Oil and gas price determining in the conditions of economic crisis

Given that oil and gas have the largest share in the total consumption of energy in the world, the author of this article points out the price of these fuels as an economic category that is necessarily interfere with the economic picture of each individual and therefore the global economy. Except as a fuel, oil has an extremely wide application in the manufacture of various products, which further affects the significance of this resource and justifies the name of "black gold" as it's also called. The level of oil and gas prices has a direct impact on the volume and efficiency of economic activity, but also to the standard of living. As such economic categories oil and gas are in direct or indirect relationship with the economic crisis and political instability around the world. On the one hand we have a net importer and a net exporter of oil at the other. The reduction of production by the exporter has a significant impact on the oil market itself but also to the economic activity of importers of this important resource. Since oil and gas are non-renewable sources of energy, it can be noted that through the history have often been the cause of great international tensions and the reason for making war in order to capture these energy sources. More oil shocks affected the world economy during the sixties and seventies of the last century, embodied the embargo and oil crisis. Special attention will be paid to fluctuations in the price of oil and gas as a result of the global economic crisis in 2008. year. If we look at the relationship between oil and gas prices, on the one hand, and the man on the other hand, we can easily realize that the daily life of man forms depending on the level of prices of these fuels if any person occurs as a direct consumer of petroleum products and natural gas, or so what is the price of these fuels embedded in almost all the products that one uses in everyday life. The author will give attention to the role and importance of oil and gas for Serbian economy and way of its pricing. It will be done the study of supply chain in oil and gas users in Serbia and policy formation rates of these fuels. Also, this work will analyses the strategic position of Serbia in the supply chain of these fuels in the “Јužni tok”

Samoprijavljene alergije na lijekove kod kirurških bolesnika u Srbiji

History of drug allergy is of major concern during perioperative period. Medical records usually lack documents confirming the stated allergy. This study aimed to investigate the prevalence of self-reported drug allergies and their characteristics in adult Serbian surgical population, and to analyze their influence on drug prescription during perioperative period. The study enrolled patients scheduled for general surgery during a one-year period at a tertiary care hospital. They were questioned using a structured questionnaire about the existence of drug allergy and its nature. Medical records were examined after discharge to assess medical prescription during hospitalization. Of 1126 patients evaluated during the study period, 434 (38.5%) reported a total of 635 drug reactions. The most common allergy claim was to antibiotics (68%), nonsteroidal antiinflammatory drugs (16.4%) and iodine (3.9%). Women, urban residents and herbal drug consumers were more likely to state an allergy. The majority of reported reactions were cutaneous (72%) and respiratory (34%), while anaphylaxis was reported by 3.2% of patients. Only 38 (8.7%) patients had previously undergone any allergology testing. Retrospective chart review revealed that 26 (6%) patients were administered the drug to which they had reported allergic reaction in the past, with no adverse effects. Drug allergies are frequently self-reported in surgical population in Serbia, which is in contrast to a very low rate of explored and documented allergies. In order not to deny an effective treatment or postpone a surgery, health care practitioners should pay more attention to an accurate classification of adverse drug reactions.Podatak o alergiji na lijekove je od velikog značenja u perioperacijskom razdoblju, a medicinska dokumentacija obično ne sadrži dokumente koji potvrđuju prijavljenu alergiju. Cilj ovoga istraživanja bio je ispitati učestalost i značajke samoprijavljenih alergija na lijekove od strane odraslih kirurških bolesnika u Srbiji i analizirati utjecaj takvog anamnestičkog podatka na propisivanje lijekova u perioperacijskom razdoblju. Studija je obuhvatila bolesnike podvrgnute elektivnim kirurškim intervencijama iz područja opće kirurgije tijekom jednogodišnjeg razdoblja u tercijarnoj zdravstvenoj ustanovi. Oni su ispitivani primjenom strukturiranog upitnika o postojanju alergija i njihovoj naravi. Medicinska dokumentacija je pregledana nakon otpusta iz bolnice kako bi se ispitalo propisivanje lijekova tijekom hospitalizacije. Od 1126 bolesnika evaluiranih tijekom studije, 434 (38,5%) ih je prijavilo ukupno 635 reakcija na lijekove. Najčešće samoprijavljene alergijske reakcije su bile na antibiotike (68%), nesteroidne protuupalne lijekove (16,4%) i jodni kontrast (3,9%). Samoprijavljivanje alergija je bilo češće kod žena, stanovnika urbanih područja i korisnika biljnih lijekova. Većinu prijavljenih reakcija su činile kožne (72%) i respiracijske (34%), dok je anafilaksu prijavilo 3,2% bolesnika. Samo 38 (8,7%) bolesnika je nakon reakcije podvrgnuto nekom alergološkom testiranju. Pregled povijesti bolesti je pokazao da je 26 (6%) bolesnika tijekom hospitalizacije primilo lijek na koji su prijavili alergijsku reakciju u prošlosti, što nije bilo praćeno neželjenim učincima. Samoprijavljivanje alergija na lijekove je veoma često kod kirurških bolesnika u Srbiji, što je u suprotnosti s niskom stopom ispitanih i dokumentiranih alergija. Kako se bolesnicima ne bi uskratila učinkovita terapija ili odlagala operacija, zdravstveni radnici bi trebali više pozornosti posvetiti preciznoj klasifikaciji neželjenih reakcija na lijekove

DIFFERENCES IN EXPLOSIVE STRENGTH OF ELITE FEMALE HANDBALL PLAYERS DURING THE COMPETITION SEASON

The aim of our research was to determine the explosive strength of the legs i.e., the height of the jump of the top-ranked female handball players during the season. 15 female players underwent the following tests for estimating the explosive strength of the legs: SJ, CMJ, CMJ free arm, CMJ right leg and CMJ left leg. The Student’s t-test was applied for establishing the changes between the measuring sessions during the season. The results obtained show that there were statistically significant changes and better results at the end of the season in the following parameters: CMJ right leg =.002 and CMJ left leg = .018, whereas no significant changes occurred in all the other two-leg jumps. Taking into consideration the fact that in performing different throws and goal shooting the most prominent movements in handball are done on one leg, the results were expected. It is recommended that throughout the season the training process should include additional exercises for improving and maintaining the ability of the handball players to jump (plyometric, proprioceptive and the combination of the two with the common strength improving exercises), since their positive effects have been proven by quite a few studies

Potentials of cultural-historical and tourism heritage for the development of tourism in the Timok region

In recent years, the term "industrial tourism" has been increasingly used in the literature. It describes an area that includes industrial monuments and abandoned buildings, and above all rare ones that are still in function. Industrial tourism includes all plants used for food processing, wood processing and textile industry, there are also mills, ports, mines, car and aviation industry, shipyards, etc. Within the doctoral dissertation entitled "Potentials of cultural-historical and economic heritage for the development of industrial tourism in the Timok region", a research was conducted that deals with the growing interest of industrial tourism in Eastern Serbia, more precisely in the Timok region. This branch of tourism is no longer a sphere of interest only for certain groups of technical experts, but also for regular tourists who are interested in touring certain regions. The aim of the research is to present the possibilities for the development of industrial tourism in the Timok region, as well as to obtain data on the current situation. The research is based on the experiential information of tourism workers who, due to the nature of their work and interests, are relevant to the proposed topic. The surveyed respondents are employed in the field of tourism in various positions, as well as students who are educated in the field of tourism. The data obtained during the research indicate respondents believe that the media do not sufficiently inform potential tourists about industrial tourism attractions, the potential of the tourist offer, but also about the Timok region itself, both locally and beyond, in Serbia and abroad. Such data indicate the possibility of improvement through the application of an adequate strategy to promote and inform potential users, as well as the insufficient usage of the industrial potential of the region itself. Investing certain resources in the marketing and development of industrial tourism would create additional demand, and this would result in the improvement of the tourist offer. Valorization of industrial heritage in Eastern Serbia can stimulate regional identity, revitalize the area and create additional tourist attractions. Plans and results from certain projects of this type are very important for the region, but also for the state

Proizvodnja lipaze iz Pseudozyma aphidis i utvrđivanje aktivnosti i stabilnosti lipaze u polarnim organskim rastvaračima

The production of lipase from Pseudozyma aphidis (DSM 70725) was determined in six different media. The highest lipase production was observed in a medium with glucose as the sole carbon source, and yeast extract and sodium nitrate as the nitrogen sources. The time course studies of growth and lipase production in the optimal medium revealed that the highest lipase production was achieved at the end of the log phase of growth, reaching the value of 35.0 U cm(-3) in the fifth day of cultivation. The effects of various polar, water-miscible, organic solvents on the activity and stability of the crude lipase produced by P. aphidis were evaluated. The hydrolytic activity of the crude lipase towards p-nitrophenyl palmitate (p-NPP) in aqueous media and in organic solvents was determined, using the same spectrophotometric assay in both the aqueous and organic media. The crude lipase preparation exhibited activity towards p-NPP only in acetone and acetonitrile, while the lipase was stable only in acetone, with 23 % residual activity after 24 h of incubation. These results suggested that lipase from P. aphidis can be used as a biocatalyst for potential applications in such organic solvents.Proizvodnja lipaze iz Pseudozyma aphidis utvrđena je u šest različitih medijuma. Najviša proizvodnja uočena je u medijumu gde je glukoza bila izvor ugljenika, a ekstrakt kvasca i natrijum-nitrat izvori azota. Praćenjem dinamike rasta i proizvodnje lipaze u optimalnom medijumu, uočeno je da se najviša proizvodnja lipaze dostiže pred kraj logaritamske faze rasta, i dostiže vrednost od 35 U cm-3 u petom danu kultivacije, što je četri puta veća proizvodnja od one do sada prijavljene u literaturi. Utvrđen je efekat različitih polarnih organskih rastvarača, mešljivih sa vodom, na aktivnost i stabilnost lipaze iz P. aphidis. Hidrolitička aktivnost lipaze prema para-nitrofenil-palmitatu (p-NPP-u) u vo- denoj sredini i organskim rastvaračima utvrđena je upotrebom istog spektrofotometrijskog testa. Pokazano je da lipaza ima aktivnost prema p-NPP-u samo u acetonu i acetonitrilu, dok je enzim stabilan jedino u acetonu i zadržava 23% aktivnosti nakon 24 časa inkubacije. Dobijeni rezultati ukazuju da lipaza iz P. aphidis može biti korišćena kao biokatalizator za potencijalne primene u acetonu kao medijumu

Enzymatic synthesis of vitamin B6 precursor

3-Cyano-4-ethoxymethyl-6-methyl-2-pyridone is an important precursor in the synthesis of vitamin B6, obtained in the addition reaction between 2-cyanoacetamide and 1-ethoxy-2,4-pentanedione catalyzed by lipase from Candida rugosa (triacylglycerol ester hydrolases, EC 3.1.1.3). This work shows new experimental data and mathematical modeling of lipase catalyzed synthesis of 3-cyano-4-ethoxymethyl-6-methyl-2-pyridone, starting from 1-ethoxy-2,4-pentanedione and 2-cyanoacetamide. Kinetic measurements were done at 50 oC with enzyme concentration of 1.2 % w/v. Experimental results were fitted with two kinetic models: the ordered bi-ter and ping-pong bi-ter model, and the initial rates of the reaction were found to correlate best with a ping-pong bi-ter mechanism with inhibition by 2-cyanoacetamide. Obtained specificity constants indicated that lipase from C. rugosa had higher affinity towards 1-ethoxy-2,4-pentanedione and less bulky substrates. [Projekat Ministarstva nauke Republike Srbije, br. 172013, br. III 46010 and br. 172049

Uticaj kose sadnje i modifikovanja uzgojne forme na proizvodne osobine sorti jabuke

This study examines influence of slope planting apple trees and bending central leader, on generative potential and productivity properties of three cultivars ‘Scarlet Spur’, ‘Galaxy’ and ‘Tentation’, on conditions of Obrenovacka Posavina area (2010-2011). Ap­ple trees of same cultivars in standard slender spindle form are used as control. The study include number of flower buds per three, number of flowers per three, number of fruits per tree, percentage of fruit set, fruit weight and yield per tree and per hectare. The treatment and control trees did not show statistically significant differences in the generative potential, but all the cultivars achieved best performances in the treatment of slope planting trees with the bent central leader. This result was achieved by increasing tree density per unit area, but due to the modification of the training system. Absolutely the highest average fruit yield in this treatment was recorded in cultivar ‘Tentation’ (81.7 t ha-1).U radu su prikazani rezultati ispitivanja uticaja kose sadnje vitkog vretena i povijanja vodice stabala jabuke, na generativni potencijal i proizvodna svojstva tri sorte ove vrste voćaka - Scarlet Spur, Galaxy i Tentation - u uslovima Obrenovačke Posavine (2010-2011). Kao kontrolna varijanta korišćen je standardni zasad istih sorti jabuke sa vertikalno posađenim stablima oblikovanim u formi vitkog vretena. Od pokazatelja vegetativnog potencijala i proizvodnih svojstava sorti u ogledu su praćeni: broj cvetnih pupoljaka po stablu, broj cvetova po stablu, broj plodova po stablu, procenat oplodnje, masa ploda i prinosi po stablu i hektaru zasada. Stabla tretmana i kontrole nisu iskazala statistički značajne razlike u generativnom potencijalu, ali su sve ispitivane sorte najbolji proizvodni rezultat ostvarile u tretmanu kose sadnje stabala sa povijenom vodicom. Ovaj rezultat je postignut zahvaljujući većem broju stabala po jedinici površine, ali zahvaljujući i modifikovanju uzgojnog oblika. Apsolutno najveći prosečan prinos plodova u ovom tretmanu zabeležen je kod sorte Tentation od 81,7 t ha-1

Stabilizacija lipaza iz Candida rugosa jednostavnom i efikasnom imobilizacijom na hidroksiapatitu

Razvili smo brz i efikasan metod imobilizacije industrijski veoma vrednih Candida rugosa lipaza (CRL) na ekonomičan, biokompatibilan nosač - hidroksiapatit, sa visokim prinosom imobilizacije (blizu 100 %) i prinosom aktivnosti od 50 %. Imobilizovane lipaze su pokazale značajno višu stabilnost nego slobodni enzim, nakon termalnog tretmana na 60 oC i u prisustvu različitih 95 % polarnih organskih rastvarača, pre svega kratkolančanih alifatičnih alkohola, značajnih polaznih sirovina u sintezi brojnih estara i drugih značajnih proizvoda. Predstavljeni rezultati ukazuju na veliki upotrebni potencijal dobijenog preparata u različitim industrijskim procesima, koji iziskuju rad u nekonvencionalnim reakcionim uslovima.We have developed a simple and highly effective method for immobilising industrially very appreciated and valuable Candida rugosa lipases from commercial preparation on ecologically suitable, biodegradable and economical hydroxyapatite support. Our immobilisation protocol resulted in excellent immobilisation yield of nearly 100 % and activity yield of 50 %, which is significantly higher in comparison to other immobilisation protocols for different enzymes on the same support. Immobilised lipase formulation has proven to have superior stability, compared to free enzyme, at both high temperature (60 o C) and in the presence of different polar organic solvents, especially short-chain alcohols: methanol, ethanol and iso-propanol. Therefore, presented experimental data strongly support the great future potential of the prepared Candida rugosa immobilisat

Influence of planting density on yield of peach and nectarine

The influence of three different planting densities on yield of three peach cultivars: ‛Early O’ Henry’, ‛Sunprince’, and ‛Autumn Glo’, and two nectarine cultivars: ‘Vinčanka’ (clone of ‛Stark Redgold’) and ‛Max 7’ was studied during three-year period (2009-2011). In high density planting, seedlings of vineyard peach were planted at the space of 3.5 x 1 m (2,800 trees ha-1) and grafted at the height of 50 cm. The trees were trained as a new original training system named ‘Sloping Leader’ that is characterized with a central leader that is bent and follows row direction at an angle of 25° to the trunk. In standard experimental plot, one-year old peach trees were planted and trained as ‘Fusetto’ form (4 x 2 m; 1,250 trees ha-1) and Open Vase (4 x 4 m, 625 trees ha-1). The following characteristics were studied: yield per tree and unit area (ha), as well as yield efficiency based on trunk cross-sectional area and on crown projection area. In the first three years of cropping significantly higher yields were achieved in the high-density planting system. Yield efficiency expressed based on the crown projection area, was also significantly higher in the high-density planting system