The incision of major Amazonian white-water rivers, driven by Andean uplift, shaped regional hydrological systems and generated distinct terrace levels above the Caquetá-Japurá floodplains during the upper Pleniglacial period. On poorly drained low terraces (PDLT), flooded by rainfall and secondary watercourses, diverse swamp forest types developed that remain poorly understood in western Amazonia. We aimed to identify and characterize these forest types by evaluating alpha diversity, vegetation structure, and their relationships with edaphic conditions. Tree height and diameter at breast height, together with 16 soil variables, were measured in 30 plots distributed along four transects. Taxonomic and phylogenetic beta diversity between PDLT forest types and adjacent várzea and terra firme forests were also assessed. Hierarchical cluster analysis identified four forest types: paleo-várzea, Mauritia-dominated, igapó, and transitional forests toward white-sand systems. Ordination analyses showed that floristic composition varied along gradients of species diversity and dominance and was strongly associated with a transition from organic to mineral soils and from phosphorus-rich organic to aluminum-rich mineral soils. Floristic composition was significantly correlated with soil properties and geographic position. High taxonomic and phylogenetic beta diversity revealed pronounced species turnover between PDLT forests and adjacent várzea and terra firme forests, driven primarily by edaphic and hydrological gradients and stronger evolutionary affinities between PDLT and várzea forests than with terra firme forests. Our results show that fine-scale edaphic heterogeneity and long-term hydrological dynamics, rather than geographic proximity alone, play a central role in structuring forest communities and maintaining the exceptional biodiversity of western Amazonia.

QuestionsThe fluvial dynamics of meandering white-water rivers of Amazonia drive vegetation primary succession. Directional successional processes have been recorded for the seasonal varzea forests that occupy well-drained soils on levees and point bars across the spatial gradient of the flood-plains. However, the types of forests occupying the swampy depressions interspersed between the point bars and their distribution along the flood-plain's spatial gradient are poorly understood. Here, we aimed to unravel the spatial patterns of swamp forests along the sequence defined by an axis perpendicular to the river and the relationship with edaphic and spatial factors.LocationThe flood-plains of the middle Caqueta River basin, Colombian Amazonia.MethodsForest types were identified by cluster analysis performed on 42 square plots (33 m x 33 m) set in poorly drained depressions of the flood-plain. Floristic composition and vegetation structure as response data, and edaphic and spatial variables as predictors, were analyzed through partial redundancy analysis (pRDA). The effect of geographic position was included by using the first two axes of a principal coordinates of neighbor matrix analysis as conditional factors in the pRDA.ResultsThe three identified swamp forest types were not arranged along a directional spatial pattern. Permanent varzea forests, closest to the river, showed the greatest diversity and alluvial sediment input. Oxandrales, furthest from the river, dominated by Oxandra polyantha, showed the greatest tree density, basal area and soil sand content, and received additional flooding from black-water streams. Cananguchales, dominated by Mauritia flexuosa, exhibited the highest dominance and soil organic matter layer thickness. Distribution of the permanent varzea and oxandrales was relatively constrained by the distance to the river, whereas that of the cananguchales was not.ConclusionsFlooding dynamics delay vegetation development of the swamp forests in permanent varzea and oxandrales. Cananguchales keep accumulating organic matter, becoming ombrotrophic peats after isolation from the river flooding influence. The swamp forests across these flood-plains are far from being arranged along a linear sequence. We identified three types of swamp forests across the flood-plains of the Caqueta River: permanent varzea, oxandrales and cananguchales. These forests showed successional patterns dissociated from their position relative to the main river channel. Still, they seemed more influenced by the interaction of floodings, sediment and nutrients input from white-water and/or black-water rivers, and peat accumulation.image

Magnetite nanoparticles (MNPs), with their distinct properties and controllability by using magnetic fields, have secured a central position in various industrial applications. Nevertheless, the surging demand for MNPs necessitates a meticulous examination of the sustainability of their production processes. This study embarks on a comprehensive evaluation of four case studies associated with the large-scale production of MNPs, specifically focused on environmental, economic, and exergy aspects. Our environmental assessment, employing life cycle assessment, revealed that the MNPs production using microfluidic devices (Case Study 4) showcased a promising environmental footprint. With the lowest electricity impact constituting only 8% of the overall environmental impact, it substantiates the efficacy of microfluidic devices in mitigating ecological repercussions. Economic analysis further reinforced the sustainability of Case Study 4. They exhibited superior financial viability, boasting a net present value of US$ 28,033,346, a modified internal rate of return of 19.73%, and a benefit-cost ratio of US$ 2.07. These figures underscore the economic robustness of this production methodology, suggesting an enticing prospect for large-scale MNP manufacturers. Finally, our exergetic evaluation demonstrated that Case Study 4 exhibited the least total exergy destruction, thereby displaying a superior thermodynamic efficiency. In summary, this study indicates that the adoption of microfluidic devices in MNPs production significantly enhances the environmental performance, economic feasibility, and energy utilization. These findings offer vital insights for those seeking to balance the demands of industrial production with sustainability objectives.

The extent to which historical dispersal, environmental features and geographical barriers shape the phylogenetic structure and turnover of tree communities in northwestern Amazonia at multiple spatial scales remains poorly understood. We used 85 floristically standardized 0.1-ha plots (DBH >= 2.5 cm) distributed in three subregions of northwestern (NW) Amazonia across three main habitat types (floodplain, swamp and terra firme forests) to hypothesize that (a) historical dispersal overcome geographical barriers, which meant low local phylogenetic relatedness and low phylogenetic turnover. (b) Geographical barriers triggered dispersal limitation, causing high local and subregional phylogenetic clustering and high regional phylogenetic turnover. (c) Edaphic properties and flooding were negatively associated with stem size and determined the tree phylogenetic structure and turnover at local and regional scales in Amazon forests. We found that the extent to which environmental or evolutionary features shaped the phylogenetic structure and phylogenetic similarity of tree communities in NW Amazonia was scale dependent. Specifically, we show that the relative importance of environmental factors increases as spatial scale and species pool decreases. Furthermore, we find that these results are generally robust for both adult and juvenile trees. Synthesis. Our analysis at the regional (NW Amazon) scale lends support to the idea of Amazonian forests as a large meta-community primarily structured by historical dispersal at large spatial scales with an increasing importance of environmental factors at finer spatial scales. The convergence of ancestral lineages across habitat types may have been due to the relatively recent formation of geographical barriers that promoted local isolation and allopatric speciation.

The forests of Amazonia are among the most biodiverse plant communities on Earth. Given the immediate threats posed by climate and land-use change, an improved understanding of how this extraordinary biodiversity is spatially organized is urgently required to develop effective conservation strategies. Most Amazonian tree species are extremely rare but a few are common across the region. Indeed, just 227 ‘hyperdominant’ species account for >50% of all individuals >10 cm diameter at 1.3 m in height. Yet, the degree to which the phenomenon of hyperdominance is sensitive to tree size, the extent to which the composition of dominant species changes with size class and how evolutionary history constrains tree hyperdominance, all remain unknown. Here, we use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, midstory and canopy. We further find that, although species belonging to a range of phylogenetically dispersed lineages have become hyperdominant in small size classes, hyperdominants in large size classes are restricted to a few lineages. Our results demonstrate that it is essential to consider all forest strata to understand regional patterns of dominance and composition in Amazonia. More generally, through the lens of 654 hyperdominant species, we outline a tractable pathway for understanding the functioning of half of Amazonian forests across vertical strata and geographical locations.

Sin duda, la frontera entre Estados Unidos y México es un espacio territorial de la mayor relevancia en la geopolítica en América. En este artículo se hace una mirada a esta frontera desde la perspectiva de los imaginarios, los medios y el arte, que complemente aquella centrada en la geopolítica, que es la manera en que tradicionalmente se ha estudiado. Se indaga en la percepción de los ciudadanos de frontera, particularmente en los que habitan en El Paso, Texas, y en Ciudad Juárez, México, con el objetivo de ubicar los imaginarios que tienen sobre este territorio de separación y de encuentro de manera simultánea, y en espacial sobre tres objetos que definen esta frontera: el muro, el río Bravo y el desierto. Asimismo, se analizan diversas producciones artísticas y mediáticas para ampliar la perspectiva de configuración de los imaginarios fronterizos.

Objetivo. Determinar la presencia de anticuerpos anti-Mycobacterium avium subsp. paratuberculosis (MAP) en venados de cola blanca (Odocoileus virginianus) y venados de páramo (Mazama rufina), capturados en las regiones de la Orinoquía y el Caribe de Colombia. Materiales y métodos. Un total de 44 muestras de suero sanguíneo de venados de las especies M. rufina y O. virginianus fueron colectadas en condiciones de campo entre 2014 y 2016. Se utilizó un kit comercial de ELISA para la detección de anticuerpos anti-MAP. Un animal se consideró positivo a ELISA cuando la relación muestra-positivo (S/P%) fue ≥0.4, según lo recomendado por el fabricante. Resultados. El 50% (22/44) de los animales muestreados resultaron positivos, lo que corresponde a 10 hembras y 12 machos. Un 81.8% (18/22) y 77.3% (17/22) de estos animales seropositivos fueron capturados en la región de la Orinoquía y fueron reportados como adultos, respectivamente. Conclusiones. No se sabe cómo o cuándo se introdujo MAP en la población de ciervos colombianos en las regiones de estudio. La hipótesis más plausible para explicar la presencia de anticuerpos anti-MAP en estas poblaciones silvestres es la transmisión por contacto con el ganado bovino infectado, ya que en ambas regiones estas especies comparten pasturas. Este es el primer estudio en explorar la infección por MAP en animales silvestres en Colombia. Estos hallazgos respaldan la necesidad de realizar más estudios utilizando técnicas de diagnóstico directo, y aproximaciones investigativas que permitan la definición de vínculos en la dinámica de la infección entre mamíferos silvestres y domésticos en Colombia.

Objective. To determine the presence of anti-Mycobacterium avium subsp. paratuberculosis (MAP) antibodies in white-tailed deer (Odocoileus virginianus) and red brocket deer (Mazama rufina), captured in the Orinoquia and Caribbean regions in Colombia. Materials and methods. A total of 44 blood serum samples from deer of species M. rufina and O. virginianus were collected under field conditions between 2014 and 2016. An ELISA commercial kit was used to detect anti-MAP antibodies. An animal was considered ELISA-positive at a sample-to-positive ratio (S/P%) of >= 0.4, as recommended by the manufacturer. Results. The 50% (22/44) of the animals were positive, corresponding to 10 females and 12 males. An 81.8% (18/22) and 77.3% (17/22) of these seropositive animals were captured in the Orinoquia region and were reported as adults, respectively. Conclusions. It is not known how or when MAP was introduced in the Colombian deer population in the study regions. The most plausible hypothesis to explain the presence of antibodies against MAP in these wild populations is transmission by contact with infected bovine cattle since, in both regions, these species share pastures. This is the first study to explore MAP infection in wild animals in Colombia. These findings support the need for further studies using different direct diagnostic techniques and research approaches that allow the definition of links in the infection dynamics between wild and domestic mammals in Colombia.

The use of established technologies such as synchrophasor measurement and the use of emerging technologies such as Real-Time Digital Simulators -RTS- are gaining relevance in the design and testing of applications associated with the protection of power networks from a systemic point of view. This paper introduces the reasons that led to the decision to renew the Special Protection Scheme -SPS- in charge of separating the Colombian and Ecuadorian power networks in the presence of conditions that threaten the stability of either system. A brief history of the use of synchrophasor measurement in Colombia and several success cases in the implementation of PMU-based SPS worldwide are also given. The proposed protection functions implemented in the new SPS and a novel platform for testing SPS based on the use of Real-Time Digital Systems -RTS- in a Hardware in the Loop scheme -HIL- are described. Finally, lessons learned and conclusions are given.

The Synchrophasor initiative in Colombia, led by the Colombian Electric Power System Operator XM, has deployed a Wide Area Measurement System (WAMS) aimed to increase the supervision capabilities, promote new automatic control/protection schemes and improve situational awareness. Currently there are over 120 phasor measurement units (PMU) installed across the country, all of them integrated to the National Control Center (CND by its Spanish name). As the energetic transition of the country continues, several changes in the regulatory framework will take place in the short term, and as a consequence it is expected that in the next five years about 2000 new PMU will be deployed in substations, conventional power generators and renewable energy resources. The continuously growing amount of data produced by the WAMS compared with the traditional approach poses new challenges from the point of view of signal processing, data management and network infrastructure. Since 2008, XM has conceptualized and implemented a communications network dedicated to information traffic associated with the operation of the national electricity grid, mainly synchrophasors. iSAACnet, as it is known, works under the publisher / subscriber paradigm, in which information flows on a data bus and each node can produce or consume information on demand, with the particularity that in iSAACnet each node is an intelligent decision device (iDD) capable of performing advanced processing and serve as multiprotocol gateway. iSAACnet is currently composed of six nodes distributed in substations, the data bus is backed by a multiprotocol label switching (MPLS) network. This paper reviews the history of the use of synchrophasor measurements in Colombia, and shares the efforts that XM has made to achieve in the short term having a scalable communications network oriented to the management and processing of information associated to the national grid operation.

We studied the floristic composition of palm communities and their relation with soil nutrients in two localities of the Chocó biogeographic region to undestand (1) How soil nutrients vary between the two localities? (2) What is the relationship between soil nutrients and palm floristic composition? (3) What are the most important nutrients that explain the variation in floristic composition of palm communities? (4) How the abundance of the most abundant understory and canopy palm species varies along the concentration gradient of the most important nutrients? We established 20 transects (5 x 500 m) and identified all palm individuals of all growth stages. Soil samples were taken at each transect at the beginning, middle and end. Macronutrients (Al, Ca, Mg, K, P) were extracted with the Mehlich-III technique and their concentrations were analyzed by inductively coupled plasma emission spectrometry (ICP-OES). The concentration of nutrients was related to the floristic composition using Mantel, partial Mantel tests, linear regressions and non-metric multidimensional scaling. We found a total of 9158 individuals and 33 species of palms in the 5 ha covered by our transects. Species composition had a positive and significant correlation with soil nutrients (rM = 0.63-0.69) and with geographical distance between transects (rM= 0.71-0.75), whereas the soil nutrients were highly correlated with geographical distance (rM = 0.72). We found a small yet significant relationship between soil fertility and the abundance of undestorey palms, but no relationship with canopy palms. Our results demonstrate for the first time that soils play an important role in the composition of palm communities at local scales in the Chocó region, and that infertile and phosphorus-rich soils have the highest palm diversity.

The symbiotic association of the leaf-cutter ants with the fungus Leucoagaricus gongylophorus implies that the negative impact on the fungi will affect the survival of the ants. After a promising antifungal bioactivity, Carica papaya was studied leading to the bioassay-guided isolation of squalene, 4,5-dihydrohumulen, the flavanol-glycosides quercetin, kaempferol, and rutin, and the alkaloid carpaine. Carpaine and squalene were found to have a moderate individual activity, which increased when evaluated together. Based on the presence of these compounds, standardized extracts were formulated for field tests on nests of Acromyrmex octospinosus. All the nests treated were negatively affected evidencing a promising lead for the integrated management of leaf-cutter ants.

Los bosques tropicales del Chocó biogeográfico presentan una de las mayores concentraciones de especies de plantas del mundo. Las palmas (Arecaceae) son una de las familias más importantes en las tierras bajas del Chocó, pero su ecología está poco estudiada. Investigamos la diversidad de comunidades de palmas en el Chocó y su relación con la precipitación en 48 transectos distribuidos en un gradiente de 2000–10 000 mm de precipitación. En cada transecto (5×500 m) se identificaron todas las especies de palmas y se contabilizaron todos los individuos. Registramos un total de 57 especies de palmas (promedio ± DS: 17 ± 8 por transecto) y 37 955 individuos (791 ± 446). Encontramos que la riqueza y abundancia de palmas están significativamente relacionadas con la precipitación (r² = 0,86; P > 0,001). Se registró una fuerte correlación positiva entre la composición florística de las comunidades de palmas y la distancia geográfica (rm = 0,63; P = 0,001). La riqueza registrada es una de las más altas para el Neotrópico. La relación entre la precipitación, riqueza y abundancia de palmas por primera vez se documenta a escala regional en este punto caliente de biodiversidad.

One of the most important questions in ecology is: which are the environmental factors that explain the high plant diversity of tropical forests? We studied the floristic composition of palm communities and their relationship to soil nutrients in two localities of the Choco region to understand (1) how soil nutrients vary between the two localities; (2) what is the relationship between soil nutrients and palm floristic composition; (3) what are the most important nutrients that explain the variation in floristic composition of palm communities; and (4) how does the abundance of the most exuberant understory and canopy palm species vary along the concentration gradient of the most important nutrients? We established 20 transects (5 x 500 m) and identified all palm individuals of all growth stages. Soil samples were taken at each transect at the beginning, middle, and end. Macronutrients (Al, Ca, Mg, K, P) were extracted with the Mehlich-III technique and their concentrations were analyzed by inductively coupled plasma emission spectrometry (ICP-OES). We used Mantel test, partial Mantel tests, linear regressions, and non-metric multidimensional scaling to determine if the concentration of nutrients was related to the floristic composition. We found a total of 9 158 individuals and 33 species of palms in the 5 ha covered by our transects. Floristic composition had a positive and significant correlation with soil nutrients (r(M) = 0.63-0.69) and with geographical distance between transects (r(M) = 0.71-0.75), whereas the soil nutrients were highly correlated with geographical distance (r(M) = 0.72). We also found a small, yet significant, relationship between soil fertility and the abundance of understory palms, but no relationship with canopy palms. Our results demonstrate for the first time that soils play an important role in the composition of palm communities at local scales in the Choco region, and that infertile and phosphorus-rich soils have the highest palm diversity.

This work shows a procedure for modeling and control of level and flow processes. It uses the EMSO simulator to connect to a process by means of a SIMATIC S7-200 PLC as interface for the communication between the process instrumentation and the controller computing system. In order to supervise the variables, a SIMULINK model was connected to a laboratory process module through OPC communication. The model obtained was used in the design of controllers PID and PBSM, which were tested for step disturbances of the set point and an imposed set point trajectory.

In this work, the energy audits and evaluation of the kilns used in the calcination stage of the calcium oxide production process of two Colombian factories are shown. The energy intensity and usage distribution were evaluated, as well as the technological state of the presently used heating equipment as compared with the most advanced technology available for the calcination process. For the energy audits, key process data - such as fuel consumption, flue gas temperature and composition, material flows, wall temperature, and furnace configuration - was gathered in-field during visits to production plants. The energy efficiency of the vertical kilns was calculated according to the ISO - 13579 Standard. Substantial heat losses were found especially through the flue gases and kiln walls. The kiln thermal efficiencies calculated were in the range of 54-59%, with combustion efficiencies of 74-78%. The energy performance indicators of the vertical kilns were significantly below those of the most advanced technology available for the calcination stage. Potential energy savings through the introduction of the state-of-the-art kiln technology in the Colombian lime industry is discussed. (C) 2017 Elsevier Ltd. All rights reserved.

Durante un periodo de siete meses y con la colaboración de dos conocedores se realizó un registro de plantas medicinales del Corregimiento de San Cristóbal, ejecutándose el inventario de las mismas en tres veredas de la localidad e identificándose un total de 105 especies pertenecientes a 43 familias. El objetivo principal del estudio fue determinar la posibilidad de anticipar el uso medicinal de una especie de planta, si se conoce la familia botánica a la cual pertenece la misma. Mediante un análisis de cluster se estableció la relación entre la familia botánica y el tipo de uso medicinal asignado, conformándose siete grupos de familias asociado cada uno a un conjunto particular de categorías médicas. La relación familia botánica-categoría de uso medicinal establecida, demuestra que una planta en particular puede ser utilizada para diversos fines medicinales. Se concluye que no es posible predecir solo un uso, sino un conjunto de usos medicinales de una planta si se conoce la familia botánica a la cual pertenece. En la zona estudiada, al igual que en otras tierras altas de Suramérica, las familias con uso medicinal mejor representadas, de acuerdo al número de especies y por citación de los colaboradores locales, en general son las mismas, siendo las principales: Asteraceae, Lamiaceae, Apiaceae y Solanaceae.

Mauritia flexuosa is a keystone species with a broad geographic distribution throughout the Amazon. Environmental changes can impact the reproductive success in a keystone species such as M. flexuosa, which results in a cascade of events that impacts many other species. The present study examined the reproductive phenology in the palm M. flexuosa between December 2010 and November 2012. A 1-ha plot was established in the central Amazon and all palms ≥14 m tall were labelled for measuring. The following five phenophases were recorded monthly for each labelled palm: (i) spadix formation; (ii) buds; (iii) open flowers; (iv) infructescences with green fruits; and (v) infructescences with ripe fruits. ANOVA and multiple range tests were used to evaluate significant differences among variables for each year. The phenological activity index for each phase was related with regional climate variables, including maximum and minimum daily temperature, monthly accumulated precipitation, cloudiness, flood and water table levels in the plot using a redundancy analysis. Overall, fruiting and flowering AIs exhibited significant differences; however, increased synchronous flowering was recorded during the first year associated with maximum temperatures and a drought period; the second year indicated precipitation sufficient for higher fruit production. Climate also influenced seedling mortality, recruitment, and establishment.

Palms are majestic and emblematic in tropical forests where they sometimes form dense monodominat palm communities and at other times form communities with high richness of a variety of species and growth forms. Colombia's high palm species richness is associated with its geographical expansion and position in north-western South America at the cross-roads between Central and South America. This chapter gives detailed information concerning diversity and abundance of palms of the eastern Colombian Amazon near the frontiers of Brazil and Peru. The forest of the Colombian Amazon, known for its many palms, is a humid tropical forest. Terra firme forests in the Amazon harbor high diversities of palms. Floodplain and terrace forests had fewer species of palms compared to the Terra firme forest, but the palms were more abundant with 3,737 vs. 2,900 individuals per hectare on average.

Grain (size of sampling units) affects the spatial resolution at which ecological patterns can be observed and analysed, and potentially has an important effect on the results of broad‐scale studies on diversity gradients. Here we examine the effect of grain on patterns of species richness and turnover in lowland rainforests of western Amazonia (Peru and Colombia). We inventoried pteridophytes (ferns and lycophytes), melastomes (Melastomataceae) and palms (Arecaceae) in four line transects of 22–29 km length. Different grains were obtained by aggregating original 100‐m‐long sampling units into larger segments up to 19.2 km long. With any given grain and plant group, local species richness varied considerably both within and among transects, and a transect segment that was species‐rich with one grain could be relatively species‐poor with another. Which transect had the highest vs lowest mean species richness per sampling unit (α richness) differed among plant groups. It also varied to some degree with grain, as transects differed in how rapidly local species richness increased with increasing grain. Patterns of species turnover were more consistently correlated among plant groups than patterns of species richness were, and NMDS ordinations were rather similar with all grains and plant groups. Floristic heterogeneity within the Amazonian terra firme rainforest seems to contain a general compositional pattern that is sufficiently robust to be detectable with various sampling schemes, but patterns of species richness appear more case‐specific. Therefore, using one plant group as an indicator for patterns in other plant groups can be expected to work better for species turnover than for species richness.