Infinite symmetric products of rational algebras and spaces

We show that the infinite symmetric product of a connected graded-commutative algebra over the rationals is naturally isomorphic to the free graded-commutative algebra on the positive degree subspace of the original algebra. In particular, the infinite symmetric product of a connected commutative (in the usual sense) graded algebra over the rationals is a polynomial algebra. Applied to topology, we obtain a quick proof of the Dold-Thom theorem in rational homotopy theory for connected spaces of finite type. We also show that finite symmetric products of certain simple free graded commutative algebras are free; this allows us to determine minimal Sullivan models for finite symmetric products of complex projective spaces

Winter wheat yield and quality depending on the level of nitrogen, phosphorus and potassium fertilization

Tests were carried out on stationary field trial, soil type vertisol in the process of degradation. The land on which the view is derived is characterized by low pH (pH lt 5.0). The Dose of nitrogen was 120 kg N/ha, which was administered in combination with phosphorous and potassium fertilizer. The tests showed a significant grain yield. Nitrogen had a most significant impact on the yield of wheat. The average grain yield of all treatments in the 2008/09 growing season was significantly greater than in the following years, mostly as the result of highly favourable weather conditions at major stages of plant development. The average highest yield was achieved in the variant N120P100K60 (5.528 t/ha), although the high yield of more than 5 t/ha was obtained and the triple treatments NPK where nitrogen is applied in the maximum amount of 120 kg/ha, 60 kg/ha P2O5 and 60 kg/ha K2O as well as variants NP in a quantity of 100 kg/ha P2O5 and 60 kg/ha K2O. Also, the 1000-grain weight was highest in balanced fertilization with all nutrients NPK (40 g), in a quantity of 120 kg N/ha, 100 kg/ha P2O5 and 60 kg/ha K2O. Averaged across years, significantly higher values for test weight were found in the control (76.91 kg/hl). Variance analysis showed statistically significant differences for grain yield and test weight between the vegetation seasons. Significant differences for 1000 grain weight between the variants of fertilization

Uticaj genotipa i uzrasta na proizvodne osobine lakih linijskih hibrida kokoši

The aim of this work was parallel investigation of the producing characteristics of light line hen hybrids. Investigation enclosed two hen proveniences: Hisex Brown and Shawer 579. Within the period of 19 up to 63 weeks we followed next parameters: egg-laying hen body mass, mortality, food consumption and egg-laying capacity. Hens body mass on the beginning of the examination, within the 19 weeks of growth was, for Hisex Brown provenience 1607g, and for Shawer 579 provenience 1563g. Hisex Brown provenience achieved about 250 g higher body mass on the end of investigation. During the experiment, mortality at Hisex Brown egg-laying hen was a little bit smaller (5,40%), while the Shawer 579 had 5,56% of dead hens. Globally, the mortality at both hen hybrids was in the range of technological normative. The average consumption of the food at Hisex Brown provenience was higher and it was 127,28g, and at Shawer 579 provenience 125,14g. The average consumption of the nutrition for egg production at both provenience was the same (150g).Cilj ovog rada bio je da se izvrši uporedno ispitivanje proizvodnih sposobnosti lakih linijskih hibrida kokoši. Ispitivanjima su obuhvaćene dve provenijence kokoši: Hisex Brown i Shawer 579. U periodu od 19. do 63. nedelje starosti praćeni su sledeći parametri: telesna masa nosilja, mortalitet, utrošak hrane i nosivost. Telesna masa kokoši na početku ispitivanja, sa 19 nedelja uzrasta, za provenijencu Hisex Brown, iznosila je 1607 g, a za provenijencu Shawer 579-1563 g. Veću telesnu masu na kraju eksperimenta, za oko 250 g postigle su nosilje provenijence Hisex Brown. U toku ispitivanja, mortalitet kod Hisex Brown nosilja je bio nešto manji (5,40%), dok je Shawer 579 imao 5,56% uginulih nosilja. Posmatrano u celini, mortalitet nosilja kod oba hibrida, bio je u granicama tehnoloških normativa. Prosečna dnevna potrošnja hrane kod provenijence Hisex Brown je veća i iznosila je 127,28 g, a kod Shawer 579-125,14 g. Prosečna potrošnja hrane za proizvodnju jajeta kod obe provenijence je bila ista (150 g)

Comprehensive characterization of BiFeO3 powder synthesized by the hydrothermal procedure

In this paper, bismuth ferrite (BFO) particles synthesized by controlled hydrothermal process, where the particles of small sizes and with high purity were obtained. Structural analysis showed that non-annealed powder can be perfectly fitted to rhombohedral space group R3c and contains a very small amount of secondary phase, whereas the final product (annealed at 800 °C) represents single-phase perovskite powder with high crystallinity. HRTEM analysis confirmed existence of twin stacking faults, which are responsible for enhanced magnetic properties. EPR measurements suggested existence of electrons trapped by vacancies or defects. It has been proposed that existence of Fe3+ −OV defect complex could be generated at elevated temperatures followed by formation of trivalent Fe ions, which intensely provide local 3d moments

Sodium-alginate biopolymer as a template for the synthesis of nontoxic red emitting Mn2+-doped CdS nanoparticles

Manganese-doped cadmium sulfide (CdS:Mn) nanoparticles were prepared by chemical synthesis using sodium-alginate as template. The preparation of the nanocomposites involved ionic crosslinking of the biopolymer by dimerization of its alpha-L-guluronic monomers with Cd2+ and subsequent formation of the semiconductor nanoparticles upon addition of sulfide ions in the presence of Mn2+. The crystalline phase of CdS in the material was confirmed by XRD. The surface morphology of the nanocomposites was investigated by SEM. The observation by TEM showed that the CdS:Mn particles were spherical in shape with diameters of approximately 4 nm. EPR measurements of the CdS:Mn-alginate nanocomposite showed that the Mn2+ ions were incorporated in cationic sites of CdS with lower symmetry. Due to a distorted crystal field induced by the Mn2+ ions, photoluminescence spectra of the CdS:Mn-alginate showed red fluorescence between 650 nm and 750 nm falling into the optical window for bioimaging in which the light has its maximum tissue penetration depth. It was demonstrated that the interaction between the nanoparticles and the matrix prevents release of CdS into the environment, leading to low acute toxicity of the nanocomposites

Uticaj Prohexadione-Ca i zakidanja prvih serija mladih izdanaka na fiziološka svojstva lista i ploda sorte maline 'Willamette'

The research was designed to evaluate the effect of growth regulator Prohexadione-Ca (ProCa) and young canes removal on the changes of photosynthetic pigment content and modification activities of antioxidant enzyme defense system in leaves and fruits of raspberry cultivar 'Willamette' (Rubus idaeus L.). The experiment was performed in the period of 2011-2012. It consisted of five treatments: control - no treatment; 2ProCa - with 2 ProCa applications; Z - one removal of young canes; Z+2ProCa - young canes removal with 2 ProCa applications; 2Z - two removals of young canes. The first series of young canes were removed for the first time in mid-April and for the second time at the begining of May. In 2ProCa and Z+2ProCa treatments foliar application of ProCa was carried out twice during the period of April-May in interval of three weeks, i.e. when the primocane growth reached 30 cm in height. The following concentrations of ProCa: 125 ppm (first application) and 200 ppm (second application) were applied. Significantly higher mean values of chlorophyll b content were registered in the 2ProCa (42.84 μg·g-1 FW) and Z+2ProCa (46.12 μg·g-1 FW) treatment. The highest SOD and POD activities were found in leaves of new young canes which developed after the young canes removal was applied. Z+2ProCa treatment significantly increased CAT activity in raspberry leaves (63.51 U mg-1 prot.). Both of implemented measures, especially applied in combination, resulted in higher activity of CAT, POD and SOD enzymes in the fruits of the examined cultivar.U radu je proučavan uticaj retardanta rasta Prohexadione-Ca (ProCa) i pomotehničke mere zakidanja prvih serija mladih izdanaka na promene u sadržaju fotosintetskih pigmenata i modifikaciju aktivnosti enzima antioksidacionog zaštitnog sistema u listovima i plodovima sorte maline 'Willamette' (Rubus idaeus L.). Eksperiment izveden u periodu 2011-2012. godine obuhvatio je pet tretmana: kontrola - bez tretiranja; 2ProCa - sa dva tretiranja ProCa i bez zakidanja izdanaka; Z - sa jednim zakidanjem izdanaka i bez tretiranja ProCa; Z+2ProCa - sa jednim zakidanjem izdanaka i dva tretiranja ProCa; 2Z - sa dva zakidanja izdanaka i bez tretiranja ProCa. Prvo zakidanje mladih izdanaka je obavljeno sredinom aprila, a drugo krajem aprila u obe godine ispitivanja. U 2ProCa i Z+2ProCa tretmanu folijarna aplikacija sa ProCa vršena je dva puta u periodu april-maj u intervalu od tri nedelje srazmerno dinamici porasta novih izdanaka tj. u momentu kada oni dostignu visinu od 30 cm. Primenjene su sledeće koncentracije ProCa: 125 ppm (kod prvog tretiranja) i 200 ppm (kod drugog tretiranja). Statistički značajno veća prosečna vrednost sadržaja hlorofila b registrovana je u 2ProCa (42,84 μg·g-1 sveže mase lista) i Z+2ProCa (46,12 μg·g-1 sveže mase lista) tretmanima. Najveća aktivnost enzima superoksid dismutaze i peroksidaze registrovana je u listovima novih mladih izdanaka, koji su se razvili nakon primenjene mere zakidanja izdanaka. Z+2ProCa tretman je uticao na značajno povećanje aktivnosti katalaza u listovima maline (63,51 U mg-1 proteina). Obe navedene mere, a naročito primenjene u kombinaciji, uticale su na povećanje aktivnosti pomenutih enzima u plodu ispitivane sorte

Uticaj sive protivgradne mreže na kvalitet ploda borovnice (Vaccinium corymbosum L.) sorte "Bluecrop"

The main focus of our study was to investigate effects of the modified microclimate under a grey hail protection net (HPN) on biometrical fruit characteristics (fruit weight, index of fruit shape, and seed number per fruit) and nutritional value (soluble solid content - SSC, titratable acidity - TA, total anthocyanins - TACY, total phenolics - TPH and total antioxidant capacity - TAC) of the 'Bluecrop' highbush blueberry (Vaccinium corymbosum L.). The study was conducted in the 'Bluecrop' highbush blueberry plantation located in Mladenovac (Serbia) during two consecutive years (2013, 2014). The orchard was established using two-year-old nursery trees in spring 2011, at a planting density of 3,300 bushes per ha. The grey polyethylene net (SILVERLUX®, Helios Group, Lurano, Italy) with a Leno wave structure and a mesh size of 2.8 x 8 mm was used. During the research period, light intensity was measured weekly at 12.00 hr using a digital lux-meter 'Peak teck' PT-5025 (Germany). Air temperature and relative humidity within the canopy were recorded using climate dataloggers (type DT-171, Shenzhen Flus Technology Co., Ltd, China) both under HPN and in the open field (OF). Twelve readings per treatment were taken at 2-hour intervals every day in each season. In both years of observation, light was reduced by 5-20% under HPN, whereby daily maximum temperature was 2.4°C lower causing 4% higher daily minimum relative air humidity than in OF. 'Bluecrop' had significantly higher average fruit weights under HPN ranging from 1.93 g (2013) to 1.86 g (2014) in comparison to those observed in OF. The SSC did not differ between the treatments in 2014, whereas a significantly higher mean value was registered in the fruits harvested under HPN (12.8%) compared to those from OF in 2013. The mean TA was higher under HPN in 2014 (0.57%), whereas in 2013 a significantly higher TA content was found in OF (0.87%). HPN showed a positive effect on the TPH content (7.12 mg GA/g FW), but an almost 2-fold higher value was registered in 2013. Similar to this, TAC was 2.5-fold higher in 2013, without a significant effect of HPN in both experimental years.U ovom radu su ispitivani efekti izmenjene mikroklime pod sivom protivgradnom mrežom (PGM) na fizičke osobine ploda (masa ploda, indeks oblika ploda i broj semenki u plodu) i nutritivnu vrednost (sadržaj rastvorljive suve materije - RSM, ukupnih kiselina i ukupnih fenola, kao i ukupni antioksidativni kapacitet ploda) sorte borovnice "Bluecrop" (Vaccinium corymbosum L.). Ispitivanja su izvedena u periodu 2013-2014. godina, u zasadu borovnice koji se nalazi u blizini Mladenovca. Zasad je podignut u proleće 2011. godine sa trogodišnjim sadnicama i gustinom sadnje od 3.300 žbunova po ha. Primenjena je siva PGM (SILVERLUX®, Helios Group, Lurano, Italy), težine 48 g/m2, sa veličinom otvora 2,8 x 8 mm. Tokom perioda ispitivanja, intenzitet svetlosti je meren jedanput nedeljno u 12 h korišćenjem luks metra "Peak teck" PT-5025 (Germany). Temperatura i relativna vlažnost vazduha su merene uređajem za evidentiranje podataka (engl. data logger, DT-171, Shenzhen Flus Technology Co., Ltd, China) na svaka 2 h pod PGM i na otvorenom polju (kontrolni tretman) od početka cvetanja do kraja zrenja borovnice u obe ispitivane godine. Intenzitet svetlosti pod PGM je bio u proseku smanjen za 5-20% u obe eksperimentalne godine. Dnevne maksimalne temperature bile su za 2,4 oC niže pod PGM uslovljavajući za 4% višu minimalnu dnevnu relativnu vlažnost vazduha u poređenju sa otvorenim poljem. Značajno veća prosečna vrednost mase ploda kod ispitivane sorte borovnice registrovana je pod PGM u poređenju sa otvorenim poljem, i kretala se od 1,93 g (2013) do 1,86 g (2014). Sadržaj RSM se nije značajno razlikovao između tretmana u 2014. godini, dok je u 2013. godini značajno povećanje registrovano u plodovima koji su ubrani pod PGM (12,8%) u poređenju sa otvorenim poljem (11,6%). Prosečna vrednost sadržaja ukupnih kiselina je bila veća pod PGM u 2014. godini (0,57%), dok je u 2013. godini značajno veći sadržaj pronađen u plodovima ubranim na otvorenom polju (0,87%). PGM je ispoljila pozitivan efekat na sadržaj ukupnih fenola (7,12 mg galne kis. g-1sv.m.pl.), međutim skoro dva puta viša vrednost je bila registrovana u 2013. godini. Slično sadržaju ukupnih fenola, ukupni antioksidativni kapacitet ploda je bio za 2,5 puta veći u 2013. godini, bez značajnog uticaja PGM u obe ispitivane godine

COMPARISON OF FIELD PERFORMANCE AND FRUIT QUALITY AMONG NEWLY RELEASED ITALIAN JUNE-BEARING STRAWBERRY CULTIVARS

This study illustrates the differences in phenology, vegetative growth, productivity and fruit quality of newly released June-bearing strawberry cultivars (‘Quicky’, ‘Sandra’, ‘Lofty’, ‘Mila’ and ‘Aprica’) aiming to recognize their potential for wider cultivation. A field study was carried out in a strawberry plantation situated in municipality of Šid (Serbia), during the period of 2021 to 2022. The orchard was planted in July 2020 in double rows on beds covered with black polyethylene foil. Cultivars were evaluated for their flowering and ripening time, yield components, plant growth, as well as for biometrical fruit traits (fruit weight, index of fruit shape) and nutritional value (content of soluble solids - SS, total acids - TA, vitamin C, total anthocyanins –TACY, total phenolics - TPC and total antioxidant capacity - TAC). The results showed that cv. ‘Quicky’ started to ripen earliest, while cv. ‘Aprica’ was the latest in both experimental years. The number of branch crowns per plant was significantly higher in cvs. ‘Sandra’ and ‘Lofty’, whereby cv. ‘Sandra’ had also the highest number of leaves per rosette (41.5) in comparison with the other tested cultivars. Cv. ‘Aprica’ was superior in terms of productivity (1061 g/plant and 4.67 kg/m2) accompanied by the largest fruit weight (29.9 g) and index of fruit shape (1.15). Contrary to this, the lowest yield potential was found in cv. ‘Mila’ (608 g/plant and 2.68 kg/m2). Cvs. ‘Lofty’ and ‘Sandra’ ranked the highest in terms of SSC and they are also characterized by a considerably high level of TPC (1.29 mg GAE eq g-1 FW) and TACY (24.4 mg pg-3-g eq100 g-1 FW ), respectively.&nbsp

Structural, optical, and bioimaging characterization of carbon quantum dots solvothermally synthesized from o-phenylenediamine

Carbon quantum dots as a novel type of carbon nanomaterials have attracted the attention of many researchers because of their unique optical, antibacterial, and anticancer properties as well as their biocompatibility. In this study, for the first time, carbon quantum dots were prepared from o-phenylenediamine dissolved in toluene by a solvothermal route. Subsequently, the prepared carbon quantum dots were encapsulated into polyurethane films by a swelling–encapsulation–shrink method. Analyses of the results obtained by different characterization methods (AFM, TEM, EDS, FTIR, photoluminescence, and EPR) indicate the significant influence of the precursor on structural, chemical, and optical properties. Antibacterial and cytotoxicity tests showed that these dots did not have any antibacterial potential, because of the low extent of reactive oxygen species production, and showed low dark cytotoxicity. By investigating the cellular uptake, it was established that these dots penetrated the HeLa cells and could be used as probes for bioimaging

Highly Efficient Antibacterial Polymer Composites Based on Hydrophobic Riboflavin Carbon Polymerized Dots

Development of new types of antimicrobial coatings is of utmost importance due to increasing problems with pathogen transmission from various infectious surfaces to human beings. In this study, new types of highly potent antimicrobial polyurethane composite films encapsulated by hydrophobic riboflavin-based carbon polymer dots are presented. Detailed structural, optical, antimicrobial, and cytotoxic investigations of these composites were conducted. Low-power blue light triggered the composites to eradicate Escherichia coli in 30 min, whereas the same effect toward Staphylococcus aureus was reached after 60 min. These composites also show low toxicity against MRC-5 cells. In this way, RF-CPD composites can be used for sterilization of highly touched objects in the healthcare industry