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Abstract The addition of nanoparticles in the base fluid increases the thermal conductivity of the fluid but the stability of the fluid gets affected due to the presence of nanoparticles in the base fluid. The addition of motile microorganisms in the nanofluid increases the stability of the nanofluid by enhancing thermal conductivity as well as mass transport. In this perspective, the current investigation deals with the study of the behavior of microorganisms in bioconvection over the fluid variables in the non-Darcy background. A two-dimensional Prandtl-nanofluid moving along an inclined stretching flat surface subject to inlet and outlet rate of flow to the surface under the action magnetic drag force normal to the surface. The non-linear partial differential equations are transmuted to ODEs through appropriate similarity transformations. The MATLAB inbuilt bvp4c solver has been employed to generate the solution of the transformed ODEs. The stability of the finite difference scheme is demonstrated by a stability test, and the influence of various parameters on the nanofluid velocity, thermal as well as concentration, and density of motile microorganisms is depicted using graphs for each of them. Additionally, interested physical quantities, shearing stresses, rate of thermal diffusion, rate of mass diffusion, and rate of motile microorganism at the surface, have been plotted by varying the controlling parameters. Growth in the shear stress as well as the rate of thermal diffusion has been detected for the increasing values of δ and β . However, the Sherwood number decays for augmented values of δ . The findings could be utilized to increase the thermal efficiency of heat exchangers in order to maintain thermal balance management in small heat-density equipment and gadgets, as well as the thermal efficiency of microbial fuel cells, enzyme biosensors, and microfluidics devices. [ABSTRACT FROM AUTHOR]

Background and importanceApraxia of speech is a disorder of articulatory coordination and planning in speech sound production. Its diagnosis is based on deficits in articulation, prosody, and fluency. It is often described concurrent with aphasia or dysarthria, while pure apraxia of speech is a rare entity.Clinical presentationA right-handed man underwent focal surgical resection of a recurrent grade III astrocytoma in the left hemisphere dorsal premotor cortex located in the posterior middle frontal gyrus. After the procedure, he experienced significant long-term speech production difficulties. A battery of standard and custom language and articulatory assessments were administered, revealing intact comprehension and naming abilities, and preserved strength in orofacial articulators, but considerable deficits in articulatory coordination, fluency, and prosody-consistent with diagnosis of pure apraxia of speech. Tractography and resection volumes compared with publicly available imaging data from the Human Connectome Project suggest possible overlap with area 55b, an under-recognized language area in the dorsal premotor cortex and has white matter connectivity with the superior longitudinal fasciculus.ConclusionThe case reported here details a rare clinical entity, pure apraxia of speech resulting from resection of posterior middle frontal gyrus. While not a classical language area, emerging literature supports the role of this area in the production of fluent speech, and has implications for surgical planning and the general neurobiology of language.