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The Igwisi Hills volcanoes (IHV), Tanzania, are unique and important in preserving extra-crater lavas and pyroclastic edifices. They provide critical insights into the eruptive behaviour of kimberlite magmas that are not available at other known kimberlite volcanoes. Cosmogenic 3He dating of olivine crystals from IHV lavas and palaeomagnetic analyses indicates that they are Upper Pleistocene to Holocene in age. This makes them the youngest known kimberlite bodies on Earth by >30 Ma and may indicate a new phase of kimberlite volcanism on the Tanzania craton. Geological mapping, Global Positioning System surveying and field investigations reveal that each volcano comprises partially eroded pyroclastic edifices, craters and lavas. The volcanoes stand 102 to 106 Pa s) for kimberlite, attributed to degassing and in-vent cooling. Each volcano is inferred to be the result of a small-volume, short-lived (days to weeks) monogenetic eruption. The eruptive processes of each Igwisi volcano were broadly similar and developed through three phases: (1) fallout of lithic-bearing pyroclastic rocks during explosive excavation of craters and conduits; (2) fallout of juvenile lapilli from unsteady eruption columns and the construction of pyroclastic edifices around the vent; and (3) effusion of degassed viscous magma as lava flows. These processes are similar to those observed for other small-volume monogenetic eruptions (e.g. of basaltic magma).

We previously described a communication strategy for the delivery of the diagnosis of psychogenic non-epileptic seizures (PNES) that was acceptable and effective at communicating the psychological cause of PNES. This prospective multicenter study describes the short-term seizure and psychosocial outcomes after the communication of the diagnosis and with no additional treatment. Participants completed self-report measures at baseline, two and six months after the diagnosis (seizure frequency, HRQoL, health care utilization, activity levels, symptom attributions and levels of functioning). Thirty-six participants completed the self-report questionnaires. A further eight provided seizure frequency data. After six months, the median seizure frequency had dropped from 10 to 7.5 per month (p = 0.9), 7/44 participants (16%) were seizure-free, and an additional 10/44 (23%) showed greater than 50% improvement in seizure frequency. Baseline questionnaire measures demonstrated high levels of impairment, which had not improved at follow-up. The lack of change in self-report measures illustrates the need for further interventions in this patient group.

Evidence suggests that interoceptive and exteroceptive attention might have different perceptual effects. However, the effects of these different types of body-focused attention have never been directly compared. The current research investigated how interoceptive and exteroceptive attention affect subsequent performance on the somatic signal detection task (SSDT). In Experiment 1, 37 participants completed the SSDT under usual testing conditions and after performing an interoceptive heartbeat perception task. This task led to a more liberal response criterion, leading to increased touch reports in the presence and absence of a target vibration. This finding is consistent with suggestions that attending internally contributes to physical symptom reporting in patients with medically unexplained symptoms (MUS). In Experiment 2, 40 participants completed the SSDT before and after an exteroceptive grating orientation task. This task led to a more stringent response criterion, leading to decreased touch reports in the presence and absence of the target, possibly via a reduction in sensory noise. This work demonstrates that internal and external body-focused attention can have opposite effects on subsequent somatic perceptual decision making and suggests that attentional training could be useful for patients reporting MUS. © 2012 Copyright The Experimental Psychology Society.

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Kimberlites are volatile-rich magmas from mantle depths of ≥ 150 km and are the primary source of diamonds. Kimberlite volcanism involves the formation of diverging pipes or diatremes, which are the locus of high-intensity explosive eruptions. A conspicuous and previously enigmatic feature of diatreme fills are 'pelletal lapilli'--well-rounded clasts consisting of an inner 'seed' particle with a complex rim, thought to represent quenched juvenile melt. Here we show that these coincide with a transition from magmatic to pyroclastic behaviour, thus offering fundamental insights into eruption dynamics and constraints on vent conditions. We propose that pelletal lapilli are formed when fluid melts intrude into earlier volcaniclastic infill close to the diatreme root zone. Intensive degassing produces a gas jet in which locally scavenged particles are simultaneously fluidised and coated by a spray of low-viscosity melt. A similar origin may apply to pelletal lapilli in other alkaline volcanic rocks, including carbonatites, kamafugites and melilitites.

This study formed part of an evaluation of a brief educational intervention for patients with psychogenic non-epileptic seizures (PNES). The sessions provide information, seizure control techniques and management planning. The qualitative component of the research reported here aimed to provide insight into the participants' perceptions following the intervention. Semi-structured interviews were conducted with twelve patients. Interviews were tape-recorded, transcribed and analyzed, using principles of thematic analysis. Six key themes were identified: getting answers; understanding the link with emotions; seeking a physiological explanation; doubting the diagnosis; the role of medication; and finding a way forward. The findings highlight considerable individual variation in response, with evidence of changed perceptions or enhanced understanding in some patients while others continued to seek answers or explanations about the cause of their seizures. There were no clear links between reported improved understanding or acceptance of the diagnosis and a perceived improvement in the condition.

Newly identified ´a´ā lava flows outcrop intermittently over an area of ~110 km2 in the western Deccan Volcanic Province (DVP), India. They occur in the upper Thakurvadi Formation in the region south of Sangamner. The flows, one of which is compound, are 15–25 m thick, and exhibit well-developed basal and flow-top breccias. The lavas have microcrystalline groundmasses and are porphyritic or glomerocrystic and contain phenocrysts of olivine, clinopyroxene or plagioclase feldspar. They are chemically similar to compound pāhoehoe flows at a similar stratigraphic horizon along the Western Ghats. Petrographic and geochemical differences between ´a´ā flows at widely spaced outcrops at the same stratigraphic horizon suggest that they are the product of several eruptions, potentially from different sources. Their presence in the DVP could suggest relative proximity to vents. This discovery is significant because ´a´ā lavas are generally scarce in large continental flood basalt provinces, which typically consist of numerous inflated compound pāhoehoe lobes and sheet lobes. Their scarcity is intriguing, and may relate to either their occurrence only in poorly preserved or exposed proximal areas or to the flat plateau-like topography of flood basalt provinces that may inhibit channelization and ´a´ā formation, or both. In this context, the ´a´ā flow fields described here are inferred to be the products of eruptions that produced unusually high-effusion-rate lavas compared to typical flood basalt eruptions. Whether these phases were transitional to lower intensity, sustained eruptions that fed extensive low effusion rate pāhoehoe flow fields remains unclear.

When attempting to detect a near-threshold signal, participants often incorrectly report the presence of a signal, particularly when a stimulus in a different modality is presented. Here we investigated the effect of prior experience of bimodal visuotactile stimuli on the rate of falsely reported touches in the presence of a light. In Experiment 1, participants made more false alarms in light-present than light-absent trials, despite having no experience of the experimental visuotactile pairing. This suggests that light-evoked false alarms are a consequence of an existing association, rather than one learned during the experiment. In Experiment 2, we sought to manipulate the strength of the association through prior training, using supra-threshold tactile stimuli that were given a high or low association with the light. Both groups still exhibited an increased number of false alarms during light-present trials, however, the low association group made significantly fewer false alarms across conditions, and there was no corresponding group difference in the number of tactile stimuli correctly identified. Thus, while training did not affect the boosting of the tactile signal by the visual stimulus, the low association training affected perceptual decision-making more generally, leading to a lower number of illusory touch reports, independent of the light. © 2011 Elsevier B.V.

Palaeomagnetic techniques for estimating the emplacement temperatures of volcanic deposits have been applied to pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa. Lithic clasts were sampled from a variety of lithofacies from three pipes for which the internal geology is well constrained (the Cretaceous A/K1 pipe, Orapa Mine, Botswana, and the Cambrian K1 and K2 pipes, Venetia Mine, South Africa). The sampled deposits included massive and layered vent-filling breccias with varying abundances of lithic inclusions, layered crater-filling pyroclastic deposits, talus breccias and volcaniclastic breccias. Basalt lithic clasts in the layered and massive vent-filling pyroclastic deposits in the A/K1 pipe at Orapa were emplaced at >570°C, in the pyroclastic crater-filling deposits at 200-440°C and in crater-filling talus breccias and volcaniclastic breccias at 560°C, although the interpretation of these results is hampered by the presence of Mesozoic magnetic overprints. These temperatures are comparable to the estimated emplacement temperatures of other kimberlite deposits and fall within the proposed stability field for common interstitial matrix mineral assemblages within vent-filling volcaniclastic kimberlites. The temperatures are also comparable to those obtained for pyroclastic deposits in other, silicic, volcanic systems. Because the lithic content of the studied deposits is 10-30%, the initial bulk temperature of the pyroclastic mixture of cold lithic clasts and juvenile kimberlite magma could have been 300-400°C hotter than the palaeomagnetic estimates. Together with the discovery of welded and agglutinated juvenile pyroclasts in some pyroclastic kimberlites, the palaeomagnetic results indicate that there are examples of kimberlites where phreatomagmatism did not play a major role in the generation of the pyroclastic deposits. This study indicates that palaeomagnetic methods can successfully distinguish differences in the emplacement temperatures of different kimberlite facies. © 2011 Springer-Verlag.

Triprolidine, used extensively as an antihistamine, was studied for subchronic toxicity by administration as an admixture in the diet to male and female Fischer 344 rats at dosage levels of 0, 156, 312, 625, 1250, and 2500 parts per million (ppm) for 14 days and in a second study at 0, 250, 500, 1000, 2000, and 4000 ppm for 90 days. In the 14-day study, the only sign of toxicity observed either clinically or histologically was a reduction of final body weights (less than 10%) of both male and female rats in the 2500 ppm dosage group associated with reduced food consumption. In the 90-day study, final body weights were reduced, compared to controls, at the higher dosage levels with 4000 ppm resulting in a 20% and 13.4% reduction in males and females, respectively. Target organs were identified as the liver with hepatic fatty change and the parotid salivary gland, which exhibited treatment-related cytoplasmic alterations of the acinar cells. Males were more susceptible than females to both of these effects. These results indicate that rats would tolerate 2000 ppm triprolidine in a 2-year chronic bioassay without significant shortening of life span.

Objective Medically unexplained symptoms (MUS) have been hypothesized to result from a distortion in perception, whereby top-down factors influence the process of body representation. Perceptual illusions provide a novel method of investigating this hypothesis. This study aimed to investigate whether self-reported unexplained symptoms are associated with altered experience of the rubber hand illusion (RHI). Methods A non-clinical MUS group with high scores on the Somatoform Dissociation Questionnaire (SDQ), and a control group with low scores on this scale, were exposed to the RHI. Illusion experience was measured by self-reports and by proprioceptive alteration. Results After controlling for somatosensory amplification and trait anxiety, the low-SDQ group responded significantly more strongly to the RHI on both questionnaire and proprioceptive measures of the illusion. In contrast, the high-SDQ group scored significantly higher on the Perceptual Aberrations Scale, a measure of bodily distortions in daily life. Conclusion These findings support the proposed link between MUS and disturbances in body representation, and suggest that a decreased reliance on current sensory inputs may contribute to symptom experience in susceptible individuals.

It is well known that stimuli grab attention to their location, but do they also grab attention to their sensory modality? The modality shift effect (MSE), the observation that responding to a stimulus leads to reaction time benefits for subsequent stimuli in the same modality, suggests that this may be the case. If noninformative cue stimuli, which do not require a response, also lead to benefits for their modality, this would suggest that the effect is automatic. We investigated the time-course of the visuotactile MSE and the difference between the effects of cues and targets. In Experiment 1, when visual and tactile tasks and stimulus locations were matched, uninformative cues did not lead to reaction time benefits for targets in the same modality. However, the modality of the previous target led to a significant MSE. Only stimuli that require a response, therefore, appear to lead to reaction time benefits for their modality. In Experiment 2, increasing attention to the cue stimuli attenuated the effect of the previous target, but the cues still did not lead to a MSE. In Experiment 3, a MSE was demonstrated between successive targets, and this effect decreased with increasing intertrial intervals. Overall, these studies demonstrate how cue- and target-induced effects interact and suggest that modalities do not automatically capture attention as locations do; rather, the MSE is more similar to other task repetition effects.

Objective: Unexplained neurological symptoms ("somatoform dissociation") are common in health care settings and associated with disproportionately high levels of distress, disability, and resource utilization. Theory suggests that somatoform dissociation is associated with disturbed attentional processing, but there is a paucity of research in this area and the available evidence is contradictory. Methods: We compared undergraduate participants (n=124) with high and low scores on the Somatoform Dissociation Questionnaire (SDQ-20) on a tactile cueing paradigm measuring the time course of attention to touch, following either a neutral film or a film designed to simulate the emotional effects of trauma exposure. Results: Following the neutral film, high SDQ-20 participants exhibited delayed disengagement from tactile cue stimuli compared to the low SDQ-20 group. Following the "trauma" film, however, the high SDQ-20 group showed attentional effects suggesting avoidance of the tactile stimuli in this condition. Early attention to tactile cues following the trauma film predicted film-related intrusive thoughts after the experiment. Conclusion: These findings suggest that both body vigilance and body avoidance may be involved in the expression of somatoform dissociation. © 2010 Elsevier Inc.

The sudden death of Harvie Ramsay from a brain haemorrhage on 24 April this year at the age of fifty-one greatly shocked and saddened his many friends and colleagues in the academic world and elsewhere. It has also deprived us of someone who had contributed so much to the areas of research and writing covered by this journal, for which he had been a member of the Editorial Board, and who still had so much to contribute.

Objective The psychological mechanisms of somatoform dissociation (i.e., pseudoneurological symptoms) are poorly understood. This study evaluated recent theoretical predictions regarding the role of tactile perception in the development of somatoform dissociative symptoms. Methods Eighty nonclinical participants scoring either high or low on the Somatoform Dissociation Questionnaire (SDQ-20) completed the Somatic Signal Detection Task (SSDT), a novel perceptual paradigm designed to simulate the occurrence of somatoform symptoms in the laboratory. Prior to the SSDT, participants completed a memory task designed to produce either minimal or maximal activation of tactile representations in memory. Results The high SDQ-20 group exhibited a more liberal response criterion (c) on the SSDT than the low SDQ-20 group after controlling for negative affectivity, somatosensory amplification and depression. This effect was mainly attributable to an increased number of false alarms (i.e., illusory experiences of touch) in the high SDQ-20 group rather than an increased hit rate. General perceptual ability (i.e., tactile sensitivity) was comparable between the two groups. The memory manipulation had no effect on SSDT performance. Conclusions Somatoform dissociators appear more likely to experience illusory perceptual events under conditions of sensory ambiguity than nondissociators, despite comparable perceptual abilities more generally. These findings support theories that identify distorted perceptual processing as a feature of somatoform dissociation. The SSDT has potential as a tool for further research in this area.

The performance of AlGaN/GaN high electron mobility transistors (HEMTs) with an Al x Si y N z passivation is reported for the first time. Thin films (30 nm) of Al x Si y N z and Si y N z were used to passivate devices (fabricated side-by-side) and their performance was compared in both small signal and large signal measurement environments. Examination of MIS structures with each dielectric by capacitance-voltage measurements revealed the Al x Si y N z provides a net negative fixed charge density allowing controlled depletion of the two dimensional electron gas (2DEG) in ungated regions of the channel. This is in contrast to Si y N z passivation where the surface depletion of the 2DEG is almost completely removed [1], which results in the full channel charge existing in the ungated portions of the channel. Reducing the charge in the ungated portions of the channel can be used to reduce the electric field at high drain bias with small increases in source and drain access resistance. Reduction of channel charge using a MIS gate extension (field plate) is now commonly used to increase the device performance at large drain bias. The charged dielectric approach described in this study allows for the elimination of the field plate (and its associated parasitic capacitances) while maintaining state-of-the-art performance at drain biases up to 55 V for a device with a 0.2 micron gate length.

In order to understand the molecular mechanisms underlying the regenerative ability of the urodele limb, it is important to identify regeneration-associated proteins and to study their regulation. We have recently shown that the anti-cytokeratin monoclonal antibody LP1K reacts strongly with newt blastemal cells, while its reactivity is restricted in normal limbs. By screening a cDNA expression library from the newt blastema with LP1K, we have identified cDNA clones coding for a type II keratin (NvKH) expressed both in the mesenchyme and the specialized wound epithelium of the blastema. While the rod domain of the protein is highly conserved, the homology between NvKII and mammalian type II keratins drops markedly at the N- and C-terminal regions. The expression of this keratin was analysed by Northern blotting and RNAase protection analysis of various newt tissues, and appears to be organ specific, since it is restricted to normal and regenerating limbs and tails. In particular, we have investigated the expression of this keratin mRNA in normal and regenerating limbs. The transcript is barely detectable in the proximal portion of the normal limb, but its level is high in the distal one. After amputation, NvKH mRNA is expressed both in proximal and distal blastemas, although at higher levels distally, indicating that this keratin is regeneration associated. The NvKH transcript is detectable both in mesenchyme and in the wound epithelium of the regenerate, while no transcript is detectable in normal epidermis. The level of NvKH mRNA is markedly down-regulated both in normal and regenerating limbs following intraperitoneal injection with retinoic acid, a putative endogenous morphogen in limb regeneration.

Adult urodele amphibians are able to regenerate their limbs through the formation of a blastema, a growth zone of undifferentiated mesenchymal cells that arises locally at the plane of amputation. In an effort to define genes involved in pattern formation by the blastema, we isolated from a newt forelimb blastema library cDNA clones that identify a homeobox gene termed NvHbox 2. The amino acid sequence of the homeodomain is identical to that of the recently identified human H0X-4f gene (Acampora et al. 1989) and of the mouse Hox-5.5 (Dolle et al. 1989). NvHbox 2 is expressed in the limb blastema as a transcript of 3.4 kb that is not detectable in the normal limb. Analysis by RNAase protection demonstrates expression in limb and tail blastemas, but not in any of the adult tissues or organs tested. In the limb blastema NvHbox 2 was expressed in mesenchymal but not epithelial tissue. When matched and normalised samples of RNA from proximal (mid-humerus) and distal forelimb (mid-radius) blastemas were compared, the level of expression of NvHbox 2 was found to be 3- to 5-fold higher proximally. At two time points after injection of a proximalising dose of retinoic acid, the level of expression in a distal blastema was not increased in comparison to controls.

Breast cancer is one of the most prevalent forms of cancer in the world today. The search for effective treatment and screening methods is a highly active area of research. The Digital Image-based Elasto-Tomography (DIET) project is a new breast cancer screening system under development, where surface motion from the mechanically actuated breast is measured in 3D, and used as input to an inverse problem solving for breast elasticity. Cancerous lesions appear as high contrast features, being an order of magnitude stiffer than healthy tissue. The 3D motion capture is measured by an array of digital cameras using computer vision techniques. This paper presents a computer vision imaging system for the capture of 3D breast surface motion for the DIET system, including the image acquisition system, camera calibration, and 3D surface and motion reconstruction. Results are presented for experiments performed with silicone gel phantoms, with conditions designed to replicate the clinical procedure. Full 3D surface motion is successfully captured using an array of five cameras. Some successful results from the DIET inverse problem are also presented to demonstrate the viability of the system in practice.

Bartumeus et al. [Phys. Rev. Lett. 88, 097901 (2002)] compared the efficiency of a Lévy random walk predator strategy with a Brownian random walk strategy in a periodic one-dimensional domain with nonrevisitable moving targets. Their findings from numerical simulations conclude that "a Lévy search strategy is the best option in some, but not all, cases for a random search process." Using the same methodology, we show that the simplest random search strategy of all, ballistic motion in a random direction, outperforms a Lévy strategy in almost every case. We further show that, in the small set of cases where the ballistic strategy is not optimal, the periodic model does not capture the more realistic nonperiodic case. In the nonperiodic case, the ballistic strategy again outperforms the Lévy strategy.

BACKGROUND: Fetal exposure of male rats to di(n-butyl) phthalate (DBP) induces reproductive disorders similar to those in human testicular dysgenesis syndrome (TDS), including infertility, cryptorchidism, focal "dysgenetic areas," and Sertoli cell-only tubules in the adult testis. Humans are widely exposed to DBP, but it much lower levels than those causing adverse effects in rats.OBJECTIVES: The objective of this study was to evaluate end points affected by DBP action in rats in fetal and adult life that are relevant to human TDS, and to compare their dose sensitivity.METHODS: Pregnant rats were gavaged daily with corn oil (control) or with 4, 20, 100, or 500 mg/kg DBP. We examined adult end points of TDS (infertility, cryptorchidism) and indicators within the fetal testis of dysgenesis [abnormal Leydig cell (LC) aggregation, multinucleated gonocytes (MNGs)], as well as conditions that may result from these indicators in adulthood (occurrence of focal dysgenetic areas). Fetal testis weight and testicular testosterone levels were also evaluated.RESULTS: The fetal end points analyzed (testicular testosterone levels, abnormal LC aggregation, occurrence of MNGs) were most sensitive to disruption by DBP, as all were significantly affected at a dose of 100 mg/kg/day DBP, with a trend toward effects occurring at 20 mg/kg/day DBP; adult end points were affected consistently only, by 500 mg/kg/day DBP.CONCLUSIONS: The fetal end points we evaluated can be objectively quantified and may prove helpful in evaluating the health risk of exposure to DBP and other phthalates, as well as identifying DBP-sensitive fetal events that have adult consequences/end points that arc identifiable in human TDS.

Peripheral cues are thought to facilitate responses to stimuli presented at the same location because they lead to exogenous attention shifts. Facilitation has been observed in numerous studies of visual and auditory attention, but there have been only four demonstrations of tactile facilitation, all in studies with potential confounds. Three studies used a spatial (finger versus thumb) discrimination task, where the cue could have provided a spatial framework that might have assisted the discrimination of subsequent targets presented on the same side as the cue. The final study circumvented this problem by using a non-spatial discrimination; however, the cues were informative and interspersed with visual cues which may have affected the attentional effects observed. In the current study, therefore, we used a non-spatial tactile frequency discrimination task following a non-informative tactile white noise cue. When the target was presented 150 ms after the cue, we observed faster discrimination responses to targets presented on the same side compared to the opposite side as the cue; by 1000 ms, responses were significantly faster to targets presented on the opposite side to the cue. Thus, we demonstrated that tactile attentional facilitation can be observed in a non-spatial discrimination task, under unimodal conditions and with entirely non-predictive cues. Furthermore, we provide the first demonstration of significant tactile facilitation and tactile inhibition of return within a single experiment.

This special issue is devoted to the topic of medically unexplained symptoms (MUS), a heterogeneous group of conditions characterized by persistent physical symptoms that cannot be explained by medical illness or injury. Although psychological factors have long been regarded as central to these problems, patients with MUS have typically been managed within medical settings and referrals to mental health services have been relatively rare. In recent years, however, interest in the psychological nature and treatment of MUS has expanded, culminating in the development of tailored psychological interventions for these conditions. This, coupled with the increasing willingness of practitioners to diagnose conditions such as chronic fatigue syndrome, fibromyalgia and irritable bowel syndrome, has led to an increase in the number of patients who are referred for psychological treatment. At present, however, many psychological therapists are unfamiliar with the literature on MUS. With this in mind, this special issue presents a series of papers that provide an overview of what is known about the nature, aetiology and treatment of medically unexplained illness. This introductory paper provides general information about the clinical presentation, diagnosis, classification, terminology and epidemiology of MUS in adults, and concludes with an examination of important areas for future development in the field. Subsequent papers address the psychological mechanisms [Deary, V., Chalder, T., & Sharpe, M. (2007-this issue). The cognitive behavioural model of medically unexplained symptoms: A theoretical and empirical review. Clinical Psychology Review; Iverson, A., Chalder, T., & Wessely, S. (2007-this issue). Gulf war illness: Lessons from medically unexplained illness. Clinical Psychology Review; Rief, W., & Broadbent, E. (2007-this issue). Explaining medically unexplained symptoms: Models and mechanisms. Clinical Psychology Review; Roelofs, K., & Spinhoven, P. (2007-this issue). Trauma and medically unexplained symptoms: Towards an integration of cognitive and neuro-biological accounts. Clinical Psychology Review] and management [Deary, V., Chalder, T., & Sharpe, M. (2007-this issue). The cognitive behavioural model of medically unexplained symptoms: A theoretical and empirical review. Clinical Psychology Review] of these conditions. A separate overview of the literature on MUS in children and adolescents is provided by Eminson [Eminson, J. (2007-this issue). Medically unexplained symptoms in children and adolescents. Clinical Psychology Review].

Arising from: L. Wilson & J. W. Head III , 53–57 (2007)10.1038/nature05692 ; Wilson & Head reply Wilson and Head1 model kimberlite ascent and eruption by considering the propagation of a volatile-rich dyke. Wilson and Head’s model has features in common with Sparks et al.2, but it is inconsistent with geological observations and constraints on volatile solubility. Here we show that this may be due to erroneous physical assumptions.

A Digital Image-based Elasto-Tomography (DIET) system for breast cancer screening has been proposed in which the elastic properties of breast tissue are recovered by solving an inverse problem on the surface motion of a breast under low frequency (50-100 Hz) mechanical actuation. The proposed means for capturing the surface motion of the breast in 3D is to use a stroboscope to capture images from multiple digital cameras at preselected phase angles. Photogrammetric techniques are then used to reconstruct matched point features in 3D. Since human skin lacks high contrast visual features, it is necessary to introduce artificial fiducials which can be easily extracted from digital images. The chosen fiducials are points in three different colours in differing proportions randomly applied to the skin surface. A three-dimensional signature which is invariant to locally Euclidean transformations between images is defined on the points of the lowest proportion colour. The approximate local Euclidean invariance between adjacent frames enables these points to be matched using this signature. The remaining points are matched by interpolating the transformation of the matched points. This algorithm has significant performance gains over conventional gradient-based tracking algorithms because it utilises the intrinsic problem geometry. Successful results are presented for simulated image sequences and for images of a mechanically actuated viscoelastic gel phantom with tracking errors within 3 pixels. The errors in the phantom sequence correspond to less than 0.3 mm error in space, which is more than sufficient accuracy for the DIET system.

Digital Image-based Elasto-Tomography (DIET) is an emerging technology for non-invasive breast cancer screening. This technology actuates breast tissue and measures the surface motion using digital imaging technology. The internal distribution of stiffness is then reconstructed using Boundary Element or Finite Element Methods (FEM or BEM). However, obtaining accurate imaging at high frequency and high resolution in terms of numbers of pixels is challenging if enough accuracy is to be obtained in the motion sensing to deliver a useful result. The overall focus of such mechatronic and digitally centred systems is on providing a low-cost, radiation dose-free and portable screening system capable of screening numerous patients per day — in direct contrast to current low throughput, non-portable and high cost x-ray and MRI based approaches. Thus, DIET technology relies on obtaining high resolution images of a breasts surface under high frequency actuation, typically in the range of 50–100Hz. Off-the-shelf digital cameras and imaging elements are unable to capture images directly at these speeds. A method is presented for obtaining the required high speed image capture at a resolution of 1280×1024 pixels and actuation frequency of 100Hz. The prototype apparatus presented uses two imaging sensors in combination with frame grabbers and a dSpace™ control system, to produce an automated image capture system. The system integrates a precision controlled strobe lighting system to selectively capture sinusoids at different points in the sinusoidal cycle of response. The final working system produced images that enabled effective 3D motion tracking of the surface of a silicon phantom actuated at 100Hz. The surface of the phantom was strobed at pre-selected phases from 0 to 360 degrees, and an image was captured for each phase. The times at which image capture occurred were calculated for a phase lag increment of 10 degrees resulting in an image effectively every 0.00028s for the actuator cycle of 0.01s. The comparison of the actual trigger times and pre-selected ideal trigger times gave a mean absolute error of 1.4%, thus demonstrating the accuracy of the final system. Final validation is performed using this system to track motion in a silicon gel phantom. The motion is tracked accurately using a novel Euclidean Invariant signature method. Both cameras delivered similar results with over 90% of points tracked to within 1–2%. This level of accuracy confirms the ability to effectively accurately reconstruct the stiffness as validated in other related studies.

Pressure Sensitive Paints (PSP) are one of the breakthrough technologies for the measurement of aerodynamic sound from automobiles. Potential problems in applying Pressure Sensitive Paints to automobiles are low time resolution and less accuracy in the low-speed flow field. In this investigation, we attempted to improve the accuracy of PSP in a low-speed flow. A suction-type wind tunnel, which has a square test section of 75 mm by 150 mm, was developed to remove the influence of temperature differences during the wind tunnel experiments. A carefully selected array of ultraviolet LEDs was utilised as a lighting system to match the effective excitation wavelength of the developed PSP (390 nm). The surface pressure of a square cylinder was measured at velocities ranging from 35 m/s to 75 m/s with PSP and a conventional pressure sensor. The experimental data were compared with the results of conventional pressure measurements and numerical simulations. The experimental results showed that the accuracy of the PSP was about 10% at the velocities of 65 m/s or higher. The pressure profiles can be clearly observed at the uniform velocity of 75 m/s. Conversely, accuracy within the 35 m/s to 55 m/s velocity range was not high enough because of insufficient CCD camera resolution. Despite large error values, the colour depths of the luminescence images were almost identical for the same experimental conditions. This indicated that the calibration coefficients of the Stern-Volmer relation were almost constant during the experiments. It revealed that the suction-type wind tunnel is suitable for PSP measurements.

Objective We describe the roll-out of a brief psycho-education intervention for individuals with non-Epileptic Attack Disorder (NEAD), which has been developed for healthcare professionals with limited experience in delivering psychological treatments. Method The psycho-education package is comprised of four one-to-one sessions. The first session provides an explanation of the NEAD diagnosis and introduces the patient to idea that mind and body are linked. The second session teaches behavioural strategies for controlling seizures, including sensory grounding, relaxation and imagery. The third session focuses on identifying and reducing avoidance behaviours that may have been adopted due to seizure symptoms. The final session focuses on values and going forward. Eighteen nurses and therapists attended a training to deliver this package. The two day training intervention included lectures and interactive workshops with actors. The initial roll out stage involved fourteen NHS trusts across the country. Ten months following training, therapists were asked to complete a survey to assess the extent they used this intervention and that they found it to be relevant, comprehensive, and sufficient. Patients with NEAD who attended for psycho-education were also asked to complete pre and post questionnaires including the following measures; Work and Social Adjustment scale (WSAS), Brief Illness Perception Questionnaire (Brief IPQ), Clinical outcomes in routine evaluation (CORE) and the EuroQoL-5D3L and NewQOL quality of life measures. Results Since the training, the package has been delivered in four centres. Recruitment and data collection are ongoing. Preliminary analysis of the pre and post participant data shows that following intervention, participants viewed their seizures as significantly less threatening (IPQ, p=0.002), and reported significantly less distress (CORE, p=0.01) The collection of therapist feedback about the use of the intervention is ongoing. Conclusion It is feasible for healthcare professionals with minimal training in psychological intervention to deliver a brief psycho-education package for individuals with NEAD. Further analysis is needed to understand the full effectiveness of this intervention but preliminary results show that this intervention may have positive effects on the way individuals view their seizures and on their overall wellbeing.

Objective Body-focused attention is regarded as an important maintaining factor for somatoform illness, although there is limited empirical evidence pertaining to this hypothesis. This study was conducted to assess whether individual differences in somatoform dissociation and somatosensory amplification were associated with biased attention towards the tactile modality, particularly following exposure to threatening body-related stimuli. Methods Forty-eight nonclinical participants completed the Somatoform Dissociation Questionnaire (SDQ-20; a proxy measure of somatoform symptomatology), the Somatosensory Amplification Scale (SSAS), and a modality bias task. The task consisted of a series of body-relevant or body-irrelevant (scene) picture stimuli, half of which were threatening and half were neutral, followed by target stimuli in either the visual or the tactile modality. Participants judged the location of each target stimulus, and performance data were used to calculate the degree to which participants were biased towards the tactile modality following each of the picture types. Results Participants in the high SDQ-20 group (defined by median split) showed a significant increase in tactile bias when responding to targets occurring 250 ms after the presentation of threatening body-relevant stimuli only. This effect was not observed for the low SDQ-20 group. Scores on the SSAS correlated negatively with tactile bias for both threatening and neutral body-relevant stimuli at 250 ms. Conclusions Individuals with a tendency to experience somatoform symptoms focus more on stimuli in the tactile modality immediately following exposure to threatening body-relevant information. In contrast, self-reported somatosensory amplification appears to be associated with attention away from the tactile modality rather than with increased tactile focus.

A number of theoretical models have identified dissociation as a possible cognitive mechanism underlying medically unexplained symptoms (''hysteria''). A review of research and theory in this area indicates that the dissociation concept is a useful explanation of this phenomenon. However, existing models of dissociation have a number of explanatory shortcomings.This article describes a recent model of unexplained illness that aims to extend the dissociation concept by reference to research and theory from contemporary cognitive psychology.According to this view, unexplained symptoms should be regarded as disturbances of consciousness and behavioural control, resulting from the chronic activation of stored symptom representations within memory. This process is driven by the repeated reallocation of high-level attention on to symptom representations.The model offers a fresh perspective on the nature of unexplained symptoms, providing an explicit account of the factors involved in the creation and maintenance of this phenomenon.

This paper reports on a design case study for a mobile learning (M-learning) environment that follows a user-centred design approach. This development of the system applied an M-learning design framework to identify appropriate design requirements in practice.

Airflow over mountainous terrain can produce atmospheric waves in the lee of the mountains that have large vertical air velocities. These waves are used as sources of lift by sailplane pilots. Methods are developed for inverting flight data of airspeed and GPS-derived position to obtain estimates of the vector windspeed in mountain waves. Data from flight path segments with significantly different ground velocities within a region of constant windspeed give a well-determined solution for the windspeed. The methods are applied to flight data from a Perlan Project flight in lee waves of the Sierra Nevada Mountains in California.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Introduction. Michael Heap, Richard J. Brown, David A. Oakley, High Hypnotizability: Key Issues. Amanda J. Barnier, Kevin M. McConkey, Defining and Identifying the Highly Hypnotizable Person. Kevin M. McConkey, Amanda J. Barnier, High Hypnotizability: Unity and Diversity in Behaviour and Experience. Graham F. Wagstaff, High Hypnotizability in a Sociocognitive Framework. Judith Rhue, Developmental Determinants of High Hypnotizability. James E. Horton, Helen J. Crawford, Neurophysiological and Genetic Determinants of High Hypnotizability. Richard J. Brown, David A. Oakley, An Integrative Cognitive Theory of Hypnosis and High Hypnotizability. Steven Jay Lynn, Eric Meyer, Kelley Shindler, Clinical Correlates of High Hypnotizability. Donald R. Gorassini, Enhancing Hypnotizability. Graham Turpin, High Hypnotizability: Relevance and Utility to Cognitive and Clinical Psychology?

Background: Patients with neurologically unexplained symptoms (NUS) often have a previous history of other medically unexplained symptoms. A past history of such symptoms can help make a positive diagnosis of a somatoform or affective disorder, and enable appropriate management strategies. However, information on past medical diagnoses is primarily obtained from patient interviews and may be inaccurate, particularly in patients with NUS. Objective: To assess the reliability of past medical diagnoses reported by patients with NUS compared with patients with confirmed neurological disease (ND) without suspicion of somatoform illness. Methods: 21 patients with NUS and 16 patients with ND were interviewed about their current and past medical problems and diagnoses. The accuracy of the reported diagnoses was assessed through examination of their complete general practice notes. Results: The median number of previous diagnoses reported by patients with NUS was significantly higher than in controls (7 v 3, p = 0.001). There was no difference in the median number of confirmed diagnoses between the two groups (2 v 2.5); however, the median percentage of reported diagnoses confirmed by investigations was significantly smaller in the NUS group (22% v 80%, p = 0.001). The additional diagnoses reported by patients with NUS not only comprised functional syndromes such as irritable bowel syndrome or non-cardiac chest pain (6% v 0%, p = 0.01), but also organic diagnoses which had either been unequivocally excluded (5% v 0%, p = 0.006), were based on equivocal findings often found after multiple investigations (9% v 0%, p = 0.01), or had not been investigated before a clinical diagnosis was made (50% v 18%, p = 0.04). Conclusion: Reported previous diagnoses should not be taken at face value when the current differential diagnosis includes a functional/somatoform neurological syndrome, particularly if the list of past medical diagnoses is long. Confirmation of previous diagnoses from alternative sources may contribute to a diagnosis of somatoform disorder, allowing appropriate management strategies for the current (and past) complaints to be initiated.

Aims Apathy is a neurocognitive syndrome of reduced goal-directed behaviour, which is an important cause of disability in neurodegenerative disorders. We aimed to test the hypothesis that apathy in two disorders would be associated with reduced activation in the dorsolateral prefrontal cortex and supplementary motor area during a novel fMRI paradigm specifically examining volitional behaviour. Methods A new fMRI paradigm, designed to avoid confounding by working memory and to be easy for patients to perform, was first used in a group of 15 healthy volunteers. 21 patients with Progressive Supranuclear Palsy and 20 patients with Alzheimer9s disease provided data for the clinical study. Patients were defined as apathetic or non-apathetic by a Clinical Global Impression of Apathy, based on the use of established rating scales. These sub-groups were well-matched for important demographic and clinical characteristics and all patients were able to perform the task successfully. Results As expected, healthy volunteers showed increased activation in the DLPFC and SMA during self-initiated compared with cued actions. Using a conservative whole brain analysis, there were no significant differences in activation associated with self-initated action between apathetic and non-apathetic patients. However, using a hypothesis-driven region of interest approach we found significantly reduced activation among apathetic patients in the DLPFC (in both PSP and AD) and in the SMA (in PSP only). Conclusions These findings support the notion that deficits in self-initiated behaviour are a key part of the cognitive basis of apathy symptoms and that altered function in the DLPFC and SMA may be important in the neurobiology of apathy across different neurological disorders.

One of the UK Government's key commitments is to develop an integrated transport policy and its intention is to produce a White paper during 1998. The purpose of this paper is to discuss how intelligent transport systems (ITS) might contribute to delivering that policy and identify what actions are required if we are to fully exploit its potential. The paper covers the following areas: background to the current policy position; contribution of ITS to Government policy aims; potential benefits of ITS facilities; and national action plan.

We consider approaches to the numerical difficulties posed by modelling resistive networks with dynamically changing resistances according to a set of coupled ordinary differential equations (ODEs). The prototype problem is autoregulation on a cerebral microvascular network. In this network the amount of perfusion, or tissue blood supply, is determined by the resistance of the vascular network. This resistance can be dynamically altered to regulate the amount of blood flow and hence maintain a balance of chemicals and nutrients in the tissue. The mechanisms responsible for this are primarily local, and are due to various chemical pathways to the vascular smooth muscle cells lining the arterioles and arteries in the vasculature. These cells contract and dilate, which alters the radii and hence resistance of the vessels. Because of the global coupling induced by the resistive network, the resulting stiff system of ODEs has a dense Jacobian which precludes the direct application of traditional implicit numerical solution methods. We consider a means of remedying this problem by taking a block diagonal Jacobian approximation which allows use of an implicit method but retains the desirable property of explicit solvers of linear solution time scaling with problem size. precludes the direct application of traditional implicit numerical solution methods. We consider a means of remedying this problem by taking a block diagonal Jacobian approximation which allows use of an implicit method but retains the desirable property of explicit solvers of linear solution time scaling with problem size.

Studies into tactile detection have found that a simultaneous light stimulus affects judgments of the presence or absence of a near threshold tactile stimulus, leading to higher numbers of false alarms, whereby participants report feeling a touch in the absence of a stimulus, as well as modest improvements in tactile sensitivity (Lloydet al., 2008; McKenzieet al., 2010, 2012). Anecdotally, the reported intensity of the bi-modal stimuli was also enhanced — an effect that was investigated in the current studies. In Experiment 1 participants discriminated between ‘weak’ and ‘strong’ tactile stimuli, which were accompanied by a light flash on 50% of trials. We observed a bias towards classifying light-present vibrations as ‘strong’ regardless of signal strength, as well as some evidence for improved accuracy in discrimination. In Experiment 2, participants gave a subjective intensity rating on a 6-point scale, which showed an increase in magnitude ratings for both ‘weak’ and ‘strong’ vibrotactile stimuli when the light was present. This shows that a simultaneous light can both improve tactile discrimination and lead to both types of tactile stimulus being rated as stronger. Primary somatosensory cortex may underlie these effects, as it receives direct projections from visual cortex and indirect projections from association areas of the brain. However, it is as yet unclear whether or not these effects are due to the same underlying mechanism, or at which processing stage they occur. Therefore, we are currently exploring the neural underpinnings of this amplification effect using both fMRI and EEG.

The effects of practice on the serial performance of auditory and visual attention tasks were investigated in 10 healthy volunteers tested at 2 to 4 weekly intervals over eight test sessions using a battery of psychometric tests. Subjects as a group showed an ability to significantly (p = .05) improve their performances over time on all tests except for the Simple Reaction Time and Symbol Digit Modalities Test, the latter demonstrating a trend towards improvement (p = .07). Improvement when it occurred was almost uniformly linear and on tests such as the Pegboard and Stroop, was still discernable at the eighth session. On tests such as Paced Visual Serial Addition Task, floor effects were noted after five sessions and no further improvement was possible. In general, younger subjects tended to make fewer errors, perform quicker and improve for longer periods than their older counterparts. The results indicate that on tests of attention, healthy subjects have the ability to significantly improve performance with practice and this may extend over as many as eight discrete test sessions. The implications for neuropsychological research are discussed.