Valparaiso Region Research Articles

Engineering the cell wall reactive groups of Plant Growth Promoting Rhizobacteria by culture strategy for heavy metal removal

This research delved into the effects of nutrient limitation on the level of sporulation and the cadmium adsorption capacity of the bacterium Bacillus sp. isolated from the rhizosphere of endemic soils in the Region of Valparaiso, Chile. The bacteria were subjected to nitrogen limitation in fed-batch mode and were compared to bacteria grown in batch culture without nutrient limitation. The cultures were carried out in a 3 L bioreactor with an external nitrogen supply of ammonium at a flow of 0.123 L h−1. The specific maximum growth rate was 0.42 h−1 in batch and 0.45 h−1 in the exponential phase of the fed-batch.The analysis of sporulation did not show any significant difference between the biomass coming from the fed-batch and batch cultures.It was found that maximum cadmium adsorption capacity varied with culture strategy. The dry biomass grown without nutrient limitation exhibited a maximum adsorption capacity for cadmium of 65.0 mgCd g−1biomass. Conversely, the limited biomass achieved a lower cadmium adsorption capacity of approximately 36.0 mgCd g−1biomass. FTIR analysis showed that nitrogen limitation induced changes in the composition of the outer cell wall, specifically an increase of deacetlylated polysaccharides, reducing the relative amount of secondary amines and proteins from the peptidoglycan matrix. Amino groups from acetylated polysaccharides and proteins have been associated elsewhere with greater cadmium affinity, which could explain the poor results obtained with the nitrogen-restricted biomass. This study shows that new physiological states displaying different adsorption capabilities were effectively obtained by engineering the cell coverage of the bacteria using varying culture strategies. The fed-batch culture proved to be a valuable tool for studying PGPR strains for biosorption and other applications. Exploring diverse nutrient limitations and other pollutants in this bacterium and other members of the PGPR family offer great opportunities to tailor biosorption strategies based on specific conditions, ultimately contributing to sustainable environmental solutions.

Multi-criteria analysis for sustainable and cost-effective development of desalination plants in Chile

In Chile, there is an increasing demand for freshwater supply for human consumption, agriculture, and industrial activities. In this sense, the country is highly threatened by climate change, which is drastically affecting the availability of water resources in the north-central region due to desertification processes. Therefore, seawater reverse osmosis (SWRO) desalination is becoming one of the most feasible alternatives to address current and future challenges regarding water scarcity in the country. This investigation aims to evaluate potential locations for a sustainable and cost-effective installation of desalination projects; the latter, under a multi-criteria and geographic information system (GIS)-model. The model was tested in the highly water scarcity-threatened Valparaiso Region, Chile, as a case study. The model was developed integrating economic and socio-environmental criteria involved in the development and/or construction of desalination projects. The results of the multi-criteria analysis show that the Valparaıso Region presents optimal areas for developing SWRO projects. Both the northern and central areas of the Region show appropriate locations for installing SWRO plants and their freshwater distribution lines, ensuring short- and long-term water supply, especially for agriculture and population consumption. The results obtained in this study could be extrapolated as a tool to assess the desalination projects development in other world regions to make future desalination projects more viable and sustainable for addressing global water demands.

Radiation dosis in computed tomography: observation in three hospitals from the Region of Valparaiso, Chile

Radiation dosis in computed tomography: observation in three hospitals from the Region of Valparaiso, Chile

Coastal zone in central Chile, delimitation proposal of Valparaiso region

Coastal zone in central Chile, delimitation proposal of Valparaiso region

Developing an assessment model for uncovering potential synergies of regional industrial symbiosis: A case study of Valparaiso region, Chile

Waste management is considered as one of the main challenges of policy makers. In regional scale, industrial waste affects waste management planning as it requires strict policy control and implementation. Industrial symbiosis is known as a potential solution to reduce the volume of dumping waste by introducing the waste to input resources of the companies. This study contributes on developing a methodical framework on quantifying and ranking the synergy potential of symbiosis between companies in the industrial sector of Valparaiso region since it hosts major industrial activities in the central zone of Chile. The proposed methodology includes a waste-to-resource complementary arrangement which merges the waste database declared by the Chilean government with potential generation of new alternative resources and corresponding recipients. This methodology suggests two indicators to calculate the potential synergies: (1) number of connections between companies; (2) accumulated weight of waste-to-resource materials between companies. In total, 9582 connections and 62, 781, 963 tons of accumulated waste to resource materials between companies were identified in 5 territorial clusters. The results present a comparative basis of internal and external potential synergies identifying the pros and cons of each regional cluster. The assessment model developed for the Valparaiso region can be adapted to other regions in Chile or worldwide to quantify and rank the potential synergies to promote industrial symbiosis towards sustainable environment in macro scales.

Geographies of discontent: measuring and understanding the feeling of abandonment in the Chilean region of Valparaiso (2019–2021)

Abstract Political discontent, frequently mirrored in voting patterns, extends beyond ballot votes. By focusing on Valparaiso, Chile, we introduce a more comprehensive measure, external political efficacy (EPE), capturing a sense of abandonment and gauging public sentiment towards the political system’s responsiveness to their needs. Our analysis addresses individual and area-level factors underpinning individual variations in EPE. The evidence suggests that long-term territorial socio-economic disadvantage, rather than low-paid employment, is significantly related to individual discontent, highlighting lowered beliefs in system responsiveness.

Water Reservoir Placement Methodology for Forest Firefighting: A Case Study of Valparaíso, Chile

Climate change has a significant impact on generating forest fires. These fires damage property, interrupt productive processes, reduce employment sources, and generate direct economic losses. Also, fires contribute to climate change, resulting in a negative cycle. Therefore, the effective management of forest fires is of vital importance. This research focuses on the combat and mitigation phase of forest fires, with special emphasis on using helicopters to transport water from nearby reservoirs to the fire site. The location of these reservoirs is key since a greater distance traveled by helicopter means a longer delay in water transport, which favors the spread of the fire. For this reason, this research proposes an optimization model to determine the optimal location of these reservoirs in a territory. The proposed model is illustrated with a case study of the region of Valparaiso, demonstrating its usefulness for management and decision making when locating reservoirs for firefighting.

Network Governance at the Margin of the State: Rural Drinking Water Communities in Chile

We focus on the relationship between the network structure of Chilean rural drinking water associations (APRs) and effective governance outcomes regarding the provision of infrastructure and drinking water to peripheral rural communities in the Valparaiso region. Based on a comparative regional multi-method case study, we assess the coherence of differences in the governance network structure with the corresponding governance outcomes. Using qualitative interviews, participant observation, and a network survey of collaboration and legitimacy relationships among leaders of local APRs, we find that when isolated APRs establish collective organizations, they can generate better governance outcomes even without support from the state. We demonstrate that higher levels of collaboration as well as a more integrative distribution of legitimacy relations in the network are coherent with more effective governance outcomes. The findings suggest to strengthen social and organizational capacity at the local level of water governance in order to overcome the challenges of megadroughts and of a lack of public infrastructure in peripheral rural areas.

The effect of rock lithology on the background concentrations of trace elements in alluvial soils: Implications for environmental regulation

To assess the extent of soil contamination with a potentially toxic element, it is important to determine the background concentration of that element in the soil. In this study we decided to investigate the relationship between trace element concentrations in soils and the lithology of their parent rocks. We collected 85 topsoils (0–20 cm) samples from the Petorca, La Ligua, Aconcagua, and Casablanca River basins (Valparaiso region, central Chile). For soil sampling, we chose 11 tributary watersheds free of anthropogenic influence. The areas that contributed to the formation of each alluvial soil were delineated and the parent lithologies were acquired from 1:250,000 geological maps. The results show that the total concentrations of arsenic (As), copper (Cu), lead (Pb), and zinc (Zn) in soil vary considerably among the four river basins studied. Soil concentrations of all elements under study are positively correlated with the presence of andesitic volcanic rocks. Furthermore, soils formed from marine sediments and felsic volcanic rocks had the highest concentrations of Pb and As. The carbonate-bearing marine sediments may have adsorbed As and Pb released by weathering of felsic volcanic rocks found upstream of the study area. In contrast, lithologies dominated by continental sedimentary and plutonic rocks showed negative correlations with the concentrations of As, Cu, Pb, and Zn in the soil. Thus, the differences in soil element concentrations in the watersheds under study were due to the different rock types present in the area. We argue that absolute “one-limit-fits-all” background trace element values may be inadequate to assess the extent of soil contamination. Therefore, it is important to determine background concentrations of soil elements in each river basin in the anthropogenically impacted areas. In contrast, erroneous conclusions can be drawn when background concentrations are determined in one region and then applied in another region that is lithologically different.

Rediscovery of Ivania juncalensis Al-Shehbaz (Thelypodieae; Brassicaceae), an endemic and threatened species from the Andes of Central Chile

The genus Ivania is endemic to the Andes in Central Chile and comprises two species of range-restricted perennial herbs. Ivania juncalensis was described based on a single herbarium specimen collected in 1976, at a high elevation in the Río Juncal watershed. Given that the population site and status were unknown for more than 30 years, this species was considered potentially extinct. In this article we report the rediscovery of I. juncalensis in the Andes of Valparaiso region. Additionally, we provide an expanded description and new information about its distribution, habitat, ecology, and conservation status.

Relationship between pollution levels and poverty: regions of Antofagasta, Valparaiso and Biobio, Chile

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Size overlap in intertidal decapod communities on a central Chilean rocky beach (El Quisco, 32°24′S, Valparaiso region, Chile)

Abstract The intertidal crustaceans on the Chilean coast are characterized by high diversity and niche specialization. The present study applied a size-overlap null model analysis for intertidal decapod communities in a central Chilean rocky beach (El Quisco, 32°24′S). The application of six models simulations revealed that there is a size overlap, confirmed by the results of all those six simulations. This means that the reported species would share their ecological niches. The results agree with the first classical ecological descriptions for Chilean intertidal decapods at a local scale and support the observations for similar species on the southern Pacific and southern Atlantic coasts, and the results of the null model agree with a first comparative study of decapods in the north and on the central Chilean rocky coast.

Drivers of Flammability of Eucalyptus globulus Labill Leaves: Terpenes, Essential Oils, and Moisture Content

Mediterranean climate regions have become more vulnerable to fire due to the extreme weather conditions and numerous Eucalyptus globulus plantation areas. The aim of this study is to analyze the fire hazard related to E. globulus in a forest fire scenario, based on the contrast of thermochemical parameters and their relationship with chemical properties, considering the predominant exotic forest species (E. globulus, Pinus radiata, Acacia dealbata, and Acacia melanoxylon) present in the Valparaiso region, Chile. The results revealed that although all of the studied species were highly flammable, E. globulus was extremely flammable, as its leaves contain high concentrations of essential oils, monoterpenes, and sesquiterpenes, which can generate a flammable atmosphere due to their low flashpoint and the strong negative influence shown between the essential oils, volatile terpenes, and limonene concentration. Moreover, the heat of combustion of E. globulus was positively correlated with its high essential oil contents. Finally, all of the studied species had low flashpoints and high heating values; therefore, they are predisposed to ignite in the presence of a heat source, releasing high amounts of energy during combustion, which contributes to the risk of the formation and spread of canopy fires among these tree formations.

Segmentation of Consumer Preferences for Vegetables Produced in Areas Depressed by Drought

The megadrought in Chile’s north and central zones has impacted the horticultural production of family farming. One way to mitigate these effects is by adding value to vegetables. However, no studies show the main attributes consumers value of vegetables produced in the megadrought zone. The study’s objective was to evaluate consumer preferences and identify segments based on the extrinsic attributes of vegetables grown in areas depressed by drought. We surveyed 946 vegetable buyers from the Antofagasta, Valparaiso, and Maule regions. Through the conjoint analysis technique, we identified that the main attributes preferred by consumers were presentation (45.3%) and type of vegetables (21.8%), followed by labeling (15.9%), producers (10.3%), and origin (6.7%). The cluster analysis revealed the existence of three segments. The largest segment is motivated by the way vegetables are presented (49.7%), followed by a second segment that values multi-attributes (31.9%) and a smaller segment that is interested in labeling (18.4%). These findings can help position these products in the market and raise awareness of family farming and the economic and production problems that they currently face.

Political Disaffection in the Digital Age: The Use of Social Media and the Gap in Internal and External Efficacy

This work analyzes the relationship between social media use and the development of internal and external political efficacy, using five 1,650-person polls conducted in 2017–2021 in the 10 most populated municipalities of in the Valparaiso Region in Chile, a country characterized by high levels of political discontent and social protests, especially in 2019. With Structural Equation Models, we report positive impacts of different magnitudes of the civic use of social media on internal and external efficacy and no effect of the non-civic use of social media on either type of efficacy. As lower internal and external political efficacy feeds political disaffection, the differentiated use of social media can deepen the gap between engaged and disaffected citizens.

EPPO Datasheet: Naupactus xanthographus

EPPO Datasheet: <i>Naupactus xanthographus</i>

Chickpeas from a Chilean Region Affected by a Climate-Related Catastrophe: Effects of Water Stress on Grain Yield and Flavonoid Composition.

The Valparaiso region in Chile was decreed a zone affected by catastrophe in 2019 as a consequence of one of the driest seasons of the last 50 years. In this study, three varieties (‘Alfa-INIA’, ‘California-INIA’, and one landrace, ‘Local Navidad’) of kabuli-type chickpea seeds produced in 2018 (control) and 2019 (climate-related catastrophe, hereafter named water stress) were evaluated for their grain yield. Furthermore, the flavonoid profile of both free and esterified phenolic extracts was determined using liquid chromatography-mass spectrometry, and the concentration of the main flavonoid, biochanin A, was determined using liquid chromatography with diode array detection. The grain yield was decreased by up to 25 times in 2019. The concentration of biochanin A was up to 3.2 times higher in samples from the second season (water stress). This study demonstrates that water stress induces biosynthesis of biochanin A. However, positive changes in the biochanin A concentration are overshadowed by negative changes in the grain yield. Therefore, water stress, which may be worsened by climate change in the upcoming years, may jeopardize both the production of chickpeas and the supply of biochanin A, a bioactive compound that can be used to produce dietary supplements and/or nutraceuticals.

The Future of Rurality: Place Attachment among Young Inhabitants of Two Rural Communities of Mediterranean Central Chile

Rural livelihoods are under threat, not only from climate change and soil erosion but also because young people in rural areas are increasingly moving to urbanized areas, seeking employment and education opportunities. In the Valparaiso region of Chile, megadrought, soil degradation, and industrialization are driving young people to leave agricultural and livestock activities. In this study, our main objective was to identify the factors influencing young people living in two rural agricultural communities (Valle Hermoso and La Vega). We conducted 90 online surveys of young people aged 13–24 to evaluate their interest in living in the countryside (ILC). We assessed the effect of community satisfaction, connectedness to nature, and social valuation of rural livelihoods on the ILC. The results show that young people were more likely to stay living in the countryside when they felt satisfied and safe in their community, felt a connection with nature, and were surrounded by people who enjoyed the countryside. These results highlight the relevance of promoting place attachment and the feeling of belonging within the rural community. Chilean rural management and local policies need to focus on rural youth and highlight the opportunities that the countryside provides for them.

Relationship between Wildfire Smoke and Children’s Respiratory Health in the Metropolitan Cities of Central-Chile

Wildfire causes multiple problems for people living in cities. One of them is the deterioration of air quality as a result of wildfire smoke. This smoke can consequently have effects on human health. The present study aims to characterize the relationship between the occurrence of wildfires in central Chile and the effects on children’s respiratory health. Public databases provided the number of emergency care visits, wildfires, and concentration of air pollutants, demographics and meteorological variables for the regions of Santiago and Valparaiso from 2010 to 2013. Time series analysis was used monthly on health care visits to determine the relative health risk in children when in the presence of additional wildfires. Significant health risks were observed in Santiago for children younger than 1-year-old of bronchitis (RR 1.007, CI 95% 1.007–1.008; chronic lower respiratory diseases (RR 1.012, CI 95% 1.012–1.013); and pneumonia (RR 1.026 CI 95% 1.026–1.027) and in children aged one to four years old (RR 1.016 CI 95% 1.015–1.016). A dose-response relationship was also observed for pneumonia, showing that it affects younger children particularly when there is an increase in the number of wildfires. In the Region of Valparaíso, wildfires did not significantly change the risk of respiratory illness, this could be due to favorable ventilation. Currently, Santiago has an urgent need for monitoring and the evaluation of the damage to children’s respiratory health, along with the development of comprehensive prevention strategies.

Green Hydrogen Value Chain in the Sustainability for Port Operations: Case Study in the Region of Valparaiso, Chile

The paper presents a complete value chain for the use of green hydrogen in a port facility. The main objective was to propose the sizing of the main components that make up green hydrogen to ensure the supply of 1 MWe in replacing the diesel generator. The energy demand required for the port was determined by establishing the leading small and large-scale conventional energy-consuming equipment. Hence, 60 kgH2 was required to ensure the power supply. The total electrical energy to produce all the hydrogen was generated from photovoltaic solar energy, considering three-generation scenarios (minimum, maximum and the annual average). In all cases, the energy supply in the electrolyzer was 3.08 MWe. In addition, the effect of generating in the port facility using a diesel generator and a fuel cell was compared. The cost of 1 kgH2 could be 4.09 times higher than the cost of 1 L of diesel, meaning that the output kWh of each system is economically similar. In addition, the value of electrical energy through a Power Purchase Agreement (PPA) was a maximum of 79.79 times the value of a liter of diesel. Finally, the Levelized Cost of Energy (LCOE) was calculated for two conditions in which the MWe was obtained from the fuel cell without and with the photovoltaic solar plant.