Adhesion of volcanic ash particles under controlled conditions and implications for their deposition in gas turbines

A particular (representative) type of ash has been used in this study, having a particle size range of ~10-70 µm. Experimental particle adhesion rate data are considered in conjunction with CFD modeling of particle velocities and temperatures. This ash becomes soft above ~700˚C and it has been confirmed that a sharp increase is observed in the likelihood of adhesion as particle temperatures move into this range. Particle size is important and those in the approximate range 10-30 µm are most likely to adhere. This corresponds fairly closely with the size range that is most likely to enter a combustion chamber and turbine.This work forms part of a research programme funded by EPSRC (EP/K027530/1). In conjunction with this project, a consortium of partners has been set up under the PROVIDA ("PROtection against Volcanic ash Induced Damage in Aeroengines") banner and information about its operation is available at http://www.ccg.msm.cam.ac.uk/initiatives/provida. The invaluable assistance of Kevin Roberts (Materials Department in Cambridge) with operation of the plasma spray facility is gratefully acknowledged. The authors are also grateful to Dr. Margaret Hartley, of the University of Manchester, for kindly collecting the Laki ash (and several other types) during field trips to Iceland, which were funded by EasyJet.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/adem.201500371 In compliance with current EPSRC requirements, input data for the modelling described in this paper, including meshing and boundary condition specifications, are available at the following URL: www.ccg.msm.cam.ac.uk/publications/resources. These files can be downloaded and used in COMSOL Multiphysics packages. Data supplied are for a representative case

The effector T cell response to influenza infection

Influenza virus infection induces a potent initial innate immune response, which serves to limit the extent of viral replication and virus spread. However, efficient (and eventual) viral clearance within the respiratory tract requires the subsequent activation, rapid proliferation, recruitment, and expression of effector activities by the adaptive immune system, consisting of antibody producing B cells and influenza-specific T lymphocytes with diverse functions. The ensuing effector activities of these T lymphocytes ultimately determine (along with antibodies) the capacity of the host to eliminate the viruses and the extent of tissue damage. In this review, we describe this effector T cell response to influenza virus infection. Based on information largely obtained in experimental settings (i.e., murine models), we will illustrate the factors regulating the induction of adaptive immune T cell responses to influenza, the effector activities displayed by these activated T cells, the mechanisms underlying the expression of these effector mechanisms, and the control of the activation/differentiation of these T cells, in situ, in the infected lungs

From Input to Intake: Researching Learner Cognition

The distinction between input, what the teachers say to their learners, and intake, what the learners hear, has been recognised in research into second language acquisition at least since Corder (1967). The distinction is important because language development does not result from the input to which learners are exposed but what the learners take in. If a teacher in a class focussing on the past simple says “Harry and Megan cooked a curry last weekend,” the input that the learners are exposed to is “Harry and Megan cooked a curry last weekend.” However, if a learner hears “Harry and Megan cook a curry last weekend” then this sentence, in all its non-standard grammaticality, is the intake and this episode is unlikely to contribute to the learner’s command of the past tense. If, for example, researchers were interested in identifying the number of instances of the past tense needed for learners to acquire this tense, research that counted the number of times the teacher used the past tense will only help us to understand the acquisition process if there is a systematic relationship between what the teacher says, the input, and what the learner hears, the intake. However, the conceptual distinction between input and intake in second language acquisition (SLA) has been poorly operationalized and much research treats input as a straightforward proxy for intake. This article explores the relationship between input and intake in order to identify strategies for researching language development that are based on a more solid understanding of the connections between input and intake

The effectiveness and cost-evaluation of manual therapy and physical therapy in patients with sub-acute and chronic non specific neck pain. Rationale and design of a Randomized Controlled Trial (RCT)

Contains fulltext : 88910.pdf (publisher's version ) (Open Access)BACKGROUND: Manual Therapy applied to patients with non specific neck pain has been investigated several times. In the Netherlands, manual therapy as applied according to the Utrecht School of Manual Therapy (MTU) has not been the subject of a randomized controlled trial. MTU differs in diagnoses and treatment from other forms of manual therapy. METHODS/DESIGN: This is a single blind randomized controlled trial in patients with sub-acute and chronic non specific neck pain. Patients with neck complaints existing for two weeks (minimum) till one year (maximum) will participate in the trial. 180 participants will be recruited in thirteen primary health care centres in the Netherlands.The experimental group will be treated with MTU during a six week period. The control group will be treated with physical therapy (standard care, mainly active exercise therapy), also for a period of six weeks.Primary outcomes are Global Perceived Effect (GPE) and functional status (Neck Disability Index (NDI-DV)). Secondary outcomes are neck pain (Numeric Rating Scale (NRS)), Eurocol, costs and quality of life (SF36). DISCUSSION: This paper presents details on the rationale of MTU, design, methods and operational aspects of the trial. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00713843

Autonomous role of medullary thymic epithelial cells in central CD4+ T cell tolerance

International audienceMedullary thymic epithelial cells (mTECs) serve an essential function in central tolerance through expressing peripheral tissue-antigens. These antigens may be transferred to and presented by dendritic cells. Therefore, it is unclear whether mTECs, besides being an 'antigen-reservoir', also serve a mandatory function as antigen presenting cells. Here, we reduced MHC class II on mTECs through transgenic expression of a C2TA-specific 'designer miRNA'. This resulted in an enlarged polyclonal CD4 single-positive compartment and, among thymocytes specific for model-antigens expressed in mTECs, enhanced selection of regulatory T cells (Treg) at the expense of deletion. Our data document an autonomous contribution of mTECs to dominant and recessive mechanisms of CD4+ T cell tolerance and support an avidity model of Treg development versus deletion