Search results for "Environment"

Preliminary analysis of CH3D from 3250 to 3700 cm(-1)

2006

International audience; The infrared spectrum of CH3D from 3250 to 3700 cm(-1) was studied for the first time to assign transitions involving the nu(2) + nu(3), nu(2) + nu(5), nu(2) + nu(6), nu(3) + 2(nu 6) and 3 nu(6) vibrational states. Line positions and intensities were measured at 0.011 cm(-1) resolution using Fourier transform spectra recorded at Kitt Peak with isotopically enriched samples. Some 2852 line positions (involving over 900 upper state levels) and 874 line intensities were reproduced with RMS values of 0.0009 cm(-1) and 4.6%, respectively. The strongest bands were found to be nu(2) + nu(3) at 3499.7 cm(-1) and nu(2) + nu(6) at 3342.5 cm(-1) with integrated strengths, respe…

Liquid Phase Micro-Extraction of Linear Alkylbenzene Sulfonate Anionic Surfactants in Aqueous Samples

2011

Hollow fiber liquid phase micro-extraction (LPME) of linear alkylbenzene sulfonates (LAS) from aqueous samples was studied. Ion pair extraction of C10, C11, C12 and C13 homologues was facilitated with trihexylamine as ion-pairing agent, using di-n-hexylether as solvent for the supported liquid membrane (SLM). Effects of extraction time, acceptor buffer concentration, stirring speed, sample volume, NaCl and humic acids were studied. At 10–50 µg L−1 linear R2-coefficients were 0.99 for C10 and C11 and 0.96 for C12. RSD was typically ~15%. Three observations were especially made. Firstly, LPME for these analytes was unusually slow with maximum enrichment observed after 15–24 h (depending on sa…

Professional communicative repertoires and trajectories of socialization into global working life

2013

Zīmju un verbālās valodas bilingvālā mācību metode bērniem ar dzirdes traucējumiem

2013

Elektroniskā versija nesatur pielikumus

Comunicación y lingüística: metodología de análisis redaccional en perspectiva ética

2020

El objetivo de este artículo es presentar un modelo de análisis de redacción periodística o publicitaria, tomando en cuenta cuatro elementos lingüísticos: sintaxis, semántica, ortografía y morfología, con una mirada ética. La fundamentación parte de lo que denomino la "ética de la palabra", que no es de aplicación exclusiva en el periodismo o en la lingüística; es transversal. Los periodistas han de poner especial cuidado en el lenguaje de manera que en la pretensión de información no caigan en el vicio de la desinformación. Por la vía de la hermenéutica crítica, se toma la metodología de análisis lingüística para arroparlo con una orientación ética, bien por la búsqueda de la excelencia de…

Blue-copper binding proteins of Medicago truncatula: Characterization of the expression of two genes related to the arbuscular mycorrhizal symbiosis

2009

International audience; Expression profiling of two paralogous arbuscular mycorrhizal (AM)-specific blue copper-binding gene (MtBcpla and MtBcp1b) isoforms was performed by real-time quantitative polymerase chain reaction in wild-type Medicago truncatula Jemalong 5 (J5) during the mycorrhizal development with Glomus intraradices for up to 7 weeks. Timecourse analysis in J5 showed that expression of both MtBcp1 genes increased continuously and correlated strongly with the colonization intensity and arbuscule content. MtPT4, selected as a reference gene of the functional plant-fungus association, showed a weaker correlation to mycorrhizal development. In a second experiment, a range of mycorr…

A multiresidue analytical method for trace level determination of antibiotics and antiretroviral drugs in wastewater and surface water using SPE-LC-M…

2016

An analytical method for simultaneous determination of seven commonly used antibiotics and three antiretrovirals in surface water and urban wastewater at the ng L−1 level has been developed. The method involves concentration and clean-up by solid phase extraction (SPE) followed by identification and quantification by liquid chromatography tandem mass spectrometry (LC-ESI-MS/MS). The use of matrix-matched calibration curves constructed by spiking surface water was evaluated for quantification and compared with the internal standard method using isotopically labelled compounds. The method gave absolute recoveries of 41–116% with most of the compounds having recoveries >50%. The LOQs ranged fr…

Liquid membranes as a sample preparation method in environmental analysis

2014

Because of the complexity of environmental matrices, there is a great need of application efficient sample preparation procedures for environmental analysis. One of such possibilities is using, during sample-pretreatment step, the membrane extraction (ME) methods. They include, for instance, a three-phase extraction system named supported liquid membranes that has been used in recent years many times for isolation and preconcentration of various analytes from complex sample matrices. The examples of application the commonly used types of SLMs, hollow fiber supported liquid membrane and flat sheet supported liquid membrane, are listed and described. Additionally, the area of membrane extract…

Evidence of autoinduction heterogeneity via expression of the agr system of listeria monocytogenes at the single-cell level

2011

ABSTRACT To investigate if the primary function of the Agr system of Listeria monocytogenes is to monitor cell density, we followed Agr expression in batch cultures, in which the autoinducer concentration was uniform, and in biofilms. Expression was heterogeneous, suggesting that the primary function of Agr is not to monitor population density.

Changes in gene expression during adaptation of Listeria monocytogenes to the soil environment

2011

project SEST 009; International audience; Listeria monocytogenes is a ubiquitous opportunistic pathogen responsible for listeriosis. In order to study the processes underlying its ability to adapt to the soil environment, whole-genome arrays were used to analyse transcriptome modifications 15 minutes, 30 minutes and 18 h after inoculation of L. monocytogenes EGD-e in soil extracts. Growth was observed within the first day of incubation and large numbers were still detected in soil extract and soil microcosms one year after the start of the experiment. Major transcriptional reprofiling was observed. Nutrient acquisition mechanisms (phosphoenolpyruvate-dependent phosphotransferase systems and…