The Boltzmann-Gibbs distribution of money

To delo obravnava uporabo metod fizike na statističnih modelih za porazdelitev denarja, kot primer pristopa ekonofizike. V zaprtem gospodarskem sistemu se denar ohranja. Po analogiji z energijo mora ravnotežje verjetnostne porazdelitve denarja slediti Boltzmann-Gibbsovem zakonu, pri čemer je efektivna temperatura enaka povprečnemu znesku denarja na agenta. Numerične simulacije kažejo, da to drži vsaj takrat, ko je število agentov in povprečni znesek denarja na agenta velik. Glavni cilj diplomskega dela je ta rezultat dokazati.This paper is concerned with the application of the methods of physics to statistical models for money distribution as an example of the approach of econophysics. In a closed economic system, money is conserved. By analogy with energy, the equilibrium probability distribution of money must follow the exponential Boltzmann-Gibbs law characterized by an effective temperature equal to the average amount of money per economic agent. Numerical simulations suggest that at least when the number of agents and the average amount of money per agent are large, this is true. The main objective of this paper is to give a rigorous proof of this result

Testing of begomoviruses capable of infecting tomatoes and plants of the family Cucurbitaceae by PCR

Detection of begomoviruses capable of infecting tomatoes and plants of the family Cucurbitaceae

Filling the gaps in diagnostics of Pepino mosaic virus and Potato spindle tuber viroid in water and tomato seeds and leaves

Waterborne and seedborne Pepino mosaic virus (PepMV) and Potato spindle tuber viroid (PSTVd) pose serious threats to tomato production due to seed transmission and mechanical transmission, coupled with their long-term stability outside the host plant. Therefore, rapid and sensitive diagnostic procedures are needed to prevent the spread of these quarantine pathogens. In particular, water and seed contamination are difficult to detect and confirm without efficient concentration methods. This study presents procedures that improve detection of PSTVd from tomato seeds and leaf tissue, and PepMV from water and tomato leaf tissue. For efficient concentration of PepMV from water samples, a procedure was optimized using convective interaction media monolithic chromatography columns, which provides concentration by three orders of magnitude. For concentration of PSTVd from seed extracts, an easy-to-use and efficient method was developed based on RNA binding to positively charged anion-exchange resin beads that provides up to 100-fold more sensitive detection in comparison with procedures without a concentration step. This thus allows confirmation of RT-qPCR results with sequencing of RT-PCR products in samples with low viroid levels. In addition, reverse-transcription loop-mediated isothermal amplification assays for detection of PSTVd and PepMV were optimized and adapted to both laboratory and on-site testing requirements. This allows rapid detection of these pathogens in crude leaf homogenates, in under 30 min. These procedures of concentration and detection are shown to be efficient and to fill the gaps in diagnostics of PepMV and PSTVd, especially when these pathogens are present at low levels in difficult matrices such as water and seeds

Rapid loop-mediated isothermal amplification assays for grapevine yellows phytoplasmas on crude leaf-vein homogenate has the same performance as qPCR

A fluorescence-based real-time loop-mediated isothermal amplification (LAMP) assay for ‘Candidatus Phytoplasama solani’ (Bois noir phytoplasmaBNp) detection was developed and optimised for rapid laboratory and on-site BNp detection. This assay is highly specific, rapid and as sensitive as qPCR. It was validated according to European and Mediterranean Plant Protection Organisation recommendations. In addition, 286 grapevine leaf samples from the 2015 growing season were tested with this new real-time LAMP assay and an assay previously developed for detection of Flavescence dorée phytoplasma (FDp). These LAMP assays for detection of both BNp and FDp used without any DNA extraction step, which is a required step for qPCR analysis, were comparably effective to qPCR, and positive results were obtained in less than 35 min

Epidemiology of flavescence dorée and hazelnut decline in Slovenia: geographical distribution and genetic diversity of the associated 16SrV phytoplasmas

Flavescence dorée (FD) phytoplasma from 16SrV-C and -D subgroups cause severe damage to grapevines throughout Europe. This phytoplasma is transmitted from grapevine to grapevine by the sap-sucking leafhopper Scaphoideus titanus. European black alder and clematis serve as perennial plant reservoirs for 16SrV-C phytoplasma strains, and their host range has recently been extended to hazelnuts. In Slovenia, hazelnut orchards are declining due to 16SrV phytoplasma infections, where large populations of the non-autochthonous leafhopper Orientus ishidae have been observed. To better characterise the phytoplasma-induced decline of hazelnut and possible transmission fluxes between these orchards and grapevine, genetic diversity of 16SrV phytoplasmas in grapevine, hazelnut and leafhoppers was monitored from 2017 to 2022. The nucleotide sequence analysis was based on the map gene. The most prevalent map genotype in grapevine in all wine-growing regions of Slovenia was M54, which accounted for 84 % of the 176 grapevines tested. Besides M54, other epidemic genotypes with lower frequency were M38 (6 %), M51 (3 %), M50 (2 %) and M122 (1 %). M38, M50 and M122 were also detected in infected cultivated hazelnuts and in specimens of O. ishidae leafhopper caught in declining hazelnut orchards. It suggests that this polyphagous vector could be responsible for phytoplasma infection in hazelnut orchards and possibly for some phytoplasma exchanges between hazelnuts and grapevine. We hereby describe new genotypes: M158 in grapevine as well as four never reported genotypes M159 to M162 in hazelnut. Of these four genotypes in hazelnut, one (M160) was also detected in O. ishidae. Analysis of additional genes of the new genotypes allowed us to assign them to the VmpA-III cluster, which corresponds to the 16SrV-C strains previously shown to be compatible with S. titanus transmission

Epidemiology of flavescence dorée and hazelnut decline in Slovenia: geographical distribution and genetic diversity of the associated 16SrV phytoplasmas

Flavescence dorée (FD) phytoplasma from 16SrV-C and -D subgroups cause severe damage to grapevines throughout Europe. This phytoplasma is transmitted from grapevine to grapevine by the sap-sucking leafhopper Scaphoideus titanus . European black alder and clematis serve as perennial plant reservoirs for 16SrV-C phytoplasma strains, and their host range has recently been extended to hazelnuts. In Slovenia, hazelnut orchards are declining due to 16SrV phytoplasma infections, where large populations of the non-autochthonous leafhopper Orientus ishidae have been observed. To better characterise the phytoplasma-induced decline of hazelnut and possible transmission fluxes between these orchards and grapevine, genetic diversity of 16SrV phytoplasmas in grapevine, hazelnut and leafhoppers was monitored from 2017 to 2022. The nucleotide sequence analysis was based on the map gene. The most prevalent map genotype in grapevine in all wine-growing regions of Slovenia was M54, which accounted for 84% of the 176 grapevines tested. Besides M54, other epidemic genotypes with lower frequency were M38 (6%), M51 (3%), M50 (2%) and M122 (1%). M38, M50 and M122 were also detected in infected cultivated hazelnuts and in specimens of O. ishidae leafhopper caught in declining hazelnut orchards. It suggests that this polyphagous vector could be responsible for phytoplasma infection in hazelnut orchards and possibly for some phytoplasma exchanges between hazelnuts and grapevine. We hereby describe new genotypes: M158 in grapevine as well as four never reported genotypes M159 to M162 in hazelnut. Of these four genotypes in hazelnut, one (M160) was also detected in O. ishidae . Analysis of additional genes of the new genotypes allowed us to assign them to the VmpA-III cluster, which corresponds to the 16SrV-C strains previously shown to be compatible with S. titanus transmission

List of tests for validation

We prepared a list of methods and tests for validation in test performance study (TPS) Round 1, both for laboratory and on-site use, for 6 selected pests: Erwinia amylovora, Pantoea stewartiisubsp. stewartii, citrus tristeza virus, plum pox virus, Fusarium circinatum and Bursaphelenchus xylophilus. The listed tests were first validated in preliminary studies by TPS organizers in order to select the final tests for TPS, based on the scope and criteria prepared in D1.1