350 research outputs found
UK regional scale modelling of natural geohazards and climate change
For over 10 years, the British Geological Survey (BGS) has been investigating geotechnical and
mineralogical factors controlling volume change behaviour of UK clay soils and mudrocks. A
strong understanding of the relationship between these parameters and the clays' shrink-swell
properties has been developed. More recently, partly resulting from concerns of users of this
knowledge, a study of the relationships between climate change and shrink-swell behaviour
over the last 30 years has been carried out. Information on subsidence insurance claims has been
provided by the Association of British Insurers (ABI) and the UK Meteorological Office (UKMO)
historical climate station data has also been utilised. This is being combined with the
BGS's GeoSure national geohazard data, to build a preliminary GIS model to provide an understanding
of the susceptibility of the Tertiary London Clay to climate change. This paper summarises
the data analysis and identifies future work for model construction and refinement
The Induced Heart Rate Response to Fish Kairomones in \u3ci\u3eDaphnia pulex\u3c/i\u3e
Daphnia pulex have been shown to respond to kairomones emitted by predatory Chaoborus and planktivorous fish, though these two groups of predators differ significantly in their predation styles. The effects of predation vary across Daphnia size range, and heart rate response to Chaoborus kairomones has been shown to vary across size. I found that heart rate of individuals in the small size class in a clonal population of Daphnia pulex respond more strongly to bluegill (Lepomismacrochirus) kairomones than heart rate of medium or large size classes. The two largest classes showed no difference in heart rate between control and fish kairomone treatments. This is possibly due to physiological differences between small and large Daphnia pulex, or it could be an adaptive response based on the futility of escape from fish predation for large Daphnia and the lower detection rates for small Daphnia
Enrichment of innate lymphoid cell populations in gingival tissue
Innate lymphoid cells (ILCs) are a population of lymphocytes that act as the first line of immunologic defense at mucosal surfaces. The ILC family in the skin, lungs, and gastrointestinal tissues has been investigated, and there are reports of individual subsets of ILCs in the oral tissues. We sought to investigate the whole ILC population (group 1, 2, and 3 subsets) in the murine gingivae and the lymph nodes draining the oral cavity. We show that ILCs made up a greater proportion of the whole CD45+ lymphocyte population in the murine gingivae (0.356% ± 0.039%) as compared with the proportion of ILCs in the draining lymph nodes (0.158% ± 0.005%). Cytokine profiling of the ILC populations demonstrated different proportions of ILC subsets in the murine gingivae versus the regional lymph nodes. The majority of ILCs in the draining lymph nodes expressed IL-5, whereas there were equal proportions of IFN-γ- and IL-5 expressing ILCs in the oral mucosa. The percentage of IL-17+ ILCs was comparable between the murine gingivae and the oral draining lymph nodes. These data suggest an enrichment of ILCs in the murine gingivae, and these ILCs reflect a cytokine profile discrepant to that of the local draining lymph nodes. These studies indicate diversity and enrichment of ILCs at the oral mucosal surface. The function of ILCs in the oral cavity remains to be determined; here, we provide a premise of ILC populations that merits future consideration in investigations of mouse models and human tissues
The immunopathology of dengue and Zika virus infections.
A large proportion of the world's population live in areas with dengue virus (DENV) transmission resulting in tens of millions of symptomatic dengue cases each year. Serious complications following DENV infection occur more frequently in those suffering from a second or subsequent infection implicating virus-specific immunity as having a role in pathogenesis. In recent years outbreaks of the related Zika virus (ZIKV) have been associated with birth defects and neurological complications. As DENV and ZIKV share a viral vector sequential infections can occur. Given the sequence homology between the two viruses, the generation of cross-reactive immune responses is highly likely. This review examines the role immunopathogenesis plays during DENV infection as well as highlighting recent studies that demonstrate DENV immunity may have an effect on the outcome of ZIKV infection
The Flipped Classroom Model as Applied to an Augmentative and Alternative Communication Course
The Flipped Classroom Model (FCM) is an andragogical approach where students complete content-related work outside of the class and engage in activities related to this content during the class period. This approach has garnered recent attention in the field of speech-language pathology, but its implementation has not been studied in an augmentative and alternative communication (AAC) course and there is limited information on student perspectives of the experience. This study presents the results of a qualitative investigation designed to investigate the preferences and experiences of preservice speech-language pathology graduate students in an AAC course utilizing the FCM. Semi-structured interviews with eight students were transcribed and analyzed utilizing a phenomenological framework. The themes that emerged from the data included course design, course delivery, instructor characteristics, student preferences, student characteristics, online versus in-person learning, and career relevance. Recommendations for implementing the FCM in teaching AAC are discussed in light of the results presented
Application of OCT to examination of easel paintings
We present results of applying low coherence interferometry to gallery paintings. Infrared low coherence interferometry is capable of non-destructive examination of paintings in 3D, which shows not only the structure of the varnish layer but also the paint layers
Chapter 6 Collapsible Soils in the UK
Metastable soils may collapse because of the nature of their fabric. Generally speaking, these soils have porous textures, high void ratios and low densities. They have high apparent strengths at their natural moisture content, but large reductions of void ratio take place upon wetting and, particularly, when they are loaded because bonds between grains break down upon saturation. Worldwide, there is a range of natural soils that are metastable and can collapse, including loess, residual soils derived from the weathering of acid igneous rocks and from volcanic ashes and lavas, rapidly deposited and then desiccated debris flow materials such as some alluvial fans; for example, in semi-arid basins, colluvium from some semi-arid areas and cemented, high salt content soils such as some sabkhas. In addition, some artificial non-engineered fills can also collapse. In the UK, the main type of collapsible soil is loess, though collapsible non-engineered fills also exist. Loess in the UK can be identified from geological maps, but care is needed because it is usually mapped as ‘brickearth’. This is an inappropriate term and it is suggested here that it should be replaced, where the soils consist of loess, by the term ‘loessic brickearth’. Loessic brickearth in the UK is found mainly in the south east, south and south west of England, where thicknesses greater than 1 m are found. Elsewhere, thicknesses are usually less than 1 m and, consequently, of limited engineering significance. There are four steps in dealing with the potential risks to engineering posed by collapsible soils: (1) identification of the presence of a potentially collapsible soil using geological and geomorphological information; (2) classification of the degree of collapsibility, including the use of indirect correlations; (3) quantification of the degree of collapsibility using laboratory and/or in situ testing; (4) improvement of the collapsible soil using a number of engineering options
The acute pressure natriuresis response is suppressed by selective ETA receptor blockade
Hypertension is a major risk factor for cardiovascular disease. In a significant minority of people, it develops when salt intake is increased (salt-sensitivity). It is not clear whether this represents impaired vascular function or disruption to the relationship between blood pressure (BP) and renal salt-handling (pressure natriuresis, PN). Endothelin-1 (ET-1) regulates BP via ET(A) and ET(B) receptor subtypes. Blockade of ET(A) receptors reduces BP but promotes sodium retention by an unknown mechanism. ET(B) blockade increases both BP and sodium retention. We hypothesized that ET(A) blockade promotes sodium and water retention by suppressing PN. We also investigated whether suppression of PN might reflect off-target ET(B) blockade. Acute PN was induced by sequential arterial ligation in male Sprague Dawley rats. Intravenous atrasentan (ET(A) antagonist, 5 mg/kg) halved the normal increase in medullary perfusion and reduced sodium and water excretion by >60%. This was not due to off-target ET(B) blockade because intravenous A-192621 (ET(B) antagonist, 10 mg/kg) increased natriuresis by 50% without modifying medullary perfusion. In a separate experiment in salt-loaded rats monitored by radiotelemetry, oral atrasentan reduced systolic and diastolic BP by ∼10 mmHg, but additional oral A-192621 reversed these effects. Endogenous ET(A) stimulation has natriuretic effects mediated by renal vascular dilation while endogenous ET(B) stimulation in the kidney has antinatriuretic effects via renal tubular mechanisms. Pharmacological manipulation of vascular function with ET antagonists modifies the BP set-point, but even highly selective ET(A) antagonists attenuate PN, which may be associated with salt and water retention
Efficacy of pimobendan in the prevention of congestive heart failure or sudden death in doberman pinschers with preclinical dilated cardiomyopathy (the PROTECT study)
<p>Background: The benefit of pimobendan in delaying the progression of preclinical dilated cardiomyopathy (DCM) in Dobermans is not reported.</p>
<p>Hypothesis: That chronic oral administration of pimobendan to Dobermans with preclinical DCM will delay the onset of CHF or sudden death and improve survival.</p>
<p>Animals: Seventy-six client-owned Dobermans recruited at 10 centers in the UK and North America.</p>
<p>Methods: The trial was a randomized, blinded, placebo-controlled, parallel group multicenter study. Dogs were allocated in a 1:1 ratio to receive pimobendan (Vetmedin capsules) or visually identical placebo.</p>
<p>The composite primary endpoint was prospectively defined as either onset of CHF or sudden death. Time to death from all causes was a secondary endpoint.</p>
<p>Results: The proportion of dogs reaching the primary endpoint was not significantly different between groups (P = .1). The median time to the primary endpoint (onset of CHF or sudden death) was significantly longer in the pimobendan (718 days, IQR 441–1152 days) versus the placebo group (441 days, IQR 151–641 days) (log-rank P = 0.0088). The median survival time was significantly longer in the pimobendan (623 days, IQR 491–1531 days) versus the placebo group (466 days, IQR 236–710 days) (log-rank P = .034).</p>
<p>Conclusion and Clinical Importance: The administration of pimobendan to Dobermans with preclinical DCM prolongs the time to the onset of clinical signs and extends survival. Treatment of dogs in the preclinical phase of this common cardiovascular disorder with pimobendan can lead to improved outcome.</p>
Agent-based and continuous models of hopper bands for the Australian plague locust: How resource consumption mediates pulse formation and geometry
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