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Biology subjects

Aviles, A.

Publications and source records attributed to Aviles, A..

6 recordsLinked to original sources

Microplastic exposure alters immune-related gene expression in Culex quinquefasciatus mosquitoes and larval microbiota diversity

Background: Microplastics have been detected in many freshwater ecosystems, including stagnant waters where mosquito larvae develop. Larvae are therefore exposed to microplastic pollution, which may affect their life history traits or microbiota along with immune gene expression. However, these effects have never been tested in mosquitoes, despite their major public health importance as vectors of numerous pathogens. Method: We exposed mosquito larvae, from hatching to adult emergence, to four concentrations of polyethylene microplastics (MPs): 0, 60, 200, and 600 MPs/mL. Fourth-instar larvae and newly emerged adult females were collected for each treatment. To investigate the effects of MPs on gene expression and bacterial microbiota, RNA sequencing and 16S metabarcoding approaches were performed on three biological replicates for each developmental stage. Results: Microplastic exposure induced a non-monotonic dose-dependent transcriptomic response. In larvae, only a limited number of genes were differentially expressed (five to eight per concentration), with immune-related genes downregulated at both low and high concentrations. In adult females, the intermediate concentration (200 MPs/mL) elicited the strongest response with 14 differentially expressed genes (DEGs). Regarding the microbiota, microplastic exposure reduced bacterial diversity in larvae, with the lowest diversity observed at the highest concentration. However, no significant changes were detected in the microbiota of adult females. Conclusion: Overall, this study shows that adult females are affected by larval exposure to MPs (i.e. differential expression in immune-related genes) and warrants further studies in this field. This includes: 1) investigating further the effects of MPs on mosquitoes' populations (e.g. through multi-generational studies), 2) gaining more environmentally relevant knowledge on MP effects (i.e. using MPs with a biofilm and/or adsorbed pollutants) and 3) focusing on the effects of MPs on mosquitoes' vectorial capacities.

ecology↗

The Missing Memory Imprint

We provide evidence that the brain searches for salient stimuli below the level of conscious awareness. We show that, while targets are found very efficiently in Rapid Serial Visual Presentation (RSVP), distractors do not leave a strong memory trace, especially if the memory probe is unexpected. This fits with traditional theories of late attentional selection, whereby "correct rejections" of non-targets are performed with very little processing cost. Our findings are also consistent with the tokenized percept theory of conscious perception, one element of which is that conscious awareness is required to provide sustained representations.

animal behavior and cognition↗

Presence of Ecuador in the Web of Science from open access in post-pandemic period 2019-2021: A multivariate analysis.

The study analyzed the presence of Ecuador in the post-pandemic Web of Science (WoS) from a multivariate dynamic, highlighting a significant transformation in scientific communication towards open access (OA). The methodology integrated multivariate statistical techniques, using R and specialized tools, to process 9,085 relevant articles. Between 2019 and 2021, 52% of Ecuadorian publications in WoS were open access. This movement reflects a commitment to quality research and accessibility, evidencing an increase in publications and citations under OA. The research highlights the importance of establishing robust national OA policies in Ecuador to promote scientific collaboration and an equitable distribution of knowledge. The dynamic biplot showed how universities in the post-pandemic period had stable and erratic behaviors towards open access. Of all the universities, the State University of Cuenca stands out in terms of quantity of production and migration to open access.

scientific communication and education↗

Changes in local interaction rules during ontogeny underlie the evolution of collective behavior

Collective motion emerges from individual interactions which produce groupwide patterns in behavior. While adaptive changes to collective motion are observed across animal species, how local interactions change when these collective behaviors evolve is poorly understood. Here, we use the Mexican tetra, A. mexicanus, which exists as a schooling surface form and a non-schooling cave form, to study differences in how fish alter their swimming in response to neighbors across ontogeny and between evolutionarily diverged populations. We find that surface fish undergo a transition to schooling during development that occurs through increases in inter-individual alignment and attraction mediated by changes in the way fish modulate speed and turning relative to neighbors. Cavefish, which have evolved loss of schooling, exhibit neither of these schooling-promoting interactions at any stage of development. These results reveal how evolution alters local interaction rules to produce striking differences in collective behavior.

evolutionary biology↗

Understanding the microbial biogeography of ancient human dentitions to guide study design and interpretation

The oral cavity is a heterogeneous environment, varying in factors such as pH, oxygen levels, and salivary flow. These factors affect the microbial community composition and distribution of species in dental plaque, but it is not known how well these patterns are reflected in archaeological dental calculus. In most archaeological studies, a single sample of dental calculus is studied per individual and is assumed to represent the entire oral cavity. However, it is not known if this sampling strategy introduces biases into studies of the ancient oral microbiome. Here, we present the results of a shotgun metagenomic study of a dense sampling of dental calculus from four Chalcolithic individuals from the southeast Iberian peninsula (ca. 4500-5000 BP). Inter-individual differences in microbial composition are found to be much larger than intra-individual differences, indicating that a single sample can indeed represent an individual in most cases. However, there are minor spatial patterns in species distribution within the oral cavity that should be taken into account when designing a study or interpreting results. Finally, we show that plant DNA identified in the samples may be of environmental origin, showing the importance of including environmental controls or several lines of biomolecular evidence.

microbiology↗

Sedation modulates fronto-temporal predictive coding circuits and the double surprise acceleration effect

Two important theories in cognitive neuroscience are predictive coding and the global workspace theory. A key research task is to understand how these two theories relate to one another, and particularly, how the brain transitions from a predictive early state to the eventual engagement of a brain-scale state (the global workspace). To address this question, we present a source-localisation of EEG responses evoked by the local-global task - an experimental paradigm that engages a predictive hierarchy, which encompasses the global workspace. The results of our source reconstruction suggest three-phases of processing. The first phase involves the sensory (here auditory) regions of the superior temporal lobe and predicts sensory regularities over a short timeframe (as per the local effect). The third phase is brain-scale, involving inferior frontal, as well as inferior and superior parietal regions; consistent with a global neuronal workspace (as per the global effect). Crucially, our analysis suggests that there is an intermediate (second) phase, involving modulatory interactions between inferior frontal and superior temporal regions. Furthermore, sedation with propofol reduces modulatory interactions in the second phase. This selective effect is consistent with a predictive coding explanation of sedation, with propofol acting on descending predictions of the precision of prediction errors; thereby constraining access to the global neuronal workspace.

neuroscience↗