Biology subjects

Robbins, C.

Publications and source records attributed to Robbins, C..

6 recordsLinked to original sources

bioRxiv2026

MyoAssist 1.0: An Open-Source Framework for Neuromechanical Simulation of Physical Human-Device Interaction

Physical human-device interaction is central to many emerging technologies in neurorehabilitation and assistive robotics, but simulation-based research in this area remains fragmented across musculoskeletal models, assistive-device representations, task definitions, and controller-development workflows. This fragmentation limits the accessibility, reproducibility, and extensibility of studies on prostheses, exoskeletons, wearable rehabilitation devices, and related human-device systems. Here we introduce MyoAssist 1.0, an open-source framework for neuromechanical simulation of physical human-device interaction built within the MyoSuite ecosystem. MyoAssist organizes each simulation environment as a composed human-device-task system that combines compatible musculoskeletal, assistive-device, and task-scenario components through a shared composition pipeline. The current release includes 15 assistive-device models spanning gait assistance, upper-body support, manipulation, and seated mobility and supports compatible musculoskeletal models ranging from reduced lower-limb models to a 416-muscle full-body model. These human-device systems can be simulated within the broad task scenarios provided by MyoSuite, while MyoAssist adds locomotion-specific task scenarios with configurable terrain and target-velocity conditions for gait-assistive studies. MyoAssist also provides two complementary controller-development frameworks: a reinforcement-learning framework for training adaptive policies and a controller-optimization framework for tuning structured, interpretable human and device controllers. Both frameworks operate on the same simulation environments and provide standardized evaluation outputs for inspecting, comparing, reusing, and extending learned and structured control strategies. By integrating modular human models, assistive-device models, task scenarios, and training workflows under a shared open-source interface, MyoAssist aims to lower the barrier to reproducible simulation-based research and to support collaborative development of assistive technologies for neurorehabilitation and physical human-device interaction.

bioengineering↗

bioRxiv2025

Diurnal plant and Rhizophagus irregularis transcriptional patterns are linked to shifts in cassava tissue partitioning in the field

O_LICassava is a globally-important crop whose yields can radically increase with arbuscular mycorrhizal fungi (AMF) inoculation. However, extensive background noise in field environments makes it very challenging to understand how the cassava-AMF symbiosis confers benefits, which is especially important for future applications of AMF treatments. C_LIO_LIIn two field experiments, we combined transcriptomics and allometric analyses to investigate functional variation in cassava-AMF interactions using sterile, single isolates of Rhizophagus irregularis. We developed a novel Index of Symbiotic Transcriptional Activity (ISTA) and accounted for sampling times to reduce transcriptomic noise and improve links to biomass traits. C_LIO_LIISTA significantly correlated with cassava shoot biomass in an isolate-dependent manner, and allometric analyses revealed that R. irregularis isolates can either reinforce or uncouple cassava shoot-root relationships to maximize root yields. Differential expression and co-expression network analyses uncovered isolate-specific plant and fungal gene module responses. Including ISTA and sampling time as random effects enhanced detection of gene candidates, including down-regulated genes linked to higher yield. C_LIO_LIOur study uses novel and translatable transcriptomic tools to readily dissect variably field data, allowing new links to be found between AMF symbiotic functions and cassava yields. C_LI

molecular biology↗

bioRxiv2025

Cigarette smoke exposure sets up a pro-inflammatory circuit in the lung that induces the hyper-activation of myelin-specific T helper cells

Cigarette smoke (CS) exposure increases the risk of multiple sclerosis; however, the mechanisms are unclear. To investigate this, we exposed C57BL6/J mice to CS or ambient air (AA) for 8 weeks using a protocol modelling human chronic CS exposure and studied the impact of these exposures on the development of experimental autoimmune encephalomyelitis (EAE). We found that CS increased the incidence of neurological signs in 2D2 myelin oligodendrocyte glycoprotein (MOG) T cell receptor transgenic mice, whereas in active EAE induced by MOG peptide and Complete Freunds adjuvant, CS delayed the onset of disease. In both cases, the effects of CS tended to be greater in the males who also developed greater leukocyte infiltration and expression of IL-12p40 and other cytokines. To gain insights into the paradoxical effects of CS in these EAE models, we transferred congenically-marked pMOG-reactive T helper cells into AA- or CS-exposed mice and examined the phenotype of these cells in the lungs, spleen, and spinal cord. We found that CS-exposed lungs acted as a sink for the pMOG-reactive T cells, in that more of these T cells homed to the lungs instead of the spinal cord. However, these CS-educated pMOG Th cells exhibited a hyperactivated Th phenotype with greater expression of activation markers, IL-17, and GM-CSF, a cytokine that is essential for EAE development. Intranasal treatment with anti-IL-12p40 negated these effects of CS on the expression of pro-inflammatory cytokines by pMOG Th cells. These studies suggest that CS sets up a pro-inflammatory circuit in the lung that amplifies the encephalitogenic properties of myelin-specific T effector cells. HighlightsO_LICS exposure enhances the development of spontaneous neuroimmunity. C_LIO_LIMyelin-reactive T helper 1 responses are enhanced by CS exposure. C_LIO_LICS-exposed lung attracts myelin-specific T helper cells to this site. C_LIO_LICS enhances myelin-specific Th1/Th17 cytokine production and GM-CSF through lung IL-12p40 C_LI

immunology↗

bioRxiv2025

Adjustable Compliance Footwear Technology to Investigate Gait Adaptation

Kinetic asymmetries in gait caused by neurological impairments are a major factor in mobility deficiency. Gait perturbation training has shown promise for rehabilitating neurological gait asymmetry, but the transfer of benefits from treadmill training to overground walking is limited. To enable kinetic gait perturbation training on treadmills and overground, we developed novel adjustable compliance footwear technology. The system consists of a wearable pneumatic actuation module which controls the pressure of custom air pockets embedded in a soft lattice midsole, and is capable of independently and wirelessly adjusting the midsole compliance under each foot from 300 kN/m and 60% energy absorption to 18 kN/m and 75% energy absorption in under 4 seconds. Hindfoot and forefoot sole deflection data are measured via Hall effect sensors and paired magnets characterized to 1.7 mm accuracy. To demonstrate the experimental capability of the system, we successfully triggered multiple compliance changes during overground walking and recorded ground reaction forces and embedded sensor values during a prolonged asymmetric compliance walking bout on a treadmill. Future work will include a full experimental study of gait adaptation to asymmetric footwear compliance perturbations.

bioengineering↗

bioRxiv2020

Interrupting reactivation of immunological memory reprograms allergy and averts anaphylaxis

IgE production against innocuous antigens can lead to life-threatening reactions such as anaphylaxis. While IgE levels drastically decline with strict allergen avoidance, the ability to regenerate IgE can persist for a lifetime, as is the case for peanut allergy. The mechanism by which IgE regenerates remains unresolved. A novel culture system and application of single-cell RNA-sequencing, elucidated the transcriptomic signature of human peanut-reactive B and T cells and revealed IL-4/IL-13 as a signaling pathway critical for the IgE recall response. Indeed, interruption of this pathway not only prevented IgE production and anaphylaxis, but also reprogrammed the pathogenic response against peanut. This investigation advances our understanding of the mechanism that regenerates IgE in food allergy and spotlights IL-4/IL-13 blockade as a therapeutic with disease-transforming potential. One Sentence SummarySingle-cell transcriptomics of allergic memory responses reveals how to teach the immune system to forget.

immunology↗

bioRxiv2019

Using variation in arbuscular mycorrhizal fungi to drive the productivity of the food security crop cassava

The unprecedented challenge to feed the rapidly growing human population can only be achieved with major changes in how we combine technology with agronomy1. Despite their potential few beneficial microbes have truly been demonstrated to significantly increase productivity of globally important crops in real farming conditions2,3. The way microbes are employed has largely ignored the successes of crop breeding where naturally occurring intraspecific variation of plants has been used to increase yields. Doing this with microbes requires establishing a link between variation in the microbes and quantitative traits of crop growth along with a clear demonstration that intraspecific microbial variation can potentially lead to large differences in crop productivity in real farming conditions. Arbuscular mycorrhizal fungi (AMF), form symbioses with globally important crops and show great potential to improve crop yields2. Here we demonstrate the first link between patterns of genome-wide intraspecific AMF variation and productivity of the globally important food crop cassava. Cassava, one of the most important food security crops, feeds approximately 800 million people daily4. In subsequent field trials, inoculation with genetically different isolates of the AMF Rhizophagus irregularis altered cassava root productivity by up to 1.46-fold in conventional cultivation in Colombia. In independent field trials in Colombia, Kenya and Tanzania, clonal sibling progeny of homokaryon and dikaryon parental AMF enormously altered cassava root productivity by up to 3 kg per plant and up to a 3.69-fold productivity difference. Siblings were clonal and, thus, qualitatively genetically identical. Heterokaryon siblings can vary quantitatively but monokaryon siblings are identical. Very large among-AMF sibling effects were observed at each location although which sibling AMF was most effective depended strongly on location and cassava variety. We demonstrate the enormous potential of genetic, and possibly epigenetic variation, in AMF to greatly alter productivity of a globally important crop that should not be ignored. A microbial improvement program to accelerate crop yield increases over that possible by plant breeding or GMO technology alone is feasible. However, such a paradigm shift can only be realised if researchers address how plant genetics and local environments affect mycorrhizal responsiveness of crops to predict which fungal variant will be effective in a given location.

microbiology↗