Successful Aging

This issue's Works in Progress department presents six abstracts for projects that are developing interesting solutions to the elderly's quality of life challenges. The first two abstracts discuss projects that will help provide the elderly with freedom and independence by instrumenting their environments with supportive technology. The next two abstracts discuss projects building specialized user interfaces for addressing some of the challenges associated with aging, such as vision impairment. The final two abstracts present projects that will aid independence for the elderly by providing remote monitoring and assistance.     

Performance and the i860 microprocessor

The internal design of the i860 CPU, which exploits pipelining and parallelism more than previous microprocessors, is described. The i860 uses RISC concepts and memory-performance optimizations in several novel ways. Other innovations include simultaneous floating-point operations similar to digital signal processing, a two-instruction-per-clock mode, fast floating-point pipelines graphics instructions, and high-bandwidth registers and caches on-chip. These features make it one of the fastest single-chip processors available     

Esophageal cyst--a rare cause of backache

BACKGROUND: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. METHODS: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg.kg-1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg.kg-1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg.kg-1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. RESULTS: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). CONCLUSION: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Scanning probe microscopy of intrafibrillar crystallites in calcified collagen

Vertebrate mineralized tissues are composite materials formed by the organized growth of carbonated apatite crystals within a matrix of collagen fibres. Calcified collagen from turkey tendon was investigated using scanning tunnelling microscopy (STM) and atomic force microscopy (AFM). Samples were treated with hydrogen peroxide to enhance the mineralized phase by removing part of the collagen matrix and the results compared with the untreated material. Plate-like crystalline entities with dimensions 35 nm × 5–8 nm by 1.5 nm were seen. These dimensions are consistent with previous reports using transmission electron microscopy (TEM) of calcified tendon and topographic imaging of tendon crystals. The resolution of the images obtained using STM is better than the previously reported pictures obtained using TEM or scanning electron microscopy (SEM). The value of 35 nm is the same as the gap region in the structure of the collagen fibrils. Stacking of plates and plate-aggregates are a dominant feature in the scanning images. These results support the concept of organized intra-fibril mineral crystals within the organic collagen matrix. Electron diffraction and X-ray diffraction were undertaken on the samples and the patterns recorded match those previously reported for carbonated apatite.     

Honey bees find the shortest path: a collective flow-mediated approach

Artificial Life and Robotics - Honey bees (Apis mellifera L.) are social insects that makes frequent use of volatile pheromone signals to collectively navigate unpredictable and unknown...     

Assessment of the nutritional state of dialysis patients

Obstructive sleep apnea syndrome (OSAS) has been associated with a higher than normal cardiovascular morbidity and mortality. Some OSAS patients lack the sleep-related, nocturnal decrease, or "dip," in blood pressure which is seen in normal individuals. These subjects, called "non-dippers," may be at greater risk for cardiovascular problems. We studied 40 OSAS patients (including 3 women) and 6 control subjects, all identified by polysomnography, for nocturnal blood pressure "dipping." We performed a second nocturnal polysomnogram to determine their apnea and hypopnea indices, (A + H)I, and oxygen saturation levels at the beginning of the study and then initiated 48 hours of ambulatory blood pressure monitoring, with data points collected every 30 minutes. Controls, which included one hypertensive subject, were all dippers. Nineteen OSAS subjects (48% of OSAS individuals) were systolic non-dippers and only 9 of them (22.5%) were diastolic non-dippers. We considered the following clinical variables as potential predictors of non-dipping: age, body mass index, respiratory disturbance index, years of reported loud snoring by bed partners, lowest oxygen saturation during nocturnal sleep, and percentage of sleep time spent with oxygen saturation below 90%. Multiple regression analyses indicated respiratory disturbance index as the only significant variable for systolic (p = 0.04) and diastolic (p = 0.03) blood pressure non-dipping. When we forced the following two nonsignificant variables into the model, they showed a very meager impact: number of years with reported loud snoring (p = 0.4 and p = 0.5, respectively for systolic and diastolic blood pressure non-dipping) and age (p = 0.5 and p = 0.6). The calculated model explained only a low percentage of the variance with an r2 of 0.25 and 0.26 for systolic and diastolic blood pressure non-dipping, respectively. Analysis of hypertension/normotension and dipping/non-dipping failed to show a significant relationship in the studied population. Fifty percent of the normotensive OSAS subjects were non-dippers and 43% of the hypertensive OSAS subjects were also non-dippers. We found a relationship between increasing respiratory disturbance index and increasing average 24-hour systolic blood pressure only when OSAS subjects were non-dippers and hypertensive.     

An ontology based multi-agent system to support HABIO outsourcing framework

In recent years the widespread application of outsourcing to help improve finance and maintain competitiveness is growing rapidly, and has been accompanied by a growth of academic research in this field. Most of the outsourcing literature has focused primarily on the social and cultural impacts, the organisational and management perspectives of outsourcing and very few tools have been developed to assist managers in making outsourcing decisions. Incorrect decision-making in outsourcing can lead to devastating consequences for their business. To guide decision makers in managing the complexity of outsourcing a holistic approach to outsourcing has been developed by taking business, information and organisational perspectives (HABIO). The purpose of this paper is to demonstrate how HABIO can be applied to help managers evaluate the impact of their decision-making by providing them with a set of ‘what-if’ scenarios, which are enacted by intelligent agents. The case example, discussed in this paper, demonstrates that HABIO can be applied effectively using a multi-agent system to analyse the outsourcing decision for a call centre sector in the retail industry. A prototype of the multi-agent system is presented where intelligent agents are endowed with specific domain ontologies, appropriate to solve a specific problem, and with a reasoning mechanism to achieve specific goals and to collaborate together to produce a set of “what-if scenarios” to the outsourcing managers.     

Development of the technical capabilities needed to build and position a prepolarization coil for a magnetic resonance imaging magnet

An experiment to show that a magnetic resonance imaging (MRI) magnet could be assembled around a patient, and used as part of a prepolarization system in which substantial transient forces are applied to parts of it, is described. The paper describes the circumstances that develop as a result of the application of the large transient fields used in this type of study, and outlines the reason for the tolerances that are permissible on the alignment of the system components. It then describes a test rig used to evaluate how the various problems might be overcome, and reports on the performance achieved with this rig. On the basis of this work, it appears that a system could be developed that would allow the application of these methods in clinical MRI.     

Infidelity in Couples Seeking Marital Therapy.

The revelation of an affair is often an emotionally explosive event for a couple, yet little is known about specific individual and relationship factors that accompany infidelity. The present study examined the qualities of individuals and couples that differentiate couples with (n = 19) and without (n = 115) infidelity using couples from a randomized clinical trial of marital therapy. Findings indicated that couples with infidelity showed greater marital instability, dishonesty, arguments about trust, narcissism, and time spent apart. Gender also proved to be a significant moderator of several effects. Men who had participated in affairs showed increased substance use, were older, and were more sexually dissatisfied. Results offer initial clues to concomitants of affairs for couple therapists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)