Precise subtyping for synchronous multiparty sessions

The notion of subtyping has gained an important role both in theoretical and applicative domains: in lambda and concurrent calculi as well as in programming languages. The soundness and the completeness, together referred to as the preciseness of subtyping, can be considered from two different points of view: operational and denotational. The former preciseness has been recently developed with respect to type safety, i.e. the safe replacement of a term of a smaller type when a term of a bigger type is expected. The latter preciseness is based on the denotation of a type which is a mathematical object that describes the meaning of the type in accordance with the denotations of other expressions from the language. The result of this paper is the operational and denotational preciseness of the subtyping for a synchronous multiparty session calculus. The novelty of this paper is the introduction of characteristic global types to prove the operational completeness

Dynamic Role Authorization in Multiparty Conversations

Protocol specifications often identify the roles involved in communications. In multiparty protocols that involve task delegation it is often useful to consider settings in which different sites may act on behalf of a single role. It is then crucial to control the roles that the different parties are authorized to represent, including the case in which role authorizations are determined only at runtime. Building on previous work on conversation types with flexible role assignment, here we report initial results on a typed framework for the analysis of multiparty communications with dynamic role authorization and delegation. In the underlying process model, communication prefixes are annotated with role authorizations and authorizations can be passed around. We extend the conversation type system so as to statically distinguish processes that never incur in authorization errors. The proposed static discipline guarantees that processes are always authorized to communicate on behalf of an intended role, also covering the case in which authorizations are dynamically passed around in messages.Comment: In Proceedings BEAT 2014, arXiv:1408.556

A Typed Model for Dynamic Authorizations

Security requirements in distributed software systems are inherently dynamic. In the case of authorization policies, resources are meant to be accessed only by authorized parties, but the authorization to access a resource may be dynamically granted/yielded. We describe ongoing work on a model for specifying communication and dynamic authorization handling. We build upon the pi-calculus so as to enrich communication-based systems with authorization specification and delegation; here authorizations regard channel usage and delegation refers to the act of yielding an authorization to another party. Our model includes: (i) a novel scoping construct for authorization, which allows to specify authorization boundaries, and (ii) communication primitives for authorizations, which allow to pass around authorizations to act on a given channel. An authorization error may consist in, e.g., performing an action along a name which is not under an appropriate authorization scope. We introduce a typing discipline that ensures that processes never reduce to authorization errors, even when authorizations are dynamically delegated.Comment: In Proceedings PLACES 2015, arXiv:1602.0325

Note on the cardinality of some sets of clones

All minimal clones containing a three-element grupoid have been determined in [3]. In this paper we solve the problem of the cardinality of the set of clones which contain some of these clones

An insight into the bryophyte flora of the Ibar gorge and its surroundings (Central and SW Serbia)

A total of 126 bryophyte taxa (12 liverworts and 114 mosses) were collected in the Ibar gorge and its surroundings. The climate of the gorge receives Mediterranean influence, hence almost one fourth part of the species found are Mediterranean, sub-Mediterranean, or sub-Atlantic elements. Several rare species in Serbia and in the Balkans can be found in the territory (e.g. Bryum gemmiferum, Dialytrichia mucronata, Didymodon nicholsonii, Grimmia lisae, Gymnostomum viridulum, Hygroamblystegium humile, Orthotrichum obtusifolium, Syntrichia latifolia). One species (Buxbaumia viridis) is included in the Bern Convention and the European Union Habitats and Species Directives. The Ibar gorge maintains a unique bryophyte assemblage due to the serpentine bedrock and continental, Mediterranean climatic influence, which are the main characteristics of the region

Physcomitrium eurystomum and Pohlia proligera, new mosses in the bryophyte flora of Serbia

Physcomitrium eurystomum Sendtn. and Pohlia proligera (Kindb.) Lindb. ex Broth. were recently discovered as new moss species for the bryophyte flora of Serbia. Both species were recorded in the Vlasina Lake area, a large highland wetland plateau in southeastern Serbia

Effects of different strength training methods onanthropological status of males in late adolescence

Главни циљ овог истраживања је био утврдити да ли и како експериментални рад применом три различите методе тренинга снаге утиче на ниво снаге, морфолошке карактеристике и телесни састав посматраног узорка. Узорак испитаника је чинио 75 здравих адолесцената студената Факултета спорта и физичког васпитања у Новом Саду узраста 20 ±0.5 година. У петонедељни експериментални програм је укључено 45 студената насумично подељених у три експерименталне групе. Прва експериментална Е1 група (n=15) је упражњавала комплексни тренинг, друга експериментална група Е2 (n=15) је упражњавала неуромишићну електростимулацију, а трећа експериментална Е3 група (n=15) је упражњавала вибрациони тренинг. Четврта група од 30 студената је упражњавала уобичајен програм практичних предавања на Факултету спорта и физичког васпитања, и користила се као контролна група (К). Разлике између група на иницијалном мерењу тестиране су применом мултиваријатне и униваријатне анализе варијансе за све примењене варијабле. За утврђивање ефекта примењеног третмана примењен је т тест, мултиваријатна анализа коваријансе за цео систем примењених варијабли, а за поједине варијабле униваријатна анализа коваријансе. На основу резултата мултиваријатне анализе варијансе за целокупан систем моторичких варијабли уочена је статистичка значајност од F = 2,85 P = 0,01. У варијаблама вертикалне скочности испитаници Е1 групе остварили напредак који је статистички значајан, у варијаблама: скок из получучња (0,01), скок кроз получучањ (0,02). Такође је уочен напредак код испитаника Е2 групе: скок из получучња (0,00), скок кроз получучањ (0,00), просечна висина узастопних скокова кроз получучањ (0,01), просечна сила скокова кроз получучањ (0,01). Није забележен напредак у варијаблама вертикалне скочности код испитаника Е3 групе. У варијаблама трчања на 30 m све три групе су оствариле статистички значајан напредак. на рачун стартног убрзања напредак су оствариле Е1 и Е3 група, док је Е2 група свој напредак остварила у фази постизања максималне брзине трчања. У морфолошким и варијаблама телесног састава нису уочене статистички значајне промене настале применом различитих метода тренинга снаге (P=0,09; F = 1,488). Закључак овог истраживања је да би унутар комплексног тренинга било пожељно имплементирати и друга два истраживана метода у циљу постизања максималних резултата у развоју ексползивне снаге.Glavni cilj ovog istraživanja je bio utvrditi da li i kako eksperimentalni rad primenom tri različite metode treninga snage utiče na nivo snage, morfološke karakteristike i telesni sastav posmatranog uzorka. Uzorak ispitanika je činio 75 zdravih adolescenata studenata Fakulteta sporta i fizičkog vaspitanja u Novom Sadu uzrasta 20 ±0.5 godina. U petonedeljni eksperimentalni program je uključeno 45 studenata nasumično podeljenih u tri eksperimentalne grupe. Prva eksperimentalna E1 grupa (n=15) je upražnjavala kompleksni trening, druga eksperimentalna grupa E2 (n=15) je upražnjavala neuromišićnu elektrostimulaciju, a treća eksperimentalna E3 grupa (n=15) je upražnjavala vibracioni trening. Četvrta grupa od 30 studenata je upražnjavala uobičajen program praktičnih predavanja na Fakultetu sporta i fizičkog vaspitanja, i koristila se kao kontrolna grupa (K). Razlike između grupa na inicijalnom merenju testirane su primenom multivarijatne i univarijatne analize varijanse za sve primenjene varijable. Za utvrđivanje efekta primenjenog tretmana primenjen je t test, multivarijatna analiza kovarijanse za ceo sistem primenjenih varijabli, a za pojedine varijable univarijatna analiza kovarijanse. Na osnovu rezultata multivarijatne analize varijanse za celokupan sistem motoričkih varijabli uočena je statistička značajnost od F = 2,85 P = 0,01. U varijablama vertikalne skočnosti ispitanici E1 grupe ostvarili napredak koji je statistički značajan, u varijablama: skok iz polučučnja (0,01), skok kroz polučučanj (0,02). Takođe je uočen napredak kod ispitanika E2 grupe: skok iz polučučnja (0,00), skok kroz polučučanj (0,00), prosečna visina uzastopnih skokova kroz polučučanj (0,01), prosečna sila skokova kroz polučučanj (0,01). Nije zabeležen napredak u varijablama vertikalne skočnosti kod ispitanika E3 grupe. U varijablama trčanja na 30 m sve tri grupe su ostvarile statistički značajan napredak. na račun startnog ubrzanja napredak su ostvarile E1 i E3 grupa, dok je E2 grupa svoj napredak ostvarila u fazi postizanja maksimalne brzine trčanja. U morfološkim i varijablama telesnog sastava nisu uočene statistički značajne promene nastale primenom različitih metoda treninga snage (P=0,09; F = 1,488). Zaključak ovog istraživanja je da bi unutar kompleksnog treninga bilo poželjno implementirati i druga dva istraživana metoda u cilju postizanja maksimalnih rezultata u razvoju ekspolzivne snage.The main aim of this study was to determine whether and how the experimental treatment using three different methods of strength training affects the power level, the morphological characteristics and body composition of the research sample. The sample was consisted of 75 healthy adolescents, students of the Faculty of Sport and Physical Education in Novi Sad, aged 20 ± 0.5 years. The five-week experimental program involved 45 students randomly assigned in three experimental groups during five weeks period.  The first experimental E1 group (n = 15) performed complex training, the second experimental group E2 (n = 15) performed neuromuscular electrostimulation, and the third experimental E3 group (n = 15) performed whole body vibration training. The fourth group of 30 students practiced the usual program of practical lectures at the Faculty of Sport and Physical Education, and it was used as a control group (K). Baseline differences between groups were analyzed using multivariate and univariate analysis of variance. Effects of experimental protocols were assessed using t test, multivariate and univariate analysis of covariance. Results of multivariate analysis of covariance revealed statistically significant differences in observed sample (P=0,01). The variables of vertical jumping subjects from E1 groups made statistically significant progress in: squat jump (0.01), countermovement jump (0.02). It was also observed statistically significant improvement in E2 group subjects: squat jump (0.00), countermovement jump (0.00), countinuous jump with bent legs (0.01), the average force - countinuous jump with bent legs (0.01). There has been no progress in the variables of vertical jumping test in E3 group subjects. The variables running at 30 m all three groups showed statistically significant improvement. On account of the starting acceleration, progress was achieved in E1 and E3 group, while E2 group achieved progress in phase of maximal speed. Analysis of morphological characteristics and body composition showed no statistically significant changes after implemented experimental protocol (P=0,09; F = 1,488).  Conclusion of this research leads to notice that for achieving maximal results in muscle power development, into complex training method should be implemented other two investigated experimental methods

The role of adenosine monophosphate-activated protein kinase and mTOR complex 1 in the cytotoxic effect of nonsteroidal anti-inflammatory drugs on glioma cells in vitro

Gliomi su najčešći primarni tumori centralnog nervnog sistema. Glioblastom je gliom gradusa IV, terapijski rezistentan maligni tumor centralnog nervnog sistema. Nesteroidni anti-inflamatorni lekovi (NSAIL) su strukturno različite grupe molekula sa anti-inflamatornim i analgetskim dejstvom koji ispoljavaju i jak antitumorski efekat kako in vitro tako i in vivo. U ovoj doktorskoj disertaciji ispitivano je citotoksično dejstvo NSAIL na ćelije humane linije glioma U251 i ćelije primarne kulture glioblastoma izolovane iz tkiva obolelih pacijenata. Takođe, istraživali smo ulogu signalnog puta adenozin-monofosfatom aktivirane protein-kinaze (AMPK) i mTOR kompleksa 1 (mTORC1 - engl. mammalian target of rapamycin complex 1) u antigliomskom dejstvu NSAIL. Indometacin je snažnije od ostalih NSAIL (diklofenaka, naproksena i ketoprofena) smanjivao vijabilitet U251 ćelija humanog glioblastoma. Antigliomski efekat indometacina je bio povezan sa ekspresijom tumor supresorskog proteina p21 i zastojem ćelijskog ciklusa u G2M fazi, indukcijom oksidativnog stresa, depolarizacijom mitohondrija, aktivacijom kaspaza i indukcijom apoptoze. Indometacin je jedini od ispitivanih NSAIL povećavao fosforilaciju AMPK i nishodnih molekula koje ona fosforiliše, Raptor-a i acetil-CoA karboksilaze (ACC). Aktivaciju AMPK pratilo je smanjenje fosforilacije mTOR i molekula čiju aktivnost mTORC1 reguliše, kao što su ribozomalna p70S6 kinaza (S6K) i PRAS40 (Ser183). Genetska inhibicija AMPK RNK interferencijom, kao i tretman ćelija aktivatorom mTORC1 leucinom doveli su do delimičnog poništavanja citotoksičnih efekata izazvanih indometacinom. Sa druge strane, farmakološki aktivatori AMPK metformin i AICAR su poput indometacina ispoljavali antigliomski efekat inhibicijom mTORC1. Aktivacija AMPK u ćelijama tretiranim indometacinom korelirala je sa smanjenjem ćelijskog ATP i porastom AMP/ATP odnosa, ali je bila nezavisna od inhibicije COX i povećanja intraćelijskog nivoa kalcijuma. Takođe, citotoksični efekat indometacina na ćelije primarne kulture glioblastoma bio je posredovan aktivacijom AMPK/Raptor/ACC i inhibicijom mTORC1/S6K signalnih molekula...Gliomas are the most common primary tumors of the central nervous system. Glioblastoma is grade IV glioma, therapy-resistant malignant tumor of the central nervous system. Non-steroidal anti-inflammatory drugs (NSAID) are structurally different groups of molecules with anti-inflammatory and analgesic effects that exert strong antitumor effect, both in vitro and in vivo. In this doctoral dissertation, the cytotoxic effect of NSAID on U251 human glioma cell line and the primary culture of glioblastoma cells isolated from patients has been examined. The role of the intracellular energy-sensing AMP-activated protein kinase (AMPK)/mammalian target of rapamycin complex 1 (mTORC1) pathway in the in vitro antiglioma effect of NSAID has been investigated. Indomethacin was more potent than other NSAID (diclofenac, naproxen, and ketoprofen) in reducing the viability of U251 human glioma cells. Antiglioma effect of indomethacin was associated with p21 increase and G2M cell cycle arrest, as well as with oxidative stress, mitochondrial depolarization, caspase activation, and the induction of apoptosis. Indomethacin increased the phosphorylation of AMPK and its targets Raptor and acetyl-CoA carboxylase (ACC), and reduced the phosphorylation of mTOR and mTORC1 substrates p70S6 kinase and PRAS40 (Ser183). AMPK knockdown by RNA interference, as well as the treatment with the mTORC1 activator leucine, prevented indomethacin-mediated mTORC1 inhibition and cytotoxic action. On the other hand, AMPK activators metformin and AICAR mimicked mTORC inhibition-dependent cytotoxic effects of the drug. AMPK activation by indomethacin correlated with intracellular ATP depletion and increase in AMP/ATP ratio, and was apparently independent of COX inhibition or the increase in intracellular calcium. The toxicity of indomethacin towards primary human glioblastoma cells was also associated with the activation of AMPK/Raptor/ACC and subsequent suppression of mTORC1/S6K. Finally, the ability of indomethacin to induce autophagy in U251 VIII human glioma cells has been investigated..

Contributions to the bryophyte flora of the Pešter Plateau, SW Serbia

211 bryophytes (37 liverworts and 174 mosses) were recently collected in the Pešter plateau (SW Serbia). Of these collections, five species (Riccia canaliculata, Scapania praetervisa, Bryum canariense, Myurella sibirica, Pseudoleskeella rupestris) were found to be new records for Serbia. Four species (Lophozia ascendens, Buxbaumia viridis, Hamatocaulis vernicosus, Myurella sibirica) are included in the Red data book of European bryophytes. An additional 19 taxa can be regarded as rare in the Balkans