Toward inquiry-based education through interacting software agents

The University of Michigan Digital Library (UMDL) project is creating an infrastructure for rendering library services over a digital network. When fully developed, the UMDL will provide a wealth of information sources and library services to students, researchers, and educators. Tasks are distributed among numerous specialized modules called agents. The three classes of agents are user interface agents, mediator agents, and collection interface agents. Complex tasks are accomplished by teams of specialized agents working together-for example, by interleaving various types of search. The UMDL is being deployed in three arenas: secondary-school science classrooms, the University of Michigan library, and space-science laboratories. The development team expects the scale and diversity of the project to test their technical ideas about distributed agents, interoperability, mediation, and economical resource allocation     

Preschoolers' understanding of the link between thinking and feeling: cognitive cuing and emotional change

In 3 studies we investigated 3- through 6-year-olds' knowledge of thinking and feeling by examining their understanding of how emotions can change when memories of past sad events are cued by objects in the current environment. In Study 1, 48 4-, 5-, and 6-year-olds were presented with 4 illustrated stories in which focal characters experience minor sad events. Later, each story character encounters a visual cue that is related to one of his or her previous sad experiences. Children were told that the character felt sad, and they were asked to explain why. Study 1 suggested considerable competence as well as substantial development in the years between 4 and 6 in the understanding of the influence of mental activity on emotions. Studies 2 and 3 more systematically explored preschoolers' understanding of cognitive cuing and emotional change with different types of situations and cues. Across these 2 studies, 108 3-, 4-, and 5-year-olds listened to illustrated stories that featured story characters who each experienced a sad event and who were later exposed to a related cue. Children were not only asked to explain why the characters suddenly felt sad, but in some stories, they were also asked to predict and explain how another character, who was never at the past sad event, would feel. Results of Studies 2 and 3 showed an initial understanding of cognitive cuing and emotion in some children as young as 3, replicated and extended the evidence for significant developmental changes in that understanding during the preschool years, and revealed that the strength and consistency of preschoolers' knowledge of cognitive cuing and emotion was affected by whether cues were the same, or only similar to, parts of the earlier events.     

The differences in electroencephalographic changes in patients undergoing carotid endarterectomies while under local versus general anesthesia

OBJECTIVE: This study compared the electroencephalographic (EEG) changes occurring during carotid occlusion in 225 consecutive patients undergoing carotid endarterectomies performed by two surgeons, one using local and the other using general anesthesia. METHODS: A retrospective review of patients undergoing carotid endarterectomies for carotid occlusive disease was conducted. EEG changes associated with intraoperative ischemia (decreased amplitude, generalized slowing, and loss of fast activity) resulting in the need for an indwelling arterial shunt were recorded for the two anesthesia groups. To determine the similarities or differences between the two groups, the groups were compared regarding age, risk factors, and indications for surgery. RESULTS: Significant EEG changes were noted in 6 of 96 patients (6.3%) in the local anesthesia group versus 19 of 121 patients (15.7%) in the general anesthesia group. EEG changes consisted solely of generalized slowing in the local anesthesia group, whereas a more varied spectrum was observed in the general anesthesia group. The two groups were similar regarding age and risk factors. Although the local anesthesia group had more asymptomatic patients, symptomatic patients did not have a greater incidence of EEG changes. CONCLUSION: There is a large difference in EEG changes potentially requiring shunt placement in patients undergoing surgery while under local (6.3%) versus general (15.7%) anesthesia. This could not be explained based on age, risk factors, interpretation of EEG findings, or indications between the two groups. We conclude that EEG monitoring may be insensitive and may fail to detect ischemia in patients who are under regional anesthesia. Alternately, the presence of general anesthetics may alter the character of the EEG findings and increase the sensitivity of EEG monitoring to ischemic events.     

Pharmacology of barbiturate tolerance/dependence: GABAA receptors and molecular aspects

Barbiturates are central nervous system depressants that are used as sedatives, hypnotics, anesthetics and anticonvulsants. However, prolonged use of the drugs produces physical dependence, and the drugs have a high abuse liability. The gamma-aminobutyric acidA (GABAA) receptor is one of barbiturates' main sites of action, and therefore it is thought to play a pivotal role in the development of tolerance to and dependence on barbiturates. Recent advances in the study of the GABAA receptor/chloride channel complex allow us to examine possible mechanisms that underlie barbiturate tolerance/dependence in a new light. In this minireview, we mainly focus on molecular and cellular aspects of the action of barbiturates and the possible mechanisms that contribute to development of tolerance to and dependence on barbiturates.     

Radiosotope evaluation of experimental hydrosyringomyelia

Kaolin-induced hydrosyringomyelia in dogs has been investigated by radioisotope ventriculography using both cerebrospinal fluid radioassay and scintigraphy. The hydromyelic central canal can be differentiated from the spinal subarachnoid space by scintigraphy, Serial studies show that hydromyelia arises rapidly to decompress the associated hydrocephalus in surviving animals. Syringomyelia, after a delayed onset, originates from the enlarged central canal. Radioisotope ventriculography may be a useful clinical aid in the diagnosis of hydrosyringomyelia.     

Deliberate memory behavior in the delayed reactions of very young children.

34 3-yr-olds (Exp I), 23 2-yr-olds (Exp II), and 30 3-4 yr olds (Exp III) were presented a memory task that required recalling a particular location at the end of a delay. At the beginning of the delay, half of the children were instructed to remember the location and half were instructed simply to wait. 3-yr-olds who were instructed to remember were observed to engage in behaviors during the delay which seemed to increase their recall, in contrast to 3-yr-olds who were instructed to wait. Additional observations in Exp III also showed that a positive relation existed between such delay period memory behavior and later recall. This differentiated, deliberate memory behavior was not observed for 2-yr-olds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discussion of "Electric arcing burn hazards"

For original article by A.D. Stokes and D.K. Sweeting see ibid., vol.42, no.1, p.134-41, Jan./Feb. 2006.