The present technique was developed to overcome some of the disadvantages of measuring cerebral blood flow by radionuclide methods, such as poor localization of flow values and errors that result if the brain is pathological and local partition coefficients are altered. Serial CT scanning in humans was carried out during and after inhalation of 50 to 70% non-radioactive xenon. This diffusible g...

Cerebral blood flow was measured with xenon in 21 fetal sheep and 14 newborn lambs under 48 hours old. When the ewe breathed air, the average gray matter blood flow in the fetuses was 70.6 ml/100 g/min, the average white matter blood flow 15.4 ml/100 g/min and average gray matter oxygen consumption 2.06 ml/100 g/min. The corresponding values in the newborn lambs were 87.2, 17.8, and 2.98 ml/100...

Accurate estimation of motion from time-varying imagery has been a popular problem in vision studies, This information can be used in segmentation, 3D motion and shape recovery, target tracking, and other problems in scene analysis and interpretation. We have presented a dynamic image model for estimating image motion from image sequences, and have shown how the solution can be obtained from a ...

Current guidelines for the location and design of bus stops do not take into account air quality or exposure considerations for waiting passengers. This paper compares the exposure of transit riders waiting at three-sided bus stop shelters that either: 1) face roadway traffic, or 2) face away from roadway traffic. Shelters were instrumented with devices to monitor particulate matter concentrati...

Due to the lack of political consensus at the previous General Agreement on Trade on Services (GATS), negotiations on the temporary movement of natural persons (Mode 4) have stagnated. The growth in the economic literature surrounding this issue has also been lackluster; despite the large welfare gains that have been demonstrated to result from relatively small multilateral liberalizations on s...

Wireless Sensor Networks (WSNs) is getting larger in size and coverage area. Currently, some WSNs are having thousands of sensor nodes deployed to monitor critical regions or watch out for ecological phenomenon. Large Scale WSNs place strong challenges on many aspects of network modeling, deployment, protocols, and data gathering. Existing policies and techniques in WSNs need to be scaled effic...

the neighborhood has had a long history in iranian urbanization. since urban plans wereintroduced by the authorities to shape urban development in iran half a century ago, the concept of iranian traditional neighborhood has been neglected gradually. the concept of neighborhood has not found the appropriate status in urban design and planning yet. one of the main reasons is that academics, profe...

In general the images used for compression are of different types like dark image, high intensity image etc. When these images are compressed using Counter Propagation Neural Network, it takes longer time to converge. The reason for this is that the given image may contain a number of distinct gray levels with narrow difference with their neighborhood pixels. If the gray levels of the pixels in...

I provide the theoretical basis for an error calculus for measurements of cerebral blood flow using a freely diffusible tracer substance such as xenon-133. The use of the error calculus is exemplified by a study of the effect on the error margins in measurements of gray matter blood flow from flow level, relative weight of the gray matter compartment, and use of the earliest parts of the cleara...

The optimum surface-fitting method for binary images is extended in order to treat gray images, and a new method to extract edges in three-dimensional gray images is proposed. If voxels that have similar values to the voxel of interest (VOI) are distributed like a two-dimensional curved surface, it is thought that there would be a curved surface at the VOI. To apply the fitting method to gray i...