Arsenic is a carcinogenic groundwater contaminant that is toxic even at the parts-per-billion (ppb) level and its on-site determination remains challenging. Colorimetric test strips, though cheap and widely used, often fail to give reliable quantitative data. On the other hand, electrochemical detection is sensitive and accurate but considerably more expensive at the onset. Here, we present a study on arsenic detection in groundwater using a low-cost, open-source potentiostat based on Arduino technology. We tested different types of gold electrodes (screen-printed and microwire) with anodic stripping voltammetry (ASV), achieving low detection limits (0.7 μg L-1). In a study of arsenic contaminated groundwaters in Mexico, the microwire technique provides greater accuracy than test strips (reducing the median error from -50% to +2.9%) and greater precision (reducing uncertainties from ±25% to ±4.9%). Most importantly, the rate of false negatives versus the World Health Organisation’s 10 μg L-1 limit was reduced from 50% to 0% (N = 13 samples). Arsenic determination using open-source potentiostats may offer a low-cost option for research groups and NGOs wishing to perform arsenic analysis in-house, yielding superior quantitative data than the more widely used colorimetric test strips.

There is evidence of the risk of overexposure of children on social networks by parents working as influencers. A cross-sectional study of the profiles of the sixteen most-followed Instamoms in Spain was carried out. An analysis of these profiles was performed over a full month (April 2022), three times a week, to describe the representation of influencers’ children in the posts shared by them, as well as their role in the Instamoms’ marketing. A total of 192 evaluations of the profiles were performed in the study period. The average number of children exposed by an Instamom was three, generally preschoolers and schoolchildren. The children appear in a context of the family home and accompanied by their mother. The type of advertising that accompanies the appearance of underage children is usually women or children’s clothing, but also food products, leisure, etc. Appearance of children in the posts had a statistically significant influence on followers measured by the number of likes. Results provided the identification of two Instamom clusters with differentiated behaviors in relation to appearance of children in posts. It is important to involve Social Pediatrics in the protection of the privacy and interests of children given the increase in sharenting. The authors believe that there are concerns about their explicit consent to public exposure from early childhood and about the medium and long-term effect that this may have on their future well-being.

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Las relaciones entre la Iglesia y el Estado no siempre han sido armónicas en Venezuela y durante el gobierno de Hugo Chávez el conflicto se ha ahondado. Este trabajo estudia un macro acto de habla constituido por el insulto de Chávez al Cardenal Urosa Savino y la respuesta de éste. Basándonos en el análisis crítico del discurso y la teoría de la cortesía, observamos la complejidad del episodio, que tiene aspectos civiles, religiosos y diplomáticos; asimismo, dado el peso institucional de los interlocutores tiene además un efecto perlocutivo importante. Como lo señalan Jucker y Taatsvisainen (2000), el insulto se define por la reacción del interlocutor. En el caso analizado, la reacción fue una respuesta contundente por parte del prelado, al señalar que el Presidente no tenía el derecho a insultar, al mismo tiempo que le hace una fuerte crítica a él y a su gestión de gobierno. Ninguno de los interlocutores es cortés, ni muestra interés en resolver el conflicto de forma amistosa.