Biology subjects

Guimaraes, P.

Publications and source records attributed to Guimaraes, P..

5 recordsLinked to original sources

bioRxiv2025

Brazil Seed Transfer Zones: Supporting Seed Sourcing for Climate-Resilient Ecosystem Restoration

O_LIEcosystem restoration is key to jointly address the biodiversity, climate, and social inequality crises. In Brazil, large-scale seed-based restoration is gaining momentum, but a national framework to match seed sources with planting sites is still lacking, undermining long-term success. C_LIO_LIWe developed the first Seed Transfer Zones (STZs) for Brazil using 25 environmental variables. We assessed restoration supply and demand within each STZ and projected the zones into the future under contrasting climate change scenarios. C_LIO_LIWe identified 48 STZs, distributed across Brazils six major vegetation regions (Amazon, Cerrado, Atlantic Forest, Caatinga, Pantanal, and Pampa). Overlaying the STZs with data on seed collection capacity and restoration opportunities revealed priority regions where seed supply is unlikely to meet demand (e.g., Cerrado). Future climate projections also indicate substantial reshaping of STZs, with 51-88% of Brazils land area expected to experience mismatches between current and future seed zones. C_LIO_LIThe creation of Brazils first STZs provides a scalable framework to guide seed sourcing for restoration, aligning supply with demand, and future-proofing projects to deliver lasting benefits for biodiversity, climate, and society. C_LI Societal Impact StatementTens of millions of hectares of degraded land in Brazil are in need of ecosystem restoration to achieve national and global biodiversity and climate goals. Sowing genetically diverse native seeds is key to restoring degraded lands to climate-resilient landscapes, but we still lack guidance on how to effectively match seed sources to restoration sites across broad geographic scales, within the context of a changing climate. We addressed this by identifying 48 Seed Transfer Zones (STZs) based on current and expected future climatic conditions. These zones will help ensure that the right seeds are used in the right places, enabling more effective and climate-smart restoration for nature and people.

ecology↗

bioRxiv2025

The novel phenomenon of inter-retinal coupling predicts cortical neurovascular responses in health and disease

It has recently been discovered that physiological crosstalk exists between human retinas. Accordingly, visual stimulation of one retina elicited a neurovascular coupling (NVC) response of the contralateral retina in about 30% of individuals. The functional significance of this feature in health and disease remains unknown. Here, we asked the question whether inter-retina crosstalk predicts the nature of neurovascular coupling in the brain. To test this hypothesis, we assessed BOLD fMRI (blood-oxygen-level-dependent functional magnetic resonance imaging signal) in healthy individuals and a disease model of neurovascular coupling, type 1 diabetes. We used three visual paradigms: a Threshold speed and Sub-maximum speed discrimination tasks, and flicker stimulation. The presence or absence of inter-retinal coupling was predictive of the time course of the cortical hemodynamic response, either during the initial or late phases. The presence of interocular coupling predicted larger BOLD responses. Diabetic patients with interocular coupling showed a very similar profile to the healthy group. In sum, we identified a direct relationship between interocular physiological coupling and cortical hemodynamic responses, suggesting that this NVC response may serve as a disease biomarker in diabetes. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/684136v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@74ae56org.highwire.dtl.DTLVardef@61a2ccorg.highwire.dtl.DTLVardef@7349dorg.highwire.dtl.DTLVardef@10f61b2_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2021

The role of evolutionary modes for trait-based cascades in mutualistic networks

The erosion of functional diversity may foster the collapse of ecological systems. Functional diversity is ultimately determined by the distribution of species traits. As species traits are a legacy of species evolutionary history, one might expect that the mode of trait evolution influences community resistance under the loss of functional diversity. In this paper, we investigate the role of trait evolutionary dynamics on the robustness of mutualistic networks undergoing the following scenarios of species loss: i) random extinctions, ii) loss of functional distinctiveness and iii) extinctions biased towards larger sizes. We simulated networks defined by models of single trait complementary and evolutionary modes where traits can arise in recent diversification events with weak phylogenetic signal, in early diversification events with strong phylogenetic signal, or as a random walk through evolutionary time. Our simulations show that mutualistic networks are especially vulnerable to extinctions based on trait distinctiveness and more robust to random extinction dynamics. The networks show an intermediate level of robustness against size-based extinctions. Despite the small range of variation in network robustness, our results show that the mode of trait evolution matters for network robustness in all three scenarios. Networks with low phylogenetic signal are more robust than networks with high phylogenetic signal across all scenarios. As a consequence, our results predict that mutualistic networks based upon current adaptations are more likely to cope with extinction dynamics than those networks that are based upon conserved traits.

ecology↗

bioRxiv2020

Deep sncRNA-seq of the PPMI cohort to study Parkinson's disease progression

Coding and non-coding RNAs have diagnostic and prognostic importance in Parkinsons diseases (PD). We studied circulating small non-coding RNAs (sncRNAs) in 7, 003 samples from two longitudinal PD cohorts (Parkinsons Progression Marker Initiative (PPMI) and Luxembourg Parkinsons Study (NCER-PD)) and modelled their influence on the transcriptome. First, we sequenced sncRNAs in 5, 450 blood samples of 1, 614 individuals in PPMI. The majority of 323 billion reads (59 million reads per sample) mapped to miRNAs. Other covered RNA classes include piRNAs, rRNAs, snoRNAs, tRNAs, scaRNAs, and snRNAs. De-regulated miRNAs were associated with the disease and disease progression and occur in two distinct waves in the third and seventh decade of live. Originating mostly from a characteristic set of immune cells they resemble a systemic inflammation response and mitochondrial dysfunction, two hallmarks of PD. By profiling 1, 553 samples from 1, 024 individuals in the NCER-PD cohort using an independent technology, we validate relevant findings from the sequencing study. Finally, network analysis of sncRNAs and transcriptome sequencing of the original cohort identified regulatory modules emerging in progressing PD patients.

neuroscience↗

bioRxiv2017

Analyzing ecological networks of species interactions

Networks provide one of the best representations for ecological communities, composed of many species with sometimes complex connections between them. Yet the methodological literature allowing one to analyze and extract meaning from ecological networks is dense, fragmented, and unwelcoming. We provide a general overview to the field of using networks in community ecology, outlining both the intent of the different measures, their assumptions, and the contexts in which they can be used. When methodologically justified, we suggest good practices to use in the analysis of ecological networks. We anchor this synopsis with examples from empirical studies, and conclude by highlighting what identified as needed future developments in the field.

ecology↗