2,007 research outputs found
Experimental rat models of chronic allograft nephropathy: a review
Chronic allograft nephropathy (CAN) is the leading cause of late allograft loss after renal transplantation (RT), which continues to remain an unresolved problem. A rat model of CAN was first described in 1969 by White et al. Although the rat model of RT can be technically challenging, it is attractive because the pathogenesis of CAN is similar to that following human RT and the pathological features of CAN develop within months as compared with years in human RT. The rat model of RT is considered as a useful investigational tool in the field of experimental transplantation research. We have reviewed the literature on studies of rat RT reporting the donor and recipient strain combinations that have investigated resultant survival and histological outcomes. Several different combinations of inbred and outbred rat combinations have been reported to investigate the multiple aspects of transplantation, including acute rejection, cellular and humoral rejection mechanisms and their treatments, CAN, and potential targets for its prevention
Biological Pathways and Potential Targets for Prevention and Therapy of Chronic Allograft Nephropathy
Renal transplantation (RT) is the best option for patients with end-stage renal disease, but the half-life is limited to a decade due to progressive deterioration of renal function and transplant failure from chronic allograft nephropathy (CAN), which is the leading cause of transplant loss. Extensive research has been done to understand the pathogenesis, the biological pathways of fibrogenesis, and potential therapeutic targets for the prevention and treatment of CAN. Despite the advancements in the immunosuppressive agents and patient care, CAN continues to remain an unresolved problem in renal transplantation. The aim of this paper is to undertake a comprehensive review of the literature on the pathogenesis, biological pathways of RT fibrogenesis, and potential therapeutic targets for the prevention and therapy of CAN
PANEL STRATIFICATION IN META-ANALYSIS OF ENVIRONMENTAL AND NATURAL RESOURCE ECONOMIC STUDIES
Meta-analyses of past research outcomes are becoming more popular, however, the issue of the panel nature of data has not been empirically investigated. We test various forms of data stratifications into panels for outdoor recreation economic studies but do not find any significant effects, possibly because of inherent data complexity.Environmental Economics and Policy, Resource /Energy Economics and Policy,
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The effect of embedded academic literacy activities on student writing in a distance learning module
Academic literacy (AL) is widely considered as central to academic knowledge building and success (Coffin & Donohue, 2014; Snow, 2010; Woodward-Kron, 2002). Evidence also indicates that AL may pose challenges to many students at risk of underachievement (Cummins, 2014). Given the disciplinary variation and associated AL practices (Haneda, 2014), early childhood studies is distinct from other disciplines. However, it is recognised that not all students come to higher education equipped with it and often students are blamed for this (Wingate, 2018). Importantly, there is limited evidence of how embedding AL in a discipline such as early childhood studies supports first year students (cf. Veitch, Johnson, & Mansfield, 2016). This paper, which relates to the conference theme of Curriculum Development, reports on an exploratory study examining Early Childhood degree students’ perspectives on the effect of embedded AL activities (e.g., constructing an academic argument, designing an essay introduction) on their academic writing.
The study context was a collaboration between an AL specialist and a team of early childhood studies academics to innovate an early childhood course. The research involved a mixed methods approach with the aim of supporting the corroboration of findings. Data gathering was sequential (Johnson and Onwuegbuzie 2009) with the main focus on generating qualitative data initially and quantitative information at the final stage. The data was drawn from student interviews (15 transcripts), an online survey (35 responses) and written assignments (30 scripts). The five student interviews were conducted by an independent researcher after they completed the second, fourth and final assignment. The written assignments were collected from the interviewees soon after each interview. The survey was administered at the end of the course. The student interviews were thematically analysed using an approach informed by grounded theory (Corbin, Strauss, & Strauss, 2008) while the written assignments were examined through a genre analysis approach drawing on Martin and Rose (2008).
The findings reveal that students were engaged in AL activities which had positive impacts on their self-confidence in writing assignments and in their professional communication, and their knowledge about AL. The analysis of the student assignments indicated students’ growing understanding of the core AL skills and knowledge introduced in the module as evidenced in their assessed writing. This study has implications for designing a subject curriculum which aims to develop both disciplinary knowledge and AL to understand and communicate such knowledge. Equally, it provides further insights into disciplinary writing pedagogy
Planning for sustainable development: 'wicked problems' at Sydney's Malabar Headland
This chapter explores a set of wicked problems in the Malabar Headland in Sydney, Australia. By employing a mix of qualitative and quantitative methods, it was found that wicked problems were produced, reproduced and perpetuated in the Malabar Headland due mainly to two principal reasons: a) operational – relating to the complex and conflicting valuesets among stakeholders and multiple uses; and b) structural – relating to the institutional and interest group politics inherent within the layered federal system of government in Australia
Upregulation of Transglutaminase andε(γ-Glutamyl)-Lysine in the Fisher-Lewis Rat Model of Chronic Allograft Nephropathy
Background. Tissue transglutaminase (TG2), a cross-linking enzyme, modulates deposition of extracellular matrix protein in renal fibrosis. This study aimed to examine TG2 and its cross-link product ε(γ-glutamyl)-lysine in the Fisher-Lewis rat renal transplantation (RTx) model of chronic allograft nephropathy (CAN). Materials and Methods. Left renal grafts from male Fisher and Lewis were transplanted into Lewis rats, generating allografts and isografts, respectively. Blood pressure, renal function, and proteinuria were monitored for up to 52 weeks. At termination, CAN was assessed in the renal tissue by light and electron microscopy, TG2 and ε(γ-glutamyl)-lysine by immunofluorescence, and the urinary ε(γ-glutamyl)-lysine by high performance liquid chromatography.
Results. Compared to the isograft, the allografts were hypertensive, proteinuric, and uraemic and developed CAN. Extracellular TG2 (glomerulus: 64.55 + 17.61 versus 2.11 + 0.17, P<0.001; interstitium: 13.72 + 1.62 versus 3.19 + 0.44, P<0.001), ε(γ-glutamyl)-lysine (glomerulus: 21.74 + 2.71 versus 1.98 + 0.37, P<0.01; interstitium: 37.96 + 17.06 versus 0.42 + 0.11, P<0.05), TG2 enzyme activity (1.09 + 0.13 versus 0.41 + 0.03 nmol/h/mg protein, P<0.05), TG2 mRNA (20-fold rise), and urinary ε(γ-glutamyl)-lysine (534.2 + 198.4 nmol/24 h versus 57.2 + 4.1 nmol/24 h,P<0.05) levels were significantly elevated in the allografts and showed a positive linear correlation with tubulointerstitial fibrosis. Conclusion. CAN was associated with upregulation of renal TG2 pathway, which has a potential for pharmacological intervention. The elevated urinary ε(γ-glutamyl)-lysine, measured for the first time in RTx, is a potential biomarker of CA
Fungi isolated from Miscanthus and sugarcane: biomass conversion, fungal enzymes, and hydrolysis of plant cell wall polymers.
BackgroundBiofuel use is one of many means of addressing global change caused by anthropogenic release of fossil fuel carbon dioxide into Earth's atmosphere. To make a meaningful reduction in fossil fuel use, bioethanol must be produced from the entire plant rather than only its starch or sugars. Enzymes produced by fungi constitute a significant percentage of the cost of bioethanol production from non-starch (i.e., lignocellulosic) components of energy crops and agricultural residues. We, and others, have reasoned that fungi that naturally deconstruct plant walls may provide the best enzymes for bioconversion of energy crops.ResultsPreviously, we have reported on the isolation of 106 fungi from decaying leaves of Miscanthus and sugarcane (Appl Environ Microbiol 77:5490-504, 2011). Here, we thoroughly analyze 30 of these fungi including those most often found on decaying leaves and stems of these plants, as well as four fungi chosen because they are well-studied for their plant cell wall deconstructing enzymes, for wood decay, or for genetic regulation of plant cell wall deconstruction. We extend our analysis to assess not only their ability over an 8-week period to bioconvert Miscanthus cell walls but also their ability to secrete total protein, to secrete enzymes with the activities of xylanases, exocellulases, endocellulases, and beta-glucosidases, and to remove specific parts of Miscanthus cell walls, that is, glucan, xylan, arabinan, and lignin.ConclusionThis study of fungi that bioconvert energy crops is significant because 30 fungi were studied, because the fungi were isolated from decaying energy grasses, because enzyme activity and removal of plant cell wall components were recorded in addition to biomass conversion, and because the study period was 2 months. Each of these factors make our study the most thorough to date, and we discovered fungi that are significantly superior on all counts to the most widely used, industrial bioconversion fungus, Trichoderma reesei. Many of the best fungi that we found are in taxonomic groups that have not been exploited for industrial bioconversion and the cultures are available from the Centraalbureau voor Schimmelcultures in Utrecht, Netherlands, for all to use
Do Stock Market Fluctuations Affect Suicide Rates?
In this study, we extend the standard economic model of suicide by considering a new influential factor driving the voluntary death rate. Using an international sample, we estimate the model and document a robust and significant inverse relationship between stock market returns and the percentage increase in suicide rates. Trends in male and female suicide are affected by market fluctuations, both contemporaneously and at a lag. This predictive quality of stock returns offers the potential to implement pro-active suicide prevention strategies for those who could be affected by the vagaries of the market and general economic downturns
CodeProcess Charts: Visualizing the Process of Writing Code
Instructors of computer programming courses evaluate student progress on code submissions, exams, and other activities. The evaluation of code submissions is typically a summative assessment that gives very little insight into the process the student used when designing and writing the code. Thus, a tool that offers instructors a view into how students actually write their code could have broad impacts on assessment, intervention, instructional design, and plagiarism detection. In this article we propose an interactive software tool with a novel visualization that includes both static and dynamic views of the process that students take to complete computer programming assignments. We report results of an exploratory think-aloud study in which instructors offer thoughts as to the utility and potential of the tool. In the think-aloud study, we observed that the instructors easily identified multiple coding strategies (or the lack of thereof), were able to recognize plagiarism, and noticed a clear need for wider dissemination of tools for visualizing the programming process.Peer reviewe
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