Arbuscular mycorrhizal fungi alter Hg root uptake and ligand environment as studied by X-ray absorption fine structureAlojz Kodre
, Iztok Arčon
, Marta Debeljak
, Mateja Potisek
, Matevž Likar
, Katarina Vogel-Mikuš
, 2017, izvirni znanstveni članek
Opis: Mercury (Hg) – plant – fungal interactions are only poorly studied. Hg speciation and ligand environment
in maize roots inoculated with arbuscular mycorrhizal (AM) fungi were investigated in order to better
understand the role of AM in Hg soil to root transfer.
The maize plants were grown in Hg polluted substrate (50 mg g1 as dissolved HgCl2) and inoculated
with AM fungi originating from: a) highly Hg polluted environment of a former Hg smelting site in Idrija,
Slovenia, (Glomus sp. – sample AmI), and b) non-polluted environment (commercial AM inoculum
Symbivit1 – sample AmC). Hg speciation and ligand environment in maize roots was studied by Hg-L3
XANES and EXAFS with emphasis on XAS methodology – modelling and fitting the XAFS spectra to extract in a reliable way as much information on Hg coordination as possible. The AmI plants developed more arbuscules and less vesicles than the AmC plants, and also
accumulated more Hg in the roots. A clear difference in Hg coordination between the AM (AmC & AmI)
and the control (ConC & ConI) plants is recognized in Hg L3-edge EXAFS analysis: in the ConC & ConI
maize roots 73–80% of Hg is attached between two sulphur atoms at the distance of 2.34 Å. The remaining
ligand is nitrogen at 2.04 Å. In AmI & AmC roots another Hg-S attachment encompassing four thiol groups
at the S-distance of 2.50 Å are identified, accounting for 21–26%. AM fungi can modify Hg ligand environment in plant roots, thus playing an important role in biogeochemical cycling of Hg in terrestrial
Najdeno v: ključnih besedah
Ključne besede: EXAFS
Objavljeno: 27.09.2016; Ogledov: 1355; Prenosov: 0
Polno besedilo (1,82 MB)
Heavy metal analysis with in-situ prepared copper film electrode as a tool for environmental monitoringNana Ivana Hrastnik
, 2017, magistrsko delo
Opis: Monitoring and measuring heavy metals in the environment is of great importance and requires sensitive and reliable analytical techniques capable of detecting trace level concentrations.
Nowadays, measurements of heavy metals are usually performed using sophisticated and expensive instrumental techniques, such as atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES) etc. In this aspect, advanced electroanalytical (stripping) techniques represent a favourable alternative, facilitating sensitive and selective measurements of various analytes using relatively simple, portable and non-expensive instrumentation.
This work is an investigation of novel copper-based electrodes for measuring trace levels of selected heavy metal ions, i.e. mercury(II), lead(II), tin(IV) and nickel(II).
The methods of choice were anodic stripping voltammetry (ASV) in combination with the in-situ prepared copper film electrode (CuFE) for measuring low concentrations of mercury(II) and lead(II) (simultaneously) and tin(IV) in the test solutions and adsorptive cathodic stripping voltammetry (AdCSV) for determination of nickel(II).
Metal-film electrodes are regularly employed in electrochemical stripping analysis due to their simple fabrication and surface regeneration. The newly developed CuFE appears to be a cheaper alternative to gold-based electrodes with several attractive electroanalytical characteristics, i.e. with low limits of detection (LOD), good repeatability and favourable linear response.
Najdeno v: ključnih besedah
Ključne besede: Copper film electrode, anodic stripping voltammetry, adsorptive cathodic stripping voltammetry, heavy metals, environment.
Objavljeno: 12.09.2017; Ogledov: 644; Prenosov: 43
Polno besedilo (1,78 MB)
W OMEN W RITERS D ATABASE AND VIRTUAL RESEARCH ENVIRONMENT BEYOND THE CURRICULA OF LITERARY SCHOLARSHIPNarvika Bovcon
, Aleš Vaupotič
, 2017, objavljeni povzetek znanstvenega prispevka na konferenci
Opis: The study of informatics typically includes information visualization and the rhetoric of user
interface. Such courses are expanding the core computer science curricula towards multimedia
communication design. However, to practice visualization on datasets in a non-focused way may
diminish the quality of educational effect as well as the quality of the results of students' projects. A
collaboration with domain experts has proven to be very beneficial by involving students in various
research projects and platforms. The students of informatics at the Faculty of Computer and
Information Science, University of Ljubljana, have touched upon humanities projects in different
special domains: the datasets provided by Institute of Contemporary History (INZ, Ljubljana),
interface design for electronic scholarly editions based on TEI XML files, documentation of new
media art exhibitions, and others. As noted by some contributors in A New Companion to Digital
Humanities (2016) with relevance to the latter aspect of interdisciplinary contact, the domain of new
media art constitutes an essential inspiration for the study of digital humanities methods and
approaches. In the second part of the paper, the multi-year collaboration between the University of
Nova Gorica and University of Ljubljana computer-science curricula will be presented. The
WomenWriters database, as well as subsequently the NEWW VRE, has been used in different models
of interdisciplinary collaboration.
Najdeno v: ključnih besedah
Ključne besede: virtual research environment, WomenWriters database, interdisciplinary collaboration, digital humanities, information visualization
Objavljeno: 05.03.2018; Ogledov: 282; Prenosov: 0
Polno besedilo (7,39 MB)
DISTRIBUTION OF ENTERIC VIRUSES IN THE GULF OF TRIESTE AND THEIR INTERACTIONS WITH ENVIRONMENTAL AND BIOLOGICAL PARAMETERSJosé Manuel Carita Gonçalves
, 2018, doktorska disertacija
Opis: The available classical diagnostic methods, due to many disadvantages, do not allow effective detection of pathogenic enteric viruses in environmental samples. Due to low concentrations of pathogenic viruses in the sea, it is important to develop an effective concentration procedure for their successful detection.
In the first part of the doctoral thesis, we focused primarily on the development of a protocol for an effective concentration of pathogenic enteric viruses in coastal water samples. Monolithic chromatographic columns (BIAseparations) were used for the concentration of rotaviruses and noroviruses, prior to the detection with reverse transcription quantitative PCR in real time (RT-qPCR). We tested the efficiency of concentration using columns of various chemical properties and selected pathogenic enteric viruses (rotavirus and norovirus). Among them, hydrophobic interaction monolithic column (CIM® C4) was the most effective. CIM C4 was used to optimize the concentration step and tested in waters with different salinities.
The presence of concentrated viruses was confirmed by RT-qPCR and transmission electron microscope. We have developed a protocol that enables rapid concentration of viruses in coastal waters of various salinities and can be used on-site.
The presence of RoV and NoV was surveyed, using the developed concentration protocol, prior to one-step RT-qPCR molecular detection, in the inner part of the Bay of Koper, in mussel farming areas and a swimming area. Rotaviruses, noroviruses and fecal indicator bacteria were frequently detected in the inner part of the Bay of Koper.
Rotaviruses and noroviruses were detected in the studied area, with higher rates close to the outfall of the wastewater treatment plant in the estuary of river Rižana and were also detected in the middle of the Bay of Koper and in areas used for recreation and mussel farming.
The results show that water bodies, which are otherwise defined as suitable for bathing or mussel farming, based on the results of fecal indicator bacteria, still contain low concentrations of pathogenic enteric viruses.
In addition to human pathogenic enteric viruses and faecal coliforms, changes in abundance of bacteria and virus particles were studied in relation to temperature, salinity, inorganic and organic nutrient concentrations in the organically polluted Rižana estuary. Preliminary results showed spatially and seasonally changes in bacterial and viral particles abundance, and bacterial composition spatially and seasonally. However, seasonality plays a greater role in bacterial dynamics.
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Ključne besede: Concentration of viruses, Enteric viruses, Rotavirus, Norovirus, Feacal coliforms, Feacal contamination, qPCR, RT-qPCR, Monolithic columns, Sewage, Seasonal dynamics, Concentration, Coastal environment, Gulf of Trieste
Objavljeno: 02.07.2018; Ogledov: 110; Prenosov: 25
Polno besedilo (1,95 MB)