An investigation of benthic recovery and climate change resilience in the Englishman River estuary

SNAPSHOT: A benthic monitoring program will be added in 2018 to the ongoing Englishman River Estuary recovery study, situated on the east coast of Vancouver Island. This will complement investigations which have been ongoing, prior to and following the removal of a berm during 2017. Changes in salinity patterns, flow regimes, channel morphology, elevation, sediment size, and vegetation distribution are being assessed and these variables will be used to map distinctive areas of the estuary. Benthic samples will be collected from representative areas and monitored over the long term. Relative and total abundance, species diversity, biomass, and various derivatives of these data, such as mean body weight, dominant faunal groups by weight and abundance, and species diversity/richness indices will be used to assess changes in the benthos following berm removal, and to determine community resiliency to climate change. The study will be used to develop protocol for a BC coastal wide estuary monitoring program investigating ecosystem resilience to climate change. It is being led by members of the West Coast Conservation Land Management Program and is supported by The Nature Trust of BC, The Habitat Conservation Trust Foundation, Ducks Unlimited, Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Environment and Climate Change Canada, Fisheries and Oceans Canada, BC Conservation Foundation and stewardship groups

Recent advances in the modelling of crack growth under fatigue loading conditions

Fatigue crack growth associated with cyclic (secondary) plastic flow near a crack front is modelled using an incremental formulation. A new description of threshold behaviour under small load cycles is included. Quasi-static crack extension under high load excursions is described using an incremental formulation of the R-(crack growth resistance)- curve concept. The integration of the equations is discussed. For constant amplitude load cycles the results will be compared with existing crack growth laws. It will be shown that the model also properly describes interaction effects of fatigue crack growth and quasi-static crack extension. To evaluate the more general applicability the model is included in the NASGRO computer code for damage tolerance analysis. For this purpose the NASGRO program was provided with the CORPUS and the STRIP-YIELD models for computation of the crack opening load levels. The implementation is discussed and recent results of the verification are presented

On the development of unmodified mud grouts for repairing earth constructions: rheology, strength and adhesion

The conservation and rehabilitation of several sites of cultural heritage and of the large housing stock built from earth requires the development of techniques and materials compatible with this kind of construction. Grout injection is one repair solution which has been put forward over the last few years, whereas there is preference for employing grouts that incorporate earth in their composition. However, knowledge of such grouts is still very limited and requires further research. The experimental program discussed in this paper contributes to the comprehension of the influence of the composition of an unmodified mud grout, namely regarding its fresh-state rheology, hardened-state strength and adhesion. In general, the results obtained showed that the rheological behaviour of a mud grout greatly depends on the colloid behaviour of the clay fraction, and that the addition of a deflocculant and modification of the clay content (with a silt size material) is required to obtain grouts with adequate solid fractions.The authors wish to express their gratitude to the Portuguese Science and Technology Foundation for the scholarship granted to the first author (SFRH/BD/39145/2007) and to the companyWienerberger (Belgium) for kindly providing the kaolin

A restoration and climate change resiliency monitoring program for coastal BC estuaries

The Englishman River estuary and associated habitats, on the south east coast of Vancouver Island, has long been recognized as an important and productive ecosystem, supporting more than 250 bird species, all seven species of Pacific salmon, forage fish, at-risk plant communities and many other fish and wildlife species. The estuary is located within the Parksville/Qualicum Wildlife Management Area and is managed through the collaborative efforts of several ENGOs and government agencies. Last year, 2017, marked the first-year of a five-year restoration and monitoring program which aims to re-establish natural estuarine circulation patterns and restore intertidal and upland marsh habitat. For more than 100 years the estuarine ecosystem has been altered and habitat destroyed through the construction of dykes, roads, sediment removal and filling, log boom storage, agriculture and the introduction of invasive species. These modifications caused changes to estuarine circulation patterns and morphology, habitat availability, ecological function and community composition. In July 2017, a berm from an abandoned road was removed, improving tidal flows to channels and marsh areas that were subject to restricted flow regimes for many years. The West Coast Conservation Land Management Program is leading a research consortium which is monitoring changes in channel morphology, water level, salinity patterns, vegetation distribution and composition, fish, bird and wildlife populations, and in 2018 a benthos monitoring component will be added. The Englishman study provides an opportunity to develop protocol for a BC coastal wide estuary monitoring program which will investigate response to environmental change and ecosystem resilience to climate change. This program is supported by The Nature Trust of BC, The Habitat Conservation Trust Foundation, Ducks Unlimited, Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Environment and Climate Change Canada, Fisheries and Oceans Canada, BC Conservation Foundation and stewardship groups

Implementation of lung cancer screening in Europe:challenges and potential solutions: summary of a multidisciplinary roundtable discussion

Recent randomised trials on screening with low-dose CT have shown important reductions in lung cancer (LC) mortality and have triggered international efforts to implement LC screening. Detection rates of stage I LC with volume CT approaching 70% have been demonstrated. In April 2019 'ESMO Open - Cancer Horizons' convened a roundtable discussion on the challenges and potential solutions regarding the implementation of LC screening in Europe. The expert panel reviewed the current evidence for LC screening with low-dose CT and discussed the next steps, which are covered in this article. The panel concluded that national health policy groups in Europe should start to implement CT screening as adequate evidence is available. It was recognised that there are opportunities to improve the screening process through 'Implementation Research Programmes'

Impaired Thymic Selection and Abnormal Antigen-Specific T Cell Responses in Foxn1Δ/Δ Mutant Mice

Foxn1(Δ/Δ) mutant mice have a specific defect in thymic development, characterized by a block in TEC differentiation at an intermediate progenitor stage, and blocks in thymocyte development at both the DN1 and DP cell stages, resulting in the production of abnormally functioning T cells that develop from an atypical progenitor population. In the current study, we tested the effects of these defects on thymic selection.We used Foxn1(Δ/Δ); DO11 Tg and Foxn1(Δ/Δ); OT1 Tg mice as positive selection and Foxn1(Δ/Δ); MHCII I-E mice as negative selection models. We also used an in vivo system of antigen-specific reactivity to test the function of peripheral T cells. Our data show that the capacity for positive and negative selection of both CD4 and CD8 SP thymocytes was reduced in Foxn1(Δ/Δ) mutants compared to Foxn1(+/Δ) control mice. These defects were associated with reduction of both MHC Class I and Class II expression, although the resulting peripheral T cells have a broad TCR Vβ repertoire. In this deficient thymic environment, immature CD4 and CD8 SP thymocytes emigrate from the thymus into the periphery. These T cells had an incompletely activated profile under stimulation of the TCR signal in vitro, and were either hypersensitive or hyporesponsive to antigen-specific stimulation in vivo. These cell-autonomous defects were compounded by the hypocellular peripheral environment caused by low thymic output.These data show that a primary defect in the thymic microenvironment can cause both direct defects in selection which can in turn cause indirect effects on the periphery, exacerbating functional defects in T cells

Population-Specific Responses to Interspecific Competition in the Gut Microbiota of Two Atlantic Salmon (Salmo salar) Populations

The gut microbial community in vertebrates plays a role in nutrient digestion and absorption, development of intestine and immune systems, resistance to infection, regulation of bone mass and even host behavior and can thus impact host fitness. Atlantic salmon (Salmo salar) reintroduction efforts into Lake Ontario, Canada, have been unsuccessful, likely due to competition with non-native salmonids. In this study, we explored interspecific competition effects on the gut microbiota of two Atlantic salmon populations (LaHave and Sebago) resulting from four non-native salmonids. After 10 months of rearing in semi-natural stream tanks under six interspecific competition treatments, we characterized the gut microbiota of 178 Atlantic salmon by parallel sequencing the 16S rRNA gene. We found 3978 bacterial OTUs across all samples. Microbiota alpha diversity and abundance of 27 OTUs significantly differed between the two populations. Interspecific competition reduced relative abundance of potential beneficial bacteria (six genera of lactic acid bacteria) as well as 13 OTUs, but only in the LaHave population, indicating population-specific competition effects. The pattern of gut microbiota response to interspecific competition may reflect local adaptation of the host-microbiota interactions and can be used to select candidate populations for improved species reintroduction success