The no-four-on-circle problem

AbstractErdős and Purdy ask how many points can be chosen from the n × n-grid with no four of them on a circle. They proved a lower bound of n23 − ε. In this note we improve the lower bound to (14 − ε · n

A new policy paradigm from the LSE Maryam Forum: 4. a new path on climate change, oceans and financial risks

COVID recovery packages offer big opportunities to invest in climate and ocean resilience. But for that to happen, the climate emergency needs to be recognised as a threat to financial stability. Swenja Surminski (LSE), Torsten Thiele (LSE), Karina Rodriguez (LSE) and the LSE Maryam Forum Climate Change and Oceans Working Group set out their recommendations. Humanity faces horrendous risks if ... Continue

The common heritage of mankind as a means to assess and advance equity in deep sea mining

A key objective of the United Nations Convention on the Law of the Sea (UNCLOS) as stated in its Preamble, is to contribute to the realisation of a just and equitable international economic order which takes into account the interests and needs of mankind as a whole and, in particular, the special interests and needs of developing countries. As for any other principles of international law, the context within which the principle of the common heritage of mankind (CHM) has been developed is essential to understanding the philosophy behind it, its evolution and more particularly, the challenges faced today for is effective implementation as a means to advance the concept of equity in the context of deep sea mining (DSM mining)

Inclusive innovation : Enhancing global participation in and benefit sharing linked to the utilization of marine genetic resources from areas beyond national jurisdiction

Funding This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement ID: GA 721421 H2020-MSCA-ITN-2016. Declaration of competing interest MJ is founder of, has shares in, and consultant to GyreOx Ltd, a company that uses marine genetic resources from areas within national jurisdiction to develop potential drug molecules. Acknowledgements Many thanks to Arianna Broggiato and Abbe Brown for helpful discussions and comments on the manuscript. Thanks also to the Marie Curie H2020 fund for supporting this research.Peer reviewedPublisher PD

Gold-reinforced silver nanoprisms on optical fiber tapers - A new base for high precision sensing

Due to their unique optical properties, metallic nanoparticles offer a great potential for important applications such as disease diagnostics, demanding highly integrated device solutions with large refractive index sensitivity. Here we introduce a new type of monolithic localized surface plasmon resonance (LSPR) waveguide sensor based on the combination of an adiabatic optical fiber taper and a high-density ensemble of immobilized gold-reinforced silver nanoprisms, showing sensitivities up to 900 nm/RIU. This result represents the highest value reported so far for a fiber optic sensor using the LSPR effect and exceeds the corresponding value of the bulk solution by a factor of two. The plasmonic resonance is efficiently excited via the evanescent field of the propagating taper mode, leading to pronounced transmission dips (−20 dB). The particle density is so high (approx. 210 particle/μm2) that neighboring particles are able to interact, boosting the sensitivity, as confirmed by qualitative infinite element simulations. We additionally introduce a qualitative model explaining the interaction of plasmon resonance and taper mode on the basis of light extinction, allowing extracting key parameters of the plasmonic taper (e.g., modal attenuation). Due to the monolithic design and the extremely high sensitivity we expect our finding to be relevant in fields such as biomedicine, disease diagnostics, and molecular sensing

Klimaschutz durch Meeresnatur

KLIMASCHUTZ DURCH MEERESNATUR Klimaschutz durch Meeresnatur / Röschel, Lina (Rights reserved) ( -

Towards integrated superconducting detectors on lithium niobate waveguides

Superconducting detectors are now well-established tools for low-light optics, and in particular quantum optics, boasting high-efficiency, fast response and low noise. Similarly, lithium niobate is an important platform for integrated optics given its high second-order nonlinearity, used for high-speed electro-optic modulation and polarization conversion, as well as frequency conversion and sources of quantum light. Combining these technologies addresses the requirements for a single platform capable of generating, manipulating and measuring quantum light in many degrees of freedom, in a compact and potentially scalable manner. We will report on progress integrating tungsten transition-edge sensors (TESs) and amorphous tungsten silicide superconducting nanowire single-photon detectors (SNSPDs) on titanium in-diffused lithium niobate waveguides. The travelling-wave design couples the evanescent field from the waveguides into the superconducting absorber. We will report on simulations and measurements of the absorption, which we can characterize at room temperature prior to cooling down the devices. Independently, we show how the detectors respond to flood illumination, normally incident on the devices, demonstrating their functionality.Comment: 7 pages, 4 figure

Financing a sustainable ocean economy

The ocean, which regulates climate and supports vital ecosystem services, is crucial to our Earth system and livelihoods. Yet, it is threatened by anthropogenic pressures and climate change. A healthy ocean that supports a sustainable ocean economy requires adequate financing vehicles that generate, invest, align, and account for financial capital to achieve sustained ocean health and governance. However, the current finance gap is large; we identify key barriers to financing a sustainable ocean economy and suggest how to mitigate them, to incentivize the kind of public and private investments needed for topnotch science and management in support of a sustainable ocean economy