Esculturas de acero: observaciones de corrosión e inhibición mediante una cámara de niebla salina, sensores y un microscopio de bajo costo
Novoa Jerez, J., Alfaro Guerra, M., & Alfaro Alcaíno, I.
La presencia de partículas de NaCl en el aerosol marino produce corrosión en esculturas de acero de interés patrimonial, valor artístico y arquitectónico. Es aquí donde la observación de la corrosión utilizando una cámara de neblina, sensores y un microscopio de bajo costo podría permitir su estudio, junto con la ventaja de poder desarrollar proyectos en conjunto entre carreras de Pedagogía en Química con carreras de Pedagogía en Historia y Geografía y Pedagogía en Matemáticas y Computación, además del estudio de las propiedades anticorrosivas de Metamizol frente al acero al carbono sometido al aerosol marino en la cámara de neblina mediante la utilización de fotomicrografías.
Palabras claves: Corrosión atmosférica, Aerosol marino, Esculturas de acero, Cámara de neblina, Sensores, Microscopio de bajo costo.
Referencia APA: Novoa Jerez, J., Alfaro Guerra, M., & Alfaro Alcaíno, I. (2019). Esculturas de acero: observaciones de corrosión e inhibición mediante una cámara de niebla salina, sensores y un microscopio de bajo costo. Retrieved 25 July 2019, from Educación Química (Vol 30, No 2).
Unexpected population fragmentation in an endangered seabird: the case of the Peruvian diving-petrel
Cristofari, R., Plaza, P., Fernández, C., Trucchi, E., Gouin, N., Le Bohec, C., Zavalaga, C., Alfaro-Shigueto, J., Luna-Jorquera, G.
In less than one century, the once-abundant Peruvian diving petrel has become the first endangered seabird of the Humboldt Current System (HCS). This small endemic petrel of the South American Pacific coast is now an important indicator of ongoing habitat loss and of the success of local conservation policies in the HCS - an ecoregion designated as a priority for the conservation of global biodiversity. Yet so far, poorly understood life history traits such as philopatry or dispersal ability may strongly influence the species’ response to ecosystem changes, but also our capacity to assess and interpret this response. To address this question, we explore the range-wide population structure of the Peruvian diving petrel, and show that this small seabird exhibits extreme philopatric behavior at the island level. Mitochondrial DNA sequences and genome-wide SNP data reveal significant isolation and low migration at very short distances, and provide strong evidence for questioning the alleged recovery in the Peruvian and Chilean populations of this species. Importantly, the full demographic independence between colonies makes local population rescue through migration unlikely. As a consequence, the Peruvian diving petrel appears to be particularly vulnerable to ongoing anthropogenic pressure. By excluding immigration as a major factor of demographic recovery, our results highlight the unambiguously positive impact of local conservation measures on breeding populations; yet at the same time they also cast doubt on alleged range-wide positive population trends. Overall, the protection of independent breeding colonies, and not only of the species as a whole, remains a major element in the conservation strategy for endemic seabirds. Finally, we underline the importance of considering the philopatric behavior and demographic independence of breeding populations, even at very fine spatial scales, in spatial planning for marine coastal areas.
Referencia APA: Cristofari, R., Plaza, P., Fernández, C., Trucchi, E., Gouin, N., Le Bohec, C., Zavalaga, C., Alfaro-Shigueto, J., Luna-Jorquera, G. (2019). Unexpected population fragmentation in an endangered seabird: the case of the Peruvian diving-petrel. Scientific Reports, 9(1). doi: 10.1038/s41598-019-38682-9
Effect of high hydrostatic pressure treatment on physical parameters, ultrastructure and shelf life of pre- and post-rigor mortis palm ruff (Seriolella violacea) under chilled storage
Roco, T., Torres, M., Briones-Labarca, V., Reyes, J., Tabilo-Munizaga, G., & Stucken, K., Lemus-Mondaca, R., Pérez-Won, M.
To identify processing conditions that better maintain palm ruff quality attributes, high hydrostatic pressure (HHP) was applied to pre- and post-rigor fillets. Physical parameters as whiteness index (WI), water holding capacity (WHC), texture and ultrastructure and shelf life were evaluated after the application of 450 and 550 MPa (3 and 4 min) and during cold storage. Pre-rigor fillets retained less water and were softer than post-rigor, although the onset of rigor increased palm ruff's WHC and firmness. Application of HHP whitened palm ruff's dark flesh; however, this effect reverted at the end of the storage. Pressurized post-rigor samples retained less water than the control and storage caused a WHC increase in samples pressurized at 550 MPa, independent on the rigor condition. Post-rigor fillets softened at pressures of 450–550 MPa appearing to have a lower threshold than beef or cod (above 600 MPa). Ultrastructural changes revealed a subtle contraction (7.4%) of the myofibrils in the unpressurized post-rigor muscle compared to pre-rigor; after 26 days' storage both samples presented extensive muscle degradation and sarcomere length was reduced in 30%. HHP induced pressure-dependent shortening of the sarcomere and modifications to the structure which after 550 MPa was hardly recognizable. After 26 days' storage, there was only slight degradation of the ultrastructure, showing that beyond the structural modifications caused by HHP, post-mortem deterioration is delayed in HHP-treated fillets. Furthermore, HHP extended palm ruff's shelf life to 14–23 days. Thus, HHP may be considered as a technology that maintains the textural quality and shelf life of fresh and stored fish.
Palabras claves: Palm ruff, Rigor mortis, High hydrostatic pressure, Shelf life, StorageTexture, Ultrastructure
Referencia APA: Roco, T., Torres, M., Briones-Labarca, V., Reyes, J., Tabilo-Munizaga, G., & Stucken, K., Lemus-Mondaca, R., Pérez-Won, M. (2018). Effect of high hydrostatic pressure treatment on physical parameters, ultrastructure and shelf life of pre- and post-rigor mortis palm ruff (Seriolella violacea) under chilled storage. Food Research International, 108, 192-202. doi: 10.1016/j.foodres.2018.03.009
Optimization of extraction yield, flavonoids and lycopene from tomato pulp by high hydrostatic pressure-assisted extraction
Briones-Labarca, V., Giovagnoli-Vicuña, C., & Cañas-Sarazúa, R.
Tomato pulp is a useful source of antioxidants, which can be extracted by high hydrostatic pressure (HHPE). This study aimed to optimize the individual and interactive effect of operating high pressure and solvent polarity (solvent mixture) on yield extraction, flavonoid and lycopene content from tomato pulp (Solanum lycopersicum) by using response surface methodology (RSM). The results showed that the selected factors (high pressure and solvent mixture) have a significant influence on extraction yield, flavonoid and lycopene content. Extraction at 450 MPa and 60% hexane concentration in the solvent mixture was considered the optimal HHPE condition since it provided the maximum extraction yield (8.71%), flavonoid (21.52 ± 0.09 mg QE/g FW) and lycopene content (2.01 ± 0.09 mg QE/100 g FW). Therefore, HHPE could be a useful tool improve the extraction and release of potentially health-related compounds while providing information on the cumulative effect of solvent polarity and high-pressure extraction on antioxidant compounds of fruits.
Palabras claves: Tomato, High hydrostatic pressure, Antioxidant capacity, Response surface methodology
Referencia APA: Briones-Labarca, V., Giovagnoli-Vicuña, C., & Cañas-Sarazúa, R. (2018). Optimization of extraction yield, flavonoids and lycopene from tomato pulp by high hydrostatic pressure-assisted extraction. Food Chemistry, 278, 751-759. doi: 10.1016/j.foodchem.2018.11.106
Partitioning genetic and species diversity refines our understanding of species–genetic diversity relationships
Pfeiffer, V., Ford, B., Housset, J., McCombs, A., Blanco‐Pastor, J., & Gouin, N., Manel, S., Bertin, A
Disentangling the origin of species–genetic diversity correlations (SGDCs) is a challenging task that provides insight into the way that neutral and adaptive processes influence diversity at multiple levels. Genetic and species diversity are comprised by components that respond differently to the same ecological processes. Thus, it can be useful to partition species and genetic diversity into their different components to infer the mechanisms behind SGDCs. In this study, we applied such an approach using a high‐elevation Andean wetland system, where previous evidence identified neutral processes as major determinants of the strong and positive covariation between plant species richness and AFLP genetic diversity of the common sedge Carex gayana. To tease apart putative neutral and non‐neutral genetic variation of C. gayana, we identified loci putatively under selection from a dataset of 1,709 SNPs produced using restriction site‐associated DNA sequencing (RAD‐seq). Significant and positive relationships between local estimates of genetic and species diversities (α‐SGDCs) were only found with the putatively neutral loci datasets and with species richness, confirming that neutral processes were primarily driving the correlations and that the involved processes differentially influenced local species diversity components (i.e., richness and evenness). In contrast, SGDCs based on genetic and community dissimilarities (β‐SGDCs) were only significant with the putative non‐neutral datasets. This suggests that selective processes influencing C. gayana genetic diversity were involved in the detected correlations. Together, our results demonstrate that analyzing distinct components of genetic and species diversity simultaneously is useful to determine the mechanisms behind species–genetic diversity relationships.
Palabras claves: Genetic outlier, high Andean wetlands, SNP, species–genetic diversity correlation
Referencia APA: Pfeiffer, V., Ford, B., Housset, J., McCombs, A., Blanco‐Pastor, J., & Gouin, N., Manel, S., Bertin, A. (2018). Partitioning genetic and species diversity refines our understanding of species–genetic diversity relationships. Ecology And Evolution. doi: 10.1002/ece3.4530
Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change
Espinosa, M., Gouin, N., Squeo, F., López, D., & Bertin, A.
Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. This is of particular concern for biodiversity preservation in drylands, since water limited landscapes are typically characterized by little suitable habitat cover, high habitat fragmentation, harsh matrices, and are being rapidly degraded at a global scale. In this study, we modelled landscape connectivity between 11 guanaco Lama guanicoe populations in Chile’s arid Norte Chico, a region that supports the last remnant coastal populations of this emblematic herbivore indigenous to South America. We produced a habitat suitability model to derive a regional surface resistance map, and used circuit theory to map functional connectivity, investigate the relative isolation between populations, and identify those that contribute most to the patch connectivity network. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e., 29,173 km2) and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide, continuous connectivity corridor, enabling connectivity between all high Andean populations. Coastal populations, in contrast, were more isolated. These groups demonstrate no inter-population connectivity between themselves, only with higher altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings along the Pan-American highway. Our results indicate that functional connectivity is an issue of concern for L. guanicoe in Chile’s Norte Chico, implying that future conservation and management plans should emphasize strategies aimed at conserving functional connectivity between coastal and Andean populations, as well as the protection of habitat patches likely to act as stepping stones within the connectivity network.
Referencia APA: Espinosa, M., Gouin, N., Squeo, F., López, D., & Bertin, A. (2018). Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change. Peerj, 6, e4429. doi: 10.7717/peerj.4429
A hyper‐arid environment shapes an inverse pattern of the fast–slow plant economics spectrum for above‐, but not below‐ground resource acquisition strategies
Carvajal, D., Loayza, A., Rios, R., Delpiano, C., & Squeo, F.
The fast–slow plant economics spectrum predicts that because of evolutionary and biophysical constraints, different plant organs must be coordinated to converge in a unique ecological strategy within a continuum that shifts from fast to slow resource acquisition and conservation. Therefore, along a gradient of aridity, taxa with different strategies will be expected to be successful because selection pressures for slow resource acquisition become stronger as the environment becomes drier. In extremely arid and seasonal environments, however, a slow strategy may become disadvantageous because slow traits are costly to maintain. Additionally, as the availability of water decreases, selection pressures increase, reducing the variation in ecological strategies.
Using shrub assemblages along an aridity gradient in the Atacama Desert, we test the hypothesis that selection pressures imposed by hyper‐aridity act simultaneously on the variation and coordination of trait attributes, leading to an inverse pattern in the fast–slow plant economics spectrum, where strategies shift from slow to fast as the environment becomes drier.
We established 20–22 plots at each of four sites along the gradient to estimate plant community structure and functional variation. For all species recorded, we quantified a set of leaf, stem, and root traits.
Results revealed an inverse pattern of the fast–slow economics spectrum for leaf and stem traits, but not for root traits; that is, as aridity further increased, above‐ground traits exhibited a shift from a slow to a fast strategy with some level of coordination. Below‐ground traits, however, did not shift accordingly with our prediction, rather they showed more complex pattern of shift and coordination with above‐ground traits along the gradient. We also found that trait variation showed an idiosyncratic pattern of variation along the gradient, indicating that ecological strategies are driven by local processes within sites.
Synthesis. Our results increase our understanding of the fast–slow plant economics spectrum by showing that environmental gradients, as well as local process can simultaneously shape different below‐ and above‐ground resource acquisition strategies in extremely poor resource environments.
Palabras claves: Aridity gradient, Atacama Desert, Functional traits, Functional trait variation, Leaf root, Shrub communities, Stem.
Referencia APA: Carvajal, D., Loayza, A., Rios, R., Delpiano, C., & Squeo, F. (2018). A hyper‐arid environment shapes an inverse pattern of the fast–slow plant economics spectrum for above‐, but not below‐ground resource acquisition strategies. Journal Of Ecology, 107(3), 1079-1092. doi: 10.1111/1365-2745.13092
Isolation and cross-amplification of the first set of polymorphic microsatellite markers of two high-Andean cushion plants
Acuña-Rodríguez, I., Gouin, N., Cifuentes-Lisboa, L., & Squeo, F.
In the southern Andes mountains (27– 39∘S ) Azorella madreporica and Laretia acaulis, two Apiaceae cushion plant species commonly known as yaretas, conform a well-established altitudinal vegetation belt along the lower Andean zone. These species have been considered as fundamental components of several ecological dynamics within their communities; however, high-mountain ecosystems are increasingly threatened worldwide by natural and anthropogenic pressures and the southern Andes are not the exception. Recognizing that genetic information is crucial for the success of any conservation or restoration initiative in wild populations, we developed and cross-amplified 28 specifically designed microsatellite markers (14 in A. madreporica and 14 in L. acaulis), and also tested the cross amplification of 25 markers from the related species Azorella selago. In a region which is particularly vulnerable to global change trends, this new polymorphic microsatellite loci will be useful in the study of the genetic diversity of these high-mountain cushion plants, which are pivotal in the structuring of their native ecosystems.
Palabras claves: Cushion plants, High-Andes, Microsatellite markers, Azorella madreporica, Laretia acaulis.
Referencia APA: Acuña-Rodríguez, I., Gouin, N., Cifuentes-Lisboa, L., & Squeo, F. (2018). Isolation and cross-amplification of the first set of polymorphic microsatellite markers of two high-Andean cushion plants. Journal Of Genetics, 97(S1), 95-100. doi: 10.1007/s12041-018-0999-4
Fuzzy-based assessment of groundwater intrinsic vulnerability of a volcanic aquifer in the Chilean Andean Valley
Duhalde, D., Arumí, J., Oyarzún, R. and Rivera, D.
A fuzzy logic approach has been proposed to face the uncertainty caused by sparse data in the assessment of the intrinsic vulnerability of a groundwater system with parametric methods in Las Trancas Valley, Andean Mountain, south-central Chile, a popular touristic place in Chile, but lacking of a centralized drinking and sewage water public systems; this situation is a potentially source of groundwater pollution. Based on DRASTIC, GOD, and EKv and the expert knowledge of the study area, the Mamdani fuzzy approach was generated and the spatial data were processed by ArcGIS. The groundwater system exhibited areas with high, medium, and low intrinsic vulnerability indices. The fuzzy approach results were compared with traditional methods results, which, in general, have shown a good spatial agreement even though significant changes were also identified in the spatial distribution of the indices. The Mamdani logic approach has shown to be a useful and practical tool to assess the intrinsic vulnerability of an aquifer under sparse data conditions.
Palabras claves: Aquifer vulnerability, Data scarcity, Fuzzy logic
Referencia APA: Duhalde, D., Arumí, J., Oyarzún, R. and Rivera, D. (2018). Fuzzy-based assessment of groundwater intrinsic vulnerability of a volcanic aquifer in the Chilean Andean Valley. Environmental Monitoring and Assessment, 190(7).
Protected areas in Chile: are we managing them?
Petit, I., Campoy, A., Hevia, M., Gaymer, C. and Squeo, F.
Human population growth since the mid-1900s has been accompanied by an unsustainable use of natural resources and a corresponding impact on terrestrial and marine biota. In response, most states have established protected areas as tools to decrease biodiversity loss, being Chile one of the signatories of international conservation agreements such as the Convention on Biological Diversity (CBD) and the 2010 Aichi Targets. This study reviews the Chilean protected areas that have been created to date, with an emphasis on the existence and effectiveness of management plans for all terrestrial and marine protected areas.
Effectiveness was individually evaluated using two filters: 1) the age of the management plan and 2) the first four steps of the Protected Areas Management Effectiveness (PAME) methodology recommended by the IUCN.
We show that 84 out of a total of 145 protected areas (PAs), and only five out of a total of 20 marine protected areas (MPAs), have management plans. Only 12% (N = 16) of PAs are effectively managed; while in the marine realm, no MPA has an effective plan.
Our results show the lack of both the effectiveness of and updates to the management plans for the vast majority of the national territory and raise the following question: is it sustainable to continue adding protected areas to the national system even though it is clear that the existing support is insufficient to meet the minimum requirements for full implementation?
Palabras claves: AICHI targets, Biodiversity, Conservation, Chile, Effective management, MPA
Referencia APA: Petit, I., Campoy, A., Hevia, M., Gaymer, C. and Squeo, F. (2018). Protected areas in Chile: are we managing them?. Revista Chilena de Historia Natural, 91(1). dx.doi.org/10.1186/s40693-018-0071-z
The impact of different agroecological conditions on the nutritional composition of quinoa seeds
Reguera, M., Conesa, C., Gil-Gómez, A., Haros, C., Pérez-Casas, M., Briones-Labarca, V., Bolaños, L., Bonilla, I., Álvarez, R., Pinto, K., Mujica, Á. and Bascuñán-Godoy, L.
Quinoa cultivation has been expanded around the world in the last decade and is considered an exceptional crop with the potential of contributing to food security worldwide. The exceptional nutritional value of quinoa seeds relies on their high protein content, their amino acid profile that includes a good balance of essential amino acids, the mineral composition and the presence of antioxidants and other important nutrients such as fiber or vitamins. Although several studies have pointed to the influence of different environmental stresses in certain nutritional components little attention has been paid to the effect of the agroecological context on the nutritional properties of the seeds what may strongly impact on the consumer food's quality. Thus, aiming to evaluate the effect of the agroecological conditions on the nutritional profile of quinoa seeds we analyzed three quinoa cultivars (Salcedo-INIA, Titicaca and Regalona) at different locations (Spain, Peru and Chile). The results revealed that several nutritional parameters such as the amino acid profile, the protein content, the mineral composition and the phytate amount in the seeds depend on the location and cultivar while other parameters such as saponin or fiber were more stable across locations. Our results support the notion that nutritional characteristics of seeds may be determined by seed's origin and further analysis are needed to define the exact mechanisms that control the changes in the seeds nutritional properties.
Palabras claves: Agroecological conditions; Nutritional properties; Quinoa; Seed
Referencia APA: Reguera, M., Conesa, C., Gil-Gómez, A., Haros, C., Pérez-Casas, M., Briones-Labarca, V., Bolaños, L., Bonilla, I., Álvarez, R., Pinto, K., Mujica, Á. and Bascuñán-Godoy, L. (2018). The impact of different agroecological conditions on the nutritional composition of quinoa seeds. PeerJ, 6, p.e4442.
Roof-integrated dew water harvesting in Combarbalá, Chile
Carvajal, D., Minonzio, J., Casanga, E., Muñoz, J., Aracena, A., Montecinos, S., & Beysens, D.
Dew harvesting can be a supplementary source of freshwater in semiarid and arid areas. Several experiments on small-scale dew condensers (usually of 1 m2) have been carried out in many places in the world; however, few experiments have been conducted on large-scale collectors integrated into buildings. This work aims to assess one year of dew water harvesting in Combarbalá (Chile) using a painted galvanised steel roof as collecting surface. The roof (36 m2) was coated with a high-infrared-emissivity paint containing aluminosilicate minerals (OPUR, France). Dew measurements were conducted daily from September 2014 to August 2015. The dew yield and its relationship with meteorological variables were analysed. The results show that despite the low nocturnal relative humidity throughout the year (average: 48%), dew collection occurred on 56.1% of the recorded days. The daily average collection rate was 1.9 L d−1, with a maximum of 15 L d−1. The maximum daily dew yield is correlated strongly with relative humidity and correlated weakly with air temperature and wind speed. Considering the same rooftop can collect dew and rain, it was estimated that over one year dew water could contribute to roughly 8.2% of the total water collected, considering both sources.
Palabras claves: Atmospheric water, dew collection, radiative cooling, water resources
Referencia APA: Carvajal, D., Minonzio, J., Casanga, E., Muñoz, J., Aracena, A., Montecinos, S., & Beysens, D. (2018). Roof-integrated dew water harvesting in Combarbalá, Chile. Journal Of Water Supply: Research And Technology - Aqua, 67(4), 357-374. doi: 10.2166/aqua.2018.174