Extraordinarily high leaf selenium to sulfur ratios define ‘se-accumulator’ plants

Background and Aims: Selenium (Se) and sulfur (S) exhibit similar chemical properties. In flowering plants (angiosperms) selenate and sulfate are acquired and assimilated by common transport and metabolic pathways. It is hypothesized that most angiosperm species show little or no discrimination in the accumulation of Se and S in leaves when their roots are supplied a mixture of selenate and sulfate, but some, termed Se-accumulator plants, selectively accumulate Se in preference to S under these conditions. Methods: This paper surveys Se and S accumulation in leaves of 39 angiosperm species, chosen to represent the range of plant Se accumulation phenotypes, grown hydroponically under identical conditions. Results: The data show that, when supplied a mixture of selenate and sulfate: (1) plant species differ in both their leaf Se ([Se]leaf) and leaf S ([S]leaf) concentrations; (2) most angiosperms show little discrimination for the accumulation of Se and S in their leaves and, in non-accumulator plants, [Se]leaf and [S]leaf are highly correlated; (3) [Se]leaf in Se-accumulator plants is significantly greater than in other angiosperms, but [S]leaf, although high, is within the range expected for angiosperms in general; and (4) the Se/S quotient in leaves of Se-accumulator plants is significantly higher than in leaves of other angiosperms. Conclusion: The traits of extraordinarily high [Se]leaf and leaf Se/S quotients define the distinct elemental composition of Se-accumulator plants

The impact of electronic monitoring on fleet wide discarding of small cod in Scottish demersal fisheries

Acknowledgments The authors of this paper would like to acknowledge the fishers, fisheries inspectors, and video reviewers who participated in or supported the Scottish cod catch quota management scheme. Additionally, we thank two anonymous reviewers for their encouraging and insightful comments and suggestions.Peer reviewedPublisher PD

The effect of intermittent hypoxic training on performance

This study aimed to verify whether the “live low, train high” approach is beneficial for endurance and/or anaerobic cycling performance. Sixteen well-trained athletes completed 90 min of endurance training (60-70% of heart rate reserve) followed by two 30-s all-out sprints (Wingate test), daily for 10 consecutive days. Nine subjects (IHT group) trained with an F₁O₂ set to produce arterial oxygen saturations of ~88% to ~82%, while 7 subjects (placebo group) trained while breathing a normal gas mixture (F₁O₂ = 0.21). Four performance tests were conducted at sea-level including a familiarisation and baseline trial, followed by repeat trials at 2 and 9 days post-intervention. Relative to the placebo group mean power during the 30-s Wingate test increased by 3.0% (95% Confidence Limits, CL ± 3.5%) 2 days, and 1.7% (± 3.8%) 9 days post-IHT. Changes in other performance variables (30-s peak power, 20-km mean power, 20-km oxygen cost) were unclear. During the time trial the IHT participants‟ blood lactate concentration, RER and SpO₂ relative to the placebo group, was substantially increased at 2 days post-intervention. The addition of IHT into the normal training programme of well-trained athletes produced worthwhile gains in 30-s sprint performance possibly through enhanced glycolysis.Lincoln University Research Fund, Sport and Recreation New Zealan

Human rights of refugee-survivors of sexual and gender-based violence with communication disability

Article 19 of the Universal Declaration of Human Rights (United Nations, 1948) states that all people have the right to seek, receive and impart information using any means. Ensuring that people with communication disabilities achieve this right is inherently challenging. For people with communication disability, who are refugee-survivors of sexual and gender-based violence (SGBV), additional human rights are challenged, including the right to education, protection from discrimination, a safe place to live, security of person and legal protection. Their experiences and needs, however, are poorly understood. This paper reports on a literature review of the intersectionality between SGBV, being a refugee and having a communication disability, and a preliminary investigation of the situation of refugee-survivors of SGBV with communication disability, in Rwanda. The project involved 54 participants, including 50 humanitarian and partner organisation staff and 4 carers of refugees with communication disabilities, from two locations (camp-based and urban refugees). Findings from both revealed that, for people with communication disability, barriers are likely to occur at each step of preventing and responding to SGBV. Moreover, stigmatisation of people with communication disability challenges SGBV prevention/support and people with communication disability may be targeted by SGBV perpetrators. SGBV service providers acknowledge their lack of knowledge and skills about communication disability, but wish to learn. Findings highlight the need for increased knowledge and skill development, in order to improve the situation for refugee-survivors of SGBV with communication disability

Integrated stratigraphy of the Kimmeridge Clay Formation (Upper Jurassic) based on exposures and boreholes in south Dorset, UK

For the purposes of a high-resolution multi-disciplinary study of the Upper Jurassic Kimmeridge Clay Formation, two boreholes were drilled at Swanworth Quarry and one at Metherhills, south Dorset, UK. Together, the cores represent the first complete section through the entire formation close to the type section. We present graphic logs that record the stratigraphy of the cores, and outline the complementary geophysical and analytical data sets (gamma ray, magnetic susceptibility, total organic carbon, carbonate, [delta]13Corg). Of particular note are the new borehole data from the lowermost part of the formation which does not crop out in the type area. Detailed logs are available for download from the Kimmeridge Drilling Project web-site at http://kimmeridge.earth.ox.ac.uk/. Of further interest is a mid-eudoxus Zone positive shift in the [delta]13Corg record, a feature that is also registered in Tethyan carbonate successions, suggesting that it is a regional event and may therefore be useful for correlation. The lithostratigraphy of the cores has been precisely correlated with the nearby cliff section, which has also been examined and re-described. Magnetic-susceptibility and spectral gamma-ray measurements were made at a regular spacing through the succession, and facilitate core-to-exposure correlation. The strata of the exposure and core have been subdivided into four main mudrock lithological types: (a) medium-dark–dark-grey marl; (b) medium-dark–dark grey–greenish black shale; (c) dark-grey–olive-black laminated shale; (d) greyish-black–brownish-black mudstone. The sections also contain subordinate amounts of siltstone, limestone and dolostone. Comparison of the type section with the cores reveals slight lithological variation and notable thickness differences between the coeval strata. The proximity of the boreholes and different parts of the type section to the Purbeck–Isle of Wight Disturbance is proposed as a likely control on the thickness changes

A Model of the Ocean Overturning Circulation with Two Closed Basins and a Reentrant Channel

Zonally averaged models of the ocean overturning circulation miss important zonal exchanges of waters between the Atlantic and Indo-Pacific Oceans. A two-layer, two-basin model that accounts for these exchanges is introduced and suggests that in the present-day climate the overturning circulation is best described as the combination of three circulations: an adiabatic overturning circulation in the Atlantic Ocean associated with transformation of intermediate to deep waters in the north, a diabatic overturning circulation in the Indo- Pacific Ocean associated with transformation of abyssal to deep waters by mixing, and an interbasin circulation that exchanges waters geostrophically between the two oceans through the Southern Ocean. These results are supported both by theoretical analysis of the two-layer, two-basin model and by numerical simulations of a three-dimensional ocean model. Keywords: Ocean; Meridional overturning circulation; Ocean circulation; Mixing; Thermohaline circulationNational Science Foundation (U.S.) (Award OCE-1536515)National Science Foundation (U.S.) (Award OCE-1233832

Gill's model of the Antarctic Circumpolar Current, revisited: the role of latitudinal variations in wind stress

Adrian Gill’s (1968) model of the Antarctic Circumpolar Current (ACC) is reinterpreted for a stratified, reduced-gravity ocean, where the barotropic streamfunction is replaced by the pycnocline depth, and the bottom drag coefficient by the Gent and McWilliams eddy diffusivity. The resultant model gives a simple description of the lateral structure of the ACC that is consistent with contemporary descriptions of ACC dynamics. The model is used to investigate and interpret the sensitivity of the ACC to the latitudinal profile of the surface wind stress. A substantial ACC remains when the wind jet is shifted north of the model Drake Passage, even by several thousand kilometers. The integral of the wind stress over the circumpolar streamlines is found to be a useful predictor of the magnitude of the volume transport through the model Drake Passage, although it is necessary to correct for basin-wide zonal pressure gradients in order to obtain good quantitative agreement

Quantifying the contribution of riparian soils to the provision of ecosystem services

Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a diverse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types; 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils; and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7–17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research is required to critically test this across a wider range of ecosystems

Delineating and mapping riparian areas for ecosystem service assessment

Riparian buffers, the interface between terrestrial and freshwater ecosystems, have the potential to protect water bodies from land-based pollution, and also for enhancing the delivery of a range of ecosystem services. The UK currently has no defined optimal width or maximum extent of riparian buffers for specific ecosystem services. Here, we present the first study, which attempts to (a) compare and critique different riparian buffer delineation methods and (b) investigate how ecological processes, for example, pollutant removal, nutrient cycling, and water temperature regulation, are affected spatially by proximity to the river and also within a riparian buffer zone. Our results have led to the development of new concepts for riparian delineation based on ecosystem service-specific scenarios. Results from our study suggest that choice of delineation method will influence not only the total area of potential riparian buffers but also the proportion of land cover types included, which in turn will determine their main ecosystem provision. Thus, for some ecological processes (e.g., pollutant removal), a fixed-distance approach will preserve and protect its ecosystem function, whereas for processes such as denitrification, a variable-width buffer will reflect better riparian spatial variability maximizing its ecological value. In summary, riparian delineation within UK habitats should be specific to the particular ecosystem service(s) of interest (e.g., uptake of nutrients and shading), and the effectiveness of the buffer should be ground-truthed to ensure the greatest level of protection