The development of endo-selective epoxide-opening cascades in water

This tutorial review traces the development of endo-regioselective epoxide-opening reactions in water. Templated, water-promoted epoxide-opening cyclization reactions can offer rapid access to subunits of the ladder polyethers, a fascinating and complex family of natural products. This review may be of interest to those curious about the ladder polyethers and their hypothesized biogenesis, about organic reactions in water, and about the development and application of cascade reactions in organic synthesis

Fully-automated in vivo single cell electrophysiology

In this work, we report progress in developing a device that allows fully autonomous sequential patch clamp experimentation. The machine works by integrating a storage magazine of pre-filled pipettes that can be accessed, and swapped, by the headstage at the conclusion of each experiment. In operation, following each neuron measurement, the program enters “swap” state where a set of programmed actuator movements take place. First, the headstage translates towards the pipette storage assembly and deposits its used pipette. The storage assembly rotates to index a fresh pipette, its is grasped, and finally, the headstage returns to its previously designated home position in preparation of subsequent experiments

Towards Real Time Optimal Auto-tuning of PID Controllers

The Proportional-Integral-Derivative (PID) controller has been widely used by the process control industry for many years. Design methods for PID Controllers are mature and have been heavily researched and evaluated. For most of its modern history the Ziegler-Nichols methods have been used for tuning PID controllers into desired operating conditions. Recently, automatic tuning methods have been formulated and used to generate stable PID controlled systems. These methods have also been implemented on real time systems. However, the use of optimal methods for auto tuning PID controllers on real time systems has not seen much discussion. In this thesis we explore the applicability of optimal PID design methods from Datta, Ho, and Bhattacharrya, to real time system control. The design method is based on a complete characterization of the set of stabilizing PID parameters for various plant models and a subsequent search over the stabilizing set for the optimal controller. A full implementation of the algorithms is completed on an embedded system with DSP hardware. These implementations are then tested against a large number of examples to determine both accuracy and applicability to real time systems. The major design constraint for application of these algorithms to real time systems is computation time. The faster the optimal result can be computed the more applicable the algorithm is to a real time environment. In order to bring each of these algorithms into a real time system, fast search algorithms were developed to quickly compute the optimal result for the given performance criterion. Three different search methods were developed, compared and analyzed. The first method is a brute force search used as a basis to compare the two additional fast search methods. The two faster search methods prove to be vastly superior in determining the optimal result with the same level of accuracy as brute force search, but in a greatly reduced time. These search methods achieve their superior speeds by reducing the search space without sacrificing accuracy of the results. With these two fast search methods applied to the complete characterization of stabilizing PID controllers, application to real time systems is achieved and demonstrated through examples of various performance criteria

Effects of Cover Crop, N and Residue Management on the Financial Sustainability of Processing Tomatoes in Southwestern Ontario

Given the potential environmental and economic sustainability consequences of cover crop adoption, N fertilizer application, and residue management, this study focuses on the yield and financial effects of these on processing tomato production in Ontario, Canada. The study employs financial modeling using field data from a long-term cover crop experiment (oat, cereal rye, radish, and a radish-rye mixture) from 2010 to 2020. Averaged over six experimental years, compared to no cover (87 Mg ha−1) radish (99.6 Mg ha−1) and radish-rye mix (95.2 Mg ha−1) cover crops produce statistically significantly higher tomato yields as isolated practices, increasing farm net returns by $1120 ha−1 and$604 ha−1, respectively. When combined with N application, rye application additionally results in tomato yields statistically significantly higher than the base practice of no cover crop, zero N application and retained residue. Oat cover does not appear to have a statistically significant effect on tomato yields in this dataset. The application of N fertilizer results in statistically significantly higher tomato yield, increasing net returns by $882 ha−1, while residue management does not

Race, Ethnicity and Higher Education in the African Diaspora: Guest Editors\u27 Introductory Note

Authors in this issue of Alliance for African Partnership Perspectives, Race, Ethnicity, and Higher Education in the African Diaspora, responded to a Call for Thought Pieces from anywhere in the world—urgent, critical reflections of issues around race and ethnicity in higher education institutions and key stakeholder and collaborator organizations in Africa and the African Diaspora.https://scholarworks.smith.edu/afr_books/1008/thumbnail.jp

Photodynamic and anti- VEGF therapy for polypoidal choroidal vasculopathy - 'real world' outcomes in a caucasian population

Background: The prevalence of polypoidal choroidal vasculopathy (PCV) is significantly higher amongst Asian populations compared to Caucasian, and evidence regarding the clinical outcomes of Caucasian patients is limited. Objective: This retrospective study sought to investigate real-world clinical outcomes of Caucasian PCV patients treated with polypoidal verteporfin photodynamic therapy (PDT) in combination with anti-VEGF therapy up to 36 months post-treatment. Methods: Consecutive PCV patients who received PDT between 2011 and 2017 were included. Mean change in visual acuity (VA) measured by ETDRS letter score and mean change in central subfield thickness (CST) were the main outcome measures. Data were collected at baseline, 3, 12, 24 and 36 months. Regression analyses were carried out on pre-treatment clinical features to determine if there were any factors associated with a good visual outcome (better than or equal to 70 ETDRS letters at 12 months). Results: Seventy six patients (96% Caucasian) and seventy eight eyes were included in the analysis. Mean change in VA was-1,-4, and 0 ETDRS letters at 12, 24, and 36 months, respectively. CST was reduced by a mean of-51,-54, and-55 microns at 12, 24, and 36 months, respectively. Better pre-treatment VA was the only pre-treatment clinical feature associated with a good visual outcome at 12 months (OR 1.16, p<0.001). Conclusion: PDT, in combination with anti-VEGF therapy, maintains VA and may reduce the anti-VEGF therapy burden in Caucasian patients with PCV. Better pre-treatment VA is associated with a good visual outcome

Data-driven biomarkers better associate with stroke motor outcomes than theory-based biomarkers.

Chronic motor impairments are a leading cause of disability after stroke. Previous studies have associated motor outcomes with the degree of damage to predefined structures in the motor system, such as the corticospinal tract. However, such theory-based approaches may not take full advantage of the information contained in clinical imaging data. The present study uses data-driven approaches to model chronic motor outcomes after stroke and compares the accuracy of these associations to previously-identified theory-based biomarkers. Using a cross-validation framework, regression models were trained using lesion masks and motor outcomes data from 789 stroke patients from the Enhancing NeuroImaging Genetics through Meta Analysis (ENIGMA) Stroke Recovery Working Group. Using the explained variance metric to measure the strength of the association between chronic motor outcomes and imaging biomarkers, we compared theory-based biomarkers, like lesion load to known motor tracts, to three data-driven biomarkers: lesion load of lesion-behaviour maps, lesion load of structural networks associated with lesion-behaviour maps, and measures of regional structural disconnection. In general, data-driven biomarkers had stronger associations with chronic motor outcomes accuracy than theory-based biomarkers. Data-driven models of regional structural disconnection performed the best of all models tested (R 2 = 0.210, P < 0.001), performing significantly better than the theory-based biomarkers of lesion load of the corticospinal tract (R 2 = 0.132, P < 0.001) and of multiple descending motor tracts (R 2 = 0.180, P < 0.001). They also performed slightly, but significantly, better than other data-driven biomarkers including lesion load of lesion-behaviour maps (R 2 = 0.200, P < 0.001) and lesion load of structural networks associated with lesion-behaviour maps (R 2 = 0.167, P < 0.001). Ensemble models - combining basic demographic variables like age, sex, and time since stroke - improved the strength of associations for theory-based and data-driven biomarkers. Combining both theory-based and data-driven biomarkers with demographic variables improved predictions, and the best ensemble model achieved R 2 = 0.241, P < 0.001. Overall, these results demonstrate that out-of-sample associations between chronic motor outcomes and data-driven imaging features, particularly when lesion data is represented in terms of structural disconnection, are stronger than associations between chronic motor outcomes and theory-based biomarkers. However, combining both theory-based and data-driven models provides the most robust associations

Protecting 30% of the planet for nature: costs, benefits and economic implications

A. Waldron, K. Nakamura, J. Sze, T. Vilela, A. Escobedo, P. Negret Torres, R. Button, K. Swinnerton, A. Toledo, P. Madgwick, N. Mukherjee were supported by National Geographic and the Resources Legacy Fund. V. Christensen was supported by NSERC Discovery Grant RGPIN-2019-04901. M. Coll and J. Steenbeek were supported by EU Horizon 2020 research and innovation programme under grant agreement No 817578 (TRIATLAS). D. Leclere was supported by TradeHub UKRI CGRF project. R. Heneghan was supported by Spanish Ministry of Science, Innovation and Universities, Acciones de Programacion Conjunta Internacional (PCIN-2017-115). M. di Marco was supported by MIUR Rita Levi Montalcini programme. A. Fernandez-Llamazares was supported by Academy of Finland (grant nr. 31176). S. Fujimori and T. Hawegawa were supported by The Environment Research and Technology Development Fund (2-2002) of the Environmental Restoration and Conservation Agency of Japan and the Sumitomo Foundation. V. Heikinheimo was supported by Kone Foundation, Social Media for Conservation project. K. Scherrer was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 682602. U. Rashid Sumaila acknowledges the OceanCanada Partnership, which funded by the Social Sciences and Humanities Research Council of Canada (SSHRC). T. Toivonen was supported by Osk. Huttunen Foundation & Clare Hall college, Cambridge. W. Wu was supported by The Environment Research and Technology Development Fund (2-2002) of the Environmental Restoration and Conservation Agency of Japan. Z. Yuchen was supported by a Ministry of Education of Singapore Research Scholarship Block (RSB) Research Fellowship