Identification of Agrobacterium vitis as a causal agent of grapevine crown gall in Serbia

In 2010, a serious outbreak of crown gall disease was observed on grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) in several commercial vineyards located in the Vojvodina province, Serbia. Bacteria were isolated from the young tumor tissue on nonselective YMA medium and five representative strains were selected for further identification. Tumorigenic (Ti) plasmid was detected in all strains by PCR using primers designed to amplify the virC pathogenicity gene, producing a 414-bp PCR product. The strains were identified as Agrobacterium vitis using differential physiological and biochemical tests, and a multiplex PCR assay targeting 23S rRNA gene sequences. In the pathogenicity assay, all strains induced characteristic symptoms on inoculated tomato and grapevine plants. They were less virulent on tomato plants in comparison to the reference strains of A. tumefaciens and A. vitis. [Ministarstva nauke Republike Srbije, br. III46008: Development of integrated management of harmful organisms in plant production in order to overcome resistance and to improve food quality and safety

Determination of nickel, cobalt and chromium in a soda-lime glass by using LIBS based on pulses IR laser

This work presents a study of the applicability of laser-induced breakdown spectroscopy (LIBS), based on Infrared Transversally Excited Atmospheric CO2 pulsed laser (TEA CO2), to determine nickel, cobalt, and chromium in a window glass samples. Estimated limits of detection (LODs) for Ni, Co, and Cr, were 2.1, 3.2, and 0.4 ppm, respectively. In addition, two main plasma parameters, electron number density and temperature, were determined to characterize the laser-induced plasma. The electron number density (Ne) was determined from the measured Stark width of the Al I 396.15 nm line, and the intensity ratio of two atomic iron lines (342.71 nm and 344.06 nm) was used to determine the excitation temperature (Texc). The obtained values were Ne= 8.3·1016 cm-3 and Texc= 7700 K.The book of abstracts available at: [http://www.socphyschemserb.org/media/physical-chemistry-2022/abstracts.pdf

A near-infrared spectroscopy study on thermal transitions of PMMA and PMMA/SiO2 nanocomposites

In this work infrared spectroscopy in the near infrared (NIR) range is used to study the dynamics of polymethylmethacrylate (PMMA) as a pure polymer and when it is modified with silica nanoparticles. Different ways of analyzing FT-NIR spectra were explored taking the temperature as the variable of the systems: i) bands shifts in terms of the first moment of the wavenumber; ii) bands shifts in terms of an absorbance ratio method and iii) absorbance variations in terms of the integrated absorbance. The spectroscopic analysis allowed to study thermal transitions in PMMA and PMMA based nanocomposites. In particular the method based on the use of an absorbance ratio is the most sensible to analyze the thermal transitions. All bands considered could be used to detect thermal transitions reflecting how the vibrations of the groups CH2; CH3 and C¼O are affected by changes in the free volume of the PMMA. It seems that the PMMA dynamics is more driven by the lateral groups than the backbone of the polymer. The presence of silica nanoparticles, at least when 1% by weight is used, restrains the PMMA motion increasing the relaxation temperatures that can be associated with the glass transitions

Relationships among hygiene indicators in take-away foodservice establishments and the impact of climatic conditions

AimsThis paper examined the relationships among hygiene indicators in take-away foodservice establishments and the impact of climatic conditions. Methods and ResultsA total of 7545 samples were collected encompassing 2050 from food handlers' (HF) hands, 3991 from stainless steel food contact surfaces (FCS) and 1504 samples from plastic FCS. The study covered a period of 43months. Hygiene-indicator bacteria (total plate count, Enterobacteriaceae Staphylococcus) were determined from the samples collected from 559 different take-away establishments. Climatic conditions were evaluated in respect to the outside temperature, pressure, humidity and precipitation. Logistic regression confirmed that the presence of precipitation was associated with an increased likelihood of exhibiting both Enterobacteriaceae and Staphylococcus on HF' hands as well as exhibiting Enterobacteriaceae on both types of FCS. Numerable Enterobacteriaceae and Staphylococcus levels on HF' hands were detected when higher outside temperatures and higher precipitations occurred. Higher outside temperatures were observed when Enterobacteriaceae were detected on both plastics (P lt 005) and stainless steel (P>005). Higher precipitation was observed when Enterobacteriaceae was detected on stainless steel while in contrast, this indicator was detected on plastics in periods with lower precipitation. ConclusionsThis research confirms relationships between hygiene indicators in take-aways and climatic conditions, mostly temperature and precipitation. Significance and Impact of the StudyThis study provides another perspective into the possible nature of cross-contamination and foodborne outbreaks originating in foodservice establishments and brings to attention the necessity of analysing various climatic conditions

Durum wheat-Thinopyrum ponticum recombinant lines: a tool to finely describe homoeologous 7L arm regions.

As one important result of wheat chromosome engineering, creation of arrays of wheat-alien recombinant chromosomes allows assignment of markers and genes to defined physical locations, hence improving knowledge of structural-functional organization of wheat and alien chromosomal regions and to identify suitable markers for MAS of target genes. Regions involved in our research are the distal portions of wheat 7AL and Thinopyrum ponticum (tall wheatgrass, a wild wheat relative) 7AgL arms, the latter containing several genes of value for wheat improvement

Environmental geochemistry of the polymetallic ore deposits: Case studies from the Rude and the Sv. Jakob historical mining sites, NW Croatia

This paper presents the results of the sampling surveys carried out in order to evaluate the environmental impact of the Rude and the Sv. Jakob historical mining sites, NW Croatia. The studied polymetallic ore deposits are differing in the mineralogical and geochemical features as well as in the host rock lithology. The Rude Fe-Cu-Pb-Zn-Ba deposit is hosted by Permian siliciclastic sediments. Siderite, hematite, galena, sphalerite, chalcopyrite, pyrite, barite and gypsum are the major ore minerals, whereas quartz is the principal gangue mineral. The Sv. Jakob Pb-Zn-Ag deposit occurs in the Middle Triassic dolostone. The most abundant ore minerals are galena, sphalerite and pyrite. Calcite and quartz represent the principal gangue minerals. Although the deposits represent the potential sources of numerous toxic metals, the pollution of the drainage streams and associated stream sediments was not recorded. The studied mining sites are characterized by the high carbonate/sulfide ratios responsible for the alkaline character of the drainage streams. Consequently, the mining sites have very low potential for generation of acid mine drainage as well as very low potential for leaching of heavy metals into the drainage systems. Furthermore, the presented study revealed that the populated areas (stream waters with decreased redox potential, increased organic matter content, high NO3-, NH4+ and PO43- concentrations; stream sediments enriched in exchangeable Pb and Zn) and the Sava river alluvium (overflowing streams enriched in Hg) represent bigger environmental threat than the investigated polymetallic ore deposits. </span

Stipetum novakii ass. nova – a new association of serpentine rocky grassland vegetation (Halacsyetalia sendtneri) in Serbia

Phytosociological characteristics of grassland communities above serpentines (order Halacsyetalia sendtneri H. Ritter-Studni~ka 1970) in Serbia, are analyzed according to Braun-Blanquet methodology. In order to detect the basic floristic differentiation of analyzed communities ordinary correspondence analysiswas applied. Cluster analysis was also performed to see the structure and separation of the communities based on the floristic composition. In order to determine diagnostic species, fidelity indices with presence/ absence data and the size of all groups standardized to equal size were calculated. The new association Stipetum novakii is described in open rocky serpentine grasslands in Brdjani Gorge

The use of nanoparticles to improve the analytical capabilities of LIBS for solution sample analysis

Laser-induced breakdown spectroscopy (LIBS) is a diagnostic technique based on optical emission spectroscopy, suitable for rapid, in situ, and multi-element analysis of all sample types. LIBS has demonstrated its greatest potential in the analysis of solids, both conducting and nonconducting. However, when it comes to quantitative LIBS analysis of liquids, there are still some drawbacks that limit its applicability, such as poor repeatability and low sensitivity. To some extent LIBS performance may be improved if directly performing LIBS on the solution is avoided by converting the liquid into a solid phase. Another recently proposed method to resolve the difficulties in LIBS analysis of liquid samples is the application of Nanoparticle - Enhanced LIBS (NELIBS) [1,2]. The aim of the present work was to examine the effect of copper oxide nanoparticles (NPs) on the analytical capabilities of LIBS analysis of lead in aqueous solutions. The apparatus for NELIBS experiments comprises a laser source, a spectrograph (F=850 mm, grating 1800 groves/mm, F/11) coupled with a CCD, and the focusing and collecting optics, i.e. the same as used in conventional LIBS. A double pulse Q-switched Nd:YAG laser at 1064 nm, pulse duration 10 ns, pulse energy 50 mJ, interpulse delay 1 μs was used. The spectra were registered in a time-integrated mode (integration time 1 ms). A glass plate was chosen as the substrate to ensure there is no interference between NPs and the substrate. The first type of samples was prepared by drying a droplet of a Pb solution (10 μl, concentration 100 ppm) on the glass substrate. The second type was prepared by drying a droplet of the copper oxide colloidal solution on the glass, prior to the deposition of the analyte solution. Three sets of the LIBS spectra were acquired; spectra of glass with deposited CuO NPs, of glass with deposited sample solution of Pb, and of the glass with deposited NPs of CuO and the sample solution of Pb. The spectra were obtained in the 395-415 nm spectral range. Only in the third case, intense Pb lines appeared in the spectrum. Estimation of the limit of detection (LOD) for the resonance Pb line at 405.78 nm, without additional optimization of the measurement parameters, gave a value of 3.6 ppm. Regarding the fact that without the addition of the NPs layer no analyte signal was obtained, it can be concluded that the enhancement of the lead emission line intensity is caused by the presence of the NPs, i.e. by the lower plasma formation threshold and more efficient atomization of the analyte deposited on the NP layer. The main benefits of using NELIBS for the analysis of solutions lie in its simplicity, speed, the small amount of solution needed (few microliters), and the ability to analyze very dense or slurry samples.VII International School and Conference on Photonics : PHOTONICA2019 : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 26-30; Belgrad