116 research outputs found
Statistical assessment of automotive PLC multipath channel modelss
This paper addresses the modeling of in-vehicle power line communication channels via multipath parametric representations. The study is based on a set of frequency-domain measurements carried out on a commercial automobile. The proposed procedure for the computation of model parameters from real measured data is briefly summarized and a systematic assessment aimed at collecting some useful statistical information on both the estimated models and the channel features is thoroughly discussed. Specific emphasis is given to the definition of the range of the key parameters that allow characterizing real automotive PLC channel
Multipath Modeling of Automotive Power Line Communication Channels
In this paper an in-vehicle power line channel mathematical multipath representation is proposed. The selected approach aims at describing the transmission of a signal on a possibly complex power network by means of a finite number of delayed echoes. Model parameters are computed via a welldefined step-by-step procedure from frequency-domain channel characteristics. The feasibility and strength of the method are demonstrated by means of a measurement campaign. Two-port scattering measurements have been carried out on a commercial automobile and the effect of the measurement setup has been considered in the analysis
Feeding emitters for microirrigation with a digestate liquid fraction up to 25% dilution did not reduce their performance
Irrigation with wastewater can strongly contribute to the reduction of water abstraction in agriculture with an especial interest in arid and semiarid areas. However, its use can have drawbacks to both soil and micro-irrigation systems, especially when the total solids in the wastewater are high, such as in digestate liquid fractions (DLF) from plant material. The aim of this study was thus to evaluate the performances of a serpentine shaped micro-emitter injected with a hydrocyclone filtered DLF (HF-DLF) from corn + barley biomass and evaluate the traits of the liquid released within a 8-h irrigation cycle. HF-DLF was injected at 10%, 25%, and 50% dilution compared to tap water (at pH = 7.84) and the system performances were measured. No clogging was found, which likely depended on both the shape of the emitter and the high-pressure head (200 kPa). HF-DLF dilution at 10%, 25%, and 50% consisted in +1.9%, +3.5, and -4.9% amount of liquid released compared to the control. Fluid temperature during irrigation (from 9:00 to 17:00) did not explain the difference in the released amounts of liquid. In 10% HF-DLF % and 25% HF-DLF, a pH difference of + 0.321 ± 0.014 pH units compared to the control was found, and such difference was constant for both dilutions and at increasing the time. In contrast, 50% HF-DLF increased pH by around a half point and such difference increased with time. Similar differences among treatments were found for the total solids in the liquid. These results indicate that 50% HF-DLF was accumulating materials in the serpentine. These results suggest that a low diluted HF-DLF could directly be injected in irrigation systems with few drawbacks for the irrigation system and contribute to water conservation since such wastewater are available from the late spring to the early fall, when water requirements are high
A busca ativa de tuberculose pulmonar em TeresĂłpolis, RJ, Brasil: a procura de sintomĂĄticos respiratĂłrios na emergĂȘncia do Hospital das ClĂnicas de TeresĂłpolis Costantino Ottaviano, Fundação Educacional Serra dos ĂrgĂŁos
The aim of the present study was to investigate the detection percentage of tuberculosis among patients that are respiratory symptomatic (TB suspects). In this work, we present the preliminary results of research carried out at "Hospital das ClĂnicas de TeresĂłpolis Costantino Ottaviano da Fundação Educacional Serra dos ĂrgĂŁos (FESO)" from November 2003 to April 2004. Among the 40 respiratory symptomatic individuals identified and referred to the Tuberculosis Control Program in TeresĂłpolis, two (5.0%) were characterized as smear-positive. These results confirm reports in the literature and underscore the need for and importance of this strategy.Investigar o percentual de detecção de tuberculose entre sintomĂĄticos respiratĂłrios Ă© o objetivo do presente estudo. Nesta nota prĂ©via, apresentam-se os resultados preliminares da pesquisa desenvolvida no Hospital das Clinicas de TeresĂłpolis Costantino Ottaviano da Fundação Educacional Serra dos ĂrgĂŁos (FESO), de novembro de 2003 a abril de 2004. Dos 40 sintomĂĄticos respiratĂłrios identificados e encaminhados ao Programa de Controle da Tuberculose do municĂpio de TeresĂłpolis, dois (5.0%) foram caracterizados como bacilĂferos. Esses resultados corroboram com os relatos da literatura e confirmam a necessidade e importĂąncia desta estratĂ©gia
The N-Terminal residues 43 to 60 form the interface for dopamine mediated α-synuclein dimerisation
α-synuclein (α-syn) is a major component of the intracellular inclusions called Lewy bodies, which are a key pathological feature in the brains of Parkinson's disease patients. The neurotransmitter dopamine (DA) inhibits the fibrillisation of α-syn into amyloid, and promotes α-syn aggregation into SDS-stable soluble oligomers. While this inhibition of amyloid formation requires the oxidation of both DA and the methionines in α-syn, the molecular basis for these processes is still unclear. This study sought to define the protein sequences required for the generation of oligomers. We tested N- (α-syn residues 43-140) and C-terminally (1-95) truncated α-syn, and found that similar to full-length protein both truncated species formed soluble DA: α-syn oligomers, albeit 1-95 had a different profile. Using nuclear magnetic resonance (NMR), and the N-terminally truncated α-syn 43-140 protein, we analysed the structural characteristics of the DA:α-syn 43-140 dimer and α-syn 43-140 monomer and found the dimerisation interface encompassed residues 43 to 60. Narrowing the interface to this small region will help define the mechanism by which DA mediates the formation of SDS-stable soluble DA:α-syn oligomers
Oxidative Stress Correlates with Headache Symptoms in Fibromyalgia: Coenzyme Q10 Effect on Clinical Improvement
This is an open-access article distributed under the terms of the Creative Commons Attribution License.[Background]: Fibromyalgia (FM) is a chronic pain syndrome with unknown etiology and a wide spectrum of symptoms such as allodynia, debilitating fatigue, joint stiffness and migraine. Recent studies have shown some evidences demonstrating that oxidative stress is associated to clinical symptoms in FM of fibromyalgia. We examined oxidative stress and bioenergetic status in blood mononuclear cells (BMCs) and its association to headache symptoms in FM patients. The effects of oral coenzyme Q 10 (CoQ 10) supplementation on biochemical markers and clinical improvement were also evaluated. [Methods]: We studied 20 FM patients and 15 healthy controls. Clinical parameters were evaluated using the Fibromyalgia Impact Questionnaire (FIQ), visual analogues scales (VAS), and the Headache Impact Test (HIT-6). Oxidative stress was determined by measuring CoQ 10, catalase and lipid peroxidation (LPO) levels in BMCs. Bioenergetic status was assessed by measuring ATP levels in BMCs. [Results]: We found decreased CoQ 10, catalase and ATP levels in BMCs from FM patients as compared to normal control (P<0.05 and P<0.001, respectively) We also found increased level of LPO in BMCs from FM patients as compared to normal control (P<0.001). Significant negative correlations between CoQ 10 or catalase levels in BMCs and headache parameters were observed (r = -0.59, P<0.05; r = -0.68, P<0.05, respectively). Furthermore, LPO levels showed a significant positive correlation with HIT-6 (r = 0.33, P<.05). Oral CoQ 10 supplementation restored biochemical parameters and induced a significant improvement in clinical and headache symptoms (P<0.001). [Discussion]: The results of this study suggest a role for mitochondrial dysfunction and oxidative stress in the headache symptoms associated with FM. CoQ10 supplementation should be examined in a larger placebo controlled trial as a possible treatment in FM.This work has been supported by IV Plan Propio de InvestigaciĂłn (University of Seville, ref. 2010/00000453), FIS PI10/00543 grant, FIS EC08/00076 grant, Ministerio de Sanidad, Spain and Fondo Europeo de Desarrollo Regional (FEDER-UniĂłn Europea), SAS 111242 grant, Servicio Andaluz de Salud-Junta de AndalucĂa, Proyecto de InvestigaciĂłn de Excelencia de la Junta de AndalucĂa CTS-5725 and FederaciĂłn Andaluza de Fibromialgia y Fatiga CrĂłnica (ALBA AndalucĂa).Peer Reviewe
Inhibition of alpha-synuclein fibrillization by dopamine is mediated by interactions with five C-terminal residues and with E83 in the NAC region
The interplay between dopamine and alpha-synuclein (AS) plays a central role in Parkinson's disease (PD). PD results primarily from a severe and selective devastation of dopaminergic neurons in substantia nigra pars compacta. The neuropathological hallmark of the disease is the presence of intraneuronal proteinaceous inclusions known as Lewy bodies within the surviving neurons, enriched in filamentous AS. In vitro, dopamine inhibits AS fibril formation, but the molecular determinants of this inhibition remain obscure. Here we use molecular dynamic (MD) simulations to investigate the binding of dopamine and several of its derivatives onto conformers representative of an NMR ensemble of AS structures in aqueous solution. Within the limitations inherent to MD simulations of unstructured proteins, our calculations suggest that the ligands bind to the (125)YEMPS(129) region, consistent with experimental findings. The ligands are further stabilized by long-range electrostatic interactions with glutamate 83 (E83) in the NAC region. These results suggest that by forming these interactions with AS, dopamine may affect AS aggregation and fibrillization properties. To test this hypothesis, we investigated in vitro the effects of dopamine on the aggregation of mutants designed to alter or abolish these interactions. We found that point mutations in the (125)YEMPS(129) region do not affect AS aggregation, which is consistent with the fact that dopamine interacts non-specifically with this region. In contrast, and consistent with our modeling studies, the replacement of glutamate by alanine at position 83 (E83A) abolishes the ability of dopamine to inhibit AS fibrillization
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