18,788 research outputs found

    Aspects of the population biology of Octopus vulgaris in False Bay, South Africa

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    The population biology of the octopus Octopus vulgaris was studied from specimens collected by SCUBA in False Bay, South Africa, between 1997 and 1998. In all, 83% of the specimens collected were found in shelter. Small octopuses were more active than large individuals during the day, 37% of the former and 8% of the latter being found outside of shelters. All males >170 g were mature, the smallest male being 136 g. No mature females were found in the study area, and maturing females spanned a broad size range caught (275–3 600 g). Average size at spawning is probably between 1 500 and 2 500 g. Although there were no significant overall differences in mass between sexes (p > 0.05), the average mass of octopus in winter (766 g) was significantly smaller than in summer (1 161 g) and spring (964 g). Fluctuations in the average size of octopus tracked subsurface water temperature. The overall sex ratio was significantly biased towards males (0.6F:1.0M, p < 0.01), largely because fewer females were caught during spring and summer. Spawning likely occurs throughout the year. However, significantly higher (p < 0.01) female gonadal somatic indices of 0.52 and 0.46 found in spring and summer respectively (periods of warmer water in False Bay) may indicate peak spawning during those seasons.Keywords: maturation, morphometrics, Octopus vulgaris, population biology, sex ratio, spawning seasonAfrican Journal of Marine Science 2002, 24: 185–19

    A Computational and Experimental Compressor Design Project for Japanese and British High-School Students

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    This paper describes an innovative, three-day, turbomachinery research project for Japanese and British high-school students. The project is structured using modern teaching theories which encourage student curiosity and creativity. The experience develops team-work and communication, and helps to break-down cultural and linguistic barriers between students from different countries and backgrounds. The approach provides a framework for other hands-on research projects which aim to inspire young students to undertake a career in engineering. The project is part of the Clifton Scientific Trust's annual UK-Japan Young Scientist Workshop Programme. The work focuses on compressor design for jet engines and gas turbines. It includes lectures introducing students to turbomachinery concepts, a computational design study of a compressor blade section, experimental tests with a low-speed cascade and tutorials in data analysis and aerodynamic theory. The project also makes use of 3D printing technology, so that students go through the full engineering design process, from theory, through design, to practical experimental testing. Alongside the academic aims, students learn what it is like to study engineering at university, discover how to work effectively in a multinational team, and experience a real engineering problem. Despite a lack of background in fluid dynamics and the limited time available, the lab work and end of project presentation show how far young students can be stretched when they are motivated by an interesting problem

    A cross sectional study of water quality from dental unit water lines in dental practices in the West of Scotland

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    OBJECTIVE: To determine the microbiological quality of water from dental units in a general practice setting and current practice for disinfection of units. DESIGN: A cross-sectional study of the water quality from 40 dental units in 39 general practices and a questionnaire of the disinfection protocols used in those practices. SETTING: NHS practices in primarydental care. SUBJECTS: Thirty-nine general practices from the West of Scotland. METHODS: Water samples were collected on two separate occasions from dental units and analysed for microbiological quality by the total viable count (TVC) method. Water specimens were collected from the triple syringe, high speed outlet, cup filler and surgery tap. Each participating practitioner was asked to complete a questionnaire. Results Microbial contamination was highest from the high speed outlet followed by the triple syringe and cup filler. On average, the TVC counts from the high speed water lines at 37 degrees C and for the high speed lines, triple syringe and cup filler at 22 degrees C were significantly higher than that from the control tap water specimens. The study included units from 11 different manufacturers with ages ranging from under one year to over eight years. The age of the dental unit analysed did not appear to influence the level of microbial contamination. Five of the practices surveyed used disinfectants to clean the dental units but these had no significant effect on the microbiological quality of the water. The majority of dental units (25 out of 40) were never flushed with water between patients. A number of different non-sterile irrigants were used for surgical procedures. CONCLUSION: The microbiological quality of water from dental units in general dental practice is poor compared with that from drinking water sources. Suitable sterile irrigants should be used for surgical procedures in dental practice. Further work is required for pragmatic decontamination regimens of dental unit water lines in a general dental practice setting

    Usability engineering in the design and evaluation of a functional electrical stimulation system for upper limb rehabilitation

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    Chronic physical impairment of the hemiplegic upper limb (UL) is seen in an estimated 50-70% of stroke patients, who place a high priority on regaining upper limb function. Current therapy is insufficiently intensive, often not task-oriented and hence poorly aligned with the evidence base. Functional electrical stimulation (FES) has the potential to not only increase the intensity of task-focused therapy, but also provide certain unique features, notably direct excitation of lower motor neurons. However, current FES systems are limited in their functionality and/or difficult to use. Systems are also poorly aligned to therapists’ ways of working and uptake remains limited. To address these problems, a novel FES technology (UL FES Rehab Tool) has been developed. The control system design is reported in Sun, (2014). The aims of my thesis were to: 1) design a Graphical User Interface (GUI) that would enable therapists to quickly and easily set up an individually tailored library of FES tasks for each patient; 2) evaluate the usability and functionality of the UL FES Rehab Tool(software and hardware) in both laboratory (lab) and clinical settings. An iterative, mixed methods, five-phase usability engineering approach was used to design and evaluate the UL FES Rehab Tool. Phases one to three incorporated identification of therapists’ requirements, a user ‘assisted walkthrough’ of the software with expert and novice FES users and ‘rapid prototyping’ of the full system, using healthy participants. Further usability testing of the software & hardware was conducted in phase four with 1 physiotherapist and 6 patients, (total of 24 visits), in the chronic stage post-stroke. The work demonstrated in detail, for the first time, the impact of therapist involvement in the design of novel rehabilitation technology. To address therapists’ focus on setup time, using the phase four data set, a novel model to predict setup time was devised. This model was able to explain 51% of the variance in setup time based on two parameters, task complexity and patient impairment. Finally, in phase five, a summative usability evaluation of the final prototype was carried out in 2 sub-acute stroke units. Four therapists and 1 rehabilitation assistant used the UL FES Rehab Tool with 6 patients in the acute stage post-stroke. The UL FES Rehab Tool enabled all therapists and one therapy assistant to effectively deliver FES assisted upper limb task-oriented therapy to a range of stroke patients (Fugl-Meyer scores 8–65). The usability methods effectively captured objective and subjective feedback from therapists and patients. However the previous setup time model was unable to predict setup time, suggesting other factors were important in a clinical setting. Although participant numbers were low, the results suggested therapists’ predisposition to using technology and post-training confidence in using the technology may influence their willingness to engage with novel rehabilitation technologies. This study is the first to describe in detail the impact of a usability engineering approach on the design of a complex upper limb rehabilitation technology from early stage design to clinical evaluation. These methods can be generalised to other studies seeking to explore the usability of new forms of rehabilitation technologies
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