842 research outputs found

    Modelling regional maize market and transport distances for biogas production in Germany

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    Our location model aims to simulate location decisions for biogas plants based on profit maximisation to generate regional demand functions for maize and corresponding plant size structure and transport distances. By linking it with an agricultural sector model we derived regional maize markets. Comparing results for the REA with a scenario applying uniform per unit subsidy and producing the same energy, we see higher subsidy costs with the REA but lower transportation distances.Biogas, environmental effects, transport costs, choice of location, Agricultural Finance, Environmental Economics and Policy,

    Towards a certification of biomass: Feasibility of a certifications scheme of sustainability standards for trade and production of bioethanol in Brazil

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    Bioenergy produced from biomass is increasingly used to substitute fossil energy sources. Trade of biomass is expected to increase in the following years due to disparities in production costs and potentials in countries and regions. In this paper the possibility of a certification scheme for minimizing negative socio-ecological impacts and for increasing a sustainable production of biomass is discussed, taking Brazilian bioethanol as an example. This case-study comes up with a first set of feasible sustainability standards for Brazilian bioethanol and discusses issues to be considered when developing sustainability standards. At the same time problematic aspects are identified. When incorporating opinions of different stakeholders, the setting of sustainability standards holds the inherent danger of being used as non-tariff trade barriers. This leads to the need for a regionalisation of sustainability standards and raises questions on structure and level of a certification scheme.certification, sustainability standards, bioethanol, Environmental Economics and Policy, Institutional and Behavioral Economics, International Relations/Trade, Resource /Energy Economics and Policy, F18, Q24,

    A certain legal practitioner: reconstructing the life of Shulamith Muller

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    M.A. University of the Witwatersrand, Faculty of Humanties, School of Social Sciences (History), 2012This study is a partial historical biography of the life of one woman, Shulamith Muller. The child of a Jewish immigrant family, she traversed many of her native country's generally impermeable social boundaries to become truly South African. She married an Afrikaner, product of another closed, white community but her politics, and that of her husband, led them both into a completely different South Africa. In this wider world her commitment to, and belief in, the rule of law, justice and the principle of equality before the law gave her a place in a broader black community of her many clients and political comrades, both rural and urban. The study also documents the role of this same irrepressible woman in a political “coup” within another closed society, that of the Pretoria Communist Party in the 1940s, which reflected many of the tensions that were playing out on a larger world stage

    Functional analysis of the role of interferon gamma through the characterisation of conditional interferon gamma receptor two mouse mutants

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    The data presented within this thesis shows the generation and characterisation of a complete-, macrophage/granulocyte- and T cell-specific IFNγR2 deficient mouse mutant. This mutant mouse is a valuable tool in dissecting the mechanism of action of the pleiotrophic cytokine IFNγ.The global mutant mouse was tested in three models in vivo - DSS induced colitis, Trichuris muris infection and EAE. The aim of the DSS-induced colitis model was to test the role of IFNγ in the innate immune system and, despite previous reports demonstrating IFNγ deficient mice are protected from DSS-colitis, our IFNγR2 deficient mice displayed equal or more severe colitis than control mice. We hypothesise that this discrepancy is due to differences in the gut microbiota.The Trichuris muris model was utilised as a method of examining the role of IFNγ in the adaptive immune system. The complete IFNγR2 mutant was resistant to a low dose T. muris infection; however, neither the T cell specific nor the macrophage/granulocyte specific mutant duplicated the resistant phenotype observed in the global knock-out mice. Analysis of a double conditional T cell and macrophage/granulocyte specific IFNγR2 mutant produced inconsistent results. Initial experiments suggested that, in combination, these deficiencies are sufficient to duplicate the resistant phenotype observed in the global mutant mice, but this was not reproducible.The final in vivo model that we used to analyse IFNγR2 mutant mice was EAE. This model was chosen as, for a long time, the mechanism of action and the involvement of IFNγ in EAE has been a matter of uncertainty. These results demonstrated that global IFNγR2 mutant mice demonstrate an atypical phenotype, with no signs of recovery. In contrast, control mice develop classical EAE symptoms with almost complete recovery prior to the termination of the experiment. The IFNγ receptor mutant mouse generated will be of great value to the scientific community as IFNγ has been demonstrated to play a role in multiple diseases and this tool allows the mechanism of action of this cytokine to be unravelled.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Risk of bloodstream infection in children admitted to paediatric intensive care units in England and Wales following emergency inter-hospital transfer.

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    PURPOSE: Adherence to full sterile procedures may be compromised when central venous catheters are inserted as part of emergency resuscitation and stabilisation, particularly outside the intensive care unit. Half of emergency admissions to paediatric intensive care units (PICU) in the UK occur after stabilisation at other hospitals. We determined whether bloodstream infection (BSI) occurred more frequently in children admitted to PICU after inter-hospital transfer compared to within-hospital admissions. METHODS: Data on emergency admissions to 20 PICUs in England and Wales for children <16 years between 2003-2012 were linked from the national PICU audit database (PICANet) and national infection surveillance (LabBase2). PICU-acquired BSI was defined as any positive blood culture sampled between 2 days after admission and 2 days following discharge from PICU. RESULTS: A total of 32,861/62,515 (53%) admissions were inter-hospital transfers. Multivariable regression showed no significant difference in rates of PICU-acquired BSI by source of admission (incidence-rate ratio for inter-hospital transfer versus within-hospital admission = 0.97; 95% CI 0.87-1.07) after adjusting for other risk-factors. Rates decreased more rapidly between 2003 and 2012 for inter-hospital transfers: 17.0% (95% CI 14.9-19.0% per year) compared with 12.4% (95% CI 9.9-14.9% per year) for within-hospital admissions. The median time to first PICU-acquired BSI did not differ significantly between inter-hospital transfers (7 days; IQR 4-13) and within-hospital admissions (8 days; IQR 4-15). CONCLUSIONS: Nationally, inter-hospital transfer is no longer a significant risk factor for PICU-acquired BSI. Given the large proportion of infection occurring in the second week of admission, initiatives to further reduce PICU-acquired BSI should focus on maintaining sterile procedures after admission

    Is there evidence of a wage penalty to female part-time employment in South Africa?

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    Accepted for publication by The South African Journal of Economics 76(3)2008. The definitive version is available at: http://onlinelibrary.wiley.com/doi/10.1111j.1813-6982.2008.00197.x/pdf on Wiley Online Library.In this paper, we investigate female part-time employment in South Africa. Using household survey data for South Africa from 1995 to 2004, we show that women are over-represented in part-time employment, and that the growth in part-time work has been an important feature of the feminisation of the labour force. In contrast to many studies of part-time work in other countries, however, we find evidence of a significant wage premium to female part-time employment. The premium is also robust to fixed effects estimations using Labour Force Survey panel data from 2001 to 2004, where controlling for unobservable differences increases its size. The premium persists with different hourly thresholds defining part-time employment and when we account for possible reporting errors in hours worked

    Challenges in linking administrative data for monitoring bloodstream infection in neonatal units in England and Wales

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    Introduction Monitoring risk-adjusted trends of neonatal bloodstream infection (BSI) is vital and linkage of neonatal electronic health records to national infection surveillance enables this. We demonstrate why changes in data quality and collection methods over time must be accounted for to minimise spurious findings. Objectives and Approach First, we determined the effect of a system change in 2014 (changed from only clinically relevant BSI to automated reporting of all BSI), by investigating changes in number of all BSI and BSI excluding the contaminants coagulase-negative staphylococci for infants aged <1 year reported to infection surveillance, using interrupted-time-series Poisson regression. Second, we evaluated the impact of changes in identifier completeness over time in each database, and determined variation in infection rates according to linkage method (deterministic linkage on NHS number or probabilistic linkage). Third, we will use multiple imputation when link status cannot be determined due to missing identifiers. Results The number of BSI reported to infection surveillance system following the change in data collection increased by 34% (incidence rate ratio (IRR) of 1.34, 95% confidence interval 1.28-1.40) for all BSI compared to 19% (IRR 1.19, 1.12-1.27) excluding coagulase-negative staphylococci. Completeness of NHS number in infection surveillance increased from 69% (3,296/4,792) in 2010 to 92% (3,037/3,307) in 2017. We linked 12,003 neonatal admissions to 15,571 BSI episodes (2% of 497,936 admissions and 41% of 37,660 BSI). The proportion of links that were deterministic changed from 83% (1,089/1,307) in 2010 to 96% (968/1,008) in 2017. There were 12,094 BSI for which the link status could not be determined due to missing identifiers; multiple imputation will be used to determine if any are links. Conclusion/Implications Spurious trends in infection incidence can arise from changes in data collection and quality, impacting the quality of linkage to clinical data. Data quality and system changes must be explored in each source dataset before analysis. Probabilistic linkage and imputation of missing data minimises spurious findings due to data quality

    Challenges in linking administrative data for monitoring bloodstream infection in neonatal units in England and Wales

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    Monitoring risk-adjusted trends of neonatal bloodstream infection is vital and linkage of neonatal electronic health records to national infection surveillance enables this. We demonstrate why changes in data quality over time must be accounted for to minimise spurious findings. First, we evaluated the impact of changes in identifier completeness over time in each database, and determined variation in infection rates according to linkage method (deterministic linkage on NHS number or probabilistic linkage). Second, we will use multiple imputation when link status cannot be determined due to missing identifiers. Completeness of NHS number in infection surveillance increased from 69% (3,296/4,792) in 2010 to 92% (3,037/3,307) in 2017. We linked 12,003 neonatal admissions to 15,571 infection episodes (2% of 497,936 admissions and 41% of 37,660 infections). The proportion of links that were deterministic changed from 83% (1,089/1,307) in 2010 to 96% (968/1,008) in 2017. Link status could not be determined for 12,094 infections due to missing identifiers; multiple imputation will be used to determine if any are links. Spurious infection incidence rates can arise from changes in data quality, impacting the quality of linkage to clinical data. Linkage and imputation of missing data minimises spurious findings due to data quality

    xxAI - Beyond Explainable AI

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    This is an open access book. Statistical machine learning (ML) has triggered a renaissance of artificial intelligence (AI). While the most successful ML models, including Deep Neural Networks (DNN), have developed better predictivity, they have become increasingly complex, at the expense of human interpretability (correlation vs. causality). The field of explainable AI (xAI) has emerged with the goal of creating tools and models that are both predictive and interpretable and understandable for humans. Explainable AI is receiving huge interest in the machine learning and AI research communities, across academia, industry, and government, and there is now an excellent opportunity to push towards successful explainable AI applications. This volume will help the research community to accelerate this process, to promote a more systematic use of explainable AI to improve models in diverse applications, and ultimately to better understand how current explainable AI methods need to be improved and what kind of theory of explainable AI is needed. After overviews of current methods and challenges, the editors include chapters that describe new developments in explainable AI. The contributions are from leading researchers in the field, drawn from both academia and industry, and many of the chapters take a clear interdisciplinary approach to problem-solving. The concepts discussed include explainability, causability, and AI interfaces with humans, and the applications include image processing, natural language, law, fairness, and climate science.https://digitalcommons.unomaha.edu/isqafacbooks/1000/thumbnail.jp

    CXCL16-mediated cell recruitment to rheumatoid arthritis synovial tissue and murine lymph nodes is dependent upon the MAPK pathway

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    Objective Rheumatoid arthritis (RA) is characterized by profound mononuclear cell (MNC) recruitment into synovial tissue (ST), thought to be due in part to tumor necrosis factor Α (TNFΑ), a therapeutic target for RA. Although chemokines may also be involved, the mechanisms remain unclear. We undertook this study to examine the participation of CXCL16, a novel chemokine, in recruitment of MNCs to RA ST in vivo and to determine the signal transduction pathways mediating this process. Methods Using a human RA ST–SCID mouse chimera, immunohistochemistry, enzyme-linked immunosorbent assay, real-time reverse transcription–polymerase chain reaction, flow cytometry, and in vitro chemotaxis assays, we defined the expression and function of CXCL16 and its receptor, CXCR6, as well as the signal transduction pathways utilized by them for MNC homing in vitro and in vivo. Results CXCL16 was markedly elevated in RA synovial fluid (SF) samples, being as high as 145 ng/ml. Intense macrophage and lining cell staining for CXCL16 in RA ST correlated with increased CXCL16 messenger RNA levels in RA ST compared with those in osteoarthritis and normal ST. By fluorescence-activated cell sorting analysis, one-half of RA SF monocytes and one-third of memory lymphocytes expressed CXCR6. In vivo recruitment of human MNCs to RA ST implanted in SCID mice occurred in response to intragraft injection of human CXCL16, a response similar to that induced by TNFΑ. Lipofection of MNCs with antisense oligodeoxynucleotides for ERK-1/2 resulted in a 50% decline in recruitment to engrafted RA ST and a 5-fold decline in recruitment to regional lymph nodes. Interestingly, RA ST fibroblasts did not produce CXCL16 in response to TNFΑ in vitro, suggesting that CXCL16 protein may function in large part independently of TNFΑ. Conclusion Taken together, these results point to a unique role for CXCL16 as a premier MNC recruiter in RA and suggest additional therapeutic possibilities, targeting CXCL16, its receptor, or its signaling pathways.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49514/1/21662_ftp.pd
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