22 research outputs found
Desarrollo de una metodología para aplicar la estructura de control MPC unificada
El último par de décadas ha dado testimonio de un crecimiento en el uso de computadoras para el control avanzado de plantas de proceso. Rápidos incrementos en hardware de computación, combinado con la competencia empresarial y regulaciones gubernamentales han sido principalmente responsables para este desarrollo. El MPC (Propoi, 1963; Rafal y Stevens, 1968; Nour-Eldin, 1971) se llevó a cabo primero en la industria antes de que una comprensión completa de sus propiedades teóricas estuviese disponible. El interés académico en MPC empezó a crecer a mediados de los años ochenta, particularmente después de dos talleres organizados por la Shell (Prett y Morari, 1987; Prett et al., 1990). La comprensión de las propiedades MPC generada por las investigaciones esencialmente académicas (Morari y García, 1982; Rawlings y Muske, 1993) han construido una fuerte estructura conceptual y práctica para practicantes y teóricos. Aunque varios problemas en esa estructura son todavía abiertos, existe una fundamentación fuerte. Este trabajo reúne los elementos académicos, técnicos y administrativos; los funciona con el fin de presentar un punto de vista unificado del como se utiliza en la actualidad en forma integrada la estructura de control MPC. Es un compendio de abstracciones y extractos de libros, artículos y notas de clase que luego de un proceso de selección riguroso permiten formar un documento de primera mano para los interesados en el tema MPC. / Abstract: The last couple of decades has given testimony of a growth in the use of computers for the advanced control of process plants. Quick increments in calculation hardware, cocktail with the managerial competition and government regulations have been mainly responsible for this development. The MPC (Propoi, 1963; Rafal and Stevens, 1968; Nour-Eldin, 1971) it was carried out first in the industry before a complete understanding of its theoretical properties is available. The academic interest in MPC began to grow by the middle of the years eighty, particularly after two shops organized by the Shell (Prett and Morari, 1987; Prett et to the., 1990). The understanding of the properties MPC generated by the essentially academic investigations (Morari and Garc´ıa, 1982; Rawlings and Muske, 1993) they have built a strong conceptual structure and practice for practitioners and theoretical. Although several problems in that structure are still open, a strong foundation exists. This work gathers the academic elements, technicians and administrative; it works them with the purpose of presenting an unified point of view of the like it is used at the present time in integrated form the control structure MPC. It is a summary of abstractions and extracts of books, articles and class notes that allow to form a document first hand for the interested ones in the topic MPC after a rigorous selection process.Maestrí
Competitividad del pollo de engorde
El articulo tiene como objeto reflexionar sobre el capítulo III del trabajo de grado
“COMPETITIVIDAD DEL SECTOR AVÍCOLA COLOMBIANO” de Calle (2018), teniendo
como referencia el conocimiento del autor abordaremos una forma de medir la competitividad de
las empresas, es decir la capacidad que tiene una empresa de hacer las cosas mejor que su
competencia, ya sea en términos de producto, producción, costes o calidad, de acuerdo con sus
características y factores determinados en la región, y así mismo las 4 dimensiones de la
competitividad consideradas por el autor, que son: conocimiento, productiva, económica y
tecnológica. El trabajo de grado tiene como objeto proponer una forma de medir o evaluar la
competitividad del pollo de engorde, en la cual se tengan en cuenta otras variables diferentes al
crecimiento de las ventas, que permitan estimar la capacidad que tienen las empresas del sector
avicola para mantener y aumentar su cuota de mercado.
En vista de la sensibilidad que el sector avícola nacional posee frente a los cambios en la dinámica
de la economía a nivel mundial, es de vital importancia contar con la información certera y oportuna para la toma de decisiones a nivel sectorial, gremial y empresarial, esto con el objetivo
de mejorar la competitividad del sector avícola. Con base en este objetivo es necesario diseñar
herramientas que midan o identifiquen dichas ventajas competitivas, para que los países en vía de
desarrollo como el nuestro creen valor agregado en este sector para posicionar estos productos en
el exterior.
Por motivo de que el mayor rubro de la producción avícola es el alimento, y por consiguiente para
su fabricación es necesario que toda su materia prima (Maíz) sea importada principalmente de
Estados Unidos, se limita la competitividad, debido a que para muchas empresas no es sostenible
la tasa cambiaria.Universidad Libre Seccional Pereira -- Facultad de Ciencias Económicas, Administrativas y Contables -- Especialización en Planeación y Gestión EstratégicaThe article aims to reflect on chapter III of the degree work "COMPETITIVENESS OF THE
COLOMBIAN POULTRY SECTOR" by Calle (2018), having as reference the author's knowledge we will
address a way to measure the competitiveness of companies, that is, the ability of a company to do things
better than its competition, either in terms of product, production, costs or quality, according to its
characteristics and factors determined in the region, and likewise the 4 dimensions of competitiveness
considered by the author, which are: knowledge, productive, economic and technological. The purpose of
this work is to propose a way to measure or evaluate the competitiveness of broiler chicken, in which other
variables different from sales growth are taken into account, which allow estimating the capacity of the
companies in the poultry sector to maintain and increase their market share. In view of the sensitivity of the national poultry sector to changes in the dynamics of the world economy, it
is of vital importance to have accurate and timely information for decision making at the sector, guild and
business levels, with the objective of improving the competitiveness of the poultry sector. Based on this
objective, it is necessary to design tools that measure or identify these competitive advantages, so that
developing countries such as ours can create added value in this sector to position these products abroad.
Because the main item of poultry production is feed, and therefore for its manufacture it is necessary that
all its raw material (corn) is imported mainly from the United States, competitiveness is limited, because for
many companies the exchange rate is not sustainable
When a discriminating dose assay is not enough: measuring the intensity of insecticide resistance in malaria vectors
Background
Guidelines from the World Health Organization for monitoring insecticide resistance in disease vectors recommend exposing insects to a predetermined discriminating dose of insecticide and recording the percentage mortality in the population. This standardized methodology has been widely adopted for malaria vectors and has provided valuable data on the spread and prevalence of resistance. However, understanding the potential impact of this resistance on malaria control requires a more quantitative measure of the strength or intensity of this resistance.
Methods
Bioassays were adapted to quantify the level of resistance to permethrin in laboratory colonies and field populations of Anopheles gambiae sensu lato. WHO susceptibility tube assays were used to produce data on mortality versus exposure time and CDC bottle bioassays were used to generate dose response data sets. A modified version of the CDC bottle bioassay, known as the Resistance Intensity Rapid Diagnostic Test (I-RDT), was also used to measure the knockdown and mortality after exposure to different multipliers of the diagnostic dose. Finally cone bioassays were used to assess mortality after exposure to insecticide treated nets.
Results
The time response assays were simple to perform but not suitable for highly resistant populations. After initial problems with stability of insecticide and bottle washing were resolved, the CDC bottle bioassay provided a reproducible, quantitative measure of resistance but there were challenges performing this under field conditions. The I-RDT was simple to perform and interpret although the end point selected (immediate knockdown versus 24 h mortality) could dramatically affect the interpretation of the data. The utility of the cone bioassays was dependent on net type and thus appropriate controls are needed to interpret the operational significance of these data sets.
Conclusions
Incorporating quantitative measures of resistance strength, and utilizing bioassays with field doses of insecticides, will help interpret the possible impact of resistance on vector control activities. Each method tested had different benefits and challenges and agreement on a common methodology would be beneficial so that data are generated in a standardized format. This type of quantitative data are an important prerequisite to linking resistance strength to epidemiological outcomes
Pyriproxyfen is metabolized by P450s associated with pyrethroid resistance in An. gambiae.
Pyrethroid resistance is widespread in the malaria vector Anopheles gambiae leading to concerns about the future efficacy of bednets with pyrethroids as the sole active ingredient. The incorporation of pyriproxyfen (PPF), a juvenile hormone analogue, into pyrethroid treated bednets is being trialed in Africa. Pyrethroid resistance is commonly associated with elevated levels of P450 expression including CYPs 6M2, 6P2, 6P3, 6P4, 6P5, 6Z2 and 9J5. Having expressed these P450s in E. coli we find all are capable of metabolizing PPF. Inhibition of these P450s by permethrin, deltamethrin and PPF was also examined. Deltamethrin and permethrin were moderate inhibitors (IC50 1-10 μM) of diethoxyfluorescein (DEF) activity for all P450s apart from CYP6Z2 (IC50 > 10 μM), while PPF displayed weaker inhibition of all P450s (IC50 > 10 μM) except CYP's 6Z2 and 6P2 (IC50 1-10 μM). We found evidence of low levels of cross resistance between PPF and other insecticide classes by comparing the efficacy of PPF in inhibiting metamorphosis and inducing female sterility in an insecticide susceptible strain of An. gambiae and a multiple resistant strain from Cote d'Ivoire
Diferenciación genética de tres poblaciones colombianas de Triatoma dimidiata (Latreille, 1811) mediante análisis molecular del gen mitocondrial ND4
Introduction. Triatoma dimidiata is the second most important vector of Chagas disease in Colombia after Rhodnius prolixus. Population genetic studies are essential for the adequate design and implementation of vector control and surveillance strategies.Objective. The level of genetic variability and population differentiation was surveyed among three Colombian populations of T. dimidiata from different geographic locations and ecotopes, using ND4 mitochondrial gene.Materials and methods. Genetic comparison was made between two wild populations from La Guajira (n=10) and Santander (n=10) provinces, and one intra (n=15) and one peridomiciliary (n=5) population from the Cesar province. The polymorphism frequencies of the ND4 mitochondrial gene sequence were analyzed to deduce population structure based on the 40 samples.Results. Colombian T. dimidiata showed a high nucleotide (π: 0.034) and haplotype diversity (Hd: 0.863), as well as significant population subdivision (fST: 0.761) and a low migration rate (Nm: 0.157).Genetic distances and variability differences among populations indicate distinct population subdivision amongst the three provinces.Conclusion. ND4 proved useful in elucidating the significant genetic differentiation that has occurred among T. dimidiata populations from La Guajira, Cesar and Santander. The analysis suggested a relationship between population subdivision and some eco-epidemiological attributes of this vector from the central eastern and northwestern regions of Colombia.Introducción. Triatoma dimidiata es el segundo vector más importante de la enfermedad de Chagas en Colombia, después de Rhodnius prolixus. El conocimiento de la composición genética y la diferenciación de poblaciones es fundamental para el adecuado diseño e implementación de estrategias de control y vigilancia vectorial.Objetivo. Determinar el nivel de variabilidad y diferenciación genética en tres poblaciones colombianas de T. dimidiata provenientes de distintas localidades y hábitats, mediante el análisis molecular de un fragmento del gen mitocondrial ND4.Materiales y métodos. Se analizó el nivel de polimorfismo y la estructura genética de dos poblaciones silvestres de los departamentos de La Guajira (n=10) y Santander (n=10), y de una población intradomiciliaria (n=15) y peridomiciliaria (n=5) del Cesar. Para tal fin, se analizaron las secuencias de nucleótidos de un fragmento del gen mitocondrial ND4.Resultados. T. dimidiata en Colombia demostró tener gran diversidad genética, tanto a nivel de nucleótidos (π: 0,034) como de haplotipo (Hd: 0,863), además de una significativa estructuración de población (fST: 0,761) con un bajo número de migrantes (Nm: 0,157). Las distancias genéticas y las diferencias en los niveles de variabilidad genética entre las tres poblaciones fueron coherentes con una posible subdivisión de población.Conclusión. Este trabajo demostró diferenciación genética entre las poblaciones de T. dimidiata de La Guajira, Cesar y Santander. Se sugiere una posible relación entre tal subdivisión y algunas características eco-epidemiológicas que posee T. dimidiata en el centro-oriente y en el norte de Colombia. Finalmente, este trabajo describe, por primera vez, la utilidad del ND4 como un marcador molecular para el estudio de poblaciones naturales de T. dimidiata
Efficacy of Olyset Duo, a bednet containing pyriproxyfen and permethrin, versus a permethrin-only net against clinical malaria in an area with highly pyrethroid-resistant vectors in rural Burkina Faso: a cluster-randomised controlled trial
Background Substantial reductions in malaria incidence in sub-Saharan Africa have been achieved with massive deployment of long-lasting insecticidal nets (LLINs), but pyrethroid resistance threatens control. Burkina Faso is an area with intense malaria transmission and highly pyrethroid-resistant vectors. We assessed the effectiveness of bednets containing permethrin, a pyrethroid, and pyriproxyfen, an insect growth regulator, versus permethrin-only (standard) LLINs against clinical malaria in children younger than 5 years in Banfora, Burkina Faso. Methods In this two-group, step-wedge, cluster-randomised, controlled, superiority trial, standard LLINs were incrementally replaced with LLINs treated with permethrin plus pyriproxyfen (PPF) in 40 rural clusters in Burkina Faso. In each cluster, 50 children (aged 6 months to 5 years) were followed up by passive case detection for clinical malaria. Cross-sectional surveys were done at the start and the end of the transmission seasons in 2014 and 2015. We did monthly collections from indoor light traps to estimate vector densities. Primary endpoints were the incidence of clinical malaria, measured by passive case detection, and the entomological inoculation rate. Analyses were adjusted for clustering and for month and health centre. This trial is registered as ISRCTN21853394. Findings 1980 children were enrolled in the cohort in 2014 and 2157 in 2015. At the end of the study, more than 99% of children slept under a bednet. The incidence of clinical malaria was 2·0 episodes per child-year in the standard LLIN group and 1·5 episodes per child-year in the PPF-treated LLIN group (incidence rate ratio 0·88 [95% CI 0·77–0·99; p=0·04]). The entomological inoculation rate was 85 (95% CI 63–108) infective bites per transmission season in the standard LLIN group versus 42 (32–52) infective bites per transmission season in the PPF-treated LLIN group (rate ratio 0·49, 95% CI 0·32–0·66; p<0·0001). Interpretation PPF-treated LLINs provide greater protection against clinical malaria than do standard LLINs and could be used as an alternative to standard LLINs in areas with intense transmission of Plasmodium falciparum malaria and highly pyrethroid-resistant vectors. Funding EU Seventh Framework Programme
A high throughput multi-locus insecticide resistance marker panel for tracking resistance emergence and spread in Anopheles gambiae
The spread of resistance to insecticides in disease-carrying mosquitoes poses a threat to the effectiveness of control programmes, which rely largely on insecticide-based interventions. Monitoring mosquito populations is essential, but obtaining phenotypic measurements of resistance is laborious and error-prone. High-throughput genotyping offers the prospect of quick and repeatable estimates of resistance, while also allowing resistance markers to be tracked and studied. To demonstrate the potential of highly-mulitplexed genotypic screening for measuring resistance-association of mutations and tracking their spread, we developed a panel of 28 known or putative resistance markers in the major malaria vector Anopheles gambiae, which we used to screen mosquitoes from a wide swathe of Sub-Saharan Africa (Burkina Faso, Ghana, Democratic Republic of Congo (DRC) and Kenya). We found resistance association in four markers, including a novel mutation in the detoxification gene Gste2 (Gste2-119V). We also identified a duplication in Gste2 combining a resistance-associated mutation with its wild-type counterpart, potentially alleviating the costs of resistance. Finally, we describe the distribution of the multiple origins of kdr resistance, finding unprecedented diversity in the DRC. This panel represents the first step towards a quantitative genotypic model of insecticide resistance that can be used to predict resistance status in An. gambiae
Temephos Resistance in Aedes aegypti in Colombia Compromises Dengue Vector Control
Background
Control and prevention of dengue relies heavily on the application of insecticides to control dengue vector mosquitoes. In Colombia, application of the larvicide temephos to the aquatic breeding sites of Aedes aegypti is a key part of the dengue control strategy. Resistance to temephos was recently detected in the dengue-endemic city of Cucuta, leading to questions about its efficacy as a control tool. Here, we characterize the underlying mechanisms and estimate the operational impact of this resistance.
Methodology/Principal Findings
Larval bioassays of Ae. aegypti larvae from Cucuta determined the temephos LC50 to be 0.066 ppm (95% CI 0.06–0.074), approximately 15× higher than the value obtained from a susceptible laboratory colony. The efficacy of the field dose of temephos at killing this resistant Cucuta population was greatly reduced, with mortality rates <80% two weeks after application and <50% after 4 weeks. Neither biochemical assays nor partial sequencing of the ace-1 gene implicated target site resistance as the primary resistance mechanism. Synergism assays and microarray analysis suggested that metabolic mechanisms were most likely responsible for the temephos resistance. Interestingly, although the greatest synergism was observed with the carboxylesterase inhibitor, DEF, the primary candidate genes from the microarray analysis, and confirmed by quantitative PCR, were cytochrome P450 oxidases, notably CYP6N12, CYP6F3 and CYP6M11.
Conclusions/Significance
In Colombia, resistance to temephos in Ae. aegypti compromises the duration of its effect as a vector control tool. Several candidate genes potentially responsible for metabolic resistance to temephos were identified. Given the limited number of insecticides that are approved for vector control, future chemical-based control strategies should take into account the mechanisms underlying the resistance to discern which insecticides would likely lead to the greatest control efficacy while minimizing further selection of resistant phenotypes
Elaboración de propuesta para realizar la construcción del proyecto de vivienda urbanización Santa Ana en el municipio el retorno, Antioquia.
Para la ejecución de este trabajo se tuvo en cuenta lo aprendido en el seminario taller “LICITACIONES Y CONTRATACIÓN”, aplicado al proyecto “Urbanización Santa Ana”, ubicada en el municipio El Retorno, en Antioquia. De acuerdo con las instrucciones dadas en el seminario se procedió de la siguiente manera: Basados en los planos tanto arquitectónicos como estructurales se calcularon las cantidades de obra, actividades, precios, el análisis de precios unitarios (APU), los sub análisis, la programación, utilizando el programa Microsoft Project, versión 2010 y el costo final del proyecto.
El resultado está plasmado en la ejecución a través de etapas bien definidas, de la obra en cuestión, teniendo una secuencia lógica de cada una de las fases de construcción del proyecto, su programación y el presupuesto real, que sirve como base para la licitación pública, de acuerdo con la normativa vigente en Colombia.Glosario. --
Resumen. --
Abstract. --
Introducción. --
1. Planteamiento del problema. --
1.1 Descripción de la obra. --
1.1.1 Diseño arquitectónico. --
1.2 Necesidad existente. --
1.3 Localización de la obra. --
2. Justificación. --
3. Objetivos. --
3.1 Objetivo general del proyecto. --
3.2 Objetivos específicos. --
4. Marco teórico. --
4.1 Licitación pública. --
4.2 Antecedentes de ley. --
4.3 Normatividad jurídica de la contratación estatal. --
4.3.1 Constitución política de Colombia. --
4.3.2 Leyes, decretos y normas que se articulan con los objetivos de la ley 80 de 1993 y la ley 1150 de 2007. --
4.4 Descripción del proceso de contratación pública a través de licitaciones y concursos públicos. --
4.4.1 Iniciación del proceso. --
4.4.2 Conveniencia de la contratación. --
4.4.3 Elaboración de estudios técnicos. --
4.4.4 Disponibilidad presupuestal. --
4.4.5 Información a la cámara de comercio. --
4.4.6 Elaboración de los pliegos de condiciones o términos de referencia por parte de la entidad contratante. --
4.4.7 Publicación de la información. --
4.4.8 Publicación de observaciones. --
4.4.9 Desarrollo del proceso. --
4.4.10 Apertura. --
4.4.11 Plazo de la licitación. --
4.4.12 Conformación dinámica de la oferta. --
4.4.13 Audiencia de aclaración. --
4.4.14 Presentación de las propuestas. --
4.4.15 Evaluación de propuestas. --
4.4.16 Finalización del proceso. --
5. Metodología. --
5.1 Consecución de un proyecto. --
5.2 Cantidades de obra. --
5.3 Cotizaciones y listas de precios. --
5.4 Programación en microsoft Project. --
5.5 Pliego de condiciones. --
6. Impacto. --
7. Conclusiones. --
8. Recomendaciones. --
Bibliografía. --
Cibergrafía. -
Temephos resistance in Aedes aegypti in Colombia compromises dengue vector control. PLoS Negl Trop Dis 7: e2438
Abstract Background: Control and prevention of dengue relies heavily on the application of insecticides to control dengue vector mosquitoes. In Colombia, application of the larvicide temephos to the aquatic breeding sites of Aedes aegypti is a key part of the dengue control strategy. Resistance to temephos was recently detected in the dengue-endemic city of Cucuta, leading to questions about its efficacy as a control tool. Here, we characterize the underlying mechanisms and estimate the operational impact of this resistance