1,556 research outputs found

    Another look at the function of מַשָּׂא in prophetic literature

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    Abstract: A number of investigative studies have been conducted on the meaning and function of מַשָּׂא in the prophetic literature of the Hebrew Scriptures, some of which include comprehensive reviews of previous attempts to explain the use of this term either lexically (cf. Sellin 1930; Procksch 1930; de Boer 1948; Lambert 1955; Tsevat 1958; Naudé 1969; Calvin & Owen 1989) or as a form-critical tag (cf. Weis 1992; Melugin & Sweeney 1994; Sweeney 1996; Floyd 2002) with the latest study conducted by M.J. Boda (2006: 338-357), which classifies מַשָּׂא as an editorial marker. This article seeks to expand on previous attempts to explain the purpose of מַשָּׂא by categorizing the occurrence of מַשָּׂא in line with its various semantic domains. In the approach, a summative overview of the key suggestions of the term מַשָּׂא will provide a conceptual background for the investigation. Following this, the use of מַשָּׂא is systematically analysed in its various textual contexts throughout the Hebrew Scriptures to identify how this term was applied in popular speech, literature and translation. From this analysis, an attempt will be made to categorize מַשָּׂא into specific semantic domains and to determine how the sense in which מַשָּׂא is used in prophetic literature compares. The study concludes with a proposition that מַשָּׂא functions as a literary device to bind maśśā’-prophesies together intertextually into a virtual corpus

    A Moment-Based Polarimetric Radar Forward Operator for Rain Microphysics

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    There is growing interest in combining microphysical models and polarimetric radar observations to improve our understanding of storms and precipitation. Mapping model-predicted variables into the radar observational space necessitates a forward operator, which requires assumptions that introduce uncertainties into model-observation comparisons. These include uncertainties arising from the microphysics scheme a priori assumptions of a fixed drop size distribution (DSD) functional form, whereas natural DSDs display far greater variability. To address this concern, this study presents a moment-based polarimetric radar forward operator with no fundamental restrictions on the DSD form by linking radar observables to integrated DSD moments. The forward operator is built upon a dataset of > 200 million realistic DSDs from one-dimensional bin microphysical rain shaft simulations, and surface disdrometer measurements from around the world. This allows for a robust statistical assessment of forward operator uncertainty and quantification of the relationship between polarimetric radar observables and DSD moments. Comparison of "truth" and forward-simulated vertical profiles of the polarimetric radar variables are shown for bin simulations using a variety of moment combinations. Higher-order moments (especially those optimized for use with the polarimetric radar variables: the 6th and 9th) perform better than the lower-order moments (0th and 3rd) typically predicted by many bulk microphysics schemes

    A Water-Soluble Iridium Photocatalyst for Chemical Modification of Dehydroalanines in Peptides and Proteins

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    Dehydroalanine (Dha) residues are attractive non-canonical amino acids that occur naturally in ribosomally synthesised and post-translationally modified peptides (RiPPs). Dha residues are attractive targets for selective late-stage modification of these complex biomolecules. In this work, we show the selective photocatalytic modification of dehydroalanine residues in the antimicrobial peptide nisin and in the proteins Small Ubiquitin-like Modifier (SUMO) and superfolder Green Fluorescent Protein (sfGFP). For this purpose, a new water-soluble iridium(III) photoredox catalyst was used. The design and synthesis of this new photocatalyst, [Ir(dF(CF3 )ppy)2 (dNMe3 bpy)]Cl3, is presented. In contrast to commonly used iridium photocatalysts, this complex is highly water-soluble and allows modification of peptides and proteins in water and aqueous solvents under physiologically relevant conditions and with short reaction times and low reagent and catalyst loadings. This work suggests that photoredox catalysis using this newly designed catalyst is a promising strategy to modify dehydroalanine-containing natural products and thus may have great potential for novel bioconjugation strategies

    Otimização dos parâmetros hidráulicos do solo por meio de modelagem inversa utilizando o programa "PEST".

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    As informações dos parâmetros hidráulicos de solo constituem em dados importantes em estudos com modelagem do fluxo de água, transporte de solutos ou contaminantes bem como em simulação de crescimento vegetal. O objetivo desse estudo foi otimizar os parâmetros hidráulicos do solo pelo método de modelagem inversa. Os solos pertencem a duas áreas experimentais conduzidos em área comercial de cana-de-açúcar. O programa PEST (Parameter ESTimation) foi utilizado com o intuito de minimizar a soma dos quadrados dos resíduos entre o conteúdo de água no solo medido nos dois experimentos pelo método gravimétrico, com o conteúdo de água no solo simulada pelo modelo SWAP/WOFOST. A variação do índice estatístico RMSE entre o conteúdo de água no solo medida em campo com o simulado pelo modelo foi semelhante em ambos os locais e em média apresentou valor de 0,0281 e 0,0274 m3 m-3. O método de modelagem inversa realizado pelo programa PEST mostrou ser eficaz na otimização dos parâmetros hidráulicos do solo em ambos os locais de estudo

    Passive odd viscoelasticity

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    Active chiral viscoelastic materials exhibit elastic responses perpendicular to the applied stresses, referred to as odd elasticity. We use a covariant formulation of viscoelasticity combined with an entropy production analysis to show that odd elasticity is not only present in active systems but also in broad classes of passive chiral viscoelastic fluids. In addition, we demonstrate that linear viscoelastic chiral solids require activity in order to manifest odd elastic responses. To model the phenomenon of passive odd viscoelasticity we propose a chiral extension of Jeffreys model. We apply our covariant formalism in order to derive the dispersion relations of hydrodynamic modes and obtain clear imprints of odd viscoelastic behavior

    Chronic Childhood Peer Rejection is Associated with Heightened Neural Responses to Social Exclusion During Adolescence

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    This functional Magnetic Resonance Imaging (fMRI) study examined subjective and neural responses to social exclusion in adolescents (age 12-15) who either had a stable accepted (n = 27; 14 males) or a chronic rejected (n = 19; 12 males) status among peers from age 6 to 12. Both groups of adolescents reported similar increases in distress after being excluded in a virtual ball-tossing game (Cyberball), but adolescents with a history of chronic peer rejection showed higher activity in brain regions previously linked to the detection of, and the distress caused by, social exclusion. Specifically, compared with stably accepted adolescents, chronically rejected adolescents displayed: 1) higher activity in the dorsal anterior cingulate cortex (dACC) during social exclusion and 2) higher activity in the dACC and anterior prefrontal cortex when they were incidentally excluded in a social interaction in which they were overall included. These findings demonstrate that chronic childhood peer rejection is associated with heightened neural responses to social exclusion during adolescence, which has implications for understanding the processes through which peer rejection may lead to adverse effects on mental health over time.Pathways through Adolescenc

    Cationic iron porphyrins with sodium dodecyl sulphate for micellar catalysis of cyclopropanation reactions

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    Here, we report that the combination of cationic iron porphyrins with sodium dodecyl sulphate (SDS) gives rise to efficient micellar catalysis of cyclopropanation reactions of styrene derivatives, using diazoacetates as carbene precursors. This simple, yet effective approach for cyclopropanations illustrates the power of micellar catalysis
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