Enhanced optimization-based method for the generation of patient-specific models of Purkinje networks.

Cardiac Purkinje networks are a fundamental part of the conduction system and are known to initiate a variety of cardiac arrhythmias. However, patient-specific modeling of Purkinje networks remains a challenge due to their high morphological complexity. This work presents a novel method based on optimization principles for the generation of Purkinje networks that combines geometric and activation accuracy in branch size, bifurcation angles, and Purkinje-ventricular-junction activation times. Three biventricular meshes with increasing levels of complexity are used to evaluate the performance of our approach. Purkinje-tissue coupled monodomain simulations are executed to evaluate the generated networks in a realistic scenario using the most recent Purkinje/ventricular human cellular models and physiological values for the Purkinje-ventricular-junction characteristic delay. The results demonstrate that the new method can generate patient-specific Purkinje networks with controlled morphological metrics and specified local activation times at the Purkinje-ventricular junctions.

Potential Biomarkers of impulsivity in mild traumatic brain injury: A pilot study.

Very few studies have investigated cognition and impulsivity following mild traumatic brain injury (mTBI) in the general population. Furthermore, the neurobiological mechanisms underlying post-TBI neurobehavioral syndromes are complex and remain to be fully clarified. Herein, we took advantage of machine learning based-modeling to investigate potential biomarkers of mTBI-associated impulsivity. Twenty-one mTBI patients were assessed within one-month post-TBI and their data were compared to 19 healthy controls on measures of impulsivity (Barratt Impulsiveness Scale - BIS), executive functioning, episodic memory, self-report cognitive failures and blood biomarkers of inflammation, vascular and neuronal damage. mTBI patients were significantly more impulsive than controls in BIS total and subscales. Serum levels of sCD40L, Cathepsin D, IL-4, Neuropilin-1, IFN-α2, and Copeptin were associated with impulsivity in mTBI patients. Besides showing that mTBI are associated with impulsivity in non-military people, we unveiled different pathophysiological pathways potentially implicated in mTBI-related impulsivity.

Camouflaged Nests of Mischocyttarus mirificus (Hymenoptera, Vespidae).

Social wasps present various architectural patterns for their nests, which may differ in shape, size, color, and material used in construction. The distribution pattern of comb cells presented by Mischocyttarus mirificus (Zikán, 1935) is vertical with a single cell of width, resulting in a filiform shape that camouflages in the middle of the substrate. There are few studies regarding this architectural pattern for social wasps and their role in camouflage, and this study aims to detail the nesting habits of this species. In total, 40 colonies were analyzed in their natural habitat and six were dissected in the laboratory. Aspects about the construction of the nests and nesting environment have been described. A test was carried out with nest photographs, to quantify their camouflage percentage within the nesting substrate. The colonies were found mainly in riparian forests where there were elements in the environment that favored their camouflage. According to the nest photograph analysis, their camouflage levels can vary according to the position from which the photograph is taken. It is evident that M. mirificus founders select sites where they can camouflage their colonies, and this gives them advantages in exploring a new environment.