Estimating the incidence of Venezuelan migration and other socioeconomic factors on urban growth in Colombia.

This study investigates the intricate relationship between Venezuelan migration and urban growth in Colombia from 2018 to 2021. The study employs remote sensing data and social network metrics to uncover migration patterns and their impact on urban expansion. The methodology consists of three stages. Firstly, nighttime satellite imagery is used to analyze year-over-year urban growth in Colombia. Secondly, social network data estimates Venezuelan migration, overcoming challenges of underreporting and informal border crossings. Lastly, an econometric analysis explores the quantitative link between Venezuelan migration and urban growth, integrating socioeconomic variables to address endogeneity. The findings reveal the complex interplay of Venezuelan migration, socioeconomic factors, and urban growth. The study outlines remote sensing analysis, introducing the Anthropogenic Footprint Expansion Index (AFEI) to quantify urban growth. Facebook API data estimates migration trends and explores socioeconomic impacts on urban expansion. The analysis uncovers migration, poverty, aging, and urban population proportion as key factors affecting Colombia's urban landscape. Furthermore, the research underscores how Venezuelan migration affected short-term urban expansion pre- and post-COVID-19. Migration had a notable effect before the pandemic, but this influence waned afterward. The study highlights migration's short-term nature and emphasizes age demographics' role in medium-term dynamics.

A comparative framework to analyze convergence on Twitter electoral conversations.

Literature on social networks and elections has focused on predicting electoral outcomes rather than on understanding how the discussions between users evolve over time. As a result, most studies focus on a single election and few comparative studies exist. In this article, a framework to analyze Twitter conversations about the election candidates is proposed. Using DeGroot's consensus model (an assumption that all users are attempting to persuade others to talk about a candidate), this framework is useful to identify the structure and strength of connections of the mention networks on the months before an election day. It also helps to make comparisons between elections and identify patterns in different contexts. In concrete, it was found that elections in which the incumbent was running have slower convergence (more closed communities with fewer links between them) and that there is no difference between parliamentary and presidential elections. Therefore, there is evidence that the political system and the role of the incumbent in the election influences the way conversations on Twitter occur.

Evaluating the role of spatial landscape literacy in public participation processes and opinions on environmental issues and ecosystem services.

Little is known about how spatial literacy influences mapping and decision-making related to environmental management and ecosystem services. We assessed the role of spatial landscape literacy in participatory environmental management and ecosystem service assessments in peri-urban Bogota, Colombia. Spatial landscape literacy (SL) was evaluated by testing stakeholder's ability to locate specific landscapes and landmarks. We then assessed if opinions on environmental decisions and ecosystem services were significantly related to SL. We used an online instrument to capture 2,397 respondent's socioeconomic characteristics, SL, ecosystem service perceptions, and opinions concerning relevant environmental issues. We evaluated and measured respondents' self-perceived SL and ability to locate four landscapes in an integrated online map. Positional accuracy was calculated using a Spatial Landscape Literacy Index (SLI). We then tested for effects of socio-demographics on SLI, modeled the relationship between socio-demographics and SL, and tested the relationship between respondents' SL and their opinions on relevant environmental issues and ecosystem services. We found that about 75% of the respondents correctly located 2 of the 4 landscapes. The SLI model was also poorly predicted by socio-demographic variables. However, we found significant relationships between SLI and opinions concerning the environment. No relationship was found between respondents' levels of active participation in local governance and SLI. Overall, SL was little affected by education levels. Participatory processes using maps should ideally measure SL and not assume a priori that participants are spatially literate. Further research is needed to evaluate how spatial technologies and understanding stakeholder's values towards the environment can democratize participatory-based decision-making.

Deciphering the introduction and transmission of SARS-CoV-2 in the Colombian Amazon Basin.

BACKGROUND: The SARS-CoV-2 pandemic has forced health authorities across the world to take important decisions to curtail its spread. Genomic epidemiology has emerged as a valuable tool to understand introductions and spread of the virus in a specific geographic location. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the sequences of 59 SARS-CoV-2 samples from inhabitants of the Colombian Amazonas department. The viral genomes were distributed in two robust clusters within the distinct GISAID clades GH and G. Spatial-temporal analyses revealed two independent introductions of SARS-CoV-2 in the region, one around April 1, 2020 associated with a local transmission, and one around April 2, 2020 associated with other South American genomes (Uruguay and Brazil). We also identified ten lineages circulating in the Amazonas department including the P.1 variant of concern (VOC). CONCLUSIONS/SIGNIFICANCE: This study represents the first genomic epidemiology investigation of SARS-CoV-2 in one of the territories with the highest report of indigenous communities of the country. Such findings are essential to decipher viral transmission, inform on global spread and to direct implementation of infection prevention and control measures for these vulnerable populations, especially, due to the recent circulation of one of the variants of concern (P.1) associated with major transmissibility and possible reinfections.

Exploring the dynamics of migration, armed conflict, urbanization, and anthropogenic change in Colombia.

Anthropogenic change has been associated with population growth, land use change, and changing economies. However, internal migration patterns and armed conflicts are also key drivers of anthropogenic and demographic processes. To better understand the processes associated with this change, we explore the spatial relationship between forced migration due to armed conflict and changing socioeconomic factors in Colombia, a country which has a recent history of 7 million internal migrants. In addition, we use remote sensing, Google Earth Engine, as well as spatial statistical analyses of demographic data in order to measure anthropogenic change between 1984 and 2013-a socio-politically important period in Colombia's armed conflict. We also analyze spatiotemporal relationships between socioeconomic and anthropogenic changes, which are caused by forced migration. We found that forced migration is significantly and positively related to an increasing rural-urban type of migration which results from armed conflict. Results also show that it is negatively related to interregional displacement. Indeed, anthropogenic change pertaining to different regions have had different correlations with forced migration, and across different time periods. Findings are used to discuss how socioeconomic and political phenomena such as armed conflict can have complex effects on the dynamics of anthropogenic and ecological change as well as movement of humans in countries like Colombia.

Spatio-temporal dynamics of Plasmodium falciparum transmission within a spatial unit on the Colombian Pacific Coast.

As malaria control programmes concentrate their efforts towards malaria elimination a better understanding of malaria transmission patterns at fine spatial resolution units becomes necessary. Defining spatial units that consider transmission heterogeneity, human movement and migration will help to set up achievable malaria elimination milestones and guide the creation of efficient operational administrative control units. Using a combination of genetic and epidemiological data we defined a malaria transmission unit as the area contributing 95% of malaria cases diagnosed at the catchment facility located in the town of Guapi in the South Pacific Coast of Colombia. We provide data showing that P. falciparum malaria transmission is heterogeneous in time and space and analysed, using topological data analysis, the spatial connectivity, at the micro epidemiological level, between parasite populations circulating within the unit. To illustrate the necessity to evaluate the efficacy of malaria control measures within the transmission unit in order to increase the efficiency of the malaria control effort, we provide information on the size of the asymptomatic reservoir, the nature of parasite genotypes associated with drug resistance as well as the frequency of the Pfhrp2/3 deletion associated with false negatives when using Rapid Diagnostic Tests.

Ethnography of a parasite: A quantitative ethnographic observation of forest malaria in the Amazon basin.

Aims: Malaria in the Amazon basin is persistently more prevalent among low density populations (1-4 people/km2). Describing malaria transmission in small populations, such as ethnic minorities in the Amazon basin, living in reserves in groups that amount to 110-450 individuals, is fundamental for the implementation of adequate interventions. Here, we examine malaria transmission in a context of high prevalence in a small population of Nükak ethnicity (ethnic group n=400-650 individuals, study group, n=108 individuals) living in the peri-urban area of a city with 35,000 inhabitants in the Amazon basin. Methods: Using methods from behavioral ecology, we conducted a quantitative ethnography and collected data to inform of individual behavioral profiles. Individual malarial infection reports were available from the local public health offices, so each behavioral profile was associated with an epidemic profile for the past 5 years. Results: Our research shows that, in-line with current opinion, malaria among the Nükak is not associated with an occupational hazard risk and follows a holoendemic pattern, where children are most susceptible to the parasite. Parasite loads of malarial infection among the Nükak persist at much higher rates than in any other neighboring ethnicity, which indicates an association between high incidence rates and endemicity. Conclusions: We hypothesize that malarial infection in the forest follows a pattern where the parasite persists in pockets of holoendemicity, and occupational hazard risk for individuals outside those pockets is associated with behaviors that take place in the proximity of the pockets of endemicity.

Malaria intensity in Colombia by regions and populations.

Determining the distribution of disease prevalence among heterogeneous populations at the national scale is fundamental for epidemiology and public health. Here, we use a combination of methods (spatial scan statistic, topological data analysis and epidemic profile) to study measurable differences in malaria intensity by regions and populations of Colombia. This study explores three main questions: What are the regions of Colombia where malaria is epidemic? What are the regions and populations in Colombia where malaria is endemic? What associations exist between epidemic outbreaks between regions in Colombia? Plasmodium falciparum is most prevalent in the Pacific Coast, some regions of the Amazon Basin, and some regions of the Magdalena Basin. Plasmodium vivax is the most prevalent parasite in Colombia, particularly in the Northern Amazon Basin, the Caribbean, and municipalities of Sucre, Antioquia and Cordoba. We find an acute peak of malarial infection at 25 years of age. Indigenous and Afrocolombian populations experience endemic malaria (with household transmission). We find that Plasmodium vivax decreased in the most important hotspots, often with moderate urbanization rate, and was re-introduced to locations with moderate but sustained deforestation. Infection by Plasmodium falciparum, on the other hand, steadily increased in incidence in locations where it was introduced in the 2009-2010 generalized epidemic. Our findings suggest that Colombia is entering an unstable transmission state, where rapid decreases in one location of the country are interconnected with rapid increases in other parts of the country.