601 research outputs found

    Towards the Integrated Management of the Texas Citrus Mite Eutetranychus Banksi (Acari: Tetranychidae) in Spain

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    [ES] El ácaro de Texas, Eutetranychus banksi McGregor, es nativo de América y está ampliamente distribuido por el cultivo de cítricos de este continente. En 2013, esta especie se detectó en el sur de la provincia de Valencia, afectando a la principal zona citrícola de España. El ácaro produce graves daños reduciendo la fotosíntesis, causando defoliación y decoloración de los frutos, lo que podría afectar a su valor económico. En primer lugar, este trabajo evaluó el impacto ecológico producido por la especie invasora sobre las especies de ácaros tetraníquidos residentes en los cítricos valencianos Panonychus citri (McGregor) y Eutetranychus orientalis (Klein). Desde su llegada en 2013, E. banksi se ha convertido en el tetraníquido más frecuente y abundante en cítricos desplazando competitivamente a las otras especies, reduciendo su presencia y distribución geográfica, a su vez influenciada por su historia de colonización. En segundo lugar, este trabajo estudió la distribución dentro del árbol y las tendencias estacionales de la plaga y de los ácaros fitoseidos asociados, que pueden contribuir a su control. El ácaro de Texas se alimentó principalmente en la cara adaxial (haz) de las hojas en la periferia de la copa del árbol, mostrando un único pico de población a finales de verano-principios de otoño, mientras que los fitoseidos prefirieron la cara abaxial (envés) de las hojas del interior de la copa, mostrando dos picos, uno principal en primavera y otro menos abundante en otoño. Euseius stipulatus (Athias-Henriot) fue el fitoseido más frecuente y abundante, y cuando E. banksi aumentó se desplazó a las caras adaxiales de las hojas de la parte exterior de la copa y los frutos para alimentarse de su presa, cambiando su coloración de blanco a marrón rojizo evidenciando su contribución al control biológico de la plaga. Sin embargo, no fue capaz de mantener las poblaciones de E. banksi bajo densidades tolerables debido a la desfavorable relación depredador/presa que existe en verano y principios de otoño. En tercer lugar, este trabajo pretendió describir la estructura de población del ácaro de Texas y definir un plan de muestreo. Existieron diferencias en la estructura de edad en frutos y hojas, así como entre hojas de diferentes brotes. Además, a lo largo del tiempo se observaron fluctuaciones en su composición correlacionadas con variaciones en la proporción de sexos. No se observaron diferencias de agregación entre estratos vegetales, pero sí entre estadios inmaduros y adultos, siendo las hembras las menos agregadas. La alta correlación de la población total con las formas móviles y las hembras permitió utilizar ambas como estadio de referencia para el desarrollo del plan de muestreo, estableciendo un muestreo de presencia/ausencia de 100 hojas para las hembras o 400 hojas para las formas móviles. Finalmente, un ácaro fitoseido recientemente descrito, Neoseiulus madeirensis Papadoulis & Kapaxidi, se encontró asociado a E. banksi, sugiriendo que podría ser un candidato prometedor para su control biológico. En cuarto lugar, este trabajo pretendió evaluar el potencial de este depredador para controlar las poblaciones de la plaga. Neoseiulus madeirensis mostró un rápido desarrollo y altas tasas de supervivencia y reproducción alimentándose de E. banksi. El depredador se alimentó principalmente de estadios inmaduros, siendo los huevos el estadio preferido, y mostrando una respuesta funcional de tipo II para todos los estadios de presa ensayados, que se estabilizó a altas densidades de presa con una elevada puesta de huevos. Los valores de supervivencia, reproducción y depredación han sido los mejores obtenidos hasta el momento para cualquier fitoseido ensayado previamente contra E. banksi, lo convierte en un candidato idóneo para el desarrollo de un programa de control biológico basado en sueltas aumentativas, o en la importación con vistas al establecimiento de poblaciones permanentes en cítricos.[CA] L'àcar de Texas, Eutetranychus banksi McGregor, és nadiu d' Amèrica i està àmpliament distribuït pel cultiu de cítrics d'aquest continent. El 2013, esta espècie es va detectar al sud de la província de València, afectant la principal zona citrícola d'Espanya. L'àcar produeix greus danys reduint la fotosíntesi, causant defoliació i decoloració dels fruits, cosa que podria afectar el seu valor econòmic. En primer lloc, aquest treball va avaluar l'impacte ecològic produït per l'espècie invasora sobre les espècies d'àcars tetraníquids residents als cítrics valencians Panonychus citri (McGregor) i Eutetranychus orientalis (Klein). Des de la seva arribada el 2013, E. banksi s'ha convertit en el tetraníquid més freqüent i abundant en cítrics desplaçant competitivament les altres espècies, reduint la seva presència i distribució geogràfica, alhora influenciat per la seva història de colonització. En segon lloc, aquest treball va estudiar la distribució dins de l'arbre i les tendències estacionals de la plaga i dels àcars fitoseids associats, que poden contribuir al seu control. L'àcar de Texas es va alimentar principalment en la cara adaxial (fes) de les fulles a la perifèria de la copa de l'arbre, mostrant un únic pic de població a finals d'estiu-principis de tardor, mentre que els fitoseids van preferir la cara abaxial (revers) de les fulles de l'interior de la copa, mostrant dos pics, un de principal a la primavera i un altre menys abundant a la tardor. Euseius stipulatus (Athias-Henriot) va ser el fitoseid més freqüent i abundant, i quan E. banksi va augmentar es va desplaçar a les cares adaxials de les fulles de la part exterior de la copa i els fruits per alimentar-se de la presa, canviant la seva coloració de blanc a marró vermellós evidenciant la seva contribució al control biològic de la plaga. Tot i això, no va ser capaç de mantenir les poblacions d'E. banksi sota densitats tolerables a causa de la desfavorable relació depredador/presa que hi ha a l'estiu i principis de tardor. En tercer lloc, aquest treball va voler descriure l'estructura de població de l'àcar de Texas i definir un pla de mostreig. Hi hagué diferències en l'estructura d'edat de fruits i fulles, així com entre fulles de diferents brots. A més, al llarg del temps es van observar fluctuacions en la composició correlacionades amb variacions en la proporció de sexes. No es van observar diferències d'agregació entre estrats vegetals, però sí entre estadis immadurs i adults, sent les femelles les menys agregades. L'alta correlació de la població total amb les formes mòbils i les femelles va permetre utilitzar totes dues com a estadi de referència per al desenvolupament del pla de mostreig, establint un mostreig de presència/absència de 100 fulls per a les femelles o 400 fulls per a les formes mòbils. Finalment, una espècie fitoseid recentment descrit, Neoseiulus madeirensis Papadoulis & Kapaxidi, es va trobar associat a E. banksi, suggerint que podria ser un candidat prometedor per al seu control biològic. En quart lloc, aquest treball va voler avaluar el potencial d'aquest depredador per controlar les poblacions de la plaga. Neoseiulus madeirensis va mostrar un desenvolupament ràpid i altes taxes de supervivència i reproducció alimentant-se d'E. banksi. El depredador es va alimentar principalment d'estadis immadurs, sent els ous l'estadi preferit, i mostrant una resposta funcional de tipus II per a tots els estadis de presa assajats, que es va estabilitzar a altes densitats de presa amb una posta d'ous elevada. Els valors de supervivencia, depredació i reproducció han estat els millors obtinguts fins ara per a qualsevol espècie de fitoseid assajat prèviament contra E. banksi, cosa que el converteix en un candidat idoni per al desenvolupament d'un programa de control biològic basat en soltes augmentatives, o en la importació amb vista a l'establiment de poblacions permanents en cítrics.[EN] The Texas citrus mite, Eutetranychus banksi McGregor, is native to the Americas and widely distributed across this continent. In 2013 it was detected in the south of the province of Valencia, affecting the main citrus-growing area in Spain. The mite produces severe damage, reducing photosynthesis, causing defoliation, and producing a lack in fruit pigmentation, which could affect its economic value. Firstly, this work evaluated the ecological impact produced by the invasive species on the resident spider mites Panonychus citri (McGregor) and Eutetranychus orientalis (Klein). Since its arrival in 2013, E. banksi has become the most frequent and abundant spider mite on citrus, competitively displacing the other species and reducing their presence and geographic range, which is influenced by its colonisation history. Secondly, this work studies the within-tree distribution and seasonal trends of the pest and associated phytoseiid mites, which may contribute to its control. The Texas citrus mite was feeding mainly on the adaxial (upper) side of leaves in the periphery of the tree canopy showing a single population peak in late summer-early autumn, while phytoseiids preferred the abaxial (lower) sides inside the canopy showing two peaks, a main spring peak and a second, less abundant, in autumn. Euseius stipulatus (Athias-Henriot) was the most frequent and abundant phytoseiid, and when E. banksi increased, it moved to the adaxial sides on outer leaves and fruits to feed on its prey and changed its colouring from white to reddish-brown, evidencing its contribution to biological pest control. However, it was not capable of maintaining E. banksi populations under tolerable densities due to the unfavourable predator/prey ratios in summer and early autumn. Thirdly, this work aimed to describe the pest population structure and define a sampling plan. There were differences in the age structure on fruits and leaves, as well as between leaves from different flushes. Furthermore, over time, there were fluctuations in its composition correlated with variations in sex-ratio. No aggregation differences among plant strata were found, but there were significant differences between immature and adult stages, the females being the less aggregated. The high correlation of the total population with the motile forms and females allowed the use of both as a reference stage in the sampling plan, establishing a presence/absence sampling of 100 leaves for females or 400 leaves for motile forms. Finally, a recently described phytoseiid mite, Neoseiulus madeirensis Papadoulis & Kapaxidi, was found to be associated with E. banksi, suggesting that it could be a promising candidate for pest suppression. Fourthly, this work aimed to evaluate the potential of this predator to control pest populations. Neoseiulus madeirensis exhibited a short developmental time, high survival and reproductive rates feeding on E. banksi. The predator was fed mainly on immature stages, with eggs being the preferred stage, showing a type II functional response for all the prey stages tested, that stabilises at high prey densities with high egg laying. Survival, predation and reproduction values were the best obtained so far for any phytoseiid previously tested against E. banksi, making it a suitable candidate for the development of a biological control program based on augmentative releases, or importation aiming for the establishment of permanent populations on citrus.López Olmos, S. (2023). Towards the Integrated Management of the Texas Citrus Mite Eutetranychus Banksi (Acari: Tetranychidae) in Spain [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/20155

    Towards trustworthy computing on untrustworthy hardware

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    Historically, hardware was thought to be inherently secure and trusted due to its obscurity and the isolated nature of its design and manufacturing. In the last two decades, however, hardware trust and security have emerged as pressing issues. Modern day hardware is surrounded by threats manifested mainly in undesired modifications by untrusted parties in its supply chain, unauthorized and pirated selling, injected faults, and system and microarchitectural level attacks. These threats, if realized, are expected to push hardware to abnormal and unexpected behaviour causing real-life damage and significantly undermining our trust in the electronic and computing systems we use in our daily lives and in safety critical applications. A large number of detective and preventive countermeasures have been proposed in literature. It is a fact, however, that our knowledge of potential consequences to real-life threats to hardware trust is lacking given the limited number of real-life reports and the plethora of ways in which hardware trust could be undermined. With this in mind, run-time monitoring of hardware combined with active mitigation of attacks, referred to as trustworthy computing on untrustworthy hardware, is proposed as the last line of defence. This last line of defence allows us to face the issue of live hardware mistrust rather than turning a blind eye to it or being helpless once it occurs. This thesis proposes three different frameworks towards trustworthy computing on untrustworthy hardware. The presented frameworks are adaptable to different applications, independent of the design of the monitored elements, based on autonomous security elements, and are computationally lightweight. The first framework is concerned with explicit violations and breaches of trust at run-time, with an untrustworthy on-chip communication interconnect presented as a potential offender. The framework is based on the guiding principles of component guarding, data tagging, and event verification. The second framework targets hardware elements with inherently variable and unpredictable operational latency and proposes a machine-learning based characterization of these latencies to infer undesired latency extensions or denial of service attacks. The framework is implemented on a DDR3 DRAM after showing its vulnerability to obscured latency extension attacks. The third framework studies the possibility of the deployment of untrustworthy hardware elements in the analog front end, and the consequent integrity issues that might arise at the analog-digital boundary of system on chips. The framework uses machine learning methods and the unique temporal and arithmetic features of signals at this boundary to monitor their integrity and assess their trust level

    Aktuální problémy mezinárodních klimatických vyjednávání

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    Aktuální klimatická vyjednávání na mezinárodní úrovni jsou rámována historickými nespravedlnostmi mezi rozvinutými zeměmi globálního Severu a rozvojovými státy globálního Jihu. Tyto nespravedlnosti pramení z podílu na emisích skleníkových plynů, jež lidstvo vypouští do atmosféry po takřka tři století a jež bezprecedentním způsobem ovlivňují globální klima. Cílem této práce bylo definovat dominantní sféry klimatické spravedlnosti (distributivní, mezigenerační, procesní a uznávací spravedlnost) a jejich prizmatem zanalyzovat dvě globální politiky, jež mají největší potenciál cíle klimatické spravedlnosti naplnit (fond Ztrát a škod a systém emisních povolenek). Protože tomu ale jejich dosavadní nastavení zatím zcela neodpovídá, představuje práce několik doporučení, jež by k vytyčenému cíli mohly přispět.ObhájenoCurrent climate negotiations at the international level are framed by historical injustices between the developed countries of the global North and the developing states of the global South. These inequities stem from the share of greenhouse gas emissions that humanity has been releasing into the atmosphere for nearly three centuries, and which are affecting the global climate in unprecedented ways. The aim of this work was to define the dominant spheres of climate justice (distributive, intergenerational, procedural and recognition justice) and through their prism to analyze two global policies that have the greatest potential to fulfill the goals of climate justice (the Loss and Damage Fund and the emission allowance system). However, since their current settings do not fully correspond to this, the work presents several recommendations that could contribute to the set goal

    Towards a human-centric data economy

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    Spurred by widespread adoption of artificial intelligence and machine learning, “data” is becoming a key production factor, comparable in importance to capital, land, or labour in an increasingly digital economy. In spite of an ever-growing demand for third-party data in the B2B market, firms are generally reluctant to share their information. This is due to the unique characteristics of “data” as an economic good (a freely replicable, non-depletable asset holding a highly combinatorial and context-specific value), which moves digital companies to hoard and protect their “valuable” data assets, and to integrate across the whole value chain seeking to monopolise the provision of innovative services built upon them. As a result, most of those valuable assets still remain unexploited in corporate silos nowadays. This situation is shaping the so-called data economy around a number of champions, and it is hampering the benefits of a global data exchange on a large scale. Some analysts have estimated the potential value of the data economy in US$2.5 trillion globally by 2025. Not surprisingly, unlocking the value of data has become a central policy of the European Union, which also estimated the size of the data economy in 827C billion for the EU27 in the same period. Within the scope of the European Data Strategy, the European Commission is also steering relevant initiatives aimed to identify relevant cross-industry use cases involving different verticals, and to enable sovereign data exchanges to realise them. Among individuals, the massive collection and exploitation of personal data by digital firms in exchange of services, often with little or no consent, has raised a general concern about privacy and data protection. Apart from spurring recent legislative developments in this direction, this concern has raised some voices warning against the unsustainability of the existing digital economics (few digital champions, potential negative impact on employment, growing inequality), some of which propose that people are paid for their data in a sort of worldwide data labour market as a potential solution to this dilemma [114, 115, 155]. From a technical perspective, we are far from having the required technology and algorithms that will enable such a human-centric data economy. Even its scope is still blurry, and the question about the value of data, at least, controversial. Research works from different disciplines have studied the data value chain, different approaches to the value of data, how to price data assets, and novel data marketplace designs. At the same time, complex legal and ethical issues with respect to the data economy have risen around privacy, data protection, and ethical AI practices. In this dissertation, we start by exploring the data value chain and how entities trade data assets over the Internet. We carry out what is, to the best of our understanding, the most thorough survey of commercial data marketplaces. In this work, we have catalogued and characterised ten different business models, including those of personal information management systems, companies born in the wake of recent data protection regulations and aiming at empowering end users to take control of their data. We have also identified the challenges faced by different types of entities, and what kind of solutions and technology they are using to provide their services. Then we present a first of its kind measurement study that sheds light on the prices of data in the market using a novel methodology. We study how ten commercial data marketplaces categorise and classify data assets, and which categories of data command higher prices. We also develop classifiers for comparing data products across different marketplaces, and we study the characteristics of the most valuable data assets and the features that specific vendors use to set the price of their data products. Based on this information and adding data products offered by other 33 data providers, we develop a regression analysis for revealing features that correlate with prices of data products. As a result, we also implement the basic building blocks of a novel data pricing tool capable of providing a hint of the market price of a new data product using as inputs just its metadata. This tool would provide more transparency on the prices of data products in the market, which will help in pricing data assets and in avoiding the inherent price fluctuation of nascent markets. Next we turn to topics related to data marketplace design. Particularly, we study how buyers can select and purchase suitable data for their tasks without requiring a priori access to such data in order to make a purchase decision, and how marketplaces can distribute payoffs for a data transaction combining data of different sources among the corresponding providers, be they individuals or firms. The difficulty of both problems is further exacerbated in a human-centric data economy where buyers have to choose among data of thousands of individuals, and where marketplaces have to distribute payoffs to thousands of people contributing personal data to a specific transaction. Regarding the selection process, we compare different purchase strategies depending on the level of information available to data buyers at the time of making decisions. A first methodological contribution of our work is proposing a data evaluation stage prior to datasets being selected and purchased by buyers in a marketplace. We show that buyers can significantly improve the performance of the purchasing process just by being provided with a measurement of the performance of their models when trained by the marketplace with individual eligible datasets. We design purchase strategies that exploit such functionality and we call the resulting algorithm Try Before You Buy, and our work demonstrates over synthetic and real datasets that it can lead to near-optimal data purchasing with only O(N) instead of the exponential execution time - O(2N) - needed to calculate the optimal purchase. With regards to the payoff distribution problem, we focus on computing the relative value of spatio-temporal datasets combined in marketplaces for predicting transportation demand and travel time in metropolitan areas. Using large datasets of taxi rides from Chicago, Porto and New York we show that the value of data is different for each individual, and cannot be approximated by its volume. Our results reveal that even more complex approaches based on the “leave-one-out” value, are inaccurate. Instead, more complex and acknowledged notions of value from economics and game theory, such as the Shapley value, need to be employed if one wishes to capture the complex effects of mixing different datasets on the accuracy of forecasting algorithms. However, the Shapley value entails serious computational challenges. Its exact calculation requires repetitively training and evaluating every combination of data sources and hence O(N!) or O(2N) computational time, which is unfeasible for complex models or thousands of individuals. Moreover, our work paves the way to new methods of measuring the value of spatio-temporal data. We identify heuristics such as entropy or similarity to the average that show a significant correlation with the Shapley value and therefore can be used to overcome the significant computational challenges posed by Shapley approximation algorithms in this specific context. We conclude with a number of open issues and propose further research directions that leverage the contributions and findings of this dissertation. These include monitoring data transactions to better measure data markets, and complementing market data with actual transaction prices to build a more accurate data pricing tool. A human-centric data economy would also require that the contributions of thousands of individuals to machine learning tasks are calculated daily. For that to be feasible, we need to further optimise the efficiency of data purchasing and payoff calculation processes in data marketplaces. In that direction, we also point to some alternatives to repetitively training and evaluating a model to select data based on Try Before You Buy and approximate the Shapley value. Finally, we discuss the challenges and potential technologies that help with building a federation of standardised data marketplaces. The data economy will develop fast in the upcoming years, and researchers from different disciplines will work together to unlock the value of data and make the most out of it. Maybe the proposal of getting paid for our data and our contribution to the data economy finally flies, or maybe it is other proposals such as the robot tax that are finally used to balance the power between individuals and tech firms in the digital economy. Still, we hope our work sheds light on the value of data, and contributes to making the price of data more transparent and, eventually, to moving towards a human-centric data economy.This work has been supported by IMDEA Networks InstitutePrograma de Doctorado en Ingeniería Telemática por la Universidad Carlos III de MadridPresidente: Georgios Smaragdakis.- Secretario: Ángel Cuevas Rumín.- Vocal: Pablo Rodríguez Rodrígue

    From recreational to income-generating opportunities: assessment of public preferences for non-wood forest products in the Czech Republic

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    With the alarming increase in dying trees and massive logging in the Czech forests due to bark beetle infestation, the collection of non-wood forest products, a beneficial recreational activity in the Czech Republic, is now being promoted as an alternative to wood provisioning services. This paper aims to present findings on the non-wood forest product preferences in the country as part of a baseline assessment for promoting the usage. This study relied on the 2019 national survey data of public preferences in collecting forest berries, mushrooms, honey, and medicinal herbs. K-means cluster analysis was employed to classify the respondents. A binary logistic regression with a conditional forward approach was employed to identify the potential predictors of the high preference for each non-wood forest product. Data from 1,050 online respondents were included, and two groups of respondents were clustered based on their preferences for the entire non-wood forest, i.e., higher and lower utilization. The regression analysis revealed that frequent forest visitors were the primary predictor of high utilization of all non-wood forest products (between 1.437 to 4.579 odd ratios), in addition to age, gender, and location of the forest property. By clustering the respondents based on the high and low preferences in utilizing non-wood forest products, the promotion of this service, from recreational to potential livelihood activities and economic benefits, can be better targeted, e.g., target customer, infrastructure development in the location with high preferences, scenarios based on the type of owners (municipal or private forest owners), which in accordance to the national forest policy and laws, and, at the same time, maintain the ecological stability

    Gestión integrada de las áreas costeras y oceánicas que albergan mamíferos marinos: el caso de estudio del Estrecho de Gibraltar

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    The Strait of Gibraltar is a cross-border coastal and marine area in which overlapping intense maritime traffic and highly protected species of cetaceans could generate conservational or economic conflict. The current publication applies an integrated management approach in order to improve knowledge of cetaceans, maritime activities, and Whale Watching (WW), as well as to involve key stakeholders in WW and to provide insights for a sustainable public policy in the Strait. A comparative study on WW activity in the Strait of Gibraltar and in the Hauraki Gulf, New Zealand, was interrupted due to the COVID-19 pandemic. This abrupt change allowed us to investigate the effects of the human lockdowns, such as the reduction in maritime traffic, on the marine animals of the Gulf, contributing to the study of the global effects on nature. This thesis is organized into the following sections: i) Whale watching activities, ii) monitoring maritime traffic and cetaceans using ferries as platforms and iii) effects of COVID-19 lockdowns on nature. In order to achieve social, economic, and ecological sustainability, WW in the Strait of Gibraltar needs adequate management. In Tarifa (Spain) and Gibraltar (UK), between 2017 and 2019, key stakeholders (e.g., WW customers and operators, researchers, NGOs, and policymakers) were invited to fill out 637 questionnaires and a direct assessment of the WW trips was conducted. Results suggest that: (1) local WW operators only partially follow WW legislation, (2) whale watchers had high levels of education and purchasing power, and the majority of them were national tourists who showed signs of loyalty to WW and support for conservation, (3) 51% of the expenses made by WW customers directly benefited the local economy of Tarifa, (4) customers scored WW operators more highly when cetaceans were indifferent to, or approached vessels, and their satisfaction improved depending on the education provided before and during the WW trip, and (5) interviewed stakeholders recognize the scientific, recreational and educational values of WW. As a result of this study we recommend implementing educational programmes, launching national publicity campaigns targeting whale watchers, establishing administrative facilities for WW companies, monitoring WW activities, and enforcing WW legislation to promote sustainable management of WW. Furthermore, the designation of Marine Protected Areas, a regional shipping plan, and an integrated management approach could benefit the WW industry and improve its sustainability. Cetaceans and their threats were monitored using ferries as a platform of opportunity along the routes Algeciras¿Ceuta and Algeciras-Tanger Med in the Strait during 2018 and 2019, following the standardized protocol of the international cooperative project Fix Line Transect Mediterranean Monitoring Network (FLT Med Net). During 59 visual surveys 264 sightings of cetaceans were reported, including seven species and four near-miss collisions (pilot, sperm, and fin whales). Data were used to i) investigate cetaceans¿ seasonal presence and distribution and, for the bottlenose dolphin, habitat suitability in the Strait, ii) consider cetaceans' relationships with different maritime activities identifying risk areas and the consistency of the spatial conservation spatial management measures in force, and iii) compare data with the other partner of the FLT Med Net across two Habitat Directive 6-year periods (2013-2019/2008-2012), testing four potential indicators to assess short-term range and habitat trends of the Risso¿s dolphin, and of the pilot and Cuvier¿s whale (low-density species). The FLT Med Net sampling design proved adequate for trend assessment in the Western Mediterranean and Adriatic. In conclusion, together with international surveillance, the designation of a micro-sanctuary in the Bay between Algeciras and Gibraltar, and a mandatory speed reduction to 13 knots in an extended Cetacean Critical Navigation Zone can positively optimize conservation efforts in the Strait of Gibraltar. The lockdown due to the COVID-19 pandemic banned all non-essential services and travel both on land and sea in several parts of the world. In response to this sudden drop in traffic, the bigeyes fish and the bottlenose dolphin experienced an immediate increase in their communication ranges by up to 65% in the Hauraki Gulf Marine Park, demonstrating how small vessels can impact underwater soundscapes. These results were shared with the global scientific community to monitor the immediate impacts of lockdowns, demonstrating how humans are both threatening and protecting ecosystems and species. It is possible to favourably tilt this delicate balance by reducing impacts and increasing conservation effectiveness

    Behavior quantification as the missing link between fields: Tools for digital psychiatry and their role in the future of neurobiology

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    The great behavioral heterogeneity observed between individuals with the same psychiatric disorder and even within one individual over time complicates both clinical practice and biomedical research. However, modern technologies are an exciting opportunity to improve behavioral characterization. Existing psychiatry methods that are qualitative or unscalable, such as patient surveys or clinical interviews, can now be collected at a greater capacity and analyzed to produce new quantitative measures. Furthermore, recent capabilities for continuous collection of passive sensor streams, such as phone GPS or smartwatch accelerometer, open avenues of novel questioning that were previously entirely unrealistic. Their temporally dense nature enables a cohesive study of real-time neural and behavioral signals. To develop comprehensive neurobiological models of psychiatric disease, it will be critical to first develop strong methods for behavioral quantification. There is huge potential in what can theoretically be captured by current technologies, but this in itself presents a large computational challenge -- one that will necessitate new data processing tools, new machine learning techniques, and ultimately a shift in how interdisciplinary work is conducted. In my thesis, I detail research projects that take different perspectives on digital psychiatry, subsequently tying ideas together with a concluding discussion on the future of the field. I also provide software infrastructure where relevant, with extensive documentation. Major contributions include scientific arguments and proof of concept results for daily free-form audio journals as an underappreciated psychiatry research datatype, as well as novel stability theorems and pilot empirical success for a proposed multi-area recurrent neural network architecture.Comment: PhD thesis cop

    Human-elephant interactions: exploring conflicts and drivers in enduimet wildlife management area, Tanzania

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    A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyA globally rapid land use/land cover change in human-transformed landscapes alters the interface of human-wildlife interactions due to shifting socio-ecological and environmental pressures. Understanding these shifts is crucial for mitigating repeated negative interactions that escalate conflict states between people and wildlife. This study aimed to understand land use/land cover change changes between1989–2019, with more recent spatio-temporal patterns of high pressure at the human-elephant interface, and potentially underlying environmental and human driven factors that affect elephant movement patterns. The study analyzed a dataset of 923 human-elephant conflict occurrences, mainly crop foraging incidents in the Enduimet between the years 2016 and 2020 and combined these data with land use/land cover change for year 2019 to understand potential drivers of conflict. Furthermore, GPS datasets of elephants collared between 2019 to 2020 used to understand elephant movement patterns in changing land use types. Landsat image study revealed that 41% of the area had been converted into farmlands and settlements within the last three decades, which creates elephant-intolerant habitats and the potential to increase pressure at the human elephant interface. The collared elephants using Enduimet moved through all land use types and did not avoid settlements, although they moved through these at higher speeds, reflecting perception of risk. Elephants travelled slightly more slowly in farmland, likely reflecting the availability of foraging opportunities. Conclusively, communities in land use/land cover change urgently need support to increase the effective distance between their farming activities and the protected areas

    Mountain Lion Resource Selection in the California Central Coast: Modeling Habitat Suitability for a Large Carnivore in a Rapidly Changing Environment

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    Land use conversion toward agriculture such as orchards and vineyards can have severe negative impacts on habitat and wildlife, particularly large carnivores, globally through habitat fragmentation and loss. The mountain lion (Puma concolor) population in the California Central Coast is thought to provide “stepping-stone” connectivity between several severely genetically compromised coastal populations throughout the Santa Cruz Mountains and several mountain ranges in Southern California; however, the California Central Coast is one of the fastest-developing regions of California with little protection against future land use conversion. Conserving areas of and corridors between high-quality mountain lion habitat through conservation easements should be prioritized. Our results showed that this is especially important in areas currently zoned for agriculture and residential but not fully developed yet. Conserving quality habitat is not only beneficial to mountain lions, but also many species underneath their ecological “umbrella.” In my first chapter, I performed a literature review detailing what ecologists currently understand about human impacts on wildlife, with an emphasis on large carnivores, through habitat fragmentation and loss, land conversion, and human-carnivore conflict. I also reflected on mountain lion ecology and management in California and North America as a whole, before reviewing analytical methods most commonly used to study their home ranges and resource selection. In my second chapter, I used GPS collar data from seven GPS-collared mountain lions on the Fort Hunter Liggett Army Base in Monterey County, California to compare minimum convex polygon, kernel density isopleth, and adaptive-local convex hull methods to elucidate the strengths and weaknesses of each when estimating wildlife home ranges and utilization distributions. Following this, I used the GPS data to create a resource selection function to model predicted resource selection patterns of the mountain lions on the Army Base before projecting my model out to the counties comprising the greater California Central Coast. I then overlaid this habitat suitability map with zoning and land protection status maps from each county. My results provide a clear visual representation of not only mountain lion habitat suitability throughout the Central Coast, but areas wildlife and land managers should prioritize for conservation in relation to adjacent areas of varying zoning and protection statuses
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