Mission possible: diatoms can be used to infer past duckweed (lemnoid Araceae) dominance in ponds

Compared to larger lakes, ponds have rarely been the focus of palaeoecological studies. A common feature of ponds, especially those subject to eutrophication, is mass surface coverings of lemnoid Araceae (duckweed) which have severe implications for ecological processes in small waterbodies, in particular lowered oxygen content. To help understand the implications of duckweed dominance for the long-term ecology of ponds, and to determine the potential for palaeoecological studies in ponds more generally, we develop a new diatom-based Lemna-indicator metric. Recent studies of diatom host-plant relationships have shown significant associations between duckweed and the epiphytes Lemnicola hungarica and Sellaphora saugerresii (formally known as Sellaphora seminulum). To determine the potential of these species as palaeo-indicators of long-term duckweed dynamics in ponds, we investigated the diatom composition of surface sediment assemblages in sets of duckweed and non-duckweed-dominated ponds in Norfolk, eastern England. In addition, we undertook diatom analysis of two cores from a small farmland pond (Bodham Rail Pit) subject to a known duckweed dominance event (1999–2005). Both L. hungarica and S. saugerresii were significant predictors of past Lemna dominance in the surface sediments. Further, in the core study, both diatom species accurately and closely tracked the documented “on–off” duckweed cycle. Our study suggests huge potential for using ponds in palaeoecological studies and for diatom-based investigations of floating plant histories

How informed is declared altruism in clinical trials? A qualitative interview study of patient decision-making about the QUEST trials (Quality of Life after Mastectomy and Breast Reconstruction)

Background Randomised controlled trials (RCTs) often fail to recruit sufficient participants, despite altruism being cited as their motivation. Previous investigations of factors influencing participation decisions have been methodologically limited. This study evaluated how women weigh up different motivations after initially expressing altruism, and explored their understanding of a trial and its alternatives. The trial was the 'Quality of Life after Mastectomy and Breast Reconstruction' (QUEST) trial.Methods Thirty-nine women participated in qualitative interviews 1 month post-surgery. Twenty-seven women (10 trial decliners and 17 acceptors) who spontaneously mentioned 'altruism' were selected for thematic analysis. Verbatim transcripts were coded independently by two researchers. Participants' motivations to accept or decline randomisation were cross-referenced with their understanding of the QUEST trials and the process of randomisation.Results The seven emerging themes were: (1) altruism expressed by acceptors and decliners; (2) overriding personal needs in decliners; (3) pure altruism in acceptors; (4) 'hypothetical altruism' amongst acceptors; (5) weak altruism amongst acceptors; (6) conditional altruism amongst acceptors; and (7) sense of duty to participate. Poor understanding of the trial rationale and its implications was also evident.Conclusions Altruism was a motivating factor for participation in the QUEST randomised controlled trials where the main outcomes comprised quality of life and allocated treatments comprised established surgical procedures. Women's decisions were influenced by their understanding of the trial. Both acceptors and decliners of the trial expressed 'altruism', but most acceptors lacked an obvious treatment preference, hoped for personal benefits regarding a treatment allocation, or did not articulate complete understanding of the trial.Trial registration QUEST A, ISRCTN38846532 ; Date assigned 6 January 2010. QUEST B, ISRCTN92581226 ; Date assigned 6 January 2010

The Ecology and Palaeoecology of Diatom – Duckweed Relationships

This thesis focuses on the ecology and palaeoecology of diatom-duckweed relationships and utilises a combined experimental, ecological and palaeoecological approach. In particular, the study sought to determine the potential of the epiphytic diatom Lemnicola hungarica to be utilised as a proxy indicator of past dominance of duckweed (Lemna) in small ponds. To this end, contemporary sampling of epiphytic diatom assemblages from a variety of macrophytes (including multiple samples of free-floating plants) were collected from around the world and analysed for diatom epiphytes. In this study, even despite significant environmental gradients, L. hungarica showed a significant association with free-floating plants (including Lemna spp.) as did Sellaphora seminulum. To determine whether this relationship might be used to infer Lemna-dominance in sediment cores, diatom assemblages were analysed in surface sediments from English Lemna and non-Lemna covered ponds and in a core from a pond (Bodham Rail Pit, eastern England) known to have exhibited periods of Lemna-dominance in the past. In both cases, the data suggested that both L. hungarica and S. seminulum were excellent predictors of past Lemna-dominance. Finally, to infer the consequences of Lemna-dominance for the long-term biological structure and ecosystem function of the Bodham Rail Pit, the sedimentary remains of diatoms, plant pigments, and plant and animal macrofossils were enumerated from two sediment cores. These stratigraphic data were compared with the diatom Lemna-indicator metric which indicated three distinct Lemna cycles. Sediment core analyses suggested major compositional, structural and ecological changes brought about by the Lemna cycles, especially in the submerged macrophyte community and in fish-invertebrate relationships. These data reveal that duckweed proliferation, often brought about by eutrophication and terrestrialisation in ponds, can result in dramatic ecological changes due to a strong physical ecosystem engineering effect

Identifying nonalcoholic fatty liver disease patients with active fibrosis by measuring extracellular matrix remodeling rates in tissue and blood.

Excess collagen synthesis (fibrogenesis) in the liver plays a causal role in the progression of nonalcoholic fatty liver disease (NAFLD). Methods are needed to identify patients with more rapidly progressing disease and to demonstrate early response to treatment. We describe here a novel method to quantify hepatic fibrogenesis flux rates both directly in liver tissue and noninvasively in blood. Twenty-one patients with suspected NAFLD ingested heavy water (2 H2 O, 50-mL aliquots) two to three times daily for 3-5 weeks prior to a clinically indicated liver biopsy. Liver collagen fractional synthesis rate (FSR) and plasma lumican FSR were measured based on 2 H labeling using tandem mass spectrometry. Patients were classified by histology for fibrosis stage (F0-F4) and as having nonalcoholic fatty liver or nonalcoholic steatohepatitis (NASH). Magnetic resonance elastography measurements of liver stiffness were also performed. Hepatic collagen FSR in NAFLD increased with advancing disease stage (e.g., higher in NASH than nonalcoholic fatty liver, positive correlation with fibrosis score and liver stiffness) and correlated with hemoglobin A1C. In addition, plasma lumican FSR demonstrated a significant correlation with hepatic collagen FSR.ConclusionUsing a well-characterized cohort of patients with biopsy-proven NAFLD, this study demonstrates that hepatic scar in NASH is actively remodeled even in advanced fibrosis, a disease that is generally regarded as static and slowly progressive. Moreover, hepatic collagen FSR correlates with established risks for fibrotic disease progression in NASH, and plasma lumican FSR correlates with hepatic collagen FSR, suggesting applications as direct or surrogate markers, respectively, of hepatic fibrogenesis in humans. (Hepatology 2017;65:78-88)

Biomarkers of Disease and Treatment in Murine and Cynomolgus Models of Chronic Asthma

Background Biomarkers facilitate early detection of disease and measurement of therapeutic efficacy, both at clinical and experimental levels. Recent advances in analytics and disease models allow comprehensive screening for biomarkers in complex diseases, such as asthma, that was previously not feasible. Objective Using murine and nonhuman primate (NHP) models of asthma, identify biomarkers associated with early and chronic stages of asthma and responses to steroid treatment. Methods The total protein content from thymic stromal lymphopoietin transgenic (TSLP Tg) mouse BAL fluid was ascertained by shotgun proteomics analysis. A subset of these potential markers was further analyzed in BAL fluid, BAL cell mRNA, and lung tissue mRNA during the stages of asthma and following corticosteroid treatment. Validation was conducted in murine and NHP models of allergic asthma. Results Over 40 proteins were increased in the BAL fluid of TSLP Tg mice that were also detected by qRT-PCR in lung tissue and BAL cells, as well as in OVA-sensitive mice and house dust mite-sensitive NHP. Previously undescribed as asthma biomarkers, KLK1, Reg3γ, ITLN2, and LTF were modulated in asthmatic mice, and Clca3, Chi3l4 (YM2), and Ear11 were the first lung biomarkers to increase during disease and the last biomarkers to decline in response to therapy. In contrast, GP-39, LCN2, sICAM-1, YM1, Epx, Mmp12, and Klk1 were good indicators of early therapeutic intervention. In NHP, AMCase, sICAM-1, CLCA1, and GP-39 were reduced upon treatment with corticosteroids. Conclusions and clinical relevance These results significantly advance our understanding of the biomarkers present in various tissue compartments in animal models of asthma, including those induced early during asthma and modulated with therapeutic intervention, and show that BAL cells (or their surrogate, induced sputum cells) are a viable choice for biomarker examination

An analysis of the level of participation in sport by learners with disabilities in inclusive settings

A journal article on sports participation of disabled students in the education sector of Zimbabwe.The practice of physical activity goes beyond providing access to programmes and making accommodations to support participation. It embraces the principle of non- discrimination of persons with disabilities and promotion of equity. In this paper, the authors attempt to discuss the extent to which learners with disabilities participate in sport within inclusive settings. Questionnaires and interviews were administered to the teacher and pupil samples, hence, a quantitative and qualitative approach was adopted for the study. Results revealed that children with disabilities were being sidelined with regards to participation in sport. It also emerged that specially trained personnel and material resources were not available to enhance the objective of inclusive physical activity. The need for in-house training for regular school teachers is vital. Sporting environments and equipment should be adapted to facilitate participation of children with disabilities in inclusive sporting activities

Exploring metaphor use and its insight into sense making with executive coaching clients

The difficulty coaches face in relating to and understanding how clients perceive and interpret situations is that the process for clients making sense of situations is unconscious. This presents a challenge, as there isn’t a direct or obvious route to access a client’s unconscious. Understanding clients’ use of metaphor offers a potential route to access this unconscious process and gain insight into clients’ sense making. The research adopted a critical realism paradigm and used a thematic analysis methodology with semi-structured interviews of eight executive leaders. The findings suggest that metaphor can offer insight into participants’ character and values, and coaches and leaders can use an approach of working with metaphor as a potential route to reveal and understand individuals’ unconscious sense making

Tertiary students’ perceived value of practical work as contributing to the learning of science

This thesis focuses on practical work as pedagogy in the teaching and learning of science. In particular the emphasis is on students’ perceived value of practical work in science courses offered from pre-degree to final year degree level courses at a university in Auckland, New Zealand. It seems a common assumption that the teaching of science will include a practical component. For instance, the School of Applied Sciences at Auckland University of Technology (AUT) offers a significant practical component within almost every course offered. This thesis explores the assumption that practical work should be included in the delivery of science courses. A range of views on the nature of science, the acquiring of knowledge and theories of learning are investigated, as well as the ways in which these may underpin the use of practical work as pedagogy in science education. The research described in this thesis took the form of a case study in which students in a range of science courses at AUT were asked to complete a questionnaire and a small number of respondents were then interviewed. Questionnaires were used to gather a large number of responses across a range of subject areas and a range of levels of study. Interviews were utilised to gather more in-depth responses. The data collated from the questionnaires and interviews was analysed thematically. Perhaps not surprisingly, the findings of this case study indicate overwhelming support by students for practical work. The dominant themes which emerged indicated that practical work not only supports learning and understanding in science, but also provides learning opportunities that classroom learning does not provide. The findings of this thesis would seem to support and justify the continued delivery of practical work in science courses. While the responses did not reveal how students believe practical work supports their learning and understanding, some respondents affirmed the less explicit aims of practical work in science education, such as the development of a sense of inquiry, the ability to problem solve and the ability to think critically. This then leads to the question as to whether practical work, as delivered in Applied Science courses at AUT, provides opportunities to potentially meet all of the aims which are expected and hoped for by students, the researcher and her colleagues. While this thesis establishes that students value highly the practical component in science courses, the need to further investigate the style of delivery of practical work to meet wider aims also emerged from this study