Pixel-based correspondence for facial images

A pixel-based correspondence method is presented for representation of facial images. The proposed method consists of two modules: face-image matching and face-image morphing. In the face-image matching module, the correspondence between two images are calculated for all pixel locations. A novel area-based matching method is proposed that makes use of the concept of the fractal dimension, and develops a non-parametric local transform as a basis for establishing correspondence between two face images. In the face-image morphing module, a mapping is performed for deformation of the source face image onto the target face image. This is done to map the pixels in the source face image to the location of their corresponding pixels in the target image.

Facial image analysis

This thesis focuses on novel technologies for facial image analysis, which involves three topics: face recognition under uncontrolled conditions, automatic facial age estimation, and context-aware fusion of face and gait. They are either key issues bridging laboratorial research and real applications, or innovative problems that have barely been studied before.

Facial affect recognition and schizotypal personality characteristics

Aim: Deficits in facial affect recognition are well established in schizophrenia, yet relatively little research has examined facial affect recognition in hypothetically psychosis-prone or ‘schizotypal’ individuals. Those studies that have examined social cognition in psychosis-prone individuals have paid little attention to the association between facial emotion recognition and particular schizotypal personality features. The present study therefore sought to investigate relationships between facial emotion recognition and the different aspects of schizotypy.

Methods: Facial affect recognition accuracy was examined in 50 psychiatrically healthy individuals assessed for level of schizotypy using the Schizotypal Personality Questionnaire. This instrument provides a multidimensional measure of schizophrenia proneness, encompassing ‘cognitive-perceptual’, ‘interpersonal’ and ‘disorganized’ features of schizotypy. It was hypothesized that the cognitive-perceptual and interpersonal aspects of schizotypy would be associated with difficulties identifying facial expressions of emotion during a forced-choice recognition task using a standardized series of colour photographs.

Results: As predicted, interpersonal aspects of schizotypy (particularly social anxiety) were associated with reduced accuracy on the facial affect recognition task, but there was no association between affect recognition accuracy and cognitive-perceptual features of schizotypy.

Conclusions: These results suggest that subtle deficits in facial affect recognition in otherwise psychiatrically healthy individuals may be related to the vulnerability for interpersonal communication difficulties, as seen in schizophrenia.

Oxygen dependence of metabolism and cellular adaptation in vertebrate muscles: a review

The key roles the cardiovascular system play in the complex distribution of blood, and consequently oxygen, have been extensively studied in vertebrates. Numerous studies have also revealed the complex and varied ways in which tissues cope with compromised oxygen supply. The links between these two processes are the subject of much current research. This article aims to review how blood supply influences tissue oxygenation and affects metabolism, and how this might have played a role in the evolution of the complex muscle arrangements which characterise vertebrates. Muscle tissue is the greatest proportion of body mass in most vertebrates and undergoes dramatic alterations in metabolism and associated oxygen flux. Special attention is given to the myotome of fishes, in which the partitioning of the fibre types contrasts with the mosaic arrangement of tetrapods. This gives us the opportunity to study pure whole vascularised muscle blocks, rather than single fibres, and further explore the interrelationship between oxygen supply and tissue energetics.

Oxygen-dependence of metabolic rate in the muscles of craniates

We present evidence that oxygen consumption (V_O2 ) is oxygen partial pressure (P_O2) dependent in striated muscles and P_O2 -independent in the vasculature in representatives of three craniate taxa: two teleost fish, a hagfish and a rat. Blood vessel V_O2 displayed varying degrees of independence in a P_O2 range of 15–95 mmHg, while V_O2 by striated muscle tissue slices from all species related linearly to P_O2 between 0 and 125 mmHg, despite V_O2 rates varying greatly between species and muscle type. In salmon red muscle, lactate concentrations fell in slices incubated at a P_O2 of either 30 or 100 mmHg, suggesting aerobic rather than anaerobic metabolism. Consistent with this finding, potential energy, a proxy of ATP turnover, was P_O2 -dependent. Our data suggest that the reduction in V_O2 with falling P_O2 results in a decrease in ATP demand, suggesting that the hypoxic signal is sensed and cellular changes effected. Viability and diffusion limitation of the preparations were investigated using salmon cardiac and skeletal muscles. Following the initial P_O2 depletion, reoxygenation of the Ringer bathing salmon cardiac muscle resulted in V_O2^s that was unchanged from the first run. V_O2 increased in all muscles uncoupled with p-trifluoromethoxylphenyl-hydrazone (FCCP) and 2,4-dinitrophenol (DNP). Mitochondrial succinate dehydrogenase activity, quantified by reduction of 3-(4,5-dimethylthiazol)-2,5-diphenyl-2H-tetrazolium bromide (MTT) to formazan, was constant over the course of the experiment. These three findings indicate that the tissues remained viable over time and ruled out diffusion-limitation as a constraint on V_O2.

Low cost multimodal facial recognition via kinect sensors

This paper presents a novel low cost 3D facial recognition using gaming sensors such as Kinect™. The paper describes the hardware, calibration and infrared noise and pattern interference challenges of integrating multiple Kinect sensors. The preliminary results show a promising trend for low cost solutions that can be populated in crowded facilities such as malls and airports.

Artificial Muscles Based on Polypyrrole/Carbon Nanotube Laminates

A novel method for the periodical assembly of laminates of forest-drawn carbon nanotube (CNT) sheets and polypyrrole (PPy) is described. The method produces composite films in which the volume fraction and orientation of CNTs can be controlled. Actuator stroke and strength is increased and work capacity per cycle doubled when nanotube orientation is perpendicular to the actuation direction. Most importantly, these PPy/CNT laminates have dramatically decreased creep during actuation, which has been a major barrier for the application of PPy actuators.