“Ovo je trebalo biti smiješno – zašto se ne smijete!” – izvođenje povijesti i turističke šetnje u Budimpešti (Sažetak)

The turn to performativity in the social sciences has spawned a new wave of scholarship that considers tourism as a performative process. However, the manner through which scholars understand tourism as performative drama is limiting. A fundamental critique of dramaturgy stems from its inability to account for performance as a chain of emergent social processes. Using the case of free walking tours in Budapest, Hungary, we argue that treating tourism as a performance is an act of fusion that culls its technique by deploying dominant cultural codes, materiality and humor. Performance hinges on an attempt to fuse various elements in a dramatic presentation. These elements include the (1) unsettling presence of the audience’s feedback, (2) the lingering memory of previous performances, (3) the deployment of cultural codes, (4) the mundanity of the material means of symbolic presentation, and (5) the use of linguistic play through humor. We conclude this essay by elaborating other dimensions that could possibly open up more discussions on tourism as a performative phenomenon.Performativni obrat u društvenim znanostima obuhvatio je i studije o turizmu koji se u tom kontekstu promatra kao izvedbeni process. Dosadašnje studije ukazuju na određena ograničenja ovoga pristupa. Fundamentalna kritika dramaturškog pogleda jest da izvedbenost ne promatra kao niz pojavnih društvenih procesa. Na primjeru besplatnih turističkih šetnji (free walking tours) u Budimpešti, u članku se analizira turizam kao izvedbeni čin koji se realizira kombiniranjem dominantnih kulturnih kodova, upotrebom predmeta te humorom. Realiziran je kao pokušaj spajanja različitih elemenata u dramaturšku prezentaciju. U članku se raspravlja slijedećih pet elemenata izvedbe turističkih vodiča- njihova interakcija sa publikom/turistima, prethodna iskustva, upotreba kulturnih kodova, svakodnevica predmeta čije se simbolika koristi u prezentaciji te poigravanje sa jezičnim formama kroz humor. U zaključku predlažemo nekoliko dimenzija koje se mogu uključiti u daljnja promišljanja i rasprave o turizmu kao izvedbenom fenomenu

Serbia, Bulgaria and Tatars in the second half of the thirteenth century

Докторска дисертација Србија, Бугарска и Татари у другој половини XIII века паралелно посматра два низа историографских питања. Први се односи на српско-бугарске односе током поменуте епохе, а други на монголски (татарски) утицај на југоисточну Европу. Ове две теме стоје у нераскидивој вези: прву је немогуће обухватити без друге, а друга је осветљена из више перспектива захваљујући првој. Горњу хронолошку границу истраживања представља продор Монгола на Запад (1241-1242), који је оставио дубоке трагове разарања и изазвао низ миграторних кретања. Доњу чине унутрашњи сукоби епских пропорција међу Татарима у црноморским степама, који су довели до промене карактера њиховог утицаја, као и до новог масовног насељавања номадских популација јужно од Дунава. Ова епоха је у балканским оквирима започела смрћу бугарског владара Ивана Асена II (1218-1241), а завршила се покушајем стварања персоналне уније двеју држава Јужних Словена и споразумом краља Милутина са Византијом 1299. године, чиме је најављена хегемонија државе Немањића у региону. Теза је заснована на широком спектру наративних (византијски, латински, оријентални, словенски и други писци), документарних (повеље папа, угарских, српских и бугарских владара, грађа из анжујских архива) и археолошких извора. Окосницу истраживања чине политички аспекти, али су они нераскидиво испреплетани са војним, географским и друштвеним. Теза је структурално подељена на Уводне примедбе, шест поглавља и Закључна разматрања. У Уводним примедбама дат је преглед извора и литературе, осврт на географију региона и терминолошке напомене. У првом поглављу је представљен ток монголске инвазије и њене последице (1241-1242). Друго се бави образовањем монголске државе у Црноморским степама (тзв. Златна хорда) и њеним утицајем на балканске земље средином XIII века. Следећа целина је посвећена анализи српско-бугарских односа, као и унутрашњим и спољним чиниоцима који су обликовали њихов међународни положај. Четврто поглавље је окренуто успону и активностима монголског великаша Ногаја, а пето се бави његовим утицајем на прилике у Бугарској и Србији. У последњем поглављу је анализирано наслеђе Ногајеве епохе у југоисточној Европи, кроз емиграцију номадских Алана и Татара, блиске односе српске државе и северозападних бугарских земаља, као и заједничко српско-бугарско-татарско деловање против Угарске почетком XIV века. Спроведена истраживања решавају више хронолошких непознаница (време устоличења Ногаја на доњем Дунаву, датовање брака краља Милутина и угарске принцезе Јелисавете, припајање Браничева држави краља Драгутина, итд.) и откривају неоснованост неких устаљених хипотеза у науци (нпр. талаштво Теодора Светослава у Ногајевим земљама). Осим тога, истраживања показују да су до тада складни бугарско-српски односи 1284. године прерасли у фактички војни и политички савез, затим да је Србија деценију касније на кратко постала у пуном смислу вазал татарске државне творевине образоване на доњем Дунаву, као и да су блиске везе између Србије и северозападних бугарских земаља, образоване крајем XIII века под Ногајевим покровитељством, надживеле овог монголског великаша пуне две деценије.Doctoral Dissertation Serbia, Bulgaria and Tatars in the Second Half of the Thirteenth Century deals with two parallel historiographical issues. The former is Serbian-Bulgarian relations during this epoch; the latter is Mongol (Tatar) impact on Southeastern Europe in the proposed timeframe. These two topics are mutually inseparable. The first is impossible to explain without taking the latter into account, while the second is, in turn, illuminated from multiple perspectives by the first. Chronologically, the research starts with the Mongol Invasion of Europe (1241- 1242), which left deep traces of destruction and caused a series of migrations. It finishes with inner conflicts among the Tatars in the Black Sea steppes, which brought changes in the character of their influence and led to a new mass settlement of nomadic populations south of the Danube. In the Balkan frameworks, this epoch began with the death of Bulgarian ruler John Asen II (1218-1241); it ended with an attempt to create a personal union between the two South Slavic states and with king Milutin’s agreement with Byzantium in 1299, thereby announcing the hegemony of the Nemanjić state in the region. The dissertation is based upon a wide range of narrative (Byzantine, Latin, Oriental, Slavic and other writers), documentary (сharters of Popes, Hungarian, Serbian and Bulgarian rulers, material from the Angevin archives), and archaeological sources. Main focus is devoted to political aspects; they are, however, closely intertwined with the military, social and geographical aspects. Structurally, the dissertation is divided into Introductory remarks, six chapters and Conclusion. Introductory remarks provide an overview of the sources and literature, review of the regional geography and terminology used in the text. In the first chapter, the course of events during Mongol invasion of Europe (1241-1242) is presented, as well as its consequences. The second section deals with the establishment of Mongol state in the Black Sea steppes (so-called Golden Horde), and its influence on the Balkan countries in mid Thirteenth century. The next chapter is devoted to the analysis of the relations between Serbia and Bulgaria, internal and external factors that shaped their position. The fourth part is dedicated to the rise of Nogai and his career, while the next one is focused upon his impact оn Bulgaria and Serbia. The final chapter deals with his legacy, envisaged through emigration of nomadic Alans and Tatars, close relations between Serbian state and northwestern Bulgarian lands, as well as joint Serbian, Bulgarian and Tatar military activities against Hungary, at the beginning of the Fourteenth Century. The conducted researches solve several chronological issues (such as the time of Nogai’s establishment on the Lower Danube, date of marriage between king Milutin and Hungarian princess Elizabeth, inclusion of Braničevo into the state of king Dragutin, etc.). They reveal groundlesness of some of the established hypotheses in historiography (e.g. the hostage status of Bulgarian Prince Theodore Svetoslav in the Nogai’s lands). Also, it has been shown that: harmonious Bulgarian-Serbian relations grew into a de facto military and political alliance in 1284; a decade later, Serbia became a dependant of the Tatar state formed on the Lower Danube, although for a short time; the ties between Serbia and northwestern Bulgarian lands, formed in the late Thirteenth century under Nogai’s patronage, outlived him for another two decades

Invaded cluster algorithm for a tricritical point in a diluted Potts model

The invaded cluster approach is extended to 2D Potts model with annealed vacancies by using the random-cluster representation. Geometrical arguments are used to propose the algorithm which converges to the tricritical point in the two-dimensional parameter space spanned by temperature and the chemical potential of vacancies. The tricritical point is identified as a simultaneous onset of the percolation of a Fortuin-Kasteleyn cluster and of a percolation of "geometrical disorder cluster". The location of the tricritical point and the concentration of vacancies for q = 1, 2, 3 are found to be in good agreement with the best known results. Scaling properties of the percolating scaling cluster and related critical exponents are also presented.Comment: 8 pages, 5 figure

Numerical Diagonalisation Study of the Trimer Deposition-Evaporation Model in One Dimension

We study the model of deposition-evaporation of trimers on a line recently introduced by Barma, Grynberg and Stinchcombe. The stochastic matrix of the model can be written in the form of the Hamiltonian of a quantum spin-1/2 chain with three-spin couplings given by H= \sum\displaylimits_i [(1 - \sigma_i^-\sigma_{i+1}^-\sigma_{i+2}^-) \sigma_i^+\sigma_{i+1}^+\sigma_{i+2}^+ + h.c]. We study by exact numerical diagonalization of $H$ the variation of the gap in the eigenvalue spectrum with the system size for rings of size up to 30. For the sector corresponding to the initial condition in which all sites are empty, we find that the gap vanishes as $L^{-z}$ where the gap exponent $z$ is approximately $2.55\pm 0.15$. This model is equivalent to an interfacial roughening model where the dynamical variables at each site are matrices. From our estimate for the gap exponent we conclude that the model belongs to a new universality class, distinct from that studied by Kardar, Parisi and Zhang.Comment: 11 pages, 2 figures (included

Absence of phase coexistence in disordered exclusion processes with bypassing

Adding quenched disorder to the one-dimensional asymmetric exclusion process is known to always induce phase separation. To test the robustness of this result, we introduce two modifications of the process that allow particles to bypass defect sites. In the first case, particles are allowed to jump l sites ahead with the probability p_l ~ l^-(1+sigma), where sigma>1. By using Monte Carlo simulations and the mean-field approach, we show that phase coexistence may be absent up to enormously large system sizes, e.g. lnL~50, but is present in the thermodynamic limit, as in the short-range case. In the second case, we consider the exclusion process on a quadratic lattice with symmetric and totally asymmetric hopping perpendicular to and along the direction of driving, respectively. We show that in an anisotropic limit of this model a regime may be found where phase coexistence is absent.Comment: 18 pages, 10 figures, to appear in JSTA

LsbB Bacteriocin Interacts with the Third Transmembrane Domain of the YvjB Receptor

The Zn-dependent membrane-located protease YvjB has previously been shown to serve as a target receptor for LsbB, a class II leaderless lactococcal bacteriocin. Although yvjB is highly conserved in the genus Lactococcus, the bacteriocin appears to be active only against the subspecies L. lactis subsp. lactis. Comparative analysis of the YvjB proteins of a sensitive strain (YvjB(MN)) and a resistant strain (YvjB(MG)) showed that they differ from each other in 31 positions. In this study, we applied site-directed mutagenesis and performed directed binding studies to provide biochemical evidence that LsbB interacts with the third transmembrane helix of YvjB in susceptible cells. The site-directed mutagenesis of LsbB and YvjB proteins showed that certain amino acids and the length of LsbB are responsible for the bacteriocin activity, most probably through adequate interaction of these two proteins; the essential amino acids in LsbB responsible for the activity are tryptophan (Trp(25)) and terminal alanine (Ala(30)). It was also shown that the distance between Trp(25) and terminal alanine is crucial for LsbB activity. The crucial region in YvjB for the interaction with LsbB is the beginning of the third transmembrane helix, particularly amino acids tyrosine (Tyr(356)) and alanine (Ala(353)). In vitro experiments showed that LsbB could interact with both YvjB(MN) and YvjB(MG), but the strength of interaction is significantly less with YvjB(MG). In vivo experiments with immunofluorescently labeled antibody demonstrated that LsbB specifically interacts only with cells carrying YvjB(MN). IMPORTANCE The antimicrobial activity of LsbB bacteriocin depends on the correct interaction with the corresponding receptor in the bacterial membrane of sensitive cells. Membrane-located bacteriocin receptors have essential primary functions, such as cell wall synthesis or sugar transport, and it seems that interaction with bacteriocins is suicidal for cells. This study showed that the C-terminal part of LsbB is crucial for the bacteriocin activity, most probably through adequate interaction with the third transmembrane domain of the YvjB receptor. The conserved Tyr(356) and Ala(353) residues of YvjB are essential for the function of this Zn-dependent membrane-located protease as a bacteriocin receptor

Correlations in Ising chains with non-integrable interactions

Two-spin correlations generated by interactions which decay with distance r as r^{-1-sigma} with -1 <sigma <0 are calculated for periodic Ising chains of length L. Mean-field theory indicates that the correlations, C(r,L), diminish in the thermodynamic limit L -> \infty, but they contain a singular structure for r/L -> 0 which can be observed by introducing magnified correlations, LC(r,L)-\sum_r C(r,L). The magnified correlations are shown to have a scaling form F(r/L) and the singular structure of F(x) for x->0 is found to be the same at all temperatures including the critical point. These conclusions are supported by the results of Monte Carlo simulations for systems with sigma =-0.50 and -0.25 both at the critical temperature T=Tc and at T=2Tc.Comment: 13 pages, latex, 5 eps figures in a separate uuencoded file, to appear in Phys.Rev.

Defining the Structure and Receptor Binding Domain of the Leaderless Bacteriocin LsbB

Background: The bacteriocin LsbB targets a membrane-bound zinc-dependent peptidase. Results: The structure of LsbB was resolved by NMR. The C-terminal unstructured domains of LsbB and several other related bacteriocins were responsible for receptor binding. Conclusion: A subgroup of leaderless bacteriocins has been found to share a similar mechanism in receptor recognition. Significance: The study highlights the structure-function relationship of LsbB. LsbB is a class II leaderless lactococcal bacteriocin of 30 amino acids. In the present work, the structure and function relationship of LsbB was assessed. Structure determination by NMR spectroscopy showed that LsbB has an N-terminal -helix, whereas the C-terminal of the molecule remains unstructured. To define the receptor binding domain of LsbB, a competition assay was performed in which a systematic collection of truncated peptides of various lengths covering different parts of LsbB was used to inhibit the antimicrobial activity of LsbB. The results indicate that the outmost eight-amino acid sequence at the C-terminal end is likely to contain the receptor binding domain because only truncated fragments from this region could antagonize the antimicrobial activity of LsbB. Furthermore, alanine substitution revealed that the tryptophan in position 25 (Trp(25)) is crucial for the blocking activity of the truncated peptides, as well as for the antimicrobial activity of the full-length bacteriocin. LsbB shares significant sequence homology with five other leaderless bacteriocins, especially at their C-terminal halves where all contain a conserved KXXXGXXPWE motif, suggesting that they might recognize the same receptor as LsbB. This notion was supported by the fact that truncated peptides with sequences derived from the C-terminal regions of two LsbB-related bacteriocins inhibited the activity of LsbB, in the same manner as found with the truncated version of LsbB. Taken together, these structure-function studies provide strong evidence that the receptor-binding parts of LsbB and sequence-related bacteriocins are located in their C-terminal halves

A Zn-Dependent Metallopeptidase Is Responsible for Sensitivity to LsbB, a Class II Leaderless Bacteriocin of Lactococcus lactis subsp lactis BGMN1-5

Lactococcus lactis subsp. lactis BGMN1-5 produces a leaderless class II bacteriocin called LsbB. To identify the receptor for LsbB, a cosmid library of the LsbB-sensitive strain BGMN1-596 was constructed. About 150 cosmid clones were individually isolated and transferred to LsbB-resistant mutants of BGMN1-596. Cosmid pAZILcos/MN2, carrying a 40-kb insert, was found to restore LsbB sensitivity in LsbB-resistant mutants. Further subcloning revealed that a 1.9-kb fragment, containing only one open reading frame, was sufficient to restore sensitivity. The fragment contains the gene yvjB coding for a Zn-dependent membrane-bound metallopeptidase, suggesting that this gene may serve as the receptor for LsbB. Further support for this notion derives from several independent experiments: (i) whole-genome sequencing confirmed that all LsbB-resistant mutants contain mutations in yvjB; (ii) disruption of yvjB by direct gene knockout rendered sensitive strains BGMN1-596 and IL1403 resistant to LsbB; and (iii) most compellingly, heterologous expression of yvjB in naturally resistant strains of other species, such as Lactobacillus paracasei and Enterococcus faecalis, also rendered them sensitive to the bacteriocin. To our knowledge, this is the first time a membrane-bound peptidase gene has been shown to be involved in bacteriocin sensitivity in target cells. We also demonstrated a novel successful approach for identifying bacteriocin receptors