Biology subjects

Vieira, M.

Publications and source records attributed to Vieira, M..

4 recordsLinked to original sources

bioRxiv2026

Overcoming software bottlenecks for scalable passive acoustic monitoring: insights from a global expert assessment

1.Passive acoustic monitoring (PAM) enables non-invasive sampling of wildlife across broad spatial, temporal and taxonomic scales. Its ongoing and widespread use has generated unprecedented volumes of acoustic data, shifting the primary bottleneck from data collection to the storage, processing, integration, and interpretation of PAM outputs. Although many software tools exist to address these challenges, differences in their design, scope, and usability often create fragmented and complex analytical workflows. To identify the key barriers and opportunities shaping the implementation of PAM surveys, we conducted a structured expert solicitation involving 30 international practitioners working across terrestrial and aquatic ecosystems. Experts identified and ranked their most critical pain points in current PAM workflows, spanning data storage, processing, and interpretation. The top challenge identified related to accurate species identification using deep learning and artificial intelligence (AI) models, especially in noisy soundscapes or for underrepresented taxa. Eight additional priority challenges included workflow fragmentation, limited availability of user-friendly analytical and visualisation tools, uneven access to software, manual validation bottlenecks, computational constraints, and difficulties in data handling, standardisation, and sharing. Participants also proposed practical mitigation strategies for these priority challenges, supported by step-by-step guidance to help overcome key barriers. Together, these insights provide a roadmap toward more scalable, open-access, and collaborative software systems, which are increasingly essential to realise the full potential of PAM in global biodiversity monitoring.

ecology↗

bioRxiv2023

Direct interhemispheric cortical communication via thalamic commissures: a new white-matter pathway in the primate brain

Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported an additional commissural pathway in rodents, termed the thalamic commissures (TCs), as another interhemispheric axonal fiber pathway that connects cortex to the contralateral thalamus. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted magnetic resonance imaging, viral axonal tracing, and functional MRI. We present evidence of TCs in both New World (Callithrix jacchus and Cebus apella) and Old World primates (Macaca mulatta). Further, like rodents, we show that the TCs in primates develop during the embryonic period, forming anatomical and functionally active connections of the cortex with the contralateral thalamus. We also searched for TCs in the human brain, showing their presence in humans with brain malformations, although we could not identify TCs in healthy subjects. These results pose the TCs as an important fiber pathway in the primate brain, allowing for more robust interhemispheric connectivity and synchrony and serving as an alternative commissural route in developmental brain malformations. Significance statementBrain connectivity is a central topic in neuroscience. Understanding how brain areas can communicate allows for the comprehension of brain structure and function. We have described in rodents a new commissure pathway that connects the cortex to the contralateral thalamus. Here, we investigate whether this pathway exists in non-human primates and humans. The presence of these commissures poses the TCs as an important fiber pathway in the primate brain, allowing for more robust interhemispheric connectivity and synchrony and serving as an alternative commissural route in developmental brain malformations.

neuroscience↗

bioRxiv2021

Helminth infection modulates number and function of adipose tissue Tregs in high fat diet-induced obesity

BackgroundEpidemiological and experimental studies have shown a protective effect of helminth infections in weight gain and against the development of metabolic dysfunctions in the host. However, the mechanisms induced by the parasite that regulate the development of metabolic diseases in the host are unclear. The present study aimed to verify the influence of Heligmosomoides polygyrus infection in early stages of high fat diet-induced obesity. Principal FindingsThe presence of infection was able to prevent exacerbated weight gain in mice fed with high fat diet when compared to non-infected controls. In addition, infected animals displayed improved insulin sensitivity and decreased fat accumulation in the liver. Obesity-associated inflammation was reduced in the presence of infection, demonstrated by higher levels of IL10 and adiponectin, increased infiltration of Th2 and eosinophils in adipose tissue of infected animals. Of note, the parasite infection was associated with increased Treg frequency in adipose tissue which showed higher expression of cell surface markers of function and activation, like LAP and CD134. The infection could also revert the loss of function in Tregs associated with high fat diet. ConclusionThese data suggest that H. polygyrus infection can prevent weight gain and metabolic syndrome in animals fed with high fat diet associated with modulations of adipose tissue Treg cells. Author summaryHelminth infections are known to modulate the immune system being responsible for protecting the host from developing allergic and autoimmune disorders (Hygiene Hypothesis). We hypothesized that the same immunomodulatory effect can have an impact on immunometabolic diseases, such as obesity and its linked diseases such as type 2 diabetes. Weight disorders have reached epidemic levels, nearly tripling since 1975 and being responsible for almost 5 million premature deaths each year. To test our hypothesis C57BL/6 male mice were fed control or high fat diet, for five weeks, in the presence or not of Heligmosomoides polygyrus infection. Weight gain, development of metabolic disorders, inflammation and cellular migration to the adipose tissue were evaluated. In accordance with our hypothesis, we found that the presence of infection prevented the exacerbated weight gain and also improved metabolic parameters in animals fed a high fat diet. This was associated with the infections ability to modulate parameters of a cell responsible for regulatory functions: Tregs. In the light of these findings, helminth infection could be protective against weight gain and metabolic disturbances.

immunology↗

bioRxiv2020

Dissecting signalling hierarchies in the patterning of the mouse primitive streak using micro-patterned EpiLC colonies.

Molecular embryology studies have established that the patterning of the gastrula-stage mouse embryo is dependent on a regulatory network where the WNT, BMP and NODAL signalling pathways cooperate. Still, important aspects of their respective contributions to this process remain unclear. Here, studying their impact on the spatial organization and the developmental trajectories of micro-patterned Epiblast Like Cells (EpiLC) colonies, we show that when BMP is present, it dominates NODAL and WNT and imposes a posterior character to the colonies differentiation. However, the use of two Nodal mutant cell lines allowed us to show that prior to BMP action, NODAL is required to establish the mesendodermal lineage. The fact that mutant phenotypes were more severe in vitro than in vivo suggests that embryonic phenotypes are partially rescued by ligands of extra-embryonic or maternal origin. Our work demonstrates the complementarity of micro-patterned EpiLC colonies to embryological approaches.

developmental biology↗