• Genetic import and phenotype specific alleles associated with hyper-invasion in Campylobacter jejuni

      Baig, Abiyad; McNally, Alan; Dunn, Steven; Paszkiewicz, Konrad H.; Corander, Jukka; Manning, Georgina (BioMed Central, 2015-10-24)
      Background Campylobacter jejuni is a major zoonotic pathogen, causing gastroenteritis in humans. Invasion is an important pathogenesis trait by which C. jejuni causes disease. Here we report the genomic analysis of 134 strains to identify traits unique to hyperinvasive isolates. Methods A total of 134 C. jejuni genomes were used to create a phylogenetic tree to position the hyperinvasive strains. Comparative genomics lead to the identification of mosaic capsule regions. A pan genome approach led to the discovery of unique loci, or loci with unique alleles, to the hyperinvasive strains. Results Phylogenetic analysis showed that the hyper-invasive phenotype is a generalist trait. Despite the fact that hyperinvasive strains are only distantly related based on the whole genome phylogeny, they all possess genes within the capsule region with high identity to capsule genes from C. jejuni subsp. doylei and C. lari. In addition there were genes unique to the hyper-invasive strains with identity to non-C. jejuni genes, as well as allelic variants of mainly pathogenesis related genes already known in the other C. jejuni. In particular, the sequence of flagella genes, flgD-E and flgL were highly conserved amongst the hyper-invasive strains and divergent from sequences in other C. jejuni. A novel cytolethal distending toxin (cdt) operon was also identified as present in all hyper-invasive strains in addition to the classic cdt operon present in other C. jejuni. Conclusions Overall, the hyper-invasive phenotype is strongly linked to the presence of orthologous genes from other Campylobacter species in their genomes, notably within the capsule region, in addition to the observed association with unique allelic variants in flagellar genes and the secondary cdt operon which is unlikely under random sharing of accessory alleles in separate lineages.
    • Genome-based infection tracking reveals dynamics of Clostridium difficile transmission and disease recurrence

      Kumar, Nitin; Miyajima, Fabio; He, Miao; Roberts, Paul; Swale, Andrew; Ellison, Louise; Pickard, Derek; Smith, Godfrey; Molyneux, Rebecca; Dougan, Gordon; et al. (Oxford University Press (OUP), 2015-12-18)
      Background. Accurate tracking of Clostridium difficile transmission within healthcare settings is key to its containment but is hindered by the lack of discriminatory power of standard genotyping methods. We describe a whole-genome phylogenetic-based method to track the transmission of individual clones in infected hospital patients from the epidemic C. difficile 027/ST1 lineage, and to distinguish between the 2 causes of recurrent disease, relapse (same strain), or reinfection (different strain). Methods. We monitored patients with C. difficile infection in a UK hospital over a 2-year period. We performed whole-genome sequencing and phylogenetic analysis of 108 strains isolated from symptomatic patients. High-resolution phylogeny was integrated with in-hospital transfers and contact data to create an infection network linking individual patients and specific hospital wards. Results. Epidemic C. difficile 027/ST1 caused the majority of infections during our sampling period. Integration of whole-genome single nucleotide polymorphism (SNP) phylogenetic analysis, which accurately discriminated between 27 distinct SNP genotypes, with patient movement and contact data identified 32 plausible transmission events, including ward-based contamination (66%) or direct donor–recipient contact (34%). Highly contagious donors were identified who contributed to the persistence of clones within distinct hospital wards and the spread of clones between wards, especially in areas of intense turnover. Recurrent cases were identified between 4 and 26 weeks, highlighting the limitation of the standard <8-week cutoff used for patient diagnosis and management. Conclusions. Genome-based infection tracking to monitor the persistence and spread of C. difficile within healthcare facilities could inform infection control and patient management.
    • Genomic epidemiology of clinical Campylobacter spp. at a single health trust site

      Dunn, S.J.; Pascoe, B.; Turton, J.; Fleming, V.; Diggle, M.; Sheppard, S.K.; McNally, A.; Manning, G. (2018-10-11)
      Campylobacter is the leading cause of bacterial enteritis in the developed world, and infections with the organism are largely sporadic in nature. Links between sporadic cases have not been established, with the majority of infections thought to be caused by genetically distinct isolates. Using a read-mapping approach, 158 clinical isolates collected during 2014 from the greater Nottinghamshire area were analysed to assess the local population structure and investigate potential case linkages between sporadic cases of campylobacteriosis. Four instances (2.5 %) of case linkage were observed across the dataset. This study demonstrates that case linkage does occur between sporadic Campylobacter infections, and provides evidence that a dual multi-locus sequence typing/within-lineage single nucleotide polymorphism typing approach to Campylobacter genomic epidemiology provides a benefit to public-health investigations.
    • Geochemical characterization of banana, buriti palm, jute and coir fibres for use as biogeotextiles for erosion control

      Egbujuo, Charles, Izuchukwu; Fullen, Michael A.; Guerra, Antonio J.T.; Opara, Alexander Iheanyi (VGTU Press, 2018-10-09)
      Geochemical analysis of selected plant fibres used as geotextiles for erosion control was conducted to evaluate their geochemical composition and to determine the elements that could potentially be nutrients for plants or cause heavy metal contamination in soils. Analysis of the samples was performed using X-ray Diffraction and X-ray Fluorescence spectrometry. Results revealed that potassium concentrations varied from 3.63% in jute-mat (India)-50.73% in banana-leaf (São Romão, Brazil), with a mean of 27.17%. Similarly, calcium concentrations varied from 0.09% in banana-leaf (São Romão) –37.0% in banana-leaf/stem (Oleo, Brazil). Iron concentrations varied from 0.15% in banana-leaf/stem samples (Oleo) –4.47% in jute-cloth (India). Since banana-leaf/stem had the highest concentration of macro-nutrients, it is therefore proposed that banana-leaf has the highest potential for adding nutrients to the soil system when biodegraded. In addition, heavy metal analysis of the samples revealed that none of the fibres have high concentrations that may contaminate the soil upon decomposition.
    • Geochemistry and mineral chemistry of quartz mica schists within Iseyin-Oyan Schist Belt, Southwestern Nigeria

      Abdus-Salam, Maryam; Bolarinwa, Anthony; Olatunji, Akinade; Fullen, Michael A.; Afolabi, Adegoke; Omotunde, Victoria; Olajide-Kayode, Jerry; Olisa, Olusegun (Indian Society for Education and Environment, 2020-12-03)
      Background/Objectives: The Iseyin-Oyan schist belt is made up metasedimentary rocks, gneisses, granites and pegmatite intrusions. The study was aimed at identifying the schist within this belt and assess their metamorphism, geochemical characteristics and tectonic origin. Methods: Detailed geologic field mapping was undertaken where rocks were located, studied in-situ and identified. Samples of the schist were prepared for petrographic studies. Mineralogical contents were determined using X-Ray Diffraction technique. Polished sections were studied for mineral chemistry using Scanning Electron Microscope-Energy Dispersive Spectroscopy. Rock samples were analysed using X-Ray Fluorescence Spectroscopy and Inductively Coupled Plasma Emission Spectrometry. Geochemical data were elucidated using diverse geochemical discrimination diagrams. Findings: The schists are quartz mica schists and occur in close association with amphibolites, intrusive granitoids and pegmatites. The Mineral assemblage indicates upper (at the western part) to lower (at the central part) amphibolite facies grade metamorphism in the area. Pyrope-almandine garnets occur in quartz mica schist at the western parts reinforcing higher pressure-temperature metamorphic conditions. The concentration (in %) of SiO2 ranged from 56.4-71.6; Al2O3, 13.7-21.1; Fe2O3, 2-8; MgO, 0.7-2.4; and K2O, 2.1-5.5 supporting the evidence for differential degrees of metamorphism. Large iron lithophile and high field strength elements are similar to the average upper continental crust. Pronounced negative Europium anomaly pointed to the major roles played by feldspars during the geological processes. Plagioclase ranged from albite-oligoclase and oligoclase- andesine. The precursors of the quartz mica schist are possibly arkosic and greywacke sands deposited within the active continental margins. Evidence of uplift and overturning suggested for the differential metamorphism may be due to these events usually associated with active continental margins. Applications: This study has identified the once named undifferentiated schist in the study area to be quartz mica schist with details in their grades of metamorphism elucidated.
    • Geographical forwarding algorithm based video content delivery scheme for internet of vehicles (IoV)

      Sadiq, Ali Safaa; Ghafoor, Kayhan Zrar; Ke, Chih-Heng (IEEE, 2020-07-31)
      An evolved form of Vehicular Ad hoc Networks (VANET) has recently emerged as the Internet of Vehicles (IoV). Though, there are still some challenges that need to be addressed in support IoV applications. The objective of this research is to achieve an efficient video content transmission over vehicular networks. We propose a balanced video-forwarding algorithm for delivering video-based content delivery scheme. The available neighboring vehicles will be ranked to the vehicle in forwarding progress before transmitting the video frames using proposed multi-score function. Considering the current beacon reception rate, forwarding progress and direction to destination, in addition to residual buffer length; the proposed algorithm can elect the best candidate to forward the video frames to the next highest ranked vehicles in a balanced way taking in account their residual buffer lengths. To facilitate the proposed video content delivery scheme, an approach of H.264/SVC was improvised to divide video packets into various segments, to be delivered into three defined groups. These created segments can be encoded and decoded independently and integrated back to produce the original packet sent by source vehicle. Simulation results demonstrate the efficiency of our proposed algorithm in improving the perceived video quality compared with other approaches
    • Geosynthetics in Civil Engineering

      Sarsby, Robert W. (Abington: Woodhead Publishing Ltd. ALSO: CRC Press (Taylor & Francis Group), 2007)
      Discusses the fundamentals of geosynthetics. Examines various applications in areas such as filters, separators, landfills and foundation materials. Reviews quality assurance and the service life of geosynthetics. Geosynthetics are man-made polymer-based materials which facilitate cost effective building, environmental, transportation and other construction projects. Given their versatility, geosynthetics are a vital material in all aspects of civil engineering. The first section of the book covers the fundamentals of geosynthetics. Chapters discuss the design and durability of geosynthetics together with their material properties and international standards governing their use. Building on these foundations, Part 2 examines the various applications of geosynthetics in areas such as filters, separators, landfills, barriers and foundation materials. The book concludes by reviewing methods of quality assurance and the service life of geosynthetics. Written by an international team of contributors, Geosynthetics in civil engineering is an essential reference to all those involved in civil engineering. (Woodhead Publishing)
    • Geotourism and soil quality on trails within conservation units in south-east Brazil

      de Almeida Rangel, L; do Carmo Oliveira Jorge, M; Teixeira Guerra, AJ; Fullen, Michael A. (Springer Science and Business Media LLC, 2019-05-04)
      © 2019, The European Association for Conservation of the Geological Heritage. Geotourism is a growing activity in Brazil, mainly in Conservation Units, where trails are used by both visitors and local people to access geotourist attractions. The use of these trails can have negative impacts when there is inadequate planning and management. This research investigated two geotourist trails: Caixa D’Aço natural pool trail in Serra da Bocaina National Park (Rio de Janeiro State) and Água Branca waterfall trail in Serra do Mar State Park (São Paulo State). Geodiversity values were assessed at both geosites, adopting the methods of Gray (2004, 2013). Soil quality analysis was also conducted, with physico-chemical analyses of soils from 0 to 10 cm depth. The dominant soil texture on Caixa D’Aço natural pool trail is sandy clay loam, and on Água Branca trail, all samples were coarse sandy loams. Soils on Caixa D’Aco natural pool trail were compact, with a mean bulk density of 1.41 g/cm3, whereas on Água Branca trail, the mean value was 1.19 g/cm3. The geodiversity values at both sites were similar, except for supporting services, where Caixa D’Aço natural pool had a medium value, whereas Água Branca waterfall had a high value. This paper stresses the importance of geoconservation studies in publicizing the geoheritage of Brazilian Conservation Units.
    • Germination of Seeds of Selected Leguminous Tree Species Moistened with Varying Concentrations of Crude Oil-Contaminated Soil Water Extracts

      Adelusi Oyedeji, Ayodele; Kayode, Joshua; Besenyei, Lynn; Fullen, Michael A. (Scientific Research Publishing Inc., 2015-06)
      The study investigates the germination of selected leguminous tree species (LTS) native to the forest ecosystem and oil producing areas of Nigeria. Germination experiments of 250 seeds from each of the selected members of the Fabaceae family: Bauhinia monandra (Kurz), Delonix regia (Boj. ex Hook.) Raf. and Tetrapleura tetraptera (Schum. & Thonn.) Taubert were conducted in petri dishes double-layered with Whatman No. 1 filter papers for 10 days and moistened with varying concentrations of crude oil contaminated soil water extracts (0, 25, 50, 75 and 100 ml), with a view to determining the ability of these plants to germinate and establish in soil polluted with crude oil. The mean percentage germination of each tree species was thus determined. All the LTS germinated, but germination was concentration dependent, as percentage germination decreased with increased oil concentrations. Evaluation of the initial growth responses and tolerances of these LTS in oil-polluted soil may provide useful information about the potential of these plant species for phytoremediation.
    • Giant cell arteritis: a new perspective on investigations and diagnostic criteria

      Sagdeo, Amol; Askari, Ayman; Morrissey, Hana; Ball, Patrick (Research Trends, 2020-08-13)
      Giant cell arteritis (GCA) is a common form of granulomatous inflammation of large blood vessels. It can cause irreversible blindness in nearly 20% of untreated cases. It has an incidence of 15-30 per 100,000 persons aged 50 years and over in North American and European countries. GCA is a medical emergency and requires early confirmation of diagnosis and initiation of treatment. Recent development in non-invasive imaging modalities, with higher sensitivities and specificities than temporal artery biopsy (TAB), improved the standard for GCA diagnosis. The recent updates on British Society for Rheumatology guidelines elaborated on the role of ultrasound (US) in the diagnosis of GCA and use of the guidelines provides a new approach for GCA confirmatory diagnosis. A search was conducted using EMBASE and Medline databases to identify recent published research on the diagnosis of GCA. Only human studies published in English between 2010 to 2020 were considered in this systematic narrative review. This review also summarises the evidence available for non-invasive imaging and recommends an approach combining the recently published algorithm for diagnosis decision making of cranial GCA using scoring system. This review proposes a combined approach to use a clinical diagnostic decision making in suspected cranial GCA and use the scoring system based on the clinical history, examination findings, laboratory results and the imaging results combined to give a score to diagnose GCA from other vasculitides. The approach to investigate a case of GCA needs to be modified and should include newer imaging techniques available and new diagnostic criteria should be used in combination with the rapid access pathways for clinical decision.
    • Giant Snakes: A Natural History, John C. Murphy and Tom Crutchield 2019 (book review)

      O'Shea, Mark (Society for the Study of Amphibians and Reptiles, 2019-12-31)
    • Global buckling of S690 transversely-stiffened plate girders with slender webs: Behaviour and design

      Zhang, YM; Hassanein, MF; Bock, M; Shao, YB (Elsevier, 2021-02-17)
      High-strength steels (HSSs) are now used globally in different structural applications because of their constructional and environmental merits. Though, investigations on HSS elements are still relatively limited. Herein, the lateral-torsional buckling (LTB) response of laterally-unsupported plate girders with stiffened slender webs is explored considering steel S690, which is currently under extensive testing worldwide. This is done by the finite element (FE) modelling to provide numerical models that well simulate their actual behaviour. Accordingly, FE models are verified first through comparisons with available tests in the literature. After that, parametric analyses are generated to examine the effects of the geometrical characteristics of the cross-section (in terms of the effective radius of gyration for LTB (rT) and the elastic section modulus referred to compression flange (Sxc)) and the laterally-unsupported length on the behaviour and strength of these girders. The results show that by increasing the value of rT, computed as the radius of gyration about the minor-axis of the compression flange plus one-sixth of the web, the strength of the girders increase more efficiently compared with the relative increase in rT. On the other hand, while increasing the value of the section modulus Sxc is found to raise the strength of the girders, the increase in the strength has been relatively found to be less than the increase in the value of Sxc. Additionally, based on the current results, the girder slenderness parameter of 2.0 is found as the inelastic LTB limit of such girders built up with S690, from which the girders of larger slenderness become ineffective and better to be made of conventional normal-strength steels. Furthermore, the bending strengths are compared with the design models given by AISC, EC3-1-1 and AS4100. The results show that they provide highly conservative results, with the predictions of AS4100 yielding the best design values. However, enhancements to the design models are still possible to provide lighter girders under the same applied loads. Accordingly, EC3 general design model (provided in Clause 6.3.2.2) is modified by using buckling curve “a" instead of buckling curve “d".
    • Global dimensions of chronic kidney disease of unknown aetiology (CKDu); a comparison study

      Lowe, Chamodika; Aslam, Fahim (IGRPS, 2020-11-30)
      The form of Chronic Kidney Disease (CKD) with a lacking known cause of origin unlike most other forms is said to be CKD of Unknown aetiology (CKDu). This condition has been often reported from tropical and subtropical countries around the world, specially, including Asian countries like Japan from where CKDu was first reported; and shows a growing risk of spreading around the world. Due to the absence of early signs and symptoms, CKDu is not diagnosed up until it reaches an irreversible state. Researches are being carried out to find the aetiology of the disease to help patients with better prognosis. Those have been able to put forward several hypotheses including hot climate, agricultural economy, hard water, heavy metals, microbial toxins, infectious diseases and genetic predisposition as the CKDu causatives. Also these researches have paved to identify more similarities and few differences between the CKDu cases reported from different countries. With the main aim to identify the epidemiology of CKDu in Asia, this article has been written with the intension of looking the similarities and differences of CKDu found in Asian countries. Already published primary and review articles have been studied and summarized in this article to present a review on epidemiology of CKDu in Asia.
    • Golimumab induction and maintenance for moderate to severe ulcerative colitis: results from GO-COLITIS (Golimumab: a Phase 4, UK, open label, single arm study on its utilization and impact in ulcerative Colitis)

      Probert, Christopher SJ; Sebastian, Shaji; Gaya, Daniel R; Hamlin, P John; Gillespie, Gillian; Rose, Anita; Tate, Helen; Wheeler, Colin; Irving, Peter M; Probert, C; et al. (BMJ, 2018-07-07)
      GO-COLITIS aimed to measure the effectiveness of subcutaneous golimumab in tumour necrosis factor-α antagonist-naive patients with moderate to severe ulcerative colitis (UC) despite conventional treatment.GO-COLITIS was an open label, single arm, phase 4 study with a pragmatic design which reflected UK clinical practice. Adult patients were eligible if diagnosed with UC ≥3 months, partial Mayo score (PMS) 4-9. Patients received subcutaneous golimumab induction (200 mg initially and 100 mg at week 2) followed at week 6 by 50 mg or 100 mg (depending on weight) every 4 weeks until week 54 with a 12-week follow-up. Efficacy was measured by PMS at baseline, week 6, 30, 54 and 66. Health-related quality of life (HRQoL; Inflammatory Bowel Disease Questionnaire (IBDQ) and EuroQol Group 5 Dimensions Health Questionnaire (EQ-5D)) was assessed at baseline, week 6 and week 54. All safety adverse events (AEs) were recorded.207 patients were enrolled and 205 received golimumab (full analysis set (FAS)205). At week 6, 68.8% (95% CI 62.0% to 75.1%) and 38.5% (95% CI 31.8% to 45.6%) of patients were in response and remission, respectively, using PMS. At the end of the induction phase, 140/141 patients in clinical response continued into the maintenance phase (Maintenance FAS). Sustained clinical response through week 54 was achieved in 51/205 (24.9%) of the FAS205 population and 51/140 (36.4%) of the Maintenance FAS population. Statistically significant improvements from baseline to week 6 were observed for the IBDQ total score and for each IBDQ domain score (bowel symptoms, emotional function, systemic symptoms and social function), as well as the EQ-5D index score and associated visual analogue scale score (p<0.0001). Improvement of HRQoL was sustained through week 54. Serious AEs leading to treatment discontinuation occurred in 8.8% of patients.In this study measuring patient-reported outcomes in patients with moderate to severe UC, golimumab induced and maintained response as measured by PMS and significantly improved quality of life measures.NCT02092285; 2013-004583-56.
    • Google Books, Scopus, Microsoft Academic and Mendeley for impact assessment of doctoral dissertations: A multidisciplinary analysis of the UK

      Kousha, Kayvan; Thelwall, Mike (MIT Press, 2020-06-25)
      A research doctorate normally culminates in publishing a dissertation reporting a substantial body of novel work. In the absence of a suitable citation index, this article explores the relative merits of alternative methods for the large-scale assessment of dissertation impact, using 150,740 UK doctoral dissertations from 2009-2018. Systematic methods for this were designed for Google Books, Scopus, Microsoft Academic, and Mendeley. Less than 1 in 8 UK doctoral dissertations had at least one Scopus (12%), Microsoft Academic (11%) or Google Books citation (9%), or at least one Mendeley reader (5%). These percentages varied substantially by subject area and publication year. Google Books citations were more common in the Arts and Humanities (18%), whereas Scopus and Microsoft Academic citations were more numerous in Engineering (24%). In the Social Sciences, Google Books (13%) and Scopus (12%) citations were important and in Medical Sciences, Scopus and Microsoft Academic citations to dissertations were rare (6%). Few dissertations had Mendeley readers (from 3% in Science to 8% in the Social Sciences) and further analysis suggests that Google Scholar finds more citations but does not report information about all dissertations within a repository and is not a practical tool for large-scale impact assessment.
    • Google Scholar, Microsoft Academic, Scopus, Dimensions, Web of Science, and OpenCitations’ COCI: a multidisciplinary comparison of coverage via citations

      Martín-Martín, Alberto; Thelwall, Michael; Orduna-Malea, Enrique; Delgado López-Cózar, Emilio (Springer Nature, 2020-09-21)
      New sources of citation data have recently become available, such as Microsoft Academic, Dimensions, and the OpenCitations Index of CrossRef open DOI-to-DOI citations (COCI). Although these have been compared to the Web of Science Core Collection (WoS), Scopus, or Google Scholar, there is no systematic evidence of their differences across subject categories. In response, this paper investigates 3,073,351 citations found by these six data sources to 2,515 English-language highly-cited documents published in 2006 from 252 subject categories, expanding and updating the largest previous study. Google Scholar found 88% of all citations, many of which were not found by the other sources, and nearly all citations found by the remaining sources (89–94%). A similar pattern held within most subject categories. Microsoft Academic is the second largest overall (60% of all citations), including 82% of Scopus citations and 86% of WoS citations. In most categories, Microsoft Academic found more citations than Scopus and WoS (182 and 223 subject categories, respectively), but had coverage gaps in some areas, such as Physics and some Humanities categories. After Scopus, Dimensions is fourth largest (54% of all citations), including 84% of Scopus citations and 88% of WoS citations. It found more citations than Scopus in 36 categories, more than WoS in 185, and displays some coverage gaps, especially in the Humanities. Following WoS, COCI is the smallest, with 28% of all citations. Google Scholar is still the most comprehensive source. In many subject categories Microsoft Academic and Dimensions are good alternatives to Scopus and WoS in terms of coverage.
    • Government and agency response to soil erosion risk in europe

      Fullen, Michael A.; Arnalds, Andres; Bazzoffi, Paulo; Booth, Colin A.; Castillo, Victor; Martin, Philippe; Ritsema, Coen (Wiley InterScience, 2006)
      Provides an assessment of soil erosion throughout Europe, an important aspect to control and manage if landscapes are to be sustained for the future. This book focuses on issues of: area specific soil erosion rates, on and off-site impacts, government responses, soil conservation measures, and soil erosion risk maps.
    • A graphical tool for assessing the suitability of a count regression model

      Wilson, Paul; Einbeck, Jochen (Österreichische Statistische Gesellschaft (Austrian Society for Statistics), 2021-01-27)
      Whilst many numeric methods, such as AIC and deviance, exist for assessing or comparing model fit, diagrammatic methods are few. We present here a diagnostic plot, which we refer to as a ‘Quantile Band plot’, that may be used to visually assess the suitability of a given count data model. In the case of diagnosed model inadequacy, the plot has the unique feature of conveying precise information on the character of the violation, hence pointing the data analyst towards a potentially better model choice.
    • Grass ley set-aside and soil organic matter dynamics on sandy soils in Shropshire, UK

      Fullen, Michael A.; Booth, Colin A. (Wiley, 2006)
      Erosion plot studies at the Hilton Experimental Site, Shropshire, UK, evaluated the effects of set-aside on runoff, erosion and soil organic matter (SOM) dynamics. Ten runoff plots (slope angles 7-15°) were put to a grass ley in April 1991. Runoff and erosion rates during nine years were low, despite the occurrence of potentially erosive rains. Mean runoff was 0·24 per cent of precipitation (SD = 0·20, n = 89 plot years), compared with a 15-year mean value of 0·13 per cent (SD = 0·04) on permanent (control) grassland. The mean plot erosion rate was 0·21 t ha-1 a-1 (SD = 0·14, n = 69 plot years). Mean SOM content increased consistently and sign fi a tly on the set-aside plots, by a mean value of 1·07 per cent by weight (i.e. 1·07 g per 100 g of soil) in ten ye rs, from 2·04 per cent (1991) to 3·11 per cent (2001). Soil erodibility after six years of set-aside (sampling date 24 April 1997) was determined using a drip-screen rainfall simulator. Soil aggregate stability was higher on the grassed soils, compared with set-aside and bare arable soils. Despite no significant (P > 0·05) differences be w en grassland and set-asid oils, both these treatments were s gnificantly (P < 0·001) diff rent from bare soils. Contrary to the usually strong relationship between SOM and clay content, the percentage silt (r = 0·52, P < 0·001, n = 50) exhibited a stronger correlation with SOM than percentage clay content (r = 0·37, P < 0·01, n = 50). Furthermore, there were equally strong correlations between SOM and cumulative particle size fractions of both clay and silt contents (r = 0·51, P < 0·001, n = 50). In the absence of significant quantities of clay in these sandy soils, silts assist binding of SOM, which has significance for assessing soil carbon sequestration potential. Finally, future SOM and soil organic carbon benchmark work at the Hilton Site will improve harmonization of global SOM databases and enhance international estimates of rates and potential for soil carbon sequestration.