2,096 research outputs found

    Transport of anchovy and sardine eggs and larvae from The western Agulhas bank to the west coast during the 1993/94 and 1994/95 spawning seasons

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    The transport of eggs and larvae of anchovy Engraulus capensis and sardine Sardinops sagax from the western Agulhas Bank to the nursery grounds on the Cape west coast was investigated. Samples were takenmonthly between August 1993 and March 1994 and September 1994 and March 1995. A comparison of eggs and larval distributions with current features from selected months supports previous studies, indicating thatthe frontal jet plays an important role in the transport of the early life history stages of anchovy and sardine, but that the position of such transport can vary between the 200 and 500-m isobaths. During October 1994, November 1994 and February 1995, the greatest concentrations of eggs corresponded with areas of strong north-north-westerly flow just beyond the 200 m isobath off the Cape Peninsula, whereas in November 1993 and January 1994 eggs were concentrated farther offshore, increasing the vulnerability of developing larvae to further dispersion offshore. Offshore concentrations, intensified by strong south-easterly winds, occurred during January 1994. Areas of probable egg loss include the western Agulhas Bank, where currents flowing south-south-west can remove eggs before they are transported to the West Coast. Offshore currents also can develop west of the Cape Peninsula, but onshore currents are able to return eggs to the region of the jet, from where they are transported northwards. Other losses may result from offshore transport in the outer branch of the frontal jet off Cape Columbine. Variations in the ability of the jet current flowing north-north-west to transport eggs and larvae to areas favourable for growth and survival may influence recruitment success

    Synoptic-scale precursors of extreme UK summer 3-hourly rainfall

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    This is the final version. Available on open access from AGU via the DOI in this recordThe synoptic-scale meteorological conditions leading up to the 30 most extreme sub-daily summer rain events for two regions of the UK (north-west and south-east) were examined for the period 1979-2013. Using a recently available, quality controlled, national hourly rain gauge dataset, we were able to identify extreme 3-hour rainfall accumulations that may be indicative of flash flooding. Composites of the state of the atmosphere leading up to these dates were produced to investigate synoptic-scale processes, thus potentially allowing for them to be identified in coarse resolution re-analyses and in climate models. The results show that the two regions have different dominant synoptic-scale conditions leading to extreme 3-hour rainfall, which is thought to be related to the type of rainfall typically experienced in each region. In particular, positive anomalies in mean sea level pressure and the geopotential height at 200hPa over the UK are associated with extreme rainfall in the north-west, where the position of the westerly jet is also important. For the south-east, no clear anomalous synoptic-scale conditions could be identified, however localised moisture sources and unstable air masses were observed in association with extremes. These results indicate the importance of better understanding of both synoptic-scale and thermodynamic drivers of short-duration extreme rainfall, with potential implications in forecasting and flood warning, as well as for understanding the representation of key processes by regional climate models.Natural Environment Research Council (NERC)European Research CouncilWolfson FoundationRoyal Societ

    Penny dreadfuls were the true crime podcasts of their time

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    Assessing the impacts of feedstock and process control on pyrolysis outputs for tyre recycling

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    Tyres are a problematic waste stream which are associated with low recycling rates; most are dumped or incinerated, offering poor value return from this material-rich and energy intensive waste. Pyrolysis offers the potential for ~30% of a tyre to be directly recyclable as ‘recovered carbon black’ (RCb), potentiating tyre-to-tyre recycling. However, most attempts to exploit the process have failed to produce consistent, high quality RCb on a commercially viable scale. Current consensus implies that RCb quality can only be improved by expensive post-processing, such as demineralisation using chemical solvents. Here it is shown that the quality (ash and volatile matter content) and consistency of RCb can be improved significantly by careful application of feedstock and process control during pyrolysis. This was achieved via the analysis of peer reviewed data from 31 waste tyres and yields from 161 runs in 37 pyrolysis reactors. A statistical bootstrapping regime showed that by selective exclusion of high ash tyres, and mixing the remainder thoroughly, RCb ash content could be reduced from 49% (upper 99% CI) to 14%. By utilising a unique reactor classification, it was found that fixed beds performed inconsistently, whilst rotary kilns and conical spouted beds produced high quality RCb and a high oil yield, even at lower pyrolysis temperatures. Due to their higher throughput, this work therefore suggests that application of rotary kilns with feedstock control are the best mechanisms to produce consistent high-quality products from pyrolysis, increasing the recyclability of automotive tyres

    Can patterns of urban biodiversity be predicted using simple measures of green infrastructure?

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    Urban species and habitats provide important ecosystem services such as summertime cooling, recreation, and pollination at a variety of scales. Many studies have assessed how biodiversity responds to urbanization, but little work has been done to try and create recommendations that can be easily applied to urban planning, design and management practice. Urban planning often operates at broad spatial scales, typically using relatively simplistic targets for land cover mix to influence biodiversity and ecosystem service provision. Would more complicated, but still easily created, prescriptions for urban vegetation be beneficial? Here we assess the importance of vegetation measures (percentage vegetation cover, tree canopy cover and variation in canopy height) across four taxonomic groups (bats, bees, hoverflies and birds) at multiple spatial scales (100, 250, 500, 1000 m) within a major urban area (Birmingham, the United Kingdom). We found that small-scale (100–250-m radius) measures of vegetation were important predictors for hoverflies and bees, and that bats were sensitive to vegetation at a medium spatial-scale (250–500 m). In contrast, birds responded to vegetation characteristics at both small (100 m) and large (1000 m) scales. Vegetation cover, tree cover and variation in canopy height were expected to decrease with built surface cover; however, only vegetation height showed this expected trend. The results indicate the importance of relatively small patches of vegetation cover for supporting urban biodiversity, and show that relatively simple measures of vegetation characteristics can be useful predictors of species richness (or activity density, in the case of bats). They also highlight the danger of relying upon percentage built surface cover as an indicator of urban biodiversity potential

    Health Resource Utilisation and Disparities: an Ecological Study of Admission Patterns Across Ethnicity in England Between 2017 and 2020.

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    BACKGROUND AND AIM: The COVID-19 pandemic highlighted adverse outcomes in Asian, Black, and ethnic minority groups. More research is required to explore underlying ethnic health inequalities. In this study, we aim to examine pre-COVID ethnic inequalities more generally through healthcare utilisation to contextualise underlying inequalities that were present before the pandemic. DESIGN: This was an ecological study exploring all admissions to NHS hospitals in England from 2017 to 2020. METHODS: The primary outcomes were admission rates within ethnic groups. Secondary outcomes included age-specific and age-standardised admission rates. Sub-analysis of admission rates across an index of multiple deprivation (IMD) deciles was also performed to contextualise the impact of socioeconomic differences amongst ethnic categories. Results were presented as a relative ratio (RR) with 95% confidence intervals. RESULTS: Age-standardised admission rates were higher in Asian (RR 1.40 [1.38-1.41] in 2019) and Black (RR 1.37 [1.37-1.38]) and lower in Mixed groups (RR 0.91 [0.90-0.91]) relative to White. There was significant missingness or misassignment of ethnicity in NHS admissions: with 11.7% of admissions having an unknown/not-stated ethnicity assignment and 'other' ethnicity being significantly over-represented. Admission rates did not mirror the degree of deprivation across all ethnic categories. CONCLUSIONS: This study shows Black and Asian ethnic groups have higher admission rates compared to White across all age groups and when standardised for age. There is evidence of incomplete and misidentification of ethnicity assignment in NHS admission records, which may introduce bias to work on these datasets. Differences in admission rates across individual ethnic categories cannot solely be explained by socioeconomic status. Further work is needed to identify ethnicity-specific factors of these inequalities to allow targeted interventions at the local level

    Long-term disease interactions amongst surgical patients: a population cohort study.

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    BACKGROUND: The average age of the surgical population continues to increase, as does prevalence of long-term diseases. However, outcomes amongst multi-morbid surgical patients are not well described. METHODS: We included adults undergoing non-obstetric surgical procedures in the English National Health Service between January 2010 and December 2015. Patients could be included multiple times in sequential 90-day procedure spells. Multi-morbidity was defined as presence of two or more long-term diseases identified using a modified Charlson comorbidity index. The primary outcome was 90-day postoperative death. Secondary outcomes included emergency hospital readmission within 90 days. We calculated age- and sex-adjusted odds ratios (OR) with 95% confidence intervals (CI) using logistic regression. We compared the outcomes associated with different disease combinations. RESULTS: We identified 20 193 659 procedure spells among 13 062 715 individuals aged 57 (standard deviation 19) yr. Multi-morbidity was present among 2 577 049 (12.8%) spells with 195 965 deaths (7.6%), compared with 17 616 610 (88.2%) spells without multi-morbidity with 163 529 deaths (0.9%). Multi-morbidity was present in 1 902 859/16 946 808 (11.2%) elective spells, with 57 663 deaths (2.7%, OR 4.9 [95% CI: 4.9-4.9]), and 674 190/3 246 851 (20.7%) non-elective spells, with 138 302 deaths (20.5%, OR 3.0 [95% CI: 3.0-3.1]). Emergency readmission followed 547 399 (22.0%) spells with multi-morbidity compared with 1 255 526 (7.2%) without. Multi-morbid patients accounted for 57 663/114 783 (50.2%) deaths after elective spells, and 138 302/244 711 (56.5%) after non-elective spells. The rate of death varied five-fold from lowest to highest risk disease pairs. CONCLUSION: One in eight patients undergoing surgery have multi-morbidity, accounting for more than half of all postoperative deaths. Disease interactions amongst multi-morbid patients is an important determinant of patient outcome

    Consecutive recovery of recovered carbon black and limonene from waste tyres by thermal pyrolysis in a rotary kiln

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    End of life tyres are one of the most abundant and least recycled waste streams. Material recovery processes that accommodate for the complexity and heterogeneity of waste tyres, such as pyrolysis, require urgent development. Examples of recycled tyre pyrolysis products include recovered carbon black (RCb), a recycled filler, and limonene, a solvent, although investigations reporting the recovery of both are limited. In this study the pyrolysis of waste tyres was investigated in a batch rotary kiln under varying conditions (temperature, gas flow, sample mass). Characterisation analysis was then applied to selected samples of RCb (BET surface area, transmissibility of toluene extract, proximate analysis) and tyre pyrolysis oil (yield, limonene content, FTIR). The best RCb (77.7 m2/g, 0.2% volatile matter, 17.0% ash, 94.8% transmissibility of toluene extract) was produced at 550 °C with a high ratio of purge gas flow (2000 mL/min) to rubber sample mass pyrolysed (100 g), minimising the recondensation of tarry volatiles on the RCb. The highest oil and limonene yield (38.4% and 17.4 g/kg waste tyres respectively) was produced at a temperature of 550 °C with a low ratio of purge gas (400 mL/min) to rubber sample pyrolysed (200 g), as these conditions prevented the decomposition of limonene to less valuable products and improved the oil trap condensation efficiency. These findings demonstrate the importance of pyrolysis processing conditions when considering the consecutive production of RCb and solvents from waste tyre pyrolysis, which shows significant future potential to valorise waste tyres, incentivising recycling

    Post-operative intensive care: is it really necessary?

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