18 research outputs found

    Projections of climate change on the behaviour of clays in the UK

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    The impact of expected climate change on clay cuttings and embankments used for roads and railways is not well understood. Volume sensitive clays respond to seasonal variations in climate through vertical and horizontal displacements. These cause a variety of impacts at differing temporal and spatial scales, for example short term changes such as seasonal displacement of railway tracks or long term progressive failure of the slope. Daily changes in soil moisture content in the surface layers of a clay slope are simulated using a water balance model and expressed as soil moisture deficit and potential for surface runoff. Model results are validated against a 10 year run of field data in the UK. The impacts of anticipated climate change on soil water contents and equivalent pore water pressures are evaluated using stochastic climatic data over the 21st century based on the UK Climate Impacts Programme. Results indicate that recent summers considered to be exceptionally dry are likely to become the average condition later in the 21st century. Although winter rainfall is predicted to increase, average winter runoff will remain the same, although extreme wet events are still likely to occur. The implications for the design and maintenance of clay slopes and embankments are dis-cussed

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Tree induced soil suction and slope stability

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    This paper provides an investigation of moisture migration patterns in the vicinity of mature trees and soil slope stability. A numerical model is presented for unsaturated moisture flow incorporating a sink term to represent water uptake by a tree. The resulting variation in soil moisture content (or suction) is then included within an extended slope stability analysis that employs a method of estimating shear strength as a function of suction in addition to net mean stress. The moisture transfer equation is solved via application of a finite element method. The resulting water uptake predictions have been validated previously and were shown to be in reasonable agreement with field measured data. The current work provides an assessment of the importance of this aspect of the problem on slope stability. Results show that seasonal soil suctions generated by a tree can influence the facture of safety against soil slope failure in the order of 8%. The research provides a further contribution to the overall assessment of slope stability. It may be included in routine calculations where maintenance of rail/road embankments may involve alteration (or removal) of vegetation. It may also be applied to vegetated natural slopes subject to deforestation or development

    The life and adventures of Robinson Crusoe; : revised with special reference to moral tendency, and adapted to the capacity of the young : with numerous illustrations.

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    In manuscript on front flyleaf: Martin V.B. Pratt, May 14th 1844, presented by Z. Pratt."Printed by T.K. & P.G. Collins. Stereotyped by Murray & Joyce"--Title page verso.Mode of access: Internet

    Experimental staphylococcal mastitis in bitches: Clinical, bacteriological, cytological, haematological and pathological features

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    The objectives of the work were to study the features of experimentally induced canine mastitis and to present hypotheses regarding the pathogenesis of the disease. The tight caudal abdominal mammary gland of six bitches was inoculated on day 8 after whelping with Staphylococcus intermedius to induce mastitis; adjacent mammary glands were used as controls. Clinical examination, bacteriological and cytological (whiteside test, Giemsa) examination of mammary secretion, as well as haematological tests were performed from 5 days before until 34 days after challenge. Mastectomy was sequentially performed 1, 2, 4, 18, 26 and 34 days after challenge in each of the bitches, in order to carry out a pathological examination of mammary glands. All animals developed clinical mastitis: challenged glands became painful, hot, enlarged and oedematous; secretion was brownish, purulent, with flakes or clots, subsequently becoming yellowish and thick. Staphylococci were isolated from all inoculated glands (up to 22 days). WST was positive in 41/46 samples from inoculated glands and 66/138 samples from control glands; neutrophils predominated during the acute stage. Blood leukocyte counts increased, whilst platelet counts decreased. Gross pathological findings initially included congestion, purulent discharge and subcutaneous oedema; then abscesses, brownish areas and size decrease were seen. Salient histopathological features were initially neutrophilic infiltration, haemorrhages, destruction of mammary epithelial cells and alveoli, and then infiltration by lymphocytes, shrunken alveoli, loss of glandular architecture and fibrous tissue proliferation. We conclude that in bitches, intrammamary inoculation of Staphylococcus intermedius can induce clinical mastitis, followed by subclinical disease. The disorder is characterized by bacteria isolation and leukocyte influx in challenged glands, by leukocyte presence in adjacent mammary glands, by increased blood leukocyte counts and by destruction of mammary parenchyma. (c) 2007 Elsevier B.V. All rights reserved

    Asthma knowledge, attitudes, and quality of life in adolescents.

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    Adolescents with asthma, their peers, and their teachers were studied in order to establish the level of knowledge concerning asthma and its management, their attitudes towards asthma, and the degree quality of life impairment due to asthma. A community survey was conducted among year 8 high school students (n = 4161) and their teachers (n = 1104). There was a good response rate to the questionnaires from students (93%) and teachers (61%). Twenty three per cent of students had asthma and this caused mild to moderate quality of life impairment, particularly with strenuous exercise. Asthma was provoked by passive smoke exposure in 30% of asthmatic students and up to 51% of students avoided situations because of asthma triggers. Asthma knowledge was low in teachers (mean score 14.90 out of a possible 31), students without asthma (11.25) and students with asthma (14.50). Specific knowledge on the prevention and treatment of exercise induced asthma was poor. There was a moderate degree of tolerance towards asthma among all three groups. Most considered internal locus of control as important, although students without asthma also considered chance to be a determinant of outcomes for people with asthma. Asthma is a common cause of quality of life impairment among year 8 high school students. Although specific knowledge on asthma is low, students and teachers hold favourable attitudes towards asthma. There are opportunities to intervene and improve asthma management among adolescents
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