66 results on '"Juan Carlos Cabrera"'
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2. Bio-Inspired Rhamnolipids, Cyclic Lipopeptides and a Chito-Oligosaccharide Confer Protection against Wheat Powdery Mildew and Inhibit Conidia Germination
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Nour El Houda Raouani, Elodie Claverie, Béatrice Randoux, Ludovic Chaveriat, Yazen Yaseen, Bopha Yada, Patrick Martin, Juan Carlos Cabrera, Philippe Jacques, Philippe Reignault, Maryline Magnin-Robert, Anissa Lounès-Hadj Sahraoui, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), Université du Littoral Côte d'Opale (ULCO), MateriaNova Research Center (MNRS), Université de Mons-Hainaut, Unité Transformations et Agroressources [Université d'Artois] (UTA), Université d'Artois (UA)-Transformations et Agro-ressources (UT&A), UniLaSalle-UniLaSalle, Fyteko, Brussels, Belgium, Transfrontalière BioEcoAgro - UMR 1158 (BioEcoAgro), Université d'Artois (UA)-Université de Liège-Université de Picardie Jules Verne (UPJV)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-JUNIA (JUNIA), and Université catholique de Lille (UCL)-Université catholique de Lille (UCL)
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[SDV.SA.AGRO]Life Sciences [q-bio]/Agricultural sciences/Agronomy ,Pharmaceutical Science ,Oligosaccharides ,Peptides, Cyclic ,Analytical Chemistry ,Lipopeptides ,Anti-Infective Agents ,Ascomycota ,wheat ,Blumeria graminis f.sp. tritici ,Drug Discovery ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,biocontrol ,rhamnolipids ,Physical and Theoretical Chemistry ,Pesticides ,Triticum ,Disease Resistance ,Plant Diseases ,Chitosan ,Organic Chemistry ,Spores, Fungal ,cyclic lipopeptides ,Chemistry (miscellaneous) ,Molecular Medicine ,powdery mildew ,fungal disease ,chitosan ,[CHIM.OTHE]Chemical Sciences/Other - Abstract
International audience; Plant protection is mainly based on the application of synthetic pesticides to limit yield losses resulting from diseases. However, the use of more eco-friendly strategies for sustainable plant protection has become a necessity that could contribute to controlling pathogens through a direct antimicrobial effect and/or an induction of plant resistance. Three different families of natural or bioinspired compounds originated from bacterial or fungal strains have been evaluated to protect wheat against powdery mildew, caused by the biotrophic Blumeria graminis f.sp. tritici (Bgt). Thus, three bio-inspired mono-rhamnolipids (smRLs), three cyclic lipopeptides (CLPs, mycosubtilin (M), fengycin (F), surfactin (S)) applied individually and in mixtures (M + F and M + F + S), as well as a chitosan oligosaccharide (COS) BioA187 were tested against Bgt, in planta and in vitro. Only the three smRLs (Rh-Eth-C12, Rh-Est-C12 and Rh-Succ-C12), the two CLP mixtures and the BioA187 led to a partial protection of wheat against Bgt. The higher inhibitor effects on the germination of Bgt spores in vitro were observed from smRLs Rh-Eth-C12 and Rh-Succ-C12, mycosubtilin and the two CLP mixtures. Taking together, these results revealed that such molecules could constitute promising tools for a more eco-friendly agriculture.
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- 2022
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3. Increased salinity stress tolerance of Nicotiana tabacum L. in vitro plants with the addition of xyloglucan oligosaccharides to the culture medium
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Fernando Rivas-Romero, Leneidy Pérez Pelea, Doménica López, Timothy Páez-Watson, Juan Carlos Cabrera, José M. Alvarez-Suarez, Leonardo Estrada, and Lien González-Pérez
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0106 biological sciences ,0301 basic medicine ,Nicotiana tabacum ,fungi ,food and beverages ,Plant Science ,Biology ,Protein oxidation ,biology.organism_classification ,01 natural sciences ,Cell wall ,Xyloglucan ,Lipid peroxidation ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Chlorophyll ,Food science ,Proline ,Lateral root formation ,010606 plant biology & botany ,Biotechnology - Abstract
Xyloglucan oligosaccharides (XGOs), derived from the hydrolysis of plant cell wall xyloglucan, are a novel class of biostimulants that exert positive effects on plant growth and morphology and can enhance plant stress tolerance. The aim of this study was to determine the influence of the application of exogenous Tamarindus indica L. cell wall-derived XGOs on Nicotiana tabacum L. tolerance to salt stress by evaluating morphology, physiological, and metabolic changes. N. tabacum plants were grown in agar-gelled media for 2 mo under salt stress with 100 mM of sodium chloride (NaCl) ± 0.1 μM XGOs. The germination percentage (GP), number of leaves (NL), foliar area (FA), primary root length (PRL), and density of lateral roots (DLR) were measured. In addition, unaffected 21-d-old N. tabacum plants were treated with a salt shock (100 mM NaCl) ± 0.1 μM XGOs. Proline, total chlorophyll, and total carbonyl levels, in addition to lipid peroxidation degree and activities of four enzymes related to oxidative stress, were quantified. The results indicated that XGOs significantly improved N. tabacum plants development after exposure to salt stress. XGOs caused a significant increase in NL and PRL, promoted lateral root formation, and produced an increase in proline and total chlorophyll contents, while reducing protein oxidation and lipid peroxidation. Although the XGOs modulated the activity of the enzymes analyzed, they were not statistically different from the salt control. It was concluded that XGOs may act as metabolic inducers that trigger the physiological responses that counteract the negative effects of oxidative stress under saline conditions.
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- 2020
4. Efecto del momento de inducción en la interacción Bradyrhizobium-soya (Glycine max)
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Ionel Hernández, Maria Caridad Napoles Garcia, Guillaume Wégria, Reneé Pérez-Pérez, Juan Carlos Cabrera, and Daimy Costales
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response ,señales ,tiempo ,fungi ,Soil Science ,food and beverages ,signals ,simbiosis ,Agriculture ,symbiosis ,respuesta ,Agronomy and Crop Science ,time ,Food Science - Abstract
Introduction.Legume nodulation is regulated by the exchange of molecular signals between the plant and rhizobia. The bacterial nodulation genes are activated by flavonoids present in root exudates. As a result of this activation, the Nod factors are synthesized, which in turn participate in the morphogenesis and function of the nodules. It is then possible to regulate the induction of Nod factors and other signals related to the nodulation process, during the inoculants production.Objective.To determine if the moment to induce the nodulation genes inBradyrhizobiuminoculants affects the synthesis of compounds related to the nodulation process and its interaction with soybean plants.Materials and methods.The research was developed in Rizobacter S.A., Argentina and Fyteko S.A. laboratories, Belgium, and in a plant growth chamber of the first one, during May-June of 2017. TwoBradyrhizobiumstrains were induced with daidzein in three moments. The signals produced by the strains and the biological effect in soybean plants were studied.Results.Differences were detected in the molecules produced by the bacteria, but it did not affect the growing and plants nodulation related to the different moments of induction.Conclusion.The metabolites excreted byBradyrhizobiumchanged with strain and induction moment, although the latter did not affect nodulation or soybean plants growth. Introducción.La nodulación en leguminosas está regulada por el intercambio de señales moleculares entre la planta y los rizobios. Los genes de nodulación de la bacteria son activados por flavonoides presentes en los exudados de las raíces. Como resultado de esa activación se sintetizan los factores Nod, que a su vez participan en la morfogénesis y función de los nódulos. Es posible regular entonces, la inducción de factores Nod y de otras señales relacionadas con el proceso de nodulación, durante la producción de inoculantes.Objetivo.Determinar si el momento de inducir los genes de nodulación en inoculantes deBradyrhizobiumafecta la síntesis de compuestos relacionados con el proceso de nodulación y su interacción con plantas de soya.Materiales y métodos. La investigación se desarrolló en los laboratorios de dos empresas: Rizobacter S.A., Argentina y Fyteko S.A., Bélgica, así como en una cámara de crecimiento de plantas de la primera empresa, durante mayo y junio del año 2017. Dos cepas deBradyrhizobiumfueron inducidas con daidzeína en tres momentos. Se estudiaron las señales producidas por las cepas y el efecto biológico en las plantas de soya.Resultados.Se detectaron diferencias en las moléculas producidas por las bacterias, pero no en el crecimiento y la nodulación de las plantas, relacionado con los diferentes momentos de inducción.Conclusión.Los metabolitos excretados porBradyrhizobiumvariaron con la cepa y el momento de la inducción, aunque este último no afectó la nodulación ni el crecimiento de las plantas de soya.
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- 2022
5. Development of a question system for the study of the basic cardiopulmocerebral resuscitation course
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Gustavo Abel Fernández Guevara, Liana Estévez Gutiérrez, Arlet Lamas Lezcano, Raidel González Rodríguez, and Juan Carlos Cabrera Villar
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Medicine (General) ,lcsh:R5-920 ,R5-920 ,educación médica ,reanimación cardiopulmonar ,lcsh:R ,Medicine ,lcsh:Medicine ,estudiantes ,lcsh:Medicine (General) ,paro cardíaco - Abstract
Introduction: a system of questions for a particular subject must be able to constantly investigate the relevance of work, promote the acquisition of skills and strengthen a learning capacity. Objective: to develop a system of questions for the study of the basic cardiopulmocerebral resuscitation course itself. Method: a pedagogical investigation was carried out related to the study program of the basic cardiopulmocerebral resuscitation course during the 2018-2019 academic period at the “Pedro Borrás Astorga” University Polyclinic in the city of Pinar del Río, governed by the dialectical materialist method and the use of theoretical and empirical methods. The research was approved by the scientific council and institutional ethics committee. Development: a question system was developed as a tool of the teaching-learning process for students in the first year of the Medicine career who received their own basic cardiopulmocerebral resuscitation course; thereby guaranteeing comprehensive scientific training, with acquisition of knowledge and skills that are easy to understand. Conclusions: a question system was developed for the study of the basic cardiopulmocerebral resuscitation course that represents a valuable educational instrument for first year students of the Medicine career.
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- 2019
6. Assessment of transient effects of alternative nitrogen sources in continuous cultures of Arthrospira sp. using proteomic, modeling and biochemical tools
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Ruddy Wattiez, Christophe Lasseur, Laurent Poughon, Baptiste Leroy, Claude-Gilles Dussap, Neha Sachdeva, Giuseppe Giambarresi, Juan Carlos Cabrera, Institut Pascal (IP), and SIGMA Clermont (SIGMA Clermont)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)
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0106 biological sciences ,Environmental Engineering ,Denitrification ,Nitrogen ,Photobioreactor ,chemistry.chemical_element ,Bioengineering ,continuous cultivation ,010501 environmental sciences ,01 natural sciences ,7. Clean energy ,Bioplastic ,Photobioreactors ,chemistry.chemical_compound ,proteomics ,010608 biotechnology ,Spirulina ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,Ammonium ,Biomass ,Food science ,Waste Management and Disposal ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,alternative nitrogen source ,sp ,light-energy transfer ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Models, Theoretical ,6. Clean water ,chemistry ,Wastewater ,Biofuel ,Urea - Abstract
The ability of cyanobacterium Arthrospira sp. to assimilate waste nitrogen sources (ammonium and urea) makes it an important candidate for wastewater management. The aim of this work was to evaluate a cultivation approach based on continuous-transitional-feeding regime (nitrate-ammonium-nitrate) in a photobioreactor to assess the effects of ammonium salts on Arthrospira sp. PCC 8005 metabolism. Using a comprehensive biochemical, proteomic and stoichiometric profiling of biomass, this study demonstrated that the proposed cultivation approach could increase the proteins and pigments yields by 20-30%, compared to the respective yields obtained from wild-type Arthrospira sp. strain A light-energy-transfer model was used to predict the biomass and oxygen productivities of Arthrospira sp. cultivated under transitional-feeding regime. 95 ± 2% match was observed between the experimental and simulated productivities. This study thus opened new avenues for use of ammonium rich wastewater for commercial production of high value pigments, biofuel and bioplastics using Arthrospira sp.
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- 2018
7. Nunca caminarás solo. Consideraciones en torno al cántico de estadio
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Juan Carlos Cabrera Pons
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Internationalization ,Globalization ,biology ,Athletes ,Phenomenon ,Cultural values ,Cultural practice ,Sociology ,Football ,biology.organism_classification ,Social psychology ,Gaze - Abstract
Al acercarnos al fenómeno del fútbol en una época como la nuestra, resulta apropiado hablar más bien de los fútboles que del fútbol. En el mundo actual, tan abierto a procesos de globalización e internacionalización que, sin embargo, no logran homogeneizar las prácticas culturales de los seres humanos, debemos mantener una mirada abierta hacia interpretaciones particulares de los fenómenos sociales. El deporte, entendido como una práctica cultural significante, guarda una serie de implicaciones particulares para quienes participan de él desde cualquiera de sus múltiples facetas. Facetas que fluctúan dinámicamente desde el ejercicio profesional de determinada forma deportiva, hasta la afición pasiva por un cierto deportista o grupo de deportistas. As we approach the phenomenon of football at a time like ours, it is appropriate to speak rather of soccer than of soccer. In today's world, so open to globalization and internationalization processes that, however, fail to homogenize the practices cultural values of human beings, we must maintain a open gaze towards particular interpretations of the social phenomena. Sport, understood as a significant cultural practice, has a series of implications particular for those who participate in it from any of its many facets. Fluctuating facets dynamically from the professional practice of certain sports form, even the passive fondness for a certain athlete or group of athletes.
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- 2021
8. Impact of different nitrogen sources on the growth of Arthrospira sp. PCC 8005 under batch and continuous cultivation – A biochemical, transcriptomic and proteomic profile
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Orily Depraetere, Ruddy Wattiez, Frédéric Deschoenmaeker, Juan Carlos Cabrera Pino, Koenraad Muylaert, Guillaume Bayon-Vicente, Neha Sachdeva, and Baptiste Leroy
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Proteomics ,0301 basic medicine ,Cyanobacteria ,Environmental Engineering ,Nitrogen ,030106 microbiology ,Photobioreactor ,Bioengineering ,03 medical and health sciences ,chemistry.chemical_compound ,Nitrate ,Spirulina ,Bioreactor ,Ammonium ,Waste Management and Disposal ,Nitrogen cycle ,Nitrates ,biology ,Renewable Energy, Sustainability and the Environment ,Gene Expression Regulation, Bacterial ,General Medicine ,biology.organism_classification ,030104 developmental biology ,chemistry ,Biochemistry ,Urea ,Arthrospira - Abstract
The aim of the present study was to evaluate the effects of varying concentrations of different nitrogen sources (individually or in combination) on the biochemical, transcriptomic and proteomic profiles of Arthrospira sp. PCC 8005 under batch and continuous modes. In batch mode, while ammonium showed a repressive effect on nitrate-assimilation pathway of the cyanobacteria; better growth and nutrient uptake rate were observed in presence of urea than nitrate. The inhibitory effect of ammonium was further confirmed by the continuous photobioreactor study wherein the nutrient feed was transiently replaced from nitrate to ammonium (28mM turbiostat regime). The changes in lipid, exopolysaccharide, transcriptomic and proteomic profiles of cyanobacteria on transition from nitrate to ammonium indicated at an onset of nutrient stress.
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- 2017
9. Application of exogenous xyloglucan oligosaccharides affects molecular responses to salt stress in Arabidopsis thaliana seedlings
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Gabriela Viteri, Edison Bonifaz-Arcos, Eduardo Tejera, Juan Carlos Cabrera, Mayra C. Obando-Rojas, Fernando Rivas-Romero, Hilary J. Rogers, Lien González-Pérez, Timothy Páez-Watson, and José M. Alvarez-Suarez
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0106 biological sciences ,0301 basic medicine ,Arabidopsis thaliana ,Soil Science ,Plant Science ,Protein oxidation ,medicine.disease_cause ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Arabidopsis ,medicine ,xyloglucan oligosaccharides ,salinity stress ,antioxidative response ,biology ,food and beverages ,biology.organism_classification ,Xyloglucan ,030104 developmental biology ,chemistry ,Biochemistry ,Catalase ,Chlorophyll ,biology.protein ,Agronomy and Crop Science ,Oxidative stress ,010606 plant biology & botany ,Peroxidase - Abstract
Soil salinity is one of the most devastating problems which reduces crop production and increases desertification. New approaches to overcome the negative effect of salinity on plants include the use of plant biostimulants, such as Xyloglucan oligosaccharides (XGOs) derived from the breakdown of xyloglucans from plant cell walls. The present study aimed at verifying the influence of exogenous XGOs derived from Tamarindus indica L. cell walls, on Arabidopsis thaliana’s tolerance to salt stress by understanding the gene expression, enzymatic and metabolic changes resulting from its application. A. thaliana plants were grown in liquid media and after 15 days they were treated by a salt shock with 100 mM of sodium chloride, with or without XGOs at 0.1 mg L-1. Gene expression of four oxidative stress markers as well as catalase and peroxidase activities and content of glutathione, total carbonyl, polyphenolics and chlorophyll were quantified. Bioinformatic models were used to obtain the co-expression network of the four oxidative stress response gene markers from microarray data of Arabidopsis under salt stress. Results showed that in saline conditions, XGOs dramatically increased catalase gene expression and enzymatic activity, peroxidase activity, and chlorophyll a/b ratio, while reducing protein oxidation and total polyphenols. Thus, XGOs may act to counteract negative effects of oxidative stress under saline conditions.
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- 2018
10. Effect of Chitosaccharides in Nodulation and Growth in Vitro of Inoculated Soybean
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Pascal Gerbaux, Juan Carlos Cabrera, María C. Nápoles, Ruddy Wattiez, Daimy Costales, Julien De Winter, Robertus Onderwater, and A. Falcón
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0106 biological sciences ,0301 basic medicine ,Plant growth ,Inoculation ,030106 microbiology ,food and beverages ,General Medicine ,Biology ,biology.organism_classification ,01 natural sciences ,Bradyrhizobium ,In vitro ,Chitosan ,03 medical and health sciences ,chemistry.chemical_compound ,chemistry ,Agronomy ,Dry weight ,Food science ,Application methods ,Bacteria ,010606 plant biology & botany - Abstract
The influence of chitosaccharides on the symbiotic interaction between Bradyrhizobium and soybean was examined. The results show that chitosaccharides either positively or negatively affect soybean nodulation or plant growth depending on their molecular weight, concentration and the application methods. When directly added to the in vitro culture media, chitosan of high molecular weight inhibit Bradyrhizobium viability in a dose dependent manner while chitooligosaccharides reduce slightly the bacteria viability only at concentration equal or higher than 50 mg·L-1. Chitooligosaccharides significantly enhance nodule formation and dry mass in soybean roots at doses between 10 and 100 mg·L-1. Both types of chitosaccharides, at the highest doses (>500 mg·L-1), negatively affect plant height and root size, whereas medium doses (50 to 100 mg·L-1) increase slightly leave number. Under field conditions, foliar application of both chitosaccharides enhances growth and nodulation of soybean plants. Nevertheless, using this application method, chitosan remains more effective than chitooligosaccharides.
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- 2016
11. Microwave-assisted depolymerization of carrageenans from Kappaphycus alvarezii and Eucheuma spinosum: Controlled and green production of oligosaccharides from the algae biomass
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Jean-Marie Raquez, Pascal Gerbaux, Juan Carlos Cabrera, Sébastien Moins, Igor Eeckhaut, Emmanuel Colson, and Tiffani Bouanati
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chemistry.chemical_classification ,0303 health sciences ,Eucheuma ,Chromatography ,biology ,010405 organic chemistry ,Depolymerization ,Oligosaccharide ,Polysaccharide ,biology.organism_classification ,01 natural sciences ,0104 chemical sciences ,Reducing sugar ,Carrageenan ,03 medical and health sciences ,Hydrolysis ,chemistry.chemical_compound ,Kappaphycus alvarezii ,chemistry ,Agronomy and Crop Science ,030304 developmental biology - Abstract
Algae biomass is nowadays considered as a unique reservoir of a huge variety of different molecules, such as lipids, carbohydrates, proteins and secondary metabolites, awaiting development in various fields. In particular, the valorization of the algae polysaccharide content is still in its infancy and intense research activity is starting to appear. Oligosaccharides with defined molecular weight and structures are extremely interesting for different applications such as plant biostimulation or biopesticide. Oligosaccharide are often prepared in medium to large scale upon chemical-based hydrolysis reactions from the extracted polysaccharides in harsh conditions (temperature and pH), leading to the loss of the fragile groups such as the sulfate functions in carrageenans. In the present work, microwave-based hydrolysis, as a green chemistry method, is optimized to produce bioactive oligosaccharides from carrageenans. Microwave hydrolysis process is first optimized on a commercially available carrageenan and further applied on carrageenans extracted from two algae, namely Kappaphycus alvarezii or Eucheuma spinosum that are produced in large quantities in the world and have a high content of carrageenans. We also develop a complete set of characterization methods, i.e. size exclusion chromatography, reducing sugar and residual sulfate determination and mass spectrometry, to perform the follow-up of the hydrolysis reaction. We here demonstrate that fast (5 min) and controlled hydrolysis of carrageenans can be achieved in pure water under microwave activation, while preserving the nature of the active sulfate groups (>95%).
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- 2020
12. LIFE STORIES OF INDIGENOUS WOMEN IN CHIAPAS. COMMITMENTS OF THE INVESTIGATOR
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Leticia Pons Bonals, Juan Carlos Cabrera Fuentes, and Danae Estrada Soto
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lcsh:LC8-6691 ,lcsh:Special aspects of education ,Descolonización ,Mujeres indígenas ,Historia de vida ,Comunidades indígenas ,Contextualización ,lcsh:L7-991 ,lcsh:Education (General) - Abstract
This article suggests that those conducting research with indigenous women face a number of questions that disrupt their assumed role as researchers, leading them to assume a number of commitments to their research, to the people who they investigate and to themselves. Approaches are recovered from interdisciplinary fields of knowledge, such as Cultural, Gender and Postcolonial Studies to undertake research from an interpretive tradition in which those investigating commit to the decolonization of knowledge, the construction of a new narrative and personal transformation.
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- 2015
13. El Nuevo mundo y conquista de Francisco de Terrazas en la construcción de una historia criolla de la Nueva España
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Juan Carlos Cabrera Pons
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010601 ecology ,0106 biological sciences ,Nobility ,Poetry ,General Arts and Humanities ,media_common.quotation_subject ,Creole language ,General Social Sciences ,Context (language use) ,Art ,01 natural sciences ,Humanities ,media_common - Abstract
En este artículo me aproximo a una de las primeras construcciones discursivas de la historia de la Nueva España, el poema Nuevo mundo y conquista, escrito por el criollo novohispano Francisco de Terrazas a finales del siglo xvi. Para esto, se expone brevemente la constitución de una clase criolla, heredera del sentimiento de hidalguía de los primeros conquistadores de América, y posteriormente se analiza la escritura de Nuevo mundo y conquista en el marco de estas consideraciones.
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- 2015
14. Efecto de los exudados radiculares de la 'higuerilla' Ricinus communis L. (Euphorbiaceae) en la mortalidad de larvas de Gymnetis bonplandii Schaum (Coleoptera, Scarabaeidae)
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Juan Carlos Cabrera la Rosa and Andie Alexander Gonzáles Díaz
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Coleoptera ,Gymnetis bonplandii ,exudados radiculares ,Euphorbiaceae ,Scarabaeidae ,General Medicine ,root exudates ,Ricinus communis - Abstract
Resumen Los exudados radiculares son metabolitos secundarios secretados por la raiz, que cumplen diferentes funciones en la naturaleza. En la literatura, existe poca informacion sobre el efecto de estas sustancias en la biota del suelo. En esta investigacion se estudia el efecto de los exudados de cinco ecotipos de “higuerilla” Ricinus communis L. (Euphorbiaceae) sobre las larvas de primer estadio de Gymnetis bonplandii Schaum (Coleoptera, Scarabaeidae), una plaga subterranea muy comun en suelos con alto contenido de materia organica. Los cinco ecotipos de “higuerilla” fueron sembrados en bolsas de polietileno en un diseno completo al azar con nueve repeticiones y un testigo. Dos larvas de primer estadio provenientes de una crianza de laboratorio fueron acondicionadas en jaulas disenadas especialmente para confinar larvas en el suelo. A los siete dias se evaluo la mortalidad de las larvas y los datos fueron corregidos considerando la mortalidad natural con la formula Schneider-Orelli, previo al ANVA y la prueba de comparacion de Duncan usando el programa SPSS. Los resultados indicaron que los cinco ecotipos tuvieron efecto letal sobre las larvas de primer estadio de G. bonplandii Schaum y el rango de mortalidad oscilo entre el 30 y 90 %, pudiendo ser utilizados como componentes biologicos en el manejo de plagas. Palabras clave: exudados radiculares, Ricinus communis , Euphorbiaceae, Gymnetis bonplandii , Coleoptera, Scarabaeidae. Abstract Root exudates are secondary metabolites secreted by the root, which have different functions in nature. In the literature, there is little information about the effect of these substances on underground biota. In this research, we studied the effect of root exudates of five ecotypes of “castor oil plant” Ricinus communis L. (Euphorbiaceae) on the first instar larvae of Gymnetis bonplandii Schaum (Coleoptera, Scarabaeidae), a common underground pest under high organic matter soil. The five ecotypes of "castor oil plant" were planted in polyethylene bags in a random complete design with nine replicates and a control. Two first instar larvae from laboratory breeding were conditioned in specially designed cages to confine larvae in the soil. Data of seven-day larval mortality was corrected considering natural mortality using Schneider-Orelli’s formula prior to ANOVA and Duncan comparison test using the SPSS statistical program. These results indicate that the five ecotypes had lethal effect on first instar larvae of G. bonplandii Schaum and mortality ranged between 30 and 90 %, therefore they may be used as biological components in pest management. Keywords: root exudates, Ricinus communis , Euphorbiaceae, Gymnetis bonplandii , Coleoptera, Scarabaeidae.
- Published
- 2017
15. Systemic Activation of Defensive Enzymes and Protection in Tobacco Plantlets against Phytophthora nicotianae Induced by Oligosaccharins
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Ruddy Wattiez, Daimy Costales, Alejandro B. Falcón-Rodríguez, Juan Carlos Cabrera, and Miguel Ángel Martínez-Téllez
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chemistry.chemical_classification ,Spermine ,General Medicine ,Glucanase ,Biology ,Phytophthora nicotianae ,biology.organism_classification ,Chitosan ,chemistry.chemical_compound ,Enzyme ,Point of delivery ,Biochemistry ,chemistry ,Bioassay ,Pathogen - Abstract
Oligosaccharins are potent biomolecules which activate defense responses and resistance in tobacco plants. However, it is not known the systemic behavior of defensive enzymes activated by these elicitors. In this work, the dynamic behavior of key defensive enzymes was evaluated in tobacco plant leaves previously treated through the roots with chitosan polymer (CH), chitosan (COS) and pectic (OGAS) oligosaccharides and Spermine (Sp). All macromolecules tested activated protein levels and defense enzymatic activity in tobacco leaves but with different response dynamics among them and depending on the biochemical variable evaluated. Defense response above control levels were detected since 12 hours after treatments and it consisted in a biphasic behavior with two peaks for PAL (EC 4.3.1.5) and β 1 - 3 glucanase (EC 3.2.1.6) enzymatic activities. The highest enzymatic levels for these enzymes were achieved at 48 hours in plantlets elicited with COS and at 72 hours for those plants treated with chitosan polymer, while the highest POD (EC 1.11.1.6) activity was detected with CH between 48 and 72 hours. These results demonstrated systemic defense activation by oligosaccharins in tobacco whose dynamic of defense response is affected by the kind of oligosaccharins tested. When applying OGAS by foliar spray on tobacco, systemic resistance against Phytoththora nicotianae was induced and plantlets were protected with the low concentration tested by 46% under the bioassays conditions performed. Moreover, enzymatic determinations on roots and leaves previous to plant-pathogen interaction showed increments above 30% of control levels for PAL and POD activities. It means that oligosaccharins activate local and systemic defense responses in plants in the absent of pathogen infection.
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- 2014
16. PRACTICAL USE OF OLIGOSACCHARINS IN AGRICULTURE
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Sonia González, R.C.A. Onderwater, G. Wegria, Hilary J. Rogers, Gustavo Cabrera, Luis Javier González, A.B. Falcón-Rodríguez, E. Diosdado, Juan Carlos Cabrera, Daimy Costales, G. González, R. Wattiez, and M. C. Nápoles
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Abiotic component ,Engineering ,Plant propagation ,business.industry ,Crop yield ,fungi ,food and beverages ,Horticulture ,Xyloglucan ,Cell wall ,chemistry.chemical_compound ,Symbiosis ,chemistry ,Agronomy ,Agriculture ,Citrus Pectin ,business - Abstract
The potential use of cell wall derived oligosaccharides as regulators of plant defence, growth and development was already referred to nearly 20 years ago in a first review (Albersheim and Darvill, 1985). These bioactives, called oligosaccharins, are now relatively easy to produce and ready to face public acceptance because of their natural origin. In this review, we summarise the results obtained by a consortium of research institutions and companies working in the preparation, bioactivity studies, and practical use of different oligosaccharides as biostimulants in agriculture. We will start by explaining how fungal cell wall-derived chitosan and chitooligosaccharides stimulate plant defence, growth and improve crop yield and quality of many species. Then we will focus on different oligosaccharides such as oligogalacturonides, prepared from citrus pectin, that can partial or totally substitute phytohormones in the culture “in vitro” of sugar cane, citrus, coffee, tomato, rice and banana plants, reducing the time required for plant propagation, avoiding culture-induced genetic changes and increasing field survival percentage of these plants but also inducing rooting and plant growth. Then we will explain how the use of xyloglucan oligosaccharides, derived from the plant cell wall cannot only promote plant growth but also differentially act on the regulation of diverse biotic and abiotic stress-related genes. We will also discuss several field experiments where the foliar application of lipo-chitooligosaccharides, a nodulation factor in the soybean-rhizobium symbiosis, was shown to be effective in the enhancement of plant growth and production yield in soybean, wheat and corn. In short, this work aims to
- Published
- 2013
17. Nitrogen depletion in Arthrospira sp. PCC 8005, an ultrastructural point of view
- Author
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Juan Carlos Cabrera Pino, Ruddy Wattiez, Raphaël Facchini, Patrick Flammang, Frédéric Deschoenmaeker, Guillaume Bayon-Vicente, and Neha Sachdeva
- Subjects
0301 basic medicine ,Cyanobacteria ,Nitrogen ,030106 microbiology ,chemistry.chemical_element ,03 medical and health sciences ,chemistry.chemical_compound ,Bacterial Proteins ,Structural Biology ,Spirulina ,Photosynthesis ,Glycogen ,biology ,Nitrogen deficiency ,Gene Expression Regulation, Bacterial ,biology.organism_classification ,Carbon ,030104 developmental biology ,chemistry ,Biochemistry ,Starvation ,Thylakoid ,Ultrastructure ,Phycobilisome - Abstract
In cyanobacteria, the nitrogen and carbon metabolisms are functionally bridged and consequently respond to the carbon-to-nitrogen ratio. Consequently, a nitrogen deficiency results in carbon excess. For the first time, the biological adaptation of Arthrospira sp. PCC 8005 to nitrogen starvation has been deeply characterized at the cellular structure scale. The results indicated that the carbon excess is rerouted into carbon storage granules, such as the polyhydroxyalkanoate and glycogen granules corroborating existing data. Additionally, this photosynthetic organism hugely secreted exopolysaccharides, which could constitute another biological carbon reservoir. It has been reported that few cells in trichomes of Arthrospira sp. PCC 8005 still display a high level of fluorescence after a long-term nitrogen starvation. The transmission electron microscopy showed that some cells still contained thylakoids and phycobilisomes after this long-term nitrogen starvation, which could explain the remaining fluorescence.
- Published
- 2016
18. Oligosaccharins and Pectimorf® stimulate root elongation and shorten the cell cycle in higher plants
- Author
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Hilary J. Rogers, Lara Perrotta, Robert J. Herbert, Juan Carlos Cabrera, Alexis Acosta, Alenna Vázquez-Glaría, Lien González-Pérez, Dennis Francis, and Sarah A. Scriven
- Subjects
biology ,Physiology ,Cdc25 ,Nicotiana tabacum ,Lateral root ,Plant Science ,Meristem ,Cell cycle ,biology.organism_classification ,Cell biology ,Botany ,biology.protein ,Arabidopsis thaliana ,Primordium ,Agronomy and Crop Science ,Mitosis - Abstract
The aim was to test promotive effects of oligosaccharins on root growth and development at the root apical meristem and the cell cycle using the model systems, Arabidopsis thaliana and the tobacco (Nicotiana tabacum) BY-2 cell line. Arabidopsis was grown on medium supplemented with 0.1 mg L−1 oligoxyloglucan (OX), 10 mg L−1 Pectimorf® (P) or 0.5 mg L−1 indole butyric acid (IBA). Primary root length, number of lateral root primordia, root apical meristem (RAM) length and epidermal cell length were recorded. Three genotypes were used: wild type (WT) and transgenic lines expressing either Schizosaccharomyces pombe (Sp) cdc25 or over-expressing(oe) Arath;WEE1. All treatments promoted primary root elongation but repressed lateral root production. Only P had a clear positive effect on meristem length whereas all other genotype × treatment interactions showed shorter RAMs. Whilst IBA, OX and P induced an increase in cell length in Spcdc25, the same treatments caused a significant decrease in WEE1 oe . Mitotic indices were also significantly higher in roots treated with oligosaccharins suggesting a shortening of the cell cycle. This hypothesis was tested in the BY-2 cell line. Both OX and P shortened the cell cycle exclusively through a shortening of G1 whilst mitotic cell size remained constant between treatments. In conclusion, both OX and P do indeed stimulate growth and shorten the cell cycle in higher plants and at the cellular level are able to reverse large and small cell size phenotypes normally exhibited by WEE1 oe and Spcdc25 genotypes, respectively.
- Published
- 2012
19. Chitosan physico–chemical properties modulate defense responses and resistance in tobacco plants against the oomycete Phytophthora nicotianae
- Author
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Juan Carlos Cabrera, Daimy Costales, Alejandro B. Falcón-Rodríguez, and Miguel Ángel Martínez-Téllez
- Subjects
Oomycete ,Rhizosphere ,biology ,Health, Toxicology and Mutagenesis ,food and beverages ,General Medicine ,Phytophthora nicotianae ,biology.organism_classification ,Elicitor ,Chitosan ,chemistry.chemical_compound ,Point of delivery ,chemistry ,Botany ,biology.protein ,Bioassay ,Food science ,Agronomy and Crop Science ,Peroxidase - Abstract
Enzymatic defense responses and protection against Phytophthora nicotianae were studied in tobacco plants treated with chitosan of different molecular weights (MW) and degrees of acetylation (DA). The concentration and mode of chitosan application affected enzymatic induction in tobacco leaves. β-1,3-Glucanase (EC 3.2.1.6) activity required 10 times the polymer concentration relative to the oligochitosan mixture to induce the highest activity above control when treated by foliar spray, indicating the influence of molecular weight in this response. PAL (EC 4.3.1.5) and POD (EC 1.11.1.6) activities increased above control as a result of the influence of polymer degree of acetylation when treatments were applied by foliar spray. A higher DA favored PAL activity, whereas a lower DA induced higher POD activity. Using an in vitro bioassay, it was found that the three chitosan compounds caused a reduction of the infection index of P. nicotianae in tobacco plants that was dependent on elicitor concentrations. There was a significant relationship between the reduction of the infection index and an increase in PAL activity when chitosan was applied by foliar spray and by substrate drench to the plant rhizosphere. These results demonstrate the influence of chitosan physico–chemical properties in plant-induced resistance and the relevance of particular responses in plant protection against pathogens.
- Published
- 2011
20. Isolation and characterisation of pectic substances from murta (Ugni molinae Turcz) fruits
- Author
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Gustavo Cabrera, Juan Carlos Cabrera, Ana Gutiérrez-Moraga, Eduardo Pereira, Patricio Fisher, Elisa A. Zúñiga, Reynaldo Villalonga, Rory Jara, Edelio Taboada, and Manuel Gidekel
- Subjects
chemistry.chemical_classification ,food.ingredient ,Pectin ,biology ,Chemistry ,food and beverages ,General Medicine ,Ammonium oxalate ,Polysaccharide ,Ugni molinae ,biology.organism_classification ,Oxalate ,Analytical Chemistry ,Cell wall ,Ferulic acid ,chemistry.chemical_compound ,food ,Organic chemistry ,Food science ,Citrus Pectin ,Food Science - Abstract
Cell walls polysaccharides from murta fruit (Ugni molinae Turcz), an endemic Chilean species with relevant food uses, were fractionated by water, ammonium oxalate, hot diluted HCl and cold diluted NaOH extractions. The polysaccharide fractions were analysed for monosaccharide composition and physicochemical properties. Pectic substances were found in all extracts, but mainly in the oxalate and acid soluble fractions, in which they appear as homogalacturonan polymers. Murta pectin was further extracted by hot diluted acid treatment using industrial conditions, yielding 30% by weight of dry fruit. The polymer showed similar composition and physicochemical properties to those of commercial citrus pectin, presenting a galacturonic acid content of 70.9% (w/w), a molecular weight of 597. kDa, and a methoxylation degree of 57%. The FT-IR spectrum of murta pectin suggests the presence of ferulic acid residues on its structure and the NMR analysis confirmed the structure of this polysaccharide. It is concluded that murta fruit can be considered as a valuable source of high quality pectin.
- Published
- 2010
21. Chitosan oligosaccharides modulate the supramolecular conformation and the biological activity of oligogalacturonides in Arabidopsis
- Author
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Pierre Cambier, Juan Carlos Cabrera, Pierre Van Cutsem, Patrick Frettinger, and Aurelien Boland
- Subjects
Chitosan ,food.ingredient ,Cell Death ,biology ,Pectin ,Chemistry ,Arabidopsis ,Oligosaccharides ,Acetylation ,Enzyme-Linked Immunosorbent Assay ,Biological activity ,biology.organism_classification ,Plant cell ,Biochemistry ,Cell wall ,chemistry.chemical_compound ,food ,Chitin ,Carbohydrate Conformation ,Extracellular ,Pectins ,Calcium - Abstract
Plant cell walls undergo remodeling during growth and development and are the first target of many invading pathogens. Acidic pectin (homogalacturonans) binds calcium and forms chain dimers called egg boxes and even multimers at higher calcium ion concentrations. Chitosan, the deacetylated form of chitin produced by fungi when invading plant tissues, is a cationic polymer that can interact with negatively charged pectin. The interaction between chitosan oligomers (COS) and pectic egg boxes was investigated using 2F4, a monoclonal antibody specific for calcium-associated dimers of pectin. Depending on the size of the pectic molecules, the COS to pectin ratio, the degree of polymerization and the degree of acetylation of COS in the mixture, the calcium-induced egg box conformation of oligogalacturonides (OGA) was strongly stabilized or destroyed. The biological activity of COS-stabilized egg boxes was assayed on Arabidopsis cell suspensions. COS-OGA egg boxes strongly enhanced extracellular alkalinization and decreased potassium fluxes compared to control COS and OGA alone. Furthermore, OGA rescued Arabidopsis from cell death induced by higher concentrations of deacetylated COS. The stabilized COS-OGA egg boxes could constitute a combined emergency signal that informs plant cells on both cell wall degradation and pathogen presence, triggering a much stronger response than individual components alone.
- Published
- 2010
22. Effect of diet and paralarval development on digestive enzyme activity in the cephalopod Robsonella fontaniana
- Author
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Juan Carlos Cabrera, Sandra V. Pereda, and Iker Uriarte
- Subjects
Protease ,Chymotrypsin ,Ecology ,biology ,Hatching ,medicine.medical_treatment ,Acid phosphatase ,Aquatic Science ,biology.organism_classification ,Trypsin ,Enzyme assay ,Biochemistry ,Digestive enzyme ,Lithodes ,medicine ,biology.protein ,Food science ,Ecology, Evolution, Behavior and Systematics ,medicine.drug - Abstract
This study aims at establishing the maturation of the digestive system in Robsonella fontaniana by means of measuring the digestive enzyme activity in paralarvae after hatching. Different groups of newly hatched paralarvae were fed with Artemia sp. (FA), Lithodes santolla zoea (FL) or were starved to serve as negative control (ST), the experimental period lasted 27 days after hatching (DAH). The semi-quantitative assay api(A (R)) ZYM (bioM,rieux, France) was used to identify the pool of digestive enzymes present in paralarvae prior to selecting the specific enzymes acid phosphatase, total protease, trypsin and chymotrypsin for analysis. Mortality and larval protein content were also measured during the experiment. The survival of R. fontaniana hatchlings differed depending on the quality of the diet offered (ST < FA < FL), the same trend was observed with respect to paralarval protein content. Total protease and acid phosphatase activities were not related to either time of development or diet (P < 0.05). However, the activity of trypsin and chymotrypsin after DAH 10 was dependent on diet (P < 0.05). Paralarvae fed with Lithodes zoea (FL) performed better than paralarvae in the other two groups, exhibiting lower mortality, higher protein content and the highest proteolytic activity for trypsin and chymotrypsin. The results indicate that Lithodes-larvae are a better diet for R. fontaniana paralarvae than Artemia sp.
- Published
- 2009
23. Egg box conformation of oligogalacturonides : the time-dependent stabilization of the elicitor-active conformation increases its biological activity
- Author
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Johan Messiaen, Pierre Van Cutsem, Juan Carlos Cabrera, Aurelien Boland, and Pierre Cambier
- Subjects
Circular dichroism ,Stereochemistry ,Arabidopsis Proteins ,Dimer ,Arabidopsis ,Chemical modification ,chemistry.chemical_element ,Membrane Proteins ,Oligosaccharides ,Biological activity ,Calcium ,Biochemistry ,Protein Structure, Tertiary ,chemistry.chemical_compound ,Protein structure ,chemistry ,Extracellular ,Carbohydrate Conformation ,Pectins ,Carbohydrate conformation ,Dimerization ,Protein Kinases - Abstract
Circular dichroism spectrometry was used on oligogalacturonides (OGAs) and showed the existence of a calcium/sodium-induced conformational state that is intermediate between single-isolated chains and calcium-associated multimer chains. This conformation is interpreted as being egg box dimers. Using the 2F4 monoclonal antibody that specifically binds such an egg box dimer conformation of pectin, the stability of OGA dimers was investigated over a period of 24 hours. The extent to which egg box dimers were recognized by the antibody was dependent on the temperature and duration of preincubation of the OGA. This suggests a "maturation" process of the egg-box structure that consists in a progressive increase in the length of the junction sequences between two chains that slide along each other in order to form a maximum number of calcium bridges and dimer ends. The maturation of egg boxes induced both a significant increase in their binding to wall-associated kinase 1 (WAK1) and an increased extracellular alkalinization when applied to Arabidopsis thaliana cell suspensions. The chemical modification of the reducing end of the OGAs largely diminished their elicitating activity but did not hinder either dimerization or binding of these end-reduced egg boxes to WAK1. We conclude that there are at least two different perception systems for egg box dimers. One binds egg box junctions and the other binds egg box ends. The relevance of these results is discussed in terms of pectic signal perception and plant-pathogen interaction.
- Published
- 2008
24. Hip Fracture. A Nine-Year Study
- Author
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Horacio Suárez Monzón, Rolando Delgado Figueredo, Eduardo Sarmiento Sánchez, and Juan Carlos Cabrera Suárez
- Subjects
Medicine (General) ,lcsh:R5-920 ,R5-920 ,lcsh:Public aspects of medicine ,lcsh:RA1-1270 ,Public aspects of medicine ,RA1-1270 ,lcsh:Medicine (General) ,caderas - Abstract
Background: Recent studies in Cuba stated that a great number of hip fractures are caused due to accidental falls constituting an important health problem in the third age. Objective: To characterize the behaviour of hip fractures from 1997 to 2005 in Cienfuegos Province. Methods: An observational longitudinal descriptive and prospective study was carried out to all patients treated for hip fracture from 1997 to 2005 in the University Hospital ¨Dr. Gustavo Aldereguía Lima¨ in Cienfuegos city. Variable such as age, sex, and topographical diagnosis, and surgical modality, scale of disability, comorbidity, complications, lethality, and second time of admission were taken into account and collected in the analyzed period of time and in specific clinical records elaborated for this purpose. Results: 13,7 per cent of the orthopaedic complications were registered being significantly lower in regard with previous studies in similar contexts. 62 per cent of the assisted patients could get back their initial scale of disability. Conclusions: The results obtained showed the level of experience reached by the specialists using the new technologies at the surgical act.
- Published
- 2007
25. The effect of size and acetylation degree of chitosan derivatives on tobacco plant protection against Phytophthora parasitica nicotianae
- Author
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Gustavo Cabrera, Miguel Ángel Martínez-Téllez, Daimy Costales, Juan Carlos Cabrera, A. Falcón, M. A. Ramírez, and Verónica Toledo
- Subjects
Physiology ,Nicotiana tabacum ,fungi ,technology, industry, and agriculture ,food and beverages ,macromolecular substances ,General Medicine ,Biology ,Glucanase ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Hydrolysate ,carbohydrates (lipids) ,Chitosan ,chemistry.chemical_compound ,chemistry ,Acetylation ,Botany ,Bioassay ,Food science ,Growth inhibition ,Solanaceae ,Biotechnology - Abstract
Enzymatic degradation of chitosan polymer with Pectinex Ultra SPL was used to obtain derivatives with biological potential as protective agents against Phytophthora parasitica nicotianae (Ppn) in tobacco plants. The 24 h hydrolysate showed the highest Ppn antipathogenic activity and the chitosan native polymer the lowest. The in vitro growth inhibition of several Phytophthora parasitica strains by two chitosans of different DA was compared. While less acetylated chitosan (DA 1%) fully inhibited three P. parasitica strains at the doses 500 and 1000 mg/l the second polymer (DA 36.5%) never completely inhibited such strains. When comparing two polymers of similar molecular weight and different DA, again the highest antipathogenic activity was for the less acetylated polymer. However, degraded chitosan always showed the highest pathogen growth inhibition. Additionally, a bioassay in tobacco seedlings to test plant protection against Ppn by foliar application demonstrated that partially acetylated chitosan and its hydrolysate induced systemic resistance and higher levels of glucanase activity than less acetylated chitosan. Similarly, when treatments were applied as seeds coating before planting, about 46% of plant protection was obtained using chitosan hydrolysate. It was concluded that, while less acetylated and degraded chitosan are better for direct inhibition of pathogen growth, partially acetylated and degraded chitosan are suitable to protect tobacco against P. parasitica by systemic induction of plant resistance.
- Published
- 2007
26. Position control with electromechanical actuators in didactic plants
- Author
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Juan Carlos Cabrera and Andres Pantoja
- Subjects
Engineering ,business.industry ,Control system ,Control (management) ,Physical system ,Control engineering ,business ,Actuator ,Control methods ,Position control ,Two degrees of freedom - Abstract
This document is a compilation of the main results obtained in the research project about control systems for didactic plants. The features and processes for modeling and building a prototype, as well as the comparative implementation of several control methods in simulation and on the real physical system are presented. From the expertise about the use of the control techniques in the two degrees of freedom helicopter model, methodological modules for laboratory practices are proposed, such that control students can reinforce the knowledge obtained in lecture classes.
- Published
- 2015
27. Size, acetylation and concentration of chitooligosaccharide elicitors determine the switch from defence involving PAL activation to cell death and water peroxide production in Arabidopsis cell suspensions
- Author
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Pierre Van Cutsem, Johan Messiaen, Pierre Cambier, and Juan Carlos Cabrera
- Subjects
biology ,Physiology ,food and beverages ,Cell Biology ,Plant Science ,General Medicine ,Phenylalanine ammonia-lyase ,Degree of polymerization ,biology.organism_classification ,Oligomer ,Chitosan ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Polymerization ,Acetylation ,Arabidopsis ,Genetics ,Arabidopsis thaliana - Abstract
Chitosan oligomers are known elicitors of plant defence mechanisms. In this work, chitooligosaccharides of different degrees of polymerization and degrees of acetylation were prepared and characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The effect of the degree of polymerization (DP), degree of acetylation and concentration of these chitooligosaccharides on defence activation in Arabidopsis thaliana suspension-cultured cells was studied. Our study results show that fully deacetylated chitooligosaccharides (chitosan oligomers) induce, depending on their DP and concentration, phenylalanine ammonia-lyase (PAL) activation, H2O2 synthesis and cell death in A. thaliana cell suspensions. The progressive reacetylation of the chitosan oligomer elicitors progressively impaired their ability to enhance H2O2 accumulation and cell death, but did not affect the activation of PAL.
- Published
- 2006
28. Preparation of chitooligosaccharides with degree of polymerization higher than 6 by acid or enzymatic degradation of chitosan
- Author
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Pierre Van Cutsem and Juan Carlos Cabrera
- Subjects
chemistry.chemical_classification ,Environmental Engineering ,Chromatography ,technology, industry, and agriculture ,Biomedical Engineering ,Bioengineering ,macromolecular substances ,Oligosaccharide ,Degree of polymerization ,Chitosan ,Hydrolysis ,chemistry.chemical_compound ,Matrix-assisted laser desorption/ionization ,chemistry ,Polymerization ,Enzymatic hydrolysis ,Acid hydrolysis ,Biotechnology - Abstract
Chitosan was depolymerized either by HCl hydrolysis or enzymatic degradation with a commercial preparation Pectinex Ultra Spl. The chitooligosaccharides released by both methods were selectively precipitated in methanol solutions and characterized using MALDI-TOF mass spectrometry. Differences between the two methods were detected and concerned the degrees of polymerization of the fragments produced and their acetylation. The enzymatic method yielded shorter fragments with a higher proportion of fully deacetylated chitooligomers. Conversely, acid hydrolysis of the starting chitosan resulted in fragments with degrees of polymerization up to sixteen and more monoacetylated residues than with the enzymatic procedure.
- Published
- 2005
29. Assignment of acetyl groups to O-2 and/or O-3 of pectic oligogalacturonides using negative electrospray ionization ion trap mass spectrometry
- Author
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Jean-François Thibault, Marie-Christine Ralet, Bernard Quemener, Juan Carlos Cabrera Pino, and Estelle Bonnin
- Subjects
chemistry.chemical_classification ,0303 health sciences ,Electrospray ,Chromatography ,Chemistry ,Electrospray ionization ,010401 analytical chemistry ,Glycosidic bond ,Uronic acid ,01 natural sciences ,Medicinal chemistry ,Dissociation (chemistry) ,0104 chemical sciences ,Ion ,03 medical and health sciences ,chemistry.chemical_compound ,Enzymatic hydrolysis ,Ion trap ,Spectroscopy ,030304 developmental biology - Abstract
Partially acetylated and methylated oligogalacturonides produced by enzymatic hydrolysis of sugar beet pectin were analysed by negative electrospray ionization ion trap mass spectrometry (ESI-ITMS). The (18)O labelling of the oligomer reducing end allowed the precise assignment of the fragments resulting from glycosidic bond and cross-ring cleavages. The collisional-induced dissociation of the C(i) and Z(j) fragment ions through sequential MS(n) experiments always displayed (0, 2)A-type cross-ring cleavage ions which were related to C(2)H(4)O(2) losses. These (0, 2)A ions appeared to be highly diagnostic ions allowing the precise location of the acetyl groups to the O-2 and/or O-3 of the acetylated galacturonic acid residues.
- Published
- 2003
30. Aprendizaje de la investigación en un programa de posgrado: el doctorado en estudios regionales de la Universidad Autónoma de Chiapas, México / Learning to Do Research in a Graduate Program: the PhD in Regional Studies in the Autonomous University of Chiapas
- Author
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Leticia Pons Bonals and Juan Carlos Cabrera Fuentes
- Subjects
General Medicine - Abstract
In the guidelines that institutions of higher education that teach postgraduate studies in Mexico receive from international organizations, as well as those national agencies involved in institutional planning and assessment, the need to train researchers is identified. With this in mind, the question that concerns this article is how to guide the process of learning to research in a doctoral program, based on this guidelines and considering the specific conditions under which it develops? In what follows we show the results of an evaluative research conducted in the PhD in Regional Studies (DER, for its acronym in Spanish) of the Autonomous University of Chiapas (UNACH, for its acronym in Spanish), specifically in the area of training-research that addresses regional educational problems by highlighting positive and negative aspects of its design and implementation. Among the positive aspects, we highlight the strategy implemented for their students to learn to research. Within the negative aspects, we highlight the academic and administrative problems faced in the implementation of this program that is subject to rigid regulatory structures.RESUMENEn los lineamientos que las instituciones de educación superior que imparten estudios de posgrado en México reciben de parte de organismos internacionales, así como de aquellos organismos nacionales que se ocupan de la planea-ción y evaluación institucional, se identifica la necesidad de formar investigadores. Ante esto la pregunta que se responde en este artículo es ¿Cómo orientar el aprendizaje de la investigación en un programa doctoral, teniendo como base estos lineamientos y atendiendo a las condiciones concretas en las que se desarrolla? En las siguientes líneas se presentan los resultados obtenidos en una investigación evaluativa realizada al doctorado en Estudios Regionales (DER) de la Universi-dad Autónoma de Chiapas (UNACH), específicamente en la línea de formación-investigación que aborda los problemas educativos regionales, destacando los aspectos positivos y negativos de su diseño y ejecución. Entre los positivos destaca la estrategia implementada para que sus estudiantes aprendan a investigar, dentro de los negativos los problemas de corte académico-administrativo que enfrenta la implementación de este programa al contar con estructuras normativas rígidas. Contacto principal: pbonals@hotmail.com
- Published
- 2014
31. Puto: normalización institucional de la discriminación en el fútbol
- Author
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Juan Carlos Cabrera Pons
- Subjects
género ,prácticas discursivas, discriminación, homofobia, análisis del discurso, género ,análisis del discurso ,discriminación ,homofobia ,prácticas discursivas - Abstract
El pasado Mundial de fútbol, la FIFA amenazó con sancionar a la selección mexicana de fútbol por lo que le pareció una conducta homófoba realizada por los aficionados mexicanos durante los partidos de su selección contra Camerún y Brasil. La sanción fue retirada antes de ser aplicada, pero el hecho despertó diferentes comentarios tanto por parte de las instituciones implicadas como entre los aficionados y espectadores del evento. Este artículo realiza un análisis del discurso
- Published
- 2014
32. In tobacco BY-2 cells xyloglucan oligosaccharides alter the expression of genes involved in cell wall metabolism, signalling, stress responses, cell division and transcriptional control
- Author
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Lien González-Pérez, Diego Albani, Dennis Francis, Lara Perrotta, Beatrice M. Bitonti, Leonardo Bruno, Juan Carlos Cabrera, Esteban A. Orellana, Alexis Acosta, Hilary J. Rogers, and Natasha D. Spadafora
- Subjects
Tobacco BY-2 cells ,Transcription, Genetic ,Cell division ,Biology ,Q1 ,Cell Line ,NO ,Histones ,chemistry.chemical_compound ,Gene Expression Regulation, Plant ,Stress, Physiological ,Tobacco ,Gene expression ,Genetics ,Transcriptional regulation ,Glucans ,Molecular Biology ,Mitosis ,Cells, Cultured ,Regulation of gene expression ,Nicotiana tabacum ,General Medicine ,Cell cycle ,Chromatin Assembly and Disassembly ,Xyloglucan ,chemistry ,Biochemistry ,cell wall ,Xylans ,cell cycle ,Cell Division ,Signal Transduction - Abstract
Xyloglucan oligosaccharides (XGOs) are breakdown products of XGs, the most abundant hemicelluloses of the primary cell walls of non-Poalean species. Treatment of cell cultures or whole plants with XGOs results in accelerated cell elongation and cell division, changes in primary root growth, and a stimulation of defence responses. They may therefore act as signalling molecules regulating plant growth and development. Previous work suggests an interaction with auxins and effects on cell wall loosening, however their mode of action is not fully understood. The effect of an XGO extract from tamarind (Tamarindus indica) on global gene expression was therefore investigated in tobacco BY-2 cells using microarrays. Over 500 genes were differentially regulated with similar numbers and functional classes of genes up- and down-regulated, indicating a complex interaction with the cellular machinery. Up-regulation of a putative XG endotransglycosylase/hydrolase-related (XTH) gene supports the mechanism of XGO action through cell wall loosening. Differential expression of defence-related genes supports a role for XGOs as elicitors. Changes in the expression of genes related to mitotic control and differentiation also support previous work showing that XGOs are mitotic inducers. XGOs also affected expression of several receptor-like kinase genes and transcription factors. Hence, XGOs have significant effects on expression of genes related to cell wall metabolism, signalling, stress responses, cell division and transcriptional control.
- Published
- 2014
33. EFICIENCIA MASTICATORIA ENTRE PORTADORES DE PRÓTESIS TOTALES Y SOBREDENTADURAS INFERIORES
- Author
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Karin Vanessa Díaz Ceballos, Juan Carlos Cabrera Rojas, Lady Johanna Acuña Teatino, and Carlos Alirio Rueda Ordóñez
- Subjects
Physics ,masticación ,prótesis e implantes ,eficiencia ,Humanities ,Implant supported ,dental prosthesis ,Dental implants ,Efficiency - Abstract
Objective: to assess the masticatory performance among complete dental and implant overdenture wearers.Methods: a quasi-experimental study was done. The masticatory efficiency was evaluated in fifteen complete dentures wearers and fifteen upper dentures and lower overdenture wearers. The subjects filled out a satisfaction questionnaire and chewed a piece of 6 g of raw carrots. The particles were issued in the oral cavity and evaluated towers sieves of different diameters superimposed in descending order. Thus the percentage value for each sieve was obtained. The Chi2 or Fisher exact test for qualitative variables and Student t test or Mann-Whitney U for quantitative variables according to their distribution were carriet out. A value of p
- Published
- 2014
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34. Servicios no financieras implementados en Japón para apoyar a las Pyme
- Author
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Rosa Cruzado, Doris Maraví Gutarra, Ángel Hurtado, and Juan Carlos Cabrera
- Abstract
Con este artículo culmina la presentación de "Políticas gubernamentales para el desarrollo de la pequeña empresa", informe final de los participantes en el segundo curso sobre las Medidas Administrativas y Manejo Empresarial en la Promoción de la Pequeña Empresa para la República del Perú, realizado en Osaka-Japon, a fines de 1996.
- Published
- 1997
35. Políticas gubernamentales para el desarrollo de la pequeña empresa
- Author
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Arturo Caballero, Juan Carlos Cabrera, Jaime Giesecke, Edgar Robles, Doris Maraví, Rosana Cruzado, Rubén Cano, Yuri Santa Cruz, Jorge Sánchez, and Ángel Hurtado
- Subjects
Management of Technology and Innovation - Abstract
El informe comprende tres temas: el primero relacionado con las políticas gubernamentales para el desarrollo de las Pyme, el segundo con el sistema de financiamiento, y el tercero con los servicios no financieros implementados en el Japón para apoyar a las Pyme. Por la extensión del informe éste se presenta en tres partes correspondiendo a este número de la revista los dos primeros temas.
- Published
- 1997
36. Exploiting Plant Innate Immunity to Protect Crops Against Biotic Stress: Chitosaccharides as Natural and Suitable Candidates for this Purpose
- Author
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Guillaume Wégria, Alejandro B. Falcón-Rodríguez, and Juan Carlos Cabrera
- Subjects
Innate immune system ,Resistance (ecology) ,Ecology ,business.industry ,fungi ,Defence mechanisms ,food and beverages ,Plant Immunity ,Biotic stress ,Biology ,business ,Crop protection ,Biotechnology - Abstract
One of the most innovative approaches for controlling plant diseases is through the enhancement of the plant's own defence mechanisms (induced resistance), which would not involve the application of toxic compounds to plants. It has been well established for over 100 years, that plants can defend themselves; however, in the last 20 years, a significant progress in our knowledge on plant immunity, has provided the understanding required to allow induced resistance to be used in practice. In this chapter we will discuss the bioactivity of chitosaccharides as pathogen associated molecular patterns and their potentiality in crop protection.
- Published
- 2012
37. ORAL REHABILITATION WITH FIXED PARTIAL PROSTHODONTICS IN THE COMPLEX CASE OF CROSS ARCH: CASE REPORT
- Author
-
Juan Carlos Cabrera Rojas
- Abstract
Es un reto para la rehabilitación devolver la función y la estética perdida al sistema estomatognático. En el caso de tratamientos complejos, la rehabilitación oral juega un papel clave en el diagnóstico y vela para que se cumplan los objetivos propuestos dentro de parámetros académicos y prácticos. En este reporte se presenta un caso clínico de características complejas rehabilitado mediante prostodoncia parcial fija que requirió el concurso interdisciplinario de endodoncistas, periodoncistas, rehabilitadores orales y laboratoristas dentales. El Síndrome de Colapso de Mordida Posterior (SCMP) bilateral observado se destaca por su gravedad e importancia. El objetivo de este trabajo fue describir de forma integral el diagnóstico y plan de tratamiento en casos complejos realizados con prostodoncia parcial fija en rehabilitación oral y presentar un caso clínico de rehabilitación compleja.[Cabrera JC. Rehabilitación oral con prostodoncia parcial fija: reporte de un caso complejo de arco cruzado. Ustasalud 2012; 11: 45 - 53] It is a challenge for rehabilitation restores lost function and aesthetics stomatognathic system. For complex treatments, oral rehabilitation plays a key role in the diagnosis and ensures that objectives are met within academic and practical settings. This report presents a case of complex features restored by fixed partial prosthodontics requiring interdisciplinary participation of endodontists, periodontists, oral rehabilitation and dental laboratory technicians. The Collapse of Posterior Teeth (CPT) reported stands out for its seriousness and importance. The aim of this report was to describe comprehensively the diagnosis and treatment planning in a complex case performed with fixed partial prosthodontics in oral rehabilitation and present a clinical case of complex rehabilitation.
- Published
- 2012
38. Sclerotherapy in Vascular Malformations
- Author
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Dirk A. Loose and Juan Carlos Cabrera
- Subjects
medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Vascular malformation ,medicine.disease ,Gastroenterology ,Polidocanol ,Extensive Necrosis ,Internal medicine ,Sodium tetradecyl sulphate ,medicine ,Sclerotherapy ,Lymphatic malformations ,Ethanolamine Oleate ,business ,Venous malformation ,medicine.drug - Abstract
Sclerotherapy is performed mainly in venous and lymphatic malformations using different substances. Sclerosis in arteriovenous (AV) forms is contraindicated because an erroneous intra-arterial injection may produce extensive necrosis. Classical sclerosis is mainly performed in venous dysplasias with polidocanol, sodium tetradecyl sulphate and ethanol, among others, while in lymphatic malformations, OK-432 is preferred. Sclerotherapy with the microfoam technique significantly improves results.
- Published
- 2009
39. Evaluation of Pectimorf as growth regulator in the formation of callus with embriogenic structures in Ipomoea batatas
- Author
-
Orlando S . González Paneque, Juan José Silva Pupo, Margarita Hernández Espinosa, Alejandro Falcón Rodríguez, Ramón Iglesias Curbelo, Julio Rodríguez Hernández, Lizardo Arias Gómez, Juan Carlos Cabrera, and Edubar Oliva Jaume
- Subjects
lcsh:Agriculture ,lcsh:S ,lcsh:SB1-1110 ,lcsh:Plant culture - Abstract
Tuberous roots of sweet potato belonging to the clone INIVIT B 93-1, were gather ad and placed in flasks with water in the laboratory to induce the emergence of the yolks. Later on, explants of the limbo was selected to foliate (1 cm2) fields in the means of cultivation of Murashige and Skoog, 100 mg.l-1 myo-inositol, 1 mg.l-1 tiamine, 3% sucrose, 0.2% gelrite, 0.50 mg.l-1 2,4-D and 0.25 mg.l-1 6-BAP as control treatment and the same medium of above mentioned culture with different pectimorf concentrations (5.0, 10.0, 15.0 and 20.0 mg.l-1) for the formation of callus with embryogenic structures. Thirty days later the percentage of formed callus, their the callus growth, color, texture and presence of roots were evaluated. The callus stayed in incubation camera under conditions of darkness, temperature of 25 ± 2°C and relative humidity of 80-90%. Good results were obtained in the formation of callus with embryogenic structures, when used the pectimorf at 15.0 mg.l-1 concentration. Key works: embryogenesis, sweet potato, oligopectates
- Published
- 2004
40. PECTIMORF and BIOBRAS-16 utilization in the potato somatic embryogenesis
- Author
-
Jaime R. Hidrobo Luna, Eduardo Héctor Ardisana, Juan Carlos Cabrera, and Isabel Jomarrón Rodiles
- Subjects
lcsh:Agriculture ,lcsh:S ,lcsh:SB1-1110 ,lcsh:Plant culture - Abstract
With the application of PECTIMORF and BIOBRAS-16, somatic embryos were obtained in potato (Solanum tuberosum, L) c.v. Desirèe, of 40 days old callus obtained from stem micropropagated plants. These were used as possible substitutes for crop regulators used in culture media for the induction of somatic embryos. The culture media was composed for 10ml.l-1 of Murashige and Skoog salt, 0.1mg.l-1 ANA, 0.1mg.l-1 kinetin, 0.5mg.l-1 thiamine, 2.5mg.l-1 cistein, 100mg.l-1 mioinositol, 20g.l-1 sucrose and 2.0g.l-1 agar. Four culture medias were tested in distinct combinations that contained different concentration of PECTIMOR and BIOBRAS-16 as substitute of auxins and cytokinins. After 90 days, the results obtained showed the possibility of substituting the auxins (0.5mg.l-1 ANA) and the cytokinins (0.5mg.l-1 kinetin) in the culture media, because the application of PECTIMORF at 3.2mg.l-1 and BIOBRAS-16 at 1.0mg.l-1, gave friable callus, high fresh weight (more than 1.4g) and a brownish color at the end of the process, moment in which the somatic embryos of different phases, appeared at the surface of the callus. Keywords: brasinoesteroids, callus, oligopectate, somatic embryo
- Published
- 2002
41. Epidemiology and CKD - 3
- Author
-
Pietro Ravani, Ajay K. Singh, Jose Guiserix, Sergiu Gaibu, Francisco de Assis Acurcio, George Kosmadakis, Hong Li, Luis Trujillo, Dongwei Liu, Piergiorgio Messa, John J Kelly, Adrian Tanase, Bassam Fallouh, James B. Wetmore, A. Guerin, Pål Richard Romundstad, Frans Vermeiren, Arjan van der Tol, Jer-Ming Chang, Nicolas Janus, Richard Krause, Paolo Raggi, Terumasa Hayashi, Amar Amaouche, Christine Folia, Juan Carlos Santos, Kostas C. Siamopoulos, Vicente Sanchez Polo, Dimitrios Tsakiris, Tomonori Kimura, R. Lakshmy, Stein Hallan, Jaume Puig i Junoy, Mourad Farouk, Braden J. Manns, Prapaipim Thirakhupt, Antonio Santoro, R. Walker, Renato Watanabe, Kathleen Claes, Mariangela Leal Cherchiglia, Ana Benitez, Rogério B. de Paula, Elaine Leandro Machado, A. M. El Nahas, Ricardo Leiva, Enrique Rojas-Campos, Kristin Beard, Natalia Grinblat, Arvind Bagga, Jianguo Zhang, Ladan Zand, Hung-Chun Chen, Angela C Webster, Carolie Bingham, Adeera Levin, Monica Beaulieu, Viola Vaccarino, Leena Ongaiyooth, Adewale Akinsola, Igor Codreanu, Simon de Lusignan, Qi Qian, Stian Lydersen, Sergiu Popa, John Munkhaugen, John Feehally, Odilon Vanni de Queiroz, Eleni Triantou, Brenda R. Hemmelgarn, Sergio Antonio Draibe, P. Taylor, Piergiorgio Poisetti, Felipe G. Oliveira, Masanobu Miyazaki, Daniele Araújo Campos Szuster, Rachael L. Morton, Aline F. Coelho, Shang-Jyh Hwang, Tor-Erik Widerøe, Luxia Zhang, Mônica Viegas Andrade, James F Medcalf, Marion Verduijn, H. Herlitz, David C. Mendelssohn, Hugh Gallagher, Yoav Ben-Shlomo, Amnart Chaiprasert, David Fitchett, Kirsten Howard, Maria Eugênia Fernandes Canziani, Carla Bonanomi, Jorge Ayllon, Ross T. Tsuyuki, Simone Vettoretti, Corinne Isnard-Bagnis, Yoko Obata, Bruce F. Culleton, Francois L'Heureux, Paul Snelling, Stéphane Oudard, Kostas Pappas, Daniele A.C. Szuster, B.B. Phani Kumar, Athanasios Kitsos, Alessandra Maciel Almeida, Evangelia Dounousi, Tom Chan, Gilbert Deray, Aluizio B. Carvalho, Giulio Malmusi, Yoshitsugu Obi, Brigitte Bonal, Giuseppe Remuzzi, Mona H. Hashish, Marcello Tonelli, Ruth Colagiuri, Isabel Cristina Gomes, Silvia Regina Manfredi, Eli Iola Gurgel, S. Di Giulio, Margaretha Steenkamp, François Favier, Smriti Hari, Irene Ching, Riccardo Floreani, Nicola Thomas, Fatiu A Arogundade, Szu-Chia Chen, Keiko Yasuda, Indranil Dasgupta, Isabel Fortier, Maxim Untesco, Puhong Zhang, T. Raviraju, Hai-yan Wang, Somlak Vanavanan, Juan Carlos Cabrera, Atiporn Ingsathit, Silvia Tirado, Guy De Groote, Amer Malas, Sergio Carminati, Charmaine Lok, Jeremy van Vlymen, Keisuke Sasaki, Hiroshi Yamashita, Raymond Vanholder, F.H. Ibrahim, Gisele Macedo, Mohammed Hadid, Vincent Launay-Vacher, Bogdan Ene-Iordache, Mike Broce, Maria Marta Vargas, David Ansell, Laurel Thorlacius, Marcelo M. Lemos, Marcus G. Bastos, Ian Bridges, Marcora Mandreoli, Jer-Chia Tsai, Thiago C. Bignoto, Julio Teran, Alexandra Buckley, Muzamil O Hassan, Shigeru Kohno, Mark Meayeart, Harikrishnan Nair, Bjør-Egil Vikse, Damian Fogarty, Charles R.V. Tomson, Mohamed Ramdane, Stephen B. Ting, L. Er, Luminita Suveica, Thomas Dervaux, Michael Nation, Xiaomei Li, Carlos Alberto de Oliveira, Francesca Cardarelli, Neerja Jain, J.A.L. Ranga Nath, Janet Addison, Hans Hillege, Tomoya Nishino, Mio Nakazato, Juliana Álvares, Zhangsuo Liu, Angelo Rigotti, O. Djurdjev, Jo Moore, Adriana Penalba, Mark Maeyaert, Yoshiyuki Ozono, Sebastien Veillon, Friedo W. Dekker, Vera Sali, Abubakr Sanusi, Takahiro Maeda, Shahdrad Taheri, Gustavo Henrique S. Oliveira, Els Boeschoten, Eric Crets, Hala S El-Wakil, Noboru Takamura, I. Kiss, Thaís G. Casali, Carlo Alfieri, Gerjan Navis, Daniel Ford, Vasiliki Kiatou, Akira Furusu, Zahira M. Gad, Eli Iola Gurgel Andrade, Hélio L. Brito, Takashi Harada, Tao Su, Kevin Harris, Ammar Almehmi, Kathleen Eeckhaut, Norberto Perico, Graham Warwick, Scott Klarenbach, Jacque Medioni, Francis Verbeke, Su Shaoyong, Ammarin Thakkinstian, Wim Van Biesen, J. Galle, Samar Abd El-Hafez, Aikaterini Papagianni, G. Wirnsberger, Pankaj Hari, Vijay Murugan, and Sophie A. Jamal
- Subjects
Transplantation ,medicine.medical_specialty ,Nephrology ,business.industry ,Epidemiology ,Medicine ,business ,Intensive care medicine - Published
- 2009
42. Chitosans as bioactive macromolecules to protect conomically relevant crops from their main pathogens
- Author
-
Falcón, A., Rodríguez, A. T., Ramírez, M. A., Rivero, D., Martínez, B., Juan Carlos Cabrera, Costales, D., Cruz, A., González, L. G., Jiménez, M. C., Jiménez, L., Hernández, I., Gonzáles, D., and Márquez, R.
- Subjects
lcsh:Biotechnology ,lcsh:TP248.13-248.65 ,fungi ,antifungal activity ,food and beverages ,enzymatic hydrolysis ,chitosan ,induced resistance ,phytophtora nicotianae - Abstract
Studies were carried out as part of the Agriculture Biotechnology program, to prepare and characterize chemically and biologically different chitosans obtained from Cuban lobster chitin. Chitosan polymers were subjected to acid and enzymatic hydrolysis by using low·cost commercial enzymatic preparations, and the resulting oligosaccharide mixtures were further characterized. Their potential antimicrobial activities were also evaluated versus fungi and oomycetes, also testing their ability to induce defensive and protective responses in tobacco and rice plants against two economically relevant pests, Phytophthora nicotianae and Pyricularia grisea, respectively. With the aid of international collaboration, different oligochitosans mixtures were compared for activating defensive responses in suspension cultures of Arabidopsis thaliana cells. These results bring knowledge on the physical·chemical properties of the chitosans obtained, such as molar mass and acetylation grade, and their influence on activating defensive responses, the inhibition of growth in pathogens and the induction of resistance in tobacco and rice plants. Some of these chitosan derivatives were selected as possible active components to protect both type of cultivars, being applied at field·scale to evaluate their effects for the main natural pathogens and bringing very promising results. This research allowed us to establish a methodology for preparing oligochitosans, and results shown inhere were part of BSc, MSc and PhD theses, and were also published in more than 20 scientific papers and presented in more than 40 scientific conferences.
43. Drug encapsulation in pectin hydrogel beads- a systematic study of simulated digestion media
- Author
-
Juan Carlos Cabrera, Cambier, P., and Cutsem, P.
44. Mapping sugar beet pectin acetylation pattern
- Author
-
Jean-François Thibault, Marie-Christine Ralet, Pilar Hellín, Bernard Quemener, Juan Carlos Cabrera, Estelle Bonnin, ProdInra, Migration, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), and Institut National de la Recherche Agronomique (INRA)
- Subjects
food.ingredient ,Pectin ,HOMOGALACTURONANE ,Electrospray ionization ,Oligosaccharides ,Plant Science ,Horticulture ,Biochemistry ,Esterase ,03 medical and health sciences ,Hydrolysis ,0404 agricultural biotechnology ,food ,Enzymatic hydrolysis ,Pectinase ,Molecular Biology ,ComputingMilieux_MISCELLANEOUS ,[SDV.BV.PEP] Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy ,030304 developmental biology ,0303 health sciences ,Chromatography ,biology ,Viscosity ,Chemistry ,Acetylation ,04 agricultural and veterinary sciences ,General Medicine ,Chromatography, Ion Exchange ,biology.organism_classification ,040401 food science ,[SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy ,Kinetics ,Carbohydrate Sequence ,Chromatography, Gel ,Pectins ,Sugar beet ,Beta vulgaris - Abstract
Homogalacturonan-derived partly methylated and/or acetylated oligogalacturonates were recovered after enzymatic hydrolysis (endo-polygalacturonase+pectin methyl esterase+side-chain degrading enzymes) of sugar beet pectin followed by anion-exchange and size exclusion chromatography. Around 90% of the GalA and 75% of the acetyl groups present in the initial sugar beet pectin were recovered as homogalacturonan-derived oligogalacturonates, the remaining GalA and acetyl belonging to rhamnogalacturonic regions. Around 50% of the acetyl groups present in sugar beet homogalacturonans were recovered as partly methylated and/or acetylated oligogalacturonates of degree of polymerisation 5 whose structures were determined by electrospray ionization ion trap mass spectrometry (ESI-IT-MSn). 2-O-acetyl- and 3-O-acetyl-GalA were detected in roughly similar amounts but 2,3-di-O-acetylation was absent. Methyl-esterified GalA residues occurred mainly upstream 2-O-acetyl GalA. Oligogalacturonates containing GalA residues that are at once methyl- and acetyl-esterified were recovered in very limited amounts. A tentative mapping of the distribution of acetyl and methyl esters within sugar beet homogalacturonans is proposed. Unsubstituted GalA residues are likely to be present in limited amounts (approximately 10% of total GalA residues), due to the fact that methyl and acetyl groups are assumed to be most often not carried by the same residues.
45. EL SART: AUDITORÍAS DEL IESS PARA RIESGOS DEL TRABAJO
- Author
-
Juan Carlos Cabrera C
- Subjects
Social security ,Work (electrical) ,business.industry ,Process (engineering) ,Order (exchange) ,Homogeneous ,Management system ,System integration ,Accounting ,Audit ,business - Abstract
Los Sistemas de Gestión son en la actualidad el desarrollo de los estándares de eficiencia, eficacia y efectividad aplicados al Desarrollo Organizacional. Calidad, Ambiente, Inocuidad, Seguridad y Salud entre otros, se han estandarizado con la finalidad de ser homogéneos y flexibles en la integración de los Sistemas. En Ecuador, el Instituto Ecuatoriano de Seguridad Social ha cumplido su objetivo planteado hace aproximadamente una década: dejar de ser un ente de recomendación y pasar a ser un organismo auditor de los cumplimientos técnico legal en materia de Prevención de Riesgos Laborales para las empresas sujetas al régimen del IESS. El SART, es ahora, un cumplimiento legal obligatorio en Seguridad y Salud para las empresas a nivel nacional.
- Published
- 1970
46. Informe Final de Pasantía Implementación del Plan de Saneamiento Básico del Restaurante El Sabor de Mi Tierra
- Author
-
Murillo, Mateo O. and Universidad del Quindío - Colombia - Asesor - Juan Carlos Cabrera Eraso
- Subjects
Alimentos ,Procesos ,Inocuidad ,Calidad - Abstract
La inocuidad en la elaboración de alimentos son una parte esencial para la comercialización de los mismos, el programa de saneamiento básico es la base para controlar los procesos dentro del establecimiento, con el fin de entregar al consumidor alimentos de calidad y con estándares de higiene, en cuanto a los requerimientos establecidos por la resolución 2674 de 2013., 1. Introducción, 2. Problema, 3. Justificación, 4. Objetivo, 5. Presentación, 6. Resultados, 7. Conclusiones, 8. Recomendaciones y Sugerencias, 9. Imágenes, 10. Bibliografía, Pregrado, Ingeniero de Alimentos
- Published
- 2018
47. Informe Final de Pasantía MOI 24 Horas
- Author
-
Ospina Vélez, Jazmín Andrea and Universidad del Quindío - Colombia - Asesor - Juan Carlos Cabrera Eraso
- Subjects
Saneamiento ,Normatividad - Abstract
La empresa Moi 24 horas a partir del cumplimiento de la normatividad (Resolución 2674) y normas afines que apliquen a la empresa requiere del apoyo de un pasante de Ingeniería de Alimentos, el cual se encargara de llevar a cabo la implementación de los programas de saneamiento básico y manejo de formatos, además de la estandarización de procesos y productos allí elaborados., 1. Justificación, 2. Objetivos, 3. Marco teórico, 4. Metodología, 5. Resultados, 6. Conclusiones, 7. Anexos, Pregrado, Ingeniero de Alimentos
- Published
- 2018
48. Actualización e Implementación de Programas Prerrequisitos y Apoyo en las Áreas de Producción y Calidad para la Alimentación de la Fundación Shambala
- Author
-
Ladino Rendón, Heidy Carolina and Universidad del Quindío - Colombia - Asesor - Juan Carlos Cabrera Eraso
- Subjects
Alimentación ,Apoyo ,Producción ,Calidad - Abstract
En la implementación del sistema HACCP, es necesario que todos los programas prerrequisito que se encuentren trabajando, sean válidos y verídicos para el correcto funcionamiento de todo el sistema, de acuerdo a la última visita del INVIMA el día 05 de enero del 2018, a la Fundación Shambala se le asignaron ciertas tareas que deberá cumplir para la próxima visita programada para el mes de Julio del 2018, y la empresa con el fin de prestar un servicio con calidad demanda la participación activa de personal que ayude a crecer al establecimiento, dando cumplimiento a los requerimientos y además de esto, brindando supervisión en ámbitos de producción y calidad para garantizar que todas las labores cumplan con lo establecido., 1. Justificación, 2. Objetivos, 3. Presentación de la empresa, 4. Metodología, 5. Resultados y conclusiones, Pregrado, Ingeniero de Alimentos
- Published
- 2018
49. Informe Final de Pasantía Bakery Business International
- Author
-
Arango Buitrago, Claudia Marcela and Universidad del Quindío - Colombia - Asesor - Juan Carlos Cabrera Eraso
- Subjects
Productos ,Calidad - Abstract
El segmento del mercado BBI Colombia S.A.S, corresponde a todos los estratos económicos, con 282 tiendas en Bogotá la producción aumentado, ganando participación en el mercado., 1. Justificación, 2. Objetivos, 3. Presentación Empresa, 4. Resultados, 5. Conclusiones, 6. Recomendaciones y Sugerencias, Pregrado, Ingeniero de Alimentos
- Published
- 2018
50. Elaboración e Implementación de los Programas de Saneamiento Básico en la Empresa Sabimax S.A.S Montenegro Quindío
- Author
-
Jaramillo Valencia, Mónica and Universidad del Quindío - Colombia - Asesor - Juan Carlos Cabrera Eraso
- Subjects
Normatividad ,Productos ,Calidad - Abstract
En el mundo actual vemos como cada día las medianas empresas se están preocupando por ofrecer a los consumidores productos inocuos y de excelente calidad, la responsabilidad de la empresa SABIMAX.LOE S.A.S, será contribuir a que el producto cumpla con lo exigido por la normatividad correspondiente al sector de alimentos, por tal motivo el propósito de este trabajo es aplicar todos los conceptos teóricos aprendidos, ser apoyo en el área de calidad, producción y adicionalmente traer ventajas productivas a la empresa., 1. Introducción, 2. Planteamiento del problema, 3. Justificación, 4. Objetivos, 5. Marco teórico, 6. Metodología, 7. Resultados, 8. Conclusiones, 9. Bibliografía, Pregrado, Ingeniero de Alimentos
- Published
- 2018
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