1,210 research outputs found
Partitioning of starter bacteria and added exogenous enzyme activities between curd and whey during Cheddar cheese manufacture
peer-reviewedPartitioning of starter bacteria and enzyme activities was investigated at different stages of Cheddar cheese manufacture using three exogenous commercial enzyme preparations added to milk or at salting. The enzyme preparations used were: Accelase AM317, Accelase AHC50, Accelerzyme CPG. Flow cytometric analysis indicated that AHC50 or AM317 consisted of permeabilised or dead cells and contained a range of enzyme activities. The CPG preparation contained only carboxypeptidase activity. Approximately 90% of starter bacteria cells partitioned with the curd at whey drainage. However, key enzyme activities partitioned with the bulk whey in the range of 22%–90%. An increased level of enzyme partitioning with the curd was observed for AHC50 which was added at salting, indicating that the mode of addition influenced partitioning. These findings suggest that further scope exists to optimise both bacterial and exogenous enzyme incorporation into cheese curd to accelerate ripening.Department of Agriculture, Food and the Marin
Statistical estimation of trailing edge noise from finite wall-mounted airfoils
The 2016 Joint Conference of The Australian Acoustical Society and The Acoustical Society of New Zealand.
Acoustics2016 - The Second Australasian Acoustical Societies ConferenceIt is important to be able to accurately model the flow and noise generated by finite wall-mounted airfoil flows because of the many engineering applications in which these flows occur. One method for predicting turbulent trailing edge noise is the Reynolds-averaged Navier-Stokes based statistical noise model (RSNM) of Doolan et al. (Proceedings of 20th International Congress on Acoustics, ICA 2010). The RSNM method has previously been used successfully on a range of two-dimensional geometry-flow cases. In this paper a new turbulent velocity cross-spectrum model and improved implementation are proposed to allow the RSNM method to be used to effectively and efficiently predict turbulent trailing edge noise from more complex three-dimensional cases. Reynolds-averaged Navier-Stokes (RANS) simulations of a series of wing-in-junction cases are used in combination with the developed acoustic model to predict the far-field noise and compared against experimental noise measurements.Jesse Coombs, Con Doolan, Anthony Zander, Danielle Moreau and Laura Brook
Probing of a human proteome microarray with a recombinant pathogen protein reveals a novel mechanism by which hookworms suppress B-cell receptor signaling.
Na-ASP-2 is an efficacious hookworm vaccine antigen. However, despite elucidation of its crystal structure and studies addressing its immunobiology, the function of Na-ASP-2 has remained elusive. We probed a 9000-protein human proteome microarray with Na-ASP-2 and showed binding to CD79A, a component of the B-cell antigen receptor complex. Na-ASP-2 bound to human B lymphocytes ex vivo and downregulated the transcription of approximately 1000 B-cell messenger RNAs (mRNAs), while only approximately 100 mRNAs were upregulated, compared with control-treated cells. The expression of a range of molecules was affected by Na-ASP-2, including factors involved in leukocyte transendothelial migration pathways and the B-cell signaling receptor pathway. Of note was the downregulated transcription of lyn and pi3k, molecules that are known to interact with CD79A and control B-cell receptor signaling processes. Together, these results highlight a previously unknown interaction between a hookworm-secreted protein and B cells, which has implications for helminth-driven immunomodulation and vaccine development. Further, the novel use of human protein microarrays to identify host-pathogen interactions, coupled with ex vivo binding studies and subsequent analyses of global gene expression in human host cells, demonstrates a new pipeline by which to explore the molecular basis of infectious diseases.This is the author accepted version. The final version is available at http://dx.doi.org/10.1093/infdis/jiu451
The social impact of accounting processes on benefit claimants in the UK
The accounting processes of categorisation and classification are inherent in modern-day welfare systems, though little has been done to investigate the link these have to the social consequences for benefit claimants within these systems. This paper uses research from both primary and secondary sources to show how UK welfare reform has affected claimants and their inalienable human rights since its introduction in 2012. The data gathered for this work combine face-to-face interview data with press releases, and data and reports compiled and published both by the government and independent bodies. Face-to-face interviews were conducted with two illustrative participants, who were identified as being excellent examples of individuals with a close working knowledge of the welfare system. In addition to the primary data gathered, several sources of secondary data are used within the analysis to identify facts, figures and quotations from reliable government sources. Our analysis uncovers that the accounting processes inherent in the system have helped foster a culture of stigmatisation, food bank dependency and financial and emotional hardship for vulnerable welfare claimants in today’s society
Dose ratio proton radiography using the proximal side of the Bragg peak
Purpose: In recent years there has been a movement towards single-detector proton radiography, due to its potential ease of implementation within the clinical environment. One such single-detector technique is the dose ratio method, in which the dose maps from two pristine Bragg peaks are recorded beyond the patient. To date, this has only been investigated on the distal side of the lower energy Bragg peak, due to the sharp fall-off. We investigate the limits and applicability of the dose ratio method on the proximal side of the lower energy Bragg peak, which has the potential to allow a much wider range of water-equivalent thicknesses (WET) to be imaged. Comparisons are made with the use of the distal side of the Bragg peak. Methods: Using the analytical approximation for the Bragg peak we generated theoretical dose ratio curves for a range of energy pairs, and then determined how an uncertainty in the dose ratio would translate to a spread in the WET estimate. By defining this spread as the accuracy one could achieve in the WET estimate, we were able to generate look-up graphs of the range on the proximal side of the Bragg peak that one could reliably use. These were dependent on the energy pair, noise level in the dose ratio image and the required accuracy in the WET. Using these look-up graphs we investigated the applicability of the technique for a range of patient treatment sites. We validated the theoretical approach with experimental measurements using a complementary metal oxide semiconductor active pixel sensor (CMOS APS), by imaging a small sapphire sphere in a high energy proton beam. Results: Provided the noise level in the dose ratio image was 1% or less, a larger spread of WETs could be imaged using the proximal side of the Bragg peak (max 5.31 cm) compared to the distal side (max 2.42 cm). In simulation it was found that, for a pediatric brain, it is possible to use the technique to image a region with a square field equivalent size of 7.6 cm2, for a required accuracy in the WET of 3 mm and a 1% noise level in the dose ratio image. The technique showed limited applicability for other patient sites. The CMOS APS demonstrated a good accuracy, with a root-mean-square-error of 1.6 mm WET. The noise in the measured images was found to be σ =1.2% (standard deviation) and theoretical predictions with a 1.96σ noise level showed good agreement with the measured errors. Conclusions: After validating the theoretical approach with measurements, we have shown that the use of the proximal side of the Bragg peak when performing dose ratio imaging is feasible, and allows for a wider dynamic range than when using the distal side. The dynamic range available increases as the demand on the accuracy of the WET decreases. The technique can only be applied to clinical sites with small maximum WETs such as for pediatric brains
Limiting global-mean temperature increase to 1.5-2°C could reduce the incidence and spatial spread of dengue fever in Latin America
The Paris Climate Agreement aims to hold global-mean temperature well below 2°C and to pursue efforts to limit it to 1.5°C above preindustrial levels. Whilst it is recognized that there are benefits for human health in limiting global warming to 1.5°C, the magnitude with which those societal benefits will be accrued remains unquantified. Crucial to public health preparedness and response is the understanding and quantification of such impacts at different levels of warming. Using dengue in Latin America as a study case, a climatedriven dengue generalized additive mixed model was developed to predict global warming impacts using five different global circulation models, all scaled to represent multiple global-mean temperature assumptions. We show that policies to limit global warming to 2°C could reduce dengue cases by about 2.8 (0.8–7.4) million cases per year by the end of the century compared with a no-policy scenario that warms by 3.7°C. Limiting warming further to 1.5°C, produces an additional drop in cases of about 0.5 (0.2–1.1) million per year. Furthermore, we found that by limiting global warming we can limit the expansion of the disease towards areas where incidence is currently low. We anticipate our study to be a starting point for more comprehensive studies incorporating socioeconomic scenarios and how they may further impact dengue incidence. Our results demonstrate that although future climate change may amplify dengue transmission in the region, impacts may be avoided by constraining the level of warming
A clinician's guide to omics resources in dermatology
With recent advances in high-throughput technologies, we are now in an era where the use of large-scale datasets of biological samples and individual diseases can be analysed using omics methodologies. These include genomics, transcriptomics, proteomics, metabolomics, lipidomics and epigenomics. Omics approaches have been developed to deliver a holistic understanding of systems biology, to identify key biomarkers, and to aid in the interpretation of molecular, biochemical and environmental interactions. Navigating through the plethora of online datasets to find useful and concise information for comparison of data can be complex and overwhelming. The purpose of this article is to review the current repositories and databases, and to evaluate their application in dermatological research and their relevance to clinical practice. For this study, an extensive review of online platforms used in dermatology research was undertaken. Online resources for genetic disease information, genetic disease connection platforms for patients and researchers, clinical interpretation of variants, genome and DNA databases, and omics data repositories and resources were collected. This study provides a comprehensive overview of relevant databases that will aid clinicians and scientists using omics data in dermatology.</p
The glutathione biosynthetic pathway of Plasmodium is essential for mosquito transmission
1Infection of red blood cells (RBC) subjects the malaria parasite to oxidative stress. Therefore, efficient antioxidant and redox systems are required to prevent damage by reactive oxygen species. Plasmodium spp. have thioredoxin and glutathione (GSH) systems that are thought to play a major role as antioxidants during blood stage infection. In this report, we analyzed a critical component of the GSH biosynthesis pathway using reverse genetics. Plasmodium berghei parasites lacking expression of gamma-glutamylcysteine synthetase (γ-GCS), the rate limiting enzyme in de novo synthesis of GSH, were generated through targeted gene disruption thus demonstrating, quite unexpectedly, that γ-GCS is not essential for blood stage development. Despite a significant reduction in GSH levels, blood stage forms of pbggcs− parasites showed only a defect in growth as compared to wild type. In contrast, a dramatic effect on development of the parasites in the mosquito was observed. Infection of mosquitoes with pbggcs− parasites resulted in reduced numbers of stunted oocysts that did not produce sporozoites. These results have important implications for the design of drugs aiming at interfering with the GSH redox-system in blood stages and demonstrate that de novo synthesis of GSH is pivotal for development of Plasmodium in the mosquito
Assessment of humoral immune responses to blood-stage malaria antigens following ChAd63-MVA immunization, controlled human malaria infection and natural exposure.
The development of protective vaccines against many difficult infectious pathogens will necessitate the induction of effective antibody responses. Here we assess humoral immune responses against two antigens from the blood-stage merozoite of the Plasmodium falciparum human malaria parasite--MSP1 and AMA1. These antigens were delivered to healthy malaria-naïve adult volunteers in Phase Ia clinical trials using recombinant replication-deficient viral vectors--ChAd63 to prime the immune response and MVA to boost. In subsequent Phase IIa clinical trials, immunized volunteers underwent controlled human malaria infection (CHMI) with P. falciparum to assess vaccine efficacy, whereby all but one volunteer developed low-density blood-stage parasitemia. Here we assess serum antibody responses against both the MSP1 and AMA1 antigens following i) ChAd63-MVA immunization, ii) immunization and CHMI, and iii) primary malaria exposure in the context of CHMI in unimmunized control volunteers. Responses were also assessed in a cohort of naturally-immune Kenyan adults to provide comparison with those induced by a lifetime of natural malaria exposure. Serum antibody responses against MSP1 and AMA1 were characterized in terms of i) total IgG responses before and after CHMI, ii) responses to allelic variants of MSP1 and AMA1, iii) functional growth inhibitory activity (GIA), iv) IgG avidity, and v) isotype responses (IgG1-4, IgA and IgM). These data provide the first in-depth assessment of the quality of adenovirus-MVA vaccine-induced antibody responses in humans, along with assessment of how these responses are modulated by subsequent low-density parasite exposure. Notable differences were observed in qualitative aspects of the human antibody responses against these malaria antigens depending on the means of their induction and/or exposure of the host to the malaria parasite. Given the continued clinical development of viral vectored vaccines for malaria and a range of other diseases targets, these data should help to guide further immuno-monitoring studies of vaccine-induced human antibody responses
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