474 research outputs found
Sistema para el control de temperatura de una incubadora de huevos de gallina
A closed-loop PID controller tuning method is presented, as well as a control mechanism that functions as an egg incubator controller to control the temperature. The method’s performance is compared using digital simulation tests, and the PID controller gains are determined based on the system requirements. Finally, recommendations for using the tested method as well as arguments for why we reject other methods are provided.Se presenta un método de sintonización de controladores PID de lazo cerrado, un mecanismo de control que opera como regulador de una incubadora de huevos, el cual controla la temperatura. Mediante pruebas de simulación digital se compara el desempeño del método y se determinará las ganancias del controlador PID según los requerimientos del sistema. Finalmente, se ofrecen recomendaciones sobre la utilización del método probado y los argumentos por los cuales descartamos otros métodos
Feeding ecology of fish larvae from Chilean Patagonia during austral winter
Feeding habits of the ichthyoplankton from Chilean Patagonia (44-46°30’S) were studied during June-July 2012 (austral winter). Ichthyoplankton assemblage was composed by 10 species, with low abundance (3.8 to 16.73 ind. 1000 m-3). Most abundant larvae were Maurolicus parvipinnis, Leptonotus blainvilleanus and Sprattus fuegensis. These three species fed mainly on calanoid copepodites, Paracalanus indicus and Calanus sp. copepodites, and cyphonautes. Trophic overlap among dominant fish larvae was high (Schoener’s D > 0.69) and no significant differences were detected in prey composition and size. Therefore, no resource partitioning occurred in planktonic fish larvae during winter 2012 in Chilean Patagonia
Purification, structure and immunobiological activity of an arabinan-rich pectic polysaccharide from the cell walls of prunus dulcis seeds
The structure and bioactivity of a polysaccharide extracted and purified from a 4MKOH + H3BO3 solution from Prunus
dulcis seed cell wall material was studied. Anion-exchange chromatography of the crude extract yielded two sugar-rich fractions: one
neutral (A), the other acidic (E). These fractions contain a very similar monosaccharide composition: 5:2:1 for arabinose, uronic
acids and xylose, respectively, rhamnose and galactose being present in smaller amounts. As estimated by size-exclusion chromatography,
the acidic fraction had an apparent molecular mass of 762kDa. Methylation analysis (from the crude and fractions A and
E), suggests that the polysaccharide is an arabinan-rich pectin. In all cases, the polysaccharides bear the same type of structural Ara
moieties with highly branched arabinan-rich pectic polysaccharides. The average relative proportions of the arabinosyl linkages is
3:2:1:1 for T-Araf:(1!5)-Araf:(1!3,5)-Araf:(1!2,3,5)-Araf. The crude polysaccharide extract and fractions A and E induced a
murine lymphocyte stimulatory effect, as evaluated by the in vitro and in vivo expression of lymphocyte activation markers and
spleen mononuclear cells culture proliferation. The lymphocyte stimulatory effect was stronger on B- than on T-cells. No evidence
of cytotoxic effects induced by the polysaccharide fractions was found.Fundação para a Ciência e Tecnologia (FCT) - PRAXIX XXI/BD/18401/98
Neuronal deletion of GSK3beta increases microtubule speed in the growth cone and enhances axon regeneration via CRMP-2 and independently of MAP1B and CLASP2
BACKGROUND: In the adult central nervous system, axonal regeneration is abortive. Regulators of microtubule dynamics have emerged as attractive targets to promote axonal growth following injury as microtubule organization is pivotal for growth cone formation. In this study, we used conditioned neurons with high regenerative capacity to further dissect cytoskeletal mechanisms that might be involved in the gain of intrinsic axon growth capacity. RESULTS: Following a phospho-site broad signaling pathway screen, we found that in conditioned neurons with high regenerative capacity, decreased glycogen synthase kinase 3β (GSK3β) activity and increased microtubule growth speed in the growth cone were present. To investigate the importance of GSK3β regulation during axonal regeneration in vivo, we used three genetic mouse models with high, intermediate or no GSK3β activity in neurons. Following spinal cord injury, reduced GSK3β levels or complete neuronal deletion of GSK3β led to increased growth cone microtubule growth speed and promoted axon regeneration. While several microtubule-interacting proteins are GSK3β substrates, phospho-mimetic collapsin response mediator protein 2 (T/D-CRMP-2) was sufficient to decrease microtubule growth speed and neurite outgrowth of conditioned neurons and of GSK3β-depleted neurons, prevailing over the effect of decreased levels of phosphorylated microtubule-associated protein 1B (MAP1B) and through a mechanism unrelated to decreased levels of phosphorylated cytoplasmic linker associated protein 2 (CLASP2). In addition, phospho-resistant T/A-CRMP-2 counteracted the inhibitory myelin effect on neurite growth, further supporting the GSK3β-CRMP-2 relevance during axon regeneration. CONCLUSIONS: Our work shows that increased microtubule growth speed in the growth cone is present in conditions of increased axonal growth, and is achieved following inactivation of the GSK3β-CRMP-2 pathway, enhancing axon regeneration through the glial scar. In this context, our results support that a precise control of microtubule dynamics, specifically in the growth cone, is required to optimize axon regrowth
Cloning and heterologous expression of Lactobacillus reuteri uroporphyrinogen III synthase/methyltransferase gene (cobA/hemD): Preliminary characterization
Some strains of Lb. reuteri produce cobalamin (vitamin B12). Cobalamin biosynthesis relies on the sequential action of more than 25 enzymes in a complex metabolic pathway. We have cloned, expressed and characterized the gene in Lb. reuteri that codes for the S-adenosy L-methionine uroprophyrinogen III methyltransferase/synthase (CobA/HemD), a key bifunctional enzyme in the biosynthesis of cobalamin and other tetrapyrrols.Fil: Vannini, MarÃa Verónica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: RodrÃguez, Adriana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Vera, José Luis. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: de Valdéz, Graciela F.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de BioquÃmica, QuÃmica y Farmacia; ArgentinaFil: Taranto, Maria Pia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Sesma, Fernando Juan Manuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin
Combining The Pharmacophore Features Of Coumarins And 1,4-substituted 1,2,3-triazoles To Design New Acetylcholinesterase Inhibitors: Fast And Easy Generation Of 4-methylcoumarins/1,2,3-triazoles Conjugates Via Click Chemistry
Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coumarins are a large class of compounds that display a range of interesting biological properties, being considered privileged structures because of the ability of their 2H-chromen-2-one nuclei to bind to multiple pharmacological targets. We hypothesized that the linkage of a second pharmacophore nucleus to the 2H-chromen-2-one core, the 1,2,3-triazole moiety, would entail more selective and pharmacologically active coumarins. Therefore, we describe the synthesis of fourteen 4-methylcoumarins/1,4-substituted 1,2,3-triazole conjugates, which were predicted by in silico methods to inhibit acetylcholinesterase (AChE) and proved to be moderate in vitro inhibitors of this enzyme. Molecular docking simulations suggest that the most active of these compounds has a putative binding mode similar to donepezil, both occupying the peripheral anionic site of AChE, which is associated with the secondary noncholinergic functions of the enzyme. This highlights the potential of this series for further optimization in the search of new coumarins for the treatment of Alzheimer's disease.27915411550Brazilian funding agency Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Brazilian funding agency Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Brazilian funding agency Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS)Brazilian funding agency Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Brazilian funding agency Instituto Nacional de Ciencia e Tecnologia para Inovacao Farmaceutica (INCT-IF)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
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