The complementary dominance hypothesis is a novel model of motor lateralization substantiated by decades of research examining interlimb differences in the control of upper extremity movements in neurotypical adults and hemisphere‐specific motor deficits in stroke survivors. In contrast to earlier ideas that attribute handedness to the specialization of one hemisphere, our model proposes complementary motor control specializations in each hemisphere. The dominant hemisphere mediates optimal control of limb dynamics as required for smooth and efficient movements, whereas the non‐dominant hemisphere mediates impedance control, important for countering unexpected mechanical conditions and achieving steady‐state limb positions. Importantly, this model proposes that each hemisphere contributes its specialization to both arms (though with greater influence from either arm's contralateral hemisphere) and thus predicts that lesions to one hemisphere should produce hemisphere‐specific motor deficits in not only the contralesional arm, but also the ipsilesional arm of stroke survivors – a powerful prediction now supported by a growing body of evidence. Such ipsilesional arm motor deficits vary with contralesional arm impairment, and thus individuals with little to no functional use of the contralesional arm experience both the greatest impairments in the ipsilesional arm, as well as the greatest reliance on it to serve as the main or sole manipulator for activities of daily living. Accordingly, we have proposed and tested a novel intervention that reduces hemisphere‐specific ipsilesional arm deficits and thereby improves functional independence in stroke survivors with severe contralesional impairment. image

Minimization of performance and control costs and efferent coupling between bilaterally homologous muscle groups have been separately hypothesized to describe patterns of bimanual coordination. Here, we address whether the mechanisms mediating independent and codependent control between limbs can be weighted for successful task performance. Using bilaterally asymmetric visuomotor gain perturbations, we show bimanual coordination can be characterized as a negotiation along a spectrum between extremes of independent and codependent control, but not efferent control coupling.

Previously, the control coupling hypothesis and task-dependent control hypothesis have been shown to be robust in the bimanually symmetrical movement, but whether the same policy remains robust in the bimanually asymmetrical movement remains unclear. Here, with evidence from empirical and simulation data, we show that a spatiotemporal symmetry between the arms is not predicated on control coupling, but instead it is predicated on the symmetry of mechanical conditions (e.g. limb inertia) between the arms.

Natural products chemical ingredient profiling is a challenging task because of the sample complexity and the analyses required. For any natural products related study, regardless of the research focus and the final end goal, ingredient profiling (to elucidate the active compounds from a particular plant), sample comparison (to understand point of origin and to prove authenticity), quantification and identification of target compounds for quality control purpose are all routinely required. Because of the complexity of the sample and large amount of data that can be generated using the most popular approach such as LC/MS, researchers are still challenged by how to narrow down the scope and to obtain meaningful information quickly. Three different botanicals (Hoodia, Terminalia and Chamomile) and their respective dietary supplements were used for the study of targeted and non-targeted analysis of compounds. Here, a streamlined workflow was presented that enables researchers to quickly identify chemical ingredients from botanicals and dietary supplements from a single data independent LC/MS injection. The data independent acquisition provides both precursor exact mass and corresponding fragment ion information from a single injection for facile structural characterization. Data are then searched against the Traditional Medicine Scientific Library provided within the informatics platform from the instrument vendor. Structures of matched experimental and in silico corresponding fragment ions are automatically verified by a software tool imbedded within UNIFI informatics platform. Results are displayed automatically using preset workflow and report templates.