Agent Technologies for Sensor Networks

Wireless sensor networks are increasingly seen as a solution to the problem of performing continuous wide-area monitoring in many environmental, security, and military scenarios. The distributed nature of such networks and the autonomous behavior expected of them present many novel challenges. In this article, the authors argue that a new synthesis of electronic engineering and agent technology is required to address these challenges, and they describe three examples where this synthesis has succeeded. In more detail, they describe how these novel approaches address the need for communication and computationally efficient decentralized algorithms to coordinate the behavior of physically distributed sensors, how they enable the real-world deployment of sensor agent platforms in the field, and finally, how they facilitate the development of intelligent agents that can autonomously acquire data from these networks and perform information processing tasks such as fusion, inference, and prediction.     

Cytopathological analysis of sputum in patients with airflow obstruction and significant smoking histories

Advances in the understanding of lung cancer biology have led to observations that specific genetic changes occur in premalignant dysplasia. These observations have occurred predominantly in molecular studies of resected lung tumors and consequently, they may not be fully representative of those biological abnormalities characterizing premalignant lesions in individuals without overt lung cancer. Studies of premalignant epithelial cell biology and chemoprevention are needed in this patient subgroup. Such an initiative is now underway through the lung cancer Specialized Program of Research Excellence (SPORE) grant awarded to the University of Colorado Cancer Center (and affiliated institutions) by the National Cancer Institute. To identify participants for the early detection and chemoprevention trials of the Colorado SPORE, we initiated a sputum cytology screening program targeting persons with chronic obstructive pulmonary disease and smoking histories of 40 or more pack-years. During the first 26 months after activation of the screening program, sputum samples from 632 participants were evaluated. Of these, 533 (84%) of the subjects submitted specimens deemed adequate for cytopathological interpretation; 99 (16%) provided sputum samples unsuitable for cytodiagnosis. Of those participants who submitted adequate samples, 48% had cytodiagnoses of mild dysplasia, 26 % had moderate to severe dysplasia, and 2% presented with carcinoma in situ or invasive carcinoma. Logistic regression modeling was pursued to determine whether selected demographic and/or clinical status variables could be identified as statistically significant predictors of the specific cytological outcome to be expected (mild dysplasia, moderate dysplasia, and so forth). The only apparent associations found from both univariate and multivariate analyses were that the total number of pack-years of smoking history decreased with severity of cytodiagnosis and that those individuals with mild or moderate dysplasia were more likely to be ex-smokers than those with grades of regular metaplasia or lower. Based on the initial results of the Colorado SPORE sputum cytology screening program, we conclude that persons with chronic obstructive pulmonary disease and 40 or more pack-years of smoking history have a high prevalence of premalignant dysplasia detectable through sputum cytology and should be targeted for research programs focusing on lung cancer prevention, early detection, and exploratory biomarker studies.     

Advance organizers: Retrieval context hypotheses.

In six experiments we examined issues related to the retrieval context set by rereading advance organizers before recall tests. In Experiments 1 and 2, rereading advance organizers before immediate testing had no effect on recall. We hypothesized that the results of Experiments 1 and 2 were due to testing recall too soon to allow for a "loss" of the initial encoding context. Consequently, in Experiments 3–5 we varied delays between encoding and retrieval from 24 hr to 2 weeks. The results of all three experiments indicated that rereading advance organizers before delayed recall greatly facilitated memory performance. In Experiment 6 we contrasted rereading an advance organizer before delayed testing with rereading a false organizer and rereading the first paragraph of the essay. The results revealed that only rereading the advance organizer had a significant effect on recall. The results are discussed in terms of advance organizer theory and a general perspective on encoding and retrieval contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial soluble interleukin 2 receptor levels in rheumatoid arthritis: differences in response to glucocorticoid treatment and chrysotherapy

OBJECTIVE: To analyze the changes in soluble interleukin 2 receptor (sIL-2R) levels following treatment of patients with rheumatoid arthritis (RA). METHODS: Serial measurements of sIL-2R levels were made over 24 weeks in 40 patients with RA, treated with intramuscular (im) gold plus 3 im injections of either 120 mg methylprednisolone acetate or placebo. RESULTS: sIL-2R levels were reduced in the glucocorticoid treated group in contrast to the gold only group, where levels initially increased. At 24 weeks, mean sIL-2R levels did not significantly differ from pretreatment levels in either group, despite improvements in clinical measures. CONCLUSIONS: In our study, sIL-2R levels do not correlate with short term clinical measures of disease activity. Their significance for longer term prognostic use remains to be determined.     

Embedable problem-solving architectures: a study of integratingOPS5 with UMass GBB

The requirements of a problem-solving architecture that can be tightly embedded within other architectures and coexist with multiple instances of itself and of other problem-solvers are discussed. The additional effort needed to produce an embedable problem-solving architecture is minor compared to the substantial increase in applicability of the architecture. A specific need for embedable problem-solvers arose with the University of Massachusetts Generic Blackboard Framework (UMass GBB). UMass GBB is based on the blackboard paradigm, which naturally integrates heterogeneous problem-solving representations as individual knowledge sources (KSs). This need is met by developing general specifications for embedable problem-solving architectures, and the specifications are used to modify the public-domain version of OPS5 in order to embed it as an integral KS language within UMass GBB. The OPS5 modifications result in an easily integrated GBB KS language (distributed with the UMass GBB system) that has been used in several GBB applications     

Effects of across-chapter signals on recall of text.

Investigated 2 forms of across-chapter text signals: "preview" sentences, which signal contents in upcoming chapters, and "recall" sentences, which are backward signals that signal back to previously read materials. These signals may influence readers' recall of text material by guiding their attention during reading. They also may facilitate readers' activation of memory representations of previous content, thereby enhancing integrative processing. Seven experiments examined the effects of preview and recall sentences. The results of 4 experiments indicated a clear signaling effect across chapters. In Exp IV, there were significantly longer inspection times and reaction times (RTs) to secondary probes in signaled than in unsignaled paragraphs. The results of Exp V indicate that backward-signaled materials were recalled at a significantly greater rate than unsignaled materials. In addition, the signaled materials in Ss' recalls were clustered together at a significantly greater rate than unsignaled materials. Results of Exp VII indicate significantly longer inspection times and RTs to secondary probe tasks in the reading of paragraphs containing recall sentences than in the reading of paragraphs not containing signals. Results indicate that across-chapter signals have a strong effect on readers' recall of prose. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trends in cooperative distributed problem solving

The authors present an overview of cooperative distributed problem solving (CDPS), an emerging research area that combines aspects of AI (artificial intelligence) and distributed processing. CDPS can be used to study how a loosely coupled network of sophisticated problem-solving nodes can solve a complex problem which consists of a set of interdependent subproblems. Subproblems arise because of spatial, temporal, and functional distribution of data, knowledge, and processing capabilities. Application areas include distributed interpretation, distributed planning and control, cooperating expert systems, and computer-supported human cooperation. The authors survey the important approaches and empirical investigations that have been developed. The approaches covered include negotiation, functionally accurate cooperation, organizational structuring, multiagent planning, sophisticated local control, and theoretical frameworks