120 research outputs found

    Precisiones sobre la edad de las coladas volcánicas jurásicas en la región Algarinejo-Lojilla (Zona subbética)

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    A partir de un estudio geológico-regional, completado con otro paleontológico-estratigráfico de detalle, se precisa la edad de las erupciones volcánicas submarinas, que se intercalan en la serie jurásica de la región Algarinejo-Lojilla. Se datan dichas erupciones dentro de las zonas de murchisone y concavum, Aalenense medio y superior, respectivamente.Se trata de diversas coladas superpuestas, más numerosas en el sector de Lojilla que en el de Algarinejo

    Estimation of essential vegetation variables in a dehesa ecosystem using reflectance factors simulated at different phenological stages

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    [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

    Molecular characterization of the diet of the planktonic community in Málaga Bay (NW Alboran Sea)

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    The seasonal changes in structure and functioning of the pelagic trophic web in Málaga Bay (NW Alboran Sea) are related to the annual hydrological cycle. However, time series analyses have shown that the relationship between interannual hydrological variability and the plankton community composition is weak. This might be due to different human-induced pressures (nutrient pollution, coastal fisheries) acting on different compartments of the trophic web. The net effect of all these factors would depend on how the ecosystem channels changes in the composition and abundance of each trophic level. Interactions of phytoplankton-ciliates-zooplankton might have a central role in the regulation of the trophic web in Málaga Bay, although the trophic relations of the dominant groups remain still undefined. In order to identify the dominant trophic relationships we aimed to characterise the diet of key ichthyo- and mesozooplankton species in the field. Given that gut content preys (phyto- and microplankton) are fragile and not easy to identify visually, we developed species-specific molecular markers to detect their presence/absence within the predators gut

    Research-based flow cytometry assays for pathogenic assessment in the human B-cell biology of gene variants revealed in the diagnosis of inborn errors of immunity: a Bruton’s tyrosine kinase case-study

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    IntroductionInborn errors of immunity (IEI) are an expanding group of rare diseases whose field has been boosted by next-generation sequencing (NGS), revealing several new entities, accelerating routine diagnoses, expanding the number of atypical presentations and generating uncertainties regarding the pathogenic relevance of several novel variants.MethodsResearch laboratories that diagnose and provide support for IEI require accurate, reproducible and sustainable phenotypic, cellular and molecular functional assays to explore the pathogenic consequences of human leukocyte gene variants and contribute to their assessment. We have implemented a set of advanced flow cytometry-based assays to better dissect human B-cell biology in a translational research laboratory. We illustrate the utility of these techniques for the in-depth characterization of a novel (c.1685G>A, p.R562Q) de novo gene variant predicted as probably pathogenic but with no previous insights into the protein and cellular effects, located in the tyrosine kinase domain of the Bruton’s tyrosine kinase (BTK) gene, in an apparently healthy 14-year-old male patient referred to our clinic for an incidental finding of low immunoglobulin (Ig) M levels with no history of recurrent infections.Results and discussionA phenotypic analysis of bone marrow (BM) revealed a slightly high percentage of pre-B-I subset in BM, with no blockage at this stage, as typically observed in classical X-linked agammaglobulinemia (XLA) patients. The phenotypic analysis in peripheral blood also revealed reduced absolute numbers of B cells, all pre-germinal center maturation stages, together with reduced but detectable numbers of different memory and plasma cell isotypes. The R562Q variant allows Btk expression and normal activation of anti-IgM-induced phosphorylation of Y551 but diminished autophosphorylation at Y223 after anti IgM and CXCL12 stimulation. Lastly, we explored the potential impact of the variant protein for downstream Btk signaling in B cells. Within the canonical nuclear factor kappa B (NF-κB) activation pathway, normal IκBα degradation occurs after CD40L stimulation in patient and control cells. In contrast, disturbed IκBα degradation and reduced calcium ion (Ca2+) influx occurs on anti-IgM stimulation in the patient’s B cells, suggesting an enzymatic impairment of the mutated tyrosine kinase domain

    High prevalence and diversity of HIV-1 non-B genetic forms due to immigration in southern Spain: A phylogeographic approach

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    Phylogenetic studies are a valuable tool to understand viral transmission patterns and the role of immigration in HIV-1 spread. We analyzed the spatio-temporal relationship of different HIV-1 non-B subtype variants over time using phylogenetic analysis techniques. We collected 693 pol (PR+RT) sequences that were sampled from 2005 to 2012 from naïve patients in different hospitals in southern Spain. We used REGA v3.0 to classify them into subtypes and recombinant forms, which were confirmed by phylogenetic analysis through maximum likelihood (ML) using RAxML. For the main HIV-1 non-B variants, publicly available, genetically similar sequences were sought using HIV-BLAST. The presence of HIV-1 lineages circulating in our study population was established using ML and Bayesian inference (BEAST v1.7.5) and transmission networks were identified. We detected 165 (23.4%) patients infected with HIV-1 non-B variants: 104 (63%) with recombinant viruses in pol: CRF02_AG (71, 43%), CRF14_BG (8, 4.8%), CRF06_cpx (5, 3%) and nine other recombinant forms (11, 6.7%) and unique recombinants (9, 5.5%). The rest (61, 37%) were infected with non-recombinant subtypes: A1 (30, 18.2%), C (7, [4.2%]), D (3, [1.8%]), F1 (9, 5.5%) and G (12, 7.3%). Most patients infected with HIV-1 non-B variants were men (63%, p < 0.001) aged over 35 (73.5%, p < 0.001), heterosexuals (92.2%, p < 0.001), from Africa (59.5%, p < 0.001) and living in the El Ejido area (62.4%, p<0.001). We found lineages of epidemiological relevance (mainly within Subtype A1), imported primarily through female sex workers from East Europe. We detected 11 transmission clusters of HIV-1 non-B Subtypes, which included patients born in Spain in half of them. We present the phylogenetic profiles of the HIV-1 non-B variants detected in southern Spain, and explore their putative geographical origins. Our data reveals a high HIV-1 genetic diversity likely due to the import of viral lineages that circulate in other countries. The highly immigrated El Ejido area acts as a gateway through which different subtypes are introduced into other regions, hence the importance of setting up epidemiological control measures to prevent future outbreaks

    Counteranion and Solvent Assistance in Ruthenium-Mediated Alkyne to Vinylidene Isomerizations

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    The complex [Cp*RuCl(iPr2PNHPy)] (1) reacts with 1-alkynes HC≡CR (R = COOMe, C6H4CF3) in dichloromethane furnishing the corresponding vinylidene complexes [Cp*Ru≡C≡CHR(iPr2PNHPy)]Cl (R = COOMe (2a- Cl), C6H4CF3 (2b-Cl)), whereas reaction of 1 with NaBPh4 in MeOH followed by addition of HC≡CR (R = COOMe, C6H4CF3) yields the metastable π-alkyne complexes [Cp*Ru(η2-HC≡CR)(iPr2PNHPy)][BPh4] (R = COOMe (3a-BPh4), C6H4CF3 (3b-BPh4)). The transformation of 3a-BPh4/3b-BPh4 into their respective vinylidene isomers in dichloromethane is very slow and requires hours to its completion. However, this process is accelerated by addition of LiCl in methanol solution. Reaction of 1 with HC≡CR (R = COOMe, C6H4CF3) in MeOH goes through the intermediacy of the π-alkyne complexes [Cp*Ru(η2-HC≡CR)(iPr2PNHPy)]Cl (R = COOMe (3a-Cl), C6H4CF3 (3b-Cl)), which rearrange to vinylidenes in minutes, i.e., much faster than their counterparts containing the [BPh4]− anion. The kinetics of these isomerizations has been studied in solution by NMR. With the help of DFT studies, these observations have been interpreted in terms of chloride- and methanolassisted hydrogen migrations. Calculations suggest participation of a hydrido−alkynyl intermediate in the process, in which the hydrogen atom can be transferred from the metal to the β-carbon by means of species with weak basic character acting as proton shuttles

    Stratification of radiosensitive brain metastases based on an actionable S100A9/RAGE resistance mechanism

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    Whole-brain radiotherapy (WBRT) is the treatment backbone for many patients with brain metastasis; however, its efficacy in preventing disease progression and the associated toxicity have questioned the clinical impact of this approach and emphasized the need for alternative treatments. Given the limited therapeutic options available for these patients and the poor understanding of the molecular mechanisms underlying the resistance of metastatic lesions to WBRT, we sought to uncover actionable targets and biomarkers that could help to refine patient selection. Through an unbiased analysis of experimental in vivo models of brain metastasis resistant to WBRT, we identified activation of the S100A9–RAGE–NF-κB–JunB pathway in brain metastases as a potential mediator of resistance in this organ. Targeting this pathway genetically or pharmacologically was sufficient to revert the WBRT resistance and increase therapeutic benefits in vivo at lower doses of radiation. In patients with primary melanoma, lung or breast adenocarcinoma developing brain metastasis, endogenous S100A9 levels in brain lesions correlated with clinical response to WBRT and underscored the potential of S100A9 levels in the blood as a noninvasive biomarker. Collectively, we provide a molecular framework to personalize WBRT and improve its efficacy through combination with a radiosensitizer that balances therapeutic benefit and toxicity.We thank all members of the Brain Metastasis Group and A. Chalmers, E. Wagner, O. Fernández-Capetillo, R. Ciérvide and A. Hidalgo for critical discussion of the manuscript; the CNIO Core Facilities for their excellent assistance; and Fox Chase Cancer Center Transgenic Facility for generation of S100A9 mice. We thank EuCOMM repository for providing S100A9 targeted embryonic stem cells. We also thank J. Massagué (MSKCC) for some of the BrM cell lines and M. Bosenberg (Yale) for the YUMM1.1 cell line. Samples from patients included in this study that provided by the Girona Biomedical Research Institute (IDIBGI) (Biobanc IDIBGI, B.0000872) are integrated into the Spanish National Biobanks Network and in the Xarxa de Bancs de Tumors de Catalunya (XBTC) financed by the Pla Director d’Oncologia de Catalunya. All patients consented to the storage of these samples in the biobank and for their use in research projects. This study was funded by MINECO (SAF2017-89643-R) (M.V.), Fundació La Marató de TV3 (201906-30-31-32) (J.B.-B., M.V. and A.C.), Fundación Ramón Areces (CIVP19S8163) (M.V.) and CIVP20S10662 (E.O.P.), Worldwide Cancer Research (19-0177) (M.V. and E.C.-J.M.), Cancer Research Institute (Clinic and Laboratory Integration Program CRI Award 2018 (54545) (M.V.), AECC (Coordinated Translational Groups 2017 (GCTRA16015SEOA) (M.V.), LAB AECC 2019 (LABAE19002VALI) (M.V.), ERC CoG (864759) (M.V.), Portuguese Foundation for Science and Technology (SFRH/bd/100089/2014) (C.M.), Boehringer-Ingelheim Fonds MD Fellowship (L.M.), La Caixa International PhD Program Fellowship-Marie Skłodowska-Curie (LCF/BQ/DI17/11620028) (P.G.-G.), La Caixa INPhINIT Fellowship (LCF/BQ/DI19/11730044) (A.P.-A.), MINECO-Severo Ochoa PhD Fellowship (BES-2017-081995) (L.A.-E.) and an AECC postdoctoral fellowship (POSTD19016PRIE) (N.P.). M.V. is an EMBO YIP member (4053). Additional support was provided by Gertrud and Erich Roggenbuck Stiftung (M.M.), Science Foundation Ireland Frontiers for the Future Award (19/FFP/6443) (L.Y.), Science Foundation Ireland Strategic Partnership Programme, Precision Oncology Ireland (18/SPP/3522) (L.Y.), Breast Cancer Now Fellowship Award with the generous support of Walk the Walk (2019AugSF1310) (D.V.), Science Foundation Ireland (20/FFP-P/8597) (D.V.), Paradifference Foundation (C.F.-T.), “la Caixa” Foundation (ID 100010434) (A.I.), European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement 847648 (CF/BQ/PI20/11760029) (A.I.), Champalimaud Centre for the Unknown (N.S.), Lisboa Regional Operational Programme (Lisboa 2020) (LISBOA01-0145-FEDER-022170) (N.S.), NCI (R01 CA227629; R01 CA218133) (S.I.G.), Fundació Roses Contra el Càncer (J.B.-B.), Ministerio de Universidades FPU Fellowship (FPU 18/00069) (P.T.), MICIN-Agencia Estatal de Investigación Fellowships (PRE2020-093032 and BES-2017-080415) (P.M. and E. Cintado, respectively), Ministerio de Ciencia, Innovación y Universidades-E050251 (PID2019-110292RB-I00) (J.L.T.), FCT (PTDC/MED-ONC/32222/2017) (C.C.F.), Fundação Millennium bcp (C.C.F.), private donations (C.C.F.) and the Foundation for Applied Cancer Research in Zurich (E.L.R. and M.W.)

    A Search for Photons with Energies Above 2 × 1017^{17} eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory

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    Ultra-high-energy photons with energies exceeding 1017^{17} eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 1015^{15} eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 1017^{17} eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 1017^{17} and 1018^{18} eV

    Cosmological implications of photon-flux upper limits at ultra-high energies in scenarios of Planckian-interacting massive particles for dark matter

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    We present a thorough search for signatures that would be suggestive of super-heavy XX particles decaying in the Galactic halo, in the data of the Pierre Auger Observatory. From the lack of signal, we derive upper limits for different energy thresholds above 108{\gtrsim}10^8\,GeV on the expected secondary by-product fluxes from XX-particle decay. Assuming that the energy density of these super-heavy particles matches that of dark matter observed today, we translate the upper bounds on the particle fluxes into tight constraints on the couplings governing the decay process as a function of the particle mass. We show that instanton-induced decay processes allow us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: \alpha_X \alt 0.09, for 10^{9} \alt M_X/\text{GeV} < 10^{19}. This upper limit on αX\alpha_X is complementary to the non-observation of tensor modes in the cosmic microwave background in the context of Planckian-interacting massive particles for dark matter produced during the reheating epoch. Viable regions for this scenario to explain dark matter are delineated in several planes of the multidimensional parameter space that involves, in addition to MXM_X and αX\alpha_X, the Hubble rate at the end of inflation, the reheating efficiency, and the non-minimal coupling of the Higgs with curvature.Comment: 15 pages, 8 figures, Accompanying paper of arXiv:2203.0885
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