Effect of the kanamycin resistance marker on stability of 2μ-based expression plasmids

U ovom radu opisan je uticaj gena za kanamicinsku rezistenciju (Kmr) na održavanje 2μm plazmida u Saccharomyces cerevisiae. Prisustvo ovog marker gena dovodi do gubitka stabilnog model-vektora konstantnom stopom nezavisnom od izvora ugljenika i stope rasta kulture. Kod sojeva za sintezu heterolognih proteina sa galaktoznog promotora (GALUAS) uvođenje Kmr rezultira "čišćenjem" od kvaščevih epizomalnih plazmida (YEp) u svega nekoliko generacija. Primena selektivnog pritiska na sojeve koji proizvode rekombinantnu penicilin G amidazu (rPGA) nije dovela do očekivanog povećanja prinosa proteina. Ispitivanjem uticaja samih genetičkih elemenata za proizvodnju heterolognih proteina na stabilnost vektora pokazano je da najjače destabilišuće dejstvo ima prisustvo i eksprecija stranog gena.In this paper we describe the effect of the kanamycin resistance gene (Kmr) on 2μm-based plasmid maintenance in Saccharomyces cerevisiae. The influence of this marker gene on the loss of the stable model-vectors proved to be constant, as well as independent of carbon source and culture growth rates. In strains for GALUAS - driven heterologous protein production introduction of Kmr resulted in curing of the yeast episomal plasmid (YEp) from the population in a small number of generations. Application of selective pressure on the strain producing recombinant penicillin G amidase (rPGA) did not provide the expected increase of protein yield. The influence of genetic elements for heterologous protein production on vector stability was examined, and the most destabilizing factors prove to be the presence and expression of the foreign gene

Uticaj kalcifikacije na promene agrohemijskih osobina pseudogleja i prinos lucerke

The paper examines the effects of lime application at the rate of 3 t/ha on pseudogley soil agrochemical changes and alfalfa yield during a two-year period. The applied lime in combination with mineral fertilizers significantly decreased acidity in H20 (by 0.6 pH units) and in nKCl (by 0.81 pH units). At the same time, there was increase in phosphorus availability (from 6.2 mg/100g of soil, control, to 19.1 mg/100 g of soil, variant with lime) and soil base saturation percentage in the 0-30 cm arable horizon. The performed liming intensified organic matter mineralization, which caused decrease of humus content as well as of mobile Al and Fe content compared to control. Moderate liming improved pseudogley agrochemical properties, which was manifested by increased alfalfa yield. In the first study year 19.7 t/ha of forage and 5.7 t/ of hay, respectively, was produced in control variant, while 28.5 t/ha of forage and 8.2 t/ha of hay, respectively, was produced in a variant with liming. Even higher yield was achieved in the second year of alfalfa utilization (8.5 t/ha of forage and 2.2 t/ha of hay, respectively, was produced in control, and 71 t/ha of forage and 16.3 t/ha of hay, respectively, in a variant with liming). .Loše agrofizičke, a naročito agrohemijske osobine pseudoglejnih zemljišta okoline Kraljeva su ograničavajući faktor za gajenje lucerke. Cilj ovih istraživanja je bio da se melirativnom đubrenjem zemljišta-primenom kalcifikacije poprave agrohemijska svojstva pseudogleja i povisi prinos zelene krme i sena lucerke. Rezultati ovih istraživanja pokazuju da se umerenom kalcifikacijom od 3 t/ha kreča može značajno smanjiti kiselost za 0,6 pH jedinica u r^O, i za 0,81 pH jedinicu u nKCl. Smanjenjem kiselosti povećana je pristupačnost fosfora (sa 6,2 mg/100g zemljišta, kontrola, na 19,1 mg/100g zemljišta varijanta sa primenom kreča) i povećan stepen zasićenosti zemljišta bazama u oraničnom horizontu od 0-30cm. Izvedena kalcifikacija pojačala je mineralizaciju organske materije što je uticalo na smanjenje sadržaja humusa, a takođe smanjenje i sadržaja mobilnog Al i Fe u odnosu na kontrolu varijantu. Popravljena agrohemijska svojstva pseudogleja doprinela su povećanju prinosa krme i sena lucerke. U prvoj godini na kontrolnoj varijanti ostvaren je prinos krme od 19,7 t/ha, odnosno 5,7 t/ha sena, dok na varijanti sa primenom kreča 28,5 t/ha krme, odnosno 8,2 t/ha sena. To povećanje prinosa još je vise bilo izraženo u drugoj godini iskorišćavanja lucerke (kontrola 8,5 t/ha krme, odnosno 2,2 t/ha sena, a varijanta sa krečom 71,4 t/ha krme, odnosno 16,3 t/ha sena)

Prinos i kvalitet lucerke u zavisnosti od genotipa i tehnologije gajenja

It is essential to apply advanced management for successful production of alfalfa hay with premium quality (high content of protein and minerals). The maximum yield and the best quality of alfalfa in Serbia can be obtained by cutting four or five times per year. In alfalfa stands, use of cutting system with three cuts per year is inefficient and does not allow full exploitation of cultivar genetic potential and environmental conditions. It is possible, and economically beneficial to grow alfalfa on pseudoglay soils after application of lime and organic manure, with recommended rates 2.5 t ha-1 lime and 30 t ha-1 manure. Cutting alfalfa at the beginning of flowering stage (5 cuts per year) provides hay with better quality - higher content of crude protein and lower portion of fibre fractions (neutral detergent fibre, acid detergent fibre, acid detergent lignin), and there is no reduction in dry matter yield. There is no differences in alfalfa quality after application of lower (2.5 t ha-1) and higher dose (5.0 t ha-1) of lime + 30 t ha-1 of organic manure, but there is significant increase of dry matter yield and protein yield per hectare followed by higher level of metabolic energy per unit area. Upon the results of this study, base of successful alfalfa production would be to develop management system and cultivars for different environments that would maximize hay yields without significant loses of quality.Cilj rada je bio da se utvrdi uticaj genotipa i tehnologije gajenja na prinos i kvalitet lucerke. Postavljena su dva ogleda sa istim setom sorti (Banat VS, Nijagara, NS Alfa i NS Mediana ZMS V) na lokalitetima Rimski šančevi i Drakčići - rejon Kraljeva. Na lokalitetu Čenej ispitivan je uticaj sorte i sistema kosidbe na prinos i kvalitet lucerke, dok je u regionu Kraljeva ispitivan uticaj genotipa i različitih tretmana đubrenja krečom i stajnjakom. Dobijeni rezultati ukazuju da za uspešnu proizvodnju treba sejati sortno seme lucerke, a da izbor sorte zavisi od ekoloških uslova (zemljišta) i primenjene agrotehnike (režima kosidbe, đubrenja, navodnjavanja). Košenjem lucerke 3 puta godišnje ne iskorišćavaju se genetički potencijal sorte i agroekološki uslovi naše zemlje. Na pseudoglejnim zemljištima se može gajiti lucerka, posle primene krečnog materijala i stajnjaka. Rezultati ukazuju na značaj primene 2,5 t/ha kreča i 30 t/ha stajnjaka. Košenjem u fazi početka cvetanja (5 otkosa) dobija se bolji kvalitet - veći sadržaj sirovih proteina i manji udeo frakcija celuloze (NDF, ADF, ADL), a ne dolazi do smanjenja prinosa suve materije lucerke. Kvalitet lucerke se ne razlikuje posle primene niže (2,5 t/ha) i više (5,0 t/ha) doze krečnog materijala i 30 t/ha stajnjaka, ali dobija se povećanje prinosa suve materije, a time i veći prinos proteina i veća metabolička energija (NEM, NEL) po jedinici površine. Prinos i kvalitet suve materije lucerke najviše zavise od tehnologije gajenja (nivoa agrotehnike) i izbora sorte

Effect of iron supplementation on maximal oxygen uptake in female athletes

Background/Aim. Iron is a vital constituent of hemoglobin, myoglobin, and some mitochondrial enzymes; therefore, body iron deficiency may result in reduced aerobic capacity. The aim of this study was to evaluate the effects of daily oral iron supplementation on body iron status, and the maximal oxygen uptake (VO2max) in female athletes with latent iron deficiency, as well as with irondeficiency anemia. Methods. A total of 37 female volleyball players were included in the study. Seventeen female athletes had latent iron deficiency, and 20 ones iron deficiency anemia. Both groups were divided into the experimental and the control group. The experimental groups received a daily oral iron supplement (200 mg ferrous sulfate), for a two-month training course. Iron status was determined by serum parameters as follows: red blood cells count, hemoglobin concentration, serum iron and ferritin levels, an unsaturated iron binding capacity, total iron binding capacity and transferrin saturation. VO2max was determined by an indirect test. Results. Statistical difference between the latent iron deficient group versus the iron deficient anemic group was found regarding VO2max (p < 0.001). There were correlations between hemoglobin concentration and VO2max in the latent iron deficient group, as well as in the iron deficient anaemic group (p < 0.05). After two months, there was a significant increase in VO2max in all groups (from 7.0% to 18.2%). Values of VO2max at the end of training period were significantly different (45.98 ± 1.76 vs 42.40 ± 1.22 mL/kg/min; p <0.001) between the experimental and the control group only in female athletes with iron deficiency anemia. After the supplementation, markers of iron status were significantly higher in supplemented groups than in the controls. Conclusion. VO2max was significantly lower in the iron deficient anemic group versus the latent iron deficient group. Iron supplementation during a two-month training period significantly improved body iron status in the iron deficient female athletes with or without anemia, and significantly increased VO2max only in the subjects with iron deficiency anemia

Nanostructured SnO2 thick films for gas sensor application: analysis of structural and electronic properties

This research is focused on structural and electrical characterisation of tin oxide (SnO2) applied as a thick film and investigation of its properties as gas sensitive material. Micron sized SnO2 powder was milled in an agate mill for six hours to fabricate SnO2 nanopowder, which was afterwards sieved by 325 mesh sieve and characterized by XRD and SEM. This powder was used as functional part in the production of thick film tin oxide paste containing a resin vehicle with 4 wt. % nanosize glass frits acting as permanent binder. The glass frits where additionally milled for twelve hours in the agate mills to nanosized powder and sieved by a 325 mesh sieve as well. The achieved thick film paste was screen printed on alumina and fired at 850oC peak temperature for 10 minutes in air. After the sintering process, thick film samples where characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The reflectivity was measured on the same samples by UV-VIS spectrophotometer: the band gap was determined from the slope of reflectance. After that a matrix of different interdigitated electrode structure of PdAg paste was printed and sintered using the mentioned sintering conditions. The tin oxide thick film was printed over the interdigitated electrodes as a top layer and sintered again under the same conditions. The total electrical resistance was measured as a function of the electrode spacing and temperature. A negative temperature coefficient (NTC) was identified and measured in the range from room temperature (27°C) to 180°C in a climate chamber. Finally the samples were placed into a gas reactor with NOx and CO gas and the resistance was measured in the same temperature range (27°C-200°C)

Troškovi korišćenja uređaja za aeraciju vode na toplovodnim ribnjacima

Modern fish production requires utilization of new technologies, which assumes application of appropriate mechanization and devices. In the process of the fish production in the warm-water fish-ponds it frequently appears a problem of lacking the oxygen dissolved in water. This problem may be solved by utilization of water aeration device. Selection of the water aeration device is usually carried out in our practice on the basis of its technological and exploitation characteristics, without knowledge of economic effects both of its provision and utilization of concrete technical solution. Economic effects of aeration device utilization suppose complete knowledge of methodological procedure for calculation of costs, as well as disposal of reliable initial data necessary for calculation of the costs for such devices.Savremena proizvodnja ribe podrazumeva primenu novih tehnologija, koje za sobom povlače i upotrebu odgovarajućih sredstava mehanizacije i uređaja. U uzgoju ribe na toplovodnim ribnjacima se kao čest problem javlja nedostatak kiseonika rastvorenog u vodi, što se može rešiti primenom uređaja za aeraciju vode. Odabir uređaja za aeraciju vode se u našoj praksi najčešće vrši na osnovu njegovih tehnološko-eksploatacionih karakteristika, bez poznavanja ekonomskih efekata nabavke i primene konkretnog tehničkog rešenja. Ekonomski efekti upotrebe uređaja za aeraciju podrazumevaju potpuno poznavanje metodološkog postupka za određivanje troškova, kao i raspolaganje pouzdanim polaznim podacima koji su neophodni za izračunavanje troškova eksploatacije ovakvih uređaja

Prinos i ekonomičnost proizvodnje sena lucerke u zavisnosti od đubrenja

Alfalfa is the most important forage crop in Serbia grown for high yields of quality fodder. In order to expand alfalfa production on pseudogleys, research was conducted in the vicinity of Kraljevo. Results suggest the potential for growing alfalfa on acid soils in Serbia. The combined use of 2.5 t ha-1 and 5 t ha-1 lime and 30 t ha-1 manure on the pseudogley increases the soil pH, humus content and available phosphorus and potassium levels, while decreasing the content of mobile aluminum, thus making the soil suitable for alfalfa production and high biomass yields (115.9 t ha-1) during 3-4 years of stand utilization.Lucerka je najznačajnija krmna biljka u Srbiji jer daje visoke prinose kvalitetne kabaste stočne hrane, koja se najviše koristi u ishrani preživara, uglavnom kao seno. Zbog izuzetne osetljivosti na niske pH vrednosti zemljišta, u cilju proširenja areala, lucerka je gajena na pseudogleju, na području Kraljeva. Đubrenje lucerke samo mineralnim đubrivima ne utiče na promenu agrohemijskih osobina pseudogleja, ali se dodavanjem kreča prinos lucerke značajno povećava. Rezultati ukazuju na mogućnost gajenja lucerke na ovom tipu zemljišta uz odgovarajuće đubrenje. Primenom 2,5 t ha-1 i 5 t ha-1 kreča u kombinaciji sa 30 t ha-1 stajnjaka na pseudogleju se povećava pH vrednost zemljišta, raste sadržaj humusa, pristupačnog fosfora i kalijuma, i smanjuje se sadržaj mobilnog aluminijuma, što ga čini podesnim za gajenje lucerke i postizanje visokih prinosa biomase (115,9 t ha-1) tokom perioda iskorišćavanja od 3-4 godine. U gajenju lucerke na kiselim zemljištima, mora se voditi računa o ekonomičnosti primene mineralnih đubriva i kreča

Erosion control and protection from torrential floods in Serbia-spatial aspects

Torrential floods represent the most frequent phenomenon within the category of “natural risks” in Serbia. The representative examples are the torrential floods on the experimental watersheds of the rivers Manastirica (June 1996) and Kamišna (May 2007). Hystorical maximal discharges (Qmaxh) were reconstructed by use of ″hydraulics flood traces″ method. Computations of maximal discharges (Qmaxc), under hydrological conditions after the restoration of the watersheds, were performed by use of a synthetic unit hydrograph theory and Soil Conservation Service methodology. Area sediment yields and intensity of erosion processes were estimated on the basis of the “Erosion Potential Method”. The actual state of erosion processes is represented by the coefficients of erosion Z=0.475 (Manastirica) and Z=0.470 (Kamišna). Restoration works have been planned with a view to decreasing yields of erosive material, increasing water infiltration capacity and reducing flood runoff. The planned state of erosion processes is represented by the coefficients of erosion Z=0.343 (Manastirica) and Z=0.385 (Kamišna). The effects of hydrological changes were estimated by the comparison of historical maximal discharges and computed maximal discharges (under the conditions after the planned restoration). The realisation of restoration works will help decrease annual yields of erosive material from Wа=24357 m3 to Wа=16198.0 m3 (Manastirica) and from Wа=19974 m3 to Wа=14434 m3 (Kamišna). The values of historical maximal discharges (QmaxhMan=154.9 m3•s-1; QmaxhKam=76.3 m3•s-1) were significantly decreased after the restoration (QmaxcMan=84.5 m3 •s-1; QmaxcKam=43.7 m3•s-1), indicating the improvement of hydrological conditions, as a direct consequence of erosion and torrent control works. Integrated management involves biotechnical works on the watershed, technical works on the hydrographic network within a precisely defined administrative and spatial framework in order to achieve maximum security for people and their property and to meet other requirements such as: environmental protection, sustainable soil usage, drinking water supply, rural development, biodiversity sustaining, etc. The lowest and the most effective level is attained through PAERs (Plans for announcement of erosive regions) and PPTFs (Plans for protection from torrential floods), with HZs (Hazard zones) and TAs (Threatened areas) mapping on the basis of spatial analysis of important factors in torrential floods formation. Solutions defined through PAERs and PPTFs must be integrated into Spatial Plans at local and regional levels

Autonomous Vehicles and Automated Warehousing Systems for Industry 4.0

The rapid development of new technologies that enabled the emergence of important development segments such as the Internet of Things, Cyber Physical Systems, Information and Communication Technologies, Enterprise Architecture, and Enterprise Integration, have led to completely new manufacturing paradigms, which is called under the common name – Industry 4.0. The constantly growing use of autonomous vehicles and associated logistics solutions is among the most influential factors that foster this novel intelligent production framework. This paper describes the results of the latest research activities of the Laboratory for Robotics and Intelligent Control Systems in the Industry 4.0 domain where the focus lies on the shop floor digitalization and advanced control concepts that enable the transfer of technology and delivery of high-scalable logistic solutions