Construction and testing of a low-cost device for the collection of rainfall samples destined for stable isotope analysis

Oxygen- and hydrogen-isotope ratios in rainfall provide important hydroclimatic information, yet despite a global network of rainfall isotope measurements, significant geographical gaps exist in data coverage, with only three long-term stations spanning the southern African region. Project-based, ad hoc collections of rainfall for isotope analysis can improve this coverage. However, all rainfall samples that are destined for stable isotope analysis must be collected in such a way to avoid evaporation and resultant isotope fractionation. While such rainwater collectors are available commercially, both the product and shipping are prohibitively costly. We describe the construction of a simple rainfall collector using a design from the literature and materials that are readily available in South African hardware stores. Our rainwater collector can be constructed for the much lower cost of just under ZAR820 in comparison with the cost of ZAR9300 inclusive of shipping from commercial outlets (2022 prices). Our design modifications have the added advantage of portability, with the rainwater collector housed in a bucket with a handle. The device was tested by comparing its performance, in terms of evaporative water loss and isotopic fractionation, with that of an open bottle, using tap water in both cases. Testing confirmed that the collector prevented evaporation over a one-week period, indicating that it is suitable for weekly or more frequent sampling of rainfall. Although the design described was based on materials procured in South Africa, it could easily be adapted for construction elsewhere

Sugar intake and dental decay : results from a national survey of children in Scotland

Peer reviewedPreprin

Variation in prey delivered to common Black-Hawk (Buteogallus anthracinus) nests in Arizona drainage basins

Understanding how raptor diets vary across local and regional scales can be important when human actions have the potential to alter prey abundances. We combined data on prey delivered to 16 Common Black-Hawk (Buteogallus anthracinus) nests in three tributaries of the Verde River, Arizona, in 2008 and 2009 with similar data reported previously (1994) for three other Arizona drainage basins to better understand variation in diet composition within and across drainage basins. Within the three drainage basins studied in 2008 and 2009, nests clustered into two groups: those along Fossil Creek, where fish and amphibians were common, and those in Wet Beaver and Oak Creek drainage basins, where reptiles and nonnative crayfish were more abundant. When data from all six drainage basins were combined, drainage basins again clustered into two groups, with prey deliveries in one cluster dominated by fish and amphibians and in the other cluster by reptiles. These results confirm the opportunistic nature of prey use by Common Black-Hawks and highlight the variation in diet that can occur both within and among drainage basins. Management targeting the eradication of nonnative crayfish or the reintroduction of native amphibians and fish could alter prey availability for this raptor species

Construction and testing of a low-cost device for the collection of rainfall samples destined for stable isotope analysis

Oxygen- and hydrogen-isotope ratios in rainfall provide important hydroclimatic information, yet despite a global network of rainfall isotope measurements, significant geographical gaps exist in data coverage, with only three long-term stations spanning the southern African region. Project-based, ad hoc collections of rainfall for isotope analysis can improve this coverage. However, all rainfall samples that are destined for stable isotope analysis must be collected in such a way to avoid evaporation and resultant isotope fractionation. While such rainwater collectors are available commercially, both the product and shipping are prohibitively costly. We describe the construction of a simple rainfall collector using a design from the literature and materials that are readily available in South African hardware stores. Our rainwater collector can be constructed for the much lower cost of just under ZAR820 in comparison with the cost of ZAR9300 inclusive of shipping from commercial outlets (2022 prices). Our design modifications have the added advantage of portability, with the rainwater collector housed in a bucket with a handle. The device was tested by comparing its performance, in terms of evaporative water loss and isotopic fractionation, with that of an open bottle, using tap water in both cases. Testing confirmed that the collector prevented evaporation over a one-week period, indicating that it is suitable for weekly or more frequent sampling of rainfall. Although the design described was based on materials procured in South Africa, it could easily be adapted for construction elsewhere. Significance: • Hydrogen and oxygen isotope composition of rainfall provides valuable climatic information. • Rainwater collectors for stable isotope samples must prevent evaporation, as evaporation will alter the isotopic signature. • We describe the construction and testing of a bespoke, low-cost and portable device that can be used to collect rainfall samples destined for oxygen- and hydrogen-isotope analysis without significant evaporation

Does gender matter? A cross-national investigation of primary class-room discipline.

© 2018 Informa UK Limited, trading as Taylor & Francis GroupFewer than 15% of primary school teachers in both Germany and the UK are male. With the on-going international debate about educational performance highlighting the widening gender achievement gap between girl and boy pupils, the demand for more male teachers has become prevalent in educational discourse. Concerns have frequently been raised about the underachievement of boys, with claims that the lack of male ‘role models’ in schools has an adverse effect on boys’ academic motivation and engagement. Although previous research has examined ‘teaching’ as institutional talk, men’s linguistic behaviour in the classroom remains largely ignored, especially in regard to enacting discipline. Using empirical spoken data collected from four primary school classrooms in both the UK and in Germany, this paper examines the linguistic discipline strategies of eight male and eight female teachers using Interactional Sociolinguistics to address the question, does teacher gender matter?Peer reviewedFinal Accepted Versio

Effects of Changing Climate and Water Availability on Four Riparian Species in the Southwestern United States

The Lower Colorado River and Rio Grande Basins are home to many riparian species of different degrees of rarity. In our study we focused on two species of birds and two species of gartersnakes that are associated with water: the Yellow-Breasted Chat (Icteria virens), the American Yellow Warbler (Setophaga petechia), the Mexican Gartersnake (Thamnophis eques) and the Narrow-headed Gartersnake (T. rufipunctatus). While the extent of distributions of these species is relatively large, they are often patchily distributed in populations that are small. To evaluate the vulnerability of these species at a landscape scale due to changes in hydrology, we built models of suitability of current and future landscapes for these species. We relied on climatic and hydrological predictions, developed by the Bureau of Reclamation (as part of the WATERSmart program) and NASA’s Moderate-Resolution Imaging Spectroradiometer (MODIS), to derive spatially-explicit metrics that quantify the greenness of riparian vegetation in time. Using WATERSmart data, we were able to project these metrics into the future. The projected changes in water availability by end of the century will directly affect the availability of permanent water and riparian vegetation that surrounds suitable habitats of our study species. Our results suggest significant changes in future landscape suitability (up to 64% of area) for all species that are in addition to other threats. Best models included riparian vegetation as an important component of the predictions but we note that finer scale examination of hydrology and climate effects on habitats would be more useful for effective management

Final Report: Predicting Effects of Climate Change on Riparian Obligate Species in the Southwestern United States

The Lower Colorado River and Rio Grande Basins are home to many riparian vertebrate species with different degrees of rarity. In our study, we focused on two species of birds and two species of gartersnakes that are associated with riparian areas: the Yellow-breasted Chat (Icteria virens), the Yellow Warbler (Setophaga petechia), the Northern Mexican Gartersnake (Thamnophis eques megalops) and the Narrow-headed Gartersnake (T. rufipunctatus). While the extent of distributions of these species is relatively large, they are often patchily distributed in populations that are small; in addition, both gartersnake species are listed as threatened under the Endangered Species Act. Aside from detrimental effects of direct habitat loss and degradation throughout the southwestern United States, future changes in water availability might threaten the long-term persistence of populations of any one of these species. To evaluate this vulnerability at a landscape scale, we built species distribution models under current and future projected climates for each species. For modeling, we relied on climatic and hydrological predictions (downscaled CMIP3 climate and hydrology projections) developed by the Bureau of Reclamation and its partners as part of the West-Wide Climate Risk Assessments within the WATERSmart initiative. We also relied on NASAs Moderate-Resolution Imaging Spectroradiometer (MODIS) to derive a spatially explicit index that quantifies riparian vegetation in space and time. Using downscaled climate projections and other landscape data, we were able to project these riparian vegetation metric forward in time. The projected changes in water availability by end of the century will directly affect the availability of permanent water and riparian vegetation creating the habitats of our study species. Our results suggest significant and negative changes in future landscape suitability for all species (up to 64% loss of suitable area), which are in addition to already identified threats facing these species. Best models included the index of riparian vegetation (linked to water availability) as an important component of the predictions, but we also note that finer scale examination of hydrology and climate effects on habitats would be much more useful for effective management.\u2

Permafrost degradation and nitrogen cycling in Arctic rivers: Insights from stable nitrogen isotope studies

Abstract. Across the Arctic, vast areas of permafrost are being degraded by climate change, which has the potential to release substantial quantities of nutrients, including nitrogen into large Arctic rivers. These rivers heavily influence the biogeochemistry of the Arctic Ocean, so it is important to understand the potential changes to rivers from permafrost degradation. This study utilized dissolved nitrogen species (nitrate and dissolved organic nitrogen (DON)) along with nitrogen isotope values (δ15N-NO3- and δ15N-DON) of samples collected from permafrost sites in the Kolyma River and the six largest Arctic rivers. Large inputs of DON and nitrate with a unique isotopically heavy δ15N signature were documented in the Kolyma, suggesting the occurrence of denitrification and highly invigorated nitrogen cycling in the Yedoma permafrost thaw zones along the Kolyma. We show evidence for permafrost-derived DON being recycled to nitrate as it passes through the river, transferring the high 15N signature to nitrate. However, the potential to observe these thaw signals at the mouths of rivers depends on the spatial scale of thaw sites, permafrost degradation, and recycling mechanisms. In contrast with the Kolyma, with near 100 % continuous permafrost extent, the Ob River, draining large areas of discontinuous and sporadic permafrost, shows large seasonal changes in both nitrate and DON isotopic signatures. During winter months, water percolating through peat soils records isotopically heavy denitrification signals in contrast with the lighter summer values when surface flow dominates. This early year denitrification signal was present to a degree in the Kolyma, but the ability to relate seasonal nitrogen signals across Arctic Rivers to permafrost degradation could not be shown with this study. Other large rivers in the Arctic show different seasonal nitrogen trends. Based on nitrogen isotope values, the vast majority of nitrogen fluxes in the Arctic rivers is from fresh DON sourced from surface runoff through organic-rich topsoil and not from permafrost degradation. However, with future permafrost thaw, other Arctic rivers may begin to show nitrogen trends similar to the Ob. Our study demonstrates that nitrogen inputs from permafrost thaw can be identified through nitrogen isotopes, but only on small spatial scales. Overall, nitrogen isotopes show potential for revealing integrated catchment wide nitrogen cycling processes. </jats:p

Seasonal pattern of incidence and outcome of acute kidney injury: A national study of Welsh AKI electronic alerts

Objectives To identify any seasonal variation in the occurrence of, and outcome following Acute Kidney Injury. Methods The study utilised the biochemistry based AKI electronic (e)-alert system established across the Welsh National Health Service to collect data on all AKI episodes to identify changes in incidence and outcome over one calendar year (1st October 2015 and the 30th September 2016). Results There were total of 48 457 incident AKI alerts. The highest proportion of AKI episodes was seen in the quarter of January to March (26.2%), and the lowest in the quarter of October to December (23.3%, P < .001). The same trend was seen for both community-acquired and hospital-acquired AKI sub-sets. Overall 90 day mortality for all AKI was 27.3%. In contrast with the seasonal trend in AKI occurrence, 90 day mortality after the incident AKI alert was significantly higher in the quarters of January to March and October to December compared with the quarters of April to June and July to September (P < .001) consistent with excess winter mortality reported for likely underlying diseases which precipitate AKI. Conclusions In summary we report for the first time in a large national cohort, a seasonal variation in the incidence and outcomes of AKI. The results demonstrate distinct trends in the incidence and outcome of AKI