1,104 research outputs found
Liquid and vapour phase of lavandin (Lavandula × intermedia) essential oil: chemical composition and antimicrobial activity
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
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
Prediction of hearing recovery in sudden deafness treated with intratympanic steroids
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
The Internationalization of Mexican Fisheries Companies and the Rise of Theire Exports to the Italian Market
Opening up trade under the guidelines of trade agreements is presented as an area of opportunity for Mexico to diversify markets.Reality demonstrates that U.S. and Mexico hold a large concentration of commercial transactions. In the case of fishery products, the European Union, particularly the Italian market is presented as a great potential to achieve this market diversification. Therefore, in this research the characteristics of the European market are analyzed. Their purchasing power and the advantages and disadvantages for Mexican exports, particularly those derived from fishery products.Keywords. Trade Agreements, International Business, EU, Markets.JEL. F13, F23, F15, D47
The Population of Tiny Near-Earth Objects Observed by NEOWISE
Only a very small fraction of the asteroid population at size scales
comparable to the object that exploded over Chelyabinsk, Russia has been
discovered to date, and physical properties are poorly characterized. We
present previously unreported detections of 106 close approaching near-Earth
objects (NEOs) by the Wide-field Infrared Survey Explorer mission's NEOWISE
project. These infrared observations constrain physical properties such as
diameter and albedo for these objects, many of which are found to be smaller
than 100 m. Because these objects are intrinsically faint, they were detected
by WISE during very close approaches to the Earth, often at large apparent
on-sky velocities. We observe a trend of increasing albedo with decreasing
size, but as this sample of NEOs was discovered by visible light surveys, it is
likely that selection biases against finding small, dark NEOs influence this
finding.Comment: Accepted to Ap
An improved ontological representation of dendritic cells as a paradigm for all cell types
The Cell Ontology (CL) is designed to provide a standardized representation of cell types for data annotation. Currently, the CL employs multiple is_a relations, defining cell types in terms of histological, functional, and lineage properties, and the majority of definitions are written with sufficient generality to hold across multiple species. This approach limits the CL’s utility for cross-species data integration. To address this problem, we developed a method for the ontological representation of cells and applied this method to develop a dendritic cell ontology (DC-CL). DC-CL subtypes are delineated on the basis of surface protein expression, systematically including both species-general and species-specific types and optimizing DC-CL for the analysis of flow cytometry data. This approach brings benefits in the form of increased accuracy, support for reasoning, and interoperability with other ontology resources.
104. Barry Smith, “Toward a Realistic Science of Environments”, Ecological Psychology, 2009, 21 (2), April-June, 121-130.
Abstract: The perceptual psychologist J. J. Gibson embraces a radically externalistic view of mind and action. We have, for Gibson, not a Cartesian mind or soul, with its interior theater of contents and the consequent problem of explaining how this mind or soul and its psychological environment can succeed in grasping physical objects external to itself. Rather, we have a perceiving, acting organism, whose perceptions and actions are always already tuned to the parts and moments, the things and surfaces, of its external environment. We describe how on this basis Gibson sought to develop a realist science of environments which will be ‘consistent with physics, mechanics, optics, acoustics, and chemistry’
Evaluation of formal IDEs for human-machine interface design and analysis: the case of CIRCUS and PVSio-web
Critical human-machine interfaces are present in many systems including avionics systems and medical devices. Use error is a concern in these systems both in terms of hardware panels and input devices, and the software that drives the interfaces. Guaranteeing safe usability, in terms of buttons, knobs and displays is now a key element in the overall safety of the system. New integrated development environments (IDEs) based on formal methods technologies have been developed by the research community to support the design and analysis of high-confidence human-machine interfaces. To date, little work has focused on the comparison of these particular types of formal IDEs. This paper compares and evaluates two state-of-the-art toolkits: CIRCUS, a model-based development and analysis tool based on Petri net extensions, and PVSio-web, a prototyping toolkit based on the PVS theorem proving system.This work is partially supported by: Project NORTE-01-0145-FEDER-000016, financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) PhD scholarship
The bumpy light curve of supernova iPTF13z
A Type IIn supernova (SN) is dominated by the interaction of SN ejecta with
the circumstellar medium (CSM). Some SNe IIn (e.g., SN 2006jd) have episodes of
re-brightening ("bumps") in their light curves. We present iPTF13z, a SN IIn
discovered by the intermediate Palomar Transient Factory (iPTF) and
characterised by several bumps in its light curve. We analyse this peculiar
behaviour trying to infer the properties of the CSM and of the SN explosion, as
well as the nature of its progenitor star. We obtained multi-band optical
photometry for over 1000 days after discovery with the P48 and P60 telescopes
at Palomar Observatory. We obtained low-resolution optical spectra in the same
period. We did an archival search for progenitor outbursts. We analyse our
photometry and spectra, and compare iPTF13z to other SNe IIn. A simple
analytical model is used to estimate properties of the CSM. iPTF13z was a SN
IIn showing a light curve with five bumps during its decline phase. The bumps
had amplitudes between 0.4 and 0.9 mag and durations between 20 and 120 days.
The most prominent bumps appeared in all our different optical bands. The
spectra showed typical SN IIn characteristics, with emission lines of H
(with broad component FWHM ~ and narrow
component FWHM ~) and He I, but also with Fe II, Ca II,
Na I D and H P-Cygni profiles (with velocities of ~ ). A pre-explosion outburst was identified lasting days,
with mag around 210 days before discovery. Large, variable
progenitor mass-loss rates (~> 0.01 ) and CSM densities
(~> 10 g cm) are derived. We suggest that the light curve bumps
of iPTF13z arose from SN ejecta interacting with denser regions in the CSM,
possibly produced by the eruptions of a luminous blue variable star.Comment: Version 2: Update to match published paper. 21 pages, 14 figures,
abstract abridged to comply with arXiv length limit. In version 1 of the
paper on arXiv, Table 3 had some erroneous entries. Table 3 is now corrected
and available via VizieR. Version 1 comment: Accepted for publication in
Astronomy & Astrophysics (24 pages, 14 figures, abstract abridged by 20 % not
to exceed the arXiv length limit
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