46 resultados para tactile transducer


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Background The V617F mutation, which causes the substitution of phenylalanine for valine at position 617 of the Janus kinase (JAK) 2 gene (JAK2), is often present in patients with polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. However, the molecular basis of these myeloproliferative disorders in patients without the V617F mutation is unclear. Methods We searched for new mutations in members of the JAK and signal transducer and activator of transcription (STAT) gene families in patients with V617F-negative polycythemia vera or idiopathic erythrocytosis. The mutations were characterized biochemically and in a murine model of bone marrow transplantation. Results We identified four somatic gain-of-function mutations affecting JAK2 exon 12 in 10 V617F-negative patients. Those with a JAK2 exon 12 mutation presented with an isolated erythrocytosis and distinctive bone marrow morphology, and several also had reduced serum erythropoietin levels. Erythroid colonies could be grown from their blood samples in the absence of exogenous erythropoietin. All such erythroid colonies were heterozygous for the mutation, whereas colonies homozygous for the mutation occur in most patients with V617F-positive polycythemia vera. BaF3 cells expressing the murine erythropoietin receptor and also carrying exon 12 mutations could proliferate without added interleukin-3. They also exhibited increased phosphorylation of JAK2 and extracellular regulated kinase 1 and 2, as compared with cells transduced by wild-type JAK2 or V617F JAK2. Three of the exon 12 mutations included a substitution of leucine for lysine at position 539 of JAK2. This mutation resulted in a myeloproliferative phenotype, including erythrocytosis, in a murine model of retroviral bone marrow transplantation. Conclusions JAK2 exon 12 mutations define a distinctive myeloproliferative syndrome that affects patients who currently receive a diagnosis of polycythemia vera or idiopathic erythrocytosis.

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This paper introduces the application of linear multivariate statistical techniques, including partial least squares (PLS), canonical correlation analysis (CCA) and reduced rank regression (RRR), into the area of Systems Biology. This new approach aims to extract the important proteins embedded in complex signal transduction pathway models.The analysis is performed on a model of intracellular signalling along the janus-associated kinases/signal transducers and transcription factors (JAK/STAT) and mitogen activated protein kinases (MAPK) signal transduction pathways in interleukin-6 (IL6) stimulated hepatocytes, which produce signal transducer and activator of transcription factor 3 (STAT3).A region of redundancy within the MAPK pathway that does not affect the STAT3 transcription was identified using CCA. This is the core finding of this analysis and cannot be obtained by inspecting the model by eye. In addition, RRR was found to isolate terms that do not significantly contribute to changes in protein concentrations, while the application of PLS does not provide such a detailed picture by virtue of its construction.This analysis has a similar objective to conventional model reduction techniques with the advantage of maintaining the meaning of the states prior to and after the reduction process. A significant model reduction is performed, with a marginal loss in accuracy, offering a more concise model while maintaining the main influencing factors on the STAT3 transcription.The findings offer a deeper understanding of the reaction terms involved, confirm the relevance of several proteins to the production of Acute Phase Proteins and complement existing findings regarding cross-talk between the two signalling pathways.

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Little is known about similarities and differences in voice hearing in schizophrenia and dissociative identity disorder (DID) and the role of child maltreatment and dissociation. This study examined various aspects of voice hearing, along with childhood maltreatment and pathological dissociation in 3 samples: schizophrenia without child maltreatment (n = 18), schizophrenia with child maltreatment (n = 16), and DID (n = 29). Compared with the schizophrenia groups, the DID sample was more likely to have voices starting before 18, hear more than 2 voices, have both child and adult voices and experience tactile and visual hallucinations. The 3 groups were similar in that voice content was incongruent with mood and the location was more likely internal than external. Pathological dissociation predicted several aspects of voice hearing and appears an important variable in voice hearing, at least where maltreatment is present.

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In this paper I examine the transformation that the skin has undergone over the centuries. This change in conception in the skin whereby the skin is considered less a boundary space and more akin to a milieu, a meeting place for the other senses, allows me to posit the performative body as one engaged in a haptic condition, as a body in intimately lived-in spaces with tactile relations. A shift from the optical towards the haptic, in which the all- encompassing god-like view of traditional performance environments becomes replaced by a more haptic condition, as can be exemplified in performances in dispersed environments, posits the body skinned as a fragile body that wants to favour the incomplete and the fragmented. The body skinned is a body initiated by the observed and the perspectival, but it is nourished by means of the local and the embodied. It is a body that, like the skin, is more akin to a meeting place of, and for, the other senses, as well as for senses of the others. Most clearly, the body skinned brings to the fore a potential of being ‘connected a little less’. It is a body that embraces notions of the incomplete, of glances, and of fantasies, and in this light may be a body more ideally suited to environments that purposely displace performative action, such as found in network performance environments.

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The contemporary dominance of visuality has turned our understanding of space into a mode of unidirectional experience that externalizes other sensual capacities of the body while perceiving the built environment. This affects not only architectural practice but also architectural education when an introduction to the concept of space is often challenging, especially for the students who have limited spatial and sensual training. Considering that an architectural work is not perceived as a series of retinal pictures but as a repeated multi-sensory experience, the problem definitions in the design studio need to be disengaged from the dominance of a ‘focused vision’ and be re-constructed in a holistic manner. A method to address this approach is to enable the students to refer to their own sensual experiences of the built environment as a part of their design processes. This paper focuses on a particular approach to the second year architectural design teaching which has been followed in the Department of Architecture at Izmir University of Economics for the last three years. The very first architectural project of the studio and the program, entitled ‘Sensing Spaces’, is conducted as a multi-staged design process including ‘sense games, analyses of organs and their interpretations into space’. The objectives of this four-week project are to explore the sense of space through the design of a three-dimensional assembly, to create an awareness of the significance of the senses in the design process and to experiment with re-interpreted forms of bodily parts. Hence, the students are encouraged to explore architectural space through their ‘tactile, olfactory, auditory, gustative and visual stimuli’. In this paper, based on a series of examples, architectural space is examined beyond its boundaries of structure, form and function, and spatial design is considered as an activity of re-constructing the built environment through the awareness of bodily senses.

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A scalable large vocabulary, speaker independent speech recognition system is being developed using Hidden Markov Models (HMMs) for acoustic modeling and a Weighted Finite State Transducer (WFST) to compile sentence, word, and phoneme models. The system comprises a software backend search and an FPGA-based Gaussian calculation which are covered here. In this paper, we present an efficient pipelined design implemented both as an embedded peripheral and as a scalable, parallel hardware accelerator. Both architectures have been implemented on an Alpha Data XRC-5T1, reconfigurable computer housing a Virtex 5 SX95T FPGA. The core has been tested and is capable of calculating a full set of Gaussian results from 3825 acoustic models in 9.03 ms which coupled with a backend search of 5000 words has provided an accuracy of over 80%. Parallel implementations have been designed with up to 32 cores and have been successfully implemented with a clock frequency of 133?MHz.

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Previous studies have shown that low levels of copper (down to 0.8 muM) induce bradycardia in the blue mussel (Mytilus edulis) and that this is not caused by prolonged Valve closure. The aim of this study was to determine the precise mechanism responsible. To establish if copper was directly affecting heart cell physiology, recordings of contractions from isolated ventricular strips were made using an isometric force transducer, in response to copper concentrations (as CuCl2) ranging between 1 muM and 1 mM. Inhibition of mechanical activity only occurred at 1 mM copper, suggesting that the copper-induced bradycardia observed in whole animals cannot be attributed to direct cardiotoxicity. Effects of copper on the cardiac nerves were subsequently examined. Following removal of visceral ganglia (from where the cardiac nerves originate), exposure to 12.5 muM copper had no effect on the heart rate of whole animals. The effect of copper on the heart rate of mussels could not be abolished by depletion of the monoamine content of the animal using reserpine. However, pre-treatment of the animals with alpha -bungarotoxin considerably reduced the sensitivity of the heart to copper. These results indicated that the influence of copper on the heart of M. edulis might be mediated by a change in the activity of cholinergic nerves to heart. In the final experiments, mussels were injected with either benzoquinonium or D-tubocurarine, prior to copper exposure, in an attempt to selectively block the inhibitory or excitatory cholinoreceptors of the heart. Only benzoquinonium decreased the susceptibility of the heart to copper, suggesting that copper affects the cardiac activity of blue mussels by stimulating inhibitory cholinergic nerves to the heart. (C) 2001 Elsevier Science B.V. All rights reserved.

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The pharyngeal component of the enteric nervous system of the parasitic nematode, Ascaris suum exhibits immunoreactivity for serotonin (5-hydroxytryptamine or 5-HT) and for FMRFamide-like peptides. This paper describes the application of an in vitro pharmacological approach to investigate the functional role of 5-HT and FMRFamide-like peptides. The pharyngeal pumping behaviour of Ascaris suum was monitored using a modified pressure transducer system which measures pharyngeal pressure changes and therefore pumping. The pharynx did not contract spontaneously; however, 5-HT (10-1000 mu M) stimulated pumping at a frequency of 0 . 5 Hz. FMRFamide had no apparent effect on pharyngeal pumping. The native nematode FMRFamide-related peptide (FaRP), KSAYMRFamide inhibited the pumping elicited by 5-HT. The duration of inhibition was dose-dependent (0 . 1-1000 nM) with a threshold of 0 . 1 nM. In 4 preparations, the inhibition of the pharyngeal muscle was preceded by an initial excitation and increase in the amplitude of pharyngeal pressure changes. The pharynx is involved in various nematode processes, including feeding, regulation of hydrostatic pressure and excretion. The role of 5-HT and KSAYMRFamide in the pharyngeal function of nematodes is discussed.

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The physiological effects of synthetic replicates of the nematode FaRPs, AF1 (KNEFIRFamide), AF2 (KHEYLRFamide), PF1 (SDPNFLRFamide), PF2 (SADPNFLRFamide), AF8/PF3 (KSAYMRFamide) and PF4 (KPNFIRFamide) were examined on muscle preparations of the liver fluke, Fasciola hepatica. Changes in contractility following the addition of the test compound were recorded using a photo-optic transducer system. Unlike the varied effects these peptides have on nematode somatic musculature, all were found to induce excitatory responses in the muscle activity of F. hepatica. While qualitative effects of the nematode peptides were similar in that they induced increases in both the amplitude and frequency of F. hepatica muscle contractions, they varied considerably in the potency of their excitatory effects. The threshold activity for each peptide was as follows: 10 mu M, PF1 and PF2; 3 mu M, AF1 and PF3; 1 mu M, AF2; and 30 nM, PF4. The results demonstrate, for the first time, the cross-phyla activity of nematode neuropeptides on the neuromuscular activity of a trematode.

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The effects of each of the known platyhelminth neuropeptides were determined on muscle-strip preparations from the liver fluke, Fasciola hepatica. The activity of synthetic replicates of the C-terminal nonapeptide of neuropeptide F (NPF9, Moniezia expansa), and the FMRFamide-related peptides (FaRPs), GNFFRFamide, RYIRFamide, GYIRFamide and YIRFamide, were examined. Muscle-strip activity was recorded from 1 mm segments of muscle prepared from 28 to 32-day-old worms, using a photo-optic transducer system. None of the peptides (less than or equal to 10 mu M) altered baseline tension significantly; however, each of the peptides increased the amplitude and frequency of muscle contraction. The threshold for activity of each of the peptides examined was, respectively, 1 nM (RYIRFamide), 0.3 mu M (GYIRFamide and YIRFamide), and 10 mu M (GNFFRFamide and NPF9). All of the effects were reversible and repeatable, following wash-out. Muscle-strip integrity was tested following experimentation, using arecoline (10 mu M) and high-K+ bathing medium (90 mM K+).

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Background: Objective structured clinical examinations (OSCEs) are a
commonly used method of assessing clinical competency in healthcare education. They can providean opportunity to observe candidates interacting with patients.
There are many challenges in using real patients in OSCEs, and increasingly standardised patients are being used as a preference. However, by using standardised patients there is a risk of making the encounter arti?cial and removed from actual clinical practice.
Context: Efforts made in terms of cognitive, auditory, visual, tactile, psychological and emotional cues can minimise the differences between a simulated
and real clinical scenario. However, a number of factors, including feasibility, cost and usability, need to be considered if such techniques are to be practicable
within an OSCE framework.
Innovation: This article describes a series of techniques that have been used in our institution to enhance the realism of a standardised patient encounter in an
OSCE. Efforts in preparing standardised patient roles, and how they portray these roles, will be considered. A wide variety of equipment can also be used in
combination with a patient and the surrounding environment, which can further enhance the authenticity of the simulated scenario.
Implications: By enhancing the realism in simulated patient OSCE encounters, there is potential to trigger more authentic conscious responses from candidates and implicit reactions that the candidates themselves may be less
aware of. Furthermore, using such techniques may allow faculty members to select scenarios that were previously not thought possible in an OSCE

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Activating mutations of the FMS-like tyrosine kinase 3 gene (FLT3) occur in approximately one-third of patients with acute myeloid leukaemia (AML) and predict for a poor outcome. Heat shock protein 90 (Hsp90) is a molecular chaperone that is frequently used by cancer cells to stabilise mutant oncoproteins. Mutant FLT3 is chaperoned by Hsp90 in primary AML blasts whereas unmutated FLT3 is not, making Hsp90 inhibitors potentially useful therapeutically. The present study showed that inhibition of Hsp90 by 17-allylamino-17-demethoxygeldanamycin (17-AAG) was cytotoxic to primary AML cells expressing mutant FLT3. Inhibition of Hsp90 results in altered downstream signalling effects in primary AML cells with disruption of Janus kinase-signal transducer and activator of transcription (JAK-STAT), mitogen-activated protein kinase and phosphatidylinositol 3/AKT signalling pathways. Co-treatment of blasts with 17-AAG and cytarabine resulted in a synergistic or additive effect in approximately 50% of AML cases tested. Our results confirm that Hsp90 is a valid molecular target in the therapy of AML. Inhibition of Hsp90 in parallel with conventional AML therapies may have particular benefit in those patients with the poor prognostic FLT3 mutant disease.

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OBJECTIVES:: Preterm infants undergo frequent painful procedures in the neonatal intensive care unit. Electroencephalography (EEG) changes in reaction to invasive procedures have been reported in preterm and full-term neonates. Frontal EEG asymmetry as an index of emotion during tactile stimulation shows inconsistent findings in full-term infants, and has not been examined in the context of pain in preterm infants. Our aim was to examine whether heel lance for blood collection induces changes in right-left frontal asymmetry, suggesting negative emotional response, in preterm neonates at different gestational age (GA) at birth and different duration of stay in the neonatal intensive care unit. MATERIALS AND METHODS:: Three groups of preterm infants were compared: set 1: group 1 (n=24), born and tested at 28 weeks GA; group 2 (n=22), born at 28 weeks GA and tested at 33 weeks; set 2: group 3 (n=25), born and tested at 33 weeks GA. EEG power was calculated for 30-second artifact-free periods, in standard frequency bandwidths, in 3 phases (baseline, up to 5 min after heel lance, 10 min after heel lance). RESULTS:: No significant differences were found in right-left frontal asymmetry, or in ipsilateral or contralateral somatosensory response, across phases. In contrast, the Behavioral Indicators of Infant Pain scores changed across phase (P

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The low tactile threshold in preterm infants when they are in the neonatal intensive care unit (NICU), while their physiological systems are unstable and immature, potentially renders them more vulnerable to the effects of repeated invasive procedures. There is a small but growing literature on pain and tactile responsivity following procedural pain in the NICU, or early surgery. Long-term effects of repeated pain in the neonatal period on neurodevelopment await further research. However, there are multiple sources of stress in the NICU, which contribute to inducing high overall 'allostatic load', therefore determining specific effects of neonatal pain in human infants is challenging.

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Acute pain is a significant stressor for preterm infants in neonatal intensive care units (NICU); however, little is known about the effects of acute pain on subsequent motor responses during clusters of tactile handling.