Development of Postural Muscles and Their Innervation

Control of posture is a prerequisite for efficient motor performance. Posture depends on muscles capable of enduring contractions, whereas movements often require quick, forceful muscle actions. To serve these different goals, muscles contain fibers that meet these different tasks. Muscles with strong postural functions mainly consist of slow muscle fibers with a great resistance against fatigue. Flexor muscles in the leg and arm muscles are mainly composed of fast muscle fibers producing relatively large forces that are rapidly fatigable. Development of the neuromuscular system continues after birth. We discuss in the human baby and in animal experiments changes in muscle fiber properties, regression from polyneural into mononeural innervation, and developmental changes in the motoneurons of postural muscles during that period. The regression of poly-neural innervation in postural muscles and the development of dendrite bundles of their motoneurons seem to be linked to the transition from the immature into the adult-like patterns of moving and postural control

Making smallholder value chain partnerships inclusive: exploring digital farm monitoring through farmer friendly smartphone platforms

Open Access Journal; Published online: 04 Jun 2020Value chain partnerships face difficulties achieving inclusive relations, often leading to unsustainable collaboration. Improving information flow between actors has been argued to contribute positively to a sense of inclusion in such partnership arrangements. Smallholders however usually lack the capability to use advanced communication technologies such as smartphones which offer a means for elaborate forms of information exchange. This study explores to what extent co-designing smartphone platforms with smallholders for farm monitoring contributes to smallholder ability to communicate, and how this influences smallholder sense of inclusion. The study uses an Action Design Research approach in engaging smallholders in Ghana, through multi-stakeholder and focus group discussions, in a reflexive co-design process. The research finds that co-designing a platform interface was significant in improving farmer ability to comprehend and use smartphone based platforms for communicating farm conditions and their needs with value chain partners. Farmers were however skeptical of making demands based on the platform due to their lack of power and mistrust of other actors. This highlights a need for adjusting the social and political dimensions of partnership interactions, in tandem with the advancement of digital tools, in order to effectively facilitate a sense of inclusiveness in partnerships

Reuleaux plasticity: improving Mohr-Coulomb and Drucker-Prager

The yielding of soil exhibits both a Lode angle dependency and a dependency on the intermediate principal stress. Ignoring these leads to a loss of realism in geotechnical analysis, yet neither of the widely used Mohr-Coulomb (M-C) or Drucker-Prager (D-P) models include both. This paper presents a simple pressure-dependent plasticity model based on a modified Reuleaux (mR) triangle which overcomes these limitations and yet (like the M-C and D-P formulations) allows for an analytical backward-Euler stress integration solution scheme. This latter feature is not found in more sophisticated (and computationally expensive) models. The mR deviatoric function is shown to provide a significantly improved fit to experimental data when compared with the M-C and D-P functions. Finite deformation finite-element analysis of the expansion of a cylindrical cavity is presented, verifying the use of the mR constitutive model for practical analyses

Legacy effects of nitrogen and phosphorus additions on vegetation and carbon stocks of upland heaths

Open Access via the Wiley Jisc Agreement. Funding Information Scottish Natural Heritage Royal Society of Edinburgh Fellowship Scottish Government Rural and Environment Science and Analytical Services Division (RESAS) N8 AgriFoodPeer reviewedPublisher PD

Corticotropin-releasing factor receptor types 1 and 2 are differentially expressed in pre- and post-synaptic elements in the post-natal developing rat cerebellum

Corticotropin-releasing factor (CRF)-like proteins act via two G-protein-coupled receptors (CRF-R1 and CRF-R2) playing important neuromodulatory roles in stress responses and synaptic plasticity. The cerebellar expression of corticotropin-releasing factor-like ligands has been well documented, but their receptor localization has not. This is the first combination of a light microscopic and ultrastructural study to localize corticotropin-releasing factor receptors immunohistologically in the developing rat cerebellum. Both CRF-R1 and CRF-R2 were expressed in climbing fibres from early stages (post-natal day 3) to the adult, but CRF-R2 immmunoreactivity was only prominent throughout the molecular layer in the posterior cerebellar lobules. CRF-R1 immunoreactivity was concentrated in apical regions of Purkinje cell somata and later in primary dendrites exhibiting a diffuse cytoplasmic appearance. In Purkinje cells, CRF-R1 immunoreactivity was never membrane bound post-synaptically in dendritic spines while CRF-R2 immunoreactivity was found on plasmic membranes of Purkinje cells from post-natal day 15 onwards. We conclude that the localization of these receptors in cerebellar afferents implies their pre-synaptic control of the release of corticotropin-releasing factor-like ligands, impacting on the sensory information being transmitted from afferents. Furthermore, the fact that CRF-R2 is membrane bound at synapses, while CRF-R1 is not, suggests that ligands couple to CRF-R2 via synaptic transmission and to CRF-R1 via volume transmission. Finally, the distinct expression profiles of receptors along structural domains of Purkinje cells suggest that the role for these receptors is to modulate afferent inputs