409 research outputs found
Enrichissement microbien de consortiums nitrifiants issus de l'estuaire du Saint-Laurent, caractérisation de leur activité nitrifiante et de leur diversité taxonomique
RÉSUMÉ : La nitrification est un processus microbien essentiel du cycle de l'azote qui convertit l'azote ammoniacal en nitrate. Ce processus biologique est fréquemment utilisé dans le domaine des biotechnologies industrielles pour éliminer l'ammoniaque présent dans différents systèmes (ex : aquariophilie, traitement des eaux usées). Les consortiums microbiens utilisés pour ces applications, souvent d'origine terrestre ou de milieux aquatiques dulcicoles, présentent toutefois une faible activité nitrifiante à basse température et en milieu salé. L'objectif principal de ce projet de maîtrise est de développer un consortium nitrifiant performant à basse température (10°C) et en eau salée (25 psu) à partir du microbiome de l'estuaire du Saint-Laurent. Les hypothèses sont (1) que l'estuaire du Saint-Laurent possède des souches nitrifiantes fonctionnelles pouvant être performantes à 10°C et 25 psu et (2) que l'augmentation de l'abondance relative des bactéries nitrifiantes, par enrichissement sélectif, induira une activité nitrifiante accrue des consortiums. L'efficacité de la première étape d'enrichissement a été démontrée en étudiant la diversité microbienne des consortiums par métabarcodage (ADNr 16S) avant et après l'enrichissement. Deux genres nitrifiants, Nitrosomonas et Candidatus Nitrotoga, sont ressortis comme étant les principaux nitrifiants après enrichissement dans tous les échantillons de sédiments et d'eau de mer (abondance relative médiane de 10,5% et 11,2%, respectivement). Après les deux dernières étapes d'enrichissement, le consortium (S2F) a atteint un taux de nitrification 2 fois plus élevé qu'un homologue commercial à 10°C et 25 psu. Avec une telle performance, le consortium S2F présente un potentiel commercial intéressant pour la nitrification en eau salée et froide. De plus, cette étude constitue un exemple mettant en évidence le potentiel de valorisation de la biomasse microbienne de l'estuaire du Saint-Laurent dans le domaine des biotechnologies marines et industrielles. -- Mot(s) clé(s) en français : Enrichissement microbien, métabarcodage, nitrification, cycle de l'azote, bactéries oxydant l'ammoniac, archées oxydant l'ammoniac, bactéries oxydant le nitrite, basse température, milieu marin, estuaire du Saint-Laurent. --
ABSTRACT : Nitrification is an essential microbial process from the nitrogen cycle that converts ammonia into nitrate. This biological process is frequently used in the field of industrial biotechnology to remove ammonia from various systems (e.g. aquariums, wastewater treatment plants). The microbial consortia used for these applications, often of terrestrial or freshwater origin, present however a weak nitrification activity at low temperatures and in salty environments. To overcome this limitation, natural consortia evolving in the cold marine environment of the St. Lawrence Estuary (Quebec, Canada) were targeted to then increase their overall nitrifying activity by microbial enrichment in the laboratory. The main objective of this M. Sc. project was to develop a nitrifying consortium from the microbiome of the St. Lawrence Estuary that performs well in salty (25 psu) and low temperature (10°C) waters. It was hypothesized (1) that the St. Lawrence Estuary harbors functional nitrifying strains that can perform well at 10°C and 25 psu and (2) that increasing the relative abundance of the nitrifying bacteria by selective enrichment will induce an increased nitrifying activity of the consortium. The effectiveness of the first enrichment step was demonstrated by studying the microbial diversity of the consortia by metabarcoding (16S rDNA) before and after enrichment. Two nitrifying genera, Nitrosomonas and Candidatus Nitrotoga, emerged as the main nitrifiers after enrichment in all sediment and seawater samples (median relative abundance of 10.5% and 11.2%, respectively). After the last two steps of the enrichment strategy, the S2F consortium achieved a 2-fold higher nitrification rate than a commercial counterpart at 10°C and 25 psu. With such a high performance, the S2F consortium exhibited an interesting commercial potential for nitrification in cold and salty waters. In addition, this study is an example of the potential for valorization of the microbial biomass of the St. Lawrence Estuary in the field of marine and industrial biotechnologies. -- Mot(s) clé(s) en anglais : Microbial enrichment, metabarcoding, nitrification, nitrogen cycle, ammonia-oxidizing bacteria, ammonia-oxidizing archaea, nitrite-oxidizing bacteria, low temperature, marine environment, St. Lawrence Estuary
Estimating Gene Flow between Refuges and Crops: A Case Study of the Biological Control of Eriosoma lanigerum by Aphelinus mali in Apple Orchards
Parasitoid disturbance populations in agroecosystems can be maintained through the provision of habitat refuges with host resources. However, specialized herbivores that feed on different host plants have been shown to form host-specialized races. Parasitoids may subsequently specialize on these herbivore host races and therefore prefer parasitizing insects from the refuge, avoiding foraging on the crop. Evidence is therefore required that parasitoids are able to move between the refuge and the crop and that the refuge is a source of parasitoids, without being an important source of herbivore pests. A North-South transect trough the Chilean Central Valley was sampled, including apple orchards and surrounding Pyracantha coccinea (M. Roem) (Rosales: Rosacea) hedges that were host of Eriosoma lanigerum (Hemiptera: Aphididae), a globally important aphid pest of cultivated apples. At each orchard, aphid colonies were collected and taken back to the laboratory to sample the emerging hymenopteran parasitoid Aphelinus mali (Hymenoptera: Aphelinidae). Aphid and parasitoid individuals were genotyped using species-specific microsatellite loci and genetic variability was assessed. By studying genetic variation, natural geographic barriers of the aphid pest became evident and some evidence for incipient host-plant specialization was found. However, this had no effect on the population-genetic features of its most important parasitoid. In conclusion, the lack of genetic differentiation among the parasitoids suggests the existence of a single large and panmictic population, which could parasite aphids on apple orchards and on P. coccinea hedges. The latter could thus comprise a suitable and putative refuge for parasitoids, which could be used to increase the effectiveness of biological control. Moreover, the strong geographical differentiation of the aphid suggests local reinfestations occur mainly from other apple orchards with only low reinfestation from P. cocinnea hedges. Finally, we propose that the putative refuge could act as a source of parasitoids without being a major source of aphids
Prevalencia de factores de riesgo para síndrome metabólico en pacientes de 45 a 65 años, con diagnóstico de hipertensión arterial crónica en el ECOS-F San Cristobal, San Salvador, en el periodo de Agosto a Noviembre del 2018
En el presente trabajo de investigacion se revisaron los factores de riesgo que
desarrollan el síndrome metabólico en las personas con diagnóstico de
hipertensión arterial cronica, en el rango de edad de 45 a 65 años, que lleven
sus controles en la Unidad Comunitaria de Salud Familiar Básica (UCSFB) San
Cristobal, en el periodo comprendido desde agosto hasta noviembre del año
2018
Dynamic scaling exponents of copper electrodeposits from scanning force microscopy imaging : Influence of a thiourea additive on the kinetics of roughening and brightening
Changes in the topography of Cu electrodeposits grown on polycrystalline Cu substrates at low constant current density from still aqueous concentrated CuSO4 + H2SO4 solutions, at 298 K, were studied by scanning force microscopy (SFM) at different scale lengths (L) from the nanometer level upward. The dynamic scaling theory applied to SFM images leads to exponents α = 0.87 ± 0.06 and β = 0.63 ± 0.08, which are consistent with an interface growing under an unstable regime. For similar conditions, the addition of 1,3-diethyl-2-thiourea reduces the average crystal size (〈ds〉) of electrodeposits leading to scaling exponents α = 0.86 ± 0.06 and β = 0.24 ± 0.05 for L s⟩ and a logarithmic dependence for the spatial and temporal evolution of the interface for L > 3 μm and t → 0. In an additive-free plating bath, the unstable growth regime appears to be originated by enhanced electrodeposition at protrusions due to curvature effects and further sustained by the electric and concentration fields built up around the growing deposit. The presence of the additive hinders the development of instabilities driving the evolution of the growing interface to that predicted by the Edwards-Wilkinson growth model on the asymptotic limit.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta
Dynamic scaling exponents of copper electrodeposits from scanning force microscopy imaging : Influence of a thiourea additive on the kinetics of roughening and brightening
Changes in the topography of Cu electrodeposits grown on polycrystalline Cu substrates at low constant current density from still aqueous concentrated CuSO4 + H2SO4 solutions, at 298 K, were studied by scanning force microscopy (SFM) at different scale lengths (L) from the nanometer level upward. The dynamic scaling theory applied to SFM images leads to exponents α = 0.87 ± 0.06 and β = 0.63 ± 0.08, which are consistent with an interface growing under an unstable regime. For similar conditions, the addition of 1,3-diethyl-2-thiourea reduces the average crystal size (〈ds〉) of electrodeposits leading to scaling exponents α = 0.86 ± 0.06 and β = 0.24 ± 0.05 for L s⟩ and a logarithmic dependence for the spatial and temporal evolution of the interface for L > 3 μm and t → 0. In an additive-free plating bath, the unstable growth regime appears to be originated by enhanced electrodeposition at protrusions due to curvature effects and further sustained by the electric and concentration fields built up around the growing deposit. The presence of the additive hinders the development of instabilities driving the evolution of the growing interface to that predicted by the Edwards-Wilkinson growth model on the asymptotic limit.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta
Lorentzian Lie 3-algebras and their Bagger-Lambert moduli space
We classify Lie 3-algebras possessing an invariant lorentzian inner product. The indecomposable objects are either one-dimensional, simple or in one-to-one correspondence with compact real forms of metric semisimple Lie algebras. We analyse the moduli space of classical vacua of the Bagger-Lambert theory corresponding to these Lie 3-algebras. We establish a one-to-one correspondence between one branch of the moduli space and compact riemannian symmetric spaces. We analyse the asymptotic behaviour of the moduli space and identify a large class of models with moduli branches exhibiting the desired N3/2 behaviour
La enseñanza de la química desde la perspectiva de la Química Verde
Green Chemistry (GC), as a research area, understood as the development of methodologies to modify products or processes in order to reduce or eliminate the risks posed to the environment and human health. Thus it is allowing research project lines in building knowledge and didactic approaches of the sciences, and to be considered as part of the ministerial programs. The objective of this study was to know and understand the significance given by teachers in the area to GC as a perspective for education. From the speeches issued by teachers participating in the study, four categories, was built. GC as: context for teaching chemistry, through significant learning chemistry appropriation, motivating environmental awareness and reflection of the institution and its relationship with teachers.La Química Verde, como área de investigación, se comprende como el desarrollo de metodologías para modificar los productos o procesos con la finalidad de reducir o eliminar los riesgos que existen para el medio ambiente y la salud. De este modo, permite proyectar líneas de investigación en la construcción de un conocimiento y enfoques didácticos de las ciencias, y para ser considerada como parte de los programas Ministeriales. El objetivo del estudio fue conocer y comprender el significado que le otorgan los(as) docentes del área a la Química Verde como perspectiva para su enseñanza. A partir de los discursos emanados por los docentes participantes del estudio, se construyeron 4 categorías, las cuales son: la Química Verde como: contexto para la enseñanza de la química, medio de apropiación significativo del aprendizaje de la química, motivadora de la conciencia ambiental y reflejo de la Institución y su relación con los docentes
Cultivando la educación agroecológica: el huerto colectivo urbano como espacio educativo
The current planetary socioecological crisis and the growing urbanization of human life are interdependent phenomena that impel education to rethink its objectives and processes. The notion of "sustainability" provides a broad framework of construction for activities in teaching, research, and outreach programs. Among the proposals aimed at promoting sustainability, agroecology stands out as a set of integrating practices and theories capable of transforming the productive, sociopolitical, economic, and cultural relations of the food system. Our objective in this article is to present the contributions of urban agroecology and to analyze its connection with education. Following this purpose, we share the experience of Huerto UV, an agroecological education project developed by students and researchers at Universidad Veracruzana, in association with inhabitants of the city of Xalapa, Veracruz.La actual crisis socioecológica planetaria y la creciente urbanización de la vida humana son fenómenos interdependientes que incitan a la educación a repensar sus objetivos y procesos. La noción de "sustentabilidad" provee un amplio marco en construcción para actividades docentes, de investigación y vinculación. Entre otras propuestas orientadas a promover la sustentabilidad, la agroecología se destaca como un conjunto de teorías y prácticas integradoras, capaz de transformar las relaciones productivas, sociopolíticas, económicas y culturales del sistema alimentario. Nuestro objetivo en este artículo es presentar las contribuciones de la agroecología urbana y analizar su conexión con la educación, compartiendo para ello la experiencia de Huerto UV, un proyecto de educación agroecológica desarrollado por estudiantes y profesores de la Universidad Veracruzana en vinculación con habitantes la ciudad de Xalapa, Veracruz, México
Dynamic scaling exponents of copper electrodeposits from scanning force microscopy imaging : Influence of a thiourea additive on the kinetics of roughening and brightening
Changes in the topography of Cu electrodeposits grown on polycrystalline Cu substrates at low constant current density from still aqueous concentrated CuSO4 + H2SO4 solutions, at 298 K, were studied by scanning force microscopy (SFM) at different scale lengths (L) from the nanometer level upward. The dynamic scaling theory applied to SFM images leads to exponents α = 0.87 ± 0.06 and β = 0.63 ± 0.08, which are consistent with an interface growing under an unstable regime. For similar conditions, the addition of 1,3-diethyl-2-thiourea reduces the average crystal size (〈ds〉) of electrodeposits leading to scaling exponents α = 0.86 ± 0.06 and β = 0.24 ± 0.05 for L s⟩ and a logarithmic dependence for the spatial and temporal evolution of the interface for L > 3 μm and t → 0. In an additive-free plating bath, the unstable growth regime appears to be originated by enhanced electrodeposition at protrusions due to curvature effects and further sustained by the electric and concentration fields built up around the growing deposit. The presence of the additive hinders the development of instabilities driving the evolution of the growing interface to that predicted by the Edwards-Wilkinson growth model on the asymptotic limit.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta
Diplomado de profundización en farmacovigilancia
El diplomado de profundización en farmacovigilancia hace parte del campo de formación disciplinar y se realiza como opción de grado para obtener el título de tecnólogo en regencia de farmacia. Para la elaboración de este documento se hace un resumen de los temas de mayor relevancia que se trabajaron a lo largo del curso, donde se obtuvo conocimientos sobre temas de gran importancia para el desempeño como futuros regentes de farmacia ya que no se debe desconocer la importancia de la farmacovigilancia como herramienta para prevenir y disminuir los diferentes problemas asociados al uso de medicamentos y de esta manera reducir los riesgos que se pueden producir por el uso inadecuado de los medicamentos; Algunos de los temas más relevantes fueron las generalidades de la farmacovigilancia, eventos adversos asociados al uso de medicamentos haciendo un reconocimiento de los estos, para de esta manera tratar de prevenirlos; el quehacer del farmacéutico profundizando en la descripción de los procesos del servicio farmacéutico y la relación con la farmacovigilancia y por último se hace un reconocimiento de la evaluación y efectividad de los tratamientos farmacológicos en las enfermedades de mayor incidencia en el país que son la hipertensión arterial, diabetes mellitus, enfermedad renal crónica, enfermedad cerebrovascular y dislipidemia.The in-depth diploma in pharmacovigilance is part of the disciplinary training field and is carried out as a degree option to obtain the title of technologist in pharmacy regency. For the preparation of this document, a summary of the most relevant topics that were worked on throughout the course is made, where knowledge was obtained on topics of great importance for the performance as future pharmacy regents since the importance should not be ignored of pharmacovigilance as a tool to prevent and reduce the different problems associated with the use of drugs and in this way reduce the risks that can be produced by the inappropriate use of drugs; Some of the most relevant topics were the generalities of pharmacovigilance, adverse events associated with the use of drugs, making a recognition of these, in order to try to prevent them; the work of the pharmacist deepening in the description of the processes of the pharmaceutical service and the relationship with pharmacovigilance and finally a recognition is made of the evaluation and effectiveness of pharmacological treatments in the diseases with the highest incidence in the country, which are arterial hypertension , diabetes mellitus, chronic kidney disease, cerebrovascular disease, and dyslipidemia
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