25 research outputs found

    Formulation of a soybean price model

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    82 p.The soybeans is considered to be one of the most important oilseeds, contributing biologically and chemically to the soil, having intrinsic protein characteristics in and possessing oil quality and quantity. Moreover, it represents an excellent crop rotation alternative, particularly with maize and rice, which benefits from the symbiotic process of this legume and the favorable rotation between gramineuos and legume soybean is a crop whose evolution has been market by requirements of the agro industry. Due to its high oil (20-22%) and protein (30-46%) content, the soybean is the fundamental raw material for the production of edible oils and concentrated animal feed. This paper attempts to achieve the following goals: Formulation of a soybean price forecast model that includes only soybean substitutes and Identification of the main factors influencing soybean prices. This study formulates a soybean world price forecasting model that should only include soybean substitutes. The soybean substitutes included in the model (maize, fish meal and palm oil) at the beginning of the study showed a low influence in soybean world price determination, and, as a result, were excluded from the model. The final model obtained included only the world soybean lag prices. The present study has also generated the following recommendations that could improve future studies: -The model used for the estimation of the obtained coefficients should be tried in the future with the vector autoregression (VAR) model. The VAR model does not include any a priori distinction between endogenous and exogenous variables. This model avoids the misspecification of endogenous variables as exogenous variables and vice versa. Besides the influencing factors named above, other variables should be included in the model, not only substitutes. Variables like, e.g., soybean world stocks, stocks-to-use ratio, and future market prices and future crop or price predictions generated by different institutions

    Identity Determinants of the Translocation Signal for a Type 1 Secretion System

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    The toxin hemolysin A was first identified in uropathogenic E. coli strains and shown to be secreted in a one-step mechanism by a dedicated secretion machinery. This machinery, which belongs to the Type I secretion system family of the Gram-negative bacteria, is composed of the outer membrane protein TolC, the membrane fusion protein HlyD and the ABC transporter HlyB. The N-terminal domain of HlyA represents the toxin which is followed by a RTX (Repeats in Toxins) domain harboring nonapeptide repeat sequences and the secretion signal at the extreme C-terminus. This secretion signal, which is necessary and sufficient for secretion, does not appear to require a defined sequence, and the nature of the encoded signal remains unknown. Here, we have combined structure prediction based on the AlphaFold algorithm together with functional and in silico data to examine the role of secondary structure in secretion. Based on the presented data, a C-terminal, amphipathic helix is proposed between residues 975 and 987 that plays an essential role in the early steps of the secretion process.</jats:p

    The structure of MadC from Clostridium maddingley reveals new insights into class I lanthipeptide cyclases

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    The rapid emergence of microbial multi-resistance against antibiotics has led to intense search for alternatives. One of these alternatives are ribosomally synthesized and post-translationally modified peptides (RiPPs), especially lantibiotics. They are active in a low nanomolar range and their high stability is due to the presence of characteristic (methyl-) lanthionine rings, which makes them promising candidates as bacteriocides. However, innate resistance against lantibiotics exists in nature, emphasizing the need for artificial or tailor-made lantibiotics. Obviously, such an approach requires an in-depth mechanistic understanding of the modification enzymes, which catalyze the formation of (methyl-)lanthionine rings. Here, we determined the structure of a class I cyclase (MadC), involved in the modification of maddinglicin (MadA) via X-ray crystallography at a resolution of 1.7 Ã…, revealing new insights about the structural composition of the catalytical site. These structural features and substrate binding were analyzed by mutational analyses of the leader peptide as well as of the cyclase, shedding light into the mode of action of MadC

    EBook proceedings of the ESERA 2011 conference : science learning and citizenship

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    This ebook contains fourteen parts according to the strands of the ESERA 2011 conference. Each part is co-edited by one or two persons, most of them were strand chairs. All papers in this ebook correspond to accepted communications during the ESERA conference that were reviewed by two referees. Moreover the co-editors carried out a global reviewing of the papers.ESERA - European Science Education Research Associatio

    A Framework for Dynamic Connectivity Meshes

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    Implementing algorithms that are based on dynamic triangle meshes often requires updating internal data-structures as soon as the connectivity of the mesh changes. The design of a class hierarchy that is able to deal with such changes is particularly challenging if the system reaches a certain complexity. The paper proposes a software design that enables the users to efficiently implement algorithms that can handle these dynamic changes while still maintaining a certain encapsulation of the single components. Our design is based on a callback mechanism. A client can register at some {\tt Info}-object and gets informed whenever a change of the connectivity occurs. This way the client is able to keep internal data up-to-date. Our framework enables us to write small client classes that cover just a small dedicated aspect of necessary updates related to the changing connectivity. These small components can be combined to more complex modules and can often easily be reused. Moreover, we do not have to store related 'dynamic data' in one central place, e.g. the mesh, which could lead to a significant memory overhead if an application uses some modules just for a short time. We have used and tested this class design extensively for implementing 'Dynamic Connectivity Meshes and Applications~\cite{Vorsatz:2003:DRA}'. Additionally, as a feasibility study, we have implemented and integrated our concept in the \OM-framework

    Functional reconstitution and structural characterization of the plant hormone receptor ETR1 in lipid nanodiscs

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    The plant hormone receptor ETR1 regulates many highly relevant agronomic processes. Today, significant functional and structural questions remain unanswered regarding its multi-pass transmembrane sensor domain able to bind and respond to the gaseous plant hormone ethylene at femtomolar concentrations. A significant reason for this is the lack of structural data on full-length ETR1 in a lipid environment. Herein, we present the functional reconstitution of recombinant full-length ETR1 purified and solubilized from a bacterial host into lipid nanodiscs, allowing the study of the purified plant receptor for the first time in a detergent-free membrane-like environment

    The N-terminal Region of Nisin Is Important for the BceAB-Type ABC Transporter NsrFP from Streptococcus agalactiae COH1

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    Lantibiotics are (methyl)-lanthionine-containing antimicrobial peptides produced by several Gram-positive bacteria. Some human pathogenic bacteria express specific resistance proteins that counteract this antimicrobial activity of lantibiotics. In Streptococcus agalactiae COH1 resistance against the well-known lantibiotic nisin is conferred by, the nisin resistance protein (NSR), a two-component system (NsrRK) and a BceAB-type ATP-binding cassette (ABC) transporter (NsrFP). The present study focuses on elucidating the function of NsrFP via its heterologous expression in Lactococcus lactis. NsrFP is able to confer a 16-fold resistance against wild type nisin as determined by growth inhibition experiments and functions as a lantibiotic exporter. Several C-terminal nisin mutants indicated that NsrFP recognizes the N-terminal region of nisin. The N-terminus harbors three (methyl)-lanthionine rings, which are conserved in other lantibiotics
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