Arthropod communities in a changing world: combined impacts of climate change and land-use intensification on arthropod communities

Global change poses increasing threats to ecological communities and ecosystem functioning. To improve our understanding of how arthropod communities, and associated ecosystem functions respond to combined impacts of future climate change and land-use intensification in grassland ecosystems, I used the experimental set-up of the Global Change Experimental Facility (GCEF). In my first chapter, I studied the combined effects of climate change and land-use intensity on arthropod community composition at the whole community level and of four trophic groups (predators, herbivores, detritivores and omnivores). I found that climate change and land-use intensification simultaneously shift species composition across trophic levels, through changes in abundance, species richness, and evenness. In my second chapter, I present a comprehensive set of linear regressions to estimate live body mass using data on body length and width, taxonomy and geographic origin. Furthermore, I quantified prediction discrepancy when using parameters from arthropods of a different geographic region. Incorporating body width into taxon- and region-specific length-mass regressions substantially increased prediction accuracy for live body mass. In my third research chapter, I studied the impacts of future climate change and land-use intensification on ecosystem functioning and the stability of arthropod food-webs. I furthermore studied the response of underlying community characteristics driving these ecosystem processes. Specifically, I tested the response of mean body mass, biomass and community metabolism of the whole community and four trophic groups to climate change and land-use intensification. Despite changes in community characteristics of the trophic groups, community ecosystem processes and food-web stability remained stable under climate change and land-use intensification, while the composition of total ecosystem processes changed

The Final Hurdle?: Security of supply, the Capacity Mechanism and the role of interconnectors

The UK Government has developed a carefully designed Capacity Mechanism to ensure security of supply in the GB electricity system. This paper criticises the methods used to determine the amount of capacity to procure, and argues that the amount finally proposed is likely to be excessive, particularly (but not exclusively) in ignoring the contribution from interconnectors. More broadly, there has been too little attention to either the political economy, or the option value aspects. Procuring too little is risky, but fear of'the lights going out' can easily become a catch-all argument for excessive procurement, and associated subsidy. The risk of over-procurement, particularly of new capacity on long-term contracts, is that it drives up the costs to consumers; undermines renewable energy by transferring capped resources from renewable to fossil fuel producers; and impedes the Single Market including by weakening the business case for future interconnectors. The paper argues that the development of technologies and markets, particularly on the demand- side and of potentially available – 'latent' – capacity - further lowers the risks and increases options. This implies greater potential to defer more capacity procurement – and enhances the value of a more appropriate treatment of interconnectors in security assessments

Real-time label-free biosensing with integrated planar waveguide ring resonators

We review the use of planar integrated optical waveguide ring resonators for label free bio-sensing and present recent results from two European biosensor collaborations: SABIO and InTopSens. Planar waveguide ring resonators are attractive for label-free biosensing due to their small footprint, high Q-factors, and compatibility with on-chip optics and microfluidics. This enables integrated sensor arrays for compact labs-on-chip. One application of label-free sensor arrays is for point-of-care medical diagnostics. Bringing such powerful tools to the single medical practitioner is an important step towards personalized medicine, but requires addressing a number of issues: improving limit of detection, managing the influence of temperature, parallelization of the measurement for higher throughput and on-chip referencing, efficient light-coupling strategies to simplify alignment, and packaging of the optical chip and integration with microfluidics. From the SABIO project we report refractive index measurement and label-free biosensing in an 8-channel slotwaveguide ring resonator sensor array, within a compact cartridge with integrated microfluidics. The sensors show a volume sensing detection limit of 5 × 10-6 RIU and a surface sensing detection limit of 0.9 pg/mm2. From the InTopSens project we report early results on silicon-on-insulator racetrack resonators

Vertical multiple-slot waveguide ring resonators in silicon nitride

This article describes the first demonstration of ring resonators based on vertical multiple-slot silicon nitride waveguides. The design, fabrication and measurement of multiple-slot waveguide ring resonators with several coupling distances and ring radii (70 μm, 90 μm and 110 μm) have been carried out for TE and TM polarizations at the wavelength of 1.3 μm. Quality factors of 6,100 and 16,000 have been achieved for TE and TM polarization, respectively

High quality optical microring resonators in Si3N 4/SiO2

We have experimentally demonstrated high Q-factors strip waveguide resonators using the Si3N4/SiO2 material platform at the wavelength of 1.31μm. The analyzed filters demonstrate high quality factors reaching 133,000. The dependence on resonator radii and coupling gap is also discussed

Оценка ультразвукового исследования в диагностике патологии эндометрия в постменопаузе

ЭНДОМЕТРИЙПАТОЛОГИЯПОСТМЕНОПАУЗАУЛЬТРАСОНОГРАФИ

Label-free optical biosensing with slot-waveguides.

We demonstrate label-free molecule detection by using an integrated biosensor based on a Si3N4 /SiO2 slotwaveguide microring resonator. Bovine serum albumin (BSA) and anti-BSA molecular binding events on the sensor surface are monitored through the measurement of resonant wavelength shifts with varying biomolecule concentrations. The biosensor exhibited sensitivities of 1.8 and 3.2 nm/ _ng/mm2_ for the detection of anti-BSA and BSA, respectively. The estimated detection limits are 28 and 16 pg/mm2 for anti-BSA and BSA, respectively, limited by wavelength resolutio

High efficiency silicon nitride surface grating couplers

High efficiency surface grating couplers for silicon nitride waveguides have been designed, fabricated, and characterized. Coupling efficiencies exceeding 60 % are reported at a wavelength of 1.31 μm, as well as angular and wavelength -3 dB tolerances of 4° and 50 nm, respectively. When the wavelength is increased from 1310 nm to 1450 nm the coupling efficiency progressively decreases but remains above 20 % at 1450 nm. The influence of the duty ratio of the grating has also been investigated: maximum coupling efficiency was obtained at 50 % duty ratio

Light coupling and distribution for Si3N4/SiO2 integrated multichannel single-mode sensing system

We present an efficient and highly alignment-tolerant light coupling and distribution system for a multichannel Si3 N4 /Si O 2 single-mode photonics sensing chip. The design of the input and output couplers and the distribution splitters is discussed. Examples of multichannel data obtained with the system are given