Enhancement of bend sensor properties as applied in a glove for use in neurorehabilitation settings

Following hand function impairment caused by a neurological disorder, the functional level of the upper extremities has to be assessed in the clinical and rehabilitation settings. Current hand function evaluation tests are somewhat imprecise. Instrumented gloves allow finger motion monitoring during the performance of skilled tasks, such as grasping objects. As a result, they provide an objective tool for evaluating slight changes in the fine motor skills of the hand. Numerous gloves are based on resistive bend sensors, given that this is an easy to handle, low-cost, and reliable sensing element. When bending is not applied homogeneously along such a sensor, as is the case with finger-joint bending, its output response varies with the sensor's longitudinal position. Our goal is to determine the optimal sensor position with respect to the finger-joint in order to enhance the resolution of the sensors embedded in a glove. The validity of the integrated sensors is evaluated and the accuracy values are given

Design and evaluation of a low-cost instrumented glove for hand function assessment

BACKGROUND: The evaluation of hand function impairment following a neurological disorder (stroke and cervical spinal cord injury) requires sensitive, reliable and clinically meaningful assessment tools. Clinical performance measures of hand function mainly focus on the accomplishment of activities of daily living (ADL), typically rather complex tasks assessed by a gross ordinal rating; while the motor performance (i.e. kinematics) is less detailed. The goal of this study was to develop a low-cost instrumented glove to capture details in grasping, feasible for the assessment of hand function in clinical practice and rehabilitation settings. METHODS: Different sensor types were tested for output signal stability over time by measuring the signal drift of their step responses. A system that converted sensor output voltages into angles based on pre-measured curves was implemented. Furthermore, the voltage supply of each sensor signal conditioning circuit was increased to enhance the sensor resolution. The repeatability of finger bending trajectories, recorded during the performance of three ADL-based tasks, was established using the intraclass correlation coefficient (ICC). Moreover, the accuracy of the glove was evaluated by determining the agreement between angles measured with the embedded sensors and angles measured by traditional goniometry. In addition, the feasibility of the glove was tested in four patients with a pathological hand function caused by a cervical spinal cord injury (cSCI). RESULTS: A sensor type that displayed a stable output signal over time was identified, and a high sensor resolution of 0.5° was obtained. The evaluation of the glove's reliability yielded high ICC values (0.84 to 0.92) with an accuracy error of about ± 5°. Feasibility testing revealed that the glove was sensitive to distinguish different levels of hand function impairment in cSCI patients. CONCLUSIONS: The device satisfied the desired system requirements in terms of low cost, stable sensor signal over time, full finger-flexion range of motion tracking and capability to monitor all three joints of one finger. The developed rapid calibration system for easy use (high feasibility) and excellent psychometric properties (i.e. reliability and validity) qualify the device for the assessment of hand function in clinical practice and rehabilitation settings

Translocation of copper in an alpine chronosequence by phenolic-type vectors

Repeated applications of Cu for phytosanitary treatments of vineyards and orchards have contributed to a considerable increase of Cu levels in soils over the last decades. Therefore the risk of migration and Cu contamination of the groundwater and the drinking water supply has also increased. In order to contribute to a better understanding of these parameters, which control either the retention of Cu to soil or its mobilisation, a study has been carried out on the translocation of Cu in low polluted soils of an alpine chronosequence characterised by extremely low pH values. In particular the role of natural phenols released by plants and the organic fractions of soils was investigated by a two scale approach. On one hand field measurements were performed at the Arpette valley site and on the other hand mechanistic studies were carried out in the laboratory about the role of complexation reactions and polymerisation dynamics on these processes. The use of Electron Spin Resonance Spectroscopy (ESR), potentiometry, dynamic simulations and UV absorption revealed that ortho-dihydroxyphenols (ODP's) were the main complexing agents of Cu(II). They were even able to form complexes at very low pH values such as pH 4. The potential of ODP's released by the different plant species from the vegetation cover was determined for the different soils. Catechol, caffeic acid and protocatechuic acid were the dominant species present. Parameters responsible for the migration of Cu were determined through sampling of the soil solution with a tension free lysimeter device. Seasonal factors such as air and soil temperature amplitude, rainfall, solar radiation as well as physico-chemical parameters of the soil solution (pH, T°, DOC, phenols, Cu) were measured. Parameters responsible for the retention of Cu were studied by performing sorption isotherms of Cu in the presence of different horizons of a PODZOSOL OCHRIQUE. Despite the strong affinity of Cu for the insoluble organic fraction of the A-horizons, vertical migration of Cu was observed. These migrations were always higher between the O- and the A-horizon than between the A- and the under-laying horizons. The quantity of migration was always proportional to the levels of Cu present in the horizons of origin. The strong correlation observed between phenol concentration and Cu migration events suggested that phenols were the favourite translocation vectors of Cu in these soils at the cost of the DOC (dissolved organic carbon) fraction. Mechanistic studies also permitted to identify two types of functional reactivities around the phenol molecules: while ortho-dihydroxyphenols had strong chelating properties and were responsible for the complexation of Cu, carboxylic groups (COOH) which were not directly involved in the complexation reaction, played a key role by maintaining these complexes in a hydrosoluble form

Platelet-Endothelial Cell Adhesion Molecule-1 Regulates Endothelial NO Synthase Activity and Localization Through Signal Transducers and Activators of Transcription 3-Dependent NOSTRIN Expression

Nitric oxide (NO) produced by the endothelial NO synthase (eNOS) is an important regulator of cardiovascular physiology and pathology. eNOS is activated by numerous stimuli and its activity is tightly regulated. Platelet-endothelial cell adhesion molecule-1 (PECAM-1) has been implicated in regulating eNOS activity in response to shear stress. The goal of the current study is to determine the role of PECAM-1 in the regulation of basal eNOS activity

Socialization, Professional Identity Formation and Training for Uncertainty

Clinical knowledge, group facilitation skills, and cognitive congruence are considered important factors for the successful tutoring of Problem Based Learning sessions. In addition, the theory of Community of Practice has become an important tool to approach social learning and knowledge integration in medical education and organizational studies. More research is needed to link these two strands of research. We look at novice medical students’ experiences and comparative reflections on student-tutors and clinician-tutors as facilitators of PBL sessions in a participatory, randomized cross-over design. Qualitative methodologies were used to probe the experiences of participants. In this study, the main factor for successful PBL sessions for first-year students was the creation of a non-hierarchical learning atmosphere, which starkly differentiated itself from the rigidity of a PBL structure organized around clinician-tutors and their hierarchically-imparted knowledge. In contrast, a more flexible strategy of student tutors and their constructive management of “not-knowing” enabled novice students to take steps on their own — of which they were highly appreciative, stressing how it allowed them to develop earlier autonomy with regard to PBL methodology, manage uncertainty, and create a shared identity as a community of learners

How to characterize the function of a brain region

Many brain regions have been defined, but a comprehensive formalization of each region’s function in relation to human behavior is still lacking. Current knowledge comes from various fields, which have diverse conceptions of ‘functions’. We briefly review these fields and outline how the heterogeneity of associations could be harnessed to disclose the computational function of any region. Aggregating activation data from neuroimaging studies allows us to characterize the functional engagement of a region across a range of experimental conditions. Furthermore, large-sample data can disclose covariation between brain region features and ecological behavioral phenotyping. Combining these two approaches opens a new perspective to determine the behavioral associations of a brain region, and hence its function and broader role within large-scale functional networks

Excision of HIV-1 Proviral DNA by Recombinant Cell Permeable Tre-Recombinase

Over the previous years, comprehensive studies on antiretroviral drugs resulted in the successful introduction of highly active antiretroviral therapy (HAART) into clinical practice for treatment of HIV/AIDS. However, there is still need for new therapeutic approaches, since HAART cannot eradicate HIV-1 from the infected organism and, unfortunately, can be associated with long-term toxicity and the development of drug resistance. In contrast, novel gene therapy strategies may have the potential to reverse the infection by eradicating HIV-1. For example, expression of long terminal repeat (LTR)-specific recombinase (Tre-recombinase) has been shown to result in chromosomal excision of proviral DNA and, in consequence, in the eradication of HIV-1 from infected cell cultures. However, the delivery of Tre-recombinase currently depends on the genetic manipulation of target cells, a process that is complicating such therapeutic approaches and, thus, might be undesirable in a clinical setting. In this report we demonstrate that E.coli expressed Tre-recombinases, tagged either with the protein transduction domain (PTD) from the HIV-1 Tat trans-activator or the translocation motif (TLM) of the Hepatitis B virus PreS2 protein, were able to translocate efficiently into cells and showed significant recombination activity on HIV-1 LTR sequences. Tre activity was observed using episomal and stable integrated reporter constructs in transfected HeLa cells. Furthermore, the TLM-tagged enzyme was able to excise the full-length proviral DNA from chromosomal integration sites of HIV-1-infected HeLa and CEM-SS cells. The presented data confirm Tre-recombinase activity on integrated HIV-1 and provide the basis for the non-genetic transient application of engineered recombinases, which may be a valuable component of future HIV eradication strategies