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Increasing energy production through renewable sources is a challenge for islands. This paper investigates the potential of hydropower as a renewable energy source for islands in the Macaronesia region, which includes the Azores, Madeira, Canary Islands, and Cape Verde. Ecological transition towards renewable energy sources is crucial for these islands due to their current dependence on imported fossil fuels and their remoteness. The methodology used in this paper combines a SWOT analysis with a review of relevant literature. The SWOT analysis evaluates the Strengths, Weaknesses, Opportunities, and Threats associated with hydropower development on each island. The results show that each island has unique characteristics that influence its hydropower potential. The Azores has existing mini-hydropower plants and opportunities for pumped storage systems due to its rainfall and volcanic features. Madeira also utilizes hydropower, including the world's first underground pumped storage plant (UPHS) in Socorridos. However, limitations exist due to the mountainous terrain and competition for water resources. The Canary Islands showcase the success story of El Hierro Island, which significantly increased renewable energy penetration through a wind farm and pumped storage hydropower system. The topography and lack of rainfall on Cape Verde make the development of hydropower a significant challenge and, as a result, the focus has shifted to wind power. The study concludes that hydropower can play a significant role in the ecological transition of these islands. However, careful planning and consideration of environmental factors are necessary to maximize the benefits and minimize the potential drawbacks. The paper emphasizes the importance of islandspecific assessments and exploring opportunities for pumped storage systems. [ABSTRACT FROM AUTHOR]

In this paper, we analyse the long-run equilibrium demand of the peer-to-peer sharing economy. Our panel data demand model relates occupancy rates to relative prices of Airbnb and HomeAway listings, prices of competitors (hotels and apartments) and a proxy for income of tourists visiting the Canary Islands (Spain). We use a fractional heterogeneous panel data model which allows for a more general persistence and cointegration relationship and incorporates individual and interactive fixed effects. We find some evidence for (fractional) cointegration in P2P at the listing level. Regarding elasticities, classic cointegration methods give larger estimates for individual slopes and mean group coefficients than the fractional integrated heterogeneous model. Finally, own-price elasticities are inelastic, and the cross-price elasticity indicates that P2P listings and hotels are substitute goods. Income elasticity is lower than 1 and is not statistically significant, indicating that the demand for tourism in the Canary Islands is not sensitive to the economic conditions in the origin countries. [ABSTRACT FROM AUTHOR]

Cetaceans are considered ecosystem engineers and useful bioindicators of the health of marine environments. The Eastern North Atlantic is an area of great geographical and oceanographic complexity that favours ecosystem richness and, consequently, cetacean occurrence. Although this occurrence has led to relevant scientific research on this taxon, information on the composition of this research has not been assessed.We aimed to describe and quantify the evolution of research on cetaceans in the Eastern North Atlantic, highlighting the main focal areas and trends.We considered 380 peer‐reviewed publications between 1900 and 2018. For each paper, we collected publication year, research topics and regions, and species studied. We assessed differences among regions with distinct socio‐economic landscapes, and between coastal and oceanic habitats. To evaluate the changes in scientific production over time, we fitted a General Additive Model to the time series of numbers of papers.Although research in this region has been increasing, the results show relatively little research output in North African and coastal regions within the study area. Moreover, except for four studies, research was restricted to a few miles around the coast of the main islands, leaving offshore regions less well surveyed. There was little research on genetics, acoustics, and behaviour. Most papers were focused on the Azores and Canary Islands, and mostly involved Tursiops truncatus, Delphinus delphis, and Physeter macrocephalus. Species considered Endangered or Near Threatened were the subjects of only 10% of the studies.We suggest a greater research focus on beaked whales (Ziphiidae) in Macaronesia, as well as collaborative efforts between research teams in the region, by sharing data sets, and aiming to produce long‐term research. Moreover, a Delphi method approach, based on questionnaires answered by experts, could be attempted to identify priority research for cetaceans in these areas. [ABSTRACT FROM AUTHOR]

The article presents uncertainty analysis of the carbon monoxide (CO) measurements in troposphere carried out by Izaña Global Atmosphere Watch (GAW) mountain station in Tenerife, Canary Islands. It mentions that uncertainty analysis considered measurement system configuration, response function, and the data processing. It adds the comparison of the measurement with the collocated flasks from U.S. National Oceanic and Atmospheric Administration (NOAA) as part of quality assurance.

Water scarcity is a global problem that particularly affects islands located in arid regions or regions with limited water resources. This issue has prompted the development of non-conventional water sources such as fossil fuel-powered desalination systems. Concern about the high energy and environmental costs associated with this type of facility has created the ideal framework for the proliferation of desalination projects powered by renewable energies, especially wind energy due to the multiple advantages it offers. This article provides a bibliometric analysis to identify the advances made in wind-powered desalination on islands. While many studies explore wind-powered desalination, none compile references specific to islands. This paper analyses islands' desalination needs and showcases wind-powered systems, exploring their types and uses. Firstly, the most relevant international scientific journals are identified to allow the subsequent selection and quantitative and qualitative analysis of articles directly dealing with wind-powered desalination systems. A total of 2344 articles obtained from the Scopus database were analyzed, of which 144 including 181 case studies were selected. Among the results of this study, an increasing year-on-year trend is observed in the number of published studies tackling wind-powered desalination. Finally, this paper presents a series of maps showing the most relevant facilities, projects, and data in this field, and provides an overview of the lessons learned in the decarbonization of desalination. [ABSTRACT FROM AUTHOR]

With the increasing popularity of IoT (Internet-of-Things) devices, their security becomes an increasingly important issue. Buffer overflow vulnerabilities have been known for decades, but are still relevant, especially for embedded devices where certain security measures cannot be implemented due to hardware restrictions or simply due to their impact on performance. Therefore, many buffer overflow detection mechanisms check for overflows only before critical data are used. All data that an attacker could use for his own purposes can be considered critical. It is, therefore, essential that all critical data are checked between writing a buffer and its usage. This paper presents a vulnerability of the ESP32 microcontroller, used in millions of IoT devices, that is based on a pointer that is not protected by classic buffer overflow detection mechanisms such as Stack Canaries or Shadow Stacks. This paper discusses the implications of vulnerability and presents mitigation techniques, including a patch, that fixes the vulnerability. The overhead of the patch is evaluated using simulation as well as an ESP32-WROVER-E development board. We showed that, in the simulation with 32 general-purpose registers, the overhead for the CoreMark benchmark ranges between 0.1% and 0.4%. On the ESP32, which uses an Xtensa LX6 core with 64 general-purpose registers, the overhead went down to below 0.01%. A worst-case scenario, modeled by a synthetic benchmark, showed overheads up to 9.68%. [ABSTRACT FROM AUTHOR]

Simple Summary: The main assumption of the so-called theory of island biogeography is that larger islands are home to more species than smaller ones. However, species richness on an island is affected not only by its size but also by other features, such as the island's distance from the mainland or its geological age. The two Canary Islands Tenerife and La Gomera are a good model for testing the relationship between species richness and island area, as they differ considerably in size (the former has an area 5.5 times that of the latter) but are similar in location and age. They lie close to each other (less than 30 km apart) in the central-western part of the archipelago, about 300 km from the African coast. Both were formed as a result of volcanic activity some 11.5–12 million years ago. We compared the species composition and species richness of ladybird beetles on these two islands based on our field surveys and the literature data. As expected, clearly more ladybird species have been recorded on Tenerife (47 species) than on La Gomera (26 species). Being the largest of the Canary Islands, Tenerife has the richest ladybird fauna of all the islands in the archipelago, but it is also more susceptible to colonization by non-native ladybirds than the other islands: to date, ten species of non-native ladybirds have been recorded on Tenerife, compared to between three and seven on the other islands (five on La Gomera). Among the non-native ladybirds established on Tenerife (but not on any other island in the archipelago) is the harlequin ladybird (Harmonia axyridis), a highly invasive species of Asiatic origin that has spread nearly worldwide. This paper provides new data on the ladybird beetles (Coccinellidae) from two islands in the Canary archipelago: Tenerife, the largest island, and La Gomera, the second smallest. As they clearly differ in size but are similar in location and geological age, they are a suitable model for testing the species–area relationship. Our study shows that, in line with this main assumption of the theory of island biogeography, clearly more species occur on a large island (Tenerife) than on a small one (La Gomera). The field surveys documented the occurrence of 35 ladybird species on Tenerife (including 5 not previously reported from this island) and of 20 species on La Gomera (2 species new to the island). Coelopterus sp. collected on Tenerife (a single female that could not be identified to species) is the first record of this genus for the whole Canary Islands. Taking our data and previously published records into account, 47 species of Coccinellidae are known to occur on Tenerife and 26 species on La Gomera. Tenerife has by far the richest ladybird fauna of all the Canary Islands (the next in line, Gran Canaria, has 41 recorded species), but it also has the highest number of non-native ladybird species. All of the ten non-native species recorded in the Canary Islands are found on Tenerife, and for most of them, Tenerife was the island of their first appearance in the archipelago. This island, much more distant from the mainland than the other relatively large islands (Fuerteventura, Lanzarote), appears to be the main recipient of ladybirds immigrating to the Canary Islands. Tenerife can play this role probably because of its great habitat diversity and altitude variation, as well as intensive tourism and trade-related transport. [ABSTRACT FROM AUTHOR]

The plankton community response to natural fertilization caused by the Saharan dust was studied in the Canary Islands waters during winter--spring 2010. For this, a weekly sampling was carried out to characterize the pico-, nano- and microplankton communities. During this period several dust events were identified from atmospheric suspended matter and metal composition. Temperatures above 19 °C in the mixed layer, high stratification and a very low concentration of chlorophyll a, indicated the absence of the characteristic late winter bloom during this year. However, relatively high primary production rates were measured, probably fuelled by nutrient release from the deposited atmospheric dust. In fact, this winter--spring was one of the most intense dust periods during the last years and Saharan dust events were identified in every month. The effect of the Saharan dust over the plankton community mainly consisted in the enhancement of primary producers, mostly diatoms, and the increase of the mesozooplankton stock, whereas cyanobacteria and autotrophic picoeukaryotes were negatively affected. These results suggest that the Saharan dust deposition would be partly fuelling the primary production in these oligotrophic waters of the northeast Atlantic, and could be especially significant during stratified periods, when the atmospheric dust would be the most important nutrient source. [ABSTRACT FROM AUTHOR]

The article presents a study which focuses on the development of a technique for the satellite remote sensing of greenhouse gases in the Canary Islands. It outlines the acquisition of global set of altitude-resolved concentration measurements via the absorption of short-wave infrared (SWIR) laser signals transmitted between counter-rotating satellites in low earth orbit. The measurement of carbon dioxide over an open path of 144 kilometers is also discussed.

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In this paper, we introduce LagunAR, a mobile outdoor Augmented Reality (AR) application for providing heritage information and 3D visualization on a city scale. The LagunAR application was developed to provide historical information about the city of La Laguna in the XVI century, when it was the main city in the Canary Islands. The application provides a reconstructed 3D model of the city at that time that is shown on a mobile phone over-imposed on the actual city using geolocation. The geolocated position is used also for providing information of several points of interest in the city. The paper describes the design and implementation of the application and details the optimization techniques that have been used to manage the full information of the city using a mobile phone as a sensor and visualization tool. We explain the application usability study carried out using a heuristic test; in addition it is probed by users in a qualitative user test developed as preliminary research. Results show that it is possible to develop a real-time application that shows the user a city-scale 3D model and also manages the information of the points of interest. [ABSTRACT FROM AUTHOR]

Gurenko et al. (Contrib Mineral Petrol 162:349-363, ) report laser-assisted fluorination (LF) and secondary ionization mass spectrometry (SIMS) O/O datasets for olivine grains from the Canary Islands of Gran Canaria, Tenerife, La Gomera, La Palma and El Hierro. As with prior studies of oxygen isotopes in Canary Island lavas (e.g. Thirlwall et al. Chem Geol 135:233-262, ; Day et al. Geology 37:555-558, , Geochim Cosmochim Acta 74:6565-6589, ), these authors find variations in δO (~4.6-6.0 ‰) beyond that measured for mantle peridotite olivine (Mattey et al. Earth Planet Sci Lett 128:231-241, ) and interpret this variation to reflect contributions from pyroxenite-peridotite mantle sources. Furthermore, Gurenko et al. (Contrib Mineral Petrol 162:349-363, ) speculate that δO values for La Palma olivine grains measured by LF (Day et al. Geology 37:555-558, , Geochim Cosmochim Acta 74:6565-6589, ) may be biased to low values due to the presence of altered silicate, possibly serpentine. The range in δO values for Canary Island lavas are of importance for constraining their origin. Gurenko et al. (Contrib Mineral Petrol 162:349-363, ) took a subset (39 SIMS analyses from 13 grains from a single El Hierro lava; EH4) of a more extensive dataset (321 SIMS analyses from 110 grains from 16 Canary Island lavas) to suggest that δO is weakly correlated ( R = 0.291) with the parameter used by Gurenko et al. (Earth Planet Sci Lett 277:514-524, ) to describe the estimated weight fraction of pyroxenite-derived melt ( Xpx). With this relationship, end-member δO values for HIMU-peridotite (δO = 5.3 ± 0.3 ‰) and depleted pyroxenite (δO = 5.9 ± 0.3 ‰) were defined. Although the model proposed by Gurenko et al. (Contrib Mineral Petrol 162:349-363, ) implicates similar pyroxenite-peridotite mantle sources to those proposed by Day et al. (Geology 37:555-558, , Geochim Cosmochim Acta 74:6565-6589, ) and Day and Hilton (Earth Planet Sci Lett 305:226-234, ), there are significant differences in the predicted δO values of end member components in the two models. In particular, Day et al. (Geochim Cosmochim Acta 74:6565-6589, ) proposed a mantle source for La Palma lavas with low-δO (<5 ‰), rather than higher-δO (c.f. the HIMU-peridotite composition of Gurenko et al. in Contrib Mineral Petrol 162:349-363, ). Here we question the approach of using weakly correlated variations in δO and the Xpx parameter to define mantle source oxygen isotope compositions, and provide examples of why this approach appears flawed. We also provide reasons why the LF datasets previously published for Canary Island lavas remain robust and discuss why LF and SIMS data may provide complementary information on oxygen isotope variations in ocean island basalts (OIB), despite unresolved small-scale uncertainties associated with both techniques. [ABSTRACT FROM AUTHOR]

The comment by Day et al. (Contrib Mineral Petrol, ) (1) discusses the validity of the previously obtained oxygen isotope data for El Hierro and La Palma (Canary Island) olivines, (2) questions the approach by Gurenko et al. (Contrib Mineral Petrol 162:349-363, ) of using weakly correlated variations of δO values with X (proportion of pyroxenite-derived melt in the parental magma), and (3) provides reasons why oxygen isotope data by secondary ion mass spectrometry (SIMS) 'offer sensitive means for detecting melt-crust interactions.' We respond these comments and report a new set of oxygen isotope measurements performed by SIMS and single-grain laser fluorination methods. These measurements confirm our previous data and conclusions and demonstrate the ability of the SIMS technique to analyze O isotopes in terrestrial samples with 2-sigma uncertainty better than ±0.25 ‰. [ABSTRACT FROM AUTHOR]

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Avocado production has boomed worldwide in recent years, and Spain, including the Canary Islands, has been no exception. The number of avocado growers in the region has increased significantly as growers recognize the potential of this crop. However, several species of spider mites (Tetranychidae) pose a risk to this crop, with the genus Oligonychus being the most diverse and having the greatest economic impact. In particular, Oligonychus perseae (Tuttle, Baker and Abbatiello) has been reported as the one mainly responsible for the economic damage in major avocado-producing regions worldwide. In this paper, we aim to present an overview of the studies conducted and the measures implemented to mitigate the impact of O. perseae after its arrival in the Canary Islands. Our objective is to provide a detailed description of the current status of this pest (O. perseae), with special attention to its situation 17 years after its first appearance in avocado crops in the Canary Islands. In doing so, we aim to provide valuable insights and knowledge to understand and manage better the challenges posed by O. perseae in this region. [ABSTRACT FROM AUTHOR]

This paper analyses whether peer-to-peer (P2P) accommodation substitutes traditional accommodation, taking into account dynamic and spatial spillover effects. We also analyse the impact of the COVID-19 pandemic crisis on the demand and substitution effect. To do this, we use a spatial dynamic panel data demand model for occupancy rates related to prices of P2P accommodation units, prices of competitors (hotels and apartments) and income. Its dynamic component allows estimation of the short- and long-term effects of prices and income on P2P accommodation demand. The model was applied to the P2P accommodation demand in the Canary Islands, Spain. The results indicate that, in the pre-pandemic period, occupancy rates were positively autocorrelated, demand was own-price elastic and substitution with hotels was significant in the short-term. This substitution effect and consumer sensitivity to prices and substitution increase in the long term. However, the irruption of COVID-19 largely distorted price and income-elasticities. [ABSTRACT FROM AUTHOR]

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Simple Summary: The ladybird beetle fauna of the Canary Islands is quite specific due to the presence of a number of species that do not occur anywhere else (the so-called endemic species). However, many ladybirds recorded in the archipelago are relatively recent arrivals from various parts of the world, as shown by our previous surveys carried out in several of the Canary Islands, including Fuerteventura, Lanzarote, Gran Canaria, and El Hierro. In this paper, we analyze the ladybird fauna of La Palma, one of the western islands of the archipelago, based on our field survey and already published data. The survey resulted in the recording of 26 species, seven of which had not previously been recorded on La Palma, and two of these seven had not been recorded on any of the Canary Islands. Combining our data and literature reports gives a figure of at least 35 ladybird species recorded to date on La Palma. This is fewer than on the central islands of the Canary archipelago (Gran Canaria and Tenerife), but more than on the other four islands (Fuerteventura, Lanzarote, La Gomera, and El Hierro). This study confirms previous observations that the Canary Islands are often colonized by exotic ladybird species. This paper provides new data on the ladybird beetles (Coccinellidae) of La Palma, one of the western islands of the Canarian archipelago. The field survey of 54 study sites resulted in recording 2494 ladybird individuals belonging to 26 species. Seven of the species recorded were new to La Palma, including two, Harmonia quadripunctata (Pontoppidan) and Nephus reunioni (Fürsch), which were not registered so far on any of the Canary Islands. Novius conicollis (Korschefsky) is synonymized with N. cruentatus (Mulsant). Taking our survey and literature reports into account, a total of at least 35 species of Coccinellidae have so far been recorded on La Palma. This richness in species is lower compared to that of the central islands of the Canarian archipelago, Gran Canaria (42 species) and Tenerife (41 species), but higher than that of the remaining four islands (between 22 and 27 species). The detection of two alien species new to La Palma, Nephaspis bicolor Gordon and Nephus reunioni (Fürsch), confirms earlier observations that colonization of the Canary Islands by ladybird species of exotic origins seems to be a frequent phenomenon. [ABSTRACT FROM AUTHOR]

The article presents a study that analyzes the structure and composition of samples of rocks found in the south coast of El Hierro, Canary Islands. It concludes that restingolites are in fact xenoliths from pre-island sedimentary rocks that were picked up and heated by the ascending magma causing them to partially melt and vesiculate. It suggests that the occurrence of restingolites does not the presence of an explosive high-silica magma that is involved in the ongoing eruption.

Seagrass and seaweed meadows hold a very important role in coastal and marine ecosystems. However, anthropogenic impacts pose risks to these delicate habitats. This paper analyses the multitemporal impact of the construction of the largest industrial port in the Canary Islands, near the Special Area of Conservation Natura 2000, on Cymodocea nodosa seagrass meadows (sebadales) of the South of Tenerife, in the locality of Granadilla (Canary Islands, Spain). Very-high-resolution WorldView-2 multispectral satellite data were used for the analysis. Specifically, three images were selected before, during, and after the construction of the port (2011, 2014, and 2022, correspondingly). Initially, advanced pre-processing of the images was performed, and then seabed maps were obtained using the machine learning K-Nearest Neighbors (KNN) supervised classification model, discriminating 12 different bottom types in Case-2 complex waters. The maps achieved high-quality metrics with Precision values of 85%, 81%, and 80%, recall of 76%, 77%, and 77%, and F1 scores of 80%, 79%, and 77% for 2011, 2014, and 2022, respectively. The results mainly show that the construction directly affected the seagrass and seaweed habitats. In particular, the impact of the port on the meadows of Cymodocea nodosa, Caulerpa prolifera, and maërl was assessed. The total maërl population was reduced by 1.9 km2 throughout the study area. However, the Cymodocea nodosa population was maintained at the cost of colonizing maërl areas. Furthermore, the port sedimented a total of 0.98 km2 of seabed, especially Cymodocea nodosa and maërl. In addition, it was observed that Caulerpa prolifera was established as a meadow at the entrance of the port, replacing part of the Cymodocea nodosa and maërl areas. As additional results, bathymetric maps were generated from satellite imagery with the Sigmoid model, and the presence of a submarine outfall was, as well, presented. [ABSTRACT FROM AUTHOR]

The first ground-based experiment to prove the concept of a novel space-based observation technique for microwave and infrared-laser occultation between Low Earth Orbit satellites (LMIO) was performed in the Canary Islands between La Palma and Tenerife in July 2011. This experiment aimed to demonstrate the infrared-laser differential transmission principle for the measurement of greenhouse gases (GHGs) in the free atmosphere. Such global and long-term stable measurements of GHGs, accompanied also by measurements of thermodynamic parameters and line-of-sight wind in a self-calibrating way, have become very important for climate change monitoring. The experiment delivered promising initial data for demonstrating the new observation concept by retrieving volume mixing ratios of GHGs along a ~ 144 km signal path at altitudes of ~ 2.4 km. Here, we present a detailed analysis of the measurements, following a recent publication that introduced the experiment's technical setup and first results for an example retrieval of CO2. We present the observational and validation datasets, the latter simultaneously measured at the transmitter and receiver sites, the measurement data handling, and the differential transmission retrieval procedure. We also determine the individual and combined uncertainties influencing the results and present the retrieval results for 12CO2, 13CO2, C18OO, H2O and CH4. The new method is found to have a reliable basis for monitoring of greenhouse gases such as CO2, CH4, and H2O in the free atmosphere. [ABSTRACT FROM AUTHOR]

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This study uses an inbound measuring instrument to segment the cellar's e-commerce in the Canary Islands. One of the central claims of this paper is that inbound marketing comprises several dimensions such as content resources, SEO, social media, digital maturity, and e-commerce growth, such that it implies superior levels of personalisation, flexibility, service, security, and privacy, product and shop transparency, advanced technology, and data mining. After raising three research questions, this study performed fieldwork based on web analytics procedures, extracting metrics from 59 cellars' websites thanks to employing a broad range of software. The sampling procedure was non-probabilistic and judgmental, took place in the spring of 2023, and gathered relevant metrics to build an inbound scale. The data prove that the inbound measuring instrument can rank and segment the Canary Islands' marketplace. Although this study has put forward a tentative explanation and application of the inbound marketing notion and tools, findings suggest a need for a more significant effort to explore how generalizable the created measuring instrument is. [ABSTRACT FROM AUTHOR]

This paper analyses the determinants of tourist length of stay in sharing accommodation. Methodologically, the paper proposes a new approach to account for the observed bimodality of length of stay. More specifically, the determinants of length of stay are analyzed by modeling both the conditional mean and conditional modal frequencies, which represent shorter and longer tourist stays, unlike previous contributions on length of stay where modeling has been based exclusively on the conditional mean. The empirical analysis examines the length of stay in sharing accommodation lodgings (Airbnb and Homeaway) of tourists visiting the Canary Islands (Spain) before and after the outbreak of the COVID-19 pandemic. The results show a bimodal distribution of length of stay: 1 and 7 nights in the pre-pandemic period, reduced to 1 and 2 nights in the pandemic period. The results also indicate that the model approach followed in this paper is preferable to other previous bimodality models in terms of estimation simplicity and fit. In addition, the model allows an analysis of the determinants of length of stay and differentiation of the influence of each determinant on shorter and longer stays. [ABSTRACT FROM AUTHOR]

Many real 3D objects have complex geometric shapes in various types of analyses. Image of these objects is recorded in the form of a 2D map. In the analysis, a simplification of this image to basic 2D figures with defined geometry is often needed. The paper presents an analysis of the geometry of a flat image (an image of a 3D object) using regular polygons. Geometry properties (F form, C centroid, S size) were determined to describe the object. Various criteria of selection of the 'best ' regular n-sided polygon for a given 2D object (solved theoretically) were put forward. In the paper, criteria for describing a 2D object by regular n-sided polygons were defined on the basis of determining the measure of object shape elongation (e). In the 'blind ' theoretical example, it was tested whether the individual shape measures listed in the paper allow for correct identification of the shapes of given 2D objects. The practical application of measures is illustrated by two actual examples. While in the first example the shape of the Canary Islands is analysed, the second example describes the shape of Poland 's borders. Actual examples deliver different results for different measures. In effect, there is no clear objective criterion for selecting a polygon shape. The simplifications of the shape of an object presented in the paper should not be equated with the object 's generalization. Such simplifications are used in GIS to visualize geographic analyses based on the data available in the primary database, because the object will retain the character of the shape in the simplest possible geometry and neighborhood, and does not lose any of the scope and accuracy of the attributes assigned to a given object in the database. [ABSTRACT FROM AUTHOR]

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Renewable energy has a key role to play in the transition towards a low‐carbon society. Despite its importance, relatively little attention has been focused on the crucial impact of weather and climate on energy demand and supply, or the generation or operational planning of renewable technologies. In particular, to improve the operation and longer‐term planning of renewables, it is essential to consider seasonal and subseasonal weather forecasting. Unfortunately, reports that focus on these issues are not common in scientific literature. This paper presents a systematic review of the seasonal forecasting of wind and wind power for the Iberian Peninsula and the Canary Islands, a region leading the world in the development of renewable energies (particularly wind) and thus an important illustration in global terms. To this end, we consider the scientific literature published over the last 13 years (2008–2021). An initial search of this literature produced 14,293 documents, but our review suggests that only around 0.2% are actually relevant to our purposes. The results show that the teleconnection patterns (North Atlantic Oscillation [NAO], East Atlantic [EA] and Scandinavian [SCAND]) and the stratosphere are important sources of predictability of winds in the Iberian Peninsula. We conclude that the existing literature in this crucial area is very limited, which points to the need for increased research efforts, that could lead to great returns. Moreover, the approach and methods developed here could be applied to other areas for which systematic reviews might be either useful or necessary. [ABSTRACT FROM AUTHOR]

The use of renewable energy for desalination started in the 1980s, in order to provide a sustainable water supply in windy/sunny areas with water shortages. Nevertheless, this initiative has been generally limited to the R&D field and prototypes, with few units operating under real conditions. The research tradition in this field carried out by the Canary Islands Institute of Technology, based on pilot facilities, resulted in wide expertise on practical issues, as well as a deep knowledge on the state of the art. This paper deals with the most relevant technical aspects to be considered in the optimal design and operation of wind/photovoltaic (PV)-powered reverse-osmosis (RO) systems, focusing on practical indications: appropriate pre-treatment, the use and selection of the RO energy recovery system (ERD), the selection of an energy storage system, key recommendations for the O&M actions in wind- and PV-powered RO systems (extracted from the experience of operating different units in remote locations (PV and RO) and coastal areas (wind and RO)), and an identification of the pros and cons of hybrid systems. A selection of economic data is given, indicating the main aspects of the minimization of the cost of water. Finally, the paper mentions the latest advances in the involved technologies. [ABSTRACT FROM AUTHOR]

An intertidal sandstone reef, named barra de Las Canteras, protects the western coast of Las Palmas de Gran Canaria city (Canary Islands, Spain). The beach-reef system of Las Canteras constitutes one of the most valuable coastal geomorphological sites in the archipelago. Stratigraphic studies have identified the formation of the reef in the Last Interglacial (MIS 5e) in a coastal sedimentary paleo-environment. The rock structure is highly exposed to the Atlantic swell and consists mainly of a sandstone beachrock with a medium resistance to erosional processes. However, the historical and current erosion rates and the original extent of the reef are not known to date. This paper explores the geomorphological structure of the reef by combining a topo-bathymetric analysis (obtained by differential GPS, multibeam echosounder and hyperspectral sensor) and the analysis of geomorphological features on high-resolution images, obtained with a hyperspectral camera mounted on a UAV. The results provide a comprehensive, high-resolution image of the subaerial and submerged morphology of the reef. The structure reflects the distribution of erosional fronts and the existence of collapsing submarine blockfields and nearshore, uneroded, remnant reliefs. Detailed analysis of these features allows to estimate the probable original extent of the sandstone reef and to relate the erosional retreat processes to the sea-level dynamics during the Holocene. [ABSTRACT FROM AUTHOR]

Ecosystem services' (ES) assessments can inform sustainability policies but often translate poorly into practical decision‐making due to their disconnection from local challenges. Problem framing is a crucial step in improving the operationalization of ecosystem studies. First, the study analyzes the challenges and opportunities for sustainability in three European outermost regions: the Canary Islands, French Guiana, and Reunion Island. Second, it proposes strategies to make use of ES assessments as a means to address these sustainability issues. We used a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis for strategic planning, extended with a PESTEL analysis, standing for Political, Economic, Socio‐cultural, Technological, Environmental, Legal, and Regulatory. Semi‐structured interviews (n = 38) were conducted to identify PESTEL factors facilitating or impeding sustainability in the case studies. Interviews were coded into PESTEL factors before being synthesized and reported into SWOT matrices. We suggest seven ESs implementation strategies addressing these challenges from these SWOT matrices. Finally, this paper highlights the potential contributions of ES‐based strategies to achieving multiple United Nations' 2015 Sustainable Development Goals (SDGs). On average, the strategies are expected to affect the delivery of six ESs. The suggested strategies are expected to contribute to the achievement of SDGs 15 (Life on Land), 2 (Zero Hunger), 14 (Life Below Water), and 11 (Sustainable Cities and Communities). These results pinpoint the key factors to consider, through stakeholder consultation, when designing a practical ES study. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Historia is the property of Universidad de Chile, Facultad de Filosofia y Humanidades and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite their attractive appearance, the velvet spiders of the genus Eresus are an understudied group in some parts of their range. Such areas include the south-western Mediterranean. In this paper we present a description of a new species from Morocco and Algeria, Eresus elhennawyi sp. n. We named it after the Egyptian arachnologist Hisham El-Hennawy, who has worked on the arachnids of North Africa for several decades. This species lives under rocks in semi-desert habitats, so unlike most species of the genus Eresus, it does not burrow. Adult males seek out females in April. Their colouration is obviously a mimicry of co-occurring stinging mutilid wasps. The most morphologically similar species is Eresus crassitibialis Wunderlich, 1987 from the nearby Canary Islands. [ABSTRACT FROM AUTHOR]

Copyright of Revista del Museo de Antropología is the property of Museo de Antropologia - IDACOR and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The purpose of this paper is to analyse the information shared by SMEs with their main customers and suppliers and its implications on their performance. Design/methodology/approach: The paper puts forward the concept of arcs of communication based on the frequency and direction of the information exchanged by SMEs with their main customers and suppliers. SMEs are classified by the arc of communication they belong to using data from a survey carried out in the Canary Islands (Spain). The Rasch Measurement Theory is applied. Findings: The largest group of small- and medium-sized enterprises (SMEs) shares information frequently with both customers and suppliers (broad arc of communication). Differences were detected in the performance of SMEs belonging to this broad arc, as well as, in those firms that communicated frequently with their main suppliers (asymmetrical arc of communication towards suppliers). In both cases, these firms were better than their competitors in innovation. Practical implications: This study demonstrates the need for better management of the links between SMEs and their suppliers and with their customers in accordance with their strategies, promoting a greater cooperative behaviour throughout the supply chain. Originality/value: SMEs' customers and suppliers are their main sources of information compared to large firms, which have greater resources to search for and acquire information. This paper investigates the information exchanged by SMEs with their main customers and suppliers from a strategic focus by adding to the literature the concept of arcs of communication. It also has the added value of applying the Rasch Measurement Theory (Rasch, 1960/1980). [ABSTRACT FROM AUTHOR]

Nationality is considered a highly relevant determinant of tourism expenditure. In this paper, we use survey data to estimate the main determinants of daily tourism expenditure in 2019 for five nationalities of a major coastal destination, the Canary Islands. A total of 38 regressors, based on literature, are used with the help of quantile regression analysis to understand the behaviour patterns of different expenditure segments. To obtain segmented information on the determinants of expenditure, independent quantile regression models for each nationality are estimated and compared. Results show that there are similarities but also some remarkable differences between nationalities regarding income, age, travel group, educational level, or content of the package that can be used in destination management and marketing. [ABSTRACT FROM AUTHOR]

Throughout the first decades of the 21st century, the maritime borders of the European Union have witnessed a growing and increasingly complex mobility of an irregular nature. Moreover, the effects of the COVID-19 crisis on many African countries revealed the weakness of the maritime border and its permeability, as well as its increased danger. This research aims to study these irregular migration flows by sea during 2020 and 2021, through the Atlantic border between the Canary Islands and Africa. The so-called "Canary route" is one of the most dangerous maritime routes in the world due to the ocean conditions, the distances that must be covered and the way in which migrants move. Our analysis will therefore focus on one of the central aspects of this crossing, its danger and associated accident rate, which can be measured in terms of the number of shipwrecks, deaths, and missing persons. The objectives of this paper are: i) to show the spatial location of those wrecks; ii) to give an estimate of data on missing persons and deaths; iii) to focus on the study of those persons affected; iv) to delve into the underlying causes; and v) to analyse the border control actions developed during the pandemic. With this aim, information has been compiled from different national and international sources: official records, contrasted data provided by some NGOs and the IOM, and testimonies of the agents involved. This material is used to reflect on the normalization of border control as a factor that inevitably leads to deaths and disappearances. It suggests that this event should be a central element in European migration policy, contributing to designing border control actions that go beyond containment, thereby preventing the loss of human lives. [ABSTRACT FROM AUTHOR]

Context. The Event Horizon Telescope (EHT) has recently published the first images of the supermassive black hole at the center of our Galaxy, Sagittarius A* (Sgr A*). Imaging Sgr A* is plagued by two major challenges: variability on short (approximately minutes) timescales and interstellar scattering along our line of sight. While the scattering is well studied, the source variability continues to push the limits of current imaging algorithms. In particular, movie reconstructions are hindered by the sparse and time-variable coverage of the array. Aims. In this paper, we study the impact of the planned Africa Millimetre Telescope (AMT, in Namibia) and Canary Islands telescope (CNI) additions to the time-dependent coverage and imaging fidelity of the EHT array. This African array addition to the EHT further increases the eastwest (u, v) coverage and provides a wider time window to perform high-fidelity movie reconstructions of Sgr A*. Methods. We generated synthetic observations of Sgr A*'s accretion flow and used dynamical imaging techniques to create movie reconstructions of the source. To test the fidelity of our results, we used one general-relativistic magneto-hydrodynamic model of the accretion flow and jet to represent the quiescent state and one semi-analytic model of an orbiting hotspot to represent the flaring state. Results. We found that the addition of the AMT alone offers a significant increase in the (u, v) coverage, leading to robust averaged images during the first hours of the observating track. Moreover, we show that the combination of two telescopes on the African continent, in Namibia and in the Canary Islands, produces a very sensitive array to reconstruct the variability of Sgr A* on horizon scales. Conclusions. We conclude that the African expansion to the EHT increases the fidelity of high-resolution movie reconstructions of Sgr A* to study gas dynamics near the event horizon. [ABSTRACT FROM AUTHOR]

Predicting brain aging can help in the early detection and prognosis of neurodegenerative diseases. Longitudinal cohorts of healthy subjects scanned through magnetic resonance imaging (MRI) have been essential to understand the structural brain changes due to aging. However, these cohorts suffer from missing data due to logistic issues in the recruitment of subjects. This paper proposes a methodology for filling up missing data in longitudinal cohorts with anatomically plausible images that capture the subject‐specific aging process. The proposed methodology is developed within the framework of diffeomorphic registration. First, two novel modules are introduced within Synthmorph, a fast, state‐of‐the‐art deep learning‐based diffeomorphic registration method, to simulate the aging process between the first and last available MRI scan for each subject in three‐dimensional (3D). The use of image registration also makes the generated images plausible by construction. Second, we used six image similarity measurements to rearrange the generated images to the specific age range. Finally, we estimated the age of every generated image by using the assumption of linear brain decay in healthy subjects. The methodology was evaluated on 2662 T1‐weighted MRI scans from 796 healthy participants from 3 different longitudinal cohorts: Alzheimer's Disease Neuroimaging Initiative, Open Access Series of Imaging Studies‐3, and Group of Neuropsychological Studies of the Canary Islands (GENIC). In total, we generated 7548 images to simulate the access of a scan per subject every 6 months in these cohorts. We evaluated the quality of the synthetic images using six quantitative measurements and a qualitative assessment by an experienced neuroradiologist with state‐of‐the‐art results. The assumption of linear brain decay was accurate in these cohorts (R2 ∈ [.924,.940]). The experimental results show that the proposed methodology can produce anatomically plausible aging predictions that can be used to enhance longitudinal datasets. Compared to deep learning‐based generative methods, diffeomorphic registration is more likely to preserve the anatomy of the different structures of the brain, which makes it more appropriate for its use in clinical applications. The proposed methodology is able to efficiently simulate anatomically plausible 3D MRI scans of brain aging of healthy subjects from two images scanned at two different time points. [ABSTRACT FROM AUTHOR]

Canary Island date palms (Phoenix canariensis) have been planted as a landscaping feature plant throughout warm, temperate, and subtropical climates. The physical amenity provisioning of this species (shade effects, microclimate amelioration, water usage, etc.) has so far not been systematically assessed. This paper reports on temperature and humidity measurements in both a suburban and a rural location in SE Australia. The study demonstrates the effects of the palm canopy as regulator of humidity and provider of shade and, thus, amenity values in urban landscape settings. Drawing on published energy savings and growth requirements of the plant, the paper argues that Canary Island date palms are landscaping plants suitable to ameliorate the microclimate in urban neighborhoods with varied socio-economic conditions. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Geografía is the property of Universitat de Valencia, Departament de Geografia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Boletín de la Asociación de Geógrafos Españoles is the property of Asociacion de Geografos Espanoles and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Canary Island Long-Baseline Observatory (CILBO) is a double-station meteor camera setup located on the Canary Islands operated by ESA's Meteor Research Group since 2010. Observations of meteors are obtained in the visual wavelength band by intensified video cameras from both stations, supplemented by an intensified video camera mounted with a spectral grating at one of the locations. The cameras observe during cloudless and precipitation-free nights, and data are transferred to a main computer located at ESA/ESTEC once a day. The image frames that contain spectral information are calibrated, corrected, and finally processed into line intensity profiles. An ablation simulation, based on Bayesian statistics using a Markov chain Monte Carlo method, allows determining a parameter space, including the ablation temperatures, chemical elements, and their corresponding line intensities, to fit against the line intensity profiles of the observed meteor spectra. The algorithm is presented in this paper and one example is discussed. Several hundred spectra have been processed and made available through the Guest Archive Facility of the Planetary Science Archive of ESA. The data format and metadata are explained. [ABSTRACT FROM AUTHOR]

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Copyright of Naveg@mérica is the property of Servicio de Publicaciones de la Universidad de Murcia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Spain is an eminently tourist country, which allows the creation of countless jobs and contributes greatly to GDP growth. Millions of people visit this country every year, and more than 80% do so through air transport. This paper studies whether the 13 Spanish airlines with the highest revenues in 2018 were efficient in that year, thus filling a gap in the tourism literature. For this purpose, the non-parametric DEA technique has been used, using as inputs the total number of workers in the company and the total number of seats available (airline capacity). Total revenue and number of passengers have been used as outputs. The results obtained show that all the airlines studied within the IAG group (Iberia, Vueling, Air Nostrum, Iberia Express) are efficient, in addition to the Canary Islands airlines (Binter Canarias, Canarias Airlines and Canary Fly) and Air Europa. Likewise, the reference airlines for the inefficient ones have been determined, which will have to reduce the number of workers or make changes in capacity in order to achieve greater income and be efficient. [ABSTRACT FROM AUTHOR]

Copyright of Monografies de la Societat ďHistòria Natural de les Balears is the property of Societat d'Historia Natural de les Balears and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper examines how Eurocentric and colonial assumptions that until recently guided the handling of human remains in archaeology and museography are now regarded as problematic, focusing on the situation on the Canary Islands, which has recently passed new legislation (Canary Islands Law 11/2019) on cultural heritage that includes an amendment on human remains. Museums in the Canary Islands continue to display Indigenous bones and embalmed bodies in glass cases, and bone material is even used in contemporary art installations. The paper examines the new law in relation to the ICOM Code of Ethics for Museums as well as other ethical and legal frameworks that address the issue of human remains. We also draw attention to the role of politics, social scientists and society in this debate. [ABSTRACT FROM AUTHOR]

Copyright of Erdkunde is the property of Universitaet Bonn, Geographisches Institut and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper draws inference on the effect of changes in indirect taxation on household spending on cinema and performing arts using data from the Spanish household expenditure survey. As of September 2012, value-added tax (VAT) on cinema and performing arts in Spain was raised 13 percent points, with the exception of the Canary Islands which are not part of the Spanish VAT territory. Indirect taxation levied on cinema and performing arts through the General Indirect Tax of Canary Islands (Impuesto General Indirecto de Canarias, IGIC) had changed in July 2012 by only 2 percent points. Such an uneven raise in the tax rates is the source of exogenous variation used for identification in this paper. As the sample of treated households (exposed to the VAT rise) is much larger than the sample of untreated households (exposed to the IGIC rise), we use causal inference methods to estimate the average treatment effect of the VAT rise on the untreated households. We find that the average household expenditure on cinema and performing arts of the untreated households would not have changed significantly, had untreated households been exposed to the VAT rise. However, this average treatment effect would not have been homogeneous, as we identify an average treatment effect conditional on participation of 52.37 euros. Thus, the tax rise would have increased the annual expenditure of those households that spend on cinema and performing arts regularly. [ABSTRACT FROM AUTHOR]