Both depressive and psychotic symptoms were associated with overall behavioral disturbances in patients with dementia. Psychotic symptoms and depressive symptoms were associated with different types of behavioral disturbances. Our findings support the contention that underlying depression or psychosis may partially account for different behavioral disturbances and that not all behavioral disturbances should be globally labeled "agitation." Future studies should address symptom-specific treatment of behaviorally disturbed patients.

This study investigated the correlates of change in behavioral disturbance in geropsychiatric inpatients with dementia. It was hypothesized that improvement in specific psychiatric symptoms, such as psychosis and depression, contribute to the improvement of specific behavioral disturbances. All admissions between October 1993 and May 1995 were reviewed to identify those patients admitted to the Houston VA geropsychiatry unit with a diagnosis of dementia; 233 patients were included in the study. Improvement in behavioral disturbance symptoms was associated with decreases in depression, thought disorder, and hostility. However, the relative importance of depressive and psychotic symptoms varied depending upon the type of behavioral disturbance examined. These results may support a focused approach employing therapies specific to the type of behavioral disturbance.

Cognitive radio (CR) is an enabling technology for combating the problem of spectrum scarcity in the wireless world; however, some security challenges are threatening this emerging technology. The major security challenge to the deployment of the cognitive radio network (CRN) is the primary user emulation attack (PUEA). Since the primary user emulator (PUE) mimics the primary user (PU) signal to cause havoc in the network, to distinguish its signal from that of the PU, knowledge of the exact position of the PUE in the CRN is required. One of the methods to detect PUEs is via Localization, of which there are two major categories: range-based and range-free. The range-based class is reportedly more accurate but with higher complexity. Among this category are Angle of arrival (AoA), which uses angular measurements to localise the PUE, and the received signal strength (RSS), which uses only distance to localize the PUE. To improve performance and reduce the complexity of range-based methods, this paper proposes a hybrid of AoA and RSS methods to localize PUEs in TV white space. This scheme computes the angle at which the PU signal reaches the SUs and the distance between the transmitter and SUs in the CRN. Since in a TV white space, the PU's location is known a priori, the computed AoA and the distance obtained from the RSS are thus used to determine the position of a PU signal transmitter. This position is compared with the location of the PU to ascertain the true source of the signal, thus detecting the PUE. The location estimation is carried out by the individual SUs. Computer simulations demonstrate that the hybrid scheme estimates the position of the PUE much faster and with a much lower root mean square error (RMSE) of 0.005, which greatly outperforms the methods considered individually. Thus, the hybrid scheme is faster, more accurate, and conserves energy better than considering the methods individually. This result is quite significant when attention is given to the fact that speed and accuracy are essential in the efficient operation of CRs and that energy-efficient operations are essential for wireless systems and especially in the currently looming global energy crisis.