Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

 From the beginning of colonization, guilds were formed in Quito to defend the work of those who practiced the same trade. 

The anaco is a clothing artifact that covers the body of the Andean woman, identifying her ethnic group and shedding light on the dynamics of culture. 

The central objective of this article is to analyze transnational practices within border regions. The theoretical analysis focuses on the participation of rural workers, including members of the Landless Rural Workers’ Movement (MST), in transnational activities on the border between Brazil and Paraguay. Based on the cross-border experience of rural workers’ relations, part of a longitudinal study starting in 2012, with annual/bi-annual visits culminating in the final fieldwork in 2024, this article argues that geographical proximity and the search for a piece of land for subsistence have an essential role in cross-border transnationalism between Brazil and Paraguay. Based on own studies, defining transnationalism within border regions as proximal transnationalism is proposed. This case study also demonstrates how the participation of this group in transnationalism, encompassing agrarian issues in both countries, contributes to the formation of Brasiguaio identity (Brazilian + Paraguayan).

The article aims to understand border citizenship not as a normative model, but as an everyday experience that people talk about through their lives, struggles and survival strategies. The empirical data reported here were produced from qualitative research developed between 2014 and 2018 by the authors with the support of local researchers who, among other things, have helped to conduct field observations, interviews and focus groups on border territories of Colombia, Peru and Brazil. The fundamental outcome was to think about border citizenship at the intersection with territory, state and market, emphasizing the tactics of citizenship produced from cross-border mobilities and the quest for rights in neighboring countries, even when the authorities consider certain practices illegal. From this perspective, citizenship tactics are important social resources rooted in the everyday life of border territories.

This paper analyzes the individuation trajectories of Central American migrants residing in the Metropolitan Area of Monterrey, Mexico. The study bridges the tradition of life trajectory analysis in migration studies with theoretical approaches from the sociology of individuation. It employs the principle of narrative anchoring to examine contemporary settlement experiences, reflecting on the specific processes involved in producing individuals within the context of irregular migration. Based on life stories collected between 2017 and 2022, the research identifies and articulates three key trials that shape the trajectories and the individuation of (in)migrant subjects in this socio-historical context: the migratory journey in an irregular situation, the labor trial and the process of obtaining papers in a context of institutional withdrawal, are sustained from exceptional and precarious supports, producing highly agentic individuals.

Background. The purple snail is ancestrally important along the coast of Oaxaca as its dye is used by the indigenous Mixtec people to dye culturally valuable cotton yarns. A snail population located in a protected area named Huatulco National Park (HNP) is decreasing because specimens of all sizes are targeted more than once for dye extraction throughout the exploitation season (from October to March). This cultural practice occurs because the indigenous Mixtec people believe that dye production is continuous and increases proportionally in relation to shell length. Goals. The objective of this study was to establish the relationship between the total volume of extracted dye and the total length of the shell. Methods. In this study we implemented a neural regression model with artificial intelligence and a biological oscillatory growth model to demonstrate that dye production does not increase proportionally in relation to shell length. Results. The results suggest that snails of all sizes require a break to synthesize more dye after milking. Smaller snails of 2.7 to 4.2 cm produce a small volume of dye and conduct energy to growth, while larger snails of 4.8 to 7.7 cm produce a large volume of dye, but grow less. Conclusion. Our results allow us to conclude that dye production does not increase proportionally in relation to changes in shell length. At any size, a snail requires a rest to synthesize more dye after being milked. Special marks should be used to identify milked specimens in order to avoid repetitive dye extraction.

Background: Benthic macroalgae offer a suitable habitat for the development of different epibenthic species. Knowing the macroalgal surface area allows the study of epibenthic assemblages, as well as the evaluation of interactions between host and epibiont. Goals: The aim of this research was to estimate the specific surface area of benthic macroalgae collected at two coastal sites in Veracruz, southwestern Gulf of Mexico. Methods: From August 2016 to July 2017, 12 monthly collections were made. The formation of the Methylene Blue monolayer on the macroalgal surface was verified using the Langmuir isotherms. The biomass of brown algae was chemically treated to cause the formation of the monolayer. Results: For all examined algal species (11 Rhodophyta, 6 Chlorophyta and 4 Phaeophyceae from four morpho-functional groups) the adsorption equilibrium point was reached with a high correspondence between the experimental and calculated data (R2>0.96). The formation of the monolayer allowed estimation of the macroalgal specific surface area, which varied significantly among species, from 24 to 387 m2 g-1. The corticated algae exhibited the greatest specific surface area (143-222 m2 g-1), and the articulated calcareous forms had the least area (63-104 m2 g-1). However, no correlation between the specific surface area and the morpho-functional groups was found (P<0.05). In most algae, significant differences in specific surface area were observed in thalli of the same species (P<0.05). Conclusions: The results could be related to infraspecific variability in morphological characteristics of the thallus that occur during ontogenesis under environmental conditions. The Methylene Blue adsorption technique is suitable for determination of the surface area and allows the comparison of macroalgae of different morpho-functional groups, thus minimizing the uncertainty associated with species-specific characteristics.

The Cutzamala System supplies drinking water to part of the Metropolitan Area of the Valley of Mexico, with the Valle de Bravo (VB) reservoir being one of the primary sources. This reservoir has received impacts from domestic, agricultural, and tourist activities, resulting in a deterioration in water quality, favoring eutrophication and the development of Harmful Algal Blooms (HABs), potentially harmful to aquatic biota and human health. This study evaluated the effect of crude extracts of phytoplankton biomass from the reservoir on Danio rerio. Biomass samples were collected at six points from March to December 2019. The crude aqueous extracts were obtained by cell breakdown and were used to expose D. rerio embryos, evaluating the concentrations of 0.01, 0.1, 1, 10, and 100 mg L-1 of phytoplankton biomass. Information was available on different types of cyanotoxins and their concentration in the biomass at the sampling sites. Exposure to crude extracts on embryos produced lethal effects (coagulation and death), and sublethal responses (absence of pigmentation, yolk sac edema, curved tail), and teratogenic effects. In the biomass samples, cyanotoxins such as anabaenopeptins and microcystins were identified in various quantities during the sampling period. The presence and frequency of the effects observed in D. rerio were related to the concentration of microcystins and the probable presence of other potentially toxic secondary metabolites of cyanobacteria in VB reservoir. The results warn about the harmful effects that can occur in aquatic biota after the breakdown of cyanobacterial biomass following a bloom and also advise about the potential risks to human health when this water is processed and used for human consumption. Keywords: cyanotoxins, lethal effects, sublethal effects, Harmful Algal Blooms (HABs), Harmful Cyanobacterial Blooms (HCBs)    

Background: The knowledge of the reproductive cycle of Mugil curema at southern areas of the Gulf of Mexico is limited, so it is necessary to carry out studies as the white mullet is considered a species complex. Objective: To describe the reproductive cycle (sex maturation cycle and sex ratio) of M. curema in two localities in the southern Gulf of Mexico (GM): Laguna de Alvarado (AL) and Puerto Ceiba (PC). Methods: A total of 616 specimens were analyzed, 298 for the Laguna de Alvarado, Veracruz and 318 from Puerto Ceiba, Tabasco. Results: Females and males of M. curema reach sexual maturity (L50) with mean size of 33.26 and 34.41 and 30.02 and 30.74 cm for AL and PC, respectively. In PC, spawning occurs practically year-round from September to June with higher values from January to June, while in AL it occurred between December and April. The spawning seasons in the northern and southern areas of the GM show similar maximum values but in the south spawning lasts longer. The minimum spawning size for females and males was 27.8 and 26.3 and 27.8 and 25.6 cm for AL and PC, respectively. The Gonadosomatic Index was a good indicator were the maximum values coincide with the months with the greatest development. The female/male ratio was 1:0.6 and 1:0.5 for LA and CP, respectively. Conclusion: Spawning is different between localities, Laguna de Alvarado and Puerto Ceiba, the latter being more extensive practically throughout the year. The female/male ratio favored females in both locations. Key words: Mugil; white mullet; spawning; reproduction; Gulf of Mexico.

Background. Harmful algal blooms have increased in frequency, intensity and distribution in the last decades around the world. This increase has also been observed for the waters of the Mediterranean Sea. In November 2023, several reddish patches were observed in İzmir Bay (Aegean Sea); the dinoflagellate Polykrikos hartmannii was the causative agent. Goal. The purpose of this study was to report for the first time a bloom of this species in İzmir Bay. Methods. During the bloom, surface samples of seawater were collected using 1 liter plastic bottles at eleven sampling stations and fixed with Lugol for cell counting, which were performed under an OLYMPUS BX-50 microscope, using 1 ml Sedgewick-Rafter chambers. Samples were collected for live analysis and correct identification of the responsible species. Results. The moderate bloom occurred in November 2023 was caused by Polykrikos hartmannii. During the bloom two-celled chains were the predominant species, with single cells occurring less frequently. The highest cell abundance (4.8 x 104 cells L-1) was observed at station 29 in the inner bay. Cell sizes were 29.7 - 34.6 μm long, and 39.6 - 44.5 μm wide. Conclusions. Living samples allowed correct identification of P. hartmannii. Cells tend to become round or disrupted when preserved with Lugol’s solution. This may be why this species has not been previously reported. The maximum abundance of P. hartmannii was recorded in İzmir Bay at a water temperature of 14.84 °C and a salinity of 38.02 ‰, coinciding with highest values of nutrients. The bloom occurred in the shallowest area with limited water circulation and significant riverine inflow.