76 research outputs found

    A new platform based on IEEE802.15.4 wireless inertial sensors for motion caption and assessment

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    Abstract—Systems for motion ca¡ption and assessment in biomechanics are mostly based on photogrammetry. These systems are restricted to the movement analysis lab and moreover, they are very expensive. New advances in MEMs (Microelectromechanical) and wireless technologies enable inertial sensing as an alternatives for motion caption. This paper presents a wireless inertial sensor including 3 linear accelerometers, 3 gyroscopes and 3 magnetometers. The IMU (inertial measurement unit) includes a IEEE802.15.4 compliant transceiver. The platform expands the frontiers of movement analysis for motion caption in real scenarios like sports and wearable robotics since it does not need structurated labs. Besides the advantages, the cost of the platform is much lower comparing actual photogrammetry systems.Peer reviewe

    Validation of the German version of the STarT-Back Tool (STarT-G): a cohort study with patients from primary care practices

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    Background: Current research emphasizes the high prevalence and costs of low back pain (LBP). The STarT Back Tool was designed to support primary care decision making for treatment by helping to determine the treatment prognosis of patients with non-specific low back pain. The German version is the STarT-G. The cross-cultural translation of the tool followed a structured and widely accepted process but to date it was only partially validated with a small sample. The aim of the study was to test the psychometric properties construct validity, discriminative ability, internal consistency and test-retest-reliability of the STarT-G and to compare them with values given for the original English version. Methods: A consecutive cohort study with a two-week retest was conducted among patients with non-specific LBP, aged 18 to 60 years, from primary care practices. Questionnaires were collected before the first consultation, and two weeks later by post, using the following reference standards: the Roland and Morris disability questionnaire, the Tampa Scale of Kinesiophobia, the Pain Catastrophizing Scale and the Hospital Anxiety and Depression Scale. Psychometric properties examined included the tool’s discriminative abilities, whether the psychosocial subscale was one factor, internal consistency, item redundancy, test-retest reliability and floor and ceiling effects. Results: There were 228 patients recruited with a mean age of 42.2 (SD 11.0) years, and 53 % were female. The areas under the curve (AUC) for discriminative ability ranged from 0.70 (STarT-G Subscale - Pain Catastrophizing Scale; CI95 0.63, 0.78) to 0.77 (STarT-G Total - Composite reference standard, CI95 0.60, 0.94). Factor loadings ranged from 0.49 to 0.74. Cronbach’s alpha testing the internal consistency and redundancy for the total/subscale scores were α = 0.52/0.55 respectively. The STarT-G test-retest reliability Kappa values for the total/subscale scores were 0.67/0.68 respectively. No floor or ceiling effects were present. Conclusions: The STarT-G shows acceptable psychometric properties although not in exact agreement with the original English version. The items previously regarded as a psychosocial subscale may be better seen as an index of different individual psychosocial constructs. The relevance of using the tool at the point of consultation should be further examined

    Auxiliary Subunits Control Function and Subcellular Distribution of AMPA Receptor Complexes in NG2 Glia of the Developing Hippocampus

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    Synaptic and axonal glutamatergic signaling to NG2 glia in white matter is critical for the cells’ differentiation and activity dependent myelination. However, in gray matter the impact of neuron-to-NG2 glia signaling is still elusive, because most of these cells keep their non-myelinating phenotype throughout live. Early in postnatal development, hippocampal NG2 glia express AMPA receptors with a significant Ca2+ permeability allowing for plasticity of the neuron-glia synapses, but whether this property changes by adulthood is not known. Moreover, it is unclear whether NG2 glia express auxiliary transmembrane AMPA receptor related proteins (TARPs), which modify AMPA receptor properties, including their Ca2+ permeability. Through combined molecular and functional analyses, here we show that hippocampal NG2 glia abundantly express TARPs γ4, γ7, and γ8 as well as cornichon (CNIH)-2. TARP γ8 undergoes profound downregulation during development. Receptors of adult NG2 glia showed an increased sensitivity to blockers of Ca2+ permeable AMPA receptors, but this increase mainly concerned receptors located close to the soma. Evoked synaptic currents of NG2 glia were also sensitive to blockers of Ca2+ permeable AMPA receptors. The presence of AMPA receptors with varying Ca2+ permeability during postnatal maturation may be important for the cells’ ability to sense and respond to local glutamatergic activity and for regulating process motility, differentiation, and proliferation

    Anisotropic Panglial Coupling Reflects Tonotopic Organization in the Inferior Colliculus

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    Astrocytes and oligodendrocytes in different brain regions form panglial networks and the topography of such networks can correlate with neuronal topography and function. Astrocyte-oligodendrocyte networks in the lateral superior olive (LSO)—an auditory brainstem nucleus—were found to be anisotropic with a preferred orientation orthogonally to the tonotopic axis. We hypothesized that such a specialization might be present in other tonotopically organized brainstem nuclei, too. Thus, we analyzed gap junctional coupling in the center of the inferior colliculus (IC)—another nucleus of the auditory brainstem that exhibits tonotopic organization. In acute brainstem slices obtained from mice, IC networks were traced employing whole-cell patch-clamp recordings of single sulforhodamine (SR) 101-identified astrocytes and concomitant intracellular loading of the gap junction-permeable tracer neurobiotin. The majority of dye-coupled networks exhibited an oval topography, which was preferentially oriented orthogonal to the tonotopic axis. Astrocyte processes showed preferentially the same orientation indicating a correlation between astrocyte and network topography. In addition to SR101-positive astrocytes, IC networks contained oligodendrocytes. Using Na+ imaging, we analyzed the capability of IC networks to redistribute small ions. Na+ bi-directionally diffused between SR101-positive astrocytes and SR101-negative cells—presumably oligodendrocytes—showing the functionality of IC networks. Taken together, our results demonstrate that IC astrocytes and IC oligodendrocytes form functional anisotropic panglial networks that are preferentially oriented orthogonal to the tonotopic axis. Thus, our data indicate that the topographic specialization of glial networks seen in IC and LSO might be a general feature of tonotopically organized auditory brainstem nuclei

    Reactive microglia are the major source of tumor necrosis factor alpha and contribute to astrocyte dysfunction and acute seizures in experimental temporal lobe epilepsy.

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    Extensive microglia reactivity has been well described in human and experimental temporal lobe epilepsy (TLE). To date, however, it is not clear whether and based on which molecular mechanisms microglia contribute to the development and progression of focal epilepsy. Astroglial gap junction coupled networks play an important role in regulating neuronal activity and loss of interastrocytic coupling causally contributes to TLE. Here, we show in the unilateral intracortical kainate (KA) mouse model of TLE that reactive microglia are primary producers of tumor necrosis factor (TNF)α and contribute to astrocyte dysfunction and severity of status epilepticus (SE). Immunohistochemical analyses revealed pronounced and persistent microglia reactivity, which already started 4 h after KA-induced SE. Partial depletion of microglia using a colony stimulating factor 1 receptor inhibitor prevented early astrocyte uncoupling and attenuated the severity of SE, but increased the mortality of epileptic mice following surgery. Using microglia-specific inducible TNFα knockout mice we identified microglia as the major source of TNFα during early epileptogenesis. Importantly, microglia-specific TNFα knockout prevented SE-induced gap junction uncoupling in astrocytes. Continuous telemetric EEG recordings revealed that during the first 4 weeks after SE induction, microglial TNFα did not significantly contribute to spontaneous generalized seizure activity. Moreover, the absence of microglial TNFα did not affect the development of hippocampal sclerosis but attenuated gliosis. Taken together, these data implicate reactive microglia in astrocyte dysfunction and network hyperexcitability after an epileptogenic insult

    Connexin-43 Gap Junctions Are Responsible for the Hypothalamic Tanycyte-Coupled Network

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    Tanycytes are hypothalamic radial glia-like cells that form the basal wall of the third ventricle (3V) where they sense glucose and modulate neighboring neuronal activity to control feeding behavior. This role requires the coupling of hypothalamic cells since transient decreased hypothalamic Cx43 expression inhibits the increase of brain glucose-induced insulin secretion. Tanycytes have been postulated as possible hypothalamic neuronal precursors due to their privileged position in the hypothalamus that allows them to detect mitogenic signals and because they share the markers and characteristics of neuronal precursors located in other neurogenic niches, including the formation of coupled networks through connexins. Using wild-type (WT), Cx30−/– and Cx30−/–, Cx43fl/fl:glial fibrillary acidic protein (GFAP)-Cre (double knockout, dKO) mouse lines, we demonstrated that tanycytes are highly coupled to each other and also give rise to a panglial network specifically through Cx43. Using the human GFAP (hGFAP)-enhanced green fluorescent protein (EGFP) transgenic mouse line, we provided evidence that the main parenchymal-coupled cells were astrocytes. In addition, electrophysiological parameters, such as membrane resistance, were altered when Cx43 was genetically absent or pharmacologically inhibited. Finally, in the dKO mouse line, we detected a significant decrease in the number of hypothalamic proliferative parenchymal cells. Our results demonstrate the importance of Cx43 in tanycyte homotypic and panglial coupling and show that Cx43 function influences the proliferative potential of hypothalamic cells

    Impact of a tailored program on the implementation of evidence-based recommendations for multimorbid patients with polypharmacy in primary care practices — results of a cluster-randomized controlled trial

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    Background: Multimorbid patients receiving polypharmacy represent a growing population at high risk for negative health outcomes. Tailoring is an approach of systematic intervention development taking account of previously identified determinants of practice. The aim of this study was to assess the effect of a tailored program to improve the implementation of three important processes of care for this patient group: (a) structured medication counseling including brown bag reviews, (b) the use of medication lists, and (c) structured medication reviews to reduce potentially inappropriate medication. Methods: We conducted a cluster-randomized controlled trial with a follow-up time of 9 months. Participants were general practitioners (GPs) organized in quality circles and participating in a GP-centered care contract of a German health insurance. Patients aged >50 years, suffering from at least 3 chronic diseases, receiving more than 4 drugs, and being at high risk for medication-related events according to the assessment of the treating GP were enrolled. The tailored program consisted of a workshop for GPs and health care assistants, educational materials and reminders for patients, and the elaboration of implementation action plans. The primary outcome was the change in the degree of implementation between baseline and follow-up, measured by a summary score of 10 indicators. The indicators were based on structured surveys with patients and GPs. Results: We analyzed the data of 21 GPs (10 - intervention group, 11 - control group) and 273 patients (130 - intervention group, 143 - control group). The increase in the degree of implementation was 4.2 percentage points (95% confidence interval: −0.3, 8.6) higher in the intervention group compared to the control group (p = 0.1). Two of the 10 indicators were significantly improved in the intervention group: medication counseling (p = 0.017) and brown bag review (p = 0.012). Secondary outcomes showed an effect on patients’ self-reported use of medication lists when buying drugs in the pharmacy (p = 0.03). Conclusions: The tailored program may improve implementation of medication counseling and brown bag review whereas the use of medication lists and medication reviews did not improve. No effect of the tailored program on the combined primary outcome could be substantiated. Due to limitations of the study, results have to be interpreted carefully. The factors facilitating and hindering successful implementation will be examined in a comprehensive process evaluation. Trial registration number ISRCTN34664024, assigned 14/08/201

    26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

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    This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)
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