3,978 research outputs found

    Enantio- and Diastereoselective 1,2-Additions to α-Ketoesters with Diborylmethane and Substituted 1,1-Diborylalkanes

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    The catalytic enantioselective synthesis of boronate-substituted tertiary alcohols through additions of diborylmethane and substituted 1,1-diborylalkanes to α-ketoesters is reported. The reactions are catalyzed by readily available chiral phosphine/copper(I) complexes and produce ÎČ-hydroxyboronates containing up to two contiguous stereogenic centers in up to 99:1 e.r. and greater than 20:1 d.r. The utility of the organoboron products is demonstrated through several chemoselective functionalizations. Evidence indicates the reactions occur via an enantioenriched α-boryl-copper-alkyl intermediate

    Awareness, detection and management of new and emerging tree pests and pathogens in Europe: stakeholders' perspectives

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    Emerging and invasive tree pests and pathogens in Europe are increasing in number and range, having impacts on biodiversity, forest services, ecosystems and human well-being. Stakeholders involved in tree and forest management contribute to the detection and management of new and emerging tree pests and pathogens (PnPs). We surveyed different groups of stakeholders in European countries. The stakeholders were mainly researchers, tree health surveyors and forest managers, as well as forest owners, nurseries, policy-makers, advisors, forestry authorities, NGOs and civil society. We investigated which tools they used to detect and manage PnPs, surveyed their current PnP awareness and knowledge and collated the new and emerging PnP species of concern to them. The 237 respondents were based in 15 European coun-tries, with the majority from the United Kingdom, France and the Czech Republic. There was a strong participation of respondents with a work focus on research and surveying, whereas timber traders and plant importers were less represented. Respondents were surveyed on 18 new, emerging PnPs in Europe and listed an additional 37 pest species and 21 pathogen species as potential future threats. We found that species on EPPO's list of 'priority pests' were better known than those not listed.Stakeholders working in urban environments were more aware of PnPs compared to those working in rural areas. Stakeholders' awareness of PnPs was not related to the number of new, emerging PnP species present in a country. Stakeholders want access to more detection and management tools, including long-term citizen -sci-ence monitoring, maps showing spread and range of new PnPs, pest identification smartphone apps, hand-held detection devices, drone monitoring and eDNA metabarcoding. To help facilitate better forest health across Europe, they called for mixed forest development, reduced nursery stock movement, biosecurity and data sharing amongst organisations. These results indicate that stakeholder knowledge of a few key PnP may be good, but given that the large diversity of threats is so large and future risks unknown, we conclude that multiple and varied methods for generic detection, mitigation and management methods, many in devel-opment, are needed in the hands of stakeholders surveying and managing trees and woodlands in Europe

    Analyzing the Between-Day Reliability of Three-Dimensional Body Scanners for Body Composition Assessment

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    In the growing world of health and well-being, three-dimensional (3D) scanning is emerging as a popular tool to assess body composition. While body composition cannot be truly “measured” in living humans, it can be approximated. This, however, leads to two types of errors (i.e., technical and biological) in the body composition assessment. PURPOSE: This study was used to determine what percent or range of percentages in body fat one must exceed before concluding a real change has occurred. By conducting assessments on separate days, with only a short period of time between them, true changes in body composition are unlikely to occur. Therefore, this design can help determine the inherent, between-day error in a body fat assessment to provide context for longer-term changes. METHODS: In the present investigation, thirteen participants were scanned using three distinct 3D body scanners (Fit3D Proscanner, Sizestream SS20, and Styku S100) on two separate mornings, separated by 24 to 48 hours. Each subject had to follow the pre-assessment restrictions and ensure they fit all the eligibility requirements for this study. Then, all body fat percentage (BF%) values from the 3D scanners were recorded and analyzed to determine the between-day reliability. RESULTS: Intraclass correlation coefficients ranged from 0.971 to 0.997 for the three scanners. The least significant change (LSC) values were 1.2%, 2.6%, and 3.0% for the Styku S100, Fit3D Proscanner, and Sizestream SS20, respectively. When examining differences in BF% for individual participants, the between-day differences ranged from -1.1% to 1.0% for Styku S100, -1.9% to 3.2% for Fit3D Proscanner, and -4.0% to 3.0% for SizeStream SS20. CONCLUSION: These results collectively suggest that the Styku S100 has the highest between-day reliability and lowest technical error of the three scanning systems. Overall, however, it is important for consumers to understand that each 3D scanner contains some level of error that should be considered when interpreting the results of an assessment. This study can not only be applied to future research determining the most reliable body composition assessments, but it can also aid individuals in understanding how large of a change in body fat is needed to exceed the error of a 3D scanner and therefore be considered a “real” change

    The transcriptome of the endometrium and placenta is associated with pregnancy development but not lactation status in dairy cows

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    peer-reviewedInfertility in lactating dairy cows is explained partially by the metabolic state associated with high milk production. The hypothesis was that lactating and nonlactating cows would differ in endometrial and placental transcriptomes during early pregnancy (day 28 to 42) and this difference would explain the predisposition for lactating cows to have embryonic loss at that time. Cows were either milked or not milked after calving. Reproductive [endometrium (caruncular and intercaruncular) and placenta] and liver tissues were collected on day 28, 35, and 42 of pregnancy. The hypothesis was rejected because no effect of lactation on mRNA abundance within reproductive tissues was found. Large differences within liver demonstrated the utility of the model to test an effect of lactation on tissue gene expression. Major changes in gene expression in reproductive tissues across time were found. Greater activation of the transcriptome for the recruitment and activation of macrophages was found in the endometrium and placenta. Changes in glucose metabolism between day 28 and 42 included greater mRNA abundance of rate-limiting genes for gluconeogenesis in intercaruncular endometrium and evidence for the establishment of aerobic glycolysis (Warburg effect) in the placenta. Temporal changes were predicted to be controlled by CSF1, PDGFB, TGFB1, and JUN. Production of nitric oxide and reactive oxygen species by macrophages was identified as a mechanism to promote angiogenesis in the endometrium. Reported differences in pregnancy development for lactating vs. nonlactating cows could be explained by systemic glucose availability to the conceptus and appeared to be independent of the endometrial and placental transcriptomes

    Observing System Simulation Experiment (OSSE) for the HyspIRI Spectrometer Mission

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    The OSSE software provides an integrated end-to-end environment to simulate an Earth observing system by iteratively running a distributed modeling workflow based on the HyspIRI Mission, including atmospheric radiative transfer, surface albedo effects, detection, and retrieval for agile exploration of the mission design space. The software enables an Observing System Simulation Experiment (OSSE) and can be used for design trade space exploration of science return for proposed instruments by modeling the whole ground truth, sensing, and retrieval chain and to assess retrieval accuracy for a particular instrument and algorithm design. The OSSE in fra struc ture is extensible to future National Research Council (NRC) Decadal Survey concept missions where integrated modeling can improve the fidelity of coupled science and engineering analyses for systematic analysis and science return studies. This software has a distributed architecture that gives it a distinct advantage over other similar efforts. The workflow modeling components are typically legacy computer programs implemented in a variety of programming languages, including MATLAB, Excel, and FORTRAN. Integration of these diverse components is difficult and time-consuming. In order to hide this complexity, each modeling component is wrapped as a Web Service, and each component is able to pass analysis parameterizations, such as reflectance or radiance spectra, on to the next component downstream in the service workflow chain. In this way, the interface to each modeling component becomes uniform and the entire end-to-end workflow can be run using any existing or custom workflow processing engine. The architecture lets users extend workflows as new modeling components become available, chain together the components using any existing or custom workflow processing engine, and distribute them across any Internet-accessible Web Service endpoints. The workflow components can be hosted on any Internet-accessible machine. This has the advantages that the computations can be distributed to make best use of the available computing resources, and each workflow component can be hosted and maintained by their respective domain experts

    The Impact of a SIG on Assessment Literacy

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    A major aim of professional associations is to provide opportunities for professionals to interact with others, share ideas and develop in their chosen profession. Professional associations exist to provide specialized networking and development opportunities to a specific profession, group of individuals or field of study. To promote and support specialized research and communication, smaller subgroups within an association are often chartered or developed. These subgroups are typically known as Special Interest Groups. According to Jacob et al. (2013), association members join SIGs because they want to go deeper into a specialized content area and they enjoy networking with others who ‘speak the same language.’ The TESOL Arabia Testing, Assessment and Evaluation SIG (TAE SIG) has focused their professional development activities on an important trend in the field, that of language assessment literacy (LAL). Language assessment literacy has been a critical topic in English language teaching since the late 1990s. Unfortunately, this is mainly due to the fact that so many English language teachers are not assessment literate. In other words, many English language teachers lack the knowledge and skills to write effective language tests, evaluate the effectiveness of their tests, and use their test results in meaningful ways. The purpose of this chapter is to critically examine the status of LAL in the Middle East and North Africa (MENA) region and report on activities that the TAE SIG has implemented to increase LAL

    Comparison of Laboratory-Grade and Consumer-Grade Hand-to-Foot Bioelectrical Impedance Analyzers for Body Composition Estimation

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    Bioelectrical impedance analysis (BIA) is a simple and effective technique to estimate body composition, including body fat percentage (BFP). While these analyzers are a popular method of describing a person’s body composition, laboratory-grade devices are expensive and inaccessible to most people. As a result, they may be an unrealistic method for consumers to use. However, consumer-grade devices are increasingly available. PURPOSE: The purpose of this study was to compare laboratory-grade and consumer-grade bioelectrical impedance analyzers. METHODS: Seventy-five adults (40 F, 35 M) were evaluated using a laboratory-grade, hand-to-foot, multifrequency bioelectrical impedance analyzer (BIALAB; Seca mBCA 515) and a consumer-grade, hand-to-foot, single frequency bioelectrical impedance analyzer (BIACON; Omron HBF-516). Both devices administer undetectable electrical pulses through one extremity that are measured at another extremity, where the voltage drop (impedance) is determined. This information is used to estimate body fluids and composition. RESULTS: A strong, statistically significant correlation between devices was observed for BFP (r: 0.93, R2: 0.87, pCON overestimated BFP by 3.5 ± 3.4% (mean ± SD) relative to BIALAB (BIACON: 28.3 ± 9.6%; BIALAB: 24.8 ± 9.3%; pCONCLUSION: These results collectively suggest that while the laboratory-grade and consumer-grade analyzers in our study exhibit strong correlations when assessing a group of individuals, the consumer-grade device overestimates BFP. Additionally, the SEE indicates that 3.4% error can be expected with the consumer-grade device. Overall, the Omron HBF-516 consumer-grade device may be an adequate and affordable option to estimate body composition in some contexts, but results should be interpreted cautiously when used in individuals

    Gemini Near Infrared Spectrograph -- Distant Quasar Survey: Augmented Spectroscopic Catalog and a Prescription for Correcting UV-Based Quasar Redshifts

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    Quasars at z ≳ 1z~{\gtrsim}~1 most often have redshifts measured from rest-frame ultraviolet emission lines. One of the most common such lines, C IV λ1549{\lambda}1549, shows blueshifts up to ≈ 5000 km s−1{\approx}~5000~\rm{km~s^{-1}}, and in rare cases even higher. This blueshifting results in highly uncertain redshifts when compared to redshift determinations from rest-frame optical emission lines, e.g., from the narrow [O III] λ5007{\lambda}5007 feature. We present spectroscopic measurements for 260 sources at 1.55 â‰Č z â‰Č 3.501.55~{\lesssim}~z~{\lesssim}~3.50 having −28.0 â‰Č Mi â‰Č −30.0-28.0~{\lesssim}~M_i~{\lesssim}~-30.0 mag from the Gemini Near Infrared Spectrograph - Distant Quasar Survey (GNIRS-DQS) catalog, augmenting the previous iteration which contained 226 of the 260 sources whose measurements are improved upon in this work. We obtain reliable systemic redshifts based on [O III] λ5007{\lambda}5007 for a subset of 121 sources which we use to calibrate prescriptions for correcting UV-based redshifts. These prescriptions are based on a regression analysis involving C IV full-width-at-half-maximum intensity and equivalent width, along with the UV continuum luminosity at a rest-frame wavelength of 1350 A. Applying these corrections can improve the accuracy and the precision in the C IV-based redshift by up to ∌ 850 km s−1{\sim}~850~\rm{km~s^{-1}} and ∌ 150 km s−1{\sim}~150~\rm{km~s^{-1}}, respectively, which correspond to ∌ 8.5{\sim}~8.5 Mpc and ∌ 1.5{\sim}~1.5 Mpc in comoving distance at z = 2.5z~=~2.5. Our prescriptions also improve the accuracy of the best available multi-feature redshift determination algorithm by ∌ 100 km s−1{\sim}~100~\rm{km~s^{-1}}, indicating that the spectroscopic properties of the C IV emission line can provide robust redshift estimates for high-redshift quasars. We discuss the prospects of our prescriptions for cosmological and quasar studies utilizing upcoming large spectroscopic surveys.Comment: 20 pages (AASTeX 6.3.1), 8 figures, accepted for publication in Ap

    Mapping an atlas of tissue-specific drosophila melanogaster metabolomes by high resolution mass spectrometry

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    Metabolomics can provide exciting insights into organismal function, but most work on simple models has focussed on the whole organism metabolome, so missing the contributions of individual tissues. Comprehensive metabolite profiles for ten tissues from adult Drosophila melanogaster were obtained here by two chromatographic methods, a hydrophilic interaction (HILIC) method for polar metabolites and a lipid profiling method also based on HILIC, in combination with an Orbitrap Exactive instrument. Two hundred and forty two polar metabolites were putatively identified in the various tissues, and 251 lipids were observed in positive ion mode and 61 in negative ion mode. Although many metabolites were detected in all tissues, every tissue showed characteristically abundant metabolites which could be rationalised against specific tissue functions. For example, the cuticle contained high levels of glutathione, reflecting a role in oxidative defence; the alimentary canal (like vertebrate gut) had high levels of acylcarnitines for fatty acid metabolism, and the head contained high levels of ether lipids. The male accessory gland uniquely contained decarboxylated S-adenosylmethionine. These data thus both provide valuable insights into tissue function, and a reference baseline, compatible with the FlyAtlas.org transcriptomic resource, for further metabolomic analysis of this important model organism, for example in the modelling of human inborn errors of metabolism, aging or metabolic imbalances such as diabetes

    Not Belonging to one’s Self: Affect on Facebook’s Site Governance page

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    This article makes a contribution to a growing number of works that discuss affect and social media. I use Freudian affect theory to analyse user posts on the public Site Governance Facebook page. Freud’s work may help us to explore the affectivity within the user narratives and I suggest that they are expressions of alienation, dispossession and powerlessness that relate to the users’ relations with Facebook as well as to their internal and wider social relations. The article thus introduces a new angle on studies of negative user experiences that draws on psychoanalysis and critical theory
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