Quantum M\"{u}nchhausen effect in tunneling

It is demonstrated that radiative corrections increase tunneling probability of a charged particle

Tunable Lyapunov exponent in inverse magnetic billiards

The stability properties of the classical trajectories of charged particles are investigated in a two dimensional stadium-shaped inverse magnetic domain, where the magnetic field is zero inside the stadium domain and constant outside. In the case of infinite magnetic field the dynamics of the system is the same as in the Bunimovich billiard, i.e., ergodic and mixing. However, for weaker magnetic fields the phase space becomes mixed and the chaotic part gradually shrinks. The numerical measurements of the Lyapunov exponent (performed with a novel method) and the integrable/chaotic phase space volume ratio show that both quantities can be smoothly tuned by varying the external magnetic field. A possible experimental realization of the arrangement is also discussed.Comment: 4 pages, 6 figure

Measuring Terrestrial Area of Habitat (AOH) and Its Utility for the IUCN Red List

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species includes assessment of extinction risk for 98 512 species, plus documentation of their range, habitat, elevation, and other factors. These range, habitat and elevation data can be matched with terrestrial land cover and elevation datasets to map the species’ area of habitat (AOH; also known as extent of suitable habitat; ESH). This differs from the two spatial metrics used for assessing extinction risk in the IUCN Red List criteria: extent of occurrence (EOO) and area of occupancy (AOO). AOH can guide conservation, for example, through targeting areas for field surveys, assessing proportions of species’ habitat within protected areas, and monitoring habitat loss and fragmentation. We recommend that IUCN Red List assessments document AOH wherever practical

30% land conservation and climate action reduces tropical extinction risk by more than 50%

Limiting climate change to less than 2°C is the focus of international policy under the climate convention (UNFCCC), and is essential to preventing extinctions, a focus of the Convention on Biological Diversity (CBD). The post‐2020 biodiversity framework drafted by the CBD proposes conserving 30% of both land and oceans by 2030. However, the combined impact on extinction risk of species from limiting climate change and increasing the extent of protected and conserved areas has not been assessed. Here we create conservation spatial plans to minimize extinction risk in the tropics using data on 289 219 species and modeling two future greenhouse gas concentration pathways (RCP2.6 and 8.5) while varying the extent of terrestrial protected land and conserved areas from <17% to 50%. We find that limiting climate change to 2°C and conserving 30% of terrestrial area could more than halve aggregate extinction risk compared with uncontrolled climate change and no increase in conserved area

Explanations for less small fibre neuropathy in South Asian versus European people with type 2 diabetes mellitus in the UK.

Low foot ulcer risk in South Asian, compared with European, people with type 2 diabetes in the UK has been attributed to their lower levels of neuropathy. We have undertaken a detailed study of corneal nerve morphology and neuropathy risk factors, to establish the basis of preserved small nerve fibre function in South Asians versus Europeans.In a cross-sectional, population-based study, age- and sex-matched South Asians (n=77) and Europeans (n=78) with type 2 diabetes underwent neuropathy assessment using corneal confocal microscopy, symptoms, signs, quantitative sensory testing, electrophysiology and autonomic function testing. Multivariable linear regression analyses determined factors accounting for ethnic differences in small fibre damage. -adjusted ethnic difference in corneal nerve fibre length (P=0.032) were pack-years smoked (P=0.13), BMI (P=0.062) and triglyceride levels (P=0.062).South Asians have better preserved small nerve fibre integrity than equivalent Europeans; furthermore, classic, modifiable risk factors for coronary heart disease are the main contributors to these ethnic differences. We suggest that improved autonomic neurogenic control of cutaneous blood flow in Asians may contribute to their protection against foot ulcers

The commonness of rarity: Global and future distribution of rarity across land plants

A key feature of life’s diversity is that some species are common but many more are rare. Nonetheless, at global scales, we do not know what fraction of biodiversity consists of rare species. Here, we present the largest compilation of global plant diversity to quantify the fraction of Earth’s plant biodiversity that are rare. A large fraction, ~36.5% of Earth’s ~435,000 plant species, are exceedingly rare. Sampling biases and prominent models, such as neutral theory and the k-niche model, cannot account for the observed prevalence of rarity. Our results indicate that (i) climatically more stable regions have harbored rare species and hence a large fraction of Earth’s plant species via reduced extinction risk but that (ii) climate change and human land use are now disproportionately impacting rare species. Estimates of global species abundance distributions have important implications for risk assessments and conservation planning in this era of rapid global change

Spatial extent and historical context of North Sea oxygen depletion in August 2010

Prompted by recent observations of seasonal low dissolved oxygen from two moorings in the North Sea, a hydrographic survey in August 2010 mapped the spatial extent of summer oxygen depletion. Typical near-bed dissolved oxygen saturations in the stratified regions of the North Sea were 75–80 % while the well-mixed regions of the southern North Sea reached 90 %. Two regions of strong thermal stratification, the area between the Dooley and Central North Sea Currents and the area known as the Oyster Grounds, had oxygen saturations as low as 65 and 70 % (200 and 180 µmol dm-3) respectively. Low dissolved oxygen was apparent in regions characterised by low advection, high stratification, elevated organic matter production from the spring bloom and a deep chlorophyll maximum. Historical data over the last century from the International Council for the Exploration of the Sea oceanographic database highlight an increase in seasonal oxygen depletion and a warming over the past 20 years. The 2010 survey is consistent with, and reinforces, the signal of recent depleted oxygen at key locations seen in the (albeit sparse) historical data

Reforesting for the climate of tomorrow : recommendations for strengthening orangutan conservation and climate change resilience in Kutai National Park, Indonesia

In Indonesia, Kutai National Park is home to what is likely to be East Kalimantan’s largest population of the Critically Endangered eastern subspecies of the Bornean Orangutan, Pongo pygmaeus morio. It also hosts an astounding diversity of other species. Yet East Kalimantan faces many challenges in maintaining and protecting biodiversity from threats, including climate change. Forest restoration, also referred to as reforestation, presents a valuable opportunity to restore biodiversity and function to degraded areas that were once forested. Reforestation initiatives are being carried out in Kutai National Park, but there is a clear and pressing need to update Kutai National Park’s existing restoration practices to ensure forest integrity, provide opportunities for threatened species, and guide consideration of how to build climate change resilience. By doing so, the forests that orangutans need to survive into the future are more likely to persist. We examine restoration case studies, remind readers of restoration best practice, and present sets of tree species from a set of ~250 considered in the analysis that are likely to be suited to various restoration targets for Kutai National Park, e.g. with a focus on habitat restoration for orangutan; or a focus on conservation of rare and useful species. The intended audiences of this work include: orangutan researchers, government, mining companies, nurseries and other companies that are seeking guidance on habitat restoration for climate change resilience in East Kalimantan, as well as those wishing to support biodiversity conservation and/or restoration in the region.Plant science

Recovery of a temperate reef assemblage in a marine protected area following the exclusion of towed demersal fishing.

Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km(2) of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as 'the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls'. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries