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Objective To investigate the safety and efficacy of 50Hz repetitive Transcranial Magnetic Stimulation(rTMS) in the treatment of motor symptoms in Parkinson’s disease(PD). Background Progression of PD is characterized by the emergence of motor deficits, which eventually respond less to dopaminergic therapy and pose a therapeutic challenge. RTMS has shown promising results in improving gait, a major cause of disability, and may provide a therapeutic alternative. Controlled studies suggest increasing stimulation frequency might enhance therapeutic efficacy. Methods In this randomized, double blind, sham-controlled study, we investigated safety and efficacy of 50Hz-rTMS of the motor cortices in 8sessions over 2weeks. Assessment of safety and clinical efficacy over a 1-month period included timed tests of gait and bradykinesia, UPDRS and additional clinical, neurophysiological and neuropsychological parameters. In addition, safety of 50Hz-rTMS was tested with EMG-EEG-monitoring during and after stimulation. Results We investigated 26 patients with mild to moderate PD: 13 received 50Hz-rTMS and 13 sham-stimulation. 50Hz-rTMS did not improve gait, bradykinesia, global and motor UPDRS, but there appeared a short-lived “on”-state improvement in activities of daily living (UPDRS II). 50Hz-rTMS lengthened the cortical silent period, but other neurophysiology and neuropsychological measures remained unchanged. EMG/EEG recorded no pathological increase of cortical excitability or epileptic activity. There were no adverse effects. Conclusion 50Hz-rTMS of the motor cortices appears safe, but fails to improve motor performance and functional status in PD. Prolonged stimulation or other techniques with rTMS might be more efficacious, but need to be established in future research.

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The distributions of/i180, salinity, temperature, and nutrients have been used to quantify water sources to the Mackenzie shelf in the Beaufort Sea. Comparison of water mass analyses with satellite imagery confirms that the meteoric (runoff) water is associated with the Mackenzie plume. The seasonally variable surface layer for the shelf is viewed as cycling between a "reverse estuary" in winter, when the polar mixed layer (PML) is formed, and a positive estuary in summer when the shelf waters respond to freshwater inputs (runoff and ice melt). We infer a standing stock of 3.7 m fresh water at the end of summer 1986, of which 30% owes its origin to the melting of sea ice; our data coupled with river flow imply a freshwater flushing time for the Mackenzie shelf at about 150 days. To re-form the PML during winter requires the removal of this seasonal fresh water through the combined processes of flushing and ice formation: once this fresh water has been removed, continued ice growth can produce "new" brine which would be observed as a deeper and saltier PML from the previous year. A simple geochemical model shows that autumn conditions (freshwater accumulation) and the rate of flushing are important controls on the potential of the shelf to produce "new" brine and that winter runoff, were it to distribute evenly across the shelf, is sufficient to inhibit brine production. INTRODUCTION Arctic Ocean studies have recently focused on freshwater budgets [Aagaard and Coachman, 1975; Hanzlick and Aagaard, 1980; Anderson et al., 1983] and particularly on the two main sources, runoff (including Pacific Ocean sources) and ice melt [e.g., Tan and Strain, 1980; Ostlund and Hut, 1984]. The reason for this interest is simple: fresh water plays a key role in maintaining the Arctic halocline and, by inference, controls ice cover and deep water formation, both of which have climatic implications [Carmack, 1989]. The Arctic Ocean can be considered as a large, complex estuary where seasonal runoff impinges on wide shelves synchronously around the basin edge; in fact, the combined inflow (about 3500 km3yr -• [Treshnikov, 1985]) is surpassed in magnitude only by the Amazon. Additional runoff (estimated at 1670 km3yr -1 when referenced to salinity of 34.8 practical salinity units (psu) [Aagaard and Carmack, 1989]) enters indirectly through Bering Strait. Unique to cold region estuaries is a melt-freeze cycle which can cause positive or negative estuarine forcing [Carmack et al., this issue]. The logical place to look for reverse estuarine behavior (surface production of brine) is in the shear zone between landfast ice and the moving pack and in polynyas where water is kept open for long periods in winter. There seasonal processes have been implicated in producing brine drainage and hence maintaining the halocline [Melling and Lewis, 1982; Aagaard et al., 1981]. We expect therefore that the important estuarine processes (both negative and positive) occur over the shelves, are strongly seasonal, and are unevenly distributed within the Arc...

Brain activity during observation and imagery of gait was investigated. Sixteen subjects were scanned with a 3-Tesla MRI scanner while viewing six types of video clips: observation of gait movement (GO) from the third-person perspective, observation of stepping movement, observation of standing posture, "virtual walking" (VW) that was observation of visual scenes mimicking the visual afferent during walking, and the scrambled version of the GO and VW stimuli. In the VW condition, moving scenes provided a virtual visual environment in which subjects easily imagined as if they were actually walking from the first-person perspective. A behavioral experiment revealed a correlation of cadence during actual walking with that during imaginary walking under the influence of the VW stimuli, indicating that a gait planning mechanism was shared by actual walking and gait imagery. The VW condition activated the dorsal premotor cortex (PMd), supplementary motor area/cingulate motor area (SMA/CMA), parahippocampal gyrus, and subcortical nuclei. The GO stimuli yielded activation of the SMA, PMd, inferior frontal gyrus, and inferior parietal lobule. Moreover, the conjunction null test of GO and VW revealed common activity in the SMA/CMA and PMd, which were reportedly active during actual gait movement, in addition to visual areas. Detailed analyses of activity during stepping or standing observation supported the specificity of the SMA and PMd to GO. These findings suggest that motor planning centers of gait, including the SMA and PMd, are activated during both imagination (first-person perspective) and observation (third-person perspective) of gait behaviors.

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The genus Vigna (Fabaceae) consists of five subgenera, and includes more than 100 wild species. In Vigna, 10 crops have been domesticated from three subgenera, Vigna, Plectrotropis, and Ceratotropis. The habitats of wild Vigna species are so diverse that their genomes could harbor various genes responsible for environmental stress adaptation, which could lead to innovations in agriculture. Since some of the gene bank Vigna accessions were unidentified and they seemed to be novel genetic resources, these accessions were identified based on morphological traits. The phylogenetic positions were estimated based on the DNA sequences of nuclear rDNA-ITS and chloroplast atpB-rbcL spacer regions. Based on the results, the potential usefulness of the recently described species V. indica and V. sahyadriana, and some wild Vigna species, i.e., V. aconitifolia, V. dalzelliana, V. khandalensis, V. marina var. oblonga, and V. vexillata, was discussed.