Ecosystems across the globe are vulnerable to the effects of climate change, as are the communities that depend on them. However, ecosystems can also protect people from climate change impacts. As the evidence base strengthens, nature-based solutions (NbS) are increasingly prominent in climate change policy, especially in developing nations. Yet intentions rarely translate into measurable, evidence-based targets. As Paris Agreement signatories revise their Nationally Determined Contributions, we argue that NbS are key to meeting global goals for climate and biodiversity, and we urge researchers to work more closely with policy-makers to identify targets that benefit both people and ecosystems.

Many ecological relationships that are inherently reciprocal are often studied from one perspective only (Agrawal et al. 2007). One example is the interaction between tropical forests and nearctic-neotropical migratory songbirds (hereafter migrants). Several studies have determined that some migrant populations are limited by conditions at their tropical wintering grounds in Central America, South America and the Caribbean (Marra et al. 1998, Mills 2006); however, the ecological role of migrants in these tropical forests is poorly understood.

A simple numerical method is presented for solving the eigenvalue problem which governs the stability of Couette flow. The method is particularly useful in obtaining the eigenfunctions associated with the various modes of instability. When the cylinders rotate in opposite directions, these eigenfunctions exhibit an exponentially damped oscillatory behaviour for sufficiently large values of − μ, where μ = Ω2/Ω1. In terms of the stream function which describes the motion in planes through the axis of the cylinders, this means that weak, viscously driven cells appear in the outer layes of the fluid which, according to Rayleigh's criterion, are dynamically stable. For μ = − 3, for example, four cells are present, the amplitudes of which are in the ratios 1·0:0·0172:0·013:0·00125.

In the present study, we have investigated the viability of using tetrodotoxin (TTX) to induce selective blockade of myelinated fibre conduction in rabbit sural nerve, and explored some aspects of reflexes evoked by non-myelinated sural nerve afferents before and after application of TTX. In rabbits decerebrated under halothane-nitrous oxide anaesthesia, application of 30 nM TTX to the desheathed sural nerve completely blocked Aβ and Aδ waves of the compound action potential evoked by electrical stimulation of the nerve at 95 times threshold. The amplitude of C-fibre volleys evoked by these stimuli was reduced to a mean of 60 % of pre-treatment values. Reflexes evoked in medial gastrocnemius motoneurones by sural nerve stimulation showed corresponding changes after TTX treatment, with activation latency increasing from 5-7 ms in the control state to > 100 ms after TTX application. Temporal summation (wind up) in long latency reflexes (> 100 ms) was significantly enhanced after application of TTX. These data show that low concentrations of TTX can selectively block conduction in rabbit sural nerve A-fibres, providing a method for studying the central actions of non-myelinated C-fibres in isolation. Experimental Physiology (2003) 88.1, 13-18.

We describe detailed studies of ionically self-assembled monolayer (ISAM) photovoltaic (PV) devices incorporating various electron acceptor materials, such as fullerenes and phthalocyanines. Excitons are generated when the conducting polymer is irradiated, and the electron acceptors aid in dissociating the electron/hole pairs before they can radiatively recombine, thus improving the efficiency of the PV process. The ISAM technique allows the deposition of conducting polymer and electron acceptor materials in alternating layers of nanometer-scale thickness. This ensures that every photoexcited electron-hole pair is in proximity to an electron acceptor, thus minimizing electron-hole recombination and increasing the photocurrent. The individual thickness of each monolayer and the interpenetration of adjacent layers can be precisely controlled through the parameters of the electrolyte solutions. Using the ISAM technique, we have demonstrated that it is possible to create ultrathin films (100 nm) of PV material that have enhanced efficiencies.

GaAs layers were grown in recessed silicon trenches for monolithic integration of GaAs and silicon devices. These layers were examined using cathodoluminescence (CL) and transmission electron microscopy (TEM). The CL showed no dependence on distance from the sidewall edge within its limit of resolution. Cross-sectional TEM micrographs showed the GaAs grown on the sidewall to depend on the sidewall orientation. Material grown on the near-{111} sidewalls was comparable to that grown on the well bottom, while the GaAs grown on the near-{110} sidewalls showed poorer crystal quality. A photodetector was fabricated in the recessed GaAs/Si; this device could be easily adapted to a monolithically integrated structure.

Spatial homogeneity of the luminescence and electrical properties of gallium arsenide films grown directly on silicon substrates (GaAs/Si) by molecular beam epitaxy (MBE) have been investigated with microscopic scanning photoluminescence (PL), cathodoluminescence (CL), electron beam induced current (EBIC), and scanning deep level transient spectroscopy (SDLTS). It was found that GaAs/Si exhibits a highly nonuniform lateral distribution of speckled appearance in CL and PL images. These centers are also responsible for short minority carrier lifetimes as determined by EBIC. The observed nonuniformities appear to be a fundamental material property which is not altered by post-growth annealing. Correlations between the luminescence and electrical inhomogeneities and structural defects will be discussed.

Deep electron traps were investigated in MBE GaAs grown directly on Si substrates with orientations a few degrees off the <100> axis. Capacitance Deep Level Transient Spectroscopy (CDLTS) revealed the presence of eleven electron traps in the GaAs epilayer. Their activation energies ranged from 0.21 eV to 0.83 eV below the conduction band. Most of these traps were previously observed in homoepitaxial GaAs films grown under As-rich conditions (VPE, MBE), or in electron irradiated bulk GaAs. Trap concentrations tracked Si dopant density and MBE growth conditions. Observed deep levels are not introduced by metals or other contaminants present at the GaAs-Si interfaces. Rather, they are caused by defect complexes. These complexes involve native point defects, whose formation is favoured by As-rich environments, by lattice mismatch, and by different thermal expansion coefficients. Si dopant atoms may also participate in the formation of these defects. A similar deep level generation mechanism is proposed for the electron traps in homoepitaxial MBE GaAs layers.