1,129 research outputs found

    Research Notes : Soybean cultivar response to manganese

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    Manganese deficiency of soybeans, Glycine max (L.) Merr., commonly oc-curs in southwestern Ontario. Observation of soybean fields indicated that cultivars differed in degree of Mn-deficiency symptoms. To test this obser-vation, \u27Harosoy 63\u27 and \u27Harman\u27 were grown in 3-replicate tests at six lo-cations in 1963; and, in 1964 and 1965, these cultivars were grown along with \u27Hawkeye 63\u27 and \u27Lindarin 63\u27 in 4-replicate tests at one location

    Contextualizing Wetlands Within a River Network to Assess Nitrate Removal and Inform Watershed Management

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    Aquatic nitrate removal depends on interactions throughout an interconnected network of lakes, wetlands, and river channels. Herein, we present a network‐based model that quantifies nitrate‐nitrogen and organic carbon concentrations through a wetland‐river network and estimates nitrate export from the watershed. This model dynamically accounts for multiple competing limitations on nitrate removal, explicitly incorporates wetlands in the network, and captures hierarchical network effects and spatial interactions. We apply the model to the Le Sueur Basin, a data‐rich 2,880 km2 agricultural landscape in southern Minnesota and validate the model using synoptic field measurements during June for years 2013–2015. Using the model, we show that the overall limits to nitrate removal rate via denitrification shift between nitrate concentration, organic carbon availability, and residence time depending on discharge, characteristics of the waterbody, and location in the network. Our model results show that the spatial context of wetland restorations is an important but often overlooked factor because nonlinearities in the system, e.g., deriving from switching of resource limitation on denitrification rate, can lead to unexpected changes in downstream biogeochemistry. Our results demonstrate that reduction of watershed‐scale nitrate concentrations and downstream loads in the Le Sueur Basin can be most effectively achieved by increasing water residence time (by slowing the flow) rather than by increasing organic carbon concentrations (which may limit denitrification). This framework can be used toward assessing where and how to restore wetlands for reducing nitrate concentrations and loads from agricultural watersheds.This research was funded by NSF grant EAR-1209402 under the Water Sustainability and Climate Program (WSC): REACH (REsilience under Accelerated CHange)NSF grant EAR-1242458 under Science Across Virtual Institutes (SAVI): LIFE (Linked Institutions for Future EarthA.T.H. acknowledges support provided by NSF grant EAR- 1415206 under the Science, Engineering and Education for Sustainability (SEES

    Microarray-based comparative genomic profiling of reference strains and selected Canadian field isolates of Actinobacillus pleuropneumoniae

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    <p>Abstract</p> <p>Background</p> <p><it>Actinobacillus pleuropneumoniae</it>, the causative agent of porcine pleuropneumonia, is a highly contagious respiratory pathogen that causes severe losses to the swine industry worldwide. Current commercially-available vaccines are of limited value because they do not induce cross-serovar immunity and do not prevent development of the carrier state. Microarray-based comparative genomic hybridizations (M-CGH) were used to estimate whole genomic diversity of representative <it>Actinobacillus pleuropneumoniae </it>strains. Our goal was to identify conserved genes, especially those predicted to encode outer membrane proteins and lipoproteins because of their potential for the development of more effective vaccines.</p> <p>Results</p> <p>Using hierarchical clustering, our M-CGH results showed that the majority of the genes in the genome of the serovar 5 <it>A. pleuropneumoniae </it>L20 strain were conserved in the reference strains of all 15 serovars and in representative field isolates. Fifty-eight conserved genes predicted to encode for outer membrane proteins or lipoproteins were identified. As well, there were several clusters of diverged or absent genes including those associated with capsule biosynthesis, toxin production as well as genes typically associated with mobile elements.</p> <p>Conclusion</p> <p>Although <it>A. pleuropneumoniae </it>strains are essentially clonal, M-CGH analysis of the reference strains of the fifteen serovars and representative field isolates revealed several classes of genes that were divergent or absent. Not surprisingly, these included genes associated with capsule biosynthesis as the capsule is associated with sero-specificity. Several of the conserved genes were identified as candidates for vaccine development, and we conclude that M-CGH is a valuable tool for reverse vaccinology.</p

    Object Detection Through Exploration With A Foveated Visual Field

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    We present a foveated object detector (FOD) as a biologically-inspired alternative to the sliding window (SW) approach which is the dominant method of search in computer vision object detection. Similar to the human visual system, the FOD has higher resolution at the fovea and lower resolution at the visual periphery. Consequently, more computational resources are allocated at the fovea and relatively fewer at the periphery. The FOD processes the entire scene, uses retino-specific object detection classifiers to guide eye movements, aligns its fovea with regions of interest in the input image and integrates observations across multiple fixations. Our approach combines modern object detectors from computer vision with a recent model of peripheral pooling regions found at the V1 layer of the human visual system. We assessed various eye movement strategies on the PASCAL VOC 2007 dataset and show that the FOD performs on par with the SW detector while bringing significant computational cost savings.Comment: An extended version of this manuscript was published in PLOS Computational Biology (October 2017) at https://doi.org/10.1371/journal.pcbi.100574

    Total hip arthroplasty: what information do we offer patients on websites of hospitals?

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    Contains fulltext : 97468.pdf (publisher's version ) (Open Access)BACKGROUND: Physicians face a new challenge; the self-educated patient. The internet is an important source that patients use to become self-educated. However, the individual choice for best treatment is difficult. The aim of this study was to investigate what kind of information is offered to total hip arthroplasty patients by internet and what information is appreciated by them. METHODS: Websites of orthopedic departments of all hospitals in the Netherlands were evaluated. In addition, a cohort of 102 patients, diagnosed with arthritic joint disorders, filled in an online survey and gave their opinion concerning the importance of this information. RESULTS: Eighty different orthopedic websites of hospitals were identified. Websites presented information regarding the orthopedic staff surgeon (76%) and the postoperative rehabilitation process (66%). They also offered referral to other orthopedic websites (61%), the opportunity to make an outpatient appointment (21%), and the opportunity to submit an online question (15%). Patients rated the presence of information regarding prosthesis survival as very important (>70%). However, the information on the type of prosthesis used by the hospital, and survival data of the prosthesis, were only present in ~9% and 5% respectively, of the websites. CONCLUSIONS: The content of health information on websites of hospitals is highly variable for total hip arthroplasty. Information regarding the hip implant and prosthesis survival is highly appreciated by patients, however, mostly absent on orthopedic websites in the Netherlands. The internet provides an enormous potential for orthopedic surgeons to inform the self-educated patient

    Anticancer efficacy of the hypoxia-activated prodrug evofosfamide (TH-302) in osteolytic breast cancer murine models

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    Tumor hypoxia is a major cause of treatment failure for a variety of malignancies. However, hypoxia offers treatment opportunities, exemplified by the development of compounds that target hypoxic regions within tumors. Evofosfamide (TH-302) is a prodrug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide mustard (Br-IPM). When evofosfamide is delivered to hypoxic regions, the DNA cross-linking effector, Br-IPM, is released. This study assessed the cytotoxic activity of evofosfamide in vitro and its antitumor activity against osteolytic breast cancer either alone or in combination with paclitaxel in vivo. A panel of human breast cancer cell lines were treated with evofosfamide under hypoxia and assessed for cell viability. Osteolytic MDA-MB-231-TXSA cells were transplanted into the mammary fat pad, or into tibiae of mice, allowed to establish and treated with evofosfamide, paclitaxel, or both. Tumor burden was monitored using bioluminescence, and cancer-induced bone destruction was measured using micro-CT. In vitro, evofosfamide was selectively cytotoxic under hypoxic conditions. In vivo evofosfamide was tumor suppressive as a single agent and cooperated with paclitaxel to reduce mammary tumor growth. Breast cancer cells transplanted into the tibiae of mice developed osteolytic lesions. In contrast, treatment with evofosfamide or paclitaxel resulted in a significant delay in tumor growth and an overall reduction in tumor burden in bone, whereas combined treatment resulted in a significantly greater reduction in tumor burden in the tibia of mice. Evofosfamide cooperates with paclitaxel and exhibits potent tumor suppressive activity against breast cancer growth in the mammary gland and in bone.Vasilios Liapis, Irene Zinonos, Agatha Labrinidis, Shelley Hay, Vladimir Ponomarev, Vasilios Panagopoulos, Aneta Zysk, Mark DeNichilo, Wendy Ingman, Gerald J. Atkins, David M. Findlay, Andrew C. W. Zannettino, Andreas Evdokio

    Study of photo-proton reactions driven by bremsstrahlung radiation of high-intensity laser generated electrons

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    Photo-nuclear reactions were investigated using a high power table-top laser. The laser system at the University of Jena ( I similar to 3-5 x 10(19) W cm(-2)) produced hard bremsstrahlung photons ( kT similar to 2(9 MeV) via a laser-gas interaction which served to induce ( gamma, p) and ( gamma, n) reactions in Mg, Ti, Zn and Mo isotopes. Several ( gamma, p) decay channels were identified using nuclear activation analysis to determine their integral reaction yields

    Eurasian globalization: past and present

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    © 2020 Informa UK Limited, trading as Taylor & Francis Group. In an attempt to examine Eurasian globalization historically, this paper outlines three phases of globalization starting from 200 BCE to 1492 CE as Phase 1 and 1500 CE to 1999 CE as Phase 2 and from 2000 CE Phase 3. By historicizing the concept and the process of globalization, the paper attempts to provide a more global rather than a Europe-centred history of globalization and modernization. The paper builds on the idea of Eurasia and offers a new perspective of Eurasian globalization by pivoting on China\u27s role in both Phase 1 and Phase 3 of globalization. The paper uses historical literature that has been not only critical of the Eurocentric view of the world but also provides a more connected view of global history. Concurring with Steger and James [2019. Globalization matters. Cambridge University Press] that globalization has not outlived its utility, the paper seeks to historicize and globalize the discussion of globalization

    Massively Parallel Haplotyping on Microscopic Beads for the High-Throughput Phase Analysis of Single Molecules

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    In spite of the many advances in haplotyping methods, it is still very difficult to characterize rare haplotypes in tissues and different environmental samples or to accurately assess the haplotype diversity in large mixtures. This would require a haplotyping method capable of analyzing the phase of single molecules with an unprecedented throughput. Here we describe such a haplotyping method capable of analyzing in parallel hundreds of thousands single molecules in one experiment. In this method, multiple PCR reactions amplify different polymorphic regions of a single DNA molecule on a magnetic bead compartmentalized in an emulsion drop. The allelic states of the amplified polymorphisms are identified with fluorescently labeled probes that are then decoded from images taken of the arrayed beads by a microscope. This method can evaluate the phase of up to 3 polymorphisms separated by up to 5 kilobases in hundreds of thousands single molecules. We tested the sensitivity of the method by measuring the number of mutant haplotypes synthesized by four different commercially available enzymes: Phusion, Platinum Taq, Titanium Taq, and Phire. The digital nature of the method makes it highly sensitive to detecting haplotype ratios of less than 1∶10,000. We also accurately quantified chimera formation during the exponential phase of PCR by different DNA polymerases
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