Uticaj promena u tilakoidnim membranama na otpornost i adaptivnost prema temperaturi i suši samooplodnih linija kukuruza (Zea mays L.)

The delayed chlorophyll fluorescence method, as a non-invasive bioluminescence method, is recommended for the application in maize breeding and seed production in order to evaluate maize inbred lines for their resistance and adaptability to increased and high temperatures, as well as, to drought. The flowing thermal properties of the photosynthetic apparatus of the observed maize inbred lines: the temperature dependence within a range of 25-60oC, critical temperatures at which phase transitions occur in the thylakoid membrane were discovered and by means of its significant functional changes in the photosynthetic apparatus of observed maize inbred lines were detected. activation energies (Ea, kJ mol-1) alongside the straight lines prior and after critical temperatures were calculated. Ea are a measure of occurrence of chlorophyll DF recombination processes and by that a measure of the total changes in structure and functioning of the thylakoid membranes. Thylakoid membranes underwent significant conformational changes in the part following the maximum intensity, i.e. in the part of its sharp linear decline. Such a state fits more to a nonliving than a living organism in relation to its both, structure and functions. Results and the discussion of presented parameters of total thermal processes of chlorophyll DF, such as: temperature dependence, critical temperatures and activation energy, can be an important factor for a more exact characterization of maize inbred lines in relation to their resistance and adaptation to temperature and drought, contributing to a rapider and more rational development of the selection process.Utvrđene su termalne karakteristike fotosintetičnog aparata proučavanih samooplodnih linija kukuruza, i to: određena je temperaturna zavisnost u opsegu od 25 do 60 °C, otkrivene su kritične temperature na kojima dolazi do faznih transformacija u tilakoidnoj membrani, obračunate su energije aktivacije (Ea, kJ/mol) duž pravih linija pre i posle kritične temperature. Ea je mera nastajanja rekombinacionih reakcija povezanih sa uspostavljanjem zakasnele fluorescencije (ZF) hlorofila, a time i ukupnih promena u strukturi i funkciji tilakoidnih membrana. Rezultati i diskusija izloženih parametara ukupnih terminalnih procesa ZF hlorofila, kao što su: temperaturna zavisnost, kritične temperature i energija aktivacije, mogu doprineti egzaktnijem karakterisanju samooplodnih linija kukuruza u odnosu na njihovu otpornost i adaptivnost prema temperaturi i suši. Sve ovo doprinosi egzaktnijem, bržem i racionalnijem odvijanju procesa selekcije

Uticaj različitih tipova kombajna za ubiranje kamilice na kvalitet ubiranja i visinu dobiti u proizvodnji kamilice

This paper presents the results of three conceptually different types of chamomile harvester and their impact on the quality of the harvested chamomile and profit during the production process. Three working modes of each harvester are considered and values of realized losses and the quality of harvested chamomile are determined. It was found that choosing the type of engaged harvester and its working mode can affect the quality of harvested chamomile, as well as the profit achieved in the entire production process. .U ovom radu su prikazani rezultati istraživanja tri koncepcijski različita tipa kombajna za ubiranje kamilice i njihov uticaj na kvalitet ubrane sirovine i ostvarenu dobit tokom procesa proizvodnje. Posmatrana su tri režima rada svakog od kombajna i utvrđeni su vrednosti ostvarenih gubitaka i kvaliteta ubrane kamilice. Utvrđeno je da se izborom tipa angažovanog kombajna i režima rada može uticati na kvalitet ubrane kamilice, kao i na ostvarenu dobit u celokupnom proizvodnom ciklusu.

Serbian Citizens’ Opinion on the COVID-19 Epidemic

Aim: The Centre for International Public Policy has undertaken a public opinion research in which we tested the opinions of the citizens of Serbia on the coronavirus epidemic. The respondents had the opportunity to express their opinion on measures undertaken by the Serbian Government to combat the virus, to state their trust in the media, as well as the health system in general. In addition, we tested the prevalence of different conspiracy theories among citizens, whether the pandemic gave China a new image in the minds of the people and, most importantly, the level of solidarity among Serbian citizens as well as within the European / international community as a whole. Methods: In seven days, from 8-15th April 2020, we gathered a convenient sample of N=5989 respondents, which makes this the largest public opinion research project in Serbia on the topic of COVID-19 since the start of the epidemic. The electronic questionnaire consisted of 24 questions of mixed and closed type. Results: The findings of this research suggest that citizens of Serbia are not afraid of COVID-19, but are nevertheless cautious (86%). The percentage of those willing to consult a doctor when they notice any symptoms lies at 70%. Half of the respondents do not believe in alternative theories regarding the origin of the COVID-19 virus. The majority of the respondents (55%) hold government officials accountable for spreading panic through public speeches and daily public addresses. Moreover, 60% of the respondents do not trust the Serbian media outlets that are currently reporting on the COVID-19 pandemic. Furthermore, over half of the respondents are prepared to report their neighbour when he or she is coming from abroad and violates the obligation to self-isolate. However, mostly due to the significant fines, 65% of the respondents would not report the elderly when they are breaking the limited-movement restriction measures. Conclusion: As before the epidemic, opinions of the Serbian population on current topics are somewhat polarized. Although the majority of the respondents are cautious, a significant number also believes in conspiracy theories and does not fully trust the information provided by the media or the government.                                                                               &nbsp

Yersinia enterocolitica in the pig meat: A risk for food safety

Evropska agencija za bezbednost hrane (EFSA - European Food Safety Authority) objavila je u 2011. godini preporuke za inspekciju trupova svinja. Preporuke se odnose na najznačajnije biološke opasnosti po zdravlje ljudi koje se mogu naći u mesu. Pored Salmonella spp., Toxoplasma gondii i Trichinella spp., kao biološka opasnost navodi se i Yersinia enterocolitica. Yersinia enterocolitica, kao i druge bakterije iz familije Enterobacteriaceae, ima sposobnost opstanka u spoljašnjoj sredini, u koju dospeva preko inficiranih životinja. U Evropi, svinje su najčešći asimptomatski nosioci patogenih sojeva Y. enterocolitica za ljude, posebno soja biotipa 4 (serotipa O:3) i ne tako učestalog biotipa 2 (serotip O:9 i O:27). Uzročnici su najčešće lokalizovani u oralnoj duplji, posebno u tonzilama, submaksilarnim limfnim čvorovima, crevima i fecesu svinja. Pravilan postupak sa trupovima svinja, nakon klanja, može znatno da smanji nivo kontaminacije mesa svinja. Učestalost Y. enterocolitica kod svinja, kao rezervoara ovog patogena, veoma varira. Slučajevi jersinioze kod ljudi zabeleženi su, kako u Evropi, tako i u Japanu, SAD, Nigeriji i Brazilu.The European Food Safety Authority (EFSA - European Food Safety Authority) published in 2011. the recommendations of the inspection of carcasses of pigs. Recommendations are related to the most significant biological hazards to human health that can be found in meat. In addition to Salmonella spp., Toxoplasma gondii and Trichinella spp., as a biological hazard states and Yersinia enterocolitica. Yersinia enterocolitica, and other bacteria of the Enterobacteriaceae family having ability to survive in the environment, in which accrues through the infected animals. In Europe, pigs are the most common asymptomatic carriers of pathogenic strains of Y. enterocolitica to humans, especially biotype 4 (serotype O: 3) and not so frequent biotype 2 (serotype O: 9 and O: 27). The causes are usually localized in the oral cavity, especially in the tonsils, submaxillary lymph nodes, intestines and feces of pigs. The proper treatment of pig carcasses after slaughter, can significantly reduce the level of contamination of pig meat. The incidence of Y. enterocolitica in pigs, as reservoirs of this pathogen varies. Yersiniosis cases in humans have been reported, both in Europe and in Japan, the United States, Nigeria and Brazil

In situ architecture of the ER–mitochondria encounter structure

The endoplasmic reticulum and mitochondria are main hubs of eukaryotic membrane biogenesis that rely on lipid exchange via membrane contact sites1,2,3, but the underpinning mechanisms remain poorly understood. In yeast, tethering and lipid transfer between the two organelles is mediated by the endoplasmic reticulum–mitochondria encounter structure (ERMES), a four-subunit complex of unresolved stoichiometry and architecture4,5,6. Here we determined the molecular organization of ERMES within Saccharomyces cerevisiae cells using integrative structural biology by combining quantitative live imaging, cryo-correlative microscopy, subtomogram averaging and molecular modelling. We found that ERMES assembles into approximately 25 discrete bridge-like complexes distributed irregularly across a contact site. Each bridge consists of three synaptotagmin-like mitochondrial lipid binding protein domains oriented in a zig-zag arrangement. Our molecular model of ERMES reveals a pathway for lipids. These findings resolve the in situ supramolecular architecture of a major inter-organelle lipid transfer machinery and provide a basis for the mechanistic understanding of lipid fluxes in eukaryotic cells.<br/

Structural and Chemical Properties of Geopolymer Gels Incorporated with Neodymium and Samarium

The present work was focused on doping of 1% and 5% both of Nd2O3 and Sm2O3 in geopolymer gels. One of the main goals was to determine the influence of the behavior of Nd and Sm as dopants and structural nanoparticles changes of the final geopolymer formed. It is shown that the disorder formed by alkali activation of metakaolin can accommodate the rare earth cations Nd3+ and Sm3+ into their aluminosilicate framework structure. The main geopolymerization product identified in gels is Al-rich (Na)-AS-H gel comprising Al and Si in tetrahedral coordination. Na+ ions were balancing the negative charge resulting from Al3+ in tetrahedral coordination. The changes in the structures of the final product (geopolymer/Nd2O3; Sm2O3), has been characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analysis with energy dispersive spectrometry (EDS). Nucleation at the seed surfaces leads to the formation of phase-separated gels from rare earth phase early in the reaction process. It is confirmed that Nd and Sm have been shown to form unstable hydroxides Nd(OH)3 and Sm(OH)3 that are in equilibrium with the corresponding oxides

Analiza glavnih makroekonomskih indikatora u funkciji stabilnosti zemalja Zapadnog Balkana

U savremenim uslovima globalizacije svetske privrede, jedan od bitnih faktora koji utiče na rast i razvoj svake privrede jeste i makroekonomska stabilnost. Ekonomska politika treba da stvori uslove za makroekonomsku stabilnost i rast privrede na bazi povećanja investicija, izvoza, štednje, produktivnosti i konkurentnosti, uz smanjenje makroekonomskih neravnoteža, pogotovo fiskalnog deficita, inflacije i deficita tekućeg računa. Ključni makroekonomski ciljevi kojima teže sve privrede, pored povećanja proizvodnje, uključuju postizanje dugoročne ravnoteže, stabilnost opšteg nivoa cena i rast zaposlenosti. Da bi se uspostavila makroekonomska stabilnost kao i održiv privredni rast veoma je važno da se vodi racionalna ekonomska politika i izvrše ubrzane strukturne reforme. Glavni cilj rada jeste sagledavanje ključnih ekonomskih indikatora i analiziranje njihovog uticaja na privredni razvoj zemalja Zapadnog Balkana. Odnosno, utvrditi ulogu i snagu uticaja makroekonomske stabilnosti na ekonomski rast ovih zemalja. Ovakva analiza je veoma važna kako bi se prikazalo stanje privrede, predvidela njena stabilnost i omogućilo investitorima da pravovremeno reaguju na iznenadne i nepredvidive događaje. U radu će fokus biti na zemljama Zapadnog Balkan, dok će se za analizu koristiti sekundarni podaci baza Eurostat, UNCTAD, MMF i MOR za vremenski period 2011-2020. godina. Upoređujući zemlje Zapadnog Balkana može se zaključiti da Srbija znatno brže napreduje, s obzirom da se transformisala u rastuću ekonomiju sa niskom inflacijom, fiskalnim suficitom, opadajućim javnim dugom, manjom eksternom neravnotežom kao i oporavkom tržišta rada. U narednom periodu se može očekivati trend rasta u svim zemljama Zapadnog Balkan, što će za posledicu imati bolji ekonomski razvoj i sve veću otvorenost za nove investicije

Macracanthorhynchus in wild boars from mountain area of Serbia

Proceeding

Primena molekularnih tehnika dijagnostike u mikrobiološkoj analizi uzoraka meda

U cilju kvalitativno kvantitativnog utvrđivanja prisustva mikroorganizama, u uzorcima meda, koriste se klasiče i međunarodno priznate, standardne (ISO) metode izolacije, identifikacije, kvantifikacije i determinacije. Početkom dvadesetprvog veka a u cilju dobijanja brzih i pouzdanih rezultata laboratoriskih ispitivanja pristupa se izvođenju molekularnih metoda u uvrđivanju prisustva mikroorganizama u uzorcima meda. Navedene metode koristile su se za potvrdu i determinaciju mikroorganizama već izolovanih klasičnim i standardnim mikrobiološkim metodama ali i za direktno utvrđivanje prisustva mikroorganizama u ispitivanim uzorcima. U navedena ispitivanja uključena su ponovljena ispitivanja zbog fizičko-hemijskih karakteristika meda odnosno neravnomerne raspoređenosti mikroorganizama u ispitivanim uzorcima i mogućnosti dobijanja lažno negativnih rezultata. Molekularni pristupi u dijagnostici uključivali su osetljive i specifične testove lančane reakcije polimeraze (PCR), lančane reakcije polimeraze u realnom vremenu (Real-Time PCR) i metode gel-elektroforeze u pulsirajućem električnom polju (Pulse-Field Gel Elektrophoresis-PFGE). Detekcija mikroorganizama direktno iz neobrađenih uzoraka meda nije moguća. Zbog prisustva malog broja mikroorganizama, uglavnom spora, neophodna je priprema uzoraka meda koja mora uključiti postupak dilucije, predobogaćenja, centrifugovanja i membranske filtracije. Ovako dobijeni sadržaj koristi se za izolaciju ciljanih mikroorganizama klasičnim i standardnim metodama laboratorijske dijagnostike, odnosno za prečišćavanje i ekstrakciju nukleinskih kiselina za molekularne metode dijagnostike. U cilju detekcije mikroorganizama, u uzorcima meda, primenom molekularnih metoda dijagnostike, za svaki ispitujući uzorak moraju se izvoditi višestruka ponovljena ispitivanja zbog neravnomerne raspoređenosti mikroorganizama/spora i mogućnosti dobijanja lažno negativnih rezultata. U uzorcima meda kontaminiranim referentnim sojevima mikroorganizama, molekularnim metodama može da se dokaže prisustvo jedne ćelije/spore mikroorganizma u jednom gramu meda dok je to nemoguće dokazati klasičnim/standardnim metodama. Klasične i standardne metode mikrobiološke dijagnostike nisu podesne za detekciju mikroorganizama u uzorcima meda jer ove metode zbog niske osetljivosti daju lažno negativne rezultate.Zbornik radov

Physics informed neural networks for 1D flood routing

Machine learning methods have been widely and successfully applied in hydrological problems. Most of the methods, such as artificial neural networks, have been focused on estimating hydrological data based on observation over time. Even though these models provide good results, it can be observed that results become unreliable when the training dataset is small or when input data is significantly out of range compared to the training data. Therefore, a new approach is presented, in which artificial neural networks are trained to satisfy physical laws. This is conducted by a novel method called physics-informed neural networks (PINNs), in which physical principles are embedded in a custom loss function. This paper presents the application of physics informed neural networks for solving 1D flood wave propagation in open channels. The research has shown promising results