Abstract-Many environmental applications require high temporal frequency (rapidly changing) and spatially distributed phenomena to be sampled with high fidelity. This requires mobile sensing elements to perform guided sampling in regions of high variability. We propose a multiscale approach for efficiently sampling such phenomena. This approach introduces a hierarchy of sensors according to the sampling fidelity, spatial coverage, and mobility characteristics. In this paper, we report the development of a two-tier multiscale system where information from a lowfidelity, high spatial (global) sensor actuates a mobile robotic node, carrying a high-fidelity, low spatial coverage (spot measurement) sensor, to perform guided sampling in the regions of high phenomenon variability. As a case study of the proposed multiscale paradigm, we investigated the spatiotemporal distribution of the light intensity in a forest understory. The performance of the multiscale approach is verified in simulation and on a physical system. Results suggest that our approach is adequate for the problem of high-frequency spatiotemporal phenomena sampling and significantly outperforms traditional sampling approaches such as a raster scan.

PURPOSE: This study was performed to evaluate the incidence of seizures with its implications on disease progression and the diagnostic value of post-ictal magnetic resonance images (MRI) during the management of highgrade gliomas (HGGs). PATIENTS AND METHODS: A total of 406 consecutive patients with newly diagnosed HGGs were retrospectively reviewed. The incidence of seizure attacks during the management was investigated. In patients who experienced a seizure, the causality between seizures and disease progression was assessed by pre-ictal, post-ictal (,1 month), and follow-up (,3 months) MRI. RESULTS: After a mean follow-up of 21.9 months (range, 0.1 -88.3), seizure attacks developed in 127 patients (31%). Of the 127 patients, radiological progression at the post-ictal MRI was found in 83 patients (65%) and the follow-up MRI confirmed progression in 79 patients (62%). However, other 4 patients (3%) were shown to be progression-free. Among those without radiological progression at the post-ictal MRI, the follow-up MRI confirmed progression-free in 31 patients (24%); however, 13 patients (10%) revealed eventual progression. In the patients with a seizure, absence of preoperative seizure (p ¼ 0.003), , 95% tumor resection (p ¼ 0.001), and pre-ictal Karnofski Performance Scale score ≤ 70 (p ¼ 0.025) were significantly associated with disease progression. CONCLUSION: During the management of HGG, 31% of patients experienced seizures; of these patients, 72% harbored progressive disease. The post-ictal MRI is useful for detecting disease progression; however, there are pitfalls. Clinical settings should be considered together for diagnosing disease progression in patients with seizures.