Dynamic imaging of coherent sources reveals different network connectivity underlying the generation and perpetuation of epileptic seizures

The concept of focal epilepsies includes a seizure origin in brain regions with hyper synchronous activity (epileptogenic zone and seizure onset zone) and a complex epileptic network of different brain areas involved in the generation, propagation, and modulation of seizures. The purpose of this work was to study functional and effective connectivity between regions involved in networks of epileptic seizures. The beginning and middle part of focal seizures from ictal surface EEG data were analyzed using dynamic imaging of coherent sources (DICS), an inverse solution in the frequency domain which describes neuronal networks and coherences of oscillatory brain activities. The information flow (effective connectivity) between coherent sources was investigated using the renormalized partial directed coherence (RPDC) method. In 8/11 patients, the first and second source of epileptic activity as found by DICS were concordant with the operative resection site; these patients became seizure free after epilepsy surgery. In the remaining 3 patients, the results of DICS / RPDC calculations and the resection site were discordant; these patients had a poorer post-operative outcome. The first sources as found by DICS were located predominantly in cortical structures; subsequent sources included some subcortical structures: thalamus, Nucl. Subthalamicus and cerebellum. DICS seems to be a powerful tool to define the seizure onset zone and the epileptic networks involved. Seizure generation seems to be related to the propagation of epileptic activity from the primary source in the seizure onset zone, and maintenance of seizures is attributed to the perpetuation of epileptic activity between nodes in the epileptic network. Despite of these promising results, this proof of principle study needs further confirmation prior to the use of the described methods in the clinical praxis

The Effectiveness of Orco Mole Bait in Controlling Mole Damage

The tunneling damage caused by eastern moles (Scalopus aguaticus) and starnosed moles (Condylura cristata) is well known to professionals in lawn care, golfcourse maintenance, and turfgrass production, as well as many private landowners. Present damage control methods, including trapping, gas and smoke fumigants, and insecticide applications have a wide variety of limitations and prove impractical in some situations. An easily applied mole damage control method is needed that professional and nonprofessional applicators can use in a variety of environmental and physical conditions. This study tested the effectiveness of Orco Mole Bait, a chlorophacinone pellet placed in active tunnel systems. The bait was tested on both mole species, three soil types (sand, loam and muck), and two watering regimes (irrigated and not irrigated). Orco Mole Bait was equally effective in controlling the damage caused by both eastern and starnosed moles.Captive moles readily accepted the dry, hard bait pellets. The average time to control in field trials was 30.3 days following first application (21.5 days on dry soils, 38.7 days on irrigated soils). The bait was effective on all three soil types, but irrigation appeared to lessen effectiveness. On untreated control sites there was no correlation between precipitation, evaporation, or average maximum and minimum temperature and mole activity. Multiple occupancy and/or rapid reinvasion of abandoned tunnel systems and the use of tunnels by other fossorial species occurred on several study sites. Human alterations to the environment encourage mole activity. Several individuals utilized the areas beneath patios, wood piles and mulched areas for activity centers, and frequented artificial feeding sites such as birdfeeders. Orco mole bait was a practical, effective mole damage control agent that was more easily applied than present damage control methods

Design and modelling of ring resonators used as optical filters for communications applications

This project is a theoretical study of multiple coupled ring resonators, which offer potential applications as demultiplexing filters in DWDM optical transmission systems. The rings can be fabricated as integrated optical structures or they can be formed using micro- or nano-optical fibres. Our approach is analytical, which provides detailed predictions with minimal computer resources. The ideal filter spectral profile for most applications is as close as possible to a rectangle (known as “box-like”) and in order to achieve this we design and model multiple ring resonators. We formulate the compound ring resonator theory with complex field equations to account for phase and amplitude. Then we calculate the transfer functions. We do it in two ways: one way is using linear equations and the other is by matrix theory. We apply both methodologies to one-, two- and three-ring resonators and we show how the matrix formalism can be extended to model arrays of N identical rings. By using the transfer functions we provide detailed physical interpretations of the spectra which are required to design good filter characteristics. We show that rings of equal circumferences provide the best profiles and we derive simple analytical formulas, called “degeneracy condition”, to predict the required coupler ratios for two- and three-ring resonators. It is thus possible to provide a transfer function with single peaks of equal and unity magnitude and a depth of modulation that we choose. Provided that the couplers within the rings conform to the degeneracy condition, we can predict the finesse of a double-ring transfer function. We further extend the ring resonator matrix theory to N identical rings by using a method called “diagonal decomposition”. The amplitude transfer function for N rings can thus be derived with this more advanced mathematical technique. The result that we obtain is in a format that can be extended in future more extended studies. Throughout this project our aim is to provide tangible design guidelines for compound ring resonators, with their potential application to telecommunications networks in mind

The Effectiveness of a New Mole Repellent for Preventing Damage to Lawns by Eastern Moles

A new product containing 65% castor oil with the trade name Mole-Med was evaluated for its effectiveness in repelling eastern moles (Scalopus aquaticus) from lawns. Seven lawns in southern Michigan during September, 1993 were selected as preliminary test sites, and the ridges over mole tunnels in the lawns were flattened each day for 3 days. If some existing and new ridges were raised each day, the site was classified as having mole activity and continuing damage. The repellent was then applied according to label directions, and ridges above mole tunnels were flattened as described previously. If no tunnels were raised on the test lawn after one week, the repellent was considered to be effective. The repellent was classified as effective on all 7 test lawns. In May-July, 1994, 17 additional lawns were selected in the same way as preliminary test sites and classified as having or not having mole damage. Eleven received repellent treatment, while 6 were considered control, 3 adjacent to a treated area, 3 not adjacent to treated areas. Raised mole produced ridges were flattened on all test sites. On any site where ridges remained flattened and no new ridges were created for one week, moles were considered repelled. Mole activity as indicated by raised ridges ceased on eleven treated sites but continued on 5 of 6 control sites. The effectiveness of the repellent as indicated by the lack of new ridges continued for 65 days on one treatment site and for 30 days on the remaining treatment sites

Coordination of a heterogeneous coastal hydrodynamics application in manifold

In this paper we show how the coordination language Manifold can be used to control the interactions of multiple heterogeneous application programs. We use a concrete example from Delft Hydaulics, a consulting and research company which develops models of natural hydraulic systems (e.g., river flows, tidal currents, wave penetrations in harbours, etc.). These simulation programs accurately model water flow phenomena and are used for many places in the world. Often, however, a number of these programs need to be used in conjunction with each other to address more comprehensive problems. For example, the water level in the Rotterdam harbour is determined both by the behaviour of the North Sea and by the discharge of the rivers Rhine and Meuse. Instead of creating Unix shell scripts for each particular configuration of application programs, an executive program has been developed and implemented in Manifold that reads a configuration file and subsequently starts, interconnects and controls all relevant component programs