40 research outputs found

    Optical particle counter data collected in two inhabited sites close to an industrial hot spot during a three months survey

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    Data on this paper describe the monitoring of different size ranges of particulate matter on dwellings positioned close to an integral cycle steel plant. Data were collected by eight channel (PM0.3, PM0.5, PM0.7, PM1, PM2, PM3, PM5, PM10) optical particle counters positioned in two sites. The data were recorded as counts-per-minute for every size channel in a three months survey from June to September 2015. Basic statistical elaboration and boxplot graphs as well as raw data are included

    CyPLOS: a new family of synthetic ionophores

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    The ion transport properties of a new family of synthetic ionophores based on cyclic phosphate-linked oligosaccharide (CyPLOS) macrocycles are described

    Self-organizing map algorithm as a tool for analysis, visualization and interpretation of electronic nose high dimensional raw data

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    Electronic noses used for outdoor ambient air characterization to assess odor impacts on population can produce large datasets since usually the sampling is conducted with high frequency (e.g. data per minute) for periods that can reach several months, with a number of sensors that ranges usually from four-six as a minimum, up to above thirty. The environmental analyst has thus to deal with large datasets (millions of data) that have to be properly elaborated for obtaining meaningful interpretation of the instrumental signals. A recent review questioned the capability of some classic statistical elaboration tools for application to e-noses, highlighting how very few in field application are present in scientific literature. In the present work we describe: (i) the use of Self-Organizing Map (SOM) algorithm as a tool for analysis and visualization of e-nose raw data collected at a receptor site near a bio-waste composting facility; (ii) a second level clusterization using k-means clustering algorithm to identify "air types" that can be detected at the receptor and (iii) the use of e-nose data related to the plant odour sources as well as odour measurements of ambient air collected at the receptor site, to classify the air types. Eventually we evaluate the frequency and duration of the air type/s identified as malodorous

    On odour tolerability criteria from odorant instrumental monitoring

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    At present one of the most accepted criteria for assessing tolerability for environmental odour impacts is based on a modelling approach that requires the characterizations of the odour flow rates from stationary sources, definition of both a digital terrain model of the studied area and of relevant meteorology during the considered period of time, so to provide an estimate of the areas where the number of hours exceeds specified hourly odour threshold (e.g. 1, 3 or 5 OUE). Often the 98th percentile of hourly peak odour concentration is considered at sensible receptors. In the case of complex odour sources or if the emitting entity is not collaborative, the experimental approach focused on receptor instrumental monitoring can provide a tool for the assessment of odour nuisance tolerability, so to foster or to force mitigation actions on odour emission sources. Since nowadays instruments allowing single (e.g. H2S monitoring instruments) or multiple (e.g. e-noses) odorant concentration monitoring are available, and they are often positioned at sensible receptors, experimental measurement of the exceedance of odour threshold can be provided, if consensus odour threshold values for the odorant are available. Also for the experimental approach, the 98th percentile of hourly odour concentration can be provided. A case study based on H2S monitoring is proposed; extension to e-noses application is possible, providing their active and efficient presence in the field 12 months a year

    Testing performances of a newly designed olfactometer

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    Dynamic dilution olfactometry as regulated by EN 13725 requires instrumentation of adequate technology and in order to spread the use of Dynamic Olfactometry high usability of the device is a must. A new dynamic dilution olfactometer has been designed and manufactured after the experience gained in previous prototype development and performance studies as well as from experimental applications. Materials have been selected in order to be compliant with the expected next-to-come updates of the EN13725 technical norm and checks on pneumatic steps required by the odour concentration analysis procedure have been implemented. In order to generate specific dilutions in a wide range, a high precision stepper motor is used, instead of the more common calibrated orifices. The instrument comes with option of incrementing dilution with a factor of 1a2 (instead of more usual 2), so to increase resolution of the odour measurements. The consumption of neutral compressed air has been highly reduced in comparison with previous prototypes. The new features of the instrument as well as the available dilution steps will be presented. A careful check of accuracy and operative speed at high dilutions has been performed. Standard n-butanol, and samples from ambient air collected in close proximity from odour emitting sources have been collected for testing the olfactometer and the panel response. A market top instrument has been considered for sake of comparison

    De novo sequencing and characterization of floral transcriptome in two species of buckwheat (Fagopyrum)

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    <p>Abstract</p> <p>Background</p> <p>Transcriptome sequencing data has become an integral component of modern genetics, genomics and evolutionary biology. However, despite advances in the technologies of DNA sequencing, such data are lacking for many groups of living organisms, in particular, many plant taxa. We present here the results of transcriptome sequencing for two closely related plant species. These species, <it>Fagopyrum esculentum </it>and <it>F. tataricum</it>, belong to the order Caryophyllales - a large group of flowering plants with uncertain evolutionary relationships. <it>F. esculentum </it>(common buckwheat) is also an important food crop. Despite these practical and evolutionary considerations <it>Fagopyrum </it>species have not been the subject of large-scale sequencing projects.</p> <p>Results</p> <p>Normalized cDNA corresponding to genes expressed in flowers and inflorescences of <it>F. esculentum </it>and <it>F. tataricum </it>was sequenced using the 454 pyrosequencing technology. This resulted in 267 (for <it>F. esculentum</it>) and 229 (<it>F. tataricum</it>) thousands of reads with average length of 341-349 nucleotides. <it>De novo </it>assembly of the reads produced about 25 thousands of contigs for each species, with 7.5-8.2× coverage. Comparative analysis of two transcriptomes demonstrated their overall similarity but also revealed genes that are presumably differentially expressed. Among them are retrotransposon genes and genes involved in sugar biosynthesis and metabolism. Thirteen single-copy genes were used for phylogenetic analysis; the resulting trees are largely consistent with those inferred from multigenic plastid datasets. The sister relationships of the Caryophyllales and asterids now gained high support from nuclear gene sequences.</p> <p>Conclusions</p> <p>454 transcriptome sequencing and <it>de novo </it>assembly was performed for two congeneric flowering plant species, <it>F. esculentum </it>and <it>F. tataricum</it>. As a result, a large set of cDNA sequences that represent orthologs of known plant genes as well as potential new genes was generated.</p

    Derivatized volatile organic compound characterization of Friulano wine from Collio (Italy\u2013Slovenia) by HS-SPME-GC-MS and discrimination from other varieties by chemometrics

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    Purpose: Methods to assess the authenticity and traceability of wines have been extensively studied as enhancers of food quality, allowing producers to obtain market recognition and premium prices. Among analytical techniques, the volatilome profile attained by gas chromatography coupled with mass spectrometry is acquiring more and more attention by the scientific community, together with the use of chemometrics Design/methodology/approach: The volatilome profile of three varieties of blanc wines from the Collio area (namely Ribolla Gialla, Malvasia and Friulano) between Italy and Slovenia, was determined by head space-solid phase micro extraction-gas chromatography-mass spectrometry, enhancing the carbonyl compounds identification with O-(2, 3, 4, 5, 6-pentafluorobenzyl)-hydroxylamine with the aim of identifying the autochthonous Friulano variety. Findings: A two-step chemometric approach based on an unsupervised technique (PCA) followed by a supervised one (PLS-DA) allowed to identify possible markers for discriminating the Friulano Collio variety from the others, in particular two chemical classes were identified by PCA (ketones and long chain esters). PLS-DA showed 87% accuracy in classification. A correct classification (i.e. non-Friulano Collio) of a group of wines obtained from the same grape variety but produced in an extra-Collio area was obtained as well. The results confirmed the benefits of using a derivatization step prior to volatile organic compounds analysis. Research limitations/implications: Among methods to assess the authenticity and traceability of wines, volatilome profile of wines determined by head space-solid phase micro extraction-gas chromatography-mass spectrometry, enhanced by the carbonyl compound identifications with O-(2, 3, 4, 5, 6-pentafluorobenzyl)-hydroxylamine, may have a key role in conjunction with chemometrics and, in particular with principal component analysis and partial least square discriminant analysis. Practical implications: Among methods to assess the authenticity and traceability of Friulano wine, volatilome profile of wines determined by head space-solid phase micro extraction-gas chromatography-mass spectrometry, enhanced by the carbonyl compound identifications with O-(2, 3, 4, 5, 6-Pentafluorobenzyl)Hydroxylamine hydrochloride, may have a key role in conjunction with chemometrics. Originality/value: Few works investigated both wine traceability with a volatilome enhancer and chemometrics of the Friulano wine variety obtaining such an improvement in this wine variety discrimination

    Photoisomerizable Guanosine Derivative as a Probe for DNA Base-Pairing in Langmuir Monolayers

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    Mixtures of azo-functionalized amphiphilic derivatives of guanosine and of amphiphilic derivatives of other DNA nucleobases were deposited at an air-water interface and repeatedly irradiated with light of 340 and 440 nm wavelengths. The consequent switching between cis and trans configurations of the azobenzene moiety caused changes in the surface pressure of the film, which were analyzed using a model based on the two-dimensional Van der Waals equation of state. For mixed films of guanosine and cytidine derivatives, the analysis revealed a significant modification of the strength of intermolecular interaction caused by the optical irradiation, while no such modifications were identified in mixed films involving other nucleobases. The difference is attributed to light-induced breaking of the hydrogen bonding that is established only between specific nucleobases. The results demonstrate that photosensitive nucleoside derivatives can be used as an efficient probe for base-pairing in Langmuir monolayers

    SOMEnv: An R package for mining environmental monitoring datasets by Self-Organizing Map and k-means algorithms with a graphical user interface

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    The Self-Organizing Map (SOM) algorithm belongs to the family of artificial neural networks. It is an unsupervised method that requires no a priori knowledge regarding experimental data classification. Further, it can deal with large datasets and non-linear problems, providing powerful visualization features for outcome exploration on 2D maps. For environmental pollution assessments other unsupervised techniques are widely used, such as principal component and hierarchical cluster analyses, but their application for mining large datasets and properly visualizing the results is limited, making them difficult to use for handling of large datasets obtained by high frequency environmental monitoring. This study presents an R package (SOMEnv) that allows non-expert users to elaborate by SOM algorithm environmental variables (pollutants and/or chemical physical properties) recorded with high frequency for a long monitoring period. Additionally, SOMEnv can also be used for elaborating small datasets derived from uneven sampling. All the calculations and outcome visualizations can be done using a graphical user interface (GUI), meaning that experience in R software coding is not necessary, and only a basic knowledge regarding the employed algorithm is needed to interpret the results. The benefits of the SOMEnv package are that (i) both the software environment and tool are freely available; (ii) it is able to handle large datasets; (iii) it provides heuristic rules for SOM initialization; (iv) it has a built-in GUI for performing calculations and visualizing the results. Moreover, it comes with a wide range of visualizations, several of which are dedicated to high frequency data monitoring. An example of application is presented. The package is freely available on the Comprehensive R Archive Network (CRAN) repository
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