Biology subjects

Chawla, N.

Publications and source records attributed to Chawla, N..

4 recordsLinked to original sources

bioRxiv2026

Air Pollution, Early Adversity, and Amygdala: Environmental Correlates of Psychopathology in Preadolescents

Early life adversity (ELA) and ambient fine particulate matter (PM2.5) are hypothesized to be environmental risk factors for altered brain structure and psychopathology, but their unique and interactive effects in childhood remain unclear. This study examines the interactive associations of ELA and annual average residential PM2.5 exposure (total mass and 15 components) on total amygdala and basolateral amygdala subregion volumes and psychopathology symptoms in a subset of children (N=3,601, 45% assigned female at birth, 9-10 years) from the Adolescent Brain Cognitive Development Study. Linear mixed-effects models, adjusting for sociodemographic factors, co-pollutants, and neuroimaging covariates, showed that ELA was associated with greater bifactor model-defined general, specific internalizing, and specific externalizing symptoms of psychopathology. PM2.5 moderated ELA associations with specific externalizing symptoms, with greater symptoms in those exposed to higher ELA and higher PM2.5 exposures. Among youth with higher ELA, smaller basolateral paralaminar volumes were linked to greater general and specific externalizing symptoms. These findings underscore the importance of considering psychosocial and physical environmental co-exposures when identifying children at risk for psychopathology.

neuroscience↗

bioRxiv2026

A Functional Basis for the Developmental Sequence of the Macrostructure of the Venus Flower Basket (Euplectella aspergillum)

Despite receiving significant interest from the biological and engineering communities, several questions about the underlying reasons for the form of the deep-sea sponge Venus Flower Basket (Euplectela aspergillum) remain unanswered. In particular, the basis for the sequence of emergence of three distinct macroscopic geometric features, while speculated upon, has not been validated. These features are (i) an interwoven cross-grid in the juvenile stage, (ii) a diagonal weave atop this initial grid, and (iii) a helical ridge that emerges in the mature phase of the sponge. This work uses computational design and additive manufacturing to fabricate models of each of these phases in sequence and subjects the models to mechanical tests in compression, bending and torsion. The results show that each feature has a singular advantage, even after accounting for the increase in mass associated with their addition: increased compliance for interwoven cross-grid, increased bending stiffness for diagonal weaves, and improved torsional rigidity for the helical ridge. The work postulates that the prioritization of compliance in the juvenile phase and a transition to a stiffer structure in the mature phase is a strategy that enables the sponge to avoid high internal stresses to avoid failure in its inherently brittle, silica-derived architecture. Highlights1. The benefits of three macrostructural design elements of the Venus Flower Basket (E. aspergillum) that emerge sequentially in its development are examined: (i) the interweaving cross-grid, (ii) the diagonal weave that overlays this cross-grid, and (iii) the helical ridge reinforcement that forms over this diagonal weave. 2. For the first time, this work models each of these design features sequentially and studies their mechanical benefits through an experimental exploration of the behavior of idealized geometries in three test domains: compression, bending, and torsion. 3. Results show that each of these three structural elements has a unique functional advantage depending on the organisms growth stage, even after accounting for differences in mass: interweaving enables higher compliance under compression, the diagonal weave improves bending stiffness, and the helical ridge improves torsional stiffness.

developmental biology↗

bioRxiv2021

Global port survey quantifies commercial shippings effect on biodiversity

Spread of nonindigenous organisms by shipping is one of the largest threats to coastal ecosystems. Limited monitoring and understanding of this phenomenon currently hinder development of effective prevention policies. Surveying ports in North America, South America, Europe, Southeast Asia, and Australia we explored environmental DNA community profiles evident of ship-born species spread. We found that community similarities between ports increased with the number of ship voyages, particularly if the ports had similar environments, and when indirect stepping-stone connections were considered. We also found 57 known non-indigenous taxa, some in hitherto unreported locations. We demonstrate the usefulness of eDNA-based tools for global biodiversity surveys, and highlight that shipping homogenizes biodiversity in predictable that could inform policy and management.

ecology↗

bioRxiv2019

Higher-order patterns of aquatic species spread through the global shipping network

The introduction and establishment of non-indigenous species (NIS) through global ship movements is a significant threat to marine ecosystems and economies. While ballast-vectored invasions have been partly addressed by some national policies and an international agreement regulating the concentrations of organisms in ballast water, biofouling-vectored invasions remain a large risk. Development of additional realistic and cost-effective ship-borne NIS policies requires an accurate estimation of NIS spread risk from both ballast water and biofouling. In this paper, we demonstrate that first-order Markov assumptions limit accurate modeling of NIS spread risks through the global shipping network. In contrast, we show that higher-order patterns overcome this limitation by revealing indirect pathways of NIS transfer. We accomplish this by developing Species Flow Higher-Order Networks (SF-HON), which we developed independently for ballast and biofouling, for comparison with first-order Markovian models of ballast and biofouling. We evaluated SF-HON predictions using the largest available datasets of invasive species for Europe and the United States. We show that not only does SF-HON yield more accurate NIS spread risk predictions than first-order models and existing higher-order models, but also that there are important differences in NIS spread via the ballast and biofouling vectors. Our work provides information that policymakers can use to develop more efficient and targeted prevention strategies for ship-borne NIS spread management, especially as management of biofouling is of increasing concern.

ecology↗