420 research outputs found

    Relación óptima de metionina+cistina/lisina digestibles en gallinas isa Brown de 34 a 42 semanas de edad.

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    Los trabajos previos en los que se han estudiado las recomendaciones de metionina+cistina para gallinas ponedoras son muy numerosos, pero los resultados obtenidos presentan una gran variabilidad y, en algunos casos, son contradictorios. Esta variabilidad se explica por las condiciones en las que se ha realizado el estudio, la edad de las gallinas, la genética y el parámetro a optimizar. En este sentido, Novak et al. (2004) observaron que las necesidades totales de metionina+cistina eran mayores para maximizar el peso del huevo que para optimizar la producción de huevos o la eficacia alimenticia. Estas diferencias fueron menos importantes entre las 20 y 43 semanas (8%), que de las 44 a las 63 semanas de edad (16%). Además, las recomendaciones para optimizar la producción y el peso del huevo fueron un 17% y 11% mayores, respectivamente, en el primer periodo con respecto al segundo. Por el contrario, Waldroup y Hellwig (1995) encontraron que las necesidades totales de metionina+cistina para optimizar la producción y masa de huevo fueron más elevadas (12 y 10%, respectivamente) de 51 a 71 semanas de edad que de 25 a 45. Cuando las recomendaciones se expresan en unidades digestibles, el rango de necesidades de metionina+cistina digestibles con respecto a lisina digestible varía desde un 81 a un 107% (81%: Coon and Zhang, 1999; 90%: FEDNA, 2008; 91%: Rostagno et al., 2005; 93%: CVB, 1996; 94%: Bregendahl et al., 2008; 99%: Brumano et al., 2010a; 100%: Cupertino et al., 2009; Brumano et al., 2010a; 101%: Brumano et al., 2010b; 107%: Schmidt et al., 2009). Como consecuencia de esta alta variabilidad, es necesario seguir investigando sobre cuál sería el ratio óptimo metionina+cistina/lisina digestible para optimizar los rendimientos de gallinas ponedoras. Por tanto, el objetivo de este trabajo es determinar las necesidades óptimas de metionina+cistina digestibles con respecto a lisina digestible de gallinas Isa Brown desde las 34 a las 42 semanas de eda

    Los aminoácidos azufrados mejoran la eficacia de utilización del pienso.

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    Las recomendaciones de metronina+ostina obtenidas a partir de diferentes estudios presentan una gran variabilidad, por lo que es necesario investigar cuál es la relación óptima metronina+ostina /lisina digestible para optimizar los rendimientos de gallinas ponedoras

    Editorial Note

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    A Modeling Framework to Assess Strategies Alignment based on Collaborative Network Emotions

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    [DE] The Collaborative Networks (CN) discipline has been largely studied in last decades, addressing different problems and proposing solutions for the robust establishment of collaborative processes, within the enterprises willing to collaborate. The main aim of CN research is, therefore, to generate approaches that enable creating effective relationships in the long term, to achieve stable and agile alliances. The concept of alignment among the CN partners has been considered since the beginning of CN research. Nevertheless, novel perspectives of study in CN, such as the consideration of collaborative emotional states, within the CN, have been introduced in recent years. This paper connects the research area of strategies alignment and the CN emotion models. Accordingly, a modelling framework to assess strategies alignment considering the emotional environment within the CN is proposed. The modelling framework allows representing how the enterprises emotions affect in the selection and alignment of formulated enterprises¿ strategiesAndres, B.; Ferrada, F.; Poler, R.; Camarinha-Matos, L. (2018). A Modeling Framework to Assess Strategies Alignment based on Collaborative Network Emotions. IFIP Advances in Information and Communication Technology. 534:349-361. https://doi.org/10.1007/978-3-319-99127-6_30S349361534Camarinha-Matos, L.M.: Collaborative networks in industry and the role of PRO-VE. Int. J. Prod. Manag. Eng. 2(2), 53–57 (2014)Andres, B., Poler, R.: Models, guidelines and tools for the integration of collaborative processes in non-hierarchical manufacturing networks: a review. Int. J. Comput. Integr. Manuf. 2(29), 166–201 (2016)Bititci, U., Martinez, V., Albores, P., Parung, J.: Creating and managing value in collaborative networks. Int. J. Phys. Distrib. Logist. Manag. 34(3/4), 251–268 (2004)Carbo, B.: Align the organization for improved supply chain performance. ASCET Proj. 2, 244–447 (2002)Macedo, P., Camarinha-Matos, L.: Value systems alignment analysis in collaborative networked organizations management. Appl. Sci. 7(12), 123 (2017)Andres, B., Poler, R.: A decision support system for the collaborative selection of strategies in enterprise networks. Decis. Support Syst. 91, 113–123 (2016)Andres, B., Macedo, P., Camarinha-Matos, L.M., Poler, R.: Achieving coherence between strategies and value systems in collaborative networks. In: Camarinha-Matos, L.M., Afsarmanesh, H. (eds.) PRO-VE 2014. IFIP AICT, vol. 434, pp. 261–272. Springer, Heidelberg (2014). https://doi.org/10.1007/978-3-662-44745-1_26Ferrada, F., Camarinha-Matos, L.M.: A system dynamics and agent-based approach to model emotions in collaborative networks. In: Camarinha-Matos, L.M., Parreira-Rocha, M., Ramezani, J. (eds.) DoCEIS 2017. IFIP AICT, vol. 499, pp. 29–43. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-56077-9_3Campuzano, F., Mula, J.: Supply Chain Simulation. A System Dynamics Approach for Improving Performance. Springer, London (2011). https://doi.org/10.1007/978-0-85729-719-8Camarinha-Matos, L.M., Afsarmanesh, H.: Collaborative networks: a new scientific discipline. J. Intell. Manuf. 16(4–5), 439–452 (2005)Vicsek, T.: Complexity: the bigger picture. Nature 418(6894), 131 (2002)Sterman, J., Richardson, G., Davidsen, P.: Modelling the estimation of petroleum resources in the United States. Technol. Forecast. Soc. Chang. 33(3), 219–249 (1998)Vlachos, D., Georgiadis, P., Iakovou, E.: A system dynamics model for dynamic capacity planning of remanufacturing in closed-loop supply chains. Comput. Oper. Res. 34(2), 367–394 (2007)Campuzano-Bolarín, F., Mula, J., Peidro, D.: An extension to fuzzy estimations and system dynamics for improving supply chains. Int. J. Prod. Res. 51(10), 3156–3166 (2013)Barton, P., Bryan, S., Robinson, S.: Modelling in the economic evaluation of health care: selecting the appropriate approach. J. Heal. Serv. Res. Policy 9(2), 110–118 (2004)Eldabi, T., Paul, R.J., Young, T.: Simulation modelling in healthcare: reviewing legacies and investigating futures. J. Oper. Res. Soc. Spec. Issue Oper. Res. Heal. 58(2), 262–270 (2007)Andres, B., Poler, R., Camarinha-Matos, L.M., Afsarmanesh, H.: A simulation approach to assess partners selected for a collaborative network. Int. J. Simul. Model. 16(3), 399–411 (2017)Gohari, A., Mirchi, A., Madan, K.: System dynamics evaluation of climate change adaptation strategies for water resources management in central Iran. Water Resour. Manag. 31(5), 1413–1434 (2007)Fishera, D., Norvell, J., Sonka, S., Nelson, M.J.: Understanding technology adoption through system dynamics modeling: implications for agribusiness management. Int. Food Agribus. Manag. Rev. 3, 281–296 (2000)Lyneisa, J.M.: System dynamics for market forecasting and structural analysis. Syst. Dyn. Rev. 16(1), 3–25 (2000)Borshchev, A., Filippov, A.: From system dynamics and discrete event to practical agent based modeling: reasons, techniques, tools. In: The 22nd International Conference of the System Dynamics Society (2004)Ferrada, F.: C-EMO: A Modeling Framework for Collaborative Network Emotions Doctoral dissertation, Nova University of Lisbon, Portugal (2017). https://run.unl.pt/handle/10362/26857Scherer, K.R.: Emotions are emergent processes: they require a dynamic computational architecture. Rev. Philos. Trans. R. Soc. Biol. Sci. 364(1535), 3459–3474 (2009

    Mesophyll diffusion conductance to CO 2: An unappreciated central player in photosynthesis

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    Mesophyll diffusion conductance to CO 2 is a key photosynthetic trait that has been studied intensively in the past years. The intention of the present review is to update knowledge of g m, and highlight the important unknown and controversial aspects that require future work. The photosynthetic limitation imposed by mesophyll conductance is large, and under certain conditions can be the most significant photosynthetic limitation. New evidence shows that anatomical traits, such as cell wall thickness and chloroplast distribution are amongst the stronger determinants of mesophyll conductance, although rapid variations in response to environmental changes might be regulated by other factors such as aquaporin conductance.Gaps in knowledge that should be research priorities for the near future include: how different is mesophyll conductance among phylogenetically distant groups and how has it evolved? Can mesophyll conductance be uncoupled from regulation of the water path? What are the main drivers of mesophyll conductance? The need for mechanistic and phenomenological models of mesophyll conductance and its incorporation in process-based photosynthesis models is also highlighted.The study was financially supported by the Estonian Ministry of Science and Education (grant SF1090065s07), the Spanish Ministry of Science and Innovation through projects BFU2008-01072 (MEFORE), AGL2009-11310/AGR, BFU2011-23294 (MECOME) and CGL2009-13079-C02-01 (PALEOISOTREE), and the European Commission through European Regional Fund (the Estonian Center of Excellence in Environmental Adaptation), and the Marie Curie project MC-ERG-246725 (FP7). J.P.F. is supported by the Ramón y Cajal program (RYC-2008-02050). A.G. had a Swiss National Science Fellowship (PA00P3_126259). M.M.B. and C.R.W are supported by Future Fellowships from the Australian Research Council (FT0992063 and FT100100024). C.D. was supported by a grant from the French government and by the cooperation project Tranzfor (Transferring Research between EU and Australia–New Zealand on Forestry and Climate Change, PIRSES-GA-2008-230793) funded by the European Union

    A mathematical and computational review of Hartree-Fock SCF methods in Quantum Chemistry

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    We present here a review of the fundamental topics of Hartree-Fock theory in Quantum Chemistry. From the molecular Hamiltonian, using and discussing the Born-Oppenheimer approximation, we arrive to the Hartree and Hartree-Fock equations for the electronic problem. Special emphasis is placed in the most relevant mathematical aspects of the theoretical derivation of the final equations, as well as in the results regarding the existence and uniqueness of their solutions. All Hartree-Fock versions with different spin restrictions are systematically extracted from the general case, thus providing a unifying framework. Then, the discretization of the one-electron orbitals space is reviewed and the Roothaan-Hall formalism introduced. This leads to a exposition of the basic underlying concepts related to the construction and selection of Gaussian basis sets, focusing in algorithmic efficiency issues. Finally, we close the review with a section in which the most relevant modern developments (specially those related to the design of linear-scaling methods) are commented and linked to the issues discussed. The whole work is intentionally introductory and rather self-contained, so that it may be useful for non experts that aim to use quantum chemical methods in interdisciplinary applications. Moreover, much material that is found scattered in the literature has been put together here to facilitate comprehension and to serve as a handy reference.Comment: 64 pages, 3 figures, tMPH2e.cls style file, doublesp, mathbbol and subeqn package

    Photoperiod affects the phenotype of mitochondrial complex I mutants

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    Plant mutants for genes encoding subunits of mitochondrial Complex I (CI, NADH:ubiquinone oxidoreductase), the first enzyme of the respiratory chain, display various phenotypes depending on growth conditions. Here, we examined the impact of photoperiod, a major environmental factor controlling plant development, on two Arabidopsis thaliana CI mutants: a new insertion mutant interrupted in both ndufs8.1 and ndufs8.2 genes encoding the NDUFS8 subunit, and the previously characterized ndufs4 CI mutant. In long day (LD) condition, both ndufs8.1 and ndufs8.2 single mutants were indistinguishable from Col-0 at phenotypic and biochemical levels, whereas the ndufs8.1 ndufs8.2 double mutant was devoid of detectable holo-CI assembly/activity, showed higher AOX content/activity and displayed a growth-retardation phenotype similar to that of the ndufs4 mutant. Although growth was more affected in ndufs4 than ndufs8.1 ndufs8.2 under short day (SD) condition, both mutants displayed a similar impairment of growth acceleration after transfer to LD as compared to the WT. Untargeted and targeted metabolomics showed that overall metabolism was less responsive to the SD-to-LD transition in mutants than in the WT. The typical LD acclimation of carbon, nitrogen-assimilation and redox-related parameters was not observed in ndufs8.1 ndufs8. Similarly, NAD(H) content, that was higher in SD condition in both mutants than in Col-0, did not adjust under LD. We propose that altered redox homeostasis and NAD(H) content/redox state control the phenotype of Complex I mutants and photoperiod acclimation in Arabidopsis

    No Remdesivir Resistance Observed in the Phase 3 Severe and Moderate COVID-19 SIMPLE Trials

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    Remdesivir (RDV) is a broad-spectrum nucleotide analog prodrug approved for the treatment of COVID-19 in hospitalized and non-hospitalized patients with clinical benefit demonstrated in multiple Phase 3 trials. Here we present SARS-CoV-2 resistance analyses from the Phase 3 SIMPLE clinical studies evaluating RDV in hospitalized participants with severe or moderate COVID-19 disease. The severe and moderate studies enrolled participants with radiologic evidence of pneumonia and a room-air oxygen saturation of ≤94% or >94%, respectively. Virology sample collection was optional in the study protocols. Sequencing and related viral load data were obtained retrospectively from participants at a subset of study sites with local sequencing capabilities (10 of 183 sites) at timepoints with detectable viral load. Among participants with both baseline and post-baseline sequencing data treated with RDV, emergent Nsp12 substitutions were observed in 4 of 19 (21%) participants in the severe study and none of the 2 participants in the moderate study. The following 5 substitutions emerged: T76I, A526V, A554V, E665K, and C697F. The substitutions T76I, A526V, A554V, and C697F had an EC50 fold change of ≤1.5 relative to the wildtype reference using a SARS-CoV-2 subgenomic replicon system, indicating no significant change in the susceptibility to RDV. The phenotyping of E665K could not be determined due to a lack of replication. These data reveal no evidence of relevant resistance emergence and further confirm the established efficacy profile of RDV with a high resistance barrier in COVID-19 patients
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