111 research outputs found

    Boost invariant marginally trapped surfaces in Minkowski 4-space

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    The extremal and partly marginally trapped surfaces in Minkowski 4-space, which are invariant under the group of boost isometries, are classified. Moreover, it is shown that there do not exist extremal surfaces of this kind with constant Gaussian curvature. A procedure is given in order to construct a partly marginally trapped surface by gluing two marginally trapped surfaces which are invariant under the group of boost isometries. As an application, a proper star-surface is constructed.Comment: 13 pages, comment added in section

    Ideally embedded space-times

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    Due to the growing interest in embeddings of space-time in higher-dimensional spaces we consider a specific type of embedding. After proving an inequality between intrinsically defined curvature invariants and the squared mean curvature, we extend the notion of ideal embeddings from Riemannian geometry to the indefinite case. Ideal embeddings are such that the embedded manifold receives the least amount of tension from the surrounding space. Then it is shown that the de Sitter spaces, a Robertson-Walker space-time and some anisotropic perfect fluid metrics can be ideally embedded in a five-dimensional pseudo-Euclidean space.Comment: layout changed and typos corrected; uses revtex

    Sustained data access and tools as key ingredients to strengthening EO capacities : examples from land application perspective + powerpoint

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    Sustainably managing agriculture and forests is key for development, in particular in Africa, and for facing global challenges such as climate change or food security, but requires reliable information. As Earth Observation (EO) satellite data can contribute to these information needs, more and more institutes integrate this technology into their daily work. Facing ever-growing and evolving EO data sources (e.g. new satellites and sensors) and access technology (both online and via EUMETCast satellite broadcast), their applications require software tools to particularly facilitate (i) the exchange of data between the analysis tools, so users can take advantage of each tool’s strengths, and (ii) the processing and analysis of time series. A first example is the Land Surface Analysis Satellite Application Facility (LSA-SAF), that entered the second part of the Continuous Development and Operations Phase (CDOP-2), under the lead of the Portuguese Institute for Sea and Atmosphere (IPMA), in 2011. VITO, joining the LSA-SAF network for the first time and building on previous experiences (e.g. http://www.metops10.vito.be), aims to contribute by producing and delivering operational, 10-daily vegetation indicators based on MetOp-AVHRR. Furthermore, a software tool is developed to aid exploitation of LSA-SAF products, provisionally called “MSG Toolbox”. A second example is the AGRICAB project, that receives funding from the European Union’s 7th Framework Programme for Research (FP7) and aims to build a comprehensive framework for strengthening capacities in the use of EO for agriculture and forestry management in Africa. This framework starts from sustained access to relevant satellite data (e.g. CBERS-3, DEIMOS) and derived products, such as those from the European Copernicus Global Land service, the 15 year time series of SPOT-VEGETATION (and its transition to PROBA-V) and Meteosat Second Generation (e.g. rainfall estimates). It combines local and EO data with tools and training into applications on crop monitoring, area statistics and yield forecasting, livestock insurance and modelling, forest and fire management, all fitted to the needs of stakeholders in the African focus countries

    The relationship between sensory sensitivity and autistic traits in the general population.

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    Individuals with Autism Spectrum Disorders (ASDs) tend to have sensory processing difficulties (Baranek et al. in J Child Psychol Psychiatry 47:591–601, 2006). These difficulties include over- and under-responsiveness to sensory stimuli, and problems modulating sensory input (Ben-Sasson et al. in J Autism Dev Disorders 39:1–11, 2009). As those with ASD exist at the extreme end of a continuum of autistic traits that is also evident in the general population, we investigated the link between ASD and sensory sensitivity in the general population by administering two questionnaires online to 212 adult participants. Results showed a highly significant positive correlation (r = .775, p < .001) between number of autistic traits and the frequency of sensory processing problems. These data suggest a strong link between sensory processing and autistic traits in the general population, which in turn potentially implicates sensory processing problems in social interaction difficulties

    Visual Methods for the Design of Shape-Changing Interfaces

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    Shape-changing interfaces use physical change in shape as input and/or output. As the field matures, it will move from technology-driven design toward more formal processes. However, this is challenging: end-users are not aware of the capabilities of shape-change, devices are difficult to demonstrate, and presenting single systems can ‘trap’ user-thinking into particular forms. It is crucial to ensure this technology is developed with requirements in mind to ensure successful end-user experiences. To address this challenge, we developed and tested (n = 50) an approach that combines low-fidelity white-box prototypes and high-fidelity video footage with end-user diagram and scenario sketching to design context dependent devices. We analysed the outputs of our test process and identified themes in device design requirements, and from this constructed a shape-change stack model to support practitioners in developing, classifying, and synthesising end-user requirements for this novel technology

    Global maps of soil temperature

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    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km(2) resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km(2) pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10 degrees C (mean = 3.0 +/- 2.1 degrees C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 +/- 2.3 degrees C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 +/- 2.3 degrees C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.Peer reviewe

    Global maps of soil temperature

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    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km² resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e., offset) between in-situ soil temperature measurements, based on time series from over 1200 1-km² pixels (summarized from 8500 unique temperature sensors) across all the world’s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in-situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.Additional co-authors: Brett R. Scheffers, Koenraad Van Meerbeek, Peter Aartsma, Otar Abdalaze, Mehdi Abedi, Rien Aerts, Negar Ahmadian, Antje Ahrends, Juha M. Alatalo, Jake M. Alexander, Camille Nina Allonsius, Jan Altman, Christof Ammann, Christian Andres, Christopher Andrews, Jonas Ardö, Nicola Arriga, Alberto Arzac, Valeria Aschero, Rafael L. Assis, Jakob Johann Assmann, Maaike Y. Bader, Khadijeh Bahalkeh, Peter Barančok, Isabel C. Barrio, Agustina Barros, Matti Barthel, Edmund W. Basham, Marijn Bauters, Manuele Bazzichetto, Luca Belelli Marchesini, Michael C. Bell, Juan C. Benavides, José Luis Benito Alonso, Bernd J. Berauer, Jarle W. Bjerke, Robert G. Björk, Mats P. Björkman, Katrin Björnsdóttir, Benjamin Blonder, Pascal Boeckx, Julia Boike, Stef Bokhorst, Bárbara N. S. Brum, Josef Brůna, Nina Buchmann, Pauline Buysse, José Luís Camargo, Otávio C. Campoe, Onur Candan, Rafaella Canessa, Nicoletta Cannone, Michele Carbognani, Jofre Carnicer, Angélica Casanova-Katny, Simone Cesarz, Bogdan Chojnicki, Philippe Choler, Steven L. Chown, Edgar F. Cifuentes, Marek Čiliak, Tamara Contador, Peter Convey, Elisabeth J. Cooper, Edoardo Cremonese, Salvatore R. Curasi, Robin Curtis, Maurizio Cutini, C. Johan Dahlberg, Gergana N. Daskalova, Miguel Angel de Pablo, Stefano Della Chiesa, Jürgen Dengler, Bart Deronde, Patrice Descombes, Valter Di Cecco, Michele Di Musciano, Jan Dick, Romina D. Dimarco, Jiri Dolezal, Ellen Dorrepaal, Jiří Dušek, Nico Eisenhauer, Lars Eklundh, Todd E. Erickson, Brigitta Erschbamer, Werner Eugster, Robert M. Ewers, Dan A. Exton, Nicolas Fanin, Fatih Fazlioglu, Iris Feigenwinter, Giuseppe Fenu, Olga Ferlian, M. Rosa Fernández Calzado, Eduardo Fernández-Pascual, Manfred Finckh, Rebecca Finger Higgens, T'ai G. W. Forte, Erika C. Freeman, Esther R. Frei, Eduardo Fuentes-Lillo, Rafael A. García, María B. García, Charly Géron, Mana Gharun, Dany Ghosn, Khatuna Gigauri, Anne Gobin, Ignacio Goded, Mathias Goeckede, Felix Gottschall, Keith Goulding, Sanne Govaert, Bente Jessen Graae, Sarah Greenwood, Caroline Greiser, Achim Grelle, Benoit Guénard, Mauro Guglielmin, Joannès Guillemot, Peter Haase, Sylvia Haider, Aud H. Halbritter, Maroof Hamid, Albin Hammerle, Arndt Hampe, Siri V. Haugum, Lucia Hederová, Bernard Heinesch, Carole Helfter, Daniel Hepenstrick, Maximiliane Herberich, Mathias Herbst, Luise Hermanutz, David S. Hik, Raúl Hoffrén, Jürgen Homeier, Lukas Hörtnagl, Toke T. Høye, Filip Hrbacek, Kristoffer Hylander, Hiroki Iwata, Marcin Antoni Jackowicz-Korczynski, Hervé Jactel, Järvi Järveoja, Szymon Jastrzębowski, Anke Jentsch, Juan J. Jiménez, Ingibjörg S. Jónsdóttir, Tommaso Jucker, Radoslaw Juszczak, Róbert Kanka, Vít Kašpar, George Kazakis, Julia Kelly, Anzar A. Khuroo, Leif Klemedtsson, Marcin Klisz, Natascha Kljun, Alexander Knohl, Johannes Kobler, Jozef Kollár, Martyna M. Kotowska, Bence Kovács, Juergen Kreyling, Andrea Lamprecht, Simone I. Lang, Christian Larson, Keith Larson, Kamil Laska, Guerric le Maire, Rachel I. Leihy, Luc Lens, Bengt Liljebladh, Annalea Lohila, Juan Lorite, Benjamin Loubet, Joshua Lynn, Martin Macek, Roy Mackenzie, Enzo Magliulo, Regine Maier, Francesco Malfasi, František Máliš, Matěj Man, Giovanni Manca, Antonio Manco, Tanguy Manise, Paraskevi Manolaki, Felipe Marciniak, Radim Matula, Ana Clara Mazzolari, Sergiy Medinets, Volodymyr Medinets, Camille Meeussen, Sonia Merinero, Rita de Cássia Guimarães Mesquita, Katrin Meusburger, Filip J. R. Meysman, Sean T. Michaletz, Ann Milbau, Dmitry Moiseev, Pavel Moiseev, Andrea Mondoni, Ruth Monfries, Leonardo Montagnani, Mikel Moriana-Armendariz, Umberto Morra di Cella, Martin Mörsdorf, Jonathan R. Mosedale, Lena Muffler, Miriam Muñoz-Rojas, Jonathan A. Myers, Isla H. Myers-Smith, Laszlo Nagy, Marianna Nardino, Ilona Naujokaitis-Lewis, Emily Newling, Lena Nicklas, Georg Niedrist, Armin Niessner, Mats B. Nilsson, Signe Normand, Marcelo D. Nosetto, Yann Nouvellon, Martin A. Nuñez, Romà Ogaya, Jérôme Ogée, Joseph Okello, Janusz Olejnik, Jørgen Eivind Olesen, Øystein Opedal, Simone Orsenigo, Andrej Palaj, Timo Pampuch, Alexey V. Panov, Meelis Pärtel, Ada Pastor, Aníbal Pauchard, Harald Pauli, Marian Pavelka, William D. Pearse, Matthias Peichl, Loïc Pellissier, Rachel M. Penczykowski, Josep Penuelas, Matteo Petit Bon, Alessandro Petraglia, Shyam S. Phartyal, Gareth K. Phoenix, Casimiro Pio, Andrea Pitacco, Camille Pitteloud, Roman Plichta, Francesco Porro, Miguel Portillo-Estrada, Jérôme Poulenard, Rafael Poyatos, Anatoly S. Prokushkin, Radoslaw Puchalka, Mihai Pușcaș, Dajana Radujković, Krystal Randall, Amanda Ratier Backes, Sabine Remmele, Wolfram Remmers, David Renault, Anita C. Risch, Christian Rixen, Sharon A. Robinson, Bjorn J.M. Robroek, Adrian V. Rocha, Christian Rossi, Graziano Rossi, Olivier Roupsard, Alexey V. Rubtsov, Patrick Saccone, Clotilde Sagot, Jhonatan Sallo Bravo, Cinthya C. Santos, Judith M. Sarneel, Tobias Scharnweber, Jonas Schmeddes, Marius Schmidt, Thomas Scholten, Max Schuchardt, Naomi Schwartz, Tony Scott, Julia Seeber, Ana Cristina Segalin de Andrade, Tim Seipel, Philipp Semenchuk, Rebecca A. Senior, Josep M. Serra-Diaz, Piotr Sewerniak, Ankit Shekhar, Nikita V. Sidenko, Lukas Siebicke, Laura Siegwart Collier, Elizabeth Simpson, David P. Siqueira, Zuzana Sitková, Johan Six, Marko Smiljanic, Stuart W. Smith, Sarah Smith-Tripp, Ben Somers, Mia Vedel Sørensen, José João L. L. Souza, Bartolomeu Israel Souza, Arildo Souza Dias, Marko J. Spasojevic, James D. M. Speed, Fabien Spicher, Angela Stanisci, Klaus Steinbauer, Rainer Steinbrecher, Michael Steinwandter, Michael Stemkovski, Jörg G. Stephan, Christian Stiegler, Stefan Stoll, Martin Svátek, Miroslav Svoboda, Torbern Tagesson, Andrew J. Tanentzap, Franziska Tanneberger, Jean-Paul Theurillat, Haydn J. D. Thomas, Andrew D. Thomas, Katja Tielbörger, Marcello Tomaselli, Urs Albert Treier, Mario Trouillier, Pavel Dan Turtureanu, Rosamond Tutton, Vilna A. Tyystjärvi, Masahito Ueyama, Karol Ujházy, Mariana Ujházyová, Domas Uogintas, Anastasiya V. Urban, Josef Urban, Marek Urbaniak, Tudor-Mihai Ursu, Francesco Primo Vaccari, Stijn Van de Vondel, Liesbeth van den Brink, Maarten Van Geel, Vigdis Vandvik, Pieter Vangansbeke, Andrej Varlagin, G.F. Veen, Elmar Veenendaal, Susanna E. Venn, Hans Verbeeck, Erik Verbrugggen, Frank G.A. Verheijen, Luis Villar, Luca Vitale, Pascal Vittoz, Maria Vives-Ingla, Jonathan von Oppen, Josefine Walz, Runxi Wang, Yifeng Wang, Robert G. Way, Ronja E. M. Wedegärtner, Robert Weigel, Jan Wild, Matthew Wilkinson, Martin Wilmking, Lisa Wingate, Manuela Winkler, Sonja Wipf, Georg Wohlfahrt, Georgios Xenakis, Yan Yang, Zicheng Yu, Kailiang Yu, Florian Zellweger, Jian Zhang, Zhaochen Zhang, Peng Zhao, Klaudia Ziemblińska, Reiner Zimmermann, Shengwei Zong, Viacheslav I. Zyryanov, Ivan Nijs, Jonathan Leno
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