Implementation and analysis of several keyframe-based browsing interfaces to digital video

In this paper we present a variety of browsing interfaces for digital video information. The six interfaces are implemented on top of Físchlár, an operational recording, indexing, browsing and playback system for broadcast TV programmes. In developing the six browsing interfaces, we have been informed by the various dimensions which can be used to distinguish one interface from another. For this we include layeredness (the number of “layers” of abstraction which can be used in browsing a programme), the provision or omission of temporal information (varying from full timestamp information to nothing at all on time) and visualisation of spatial vs. temporal aspects of the video. After introducing and defining these dimensions we then locate some common browsing interfaces from the literature in this 3-dimensional “space” and then we locate our own six interfaces in this same space. We then present an outline of the interfaces and include some user feedback

Evaluating and combining digital video shot boundary detection algorithms

The development of standards for video encoding coupled with the increased power of computing mean that content-based manipulation of digital video information is now feasible. Shots are a basic structural building block of digital video and the boundaries between shots need to be determined automatically to allow for content-based manipulation. A shot can be thought of as continuous images from one camera at a time. In this paper we examine a variety of automatic techniques for shot boundary detection that we have implemented and evaluated on a baseline of 720,000 frames (8 hours) of broadcast television. This extends our previous work on evaluating a single technique based on comparing colour histograms. A description of each of our three methods currently working is given along with how they are evaluated. It is found that although the different methods have about the same order of magnitude in terms of effectiveness, different shot boundaries are detected by the different methods. We then look at combining the three shot boundary detection methods to produce one output result and the benefits in accuracy and performance that this brought to our system. Each of the methods were changed from using a static threshold value for three unconnected methods to one using three dynamic threshold values for one connected method. In a final summing up we look at the future directions for this work

Characterisation of the Hoffmann Reflex using Mechanomyography

Mechanomyography (MMG) is a technique for recording mechanical activity in contracting muscle. The MMG signal is low frequency, typically 5-100Hz.This MMG ‘sound’ is produced by lateral oscillations of muscle fibres which occur at the resonant frequency of the muscle. The analysis of MMG signals has allowed examination of various aspects of muscle function such as neuromuscular fatigue, muscle fibre type distributions and neuromuscular disorders. To date, Electromyography (EMG) has been considered the primary non-invasive technique to record and interpret the physiological properties of contracting muscle. The Hoffmann reflex (H-reflex) is the equivalent of the monosynaptic stretch reflex, elicited by electrical stimulation. The aim of this investigation was to characterise the Hoffman reflex using an MMG system. The system is based on 2-axis MEMS (Micro Electro-Mechanical System) sensors placed on the soleus muscle

Micro electro mechanical systems based sensor for mechanomyography

The purpose of this work was to design a micro electrical mechanical sensor (MEMS) based system to measure the mechanomyogram of electrically stimulated muscle. The measuring device for the mechanomyography (MMG) system consisted of a dual axis accelerometer and a signal conditioning circuit designed specifically to enhance raw MMG signals . Currently electromyography (EMG) is the standard tool for measuring muscle contraction. During electrical stimulation however, EMG measurements are corrupted with a large stimulus artefact. This obscures any contributions from the much smaller electrical activity of the muscle tissue itself for the first 10ms to 12ms, before disappearing. MMG, being based on kinetic measurements, offers an alternative in such cases. We illustrate this with a dual modality EMG/MMG simultaneous acquisition for a Hoffman-reflex study

Characterisation of the Hoffmann Reflex using Mechanomyography

Mechanomyography (MMG) is a technique for recording mechanical activity in contracting muscle. The MMG signal is low frequency, typically 5-100Hz.This MMG ‘sound’ is produced by lateral oscillations of muscle fibres which occur at the resonant frequency of the muscle. The analysis of MMG signals has allowed examination of various aspects of muscle function such as neuromuscular fatigue, muscle fibre type distributions and neuromuscular disorders. To date, Electromyography (EMG) has been considered the primary non-invasive technique to record and interpret the physiological properties of contracting muscle. The Hoffmann reflex (H-reflex) is the equivalent of the monosynaptic stretch reflex, elicited by electrical stimulation. The aim of this investigation was to characterise the Hoffman reflex using an MMG system. The system is based on 2-axis MEMS (Micro Electro-Mechanical System) sensors placed on the soleus muscle

Synthesis and structural comparisons of NHC-alanes

N-heterocyclic Carbenes (NHCs) are widely used in organometallic chemistry. Here, we examine the role of NHCs in the stabilisation of aluminium hydrides, AlH3, also known as alanes. This includes an assessment of the various synthetic strategies, comparisons of structural parameters and theoretical insight. Based on percent buried volume (%Vbur) parameters we report the largest and smallest NHC alanes to date, with noted differences in their observed stability in both the solution and solid state

Short-term serotonergic but not noradrenergic antidepressant administration reduces attentional vigilance to threat in healthy volunteers

Anxiety is associated with threat-related biases in information processing such as heightened attentional vigilance to potential threat. Such biases are an important focus of psychological treatments for anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of a range of anxiety disorders. The aim of this study was to assess the effect of an SSRI on the processing of threat in healthy volunteers. A selective noradrenergic reuptake inhibitor (SNRI), which is not generally used in the treatment of anxiety, was used as a contrast to assess the specificity of SSRI effects on threat processing. Forty-two healthy volunteers were randomly assigned to 7 d double-blind intervention with the SSRI citalopram (20 mg/d), the SNRI reboxetine (8 mg/d), or placebo. On the final day, attentional and interpretative bias to threat was assessed using the attentional probe and the homograph primed lexical decision tasks. Citalopram reduced attentional vigilance towards fearful faces but did not affect the interpretation of ambiguous homographs as threatening. Reboxetine had no significant effect on either of these measures. Citalopram reduces attentional orienting to threatening stimuli, which is potentially relevant to its clinical use in the treatment of anxiety disorders. This finding supports a growing literature suggesting that an important mechanism through which pharmacological agents may exert their effects on mood is by reversing the cognitive biases that characterize the disorders that they treat. Future studies are needed to clarify the neural mechanisms through which these effects on threat processing are mediated

Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research

Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition

The health profile of people living with Parkinson\u27s Disease managed in a comprehensive care setting

Background: Globally there are few reports of the impairments, disabilities and medications used in people living with idiopathic Parkinson’s disease. Caregiver characteristics and caregiver burden have seldom been reported. We examined the health status in a large cohort of people living with Parkinson’s disease and their caregivers managed in a comprehensive health care setting. Methods/Design: A prospective, cross sectional analysis of impairments, disabilities and Parkinson’s disease medication use was conducted in a sample of 100 people with Parkinson’s disease rated I-IV on the modified Hoehn & Yahr scale. Participants were recruited from the Victorian Comprehensive Parkinson Program in Melbourne, Australia. Their caregivers were invited to provide their views on the burden of care, services provided and support received. Results: The severity of impairments and disabilities was strongly associated with disease duration (mean of 5.5 years). Those with long standing disease or more severe disease also used more Parkinson’s disease medications and participated in fewer social roles than people who were newly diagnosed or mildly affected. The severity of impairments was strongly correlated with limitations in performing activities of daily living. Limitations in performing daily activities were also found to be a significant contributing factor for health-related quality of life (PDQ-39 SI β=0.55, p=0.000; EQ-5D SI β=0.43, p=0.001). People with Parkinson’s disease lived at home with relatives. The average caregiver was a spouse or child providing approximately 3.5 hours of care per day, with the capacity to provide 9.4 hours per day and had provided care for four years. Additional support was high (63%) for 2.5 hours per day. Conclusion: The comprehensive care setting of this cohort describes a relatively benign condition despite a wide range of disease duration and severity. This report provides a baseline with which to compare other delivery models