140 research outputs found

    A Spectral Method for Generating Surrogate Graph Signals

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    The increasing availability of network data is leading to a growing interest in processing of signals on graphs. One notable tool for extending conventional signal-processing operations to networks is the graph Fourier transform that can be obtained as the eigendecomposition of the graph Laplacian. In this letter, we used the graph Fourier transform to define a new method for generating surrogate graph signals. The approach is based on sign-randomization of the graph Fourier coefficients and, therefore, the correlation structure of the surrogate graph signals (i.e., smoothness on the graph topology) is imposed by the measured data. The proposed method of surrogate data generation can be widely applied for nonparametric statistical hypothesis testing. Here, we showed a proof-of-concept with a high-density electroencephalography dataset

    Choroidal abnormalities detected by near-infrared reflectance imaging as a new diagnostic criterion for neurofibromatosis 1

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    Objective: To investigate in a large sample of consecutive patients with neurofibromatosis type 1 (NF1) the possibility of including the presence of choroidal abnormalities detected by near-infrared reflectance (NIR) as a new diagnostic criterion for NF1. Design: Cross-sectional evaluation of a diagnostic test. Participants and Controls: Ninety-five consecutive adult and pediatric patients (190 eyes) with NF1, diagnosed based on the National Institutes of Health (NIH) criteria. Controls included 100 healthy age- and gender-matched control subjects. Methods: Confocal scanning laser ophthalmoscopy was performed for each subject, investigating the presence and the number of choroidal abnormalities. Main Outcome Measures: Sensitivity, specificity, and diagnostic accuracy for the different cutoff values of the criterion choroidal nodules detected by NIR compared with the NIH criteria. Results: Choroidal nodules detected by NIR imaging were present in 79 (82%) of 95 of the NF1 patients, including 15 (71%) of the 21 NF1 pediatric patients. Similar abnormalities were present in 7 (7%) of 100 healthy subjects, including 2 (8%) of the 25 healthy pediatric subjects. The highest accuracy was obtained at the cutoff value of 1.5 choroidal nodules detected by NIR imagery. Sensitivity and specificity of the examination at the optimal cutoff point were 83% and 96%, respectively. Diagnostic accuracy was 90% in the overall population and 83% in the pediatric population. Both of these values were in line with the most common NIH diagnostic criteria. Conclusions: Choroidal abnormalities appearing as bright patchy nodules detected by NIR imaging frequently occurred in NF1 patients. The present study shows that NIR examination to detect choroidal involvement should be considered as a new diagnostic criterion for NF1

    One week of levofloxacin plus dexamethasone eye drops for cataract surgery: an innovative and rational therapeutic strategy

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    Background: Cataract surgery is the most common operation performed worldwide. A fixed topical corticosteroid-antibiotic combination is usually prescribed in clinical practice for 2 or more weeks to treat post surgical inflammation and prevent infection. However, this protracted schedule may increase the incidence of corticosteroid-related adverse events and notably promote antibiotic resistance. Methods: This International, multicentre, randomized, blinded-assessor, parallel-group clinical study evaluated the non-inferiority of 1-week levofloxacin/dexamethasone eye drops, followed by 1-week dexamethasone alone, vs. 2-week gold-standard tobramycin/dexamethasone (one drop QID for all schedules) to prevent and treat ocular inflammation and prevent infection after uncomplicated cataract surgery. Non-inferiority was defined as the lower limit of the 95% confidence interval (CI) around a treatment difference >\u201310%. The study randomized 808 patients enrolled in 53 centres (Italy, Germany, Spain and Russia). The primary endpoint was the proportion of patients without anterior chamber inflammation on day 15 defined as the end of treatment. Endophthalmitis was the key secondary endpoint. This study is registered with EudraCT code: 2018-000286-36. Results: After the end of treatment, 95.2% of the patients in the test arm vs. 94.9% of the control arm had no signs of inflammation in the anterior chamber (difference between proportions of patients = 0.028; 95% CI: 120.0275/0.0331). No case of endophthalmitis was reported. No statistically significant difference was evident in any of the other secondary endpoints. Both treatments were well tolerated. Conclusions: Non-inferiority of the new short pharmacological strategy was proven. One week of levofloxacin/dexamethasone prevents infection, ensures complete control of inflammation in almost all patients and may contain antibiotic resistance

    EMG-based decoding of grasp gestures in reaching-to-grasping motions

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    Predicting the grasping function during reach-to-grasp motions is essential for controlling a prosthetic hand or a robotic assistive device. An early accurate prediction increases the usability and the comfort of a prosthetic device. This work proposes an electromyographic-based learning approach that decodes the grasping intention at an early stage of reach-to-grasp motion, i.e. before the final grasp/hand pre-shape takes place. Superficial electrodes and a Cyberglove were used to record the arm muscle activity and the finger joints during reach-to-grasp motions. Our results showed a 90% accuracy for the detection of the final grasp about 0.5 s after motion onset. This paper also examines the effect of different objects’ distances and different motion speeds on the detection time and accuracy of the classifier. The use of our learning approach to control a 16-degrees of freedom robotic hand confirmed the usability of our approach for the real-time control of robotic devices

    A review : a comprehensive review of soft and rigid wearable rehabilitation and assistive devices with a focus on the shoulder joint

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    The importance of the human upper limb role in performing daily life and personal activities is significant. Improper functioning of this organ due to neurological disorders or surgeries can greatly affect the daily activities performed by patients. This paper aims to comprehensively review soft and rigid wearable robotic devices provided for rehabilitation and assistance focusing on the shoulder joint. In the last two decades, many devices have been proposed in this regard, however, there have been a few groups whose devices have had effective therapeutic capability with acceptable clinical evidence. Also, there were not many portable, lightweight and user-friendly devices. Therefore, this comprehensive study could pave the way for achieving optimal future devices, given the growing need for these devices. According to the results, the most commonly used plan was Exoskeleton, the most commonly used actuators were electrical, and most devices were considered to be stationary and rigid. By doing these studies, the advantages and disadvantages of each method are also presented. The presented devices each have a new idea and attitude in a specific field to solve the problems of movement disorders and rehabilitation, which were in the form of prototypes, initial clinical studies and sometimes comprehensive clinical and commercial studies. These plans need more comprehensive clinical trials to become a complete and efficient plan. This article could be used by researchers to identify and evaluate the important features and strengths and weaknesses of the plans to lead to the presentation of more optimal plans in the future

    Environmental Risk Assessment in GMO Analysis

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    Genetically modified or engineered organisms (GMOs, GEOs) are utilised in agriculture, expressing traits of interest, such as insect or herbicide resistance. Soybean, maize, cotton and oilseed rape are the GM crops with the largest acreage in the world. The distribution of GM acreage in the different countries is related with the different positions concerning labelling of GMO products: based on the principle of substantial equivalence, or rather based on the precautionary principle. the paper provides an overview on how the risks associated with release of GMO in the environments can be analysed and predicted, in view of a possible coexistence of GM and non-GM organisms in agriculture. Risk assessment procedures, both qualitative and quantitative, are compared in the context of application to GMOs considering also legislation requirements (Directive 2001/18/EC). Criteria and measurable properties to assess harm for human health and environmental safety are listed, and the possible consequences are evaluated in terms of significance. Finally, a mapping of the possible risks deriving from GMO release is reported, focusing on gene transfer to related species, horizontal gene transfer, direct and indirect effects on non target organisms, development of resistance in target organisms, and effects on biodiversity
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