Upgrade of access and backbone network at Pošta Slovenije d.o.o.

Diplomsko delo predstavlja migracijo komunikacijskega omrežja iz zastarelih tehnologij v najsodobnejše na primeru Pošte Slovenije, ki je s tem želela ohraniti konkurenčno prednost v družbi. Nadgradnja tehnologije je potekala v dveh fazah. Prenova se je začela pri pristopnem omrežju, kjer so bili izvedeni prehodi iz zastarele Frame – Relay tehnologije na MPLS. Temu je sledila faza prenove hrbteničnega omrežja, ki je obsegala zamenjavo mrežnih stikal na treh centralnih vozliščih in zamenjava DWDM multiplekserjev z novejšimi, saj so obstoječa optična vlakna veliko bolj izkoriščena. Z nadgradnjo si je družba pridobila mnogo koristi. Na eni strani zmanjšala stroške rednega poslovanja (IP POS terminali, bankomati, IP telefonija, LOTO itd., ki so sedaj priklopljeni na lastno omrežje), na drugi pa svojim strankam ponudila nove storitve (e-arhiviranje, podatkovni centri, računalništvo v oblaku,…). Tehnologije, ki so pri prenovi največ prispevale pri povišanju kapacitet prenosa podatkov so: MPLS, ki s pomočjo labeliranja paketov in brez nepotrebnih poizvedb oziroma odločanj veliko hitreje prenaša podatke od vstopne do izstopne točke. Napredek je opazen tudi pri tehnologiji DWDM, ki je svoje kapacitete prenosa, glede na stanje pred prenovo, nekajkrat povečala. Tudi stikala so povišala svoje propustnosti s pomočjo novih tehnologij, kot sta port channel in Pseudowire, idr.The thesis presents the migration of a communication network from an outdated to an up-to-the-minute one. For Pošta Slovenije this was of utmost importance to keep the competitive edge of the company. The upgrading process consisted of two stages. The modernisation was first begun in the access network, where the transition from the outdated Frame-Relay technology to MPLS was made. This was followed by the renewal of the backbone network, which included the replacement of network switches at three central hubs and a replacement of DWDM multiplexers with newer ones, which make better use of the existing optical fibres. The upgrading has greatly benefited the company, which has (among other things) also reduced its operating costs (IP POS terminals, ATM machines, IP telephony, LOTO, etc. are now connected to its own network) and customers are offered new services (e-archiving, data centres, cloud computing, etc.). The technologies which had the greatest impact in terms of increasing the capacity of data transfer are: MPLS, which by labelling parcels and without any unnecessary searches and decisions enables a much faster data transfer from the entry point to the exit point. Progress is also noticed in DWDM technology, which has multiplied its transfer capacities in comparison to the capacities before the upgrading. The new switches have also had an increased throughput, which was enhanced by new technologies, such as port channel and Pseudowire, etc

Peri-articular histiocytic sarcoma and synovial cell sarcoma in Bernese Mountain dogs : a retrospective investigation of the prevalence of these tumours in association with previously diseased joints

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HMG-CoA reductase is regulated by environmental salinity and its activity is essential for halotolerance in halophilic fungi

The activity and level of HMG-CoA reductase (HMGR) were addressed in halophilic fungi isolated from solar saltpans. Representative fungi belonging to the orders Dothideales, Eurotiales and Wallemiales have a specific pattern of HMGR regulation, which differs from salt-sensitive and moderately salt-tolerant yeasts. In all of the halophilic fungi studied, HMGR amounts and activities were the lowest at optimal growth salinity and increased under hyposaline and hypersaline conditions. This profile paralleled isoprenylation of cellular proteins in H. werneckii. Inhibition of HMGR in vivo by lovastatin impaired the halotolerant character. HMGR may thus serve as an important molecular marker of halotolerance

Changes in the relative abundance of two Saccharomyces species from oak forests to wine fermentations

Saccharomyces cerevisiae and its sibling species S. paradoxus are known to inhabit temperate arboreal habitats across the globe. Despite their sympatric distribution in the wild, S. cerevisiae is predominantly associated with human fermentations. The apparent ecological differentiation of these species is particularly striking in Europe where S. paradoxus is abundant in forests and S. cerevisiae is abundant in vineyards. However, ecological differences may be confounded with geographic differences in species abundance. To compare the distribution and abundance of these two species we isolated Saccharomyces strains from over 1,200 samples taken from vineyard and forest habitats in Slovenia. We isolated numerous strains of S. cerevisiae and S. paradoxus as well as small number of S. kudriavzevii strains from both vineyard and forest environments. We find S. cerevisiae less abundant than S. paradoxus on oak trees both within and outside the vineyard, but more abundant on grapevines and associated substrates. Analysis of the uncultured microbiome shows that both S. cerevisiae and S. paradoxus are rare species in soil and bark samples, but can be much more common in grape must. In contrast to S. paradoxus, European strains of S. cerevisiae have acquired multiple traits thought to be important for life in the vineyard and dominance of wine fermentations. We conclude that S. cerevisiae and S. paradoxus currently share both vineyard and non-vineyard habitats in Slovenia and we discuss factors relevant to their global distribution and relative abundance

Low Water Activity Induces the Production of Bioactive Metabolites in Halophilic and Halotolerant Fungi

The aim of the present study was to investigate indigenous fungal communities isolated from extreme environments (hypersaline waters of solar salterns and subglacial ice), for the production of metabolic compounds with selected biological activities: hemolysis, antibacterial, and acetylcholinesterase inhibition. In their natural habitats, the selected fungi are exposed to environmental extremes, and therefore the production of bioactive metabolites was tested under both standard growth conditions for mesophilic microorganisms, and at high NaCl and sugar concentrations and low growth temperatures. The results indicate that selected halotolerant and halophilic species synthesize specific bioactive metabolites under conditions that represent stress for non-adapted species. Furthermore, adaptation at the level of the chemical nature of the solute lowering the water activity of the medium was observed. Increased salt concentrations resulted in higher hemolytic activity, particularly within species dominating the salterns. The appearance of antibacterial potential under stress conditions was seen in the similar pattern of fungal species as for hemolysis. The active extracts exclusively affected the growth of the Gram-positive bacterium tested, Bacillus subtilis. None of the extracts tested showed inhibition of acetylcholinesterase activity