358 research outputs found
Requirements for Differentiation of an Immature CD4+8+ T-Cell Line
The CD3ɛ and ζ chains of the TCR have been shown to possess independent signaling capabilities.
Studies with chimeric molecules containing the cytoplasmic domains of either ζ or ɛ have
suggested that these two structurally distinct members of the TCR-CD3 complex are able to
function autonomously and have redundant features in the context of TCR-signal transduction
in mature T cells. Expression of a chimeric human IL-2-receptor-ζ-chain molecule in the
CD4+8+ T-cell line, DPK, has enabled us to directly analyze responses initiated by the ζ-chain-signaling
module alone within the context of immature T-cell differentiation. In this paper, we
show that antibody crosslinking of the chimeric ζ chain delivers only a limited activation signal
as measured by Ca[2+] flux, induction of low-level CD5 expression, and minimal differentiation
as assessed by loss of cell-surface CD8 expression. TCR-induced activation through antibody
crosslinking of the endogenous CD3ɛ receptor in the absence of costimulation was also
relatively inefficient in initiating activation and differentiation. However, co-crosslinking of the
CD4 coreceptor with CD3 resulted in a synergistic response, where as there was little effect of
co-crosslinking of CD4 and the ζ-chain chimera. Striking differences were also observed in the
substrate pattern of tyrosine phosphorylation, as well as lymphokine secretion following triggering
through the intact TCR versus the ζ chain alone. These results indicate that although the
ζ-chain may possess some signaling capacities similar to that of the intact TCR, it appears to
have limited function as an autonomous subunit in initiating CD4+8+ T-cell differentiation
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
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In vitro regulation and cultivation of salmonid lymphocytes
The foundation of the research compilation presented here began
with the derivation of an improved method for obtaining optimal in vitro
mitogenic responses in salmonid lymphocyte cultures by utilizing
autologous or homologous plasma as the primary serum supplement. It was
observed that lymphocytes which were previously unresponsive to
mitogenic challenge in vitro, when cultured in fetal bovine serum, responded
well when cultured in the presence of homologous plasma. Salmonid
plasma sources not only repeatedly enhanced the mitogen-specific
proliferation of the lymphocyte cultures, but enhanced the antibody response
as well. A prolonged kinetic response further supported the contention that
former conditions of salmonid lymphocyte culture, employing only fetal
bovine serum, not only fail to provide the optimal conditions for cell growth,
but in many cases the essential conditions. Enhancement of the mitogenic
response was observed for three distinct species, using a common plasma
source, suggesting utilization of plasma as an alternate serum supplement
has broad applications and may be adapted to many fish systems.
With this improved culture system, examination of the regulation of
lymphocytes, specifically B cells, was undertaken. Evidence for the
existence of a natural regulatory cell population located in the anterior
kidney is presented. Addition of anterior kidney cells to either autologous
peripheral blood or spleen cell cultures resulted in significant suppression of
the mitogen response. The degree of suppressor activity appears to be
correlated with the anterior kidney lymphocyte's ability to respond to
mitogenic stimulus. It is demonstrated that a decrease in the anterior kidney
mitogen response correlates significantly with an increase in the suppressor
activity observed upon coculture of these same cells with peripheral blood
lymphocytes. Interestingly, while addition of anterior kidney cells to spleen
plaque forming cell cultures also resulted in suppression, anterior kidney
cells had either no effect or enhanced the antibody response of the
peripheral blood lymphocyte cultures. It is postulated that the mediator of
this anterior kidney activity is a suppressor cell population which may
possess an important immunoregulatory function
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Embedded sensor speed and width estimation
The goal of this report is to provide a novel system of estimating width and velocity of an object passing perpendicularly through a sensor field. By fixing four sensors on an axis at known angles the distance and velocity of an object can be estimated from the times of detection of each sensor using a system of equations. To develop a prototype of this system the scenario was modeled and simulated, a processor and sensors were selected, and algorithms for detection and estimation were developed. The goal of the report was to develop a self-contained sensor network and computing platform that would correctly estimate the speed of the object in miles per hour within 15% accuracy, and to estimate the width of the object within 20% accuracy. Due to prototype design errors, these requirements were not met, however useful algorithms and simulations were developed to lead towards successful future work.Electrical and Computer Engineerin
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
Identification of single nucleotide polymorphisms from the transcriptome of an organism with a whole genome duplication
BACKGROUND: The common ancestor of salmonid fishes, including rainbow trout (Oncorhynchus mykiss), experienced a whole genome duplication between 20 and 100 million years ago, and many of the duplicated genes have been retained in the trout genome. This retention complicates efforts to detect allelic variation in salmonid fishes. Specifically, single nucleotide polymorphism (SNP) detection is problematic because nucleotide variation can be found between the duplicate copies (paralogs) of a gene as well as between alleles. RESULTS: We present a method of differentiating between allelic and paralogous (gene copy) sequence variants, allowing identification of SNPs in organisms with multiple copies of a gene or set of genes. The basic strategy is to: 1) identify windows of unique cDNA sequences with homology to each other, 2) compare these unique cDNAs if they are not shared between individuals (i.e. the cDNA is homozygous in one individual and homozygous for another cDNA in the other individual), and 3) give a “SNP score” value between zero and one to each candidate sequence variant based on six criteria. Using this strategy we were able to detect about seven thousand potential SNPs from the transcriptomes of several clonal lines of rainbow trout. When directly compared to a pre-validated set of SNPs in polyploid wheat, we were also able to estimate the false-positive rate of this strategy as 0 to 28% depending on parameters used. CONCLUSIONS: This strategy has an advantage over traditional techniques of SNP identification because another dimension of sequencing information is utilized. This method is especially well suited for identifying SNPs in polyploids, both outbred and inbred, but would tend to be conservative for diploid organisms
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'
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
Final report for secure camera capture system (April 2016)
This report provides an overview of the Secure Camera Capture system produced by Team 6 in Spring 2016�s Senior Design 2 class. The project encompassed a three-part hardware and software system, used to capture, securely store, and retrieve photographs taken by an internet-equipped camera on a sixty-second timer. In the report, the project is outlined in both technical and nontechnical terms, the AES encryption method used, the Raspberry Pi microcontroller hardware, and the software used to tie them together. Specifications (both hardware and software) and how they were addressed are detailed, and a guide is provided to reconstruct the project using provided code. Finally, it provides the team�s perspective on the final product and possible improvements that could be made on the design
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