July 2023 - news - Mailing lists@ IFISC

IFISC News - New tool to predict the optimal time of intervention to control the nymphs of Philaenus spumarius, insect vector of Xylella fastidiosa in Europe
by ifisc＠ifisc.uib-csic.es 27 Jul '23

27 Jul '23

New tool to predict the optimal time of intervention to control the nymphs of Philaenus spumarius, insect vector of Xylella fastidiosa in Europe Researchers from two CSIC institutes developed a predictive tool that can help limit the populations of the main insect vector of the bacterium Xylella fastidiosa, which causes diseases that seriously affect several key crops in our agriculture, such as olive trees, vines and almond trees. Philaenus spumarius is a polyphagous insect of the group commonly known as cicadas, which is present in practically the entire northern hemisphere. For a long time, it was unknown to agriculture, but the detection of the X. fastidiosa bacterium in Europe in 2013 has considerably increased the interest in its study, since this insect is the main vector of this bacterium in Europe. In particular, strains of this bacterium have devastated olive plantations in Apulia (Italy), causing the uprooting of millions of olive trees, as well as thousands of almond trees in Mallorca and Alicante and at this moment it poses a serious threat to both vineyards and almond and also olive groves in Andalusia. Understanding the life cycle and phenology of P. spumarius is key to limiting the spread of X. fastidiosa and its impact on different plantations. The study recently published in the journal Environmental Entomology of the American Society for Entomology (ESA) was conducted between the Institute of Agricultural Sciences (ICA-CSIC) and the Institute for Cross-Disciplinary Physics and Complex Systems (IFISC, CSIC-UIB). This study, based on field data obtained in different localities of the Iberian Peninsula, proposes a mathematical model with which a tool has been built to predict the time of hatching of P. spumarius eggs. The research team monitored P. spumarius eggs, from oviposition to hatching, along with daily temperatures and relative humidities at four field locations in the Community of Madrid that were at different altitudes. The data collected were used to construct a model of growth as a function of cumulative temperature (degree-days) to predict egg hatching of the insect in the Iberian Peninsula. In addition, the model was validated with field observations made at different locations in Spain. The resulting model has been used to develop a decision support tool to calculate the optimal time to apply control measures on P. spumarius nymphs, such as surface tillage or weeding. The results suggest that applying control measures on two different dates would optimize the elimination of nymph populations in the field. This would considerably reduce the risk of disease spread. The tool developed calculates the probability of hatching of P. spumarius eggs using the information provided by AEMET stations, which can be accessed through this link: https://pseggs.ifisc.uib-csic.es/. From this information it is possible to determine the appropriate times to apply the 2 treatments proposed as optimal in the work, when the hatching probabilities are 0.35-0.4 and 0.9, respectively.Clara Lago et al., Degree-day-based model to predict egg hatching of Philaenus spumarius (Hemiptera: Aphrophoridae), the main vector of Xylella fastidiosa in Europe, Environmental Entomology, 2023; nvad013, https://doi.org/10.1093/ee/nvad013 http://ifisc.uib-csic.es/en/news/philaenus-spumarius-insect-vector-xylella-…

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IFISC News - How networks avoid collapsing under heavy navigational use?
by ifisc＠ifisc.uib-csic.es 26 Jul '23

26 Jul '23

How networks avoid collapsing under heavy navigational use? IFISC researchers discover that the evolution of networks has a hidden mechanism for naturally creating bypasses that facilitate navigability.The study, published in Proceedings of the National Academy of Sciences of the USA, shows how bypasses exist in various networks, such as in the human brain, thus achieving substantial energy and time savings.We live surrounded by networks: traffic, infrastructures, WWW, etc. We also live embedded into networks, such as those formed by our familial and friendship ties, collaborations, social media. But more importantly, we are conformed by networks, such as our muscle-bone networks, organ-organ communication networks, vascular webs, brain networks, among others. All these networks exist to allow the navigation of items between their nodes at different time scales. How is it that we are not constantly suffering from the collapse of these networks due to such intensive navigational use? Our hearts are submitted to a heavy blood flow, particularly when we perform exercise training. However, our hearts create “collateral vessels” or “natural bypasses”, formed by very small, hair-like vessels (capillaries) that interconnect coronary arteries and their service areas. These natural bypasses facilitate the blood flow in situations of high demand, such as during exercise training or when occlusions are present in the main arteries. IFISC (UIB-CSIC) researchers Ernesto Estrada and Lucas Lacasa, together with Jesús Gómez-Gardeñes (Universidad de Zaragoza), have published a study in Proceedings of the National Academy of Sciences of the USA which shows how the formation and evolution of networks has a hidden mechanism for naturally creating bypasses that, they show, facilitate network navigability. This mechanism increases the efficiency of the communication between pairs of entities (nodes) in a network as the system complexifies, by saving some energy in the process that the system can use later for other functions. In a network there are always paths that connect two nodes with a minimum number of steps. These are called shortest (geodesic) paths between the corresponding nodes. However, to navigate a network using shortest paths one necessary needs to have a map of its global structure, something which is an impossible task in many real-world situations like in the brain. Then, most of the navigation in these networks occurs through diffusive processes, such as when coffee is dropped in a glass of milk. The authors discovered that during network evolution, some randomly-created paths emerge as an alternative to the shortest ones. While these alternative paths connect the same pair of nodes using routes slightly longer than the shortest path, these paths in turn traverse less connected regions of the network. The authors developed a mathematical theory that showed that these alternative paths allow a navigator without a map of the whole network to arrive at their destination with less chances of getting lost than when using the shortest path. To quantify whether a “blind” navigator would prefer to go through the shortest or the alternative path they defined a way to quantify the amount of energy saved by going through the alternative route. Sometimes, navigating through these alternative routes compensate the navigator to use a slightly longer path. Researchers called it network “bypasses”. Bypasses cannot be created without a certain cost to the network. Such cost is paid in terms of disorder, i.e., increasing the entropy of the network. However, they found that a little increase in the disorder of a network is enough to generate useful bypasses. Estrada, Gómez-Gardeñes and Lacasa applied their findings to study a wide range of real-world networks ranging from social, technological, infrastructural, biological, and informational ones. In general, they found that most of the networks contain bypasses, but some contain significantly more than others. At the bottom of the ranking, they found networks that had not been designed to be navigated in a random way, such as power grids or electronic circuits. The lack of effective bypasses in these networks is an indication of their vulnerability, as we have seen during blackouts –a power grid failure cascade--, the authors argue. In these cases, the amount of energy saved by using the existing bypasses is indeed relatively low. Conversely, the authors found networks --such as the human brain-- where using bypasses saves a lot of energy and time in the communication process. For instance, the analysis of a human brain network displaying regions that coactivate together identifies that there are pairs of regions whose communication via bypasses represents more than 200% of time saved in comparison with the navigation via the shortest path, which points out the importance of these results to understand the plasticity of complex systems.Image: A network in which the nodes (yellow and green balls) are connected with links. The blue path linking the two green nodes is the shortest, but it turns out that the pink "brachistochronous" path is more advantageous, as it avoids congestion and is less resistive. This pink path constitutes a bypass.Estrada, Ernesto, et al. Network Bypasses Sustain Complexity. Proceedings of the National Academy of Sciences (2023). https://doi.org/10.1073/pnas.2305001120. http://ifisc.uib-csic.es/en/news/how-networks-avoid-collapsing-under-heavy-…

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IFISC News - Dr. Ernesto Estrada, IFISC researcher, elected Fellow of the Network Science Society
by ifisc＠ifisc.uib-csic.es 14 Jul '23

14 Jul '23

Dr. Ernesto Estrada, IFISC researcher, elected Fellow of the Network Science Society Dr. Ernesto Estrada, researcher at IFISC (CSIC-UIB), has been elected Fellow by the prestigious Network Science Society (NetSci). As one of only six individuals elected in the class of 2023, Dr. Estrada's exceptional contributions to the field of network science and its applications have earned him this distinction. This recognition of Dr. Estrada's research work is awarded to him “for his significant contributions to network science and its applications, including seminal works on geometric and spatial networks, chemical graph theory, as well as for his outstanding editorial work”. The announcement was made public at the awards ceremony during the NetSci 2023 conference. The Fellowship Program of the Network Science Societyhttps://netscisociety.net/award-prizes/society-fellows recognizes researchers who have made outstanding and significant contributions to network science research and to the community of network scientists. The Fellowship is awarded each year to up to 7 members of the community on the basis of their exceptional life-long individual contributions to any area of network science research and to the community of network scientists. Dr. Ernesto Estrada is a Research Professor at IFISC (CSIC-UIB) since 2021. He has received several academic distinctions, including the Wolfson Research Merit Award of the Royal Society of London, Outstanding Scientist of the International Academy of Mathematical Chemistry, elected Member of the Academia Europaea, of the Latin American Academy of Sciences, elected Fellow of the Society for Industrial and Applied Mathematics (SIAM) and elected Fellow of the Institute of Mathematics and its Applications. He is Editor in Chief of the Journal of Complex Networks, published by Oxford University Press (OUP) and member of the Editorial Board of SIAM J. Appl. Math., Proc. Roy. Soc. A, Mathematics, among others. His research is focused on the mathematical analysis of networks as well as on their applications to infrastructural, ecological, social and biological problems. In these areas he has published more than 240 papers, 15 book chapters, two books published by OUP and one edited with Springer. NetSci is a scientific society with the goal of bringing together under one umbrella a wide variety of researchers and stakeholders with a direct interest in network science, from physics to computer science to biology to social science to economics and so on. Its primary mission is to carry out the kind of activities that would help the Network Science community thrive, such as organizing the annual Network Science meeting, publishing, and working to attract funding for this effort. http://ifisc.uib-csic.es/en/news/dr-ernesto-estrada-ifisc-researcher-electe…

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IFISC News - IFISC People: Sara Cloux and Dhafer Ferchichi
by ifisc＠ifisc.uib-csic.es 06 Jul '23

06 Jul '23

IFISC People: Sara Cloux and Dhafer Ferchichi We are glad to introduce Sara Cloux and Dhafer Ferchichi to the other IFISC members.Sara Cloux completed her doctorate in Marine Sciences, Technologies, and Management at the University of Santiago de Compostela. Her research focused on the Lagrangian transport of marine debris into the ocean and the transport of moisture into the atmosphere. At IFISC she will work as a postdoctoral researcher with Cristóbal López, Emilio Hernández-García and Enrico Ser-Giacomi in the LAMARCA project. The aim of this project is to further understand the role of oceanic transport in marine litter (microplastics and meso/macrolitter) dispersion and accumulation areas in the sea surface, along the water column and over the seafloor. She will be working on this project for a year and a half.Dhafer Ferchichi comes from the Pasteur Institute in Tunisia. At IFISC he will work together with Manuel Matias and Tomàs Sintes in the SEDIMENT project. This is an European Recovery, Transformation and Resilience Plan (PRTR) project dedicated to the use of Artificial Intelligence and Machine Learning technologies for the analysis of satellite images in order to characterize the Posidonia meadows of the Balearic Islands, which are an ecosystem threatened by human activity, and its evolution over time. His research has focused on the design of agent-based models for the study of the emergence of collective behaviors, the spread of infectious diseases and, in general, the modeling of complex systems. He will be at our Institute until the end of April, 2024. http://ifisc.uib-csic.es/en/news/ifisc-people-sara-cloux-and-dhafer-ferchic…

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