1,676 research outputs found

    TMS SMART – scalp mapping of annoyance ratings and twitches caused by Transcranial Magnetic Stimulation

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    Background: The magnetic pulse generated during transcranial magnetic stimulation (TMS) also stimulates cutaneous nerves and muscle fibres, with the most commonly reported side effect being muscle twitches and sometimes painful sensations. These sensations affect behaviour during experimental tasks, presenting a potential confound for ‘online’ TMS studies. New method: Our objective was to systematically map the degree of disturbance (ratings of annoyance, pain, and muscle twitches) caused by TMS at 43 locations across the scalp. Ten participants provided ratings whilst completing a choice reaction time task, and ten different participants provided ratings whilst completing a 'flanker' reaction time task. Results: TMS over frontal and inferior regions resulted in the highest ratings of annoyance, pain, and muscle twitches caused by TMS. We predicted the difference in reaction times (RT) under TMS by scalp location and subjective ratings. Frontal and inferior scalp locations showed the greatest cost to RTs under TMS (i.e., slowing), with midline sites showing no or minimal slowing. Increases in subjective ratings of disturbance predicted longer RTs under TMS. Critically, ratings were a better predictor of the cost of TMS than scalp location or scalp-to-cortex distance. The more difficult ‘flanker’ task showed a greater effect of subjective disturbance. Comparison with existing methods: We provide the data as an online resource (www.tms-smart.info) so that researchers can select control sites that account for the level of general interference in task performance caused by online single-pulse TMS. Conclusions: The peripheral sensations and discomfort caused by TMS pulses significantly and systematically influence RTs during single-pulse, online TMS experiments. The raw data are available at www.tms-smart.info and https://osf.io/f49vn

    Vortex Counting and Lagrangian 3-manifolds

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    To every 3-manifold M one can associate a two-dimensional N=(2,2) supersymmetric field theory by compactifying five-dimensional N=2 super-Yang-Mills theory on M. This system naturally appears in the study of half-BPS surface operators in four-dimensional N=2 gauge theories on one hand, and in the geometric approach to knot homologies, on the other. We study the relation between vortex counting in such two-dimensional N=(2,2) supersymmetric field theories and the refined BPS invariants of the dual geometries. In certain cases, this counting can be also mapped to the computation of degenerate conformal blocks in two-dimensional CFT's. Degenerate limits of vertex operators in CFT receive a simple interpretation via geometric transitions in BPS counting.Comment: 70 pages, 29 figure

    Optimizing dual energy cone beam CT protocols for preclinical imaging and radiation research

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    Objective: The aim of this work was to investigate whether quantitative dual-energy CT (DECT) imaging is feasible for small animal irradiators with an integrated cone-beam CT (CBCT) system. Methods: The optimal imaging protocols were determined by analyzing different energy combinations and dose levels. The influence of beam hardening effects and the performance of a beam hardening correction (BHC) were investigated. In addition, two systems from different manufacturers were compared in terms of errors in the extracted effective atomic numbers (Z(eff)) and relative electron densities (rho(e)) for phantom inserts with known elemental compositions and relative electron densities. Results: The optimal energy combination was determined to be 50 and 90kVp. For this combination, Z(eff) and r rho(e) can be extracted with a mean error of 0.11 and 0.010, respectively, at a dose level of 60cGy. Conclusion: Quantitative DECT imaging is feasible for small animal irradiators with an integrated CBCT system. To obtain the best results, optimizing the imaging protocols is required. Well-separated X-ray spectra and a sufficient dose level should be used to minimize the error and noise for Z(eff) and rho(e). When no BHC is applied in the image reconstruction, the size of the calibration phantom should match the size of the imaged object to limit the influence of beam hardening effects. No significant differences in Z(eff) and rho(e) errors are observed between the two systems from different manufacturers. Advances in knowledge: This is the first study that investigates quantitative DECT imaging for small animal irradiators with an integrated CBCT system

    Sphingosine kinase 1 and 2 regulate the capacity of mesangial cells to resist apoptotic stimuli in an opposing manner

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    Sphingosine kinases (SKs) are key enzymes regulating the production of sphingosine-1-phosphate (S1P), which determines important cell responses including cell growth and death. Here we show that renal mesangial cells isolated from wild-type, SK-1-/-, and SK-2-/- mice show a differential response to apoptotic stimuli. Wild-type mesangial cells responded to staurosporine with increased DNA fragmentation and caspase-3 processing, which was enhanced in SK-1-/- cells. In contrast, SK-2-/- cells were highly resistant to staurosporine-induced apoptosis. Furthermore, the basal phosphorylation and activity of the anti-apoptotic protein kinase B (PKB) and of its substrate Bad were decreased in SK-1-/- but not in SK-2-/- cells. Upon staurosporine treatment, phosphorylation of PKB and Bad decreased in wild-type and SK-1-/- cells, but remained high in SK-2-/- cells. In addition, the anti-apoptotic Bcl-XL was significantly upregulated in SK-2-/- cells, which may further contribute to the protective state of these cells. In summary, our data show that SK-1 and SK-2 have opposite effects on the capacity of mesangial cells to resist apoptotic stimuli. This is due to differential modulation of the PKB/Bad pathway and of Bcl-XL expression. Thus, subtype-selective targeting of SKs will be critical when considering these enzymes as therapeutic targets for the treatment of inflammation or cance

    Speed of Rapid Serial Visual Presentation of Pictures, Numbers and Words Affects Event-Related Potential-Based Detection Accuracy

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    Rapid serial visual presentation (RSVP) based brain-computer interfaces (BCIs) can detect target images among a continuous stream of rapidly presented images, by classifying a viewer’s event related potentials (ERPs) associated with the target and non-targets images. Whilst the majority of RSVP-BCI studies to date have concentrated on the identification of a single type of image, namely pictures , here we study the capability of RSVP-BCI to detect three different target image types: pictures, numbers and words . The impact of presentation duration (speed) i.e., 100–200ms (5–10Hz), 200–300ms (3.3–5Hz) or 300–400ms (2.5–3.3Hz), is also investigated. 2-way repeated measure ANOVA on accuracies of detecting targets from non-target stimuli (ratio 1:9) measured via area under the receiver operator characteristics curve (AUC) for N=15{N}={15} subjects revealed a significant effect of factor Stimulus-Type ( pictures, numbers, words ) (F (2,28) = 7.243, p=0.003{p} = {0.003} ) and for Stimulus-Duration (F (2,28) = 5.591, p = 0.011). Furthermore, there is an interaction between stimulus type and duration: F (4,56) = 4.419, p=0.004{p} = {0.004} ). The results indicate that when designing RSVP-BCI paradigms, the content of the images and the rate at which images are presented impact on the accuracy of detection and hence these parameters are key experimental variables in protocol design and applications, which apply RSVP for multimodal image datasets

    The minimal access cranial suspension (MACS) lift:A systematic review of literature 18 years after its introduction

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    BACKGROUND: One of the most popular short-scar rhytidectomy techniques used nowadays is the minimal access cranial suspension (MACS) lift developed by Tonnard and Vaerpele. The technique uses purse-string sutures in combination with limited skin undermining to obtain a clear vertical tissue repositioning. Since its introduction, the technique has extensively been described and used around the world by facial plastic surgeons. Now, 18 years after its introduction, a systematic review concerning the results and complications of the MACS lift is presented to establish its current position in facial rejuvenation. METHODS: The MEDLINE, Embase, Cochrane Central, and Google Scholar databases were searched for studies evaluating the MACS lift (June 10, 2020). Outcomes of interest were long-term effect, satisfaction, and complications of the MACS lifting as determined by the patient and/or surgeon. RESULTS: Six studies were included, with 739 patients treated with the MACS lift in total. No major complications were reported, four studies did report on the occurrence of minor complications. All of the six studies reported relatively high levels of satisfaction. Three studies reported a shorter procedural duration for the MACS lift compared with the conventional facelift. In three of the six included studies, the level of evidence was low. The effect on neck rejuvenation is limited. CONCLUSION: The MACS lift can be considered a minimally invasive facelift procedure with a relatively low complication rate. The procedure, often combined with additional procedures, results in evident patient and/or surgeon satisfaction. To obtain a better desired result on an aged neck area, additional procedures are warranted

    Health-related quality of life in patients having undergone abdominoplasty after massive weight loss

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    Background: Due to lack of validated body contouring-specific patient-reported outcome (PRO) instruments, the outcomes of abdominoplasty after massive weight loss have been evaluated rather rarely and mainly using generic health-related quality of life (HRQoL) instruments. The aim of the current study was to examine, using body contouring-specific (BODY-Q) and generic (15D) HRQoL instruments, the HRQoL, and key factors related to HRQoL among patients having undergone massive weight loss and abdominoplasty. Methods: Altogether 52 patients who underwent abdominoplasty due to massive weight loss completed the BODY-Q and the 15D HRQoL instruments. The 15D scores were compared to those of age-, gender-, and BMI-adjusted control sample of the general population. Results: The mean score of the BODY-Q Abdomen scale was 50.7 out of 100 (SD 24.4). The HRQoL of abdominoplasty patients was lower than that of age-, gender-, and BMI-adjusted general population (p = 0.001). Sleeping, discomfort and symptoms, depression, excretion, and sexual activity were the patients' main concerns. Body image and psychological well-being were strongly associated with the perceived HRQoL. The satisfaction with appearance of the abdominal area was not associated with generic HRQoL. Conclusions: The HRQoL of abdominoplasty patients is lower than that of general population with similar age, gender and BMI. The most important factors associated with the HRQoL of the patients were body image, psychological well-being, and physical function. (C) 2020 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Density of sphingosine-1-phosphate receptors is altered in cortical nerve-terminals of insulin-resistant Goto-Kakizaki rats and diet-induced obese mice

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    Sphingosine-1-phosphate (S1P) is a phosphosphingolipid with pleiotropic biological functions. S1P acts as an intracellular second messenger, as well as extracellular ligand to five G-protein coupled receptors (S1PR1-5). In the brain, S1P regulates neuronal proliferation, apoptosis, synaptic activity and neuroglia activation. Moreover, S1P metabolism alterations have been reported in neurodegenerative disorders. We have previously reported that S1PRs are present in nerve terminals, exhibiting distinct sub-synaptic localization and neuromodulation actions. Since type 2 diabetes (T2D) causes synaptic dysfunction, we hypothesized that S1P signaling is modified in nerve terminals. In this study, we determined the density of S1PRs in cortical synaptosomes from insulin-resistant Goto-Kakizaki (GK) rats and Wistar controls, and from mice fed a high-fat diet (HFD) and low-fat-fed controls. Relative to their controls, GK rats showed similar cortical S1P concentration despite higher S1P levels in plasma, yet lower density of S1PR1, S1PR2 and S1PR4 in nerve-terminal-enriched membranes. HFD-fed mice exhibited increased plasma and cortical concentrations of S1P, and decreased density of S1PR1 and S1PR4. These findings point towards altered S1P signaling in synapses of insulin resistance and diet-induced obesity models, suggesting a role of S1P signaling in T2D-associated synaptic dysfunction

    Interaction Design and User Needs for TV Broadcasts Enriched with Linked Open Data

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    Increasingly, people are consuming television content on devices connected to the Internet that allow them to look up related information. In parallel, Europe is publishing growing amounts of Linked Open Data, including rich metadata about its cultural heritage. The goal of the LinkedTV project is to seamlessly interlink TV and Web content to enrich the user’s experience of both. Linked Data and semantic technologies enable broadcasters to achieve added value for their content at low cost through the re-use of existing metadata. We present two user studies related to different user scenarios: Interactive News and Hyperlinked Documentary). These studies reveal the different user requirements and infor
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