110 research outputs found

    A preliminary assessment of water partitioning and ecohydrological coupling in northern headwaters using stable isotopes and conceptual runoff models

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    Funded by European Research Council ERC. Grant Number: GA 335910 VEWA Swedish Science Foundation (SITES) Future Forest Formas (ForWater) SKB the Kempe foundation Environment Canada the Garfield Weston Foundation the Natural Sciences and Engineering Research Council of Canada (NSERC) the Northwest Territories Cumulative Impacts Monitoring ProgramPeer reviewedPublisher PD

    Crowdsourcing Image Extraction and Annotation: Software Development and Case Study

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    We describe the development of web-based software that facilitates large-scale, crowdsourced image extraction and annotation within image-heavy corpora that are of interest to the digital humanities. An application of this software is then detailed and evaluated through a case study where it was deployed within Amazon Mechanical Turk to extract and annotate faces from the archives of Time magazine. Annotation labels included categories such as age, gender, and race that were subsequently used to train machine learning models. The systemization of our crowdsourced data collection and worker quality verification procedures are detailed within this case study. We outline a data verification methodology that used validation images and required only two annotations per image to produce high-fidelity data that has comparable results to methods using five annotations per image. Finally, we provide instructions for customizing our software to meet the needs for other studies, with the goal of offering this resource to researchers undertaking the analysis of objects within other image-heavy archives

    Four-month moxifloxacin-based regimens for drug-sensitive tuberculosis

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    Supported by the Global Alliance for TB Drug Development with support from the Bill and Melinda Gates Foundation, the European and Developing Countries Clinical Trials Partnership, U.S. Agency for International Development, U.K. Department for International Development, Directorate General for International Cooperation of the Netherlands, Irish Aid, Australia Department of Foreign Affairs and Trade, and National Institutes of Health, AIDS Clinical Trials Group and by grants from the National Institute of Allergy and Infectious Diseases (NIAID) (UM1AI068634, UM1 AI068636, and UM1AI106701) and by NIAID grants to the University of KwaZulu Natal, South Africa, AIDS Clinical Trials Group (ACTG) site 31422 (1U01AI069469); to the Perinatal HIV Research Unit, Chris Hani Baragwanath Hospital, South Africa, ACTG site 12301 (1U01AI069453); and to the Durban International Clinical Trials Unit, South Africa, ACTG site 11201 (1U01AI069426); Bayer Healthcare for the donation of moxifloxacin; and Sanofi for the donation of rifampin.Background: Early-phase and preclinical studies suggest that moxifloxacin-containing regimens could allow for effective 4-month treatment of uncomplicated, smear-positive pulmonary tuberculosis. Methods: We conducted a randomized, double-blind, placebo-controlled, phase 3 trial to test the noninferiority of two moxifloxacin-containing regimens as compared with a control regimen. One group of patients received isoniazid, rifampin, pyrazinamide, and ethambutol for 8 weeks, followed by 18 weeks of isoniazid and rifampin (control group). In the second group, we replaced ethambutol with moxifloxacin for 17 weeks, followed by 9 weeks of placebo (isoniazid group), and in the third group, we replaced isoniazid with moxifloxacin for 17 weeks, followed by 9 weeks of placebo (ethambutol group). The primary end point was treatment failure or relapse within 18 months after randomization. Results: Of the 1931 patients who underwent randomization, in the per-protocol analysis, a favorable outcome was reported in fewer patients in the isoniazid group (85%) and the ethambutol group (80%) than in the control group (92%), for a difference favoring the control group of 6.1 percentage points (97.5% confidence interval [CI], 1.7 to 10.5) versus the isoniazid group and 11.4 percentage points (97.5% CI, 6.7 to 16.1) versus the ethambutol group. Results were consistent in the modified intention-to-treat analysis and all sensitivity analyses. The hazard ratios for the time to culture negativity in both solid and liquid mediums for the isoniazid and ethambutol groups, as compared with the control group, ranged from 1.17 to 1.25, indicating a shorter duration, with the lower bounds of the 95% confidence intervals exceeding 1.00 in all cases. There was no significant difference in the incidence of grade 3 or 4 adverse events, with events reported in 127 patients (19%) in the isoniazid group, 111 (17%) in the ethambutol group, and 123 (19%) in the control group. Conclusions: The two moxifloxacin-containing regimens produced a more rapid initial decline in bacterial load, as compared with the control group. However, noninferiority for these regimens was not shown, which indicates that shortening treatment to 4 months was not effective in this setting. (Funded by the Global Alliance for TB Drug Development and others; REMoxTB ClinicalTrials.gov number, NCT00864383.)Publisher PDFPeer reviewe

    Quantification of rubidium as a trace element in beef using laser induced breakdown spectroscopy

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    This study evaluates the potential of laser induced breakdown spectroscopy (LIBS) coupled with chemometrics to develop a quantification model for rubidium (Rb) in minced beef. A LIBSCAN 150 system was used to collect LIBS spectra of minced beef samples. Beef liver was used to spike the Rb levels in minced beef. All samples were dried, powdered and pelleted using a hydraulic press. Measurements were conducted by scanning 100 different locations with an automated XYZ sample chamber. Partial least squares regression (PLSR) was used to develop the calibration model, yielding a calibration coefficient of determination (Rc2) of 0.99 and a root mean square error of calibration (RMSEC) of 0.05ppm. The model also showed good results with leave-one-out cross validation, yielding a cross-validation coefficient of determination (Rcv2) of 0.90 and a root mean square error of cross-validation (RMSECV) of 0.22ppm. The current study shows the potential of LIBS as a rapid analysis tool for the meat processing industry

    Roan antelope Hippotragus equinus in Africa : a review of abundance, threats and ecology

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    1. The roan antelope Hippotragus equinus, Africa’s second largest antelope species, is widely distributed throughout Africa. Many populations are isolated, occur at low densities, and are declining. The species’ interactions with and adaptations to the diverse environmental conditions throughout its geographic range remain largely unknown. Most studies have taken place in southern Africa, near the range limit for the species; few studies have been conducted on the historically large Central and West African populations. 2. We reviewed available published and accessible unpublished data related to the ecology of roan antelope. We aim to: 1) review available taxonomic, abundance, distribution, and population trend data; 2) describe the threats faced by the roan antelope, and establish whether sufficient data exist to describe its ecological requirements; and 3) highlight the relevance of conserving this species throughout Africa and suggest where research on survival requirements should be focussed. 3. Roan antelope populations throughout Africa are declining due to natural and anthropogenic threats. Methodological irregularities result in uncertainty and non-comparable population data between studies. Large gaps exist in our knowledge of roan antelope diet and regional movements. Information on the population genetics of roan antelope is needed in order to assess the connectedness of different populations. 4. Data deficiency severely impedes our ability to employ powerful analytical methods aimed at understanding and predicting population persistence and viability, and to model envisaged threats from impending climate change. A unified approach to fundamental ecological research is required to inform the conservation and management of large rare mammalian ungulates such as the roan antelope in Africa.University of Pretoria and South African National Research Foundation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-29072017-04-30hb2016Mammal Research InstituteZoology and Entomolog

    First record of roan antelope (Hippotragus equinus) feeding on the fruits of the sausage tree (Kigelia africana)

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    No abstract available.National Research Foundation (NRF), Paul G. Allen Family Foundation, Wilderness Safaris, Wilderness Wildlife Trust, Komanis Foundation and Elephants Without Borders.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-20282015-12-30hb201

    Abiotically-induced plant morphological changes and host-range expansion in quarantine evaluations of candidate weed biocontrol agents : the case study Conchyloctenia hybrida (Coleoptera: Chrysomelidae)

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    Plant morphological changes mediated by growth conditions are linked to changes in host preference of herbivores. Understanding how these morphological changes influence herbivore feeding is critical in the interpretation of results of host evaluation of candidate weed biocontrol agents in quarantine and improvement of the evaluation system. We determined the effect of plant growth conditions on leaf trichomes and host choice of Conchyloctenia hybrida Boheman, an insect adapted to the removal of trichomes before feeding. The study included four Solanum species: Solanum lichtensteinii Willdenow (natural host of C. hybrida), Solanum mauritianum Scopoli, Solanum melongena L., and Solanum tuberosum L.. Plants were grown in either full sun, shade, a glasshouse, or in a growth-chamber. Plants grown in full sun had a higher leaf trichome density than those in shade or controlled environments. S. mauritianum had the highest trichome density and thickness of trichome layer. In a multiple-choice test using excised leaves, feeding by C. hybrida was higher on Solanum plants grown in the controlled environment as compared with full sun. Trichome removal from leaf surfaces of plants grown in full sun, using adhesive tape, was effective for S. lichtensteinii, S. mauritianum, and S. melongena, but not S. tuberosum. Leaf consumption by C. hybrida increased significantly where manual trichome removal using adhesive tape was effective. Structurally, leaves of S. tuberosum have simple trichomes with basal cells sunken into the mesophyll tissue. When using forceps to remove trichomes of S. tuberosum, mesophyll and vascular tissue remained attached to the trichomes. Generally, the type, density, and mat-thickness of leaf trichomes determined feeding by C. hybrida, but varied with plant species and growth conditions.The South African National Working for Water Programme of the Department of Water Affairshttp://www.entsoc.orgam201

    The molecular, morphological and genetic characterization of glyphosate resistance in Conyza bonariensis from South Africa

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    Six Conyza bonariensis (L.) Cronquist populations were screened in a pot experiment at the University of Pretoria’s Hatfield experimental farm to evaluate and confirm the degree of glyphosate response. Resistance factors ranged from 2.7- to 24.8-fold compared to the most susceptible biotype. Partial sequencing of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene found no mutation at the Thr102, Ala103 or Pro106 positions. EPSPS mRNA expression levels in glyphosate-resistant biotypes (Swellendam and Piketberg seed sampling sites) were comparable or lower than those in susceptible biotypes (George and Fauresmith sites). Additionally, the highest expression level was reported in the susceptible Fauresmith biotype. These results indicate that glyphosate resistance in the tested resistant biotypes is not caused by target-site mutations and EPSPS gene amplification. Leaf surface characteristics can influence the spread and subsequent absorption of glyphosate. The study established non-significant results in the amount of leaf wax and insufficient mean separations in cuticle thickness and trichome density data. Therefore, the observed differences in response of biotypes to glyphosate treatment could not be attributed conclusively to differences in the leaf morphological characteristics investigated. Results from the inheritance study were consistent with glyphosate resistance being inherited in an incompletely dominant manner when plants were treated with glyphosate herbicide at 900 g ae ha−1 .SUPPLEMENTARY MATERIAL : FIGURE S1. Transmission electron micrographs of outer epidermis cell wall of C. bonariensis showing cuticular membrane. FIGURE S2. Transmission electron micrographs of outer epidermis cell wall of C. bonariensis showing cuticular undulations. FIGURE S3. Scanning electron micrographs of C. bonariensis trichomes on leaf surface (A and B) and on cross section of leaf (C) showing trichomes on both adaxial and abaxial sides. FIGURE S4. Light microscope images of C. bonariensis leaf surface showing numerous trichomes on the adaxial (‘A’) and fewer trichomes on the abaxial (‘B’) leaf surfaces. Figure S5. Melting curves for the EPSPS and Actin genes of C. bonariensis. TABLE S1. qRT-PCR primer sets used in the study.This work was funded by the Organization for Women in Science for the Developing World (OWSD) and the Swedish International Development Cooperation Agency (Sida), Fund Reservation numbers 3240266448 and 3240278002, National Research Foundation (NRF) South Africa, Grant Unique Number 88750, and Monsanto South Africa under Project 07458, Herbicide crop resistance.the Organization for Women in Science for the Developing World (OWSD), the Swedish International Development Cooperation Agency (Sida), National Research Foundation (NRF) South Africa and Monsanto South Africa.https://www.mdpi.com/journal/plantsdm2022Forestry and Agricultural Biotechnology Institute (FABI)Plant Production and Soil Scienc

    Angular Conditions,Relations between Breit and Light-Front Frames, and Subleading Power Corrections

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    We analyze the current matrix elements in the general collinear (Breit) frames and find the relation between the ordinary (or canonical) helicity amplitudes and the light-front helicity amplitudes. Using the conservation of angular momentum, we derive a general angular condition which should be satisfied by the light-front helicity amplitudes for any spin system. In addition, we obtain the light-front parity and time-reversal relations for the light-front helicity amplitudes. Applying these relations to the spin-1 form factor analysis, we note that the general angular condition relating the five helicity amplitudes is reduced to the usual angular condition relating the four helicity amplitudes due to the light-front time-reversal condition. We make some comments on the consequences of the angular condition for the analysis of the high-Q2Q^2 deuteron electromagnetic form factors, and we further apply the general angular condition to the electromagnetic transition between spin-1/2 and spin-3/2 systems and find a relation useful for the analysis of the N-Δ\Delta transition form factors. We also discuss the scaling law and the subleading power corrections in the Breit and light-front frames.Comment: 24 pages,2 figure

    Sampling effects on the quantification of sodium content in infant formula using laser induced breakdown spectroscopy (LIBS)

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    Laser-induced breakdown spectroscopy (LIBS) was employed to predict the sodium content of infant formula (IF) over the range 0.5–4 mg Na g−1. Calibration models were built using partial least squares regression (PLS), correlating the LIBS spectral data with reference Na content quantified by atomic absorption spectroscopy (AAS). The main aim of this study was to demonstrate the ability of LIBS as a rapid tool for quantifying sodium in IF, but also to explore strategies concerning the acquisition and pre-processing of LIBS spectra. A range of different pre-processing techniques, measuring depths (repetition of laser shots) and accumulations were conducted and evaluated in terms of PLS performance. The best calibration model was developed using the third-layer spectra normalised by the H I 656.29 nm emission line, yielding a coefficient of determination (R2) of 0.93, and root-mean-square errors (RMSE) of 0.37 and 0.13 mg g−1 for cross-validation and validation, respectively
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