54 research outputs found

    Evaluating tree root distribution in a tree-based intercropping system with use of ground penetrating radar

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    Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.Within agroforestry systems, tree root architecture is a driver of important ecological processes such as belowground nutrient flows and C storage. Yet the belowground component of trees remains largely under-studied due to methodological restraints. Conventional subsurface sampling can overlook the heterogeneity of root systems, while complete excavations are destructive and unrepeatable. Thus, there is a need to develop non-intrusive technologies, such as ground penetrating radar (GPR), to measure root systems in situ. In this study we used GPR to detect coarse root distributions below five tree species (Quercus rubra, Juglans nigra, Populus sp., Picea abies, and Thuja occidentalis) at a temperate tree-based intercropping site in Guelph, Ontario. GPR geo-imaged transects were collected in 4.5 _ 4.5m grids that were centered on 15 individual trees. Subsequently, tree roots were identified across all geo-images (visualized as radar signal reflections) providing 3-dimensional root distribution data for each target tree. Roots detected by GPR accounted for approximately 80% of large coarse roots (ïżœ1cm) and 40% of small coarse roots (<1cm) that were later exposed in a subset of matched soil profiles. Significant inter-specific variations of coarse rooting depth preferences were detected. Additionally, preliminary analyses indicate different tree rooting patterns below the crop rows. To determine fine root distributions, fine roots were extracted from soil cores collected from the tree root study plots. Preliminary analysis indicates fine root length densities vary across species predominately in the upper 20cm. Limitations will be identified and applications will be discussed of GPR to answer ecological questions within agroforestry systems. Notably, we will highlight results from our complementary study that used the same GPR data to effectively estimate belowground biomass.Kira A. Borden (1), Marney E. Isaac (2) and Sean C. Thomas (1) ; 1. Faculty of Forestry, University of Toronto, 33 Willcocks Street, Toronto, Ontario, Canada, M5S 3B3. 2. Department of Physical and Environmental Sciences, University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ontario, Canada, M1C 1A4.Includes bibliographical references

    Novel species of Cercospora and Pseudocercospora (Capnodiales, Mycosphaerellaceae) from Australia

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    Novel species of Cercospora and Pseudocercospora are described from Australian native plant species. These taxa are Cercospora ischaemi sp. nov. on Ischaemum australe (Poaceae); Pseudocercospora airliensis sp. nov. on Polyalthia nitidissima (Annonaceae); Pseudocercospora proiphydis sp. nov. on Proiphys amboinensis (Amaryllidaceae); and Pseudocercospora jagerae sp. nov. on Jagera pseudorhus var. pseudorhus (Sapindaceae). These species were characterised by morphology and an analysis of partial nucleotide sequence data for the three gene loci, ITS, LSU and EF-1α. Recent divergence of closely related Australian species of Pseudocercospora on native plants is proposed

    Novel species of Cercospora and Pseudocercospora (Capnodiales, Mycosphaerellaceae) from Australia

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    Novel species of Cercospora and Pseudocercospora are described from Australian native plant species. These taxa are Cercospora ischaemi sp. nov. on Ischaemum australe (Poaceae); Pseudocercospora airliensis sp. nov. on Polyalthia nitidissima (Annonaceae); Pseudocercospora proiphydis sp. nov. on Proiphys amboinensis (Amaryllidaceae); and Pseudocercospora jagerae sp. nov. on Jagera pseudorhus var. pseudorhus (Sapindaceae). These species were characterised by morphology and an analysis of partial nucleotide sequence data for the three gene loci, ITS, LSU and EF-1α. Recent divergence of closely related Australian species of Pseudocercospora on native plants is proposed

    The Tale of Two States: How Policy and Funding Affect Efforts to Diversify the Teaching Corps, A study for the Minnesota Education Equity Partnership

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    Capstone paper for the fulfillment of the Master of Public Affairs degree.Approximately 96 percent of Minnesota K-12 teachers identify as white. They are teaching a much more diverse student population: 31 percent of Minnesota’s K-12 students identify as students of color or American Indian. The disproportionately white teaching corps limits the potential of students of color and American Indian students who see fewer role models during their formative years; it limits theability of school districts to incorporate more culturally-sensitive practices into their classrooms; and it limits the exposure of white students to teachers who do not look like them and often come from very different backgrounds. The Minnesota Education Equity Partnership (MnEEP) asked our Humphrey School capstone team to analyze this issue and compare Minnesota’s efforts with those in Oregon. MnEEP sees Oregon as a kindred state that has made much greater progress than Minnesota in expanding teachers of color/American Indian teachers (TOCAIT) as a share of the state’s teaching corps. Our team conducted a policy scan of both states, reviewing documents and interviewing content experts to answer the following questions: How does Minnesota’s policy efforts for recruiting and retaining TOCAIT compare to policy efforts in Oregon? And how has Minnesota distributed legislative funding for TOCAIT efforts across the educator career phases of explore, become, grow, and thrive

    Australian cultures of Botryosphaeriaceae held in Queensland and Victoria plant pathology herbaria revisited

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    The Botryosphaeriaceae is one of the most widespread and cosmopolitan endophytic group of fungi. However, the species of this group can cause severe disease when the hosts are under stressful conditions. The aim of this study was to identify living cultures from the Botryosphaeriaceae family preserved in the Queensland and Victorian Plant Pathology Herbaria using DNA sequence analyses. The 51 isolates were collected between 1971 and 2017, from 35 different host genera, with the dominant host genera being Mangifera (11 isolates), Acacia (10), and Persea (5). Multilocus sequence analyses resulted in the re-identification of 41 isolates to the genera Botryosphaeria (2 isolates), Diplodia (4), Dothiorella (1), Lasiodiplodia (19), and Neofusicoccum (15), as well as some that belonged to genera outside of the Botryosphaeriaceae (10). New records for Australia were Botryosphaeria sinensis, Diplodia alatafructa, Lasiodiplodia gonubiensis, Neofusicoccum cryptoaustrale, and N. mangroviorum. These were identified as a result of a workshop organised by the Subcommittee on Plant Health Diagnostics. The results of this study provide the fundamental information regarding the diversity of Botryosphaeriaceae species present in Australian.Plant Health Australia (PHA) who provided funds for the workshop on the identification and classification of Botryosphaeriaceae species. PHA sourced funding from the Department of Agriculture and Water Resources through a grant from the Modern Diagnostics initiative.http://link.springer.com/journal/133132020-01-01hj2019Forestry and Agricultural Biotechnology Institute (FABI

    Human Disease/Clinical Medical Sciences in Dentistry: Current state and future development of undergraduate assessments in the UK and Ireland

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    Introduction The United Kingdom and Ireland teachers of Human Disease/Clinical Medical Science for Dentistry (HD/CMSD) group continues to work together, and most recently collaborated to review current and future assessments. Materials and methods The first part of the review of assessments in HD/CMSD took place at a face‐to‐face meeting with presentations from delegates on assessments in their home institutions. The second, and larger part, comprised an online survey where all eighteen schools in the UK and Ireland participated. Results All schools had some element of formative assessment, and the majority had a stand‐alone summative assessment at the end of the HD/CMSD teaching block. Most schools had a written paper and practical elements to their assessments, most commonly a combination of a multiple‐choice type question combined with an objective structured clinical examination (OSCE). There was a trend towards the use of single best answer (SBA) questions and a willingness among participants to share a question bank. All schools incorporated elements of HD/CMSD in their final examinations. Discussion & Conclusion This collaboration promoted the sharing of developments in assessment for HD/CMSD and demonstrated a willingness to co‐operate between institutions. Assessment in HD/CMSD in the UK and Ireland continues to be refined by those responsible for its content and delivery and assessment methods are progressing following evidence‐based best practice

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Dipeptidyl peptidase-1 inhibition in patients hospitalised with COVID-19: a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial

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    Background Neutrophil serine proteases are involved in the pathogenesis of COVID-19 and increased serine protease activity has been reported in severe and fatal infection. We investigated whether brensocatib, an inhibitor of dipeptidyl peptidase-1 (DPP-1; an enzyme responsible for the activation of neutrophil serine proteases), would improve outcomes in patients hospitalised with COVID-19. Methods In a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial, across 14 hospitals in the UK, patients aged 16 years and older who were hospitalised with COVID-19 and had at least one risk factor for severe disease were randomly assigned 1:1, within 96 h of hospital admission, to once-daily brensocatib 25 mg or placebo orally for 28 days. Patients were randomly assigned via a central web-based randomisation system (TruST). Randomisation was stratified by site and age (65 years or ≄65 years), and within each stratum, blocks were of random sizes of two, four, or six patients. Participants in both groups continued to receive other therapies required to manage their condition. Participants, study staff, and investigators were masked to the study assignment. The primary outcome was the 7-point WHO ordinal scale for clinical status at day 29 after random assignment. The intention-to-treat population included all patients who were randomly assigned and met the enrolment criteria. The safety population included all participants who received at least one dose of study medication. This study was registered with the ISRCTN registry, ISRCTN30564012. Findings Between June 5, 2020, and Jan 25, 2021, 406 patients were randomly assigned to brensocatib or placebo; 192 (47·3%) to the brensocatib group and 214 (52·7%) to the placebo group. Two participants were excluded after being randomly assigned in the brensocatib group (214 patients included in the placebo group and 190 included in the brensocatib group in the intention-to-treat population). Primary outcome data was unavailable for six patients (three in the brensocatib group and three in the placebo group). Patients in the brensocatib group had worse clinical status at day 29 after being randomly assigned than those in the placebo group (adjusted odds ratio 0·72 [95% CI 0·57–0·92]). Prespecified subgroup analyses of the primary outcome supported the primary results. 185 participants reported at least one adverse event; 99 (46%) in the placebo group and 86 (45%) in the brensocatib group. The most common adverse events were gastrointestinal disorders and infections. One death in the placebo group was judged as possibly related to study drug. Interpretation Brensocatib treatment did not improve clinical status at day 29 in patients hospitalised with COVID-19
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