119 research outputs found

    Transfer learning in hand movement intention detection based on surface electromyography signals

    Get PDF
    Over the past several years, electromyography (EMG) signals have been used as a natural interface to interact with computers and machines. Recently, deep learning algorithms such as Convolutional Neural Networks (CNNs) have gained interest for decoding the hand movement intention from EMG signals. However, deep networks require a large dataset to train appropriately. Creating such a database for a single subject could be very time-consuming. In this study, we addressed this issue from two perspectives: (i) we proposed a subject-transfer framework to use the knowledge learned from other subjects to compensate for a target subject’s limited data; (ii) we proposed a task-transfer framework in which the knowledge learned from a set of basic hand movements is used to classify more complex movements, which include a combination of mentioned basic movements. We introduced two CNN-based architectures for hand movement intention detection and a subject-transfer learning approach. Classifiers are tested on the Nearlab dataset, a sEMG hand/wrist movement dataset including 8 movements and 11 subjects, along with their combination, and on open-source hand sEMG dataset “NinaPro DataBase 2 (DB2).” For the Nearlab database, the subject-transfer learning approach improved the average classification accuracy of the proposed deep classifier from 92.60 to 93.30% when classifier was utilizing 10 other subjects’ data via our proposed framework. For Ninapro DB2 exercise B (17 hand movement classes), this improvement was from 81.43 to 82.87%. Moreover, three stages of analysis in task-transfer approach proved that it is possible to classify combination hand movements using the knowledge learned from a set of basic hand movements with zero, few samples and few seconds of data from the target movement classes. First stage takes advantage of shared muscle synergies to classify combined movements, while second and third stages take advantage of novel algorithms using few-shot learning and fine-tuning to use samples from target domain to further train the classifier trained on the source database. The use of information learned from basic hand movements improved classification accuracy of combined hand movements by 10%

    Frosted branch angiitis caused by Varicella Zoster virus in an immunocompetent patient

    Get PDF
    Introduction: Frosted branch angiitis(FBA) is a panuveitis with sheating of all retinal vesssels. Case presentation: Herein we report an immunocompetent person who presented with fever, headache, atypical rash, and hazy vision. Ophthalmoscopy of both eyes revealed perivascular sheathing with frosted branch angiitis pattern in veins, patchy retinal hemorrhages. Aqueous PCR analysis turned positive for VZV. Discussion: This case illustrates that VZV should be considered in the differential diagnosis of retinal perivasculitis. Since a rapid and accurate diagnosis is crucial for prompt administration of antiviral therapy, PCR-based analysis of aqueous humor is a valuable tool for detecting viruses. © 2015, IRAN. J. MICROBIOL. All rights reserved

    Chemical control of the Lesser Date Moth, Batrachedra amydraula (Lepidoptera: Batrachedridae)

    Get PDF
    The Lesser Date Moth, Batrachedra amydraula (Lepidoptera: Batrachedridae), is a key pest of date palms in silos and storages. The efficacy of aluminium phosphide (Phostoxin® tablet 55%) @ 5 t/m3 and magnesium phosphide (Degesch® plates 56%) @ 2 p/30 m3 were assessed against this pest in Iran date silos based on a completely randomized block design. Based on Henderson-Tilton formula, on the third day after treatment, both treatments resulted in 100% mortality. Application of magnesium phosphide and aluminium phosphide can be a suitable substitution for methyl bromide, which has just been banned in many countries

    Visual intracortical and transthalamic pathways carry distinct information to cortical areas.

    Get PDF
    Sensory processing involves information flow between neocortical areas, assumed to rely on direct intracortical projections. However, cortical areas may also communicate indirectly via higher-order nuclei in the thalamus, such as the pulvinar or lateral posterior nucleus (LP) in the visual system of rodents. The fine-scale organization and function of these cortico-thalamo-cortical pathways remains unclear. We find that responses of mouse LP neurons projecting to higher visual areas likely derive from feedforward input from primary visual cortex (V1) combined with information from many cortical and subcortical areas, including superior colliculus. Signals from LP projections to different higher visual areas are tuned to specific features of visual stimuli and their locomotor context, distinct from the signals carried by direct intracortical projections from V1. Thus, visual transthalamic pathways are functionally specific to their cortical target, different from feedforward cortical pathways, and combine information from multiple brain regions, linking sensory signals with behavioral context

    The Liquisolid technique: an overview

    Get PDF
    A novel "Powder Solution Technology" involves absorption and adsorption efficiency which makes use of liquid medications, drug suspensions admixed with suitable carriers, coating materials and formulated into free flowing, dry looking, non adherent and compressible powder forms. Based upon a new mathematical model expression, improved flow characteristics and hardness of the formulation has been achieved by changing the proportion of Avicel ® PH 200 and Aerosil ® PH 200 from 50:1 ratio to 5:1 and in which the drug is dispersed in an almost molecularly state. Due to their significantly improved wetting properties a greater drug surface area is exposed to the dissolution media, resulting in an increased dissolution rate and bio availability. By using the Liquisolid technique, sustained drug delivery systems were developed for the water soluble drugs in which hydrophobic non-volatile solvents are used as vehicles.A nova "Tecnologia da Solução Sólida" envolve eficiência de absorção e de adsorção, faz uso de medicações líquidas, suspensões de fármacos e misturas com transportadores adequados, materiais de cobertura e é formulada em formas sólidas em fluxo livre, secas, não aderentes e compressíveis. Com base em novo modelo matemático, características aprimoradas de fluxo e dureza da formulação foram alcançadas modificando-se a proporção de Avicel ® PH 200 e Aerosil ® PH 200 de 50:1 para 5:1, na qual o fármaco é disperso quase que no estado molecular. Devido às propriedades de umidificação significativamente aprimoradas e à área do fármaco exposta ao meio de dissolução, que resulta na velocidade de dissolução, a biodisponibilidade foi aumentada. Utilizando a técnica Liquisólido, desenvolveram-se sistemas de liberação controlada de fármacos solúveis em água, nos quais solventes hidrofóbicos não voláteis foram usados como veículos

    Susceptibility of different populations of Tribolium confusum (Coleoptera: Tenebrionidae) to malathion (EC 57%) in flour mills of Iran

    Get PDF
    The confused flour beetle, Tribolium confusum, is a key pest of stored products such as wheat and flour. For decades, organophosphorus compounds, such as malathion and pirimiphos-methyl, have been applied against stored-product pests. In this research, susceptibility of different populations of T. confusum, collected from silos at different locations of Iran, against malathion (EC 57%), was studied in the laboratory, based on a completely randomized design. Based on pre-tests, the Bioassay Index Dose was estimated as 2 g a.i./m2. Out of 23 populations, 2 populations from Bandar-Abbas region were resistant populations against malathion (9.72% and 67.2% mortality), while one population from Khomein region was moderately resistant (86.08% mortality), and the rest of the population were susceptible to malathion (95.71% to 100% mortality). Therefore, in warm locations of Iran, where this pest has evolved resistance against malathion, other control measures shall be considered

    Studying the efficacy of fipronil (GR 0.2%) against European Mole Cricket, Gryllotalpa gryllotalpa (Orthoptera: Gryllotalpidae)

    Get PDF
    The European Mole Cricket, Gryllotalpa gryllotalpa (Orthoptera: Gryllotalpidae), is a key pest of several crops in different regions of the world, damaging seedlings, roots and tubers. The efficacy of fipronil (Regent ® GR 0.2%) @ 2, 2.5 and 3 g/m2 along with toxic bait of carbaryl (EC 85%)@ 20 g/m2 were assessed against this pest in the field based on a completely randomized block design. Based on Henderson-Tilton formula, on the third day after treatment, the efficacy of fipronil @ 2, 2.5 and 3 g/m2 and carbaryl bait was 16%, 30%, 47% and 53%, respectively; while on the third day after treatment, the efficacy was 22%, 48%, 64% and 81%, respectively. At present, carbaryl application is banned in Iran; therefore, fipronil can be a suitable substitute for this insecticide

    The role of a new electromagnetic shielding in reducing the microwave radiation for the X-band frequencies

    Get PDF
    Background and aims: X-band microwave with 8-12.5 frequency range has various applications such as air control traffic, navy communication etc. Uncontrolled exposure with microwave can lead to adverse effect on workers. Application of the shielding is superior control for prevention of microwave exposure. The aim of this study is production a new electromagnetic shielding for exposure control of X-band frequency by nano nickel oxide and epoxy resin. Methods: Nanocomposites prepared by epoxy resin and nano nickel oxide (7 wt) with 2, 4 and 6 mm thicknesses. Nanoparticles characterized by XRD and FESEM. Shielding effectiveness measured with vector network analyzer. Results: The Average of shielding effectiveness for three thicknesses were 2.68, 5.09 and 5.35 dB respectively that were equivalent to 45.98, 69.01 and 70.87 attenuation percentage. Maximum attenuation (8.96 dB or 87.29 attenuation percentage) obtained by the nanocomposite with 6mm thickness at 8.51 GHz frequency. The Average of shielding effectiveness increased with increasing the thickness. Conclusion: these nanocomposites could be used as appropriate shielding for exposure control of X-band frequency in workplace.Both Epoxy and nanocomposite with 6mm thicknesses are useful in specific frequency such as 8.52 and 8.51 GHz. However, According to economical and technical issues, nanocomposite with 4mm thickness is appropriate shield in this study. In according to required attenuation and economical benefit, attenuation matrix can be used for selecting the appropriate electromagnetic shield
    corecore