2,051 research outputs found

    Faint solar analogs: at the limit of no reddening

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    The flux distribution of solar analogs is required for calculating the spectral albedo of Solar System bodies such as asteroids and trans-Neptunian objects. Ideally a solar analog should be comparably faint as the target of interest, but only few analogs fainter than V = 9 were identified so far. Only atmospheric parameters equal to solar guarantee a flux distribution equal to solar as well, while only photometric colors equal to solar do not. Reddening is also a factor to consider when selecting faint analog candidates. We implement the methodology for identifying faint analogs at the limit of precision allowed by current spectroscopic surveys. We quantify the precision attainable for the atmospheric parameters effective temperature (TeffT_{eff}), metallicity ([Fe/H]), surface gravity (log gg) when derived from moderate low resolution (R=8000) spectra with S/N ∼100\sim 100. We calibrated TeffT_{eff} and [Fe/H] as functions of equivalent widths of spectral indices by means of the PCA regression. We derive log gg, mass, radius, and age from the atmospheric parameters, Gaia parallaxes and evolutionary tracks. We obtained TeffT_{eff}/[Fe/H]/log gg with precision of 97 K/0.06 dex/0.05 dex. We identify five solar analogs with V∼10.5V\sim10.5 (located at ∼135\sim135 pc): HIP 991, HIP 5811, HIP 69477, HIP 55619 and HIP 61835. Other six stars have TeffT_{eff} close to solar but slightly lower [Fe/H]. Our analogs show no evidence of reddening but for four stars, which present E(B−V)≥0.06E(B-V) \geq 0.06 mag, translating to at least a 200 K decrease in photometric TeffT_{eff}.Comment: Paper accepted. Fundamental parameters of the solar analogs are in Table

    A distributed computation of Interpro Pfam, PROSITE and ProDom for protein annotation

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    Interpro is a widely used tool for protein annotation in genome sequencing projects, demanding a large amount of computation and representing a huge time-consuming step. We present a strategy to execute programs using databases Pfam, PROSITE and ProDom of Interpro in a distributed environment using a Java-based messaging system. We developed a two-layer scheduling architecture of the distributed infrastructure. Then, we made experiments and analyzed the results. Our distributed system gave much better results than Interpro Pfam, PROSITE and ProDom running in a centralized platform. This approach seems to be appropriate and promising for highly demanding computational tools used for biological applications

    Antiviral Potential of Naphthoquinones Derivatives Encapsulated within Liposomes

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    HSV infections, both type 1 and type 2, are among the most widespread viral diseases affecting people of all ages. Their symptoms could be mild, with cold sores up to 10 days of infection, blindness and encephalitis caused by HSV-1 affecting immunocompetent and immunosuppressed individuals. The severe effects derive from co-evolution with the host, resulting in immune evasion mechanisms, including latency and growing resistance to acyclovir and derivatives. An efficient alternative to controlling the spreading of HSV mutations is the exploitation of new drugs, and the possibility of enhancing their delivery through the encapsulation of drugs into nanoparticles, such as liposomes. In this work, liposomes were loaded with a series of 2-aminomethyl- 3-hydroxy-1,4-naphthoquinones derivatives with n-butyl (compound 1), benzyl (compound 2) and nitrobenzene (compound 3) substituents in the primary amine of naphthoquinone. They were previously identified to have significant inhibitory activity against HSV-1. All of the aminomethylnaphthoquinones derivatives encapsulated in the phosphatidylcholine liposomes were able to control the early and late phases of HSV-1 replication, especially those substituted with the benzyl (compound 2) and nitrobenzene (compound 3), which yields selective index values that are almost nine times more efficient than acyclovir. The growing interest of the industry in topical administration against HSV supports our choice of liposome as a drug carrier of aminomethylnaphthoquinones derivatives for formulations of in vivo pre-clinical assays

    A BIOMECHANICAL MODEL OF THE CERVICAL SPINE DURING CYCLING

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    With the objective of estimating the internal forces in the cervical spine during cycling, nine subjects pedaled in three postures. The image of the sagittal posture of the spine was recorded through filming and the muscle activity of the cervical extensors was registered. Reflexive markers were placed on anatomical points on the head and the cervical spine. One subject was submitted to radiological exam of the head and cervical spine in the sagittal plane with lead markers placed on the same anatomical points of reference. Muscular force was calculated using the inverse dynamics technique. The results demonstrate that muscular strength and the RMS value increase significantly (

    LOWER LIMB FORCE, POWER AND PERFORMANCE IN SKATEBOARDING

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    The aim of this study was to quantify the contribution of muscle force and power of the lower limbs to the performance of the Ollie in beginner level skateboarders. Ten male athletes who had practiced for at least two years were submitted to three kinds of test: (1) maximal voluntary contraction of the knee and hip extensor muscles; (2) vertical jump tests, Counter Movement Jump (CMJ) and Squat Jump (SJ); and (3) a test developed specifically for this study, to measure the maximum height achieved during the Ollie manoeuvre. The data obtained were submitted to simple linear regression analysis. The results demonstrate that the variance of the Ollie manoeuvre (

    LACTATE THRESHOLD USING MATHEMATICAL DETECTION OF THE EMG DURING INCREMENTAL PEDALING EXERCISE

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    The purpose of this study was to determine the validity of using the EMG as a noninvasive method to estimate LT in non-athletes subjects. Twenty-four non-athletes subjects performed an incremental exercise protocol that consisted of stepwise increases in power output of 25W every 3 minutes until exhaustion at 80 rpm. The EMG was recorded from the right vastus lateralis and right rectus femoris each 15 seconds. Blood samples were taken every 3 minutes. The LT was determined using a log-log transformation model. The EMGT was determined mathemathically using MATLAB® software that models RMS response to gradual exercise using linear regression. The results showed high the correlation coefficients between EMGT and LT, and the validity of using EMG to estimate the LT power output was confirmed

    The use of a new calcium mesoporous silica nanoparticle versus calcium and/or fluoride products in reducing the progression of dental erosion

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    Objective: There is increasingly common the consumption more times a day of foods and acidic drinks in the diet of the population. The present study aimed to evaluate and compare the effects of a calcium mesoporous silica nanoparticle single application of other calcium and/or fluoride products in reducing the progression of dental erosion. Methodology: Half of the eroded area was covered of 60 blocks of enamel, after which the block was submitted to the following treatments: (Ca2+-MSN), casein phosphopeptide–amorphous calcium phosphate (CPP-ACP); CPP-ACP/F-(900 ppm F−); titanium tetrafluoride (TiF4 1%) (positive control); sodium fluoride (NaF 1.36%) (positive control); and Milli-Q® water (negative control) before being submitted to a second erosive challenge. A surface analysis was performed via a three-dimensional (3D) noncontact optical profilometry to assess the volumetric roughness (Sa) and tooth structure loss (TSL) and and through scanning electron microscopy (MEV). An analysis of variance (ANOVA) and Tukey’s test were performed. Results: Regarding Sa, all experimental groups exhibited less roughness than the control (p<0.05). The TSL analysis revealed that the Ca2+-MSN and NaF groups were similar (p>0.05) and more effective in minimizing tooth loss compared with the other groups (p<0.05). Conclusions: The Ca2+-MSN and NaF treatments were superior compared with the others and the negative control

    Modelagem e Desenvolvimento de um Inversor CSI Multistring Fotovoltaico de Estágio Único sem Transformador Conectado à Rede Elétrica

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    Este artigo traz o projeto e desenvolvimento de um inversor fonte de corrente (do inglês, CSI) fotovoltaico multistring de estágio único sem transformador, destinado exclusivamente a operar em conexão com a rede elétrica. Em virtude do comportamento como CSI, dentro das contribuições do presente trabalho tem-se a ampliação da literatura deste tipo de topologia a partir da implementação de técnicas de controle e operação de potência usuais em outras estruturas topológicas. Além disso, o sistema proposto foi simulado no PSIM® e os resultados computacionais e experimentais obtidos evidenciaram um comportamento satisfatório da estrutura em prol da injeção de corrente na rede elétrica com baixa distorção harmônica e elevado fator de potência, atendendo normas nacionais e internacionais
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