Biology subjects

Kayal, M.

Publications and source records attributed to Kayal, M..

4 recordsLinked to original sources

bioRxiv2023

Myeloid cell influx into the colonic epithelium is associated with disease severity and non-response to anti-Tumor Necrosis Factor Therapy in patients with Ulcerative Colitis.

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colon with sharply rising global prevalence. Dysfunctional epithelial compartment (EC) dynamics are implicated in UC pathogenesis although EC-specific studies are sparse. Applying orthogonal high-dimensional EC profiling to a Primary Cohort (PC; n=222), we detail major epithelial and immune cell perturbations in active UC. Prominently, reduced frequencies of mature BEST4+OTOP2+ absorptive and BEST2+WFDC2+ secretory epithelial enterocytes were associated with the replacement of homeostatic, resident TRDC+KLRD1+HOPX+ {gamma}{delta}+ T cells with RORA+CCL20+S100A4+ TH17 cells and the influx of inflammatory myeloid cells. The EC transcriptome (exemplified by S100A8, HIF1A, TREM1, CXCR1) correlated with clinical, endoscopic, and histological severity of UC in an independent validation cohort (n=649). Furthermore, therapeutic relevance of the observed cellular and transcriptomic changes was investigated in 3 additional published UC cohorts (n=23, 48 and 204 respectively) to reveal that non-response to anti-Tumor Necrosis Factor (anti-TNF) therapy was associated with EC related myeloid cell perturbations. Altogether, these data provide high resolution mapping of the EC to facilitate therapeutic decision-making and personalization of therapy in patients with UC.

immunology↗

bioRxiv2023

Coral demographic performances in New Caledonia, a video transect approach to operationalize imagery-based investigation of population and community dynamics

Demographic studies that quantify species performances for survival, growth, and reproduction are powerful means to understand and predict how species and communities respond to environmental change through the characterization of population dynamics and sources of demographic bottlenecks. However, demographic studies require fine-scale surveys of populations in the field, and are often too effort-intensive to be replicable at large scale and in the long-term. To surpass this obstacle, we developed a digital approach for extracting demographic data on species abundances, sizes, and positions within video-transects, facilitating back-from-the-field data acquisitions on population and community dynamics from video surveys. The approach is based on manual coral identification, size-measurements, and mapping along video-transects, mimicking what is traditionally performed in the field, thought it can be automated in the future with the deployment of artificial intelligence. We illustrate our approach with the characterizations of species demographic performances using surveys of a reef-building coral community in New Caledonia recorded with underwater cameras, therefore optimizing time spent in the field. The results provide quantitative measures of coral community composition and demographic performances as key ecological indicators of coral reef health, shed light on species life strategies and constraints to their demographics, and open paths for further quantitative investigations. Key findings include the diversity of species life strategies in terms of relative investment in survival, growth, and reproduction found among taxa dominating the coral community, indicating the diversity of demographic paths to ecological success and that several species have adapted mechanisms to prevail under limiting hydrodynamic environments. Our approach facilitates image-based extractions of demographic data, helping to accelerate empirical endeavors in ecology and ecosystem management. Author summarySustainable ecosystem management requires comprehension of key ecological processes that affect species resilience. Accurate and reoccurring measurements of species helps us understand how they are responding to various environments and predict what might happen in the future. We developed a digital approach that mimics measurements traditionally performed in the field to measure species abundance, size, and distributions using video records of the ecosystems. This transition to imagery-based surveys helps researchers and managers acquire fine-scale ecological data while optimizing time spent in the field, particularly for studying remote and extreme environments where access is limited. We illustrate the application of our approach by characterizing the dynamics of a coral community in the vast tropical reef system of New Caledonia, where such evaluations of demographic processes controlling coral resilience are inexistent but necessary.

ecology↗

bioRxiv2021

The war of corals: patterns, drivers, and implications of changing coral competitive performances across reef environments

Amidst global environmental changes, predicting species responses to future environments is a critical challenge for preserving biodiversity and associated human benefits. We explored the original idea that coral competitive performances, the ability of corals to preempt ecological space on the reef through territorial warfare, serve as indicators of species ecological niches and environmental windows, and therefore, responses to future environments. Our surveys indicated that coral performances varied with taxonomic-identity, size, and position along environmental gradients, highlighting complex interplays between life-history, warfare-strategy, and niche segregation. Our results forewarn that growing alterations of coastal environments may trigger shifts in coral dominance, with decline of major reef-building taxa like acroporids, and underscore the importance of restraining human impacts for coastal resilience. Our empirical approach untangles the complexity of species battle-like interactions and can help identify winners and losers in various communities caught in the interplay between ecological niches, environmental windows, and global changes.

ecology↗

bioRxiv2020

Marine reserve benefits and recreational fishing yields: the winners and the losers

Marine reserves constitute effective tools for preserving fish stocks and associated human benefits. However, not all reserves perform equally, and predicting the response of marine communities to management actions in the long run is challenging. Our decadal-scale survey of recreational fishing yields at Frances 45-year old Cerbere-Banyuls marine reserve indicated significant protection benefits, with 40-50% higher fishing yields per unit effort in the partial-protection zone of the reserve (where fishing is permitted but at a lower level) than in surrounding non-reserve areas. Over the period 2005-2014, catch per unit effort (CPUE) showed a similar pattern of decline inside and outside the reserve while weight per unit effort (WPUE) increased by 131% inside and decreased by 60% outside. Different CPUE and WPUE trajectories among fish families indicated changing catch assemblages, with yields increasing for the family most valued by fisheries, Sparidae (the ecological winners). However, reserve benefits were restricted to off-shore fishermen (the social winners), as on-shore yields were [~]4 times lower and declining, even inside the reserve. Our study illustrates how surveys of recreational fishing yields can help evaluate the effectiveness of marine protected areas for key social and ecological protagonists. We show that, more than four decades after its establishment, fishing efficiencies at the historical Cerbere-Banyuls marine reserve are still changing, but benefits in terms of catch abundance, weight, and composition remain predominantly restricted to off-shore fishermen. Further regulations appear necessary to guarantee that conservation strategies equitably benefit societal groups.

ecology↗