16 research outputs found
Recommended from our members
An integrated model of soil-canopy spectral radiances, photosynthesis, fluorescence, temperature and energy balance
No full textThis paper presents the model SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes), which is a vertical (1-D) integrated radiative transfer and energy balance model. The model links visible to thermal infrared radiance spectra (0.4 to 50 μm) as observed above the canopy to the fluxes of water, heat and carbon dioxide, as a function of vegetation structure, and the vertical profiles of temperature. Output of the model is the spectrum of outgoing radiation in the viewing direction and the turbulent heat fluxes, photosynthesis and chlorophyll fluorescence. A special routine is dedicated to the calculation of photosynthesis rate and chlorophyll fluorescence at the leaf level as a function of net radiation and leaf temperature. The fluorescence contributions from individual leaves are integrated over the canopy layer to calculate top-of-canopy fluorescence. The calculation of radiative transfer and the energy balance is fully integrated, allowing for feedback between leaf temperatures, leaf chlorophyll fluorescence and radiative fluxes. Leaf temperatures are calculated on the basis of energy balance closure. Model simulations were evaluated against observations reported in the literature and against data collected during field campaigns. These evaluations showed that SCOPE is able to reproduce realistic radiance spectra, directional radiance and energy balance fluxes. The model may be applied for the design of algorithms for the retrieval of evapotranspiration from optical and thermal earth observation data, for validation of existing methods to monitor vegetation functioning, to help interpret canopy fluorescence measurements, and to study the relationships between synoptic observations with diurnally integrated quantities. The model has been implemented in Matlab and has a modular design, thus allowing for great flexibility and scalability
Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas
No full textBackground - In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods - The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (Caulerpa taxifolia, Sargassum natans) was determined using GCMS. Four independent replicates were taken from each seaweed species. Results - Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs), were in the concentration range of 2-14 mg/g dry matter (DM), while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6) and/or eicosapentaenoic acids (EPA, C20:5, n-3), the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3) at ˜ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Conclusion - Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6) FA: (n-3) FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3), while in S. natans also docosahexaenoic acid (DHA, C22:6, n-3) was detected
Inclusive single-particle production in two-photon collisions at LEP II with the DELPHI detector
No full textA study of the inclusive charged hadron production in two-photon collisions is described. The data were collected with the DELPHI detector at LEP II. Results on the inclusive single-particle pT distribution and the differential charged hadrons dσ/dpT cross-section are presented and compared to the predictions of perturbative NLO QCD calculations and to published results
Estimación de variables esenciales de la vegetación en un ecosistema de dehesa utilizando factores de reflectividad simulados estacionalmente
No full text[ES] Los pastos arbolados y arbustivos son vitales para la producción ganadera extensiva y sostenible, la conservación de la biodiversidad y la provisión de servicios ecosistémicos y se localizan en áreas que serán previsiblemente más afectadas por el cambio climático. Sin embargo, las características estructurales, fenológicas, y las propiedades ópticas de la vegetación en estos ecosistemas mixtos, como los ecosistemas adehesados en la Península Ibérica que combinan un estrato herbáceo y/o arbustivo con un dosel arbóreo disperso, constituyen un serio desafío para su estudio mediante teledetección. Este trabajo combina métodos físicos y empíricos para la estimación de variables de la vegetación esenciales para la modelización de su funcionamiento: índice de área foliar (LAI, m2 /m2 ), contenido en clorofila a nivel de hoja (Cab,leaf, μg/cm2 ) y dosel (Cab,canopy, g/m2 ) y contenido en materia seca a nivel de hoja (Cm,leaf, g/cm2 ) y dosel (Cm,canopy, g/m2), en un ecosistema de dehesa. Para este propósito se construyó una base de datos espectral simulada considerando las cuatro principales etapas fenológicas del estrato herbáceo, el más dinámico del ecosistema, (rebrote otoñal, máximo verdor, inicio de la senescencia y senescencia estival) mediante la combinación de los modelos de transferencia radiativa PROSAIL y FLIGHT. Esta base de datos se empleó para ajustar diferentes modelos predictivos basados en índices de vegetación (IV) propuestos en la literatura y en Partial Least Squares Regression (PLSR). PLSR permitió obtener los modelos con mayor poder de predicción (R2 ≥ 0,93, RRMSE ≤ 10,77 %), tanto para las variables a nivel de hoja como a nivel de dosel. Los resultados sugieren que los efectos direccionales y geométricos controlan las relaciones entre los factores de reflectividad (R) simulados y los parámetros foliares. Se observa una alta variabilidad estacional en la relación entre variables biofísicas e IVs, especialmente para LAI y Cab que se confirma en el análisis PLSR. Los modelos desarrollados deben ser aún validados con datos espectrales medidos con sensores próximos o remotos.[EN] Mixed vegetation systems such as wood pastures and shrubby pastures are vital for extensive and sustainable livestock production as well as for the conservation of biodiversity and provision of ecosystem services, and are mostly located in areas that are expected to be more strongly affected by climate change. However, the structural characteristics, phenology, and the optical properties of the vegetation in these mixed -ecosystems such as savanna-like ecosystems in the Iberian Peninsula which combines herbaceous and/or shrubby understory with a low density tree cover, constitute a serious challenge for the remote sensing studies. This work combines physical and empirical methods to improve the estimation of essential vegetation variables: leaf area index (LAI, m2 / m2 ), leaf (Cab,leaf, μg / cm2 ) and canopy(Cab,canopy, g / m2 ) chlorophyll content, and leaf (Cm, leaf, g / cm2 ) and canopy (Cm,canopy, g / m2 ) dry matter content in a dehesa ecosystem. For this purpose, a spectral simulated database for the four main phenological stages of the highly dynamic herbaceous layer (summer senescence, autumn regrowth, greenness peak and beginning of senescence), was built by coupling PROSAIL and FLIGHT radiative transfer models. This database was used to calibrate different predictive models based on vegetation indices (VI) proposed in the literature which combine different spectral bands; as well as Partial Least Squares Regression (PLSR) using all bands in the simulated spectral range (400-2500 nm). PLSR models offered greater predictive power (R2 ≥ 0.93, RRMSE ≤ 10.77 %) both for the leaf and canopy- level variables. The results suggest that directional and geometric effects control the relationships between simulated reflectance factors and the foliar parameters. High seasonal variability is observed in the relationship between biophysical variables and IVs, especially for LAI and Cab, which is confirmed in the PLSR analysis. The models developed need to be validated with spectral data obtained either with proximal or remote sensors.ste estudio se ha llevado a cabo en el contexto de los proyectos FLUXPEC (CGL2012-34383) y SynerTGE (CGL2015-69095-R, MINECO/FEDER,UE) financiados por el Ministerio de Economía y Competitividad. Agradecemos el apoyo de los proyectos IB16185 de la Junta de Extremadura, MoReDEHESHyReS (No. 50EE1621, Agencia Espacial Alemana (DLR) y Ministerio Alemán de Asuntos Económicos y Energía) y el premio de la fundación Alexander von Humboldt vía Premio Max-Planck a Markus ReichsteinMartín, MP.; Pacheco-Labrador, J.; González-Cascón, R.; Moreno, G.; Migliavacca, M.; García, M.; Yebra, M.... (2020). Estimación de variables esenciales de la vegetación en un ecosistema de dehesa utilizando factores de reflectividad simulados estacionalmente. Revista de Teledetección. 0(55):31-48. https://doi.org/10.4995/raet.2020.13394OJS3148055Alonso, M., Rozados, M.J., Vega, J.A., Pérez- Gorostiaga, P., Cuiñas, P., Fontúrbel, M.T., Fernández, C. 2002. Biochemical Responses of Pinus pinaster Trees to Fire-Induced Trunk Girdling and Crown Scorch: Secondary Metabolites and Pigments as Needle Chemical Indicators. Journal of Chemical Ecology, 28(4), 687-700. https://doi.org/10.1023/A:1015276423880Armah, F., Odoi, J., Yengoh, G., Obiri, S., Yawson, D., Afrifa, E. 2011. Food security and climate change in drought-sensitive savanna zones of Ghana. Mitigation and Adaptation Strategies for Global Change, 16, 291-306. https://doi.org/10.1007/s11027-010-9263-9Baret, F., Weiss, M., Lacaze, R., Camacho, F., Makhmara, H., Pacholcyzk, P., Smets, B. 2013. GEOV1: LAI and FAPAR essential climate variables and FCOVER global time series capitalizing over existing products. Part1: Principles of development and production. Remote Sensing of Environment, 137, 299-309. https://doi.org/10.1016/j.rse.2012.12.027Béland, M., Widlowski, J.L., Fournier, R.A. 2014. A model for deriving voxel-level tree leaf area density estimates from ground-based LiDAR. Environmental Modelling & Software, 51(0), 184- 189. https://doi.org/10.1016/j.envsoft.2013.09.034Chadwick, K.D., Asner, G.P. 2016. Organismic- Scale Remote Sensing of Canopy Foliar Traits in Lowland Tropical Forests. Remote Sensing, 8(2), 87. https://doi.org/10.3390/rs8020087Cleugh, H.A., Leuning, R., Mu, Q., Running, S.W. 2007. Regional evaporation estimates from flux tower and MODIS satellite data. Remote Sensing of Environment, 106(3), 285-304. https://doi.org/10.1016/j.rse.2006.07.007Croft, H., Chen, J.M. 2017. Remote Sensing of Leaf Pigments. En S. Liang (Ed.), Comprehensive Remote Sensing (pp. 117-142). Oxford: Elsevier. https://doi.org/10.1016/B978-0-12-409548-9.10547-0Croft, H., Chen, J.M., Froelich, N.J., Chen, B., Staebler, R.M. 2015. Seasonal controls of canopy chlorophyll content on forest carbon uptake: Implications for GPP modeling. Journal of Geophysical Research: Biogeosciences, 120(8), 1576-1586. https://doi.org/10.1002/2015JG002980Croft, H., Chen, J.M., Luo, X., Bartlett, P., Chen, B., Staebler, R.M. 2017. Leaf chlorophyll content as a proxy for leaf photosynthetic capacity. Global Change Biology, 23(9), 3513-3524. https://doi.org/10.1111/gcb.13599Croft, H., Chen, J.M., Wang, R., Mo, G., Luo, S., Luo, X., He, L., Gonsamo, A., Arabian, J., Zhang, Y., Simic-Milas, A., Noland, T.L., He, Y., Homolová, L., Malenovský, Z., Yi, Q., Beringer, J., Amiri, R., Hutley, L., Arellano, P., Stahl, C., Bonal, D. 2020. The global distribution of leaf chlorophyll content. Remote Sensing of Environment, 236, 111479. https://doi.org/10.1016/j.rse.2019.111479Dash, J., Curran, P.J. 2007. Evaluation of the MERIS terrestrial chlorophyll index (MTCI). Advances in Space Research, 39(1), 100-104. https://doi.org/10.1016/j.asr.2006.02.034Dorigo, W.A., Zurita-Milla, R., de Wit, A.J.W., Brazile, J., Singh, R., Schaepman, M.E. 2007. A review on reflective remote sensing and data assimilation techniques for enhanced agroecosystem modeling. International Journal of Applied Earth Observation and Geoinformation, 9(2), 165-193. https://doi.org/10.1016/j.jag.2006.05.003Doughty, C.E., Goulden, M.L. 2008. Seasonal patterns of tropical forest leaf area index and CO2 exchange. Journal of Geophysical Research: Biogeosciences, 113(G1). https://doi.org/10.1029/2007JG000590Fan, L., Gao, Y., Brück, H., Bernhofer, C. 2009. Investigating the relationship between NDVI and LAI in semi-arid grassland in Inner Mongolia using in-situ measurements. Theoretical and Applied Climatology, 95(1), 151-156. https://doi.org/10.1007/s00704-007-0369-2Fava, F., Colombo, R., Bocchi, S., Meroni, M., Sitzia, M., Fois, N., Zucca, C. 2009. Identification of hyperspectral vegetation indices for Mediterranean pasture characterization. International Journal of Applied Earth Observation and Geoinformation, 11(4), 233-243. https://doi.org/10.1016/j.jag.2009.02.003Feret, J.-B., François, C., Asner, G.P., Gitelson, A.A., Martin, R.E., Bidel, L.P.R., Ustin, S.L., le Maire, G., Jacquemoud, S. 2008. PROSPECT-4 and 5: Advances in the leaf optical properties model separating photosynthetic pigments. Remote Sensing of Environment, 112(6), 3030-3043. https://doi.org/10.1016/j.rse.2008.02.012Fortunel, C., Garnier, E., Joffre, R., Kazakou, E., Quested, H., Grigulis, K., Lavorel, S., Ansquer, P., Castro, H., Cruz, P., DoleŽal, J., Eriksson, O., Freitas, H., Golodets, C., Jouany, C., Kigel, J., Kleyer, M., Lehsten, V., Lepš, J., Meier, T., Pakeman, R., Papadimitriou, M., Papanastasis, V.P., Quétier, F., Robson, M., Sternberg, M., Theau, J.P., Thébault, A., Zarovali, M. 2009. Leaf traits capture the effects of land use changes and climate on litter decomposability of grasslands across Europe. Ecology, 90(3), 598- 611. https://doi.org/10.1890/08-0418.1Fourty, T., Baret, F. 1997. Vegetation water and dry matter contents estimated from top-of-the-atmosphere reflectance data: A simulation study. Remote Sensing of Environment, 61(1), 34-45. https://doi.org/10.1016/S0034-4257(96)00238-6Galvão, L.S., Formaggio, A.R., Tisot, D.A. 2005. Discrimination of sugarcane varieties in Southeastern Brazil with EO-1 Hyperion data. Remote Sensing of Environment, 94(4), 523-534. https://doi.org/10.1016/j.rse.2004.11.012García, M., Popescu, S., Riaño, D., Zhao, K., Neuenschwander, A., Agca, M., Chuvieco, E. 2012. Characterization of canopy fuels using ICESat/ GLAS data. Remote Sensing of Environment, 123(0), 81-89. https://doi.org/10.1016/j.rse.2012.03.018Gitelson, A.A., Buschmann, C., Lichtenthaler, H.K. 1999. The Chlorophyll Fluorescence Ratio F735/F700 as an Accurate Measure of the Chlorophyll Content in Plants. Remote Sensing of Environment, 69(3), 296-302. https://doi.org/10.1016/S0034-4257(99)00023-1Gitelson, A.A., Peng, Y., Viña, A., Arkebauer, T., Schepers, J.S. 2016. Efficiency of chlorophyll in gross primary productivity: A proof of concept and application in crops. Journal of Plant Physiology, 201, 101-110. https://doi.org/10.1016/j.jplph.2016.05.019Gitelson, A.A., Viña, A., Arkebauer, T.J., Rundquist, D.C., Keydan, G., Leavitt, B. 2003. Remote estimation of leaf area index and green leaf biomass in maize canopies. Geophysical Research Letters, 30(5). https://doi.org/10.1029/2002GL016450González-Cascón, R., Martín, M.P. 2018. Protocol for pigment content quantification in herbaceous covers: sampling and analysis. https://doi.org/10.17504/protocols.io.qs6dwheGuillen-Climent, M., Zarco-Tejada, P., Berni, J.A.J., North, P.R.J., Villalobos, F. 2012. Mapping radiation interception in row-structured orchards using 3D simulation and high-resolution airborne imagery acquired from a UAV. Precision Agriculture, 13, 473-500. https://doi.org/10.1007/s11119-012-9263-8Haboudane, D., Miller, J.R., Tremblay, N., Zarco-Tejada, P.J., Dextraze, L. 2002. Integrated narrow-band vegetation indices for prediction of crop chlorophyll content for application to precision agriculture. Remote Sensing of Environment, 81(2), 416-426. https://doi.org/10.1016/S0034-4257(02)00018-4Haldimann, P., Gallé, A., Feller, U. 2008. Impact of an exceptionally hot dry summer on photosynthetic traits in oak (Quercus pubescens) leaves. Tree Physiology, 28(5), 785-795. https://doi.org/10.1093/ treephys/28.5.785Hernández-Clemente, R., Navarro-Cerrillo, R.M., Suárez, L., Morales, F., Zarco-Tejada, P.J. 2011. Assessing structural effects on PRI for stress detection in conifer forests. Remote Sensing of Environment, 115(9), 2360-2375. https://doi.org/10.1016/j.rse.2011.04.036Hernández-Clemente, R., North, P.R.J., Hornero, A., Zarco-Tejada, P.J. 2017. Assessing the effects of forest health on sun-induced chlorophyll fluorescence using the FluorFLIGHT 3-D radiative transfer model to account for forest structure. Remote Sensing of Environment, 193, 165-179. https://doi.org/10.1016/j.rse.2017.02.012Hill, M.J., Hanan, N.P., Hoffmann, W., Scholes, R., Prince, S., Ferwerda, J., Lucas, R.M., Baker, I., Arneth, A., Higgins, S.I., Barrett, D.J., Disney, M., Hutley, L. 2011. Remote sensing and modeling of savannas: The state of the dis-union.Inoue, Y., Guérif, M., Baret, F., Skidmore, A., Gitelson, A., Schlerf, M., Darvishzadeh, R., Olioso, A. 2016. Simple and robust methods for remote sensing of canopy chlorophyll content: a comparative analysis of hyperspectral data for different types of vegetation. Plant, Cell & Environment, 39(12), 2609-2623. https://doi.org/10.1111/pce.12815Inoue, Y., Peñuelas, J., Miyata, A., Mano, M. 2008. Normalized difference spectral indices for estimating photosynthetic efficiency and capacity at a canopy scale derived from hyperspectral and CO2 flux measurements in rice. Remote Sensing of Environment, 112(1), 156-172. https://doi.org/10.1016/j.rse.2007.04.011Jacquemoud, S., Baret, F. 1990. PROSPECT: A model of leaf optical properties spectra. Remote Sensing of Environment, 34(2), 75-91. https://doi.org/10.1016/0034-4257(90)90100-ZJacquemoud, S., Verhoef, W., Baret, F., Bacour, C., Zarco-Tejada, P.J., Asner, G.P., François, C., Ustin, S.L. 2009. PROSPECT+SAIL models: A review of use for vegetation characterization. Remote Sensing of Environment, 113, S56-S66. https://doi.org/10.1016/j.rse.2008.01.026Jin, J., Wang, Q. 2019. Evaluation of Informative Bands Used in Different PLS Regressions for Estimating Leaf Biochemical Contents from Hyperspectral Reflectance. Remote Sensing, 11(2), 197. https://doi.org/10.3390/rs11020197Korhonen, L., Korpela, I., Heiskanen, J., Maltamo, M. 2011. Airborne discrete-return LIDAR data in the estimation of vertical canopy cover, angular canopy closure and leaf area index. Remote Sensing of Environment, 115(4), 1065-1080. https://doi.org/10.1016/j.rse.2010.12.011le Maire, G., François, C., Dufrêne, E. 2004. Towards universal broad leaf chlorophyll indices using PROSPECT simulated database and hyperspectral reflectance measurements. Remote Sensing of Environment, 89(1), 1-28. https://doi.org/10.1016/j.rse.2003.09.004le Maire, G., François, C., Soudani, K., Berveiller, D., Pontailler, J.-Y., Bréda, N., Genet, H., Davi, H., Dufrêne, E. 2008. Calibration and validation of hyperspectral indices for the estimation of broadleaved forest leaf chlorophyll content, leaf mass per area, leaf area index and leaf canopy biomass. Remote Sensing of Environment, 112(10), 3846- 3864. https://doi.org/10.1016/j.rse.2008.06.005Leonenko, G., Los, S.O., North, P.R.J. 2013. Retrieval of leaf area index from MODIS surface reflectance by model inversion using different minimization criteria. Remote Sensing of Environment, 139, 257-270. https://doi.org/10.1016/j.rse.2013.07.012Li, Q., Lu, X., Wang, Y., Huang, X., Cox, P.M., Luo, Y. 2018. Leaf area index identified as a major source of variability in modeled CO2 fertilization. Biogeosciences, 15(22), 6909-6925. https://doi.org/10.5194/bg-15-6909-2018LI-COR. 2019. LAI 2200-C Plant Canopy Analyzer instruction manual. Último acceso 5 de Junio, 2020, de https://licor.app.boxenterprise.net/s/ fqjn5mlu8c1a7zir5qelLichtenthaler, H.K., Buschmann, C. 2001. Chlorophylls and Carotenoids: Measurement and Characterization by UV-VIS Spectroscopy. Current Protocols in Food Analytical Chemistry, 1(1), F4.3.1-F4.3.8. https://doi.org/10.1002/0471142913.faf0403s01Luo, T., Pan, Y., Ouyang, H., Shi, P., Ji, L., Yu, Z., Lu, Q. 2004. Leaf area index and net primary productivity along subtropical to alpine gradients in the Tibetan Plateau. Global Ecology and Biogeography, 13, 345-358. https://doi.org/10.1111/j.1466-822X.2004.00094.xMaccioni, A., Agati, G., Mazzinghi, P. 2001. New vegetation indices for remote measurement of chlorophylls based on leaf directional reflectance spectra. Journal of Photochemistry and Photobiology B: Biology, 61(1), 52-61. https://doi.org/10.1016/S1011-1344(01)00145-2Melendo-Vega, J.R., Martín, M.P., Pacheco- Labrador, J., González-Cascón, R., Moreno, G., Pérez, F., Migliavacca, M., García, M., North, P., Riaño, D. 2018. Improving the Performance of 3-D Radiative Transfer Model FLIGHT to Simulate Optical Properties of a Tree-Grass Ecosystem. Remote Sensing, 10(12), 2061. https://doi.org/10.3390/rs10122061Metternicht, G. 2003. Vegetation indices derived from high-resolution airborne videography for precision crop management. International Journal of Remote Sensing, 24(14), 2855-2877. https://doi.org/10.1080/01431160210163074Miraglio, T., Adeline, K., Huesca, M., Ustin, S., Briottet, X. 2020. Monitoring LAI, Chlorophylls, and Carotenoids Content of a Woodland Savanna Using Hyperspectral Imagery and 3D Radiative Transfer Modeling. Remote Sensing, 12(1), 28. https://doi.org/10.3390/rs12010028Moreno, G., Rolo, V. 2019. Agroforestry practices: silvopastorism. En M.R. Mosquera-Losada & R. Prabhu (Eds.), Agroforestry for sustainable agriculture (pp. 119-164): Burleigh Dodds Science Publishing Limited.Myneni, R.B., Hoffman, S., Knyazikhin, Y., Privette, J.L., Glassy, J., Tian, Y., Wang, Y., Song, X., Zhang, Y., Smith, G.R., Lotsch, A., Friedl, M., Morisette, J.T., Votava, P., Nemani, R.R., Running, S.W. 2002. Global products of vegetation leaf area and fraction absorbed PAR from year one of MODIS data. Remote Sensing of Environment, 83(1), 214-231. https://doi.org/10.1016/S0034-4257(02)00074-3North, P.R.J. 1996. Three-dimensional forest light interaction model using a Monte Carlo method. IEEE Transactions on Geoscience and Remote Sensing, 34(4), 946-956. https://doi.org/10.1109/36.508411Novara, A., Rühl, J., La Mantia, T., Gristina, L., La Bella, S., Tuttolomondo, T. 2015. Litter contribution to soil organic carbon in the processes of agriculture abandon. Solid Earth, 6, 425-432. https://doi.org/10.5194/se-6-425-2015Pacheco-Labrador, J., El-Madany, T.S., van der Tol, C., Martín, M.P., Gonzalez-Cascon, R., Perez-Priego, O., Guan, J., Moreno, G., Carrara, A., Reichstein, M., Migliavacca, M. 2020. senSCOPE: Modeling radiative transfer and biochemical processes in mixed canopies combining green and senescent leaves with SCOPE. bioRxiv, 2020.2002.2005.935064. https://doi.org/10.1101/2020.02.05.935064Pacheco-Labrador, J., González-Cascón, R., Martín, M.P., Melendo-Vega, J.R., Hernández-Clemente, R., Zarco-Tejada, P. 2017. Impact of trichomes in the application of radiative transfer models in leaves of Quercus ilex. En: VII Congreso forestal español, Plasencia, España. 26-30 Junio 2017.Pacheco-Labrador, J., Martín, M., Riaño, D., Hilker, T., Carrara, A. 2016. New approaches in multi-angular proximal sensing of vegetation: Accounting for spatial heterogeneity and diffuse radiation in directional reflectance distribution models. Remote Sensing of Environment, 187. https://doi.org/10.1016/j.rse.2016.10.051Pacheco-Labrador, J., Perez-Priego, O., El-Madany, T.S., Julitta, T., Rossini, M., Guan, J., Moreno, G., Carvalhais, N., Martín, M.P., Gonzalez-Cascon, R., Kolle, O., Reischtein, M., van der Tol, C., Carrara, A., Martini, D., Hammer, T.W., Moossen, H., Migliavacca, M. 2019. Multiple-constraint inversion of SCOPE. Evaluating the potential of GPP and SIF for the retrieval of plant functional traits. Remote Sensing of Environment, 234, 111362. https://doi.org/10.1016/j.rse.2019.111362Polley, H.W., Yang, C., Wilsey, B.J., Fay, P.A. 2019. Spectrally derived values of community leaf dry matter content link shifts in grassland composition with change in biomass production. Remote Sensing in Ecology and Conservation, n/a(n/a). https://doi.org/10.1002/rse2.145Pulido, F., Picardo, A., Campos, P., Carranza, J., Coleto, J., Díaz, M., Diéguez, E., Escudero, A., Ezquerra, F., Fernández, P., Solla, A. 2010. Libro Verde de la Dehesa. Consejería de Medio Ambiente, Junta Castilla La Mancha.Qiao, K., Zhu, W., Zhiying, X., Li, P. 2019. Estimating the Seasonal Dynamics of the Leaf Area Index Using Piecewise LAI-VI Relationships Based on Phenophases. Remote Sensing, 11(6), 689. https://doi.org/10.3390/rs11060689Reichstein, M., Bahn, M., Mahecha, M.D., Kattge, J., Baldocchi, D.D. 2014. Linking plant and ecosystem functional biogeography. Proceedings of the National Academy of Sciences, 111(38), 13697- 13702. https://doi.org/10.1073/pnas.1216065111Riaño, D., Valladares, F., Condes, S., Chuvieco, E. 2004. Estimation of leaf area index and covered ground from airborne laser scanner (LiDAR) in two contrasting forests. Agricultural and Forest Meteorology, 124(3-4), 269-275. https://doi.org/10.1016/j.agrformet.2004.02.005Riaño, D., Vaughan, P., Chuvieco, E., Zarco-Tejada, P., Ustin, S.L. 2005. Estimation of fuel moisture content by inversion of radiative transfer models to simulate equivalent water thickness and dry matter content: analysis at leaf and canopy level. IEEE Transactions on Geoscience and Remote Sensing, 43(4), 819-8
Signals from adipose tissue in morbid obesity and effect on depot specific differences
No full textSignals from adipose tissue, such as interleukin-6 (IL-6) and asymmetric dimethyl
arginine (ADMA), an endogenous nitric oxide inhibitor, explain the link between
obesity and metabolic diseases. Previously published human studies have used
omental adipose tissue to study visceral depots, based on the assumption that all
visceral adipose tissues are similar. This study, for the first time, assessed the release
of five adipokines (adiponectin, leptin, IL-6, MCP-1 and RANTES) from the
subcutaneous and two omental depots. Components of the cyclooxygenase (COX)
and the nitric oxide (NO) pathways, that regulate cytokine release in other tissues,
were also investigated for their putative role(s) in mediating adipokine release.
RANTES release was greatest from the gastric fat pad. However, significantly higher
circulating RANTES levels suggest that adipose tissue is unlikely to be the main
source of RANTES release.
Inhibition of the COX pathway, especially COX-2, reduced IL-6 release from
subcutaneous adipose tissue. Prostacyclin synthase (PGI2S) activity was higher in the
omental tissue and its protein expression was elevated in the stromavascular fraction
from this depot. PGI2S activity appears to mainly reside in the non-adipocyte cells
and is more coupled to IL-6 production in adipose tissue.
Serum insulin and CRP levels, and systolic blood pressure, directly associated with
subcutaneous tissue ADMA content, while BMI correlated with omental ADMA
release. ADMA release was higher from the omental depot. However, while DDAH2
expression was higher compared to DDAH1 in adipose tissue, there was no depot
specific difference in the expression of either isoform.
In conclusion, this study showed adipose depot specific differences of RANTES
release, a novel adipokine, from a hitherto poorly studied depot, the gastric fat pad.
Characteristics of the omental adipose tissues differed depending on location and
paracrine factors that may mediate the adipokine release. These regulatory pathways
included components of the COX and NO pathways
Measurement of the electron structure function F-2(e) at LEP energies
No full textThe hadronic part of the electron structure function F2e has been measured for the first time, using e +e - data collected by the DELPHI experiment at LEP, at centre-of-mass energies of s=91.2-209.5GeV. The data analysis is simpler than that of the measurement of the photon structure function. The electron structure function F2e data are compared to predictions of phenomenological models based on the photon structure function. It is shown that the contribution of large target photon virtualities is significant. The data presented can serve as a cross-check of the photon structure function F2γ analyses and help in refining existing parameterisations. © 2014 The Authors. Elsevier B.V
Climate and Bioinvasives drivers of change on South African Rocky shores?
No full textIncludes abstract.Includes bibliographical references.The overall aims of the thesis were to assess spatio-temporal change in macro species assemblages at sites located around the South African coast. Detected changes were considered in parallel with regional patterns of bioinvasion and climate change driven shifts in temperature trends over comparable time scales
Phytoplankton adaptation to marine ecosystems: insights into photophysiological functional diversity
No full textThe aim of this study was to investigate the diversity of the photoprotective responses activated by phytoplankton at short temporal scales, i.e. the non-photochemical quenching of Chl a fluorescence (NPQ) associated with the xanthophyll cycle (XC) activity. In this work, we tested the hypothesis that the process of photoprotection, in terms of modulation, extent and efficiency, might be considered as a functional trait in phytoplankton. This ecophysiological work has been performed on four species belonging to the phylum of Stramenopiles. The ecological diversity has been taken into account by studying the photoresponses of species isolated either in surface or deeper water layers, as well as of species adapted to grow either in oceanic or coastal or upwelling ecosystems. Species distinct photoresponses have been also assessed in relation to cell size constraints, using one microplanktonic and three picoplanktonic species.
The relation between phytoplankton ecophysiological functional diversity and ecological adaptation has been studied in three picoeukaryotes (< 3.0 μm) isolated from distinct ecosystems, through the analysis of the physiological response curves obtained by plotting a measured variable against a range of a factor (i.e. light) affecting that variable. The photophysiological flexibility as a functional trait has been discussed in relation to niche adaptation. Because of their peculiar set of biological and ecological features, related to their minute cell size, and because of their very narrow size range, picoeukaryotes are interesting model organisms to address (and answer) questions concerning the ecophysiology of algae.
The integrative physiological processes (i.e. photoacclimation, photoregulation, photosynthesis, growth), which are in part activated or modified in relation to changing light conditions, have been deeply investigated in the microplanktonic coastal diatom, Pseudo-nitzschia multistriata (Bacillariophyceae). A great plasticity in functioning and regulation has been shown to characterize the photoprotective/photoacclimative processes (XC and NPQ) of this diatom, in agreement with its ecological properties
Evaluation of the differentiation of mesenchymal cells and pre-osteoblasts in a direct and indirect co-culture system
No full textAntecedentes: Estudios acerca de ingeniería tisular establecen que los co-cultivos directos han sido útiles para comprender la interacción entre células debido a que la comunicación intercelular promueve el intercambio de señales y factores de crecimiento que favorecen la diferenciación hacia distintos linajes celulares. Adicionalmente, en otros estudios se reportan interacciones celulares en co-cultivos indirectos que proporcionan un panorama favorable para la generación de tejidos o la reconstrucción de defectos óseos. No obstante, no existe evidencia clara que compare los co-cultivos directos y los indirectos en el desarrollo de procesos de proliferación y diferenciación de células madre a OBs. Esto podría en un futuro establecer nuevas terapéuticas que brindan soluciones a la reparación de tejidos de diferentes patologías. Objetivo: Determinar y comparar el efecto en la diferenciación, proliferación y morfología de células madre mesenquimales (MSCs) derivadas de la pulpa dental (hDPSC) y pre-osteoblastos (Saos-2) co-cultivados de forma directa e indirecta in vitro. Materiales y Métodos: Se evaluó proliferación, viabilidad, morfología y diferenciación celular a partir de co- cultivo directo e indirecto de células de la pulpa dental (hDPSC) y Saos-2 en medio DMEM a los 7 , 14 y 21 días. Se utilizó control positivo con medio de diferenciación y control negativo con medio DMEM. Resultados: Se realizó inmunofenotipificación a las hDPSC donde se encontró células positivas para marcadores de superficie CD105, CD90, CD73 y se evaluaron características morfológicas donde se observó células fibroblastoides adheridas a la caja. El co-cultivo indirecto y el directo de células Saos-2+hDPSC, produjo un incremento significativo (P < 0.05) en el número de células y proliferación celular desde el 6to día en el co-cultivo indirecto y desde el cuarto día en el co-cultivo directo. En las células hDPSC y Saos-2 sin co-cultivo (control) no se observó tinción con el rojo de alizarina, mientras que las células tratadas con MDO como control positivo de diferenciación osteoblástica mostraron igualmente formación de nódulos de calcio. La mayor cantidad de rojo de alizarina como medida de absorbancia, se evidenció en las células co-cultivadas de forma indirecta y en las células directamente co-cultivadas . Estas absorbancias fueron significativamente mayores que las obtenidas en las células hDPSC y Saos-2 sin co-cultivo. Al analizar los cambios en la expresión de genes de diferenciación osteoblástica como RUNX2 y osteocalcina (OCN) se encontró que a los 7 días RUNX2 aumentó su expresión en todos los grupos experimentales excepto en las células hDPSC co-cultivadas de forma indirecta con Saos-2. Por otro lado, El mayor incremento en la expresión se evidenció en el co-cultivo directo (116 veces más que el control) y hDPSC tratadas con MDO (83 veces más que el control). La expresión se redujo significativamente en todos los grupos experimentales a los 21 días. Conclusiones: Este estudio sugiere que el co-cultivo con células Saos-2 y hDPSC tanto directo como indirecto es efectivo para inducir cambios morfológicos, en la proliferación y diferenciación osteoblástica. Por este motivo, pueden ser una herramienta útil en la investigación de terapias de regeneración para la reparación de defectos óseos.Grupo de investigación UMIMC - Unidad de manejo integral de malformaciones craneofacialesEspecialista en OrtodonciaEspecializaciónBackground: Studies on tissue engineering have demonstrated that direct co-cultures are useful for understanding cell interactions, as intercellular communication facilitates the exchange of signals and growth factors that promote differentiation into various cell lineages. Additionally, other studies report cellular interactions in indirect co-cultures that provide a favorable outlook for tissue generation or bone defect reconstruction. However, there is no clear evidence comparing direct and indirect co-cultures in the development of proliferation and differentiation processes of stem cells into OBs. This could, in the future, lead to the development of new therapies that provide solutions for tissue repair in various pathologies. Aim: To determine and compare the effect on the differentiation, proliferation, and morphology of mesenchymal stem cells (MSCs) derived from dental pulp (hDPSC) and pre-osteoblasts (Saos-2) co-cultured directly and indirectly in vitro. Methods: Cell proliferation, viability, morphology, and differentiation were evaluated from direct and indirect co-culture of dental pulp cells (hDPSC) and Saos-2 in DMEM medium at 7, 14, and 21 days. A positive control with differentiation medium and a negative control with DMEM medium were used. Results: Immunophenotyping was performed on hDPSC, where cells positive for surface markers CD105, CD90, and CD73 were identified, and morphological characteristics were evaluated, revealing that fibroblast-like cells adhered to the dish. The indirect and direct co-culture of Saos-2+hDPSC cells resulted in a significant increase (P < 0.05) in cell number and proliferation from day 6 in the indirect co-culture and from day 4 in the direct co-culture. In hDPSC and Saos-2 cells without co-culture (control), no alizarin red staining was observed, while cells treated with MDO as a positive control for osteoblastic differentiation also showed calcium nodule formation. The highest amount of alizarin red, as a measure of absorbance, was evident in both indirectly co-cultured cells and directly co-cultured cells. These absorbances were significantly higher than those obtained in hDPSC and Saos-2 cells without coculture. When analyzing changes in the expression of osteoblastic differentiation genes such as RUNX2 and osteocalcin (OCN), it was found that at 7 days, RUNX2 expression increased in all experimental groups except in hDPSC cells indirectly co-cultured with Saos-2. On the other hand, the greatest increase in expression was observed in direct co-culture (116 times higher than the control) and hDPSC treated with MDO (83 times higher than the control). Expression was significantly reduced in all experimental groups at 21 days. Conclusions: This study suggests that both direct and indirect co-culture with Saos-2 cells and hDPSC is effective in inducing morphological changes, proliferation, and osteoblastic differentiation. For this reason, they may be a useful tool in the investigation of regenerative therapies for bone defect repair
Coordinated recruitment of Spir actin nucleators and myosin V motors to Rab11 vesicle membranes
No full textThere is growing evidence for a coupling of actin assembly and myosin motor activity in cells. However, mechanisms for recruitment of actin nucleators and motors on specific membrane compartments remain unclear. Here we report how Spir actin nucleators and myosin V motors coordinate their specific membrane recruitment. The myosin V globular tail domain (MyoV-GTD) interacts directly with an evolutionarily conserved Spir sequence motif. We determined crystal structures of MyoVa-GTD bound either to the Spir-2 motif or to Rab11 and show that a Spir-2:MyoVa:Rab11 complex can form. The ternary complex architecture explains how Rab11 vesicles support coordinated F-actin nucleation and myosin force generation for vesicle transport and tethering. New insights are also provided into how myosin activation can be coupled with the generation of actin tracks. Since MyoV binds several Rab GTPases, synchronized nucleator and motor targeting could provide a common mechanism to control force generation and motility in different cellular processes
