18 results on '"yhteyttäminen"'
Search Results
2. Chlorophyll a fluorescence illuminates a path connecting plant molecular biology to Earth-system science
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Uwe Rascher, Shari Van Wittenberghe, Kadmiel Maseyk, Barry A. Logan, Ingo Ensminger, Troy S. Magney, Paulina A. Rajewicz, Steffen Grebe, Thomas Matthew Robson, Albert Porcar-Castell, Mikko Tikkanen, Janne A. Ihalainen, Fabienne Maignan, Feng Zhao, Jon Atherton, J. I. García-Plazaola, Beatriz Fernández-Marín, Zbyněk Malenovský, Yongguang Zhang, Loren P. Albert, James R. Kellner, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Viikki Plant Science Centre (ViPS), Department of Forest Sciences, Ecosystem processes (INAR Forest Sciences), Forest Ecology and Management, Institute for Atmospheric and Earth System Research (INAR), Canopy Spectral Ecology and Ecophysiology, Biosciences, and Organismal and Evolutionary Biology Research Programme
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0106 biological sciences ,klorofylli ,Chlorophyll a ,010504 meteorology & atmospheric sciences ,Earth science ,Ecology (disciplines) ,Plant Science ,ekofysiologia ,01 natural sciences ,Fluorescence ,biofysiikka ,yhteyttäminen ,chemistry.chemical_compound ,LEAF ,LEAVES ,WATER ,Photosynthesis ,CO2 ASSIMILATION ,SCOTS PINE ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Molecular Biology ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Chlorophyll A ,SUN-INDUCED FLUORESCENCE ,fluoresenssi ,Biogeochemistry ,kasvillisuus ,15. Life on land ,11831 Plant biology ,Reflectivity ,REFLECTANCE ,Plant Leaves ,Earth system science ,ddc:580 ,RESOLUTION ,chemistry ,PHOTOSYSTEM-I ,13. Climate action ,Remote Sensing Technology ,Earth Sciences ,satelliittikuvaus ,Environmental science ,kaukokartoitus ,010606 plant biology & botany - Abstract
Remote sensing methods enable detection of solar-induced chlorophyll a fluorescence. However, to unleash the full potential of this signal, intensive cross-disciplinary work is required to harmonize biophysical and ecophysiological studies. For decades, the dynamic nature of chlorophyll a fluorescence (ChlaF) has provided insight into the biophysics and ecophysiology of the light reactions of photosynthesis from the subcellular to leaf scales. Recent advances in remote sensing methods enable detection of ChlaF induced by sunlight across a range of larger scales, from using instruments mounted on towers above plant canopies to Earth-orbiting satellites. This signal is referred to as solar-induced fluorescence (SIF) and its application promises to overcome spatial constraints on studies of photosynthesis, opening new research directions and opportunities in ecology, ecophysiology, biogeochemistry, agriculture and forestry. However, to unleash the full potential of SIF, intensive cross-disciplinary work is required to harmonize these new advances with the rich history of biophysical and ecophysiological studies of ChlaF, fostering the development of next-generation plant physiological and Earth-system models. Here, we introduce the scale-dependent link between SIF and photosynthesis, with an emphasis on seven remaining scientific challenges, and present a roadmap to facilitate future collaborative research towards new applications of SIF.
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- 2021
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3. Brownification Affects Phytoplankton Community Composition But Not Primary Productivity in Eutrophic Coastal Waters: A Mesocosm Experiment in the Baltic Sea
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Kristian Spilling, Eero Asmala, Noora Haavisto, Lumi Haraguchi, Kaisa Kraft, Anne-Mari Lehto, Aleksandra M. Lewandowska, Joanna Norkko, Jonna Piiparinen, Jukka Seppälä, Mari Vanharanta, Anu Vehmaa, Pasi Ylöstalo, Timo Tamminen, Suomen ympäristökeskus, and The Finnish Environment Institute
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zooplankton ,photosynthesis ,Environmental Engineering ,Bacteria ,HuminFeed ,Chlorophyll A ,plankton ,limonologia ,perustuotanto ,Heterotrophic Processes ,vedenlaatu ,bacterial production ,Pollution ,Carbon ,fysikaaliset ominaisuudet ,yhteyttäminen ,merivesi ,sameus ,Itämeri ,Phytoplankton ,Environmental Chemistry ,Waste Management and Disposal ,vesiekologia ,Ecosystem - Abstract
Highlights • Modest brownification did not affect primary production, but increased bacterial production. • Concentration of inorganic nitrogen was the primary driver for the phytoplankton development. • Brownification benefitted picophytoplankton. Climate change is projected to cause brownification of some coastal seas due to increased runoff of terrestrially derived organic matter. We carried out a mesocosm experiment (15 d) to test the effect of this on the planktonic ecosystem expecting reduced primary production and shifts in the phytoplankton community composition. The experiment was set up in 2.2 m3 mesocosm bags using four treatments, each with three replicates: control (Contr) without any manipulation, organic carbon additive HuminFeed (Hum; 2 mg L−1), inorganic nutrients (Nutr; 5.7 μM NH4 and 0.65 μM PO4), and combined Nutr and Hum (Nutr + Hum) additions. Measured variables included organic and inorganic nutrient pools, chlorophyll a (Chla), primary and bacterial production and particle counts by flow cytometry. The bags with added inorganic nutrients developed a phytoplankton bloom that depleted inorganic N at day 6, followed by a rapid decline in Chla. Brownification did not reduce primary production at the tested concentration. Bacterial production was lowest in the Contr, but similar in the three treatments receiving additions likely due to increased carbon available for heterotrophic bacteria. Picoeukaryotes clearly benefited by brownification after inorganic N depletion, which could be due to more effective nutrient recycling, nutrient affinity, light absorption, or alternatively lower grazing pressure. In conclusion, brownification shifted the phytoplankton community composition towards smaller species with potential effects on carbon fluxes, such as sinking rates and export to the sea floor.
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- 2022
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4. Seasonal ecophysiology of Fucus vesiculosus (Phaeophyceae) in the Northern Baltic Sea
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Antti Takolander, Suomen ympäristökeskus, and The Finnish Environment Institute
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klorofylli ,rakkolevä ,fluoresenssi ,Fucus vesiculosus ,Plant Science ,Aquatic Science ,levät ,ekofysiologia ,kasvu ,ekologia ,yhteyttäminen ,Itämeri ,lämpötila ,kausivaihtelu ,makrolevät - Abstract
The brown macroalga Fucus vesiculosus is a foundation species in temperate rocky shores, subjected to seasonally fluctuating environmental conditions. To obtain a more complete picture of the seasonality of F. vesiculosus ecophysiology in the northern Baltic Sea, in situ photochemistry, elemental ratios and chlorophyll a and c content of the alga were investigated in field campaigns conducted in different months throughout the year during 2017. Carbon, nitrogen, carbon to nitrogen ratio and chlorophyll a and c content of the alga varied substantially throughout the year, with highest carbon content observed in summer, and highest nitrogen content in winter. C:N ratio in F. vesiculosus apical tissue ranged from 8.6 in February to 48.3 in July. Chlorophyll a and c content followed inversely the seasonal patterns of ambient irradiance. High chlorophyll a and c content in winter was associated with higher maximum photosynthetic efficiency of energy conversion (Fv/Fm), but not with efficiency of photosynthetic energy conversion under light limitation (α). Electron transport rate correlated strongly with seawater temperature, and the highest electron transport rates were observed in summer and correlated with highest internal carbon content of the alga. Redundancy analysis conducted on measured environmental variables against physiological responses identified day of year, temperature and macronutrients in seawater as the most important variables driving the observed seasonal patterns in F. vesiculosus ecophysiology. The results suggest elevated temperatures may increase Fucus growth and photosynthesis rates in the study area.
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- 2022
5. Simultaneous non-invasive gas analysis in artificial photosynthesis reactions using rotational Raman spectroscopy
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Jesper Schwarz, Aleksandra Ilic, Simon Kaufhold, Jussi Ahokas, Pasi Myllyperkiö, Mika Pettersson, and Kenneth Wärnmark
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Fuel Technology ,kaasut ,kemialliset reaktiot ,Renewable Energy, Sustainability and the Environment ,tutkimuslaitteet ,Energy Engineering and Power Technology ,Raman-spektroskopia ,kemiallinen analyysi ,yhteyttäminen - Abstract
Optimising reactions in artificial photosynthesis research requires screening of many reaction and operation parameters, which is often resource-intense and time-consuming. In this paper, we demonstrate the use of a rotational Raman-based spectrometer for non-invasive quantification of several gases (H2, O2, N2, CO, CO2) with short analysis times (15 s), enabling high throughput screening. Furthermore, with this device, reaction progress can be monitored in situ, by real-time simultaneous quantification of multiple gases. We have applied this instrument and developed a method to study the O2 dependency of a prototypic light-driven hydrogen evolution reaction, showcasing the value of this approach for the artificial photosynthesis community in general. peerReviewed
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- 2022
6. Ultrafast structural changes within a photosynthetic reaction centre
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Rebecka Andersson, Gisela Brändén, Gergely Katona, Michał Maj, Antoine Royant, David Arnlund, Hoi Ling Luk, Oleksandr Yefanov, Despina Milathianaki, Sergio Carbajo, Robert Bosman, Greger Hammarin, Linda C. Johansson, Adams Vallejos, Elin Claesson, Joseph Robinson, Cecilia Wickstrand, Erik Malmerberg, Cecilia Safari, Garth J. Williams, Chelsie E. Conrad, Kenneth R. Beyerlein, Richard Neutze, Anton Barty, Chufeng Li, Rajiv Harimoorthy, Daniel P. DePonte, Amit Sharma, Mark S. Hunter, Sébastien Boutet, Viktor Ahlberg Gagnér, Garrett Nelson, Dmitry Morozov, Stella Lisova, Jan Davidsson, Joachim Kübel, Petra Båth, Robert Dods, Mengning Liang, Sebastian Westenhoff, Peter Dahl, Peter Berntsen, Gerrit Groenhof, Department of Chemistry and Molecular Biology [Gothenburg], University of Gothenburg (GU), Department of Chemistry [Jyväskylä Univ] (JYU), University of Jyväskylä (JYU), Nanoscience Center [Jyväskylä Univ] (NSC@JYU), Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Department of Physics, Arizona State University (ASU), Arizona State University [Tempe] (ASU), Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory (SLAC), Stanford University-Stanford University, Australian Research Council Centre of Excellence in Advanced Molecular Imaging [Victoria, Australia], Molecular Biophysics and Integrated Bioimaging Division [Berkeley, CA, USA], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), University of Southern California (USC), Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85282, U.S.A., Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), European Synchrotron Radiation Facility (ESRF), Department of Chemistry – Ångström Laboratory, UPPSALA University, Box 538, 75120, Uppsala, Sweden, and Uppsala University
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0301 basic medicine ,Photosynthetic reaction centre ,Chlorophyll ,Models, Molecular ,klorofylli ,Cytoplasm ,Ubiquinone ,Photosynthetic Reaction Center Complex Proteins ,Electrons ,02 engineering and technology ,Photochemistry ,medicine.disease_cause ,yhteyttäminen ,bakteerit ,Electron Transport ,03 medical and health sciences ,Electron transfer ,medicine ,Molecule ,ddc:530 ,Bacteriochlorophylls ,bioenergetiikka ,ComputingMilieux_MISCELLANEOUS ,Hyphomicrobiaceae ,Multidisciplinary ,Binding Sites ,Crystallography ,[SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM] ,Chemistry ,Blastochloris viridis ,Lasers ,kalvot (biologia) ,Pheophytins ,Biological membrane ,Vitamin K 2 ,021001 nanoscience & nanotechnology ,Acceptor ,030104 developmental biology ,Picosecond ,Femtosecond ,sense organs ,Protons ,0210 nano-technology ,Oxidation-Reduction ,röntgenkristallografia - Abstract
Nature / Physical science 589, 310 - 314 (2021). doi:10.1038/s41586-020-3000-7, Photosynthetic reaction centres harvest the energy content of sunlight by transporting electrons across an energy-transducing biological membrane. Here we use time-resolved serial femtosecond crystallography1 using an X-ray free-electron laser2 to observe light-induced structural changes in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds. Structural perturbations first occur at the special pair of chlorophyll molecules of the photosynthetic reaction centre that are photo-oxidized by light. Electron transfer to the menaquinone acceptor on the opposite side of the membrane induces a movement of this cofactor together with lower amplitude protein rearrangements. These observations reveal how proteins use conformational dynamics to stabilize the charge-separation steps of electron-transfer reactions., Published by Macmillan Publishers Limited, part of Springer Nature, London
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- 2021
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7. Toward autonomous measurements of photosynthetic electron transport rates: An evaluation of active fluorescence-based measurements of photochemistry
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nopeus ,automaatio ,mittaus ,fluoresenssi ,valokemia ,elektronit ,kulkeutuminen ,arviointi ,ta218 ,yhteyttäminen - Published
- 2015
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8. Sexes in gynodioecious Geranium sylvaticum do not differ in their isotopic signature or photosynthetic capacity
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Varga, Sandra and Kytöviita, Minna-Maarit
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sexual dimorphism ,shade ,food and beverages ,gynodioecy ,isotopic signatures ,metsäkurjenpolvi ,yhteyttäminen - Abstract
In gynodioecious plants, females are expected to produce more or better seeds than hermaphrodites in order to be maintained within the same population. Even though rarely measured, higher seed production can be achieved through differences in physiology. In this work, we measured sexual dimorphism in several physiological traits in the gynodioecious plant Geranium sylvaticum. Photosynthetic rate, stomatal conductance, transpiration rate, WUE and isotopic signatures were measured in plants growing in two habitats differing in light availability. Females have been reported to produce more seeds than hermaphrodites. However, we did not observe any significant difference in seed output between the sexes in these experimental populations. Similarly, the sexes did not differ in any physiological trait measured. Seed production was strongly limited by light availability. Likewise, differences between plants growing in full light versus low light were detected in most physiological parameters measured. Our results show that the sexes in G. sylvaticum do not show any evidence of sexual dimorphism in physiology, which concurred with a lack of sexual differences in seed output. peerReviewed
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- 2017
9. Peruskoulun 8-luokkalaisten ymmärrys yhteyttämisestä ja opetuksen vaikutus ymmärrykseen
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Mörsky, Virve and Pajunen, Maija
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konstruktivismi ,oppiminen ,virhekäsitys ,ajattelu ,opetus ,oppimisprosessi ,yhteyttäminen - Abstract
Peruskoulun kahdeksasluokkalaisten ymmärrystä yhteyttämisestä ja opetuksen vaikutusta ymmärrykseen tutkittiin konstruktivistiseen oppimiskäsitykseen pohjautuen. Tutkimuskysymyksiä olivat: miten kahdeksasluokkalaiset ymmärtävät yhteyttämisen biologisena ilmiönä ja kemiallisena prosessina, millainen vaikutus opetuksella on oppilaiden ymmärrykseen ja sen muuttumiseen yhteyttämisestä sekä onko saman opetusryhmän sisällä ja opetusryhmien välillä eroa yhteyttämisen ymmärtämisessä. Tutkimuskohteena oli kaikkiaan 45 kahdeksasluokkalaista Jyväskylän Normaalikoulusta ja Mikkelin Urheilupuiston koulusta. Tutkimus toteutettiin lukuvuonna 2009–2010, jolloin aineistoa kerättiin avoimella kysymyksellä ennen opetusta ja antamamme opetuksen jälkeen sekä soveltavalla monivalintatestillä. Määrällisessä ja laadullisessa aineiston analyysissä oppilaiden vastauksista avoimeen kysymykseen tutkittiin yhteyttämiskäsitteiden hallintaa ja vastauksista muodostettiin yhteyttämisilmiön ymmärrystä kuvaavat ymmärrysluokat oppilaiden kokonaisymmärryksen selvittämiseksi. Lisäksi selvitettiin laadullisesti oppilaiden ymmärryksen muutosta opetuksen vaikutuksesta ja ymmärrykseen sisältyviä tieteellisesti virheellisiä käsityksiä yhteyttämisestä. Tutkimuksessa painotettiin laadullista tutkimustapaa. Tärkeimmät tutkimustulokset olivat, että opetus vaikutti oppilaiden keskeisten yhteyttämiskäsitteiden hallinnan lisääntymiseen ja heidän yhteyttämisen ymmärryksen syvenemiseen kahta oppilasta lukuun ottamatta. Opetusryhmien välillä ei ollut eroa. Suurin osa oppilaista saavutti perusopetussuunnitelman perusteiden asettamat tavoitteet yhteyttämisen ymmärtämiselle, vaikka heillä oli opetuksen jälkeenkin tieteellisesti vaillinainen ymmärrys yhteyttämisestä biologisena ilmiönä ja kemiallisena prosessina. Oppilailla oli ongelmia energiakäsitteen, aineen muuttumisen ja veden merkityksen ymmärtämisessä. Tutkimuksemme osoitti, että laadukas konstruktivistinen biologian opetus takaa perusopetussuunnitelman perusteiden mukaisen oppimisen.
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- 2010
10. Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae
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Janne-Markus Rintala, Sara Enberg, Anssi V. Vähätalo, Riitta Autio, Jonna Piiparinen, and Markus Majaneva
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Baltic States ,0106 biological sciences ,Baltic Sea ,010504 meteorology & atmospheric sciences ,Ultraviolet Rays ,biomassa ,ta1172 ,Sea ice ,Chlorophyta ,levät ,UVR ,Photosynthesis ,01 natural sciences ,Applied Microbiology and Biotechnology ,Microbiology ,yhteyttäminen ,Algae ,Snow ,Botany ,Solar Energy ,Ice Cover ,ultraviolettisäteily ,Biomass ,lajit ,14. Life underwater ,0105 earth and related environmental sciences ,Diatoms ,algae ,Biomass (ecology) ,Ecology ,biology ,jää ,010604 marine biology & hydrobiology ,ta1183 ,photosynthetic activity ,biology.organism_classification ,diversiteetti ,Light intensity ,Diatom ,Alveolata ,Itämeri ,Photosynthetically active radiation ,Dinoflagellida ,ta1181 ,merijää ,Green algae - Abstract
The effects of increased photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) on species diversity, biomass and photosynthetic activity were studied in fast ice algal communities. The experimental set-up consisted of nine 1.44 m(2) squares with three treatments: untreated with natural snow cover (UNT), snow-free (PAR + UVR) and snow-free ice covered with a UV screen (PAR). The total algal biomass, dominated by diatoms and dinoflagellates, increased in all treatments during the experiment. However, the smaller biomass growth in the top 10-cm layer of the PAR + UVR treatment compared with the PAR treatment indicated the negative effect of UVR. Scrippsiella complex (mainly Scrippsiella hangoei, Biecheleria baltica and Gymnodinium corollarium) showed UV sensitivity in the top 5-cm layer, whereas Heterocapsa arctica ssp. frigida and green algae showed sensitivity to both PAR and UVR. The photosynthetic activity was highest in the top 5-cm layer of the PAR treatment, where the biomass of the pennate diatom Nitzschia frigida increased, indicating the UV sensitivity of this species. This study shows that UVR is one of the controlling factors of algal communities in Baltic Sea ice, and that increased availability of PAR together with UVR exclusion can cause changes in algal biomass, photosynthetic activity and community composition.
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- 2015
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11. Interaction Effects of Light, Temperature and Nutrient Limitations (N, P and Si) on Growth, Stoichiometry and Photosynthetic Parameters of the Cold-Water Diatom Chaetoceros wighamii
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Pasi Ylöstalo, Kristian Spilling, Jukka Seppälä, Stefan G. H. Simis, Tvärminne Zoological Station, and Biological stations
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Chlorophyll ,pii ,Light ,A-RATIO ,Acclimatization ,Analytical chemistry ,lcsh:Medicine ,ravinteet ,yhteyttäminen ,chemistry.chemical_compound ,typpi ,Nutrient ,SPRING BLOOM ,Growth rate ,Bacillariophyta ,Photosynthesis ,lcsh:Science ,fosfori ,Multidisciplinary ,Phosphorus ,MARINE-PHYTOPLANKTON ,Cold Temperature ,Photorespiration ,lämpötila ,CARBON-TO-CHLOROPHYLL ,PHOTORESPIRATION ,Research Article ,Silicon ,Nitrogen ,Lowest temperature recorded on Earth ,METABOLISM ,Biology ,CHEMICAL-COMPOSITION ,kasvu ,PHYTOPLANKTON STOICHIOMETRY ,Exponential growth ,Botany ,piilevät ,Chaetoceros wighamii ,1172 Environmental sciences ,Diatoms ,Chlorophyll A ,ta1183 ,lcsh:R ,ta1182 ,Carbon ,MODEL ,chemistry ,13. Climate action ,lcsh:Q ,valo - Abstract
Light (20-450 μmol photons m(-2) s(-1)), temperature (3-11 °C) and inorganic nutrient composition (nutrient replete and N, P and Si limitation) were manipulated to study their combined influence on growth, stoichiometry (C:N:P:Chl a) and primary production of the cold water diatom Chaetoceros wighamii. During exponential growth, the maximum growth rate (~0.8 d(-1)) was observed at high temperature and light; at 3 °C the growth rate was ~30% lower under similar light conditions. The interaction effect of light and temperature were clearly visible from growth and cellular stoichiometry. The average C:N:P molar ratio was 80:13:1 during exponential growth, but the range, due to different light acclimation, was widest at the lowest temperature, reaching very low C:P (~50) and N:P ratios (~8) at low light and temperature. The C:Chl a ratio had also a wider range at the lowest temperature during exponential growth, ranging 16-48 (weight ratio) at 3 °C compared with 17-33 at 11 °C. During exponential growth, there was no clear trend in the Chl a normalized, initial slope (α*) of the photosynthesis-irradiance (PE) curve, but the maximum photosynthetic production (P(m)) was highest for cultures acclimated to the highest light and temperature. During the stationary growth phase, the stoichiometric relationship depended on the limiting nutrient, but with generally increasing C:N:P ratio. The average photosynthetic quotient (PQ) during exponential growth was 1.26 but decreased to
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- 2015
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12. A functional model of tree growth and tree architecture
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François Houllier, Daniel Barthélémy, Frédéric Blaise, Philippe de Reffye, Thierry Fourcaud, The Finnish Society of Forest Science, Suomen metsätieteellinen seura, and Finlands Forstvetenskapliga Samfund
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0106 biological sciences ,Distributed computing ,vedenkulku ,plant water relations ,simulation models ,F62 - Physiologie végétale - Croissance et développement ,Application des ordinateurs ,Logiciel ,01 natural sciences ,yhteyttäminen ,plant habit ,Software ,Simple (abstract algebra) ,fotosynteesi ,latvusmuoto ,lcsh:Forestry ,Mathematical model ,U10 - Informatique, mathématiques et statistiques ,Ecology ,Ecological Modeling ,Forestry ,Tree (data structure) ,Anatomie végétale ,Tree architecture ,Plante ,ecology ,mathematical models ,puun kasvu ,growth ,Serial port ,Biology ,Arbre ,ekofysiologia ,kasvu ,010603 evolutionary biology ,tietokonemallit ,Mesure ,simulointi ,Architecture ,Croissance ,photosynthesis ,Water transport ,plant physiology ,business.industry ,kasvifysiologia ,mallit ,latvus ,Modélisation ,lcsh:SD1-669.5 ,matemaattiset mallit ,Modèle végétal ,business ,010606 plant biology & botany - Abstract
A new approach for modelling plant growth using the software AMAPpara is presented. This software takes into consideration knowledge about plant architecture which has been accumulated at the Plant Modelling Unit of CIRAD for several years, and introduces physiological concepts in order to simulate the dynamic functioning of trees. The plant is considered as a serial connection of vegetative organs which conduct water from the roots to the leaves. Another simple description of the plant as a network of parallel pipes is also presented which allows an analytical formulation of growth to be written. This recurring formula is used for very simple architectures and is useful to understand the role of each organ in water transport and assimilate production. Growth simulations are presented which show the influence of modifications in architecture on plant development. (Resume d'auteur)
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- 1997
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13. Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome
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John C. H. Spence, Dorina Bizhga, Shigeki Owada, Eriko Nango, Petra Fromme, Andrei S. Halavaty, Takanori Nakane, Gregory Tracy, Marius Schmidt, Keith Moffat, Heikki Takala, Garrett Nelson, Jennifer Brayshaw, Yasumasa Joti, Sebastian Westenhoff, Kensure Tono, Ishwor Poudyal, Phu Duong, Rie Tanaka, Patricia M Waltz, James Hopkins, Cynthia N. Hernandez, Eiichi Mizohata, Elin Claesson, Suraj Pandey, Christopher Kupitz, Wesley B. Ozarowski, Emina A. Stojković, Ayesha Mapara, Joseph Valera, Kevin D. Gallagher, Nicole C. Woitowich, Jay How Yang, Rachael St. Peter, Hardik Patel, Shatabdi Roy-Chowdhuri, Petra Edlund, Svetlana E. Kovaleva, Janne A. Ihalainen, Tyler Norwood, Angela C. Nugent, Medicum, and Department of Anatomy
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MODULE ,0301 basic medicine ,PHOTOACTIVE YELLOW PROTEIN ,SIGNALING MECHANISM ,absorption spectra ,Mutant ,fotobiologia ,phytochromes ,Biochemistry ,yhteyttäminen ,bakteerit ,STIGMATELLA-AURANTIACA ,03 medical and health sciences ,FRUITING BODY FORMATION ,General Materials Science ,Molecular replacement ,Stigmatella aurantiaca ,lcsh:Science ,UNUSUAL BACTERIOPHYTOCHROME ,PHOTOCONVERSION ,Histidine ,030102 biochemistry & molecular biology ,biology ,Phytochrome ,Chemistry ,CRYSTALLOGRAPHY ,ta1182 ,photosynthetic bacteria ,photoreceptors ,General Chemistry ,Chromophore ,Condensed Matter Physics ,biology.organism_classification ,030104 developmental biology ,CHROMOPHORE-BINDING DOMAIN ,Biophysics ,myxobacteria ,lcsh:Q ,3111 Biomedicine ,Photosynthetic bacteria ,proteiinit ,MOLECULAR REPLACEMENT ,Binding domain - Abstract
Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr and Pfr with distinct absorption spectra in the red and far-red. They have recently been engineered as enzymatic photoswitches for fluorescent-marker applications in non-invasive tissue imaging of mammals. This article presents cryo- and room-temperature crystal structures of the unusual phytochrome from the non-photosynthetic myxobacterium Stigmatella aurantiaca (SaBphP1) and reveals its role in the fruiting-body formation of this photomorphogenic bacterium. SaBphP1 lacks a conserved histidine (His) in the chromophore-binding domain that stabilizes the Pr state in the classical BphPs. Instead it contains a threonine (Thr), a feature that is restricted to several myxobacterial phytochromes and is not evolutionarily understood. SaBphP1 structures of the chromophore binding domain (CBD) and the complete photosensory core module (PCM) in wild-type and Thr-to-His mutant forms reveal details of the molecular mechanism of the Pr/Pfr transition associated with the physiological response of this myxobacterium to red light. Specifically, key structural differences in the CBD and PCM between the wild-type and the Thr-to-His mutant involve essential chromophore contacts with proximal amino acids, and point to how the photosignal is transduced through the rest of the protein, impacting the essential enzymatic activity in the photomorphogenic response of this myxobacterium.
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14. Catchment properties and the photosynthetic trait composition of freshwater plant communities
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Thomas Sand Jespersen, Anders Winkel, Stephen C. Maberly, S. J. Moe, Lars Baastrup-Spohr, Tenna Riis, Daniel Gebler, Patricia A. Chambers, A. B. Hinke, O. Vestergaard, Ole Pedersen, Laura Sass, Tõnu Feldmann, Lars Iversen, Annette Baattrup-Pedersen, Janne Alahuhta, Kaj Sand-Jensen, Frauke Ecke, Peter Brodersen, Jani Heino, and Sebastian Birk
- Subjects
hiilidioksidi ,0106 biological sciences ,Aquatic Organisms ,climate changes ,aquatic plants ,hiili ,vesi ,01 natural sciences ,yhteyttäminen ,chemistry.chemical_compound ,Photosynthesis ,freshwater ,0303 health sciences ,Multidisciplinary ,plants ,diffusion ,food and beverages ,Adaptation, Physiological ,communities ,kasviyhdyskunnat ,kasvihuonekaasut ,environmental changes ,Environmental chemistry ,Carbon dioxide ,Trait ,articles ,päästöt ,Biologie ,ympäristönmuutokset ,bikarbonaatit ,Bicarbonate ,water ,chemistry.chemical_element ,010603 evolutionary biology ,Ecology and Environment ,03 medical and health sciences ,Magnoliopsida ,diffuusio (fysikaaliset ilmiöt) ,Rivers ,Aquatic plant ,greenhouse gases ,kasvit ,030304 developmental biology ,carbon ,trait composition ,emissions ,carbon capture and storage ,Plant community ,ilmastonmuutokset ,15. Life on land ,Carbon Dioxide ,plant communities ,Bicarbonates ,Lakes ,chemistry ,13. Climate action ,makea vesi ,Adaptation ,hiilidioksidin talteenotto ja varastointi ,Carbon - Abstract
Change in plants as bicarbonate rises Freshwater plants can be broadly divided into two major categories according to their photosynthetic traits: Some use carbon dioxide as their carbon source, whereas others use bicarbonate. Iversen et al. found that the relative concentrations of these two inorganic carbon forms in water determine the functional composition of plant communities across freshwater ecosystems (see the Perspective by Marcé and Obrador). They created global maps revealing that community composition is structured by catchment geology and not climate (in contrast to the terrestrial realm, where the trait composition is structured by temperature and rainfall). Anthropogenic influences from land-use change are causing large-scale increases in bicarbonate concentrations in freshwater catchments and are thus leading to wholesale changes in the composition of their aquatic plant communities. Unlike in land plants, photosynthesis in many aquatic plants relies on bicarbonate in addition to carbon dioxide (CO2) to compensate for the low diffusivity and potential depletion of CO2 in water. Concentrations of bicarbonate and CO2 vary greatly with catchment geology. In this study, we investigate whether there is a link between these concentrations and the frequency of freshwater plants possessing the bicarbonate use trait. We show, globally, that the frequency of plant species with this trait increases with bicarbonate concentration. Regionally, however, the frequency of bicarbonate use is reduced at sites where the CO2 concentration is substantially above the air equilibrium, consistent with this trait being an adaptation to carbon limitation. Future anthropogenic changes of bicarbonate and CO2 concentrations may alter the species compositions of freshwater plant communities. One sentence summary: The widespread photosynthetic trait of freshwater plants, bicarbonate use, has a global biogeography controlled by catchment characteristics
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15. Rate of photosynthesis of some forest mosses as a function of temperature and light intensity and effect of water content of moss cushion on photosynthetic rate
- Author
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Seppo Kellomäki and Pertti Hari
- Subjects
0106 biological sciences ,ilma ,air ,Photosynthesis ,010603 evolutionary biology ,01 natural sciences ,yhteyttäminen ,Hylocomium splendens ,mosses ,metsäsammal ,sammalet ,Botany ,metsäkerrossammal ,fotosynteesi ,Pleurozium schreberi ,kangaskynsisammal ,lcsh:Forestry ,Water content ,040101 forestry ,photosynthesis ,biology ,Ecological Modeling ,temperature ,Forestry ,04 agricultural and veterinary sciences ,säteily ,15. Life on land ,biology.organism_classification ,Moss ,forest moss ,seinäsammal ,radiation ,Light intensity ,Cushion ,Dicranum polysetum ,lcsh:SD1-669.5 ,0401 agriculture, forestry, and fisheries ,Environmental science ,lämpötila ,light - Abstract
The photosynthetic rate of (Willd.), (Hedw.) and (Sw.) grown in plastic containers was monitored with infrared gas analyser in open air under natural weather conditions. It proved that the photosynthetic rate of wet moss cushions was satisfactorily predicted by temperature and light intensity. In dry moss cushions this kind of model gave too high an estimate for photosynthetic rate. Water requirements of each moss species were found to be moderate, and water content of moss cushions limited photosynthetic rate only under serious water deficiency.Pleurosium schreberiHylocomnium splendensDicranum undulatum
- Published
- 1976
16. Annual production of some forest mosses as a function of light available for photosynthesis
- Author
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Eero Väisänen, Seppo Kellomäki, and Pertti Hari
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,tuotto ,kasvu ,Photosynthesis ,010603 evolutionary biology ,01 natural sciences ,yhteyttäminen ,Hylocomium splendens ,mosses ,metsäsammal ,sammalet ,metsäkerrossammal ,Botany ,fotosynteesi ,Pleurozium schreberi ,kangaskynsisammal ,lcsh:Forestry ,0105 earth and related environmental sciences ,photosynthesis ,Annual production ,Ecology ,Ecological Modeling ,Forestry ,säteily ,Function (mathematics) ,15. Life on land ,forest moss ,seinäsammal ,radiation ,Environmental science ,lcsh:SD1-669.5 ,production ,Dicranum polysetum ,valo - Abstract
The aim of the present paper was to study the annual production of (Brid.) Mitt., (Hedw.) B.S.G and Sw. as a function of light available for photosynthesis. The productivity of the above moss species is studied using the harvested quadrats method in Norway spruce () stands of the site type representing different stand density classes (basal area from 0 to 34 m2/ha) in Southern Finland.Pleurozium schreberiHylocomnium splendensDicranum polysetumPicea abiesMyrtillus Pleurozium schreberiDicranum polysetumHylocomnium splendens
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- 1977
17. A new approach for measuring light inside the canopy in photosynthesis studies
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Raimo Salminen, Pertti Hari, Paavo Pelkonen, Veli Pohjonen, and Mikko Huhtamaa
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0106 biological sciences ,Canopy ,photosynthesis ,method of measurement ,mittaus ,Ecological Modeling ,Forestry ,säteily ,Photosynthesis ,latvusto ,010603 evolutionary biology ,01 natural sciences ,mittausmenetelmät ,yhteyttäminen ,radiation ,Botany ,fotosynteesi ,Environmental science ,lcsh:SD1-669.5 ,lcsh:Forestry ,light ,valo ,010606 plant biology & botany - Abstract
Light intensity inside the canopy varies considerably both in space and time. A new apparatus was developed which is disturbed as little as possible by the above-mentioned variation. The construction is based on the linear relationships between light intensity (measured using silicon diodes) and photosynthesis. This procedure permits linear operations (summing and integration) to be carried out on the output of the diodes without any loss of accuracy. There are five diodes in each assimilation chamber. A model, in which the independent variables include ligth, measured with the present equipment, and temperature, fits the photosynthetic rates well even inside the canopy. The PDF includes a summary in Finnish.
- Published
- 1976
18. Photosynthetic production of Scots pine in the natural environment
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Eeva Korpilahti, The Finnish Society of Forest Science, Suomen metsätieteellinen seura, and Finlands Forstvetenskapliga Samfund
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0106 biological sciences ,mänty ,ympäristötekijät ,transpiration rate ,Photosynthesis ,ekofysiologia ,010603 evolutionary biology ,01 natural sciences ,Natural (archaeology) ,väitöskirjat ,transpiration ,yhteyttäminen ,opinnäytteet ,stomatal regulation ,environmental factors ,Botany ,rate of photosynthesis ,annual cycle ,fotosynteesi ,haihdunta ,Transpiration ,photosynthesis ,biology ,Scots pine ,temperature ,Photosynthetic production ,Pinus sylvestris ,15. Life on land ,biology.organism_classification ,Annual cycle ,Agronomy ,irradiance response ,Environmental science ,General Agricultural and Biological Sciences ,light ,metabolism ,010606 plant biology & botany - Abstract
Data were collected over 3 yr during the growing season in a 20-yr-old stand at the Forestry Field Station of the University of Helsinki, Finland, to study the relations of photosynthesis and transpiration to environmental factors (irradiance, temperature, water content of soil and air) and metabolic processes.
- Published
- 1988
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