Design and implementation of symbolic algorithms for the computation of generalized asymptotes

In this paper we present two algorithms for computing the g-asymptotes or generalized asymptotes, of a plane algebraic curve, C , implicitly or parametrically defined. The asymptotes of a curve C reflect the status of C at points with sufficiently large coordinates. It is well known that an asymptote of a curve C is a line such that the distance between C and the line approaches zero as they tend to infinity. However, a curve C may have more general curves than lines describing the status of C at infinity. These curves are known as g-asymptotes or generalized asymptotes. The pseudocodes of these algorithms are presented, as well as the corresponding implementations. For this purpose, we use the algebra software Maple. A comparative analysis of the algorithms is carried out, based on some properties of the input curves and their results to analyze the efficiency of the algorithms and to establish comparative criteria. The results presented in this paper are a starting point to generalize this study to surfaces or to curves defined by a non-rational parametrization, as well as to improve the efficiency of the algorithms. Additionally, the methods developed can provide a new and different approach in prediction (regression) or classification algorithms in the machine learning field.Agencia Estatal de Investigació

Computing branches and asymptotes of meromorphic functions

In this paper, we first summarize the existing algorithms for computing all the generalized asymptotes of a plane algebraic curve implicitly or parametrically defined. From these previous results, we derive a method that allows to easily compute the whole branch and all the generalized asymptotes of a ?special? curve defined in n-dimensional space by a parametrization that is not necessarily rational. So, some new concepts and methods are established for this type of curves. The approach is based on the notion of perfect curves introduced from the concepts and results presented in previous papers.Agencia Estatal de Investigació

An effective algorithm for computing the asymptotes of an implicit curve

In this paper, we first summarize the algorithm presented in Blasco and Pérez-Díaz (2014) for computing the generalized asymptotes of algebraic curves implicitly defined. This algorithm is based on the computation of Puiseux series. The main and very important contribution of this paper is a new and efficient method that allows to easily compute all the generalized asymptotes of an algebraic plane curve implicitly defined by just solving a triangular system of equations. The method can be easily generalized to the case of algebraic curves implicitly defined in the n-dimensional space.Agencia Estatal de Investigació

Antimicrobial Activity against Escherichia coli of Cu-Ni Nanoalloy and Combination of Ag Nanoparticles, Obtained by Different Method

Escherichia coli, is a pathogenic bacterium that causes serious infections, whose therapeutic treatment is threatened by the emergence of multiple resistance to conventional antibiotics. In recent years, metal nanoparticles (NPs) have been studied for their antimicrobial capacity and their possible applications as an alternative to antibiotics against different pathogens. NPs also vary in synthesis techniques; either by chemical, physical and biological methods. The objective of this work was to study the possible antimicrobial capacity of Cu-Ni nanoalloys obtained by a method called citrate-gel. The antimicrobial capacity of the NPs mentioned above was evaluated in vitro by the agar diffusion method. Most of the NPs evaluated showed antibacterial activity against the strain of E. coli studied. When combining chemical and biological NP, synergistic effects are observed with an increase in antibacterial activity in some cases. We can conclude that NPs derived from chemical and biological synthesis could be used as antimicrobials against E. coli and when these are combined, antibacterial effects increase. In the future, these applications of nanomaterials could be used as an alternative to the use of antibiotics against infections that have limited treatmentsFil: Fernandez, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Illanez, Yamila A.. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias; ArgentinaFil: Fernandez, Gastón. Universidad Catolica de Cuyo - Sede San Luis; ArgentinaFil: Esquivel, Marcelo Ricardo Oscar. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cangiano, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentin

Energy reserves mobilization: Strategies of three decapod species

In food deprivation assays, several different responses have been observed in crustaceans. However, studying energy reserves utilization among more than one species during the same starvation period has not yet been performed, particularly to discern whether the responses are due to intrinsic and/or environmental factors. We hypothesize that decapod species with similar feeding habits have the same strategies in the use of energetic reserves during starvation, even though they inhabit different environments. The aim of this study was to compare the energy reserves mobilization of three decapods species (Cherax quadricarinatus, Palaemon argentinus and Munida gregaria) with similar feeding habits, exposed to similar food deprivation conditions. The crayfish, shrimp and squat-lobster were experimentally kept at continuous feeding or continuous starvation throughout 15 days. Every 3rd day, the midgut gland index (MGI), and the glycogen, lipid and protein contents were measured in the midgut gland (MG) and pleon muscle. Palaemon argentinus mobilized more reserves during starvation, followed by C. quadricarinatus, and the last M. gregaria. The starved shrimps presented low MGI, whereas MG showed a reduction in glycogen (from day 6 to 15), lipid (from day 3 to 15), and protein levels (at day 9 and 15) while in their muscle, lipid reserves decreased at days 3 and 6. In C. quadricarinatus, the most affected parameters in the MG were MGI, glycogen (from day 6 to 15), and lipids (at day 12 and 15). In the MG of M. gregaria only the glycogen was reduced during fasting from 3 to 15 days. Even though the three studied species have similar feeding habitats, we found that their energetic profile utilization is different and it could be explained by the habitat, life span, temperature, organ/tissue, and metabolism of the species. Our results may be useful to understand the several different responses of crustaceans during starvation.Fil: Sacristán, Hernán Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Rodriguez, Yamila Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pereira, Nair de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Lopez, Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Fernandez Gimenez, Analia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Effects of sodium metabisulfite on the activity and protease composition of the enzymatic extracts of Argentine red shrimp Pleoticus muelleri

Los mercados a los que se exporta el langostino Pleoticus muelleri exigen un producto sin presencia de melanosis. El preservante utilizado comúnmente en esta especie es el metabisulfito de sodio (MBS). Hasta el momento no se han estudiado los efectos que podría tener sobre las proteasas del langostino. En este trabajo se evaluó el efecto del MBS sobre la actividad y composición proteásica de los extractos enzimáticos de P. muelleri. Se determinó la actividad de proteasas ácidas y alcalinas, así como la composición de enzimas de los extractos enzimáticos de langostinos tratados y sin tratar con MBS. Aquellos extractos tratados con MBS mostraron una reducción significativa de la actividad proteásica (alrededor de 80%), tanto ácida como alcalina. A su vez, las enzimas aspárticas, redujeron su actividad mientras que predominaron las enzimas cisteínicas y serínicas del tipo tripsina. Los extractos enzimáticos de P. muelleri tratados con MBS presentan una reducción de la actividad proteásica y cambios en su composición enzimática, pero aun así constituyen una fuente de enzimas con potencial para ser utilizada con diferentes fines biotecnológicos.The markets to which the Pleoticus muelleri Argentine red shrimp is exported require a product without the presence of melanosis. The preservative used in this species is sodium metabisulfite (MBS). So far, the effects that they could have on Argentine red shrimp proteases have not been studied. In this work, it is proposed to evaluate the effect of MBS on the activity and protease composition of the enzymatic extracts of P. muelleri. The acid and alkaline protease activity was determined, as well as the enzyme composition of the enzymatic extracts of Argentine red shrimps treated and untreated with MBS. Those extracts treated with MBS produced a significant reduction in protease activity (around 80%), both acidic and alkaline. In turn, the aspartic enzymes reduced their activity while the cysteine and serine enzymes of the trypsin type predominated. The enzyme extracts of P. muelleri treated with MBS show a reduction in protease activity and changes in their enzymatic composition, but still constitute a source of enzymes with the potential to be used for different biotechnological purposes.Fil: Liebana, Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Fernandez Gimenez, Analia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pereira, Nair de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Exogenous proteases from seafood processing waste as functional additives in rainbow trout aquaculture

Previous studies about enzyme additives for salmonids employed commercial proteases from bacteria, but research obtaining such enzymes from other organisms are scarce. We aimed to increase digestive protease activity in Oncorhynchus mykiss, by analysing potential sources of exogenous proteases generated from different seafood processing waste. To date, there is no information regarding the influences that exogenous enzymes have on the activity and integrity of endogenous enzymes in salmonids. The compatibility and interaction between endogenous and exogenous proteases were evaluated through protein hydrolysis and electrophoresis. We also evaluated the capacity of two types of microcapsules (Alginate–Chitosan and Alginate–Chitosan–Bentonite) to protect the protease activity after being exposed to the gastric environment of trout. The seafood wastes had activities around 0.23–2.53 U/ml at 15°C. Among all the exogenous proteases evaluated, P. granulosa's extract showed the best performance, followed by L. santolla's extract. Such extracts increased the protein hydrolysis to equal or higher levels than the commercial protease and did not alter the integrity of trout proteases. The optimal catalytic function at low temperatures of these extracts might be linked to the habitat of these arthropods. Alginate–Chitosan–Bentonite microcapsules are recommended in preference to Alginate–Chitosan capsules for delivery of enzymes in salmonids because they ensure the activity of exogenous proteases for longer in acid pH (6 vs. 4 h). This research promotes a re-evaluation of seafood processing wastes through the production of a potentially functional additive that may improve trout protein digestion.Fil: Rodriguez, Yamila Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pereira, Nair de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Laitano, María V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Moreno, Pablo. Provincia del Neuquén. Subsecretaría de Producción y Recursos Naturales. Centro de Ecología Aplicada del Neuquén; ArgentinaFil: Fernandez Gimenez, Analia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Microalgal biomass quantification from the non-invasive technique of image processing through red-green-blue (RGB) analysis

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGContinuous monitoring of biomass concentration in microalgae cultures is essential and one of the most important parameters to measure in this field. This study aims at digital image processing in RGB and greyscale models, being a simple and low-cost method for cell estimation. Images obtained from different photobioreactors with wastewater and at different conditions for the cultivation of Chlorella vulgaris were analyzed. The results suggested that this technique is very effective under controlled lighting conditions, in contrast to photobioreactors placed outdoors and of different design, presenting a lower linearity. The accuracy of the method could be improved with a high-quality charge-coupled device (CCD) camera. The development of efficient methods to assess biomass concentration is an important and necessary step towards large-scale microalgae cultivation. The colour analysis technique has a great potential to meet the needs of monitoring cultures in a cost-effective and automated way using simple and cheap instruments

Efecto del cine en el significado cultural del concepto jubilación en un grupo de jubilados agremiados

Objective: To analyze the effect of the film series “Looking and reflecting on retirement” on the cultural significance of the concept of retirement in a group of unionized retirees.Methods: Exploratory pre-experimental qualitative study, with a socio-educational intervention design through four phases: diagnosis, planning, implementation and evaluation, carried out in a day-care home for retirees in Guadalajara, Mexico, for seven continuous months in 2018. They participated retired administrative workers from the same public university. The data was collected with the free listing technique, before and after the cinema cycle. The intervention was integrated with a conference on the stages of retirement and the screening of 25 films on retirement. Analysis of cultural domains was carried out.Results: Before the intervention, the cultural meaning of the concept was rest. After the intervention, retirement was defined as joy.Conclusions: The film series modified the cultural meaning of the concept of retirement in the group of participants.Objetivo: Analizar el efecto del ciclo de cine “Mirar y reflexionar la jubilación” en el significado cultural del concepto de jubilación en un grupo de jubilados agremiados.Métodos: Estudio cualitativo pre-experimental exploratorio, con diseño de intervención socioeducativa a través de cuatro fases: diagnóstico, planificación, implementación y evaluación, realizado en una casa de día para jubilados de Guadalajara, México, durante siete meses continuos en el 2018. Participaron trabajadores administrativos jubilados provenientes de una misma universidad pública. Los datos se recolectaron con la técnica de listados libres, antes y después del ciclo de cine. La intervención se integró con una conferencia sobre las etapas de la jubilación y la proyección de 25 películas sobre jubilación. Se llevó a cabo análisis de dominios culturales.Resultados: Antes de la intervención el significado cultural del concepto fue descanso. Después de la intervención, se definió a la jubilación como alegría.Conclusiones: El ciclo de cine modificó el significado cultural del concepto de jubilación en el grupo de participantes

CHEMICAL CHARACTERIZATION OF BARK COMPOUNDS FROM CAATINGA SPECIES

This study aimed to chemically characterize the bark extracts from three tree species: Anacardium occidentale L., Ziziphus joazeiro Mart. and Mimosa caesalpiniaefolia Benth., in addition to obtaining the soluble extract content in water, alcohol and hexane from the bark of these species. The bark was collected from branches of the three species and subsequently pre-dried and milled. The extract content was then determined using the Sohxlet method aiming to quantify the total extractives in the samples, and determine the extract content soluble in water, ethyl alcohol and hexane. The extracts were further analyzed by Near Infrared Spectroscopy (NIRS) analysis to determine their chemical composition. The extract contents in the three species behaved in a similar way, with hexane being the solvent which extracted more compounds and juazeiro the species that displayed the highest total extract content. With the chemical characterization of the extracts, it was possible to identify the presence of functional groups characteristic of carbohydrates and proteins in the aqueous extracts; the presence of characteristic hydroxyl group, for example in alcohols, aldehydes, ketones and ethers in the ethanolic extracts; and the presence of fatty acids and aromatic compounds (essential oils) in hexanolic extracts. The essential oils were the compounds which presented larger quantities, and can be exploited by the pharmaco-chemical industry