68 research outputs found
Priorización de despachos con AHP difuso y Topsis
Context: The organizations present a limitation in resources when making finished product shipments from the product centers to the areas of consumption. This limitation makes it important to clearly define priorities so that those resources can be used efficiently and ensure high levels of customer satisfaction.Method: We developed a proposal to prioritize the shipments of finished product from a distribution center to n warehouses. It involves the diffuse AHP and Topsis multi-criteria tools. The diffuse Fuzzy AHP tool allows defining a series of important criteria when making the dispatches. Additionally, it allows weighing these criteria since not all have the same importance when making the decision. Finally, we used Topsis to generate a ranking that allows us to establish the priority of dispatches, considering that each destination warehouse has different values for those criteria.Results: The proposed methodology was applied to a case study. We found that it prioritizes the dispatches so that the most important warehouses, according to the set of established criteria, are the first to be met.Conclusions: The proposed methodology can be replicated in different contexts and for any organization as long as there are people involved and the objectives of the of the company are clear.Contexto: La limitación de recursos en las organizaciones a la hora de realizar los despachos de producto terminado, desde los centros de producción hacia las zonas de consumo, hace que sea importante definir con claridad las prioridades, de manera que dichos recursos puedan utilizarse eficientemente y garanticen los más altos niveles de satisfacción a los clientes. Método: En este sentido, se ha desarrollado una propuesta para priorizar los despachos de producto terminado desde un centro de distribución hacia n bodegas que involucra las herramientas multicriterio AHP difuso y Topsis. La propuesta permite definir una serie de criterios a considerar a la hora de realizar los despachos y, mediante la herramienta AHP difuso, ponderar dichos criterios dado que no todos tienen la misma importancia a la hora de tomar la decisión. Por otro lado y considerando que cada punto de destino posee unos valores diferentes de dichos indicadores se utiliza el Topsis para generar un ranking que permita establecer la prioridad a la hora de los despachos.Resultado: La metodología propuesta ha sido aplicada en un caso de estudio y se ha encontrado que permite realizar la priorización de los despachos de manera que las bodegas más importantes, según el conjunto de criterios establecidos, son las primeras que deben ser atendidas.Conclusiones: Esta metodología puede ser replicable a cualquier organización siempre y cuando se cuente con las personas involucradas y la claridad frente a los objetivos organizacionales de la compañía
Relatório de condições sistemáticas de pacientes adultos. : Faculdade de Odontologia, Universidade de Antioquia, 2011
Introduction: The goal of this research project was to determine the prevalence and concordance of reports of a group of systemic conditions by means of Dental/Medical Records (mrs) and telephonic surveys (TS) in patients consulting at two adults’ clinics at the Faculty of Dentistry of the University of Antioquia.
Methods: Cross-sectional study (n = 104). We evaluated clinical records and registered the 10 most frequent systemic diseases according to the epidemiological data in Medellin (Colombia). We used TS to corroborate previous information on the mrs. We measured the prevalence of the diseases and determined a concordance level between the results of mr and ts through a kappa index with a 95% confidence interval (95%CI); according to different variables.
Results: The most prevalent systemic disease was ocular disease (58% ts and 30% mr, statistically significant p < 0.001) and the less prevalent one was hyperthyroidism (3% mr and 5% ts, no statistically significant). Kappa analyses showed the weakest concordance in the case of hyperthyroidism (0.22; 95%CI -0.38-0.82) and in case of ocular disease (0.37; 95%ci 0.20- 0.72). Variability in the prevalence and kappa indexes was observed related to gender, type of clinic and age interval.
Conclusions: Variations in the reported prevalence between the mr and ts were found. This situation may be explained as originating in difficulties completing medical antecedents, which cause an underreporting in the MR.Introducción: el objetivo de esta investigación fue determinar la prevalencia y la concordancia en el reporte de condiciones sistémicas entre la historia clínica odontológica (hc) y la entrevista telefónica (et), en los pacientes que asisten a dos clínicas del adulto de la Facultad de Odontología de la Universidad de Antioquia.
Métodos: estudio transversal (n = 104). Se evaluaron las hc y se registraron las diez condiciones sistémicas más frecuentes según registros epidemiológicos de Medellín. Se realizó et para verificar información de las hc. Se calcularon prevalencias y el nivel de concordancia entre resultados de la hc y la et mediante el índice kappa y su intervalo de confianza al 95% (ic95%), según variables.
Resultados: la condición sistémica más prevalente fue la enfermedad ocular (58% según et y 30% según hc y diferencias significativas p < 0,001), y la menos prevalente fue el hipertiroidismo (3% según hc y 5% según et, sin diferencias significativas). El análisis kappa mostró que las concordancias más débiles se presentaron para el hipertiroidismo (0,22; ic95%-0,38-0,82) y la enfermedad ocular (0,37; ic95% 0,20-0,72). Se evidenciaron variaciones en los índices de concordancia de acuerdo con sexo, clínica y edad.
Conclusiones: existen variaciones en las prevalencias reportadas por hc y por et debidas a dificultades a la hora de diligenciar los antecedentes médicos personales, que produjeron un subregistro en la hc.
Introdução: o objetivo desta pesquisa foi determinar a prevalência e a concordância no relatório de condições sistêmicas entre o prontuário médico odontológico e a entrevista telefônica (et) nos pacientes que vão a duas clínicas do adulto da Faculdade de Odontologia da Universidade de Antioquia.
Métodos: estudo transversal (n = 104). Avaliaram-se os prontuários e se registraram as dez condições sistêmicas mais frequentes segundo registros epidemiológicos de Medellín. Realizou-se et para verificar informação dos prontuários. Calcularam-se prevalências e o nível de concordância entre resultados do prontuário e da et mediante o índice kappa e seu intervalo de confiança a 95% (ic95%), segundo variáveis.
Resultados: a condição sistêmica mais prevalente foi a doença ocular (58% segundo et e 30% segundo prontuários e diferenças significativas p < 0,001), e a menos prevalente foi o hipertireoidismo (3% segundo prontuários e 5% segundo et, sem diferenças significativas). A análise kappa mostrou que as concordâncias mais fracas se apresentaram para o hipertireoidismo (0,22; ic95%-0,38-0,82) e a doença ocular (0,37; ic95%0,20-0,72). Evidenciaram- se variações nos índices de concordância de acordo com sexo, clínica e idade.
Conclusões: existem variações nas prevalências relatadas pelo prontuário e pela et devidas a dificuldades na hora de diligenciar os antecedentes médicos pessoais, que produziram um sub-registro no prontuário
Aproximaciones contextuales sobre el devenir de las revistas contables colombianas:Perspectivas plurales de los editores
Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates
Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis).
Time period: Tree-inventory plots established between 1934 and 2019.
Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm.
Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield.
Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes.
Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests.
Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.
Location: Amazonia.
Taxon: Angiosperms (Magnoliids; Monocots; Eudicots).
Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.
Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.
Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Mapping density, diversity and species-richness of the Amazon tree flora
Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
Consistent patterns of common species across tropical tree communities
Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe
Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology
In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics
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