Impaired scaling of responses to vestibular stimulation in incomplete SCI

Patients with incomplete spinal cord injury (iSCI) have impaired postural control leading to a high danger of falling. Clinically, it is impossible to assess the extent to which postural instability due to sensorimotor deficit is influenced by a disturbance in the vestibulospinal pathways. Galvanic vestibular stimulation (GVS) was applied to investigate changes in the vestibular spinal responses and their potential influence on postural stability in iSCI patients. Six chronic iSCI patients and age-matched controls were stimulated with a bipolar binaural stimulus. The centre of pressure (CoP) and soleus EMG responses during free standing with closed eyes on firm and compliant ground were measured. The impairment in postural stability was assessed by the mean amplitude of CoP deflections during two minutes undisturbed standing. Although iSCI patients were significantly less stable than controls, direct GVS responses of the soleus EMG and postural sways tended to be increased on firm ground. The GVS responses increased when changing from firm to compliant ground, showing a close correlation between the extent of postural instability and the response amplitudes. Therefore, challenging proprioceptive feedback induced a significant up-modulation of the GVS responses. However, when we took the postural instability in iSCI patients into account, the EMG and CoP responses to GVS were reduced compared to controls. The combined assessment of EMG and CoP responses to GVS complements the clinical examination and permits evaluation of the preservation and modulation of vestibulospinal responses in iSC

Conserved microRNA editing in mammalian evolution, development and disease.

BACKGROUND: Mammalian microRNAs (miRNAs) are sometimes subject to adenosine-to-inosine RNA editing, which can lead to dramatic changes in miRNA target specificity or expression levels. However, although a few miRNAs are known to be edited at identical positions in human and mouse, the evolution of miRNA editing has not been investigated in detail. In this study, we identify conserved miRNA editing events in a range of mammalian and non-mammalian species. RESULTS: We demonstrate deep conservation of several site-specific miRNA editing events, including two that date back to the common ancestor of mammals and bony fishes some 450 million years ago. We also find evidence of a recent expansion of an edited miRNA family in placental mammals and show that editing of these miRNAs is associated with changes in target mRNA expression during primate development and aging. While global patterns of miRNA editing tend to be conserved across species, we observe substantial variation in editing frequencies depending on tissue, age and disease state: editing is more frequent in neural tissues compared to heart, kidney and testis; in older compared to younger individuals; and in samples from healthy tissues compared to tumors, which together suggests that miRNA editing might be associated with a reduced rate of cell proliferation. CONCLUSIONS: Our results show that site-specific miRNA editing is an evolutionarily conserved mechanism, which increases the functional diversity of mammalian miRNA transcriptomes. Furthermore, we find that although miRNA editing is rare compared to editing of long RNAs, miRNAs are greatly overrepresented among conserved editing targets

Repurposing of promoters and enhancers during mammalian evolution.

Promoters and enhancers-key controllers of gene expression-have long been distinguished from each other based on their function. However, recent work suggested that common architectural and functional features might have facilitated the conversion of one type of element into the other during evolution. Here, based on cross-mammalian analyses of epigenome and transcriptome data, we provide support for this hypothesis by detecting 445 regulatory elements with signatures of activity turnover (termed P/E elements). Most events represent transformations of putative ancestral enhancers into promoters, leading to the emergence of species-specific transcribed loci or 5' exons. Distinct GC sequence compositions and stabilizing 5' splicing (U1) regulatory motif patterns may have predisposed P/E elements to regulatory repurposing, and changes in the U1 and polyadenylation signal densities and distributions likely drove the evolutionary activity switches. Our work suggests that regulatory repurposing facilitated regulatory innovation and the origination of new genes and exons during evolution

Differential EMG Biofeedback for Children with ADHD: A Control Method for Neurofeedback Training with a Case Illustration

The objective of the present paper was to develop a differential electromyographic biofeedback (EMG-BF) training for children with attention-deficit/hyperactivity disorder (ADHD) matching multiple neurofeedback training protocols in order to serve as a valid control training. This differential EMG-BF training method feeds back activity from arm muscles involved in fine motor skills such as writing and grip force control. Tonic EMG-BF training (activation and deactivation blocks, involving bimanual motor tasks) matches the training of EEG frequency bands, while phasic EMG-BF training (short activation and deactivation trials) was developed as an equivalent to the training of slow cortical potentials. A case description of a child who learned to improve motor regulation in most task conditions and showed a clinically relevant reduction of behavioral ADHD symptoms illustrates the training course and outcome. Differential EMG-BF training is feasible and provides well-matched control conditions for neurofeedback training in ADHD research. Future studies should investigate its value as a specific intervention for children diagnosed with ADHD and comorbid sensorimotor problem

Characterization and modeling of strain assisted diffusion in an epoxy adhesive layer

AbstractIn this paper a coupled model for strain-assisted diffusion is derived from the basic principles of continuum mechanics and thermodynamics, and material properties characterized using diffusion experiments. The proposed methodology constitutes a significant step toward modeling the synergistic bond degradation mechanism at the bonded interface between a Fiber Reinforced Polymer (FRP) and a substrate, and for predicting debond initiation and propagation along the interface in the presence of a diffusing penetrant at the crack tip and at elevated temperatures. It is now well-known that Fick’s law is frequently inadequate for describing moisture diffusion in polymers and polymer composites. Non-Fickian or anomalous diffusion is likely to occur when a polymer is subjected to external stresses and strains, as well as elevated temperatures and humidity. In this paper, a modeling methodology based on the basic principles of continuum mechanics and thermodynamics is developed which allows characterization of the combined effects of temperature, humidity, and strain on diffusion coefficients as well as on moisture saturation level, from moisture weight gain data. For tractability, the diffusion governing equations are simplified for the special case of 1-D diffusion subjected to uniaxial strain and a uniform strain gradient. A novel test specimen that introduces a uniform strain gradient is developed, and diffusion test data for an epoxy-based primer/adhesive are presented and employed for complete characterization of material constants used in the model

Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Quantitative radar studies are an important component of studying the movements of birds. Whether a bird, at a certain distance from the radar, is detected or not depends on its size. The volume monitored by the radar is therefore different for birds of different sizes. Consequently, an accurate quantification of bird movements recorded by small-scale radar requires an accurate determination of the monitored volume for the objects in question, although this has tended to be ignored. Here, we demonstrate the importance of sensitivity settings for echo detection on the estimated movement intensities of birds of different sizes. The amount of energy reflected from a bird and detected by the radar receiver (echo power) depends not only on the bird's size and on the distance from the radar antenna, but also on the beam shape and the bird's position within this beam. We propose a method to estimate the size of a bird based on the wingbeat frequency, retrieved from the echo-signal, independent of the absolute echo power. The estimated bird-size allows calculation of size-specific monitored volumes, allowing accurate quantification of movement intensities. We further investigate the importance of applying size-specific monitored volumes to quantify avian movements instead of using echo counts. We also highlight the importance of accounting for size-specific monitored volume of small scale radar systems, and the necessity of reporting technical information on radar parameters. Applying this framework will increase the quality and validity of quantitative radar monitoring.COST – European Cooperation in Science and Technolog