817 research outputs found
Parkinson's Disease: General Features, Effects of Levodopa Treatment and Future Directions
A commentary on Basal ganglia circuits underlying the pathophysiology of levodopa-induced dyskinesia by Barroso-Chinea, P., and Bezard, E. Front. Neuroanat. 4:131. doi: 10.3389/ fnana.2010.00131. Among the neurodegenerative movement disorders, Parkinson’s disease (PD) is the most prevalent (Schapira, 2009), affecting about 1 % of people aged over 55 years, with a increase of fivefold by the age of 70, characterizing aging as the most important risk factor for this pathology (Collier et al., 2007). The first description of PD wa
Lane background removal in thin-layer chromatography images using continuous wavelet
This paper describes a new methodology to remove the background of the lanesin Thin-Layer Chromatography (TLC) images aiming at improving subsequentband detection. The storage of the biological samples to be analysed by TLC isusually done via plastic containers. Filter paper is an alternative that allowsreduced costs and higher portability, but with consequences in the image analysisstage due to a lane background alteration. In order to overcome this problem, anegative control lane is generated in every chromatographic plate. After preprocessingand lane detection stages a one-dimensional intensity profile is usedfor integrating lane information and the background influence is removed withthe help of the Continuous Wavelet Transform (CWT) decomposition. Theproposed method was tested in 78 lane images, A band detection algorithm wasapplied on lane profiles, and a superior detection rate was achieved for thebackground removed lanes
A Framework for Analyzing Fog-Cloud Computing Cooperation Applied to Information Processing of UAVs
Unmanned aerial vehicles (UAVs) are a relatively new technology. Their
application can often involve complex and unseen problems. For instance, they
can work in a cooperative-based environment under the supervision of a ground
station to speed up critical decision-making processes. However, the amount of
information exchanged among the aircraft and ground station is limited by high
distances, low bandwidth size, restricted processing capability, and energy
constraints. These drawbacks restrain large-scale operations such as large area
inspections. New distributed state-of-the-art processing architectures, such as
fog computing, can improve latency, scalability, and efficiency to meet time
constraints via data acquisition, processing, and storage at different levels.
Under these amendments, this research work proposes a mathematical model to
analyze distribution-based UAVs topologies and a fog-cloud computing framework
for large-scale mission and search operations. The tests have successfully
predicted latency and other operational constraints, allowing the analysis of
fog-computing advantages over traditional cloud-computing architectures.Comment: Volume 2019, Article ID 7497924, 14 page
Editor’s Note
[EN] Under the auspices of IMACSS –International Martial Arts and Combat Sports Scientific Society..
Extrusion of poly(vinylidene fluoride) recycled filaments : effect of the processing cycles on the degree of crystallinity and electroactive phase content
This study analyses the possibility of reprocessing used poly(vinylidene fluoride), PVDF, maintaining the main properties critical for its use in piezoelectric sensor/actuator applications. The influence of multiple reprocessing cycles of PVDF on crystallinity and ß-phase content fundamental for its electroactive behaviour, was studied. Nine reprocessing cycles were completed and it was found that the material preserved the characteristics required for its use as piezoelectric polymer without significant degradation.The authors thank the Portuguese Foundation for Science and Technology (FCT) (gs1) for financial support under Project Piezotex - PTDC (PTDC/CTM/108801/2008) and in the framework of the Strategic Project PEst-C/FIS/
UI607/20112011, PEst-C/CTM/LA0025/2011 and PEst-C/CTM/UI0264/2011. MPS thanks the FCT for financial support under grant SFRH/BD/70303/2010
Pain Modulation by Nitric Oxide in the Spinal Cord
Nitric oxide (NO) is a versatile messenger molecule first associated with endothelial relaxing effects. In the central nervous system (CNS), NO synthesis is primarily triggered by activation of N-methyl-D-aspartate (NMDA) receptors and has a Janus face, with both beneficial and harmful properties. There are three isoforms of the NO synthesizing enzyme nitric oxide synthase (NOS): neuronal (nNOS), endothelial (eNOS), and inducible nitric oxide synthase (iNOS), each one involved with specific events in the brain. In the CNS, nNOS is involved with modulation of synaptic transmission through long-term potentiation in several regions, including nociceptive circuits in the spinal cord. Here, we review the role played by NO on central pain sensitization
Effect of the processing conditions on the mechanical and electrical properties of extruded conductive PP tape and filament
Polypropylene (PP) shows a number of desirable properties that make it a versatile material among thermoplastic polymers. Due to its low cost and density, it is an excellent resin for conductive polymer composites (CPCs).[1] CPCs mainly consist on a polymer matrix with incorporated carbonaceous fillers. These multifunctional materials are routinely employed in various commercial applications due to their good electrical conductivity, corrosion resistance, light weight and enhanced mechanical properties. [2]
The filler content is the crucial aspect in conductive polymer composites fabrication: due to mechanical behaviour it must be as low as possible but enough to allow fulfilling the electrical requirements.[2]
In this work commercial conductive master batch PP was extruded in the form of tape and filament using different processing conditions, namely different draw ratios and temperatures. In order to tailor the mechanical performance of the material, different several amounts of PP homopolymer were added to the commercial conductive resin. The results show that the amount of homopolymer directly influences mechanical and electrical performance of the material. Increasing homopolymer content yields a more stretchable, and mechanically resistant, material but, on the other hand, reduces its electrical conductivity. This study focuses on the optimization of the processing conditions and composition in order to tailor the mechanical and electrical properties of the material for specific applicationsFundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/108801/2008, POCI 2010, Pluriannual program
Protein synthesis is associated with high-speed dynamics and broad-band stability of functional hubs in the brain.
L-[1-(11)C]leucine PET can be used to measure in vivo protein synthesis in the brain. However, the relationship between regional protein synthesis and on-going neural dynamics is unclear. We use a graph theoretical approach to examine the relationship between cerebral protein synthesis (rCPS) and both static and dynamical measures of functional connectivity (measured using resting state functional MRI, R-fMRI). Our graph theoretical analysis demonstrates a significant positive relationship between protein turnover and static measures of functional connectivity. We compared these results to simple measures of metabolism in the cortex using [(18)F]FDG PET). Whilst some relationships between [(18)F]FDG binding and graph theoretical measures was present, there remained a significant relationship between protein turnover and graph theoretical measures, which were more robustly explained by L-[1-(11)C]Leucine than [(18)F]FDG PET. This relationship was stronger in dynamics at a faster temporal resolution relative to dynamics measured over a longer epoch. Using a Dynamic connectivity approach, we also demonstrate that broad-band dynamic measures of Functional Connectivity (FC), are inversely correlated with protein turnover, suggesting greater stability of FC in highly interconnected hub regions is supported by protein synthesis. Overall, we demonstrate that cerebral protein synthesis has a strong relationship independent of tissue metabolism to neural dynamics at the macroscopic scale
Extrusion of piezoelectric filaments
The application of electroactive materials in textile products has a huge potential. However, the difficulties related to the integration in textile products of materials that possess those characteristics have limited the development of practical applications that fully exploit their capabilities.
This works describes the development of a technology, which pursues the production of electroactive materials easy to integrate in textile products. For this purpose, multilayer piezoelectric filaments were produced by filament coextrusion. Poly(vinylidene fluoride) (PVDF) was used as the piezoelectric material and an electrical conductive thermoplastic grade, comprising a PP matrix, was used as the electrical conductive inner layer to produce a two-layer filament with coaxial layers. The samples were produced in a monofilament coextrusion line, and were stretched to ratios up to 6 at temperatures of 80ºC to 120ºC, to obtain the PVDF in -phase, the most electroactive phase of that material. The filaments were subsequently covered with a conductive ink and the PVDF layer was poled using high voltage applied between the inner conductive layer and the conductive ink. The piezoelectric properties of the produced filaments were evaluated in a test setup, designed to stimulate the filament mechanically by bending it periodically. A charge amplifier was used to condition the output signal. The results obtained confirm the piezoelectric property of the produced coextruded filaments, opening a new field of research and development directed to mechanical sensors/actuators in filament form.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/108801/200
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