Muscle activation during gait in children with Duchenne muscular dystrophy

The aim of this prospective study was to investigate changes in muscle activity during gait in children with Duchenne muscular Dystrophy (DMD). Dynamic surface electromyography recordings (EMGs) of 16 children with DMD and pathological gait were compared with those of 15 control children. The activity of the rectus femoris (RF), vastus lateralis (VL), medial hamstrings (HS), tibialis anterior (TA) and gastrocnemius soleus (GAS) muscles was recorded and analysed quantitatively and qualitatively. The overall muscle activity in the children with DMD was significantly different from that of the control group. Percentage activation amplitudes of RF, HS and TA were greater throughout the gait cycle in the children with DMD and the timing of GAS activity differed from the control children. Significantly greater muscle coactivation was found in the children with DMD. There were no significant differences between sides. Since the motor command is normal in DMD, the hyper-activity and co-contractions likely compensate for gait instability and muscle weakness, however may have negative consequences on the muscles and may increase the energy cost of gait. Simple rehabilitative strategies such as targeted physical therapies may improve stability and thus the pattern of muscle activity

Journeys in Non-Classical Computation I: A Grand Challenge for computing research

A gateway event is a change to a system that leads to the possibility of huge increases in kinds and levels of complexity. It opens up a whole new kind of phase space to the systemÕs dynamics. Gateway events during evolution of life on earth include the appearance of eukaryotes (organisms with a cell nucleus), an oxygen atmosphere, multi-cellular organisms and grass. Gateway events during the development of mathematics include each invention of a new class of numbers (negative, irrational, imaginary, ...), and dropping Euclid's parallel postulate. A gateway event produces a profound and fundamental change to the system: Once through the gateway, life is never the same again. We are currently poised on the threshold of a significant gateway event in computation: That of breaking free from many of our current Òclassical computationalÓ assumptions. Our Grand Challenge for computer science is to journey through the gateway event obtained by breaking our current classical computational assumptions, and thereby develop a mature science of Non-Classical Computatio

Toward integration of in vivo molecular computing devices: successes and challenges

The computing power unleashed by biomolecule based massively parallel computational units has been the focus of many interdisciplinary studies that couple state of the art ideas from mathematical logic, theoretical computer science, bioengineering, and nanotechnology to fulfill some computational task. The output can influence, for instance, release of a drug at a specific target, gene expression, cell population, or be a purely mathematical entity. Analysis of the results of several studies has led to the emergence of a general set of rules concerning the implementation and optimization of in vivo computational units. Taking two recent studies on in vivo computing as examples, we discuss the impact of mathematical modeling and simulation in the field of synthetic biology and on in vivo computing. The impact of the emergence of gene regulatory networks and the potential of proteins acting as “circuit wires” on the problem of interconnecting molecular computing device subunits is also highlighted