18,656 research outputs found

    Structural features of human immunoglobulin G that determine isotype-specific differences in complement activation.

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    Although very similar in sequence, the four subclasses of human immunoglobulin G (IgG) differ markedly in their ability to activate complement. Glu318-Lys320-Lys322 has been identified as a key binding motif for the first component of complement, C1q, and is present in all isotypes of Ig capable of activating complement. This motif, however, is present in all subclasses of human IgG, including those that show little (IgG2) or even no (IgG4) complement activity. Using point mutants of chimeric antibodies, we have identified specific residues responsible for the differing ability of the IgG subclasses to fix complement. In particular, we show that Ser at position 331 in gamma 4 is critical for determining the inability of that isotype to bind C1q and activate complement. Additionally, we provide further evidence that levels of C1q binding do not necessarily correlate with levels of complement activity, and that C1q binding alone is not sufficient for complement activation

    Effects of Brief Mindfulness-Based Interventions on Health-Related Outcomes: a Systematic Review

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    Objectives Traditional mindfulness-based interventions (MBIs) have been applied successfully across many populations. The time commitment for these programs is often a barrier, and while brief MBIs have become popular, the impact of these on health-related outcomes is unclear as they have not yet been reviewed. Methods A search of databases, including Medline, Embase, and PsycINFO, was conducted with qualitative and case studies being excluded. Findings were summarized using a narrative approach for all studies that met the inclusion criteria. Results With one exception, all 85 studies that were included were randomized controlled trials and were relatively robust methodologically. Seventy-nine reported significant positive effects on at least one health-related outcome and over a quarter targeted a clinical population. The majority of studies focused on psychological outcomes, such as anxiety and depression, as well as emotion regulation, stress, and cognitive outcomes. Conclusions Despite heterogeneity of outcomes across studies, there is evidence that brief MBIs can impact numerous health-related outcomes, after only one session and with interventions as brief as 5 min. These interventions have the potential to be the initial steps leading to sustainable and positive health outcomes

    A Problem Solving Approach to Identifying Civil Engineering Infrastructure Projects

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    Civil engineering infrastructure projects are solutions to problems facing communities, societies or even an entire nation. Addressing societal needs and problems is a key element of infrastructure project success. However, recent evidence suggests that decision makers often invest in projects that do not address clearly defined problems. Therefore, this research aims to contribute towards improving the identification process of civil engineering infrastructure projects. A desk study involving mapping of a generic infrastructure project life cycle onto two problem solving process models was undertaken. It was found that if civil engineering infrastructure projects are viewed as solutions to problems, ideas of a problem solving process can be adapted and incorporated into the identification process of infrastructure projects. This led to the design of a novel two-stage identification process for civil engineering infrastructure projects. The process brings together developers and concerned stakeholders to: first agree on the problem to be addressed, and second generate solutions, assess them and then choose a preferred solution to be implemented. Identifying civil engineering infrastructure projects in this manner ensures that public funds are spent on projects that address societal problems, provide the greatest benefits to society, and that they are spent in the most efficient way

    Estimating the furrow infiltration characteristic from a single advance point

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    Management and control of surface irrigation, in particular furrow irrigation, is limited by spatio-temporal soil infiltration variability as well as the high cost and time associated with collecting intensive field data for estimation of the infiltration characteristics. Recent work has proposed scaling the commonly used infiltration function by using a model infiltration curve and a single advance point for every other furrow in an irrigation event. Scaling factors were calculated for a series of furrows at two sites and at four points down the length of the field (0.25 L, 0.5 L, 0.75 L and L). Differences in the value of the scaling factor with distance were found to be a function of the shape of the advance curves. It is concluded that use of points early in the advance results in a substantial loss of accuracy and should be avoided. The scaling factor was also strongly correlated with the furrow-wetted perimeter suggesting that the scaling is an appropriate way of both predicting and accommodating the effect of the hydraulic variability

    Coconut in the Mekong Delta: An Assessment of Competitivenessand Industry Potential

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    The numbers surrounding the world coconut industry are substantial – 55,500,000,000 coconuts produced every year from 12,000,000 hectares supporting an industry worth USD 6 billion at wholesale. Yet despite the size and wealth of the industry most coconut growers are among the poorest in their society and over 1 million tonnes of coconut dust are dumped into the environment every year. In the Mekong Delta, riverbanks shaded with coconut trees are an iconic part of the landscape, but only in the last decade has the local coconut industry taken the first steps to becoming a modern, competitive industry. Much of this recent development has happened in Ben Tre province, at the heart of the industry in the Delta with the greatest concentration of coconut trees and businesses. The Ben Tre authorities and industry leaders are now looking to help the industry mature into an internationally competitive and sustainable coconut industry that maximises the value created for the local community, businesses and coconut farmers. This study is part of that process and aims to provide evidence of the current state of the global coconut industry and the local industry in Ben Tre and the wider Mekong Delta and to assess specific opportunities for the industry’s future development. The study also identifies several promising commercial opportunities for local coconut businesses and the impacts these could have on the company’s own bottom-line profits as well as the wider industry. It supplements extensive secondary data with insights and evidence gathered through an international benchmarking exercise with leading competitor countries, including the Philippines, Sri Lanka and Thailand as well as the local industry in Ben Tre

    Creating realistic synthetic populations at varying spatial scales: A comparative critique of population synthesis techniques

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    There are several established methodologies for generating synthetic populations. These include deterministic reweighting, conditional probability (Monte Carlo simulation) and simulated annealing. However, each of these approaches is limited by, for example, the level of geography to which it can be applied, or number of characteristics of the real population that can be replicated. The research examines and critiques the performance of each of these methods over varying spatial scales. Results show that the most consistent and accurate populations generated over all the spatial scales are produced from the simulated annealing algorithm. The relative merits and limitations of each method are evaluated in the discussion

    Is There a Causal Association between Genotoxicity and the Imposex Effect?

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    There is a growing body of evidence that indicates common environmental pollutants are capable of disrupting reproductive and developmental processes by interfering with the actions of endogenous hormones. Many reports of endocrine disruption describe changes in the normal development of organs and tissues that are consistent with genetic damage, and recent studies confirm that many chemicals classified to have hormone-modulating effects also possess carcinogenic and mutagenic potential. To date, however, there have been no conclusive examples linking genetic damage with perturbation of endocrine function and adverse effects in vivo. Here, we provide the first evidence of DNA damage associated with the development of imposex (the masculinization of female gastropods considered to be the result of alterations to endocrine-mediated pathways) in the dog-whelk Nucella lapillus. Animals (n = 257) that displayed various stages of tributyltin (TBT)-induced imposex were collected from sites in southwest England, and their imposex status was determined by physical examination. Linear regression analysis revealed a very strong relationship (correlation coefficient of 0.935, p < 0.0001) between the degree of imposex and the extent of DNA damage (micronucleus formation) in hemocytes. Moreover, histological examination of a larger number of dog-whelks collected from sites throughout Europe confirmed the presence of hyperplastic growths, primarily on the vas deferens and penis in both TBT-exposed male snails and in females that exhibited imposex. A strong association was found between TBT body burden and the prevalence of abnormal growths, thereby providing compelling evidence to support the hypothesis that environmental chemicals that affect reproductive processes do so partly through DNA damage pathways

    Exploring the international linkages of the Euro area: a global VAR analysis

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    We presents a global model linking individual country vector error-correcting models in which domestic variables are related to country-specific variables as an approximate solution to a global common factor model. The model is estimated for 26 economies. It provides a theoretical framework where the GVAR is derived as an approximation to a global unobserved common factor model, and using average pair-wise cross-section error correlations, the approach is shown to be quite effective in dealing with common factor interdependencies and international co-movements of business cycles. In addition to generalised impulse response functions, we propose an identification scheme to derive structural impulse responses. We focus on identification of shocks to the US economy, particularly the monetary policy shocks, and consider the time profiles of their effects on the euro area. To this end we include the US model as the first country model and consider alternative orderings of the US variables

    Staphylococcus aureus in the oral cavity: a three-year retrospective analysis of clinical laboratory data

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    OBJECTIVE: A retrospective analysis of laboratory data to investigate the isolation of Staphylococcus aureus from the oral cavity and facial area in specimens submitted to a regional diagnostic oral microbiology laboratory. METHODS: A hand search of laboratory records for a three-year period (1998-2000) was performed for specimens submitted to the regional diagnostic oral microbiology laboratory based at Glasgow Dental Hospital and School. Data were collected from forms where S. aureus was isolated. These data included demographics, referral source, specimen type, methicillin susceptibility and clinical details. RESULTS: For the period 1998-2000, there were 5,005 specimens submitted to the laboratory. S. aureus was isolated from 1,017 specimens, of which 967 (95%) were sensitive to methicillin (MSSA) and 50 (5%) were resistant to methicillin (MRSA). The 1,017 specimens were provided from 615 patients. MRSA was isolated from 37 (6%) of patients. There was an increasing incidence of S. aureus with age, particularly in the greater than 70 years age group. The most common specimen from which MSSA was isolated was an oral rinse (38%) whilst for MRSA isolates this was a tongue swab (28%). The clinical condition most commonly reported for MSSA isolates was angular cheilitis (22%). Erythema, swelling, pain or burning of the oral mucosa was the clinical condition most commonly reported for MRSA isolates (16%). Patients from whom the MSSA isolates were recovered were most commonly (55%) seen in the oral medicine clinic at the dental hospital, whilst patients with MRSA were more commonly seen in primary care settings such as nursing homes, hospices and general dental practice (51%). CONCLUSION: In line with more recent surveys, this retrospective study suggests that S. aureus may be a more frequent isolate from the oral cavity than hitherto suspected. A small proportion of the S. aureus isolates were MRSA. There were insufficient data available to determine whether the S. aureus isolates were colonising or infecting the oral cavity. However, the role of S. aureus in several diseases of the oral mucosa merits further investigation
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