203,653 research outputs found
Exploring The Influence of The UK Construction Industry Players in Embracing Modern Methods of Construction
The ninth goal of the sustainable development goal (SDG) is to build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation while the eleventh goal is to make cities and human settlements inclusive, safe, resilient and sustainable. Despite these, there is still a wide gap between various governmental advances and the availability of homes and commercial property around the world, in Europe and most especially, in the United Kingdom. Hence, there has been a significant push for the Construction industry to embrace the use of Modern Methods of Construction (MMC) to alleviate the housing problems. However, notwithstanding the many benefits of MMC, there are still barriers to full implementation in the construction industry. This research therefore explores the understanding and the ability of the professionals in the UK construction industry to influence the adoption of this innovative construction method. This study is carried out through a combination of a literature review and a questionnaire survey of the top professionals in the UK construction industry. The result establishes that the construction professional’s understanding is appropriate in advising clients on the use and potential benefits of MMC. The findings then motivate a further investigation into other likely impediments hindering a full take-off of MMC in the UK
Regulation of B cell fate by chronic activity of the IgE B cell receptor.
IgE can trigger potent allergic responses, yet the mechanisms regulating IgE production are poorly understood. Here we reveal that IgE+ B cells are constrained by chronic activity of the IgE B cell receptor (BCR). In the absence of cognate antigen, the IgE BCR promoted terminal differentiation of B cells into plasma cells (PCs) under cell culture conditions mimicking T cell help. This antigen-independent PC differentiation involved multiple IgE domains and Syk, CD19, BLNK, Btk, and IRF4. Disruption of BCR signaling in mice led to consistently exaggerated IgE+ germinal center (GC) B cell but variably increased PC responses. We were unable to confirm reports that the IgE BCR directly promoted intrinsic apoptosis. Instead, IgE+ GC B cells exhibited poor antigen presentation and prolonged cell cycles, suggesting reduced competition for T cell help. We propose that chronic BCR activity and access to T cell help play critical roles in regulating IgE responses
Performance of lateritic concrete under environmental harsh condition
This is an investigation of weathering characteristics of Laterized concrete with laterite-fine aggregate ratio as a factor. It was done with a view of ascertaining the suitability of laterite as aggregate substitutes at 0, 10, 20, 30 and 40% of fine aggregate used in the construction industry. The weathering characteristics were examined by conditioning laterized concrete cubes to varying temperatures, chemical and alternate wetting and drying, which all represent the operating weather conditions (wet and dry seasons) in tropics, including Nigeria. The mix proportion used was 1: 2: 4, the curing age of the laterized concrete was based on 28days curing age, while the compressive strength of the treated laterized concrete cubes was determined. The result of this research showed that the compressive strength of laterized concrete with laterite-fine aggregate ratio variation decreases when subjected to alternate wetting and drying and increases when subjected to magnesium sulphate (Mg2SO4). It was also discovered that a laterized concrete with a laterite-fine aggregate ratio of 20% conditioned to a temperature range of 100oC attained optimum compressive strength of 12.90 Nmm-
Comparative Analysis Of Portland Cements In Nigeria
Portland cement remains the most common type generally in use throughout the world as a basic ingredient of concrete. Five brands of Portland cement commonly available in Nigeria were investigated through series of tests conducted to determine their strength characteristics, setting time, soundness, workability and fineness among others and examined if they meet the minimum standard as stipulated by the British Standard Institute. Five brands of cement considered were Dangote, Elephant, Burham, Diamond and Purechem. The results show that all the
brands examined meet the British Standard requirements on all the tests subjected to. Burham cement was fastest with initial setting time of 100 minutes ahead of other, while Dangote cement was the least with initial setting time of 180 minutes. The strengths characteristics of the five brands are similar with slight difference recorded. Dangote cement had the highest strength at 28th day curing period of 474 KN as the crushing load while the least strength was of Purechem at 370.6 KN as the rushing
load
Genetic variation among lambs in peripheral IgE activity against the larval stages of <i>Teladorsagia circumcincta</i>
IgA and IgE activity against Teladorsagia circumcincta was investigated in a flock of Texel lambs following natural, mixed nematode infection among lambs. The distribution of IgA activity was similar to a gamma distribution whereas IgE activity was different. Box-Cox analysis demonstrated that X0.25 was a suitable transformation to normalise IgE responses. The transformed IgE activity was under moderate to strong genetic control. Nine different allergens were identified by proteomic analysis. Tropomyosin was selected for further analysis. IgE activity against tropomyosin was moderately heritable and associated with decreased egg counts and with reduced body weight at the time of sampling
Mimotope mapping as a complementary strategy to define allergen IgE-epitopes: peach Pru p 3 allergen as a model.
Lipid transfer proteins (LTPs) are the major allergens of Rosaceae fruits in the Mediterranean area. Pru p 3, the LTP and major allergen of peach, is a suitable model for studying food allergy and amino acid sequences related with its IgE-binding capacity. In this work, we sought to map IgE mimotopes on the structure of Pru p 3, using the combination of a random peptide phage display library and a three-dimensional modelling approach. Pru p 3-specific IgE was purified from 2 different pools of sera from peach allergic patients grouped by symptoms (OAS-pool or SYS-pool), and used for screening of a random dodecapeptide phage display library. Positive clones were further confirmed by ELISA assays testing individual sera from each pool. Three-dimensional modelling allowed location of mimotopes based on analysis of electrostatic properties and solvent exposure of the Pru p 3 surface. Twenty-one phage clones were selected using Pru p 3-specific IgE, 9 of which were chosen using OAS-specific IgE while the other 12 were selected with systemic-specific IgE. Peptide alignments revealed consensus sequences for each pool: L37 R39 T40 P42 D43 R44 A46 P70 S76 P78 Y79 for OAS-IgE, and N35 N36 L37 R39 T40 D43 A46 S76 I77 P78 for systemic-IgE. These 2 consensus sequences were mapped on the same surface of Pru p 3, corresponding to the helix 2-loop-helix 3 region and part of the non-structured C-terminal coil. Thus, 2 relevant conformational IgE-binding regions of Pru p 3 were identified using a random peptide phage display library. Mimotopes can be used to study the interaction between allergens and IgE, and to accelerate the process to design new vaccines and new immunotherapy strategie
Temporal Changes in Total Serum Immunoglobulin E Levels in East German Children and the Effect of Potential Predictors
Background: Elevated total serum immunoglobulin E (IgE) levels are a prominent feature of allergic and parasitic diseases. An epidemiologic study was conducted in East German children to describe trends in the development of total serum IgE levels and analyze the impact of potential determinants. Methods: The study consisted of three cross-sectional surveys in 1992-1993, 1995-1996 and 1998-1999 and was conducted in three areas of the former German Democratic Republic. In total, 8,051 questionnaires were completed by the parents of children aged 5-14 years, supplying information on allergic symptoms and potential risk factors. A total of 5,918 measurements of total serum IgE and specific IgE to 5 common aeroallergens were available from 4,353 schoolchildren. Generalized estimating equations were applied to data from all children and stratified for atopic and nonatopic children to identify trends and estimate the effect of potential determinants on total IgE. Results: Total serum IgE levels decreased significantly with a linear trend in East German schoolchildren between 1992 and 1999, the effect being stronger in nonatopic children. The following factors were associated with lower total serum IgE levels: female gender, living in a household with fewer than 4 people, no history of helminth infestation, younger age group (5-7 years), no parental allergy and high socioeconomic status. No association was seen for `smoking at home' and close contact to pets. Conclusion: Total serum IgE declined parallel to helminth infestation; however, the latter explained the decrease only in part. Furthermore, total IgE developed in an opposite direction to specific IgE, indicating that it has determinants other than allergic sensitization. Copyright (C) 2011 S. Karger AG, Base
The structure of human CD23 and its interactions with IgE and CD21
The low-affinity immunoglobulin E (IgE) receptor, CD23 (FcɛRII), binds both IgE and CD21 and, through these interactions, regulates the synthesis of IgE, the antibody isotype that mediates the allergic response. We have determined the three-dimensional structure of the C-type lectin domain of CD23 in solution by nuclear magnetic resonance spectroscopy. An analysis of concentration-dependent chemical shift perturbations have allowed us to identify the residues engaged in self-association to the trimeric state, whereas ligand-induced changes have defined the binding sites for IgE and CD21. The results further reveal that CD23 can bind both ligands simultaneously. Despite the C-type lectin domain structure, none of the interactions require calcium. We also find that IgE and CD23 can interact to form high molecular mass multimeric complexes. The interactions that we have described provide a solution to the paradox that CD23 is involved in both up- and down-regulation of IgE and provide a structural basis for the development of inhibitors of allergic disease
A comprehensive analysis of interleukin-4 receptor polymorphisms and their association with atopy and IgE regulation in childhood
Background: The interleukin (IL) 4/IL13 pathway is involved in the regulation of IgE production associated with atopic diseases. Numerous polymorphisms have been identified in the coding region of the IL4 receptor alpha chain (IL4Ra) and previous association studies have shown conflicting results. Based on their putative functional role, polymorphisms A148G, T1432C and A1652G, located in the coding region of IL4Ra, were selected for association and haplotype studies in a large German population sample (n = 1,120). Methods: Genotyping was performed using allele-specific PCR and restriction-enzyme-based assays. Haplotypes were estimated, and population-derived IgE percentiles (50% IgE >60 IU/ml, 66% IgE >115 IU/ml and 90% IgE >457 IU/ml) were calculated as outcome variables in a haplotype trend regression analysis. Results: In our population, only polymorphism T1432C showed a trend for a protective effect against atopic rhinitis ( odds ratio, OR: 0.52, 95% confidence interval, CI: 0.26 - 1.02, p = 0.05). When haplotypes were calculated, one haplotype was significantly associated with elevated serum IgE levels at the 50th percentile ( OR 1.60, 95% CI 1.08 - 2.37, p = 0.02). Conclusions: These data indicate that IL4Ra polymorphisms, although suggested to be functionally relevant by in vitro studies, have only a minor influence on IgE regulation in our large population sample. Copyright (C) 2004 S. Karger AG, Basel
Staphylococcal enterotoxin sensitization in a community-based population : a potential role in adult-onset asthma
Background: Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult-onset asthma in community-based populations.
Objective: We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community-based adult populations.
Methods: The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age=60.2years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin-specific IgE using ImmunoCAP.
Results: Staphylococcal enterotoxin sensitization (0.35kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (61years), and inhalant allergen sensitization. Current asthma was mostly adult onset (18years old) and showed independent associations with high enterotoxin-specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin-specific IgE level was identified as the major determinant factor for total IgE level.
Conclusions and Clinical Relevance: Staphylococcal enterotoxin sensitization was independently associated with adult-onset asthma in adult community populations. Strong correlations between the enterotoxin-specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis
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