and Colleton Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LiDAR data collection was performed utilizing a Leica ALS-50 sensor, collecting multiple return x, y, and z data as well as intensity data. LiDAR data was processed...

  2. Using satellite and airborne LiDAR to model woodpecker habitat occupancy at the landscape scale

    Science.gov (United States)

    Lee A. Vierling; Kerri T. Vierling; Patrick Adam; Andrew T. Hudak

    2013-01-01

    Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. LiDAR can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based LiDAR...

  3. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    DEFF Research Database (Denmark)

    Tomaszewski, Céline; Byrne, Stephen; Foito, Alexandra

    2012-01-01

    T markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used...

  4. Retrieval of savanna vegetation canopy height from ICESat-GLAS spaceborne LiDAR with terrain correction

    CSIR Research Space (South Africa)

    Khalefa, E

    2013-11-01

    Full Text Available Light detection and ranging (LiDAR) remote sensing enables accurate estimation and monitoring of vegetation structural properties. Airborne and spaceborne LiDAR is known to provide reliable information on terrain elevation and forest canopy height...

  5. Evaluation of canola chlorophyll index and leaf nitrogen under wide range of soil moisture

    Science.gov (United States)

    Meskini-Vishkaee, Fatemeh; Mohammadi, Mohammad Hosein; Neyshabouri, Mohammad Reza; Shekari, Farid

    2015-01-01

    The paper presents a study on the effect of soil matric suction on the variation of leaf chlorophyll index and nitrogen concentration of canola. Results showed that chlorophyll index increases exponentially with soil matric suction, especially at the late season of canola growing time. At moderate matric suction (200 and 300 kPa soil suction heads), chlorophyll index remains nearly constant, but in drier soil (matric suction >300 kPa), chlorophyll index increases gradually with time. Despite the variation of the total leaf nitrogen with the soil matric suction, it is similar to the variation of the chlorophyll index, but the results showed that the chlorophyll index - nitrogen concentration curve has a demarcated bi-modal shape. We suggest that 2.7% of nitrogen and 69.8 of the chlorophyll index value represent the upper limit of the chlorophyll meter reliability for estimation of canola nitrogen under a wide range of soil moisture levels. These results confirm that the chlorophyll meter can be used as an effective tool for rapid and non-destructive estimation of the relative chlorophyll and nitrogen content in canola leaves at a wide range of soil moisture content, except for nearly wilting coefficient or extremely high drought stress

  6. Registration of vehicle based panoramic image and LiDAR point cloud

    Science.gov (United States)

    Chen, Changjun; Cao, Liang; Xie, Hong; Zhuo, Xiangyu

    2013-10-01

    Higher quality surface information would be got when data from optical images and LiDAR were integrated, owing to the fact that optical images and LiDAR point cloud have unique characteristics that make them preferable in many applications. While most previous works focus on registration of pinhole perspective cameras to 2D or 3D LiDAR data. In this paper, a method for the registration of vehicle based panoramic image and LiDAR point cloud is proposed. Using the translation among panoramic image, single CCD image, laser scanner and Position and Orientation System (POS) along with the GPS/IMU data, precise co-registration between the panoramic image and the LiDAR point cloud in the world system is achieved. Results are presented under a real world data set collected by a new developed Mobile Mapping System (MMS) integrated with a high resolution panoramic camera, two laser scanners and a POS.

  7. Influence of water-based ferrofluid upon chlorophylls in cereals

    International Nuclear Information System (INIS)

    Racuciu, Mihaela; Creanga, Dorina-Emilia

    2007-01-01

    The present experimental investigation was focused on the study of the simultaneous influence of the water-based ferrofluid and static magnetic field exposure on young cereal plants. Water-based ferrofluid, stabilized with citric acid was added daily in various concentrations, ranging between 10 and 250 μL/L, in the culture medium of maize (Zea mays) plants in their early ontogenetic stages. The used static magnetic field was about 50 mT. In order to investigate the biochemical changes of chlorophylls and total carotenoids, spectrophotometric measurements were carried out, that revealed stimulatory effects of ferrofluid and magnetic exposure upon the studied plant species

  8. Role of chlorophylls, amino acids and sugars in tea

    International Nuclear Information System (INIS)

    Dev Choudhury, M.N.

    1980-01-01

    Plucked tea shoots from clones of different varieties of tea were withered, rolled, fermented and fired by CTC and orthodox methods of manufacture. Quantitative changes in the levels of chlorophylls, amino acids and water soluble sugars during different stages of processing of tea and also changes in the contents of their degradation products were studied by feeding 14 C-labelled phenylalanine, glucose, sodium carbonate and sodium propionate to the excised shoots and subsequently analysing the products. Results are discussed and suggestions have been made about adjusting the conditions of manufacture so that the teas with desired chemical constituents are produced. (M.G.B.)

  9. Building Contour Extraction Based on LiDAR Point Cloud

    Directory of Open Access Journals (Sweden)

    Zhang Xu-Qing

    2017-01-01

    Full Text Available This paper presents a new method for solving the problem of utilizing the LiDAR data to extract the building contour line. For detection of the edge points between the building test points by using the least squares fitting to get the edge line of buildings and give the weight determining of the building of edge line slope depend on the length of the edge line. And then get the weighted mean of the positive and negative slope of the building edge line. Based on the structure of the adjacent edge perpendicular hypothesis, regularization processing to extract the edge of the skeleton line perpendicular. The experiments show that the extracted building edges have the good accuracy and have the good applicability in complex urban areas.

  10. Light-harvesting chlorophyll pigments enable mammalian mitochondria to capture photonic energy and produce ATP.

    Science.gov (United States)

    Xu, Chen; Zhang, Junhua; Mihai, Doina M; Washington, Ilyas

    2014-01-15

    Sunlight is the most abundant energy source on this planet. However, the ability to convert sunlight into biological energy in the form of adenosine-5'-triphosphate (ATP) is thought to be limited to chlorophyll-containing chloroplasts in photosynthetic organisms. Here we show that mammalian mitochondria can also capture light and synthesize ATP when mixed with a light-capturing metabolite of chlorophyll. The same metabolite fed to the worm Caenorhabditis elegans leads to increase in ATP synthesis upon light exposure, along with an increase in life span. We further demonstrate the same potential to convert light into energy exists in mammals, as chlorophyll metabolites accumulate in mice, rats and swine when fed a chlorophyll-rich diet. Results suggest chlorophyll type molecules modulate mitochondrial ATP by catalyzing the reduction of coenzyme Q, a slow step in mitochondrial ATP synthesis. We propose that through consumption of plant chlorophyll pigments, animals, too, are able to derive energy directly from sunlight.

  11. A Saponification Method for Chlorophyll Removal from Microalgae Biomass as Oil Feedstock

    Directory of Open Access Journals (Sweden)

    Tao Li

    2016-09-01

    Full Text Available Microalgae oil is an optimal feedstock for nutraceutical, pharmaceutical and biodiesel production, but its high levels of chlorophyll limit its large-scale application. To date, few effective approaches have been developed to remove chlorophyll from microalgae oil. The main purpose of this study was to present a preprocessing method of algae oil feedstock (Scenedesmus to remove chlorophyll by saponification. The results showed that 96% of chlorophyll in biomass was removed. High quality orange transparent oil could be extracted from the chlorophyll reduced biomass. Specifically, the proportion of neutral lipids and saturation levels of fatty acids increased, and the pigments composition became carotenoids-based. The critical parameters of chlorophyll reduced biodiesel conformed to the standards of the USA, China and EU. Sodium copper chlorophyllin could be prepared from the bleaching effluent. The results presented herein offer a useful pathway to improve the quality of microalgae oil and reduce the cost of microalgae biodiesel.

  12. Global Seasonal Climatologies of Ocean Chlorophyll: Blending In situ and Satellite Data for the CZCS Era

    Science.gov (United States)

    Gregg, Watson W.; Conkright, Margarita E.

    1999-01-01

    The historical archives of in situ (National Oceanographic Data Center) and satellite (Coastal Zone Color Scanner) chlorophyll data were combined using the blended analysis method of Reynolds [1988] in an attempt to construct an improved climatological seasonal representation of global chlorophyll distributions. The results of the blended analysis differed dramatically from the CZCS representation: global chlorophyll estimates increased 8-35% in the blended analysis depending upon season. Regional differences were even larger, up to 140% in the equatorial Indian Ocean in summer (during the southwest monsoon). Tropical Pacific chlorophyll values increased 25-41%. The results suggested that the CZCS generally underestimates chlorophyll. Regional and seasonal differences in the blended analysis were sufficiently large as to produce a different representation of global chlorophyll distributions than otherwise inferred from CZCS data alone. Analyses of primary production and biogeochemical cycles may be substantially impacted by these results.

  13. Substratum as a driver of variation in periphyton chlorophyll and productivity in lakes

    DEFF Research Database (Denmark)

    Vadeboncoeur, Y.; Kalff, J.; Christoffersen, Kirsten Seestern

    2006-01-01

    Quantifying periphyton (attached algal) contributions to autotrophic production in lakes is confounded by properties of substratum that affect community biomass (as chlorophyll content) and productivity. We compared chlorophyll content and productivity of natural algal communities (phytoplankton......, epipelon, epilithon, epixylon, and epiphyton) experiencing high (>10%) incident radiation in lakes in the US, Greenland, and Quebec, Canada. Chlorophyll content and productivity differed significantly among regions, but they also differed consistently among communities independent of region. Chlorophyll...... content of periphyton on hard substrata (rocks and wood) was positively related to water-column total P (TP), whereas chlorophyll content of algae on sediment (epipelon) and TP were not significantly related. Chlorophyll content was up to 100× higher on sediments than on hard substrata. Within regions...

  14. Delineation of peatland lagg boundaries from airborne LiDAR

    Science.gov (United States)

    Langlois, Melanie N.; Richardson, Murray C.; Price, Jonathan S.

    2017-09-01

    In Canada, peatlands are the most common type of wetland, but boundary delineation in peatland complexes has received little attention in the scientific literature. Typically, peatland boundaries are mapped as crisp, absolute features, and the transitional lagg zone—the ecotone found between a raised bog and the surrounding mineral land—is often overlooked. In this study, we aim (1) to advance existing approaches for detecting and locating laggs and lagg boundaries using airborne LiDAR surveys and (2) to describe the spatial distribution of laggs around raised bog peatlands. Two contrasting spatial analytical approaches for lagg detection were tested using five LiDAR-derived topographic and vegetation indices: topography, vegetation height, topographic wetness index, the standard deviation of the vegetation's height (as a proxy for the complexity of the vegetation's structure), and local indices of elevation variance. Using a dissimilarity approach (edge-detection, split-moving window analysis), no one variable accurately depicted both the lagg-mineral land and bog-lagg boundaries. Some indicators were better at predicting the bog-lagg boundary (i.e., vegetation height) and others at finding the lagg-mineral land boundary (i.e., topography). Dissimilarity analysis reinforces the usefulness of derived variables (e.g., wetness indices) in locating laggs, especially for those with weak topographic and vegetation gradients. When the lagg was confined between the bog and the adjacent upland, it took a linear form, parallel to the peatland's edge and was easier to predict. When the adjacent mineral land was flat or sloping away from the peatland, the lagg was discontinuous and intermittent and more difficult to predict.

  15. Dynamic LiDAR-NDVI classification of fluvial landscape units

    Science.gov (United States)

    Ramírez-Núñez, Carolina; Parrot, Jean-François

    2015-04-01

    The lower basin of the Coatzacoalcos River is a wide floodplain in which, during the wet season, local and major flooding are distinguished. Both types of floods, intermittent and regional, are important in terms of resources; the regional flood sediments enrich the soils of the plains and intermittent floods allow obtaining aquatic resources for subsistence during the heatwave. In the floodplain different abandoned meanders and intermittent streams are quickly colonized by aquatic vegetation. However, from the 1990s, the Coatzacoalcos River floodplain has important topographic changes due to mining, road and bridges construction; erosion and sedimentation requires continuous parcel boundaries along with the increasing demand of channel reparation, embankments, levees and bridges associated to tributaries. NDVI data, LiDAR point cloud and various types of flood simulations taking into account the DTM are used to classify the dynamic landscape units. These units are associated to floods in relation with water resources, agriculture and livestock. In the study area, the first returns of the point cloud allow extracting vegetation strata. The last returns correspond to the bare earth surface, especially in this area with few human settlements. The surface that is not covered by trees or by aquatic vegetation, correspond to crops, pastures and bare soils. The classification is obtained by using the NDVI index coupled with vegetation strata and water bodies. The result shows that 47.96% of the area does not present active vegetation and it includes 31.53% of bare soils. Concerning the active vegetation, pastures, bushes and trees represent respectively 25.59%, 11.14% and 13.25%. The remaining 1.25% is distributed between water bodies with aquatic vegetation, trees and shrubs. Dynamic landscape units' classification represents a tool for monitoring water resources in a fluvial plain. This approach can be also applied to forest management, environmental services and

  16. DUF538 protein superfamily is predicted to be chlorophyll hydrolyzing enzymes in plants

    OpenAIRE

    Gholizadeh, Ashraf

    2015-01-01

    The possible hydrolytic activity towards chlorophyll molecules was predicted for DUF538 protein superfamily in plants. It was examined by using computational as well as experimental tools including in vitro chlorophyll degradation, antioxidant compounds production and in vivo real-time gene expression tests. Comparison of the computational data with the experimental results indicated that DUF538 proteins might be chlorophyll hydrolyzing enzyme (most probably carboxyesterase) which degrade chl...

  17. The effect of a red leaf pigment on the relationship between red edge and chlorophyll concentration

    Science.gov (United States)

    Curran, Paul J.; Dungan, Jennifer L.; Macler, Bruce A.; Plummer, Stephen E.

    1991-01-01

    The effect of a leaf pigment - red amaranthin - on red edge and chlorophyll concentration is investigated in amaranth leaves by means of treatments with nitrate and salts. A near-linear relationship between red edge and chlorophyll concentration is observed for leaves with low amaranthin concentration, and no relationship is noted at high concentrations. The study demonstrates the limitation inherent in estimating chlorophyll concentration by using remotely sensed red edge.

  18. Self-assembled chlorophyll a systems as studied by californium-252 plasma desorption mass spectroscopy

    OpenAIRE

    Hunt, J. E.; Macfarlane, R. D.; Katz, J. J.; Dougherty, R. C.

    1980-01-01

    Self-assembled chlorophyll a and pheophytin a systems in thin solid films have been studied by 252Cf plasma desorption mass spectrometry (PDMS). The 252Cf-PDMS spectra of these films show monomer cation and anion molecular ions, ions of molecular aggregates, and positive and negative ion fragmentation patterns arising from the loss of various aliphatic side chains from the chlorin ring. Chlorophyll a films cast from dry carbon tetrachloride solution, in which chlorophyll a is known to occur a...

  19. Effect of gamma radiation on chlorophylls contents, net photosynthesis and respiration of chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Martin Moreno, C.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first 'b' chlorophyll affected to a greater extent than 'a' chlorophyll. Net photosynthesis and respiration decline throughout the time of the observations after irradiation, this depressing effect being much more remarkable for the first one. Net photosynthesis inhibition levels of about 30% have got only five hours post irradiation at a dose of 5000 Gy. (author)

  20. Rapid assessment of water pollution by airborne measurement of chlorophyll content.

    Science.gov (United States)

    Arvesen, J. C.; Weaver, E. C.; Millard, J. P.

    1971-01-01

    Present techniques of airborne chlorophyll measurement are discussed as an approach to water pollution assessment. The differential radiometer, the chlorophyll correlation radiometer, and an infrared radiometer for water temperature measurements are described as the key components of the equipment. Also covered are flight missions carried out to evaluate the capability of the chlorophyll correlation radiometer in measuring the chlorophyll content in water bodies with widely different levels of nutrients, such as fresh-water lakes of high and low eutrophic levels, marine waters of high and low productivity, and an estuary with a high sediment content. The feasibility and usefulness of these techniques are indicated.

  1. Instability of chlorophyll in yellow lupin seedlings grown in soil contaminated with ciprofloxacin and tetracycline.

    Science.gov (United States)

    Rydzyński, Dariusz; Piotrowicz-Cieślak, Agnieszka I; Grajek, Hanna; Michalczyk, Dariusz J

    2017-10-01

    With increasing soil concentrations of ciprofloxacin and tetracycline a decrease of leaf chlorophyll content was observed. Tetracycline was more detrimental than ciprofloxacin. The chlorophyll content in plants growing for ten days on a tetracycline containing soil decreased by 68%. The decrease of chlorophyll concentration was even sharper in new leaves that formed after application of the antibiotic (up to 81% drop). The comparison of absorption spectra of commercial, reagent grade chlorophyll, alone and incubated with antibiotics, has shown that ciprofloxacin and tetracycline can react directly with chlorophyll and decrease its concentration by 47.7% and 48.5%, respectively. The changes in fluorescence spectra confirmed the formation of chlorophyll degradation product. The chlorophyll decay was a second order reaction and depended on antibiotic concentration and duration of exposure. Reaction rate constants differed with antibiotics and their soil concentrations. With increasing contents of antibiotics in soil the constant of chlorophyll degradation rate in lupin plants increased from k = 870 M -1 day -1 for 3 mg ciprofloxacin to k = 2490 M -1 day -1 for 90 mg ciprofloxacin, and in the case of tetracycline the reaction rate constant increased from k = 1330 M -1 day -1 to k = 2910 M -1 day -1 . The sensitivity of chlorophyll to ciprofloxacin and tetracycline was confirmed by determining EC and TU indices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Estimating FPAR of maize canopy using airborne discrete-return LiDAR data.

    Science.gov (United States)

    Luo, Shezhou; Wang, Cheng; Xi, Xiaohuan; Pan, Feifei

    2014-03-10

    The fraction of absorbed photosynthetically active radiation (FPAR) is a key parameter for ecosystem modeling, crop growth monitoring and yield prediction. Ground-based FPAR measurements are time consuming and labor intensive. Remote sensing provides an alternative method to obtain repeated, rapid and inexpensive estimates of FPAR over large areas. LiDAR is an active remote sensing technology and can be used to extract accurate canopy structure parameters. A method to estimating FPAR of maize from airborne discrete-return LiDAR data was developed and tested in this study. The raw LiDAR point clouds were processed to separate ground returns from vegetation returns using a filter method over a maize field in the Heihe River Basin, northwest China. The fractional cover (fCover) of maize canopy was computed using the ratio of canopy return counts or intensity sums to the total of returns or intensities. FPAR estimation models were established based on linear regression analysis between the LiDAR-derived fCover and the field-measured FPAR (R(2) = 0.90, RMSE = 0.032, p LiDAR-predicted FPARs and results show that the LiDAR-predicted FPAR has a high accuracy (R(2) = 0.89, RMSE = 0.034). In summary, this study suggests that the airborne discrete-return LiDAR data could be adopted to accurately estimate FPAR of maize.

  3. Molluscicidal activity of chlorophyll extraction against the freshwater snails

    Directory of Open Access Journals (Sweden)

    Mona Said Mahmoud

    2013-09-01

    Full Text Available Objective: To evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against the snails Lymnaea stagnalis, Biomphalaria spp. and Physa marmorata. Methods: Chlorophyllin was extracted from deep-frozen spinach. Snails were incubated in chlorophyllin containing water with 2.5, 5.0, 10.0 and 15.0 µg/mL. All samples were kept in darkness overnight for incubation. After incubation, three samples were irradiated with simulated solar radiation for 3 h. After irradiation, the vitality of the organisms was determined. Results: The photodynamically active chlorophyllin, at low concentrations, was able to kill snails within a few hours under exposure of solar radiation. Besides, it had a killing effect by about 70% and 100% on the snails’ eggs and the newly hatched snails, respectively, after 3 h exposure to solar radiation. Conclusion: The derivates of chlorophyll was a very interesting substance for photodynamic freshwater snail control. Hence, it might be a promising and cheap new strategy which probably had the potential to replace the synthetic molluscicides for snail control.

  4. Distribution of phytoplankton groups within the deep chlorophyll maximum

    KAUST Repository

    Latasa, Mikel

    2016-11-01

    The fine vertical distribution of phytoplankton groups within the deep chlorophyll maximum (DCM) was studied in the NE Atlantic during summer stratification. A simple but unconventional sampling strategy allowed examining the vertical structure with ca. 2 m resolution. The distribution of Prochlorococcus, Synechococcus, chlorophytes, pelagophytes, small prymnesiophytes, coccolithophores, diatoms, and dinoflagellates was investigated with a combination of pigment-markers, flow cytometry and optical and FISH microscopy. All groups presented minimum abundances at the surface and a maximum in the DCM layer. The cell distribution was not vertically symmetrical around the DCM peak and cells tended to accumulate in the upper part of the DCM layer. The more symmetrical distribution of chlorophyll than cells around the DCM peak was due to the increase of pigment per cell with depth. We found a vertical alignment of phytoplankton groups within the DCM layer indicating preferences for different ecological niches in a layer with strong gradients of light and nutrients. Prochlorococcus occupied the shallowest and diatoms the deepest layers. Dinoflagellates, Synechococcus and small prymnesiophytes preferred shallow DCM layers, and coccolithophores, chlorophytes and pelagophytes showed a preference for deep layers. Cell size within groups changed with depth in a pattern related to their mean size: the cell volume of the smallest group increased the most with depth while the cell volume of the largest group decreased the most. The vertical alignment of phytoplankton groups confirms that the DCM is not a homogeneous entity and indicates groups’ preferences for different ecological niches within this layer.

  5. Comparing RIEGL RiCOPTER UAV LiDAR Derived Canopy Height and DBH with Terrestrial LiDAR.

    Science.gov (United States)

    Brede, Benjamin; Lau, Alvaro; Bartholomeus, Harm M; Kooistra, Lammert

    2017-10-17

    In recent years, LIght Detection And Ranging (LiDAR) and especially Terrestrial Laser Scanning (TLS) systems have shown the potential to revolutionise forest structural characterisation by providing unprecedented 3D data. However, manned Airborne Laser Scanning (ALS) requires costly campaigns and produces relatively low point density, while TLS is labour intense and time demanding. Unmanned Aerial Vehicle (UAV)-borne laser scanning can be the way in between. In this study, we present first results and experiences with the RIEGL RiCOPTER with VUX ® -1UAV ALS system and compare it with the well tested RIEGL VZ-400 TLS system. We scanned the same forest plots with both systems over the course of two days. We derived Digital Terrain Model (DTMs), Digital Surface Model (DSMs) and finally Canopy Height Model (CHMs) from the resulting point clouds. ALS CHMs were on average 11.5 c m higher in five plots with different canopy conditions. This showed that TLS could not always detect the top of canopy. Moreover, we extracted trunk segments of 58 trees for ALS and TLS simultaneously, of which 39 could be used to model Diameter at Breast Height (DBH). ALS DBH showed a high agreement with TLS DBH with a correlation coefficient of 0.98 and root mean square error of 4.24 c m . We conclude that RiCOPTER has the potential to perform comparable to TLS for estimating forest canopy height and DBH under the studied forest conditions. Further research should be directed to testing UAV-borne LiDAR for explicit 3D modelling of whole trees to estimate tree volume and subsequently Above-Ground Biomass (AGB).

  6. Important LiDAR metrics for discriminating forest tree species in Central Europe

    Science.gov (United States)

    Shi, Yifang; Wang, Tiejun; Skidmore, Andrew K.; Heurich, Marco

    2018-03-01

    Numerous airborne LiDAR-derived metrics have been proposed for classifying tree species. Yet an in-depth ecological and biological understanding of the significance of these metrics for tree species mapping remains largely unexplored. In this paper, we evaluated the performance of 37 frequently used LiDAR metrics derived under leaf-on and leaf-off conditions, respectively, for discriminating six different tree species in a natural forest in Germany. We firstly assessed the correlation between these metrics. Then we applied a Random Forest algorithm to classify the tree species and evaluated the importance of the LiDAR metrics. Finally, we identified the most important LiDAR metrics and tested their robustness and transferability. Our results indicated that about 60% of LiDAR metrics were highly correlated to each other (|r| > 0.7). There was no statistically significant difference in tree species mapping accuracy between the use of leaf-on and leaf-off LiDAR metrics. However, combining leaf-on and leaf-off LiDAR metrics significantly increased the overall accuracy from 58.2% (leaf-on) and 62.0% (leaf-off) to 66.5% as well as the kappa coefficient from 0.47 (leaf-on) and 0.51 (leaf-off) to 0.58. Radiometric features, especially intensity related metrics, provided more consistent and significant contributions than geometric features for tree species discrimination. Specifically, the mean intensity of first-or-single returns as well as the mean value of echo width were identified as the most robust LiDAR metrics for tree species discrimination. These results indicate that metrics derived from airborne LiDAR data, especially radiometric metrics, can aid in discriminating tree species in a mixed temperate forest, and represent candidate metrics for tree species classification and monitoring in Central Europe.

  7. Gold-chlorophyll a-hybrid nanoparticles and chlorophyll a/cetyltrimethylammonium chloride self-assembled-suprastructures as novel carriers for chlorophyll a delivery in water medium: Photoactivity and photostability.

    Science.gov (United States)

    Rizzi, Vito; Vurro, Davide; Placido, Tiziana; Fini, Paola; Petrella, Andrea; Semeraro, Paola; Cosma, Pinalysa

    2018-01-01

    The stability of Chlorophyll a in water during prolonged exposure, at room temperature, to a neon lamp has been investigated by means of UV-vis and fluorescence spectroscopies. In addition, the Chlorophyll a (photo)stability evaluation in presence of suitable carriers has been performed in order to investigate its reactivity under the same conditions, for possible and future applications in Antimicrobial Photodynamic Therapy. Cetyltrimethylammonium chloride was chosen to solubilize Chlorophyll a in water. While, cetyltrimethylammonium chloride-capped gold nanoparticles offer a great opportunity because combine the Chlorophyll a action, used as a photosensitizer in Antimicrobial Photodynamic Therapy, with gold nanoparticles effect used in photothermal therapy. Indeed, the latter ones have exhibited an interesting rise of temperature if irradiated with visible light. Overall, both examined systems, cetyltrimethylammonium chloride/Chlorophyll a and gold nanoparticles/Chlorophyll a, were able to induce the Reactive Oxygen Species formation fundamental for a potential application in Antimicrobial Photodynamic Therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Mapping river bathymetry with a small footprint green LiDAR: Applications and challenges

    Science.gov (United States)

    Kinzel, Paul J.; Legleiter, Carl; Nelson, Jonathan M.

    2013-01-01

    Airborne bathymetric Light Detection And Ranging (LiDAR) systems designed for coastal and marine surveys are increasingly sought after for high-resolution mapping of fluvial systems. To evaluate the potential utility of bathymetric LiDAR for applications of this kind, we compared detailed surveys collected using wading and sonar techniques with measurements from the United States Geological Survey’s hybrid topographic⁄ bathymetric Experimental Advanced Airborne Research LiDAR (EAARL). These comparisons, based upon data collected from the Trinity and Klamath Rivers, California, and the Colorado River, Colorado, demonstrated

  9. [A comparative study on chlorophyll content, chlorophyll fluorescence and diurnal course of leaf gas exchange of two ecotypes of banyan].

    Science.gov (United States)

    Zhao, P; Sun, G; Zeng, X; Peng, S; Mo, X; Li, Y

    2000-06-01

    The morphological differences, chlorophyll contents, fluorescence and diurnal course of leaf gas exchange between terrestrial banyan and amphibious banyan were compared with pot culture. The amphibious banyan possesses well developed aerial and hydro-adventitious roots, and wider leaf with inclination of evolution toward mesophytic traits. The chlorophyll content of terrestrial banyan was higher than that of amphibious banyan. The diurnal course of leaf gas exchange indicated that net photosynthetic rate of terrestrial banyan was slightly higher than that of amphibious banyan grown in water, but much higher than that grown in soil. The amphibious banyan grown in water had the highest transpiration rate, the terrestrial banyan had a lower one, and the amphibious banyan grown in soil had the lowest. Linear regression analysis showed a positive correlation between net photosynthetic rate and stomatal conductance, implying that the stomatal conductance was dominant factor controlling the gas exchange. In this study, the term of intrinsic water use efficiency (net photosynthetic rate/stomatal conductance ratio, Intrinsic WUE) was applied to describe the photosynthesis and water properties, and the result showed that it was a more suitable measure compared to the usual WUE(net photosynthetic rate/transpiration rate). Among the three banyan plants examined, the amphibious banyan had the highest intrinsic WUE.

  10. Contribution of Chlorophyll Fluorescence to the Apparent Reflectance of Vegetation

    Science.gov (United States)

    Campbell, P. K. Entcheva; Middleton, E. M.; Kim, M. S.

    2007-01-01

    Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance (R) measurements, whi ch provide estimates of relative vegetation vigor based primarily on chlorophyll content. Vegetation chlorophyll fluorescence (CF) offers a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, monitoring of vegetation vigor based on CF may allow earlier stress detection and more accurate carbon sequestra tion estimates, than is possible using R data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contrib utions from both the reflected and fluoresced radiation. The aim of t his study is to determine the relative R and CF fractions contributing to Ra from the vegetation in the red to near-infrared region of the spectrum. The practical objectives of the study are to: 1) evaluate t he relationship between CF and R at the foliar level for corn, soybean, maple; and 2) for corn, determine if the relationship established f or healthy (optimal N) vegetation changes under N defiiency. To obtai n generally applicable results, experimental measurements were conducted on unrelated crop and tree species (maple, soybean and corn), unde r controlled conditions and a gradient of inorganic N fertilization l evels. Optical R spectra and actively induced CF emissions were obtained on the same foliar samples, in conjunction with measurements of p hotosynthetic function, pigment levels, and C and N content. The comm on spectral trends or similarities were examined. On average, 10-20% of apparent R at 685 nm was actually due to CF. The spectral trends in steady and maximum F varied significantly, with Fs (especially red) showing higher ability for species and treatment separation. The relative contribution of ChF to R varied significantly among species, with maple emitting much higher F amounts, as

  11. Contribution of chlorophyll fluorescence to the apparent vegetation reflectance

    International Nuclear Information System (INIS)

    Campbell, P.K. Entcheva; Middleton, E.M.; Corp, L.A.; Kim, M.S.

    2008-01-01

    Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance data, which provide estimates of vigor based primarily on chlorophyll content. Chlorophyll fluorescence (ChlF) measurements offer a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, technology based on ChlF may allow more accurate carbon sequestration estimates and earlier stress detection than is possible when using reflectance data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contributions from both the reflected and fluoresced radiation. The aim of this study is to determine the relative contributions of reflectance and ChlF fractions to Ra in the red to near-infrared region (650-800 nm) of the spectrum. The practical objectives of the study are to: 1) evaluate the relationship between ChlF and reflectance at the foliar level for corn, soybean and maple; and 2) for corn, determine if the relationship established for healthy vegetation changes under nitrogen (N) deficiency. To obtain generally applicable results, experimental measurements were conducted on unrelated crop and tree species (corn, soybean and maple) under controlled conditions and a gradient of inorganic N fertilization levels. Optical reflectance spectra and actively induced ChlF emissions were collected on the same foliar samples, in conjunction with measurements of photosynthetic function, pigment levels, and carbon (C) and N content. The spectral trends were examined for similarities. On average, 10-20% of Ra at 685 nm was actually due to ChlF. The spectral trends in steady state and maximum fluorescence varied significantly, with steady state fluorescence (especially red, 685 nm) showing higher ability for species and treatment separation. The relative contribution of ChlF to Ra varied significantly among species, with maple

  12. Isolation of Crystalline Water-soluble Chlorophyll Proteins with Different Chlorophyll a and b Contents from Stems and Leaves of Lepidium virginicum

    OpenAIRE

    Reiko, Itoh; Shigeru, Itoh; Masaharu, Sugawa; Osamu, Oishi; Kenichi, Tabata; Mitsumasa, Okada; Mitsuo, Nishimura; Eijiro, Yakushiji; Department of Biology, Faculty of Science, Toho University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Toho University; Department of Biology, Faculty of Science, Kyushu University

    1982-01-01

    Two types of water-soluble chlorophyll proteins were isolated from Lepidium virginicum L. grown in Japan. The protein isolated from the leaves (CP663L) had a low chlorophyll a/b ratio (1.5-1.7), and that from the stems (CP663S) had a high ratio (3.4-3.5). CP663S showed the same crystal forms and almost the same molecular weight and subunit composition as CP663L.

  13. Estimating Forest Biomass Dynamics by Integrating Multi-Temporal Landsat Satellite Images with Ground and Airborne LiDAR Data in the Coal Valley Mine, Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Nasem Badreldin

    2015-03-01

    Full Text Available Assessing biomass dynamics is highly critical for monitoring ecosystem balance and its response to climate change and anthropogenic activities. In this study, we introduced a direct link between Landsat vegetation spectral indices and ground/airborne LiDAR data; this integration was established to estimate the biomass dynamics over various years using multi-temporal Landsat satellite images. Our case study is located in an area highly affected by coal mining activity. The normalized difference vegetation index (NDVI, enhanced vegetation index (EVI and EVI2, chlorophyll vegetation index (CVI, and tasseled cap transformations were used as vegetation spectral indices to estimate canopy height. In turn, canopy height was used to predict a coniferous forest’s biomass using Jenkins allometric and Lambert and Ung allometric equations. The biophysical properties of 700 individual trees at eight different scan stations in the study area were obtained using high-resolution ground LiDAR. Nine models (Hi were established to discover the best relationship between the canopy height model (CHM from the airborne LiDAR and the vegetation spectral indices (VSIs from Landsat images for the year 2005, and HB9 (Jenkins allometric equation and HY9 (Lambert and Ung allometric equation proved to be the best models (r2 = 0.78; root mean square error (RMSE = 44 Mg/H, r2 = 0.67; RMSE = 58.01 Mg/H, respectively; p < 0.001 for estimating the canopy height and the biomass. This model accurately captured the most affected areas (deforested and the reclaimed areas (forested in the study area. Five years were chosen for studying the biomass change: 1988, 1990, 2001, 2005, and 2011. Additionally, four pixel-based image comparisons were analyzed (i.e., 1988–1990, 1990–2005, 2005–2009, and 2009–2011, and Mann-Kendall statistics for the subsets of years were obtained. The detected change showed that, in general, the environment in the study area was recovering and

  14. Forest Roads Mapped Using LiDAR in Steep Forested Terrain

    Directory of Open Access Journals (Sweden)

    Russell A. White

    2010-04-01

    Full Text Available LiDAR-derived digital elevation models can reveal road networks located beneath dense forest canopy. This study tests the accuracy of forest road characteristics mapped using LiDAR in the Santa Cruz Mountains, CA. The position, gradient, and total length of a forest haul road were accurately extracted using a 1 m DEM. In comparison to a field-surveyed centerline, the LiDAR-derived road exhibited a positional accuracy of 1.5 m, road grade measurements within 0.53% mean absolute difference, and total road length within 0.2% of the field-surveyed length. Airborne LiDAR can provide thorough and accurate road inventory data to support forest management and watershed assessment activities.

  15. Identification of four Drosophila allatostatins as the cognate ligands for the Drosophila orphan receptor DAR-2

    DEFF Research Database (Denmark)

    Lenz, C; Williamson, M; Hansen, G N

    2001-01-01

    The allatostatins are generally inhibitory insect neuropeptides. The Drosophila orphan receptor DAR-2 is a G-protein-coupled receptor, having 47% amino acid residue identity with another Drosophila receptor, DAR-1 (which is also called dros. GPCR, or DGR) that was previously shown...... to be the receptor for an intrinsic Drosophila A-type (cockroach-type) allatostatin. Here, we have permanently expressed DAR-2 in CHO cells and found that it is the cognate receptor for four Drosophila A-type allatostatins, the drostatins-A1 to -A4. Of all the drostatins, drostatin-A4 (Thr...... weakly in the brain. The Drosophila larval gut also contains about 20-30 endocrine cells, expressing the gene for the drostatins-A1 to -A4. We suggest, therefore, that DAR-2 mediates an allatostatin (drostatin)-induced inhibition of gut motility. This is the first report on the permanent and functional...

  16. 2007 Lake County Board of County Commissioners Topographic LiDAR: Lake County, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata document describes the LiDAR point data in LAS format produced by Kucera covering the project area of Lake County, FL. The data produced is...

  17. 2007 Southwest Florida Water Management District (SWFWMD) LiDAR: Hernando County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is one component of a digital terrain model (DTM) for the Southwest Florida Water Management Districts FY2006 Digital Orthophoto (B089) and LiDAR...

  18. 2006 U.S. Geological Survey Topographic LiDAR: Alameda County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) data set is a survey of Alameda County in Northern California. The entire survey covers approximately 868.382 square miles....

  19. 2008 Northwest Florida Water Management District (NWFWMD) LiDAR: Inland Okaloosa County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Light Detection and Ranging (LiDAR) LAS dataset is a survey of inland Okaloosa County, Florida not covered in the 2008 Florida Department of Emergency...

  20. 2009 Federal Emergency Management Agency (FEMA) Topographic LiDAR: Fort Kent, Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Camp Dresser McKee Inc. contracted with Sanborn Map Company to provide LiDAR mapping services for Fort Kent, Maine. Utilizing multi-return systems, Light Detection...

  1. LiDAR-derived Vegetation Canopy Structure, Great Smoky Mountains National Park, 2011

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides multiple-return LiDAR-derived vegetation canopy structure at 30-meter spatial resolution for the Great Smoky Mountains National Park (GSMNP)....

  2. LiDAR and DTM Data from Forested Land Near Manaus, Amazonas, Brazil, 2008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides LiDAR point clouds and digital terrain models (DTM) from surveys over the K34 tower site in the Cuieiras Biological Reserve, over forest...

  3. Case of rhesus antigen weak D type 4.2. (DAR category detection

    Directory of Open Access Journals (Sweden)

    L. L. Golovkina

    2015-01-01

    Full Text Available Serological methods of Rhesus antigens identification in humans cannot identify D-antigen variants. In this article the serological characteristics of Rhesus antigen D weak type 4.2. (Category DAR are described.

  4. LiDAR Elevation Data Collection - Putnam County, NY, 2008 (NYSDEC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Summary of the surface elevation data collection project in Putnam County, NY (NYSDEC) 2008. Products generated include LiDAR point data in LAS Binary format v1.1....

  5. LiDAR Relative Reflectivity Surface (2011) for the St. Thomas East End Reserve, St. Thomas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 0.3x0.3 meter resolution relative seafloor reflectivity surface for the St. Thomas East End Reserve...

  6. 2009 Puget Sound Lidar Consortium (PSLC) Topographic LiDAR: Nooksack River

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data of the Nooksack River in Washington on February 20th - 22nd, 2009. The total area of...

  7. CMS: LiDAR Data for Forested Sites on Borneo Island, Kalimantan, Indonesia, 2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides airborne LiDAR data collected over 90 sites totaling approximately 100,000 hectares of forested land in Kalimantan, Indonesia on the island of...

  8. CMS: LiDAR-derived Canopy Height, Elevation for Sites in Kalimantan, Indonesia, 2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides canopy height and elevation data products derived from airborne LiDAR data collected over 90 sites on the island of Borneo in late 2014. The...

  9. LiDAR and DTM Data from Tapajos National Forest in Para, Brazil, 2008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides LiDAR point clouds and digital terrain models (DTM) from surveys over the Tapajos National Forest in Belterra municipality, Para, Brazil...

  10. 2006-2008 PAMAP LiDAR Data of Pennsylvania (Northern Counties)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of classified LiDAR (Light Detection and Ranging) elevation points produced by the PAMAP Program. PAMAP data are organized into blocks, which...

  11. CMS: GLAS LiDAR-derived Global Estimates of Forest Canopy Height, 2004-2008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides estimates of forest canopy height derived from the Geoscience Laser Altimeter System (GLAS) LiDAR instrument that was aboard the NASA Ice,...

  12. LiDAR Data, DEM, and Maximum Vegetation Height Product from Southern Idaho, 2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides the point cloud data derived from small footprint waveform LiDAR data collected in August 2014 over Reynolds Creek Experimental Watershed and...

  13. 2010 U.S. Geological Survey (USGS) Topographic LiDAR: San Francisco Bay, California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The primary purpose of this project was to develop a consistent and accurate surface elevation dataset derived from high-accuracy Light Detection and Ranging (LiDAR)...

  14. CMS: LiDAR Data for Mangrove Forests in the Zambezi River Delta, Mozambique, 2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides high-resolution LiDAR point cloud data collected during surveys over mangrove forests in the Zambezi River Delta in Mozambique in May 2014....

  15. 2006 Florida LiDAR: Escambia, Santa Rosa, and Walton Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ESCAMBIA: The Light Detection and Ranging (LiDAR) LAS dataset is a survey of select areas within Escambia County, Florida. These data were produced for Dewberry and...

  16. 2006-2008 PAMAP LiDAR Data of Pennsylvania (Southern Counties)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of classified LiDAR (Light Detection and Ranging) elevation points produced by the PAMAP Program. Additional information is available at the...

  17. 2007 Southwest Florida Water Management District (SWFWMD) LiDAR: Hillsborough/Little Manatee Districts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — EarthData International collected ADS-50 derived LiDAR over a portion of Hillsborough and Manatee Counties with a one meter post spacing. The period of collection...

  18. 2010 U.S. Geological Survey Topographic LiDAR: Atchafalaya Basin, Louisiana

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) dataset is a survey of the Atchafalaya Basin in south-central Louisiana. The entire survey area encompasses 981 square miles....

  19. 2011 Federal Emergency Management Agency (FEMA) Topographic LiDAR: Quinnipiac River Watershed, Connecticut

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Quinnipiac AOI consists of one 443 square mile area. Ground Control is collected throughout the AOI for use in the processing of LiDAR data to ensure data...

  20. 2009 National Renewable Energy Laboratory/Boston Redevelopment Authority Topographic LiDAR: Boston, Massachusetts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Alliance for Sustainable Energy, LLC contracted with Sanborn to provide LiDAR mapping services for the Boston area. Utilizing multi-return systems, Light...

  1. LAI and chlorophyll estimation for a heterogeneous grassland using hyperspectral measurements

    NARCIS (Netherlands)

    Darvishzadeh, R.; Skidmore, A.K.; Schlerf, M.; Atzberger, C.; Corsi, F.; Cho, M.A.

    2008-01-01

    The study shows that leaf area index (LAI), leaf chlorophyll content (LCC) and canopy chlorophyll content (CCC) can be mapped in a heterogeneous Mediterranean grassland from canopy spectral reflectance measurements. Canopy spectral measurements were made in the field using a GER 3700

  2. Nondestructive and intuitive determination of circadian chlorophyll rhythms in soybean leaves using multispectral imaging

    Science.gov (United States)

    Pan, Wen-Juan; Wang, Xia; Deng, Yong-Ren; Li, Jia-Hang; Chen, Wei; Chiang, John Y.; Yang, Jian-Bo; Zheng, Lei

    2015-06-01

    The circadian clock, synchronized by daily cyclic environmental cues, regulates diverse aspects of plant growth and development and increases plant fitness. Even though much is known regarding the molecular mechanism of circadian clock, it remains challenging to quantify the temporal variation of major photosynthesis products as well as their metabolic output in higher plants in a real-time, nondestructive and intuitive manner. In order to reveal the spatial-temporal scenarios of photosynthesis and yield formation regulated by circadian clock, multispectral imaging technique has been employed for nondestructive determination of circadian chlorophyll rhythms in soybean leaves. By utilizing partial least square regression analysis, the determination coefficients R2, 0.9483 for chlorophyll a and 0.8906 for chlorophyll b, were reached, respectively. The predicted chlorophyll contents extracted from multispectral data showed an approximately 24-h rhythm which could be entrained by external light conditions, consistent with the chlorophyll contents measured by chemical analyses. Visualization of chlorophyll map in each pixel offers an effective way to analyse spatial-temporal distribution of chlorophyll. Our results revealed the potentiality of multispectral imaging as a feasible nondestructive universal assay for examining clock function and robustness, as well as monitoring chlorophyll a and b and other biochemical components in plants.

  3. The effect of shade on chlorophyll and anthocyanin content of upland red rice

    Science.gov (United States)

    Muhidin; Syam’un, E.; Kaimuddin; Musa, Y.; Sadimantara, G. R.; Usman; Leomo, S.; Rakian, T. C.

    2018-02-01

    Upland red rice (Oryza sativa) is a staple food and contains anthocyanin, which can act as antioxidants, plays an important role both for the plant itself and for human health. Levels of antioxidants in rice can be affected by the availability of light. The results showed that the difference of shade, cultivar, and interaction both significantly affect the content of chlorophyll a, chlorophyll b and total chlorophyll. The results also showed that shade could increase chlorophyll in all cultivars tested. The highest levels of chlorophyll a were present in the moderate shade level (n2), then decreased at the shelter level (n3) and increased again at high levels (n4). While on chlorophyll content b, it appears that shade increased chlorophyll b in all cultivars tested and this increase was linear to the increase of shade. The shade treatment may increase the anthocyanin content and the increase depending on the type of cultivar. Increased levels of anthocyanin highest due to shade occurred on Jangkobembe cultivar. The original level of anthocyanin on Jangkobembe cultivar averaged 0.096 mg g-1 increased to 2.487 mg g-1 or increased 26 fold. It is concluded that the shade had a significant effect on the chlorophyll and anthocyanin content.

  4. Low light intensity and nitrogen starvation modulate the chlorophyll content of Scenedesmus dimorphus.

    Science.gov (United States)

    Ferreira, V S; Pinto, R F; Sant'Anna, C

    2016-03-01

    Chlorophyll is a photosynthetic pigment found in plants and algal organisms and is a bioproduct with human health benefits and a great potential for use in the food industry. The chlorophyll content in microalgae strains varies in response to environmental factors. In this work, we assessed the effect of nitrogen depletion and low light intensity on the chlorophyll content of the Scenedesmus dimorphus microalga. The growth of S. dimorphus under low light intensity led to a reduction in cell growth and volume as well as increased cellular chlorophyll content. Nitrogen starvation led to a reduction in cell growth and the chlorophyll content, changes in the yield and productivity of chlorophylls a and b. Transmission electron microscopy was used to investigate the ultrastructural changes in the S. dimorphus exposed to nitrogen and light deficiency. In contrast to nitrogen depletion, low light availability was an effective mean for increasing the total chlorophyll content of green microalga S. dimorphus. The findings acquired in this work are of great biotechnological importance to extend knowledge of choosing the right culture condition to stimulate the effectiveness of microalgae strains for chlorophyll production purposes. © 2015 The Society for Applied Microbiology.

  5. Presence of a chlorophyll d-like pigment in Chlorella extracts

    NARCIS (Netherlands)

    Michel-Wolwertz, M.R.; Sironval, C.; Goedheer, J.C.

    1965-01-01

    Three chlorophyll a isomers (a₁, a₂ and a₃) were separated by the chromatography of Chlorella extracts on paper 1. One of these, chlorophyll (a₃) showed additional absorption bands at 688 and 455 mμ in diethyl ether. Chromatographic analysis could not decide whether these bands were due to a₃ or

  6. Chlorophyll fluorescence: What is it and what do the numbers mean?

    Science.gov (United States)

    Gary A. Ritchie

    2006-01-01

    Although results of chlorophyll fluorescence (CF) measurements in nursery seedlings are becoming widely reported in the literature, the theory, terminology, and interpretation of these data are often obscure and confusing to nursery practitioners. This report outlines the underlying physiological basis for chlorophyll fluorometry and discusses measurement protocols and...

  7. The interpretation of satellite chlorophyll observations: The case of the Mozambique Channel

    NARCIS (Netherlands)

    Omta, A.W.; Llido, J.; Garçon, V.; Kooijman, S.A.L.M.; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467

    2009-01-01

    The surface chlorophyll concentration measured by satellites is commonly interpreted as a direct measure of phytoplankton biomass. However, one problem with this interpretation is that the amount of chlorophyll per amount of algal biomass (the Chl:C ratio) is not constant. In this article, we show

  8. Using hyperspectral remote sensing data for retrieving canopy chlorophyll and nitrogen content

    NARCIS (Netherlands)

    Clevers, J.G.P.W.; Kooistra, L.

    2012-01-01

    Plant stress is often expressed as a reduction in amount of biomass or leaf area index (LAI). In addition, stress may affect the plant pigment system, influencing the photosynthetic capacity of plants. Chlorophyll content is the main driver for this primary production. The chlorophyll content is

  9. Chlorophyll-A concentrations in relation to water quality and trophic ...

    African Journals Online (AJOL)

    The Weija Reservoir has a high algal content which has posed water quality problems in the reservoir for a long time. Chlorophyll-a has been determined in water samples from the surface (0–10 cm) of the Weija Reservoir, collected at 3 different sites in the Reservoir from 2005 to 2008 at bi-monthly intervals. Chlorophyll-a ...

  10. Substratum as a driver of variation in periphyton chlorophyll and productivity in lakes

    DEFF Research Database (Denmark)

    Vadeboncoeur, Y.; Kalff, J.; Christoffersen, Kirsten Seestern

    2006-01-01

    Quantifying periphyton (attached algal) contributions to autotrophic production in lakes is confounded by properties of substratum that affect community biomass (as chlorophyll content) and productivity. We compared chlorophyll content and productivity of natural algal communities (phytoplankton,...... of the littoral zones in nutrient and energy cycles in lakes....

  11. Effects of LEDs on chlorophyll fluorescence and secondary metabolites in Phalaenopsis

    DEFF Research Database (Denmark)

    Ouzounis, T.; Fretté, X.; Rosenqvist, Eva

    2015-01-01

    of the experiment. Chlorophyll fluorescence was also recorded with PAM-2001. Leaf area and total fresh weight were highest in the 40%B/60%R for Phalaenopsis 'Vivien', while 100%R demonstrated the highest leaf area and fresh weight for Phalaenopsis 'Purple star'. Chlorophyll fluorescence for the same treatments...

  12. The Effects of Refinery Effluent of the Chlorophyll a and Gross ...

    African Journals Online (AJOL)

    The effect of Kaduna Refinery effluent discharge on the chlorophyll a and gross primary productivity of river Rido was studied for 12 months at 3 stations in the river. Station 1 is the clean water station not affected by the discharge; stations 2 & 3 are the polluted area. The values for chlorophyll a and gross primary productivity ...

  13. Crystallization of water-soluble chlorophyll-proteins from Lepidium virginicum.

    Science.gov (United States)

    Murata, T; Itoh, R; Yakushiji, E

    1980-11-05

    Water-soluble chlorophyll-proteins were prepared from leaves of Lepidium virginicum, by means of ammonium sulfate fractionation followed by column chromatography on DEAE-cellulose and Sephacryl S-200. After intensive purification the chlorophyll-proteins were crystallized by dialysis against an ammonium sulfate solution.

  14. Diurnal patterns of chlorophyll fluorescence and CO2 fixation in orchard grown Torreya taxifolia (Arn.).

    Science.gov (United States)

    Anita C. Koehn; Robert L. Doudrick

    1999-01-01

    Diurnal patterns of chlorophyll fluorescence and CO2 fixation in orchard measurements were taken on sunny days in October 1996, on three Torreya taxifolia (Arn.) plants grown in an open canopy orchard. Information from chlorophyll fluorescence quenching analysis indicated that during periods of highest light intensity and temperatures there were...

  15. Canopy Level Chlorophyll Fluorescence and the PRI in a Cornfield

    Science.gov (United States)

    Middleton, Elizabeth M.; Cheng, Yen-Ben; Corp, Lawrence A.; Campbell, Petya K. E.; Huemmrich, K. Fred; Zhang, Qingyuan; Kustas, William P.

    2012-01-01

    Two bio-indicators, the Photochemical Reflectance Index (PRI) and solar-induced red and far-red Chlorophyll Fluorescence (SIF), were derived from directional hyperspectral observations and studied in a cornfield on two contrasting days in the growing season. Both red and far-red SIF exhibited higher values on the day when the canopy in the early senescent stage, but only the far-red SIF showed sensitivity to viewing geometry. Consequently, the red/far-red SIF ratio varied greatly among azimuth positions while the largest values were obtained for the "hotspot" at both growth stages. This ratio was lower (approx.0.88 +/- 0.4) in early July than in August when the ratio approached equivalence (near approx.1). In concert, the PRI exhibited stronger responses to both zenith and azimuth angles and different values on the two growth stages. The potential of using these indices to monitor photosynthetic activities needs further investigation

  16. Laser and sunlight-induced fluorescence from chlorophyll pigments

    Science.gov (United States)

    Kim, H. H.; Brown, K. S.

    1986-01-01

    Fluorescence properties of chlorophyll pigment bearing plant foliage utilizing a 337 nm nitrogen laser and integrating sphere were studied. Measured yields, in terms of number of photons emitted per 100 photons absorbed, range from 1.5 to 0.1 for the 685 nm peak, and from 4.2 to 0.2 for the 730 nm peak. Decreasing order of magnitude puts herbaceous leaves ahead of all others followed by broad leaves of hardwoods and coniferous needles. Meaningful quantization for the fluorescence peaks at 430 and 530 nm could not be attained. Passive monitoring of these fluorescence peaks is successful only for the 685 nm from the ocean surface. Field data show the reflectance changes at 685 nm due to the algae presence amounts to 1% at most.

  17. Chlorophyll a fluorescence to phenotype wheat genotypes for heat tolerance

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari; Andersen, Sven Bode; Ottosen, Carl-Otto

    In prospects of global climate change, heat stress is a rising constraint for the productivity of wheat (Triticum aestivum L.). It is a heat-susceptible crop beyond 17-23oC temperature throughout its phenological stages, flowering phase being the most sensitive stage. Chlorophyll a fluorescence...... parameter, maximum quantum yield efficiency of PSII (Fv/Fm) is used as a physiological marker for early stress detection in PSII in plants. We established a reproducible protocol to measure response of wheat genotypes to high temperature based on Fv/Fm. The heat treatment of 40°C in 300 µmol m-2s-1 PAR...... enabled the identification of contrasting wheat genotypes that can be used to study the genetic and physiological nature of heat stress tolerance to dissect quantitative traits into simpler and more heritable traits....

  18. Chlorophyll meter for estimating nitrogen status of irrigated wheat

    International Nuclear Information System (INIS)

    Schepers, J.S.

    2000-01-01

    Chlorophyll-meter readings, generated from the leaves of irrigated wheat at particular growth stages, were normalized to the data obtained with locally recommended rates of fertilizer N, in Chile China, India and Mexico. Normalizing permitted comparisons of crop-N status across growth stages, locations, cultivars, and years. Relative yields and meter readings at growth-stage Z-50 are presented; they revealed similar trends for India, China, and Chile, however, for Mexico, the combination of soil, wheat cultivar, and climate resulted in much less response to N fertilization in the meter data. The implications are discussed. The SPAD meter proved to be a good tool to monitor and evaluate the N status of irrigated wheat. (author)

  19. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    Science.gov (United States)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  20. The power of pigments, calibrating chemoclines with chlorophylls and carotenoids.

    Science.gov (United States)

    Junium, C. K.; Uveges, B. T.

    2017-12-01

    Phototrophic organisms produce a diversity of pigments that serve a broad range of specific biochemical functions. Pigments are either directly associated with the photosynthetic apparatus, the most notable being chlorophyll a, or are accessory pigments such as the carotenoid lutein. Their functions can also be categorized into roles that are related to light harvesting (e.g. fucoxanthin) or for photoprotection (e.g. scytonemin). The abundances of these two classes of pigments from environmental samples can provide specific information about photointensity and how it relates to environmental changes. For example, a deepening of the chemo/nutricline can result in the increased production of light gathering relative to photoprotective pigments. Here we apply a relatively simple approach that utilizes the abundance of photosynthetic relative to photoprotective pigments to help constrain changes in the water column position of the chemocline. To test the efficacy of this approach we have utilized the sedimentary record of the anoxic Lake Kivu in the East African Rift. Recent Lake Kivu sediments are punctuated by a series of sapropels that may be associated with overturn of the lake, and release of carbon dioxide and sulfide during potential limnic eruptions. Carbon and nitrogen isotopes decrease significantly at the onset of sapropel deposition and suggest that 13C-depleted dissolved inorganic carbon was upwelled into surface waters and was accompanied by high concentrations of ammonium, that allowed for 15N-depletion during incomplete nitrogen utilization. The pigment record, specifically the ratio of the photoprotective carotenoids lutein and zeaxanthin to chlorophyll a increases significantly at the onset of sapropel deposition. This suggests that the chemocline shallowed, displacing phototrophic communities toward the surface of the lake where light intensities required production of photoprotective pigments. This approach can easily be applied to a wide variety of

  1. Physical and chemical studies of chlorophyll in microemulsions. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    Studies designed to provide fundamental information on both the nature of photoreactions in microemulsions and the utility of these media as solvents for absorbers of solar energy were conducted. As a test system, the photoreduction of absorbed dye (principally methyl red) sensitized by chlorophyll a in an anionic mineral oil in water microemulsion was investiged. Using ascorbate as the water soluble reducing agent and pigment concentrations of up to eight per drop (10mM), the reaction exhibits a pseudo zero order dependence on methyl red. The effect of sensitizer, ascorbate concentration and light intensity on the quantum yield was examined, as well as the effect of varying the microemulsion charge type, product catalysis, and the use of synthetic porphyrin sensitizers. In microemulsions containing up to eight chlorophyll molecules per microdroplet, the quantum yield remains constant over five orders of magnitude concentration. The intrinsic quantum yield is independent of droplet surface charge, but is dependent on pH. One of the products of the chemical reduction of methyl red, N, N-dimethyl-p-phenylenediamine (DMPD), increases the limiting quantum yield two to three fold. Synthetic porphyrins have been found to act as sensitizers, and a number of tetrapyridyl porphyrin derivatives containing one to four carbon chains of varying length have been made and examined. The results show that the quantum yield increases with increasing chain length for the monoalkyl compounds, and also indicate the possible involvement of a sensitizer orientation effect. The transport of oil soluble electroactive species in nonionic microemulsions has been found to exhibit percolation behavior, which has potential photogalvanic applications.

  2. Modeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data

    Science.gov (United States)

    Hagar, Joan C.; Eskelson, Bianca N.I.; Haggerty, Patricia K.; Nelson, S. Kim; Vesely, David G.

    2014-01-01

    LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to address the need identified in the Recovery Plan for a more accurate estimate of the availability of nesting habitat by developing occupancy maps based on refined measures of nest-strand structure. We used murrelet occupancy data collected by the Bureau of Land Management Coos Bay District, and canopy metrics calculated from discrete return airborne LiDAR data, to fit a logistic regression model predicting the probability of occupancy. Our final model for stand-level occupancy included distance to coast, and 5 LiDAR-derived variables describing canopy structure. With an area under the curve value (AUC) of 0.74, this model had acceptable discrimination and fair agreement (Cohen's κ = 0.24), especially considering that all sites in our sample were regarded by managers as potential habitat. The LiDAR model provided better discrimination between occupied and unoccupied sites than did a model using variables derived from Gradient Nearest Neighbor maps that were previously reported as important predictors of murrelet occupancy (AUC = 0.64, κ = 0.12). We also evaluated LiDAR metrics at 11 known murrelet nest sites. Two LiDAR-derived variables accurately discriminated nest sites from random sites (average AUC = 0.91). LiDAR provided a means of quantifying 3-dimensional canopy structure with variables that are ecologically relevant to murrelet nesting habitat, and have not been as accurately quantified by other mensuration methods.

  3. Sexual behaviours and associated factors among students at Bahir Dar University: a cross sectional study

    OpenAIRE

    Mulu, Wondemagegn; Yimer, Mulat; Abera, Bayeh

    2014-01-01

    Background Sexual behaviour is the core of sexuality matters in adolescents and youths. Their modest or dynamic behaviour vulnerable them to risky sexual behaviours. In Ethiopia, there is scarcity of multicentered representative data on sexual behaviours in students to have a national picture at higher education. This study therefore conducted to assess sexual behaviours and associated factors at Bahir Dar University, Ethiopia. Methods A cross sectional study was conducted among Bahir Dar Uni...

  4. Synergy of VSWIR and LiDAR for Ecosystem Structure, Biomass, and Canopy Diversity

    Science.gov (United States)

    Cook, Bruce D.; Asner, Gregory P.

    2010-01-01

    This slide presentation reviews the use of Visible ShortWave InfraRed (VSWIR) Imaging Spectrometer and LiDAR to study ecosystem structure, biomass and canopy diversity. It is shown that the biophysical data from LiDAR and biochemical information from hyperspectral remote sensing provides complementary data for: (1) describing spatial patterns of vegetation and biodiversity, (2) characterizing relationships between ecosystem form and function, and (3) detecting natural and human induced change that affects the biogeochemical cycles.

  5. Aboveground Biomass Modeling from Field and LiDAR Data in Brazilian Amazon Tropical Rain Forest

    Science.gov (United States)

    Silva, C. A.; Hudak, A. T.; Vierling, L. A.; Keller, M. M.; Klauberg Silva, C. K.

    2015-12-01

    Tropical forests are an important component of global carbon stocks, but tropical forest responses to climate change are not sufficiently studied or understood. Among remote sensing technologies, airborne LiDAR (Light Detection and Ranging) may be best suited for quantifying tropical forest carbon stocks. Our objective was to estimate aboveground biomass (AGB) using airborne LiDAR and field plot data in Brazilian tropical rain forest. Forest attributes such as tree density, diameter at breast height, and heights were measured at a combination of square plots and linear transects (n=82) distributed across six different geographic zones in the Amazon. Using previously published allometric equations, tree AGB was computed and then summed to calculate total AGB at each sample plot. LiDAR-derived canopy structure metrics were also computed at each sample plot, and random forest regression modelling was applied to predict AGB from selected LiDAR metrics. The LiDAR-derived AGB model was assessed using the random forest explained variation, adjusted coefficient of determination (Adj. R²), root mean square error (RMSE, both absolute and relative) and BIAS (both absolute and relative). Our findings showed that the 99th percentile of height and height skewness were the best LiDAR metrics for AGB prediction. The AGB model using these two best predictors explained 59.59% of AGB variation, with an Adj. R² of 0.92, RMSE of 33.37 Mg/ha (20.28%), and bias of -0.69 (-0.42%). This study showed that LiDAR canopy structure metrics can be used to predict AGC stocks in Tropical Forest with acceptable precision and accuracy. Therefore, we conclude that there is good potential to monitor carbon sequestration in Brazilian Tropical Rain Forest using airborne LiDAR data, large field plots, and the random forest algorithm.

  6. Remote sensing of forest structure using LiDAR and SAR

    OpenAIRE

    Balzter, Heiko; Burwell, Claire; Rowland, Clare S.; Tansey, Kevin

    2008-01-01

    Forests play an important role in the global climate system because they take up and store large amounts of carbon in the form of biomass. This paper examines techniques of retrieving structural forest information using the remote sensing techniques of LiDAR and SAR. Both sensing methods can provide information on the vertical structure of forests. Certain LiDAR instruments can record a vertical waveform of reflected radiation from the forest which can be related to vertical bioma...

  7. Status and prospects for LiDAR remote sensing of forested ecosystems

    OpenAIRE

    Wulder, Michael A; Coops, Nicholas C; Hudak, Andrew T; Morsdorf, Felix; Nelson, R; Newnham, G; Vastaranta, Mikko

    2013-01-01

    The science associated with the use of airborne and satellite Light Detection and Ranging (LiDAR) to remotely sense forest structure has rapidly progressed over the past decade. LiDAR has evolved from being a poorly understood, potentially useful tool to an operational technology in a little over a decade, and these instruments have become a major success story in terms of their application to the measurement, mapping, or monitoring of forests worldwide. Invented in 1960, the laser and, a sho...

  8. Getting the most neutrinos out of IsoDAR

    Energy Technology Data Exchange (ETDEWEB)

    Ciuffoli, Emilio; Zhao, Fengyi; Deliyergiyev, Maksym [CAS, Institute of Modern Physics, Lanzhou (China); Mohammed, Hosam; Evslin, Jarah [CAS, Institute of Modern Physics, Lanzhou (China); University of the Chinese Academy of Sciences, Beijing (China)

    2017-12-15

    Several experimental collaborations worldwide intend to test sterile neutrino models by measuring the disappearance of antineutrinos produced via isotope decay at rest (IsoDAR). The most advanced of these proposals have very similar setups, in which a proton beam strikes a target yielding neutrons which are absorbed by a high isotopic purity {sup 7}Li converter, yielding {sup 8}Li whose resulting decay yields the antineutrinos. In this note, we use FLUKA and GEANT4 simulations to investigate three proposed modifications of this standard proposal. In the first, the {sup 7}Li is replaced with {sup 7}Li compounds including a deuterium moderator. In the second, a gap is placed between the target and the converter to reduce the neutron bounce-back. Finally, we consider cooling the converter with liquid nitrogen. We find that these modifications can increase the antineutrino yield by as much as 50%. The first also substantially reduces the quantity of high purity {sup 7}Li which is needed. (orig.)

  9. (Women’s Readings of Parvaz- Dar- Hobab

    Directory of Open Access Journals (Sweden)

    Jamal Mohammadi

    2008-07-01

    Full Text Available This research is an attempt to explain how audiences read and decode the dominant or preferred reading of television soap operas ( here, one of them named : Parvaz Dar Hobab . The main problem of this research is that in what way TV soap operas prefer or make dominant some meanings, ideas and values and how audiences interpret and decode these meanings and ideas and values. From this viewpoint, a soap opera is an articulation constructed of different, and sometimes contrast, elements which are unified around a nodal point. In other words, a television soap opera is an articulatory discourse which is constructed through some technical, social and ideological codes by hegemonic system. In a TV soap opera, as a discourse, some ideas and meanings are preferred over the others. The question is that how social subjects, who have an objective position in the social structure, read and decode these dominant ideas and meanings? In this research, in the first part we have used the semilogical- structuralist method to explain the preferred reading of TV soap operas, and in the second part we used focused group interview to study women readings. To mention one of the conclusions of this research, we can say that this soap opera attempts to hide that social nihilism which is the main factor of addiction. Most of the audiences have an oppositional reading of this problem.

  10. Analyzing Glacier Surface Motion Using LiDAR Data

    Directory of Open Access Journals (Sweden)

    Jennifer W. Telling

    2017-03-01

    Full Text Available Understanding glacier motion is key to understanding how glaciers are growing, shrinking, and responding to changing environmental conditions. In situ observations are often difficult to collect and offer an analysis of glacier surface motion only at a few discrete points. Using light detection and ranging (LiDAR data collected from surveys over six glaciers in Greenland and Antarctica, particle image velocimetry (PIV was applied to temporally-spaced point clouds to detect and measure surface motion. The type and distribution of surface features, surface roughness, and spatial and temporal resolution of the data were all found to be important factors, which limited the use of PIV to four of the original six glaciers. The PIV results were found to be in good agreement with other, widely accepted, measurement techniques, including manual tracking and GPS, and offered a comprehensive distribution of velocity data points across glacier surfaces. For three glaciers in Taylor Valley, Antarctica, average velocities ranged from 0.8–2.1 m/year. For one glacier in Greenland, the average velocity was 22.1 m/day (8067 m/year.

  11. Thermocline Regulated Seasonal Evolution of Surface Chlorophyll in the Gulf of Aden

    KAUST Repository

    Hoteit, Ibrahim

    2015-04-01

    The Gulf of Aden, although subject to seasonally reversing monsoonal winds, has been previously reported as an oligotrophic basin during summer, with elevated chlorophyll concentrations only occurring during winter due to convective mixing. However, the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) ocean color data reveal that the Gulf of Aden also exhibits a prominent summer chlorophyll bloom and sustains elevated chlorophyll concentrations throughout the fall, and is a biophysical province distinct from the adjacent Arabian Sea. Climatological hydrographic data suggest that the thermocline, hence the nutricline, in the entire gulf is markedly shoaled by the southwest monsoon during summer and fall. Under this condition, cyclonic eddies in the gulf can effectively pump deep nutrients to the surface layer and lead to the chlorophyll bloom in late summer, and, after the transition to the northeast monsoon in fall, coastal upwelling driven by the northeasterly winds produces a pronounced increase in surface chlorophyll concentrations along the Somali coast.

  12. Determination of phytoplankton chlorophyll concentrations in the Chesapeake Bay with aircraft remote sensing

    Science.gov (United States)

    Harding, Lawrence W., Jr.; Itsweire, Eric C.; Esaias, Wayne E.

    1992-01-01

    Remote sensing measurements of the distribution of phytoplankton chlorophyll concentrations in Chesapeake Bay during 1989 are described. It is shown that remote sensing from light aircraft can complement and extend measurements made from traditional platforms and provide data of improved temporal and spatial resolution, leading to a better understanding of phytoplankton dynamics in the estuary. The developments of the winter-spring diatom bloom in the polyhaline to mesohaline regions of the estuary and of the late-spring and summer dinoflagellate blooms in oligohaline and mesohaline regions are traced. The study presents the local chlorophyll algorithm developed using the NASA Ocean Data Acquisition System data and in situ chlorophyll data, interpolated maps of chlorophyll concentration generated by applying the algorithm to aircraft radiance data, ancillary in situ data on nutrients, turbidity, streamflow, and light availability, and an interpretation of phytoplankton dynamics in terms of the chlorophyll distribution in Chesapeake Bay during 1989.

  13. Hyperspectral imaging detection of decayed honey peaches based on their chlorophyll content.

    Science.gov (United States)

    Sun, Ye; Wang, Yihang; Xiao, Hui; Gu, Xinzhe; Pan, Leiqing; Tu, Kang

    2017-11-15

    Honey peach is a very common but highly perishable market fruit. When pathogens infect fruit, chlorophyll as one of the important components related to fruit quality, decreased significantly. Here, the feasibility of hyperspectral imaging to determine the chlorophyll content thus distinguishing diseased peaches was investigated. Three optimal wavelengths (617nm, 675nm, and 818nm) were selected according to chlorophyll content via successive projections algorithm. Partial least square regression models were established to determine chlorophyll content. Three band ratios were obtained using these optimal wavelengths, which improved spatial details, but also integrates the information of chemical composition from spectral characteristics. The band ratio values were suitable to classify the diseased peaches with 98.75% accuracy and clearly show the spatial distribution of diseased parts. This study provides a new perspective for the selection of optimal wavelengths of hyperspectral imaging via chlorophyll content, thus enabling the detection of fungal diseases in peaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The effect of storage temperature of cucumber fruit on chlorophyll fluorescence

    Directory of Open Access Journals (Sweden)

    Ryszard Kosson

    2013-12-01

    Full Text Available The effect of three storage temperature levels: 12,5°C, 20°C, and 1,5°C on basic indexes of chlorophyll fluorescence of cucumber fruits was studied. The greenhouse grown cucumber fruits cv. Wiktor F1 were stored in perforated polyethylene bags or without packages. The minimum chlorophyll fluorescence (Fo, maximum chlorophyll fluorescence (Fm, variable chlorophyll fluorescence (Fv and relative variable fluorescence (Fv/Fm of the cucumber peel were measured. Relative variable fluorescence was decTeasing when cucumbers were stored at temperature lower or higher than optimum level. The chlorophyll fluorescence measurements can be helpful for determination of appropriate temperature parameters of cucumber storage.

  15. Researches Regarding the Influence of Cold Storage on the Chlorophyll Content in Lettuce

    Directory of Open Access Journals (Sweden)

    Iuliana Cretescu

    2014-05-01

    Full Text Available The aim of the present investigations was to determine the effect of the cold storage period on the content of chlorophylls in the leaves of lettuce and arugula (rucola. The research material consisted in two types of lettuce (Lactuca sativa L. var. capitata; Lactuca sativa L. var. crispa and arugula (Eruca sativa purchased from supermarkets in Timisoara. The quantitative determination of chlorophyll pigments in leaves (SPAD was made by chlorophyll meter (SPAD 502 Konica-Minolta. During the few days cold storage at a temperature of 4ºC, the content of chlorophyll in the leaf significantly decreased, compared with that in the control group. After 3 days of cold storage arugula and lettuce (Lactuca sativa var. capitata values of chlorophyll content differ statistically very significantly (p<0.001 from the values found in the control group which for lettuce (Lactuca sativa L. var. crispa differs statistically significant (p < 0.05.

  16. Self-assembled chlorophyll a systems as studied by californium-252 plasma desorption mass spectroscopy

    Science.gov (United States)

    Hunt, J. E.; Macfarlane, R. D.; Katz, J. J.; Dougherty, R. C.

    1980-01-01

    Self-assembled chlorophyll a and pheophytin a systems in thin solid films have been studied by 252Cf plasma desorption mass spectrometry (PDMS). The 252Cf-PDMS spectra of these films show monomer cation and anion molecular ions, ions of molecular aggregates, and positive and negative ion fragmentation patterns arising from the loss of various aliphatic side chains from the chlorin ring. Chlorophyll a films cast from dry carbon tetrachloride solution, in which chlorophyll a is known to occur as the dimer, produced an abundant dimer ion. The highest degree of chlorophyll a self-assembly was observed in chlorophyll a films cast from n-octane solutions. Oligomer ions extending upwards in size to the heptamer were detected in this system. Images PMID:16592795

  17. Adaptive Covariance Estimation Method for LiDAR-Aided Multi-Sensor Integrated Navigation Systems

    Directory of Open Access Journals (Sweden)

    Shifei Liu

    2015-01-01

    Full Text Available The accurate estimation of measurements covariance is a fundamental problem in sensors fusion algorithms and is crucial for the proper operation of filtering algorithms. This paper provides an innovative solution for this problem and realizes the proposed solution on a 2D indoor navigation system for unmanned ground vehicles (UGVs that fuses measurements from a MEMS-grade gyroscope, speed measurements and a light detection and ranging (LiDAR sensor. A computationally efficient weighted line extraction method is introduced, where the LiDAR intensity measurements are used, such that the random range errors and systematic errors due to surface reflectivity in LiDAR measurements are considered. The vehicle pose change is obtained from LiDAR line feature matching, and the corresponding pose change covariance is also estimated by a weighted least squares-based technique. The estimated LiDAR-based pose changes are applied as periodic updates to the Inertial Navigation System (INS in an innovative extended Kalman filter (EKF design. Besides, the influences of the environment geometry layout and line estimation error are discussed. Real experiments in indoor environment are performed to evaluate the proposed algorithm. The results showed the great consistency between the LiDAR-estimated pose change covariance and the true accuracy. Therefore, this leads to a significant improvement in the vehicle’s integrated navigation accuracy.

  18. An Easy-to-Use Airborne LiDAR Data Filtering Method Based on Cloth Simulation

    Directory of Open Access Journals (Sweden)

    Wuming Zhang

    2016-06-01

    Full Text Available Separating point clouds into ground and non-ground measurements is an essential step to generate digital terrain models (DTMs from airborne LiDAR (light detection and ranging data. However, most filtering algorithms need to carefully set up a number of complicated parameters to achieve high accuracy. In this paper, we present a new filtering method which only needs a few easy-to-set integer and Boolean parameters. Within the proposed approach, a LiDAR point cloud is inverted, and then a rigid cloth is used to cover the inverted surface. By analyzing the interactions between the cloth nodes and the corresponding LiDAR points, the locations of the cloth nodes can be determined to generate an approximation of the ground surface. Finally, the ground points can be extracted from the LiDAR point cloud by comparing the original LiDAR points and the generated surface. Benchmark datasets provided by ISPRS (International Society for Photogrammetry and Remote Sensing working Group III/3 are used to validate the proposed filtering method, and the experimental results yield an average total error of 4.58%, which is comparable with most of the state-of-the-art filtering algorithms. The proposed easy-to-use filtering method may help the users without much experience to use LiDAR data and related technology in their own applications more easily.

  19. The application of LiDAR to investigate foredune morphology and vegetation

    Science.gov (United States)

    Doyle, Thomas B.; Woodroffe, Colin D.

    2018-02-01

    LiDAR (Light Detection and Ranging) has been used to investigate coastal landform morphology, evolution, and change for almost a decade. Repeated airborne LiDAR surveys can provide the scientific community with significant observations of how shorelines have evolved, which may then enable forecasts of future patterns of change. However, there have been few studies that have considered the application of this new technology to the specific study of foredune morphology and vegetation. The accuracy and appropriateness of airborne LiDAR needs to be assessed, particularly where the density of vegetation may obscure the underlying topography, prior to interpreting derived geomorphic features. This study: i) tests the vertical accuracy of airborne LiDAR in 37 foredune systems along the coast of south-eastern Australia, and ii) demonstrates that it can be used to describe foredune morphology and vegetation in considerable detail. There was a strong correlation between the remotely-sensed LiDAR-derived elevation and field topographic and vegetation surveys (R2 = 0.96). A protocol for obtaining foredune geomorphic and botanical parameters is described. It enables widespread biogeomorphic characterisation along coasts for which LiDAR data is available, which can benefit both coastal managers and researchers alike.

  20. Airborne LiDAR Detects Selectively Logged Tropical Forest Even in an Advanced Stage of Recovery

    Directory of Open Access Journals (Sweden)

    Rafi Kent

    2015-06-01

    Full Text Available Identifying historical forest disturbances is difficult, especially in selectively logged areas. LiDAR is able to measure fine-scale variations in forest structure over multiple kilometers. We use LiDAR data from ca. 16 km2 of forest in Sierra Leone, West Africa, to discriminate areas of old-growth from areas recovering from selective logging for 23 years. We examined canopy height variation and gap size distributions. We found that though recovering blocks of forest differed little in height from old-growth forest (up to 3 m, they had a greater area of canopy gaps (average 10.2% gap fraction in logged areas, compared to 5.6% in unlogged area; and greater numbers of gaps penetrating to the forest floor (162 gaps at 2 m height in logged blocks, and 101 in an unlogged block. Comparison of LiDAR measurements with field data demonstrated that LiDAR delivered accurate results. We found that gap size distributions deviated from power-laws reported previously, with substantially fewer large gaps than predicted by power-law functions. Our analyses demonstrate that LiDAR is a useful tool for distinguishing structural differences between old-growth and old-secondary forests. That makes LiDAR a powerful tool for REDD+ (Reduction of Emissions from Deforestation and Forest Degradation programs implementation and conservation planning.

  1. Chlorophyll 'a' and particulate organic carbon in relation to some physico-chemical parameters along southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.; Balasubramanian, T.; Jayalakshmy, K.V.; Balachandran, K.K.; Sankaranarayanan, V.N.

    Chlorophyll 'a', Particulate Organic Carbon and other environmental parameters were studied along Kerala Coast during October 1987 and 1988. High chlorophyll 'a' content at surface water and decreasing trend towards offshore was observed. Spatial...

  2. Study of Water Relations, Chlorophyll and their Correlations with Grain Yield in Wheat(Triticum aestivum L.) Genotypes

    OpenAIRE

    Mokhtar Ghobadi; Saeed Khosravi; Danial Kahrizi; Firooz Shirvani

    2011-01-01

    The objective of this experiment was to study of water relations and chlorophyll in different wheat genotypes and their correlations with grain and biological yields. 21 genotypes of bread wheat were compared in a field experiment as randomized complete blocks design with four replications. The results showed that relative water deficit, relative water loss, excised leaf water retention, cell membrane stability, chlorophyll-a, chlorophyll-b, total chlorophyll, grain yield...

  3. Photoprotective Energy Dissipation in Higher Plants Involves Alteration of the Excited State Energy of the Emitting Chlorophyll(s) in the Light Harvesting Antenna II (LHCII)*

    Science.gov (United States)

    Johnson, Matthew P.; Ruban, Alexander V.

    2009-01-01

    Non-photochemical quenching (NPQ), a mechanism of energy dissipation in higher plants protects photosystem II (PSII) reaction centers from damage by excess light. NPQ involves a reduction in the chlorophyll excited state lifetime in the PSII harvesting antenna (LHCII) by a quencher. Yet, little is known about the effect of the quencher on chlorophyll excited state energy and dynamics. Application of picosecond time-resolved fluorescence spectroscopy demonstrated that NPQ involves a red-shift (60 ± 5 cm−1) and slight enhancement of the vibronic satellite of the main PSII lifetime component present in intact chloroplasts. Whereas this fluorescence red-shift was enhanced by the presence of zeaxanthin, it was not dependent upon it. The red-shifted fluorescence of intact chloroplasts in the NPQ state was accompanied by red-shifted chlorophyll a absorption. Nearly identical absorption and fluorescence changes were observed in isolated LHCII complexes quenched in a low detergent media, suggesting that the mechanism of quenching is the same in both systems. In both cases, the extent of the fluorescence red-shift was shown to correlate with the lifetime of a component. The alteration in the energy of the emitting chlorophyll(s) in intact chloroplasts and isolated LHCII was also accompanied by changes in lutein 1 observed in their 77K fluorescence excitation spectra. We suggest that the characteristic red-shifted fluorescence emission reflects an altered environment of the emitting chlorophyll(s) in LHCII brought about by their closer interaction with lutein 1 in the quenching locus. PMID:19567871

  4. Chemical transformations of chlorophyll and its application in the design of a new generation of environmentally safe dyes

    International Nuclear Information System (INIS)

    Berezin, Boris D; Rumyantseva, Svetlana V; Moryganov, Andrey P; Berezin, Mikhail B

    2004-01-01

    Chemical transformations of chlorophyll and physicochemical properties of its derivatives are considered. These compounds can be used in the design of a new generation of chlorophyll- and porphyrin-based dyes environmentally more safe than currently used arene dyes and possessing renewable sources of raw materials. The first results on the use of chlorophyll derivatives for dyeing wool, acetate fibres and cotton are reported.

  5. Chemical transformations of chlorophyll and its application in the design of a new generation of environmentally safe dyes

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, Boris D; Rumyantseva, Svetlana V; Moryganov, Andrey P; Berezin, Mikhail B [Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo (Russian Federation)

    2004-02-28

    Chemical transformations of chlorophyll and physicochemical properties of its derivatives are considered. These compounds can be used in the design of a new generation of chlorophyll- and porphyrin-based dyes environmentally more safe than currently used arene dyes and possessing renewable sources of raw materials. The first results on the use of chlorophyll derivatives for dyeing wool, acetate fibres and cotton are reported.

  6. Quantifying Forest Carbon and Structure with Terrestrial LiDAR

    Science.gov (United States)

    Stovall, A. E.; Shugart, H. H., Jr.

    2014-12-01

    Current rising atmospheric CO2 concentrations are a major concern with significant global ramifications, however, of the carbon (C) fluxes that are known to occur on Earth, the terrestrial sink has the greatest amount of uncertainty. Improved monitoring of forest cover and change is required for reducing emissions from deforestation and forest degradation (REDD). We determine C storage from volume measurements with a high-precision Terrestrial Laser Scanner (TLS), substantially improving current standard ground validation techniques. This technology is utilized on several 30 m x 30 m plots in a Virginia temperate forest. Aboveground C is calculated on each of the study sites with commonly used allometric equations to offer a realistic comparison of field-based estimations to TLS-derived methods. The TLS and aerial LiDAR point cloud data are compared via the development of canopy height models at the plot scale. The novel method of point cloud voxelization is applied to our TLS data in order to produce detailed volumetric calculations in these complex forest ecosystems. Statistical output from the TLS data allows us to resolve and compare forest structure on scales from the individual plot to the entire forest landscape. The estimates produced from this research will be used to inform more widely available remote sensing datasets provided by NASA's Landsat satellites, significantly reducing the uncertainty of the terrestrial C cycle in temperate forests. Preliminary findings corroborate previous research, suggesting the potential for highly detailed monitoring of forest C storage as defined by the REDD initiative and analysis of complex ecosystem structure.

  7. Completing the Feedback Loop: The Impact of Chlorophyll Data Assimilation on the Ocean State

    Science.gov (United States)

    Borovikov, Anna; Keppenne, Christian; Kovach, Robin

    2015-01-01

    In anticipation of the integration of a full biochemical model into the next generation GMAO coupled system, an intermediate solution has been implemented to estimate the penetration depth (1Kd_PAR) of ocean radiation based on the chlorophyll concentration. The chlorophyll is modeled as a tracer with sources-sinks coming from the assimilation of MODIS chlorophyll data. Two experiments were conducted with the coupled ocean-atmosphere model. In the first, climatological values of Kpar were used. In the second, retrieved daily chlorophyll concentrations were assimilated and Kd_PAR was derived according to Morel et al (2007). No other data was assimilated to isolate the effects of the time-evolving chlorophyll field. The daily MODIS Kd_PAR product was used to validate the skill of the penetration depth estimation and the MERRA-OCEAN re-analysis was used as a benchmark to study the sensitivity of the upper ocean heat content and vertical temperature distribution to the chlorophyll input. In the experiment with daily chlorophyll data assimilation, the penetration depth was estimated more accurately, especially in the tropics. As a result, the temperature bias of the model was reduced. A notably robust albeit small (2-5 percent) improvement was found across the equatorial Pacific ocean, which is a critical region for seasonal to inter-annual prediction.

  8. Chlorophyll fluorescence extraction from water-leaving radiance of algae-containing water through polarization

    Science.gov (United States)

    Wang, Lin; Qiu, Zhongfeng; Pang, Huifang; Liu, Yongjian; Chen, Yanlong; Jiang, Lingling

    2017-12-01

    When measuring reflectance spectra, it is very important to accurately extract chlorophyll fluorescence from elastic- scattering light in water-leaving radiance. The elastic scattering of light by water particles produces partially polarized light. In contrast, chlorophyll fluorescence in planktonic algae yields completely unpolarized light. These properties can be used to separate fluorescent signals from the water-leaving radiance and thus to determine chlorophyll concentration. The algal species Aureococcus anophagefferens was used to conduct a laboratory polarization experiment. For the tests, we used a field spectroradiometer and a polarizer; measurements were collected using two different observation modes. The chlorophyll fluorescence curve extracted through polarization shows an excellent match with the results obtained using the fluorospectro photometer for both measurement modes, suggesting that polarization-based chlorophyll fluorescence extraction may be feasible. The extracted fluorescence is more reliable at incident zenith angles ranging from 30° to 60°. For algae-containing water, the results improve with increasing chlorophyll concentration. This method could help improve chlorophyll concentration measurement and the remote-sensing detection of resulting harmful algae blooms.

  9. Efficiency of chlorophyll in gross primary productivity: A proof of concept and application in crops.

    Science.gov (United States)

    Gitelson, Anatoly A; Peng, Yi; Viña, Andrés; Arkebauer, Timothy; Schepers, James S

    2016-08-20

    One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they have different photosynthetic pathways (C3 vs. C4), leaf structures (dicot vs. monocot) and canopy architectures (a heliotrophic leaf angle distribution vs. a spherical leaf angle distribution), they cover a large spectrum of biophysical conditions. Our results show that chlorophyll efficiency in primary productivity is highly variable and responds to various physiological and phenological conditions, and water availability. Since Chl is accessible through non-destructive, remotely sensed techniques, the use of chlorophyll efficiency for modeling and monitoring plant optimization patterns is practical at different scales (e.g., leaf, canopy) and under widely-varying environmental conditions. Through this analysis, we directly related a functional characteristic, gross primary production with a structural characteristic, canopy chlorophyll content. Understanding the efficiency of the structural characteristic is of great interest as it allows explaining functional components of the plant system. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Characterization of spatial variability of the relative chlorophyll index in wheat crop

    Directory of Open Access Journals (Sweden)

    Osmar Henrique de Castro Pias

    2014-09-01

    Full Text Available Site-specific nitrogen application, based on relative chlorophyll index from leaves, may provide many economic and environmental benefits, however, the knowledge on sampling methodologies is still incipient. Thus, this study aimed to evaluate the use of different sampling grids to characterize the spatial variability of relative chlorophyll index of leaves from wheat crop and elaborate thematic maps for site-specific nitrogen application. For determining the relative chlorophyll index, a CFL 1030 chlorophyll meter was used on a regular sampling grid of 10 m x 10 m with 472 sampling points. Based on the initial sampling grid, by using the point elimination method, the simulation was performed in the following sampling grids: 10 m x 20 m; 20 m x 20 m; 20 m x 30 m; 30 m x 30 m; 30 m x 40 m; and 40 m x 40 m. The increase of the sampling grid reduced the diagnostic accuracy of relative chlorophyll index in wheat leaves. As the sampling grid increased, the maps became more general and information on the spatial variability of the relative chlorophyll index were lost. Sampling grids smaller or equal to 20 m x 20 m were effective to detect the spatial variability of the relative chlorophyll index in wheat leaves and enable the elaboration of thematic maps for site-specific nitrogen application.

  11. Characterization of maize leaf chlorophyll content using a color palette

    Science.gov (United States)

    Arkebauer, T. J.; Nguy-Robertson, A. L.; Peng, Y.; Scoby, D.; Gitelson, A. A.

    2012-12-01

    There is a need to estimate leaf chlorophyll (CHL) content for various applications (e.g. precision agriculture, plant health status, etc.). To provide a simple and cheap alternative to commonly used hand-held sensors, this study seeks to quantify the relationship between leaf CHL and the leaf color in maize, determined by a set of four color swatches (CS: from least to most green; CS1-4). The study area included three fields located near Mead, Nebraska, USA. Two fields are irrigated continuous maize, while the third is rainfed maize/soybean rotation. All the fields were planted with maize in 2011, the year of the study. CHL content in leaves was retrieved from leaf level reflectance spectra measured by a USB2000 Ocean Optics radiometer fitted with a leaf clip and, in addition, a SPAD (Minolta) reading. A total of 183 leaf measurements were collected with 27, 31, 54, and 71 samples for each respective CS from the lowest to highest greenness. Using a technique for estimating CHL from leaf reflectance data, we found that in CS1 an average CHL content was 129.7 mg/m2 with a standard deviation (SD) of 43.3 mg/m2. For CS2, an average CHL was 218.4 mg/m2 with a SD = 60.4 mg/m2; for CS3 it was 441.2 mg/m2 with a SD =137.4 mg/m2. For the greenest class, CS4, CHL was 811.2 mg/m2 with a SD = 154.8 mg/m2. The CHL estimated for each CS determined from SPAD was closely related those found from reflectance measurements. One application for these results is to estimate total canopy chlorophyll content in conjunction with LAI measurements. We were able to use the averages determined in this study for each CS to estimate canopy CHL content throughout the growing season. This method provides a cheap and simple way to monitor leaf CHL content in crops.

  12. NASA Fluid Lensing & MiDAR: Next-Generation Remote Sensing Technologies for Aquatic Remote Sensing

    Science.gov (United States)

    Chirayath, Ved

    2018-01-01

    We present two recent instrument technology developments at NASA, Fluid Lensing and MiDAR, and their application to remote sensing of Earth's aquatic systems. Fluid Lensing is the first remote sensing technology capable of imaging through ocean waves in 3D at sub-cm resolutions. MiDAR is a next-generation active hyperspectral remote sensing and optical communications instrument capable of active fluid lensing. Fluid Lensing has been used to provide 3D multispectral imagery of shallow marine systems from unmanned aerial vehicles (UAVs, or drones), including coral reefs in American Samoa and stromatolite reefs in Hamelin Pool, Western Australia. MiDAR is being deployed on aircraft and underwater remotely operated vehicles (ROVs) to enable a new method for remote sensing of living and nonliving structures in extreme environments. MiDAR images targets with high-intensity narrowband structured optical radiation to measure an objectâ€"TM"s non-linear spectral reflectance, image through fluid interfaces such as ocean waves with active fluid lensing, and simultaneously transmit high-bandwidth data. As an active instrument, MiDAR is capable of remotely sensing reflectance at the centimeter (cm) spatial scale with a signal-to-noise ratio (SNR) multiple orders of magnitude higher than passive airborne and spaceborne remote sensing systems with significantly reduced integration time. This allows for rapid video-frame-rate hyperspectral sensing into the far ultraviolet and VNIR wavelengths. Previously, MiDAR was developed into a TRL 2 laboratory instrument capable of imaging in thirty-two narrowband channels across the VNIR spectrum (400-950nm). Recently, MiDAR UV was raised to TRL4 and expanded to include five ultraviolet bands from 280-400nm, permitting UV remote sensing capabilities in UV A, B, and C bands and enabling mineral identification and stimulated fluorescence measurements of organic proteins and compounds, such as green fluorescent proteins in terrestrial and

  13. Parallel Landscape Driven Data Reduction & Spatial Interpolation Algorithm for Big LiDAR Data

    Directory of Open Access Journals (Sweden)

    Rahil Sharma

    2016-06-01

    Full Text Available Airborne Light Detection and Ranging (LiDAR topographic data provide highly accurate digital terrain information, which is used widely in applications like creating flood insurance rate maps, forest and tree studies, coastal change mapping, soil and landscape classification, 3D urban modeling, river bank management, agricultural crop studies, etc. In this paper, we focus mainly on the use of LiDAR data in terrain modeling/Digital Elevation Model (DEM generation. Technological advancements in building LiDAR sensors have enabled highly accurate and highly dense LiDAR point clouds, which have made possible high resolution modeling of terrain surfaces. However, high density data result in massive data volumes, which pose computing issues. Computational time required for dissemination, processing and storage of these data is directly proportional to the volume of the data. We describe a novel technique based on the slope map of the terrain, which addresses the challenging problem in the area of spatial data analysis, of reducing this dense LiDAR data without sacrificing its accuracy. To the best of our knowledge, this is the first ever landscape-driven data reduction algorithm. We also perform an empirical study, which shows that there is no significant loss in accuracy for the DEM generated from a 52% reduced LiDAR dataset generated by our algorithm, compared to the DEM generated from an original, complete LiDAR dataset. For the accuracy of our statistical analysis, we perform Root Mean Square Error (RMSE comparing all of the grid points of the original DEM to the DEM generated by reduced data, instead of comparing a few random control points. Besides, our multi-core data reduction algorithm is highly scalable. We also describe a modified parallel Inverse Distance Weighted (IDW spatial interpolation method and show that the DEMs it generates are time-efficient and have better accuracy than the one’s generated by the traditional IDW method.

  14. Inversion of a radiative transfer model for estimation of rice chlorophyll content using support vector machine

    Science.gov (United States)

    Lv, Jie; Yan, Zhenguo; Wei, Jingyi

    2014-11-01

    Accurate retrieval of crop chlorophyll content is of great importance for crop growth monitoring, crop stress situations, and the crop yield estimation. This study focused on retrieval of rice chlorophyll content from data through radiative transfer model inversion. A field campaign was carried out in September 2009 in the farmland of ChangChun, Jinlin province, China. A different set of 10 sites of the same species were used in 2009 for validation of methodologies. Reflectance of rice was collected using ASD field spectrometer for the solar reflective wavelengths (350-2500 nm), chlorophyll content of rice was measured by SPAD-502 chlorophyll meter. Each sample sites was recorded with a Global Position System (GPS).Firstly, the PROSPECT radiative transfer model was inverted using support vector machine in order to link rice spectrum and the corresponding chlorophyll content. Secondly, genetic algorithms were adopted to select parameters of support vector machine, then support vector machine was trained the training data set, in order to establish leaf chlorophyll content estimation model. Thirdly, a validation data set was established based on hyperspectral data, and the leaf chlorophyll content estimation model was applied to the validation data set to estimate leaf chlorophyll content of rice in the research area. Finally, the outcome of the inversion was evaluated using the calculated R2 and RMSE values with the field measurements. The results of the study highlight the significance of support vector machine in estimating leaf chlorophyll content of rice. Future research will concentrated on the view of the definition of satellite images and the selection of the best measurement configuration for accurate estimation of rice characteristics.

  15. Correlation of electronic carotenoid-chlorophyll interactions and fluorescence quenching with the aggregation of native LHC II and chlorophyll deficient mutants

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Pen-Nan; Bode, Stefan [Technische Universitaet Braunschweig, Institute for Physical and Theoretical Chemistry, Department for Biophysical Chemistry, Hans-Sommer-Strasse 10, 38106 Braunschweig (Germany); Wilk, Laura [Max Planck Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main (Germany); Hafi, Nour [Technische Universitaet Braunschweig, Institute for Physical and Theoretical Chemistry, Department for Biophysical Chemistry, Hans-Sommer-Strasse 10, 38106 Braunschweig (Germany); Walla, Peter J., E-mail: pwalla@gwdg.de [Technische Universitaet Braunschweig, Institute for Physical and Theoretical Chemistry, Department for Biophysical Chemistry, Hans-Sommer-Strasse 10, 38106 Braunschweig (Germany); Max Planck Institute for Biophysical Chemistry, Department of Spectroscopy and Photochemical Kinetics, Am Fassberg 11, 37077 Goettingen (Germany)

    2010-07-19

    The aggregation dependent correlation between fluorescence quenching and the electronic carotenoid-chlorophyll interactions, {phi}{sub Coupling}{sup Car S{sub 1}-Chl}, as measured by comparing chlorophyll fluorescence observed after two- and one-photon excitation, has been investigated using native LHC II samples as well as mutants lacking Chl 2 and Chl 13. For native LHC II the same linear correlation between {phi}{sub Coupling}{sup Car S{sub 1}-Chl} and the fluorescence quenching was observed as previously reported for the pH and Zea-dependent quenching of LHC II . In order to elucidate which carotenoid-chlorophyll pair might dominate this correlation we also investigated the mutants lacking Chl 2 and Chl 13. However, also with these mutants the same linear correlation as for native LHC II was observed. This provides indication that these two chlorophylls play only a minor role for the observed effects. Nevertheless, we also conclude that this does not exclude that their neighboured carotenoids, lutein 1 and neoxanthin, might interact electronically with other chlorophylls close by.

  16. Correlation of electronic carotenoid-chlorophyll interactions and fluorescence quenching with the aggregation of native LHC II and chlorophyll deficient mutants

    International Nuclear Information System (INIS)

    Liao, Pen-Nan; Bode, Stefan; Wilk, Laura; Hafi, Nour; Walla, Peter J.

    2010-01-01

    The aggregation dependent correlation between fluorescence quenching and the electronic carotenoid-chlorophyll interactions, φ Coupling Car S 1 -Chl , as measured by comparing chlorophyll fluorescence observed after two- and one-photon excitation, has been investigated using native LHC II samples as well as mutants lacking Chl 2 and Chl 13. For native LHC II the same linear correlation between φ Coupling Car S 1 -Chl and the fluorescence quenching was observed as previously reported for the pH and Zea-dependent quenching of LHC II . In order to elucidate which carotenoid-chlorophyll pair might dominate this correlation we also investigated the mutants lacking Chl 2 and Chl 13. However, also with these mutants the same linear correlation as for native LHC II was observed. This provides indication that these two chlorophylls play only a minor role for the observed effects. Nevertheless, we also conclude that this does not exclude that their neighboured carotenoids, lutein 1 and neoxanthin, might interact electronically with other chlorophylls close by.

  17. Optimizing variable radius plot size and LiDAR resolution to model standing volume in conifer forests

    Science.gov (United States)

    Ram Kumar Deo; Robert E. Froese; Michael J. Falkowski; Andrew T. Hudak

    2016-01-01

    The conventional approach to LiDAR-based forest inventory modeling depends on field sample data from fixed-radius plots (FRP). Because FRP sampling is cost intensive, combining variable-radius plot (VRP) sampling and LiDAR data has the potential to improve inventory efficiency. The overarching goal of this study was to evaluate the integration of LiDAR and VRP data....

  18. Chlorophyll fluorescence in vivo as a probe for rapid measurement of tolerance to ultraviolet radiation

    International Nuclear Information System (INIS)

    Smillie, R.M.

    1983-01-01

    Chlorophyll fluorescence in vivo was progressively lost in pea leaves irradiated with either short or long-wave light. The changes were consistent with the development in the intact leaves of an inhibitory site on the photooxidizing side of photosystem II. In contrast, leaves of two species of Agave, plants regarded as more resistant to UV radiation, showed only minor changes in chlorophyll fluorescence. Agave americana was affected less than A. attenuata. The application of measurements of chlorophyll fluorescence in vivo to screening for tolerance to UV radiation is discussed. (author)

  19. Horizontal distributions of surface chlorophyll a and nitrogenous nutrients near Bering Strait and Unimak Pass

    Science.gov (United States)

    Koike, Isao; Furuya, Ken; Otobe, Hirotake; Nakai, Toshisuke; Memoto, Takahisa; Hattori, Akihiko

    1982-02-01

    Surface temperature, salinity, nitrate,aammonium, and chlorophyll a were continuously monitored along a north-south transect across the Bering Strait and Unimak Pass region of the southeastern Bering Sea in July 1978. A cold water mass, rich in nitrate and chlorophyll a, north of the Bering Strait, was examined over a distance of 40 km; it was probably associated with local upwelling. Near Unimak Pass, chlorophyll a was inversely correlated with nitrate, suggesting rapid growth of phytoplankton in nutrient-rich Alaskan Stream water during its travel into the Bering Sea. Phytoplankton species composition was consistent with this inference.

  20. Analysis of chlorophyll mutations induced by γ-rays in barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan; Chen Qiufang

    1991-06-01

    Thirty varieties of dormant barley seeds were irradiated with 137 Cs γ-rays. Dose-effect relations of chlorophyll mutation frequency in M 2 seedling and differences resulting from cultured types or radiosensitive types were investigated. Experimental results show that the relations between chlorophyll mutation frequency and doses can be fitted by a linear regression equation Y = A + BX. According to analysis of covariance, there is no considerable difference in various cultured types, but the difference of five different radiosensitive types is remarkable. The sensitive and intermediate types need much lower doses than other types to induce maximum chlorophyll mutation

  1. Influence of frequent magnetic field on chlorophyll content in leaves of sugar beet plants

    International Nuclear Information System (INIS)

    Rochalska, M.

    2005-01-01

    Chlorophyll content in plant leaves is correlated with the yield and nitrogen content in plants. Non-destructive investigations of chlorophyll content in leaves of 3 varieties of sugar beet grown from seeds revealed that a low frequent magnetic field, acting independently or in combination with other methods of seed improvement, increased chlorophyll content in leaves of the investigated plants. The treatment with the magnetic field increased nitrogen content in the examined plants. The effect was not connected with environmental conditions during vegetation seasons. (author)

  2. Calculation of the overlap factor for scanning LiDAR based on the tridimensional ray-tracing method.

    Science.gov (United States)

    Chen, Ruiqiang; Jiang, Yuesong; Wen, Luhong; Wen, Donghai

    2017-06-01

    The overlap factor is used to evaluate the LiDAR light collection ability. Ranging LiDAR is mainly determined by the optical configuration. However, scanning LiDAR, equipped with a scanning mechanism to acquire a 3D coordinate points cloud for a specified target, is essential in considering the scanning effect at the same time. Otherwise, scanning LiDAR will reduce the light collection ability and even cannot receive any echo. From this point of view, we propose a scanning LiDAR overlap factor calculation method based on the tridimensional ray-tracing method, which can be applied to scanning LiDAR with any special laser intensity distribution, any type of telescope (reflector, refractor, or mixed), and any shape obstruction (i.e., the reflector of a coaxial optical system). A case study for our LiDAR with a scanning mirror is carried out, and a MATLAB program is written to analyze the laser emission and reception process. Sensitivity analysis is carried out as a function of scanning mirror rotation speed and detector position, and the results guide how to optimize the overlap factor for our LiDAR. The results of this research will have a guiding significance in scanning LiDAR design and assembly.

  3. Chlorophyll a fluorescence to phenotype wheat genotypes for heat tolerance

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari; Andersen, Sven Bode; Ottosen, Carl-Otto

    In prospects of global climate change, heat stress is a rising constraint for the productivity of wheat (Triticum aestivum L.). It is a heat-susceptible crop beyond 17-23oC temperature throughout its phenological stages, flowering phase being the most sensitive stage. Chlorophyll a fluorescence...... parameter, maximum quantum yield efficiency of PSII (Fv/Fm) is used as a physiological marker for early stress detection in PSII in plants. We established a reproducible protocol to measure response of wheat genotypes to high temperature based on Fv/Fm. The heat treatment of 40°C in 300 µmol m-2s-1 PAR...... of 38oC for 2h showed a heritability of 7%. However, a stronger stress at 40oC for 72h in repeated experiments on 138 extreme performing selected genotypes resulted in an increased genetic component of 15% which was further increased to 29% in the third selection cycle with 41 genotypes. Our protocol...

  4. Electron transfer reactions involving porphyrins and chlorophyll a

    International Nuclear Information System (INIS)

    Neta, P.; Scherz, A.; Levanon, H.

    1979-01-01

    Electron transfer reactions involving porphyrins (P) and quinones (Q) have been studied by pulse radiolysis. The porphyrins used were tetraphenylporphyrin (H 2 TPP), its tetracarboxy derivative (H 2 TCPP), the sodium and zinc compounds (Na 2 TPP and ZnTPP), and chlorophyll a (Chl a). These compounds were found to be rapidly reduced by electron transfer from (CH 3 ) 2 CO - . Reduction by (CH 3 ) 2 COH was rapid in aqueous solutions but relatively slow in i-PrOH solutions. Transient spectra of the anion radicals were determined and, in the case of H 2 TCPP - ., a pK = 9.7 was derived for its protonation. Electron-transfer reactions from the anion radical of H 2 TCPP to benzoquinone, duroquinone, 9,10-anthraquinone 2-sulfonate, and methylviologen occur in aqueous solutions with rate constants approx. 10 7 -10 9 M -1 s -1 which depend on the pH and the quinone reduction potential. Reactions of Na 2 TPP - ., ZnTPP - ., and Chl a - . with anthraquinone in basic i-PrOH solutions occur with rate constants approx. 10 9 M -1 s -1 . The spectral changes associated with these electron-transfer reactions as observed over a period of approx. 1 ms indicated, in some cases, the formation of an intermediate complex [P...Q - .]. 8 figures, 2 tables

  5. Geotechnical applications of LiDAR pertaining to geomechanical evaluation and hazard identification

    Science.gov (United States)

    Lato, Matthew J.

    Natural hazards related to ground movement that directly affect the safety of motorists and highway infrastructure include, but are not limited to, rockfalls, rockslides, debris flows, and landslides. This thesis specifically deals with the evaluation of rockfall hazards through the evaluation of LiDAR data. Light Detection And Ranging (LiDAR) is an imaging technology that can be used to delineate and evaluate geomechanically-controlled hazards. LiDAR has been adopted to conduct hazard evaluations pertaining to rockfall, rock-avalanches, debris flows, and landslides. Characteristics of LiDAR surveying, such as rapid data acquisition rates, mobile data collection, and high data densities, pose problems to traditional CAD or GIS-based mapping methods. New analyses methods, including tools specifically oriented to geomechanical analyses, are needed. The research completed in this thesis supports development of new methods, including improved survey techniques, innovative software workflows, and processing algorithms to aid in the detection and evaluation of geomechanically controlled rockfall hazards. The scientific research conducted between the years of 2006-2010, as presented in this thesis, are divided into five chapters, each of which has been published by or is under review by an international journal. The five research foci are: (i) geomechanical feature extraction and analysis using LiDAR data in active mining environments; (ii) engineered monitoring of rockfall hazards along transportation corridors: using mobile terrestrial LiDAR; (iii) optimization of LiDAR scanning and processing for automated structural evaluation of discontinuities in rockmasses; (iv) location orientation bias when using static LiDAR data for geomechanical analysis; and (v) evaluating roadside rockmasses for rockfall hazards from LiDAR data: optimizing data collection and processing protocols. The research conducted pertaining to this thesis has direct and significant implications with

  6. Segmentation based building detection approach from LiDAR point cloud

    Directory of Open Access Journals (Sweden)

    Anandakumar M. Ramiya

    2017-06-01

    Full Text Available Accurate building detection and reconstruction is an important challenge posed to the remote sensing community dealing with LiDAR point cloud. The inherent geometric nature of LiDAR point cloud provides a new dimension to the remote sensing data which can be used to produce accurate 3D building models at relatively less time compared to traditional photogrammetry based 3D reconstruction methods. 3D segmentation is a key step to bring out the implicit geometrical information from the LiDAR point cloud. This research proposes to use open source point cloud library (PCL for 3D segmentation of LiDAR point cloud and presents a novel histogram based methodology to separate the building clusters from the non building clusters. The proposed methodology has been applied on two different airborne LiDAR datasets acquired over part of urban region around Niagara Falls, Canada and southern Washington, USA. An overall building detection accuracy of 100% and 82% respectively is achieved for the two datasets. The performance of proposed methodology has been compared with the commercially available Terrasolid software. The results show that the buildings detected using open source point cloud library produce comparable results with the buildings detected using commercial software (buildings detection accuracy: 86.3% and 89.2% respectively for the two datasets.

  7. BUILDING ROOF BOUNDARY EXTRACTION FROM LiDAR AND IMAGE DATA BASED ON MARKOV RANDOM FIELD

    Directory of Open Access Journals (Sweden)

    A. P. Dal Poz

    2017-05-01

    Full Text Available In this paper a method for automatic extraction of building roof boundaries is proposed, which combines LiDAR data and highresolution aerial images. The proposed method is based on three steps. In the first step aboveground objects are extracted from LiDAR data. Initially a filtering algorithm is used to process the original LiDAR data for getting ground and non-ground points. Then, a region-growing procedure and the convex hull algorithm are sequentially used to extract polylines that represent aboveground objects from the non-ground point cloud. The second step consists in extracting corresponding LiDAR-derived aboveground objects from a high-resolution aerial image. In order to avoid searching for the interest objects over the whole image, the LiDAR-derived aboveground objects’ polylines are photogrammetrically projected onto the image space and rectangular bounding boxes (sub-images that enclose projected polylines are generated. Each sub-image is processed for extracting the polyline that represents the interest aboveground object within the selected sub-image. Last step consists in identifying polylines that represent building roof boundaries. We use the Markov Random Field (MRF model for modelling building roof characteristics and spatial configurations. Polylines that represent building roof boundaries are found by optimizing the resulting MRF energy function using the Genetic Algorithm. Experimental results are presented and discussed in this paper.

  8. The Extraction of Vegetation Points from LiDAR Using 3D Fractal Dimension Analyses

    Directory of Open Access Journals (Sweden)

    Haiquan Yang

    2015-08-01

    Full Text Available Light Detection and Ranging (LiDAR, a high-precision technique used for acquiring three-dimensional (3D surface information, is widely used to study surface vegetation information. Moreover, the extraction of a vegetation point set from the LiDAR point cloud is a basic starting-point for vegetation information analysis, and an important part of its further processing. To extract the vegetation point set completely and to describe the different spatial morphological characteristics of various features in a LiDAR point cloud, we have used 3D fractal dimensions. We discovered that every feature has its own distinctive 3D fractal dimension interval. Based on the 3D fractal dimensions of tall trees, we propose a new method for the extraction of vegetation using airborne LiDAR. According to this method, target features can be distinguished based on their morphological characteristics. The non-ground points acquired by filtering are processed by region growing segmentation and the morphological characteristics are evaluated by 3D fractal dimensions to determine the features required for the determination of the point set for tall trees. Avon, New York, USA was selected as the study area to test the method and the result proves the method’s efficiency. Thus, this approach is feasible. Additionally, the method uses the 3D coordinate properties of the LiDAR point cloud and does not require additional information, such as return intensity, giving it a larger scope of application.

  9. Specular and diffuse object extraction from a LiDAR derived Digital Surface Model (DSM)

    International Nuclear Information System (INIS)

    Saraf, N M; Hamid, J R A; Kamaruddin, M H

    2014-01-01

    This paper intents to investigate the indifferent behaviour quantitatively of target objects of interest due to specular and diffuse reflectivity based on generated LiDAR DSM of the study site in Ampang, Kuala Lumpur. The LiDAR data to be used was initially checked for its reliability and accuracy. The point cloud LiDAR data was converted to raster to allow grid analysis of the next process of generating the DSM and DTM. Filtering and masking were made removing the features of interest (i.e. building and tree) and other unwanted above surface features. A normalised DSM and object segmentation approach were conducted on the trees and buildings separately. Error assessment and findings attained were highlighted and documented. The result of LiDAR verification certified that the data is reliable and useable. The RMSE obtained is within the tolerance value of horizontal and vertical accuracy (x, y, z) i.e. 0.159 m, 0.211 m 0.091 m respectively. Building extraction inclusive of roof top based on slope and contour analysis undertaken indicate the capability of the approach while single tree extraction through aspect analysis appears to preserve the accuracy of the extraction accordingly. The paper has evaluated the suitable methods of extracting non-ground features and the effective segmentation of the LiDAR data

  10. Performance Assessment of High Resolution Airborne Full Waveform LiDAR for Shallow River Bathymetry

    Directory of Open Access Journals (Sweden)

    Zhigang Pan

    2015-04-01

    Full Text Available We evaluate the performance of full waveform LiDAR decomposition algorithms with a high-resolution single band airborne LiDAR bathymetry system in shallow rivers. A continuous wavelet transformation (CWT is proposed and applied in two fluvial environments, and the results are compared to existing echo retrieval methods. LiDAR water depths are also compared to independent field measurements. In both clear and turbid water, the CWT algorithm outperforms the other methods if only green LiDAR observations are available. However, both the definition of the water surface, and the turbidity of the water significantly influence the performance of the LiDAR bathymetry observations. The results suggest that there is no single best full waveform processing algorithm for all bathymetric situations. Overall, the optimal processing strategies resulted in a determination of water depths with a 6 cm mean at 14 cm standard deviation for clear water, and a 16 cm mean and 27 cm standard deviation in more turbid water.

  11. LiDAR, UAV or compass-clinometer? Accuracy, coverage and the effects on structural models

    Science.gov (United States)

    Cawood, Adam J.; Bond, Clare E.; Howell, John A.; Butler, Robert W. H.; Totake, Yukitsugu

    2017-05-01

    Light Detection and Ranging (LiDAR) and Structure from Motion (SfM) provide large amounts of digital data from which virtual outcrops can be created. The accuracy of these surface reconstructions is critical for quantitative structural analysis. Assessment of LiDAR and SfM methodologies suggest that SfM results are comparable to high data-density LiDAR on individual surfaces. The effect of chosen acquisition technique on the full outcrop and the efficacy on its virtual form for quantitative structural analysis and prediction beyond single bedding surfaces, however, is less certain. Here, we compare the accuracy of digital virtual outcrop analysis with traditional field data, for structural measurements and along-strike prediction of fold geometry from Stackpole syncline. In this case, the SfM virtual outcrop, derived from UAV imagery, yields better along-strike predictions and a more reliable geological model, in spite of lower accuracy surface reconstructions than LiDAR. This outcome is attributed to greater coverage by UAV and reliable reconstruction of a greater number of bedding planes than terrestrial LiDAR, which suffers from the effects of occlusion. Irrespective of the chosen acquisition technique, we find that workflows must incorporate careful survey planning, data processing and quality checking of derived data if virtual outcrops are to be used for robust structural analysis and along-strike prediction.

  12. Using LiDAR to as a Potential Method for Detection Plastics in Water

    Science.gov (United States)

    Lee, G.; Neal, A.; Mielke, R.; Bookhagen, B.

    2010-12-01

    We conducted a series of experiments using Light Detection and Range (LiDAR) technology as an innovative way to detect the presence of plastics in water. The purpose of this study was to determine if LiDAR technology is a feasible, non-intrusive alternative to dredging in the ocean to determine the amount of plastics in the ocean. We used a tripod mounted RIEGL LMS-Z420i terrestrial LiDAR 3-D scanner and the associated operating software RiSCAN Pro. The terrestrial LiDAR is an optical remote sensing technology that measures the reflection of near infared light to find the range of a distant target that is most commonly used to create high precision digital elevation models of terrestrial surfaces. In theory, water should absorb the near infared light, while the plastics should reflect the light. The experiments consisted of different scale models of plastic pellets in water, ranging from a small plastic dish to a large tank to test the range of the LiDAR in different salt and fresh water mediums.

  13. Localized Segment Based Processing for Automatic Building Extraction from LiDAR Data

    Science.gov (United States)

    Parida, G.; Rajan, K. S.

    2017-05-01

    The current methods of object segmentation and extraction and classification of aerial LiDAR data is manual and tedious task. This work proposes a technique for object segmentation out of LiDAR data. A bottom-up geometric rule based approach was used initially to devise a way to segment buildings out of the LiDAR datasets. For curved wall surfaces, comparison of localized surface normals was done to segment buildings. The algorithm has been applied to both synthetic datasets as well as real world dataset of Vaihingen, Germany. Preliminary results show successful segmentation of the buildings objects from a given scene in case of synthetic datasets and promissory results in case of real world data. The advantages of the proposed work is non-dependence on any other form of data required except LiDAR. It is an unsupervised method of building segmentation, thus requires no model training as seen in supervised techniques. It focuses on extracting the walls of the buildings to construct the footprint, rather than focussing on roof. The focus on extracting the wall to reconstruct the buildings from a LiDAR scene is crux of the method proposed. The current segmentation approach can be used to get 2D footprints of the buildings, with further scope to generate 3D models. Thus, the proposed method can be used as a tool to get footprints of buildings in urban landscapes, helping in urban planning and the smart cities endeavour.

  14. Indicators of Coastal Water Quality: Change in Chlorophyll-a Concentration 1998-2007

    Data.gov (United States)

    National Aeronautics and Space Administration — The Change in Chlorophyll-a Concentrations 1998-2007 component of the Indicators of Coastal Water Quality Collection represents a tabular time series of the...

  15. Aquafluo 2007: chlorophyll fluorescence in aquatic sciences, an international conference held in Nové Hrady

    Czech Academy of Sciences Publication Activity Database

    Prášil, Ondřej; Sugget, D. J.; Cullen, J. J.; Babin, M.; Govindjee, M.

    -, - (2007), s. 1-5 ISSN 0166-8595 Institutional research plan: CEZ:AV0Z50200510 Keywords : aquafluo * chlorophyll fluorescence Subject RIV: EE - Microbiology, Virology Impact factor: 2.139, year: 2007

  16. [Effects of covering on growth potential and chlorophyll content of hardwood cutting of Lycium barbarum].

    Science.gov (United States)

    Zhang, Ju-qiong; Lin, Hai-ming; Lin, Nan

    2011-07-01

    To study the effect of plastic film covering, straw covering, plastic film covering in greenhouse and no-covering cutting on growth and Chlorophyll content of Lycium barbarum hardwood cutting seedlings. Single factor randomized block design method was used in this research. The effect of different covering treatments on germination rate, seedling rate and growth potential were all plastic film covering in greenhouse > plastic film covering > straw covering > no-covering cutting. Chlorophyll a, Chlorophyll b, Chlorophyll a + b content and Ca/Cb were significantly different with different coverings in different periods. The optimal covering on hardwood cutting of Lycium barbarum is plastic film covering in greenhouse. Both plastic film and straw covering are better than no-covering cutting.

  17. Five Year Mean Surface Chlorophyll Estimates in the Northern Gulf of Mexico for 2005 through 2009

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean surface chlorophyll estimates to produce seasonal representations for winter, spring, summer and fall. Winter...

  18. VIIRSN Level-3 Standard Mapped Image, Chlorophyll a, Daily, 4km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from the NPP -Suonomi Spacecraft. Measurements are gathered by the VIIRS instrument carried aboard the...

  19. Evaluation of Carotenoids and Chlorophyll as Natural Resources for Food in Spirulina Microalgae

    Directory of Open Access Journals (Sweden)

    M Ghaeni

    2014-12-01

    Full Text Available Microalgae can produce various natural products such as pigments, enzymes, unique fatty acids and vitamins that benefit humans. The objective of the study was evaluation of carotenoids (β-carotene, zeathanthin, lutein, lycopene and astaxanthin and chlorophyll a in spirulina microalgae. Spirulina powder has been produced by Jordan’s method in Iran. Carotenoids were extracted from Spirulina platensis by adopting a method described by Reboul; then the sample was prepared and injected into a HPLC instrument with triplicate injection. Chlorophyll`s biomass content was determined by spectrophotometer. After assaying the curves of HPLC, the amount of chlorophyll a, astaxanthin, beta carotene, lycopene, zeaxanthin and lutein in spirulina was determined as 4.3±0.14, 0.21±0.02, 7393±2.76, 741±2.32, 6652±3.69 and 424±2.83 μg/ml respectively (p<0.05.

  20. Transport of dissolved nutrients and chlorophyll a in a tropical estuary, southwest coast of India.

    Digital Repository Service at National Institute of Oceanography (India)

    Lallu, K.R.; Fausia, K.H.; Vinita, J.; Balachandran, K.K.; NaveenKumar, K.R.; Rehitha, T.V.

    Intra-tidal variability in the transport of materials through the Cochin estuary was studied over successive spring and neap tides to estimate the export fluxes of nutrients and chlorophyll a into the adjoining coastal zone. The results showed...

  1. HAAR TRANSFORM BASED ESTIMATION OF CHLOROPHYLL AND STRUCTURE OF THE LEAF

    OpenAIRE

    Abhinav Arora; R. Menaka; Shivangi Gupta; Archit Mishra

    2013-01-01

    In this paper, the health of a plant is estimated using various non-destructive Image Processing Techniques. Chlorophyll content was detected based on colour Image Processing. The Haar transform is applied to get size of leaf and the parameters.

  2. Riboflavin and chlorophyll as photosensitizers in electroformed giant unilamellar vesicles as food models

    DEFF Research Database (Denmark)

    Wang, Hui Jing; Liang, Ran; du, Hui Hui

    2017-01-01

    for hydrophilic riboflavin, while lipophilic chlorophyll a initiated GUV budding and subsequent disintegration under light irradiation, indicating that lipophilic photosensitizers are the more important in such structured lipids. Lipophilic β-carotene provided protection against oxidative damage induced...

  3. Correlation between chlorophyll-a and related environmental factors based on Copula in Chaohu Lake, China

    Science.gov (United States)

    Ma, Huiqun; Wang, Yong

    2018-01-01

    Chlorophyll-a is crucial to characterize the eutrophication status. Return period of Chlorophyll-a is very helpful to the treatment of lakes and reservoirs eutrophication. In this study, the Gumbel-Hougaard Copula method is applied to discern the inherent relationship between chlorophyll-a and environmental variables of Chaohu Lake, China. The result shows that Weibull probability distribution is the preferred marginal distribution for Chl-a, Gamma for TP and TN, Log-normal for SD and CODmn. The sequence of correlation between chlorophyll-a and environmental factors is CODmn, SD, TP and TN. The method proposed here presents an effective tool to analyze the interaction of eutrophic variables in complex water environment system, also could provide reference for integrated management and treatment of lakes and reservoirs.

  4. THE ACTION OF SODIUM DODECYL SULFATE ON THE CHLOROPHYLL-PROTEIN COMPOUND OF THE SPINACH LEAF.

    Science.gov (United States)

    Smith, E L

    1941-05-20

    1. Sodium dodecyl sulfate (SDS) attacks the chlorophyll-protein compound modifying its protein properties and absorption spectrum. 2. In the presence of SDS, chlorophyll is quantitatively converted to phaeophytin; i.e., magnesium is removed from the molecule. This reaction, measured spectrophotometrically, proceeds at a rate directly proportional to the hydrogen ion concentration. At constant pH, the rate is proportional to the SDS concentration until a maximum rate is achieved. 3. The chlorophyll or phaeophytin (depending on the pH) remains attached to the protein, since the prosthetic group cannot be separated by ultrafiltration, dialysis, or fractional precipitation. 4. This suggests that the magnesium plays no part in binding chlorophyll to the split protein fragments, but may be concerned in binding the larger units, since the metal becomes extremely labile when the protein is split.

  5. Effect of gamma radiation on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first b chlorophyll affected to a greater extent than a chlorophyll. Net photosynthesis and respiration decline throughout the time of the observation after irradiation, this depressing effect being much more remarkable for the first one. Met photosynthesis inhibition levels of about 30% are got only five hours post irradiation at a dose of 5000 Gy. Radio estimation by low doses, although obtained in some cases for tho 10 Gy dose, has not been statistically confirmed. (Author) 23 refs

  6. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, Indonesia

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  7. Chlorophyll Detection and Mapping of Shallow Water Impoundments Using Image Spectrometry

    International Nuclear Information System (INIS)

    Artigas, F.; Pechmann, I.; Marti, A.; Yao, N.; Pechmann, I.

    2008-01-01

    There exists a common perception that chlorophyll a concentrations in tidal coastal waters are unsuitable to be captured by remote sensing techniques because of high water turbidity. In this study, we use band index measurements to separate active chlorophyll pigments from other constituents in the water. Published single- and multiband spectral indices are used to establish a relationship between algal chlorophyll concentration and reflectance data. We find an index which is suitable to map chlorophyll gradients in the impoundments, ditches, and associated waterways of the Hackensack Meadow lands (NJ, USA). The resulting images clearly depict the spatial distribution of plant pigments and their relationship with the biological conditions of the waters in the estuary. Since these biological conditions are often determined by land usage, the methods in this paper provide a simple tool to address water quality management issues in fragmented urban estuaries.

  8. TRACKING CHANGES IN CHLOROPHYLL AND CAROTENOIDS IN THE PRODUCTION PROCESS OF FROZEN SPINACH PURÉE

    Directory of Open Access Journals (Sweden)

    Andrea Mendelová

    2014-02-01

    Full Text Available Spinach is in the professional and general public considered highly nutritious vegetable with many beneficial effects on human health. It is a rich source of antioxidant active substances, especially chlorophyll, carotenoids, flavonoids and minerals especially zinc and copper. This work studies the changes of chlorophyll and carotenoids that occur after mass production technology of freezing at -37 °C. Before freezing was used blanching operation. In this work we used a variety Boeing, Boa, Beaver, Hudson and Chica. The highest content of all monitored parameters are found in fresh leaves of sampled Hudson. We found that within the processing decreases chlorophyll in 16.6%, 13.8% of chlorophyll b and carotenoids of 6.15%. This decrease was in all cases statistically significant.

  9. Effect of road side dust pollution on the growth and total chlorophyll ...

    African Journals Online (AJOL)

    Effect of road side dust pollution on the growth and total chlorophyll contents in Vitis vinifera L. (grape). Saadullah Khan Leghari, Mudassir Asrar Zaid, Atta Muhammed Sarangzai, Muhammed Faheem, Gulam Razaq Shawani ...

  10. Chlorophyll catalyse the photo-transformation of carcinogenic benzo[a]pyrene in water

    Science.gov (United States)

    Luo, Lijuan; Lai, Xueying; Chen, Baowei; Lin, Li; Fang, Ling; Tam, Nora F. Y.; Luan, Tiangang

    2015-08-01

    Algal blooms cause great damage to water quality and aquaculture. However, this study showed that dead algal cells and chlorophyll could accelerate the photo-transformation of benzo[a]pyrene (BaP), a ubiquitous and persistent pollutant with potently mutagenic and carcinogenic toxicities, under visible light irradiation. Chlorophyll was found to be the major active substance in dead algal cells, and generated a high level of singlet oxygen to catalyse the photo-transformation of BaP. According to various BaP metabolites formed, the degradation mechanism was proposed as that chlorophyll in dead algal cells photo-oxidized BaP to quinones via photocatalytic generation of singlet oxygen. The results provided a good insight into the role of chlorophyll in the photo-transformation of organic contaminants and could be a possible remediation strategy of organic pollutants in natural environment.

  11. Upper ocean variability of the equatorial Indian Ocean and its relation to chlorophyll pigment concentration.

    Digital Repository Service at National Institute of Oceanography (India)

    Narvekar, J.; PrasannaKumar, S.

    Hydrographic data from the upper ocean together with atmospheric data and satellite data are used to understand the variability of upper ocean and its relation to surface chlorophyll in the Equatorial Indian Ocean. The sea surface temperature showed...

  12. Chlorophyll-a, Aqua MODIS, NPP, 0.025 degrees, Pacific Ocean, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  13. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, Gulf of Mexico, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  14. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, East US, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  15. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, West US, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  16. Chlorophyll-a, Terra MODIS, OSU DB, 0.0125 degrees, West US, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Terra satellite. Measurements are gathered by the Moderate Resolution Imaging...

  17. Chlorophyll-a, Aqua MODIS, OSU DB, 0.0125 degrees, West US

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua satellite. Measurements are gathered by the Moderate Resolution Imaging...

  18. Chlorophyll-a, Aqua MODIS, NPP, 0.05 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  19. Extraction of chlorophyll from pandan leaves using ethanol and mass transfer study

    Directory of Open Access Journals (Sweden)

    Putra Meilana Dharma

    2017-01-01

    Full Text Available Green pigments are used in many industrial branches including food, drinks, soap and cosmetics. Chlorophyll can substitute synthetic dyes which may affect health. Chlorophyll can be extracted from pandan leaves; the pandan crop grows in many tropical areas. The effects of temperature, 30–70°C and agitation speed, 100–400 rpm on chlorophyll extraction from pandan leaves, using ethanol and the evaluation of mass transfer coefficient, using dimensionless analysis were investigated. The optimal conditions of extraction was obtained at 60°C and 300 rpm; the chlorophyll concentration was 107.1 mg L-1. The volumetric mass transfer coefficient increased with the temperature and agitation speed. Determination of volumetric mass transfer coefficient and dimensionless correlations are useful for further process development or industrial applications.

  20. Vegetation chlorophyll estimates in the Amazon from multi-angle MODIS observations and canopy reflectance model

    Science.gov (United States)

    Hilker, Thomas; Galvão, Lênio Soares; Aragão, Luiz E. O. C.; de Moura, Yhasmin M.; do Amaral, Cibele H.; Lyapustin, Alexei I.; Wu, Jin; Albert, Loren P.; Ferreira, Marciel José; Anderson, Liana O.; dos Santos, Victor A. H. F.; Prohaska, Neill; Tribuzy, Edgard; Barbosa Ceron, João Vitor; Saleska, Scott R.; Wang, Yujie; de Carvalho Gonçalves, José Francisco; de Oliveira Junior, Raimundo Cosme; Cardoso Rodrigues, João Victor Figueiredo; Garcia, Maquelle Neves

    2017-06-01

    As a preparatory study for future hyperspectral missions that can measure canopy chemistry, we introduce a novel approach to investigate whether multi-angle Moderate Resolution Imaging Spectroradiometer (MODIS) data can be used to generate a preliminary database with long-term estimates of chlorophyll. MODIS monthly chlorophyll estimates between 2000 and 2015, derived from a fully coupled canopy reflectance model (ProSAIL), were inspected for consistency with eddy covariance fluxes, tower-based hyperspectral images and chlorophyll measurements. MODIS chlorophyll estimates from the inverse model showed strong seasonal variations across two flux-tower sites in central and eastern Amazon. Marked increases in chlorophyll concentrations were observed during the early dry season. Remotely sensed chlorophyll concentrations were correlated to field measurements (r2 = 0.73 and r2 = 0.98) but the data deviated from the 1:1 line with root mean square errors (RMSE) ranging from 0.355 μg cm-2 (Tapajós tower) to 0.470 μg cm-2 (Manaus tower). The chlorophyll estimates were consistent with flux tower measurements of photosynthetically active radiation (PAR) and net ecosystem productivity (NEP). We also applied ProSAIL to mono-angle hyperspectral observations from a camera installed on a tower to scale modeled chlorophyll pigments to MODIS observations (r2 = 0.73). Chlorophyll pigment concentrations (ChlA+B) were correlated to changes in the amount of young and mature leaf area per month (0.59 ≤ r2 ≤ 0.64). Increases in MODIS observed ChlA+B were preceded by increased PAR during the dry season (0.61 ≤ r2 ≤ 0.62) and followed by changes in net carbon uptake. We conclude that, at these two sites, changes in LAI, coupled with changes in leaf chlorophyll, are comparable with seasonality of plant productivity. Our results allowed the preliminary development of a 15-year time series of chlorophyll estimates over the Amazon to support canopy chemistry studies using future

  1. Remote sensing of sediment and chlorophyll with the test-bed aircraft multispectral scanner

    Science.gov (United States)

    Bowker, D. E.; Hardesty, C. A.; Jobson, D. J.

    1983-01-01

    An instrument known as the test-bed aircraft multispectral scanner (TBAMS) was used in a research flight over the entrance to the Chesapeake Bay. Upwelled radiances from the TBAMS data were correlated with the water parameters, particularly sediment and chlorophyll a. Several algorithms were demonstrated for monitoring sediment and chlorophyll, with a three-band ratio being the best. The primary advantage of the three-band ratio was found to be its apparent insensitivity to atmospheric and Sun-angle variations.

  2. Trends in ocean colour and chlorophyll concentration from 1889 to 2000, worldwide.

    Science.gov (United States)

    Wernand, Marcel R; van der Woerd, Hendrik J; Gieskes, Winfried W C

    2013-01-01

    Marine primary productivity is an important agent in the global cycling of carbon dioxide, a major 'greenhouse gas', and variations in the concentration of the ocean's phytoplankton biomass can therefore explain trends in the global carbon budget. Since the launch of satellite-mounted sensors globe-wide monitoring of chlorophyll, a phytoplankton biomass proxy, became feasible. Just as satellites, the Forel-Ule (FU) scale record (a hardly explored database of ocean colour) has covered all seas and oceans--but already since 1889. We provide evidence that changes of ocean surface chlorophyll can be reconstructed with confidence from this record. The EcoLight radiative transfer numerical model indicates that the FU index is closely related to chlorophyll concentrations in open ocean regions. The most complete FU record is that of the North Atlantic in terms of coverage over space and in time; this dataset has been used to test the validity of colour changes that can be translated to chlorophyll. The FU and FU-derived chlorophyll data were analysed for monotonously increasing or decreasing trends with the non-parametric Mann-Kendall test, a method to establish the presence of a consistent trend. Our analysis has not revealed a globe-wide trend of increase or decrease in chlorophyll concentration during the past century; ocean regions have apparently responded differentially to changes in meteorological, hydrological and biological conditions at the surface, including potential long-term trends related to global warming. Since 1889, chlorophyll concentrations have decreased in the Indian Ocean and in the Pacific; increased in the Atlantic Ocean, the Mediterranean, the Chinese Sea, and in the seas west and north-west of Japan. This suggests that explanations of chlorophyll changes over long periods should focus on hydrographical and biological characteristics typical of single ocean regions, not on those of 'the' ocean.

  3. Trends in ocean colour and chlorophyll concentration from 1889 to 2000, worldwide.

    Directory of Open Access Journals (Sweden)

    Marcel R Wernand

    Full Text Available Marine primary productivity is an important agent in the global cycling of carbon dioxide, a major 'greenhouse gas', and variations in the concentration of the ocean's phytoplankton biomass can therefore explain trends in the global carbon budget. Since the launch of satellite-mounted sensors globe-wide monitoring of chlorophyll, a phytoplankton biomass proxy, became feasible. Just as satellites, the Forel-Ule (FU scale record (a hardly explored database of ocean colour has covered all seas and oceans--but already since 1889. We provide evidence that changes of ocean surface chlorophyll can be reconstructed with confidence from this record. The EcoLight radiative transfer numerical model indicates that the FU index is closely related to chlorophyll concentrations in open ocean regions. The most complete FU record is that of the North Atlantic in terms of coverage over space and in time; this dataset has been used to test the validity of colour changes that can be translated to chlorophyll. The FU and FU-derived chlorophyll data were analysed for monotonously increasing or decreasing trends with the non-parametric Mann-Kendall test, a method to establish the presence of a consistent trend. Our analysis has not revealed a globe-wide trend of increase or decrease in chlorophyll concentration during the past century; ocean regions have apparently responded differentially to changes in meteorological, hydrological and biological conditions at the surface, including potential long-term trends related to global warming. Since 1889, chlorophyll concentrations have decreased in the Indian Ocean and in the Pacific; increased in the Atlantic Ocean, the Mediterranean, the Chinese Sea, and in the seas west and north-west of Japan. This suggests that explanations of chlorophyll changes over long periods should focus on hydrographical and biological characteristics typical of single ocean regions, not on those of 'the' ocean.

  4. Trends in Ocean Colour and Chlorophyll Concentration from 1889 to 2000, Worldwide

    Science.gov (United States)

    Wernand, Marcel R.; van der Woerd, Hendrik J.; Gieskes, Winfried W. C.

    2013-01-01

    Marine primary productivity is an important agent in the global cycling of carbon dioxide, a major ‘greenhouse gas’, and variations in the concentration of the ocean's phytoplankton biomass can therefore explain trends in the global carbon budget. Since the launch of satellite-mounted sensors globe-wide monitoring of chlorophyll, a phytoplankton biomass proxy, became feasible. Just as satellites, the Forel-Ule (FU) scale record (a hardly explored database of ocean colour) has covered all seas and oceans – but already since 1889. We provide evidence that changes of ocean surface chlorophyll can be reconstructed with confidence from this record. The EcoLight radiative transfer numerical model indicates that the FU index is closely related to chlorophyll concentrations in open ocean regions. The most complete FU record is that of the North Atlantic in terms of coverage over space and in time; this dataset has been used to test the validity of colour changes that can be translated to chlorophyll. The FU and FU-derived chlorophyll data were analysed for monotonously increasing or decreasing trends with the non-parametric Mann-Kendall test, a method to establish the presence of a consistent trend. Our analysis has not revealed a globe-wide trend of increase or decrease in chlorophyll concentration during the past century; ocean regions have apparently responded differentially to changes in meteorological, hydrological and biological conditions at the surface, including potential long-term trends related to global warming. Since 1889, chlorophyll concentrations have decreased in the Indian Ocean and in the Pacific; increased in the Atlantic Ocean, the Mediterranean, the Chinese Sea, and in the seas west and north-west of Japan. This suggests that explanations of chlorophyll changes over long periods should focus on hydrographical and biological characteristics typical of single ocean regions, not on those of ‘the’ ocean. PMID:23776435

  5. Chlorophyll b Reductase Plays an Essential Role in Maturation and Storability of Arabidopsis Seeds1[W

    Science.gov (United States)

    Nakajima, Saori; Ito, Hisashi; Tanaka, Ryouichi; Tanaka, Ayumi

    2012-01-01

    Although seeds are a sink organ, chlorophyll synthesis and degradation occurs during embryogenesis and in a manner similar to that observed in photosynthetic leaves. Some mutants retain chlorophyll after seed maturation, and they are disturbed in seed storability. To elucidate the effects of chlorophyll retention on the seed storability of Arabidopsis (Arabidopsis thaliana), we examined the non-yellow coloring1 (nyc1)/nyc1-like (nol) mutants that do not degrade chlorophyll properly. Approximately 10 times more chlorophyll was retained in the dry seeds of the nyc1/nol mutant than in the wild-type seeds. The germination rates rapidly decreased during storage, with most of the mutant seeds failing to germinate after storage for 23 months, whereas 75% of the wild-type seeds germinated after 42 months. These results indicate that chlorophyll retention in the seeds affects seed longevity. Electron microscopic studies indicated that many small oil bodies appeared in the embryonic cotyledons of the nyc1/nol mutant; this finding indicates that the retention of chlorophyll affects the development of organelles in embryonic cells. A sequence analysis of the NYC1 promoter identified a potential abscisic acid (ABA)-responsive element. An electrophoretic mobility shift assay confirmed the binding of an ABA-responsive transcriptional factor to the NYC1 promoter DNA fragment, thus suggesting that NYC1 expression is regulated by ABA. Furthermore, NYC1 expression was repressed in the ABA-insensitive mutants during embryogenesis. These data indicate that chlorophyll degradation is induced by ABA during seed maturation to produce storable seeds. PMID:22751379

  6. Chlorophyll b reductase plays an essential role in maturation and storability of Arabidopsis seeds.

    Science.gov (United States)

    Nakajima, Saori; Ito, Hisashi; Tanaka, Ryouichi; Tanaka, Ayumi

    2012-09-01

    Although seeds are a sink organ, chlorophyll synthesis and degradation occurs during embryogenesis and in a manner similar to that observed in photosynthetic leaves. Some mutants retain chlorophyll after seed maturation, and they are disturbed in seed storability. To elucidate the effects of chlorophyll retention on the seed storability of Arabidopsis (Arabidopsis thaliana), we examined the non-yellow coloring1 (nyc1)/nyc1-like (nol) mutants that do not degrade chlorophyll properly. Approximately 10 times more chlorophyll was retained in the dry seeds of the nyc1/nol mutant than in the wild-type seeds. The germination rates rapidly decreased during storage, with most of the mutant seeds failing to germinate after storage for 23 months, whereas 75% of the wild-type seeds germinated after 42 months. These results indicate that chlorophyll retention in the seeds affects seed longevity. Electron microscopic studies indicated that many small oil bodies appeared in the embryonic cotyledons of the nyc1/nol mutant; this finding indicates that the retention of chlorophyll affects the development of organelles in embryonic cells. A sequence analysis of the NYC1 promoter identified a potential abscisic acid (ABA)-responsive element. An electrophoretic mobility shift assay confirmed the binding of an ABA-responsive transcriptional factor to the NYC1 promoter DNA fragment, thus suggesting that NYC1 expression is regulated by ABA. Furthermore, NYC1 expression was repressed in the ABA-insensitive mutants during embryogenesis. These data indicate that chlorophyll degradation is induced by ABA during seed maturation to produce storable seeds.

  7. PIXE analysis of trace elements in relation to chlorophyll concentration in Plantago ovata Forsk

    International Nuclear Information System (INIS)

    Saha, Priyanka; Sen Raychaudhuri, Sarmistha; Chakraborty, Anindita; Sudarshan, Mathummal

    2010-01-01

    Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.

  8. Green infrastructure for flood risk management in Dar es Salaam and Copenhagen

    DEFF Research Database (Denmark)

    Mguni, Patience; Herslund, Lise Byskov; Jensen, Marina Bergen

    2015-01-01

    The risk of flooding in urban areas could be better approached by complementing conventional sewer systems with sustainable urban drainage systems (SUDS) for storm-water management. This may be the case for developing world cities like Dar es Salaam with incomplete sewer services, as well as cities...... like Copenhagen with fully developed sewer systems. This paper explores some theories relevant to understanding how the implementation of SUDS may be one option for supporting a transition towards sustainable urban water management (SUWM). Using interviews, document analysis and observation......, a comparison of the opportunities and barriers to the implementation of SUDS in Dar es Salaam and Copenhagen is presented. The results indicate that a bottom-up approach in Dar es Salaam is important, with the community level taking the lead, while in Copenhagen the top-down approach currently employed...

  9. Spatiotemporal Variation in Mangrove Chlorophyll Concentration Using Landsat 8

    Directory of Open Access Journals (Sweden)

    Julio Pastor-Guzman

    2015-11-01

    Full Text Available There is a need to develop indicators of mangrove condition using remotely sensed data. However, remote estimation of leaf and canopy biochemical properties and vegetation condition remains challenging. In this paper, we (i tested the performance of selected hyperspectral and broad band indices to predict chlorophyll concentration (CC on mangrove leaves and (ii showed the potential of Landsat 8 for estimation of mangrove CC at the landscape level. Relative leaf CC and leaf spectral response were measured at 12 Elementary Sampling Units (ESU distributed along the northwest coast of the Yucatan Peninsula, Mexico. Linear regression models and coefficients of determination were computed to measure the association between CC and spectral response. At leaf level, the narrow band indices with the largest correlation with CC were Vogelmann indices and the MTCI (R2 > 0.5. Indices with spectral bands around the red edge (705–753 nm were more sensitive to mangrove leaf CC. At the ESU level Landsat 8 NDVI green, which uses the green band in its formulation explained most of the variation in CC (R2 > 0.8. Accuracy assessment between estimated CC and observed CC using the leave-one-out cross-validation (LOOCV method yielded a root mean squared error (RMSE = 15 mg·cm−2, and R2 = 0.703. CC maps showing the spatiotemporal variation of CC at landscape scale were created using the linear model. Our results indicate that Landsat 8 NDVI green can be employed to estimate CC in large mangrove areas where ground networks cannot be applied, and mapping techniques based on satellite data, are necessary. Furthermore, using upcoming technologies that will include two bands around the red edge such as Sentinel 2 will improve mangrove monitoring at higher spatial and temporal resolutions.

  10. Estimating chlorophyll content of spartina alterniflora at leaf level using hyper-spectral data

    Science.gov (United States)

    Wang, Jiapeng; Shi, Runhe; Liu, Pudong; Zhang, Chao; Chen, Maosi

    2017-09-01

    Spartina alterniflora, one of most successful invasive species in the world, was firstly introduced to China in 1979 to accelerate sedimentation and land formation via so-called "ecological engineering", and it is now widely distributed in coastal saltmarshes in China. A key question is how to retrieve chlorophyll content to reflect growth status, which has important implication of potential invasiveness. In this work, an estimation model of chlorophyll content of S. alterniflora was developed based on hyper-spectral data in the Dongtan Wetland, Yangtze Estuary, China. The spectral reflectance of S. alterniflora leaves and their corresponding chlorophyll contents were measured, and then the correlation analysis and regression (i.e., linear, logarithmic, quadratic, power and exponential regression) method were established. The spectral reflectance was transformed and the feature parameters (i.e., "san bian", "lv feng" and "hong gu") were extracted to retrieve the chlorophyll content of S. alterniflora . The results showed that these parameters had a large correlation coefficient with chlorophyll content. On the basis of the correlation coefficient, mathematical models were established, and the models of power and exponential based on SDb had the least RMSE and larger R2 , which had a good performance regarding the inversion of chlorophyll content of S. alterniflora.

  11. Impact of culture conditions on the chlorophyll content of microalgae for biotechnological applications.

    Science.gov (United States)

    da Silva Ferreira, Veronica; Sant'Anna, Celso

    2017-01-01

    Chlorophyll is a commercially important natural green pigment responsible for the absorption of light energy and its conversion into chemical energy via photosynthesis in plants and algae. This bioactive compound is widely used in the food, cosmetic, and pharmaceutical industries. Chlorophyll has been consumed for health benefits as a nutraceutical agent with antioxidant, anti-inflammatory, antimutagenic, and antimicrobial properties. Microalgae are photosynthesizing microorganisms which can be extracted for several high-value bioproducts in the biotechnology industry. These microorganisms are highly efficient at adapting to physicochemical variations in the local environment. This allows optimization of culture conditions for inducing microalgal growth and biomass production as well as for changing their biochemical composition. The modulation of microalgal culture under controlled conditions has been proposed to maximize chlorophyll accumulation. Strategies reported in the literature to promote the chlorophyll content in microalgae include variation in light intensity, culture agitation, and changes in temperature and nutrient availability. These factors affect chlorophyll concentration in a species-specific manner; therefore, optimization of culture conditions has become an essential requirement. This paper provides an overview of the current knowledge on the effects of key environmental factors on microalgal chlorophyll accumulation, focusing on small-scale laboratory experiments.

  12. Genetic Analysis and Molecular Mapping of a Novel Chlorophyll-Deficit Mutant Gene in Rice

    Directory of Open Access Journals (Sweden)

    Xiao-qun HUANG

    2008-03-01

    Full Text Available A rice etiolation mutant 824ys featured with chlorophyll deficiency was identified from a normal green rice variety 824B. It showed whole green-yellow plant from the seedling stage, reduced number of tillers and longer growth duration. The contents of chlorophyll, chlorophyll a, chlorophyll b and net photosynthetic rate in leaves of the mutant obviously decreased, as well as the number of spikelets per panicle, seed setting rate and 1000-grain weight compared with its wild-type parent. Genetic analyses on F1 and F2 generations of 824ys crossed with three normal green varieties showed that the chlorophyll-deficit mutant character was controlled by a pair of recessive nuclear gene. Genetic mapping of the mutant gene was conducted by using microsatellite markers and F2 mapping population of 495R/824ys, and the mutant gene of 824ys was mapped on the short arm of rice chromosome 3. The genetic distances from the target gene to the markers RM218, RM282 and RM6959 were 25.6 cM, 5.2 cM and 21.8 cM, respectively. It was considered to be a new chlorophyll-deficit mutant gene and tentatively named as chl11(t.

  13. Dustfall Effect on Hyperspectral Inversion of Chlorophyll Content - a Laboratory Experiment

    Science.gov (United States)

    Chen, Yuteng; Ma, Baodong; Li, Xuexin; Zhang, Song; Wu, Lixin

    2018-04-01

    Dust pollution is serious in many areas of China. It is of great significance to estimate chlorophyll content of vegetation accurately by hyperspectral remote sensing for assessing the vegetation growth status and monitoring the ecological environment in dusty areas. By using selected vegetation indices including Medium Resolution Imaging Spectrometer Terrestrial Chlorophyll Index (MTCI) Double Difference Index (DD) and Red Edge Position Index (REP), chlorophyll inversion models were built to study the accuracy of hyperspectral inversion of chlorophyll content based on a laboratory experiment. The results show that: (1) REP exponential model has the most stable accuracy for inversion of chlorophyll content in dusty environment. When dustfall amount is less than 80 g/m2, the inversion accuracy based on REP is stable with the variation of dustfall amount. When dustfall amount is greater than 80 g/m2, the inversion accuracy is slightly fluctuation. (2) Inversion accuracy of DD is worst among three models. (3) MTCI logarithm model has high inversion accuracy when dustfall amount is less than 80 g/m2; When dustfall amount is greater than 80 g/m2, inversion accuracy decreases regularly and inversion accuracy of modified MTCI (mMTCI) increases significantly. The results provide experimental basis and theoretical reference for hyperspectral remote sensing inversion of chlorophyll content.

  14. Contribution of Co2+ in increasing chlorophyll a concentration of Nannochloropsis salina in controlled Conwy medium

    Science.gov (United States)

    Hala, Y.; Taba, P.; Suryati, E.; Kasih, P.; Firman, N. F.

    2018-03-01

    A research in determining the contribution of Co2+ on the increase of chlorophyll a concentration of Nannochloropsis salina has been caried out. The cultivation of N. salina was conducted in the Conwy medium with a salinity of 5%o and 25%o and various Co2+ concentration (2, 4, and 8 ppm). In this research, Co2+ was exposed early in the cultivation of N. salina. The growth of N. salina was observed daily by counting the number of populations using a haemocytometer while the chlorophyll a concentration was determined by a Uv-Vis spectrophotometer. The results showed that the growth of N. salina in the control was higher than that in the medium containing Co2+. The optimum growth time was achieved on 15th days (5%) and 8th days (25%). In the cultivation medium with a salinity of 5%, Co2+ with a concentration of 2 ppm increased the chlorophyll a level while Co2+ with concentrations of 4 and 8 ppm decreased it. In the medium of cultivation with a salinity of 25%, the increase in chlorophyll a level was observed at Co2+ concentrations of 2 and 4 ppm whereas the decrease in chlorophyl a level was given at a concentration of 8 ppm. It can be concluded that at low concentrations, Co2+ increased the concentration of chlorophyll a in N. salina.

  15. Nondestructive Determination of Total Chlorophyll Content in Maize Using Three-Wavelength Diffuse Reflectance

    Science.gov (United States)

    Gu, D.-D.; Wang, W.-Z.; Hu, J.-D.; Zhang, X.-M.; Wang, J.-B.; Wang, B.-S.

    2016-09-01

    Chlorophyll in leaves plays a vital role in plant growth and can be used as an indicator of a plant's nutritional status. In this paper, an experimental setup for measuring total chlorophyll content using three-wavelength diffuse reflectance is proposed, for which light-emitting diodes with peak wavelengths of 640, 660, and 940 nm are used. Two different maize strains, Zhengdan-958 and Xundan-20, fertilized at different levels before the jointing stage, were used to validate this setup. Regression analyses between remission function values of diffuse reflectance and SPAD values, as well as remission function values of diffuse reflectance and the actual total chlorophyll content, were performed. The determination coefficients between remission function values and the actual total chlorophyll content were 0.9766 for Zhengdan-958 leaves and 0.9612 for Xundan-20 leaves. The experimental results validated the feasibility of using the diffuse reflectance spectrum to determine the total chlorophyll content. This paper also provides guidance for the development of a portable instrument to determine the actual chlorophyll content.

  16. Chlorophyll and zooplankton in microbasins along the Strait of Magellan - Beagle Channel passage

    Directory of Open Access Journals (Sweden)

    Madeleine Hamamé

    1999-12-01

    Full Text Available Distributions of chlorophyll and zooplankton were compared to temperature and salinity distributions along previously defined microbasins. Results were consistent for chlorophyll: 1.- Paso Ancho-Seno Magdalena showed a shallow chlorophyll maximum (ca. 5 mg m-3 at 0 - 20 m in a vertically homogeneous cold and brackish water column, 2.- Canal Magdalena-Canal Cockburn-Canal Brecknock had relatively lower chlorophyll concentrations (2-3 mg m-3 at 0-50 m, minor stratification of salinity and a surface lens of warmer water, 3.- Canal Ballenero-Brazo Noroeste had a subsurface layer of high chlorophyll concentration (> 4 mg m-3 in a vertically stratified water column of 2 salinity layers and 3 temperature layers, 4.- Canal Beagle presented a subsurface chlorophyll maximum (> 4 mg m-3 extending to the bottom, and vertically homogeneous salinity and temperature distribution. Chaetoceros spp.-dominated phytoplankton was a common feature in the entire area. Zooplankton distributions did not match the above mentioned subdivision of microbasins despite some trends along the passage. High relative abundance of invertebrate larvae in the zooplankton was associated with a matching response to the spring bloom and implies a strong bentho-pelagic coupling.

  17. Chlorophyll and carbohydrates in Arachis pintoi plants under influence of water regimes and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Rita Manuele Porto Sales

    2013-06-01

    Full Text Available In this experiment the chlorophyll and carbohydrate contents of Arachis pintoi were evaluated to verify if the presence of nitrogen in the soil could contribute to the effectiveness of the establishment of this legume. The design was completely randomized, in a 4 × 4 factorial arrangement, with four N rates (0, 40, 80 and 120 kg ha-1 and four irrigation levels (25, 50, 75 and 100% of field capacity, with four replications. The biochemical evaluations of chlorophylls a and b and total chlorophyll and total soluble sugars, sucrose and starch were performed. The highest contents of chlorophyll a and b and total chlorophyll in leaves were found at the dose of 120 kg ha-1. The water regime of 25% of field capacity was responsible for the lowest content of reducing sugars and total soluble sugars in leaves, stolons and roots. In the roots, the sucrose contents were higher in these conditions, which can be associated with a slight tolerance of the plant to water stress. The water deficiency was responsible for the decrease of reducing sugars and total N in the whole plant and positively influenced the levels of chlorophyll and sugars in the stolon, promoting growth, especially of shoots, at the beginning of establishment.

  18. Spatial-temporal variability of leaf chlorophyll and its relationship with cocoa yield

    Directory of Open Access Journals (Sweden)

    Caique C. Medauar

    Full Text Available ABSTRACT The objective of this study was to evaluate the spatial-temporal variability of leaf chlorophyll index and its relationship with cocoa yield. The experiment was carried out in an experimental area of cocoa production located in Ilhéus, Bahia State, Brazil. Leaf chlorophyll content was measured in September, October, January, February, March and April in the 2014/2015 season, at each sampling point of a regular grid by using a portable chlorophyll meter. Under the same conditions, yield was evaluated and the data were submitted to descriptive statistics and a linear correlation study. Geostatistical analysis was used to determine and quantify the spatial and temporal variability of leaf chlorophyll index and yield. Leaf chlorophyll index varied over the period evaluated, but the months of February, March and April showed no spatial dependence in the study area, indicating absence of temporal stability. Cocoa monthly yield, except in January, presented high spatial variability. Under the conditions of this study, it was not possible to establish a relationship between leaf chlorophyll index and cocoa yield.

  19. Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data

    Energy Technology Data Exchange (ETDEWEB)

    Danny L. Anderson

    2012-05-01

    Detailed hydrographic feature extraction from high-resolution light detection and ranging (LiDAR) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from LiDAR-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates a new method of delineating a stream directly from LiDAR point clouds, without the intermediate step of deriving a DEM. Direct use of LiDAR point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the LiDAR data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.

  20. Numerical modeling of the airflow around a forest edge using LiDAR-derived forest heigths

    DEFF Research Database (Denmark)

    Boudreault, Louis-Etienne; Dellwik, Ebba; Bechmann, Andreas

    A 3D methodology to quantify the effect of forests on the mean wind flow field is presented. The methodology is based on the treatment of forest raw data of light detection and ranging (LiDAR) scans, and a computational fluid dynamics (CFD) method based on a Reynolds-averaged Navier-Stokes (Ra......NS) approach using the k−e turbulence model with a corresponding canopy model. The example site investigated is a forest edge located on the Falster island in Denmark, where a measurement campaign was conducted. The LiDAR scans are used in order to obtain the forest heights, which served as input...

  1. A Hybrid Process/Thread Parallel Algorithm for Generating DEM from LiDAR Points

    Directory of Open Access Journals (Sweden)

    Yibin Ren

    2017-09-01

    Full Text Available Airborne Light Detection and Ranging (LiDAR is widely used in digital elevation model (DEM generation. However, the very large volume of LiDAR datasets brings a great challenge for the traditional serial algorithm. Using parallel computing to accelerate the efficiency of DEM generation from LiDAR points has been a hot topic in parallel geo-computing. Generally, most of the existing parallel algorithms running on high-performance clusters (HPC were in process-paralleling mode, with a static scheduling strategy. The static strategy would not respond dynamically according to the computation progress, leading to load unbalancing. Additionally, because each process has independent memory space, the cost of dealing with boundary problems increases obviously with the increase in the number of processes. Actually, these two problems can have a significant influence on the efficiency of DEM generation for larger datasets, especially for those of irregular shapes. Thus, to solve these problems, we combined the advantages of process-paralleling with the advantages of thread-paralleling, forming a new idea: using process-paralleling to achieve a flexible schedule and scalable computation, using thread-paralleling inside the process to reduce boundary problems. Therefore, we proposed a hybrid process/thread parallel algorithm for generating DEM from LiDAR points. Firstly, at the process level, we designed a parallel method (PPDB to accelerate the partitioning of LiDAR points. We also proposed a new dynamic scheduling strategy to achieve better load balancing. Secondly, at the thread level, we designed an asynchronous parallel strategy to hide the cost of LiDAR points’ reading. Lastly, we tested our algorithm with three LiDAR datasets. Experiments showed that our parallel algorithm had no influence on the accuracy of the resultant DEM. At the same time, our algorithm reduced the conversion time from 112,486 s to 2342 s when we used the largest dataset (150

  2. Grupo DAR : Actividades didácticas y recreativas para niños

    OpenAIRE

    Bellone, María Eugenia; Rizzi, Nicolás; Figueroa, Claudio; Biber, Leonardo

    2012-01-01

    El presente artículo propone dar cuenta de las acciones llevadas a cabo por el Grupo DAR (actividades didácticas y recreativas) conformado por jóvenes estudiantes universitarios y profesionales, residentes de la Ciudad de Córdoba. El equipo coordina desde el año 2005 diversos talleres destinados a niños de entre 4 y 14 años residentes y de zonas aledañas al Barrio Ferreyra, ubicado a 12 kilómetros de la zona céntrica. La modalidad de trabajo parte de una perspectiva de int...

  3. Prevalence of teeth with untreated dental trauma among nursery and primary school pupils in Dar es Salaam, Tanzania.

    NARCIS (Netherlands)

    Kahabuka, F.K.; Plasschaert, A.J.M.; Hof, M.A. van 't

    2001-01-01

    The aim of this study was to investigate the prevalence of teeth with untreated dental trauma among children aged 4-15 years in Dar es Salaam, Tanzania. A sample of 4524 children from three districts of different socio-economic status in the Dar es Salaam area was examined for signs of dental trauma

  4. Comparison of LiDAR-derived data and high resolution true color imagery for extracting urban forest cover

    Science.gov (United States)

    Aaron E. Maxwell; Adam C. Riley; Paul. Kinder

    2013-01-01

    Remote sensing has many applications in forestry. Light detection and ranging (LiDAR) and high resolution aerial photography have been investigated as means to extract forest data, such as biomass, timber volume, stand dynamics, and gap characteristics. LiDAR return intensity data are often overlooked as a source of input raster data for thematic map creation. We...

  5. Remote Sensing of Sonoran Desert Vegetation Structure and Phenology with Ground-Based LiDAR

    Directory of Open Access Journals (Sweden)

    Joel B. Sankey

    2014-12-01

    Full Text Available Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

  6. Computer-based synthetic data to assess the tree delineation algorithm from airborne LiDAR survey

    Science.gov (United States)

    Lei Wang; Andrew G. Birt; Charles W. Lafon; David M. Cairns; Robert N. Coulson; Maria D. Tchakerian; Weimin Xi; Sorin C. Popescu; James M. Guldin

    2013-01-01

    Small Footprint LiDAR (Light Detection And Ranging) has been proposed as an effective tool for measuring detailed biophysical characteristics of forests over broad spatial scales. However, by itself LiDAR yields only a sample of the true 3D structure of a forest. In order to extract useful forestry relevant information, this data must be interpreted using mathematical...

  7. Investigating the influence of LiDAR ground surface errors on the utility of derived forest inventories

    Science.gov (United States)

    Wade T. Tinkham; Alistair M. S. Smith; Chad Hoffman; Andrew T. Hudak; Michael J. Falkowski; Mark E. Swanson; Paul E. Gessler

    2012-01-01

    Light detection and ranging, or LiDAR, effectively produces products spatially characterizing both terrain and vegetation structure; however, development and use of those products has outpaced our understanding of the errors within them. LiDAR's ability to capture three-dimensional structure has led to interest in conducting or augmenting forest inventories with...

  8. Comparing LiDAR-Generated to ground- surveyed channel cross-sectional profiles in a forested mountain stream

    Science.gov (United States)

    Brian C. Dietterick; Russell White; Ryan. Hilburn

    2012-01-01

    Airborne Light Detection and Ranging (LiDAR) holds promise to provide an alternative to traditional ground-based survey methods for stream channel characterization and some change detection purposes, even under challenging landscape conditions. This study compared channel characteristics measured at 53 ground-surveyed and LiDAR-derived crosssectional profiles located...

  9. Airborne LiDAR reflective linear feature extraction for strip adjustment and horizontal accuracy determination : executive summary.

    Science.gov (United States)

    2009-02-01

    The Office of Aerial Engineering (OAE) has been : using an Optech 30/70 ALTM airborne LiDAR system : for about four years. The introduction of LiDAR : technology was a major development towards : improving the mapping operations, and the overall : ex...

  10. Deriving leaf chlorophyll content of green-leafy vegetables from hyperspectral reflectance

    Science.gov (United States)

    Xue, Lihong; Yang, Linzhang

    Different nitrogen (N) treatments of four common green-leafy vegetable varieties with different leaf color: lettuce ( Lactuca sativa L. var. crispa L.) with yellow green leaves, pakchoi ( Brassica chinensis L.) var. aijiaohuang in Chinese (AJH) with middle green leaves, spinach ( Spinacia oleracea L.) with green leaves and pakchoi ( B. chinensis L.) var. shanghaiqing in Chinese (SHQ) with dark green leaves, were carried out to achieve a wide range of chlorophyll content. The relationship of vegetable leaf hyperspectral response to its chlorophyll content was examined in this study. Almost all reported successful leaf chlorophyll indices in the literature were evaluated for their ability to predict the chlorophyll content in vegetable leaves. Some new indices based on the first derivative curve were also developed, and compared with the chlorophyll indices published. The results showed that most of the indices showed a strong relation with leaf chlorophyll content. In general, modified indices with the blue or near red edge wavelength performed better than their simple counterpart without modification, ratio indices performed a little better than normalized indices when chlorophyll expressed on area basis and reversed when chlorophyll expressed on fresh weight basis. A normalized derivative difference ratio (BND: (D722-D700)/(D722+D700) calibrated by Maire et al. [Maire, G., Francois, C., Dufrene, E., 2004. Towards universal broad leaf chlorophyll indices using PROSPECT simulated database and hyperspectral reflectance measurements. Remote Sensing of Environment 89 (1), 1-28]) gave the best results among all published indices in this study (RMSE=22.1 mg m -2), then the mSR-like indices with the RMSE between 22.6 and 23.0 mg m -2. The new indices EBAR (ratio of the area of red and blue, ∑ dRE/∑ dB), EBFN (normalized difference of the amplitude of red and blue, (dRE-dB)/(dRE+dB)) and EBAN (normalized difference of the area of red and blue, (∑ dRE-∑ dB)/(∑ d

  11. Visualization of High-Resolution LiDAR Topography in Google Earth

    Science.gov (United States)

    Crosby, C. J.; Nandigam, V.; Arrowsmith, R.; Blair, J. L.

    2009-12-01

    The growing availability of high-resolution LiDAR (Light Detection And Ranging) topographic data has proven to be revolutionary for Earth science research. These data allow scientists to study the processes acting on the Earth’s surfaces at resolutions not previously possible yet essential for their appropriate representation. In addition to their utility for research, the data have also been recognized as powerful tools for communicating earth science concepts for education and outreach purposes. Unfortunately, the massive volume of data produced by LiDAR mapping technology can be a barrier to their use. To facilitate access to these powerful data for research and educational purposes, we have been exploring the use of Keyhole Markup Language (KML) and Google Earth to deliver LiDAR-derived visualizations. The OpenTopography Portal (http://www.opentopography.org/) is a National Science Foundation-funded facility designed to provide access to Earth science-oriented LiDAR data. OpenTopography hosts a growing collection of LiDAR data for a variety of geologic domains, including many of the active faults in the western United States. We have found that the wide spectrum of LiDAR users have variable scientific applications, computing resources, and technical experience and thus require a data distribution system that provides various levels of access to the data. For users seeking a synoptic view of the data, and for education and outreach purposes, delivering full-resolution images derived from LiDAR topography into the Google Earth virtual globe is powerful. The virtual globe environment provides a freely available and easily navigated viewer and enables quick integration of the LiDAR visualizations with imagery, geographic layers, and other relevant data available in KML format. Through region-dependant network linked KML, OpenTopography currently delivers over 20 GB of LiDAR-derived imagery to users via simple, easily downloaded KMZ files hosted at the Portal

  12. Integrated remote sensing and visualization (IRSV) system for transportation infrastructure operations and management, phase two, volume 3 : advanced consideration in LiDAR technology for bridge evaluation.

    Science.gov (United States)

    2012-03-01

    This report describes Phase Two enhancement of terrestrial LiDAR scanning for bridge damage : evaluation that was initially developed in Phase One. Considering the spatial and reflectivity : information contained in LiDAR scans, two detection algorit...

  13. Overview of Global Monitoring of Terrestrial Chlorophyll Fluorescence from Space

    Science.gov (United States)

    Guanter, Luis; Zhang, Yongguang; Kohler, Philipp; Walther, Sophia; Frankenberg, Christian; Joiner, Joanna

    2016-01-01

    Despite the critical importance of photosynthesis for the Earth system, understanding how it is influenced by factors such as climate variability, disturbance history, and water or nutrient availability remains a challenge because of the complex interactions and the lack of GPP measurements at various temporal and spatial scales. Space observations of the sun-induced chlorophyll fluorescence (SIF) electromagnetic signal emitted by plants in the 650-850nm spectral range hold the promise of providing a new view of vegetation photosynthesis on a global basis. Global retrievals of SIF from space have recently been achieved from a number of spaceborne spectrometers originally intended for atmospheric research. Despite not having been designed for land applications, such instruments have turned out to provide the necessary spectral and radiometric sensitivity for SIF retrieval from space. The first global measurements of SIF were achieved in 2011 from spectra acquired by the Japanese GOSAT mission launched in 2009. The retrieval takes advantage of the high spectral resolution provided by GOSATs Fourier Transform Spectrometer (FTS) which allows the evaluation of the in-filling of solar Fraunhofer lines by SIF. Unfortunately, GOSAT only provides a sparse spatial sampling with individual soundings separated by several hundred kilometers. Complementary, the Global Ozone Monitoring Experiment-2 (GOME-2) instruments onboard MetOp-A and MetOp-B enable SIF retrievals since 2007 with a continuous and global spatial coverage. GOME-2 measures in the red and near-infrared (NIR) spectral regions with a spectral resolution of 0.5 nm and a pixel size of up to 40x40 km2. Most recently, another global and spatially continuous data set of SIF retrievals at 740 nm spanning the 2003-2012 time frame has been produced from ENVISATSCIAMACHY. This observational scenario has been completed by the first fluorescence data from the NASA-JPL OCO-2 mission (launched in July 2014) and the upcoming

  14. Measuring solar induced chlorophyll fluorescence (SIF) in the Amazon rainforest

    Science.gov (United States)

    Kornfeld, A.; Stutz, J.; Berry, J. A.

    2016-12-01

    Measurement of solar induced chlorophyll fluorescence (SIF) has, in our hands, been fraught with missteps and puzzling problems. Here we describe lessons we have learned and the resulting novel system recently installed in the Amazon rainforest near Manaus, Brazil. The system is designed to measure light from 740 - 780 nm, enabling us to compare SIF computed from Fraunhofer lines in an optically transparent band of the atmosphere (745 - 759 nm) with SIF computed using the telluric O2A band (760 - 770 nm). Fraunhofer line analysis requires high optical resolution (better than 0.2 nm) to detect the relatively narrow lines, but we discovered that fiber-optic diffraction-grating spectrometers are sensitive to very small inhomogeneities in the lighting. Errors resulting from this autocorrelated but random noise were similar in magnitude to the SIF signal itself. Optical diffusers reduce this problem, leading to our final design: a sealed cylinder, dubbed Rotaprism, in which a rotatable prism selects whether light from upward- or downward-looking windows enters an axially-placed optical fiber. Cosine-correcting opal glass covering the windows not only solves the noise issue but also makes the measurements correspond to photon flux. Rotaprism also maximizes the amount of light reaching the spectrometer - maximizing the signal:noise ratio - by avoiding the need for lossy optical switches and fiber splitters. Rotaprism is driven by a pneumatic actuator that is controlled by electronic valves attached to a pressurized N2 source. The gas exhausts into the temperature-controlled spectrometer enclosure to help purge the optics. Finally, custom software provides fault-tolerant control and data acquisition, ensuring that measurements continue with little or no intervention at the remote field site despite unreliable power. Analysis of initial data demonstrates the advantage of Fraunhofer line SIF analysis: due to the atmosphere transparency in this band, the results are more

  15. Chlorophyll fluorescence response to water and nitrogen deficit

    Science.gov (United States)

    Cendrero Mateo, Maria del Pilar

    The increasing food demand as well as the need to predict the impact of warming climate on vegetation makes it critical to find the best tools to assess crop production and carbon dioxide (CO2) exchange between the land and atmosphere. Photosynthesis is a good indicator of crop production and CO2 exchange. Chlorophyll fluorescence (ChF) is directly related to photosynthesis. ChF can be measured at leaf-scale using active techniques and at field-scales using passive techniques. The measurement principles of both techniques are different. In this study, three overarching questions about ChF were addressed: Q1) How water, nutrient and ambient light conditions determine the relationships between photosynthesis and ChF? Which is the optimum irradiance level for detecting water and nutrient deficit conditions with ChF? ; Q2) which are the limits within which active and passive techniques are comparable?; and Q3) What is the seasonal relationship between photosynthesis and ChF when nitrogen is the limiting factor? To address these questions, two main experiments were conducted: Exp1) Concurrent photosynthesis and ChF light-response curves were measured in camelina and wheat plants growing under (i) intermediate-light and (ii) high-light conditions respectively. Plant stress was induced by (i) withdrawing water, and (ii) applying different nitrogen levels; and Exp2) coincident active and passive ChF measurements were made in a wheat field under different nitrogen treatments. The results indicated ChF has a direct relationship with photosynthesis when water or nitrogen drives the relationship. This study demonstrates that the light level at which plants were grown was optimum for detecting water and nutrient deficit with ChF. Also, the results showed that for leaf-average-values, active measurements can be used to better understand the daily and seasonal behavior of passive ChF. Further, the seasonal relation between photosynthesis and ChF with nitrogen stress was not a

  16. Chlorophyll-a retrieval in the Philippine waters

    Science.gov (United States)

    Perez, G. J. P.; Leonardo, E. M.; Felix, M. J.

    2017-12-01

    Satellite-based monitoring of chlorophyll-a (Chl-a) concentration has been widely used for estimating plankton biomass, detecting harmful algal blooms, predicting pelagic fish abundance, and water quality assessment. Chl-a concentrations at 1 km spatial resolution can be retrieved from MODIS onboard Aqua and Terra satellites. However, with this resolution, MODIS has scarce Chl-a retrieval in coastal and inland waters, which are relevant for archipelagic countries such as the Philippines. These gaps on Chl-a retrieval can be filled by sensors with higher spatial resolution, such as the OLI of Landsat 8. In this study, assessment of Chl-a concentration derived from MODIS/Aqua and OLI/Landsat 8 imageries across the open, coastal and inland waters of the Philippines was done. Validation activities were conducted at eight different sites around the Philippines for the period October 2016 to April 2017. Water samples filtered on the field were processed in the laboratory for Chl-a extraction. In situ remote sensing reflectance was derived from radiometric measurements and ancillary information, such as bathymetry and turbidity, were also measured. Correlation between in situ and satellite-derived Chl-a concentration using the blue-green ratio yielded relatively high R2 values of 0.51 to 0.90. This is despite an observed overestimation for both MODIS and OLI-derived values, especially in turbid and coastal waters. The overestimation of Chl-a may be attributed to inaccuracies in i) remote sensing reflectance (Rrs) retrieval and/or ii) empirical model used in calculating Chl-a concentration. However, a good 1:1 correspondence between the satellite and in situ maximum Rrs band ratio was established. This implies that the overestimation is largely due to the inaccuracies from the default coefficients used in the empirical model. New coefficients were then derived from the correlation analysis of both in situ-measured Chl-a concentration and maximum Rrs band ratio. This

  17. Salt tolerance in crop plants monitored by chlorophyll fluorescence in vivo.

    Science.gov (United States)

    Smillie, R M; Nott, R

    1982-10-01

    The potential of measurements of chlorophyll fluorescence in vivo to detect cellular responses to salinity and degrees of salt stress in leaves was investigated for three crop plants. Sugar beet (Beta vulgaris L.) (salt tolerant), sunflower (Helianthus annuus L.) (moderately salt tolerant), and bean (Phaseolus Vulgaris L. cv Canadian Wonder) (salt intolerant) were grown in pots and watered with mineral nutrient solution containing 100 millimolar NaCl. The fast rise in variable chlorophyll fluorescence yield that is correlated with photoreduction of photosystem II acceptors increased in leaves of sugar beet plants treated with salt suggesting stimulation of photosystem II activity relative to photosystem I. In sunflower, this fast rise was depressed by approximately 25% and the subsequent slow rate of quenching of the chlorophyll fluorescence was stimulated. These differences were more marked in the older mature leaves indicating an increasing gradient of salt response down the plant. The salt effect in vivo was reversible since chloroplasts isolated from mature leaves of salt-treated and control sunflower plants gave similar photosystem II activities. Unlike in sugar beet and sunflower, leaves of salt-treated bean progressively lost chlorophyll. The rate of slow quenching of chlorophyll fluorescence decreased indicating development of a partial block after photosystem II and possible initial stimulation of photosystem II activity. With further loss of chlorophyll photosystem II activity declined. It was concluded that measurements of chlorophyll fluorescence in vivo can provide a rapid means of detecting salt stress in leaves, including instances where photosynthesis is reduced in the absence of visible symptoms. The possible application to screening for salt tolerance is discussed.

  18. Exploring the Relationship Between Reflectance Red Edge and Chlorophyll Content in Slash Pine

    Science.gov (United States)

    Curran, Paul J.; Dungan, Jennifer L.; Gholz, Henry L.

    1990-01-01

    Chlorophyll is a key indicator of the physiological status of a forest canopy. However, its distribution may vary greatly in time and space, so that the estimation of chlorophyll content of canopies or branches by extrapolation from leaf values obtained by destructive sampling is labor intensive and potentially inaccurate. Chlorophy11 content is related positively to the point of maximum slope in vegetation reflectance spectra which occurs at wavelengths between 690-740 nm and is known as the "red edge." The red edge of needles on individual slash pine (Piniis elliottii Engelm.) branches and in whole forest canopies was measured with a spectroradiometer. Branches were measured on the ground against a spectrally flat reflectance target and canopies were measured from observation towers against a spectrally variable understory and forest floor. There was a linear relationship between red edge and chlorophyll content of branches (R(exp 2) = 0.91). Measurements of the red edge and this relationship were used to estimate the chlorophyll content of other branches with an error that was lower than that associated with the colorimetric (laboratory) method. There was no relationship between the red edge and the chlorophyll content of whole canopies. This can be explained by the overriding influence of the understory and forest floor, an influence that was illustrated by spectral mixture modeling. The results suggest that the red edge could be used to estimate the chlorophyll content in branches but it is unlikely to be of value for the estimation of chlorophyll content in canopies unless the canopy cover is high.

  19. Modification of sea surface temperature by chlorophyll concentration in the Atlantic upwelling systems

    Science.gov (United States)

    Hernandez, O.; Jouanno, J.; Echevin, V.; Aumont, O.

    2017-07-01

    The influence of the chlorophyll on the upper Tropical Atlantic Ocean is investigated with long-term (1979-2012) regional oceanic simulations with 1/4° horizontal resolution based on the NEMO3.6 model. The model solar radiation penetration scheme depends on the chlorophyll concentration. Simulations with time and spatially varying concentrations obtained from satellite ocean color observations are compared with a simulation forced with constant chlorophyll concentration of 0.05 mg m-3, representative of chlorophyll depleted waters. Results indicate that regions of the Tropical Atlantic with chlorophyll concentrations larger than in the reference simulation (i.e., [chl] > 0.05 mg m-3) get warmer at the surface, with the exception of the main upwelling regions where high chlorophyll concentrations are associated with a significant cooling of the sea surface (˜1°C in the Benguela upwelling). The analysis of the model heat balance shows that the biological differential heating causes negative temperature anomalies in subsurface source waters prior to their upwelling at the coast. The shallow mixed-layer in the eastern equatorial and tropical Atlantic favors the persistence of these subsurface anomalies and may explain why the Benguela is particularly sensitive to the biological differential heating. In spite of the presence of high chlorophyll concentrations in the upwelling regions, both the larger amount of shortwave radiation captured in the surface layers and the modifications of the horizontal and vertical advection at the coast are found to play a secondary role in the SST change in the upwelling region.

  20. Microdroplet fusion mass spectrometry: accelerated kinetics of acid-induced chlorophyll demetallation.

    Science.gov (United States)

    Lee, Jae Kyoo; Nam, Hong Gil; Zare, Richard N

    2017-01-01

    Kinetics of acid-induced chlorophyll demetallation was recorded in microdroplets by fusing a stream of microdroplets containing 40 µM chlorophyll a or b dissolved in methanol with a stream of aqueous microdroplets containing 35 mM hydrochloric acid (pH = 1·46). The kinetics of the demetallation of chlorophyll in the fused microdroplets (14 ± 6 µm diameter; 84 ± 18 m s-1 velocity) was recorded by controlling the traveling distance of the fused microdroplets between the fusion region and the inlet of a mass spectrometer. The rate of acid-induced chlorophyll demetallation was about 960 ± 120 times faster in the charged microdroplets compared with that reported in bulk solution. If no voltage was applied to the sprayed microdroplets, then the acceleration factor was about 580 ± 90, suggesting that the applied voltage is not a major factor determining the acceleration. Chlorophyll a was more rapidly demetallated than chlorophyll b by a factor of ~26 in bulk solution and ~5 in charged microdroplets. The demetallation kinetics was second order in the H+ concentration, but the acceleration factor of microdroplets compared with bulk solution appeared to be unchanged in going from pH = 1·3 to 7·0. The water:methanol ratio of the fused microdroplets was varied from 7:3 to 3:7 causing an increase in the reaction rate of chlorophyll a demetallation by 20%. This observation demonstrates that the solvent composition, which has different evaporation rates, does not significantly affect the acceleration. We believe that a major portion of the acceleration can be attributed to confinement effects involving surface reactions rather than either to evaporation of solvents or to the introduction of charges to the microdroplets.

  1. Femtosecond Visible Transient Absorption Spectroscopy of Chlorophyll f-Containing Photosystem I.

    Science.gov (United States)

    Kaucikas, Marius; Nürnberg, Dennis; Dorlhiac, Gabriel; Rutherford, A William; van Thor, Jasper J

    2017-01-24

    Photosystem I (PSI) from Chroococcidiopsis thermalis PCC 7203 grown under far-red light (FRL; >725 nm) contains both chlorophyll a and a small proportion of chlorophyll f. Here, we investigated excitation energy transfer and charge separation using this FRL-grown form of PSI (FRL-PSI). We compared femtosecond transient visible absorption changes of normal, white-light (WL)-grown PSI (WL-PSI) with those of FRL-PSI using excitation at 670 nm, 700 nm, and (in the case of FRL-PSI) 740 nm. The possibility that chlorophyll f participates in energy transfer or charge separation is discussed on the basis of spectral assignments. With selective pumping of chlorophyll f at 740 nm, we observe a final ∼150 ps decay assigned to trapping by charge separation, and the amplitude of the resulting P700 +• A 1 -• charge-separated state indicates that the yield is directly comparable to that of WL-PSI. The kinetics shows a rapid 2 ps time constant for almost complete transfer to chlorophyll f if chlorophyll a is pumped with a wavelength of 670 nm or 700 nm. Although the physical role of chlorophyll f is best supported as a low-energy radiative trap, the physical location should be close to or potentially within the charge-separating pigments to allow efficient transfer for charge separation on the 150 ps timescale. Target models can be developed that include a branching in the formation of the charge separation for either WL-PSI or FRL-PSI. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. Habitat Classification of Temperate Marine Macroalgal Communities Using Bathymetric LiDAR

    Directory of Open Access Journals (Sweden)

    Richard Zavalas

    2014-03-01

    Full Text Available Here, we evaluated the potential of using bathymetric Light Detection and Ranging (LiDAR to characterise shallow water (<30 m benthic habitats of high energy subtidal coastal environments. Habitat classification, quantifying benthic substrata and macroalgal communities, was achieved in this study with the application of LiDAR and underwater video groundtruth data using automated classification techniques. Bathymetry and reflectance datasets were used to produce secondary terrain derivative surfaces (e.g., rugosity, aspect that were assumed to influence benthic patterns observed. An automated decision tree classification approach using the Quick Unbiased Efficient Statistical Tree (QUEST was applied to produce substrata, biological and canopy structure habitat maps of the study area. Error assessment indicated that habitat maps produced were primarily accurate (>70%, with varying results for the classification of individual habitat classes; for instance, producer accuracy for mixed brown algae and sediment substrata, was 74% and 93%, respectively. LiDAR was also successful for differentiating canopy structure of macroalgae communities (i.e., canopy structure classification, such as canopy forming kelp versus erect fine branching algae. In conclusion, habitat characterisation using bathymetric LiDAR provides a unique potential to collect baseline information about biological assemblages and, hence, potential reef connectivity over large areas beyond the range of direct observation. This research contributes a new perspective for assessing the structure of subtidal coastal ecosystems, providing a novel tool for the research and management of such highly dynamic marine environments.

  3. LiDAR based prediction of forest biomass using hierarchical models with spatially varying coefficients

    Science.gov (United States)

    Chad Babcock; Andrew O. Finley; John B. Bradford; Randy Kolka; Richard Birdsey; Michael G. Ryan

    2015-01-01

    Many studies and production inventory systems have shown the utility of coupling covariates derived from Light Detection and Ranging (LiDAR) data with forest variables measured on georeferenced inventory plots through regression models. The objective of this study was to propose and assess the use of a Bayesian hierarchical modeling framework that accommodates both...

  4. The effect of El Nino on trypanosome infection in cattle in Dar es ...

    African Journals Online (AJOL)

    A retrospective study was carried out to assess the effect of El Nino on trypanosome infection in cattle. Trypanosome infection was monitored in free grazing dairy cattle before and after El Nino in Dar es Salaam. The study involved 49 smallholder dairy herds with a total of 570 dairy cattle. Trypanosomes were identified by ...

  5. Tensor-Based Sparse Representation Classification for Urban Airborne LiDAR Points

    Directory of Open Access Journals (Sweden)

    Nan Li

    2017-11-01

    Full Text Available The common statistical methods for supervised classification usually require a large amount of training data to achieve reasonable results, which is time consuming and inefficient. In many methods, only the features of each point are used, regardless of their spatial distribution within a certain neighborhood. This paper proposes a tensor-based sparse representation classification (TSRC method for airborne LiDAR (Light Detection and Ranging points. To keep features arranged in their spatial arrangement, each LiDAR point is represented as a 4th-order tensor. Then, TSRC is performed for point classification based on the 4th-order tensors. Firstly, a structured and discriminative dictionary set is learned by using only a few training samples. Subsequently, for classifying a new point, the sparse tensor is calculated based on the tensor OMP (Orthogonal Matching Pursuit algorithm. The test tensor data is approximated by sub-dictionary set and its corresponding subset of sparse tensor for each class. The point label is determined by the minimal reconstruction residuals. Experiments are carried out on eight real LiDAR point clouds whose result shows that objects can be distinguished by TSRC successfully. The overall accuracy of all the datasets is beyond 80% by TSRC. TSRC also shows a good improvement on LiDAR points classification when compared with other common classifiers.

  6. Identification of four Drosophila allatostatins as the cognate ligands for the Drosophila orphan receptor DAR-2

    DEFF Research Database (Denmark)

    Lenz, C; Williamson, M; Hansen, G N

    2001-01-01

    to be the receptor for an intrinsic Drosophila A-type (cockroach-type) allatostatin. Here, we have permanently expressed DAR-2 in CHO cells and found that it is the cognate receptor for four Drosophila A-type allatostatins, the drostatins-A1 to -A4. Of all the drostatins, drostatin-A4 (Thr...

  7. Automatic extraction of pavement markings on streets from point cloud data of mobile LiDAR

    Science.gov (United States)

    Gao, Yang; Zhong, Ruofei; Tang, Tao; Wang, Liuzhao; Liu, Xianlin

    2017-08-01

    Pavement markings provide an important foundation as they help to keep roads users safe. Accurate and comprehensive information about pavement markings assists the road regulators and is useful in developing driverless technology. Mobile light detection and ranging (LiDAR) systems offer new opportunities to collect and process accurate pavement markings’ information. Mobile LiDAR systems can directly obtain the three-dimensional (3D) coordinates of an object, thus defining spatial data and the intensity of (3D) objects in a fast and efficient way. The RGB attribute information of data points can be obtained based on the panoramic camera in the system. In this paper, we present a novel method process to automatically extract pavement markings using multiple attribute information of the laser scanning point cloud from the mobile LiDAR data. This method process utilizes a differential grayscale of RGB color, laser pulse reflection intensity, and the differential intensity to identify and extract pavement markings. We utilized point cloud density to remove the noise and used morphological operations to eliminate the errors. In the application, we tested our method process on different sections of roads in Beijing, China, and Buffalo, NY, USA. The results indicated that both correctness (p) and completeness (r) were higher than 90%. The method process of this research can be applied to extract pavement markings from huge point cloud data produced by mobile LiDAR.

  8. Key events and their effects on cycling behaviour in Dar-es-Salaam : abstract + powerpoint

    NARCIS (Netherlands)

    Nkurunziza, A.; Zuidgeest, M.H.P.; Brussel, M.J.G.; van Maarseveen, M.F.A.M.

    2012-01-01

    The paper explores key events and investigates their effects on cycling behaviour in the city of Dar-es-Salaam, Tanzania. The objective of the study is to identify specific key events during a person’s life course with a significant effect on change of travel behaviour towards cycling in relation to

  9. 2006 Federal Emergency Management Agency (FEMA) Topographic LiDAR: Cumberland and York Counties, Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the fall of 2006, Sanborn Map Company was contracted by Camp Dresser McKee, Inc (CDM) to execute a LiDAR (Light Detection and Ranging) survey campaign in the...

  10. International Journal of Arts and Humanities(IJAH) Bahir Dar- Ethiopia

    African Journals Online (AJOL)

    DrNneka

    International Journal of Arts and Humanities(IJAH). Bahir Dar- Ethiopia. Vol. 5(2), S/No 17, April, ... Commission's accreditation exercise on personnel in the business education programmes of the universities in the South-east .... education personnel in universities. Method. The study adopted descriptive survey design.

  11. Real-time surveillance system for marine environment based on HLIF LiDAR

    Science.gov (United States)

    Babichenko, Sergey; Sobolev, Innokenti; Aleksejev, Valeri; Sõro, Oliver

    2017-10-01

    The operational monitoring of the risk areas of marine environment requires cost-effective solutions. One of the options is the use of sensor networks based on fixed installations and moving platforms (coastal boats, supply-, cargo-, and passenger vessels). Such network allows to gather environmental data in time and space with direct links to operational activities in the controlled area for further environmental risk assessment. Among many remote sensing techniques the LiDAR (Light Detection And Ranging) based on Light Induced Fluorescence (LIF) is the tool of direct assessment of water quality variations caused by chemical pollution, colored dissolved organic matter, and phytoplankton composition. The Hyperspectral LIF (HLIF) LiDAR acquires comprehensive LIF spectra and analyses them by spectral pattern recognition technique to detect and classify the substances in water remotely. Combined use of HLIF LiDARs with Real-Time Data Management System (RTDMS) provides the economically effective solution for the regular monitoring in the controlled area. OCEAN VISUALS in cooperation with LDI INNOVATION has developed Oil in Water Locator (OWL™) with RTDMS (OWL MAP™) based on HLIF LiDAR technique. This is a novel technical solution for monitoring of marine environment providing continuous unattended operations. OWL™ has been extensively tested on board of various vessels in the North Sea, Norwegian Sea, Barents Sea, Baltic Sea and Caribbean Sea. This paper describes the technology features, the results of its operational use in 2014-2017, and outlook for the technology development.

  12. Validation of sentinel-1A SAR coastal wind speeds against scanning LiDAR

    DEFF Research Database (Denmark)

    Ahsbahs, Tobias Torben; Badger, Merete; Karagali, Ioanna

    2017-01-01

    for SAR wind retrieval are not fully validated here. Ground based scanning light detection and ranging (LiDAR) offer high horizontal resolution wind velocity measurements with high accuracy, also in the coastal zone. This study, for the first time, examines accuracies of SAR wind retrievals at 10 m height...... with respect to the distance to shore by validation against scanning LiDARs. Comparison of 15 Sentinel-1A wind retrievals using the GMF called C-band model 5.N (CMOD5.N) versus LiDARs show good agreement. It is found, when nondimenionalising with a reference point, that wind speed reductions are between 4......% and 8% from 3 km to 1 km from shore. Findings indicate that SAR wind retrievals give reliable wind speed measurements as close as 1 km to the shore. Comparisons of SAR winds versus two different LiDAR configurations yield root mean square error (RMSE) of 1.31 ms-1 and 1.42 ms-1 for spatially averaged...

  13. Patterns and correlates of solid waste disposal practices in Dar es ...

    African Journals Online (AJOL)

    This study examines the patterns and correlations of solid waste disposal practices among households in urbanized and populated Dar es Salaam city in Tanzania. The Tanzanian Household Budget Survey (HBS) data covering many households' characteristics was used. Multinomial Logit (MNL) model was applied to ...

  14. Post-Fire Changes in Forest Biomass Retrieved by Airborne LiDAR in Amazonia

    Science.gov (United States)

    Luciane Sato; Vitor Gomes; Yosio Shimabukuro; Michael Keller; Egidio Arai; Maiza dos-Santos; Irving Brown; Luiz Aragão

    2016-01-01

    Fire is one of the main factors directly impacting Amazonian forest biomass and dynamics. Because of Amazonia’s large geographical extent, remote sensing techniques are required for comprehensively assessing forest fire impacts at the landscape level. In this context, Light Detection and Ranging (LiDAR) stands out as a technology capable of retrieving direct...

  15. A LiDAR method of canopy structure retrieval for wind modeling of heterogeneous forests

    DEFF Research Database (Denmark)

    Boudreault, Louis-Etienne; Bechmann, Andreas; Taryainen, Lasse

    2015-01-01

    and this information is required for each grid point in the three-dimensional computational domain. By using raw data from aerial LiDAR scans together with the Beer-Lambert law, we propose and test a method to calculate and grid highly variable and realistic frontal area density input. An extensive comparison...

  16. Mapping snags and understory shrubs for LiDAR based assessment of wildlife habitat suitability

    Science.gov (United States)

    Sebastian Martinuzzi; Lee A. Vierling; William A. Gould; Michael J. Falkowski; Jeffrey S. Evans; Andrew T. Hudak; Kerri T. Vierling

    2009-01-01

    The lack of maps depicting forest three-dimensional structure, particularly as pertaining to snags and understory shrub species distribution, is a major limitation for managing wildlife habitat in forests. Developing new techniques to remotely map snags and understory shrubs is therefore an important need. To address this, we first evaluated the use of LiDAR data for...

  17. Into the third dimension: Benefits of incorporating LiDAR data in wildlife habitat models

    Science.gov (United States)

    Melissa J. Merrick; John L. Koprowski; Craig Wilcox

    2013-01-01

    LiDAR (Light detection and ranging) is a tool with potential for characterizing wildlife habitat by providing detailed, three-dimensional landscape information not available from other remote sensing applications. The ability to accurately map structural components such as canopy height, canopy cover, woody debris, tree density, and ground surface has potential to...

  18. Pit Latrine Emptying Behavior and Demand for Sanitation Services in Dar Es Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    Marion W. Jenkins

    2015-02-01

    Full Text Available Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar, Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed.

  19. planning for the automation of the university of dar es salaam library

    African Journals Online (AJOL)

    The paper examines the planning process for the automation of the University of Dar es Salaam Library. The planning phases described include the preparation phase, planning for implementation and database construction. The major issues during the preparation phase are the discussion on the context of automation, ...

  20. Modeling and mapping basal area of Pinus taeda L. plantation using airborne LiDAR data.

    Science.gov (United States)

    Silva, Carlos A; Klauberg, Carine; Hudak, Andrew T; Vierling, Lee A; Fennema, Scott J; Corte, Ana Paula D

    2017-01-01

    Basal area (BA) is a good predictor of timber stand volume and forest growth. This study developed predictive models using field and airborne LiDAR (Light Detection and Ranging) data for estimation of basal area in Pinus taeda plantation in south Brazil. In the field, BA was collected from conventional forest inventory plots. Multiple linear regression models for predicting BA from LiDAR-derived metrics were developed and evaluated for predictive power and parsimony. The best model to predict BA from a family of six models was selected based on corrected Akaike Information Criterion (AICc) and assessed by the adjusted coefficient of determination (adj. R²) and root mean square error (RMSE). The best model revealed an adj. R²=0.93 and RMSE=7.74%. Leave one out cross-validation of the best regression model was also computed, and revealed an adj. R² and RMSE of 0.92 and 8.31%, respectively. This study showed that LiDAR-derived metrics can be used to predict BA in Pinus taeda plantations in south Brazil with high precision. We conclude that there is good potential to monitor growth in this type of plantations using airborne LiDAR. We hope that the promising results for BA modeling presented herein will stimulate to operate this technology in Brazil.