Elucidating the molecular mechanisms that underlie the target control of motoneuron death

Approximately half of the motoneurons generated during normal embryonic development undergo programmed cell death. Most of this death occurs during the time when synaptic connections are being formed between motoneurons and their target, skeletal muscle. Subsequent muscle activity stemming from this connection helps determine the final number of surviving motoneurons. These observations have given rise to the idea that motoneuron survival is dependent upon access to muscle derived trophic factors, presumably through intact neuromuscular synapses. However, it is not yet understood how the muscle regulates the supply of such trophic factors, or if there are additional mechanisms operating to control the fate of the innervating motoneuron. Recent observations have highlighted target independent mechanisms that also operate to support the survival of motoneurons, such as early trophic-independent periods of motoneuron death, trophic factors derived from Schwann cells and selection of motoneurons during pathfinding. Here we review recent investigations into motoneuron cell death when the molecular signalling between motoneurons and muscle has been genetically disrupted. From these studies, we suggest that in addition to trophic factors from muscle and/or Schwann cells, specific adhesive interactions between motoneurons and muscle are needed to regulate motoneuron survival. Such interactions, along with intact synaptic basal lamina, may help to regulate the supply and presentation of trophic factors to motoneurons.

Ubiquitous travel service delivery

Free independent travelers require flexible, reactive service delivery due to their regularly changing location and activities and the lack of a wired Internet connection. A ubiquitous travel service delivery system that is able to dynamically deliver services in response to relevant events, such as changing location, availability of new last-minute specials, work opportunities, and safety issues can provide added value while retaining the flexibility that is so important to independent travelers. This article describes such a system. An engineering design research approach has been adopted to design the system. Issues addressed include traveler and service states and events, contexts, situations, and situation-action rules. An architecture is proposed that is based on distributed, cooperating software agents and mobile data technologies. The role of these agents is to continuously monitor situations that are occurring in the physical and virtual service spaces and to take the required action for any situations that are relevant to the traveler.

Further evidence for the agreement between patients with stroke and their proxies on the Frenchay Activities Index

Objective: To determine item, subscale and total score agreement on the Frenchay Activities Index (FAI) between stroke patients and proxies six months after discharge from rehabilitation. Design: Prospective study design. Setting/subjects: Fifty patient-proxy pairs, interviewed separately, in the patient's residence. Main outcome measures: Modified FAI using 13 items. Individual FAI items, subscales and total score agreement as measured by weighted kappa and intraclass correlation coefficients (ICC). Results: Excellent agreement was found for the total FAI (ICC 0.87, 95% confidence interval (CI) 0.78-0.93), and domestic (ICC 0.85, 95% CI 0.73-0.91) and outdoor (ICC 0.87, 95% CI 0.78-0.95) subscales, with moderate agreement found for the work/leisure subscale (ICC 0.63, 95% CI 0.34-0.78). For the individual FAI items, good, moderate, fair and poor agreement was found for five, three, four and one item, respectively. The best agreement was for objective items of preparing meals, washing-up, washing clothes, shopping and driving. The poorest agreement was for participation in hobbies, social outings and heavy housework. Scoring biases associated with patient or proxy demographic characteristics were found. Female proxies, and those who were spouses, scored patients lower on domestic activities; male patients, and those who were younger, scored themselves higher on outdoor activities and higher patient FIM scores were positively correlated with higher FAI scores. Conclusions: While total and subscale agreement on the FAI was high, individual item agreement varied. Proxy scores should be used with caution due to bias.

Can the Internet be used as a medium to evaluate knee angle?

Telemedicine promises to revolutionize medical care delivery in rural and remote areas. The ability to accurately evaluate physical impairment via the Internet is important to the possible future provision of Internet-based physiotherapy. This study evaluated the reliability and validity of assessing knee range of motion via the Internet. Two therapists evaluated knee angle on a single subject via two methods of assessment: the Internet and the traditional method (face-to-face). Nine random positions of the knee were chosen with the principal examiner performing 20 face-to-face and two sets of 20 Internet measures in each position (n=540). The secondary therapist performed Internet assessments only. The Internet connection was established at a readily available speed of 17 kbit/s. The Internet-based goniometer was found to be a valid tool for measuring both knee flexion and extension angles. It was shown to possess both high intra and inter-rater reliability. Difference average plots of the scores verified the consistency of measurement between both modes of assessment. The successful evaluation of the physical outcome measure of knee range of motion via the Internet assists the further development of Internet-based physiotherapy applications. (C) 2003 Elsevier Science Ltd. All rights reserved.

Reliability of scores between stroke patients and significant others on the Reintegration to Normal Living (RNL) Index

Purpose: This study measured reliability between stroke patients' and significant others' scores on items on the Reintegration to Normal Living (RNL) Index and whether there were any scoring biases. Method The 11-item RNL Index was administered to 57 pairs of patients and significants six months after stroke rehabilitation. The index was scored using a 10-point visual analogue scale. Patient and significant other demographic information and data on patients' clinical, functional and cognitive status were collected. Reliability was measured using the intra-class correlation coefficient (ICC) and percent agreement. Results: Overall poor reliability was found for the RNL Index total score (ICC=.36, 95% CI. 07 to .59) and the daily functioning subscale (ICC=.24, 95% CI -.003 to .46) and moderate reliability was found for the perception of self subscale (ICC=.55, 95 % CI .28 to .73). There was a moderate bias for patients to rate themselves as achieving better reintegration than was indicated by significant others, although no demographic or clinical factors were associated with this bias. Exact match agreement was best for the subjective items and worse for items reflecting mobility around the community and participation in a work activity. Conclusions: Caution is needed when interpreting patient information reported by significant others on the RNL Index. The use of a shorter scale to rate the RNL Index requires investigation.

Influence of shapes of selected vegetable materials on drying kinetics during fluidized bed drying

Three different particular geometrical shapes of parallelepiped, cylinder and sphere were taken from cut green beans (length:diameter = 1:1, 2:1 and 3:1) and potatoes (aspect ratio = 1:1, 2:1 and 3:1) and peas, respectively. Their drying behaviour in a fluidised bed was studied at three different drying temperatures of 30, 40 and 50 degreesC (RH = 15%). Drying curves were constructed using non-dimensional moisture ratio (MR) and time and their behaviour was modelled using exponential (MR = exp(-kt)) and Page (MR = exp(-kt(n))) models. The effective diffusion coefficient of moisture transfer was determined by Fickian method using uni- and three-dimensional moisture movements. The diffusion coefficient was least affected by the size when the moisture movement was considered three-dimensional, whereas the drying temperature had a significative effect on diffusivity as expected. The drying constant and diffusivity coefficients were on the descending order for potato, beans and peas. The Arrhenius activation energy for the peas was also highest, indicating a strong barrier to moisture movement in peas as compared to beans and skinless cut potato pieces. (C) 2003 Elsevier Science Ltd. All rights reserved.