Changes of non‐affected upper limb cortical representation in paraplegic patients as assessed by fMRI

Peripheral and central nervous system lesions can induce reorganization within central somatosensory and motor body representations. We report changes in brain activation patterns during movements of non‐affected body parts in paraplegic patients with spinal cord injury (SCI). Nine SCI patients and 12 healthy controls underwent blood oxygen level dependent signal functional MRI during sequential finger‐to‐thumb opposition, flexion and extension of wrist and of elbow, and horizontal movements of the tongue. Single subject and group analyses were performed, and the activation volumes, maximum t values and centres of gravity were calculated. The somatotopical upper limb and tongue representations in the contralateral primary motor cortex (M1) in the SCI patients were preserved without any shift of activation towards the deefferented and deafferented M1 foot area. During finger movements, however, the SCI patients showed an increased volume in M1 activation. Increased activation was also found in non‐primary motor and parietal areas, as well as in the cerebellum during movements of the fingers, wrist and elbow, whereas no changes were present during tongue movements. These results document that, in paraplegic patients, the representation of the non‐impaired upper limb muscles is modified, though without any topographical reorganization in M1. The extensive changes in primary and non‐primary motor areas, and in subcortical regions demonstrate that even distant neuronal damage has impact upon the activation of the whole sensorimotor syste

Activity and Process Stability of Purified Green Pepper (Capsicum annuum) Pectin Methylesterase

Pectin methylesterase (PME) from green bell peppers (Capsicum annuum) was extracted and purified by affinity chromatography on a CNBr-Sepharose-PMEI column. A single protein peak with pectin methylesterase activity was observed. For the pepper PME, a biochemical characterization in terms of molar mass (MM), isoelectric points (pI), and kinetic parameters for activity and thermostability was performed. The optimum pH for PME activity at 22 °C was 7.5, and its optimum temperature at neutral pH was between 52.5 and 55.0 °C. The purified pepper PME required the presence of 0.13 M NaCl for optimum activity. Isothermal inactivation of purified pepper PME in 20 mM Tris buffer (pH 7.5) could be described by a fractional conversion model for lower temperatures (55?57 °C) and a biphasic model for higher temperatures (58?70 °C). The enzyme showed a stable behavior toward high-pressure/temperature treatments. Keywords: Capsicum annuum; pepper; pectin methylesterase; purification; characterization; thermal and high-pressure stabilit

Slim binaries

The traditional path to software portability among various hardware platforms has been the provision of "fat binaries", object files that contain multiple instruction sequences for different target architectures. This paper presents an alternative approach based on "slim binaries", files that contain a target-machine-independent program representation from which native code is generated on-the-fly at load-time. The slim binaries used in our implementation are based on adaptive compression of syntax trees, and not on a virtual-machine representation such as p-code or Java byte-codes. They are highly compact and can be read from a storage medium very efficiently, significantly reducing the I/O cost of loading. The time thus saved is then spent on code generation, making the implemented system fast enough to compete with traditional loaders. Slim binaries are well suited for realizing portable software components, such as downloadable content-specific editor applets for multimedia documents on the World Wide Web, or "intelligent agents" that move from machine to machine and perform computing tasks locally

Pre- and post-operative assessment of valvular and aortic flow using 4D flow magnetic resonance imaging

ISSN:1522-9645ISSN:0195-668