96 research outputs found

    A durable gain in motor and non-motor symptoms of Parkinson’s Disease following repeated caloric vestibular stimulation: A single-case study

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    Objective: To gain ‘first-in-man’ evidence that repeated caloric vestibular stimulation (CVS), a non-invasive form of neuro-modulation, can induce a lasting and clinically-relevant reduction in Parkinson’s Disease (PD) symptoms. Methods: A 70yr old male, diagnosed with PD 7 years prior to study enrolment, self-administered CVS at home 2x20 minutes per day for three months using a solid-state portable device. Standardised neuropsychological assessments of motor, cognitive, affective and independent function were carried out prior to stimulation, at the start and end of the sham (month 1) and active (months 2-3) phases, and 5 months post-stimulation. Results: Relative to the pre-stimulation baseline, behavioural improvements that exceeded the minimal detectable change were observed on the EQ5D, Unified Parkinson’s Disease Rating Scale, Schwab and England scale, 2 minute walk, Timed up and go, Non-motor symptom assessment scale for PD, Montreal cognitive assessment, Hospital depression scale and Epworth sleepiness scale. The level of change exceeded the threshold for a minimal clinically important difference on all scales for which a threshold has been published. By contrast, little improvement was seen during the sham (i.e. placebo) phase. Conclusion: Caloric vestibular stimulation may offer a novel, home-based method of relieving everyday symptoms of PD, and merits further evaluative study

    An ELT textbook evaluation: A two-phase criterion

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    It is by now well established that materials may have an impact beyond simply learning a language they present. Thus, we need to survey thoroughly the materials to find out the influence they might have on learners' progress and attitude. Hence, in this study attempts have been made to investigate the cons and pros of a textbook (Summit 2B) which is currently being widely used in Iranian EFL classes. The textbook has been evaluated based on a model provided by McDonough and Shaw (1993) on the basis of two stages: an external evaluation that offered a brief overview of the textbook from the outside and a closer and more detailed internal evaluation. Efforts have been made to critically evaluate the textbook in terms of the layout, design, content, language type, different activities, tasks, as well as the skills emphasized in the book. The findings showed that albeit there appears to be some shortcomings, this book (Summit 2B) seems to be more efficient to meet the requirements of the Iranian EFL learners as compared with the older textbooks which have hitherto been used at different language classes. Accordingly, investigating and evaluating the book proved to be very lucrative and valuable in terms of pedagogy as well as the efficient attributes that suits the context of the present study. Finally, the implications as regards the efficiency of this particular course-book as the consequence of evaluating it have been put forward and the strengths and weaknesses related to it have been argued

    Social justice for sex trafficked females and sex workers in Jordan

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    This thesis explores social practices, policies and laws constituting criminal and social justice approaches to providing services and amenities for the sex trafficked females in Jordan. As the discussion of sex trafficked females overlaps with sex workers, this research explores the human rights of both groups who experience different forms of gender-based violence. To understand the protection, care and support that Jordan provides, I interviewed seven service providers offering protection for victims of sex trafficking. Also, I analysed the semiprohibitionist Jordanian Penal Code and the Human Trafficking Legislation that criminalise sex trafficking perpetrators and sex-related actions. This research relies on insights from intersectionality theory to enquire into how better to protect and support women who face intersecting social disadvantages and the threat of honour-based killing that impede them from accessing social and criminal justice. This thesis explores three themes, cultural context, feminism and human rights, and argues for social justice for sex trafficked victims and sex workers including those who neither want to exit sex work nor raise a complaint to the administrators of criminal justice. This thesis found that sex trafficked victims and sex workers were not offered appropriate assistance as the service providers were disempowered. It also found that failure to understand honour and morality reinforces the stereotyping of sex workers

    Numerically simulated exposure of children and adults to pulsed gradient fields in MRI

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    PurposeTo determine exposure to gradient switching fields of adults and children in a magnetic resonance imaging (MRI) scanner by evaluating internal electric fields within realistic models of adult male, adult female, and child inside transverse and longitudinal gradient coils, and to compare these results with compliance guidelines. Materials and MethodsPatients inside x-, y-, and z-gradient coils were simulated using anatomically realistic models of adult male, adult female, and child. The induced electric fields were computed for 1 kHz sinusoidal current with a magnitude of 1 A in the gradient coils. Rheobase electric fields were then calculated and compared to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) 2004 and International Electrotechnical Commission (IEC) 2010 guidelines. The effect of the human body, coil type, and skin conductivity on the induced electric field was also investigated. ResultsThe internal electric fields are within the first level controlled operating mode of the guidelines and range from 2.7V m(-1) to 4.5V m(-1), except for the adult male inside the y-gradient coil (induced field reaches 5.4V m(-1)).The induced electric field is sensitive to the coil type (electric field in the skin of adult male: 4V m(-1), 4.6V m(-1), and 3.8V m(-1) for x-, y-, and z-gradient coils, respectively), the human body model (electric field in the skin inside y-gradient coil: 4.6V m(-1), 4.2V m(-1), and 3V m(-1) for adult male, adult female, and child, respectively), and the skin conductivity (electric field 2.35-4.29% higher for 0.1S m(-1) skin conductivity compared to 0.2S m(-1)). ConclusionThe y-gradient coil induced the largest fields in the patients. The highest levels of internal electric fields occurred for the adult male model. J. Magn. Reson. Imaging 2016;44:1360-1367

    Computational modeling of a single-element transcranial focused ultrasound transducer for subthalamic nucleus stimulation

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    Objective. While transcranial focused ultrasound is a very promising neuromodulation technique for its non-invasiveness and high spatial resolution, its application to the human deep brain regions such as the subthalamic nucleus (STN) is relatively new. The objective of this study is to design a simple ultrasound transducer and study the transcranial wave propagation through a highly realistic human head model. The effects of skull morphology and skull and brain tissue properties on the focusing performance and energy deposition must therefore be known. Approach. A full-wave finite-difference time-domain simulation platform was used to design and simulate ultrasound radiation from a single-element focused transducer (SEFT) to the STN. Simulations were performed using the state-of-the-art Multimodal Imaging-based and highly Detailed Anatomical (MIDA) head model. In addition, the impact of changes in sound speed, density, and tissue attenuation coefficients were assessed through a sensitivity analysis. Main results. A SEFT model was designed to deliver an intensity of around 100 W m(-2) to the STN region; 20% of the STN volume was sonicated with at least half of the maximum of the peak intensity and it was predicted that 61.5% of the volume of the beam (above half of the peak intensity) falls inside the STN region. The sensitivity analysis showed that the skull's sound speed is the most influential acoustic parameter, which must be known with less than 1.2% error to obtain an acceptable accuracy in intracranial fields and focusing (for less than 5% error). Significance. Ultrasound intensity delivery at the STN by a simple single element transducer is possible and could be a promising alternative to complex multi-element phased arrays, or more general, to invasive or less focused (non-acoustic) neuromodulation techniques. Accurate acoustic skull and brain parameters, including detailed skull geometry, are needed to ensure proper targeting in the deep brain region

    Electromagnetic modelling and optimization for SPECT-MRI and auricular vagus nerve stimulation

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    Simulated design strategies for SPECT collimators to reduce the eddy currents induced by MRI gradient fields

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    Combining single photon emission computed tomography (SPECT) with magnetic resonance imaging (MRI) requires the insertion of highly conductive SPECT collimators inside the MRI scanner, resulting in an induced eddy current disturbing the combined system. We reduced the eddy currents due to the insert of a novel tungsten collimator inside transverse and longitudinal gradient coils. The collimator was produced with metal additive manufacturing, that is part of a microSPECT insert for a preclinical SPECT/MRI scanner. We characterized the induced magnetic field due to the gradient field and adapted the collimators to reduce the induced eddy currents. We modeled the x-, y-, and z-gradient coil and the different collimator designs and simulated them with FEKO, a three-dimensional method of moments / finite element methods (MoM/FEM) full-wave simulation tool. We used a time analysis approach to generate the pulsed magnetic field gradient. Simulation results show that the maximum induced field can be reduced by 50.82% in the final design bringing the maximum induced magnetic field to less than 2% of the applied gradient for all the gradient coils. The numerical model was validated with measurements and was proposed as a tool for studying the effect of a SPECT collimator within the MRI gradient coils
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