588 research outputs found

    EvoluciĂłn de las ciencias en la RepĂșblica Argentina : VIII. GeofĂ­sica y Geodesia

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    El tomo dedicado a la GeofĂ­sica y a la Geodesia lleva el nĂșmero ocho dentro de la ColecciĂłn EvoluciĂłn de las Ciencias en la RepĂșblica Argentina 1923-1972. En la ColecciĂłn que abarcĂł el perĂ­odo 1872-1922 ni la geofĂ­sica la geodesia contaron con un volumen especialmente dedicado a ellas. El vertiginoso avance de los conocimientos, y su cantidad, registra en los Ășltimos cincuenta años, hizo aconsejable otorgarles uno de dos libros en la presente colecciĂłn, ademĂĄs de desdoblar en otros volĂșmenes, para mantener la homogeneidad con la anterior, tĂłpicos que evidentemente se relacionan con la fĂ­sica de nuestro planeta. En el presente tomo, al igual de lo anotado en los dedicados a las demĂĄs disciplinas, se pone de relieve la intensa e inteligente labor de los investigadores argentinos.Material digitalizado en SEDICI gracias a la colaboraciĂłn de la Biblioteca de la Facultad de Ciencias AstronĂłmicas y GeofĂ­sicas (UNLP).Sociedad CientĂ­fica Argentin

    TriHex: combining formation flying, general circular orbits and alias-free imaging, for high resolution L-band aperture synthesis

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    The Soil Moisture and Ocean Salinity (SMOS) mission of the European Space Agency (ESA), together with NASA’s Soil Moisture Active Passive (SMAP) mission, is providing a wealth of information to the user community for a wide range of applications. Although both missions are still operational, they have significantly exceeded their design life time. For this reason, ESA is looking at future mission concepts, which would adequately address the requirements of the passive L-band community beyond SMOS and SMAP. This article proposes one mission concept, TriHex, which has been found capable of achieving high spatial resolution, radiometric resolution, and accuracy, approaching the user needs. This is possible by the combination of aperture synthesis, formation flying, the use of general circular orbits, and alias-free imaging.Peer ReviewedPostprint (author's final draft

    EuroGOOS roadmap for operational coastal downstream services

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    The EuroGOOS Coastal working group examines the entire coastal value chain from coastal observations to services for coastal users. The main objective of the working group is to review the status quo, identify gaps and future steps needed to secure and improve the sustainability of the European coastal service provision. Within this framework, our white paper defines a EuroGOOS roadmap for sustained “community coastal downstream service” provision, provided by a broad EuroGOOS community with focus on the national and local scale services. After defining the coastal services in this context, we describe the main components of coastal service provision and explore community benefits and requirements through sectoral examples (aquaculture, coastal tourism, renewable energy, port, cross-sectoral) together with the main challenges and barriers to user uptake. Technology integration challenges are outlined with respect to multiparameter observations, multi-platform observations, the land-coast-ocean continuum, and multidisciplinary data integration. Finally, the technological, financial, and institutional sustainability of coastal observing and coastal service provision are discussed. The paper gives special attention to the delineation of upstream and downstream services, public-private partnerships and the important role of Copernicus in better covering the coastal zone. Therefore, our white paper is a policy and practice review providing a comprehensive overview, in-depth discussion and actionable recommendations (according to key short-term or medium-term priorities) on the envisaged elements of a roadmap for sustained coastal service provision. EuroGOOS, as an entity that unites European national operational oceanography centres, research institutes and scientists across various domains within the broader field of operational oceanography, offers to be the engine and intermediary for the knowledge transfer and communication of experiences, best practices and information, not only amongst its members, but also amongst the different (research) infrastructures, institutes and agencies that have interests in coastal oceanography in Europe

    BDS GNSS for Earth Observation

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    For millennia, human communities have wondered about the possibility of observing phenomena in their surroundings, and in particular those affecting the Earth on which they live. More generally, it can be conceptually defined as Earth observation (EO) and is the collection of information about the biological, chemical and physical systems of planet Earth. It can be undertaken through sensors in direct contact with the ground or airborne platforms (such as weather balloons and stations) or remote-sensing technologies. However, the definition of EO has only become significant in the last 50 years, since it has been possible to send artificial satellites out of Earth’s orbit. Referring strictly to civil applications, satellites of this type were initially designed to provide satellite images; later, their purpose expanded to include the study of information on land characteristics, growing vegetation, crops, and environmental pollution. The data collected are used for several purposes, including the identification of natural resources and the production of accurate cartography. Satellite observations can cover the land, the atmosphere, and the oceans. Remote-sensing satellites may be equipped with passive instrumentation such as infrared or cameras for imaging the visible or active instrumentation such as radar. Generally, such satellites are non-geostationary satellites, i.e., they move at a certain speed along orbits inclined with respect to the Earth’s equatorial plane, often in polar orbit, at low or medium altitude, Low Earth Orbit (LEO) and Medium Earth Orbit (MEO), thus covering the entire Earth’s surface in a certain scan time (properly called ’temporal resolution’), i.e., in a certain number of orbits around the Earth. The first remote-sensing satellites were the American NASA/USGS Landsat Program; subsequently, the European: ENVISAT (ENVironmental SATellite), ERS (European Remote-Sensing satellite), RapidEye, the French SPOT (Satellite Pour l’Observation de laTerre), and the Canadian RADARSAT satellites were launched. The IKONOS, QuickBird, and GeoEye-1 satellites were dedicated to cartography. The WorldView-1 and WorldView-2 satellites and the COSMO-SkyMed system are more recent. The latest generation are the low payloads called Small Satellites, e.g., the Chinese BuFeng-1 and Fengyun-3 series. Also, Global Navigation Satellite Systems (GNSSs) have captured the attention of researchers worldwide for a multitude of Earth monitoring and exploration applications. On the other hand, over the past 40 years, GNSSs have become an essential part of many human activities. As is widely noted, there are currently four fully operational GNSSs; two of these were developed for military purposes (American NAVstar GPS and Russian GLONASS), whilst two others were developed for civil purposes such as the Chinese BeiDou satellite navigation system (BDS) and the European Galileo. In addition, many other regional GNSSs, such as the South Korean Regional Positioning System (KPS), the Japanese quasi-zenital satellite system (QZSS), and the Indian Regional Navigation Satellite System (IRNSS/NavIC), will become available in the next few years, which will have enormous potential for scientific applications and geomatics professionals. In addition to their traditional role of providing global positioning, navigation, and timing (PNT) information, GNSS navigation signals are now being used in new and innovative ways. Across the globe, new fields of scientific study are opening up to examine how signals can provide information about the characteristics of the atmosphere and even the surfaces from which they are reflected before being collected by a receiver. EO researchers monitor global environmental systems using in situ and remote monitoring tools. Their findings provide tools to support decision makers in various areas of interest, from security to the natural environment. GNSS signals are considered an important new source of information because they are a free, real-time, and globally available resource for the EO community

    Preventing Violence Against Women: Emerging Practices of Canadian Activism through Social Media

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    The Canadian women’s movement has seen a recent surge in attention and participation. In a rising cycle of contention, broad collective action campaigns can appear as a single social movement. This research uses a comparative case study to examine three cases of varying scale through the causal mechanisms of signaling, innovation, and campaigns/coalitions to examine how social media contribute to the emerging repertoire of contention. The three cases under investigation are a localized case: Safe Stampede, a national case: Missing and Murdered Indigenous Women, and a transnational case: Women’s March on Washington. Results show that social media are not only integral to collective action but also influence the nature of many emerging practices. Organizers utilize personalized participation and localization, favoring tactics that improve visual imagery for social media posts. In outreach efforts, they rely on the scale of social media to connect with influencers, traditional media, and conscience constituents through affordances such as hashtags and addressivity markers. The affordances of social media encourage tactics designed to generate viral content and to leverage shame as a motivator for change. A sense of duty spurs organizers and participants to greater action beyond what might be termed clicktivism. Whether a campaign targets only the local community or a global one, organizers seek to localize their message for regional supporters. In all cases, ideological differences must be resolved in order to maintain solidarity and prevent damaging divides. As social movements progress, they tend to follow predictable patterns toward institutionalization, especially as a cycle of contention begins to recede

    Ice Sheet and Sea Ice Ultrawideband Microwave radiometric Airborne eXperiment (ISSIUMAX) in Antarctica: first results from Terra Nova Bay

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    An airborne microwave wide-band radiometer (500–2000 MHz) was operated for the first time in Antarctica to better understand the emission properties of sea ice, outlet glaciers and the interior ice sheet from Terra Nova Bay to Dome C. The different glaciological regimes were revealed to exhibit unique spectral signatures in this portion of the microwave spectrum. Generally, the brightness temperatures over a vertically homogeneous ice sheet are warmest at the lowest frequencies, consistent with models that predict that those channels sensed the deeper, warmer parts of the ice sheet. Vertical heterogeneities in the ice property profiles can alter this basic interpretation of the signal. Spectra along the lengths of outlet glaciers were modulated by the deposition and erosion of snow, driven by strong katabatic winds. Similar to previous experiments in Greenland, the brightness temperatures across the frequency band were low in crevasse areas. Variations in brightness temperature were consistent with spatial changes in sea ice type identified in satellite imagery and in situ ground-penetrating radar data. The results contribute to a better understanding of the utility of microwave wide-band radiometry for cryospheric studies and also advance knowledge of the important physics underlying existing L-band radiometers operating in space.</p

    The path of the law : the establishment, abolition and remedy of involuntary sterilisation and castration in Sweden, Norway and Finland

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    Defence date: 13 May 2019Examining Board: Professor Ruth Rubio-Marín, University of Seville & European University Institute (Supervisor); Professor Laura Downs, European University Institute; Professor Anne Hellum, University of Oslo; Professor Dinah Shelton, The George Washington UniversityInvoluntary sterilisation and castration, narrowly problematised at the Nuremberg trials, were long topics incoherently regulated by international law. A supranational conceptual and remedial framework, mainly pertaining to human rights, is only recently emerging regarding the practices. Against this background, the thesis takes a closer look at Sweden, Norway and Finland, three Nordic countries that established similar sterilisation and castration laws and/or administrative regulations during the last century. The regulations have built on state control and allowed for interventions against the will of the targeted individuals. The targeted groups have been heterogeneous but can generally be divided into three subgroups: poor and marginalised women (1930s–1970s), sexual offenders and ‘deviants’ (1930s–1970s) and trans people (1970s–today). While the majority of the practices have been abolished, the three otherwise similar states have legally conceptualised said practices very differently, particularly in terms of state responsibility and remedies for victims. The thesis looks deeper into these differences and draws on legal mobilisation and social movement theory, particularly grievance formation with reference to rights. The thesis engages in doctrinal, legal-historical, socio-legal and comparative modes of analysis. Doing so, it investigates five legal and extra-legal factors to understand the differences between the countries of comparison: i) rights culture; ii) remedial and public liability culture; iii) victim mobilisation; iv) perception of victims and mass media attention; and v) public image and political party alliances. These factors have affected the unfolding of the establishment, abolition and remedy of involuntary sterilisation and castration in Sweden, Norway and Finland – practices sometimes referred to as the ‘skeleton in the closet’ of the Nordic welfare states

    Democracy promotion and presidential term limits

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    The end of the Cold War saw an unprecedented diffusion of democracy. This diffusion went hand in hand with the emergence of international democracy promotion. Through democracy promotion, democratic states attempt to support and protect democratic institutions around the world by means of bilateral and multilateral international cooperation as well as development cooperation. Yet, the 'wave of democratization' has ebbed away since the Cold War. Rather than an anabated spread of democracy, many countries that seemed on a transition-path to democracy are now stuck in a political state between autocracy and democracy, where democratic institutions formally exist but are compromised by authoritarian practices. Moreover, populist movements, illiberalism, and non-democratic institutional changes seem to challenge democracy as a political system even in countries where it was long since regarded as historically and socially consolidated. This as well as the increasing confidence of authoritarian regimes threaten to jeopardize the strides that worldwide democratization has made in the past three decades. Against this setting, the present thesis investigates the effectiveness of international democracy promotion in supporting and guarding the democratic institutionalization of political power. The research presented here zooms in on presidential term limits, a political institution meant to prevent the personalization of political power and ensure rotation in presidential office. While it was characteristic for countries, particularly in sub-Saharan Africa, that began transitioning to democracy at the end of the Cold War to introduce presidential term limits in their newly designed constitutions, many of these provisions have since been challenged by incumbent presidents. Research shows that the evasion of term limits is associated with a worsening of the general state of democracy in a country. Evasion of presidential term limits is thus seen as an important manifestation for the weak institutionalization and further de-institutionalization of democracy. Although presidential term limits and in particular their circumvention have hence become a subject matter of interest to political scientists, many scholars do not focus in this regard explicitly on the role of international democracy support. I address this gap by studying the influence that international democracy promotion has on the evasion and introduction of presidential term limits. The first chapter provides a conceptual and theoretical introduction to presidential term limits and their relation to the weak institutionalization of democracy. Democracy promotion and the different forms it may take is also introduced before a brief outlook on the thesis is presented. In chapter two my co-author and I present a broad perspective on how democracy aid, which is the implementation of democracy promotion as foreign aid in development cooperation, is associated with the risk that presidents attempt to evade term limits as well as that they actually succeed in doing so. In chapter three, my co-author and I undertake a qualitative paired comparison of two cases where incumbent presidents attempted to circumvent a term limit but failed at different stages during the process. We compare the role that different means, or 'instruments' of democracy promotion played in both cases and how their effectiveness was predicated on favourable domestic conditions, particularly popular pro-democratic attitudes. In chapter four, I provide an 'in-depth' description of one of the two cases. The chapter employs a qualitative methodology designed to trace closely the influence of different factors for an outcome. I make use of this by systematically assessing how different democracy promotion instruments acted alone and in conjunction with domestic factors on the case's outcome. Finally, chapter five shifts the focus from the evasion of term limits to the introduction of term limits. Interested in the 'on-the-ground' practice of democracy promotion during ad hoc emerging reform episodes, I study the interactions between on the one hand domestic civil society and political opposition parties and on the other hand external embassies and international organizations. The research results show that international democracy promotion often has a limited, conditional influence on preventing the de-institutionalization of democracy. While it is evident according to a presented statistical analysis that democracy promotion through foreign aid is associated with lower risks of term limit evasions, this relation is substantial in effect size only for medium to high \emph{per capita}-amounts of democracy aid. Furthermore, results of the qualitative case studies show that democracy promotion operates through largely two mechanisms, a 'hard power' mechanism functioning according to a logic of consequentiality, conditionality, and leverage; and a 'soft power' mechanism functioning according to a logic of appropriateness and linkage. However, both work best in tandem, and are predicated on domestic conditions, particularly on favourable popular (pro-)democratic attitudes and a civil society that is free to mobilize. Finally, the research presented here also emphasizes the quandaries to which democracy promoters themselves are subject, especially when they need to respond ad hoc to a push for political liberalization in an hitherto (semi-)authoritarian country context. The thesis contributes to two interescting research fields, one on the evasion of presidential term limits, and the other on the role that international democracy support can play in preserving and promoting democratic institutions. Its results suggest policy implications particularly for the practice and implementation of democracy promotion. Foremost among these are that the level of spending of democracy aid in development cooperation as well as its temporal continuation can have substantial effects on guarding democratic institutions (chapter two); that 'hard power' and 'soft power' approaches of democracy promotion need to be used wisely in complementarity to one another (chapter three and four); that foreign states and international organizations need to react decisively against the curbing of the civic space, and also need to defend institutions integral to 'democracy as democracy' against transgressions and violations (chapters three to five); and finally, that democracy supporters, particularly foreign governments as democracy supporters, need to critically reflect on self-imposed internal restraints besides encountered external constraints in the practice of international democracy promotion
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