Comprehensive sequence-to-function mapping of cofactor-dependent RNA catalysis in the glmS ribozyme.

Massively parallel, quantitative measurements of biomolecular activity across sequence space can greatly expand our understanding of RNA sequence-function relationships. We report the development of an RNA-array assay to perform such measurements and its application to a model RNA: the core glmS ribozyme riboswitch, which performs a ligand-dependent self-cleavage reaction. We measure the cleavage rates for all possible single and double mutants of this ribozyme across a series of ligand concentrations, determining kcat and KM values for active variants. These systematic measurements suggest that evolutionary conservation in the consensus sequence is driven by maintenance of the cleavage rate. Analysis of double-mutant rates and associated mutational interactions produces a structural and functional mapping of the ribozyme sequence, revealing the catalytic consequences of specific tertiary interactions, and allowing us to infer structural rearrangements that permit certain sequence variants to maintain activity

PERTUMBUHAN DAN PRODUKSI TANAMAN KAILAN (BRASSICA OLERACEA VAR. ALBOGLABRA) PADA BERBAGAI MEDIA TANAM DAN KONSENTRASI NUTRISI AB MIX DENGAN SISTEM HIDROPONIK SUBSTRAT

Kailan (Brassica oleracea var. alboglabra) merupakan sayuran daun yang memiliki nilai jual tinggi dan memerlukan unsur N untuk mendukung pertumbuhannya. Pemberian media tanam dan konsentrasi nutrisi AB Mix yang ideal dengan menggunakan sistem hidroponik substrat dapat meningkatkan pertumbuhan dan produksi kailan. Penelitian ini bertujuan untuk mengetahui pengaruh media tanam dan konsentrasi nutrisi AB Mix terhadap pertumbuhan dan produksi tanaman kailan dengan sistem hidroponik substrat. Penelitian ini menggunakan Rancangan Acak Kelompok Faktorial, yaitu media tanam (arang sekam, cocopeat, skerwool) dan konsentrasi nutrisi AB Mix (50 % R (3 ml/l), 100 % R (6 ml/l), dan 150 % R (9 ml/l)). Hasil penelitian menunjukkan bahwa pertumbuhan dan produksi tanaman kailan pada media tanam cocopeat tidak berbeda nyata dengan skerwool, tetapi nyata lebih besar dibandingkan dengan media tanam arang sekam, pada semua peubah kecuali jumlah daun. Pemberian konsentrasi nutrisi AB Mix 6 ml/l dan 9 ml/l, nyata meningkatkan tinggi tanaman, diameter tajuk, warna daun, diameter batang, luas daun, bobot segar dan bobot kering dibandingkan dengan pemberian nutrisi AB Mix 3 ml/l

Durabilité agro-écologique des exploitations agricoles dans la commune de Gogounou au Bénin

Cette recherche a pour objectif d’évaluer la durabilité agro-écologique de dix-neuf (19) exploitations agricoles de la commune de Gogounou au Nord Bénin. C’est une commune de grande production et des exploitations qui connaissent de grandes extensions de superficies cultivées avec l’introduction du matériel agricole du troisième niveau de la mécanisation agricole proposé par le programme de promotion de la mécanisation agricole. La méthode IDEA (Indicateurs de Durabilité des Exploitations Agricoles) de Vilain (2008), a été utilisée pour évaluer cette dimension de la durabilité. Les scores de durabilités, par indicateur puis par composante, déterminés avec les modalités proposées par la dite méthode, révèlent une bonne durabilité agro-écologique (avec un score de 74,3 / 100) des exploitations dans leur état actuel. Les composantes «diversité domestique» et «pratiques agricoles» contribuent fortement à ce niveau de durabilité alors que la composante «organisation de l’espace» constitue un facteur limitant. Par ailleurs, la mauvaise gestion des matières organiques cumulée à la facilité d’accès aux intrants chimiques (engrais et pesticides) ont négativement contribué aux scores de durabilité agro-écologiques. Limiter l’accès aux intrants chimiques et donc faciliter l’accès aux intrants compatibles à une agriculture durable seraient entre autres des leviers d’actions à envisager. L’évaluation de la durabilité agro-écologique de ces exploitations met en évidence les caractéristiques et pratiques agricoles favorables et défavorables qu’il faille, maximiser d’une part et, décourager d’autre part, pour éviter les situations extrêmes en matière de préservation de la diversité biologique et plus globalement d’agriculture durable.Mots-clés: indicateurs de durabilité, système de culture, mécanisation, Gogounou, Bénin. Agro-ecological sustainability of farms in the commune of Gogounou in BeninThis research aims to evaluate the agro-ecological sustainability of nineteen (19) were operating in the agricultural town Gogounou in northern Benin. It is a common high production and farm acreage experiencing exponential expansions grown with the introduction of agricultural machinery in the third level of agricultural mechanization offered by the promotion of agricultural mechanization program. The IDEA method (Agricultural Holdings Sustainability Indicators) Villain (2008), was used to assess this dimension of sustainability. Scores durabilities by indicator and by component, determined with the terms proposed by the method reveal good agro-ecological sustainability (with a score of 74.3 / 100) holdings in their current state. Components "domestic diversity" and "farming practices" contribute greatly to this level of durability while the component "space organization" is a limiting factor. In addition, poor management of cumulative organic matter to the ease of access to chemical inputs (fertilizers and pesticides) contributed negatively to agro-ecological sustainability scores. Limit access to chemical inputs and thus facilitate access to compatible inputs for sustainable agriculture would, among other actions levers to consider. The evaluation of the agro-ecological sustainability of these farms highlights the features and favorable and unfavorable farming practices that we should, on the one hand and maximize discourage other, to avoid extreme situations in preserving biodiversity and globally sustainable agriculture.Keywords: sustainability indicators, culture system, mechanization, Gogounou, Beni

XFEM formulation with sub-interpolation, and equivalence to zero-thickness interface elements

This is the accepted version of the following article: Crusat L, Carol I, Garolera D. XFEM formulation with sub‐interpolation, and equivalence to zero‐thickness interface elements. Int J Numer Anal Methods Geomech. 2019;43:45–76. https://doi.org/10.1002/nag.2853, which has been published in final form at https://doi.org/10.1002/nag.2853This paper describes a particular formulation of the extended finite element method (XFEM) specifically conceived for application to existing discontinuities of fixed location, for instance, in geological media. The formulation is based on two nonstandard assumptions: (1) the use of sub-interpolation functions for each subdomain and (2) the use of fictitious displacement variables on the nodes across the discontinuity (instead of the more traditional jump variables). Thanks to the first of those assumptions, the proposed XFEM formulation may be shown to be equivalent to the standard finite element method with zero-thickness interface elements for the discontinuities (FEM+z). The said equivalence is theoretically proven for the case of quadrangular elements cut in two quadrangles by the discontinuity, and only approximate for other types of intersections of quadrangular or triangular elements, in which the XFEM formulation corresponds to a kinematically restricted version of the corresponding interface plus continuum scheme. The proposed XFEM formulation with sub-interpolation, also helps improving spurious oscillations of the results obtained with natural interpolation functions when the discontinuity runs skew to the mesh. A possible explanation for these oscillations is provided, which also explains the improvement observed with sub-interpolation. The paper also discusses the oscillations observed in the numerical results when some nodes are too close to the discontinuity and proposes the remedy of moving those nodes onto the discontinuity itself. All the aspects discussed are illustrated with some examples of application, the results of which are compared with closed-form analytical solutions or to existing XFEM results from the literature.Peer ReviewedPostprint (author's final draft

Comparison of knowledge, attitude and practice of Urban and rural households toward iron deficiency anemia in three provinces of Iran

Background: Lack of nutritional knowledge is one of the most important reasons of nutritional problems and consequently improper practice, which can lead to several complications. This study has been designed in order to compare knowledge, attitude and practices of the urban and rural households regarding iron deficiency anemia (IDA) in Boushehr, Golestan and Sistan & Balouchestan provinces in 2004. Methods: The sampling method at household's level in each province was the single-stage cluster sampling with equal size clusters. The necessary data were gathered with a structured questionnaire and via the interviews between the questioners and the eligible people in each household. Comparison of frequency of variables between urban and rural areas were tested by chi square test. Results: A total of 2306 households were selected as overall sample size. In urban areas, people recognized iron food sources better than rural areas. Knowledge level of respondents about vulnerable group for IDA and the favorite attitude of households toward IDA were better in urban areas of Sistan & Blouchestan and Golestan provinces. In Sistan & Balouchestan and Golestan, rural households who drank tea immediately before or after meal was more than urban ones. The majority of pregnant and lactating mothers (except for rural areas of Bushehr) did not take iron supplement regularly. Less than 60 percent of children used iron drop regularly. Conclusion: Knowledge, attitude, and practice levels of households toward IDA were not acceptable. One of the best ways of improving nutritional practice is nutritional education with focus on applying available food resources