Experimental evidence exists that especially the heterogeneity in contrast enhancement as evaluated by dynamic contrast enhanced MRI (DCE-MRI) is a predictive feature for treatment outcome in a variety of tumor types. In this study it is investigated whether texture descriptors derived from DCE-MRI based heuristic feature maps are suitable to quantify the heterogeneity in contrast uptake. An automated analysis method is proposed that for each voxel first partitions the signal intensity curve into different temporal regions indicating different stages of enhancement. Within these regions, heuristic features describing the contrast dynamics are estimated. The corresponding features maps are used as the basis for texture analysis, based on cooccurrence matrices, to assess tumor contrast uptake heterogeneity. The method has been applied in pre- and post treatment DCE-MRI data in ten patients with soft tissue sarcomas who underwent isolated limb perfusion. The correspondence between texture measures and the heterogeneity in contrast uptake as visually assessed by a radiologist has been evaluated, and the ability of the texture measures to discriminate between two treatment outcome classes has been assessed. The preliminary results suggest that some of the proposed texture measures are suitable to quantify the heterogeneity in contrast uptake in tumor tissue

To minimize QoS degradations during nonstationary packet loadings, predictive rate schedulers adapt the operation according to anticipated packet arrival rates deduced via specified estimation algorithm. Existing predictive rate schedulers are developed under the assumption of perfect estimation, which may not be possible in future CDMA-based cellular networks characterized with highly nonstationary and bursty traffic. Additional shortcoming of existing rate schedulers is the coupling of delay and bandwidth, that is, close interdependence of delay and bandwidth (rate), whereby controlling one is accomplished solely by changing the other. In order to mitigate for the arrival rate estimation errors and delay-bandwidth coupling, this paper presents the feedback-enhanced target-tracking weighted fair queuing (FT-WFQ) rate scheduler. It is an adaptive rate scheduler over multiclass CDMA systems with predictive adaptation control to adapt to nonstationary loadings; and feedback-enhanced reactive adaptation control to counteract arrival rate estimation errors. When the predictive adaptation control is not able to maintain long-term delay targets, feedback information will trigger reactive adaptation control. The objective of FT-WFQ scheduler is to minimize deviations from delay targets subject to maximum throughput utilization. Analytical and simulation results indicate that FT-WFQ is able to substantially reduce degradations caused by arrival rate estimation errors and to minimize delay degradations during nonstationary loading conditions.

A high-resolution transmission electron microscopy (HRTEM) investigation of a family of supported Ru catalysts prepared from Ru hydroxyl-terminated poly(amidoamine) dendrimer-metal nanocomposite (DMN) precursors has been conducted. Ru particle sizes observed following deposition of DMNs on a HRTEM grid can be controlled within a 0.9-1.4 nm range depending on the metal-to-dendrimer molar ratio. The average particle size in this case correlates well with the theoretically predicted particle size from the molar loading of Ru in the dendrimer. Upon impregnation of Ru-DMNs on Al(2)O(3) and subsequent thermal removal of the dendrimer via reduction at 300 degrees C, significant sintering of the Ru particles was observed. Nevertheless, the resulting supported Ru particles maintained a narrow particle size distribution and average particle size below 2.5 nm. These particle sizes no longer correlate with the metal-to-dendrimer molar ratio but do correlate with the metal-to-dendrimer weight ratio, suggesting that the dendrimer may be acting as a "sintering-control" agent on the catalyst surface. This process is not affected by the surface area of the support, since almost identical particle size distributions were obtained on three different commercial supports.