Pager messages as self reminders: A case study of their use in memory impairment

Each year many people suffer an accident or illness which leaves them with a permanent memory impairment. As a result they will fail to remember to do things, making it difficult for them to maintain employment or independent leisure activities. Conventional memory aids offer little assistance because their use depends on relatively normal memory functioning. A system designed specifically for memory-impaired people has been developed recently in the USA, however. NeuroPage uses a combination of computing and telecommunications to store and transmit reminders to a pager worn by the user. The system is designed to place minimal demands on memory. This paper presents a case study evaluation of NeuroPage in use by a young man with a severe memory impairment. The pager messages led to a marked increase in the probability that he would carry out his intended tasks. Issues of usability and acceptability of the system to the user and his family are also reported. A number of possible developments to the system are considered, including the incorporation of artificial intelligence and context-sensitivity. Broader issues in the design of memory aids for people with and without memory impairments are also considered, as well as the potential role of memory-impaired people in the design of technology for their own use.     

A multicenter study to improve emergency medicine residents' recognition of intracranial emergencies on computed tomography

STUDY OBJECTIVE: Cranial computed tomography (CT) has assumed a critical role in the practice of emergency medicine for the evaluation of intracranial emergencies. Several recent studies have documented a deficiency in the emergency physician's ability to interpret these studies. The purpose of this study was to quantify the baseline ability of emergency medicine residents to interpret cranial CTs, and to test a novel method of cranial CT interpretation designed for the emergency physician in training. METHODS: A standardized pretest was administered to assess baseline ability to interpret CT scans. A standardized posttest was given 3 months after the course. Each test consisted of 12 CT scans with a short accompanying history. All scans were validated by 3 expert reviewers for difficulty and diagnosis. A 2-hour course based on the mnemonic "Blood Can Be Very Bad" was then administered. "Blood" reminds the examiner to search for blood, "Can" prompts the examiner to identify 4 key cisterns, "Be" denotes the need to examine the brain, "Very" prompts a review of the 4 ventricles, and finally "Bad" reminds the examiner to evaluate the bones of the cranium. RESULTS: Eighty-three residents at 5 institutions were initially examined. The mean percentage correct before the course was 60% (95% confidence interval [CI] 58%-64%) on the standardized pretest. At retesting 3 months after the course, the accuracy rate increased to 78% (n=61, 95% CI 75%-81%, P<.001 paired t test). CONCLUSION: Emergency medicine residents are deficient in their ability to interpret cranial CT scans. A novel educational course was demonstrated to significantly improve this ability.     

Comparison of NIST and manufacturer calibrations of 90Sr+90Y ophthalmic applicators

Since the resumption of the NIST calibration service for 90Sr+90Y beta-particle ophthalmic applicators, 65 sources have been calibrated using the revised technique [C. G. Soares, Med. Phys. 18, 787-793 (1991)]. For 59 of these sources, the manufacturer's calibration results were available for comparison to the NIST calibration results. The 59 sources represent eight different manufacturers, only one of which is still selling new sources. Manufacturer calibration dates range from the present back to 1954. The results of the comparisons are present, broken down by both manufacturer and calibration date; there are interesting and significant trends in both, with average differences of 20% not uncommon. The obsolete unit, "roentgen-equivalent-beta" (reb), in which some of the manufacturer calibrations are expressed, is discussed, and a factor (0.00982 Gy reb-1) for its conversion to absorbed dose is suggested.     

Flight-mediated attraction ofBiprorulus bibax breddin (Hemiptera: Pentatomidae) to natural and synthetic aggregation pheromone

The attraction of female spined citrus bugs,Biprorulus bibax, to natural and synthetic aggregation pheromone was studied using an olfactometer and a large flight cage. No locomotory response by postdiapause, prereproductive females to heptane extracts of male dorsal abdominal glands (DAGs) (site of pheromone production) was recorded in the olfactometer study. However, postdiapause, prereproductive females showed significant attraction to sites baited with DAG extracts in the flight cage (1.9–3.0 times that of unbaited sites). Prereproductive and reproductive females showed greatest attraction to sites baited with a synthetic blend of pheromone [(3R,4S,1E-3,4-bis(1-butenyl)tetrahydro-2-furanol, linalool, farnesol, nerolidol] (2.3–4.7 times the attraction of unbaited sites). Females also responded significantly to sites baited with the hemiacetal major component alone (1.7–2.2×). Diapausing females collected from fall populations did not respond to natural or synthetic pheromone baits. Potential applications of the synthetic aggregation pheromone are discussed with respect toB. bibax management.     

Volatile male-specific natural products of a coreid bug (Hemiptera: Heteroptera)

The large coreid bug,Pachylis laticornis (Hemiptera: Coreidae), feeds on several mimosaceous trees in Guanacaste, Costa Rica. In addition to the presumably defensive metathoracic exocrine glands that occur in both sexes of this species, the adult males also possess a ventral abdominal gland, opening midventrally in the 7–8th abdominal intersegmental membrane, that releases volatile compounds. Two esters, (E)-2-hexenyl tiglate and (E)-2-hexenyl (E)-2-hexenoate, account for over 90% of the total volatiles in the ventral abdominal gland secretion of males. (E)-2-Octenyl tiglate and (E)-2-hexenyl benzoate are present at low concentrations, as are at least three other unidentified compounds. The biological role for this fragrant male-specific exudate is unknown.     

Manganese deficiency can replace high oxygen levels needed for lignin peroxidase formation by Phanerochaete chrysosporium

The combined effects of Mn and oxygen on lignin peroxidase (LIP) activity and isozyme composition in Phanerochaete chrysosporium were studied by using shallow stationary cultures grown in the presence of limited or excess N. When no Mn was added, LIP was formed in both N-limited and N-excess cultures exposed to air, but no LIP activity was observed at Mn concentrations greater than 13 mg/liter. In oxygen-flushed, N-excess cultures, LIP was formed at all Mn concentrations, and the peak LIP activity values in the extracellular fluid were nearly identical in the presence of Mn concentrations ranging from 3 to 1,500 mg/liter. When the availability of oxygen to cultures exposed to air was increased by growing the fungus under nonimmersed liquid conditions, higher levels of Mn were needed to suppress LIP formation compared with the levels needed in shallow stationary cultures. The composition of LIP isozymes was affected by the levels of N and Mn. Addition of veratryl alcohol to cultures exposed to air did not eliminate the suppressive effect of Mn on LIP formation. A deficiency of Mn in N-excess cultures resulted in lower biomass and a lower rate of glucose consumption than in the presence of Mn. In addition, almost no activity of the antioxidant enzyme Mn superoxide dismutase was observed in Mn-deficient, N-excess cultures, but the activity of this enzyme increased as the Mn concentration increased from 3 to 13 mg/liter. No Zn/Cu superoxide dismutase activity was observed in N-excess cultures regardless of the Mn concentration.     

ANN-DT: an algorithm for extraction of decision trees fromartificial neural networks

Although artificial neural networks can represent a variety of complex systems with a high degree of accuracy, these connectionist models are difficult to interpret. This significantly limits the applicability of neural networks in practice, especially where a premium is placed on the comprehensibility or reliability of systems. A novel artificial neural-network decision tree algorithm (ANN-DT) is therefore proposed, which extracts binary decision trees from a trained neural network. The ANN-DT algorithm uses the neural network to generate outputs for samples interpolated from the training data set. In contrast to existing techniques, ANN-DT can extract rules from feedforward neural networks with continuous outputs. These rules are extracted from the neural network without making assumptions about the internal structure of the neural network or the features of the data. A novel attribute selection criterion based on a significance analysis of the variables on the neural-network output is examined. It is shown to have significant benefits in certain cases when compared with the standard criteria of minimum weighted variance over the branches. In three case studies the ANN-DT algorithm compared favorably with CART, a standard decision tree algorithm.     

The Epworth Sleepiness Scale may not reflect objective measures of sleepiness or sleep apnea

OBJECTIVE: To assess the validity of the Epworth Sleepiness Scale score (ES) as a measure of sleepiness among patients suspected or confirmed to have obstructive sleep apnea syndrome. BACKGROUND: The ES is used with increasing frequency as a measure of excessive daytime sleepiness in part because several studies suggested that the ES correlates with mean sleep latency (MSL) on the Multiple Sleep Latency Test and with severity of sleep apnea among patients with that disorder. However, associations identified between the ES and other measures were not strong or consistent. METHODS: The authors used regression models and retrospective data from a relatively large series of 237 patients to restudy how ES relates to MSL, to a simple self-rating of problem sleepiness (available for 141 patients), and to two polysomnographic measures of sleep apnea severity: the number of apneas or hypopneas per hour of sleep and the minimum recorded oxygen saturation. RESULTS: The ES had a statistically significant association with self-rated problem sleepiness but not with MSL or measures of sleep apnea severity. Male gender, adjusted for potential confounding variables, had considerably more influence on the ES than did MSL or measures of sleep apnea severity. CONCLUSIONS: Our data suggest that the subjectively derived ES cannot be used as a surrogate for the objectively determined MSL.     

Expression of polysialylated NCAM but not L1 or N-cadherin by regenerating adult mouse optic fibers in vitro

Persistent/latent viral infections of insect cells are a prominent though poorly understood phenomenon. In this study, the long-term association between the Hz-1 virus and insect host cells, conventionally referred to as persistent viral infection, is described. With the aid of a newly developed fluorescent cell-labeling system, we found that productive viral replication occurs by spontaneous viral reactivation in fewer than 0.2% of persistently infected cell lines over a 5-day period. Once viral reactivation takes place, the host cell dies. The persistently infected cells contain various amounts of viral DNA, and, in an extreme case, up to 16% of the total DNA isolated from infected cells could be of viral origin. Both pulsed-field gel electrophoresis and in situ hybridization experiments showed that some of these viral DNA molecules are inserted into the host chromosomes but that the rest of viral DNA copies are free from host chromosomes. Thus, Hz-1 virus is the first nonretroviral insect virus known to insert its genome into the host chromosome during the infection process. These data also suggest that the previously described persistent infection of Hz-1 virus in insect cells should be more accurately referred to as latent viral infection.     

Functional consequences of a decreased potassium affinity in a potassium channel pore. Ion interactions and C-type inactivation

We have shown previously that the inactivation of macrophages in nonobese diabetic (NOD) mice results in the prevention of diabetes; however, the mechanisms involved remain unknown. In this study, we found that T cells in a macrophage-depleted environment lost their ability to differentiate into beta cell-cytotoxic T cells, resulting in the prevention of autoimmune diabetes, but these T cells regained their beta cell-cytotoxic potential when returned to a macrophage-containing environment. To learn why T cells in a macrophage-depleted environment lose their ability to kill beta cells, we examined the islet antigen-specific immune response and T cell activation in macrophage-depleted NOD mice. There was a shift in the immune balance, a decrease in the T helper cell type 1 (Th1) immune response, and an increase in the Th2 immune response, due to the reduced expression of the macrophage-derived cytokine IL-12. As well, there was a deficit in T cell activation, evidenced by significant decreases in the expression of Fas ligand and perforin. The administration of IL-12 substantially reversed the prevention of diabetes in NOD mice conferred by macrophage depletion. We conclude that macrophages play an essential role in the development and activation of beta cell-cytotoxic T cells that cause beta cell destruction, resulting in autoimmune diabetes in NOD mice.