Derivative corrections to the Born-Infeld action through beta-function calculations in N=2 boundary superspace

We calculate the beta-functions for an open string sigma-model in the presence of a U(1) background. Passing to N=2 boundary superspace, in which the background is fully characterized by a scalar potential, significantly facilitates the calculation. Performing the calculation through three loops yields the equations of motion up to five derivatives on the fieldstrengths, which upon integration gives the bosonic sector of the effective action for a single D-brane in trivial bulk background fields through four derivatives and to all orders in alpha'. Finally, the present calculation shows that demanding ultra-violet finiteness of the non-linear sigma-model can be reformulated as the requirement that the background is a deformed stable holomorphic U(1) bundle.Comment: 25 pages, numerous figure

Confusing the extragalactic neutrino flux limit with a neutrino propagation limit

We study the possible suppression of the extragalactic neutrino flux due to a nonstandard interaction during its propagation. In particular, we study neutrino interaction with an ultra-light scalar field dark matter. It is shown that the extragalactic neutrino flux may be suppressed by such an interaction, leading to a new mechanism to reduce the ultra-high energy neutrino flux. We study both the cases of non-self-conjugate as well as self-conjugate dark matter. In the first case, the suppression is independent of the neutrino and dark matter masses. We conclude that care must be taken when explaining limits on the neutrino flux through source acceleration mechanisms only, since there could be other mechanisms for the reduction of the neutrino flux.Comment: 15 pages, 4 figures. Important changes implemented. Abstract modified. Conclusions remain. To be published in JCA

Natura Alert: Monitoring biodiversity threats using citizen science

Since the late 1970s, the BirdLife Partnership has been working collectively to identify, document and protect places on the Earth with the greatest significance for the conservation of the world’s birds. As a result, over 13,000 Important Bird and Biodiversity Areas (IBAs) have been identified. However, we lack comprehensive monitoring of the condition of these sites, with an increasing number of IBAs under threat from damaging development – the majority of which appears to be poorly planned and does not take environmental values into account. Sites face a wide range of problems, which require an equally wide range of solutions. To address this problem, Natura Alert has been developed within the Horizon 2020-funded LandSense Citizen Observatory project. Natura Alert is a mobile app and web portal that allows users to pinpoint the location of threats to biodiversity and habitat changes, to prevent the further damage or loss to our biodiversity. We are particularly interested in threats that are occurring inside IBAs, Key Biodiversity Areas (KBAs) and Natura 2000 sites in the European Union, although submitting records in other areas is also possible. Information on the condition of these sites, the threats to them, the conservation measures in place and the changes in these aspects over time are essential to set priorities, hold governments to account and inform policies and decision-makers. Volunteers can share their observations with the wider community and help to map the state of our most valuable sites around the world. They can download our mobile app to quickly record their observations in the field or use the web app to discover more functionalities, such as visualizing reports from other users, creating dashboards per country and downloading their own reports. Natura Alert is being tested in Spain and Indonesia, thanks to the volunteer network of two BirdLife partners: SEO/BirdLife and Burung. While the Spanish volunteers are focusing on threats to birds and habitats within IBAs and Natura 2000 sites, the Indonesian communities are validating alerts from satellite-image analysis for forest change on Flores island. Citizen observations trigger real-time alerts to national and regional IBA/KBA coordinators at BirdLife International, who will ensure that the data are of high quality and produce regional and global monitoring assessments that could help monitor the indicators of the Sustainable Development Goals (SDGs) and the Convention on Biological Diversity (CBD). Also, researchers and practitioners around the globe can benefit from this type of data, as well as institutions and stakeholders from the private sector willing to make better decisions based on high quality data via the Integrated Biodiversity Assessment Tool (IBAT)

Natura Alert: Monitoring biodiversity threats using citizen science

Since the late 1970s, the BirdLife Partnership has been working collectively to identify, document and protect places on the Earth with the greatest significance for the conservation of the world’s birds. As a result, over 13,000 Important Bird and Biodiversity Areas (IBAs) have been identified. However, we lack comprehensive monitoring of the condition of these sites, with an increasing number of IBAs under threat from damaging development – the majority of which appears to be poorly planned and does not take environmental values into account. Sites face a wide range of problems, which require an equally wide range of solutions. To address this problem, Natura Alert has been developed within the Horizon 2020-funded LandSense Citizen Observatory project. Natura Alert is a mobile app and web portal that allows users to pinpoint the location of threats to biodiversity and habitat changes, to prevent the further damage or loss to our biodiversity. We are particularly interested in threats that are occurring inside IBAs, Key Biodiversity Areas (KBAs) and Natura 2000 sites in the European Union, although submitting records in other areas is also possible. Information on the condition of these sites, the threats to them, the conservation measures in place and the changes in these aspects over time are essential to set priorities, hold governments to account and inform policies and decision-makers. Volunteers can share their observations with the wider community and help to map the state of our most valuable sites around the world. They can download our mobile app to quickly record their observations in the field or use the web app to discover more functionalities, such as visualizing reports from other users, creating dashboards per country and downloading their own reports. Natura Alert is being tested in Spain and Indonesia, thanks to the volunteer network of two BirdLife partners: SEO/BirdLife and Burung. While the Spanish volunteers are focusing on threats to birds and habitats within IBAs and Natura 2000 sites, the Indonesian communities are validating alerts from satellite-image analysis for forest change on Flores island. Citizen observations trigger real-time alerts to national and regional IBA/KBA coordinators at BirdLife International, who will ensure that the data are of high quality and produce regional and global monitoring assessments that could help monitor the indicators of the Sustainable Development Goals (SDGs) and the Convention on Biological Diversity (CBD). Also, researchers and practitioners around the globe can benefit from this type of data, as well as institutions and stakeholders from the private sector willing to make better decisions based on high quality data via the Integrated Biodiversity Assessment Tool (IBAT)

Spectra of PP-Wave Limits of M-/Superstring Theory on AdS_p x S^q Spaces

In this paper we show how one can obtain very simply the spectra of the PP-wave limits of M-theory over AdS_7(4) x S^4(7) spaces and IIB superstring theory over AdS_5 x S^5 from the oscillator construction of the Kaluza-Klein spectra of these theories over the corresponding spaces. The PP-wave symmetry superalgebras are obtained by taking the number P of ``colors'' of oscillators to be large (infinite). In this large P limit, the symmetry superalgebra osp(8*|4) of AdS_7 x S^4 and the symmetry superalgebra osp(8|4,R) of AdS_4 x S^7 lead to isomorphic PP-wave algebras, which is the semi-direct sum of su(4|2) with H^(18,16), while the symmetry superalgebra su(2,2|4) of AdS_5 x S^5 leads to the semi-direct sum of [psu(2|2) + psu(2|2) + u(1)] with H^(16,16) as its PP-wave algebra [H^(m,n) denoting a super-Heisenberg algebra with m bosonic and n fermionic generators]. The zero mode spectra of M-theory or IIB superstring theory in the PP-wave limit corresponds simply to the unitary positive energy representations of these algebras whose lowest weight vector is the Fock vacuum of all the oscillators. General positive energy supermultiplets including those corresponding to higher modes can similarly be constructed by the oscillator method.Comment: Typos corrected; references added; minor modifications to improve presentation; 37 pages, LaTeX fil

Capturing and communicating impact of citizen science for policy: A storytelling approach

In response to the need for approaches to understand how citizen science is currently influencing environmental policy and associated decision making, we devised the Citizen Science Impact StoryTelling Approach (CSISTA). We iteratively designed instruments to be used as tools primarily for citizen science practitioners seeking to understand or communicate policy impacts. We then trialled the CSISTA and associated instruments on four exemplary citizen science initiatives, using different forms of inquiry and collaboration with respective initiative leaders. In this paper, we present CSISTA, with details of the steps for implementing inquiry and storytelling instruments. Additionally, we reflect on insights gained and challenges encountered implementing the approach. Overall, we found the versatility and structure of CSISTA as a process with multiple guiding instruments useful. We envision the approach being helpful, particularly with regards to: 1) gaining an understanding of a citizen science initiative's policy and decision-making impacts; 2) creating short policy impact stories to communicate such impacts to broader audiences; or 3) fulfilling both goals to understand and communicate policy impacts with a unified approach. We encourage others to explore, adapt, and improve the approach. Additionally, we hope that explorations of CSISTA will foster broader discussions on how to understand and strengthen interactions between citizen science practitioners, policy makers, and decision makers at large, whether at local, national, or international scales

Role of chaos for the validity of statistical mechanics laws: diffusion and conduction

Several years after the pioneering work by Fermi Pasta and Ulam, fundamental questions about the link between dynamical and statistical properties remain still open in modern statistical mechanics. Particularly controversial is the role of deterministic chaos for the validity and consistency of statistical approaches. This contribution reexamines such a debated issue taking inspiration from the problem of diffusion and heat conduction in deterministic systems. Is microscopic chaos a necessary ingredient to observe such macroscopic phenomena?Comment: Latex, 27 pages, 10 eps-figures. Proceedings of the Conference "FPU 50 years since" Rome 7-8 May 200

Reinforcement learning for clinical decision support in critical care: Comprehensive review

10.2196/18477Journal of Medical Internet Research227e1847