Promjenom uvjeta rada prouzročenom zarazom pandemijskih razmjera nametnuta je potreba usklađenja procjene rizika s obzirom na novonastalu situaciju. Razvoj bolesti ovisan je o broju osoba koje se ...istovremeno nalaze na mjestu rada. U tom pogledu najugroženija su ona radna mjesta i poslovi koji su dosadašnjim procjenama rizika svrstani u kategoriju poslova s malim rizikom, ali pojavom koronavirusa razina rizika znatno se povećala uz pojavu bolesti sa smrtnim ishodom. Iz tih razloga nameće se obveza procjenjivanja rizika uredskog poslovanja, naročito u „kontakt-centrima“ gdje se na istom mjestu istodobno nalazi veći broj radnika.
U radu je prikazan metodološki način procjene rizika na primjeru rada „kontakt-centra“ s težištem na biološke štetnosti te plan mjera koji je potrebno provesti kako bi se smanjila razina rizika.
The changed work conditions caused by the world-wide pandemic have brought about the need to review risk assessment in this new situation. The development of illness is directly related to the number of persons occupying the place of work at the same time. In that respect, the jobs that had previously been assessed as low risk have with the onset of the pandemic become much more high risk, often including deaths. For this reason, risk of office work must be reassessed, particularly in contact centres where many workers may occupy the premises at the same time. The paper presents a method for risk assessment on the example of a contact centre, with focus on biological hazard, as well as offering a set of measures to be implemented in order to reduce the risks.
This paper is aimed to characterize young poplar plants under the influence of water stress provoked by polyethileneglycol 6000 (PEG 6000). Three polar genotypes (M1, B229, and PE19/66) were grown in ...hydroponics and subjected to 100 and 200 mOsm PEG 6000 during six days. Polyphenol characterization, two enzymatic markers and antioxidant capacity in leaves and roots were investigated in stressed plants. Total phenol content, ferric reducing antioxidant capacity (FRAP) and DPPH antiradical power (DPPH ARP) were determined for estimating total antioxidant capacity. Polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were determined as enzymatic markers. Polyphenol characterization of poplar samples was performed by HPLC-PDA analysis. All results were subjected to correlation analysis and principal component analysis (PCA). Inspite of the decrease of total phenol content in investigated genotypes, as well as total antioxidant capacity, some of polyphenols were affected by stress like flavonoids chrysin, myricetine, kaempferol and isoferulic acid in roots of B229 genotype (Populus deltoides). Genotype B229 also showed the increase of antioxidant capacity and PAL activity in root and leaves under stress what could be the indicator of the adaptability of poplar plants to water stress. Significant positive correlations were obtained between PAL, antioxidant capacity as well as phenolic acids among themselves. Chemometric evaluation showed close interdependence between flavonoids, FRAP, DPPH antiradical power and both investigated enzymes of polyphenol metabolism, PAL and PPO.
•Water stress in poplar induced by PEG 6000.•Water stress induces changes in polyphenol profile of poplar.•Water stress induces changes in antioxidant capacity of poplar.
Apple hammerhead viroid (AHVd, Pelamoviroid, Avsunviroidae) is one of the five viroids infecting apples. It has been identified on all continents except Australia since its viroid nature was ...confirmed (DiSerio et al. 2018; CABI and EPPO 2022). AHVd has been found in apple trees showing leaf mosaic, ringspot and dieback (Hamdi et al., 2021). Apple (Malus domestica Borkh.) and its wild relatives are traditionally grown in Montenegro. With an annual production of 7767 tons on 216 ha, it is the second most important fruit tree (after plum) in the country (Anonymous 2022). In a 2020-2022 survey, 29 apple trees exhibiting virus-like symptoms (e.g. mosaic, necrosis) were sampled throughout Montenegro, including 16 locations in eight municipalities (Podgorica, Danilovgrad, Niksic, Mojkovac, Bijelo Polje, Berane, Pljevlja and Savnik). Small RNAs were isolated using the mirVana miRNA Isolation Kit (Ambion, Life Technologies) and pooled into three bulk samples. Each bulk contained 9 to 10 samples. Libraries of sRNAs were constructed using the Ion Total RNA-Seq Kit v2 and barcoded using the Xpress RNA-Seq Barcode 1–16 Kit (Ion Torrent) according to the manufacturer's instructions. Small RNA library sequencing was performed on Illumina platform (Novogene Europe) yielding 9.9, 9.8 and 18.6 million reads in the three libraries. The CLC Genomics Workbench software was used to demultiplex the reads into pools using the 'Demultiplex Reads' tool. The online program VirusDetect (Zheng et al. 2017) was used for virus/viroid detection and identification. Besides viruses known to infect apple (apple stem grooving virus, apple stem pitting virus, apple mosaic virus), contigs mapping to AHVd were identified in all three bulks enabling full AHVd genomes reconstruction. To verify AHVd presence, all 29 apple samples were tested by reverse transcription-polymerase chain reaction (RT-PCR) using the AHVd PG13f/PG12r primers (Messmer et al. 2017). AHVd amplicons were obtained in three samples (30/21, 32/21 and 38/21) from bulk 1 and two samples (47/21 and 55/21) from bulk 2, while all samples from bulk 3 tested negative potentially due to the low titer of the pathogen or nucleotide mismatches at the 3’ end of the primers. The three amplicons from bulk 1 were Sanger sequenced and partial AHVd genomes over 200 nts were obtained from two of them (30/21 and 32/21) (GenBank acc. nos. OQ863319 and OR020603). Furthermore, three full consensus AHVd genomes were assembled in Geneious Prime by mapping Sanger sequences onto contigs from Virus Detect and named 30/21, 32/21 and 38/21 (acc. nos. PP133245, -46, and -47, respectively). All three genomes exhibited conserved hammerhead motifs (Messmer et al. 2017). In BLASTn analysis, the isolate 30/21 from Montenegro shared the highest nt identity (98.8%) with the isolate SA-36 (ON564299) from Czechia, while 32/21 and 38/21 showed the highest identities (95.4% and 92.3%) with isolates SD17_2-3 (MK188691) from Canada and JF2 (ON564298) from Czechia, respectively. To the best of our knowledge, this is the first report of AHVd infecting Malus domestica in Montenegro. The AHVd-positive samples 30/21 and 32/21 originated from at least two-decade-old apple trees from Niksic, whilst 38/21 came from a 40-year-old tree from Mojkovac district, suggesting that this viroid has long been present in different parts of the country. The AHVd discovery in Montenegro should be considered in any phytosanitary regulations and pome fruit certification program in the country.
This paper deals with both conditional and regular distributivity between the special class of uni-nullnorms and general uninorms. The presented research is a natural continuation and extension of ...some previous works with a shift in focus from uninorms from the class
to a much wider class of uninorms.
Viroids, the smallest known pathogens, unable to encode any proteins, can cause severe diseases in their host plants. One of the proposed mechanisms of their pathogenicity includes silencing the ...host's genes via viroid-derived small RNAs, which are products of the host's immune response to the viroid's double stranded RNA. Humulus lupulus (hop) plants are hosts to several viroids; two of them, HLVd and CBCVd, are interesting models for studying host-viroid interactions, due to the symptomless infection of the former and severe stunting disease caused by the latter. To study these interactions, we constructed a deep hop NGS transcriptome based on 35 Gb paired-end sequencing data assembled into over 74 Mb of contigs. These transcripts were used for in-silico prediction of target transcripts of vd-sRNA of the two aforementioned viroids, using two different software tools. Prediction models revealed that 1062 and 1387 hop transcripts share nucleotide similarities with HLVd- and CBCVd-derived small RNAs, respectively, so they could be silenced in an RNA interference process. Furthermore, we selected 17 transcripts from 4 groups of targets involved in the metabolism of plant hormones, small RNA biogenesis, transcripts with high complementarity with viroid-derived small RNAs and transcripts targeted by CBCVd-derived small RNAs with high cellular concentrations. Their expression was monitored by reverse transcription quantitative PCR performed using leaf, flower and cone samples. Additionally, the expression of 5 pathogenesis related genes was monitored. Expression analysis confirmed high expression levels of four pathogenesis related genes in leaves of HLVd and CBCVd infected hop plants. Expression fluctuations were observed for the majority of targets, with possible evidence of downregulation of GATA transcription factor by CBCVd- and of linoleate 13S-lipoxygenase by HLVd-derived small RNAs. These results provide a deep transcriptome of hop and the first insights into complex viroid-hop plant interactions.
Toxoplasmosis is one of the most widespread parasitic diseases caused by an obligate intracellular protozoan Toxoplasma gondii. It is estimated that one-third of the human population is infected with ...this parasite. In immunocompetent subjects, the infection is mostly asymptomatic or is presented with flu-like symptoms, but in fetuses and immunocompromised patients, the infection may even be life-threatening. The prevalence of T. gondii infection varies among different countries of the world (0.5 - 87.7%) and within different regions of the same country. In Africa, the prevalence is the highest (20.8 - 87.7%), in Asia is the lowest (0.5 - 82.6%), while in Europe, the prevalence of toxoplasmosis ranges from low in the North to moderate in the South of the continent (8.2% - 59.0%). The worldwide decline in the prevalence of T. gondii infection has been sustained over the past few decades. In Serbia, the prevalence of toxoplasmosis tended to increase from the 1960s to the 1980s followed by a dramatic decline after that period, as in the entire Europe. The most prominent decline in the prevalence of T. gondii infection was recorded in the period from 1988 to 2007 in the population of women of reproductive age from 86% to 32.5%. The decreasing tendency of the prevalence of toxoplasmosis in Serbia remains continuous even after that period, further confirmed by the latest results of research conducted in 2017 - 2018 in the population of blood donors in Belgrade (20.5%) and in the general population of Vojvodina during the 2008 - 2021 period (20%). Despite the encouraging epidemiological data that indicate the trend of continuous decline in the prevalence of toxoplasmosis in the world and our country, it is still necessary to conduct additional research to identify specific risk factors that contribute to the decrease in the prevalence of T. gondii infection in the population.
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