1,705 research outputs found

    Liquid and vapour phase of lavandin (Lavandula × intermedia) essential oil: chemical composition and antimicrobial activity

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    Essential oils from Lavandula genus and the obtained hybrids are widely used for different purposes such as perfume production in the cosmetic field and for its biological properties. This is the first study on the liquid and vapour phase of Lavandula × intermedia “Grosso” essential oil grown in the Lazio Region, Italy, investigated using headspace coupled to gas chromatography and mass spectrometry (HS-GC/MS). The results showed the most abundant components were linalool and linalyl acetate, followed by 1,8-cineole and terpinen-4-ol, while lavandulyl acetate and borneol were identified as minor compounds, maintaining the same proportion in both the liquid and vapour phase. Furthermore, we tested lavandin liquid and vapour phase essential oil on gram-negative bacteria (Escherichia coli, Acinetobacter bohemicus, and Pseudomonas fluorescens) and gram-positive bacteria (Bacillus cereus and Kocuria marina)

    Chemical investigation of a biologically active schinus molle L. leaf extract

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    The pepper tree Schinus molle L. is an evergreen ornamental plant belonging to the Anacardiaceae family, native to South America and widespread throughout the world. It has biological activities and is used in folk medicine. This paper aims to contribute to a deeper knowledge of its chemical composition and biological properties. S. molle leaf extracts were obtained by sequential extraction with solvents of different polarities and subsequently tested on the HL-60 human leukaemia cell line to define a possible cytotoxic activity. Among the investigated extracts, the petroleum ether extract revealed a high cytotoxic activity, and its chemical composition was further investigated. By a silica column chromatography, eight fractions were obtained, and their compositions were determined by GC-MS analysis. Compounds and relative abundance differed widely among the fractions; sesquiterpenes resulted the main component and alcoholic sesquiterpenes the most abundant

    NEOWISE observations of comet C/2013 A1 (Siding Spring) as it approaches Mars

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    The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission observed comet C/2013 A1 (Siding Spring) three times at 3.4 {\mu}m and 4.6 {\mu}m as the comet approached Mars in 2014. The comet is an extremely interesting target since its close approach to Mars in late 2014 will be observed by various spacecraft in-situ. The observations were taken in 2014 Jan., Jul. and Sep. when the comet was at heliocentric distances of 3.82 AU, 1.88 AU, and 1.48 AU. The level of activity increased significantly between the Jan. and Jul. visits but then decreased by the time of the observations in Sep., approximately 4 weeks prior to its close approach to Mars. In this work we calculate Af\r{ho} values, and CO/CO2 production rates.Comment: 9 pages, 3 figures, accepted by Astrophysical Journal Letter

    The INGV tectonomagnetic network: 2004?2005 preliminary dataset analysis

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    International audienceIt is well established that earthquakes and volcanic eruption can produce small variations in the local geomagnetic field. The Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV) tectonomagnetic network was installed in Central Italy since 1989 to investigate possible effects on the local geomagnetic field related to earthquakes occurrences. At the present time, total geomagnetic field intensity data are collected in four stations using proton precession magnetometers. We report the complete dataset for the period of years 2004?2005. The data of each station are differentiated respect to the data of the other stations in order to detect local field anomalies removing the contributions from the other sources, external and internal to the Earth. Unfortunately, no correlation between geomagnetic anomalies and the local seismic activity, recorded in Central Italy by the INGV Italian Seismic National Network, was found in this period. Some deceptive structures present in the differentiated data are pointed out

    Demonstrating that Medical Devices Satisfy User Related Safety Requirements

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    One way of contributing to a demonstration that a medical device is acceptably safe is to show that the device satisfies a set of requirements known to mitigate hazards. This paper describes experience using formal techniques to model an IV infusion device and to prove that the modelled device captures a set of requirements. The requirements chosen for the study are based on a draft proposal developed by the US Food and Drug Administration (FDA). A major contributor to device related errors are (user) interaction errors. For this reason the chosen models and requirements focus on user interface related issues.FEDER - Federación Española de Enfermedades Raras(000062)This work has been funded by the EPSRC research grant EP/G059063/1: CHI+MED (Computer–Human Interaction for Medical Devices). J. C. Campos was funded by project NORTE-07-0124-FEDER-00006

    The INGV tectonomagnetic network: 2004-2005 preliminary dataset analysis

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    It is well established that earthquakes and volcanic eruption can produce small variations in the local geomagnetic field. The Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV) tectonomagnetic network was installed in Central Italy since 1989 to investigate possible effects on the local geomagnetic field related to earthquakes occurrences. At the present time, total geomagnetic field intensity data are collected in four stations using proton precession magnetometers. We report the complete dataset for the period of years 2004-2005. The data of each station are differentiated respect to the data of the other stations in order to detect local field anomalies removing the contributions from the other sources, external and internal to the Earth. Unfortunately, no correlation between geomagnetic anomalies and the local seismic activity, recorded in Central Italy by the INGV Italian Seismic National Network, was found in this period. Some deceptive structures present in the differentiated data are pointed out

    Variability Flagging in the Wide-field Infrared Survey Explorer Preliminary Data Release

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    The Wide-field Infrared Survey Explorer Preliminary Data Release Source Catalog contains over 257 million objects. We describe the method used to flag variable source candidates in the Catalog. Using a method based on the chi-square of single-exposure flux measurements, we generated a variability flag for each object, and have identified almost 460,000 candidate sources that exhibit significant flux variability with greater than ~7σ confidence. We discuss the flagging method in detail and describe its benefits and limitations. We also present results from the flagging method, including example light curves of several types of variable sources including Algol-type eclipsing binaries, RR Lyr, W UMa, and a blazar candidate

    Prediction of hearing recovery in sudden deafness treated with intratympanic steroids

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    The present study aims to obtain a probability model allowing the prediction of the auditory recovery in patients affected by sudden sensorineural hearing loss treated exclusively with intratympanic steroids. A monocentric retrospective chart review of three-hundred eighty-one patients has been performed. A Probit model was used to investigate the correlation between the success of the treatment (marked or total recovery according to Furuashi's criteria), and the delay between the onset of disease and the beginning of therapy. The age of the patients and the audiometric curve shapes were included in the analysis. Results show that delay is negatively correlated with the variable success. Considering the entire sample, each day of delay decreases by 3% the probability of success. The prediction model shows that for every day that passes from the onset of the disease the probability of success declines in absence of the medical treatment, hence we conclude that early treatment is strongly recommended

    Using PVS to support the analysis of distributed cognition systems

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    The rigorous analysis of socio-technical systems is challenging, because people are inherent parts of the system, together with devices and artefacts. In this paper, we report on the use of PVS as a way of analysing such systems in terms of distributed cognition. Distributed cognition is a conceptual framework that allows us to derive insights about plausible user trajectories in socio-technical systems by exploring what information in the environment provides resources for user action, but its application has traditionally required substantial craft skill. DiCoT adds structure and method to the analysis of socio-technical systems from a distributed cognition perspective. In this work, we demonstrate how PVS can be used with DiCoT to conduct a systematic analysis. We illustrate how a relatively simple use of PVS can help a field researcher to (i) externalise assumptions and facts, (ii) verify the consistency of the logical argument framed in the descriptions, (iii) help uncover latent situations that may warrant further investigation, and (iv) verify conjectures about potential hazards linked to the observed use of information resources. Evidence is also provided that formal methods and empirical studies are not alternative approaches for studying a socio-technical system, but that they can complement and refine each other. The combined use of PVS and DiCoT is illustrated through a case study concerning a real-world emergency medical dispatch system
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