24529809
Multiple-electrode nerve cuffs for low-velocity and velocity-selective neural recording
In the paper, a method using multiple-electrode nerve cuffs is presented that enables electroneurographic signals (ENG) to be recorded selectively by action potential velocity. The theory uses a one-dimensional model of the electrodes in the cuff. Using this model, the transfer function for a single tripole is derived, and it is shown that more than one tripole signal can be recorded from within a cuff. When many tripole signals are available and are temporally aligned by artificial delays and summed, there is a significant increase in the amplitude of the recorded action potential, depending on the cuff length and the action potential velocity, with the greatest gain occurring for low velocities. For example, a cuff was considered that was constrained by surgical considerations to 30 mm between the end electrodes. For action potentials with a velocity of 120 ms−1, it was shown that, as the number of tripoles increased from one, the peak energy spectral density of the recorded output increased by a factor of about 1.6 with three tripoles, whereas, for 20 ms−1, the increase was about 19, with ten tripoles. The time delays and summation act as a velocity-selective filter. With consideration of the energy spectral densities at frequencies where are maximum (to give the best signal-to-noise ratio), the tuning curves are presented for these velocity-selective filters and show that useful velocity resolution is possible using this method. For a 30 mm cuff with nine tripoles, it is demonstrated that it is possible to resolve at least five distinct velocity bands in the range 20–120 ms−1.
11981798
The theory of velocity selective neural recording: a study based on simulation
This paper describes the improvements to the theory of velocity selective recording and some simulation results. In this method, activity in different groups of axons is discriminated by their propagation velocity. A multi-electrode cuff and an array of amplifiers produce multiple neural signals; if artificial delays are inserted and the signals are added, the activity in axons of the matched velocity are emphasized. We call this intrinsic velocity selective recording. However, simulation shows that interpreting the time signals is then not straight-forward and the selectivity Qv is low. New theory shows that bandpass filters improve the selectivity and explains why this is true in the time domain. A simulation study investigates the limits on the available velocity selectivity both with and without additive noise and with reasonable sampling rates and analogue-to-digital conversion parameters. Bandpass filters can improve the selectivity by factors up to 7 but this depends on the speed of the action potential and the signal-to-noise ratio.
21326002
Life events and peer substance use and their relation to substance use problems in college students.
Substance use disorders among college students are not well understood, and the present study examined the relationship of two environmental factors to alcohol and drug use problems in 616 (316 women) college students. Participants completed measures assessing substance use problems, life events, and substance use among peers. Alcohol use problems were significantly associated with higher drug use problems and regular use of illicit drugs among friends. Drug use problems were significantly associated with male gender, higher alcohol use problems, regular use of alcohol and drugs among friends, illicit drug use among romantic partners, and higher numbers of negative life events. Results extend previous research and suggest that college students who experience multiple negative life events and/or affiliate with substance using friends and romantic partners may be at risk for developing a substance use problem.
9219755
Consumer expectations of nonprescription medications according to location of sale.
OBJECTIVE
To determine whether the public has different expectations of nonprescription medications based on location of sale.


DESIGN
Cross-sectional, descriptive.


SETTING
Saskatoon, Saskatchewan, Canada, during the summer of 2003.


PARTICIPANTS
2,102 randomly selected citizens.


INTERVENTION
Mail survey.


MAIN OUTCOME MEASURES
Differences in expectations for potency, safety, adverse effects, effectiveness, and package information of products sold in pharmacies versus convenience stores.


RESULTS
The response rate was 57.2%. Most participants (81.2%) were aware that nonprescription medications could be purchased in convenience stores, but far fewer (42.3%) had done so. As one potential resource during purchases, pharmacists were held in reasonably high regard. Expectations with the greatest difference were of a merchandising nature. Respondents expected pharmacies to have a better quality and selection of products and lower prices. For drug-related attributes, differences were minimal but statistically significant.


CONCLUSION
Location of sale does not appear to have any practical influence on consumer expectations of the drug-related attributes of nonprescription medications. Buyers of such products expect similar properties to be present regardless of location.
45621123
Acquisition and severity of driving-related fears.
Rachman's theory of fear acquisition proposes that directly-conditioned fears will differ from indirectly-conditioned fears in magnitude and anxiety response patterns, however the theory has received inconsistent empirical support. The aim of the present study was to describe the fear acquisition pathways for a community sample who reported driving-related fears, and to test Rachman's theory of fear acquisition. One hundred and ninety participants completed a questionnaire which assessed a variety of driving-related situations, reactions to motor vehicle accidents (MVAs), and anxiety response patterns. Professional psychological helpseeking and perceived need for treatment for driving-related fears were also assessed. Results failed to support Rachman's predictions. However, it was confirmed that respondents who had been involved in an MVA were more likely to ascribe their fears to a directly-conditioned pathway. The theoretical and methodological implications of the findings are discussed, along with suggestions for assessment of those with driving-related fears.
12851840
Flood management: prediction of microbial contamination in large-scale floods in urban environments.
With a changing climate and increased urbanisation, the occurrence and the impact of flooding is expected to increase significantly. Floods can bring pathogens into homes and cause lingering damp and microbial growth in buildings, with the level of growth and persistence dependent on the volume and chemical and biological content of the flood water, the properties of the contaminating microbes, and the surrounding environmental conditions, including the restoration time and methods, the heat and moisture transport properties of the envelope design, and the ability of the construction material to sustain the microbial growth. The public health risk will depend on the interaction of these complex processes and the vulnerability and susceptibility of occupants in the affected areas. After the 2007 floods in the UK, the Pitt review noted that there is lack of relevant scientific evidence and consistency with regard to the management and treatment of flooded homes, which not only put the local population at risk but also caused unnecessary delays in the restoration effort. Understanding the drying behaviour of flooded buildings in the UK building stock under different scenarios, and the ability of microbial contaminants to grow, persist, and produce toxins within these buildings can help inform recovery efforts. To contribute to future flood management, this paper proposes the use of building simulations and biological models to predict the risk of microbial contamination in typical UK buildings. We review the state of the art with regard to biological contamination following flooding, relevant building simulation, simulation-linked microbial modelling, and current practical considerations in flood remediation. Using the city of London as an example, a methodology is proposed that uses GIS as a platform to integrate drying models and microbial risk models with the local building stock and flood models. The integrated tool will help local governments, health authorities, insurance companies and residents to better understand, prepare for and manage a large-scale flood in urban environments.
42040828
The Station Community Mental Health Centre Inc: nurturing and empowering.
INTRODUCTION
Consumer-driven community mental health services play an important role in rehabilitation, recovery, and advocacy in rural and remote Australia. The origins of services often lie in the need to provide options for people with mental illness and their carers when there is a lack of on-the-ground support. This article adds to the information about the strengths and limitations of consumer-driven mental health services by presenting the findings of an evaluation of The Station Inc. in rural South Australia. This consumer-driven mental health service provides a safe and supportive environment, social connections, and activities for its members (those with a lived experience of mental illness). Using a realist evaluation approach, the evaluation identified the contextual factors and the program mechanisms that produce positive outcomes for members.


METHOD
The evaluation was conducted as participatory action research with The Station members, volunteers, management committee members, and staff involved in all phases of the research process. Because of the complexity of The Station's functioning a realist evaluation using qualitative data was conducted to identify how the program worked, for whom, and in what circumstances. Twenty-five in-depth interviews were conducted with participants who were randomly selected from within the groups identified above. Interviews focused on The Station's role in assisting recovery from mental illness, the limitations and strengths of the program, and relationships with the mental health system. The Station's goals, policies and procedures, and the role of stakeholders were analysed in order to identify any links among these contextual factors, program mechanisms, and program outcomes. Qualitative data were entered into descriptive categories in N6 software (QSR; www.qsr.international.com). Data from the stakeholder analysis were entered into Microsoft Excel. Using an iterative approach to include the three data sets, a model was developed that identified important contextual factors that linked with two groups of program mechanisms that produced positive outcomes for members.


RESULTS
Program mechanisms are categorised by descriptive themes referred to as 'nurturing' and 'empowering'. Nurturing' is experienced as feeling of belonging and being accepted 'as one is' and 'empowerment' mechanisms engender a belief in oneself. Respondents identified features of The Station's program, policies, atmosphere, connections and networks, stakeholder relationships, and staff and volunteers that are nurturing and empowering. Five key contextual factors enable the program mechanisms to work. The Station's coordinators ensure that nurturing and empowerment processes are highlighted through careful facilitation. The governance arrangements, policies, and administrative systems at The Station are well developed but flexibly implemented so that they support the nurturing and empowerment processes. Support and legitimacy for the program is obtained from the mental health system at state and local levels. The Station obtains resources and connections to its rural community through key stakeholders and a peak organisation One Voice Network acts as an advocate.


CONCLUSIONS
Information about the benefits and limitations of consumer-driven mental health services in rural and remote Australia is in short supply. Increasing the available information about the contribution these services make may result in services being legitimised, understood, and resourced within mental health systems thus making the services sustainable. The benefits of consumer-driven services are that they provide flexibility and adaptation, an ability to capture the energy and passion of rural communities to improve the wellbeing of community members, and they overcome the power differential that exists between professionals and 'patients' or 'clients'.