Specific transformations of mineral forms of nitrogen in acid soils

Investigations were performed on soils of different acidity, ranging in the pH interval 4.65–5.80 (in water). Changes of the mineral nitrogen forms in the examined soils were studied by applying short-term incubation experiments performed under aerobic conditions, with a humidity of 30 % and a temperature of 20 °C, both with and without the addition of 100 and 300 ppm NH4–N. The results of the incubation experiments showed that retarded nitrification was present in all the examined soils. Increased and toxic quantities of nitrites (35.7 ppm) were formed during the incubation, which remained in the soil solution for several days, and even weeks, in spite of favorable conditions of moisture, aeration and temperature for the development of the process of chemo-autotrophic nitrification. Decelerated chemoautotrophic nitrification was the source of the occurrence of nitrite in the examined less acid soil (soil 1), while in soils of higher acidity (soils 2 and 3) after addition of 100 and 300 ppm NH4–N, nitrite occurred due to chemical denitrification (chemodenitrification). Nitrites formed in the process of chemodenitrification underwent spontaneous chemical oxidation resulting in nitrate formation (chemical nitrification). The content of mineral nitrogen (NH4 + NO3 + NO2–N) decreased during the incubation period, proving gaseous losses from the examined soils. Application of lower doses of nitrogen fertilizers could decrease nitrogen losses by denitrification as well as the occurrence of nitrite in toxic quantities in the investigated pseudogley soil

Genetic correlation between amyotrophic lateral sclerosis and schizophrenia

A. Palotie on työryhmän Schizophrenia Working Grp Psychiat jäsen.We have previously shown higher-than-expected rates of schizophrenia in relatives of patients with amyotrophic lateral sclerosis (ALS), suggesting an aetiological relationship between the diseases. Here, we investigate the genetic relationship between ALS and schizophrenia using genome-wide association study data from over 100,000 unique individuals. Using linkage disequilibrium score regression, we estimate the genetic correlation between ALS and schizophrenia to be 14.3% (7.05-21.6; P = 1 x 10(-4)) with schizophrenia polygenic risk scores explaining up to 0.12% of the variance in ALS (P = 8.4 x 10(-7)). A modest increase in comorbidity of ALS and schizophrenia is expected given these findings (odds ratio 1.08-1.26) but this would require very large studies to observe epidemiologically. We identify five potential novel ALS-associated loci using conditional false discovery rate analysis. It is likely that shared neurobiological mechanisms between these two disorders will engender novel hypotheses in future preclinical and clinical studies.Peer reviewe

The effects of some agrotechnical measures on the uptake of nickel by maize plants

Nickel is a non-essential element in the nutrition of the majority of plant species and can be toxic to plants when its concentration in soils is high. Several soil properties have an effect on the uptake of this heavy metal by plants. The purpose of this investigation was to determine the effect of fertilization, soil acidification and liming on the uptake of Ni by maize plants grown on some alluvial soils. A pot experiment with maize plants grown on soils having various properties and elevated content of Ni was set up. The experiment lasted six weeks. The roots and shoots were analyzed for the concentration of Ni. From the results of the experiment, it can be concluded that the roots had higher concentrations of Ni than the shoots. The addition of mineral fertilizers (without application of other measures) mainly decreased the concentration and uptake of Ni by the roots and the transport of Ni to the shoots. Soil acidification (to pH 4.5) caused an increase in the Ni concentration in the plants and in its removal from the soil. Liming of acid soils had a positive effect on the uptake of Ni by young maize plants. The obtained results are important from the standpoint of reducing the pollution of plants by potentially toxic heavy metals.Nikl nije neophodan element za ishranu većine biljnih vrsta i on može biti toksičan za biljke kada je njegova koncentracija u zemljištu visoka. Nekoliko osobina zemljišta ima uticaja na usvajanje ovog metala biljkama. Cilj ovog istraživanja je bio da se utvrdi uticaj đubrenja, zakiseljavanja zemljišta i kalcizacije na usvajanje Ni biljkama kukuruza gajenim na nekim aluvijalnim zemljištima. Postavljen je ogled u sudovima sa biljkama kukuruza koje su gajene na pomenutim zemljištima. Ogled je trajao 6 nedelja. Korenovi i nadzemni delovi su analizirani na sadržaj Ni. Može se zaključiti iz rezultata ogleda da korenovi imaju veće koncentracije Ni u odnosu na nadzemne delove. Dodavanje mineralnih đubriva (bez primene drugih mera) uglavnom je smanjilo koncentraciju i usvajanje Ni korenovima kao i njegov transport do nadzemnih delova. Zakiseljavanje zemljišta (do pH 4,5) povećalo je usvajanje Ni korenovima i njegov transport do nadzemnih delova biljaka. Kalcizacija kiselih zemljišta je imala pozitivan uticaj na usvajanje Ni mladim biljkama kukuruza. Dobijeni rezultati su značajni za smanjenje zagađivanja biljaka potencijalno toksičnim teškim metalima

Specifični agrotehnički uslovi gajenja miskantusa

Miscanthus is a perrenial, rhizomatous, highly productive C4-grass, originating from Eastern Asia. Miscanthus represents a plant species convenient for intensive cultivation, the biomass of which should enable in the near future a substantial replacement of the existing energy sources by new, renewable sources, in order to minimize CO2 emission. Myscanthus belongs to so-called »bioenergetic crops«, which are specifically cultivated to be harvested and combusted in boilers, as an alternative to the existing energy sources. It is planted in spring, let to grow in the summer, and harvested in winter (between January and March). Once established, Miscanthus plantation persists 15 to 20 years. By adequate application of agricultural machines, high biomass yields (15-25 t/ha per year) may be achieved. The paper presents certain specificities of Miscanthus cultivation in comparison with other crops with the aim of introducing this promising plant species into agricultural production in Serbia.Мискантус је вишегодишња, високо продуктивна, С4-трава, пореклом из источне Азије. Mискантус представља биљну врсту подесну за интензивно гајење, која би својом биомасом требало у блиској будућности да омогући значајну супституцију постојећих енергетских извора са новим, обновљивим изворима, којим ће се смањити емисија СО2. Мискантус се убраја у групу тзв. „биоенергетских усева“, који се специфично узгајају да би се пожњели и сагорели у котловским постројењима, као алтернатива постојећим енергетским изворима. Сади се у пролеће, израсте током лета, а жање у зиму (од јануара до марта). Једном заснована култура мискантуса опстаје 15-20 година. Адекватним коришћењем стандардне пољопривредне механизације могу се остварити високи приноси биомасе (15-25 т/ха годишње). У раду су приказане одређене специфичности гајења мискантуса у односу на друге ратарске културе, а с циљем увођења у пољопривредну производњу ове перспективне биљне врсте и код нас

Some negative chemical properties of acid soils

Some important chemical properties of various samples of two types of acid soil fromWestern Serbia (pseudogley and brown forest) are presented in this paper.Mobile Al was found in elevated and toxic quantities (10–30 mg/100 g) in the more acid samples of pseudogley soil. All samples of brown forest soil were very acid and the quantities ofmobile Al were in the range from 12.8 to 90.0mg/100 g. In a selected number of pseudogley soils, the influence of pH and other soil properties on the mineralization and nitrification processeswas investigated. Strong inhibition of nitrification at low soil pH was found to be related to high quantities of mobile Al. At pH values less than 4.0 (in 1 M KCl), processes of chemical nitrification and denitrification of applied nitrites were registered in the pseudogley soils

Uticaj ekološkog zagađenja izazvanog delovanjem NATO alijanse na prostorima Srbije na fiziološki status proizvoda tipa "Radler"

Beer-based drinks, 'Radler' type products in particular, arouse interest for a number of reasons. These newly produced drinks were obtained by mixing beer and soft drinks and are intended for a larger number of target groups than their each single component. Also, they combine advantages of both components in physiological respect. They have lower alcohol content than beer, are more palatable and refreshing, can be consumed in larger amounts, retaining beneficial and physiological value of beer. As NATO air strikes resulted in heavy environmental contamination, the question is raised about the safety of these drinks and the level of toxic elements in them as well about the level of micro- and macro-elements having beneficial effects on the body. The paper gives the analysis results for 35 samples of different 'Radler' Beer-based products manufactured by domestic producers. The level of elements belonging to three distinct groups of heavy metals and that of the most important micro- and macro-elements, of therapeutic and physiological value for the body, were determined. The obtained values were compares with available data on similar products in the world, with values obtained for domestic products in the period preceding environmental contamination, and, in the case of biologically important elements, with their contents in one of oligomineral-vitamin products.Pića na bazi piva, a pogotovo proizvodi tipa „Radler" interesantni su sa više aspekata. Predstavljaju jedan nov proizvod dobijen kombinacijom piva i gaziranih bezalkoholnih pića namenjen većem broju ciljnih grupa od pojedinačnih komponenata od kojih su proizvedeni, a ujedno sa fiziološkog aspekta objedinjuju prednosti svakog od njih. Sadrže niži sadržaj alkohola od piva, pitkija su i više osvežavaju, mogu se piti u većim količinama, a istovremeno u određenoj meri zadržavaju blagotvorna i fiziološki vrlo povoljna svojstva piva. Upravo iz tog razloga postavlja se pitanje njihove zdravstvene ispravnosti i prisustva pojedinih toksičnih elemenata kao posledica ekološkog zagađenja uzrokovanog vazdušnim dejstvima NATO alijanse, odnosno mikro- i makro elemenata čiji sadržaj ima povoljno delovanje na organizam. U radu su prikazani rezultati analize 35 uzoraka različitih Radler proizvoda dobijenih na bazi piva različitih domaćih proizvođača. Određen je sadržaj elemenata koji spadaju u tri karakteristične grupe teških metala kao i najznačajnijih mikro- i makroelemenata koji imaju terapeutski i fiziološki značaj za organizam. Rezultati analize 35 uzoraka proizvoda tipa „Radler" proizvedenih nakon završetka ratnih dejstava, pokazuju da u pogledu ni jednog toksičnog elementa nije došlo do porasta sadržaja i da su nađene vrednosti u granicama, ili čak ispod vrednosti karakterističnih za proizvode ove vrste na domaćem tržištu. Vrednosti su znatno ispod zakonski regulisanih maksimuma i u granicama koje se sreću i u srodnim proizvodima u svetu. Sa druge strane, interesantni su podaci koji se odnose na prisustvo biogenih elemenata koji su uzrok povoljnog delovanja piva na organizam. Njihov sadržaj u proizvodima tipa „Radler" je niži u odnosu na pivo i ovi proizvodi se ne mogu tretirati kao njihov izvor. Međutim, poređenje sa oligomineralnim vitaminskim preparatom „Oligovitom" (ICN) ukazuje na neke interesantne činjenice. Unošenjem 1 l ovih proizvoda unosi se 10% Mg, 10-60% Mn, 30% Cu, 50% Zn i 50% Co koja se inače unosi pilulom „Oligovita" kao preporučena dnevna dopuna svakodnevne ishrane dece i odraslih

Some negative chemical properties of acid soils

Some important chemical properties of various samples of two types of acid soil from Western Serbia (pseudogley and brown forest) are presented in this paper. Mobile Al was found in elevated and toxic quantities (10–30 mg/100 g) in the more acid samples of pseudogley soil. All samples of brown forest soil were very acid and the quantities of mobile Al were in the range from 12.8 to 90.0 mg/100 g. In a selected number of pseudogley soils, the influence of pH and other soil properties on the mineralization and nitrification processes was investigated. Strong inhibition of nitrification at low soil pH was found to be related to high quantities of mobile Al. At pH values less than 4.0 (in 1 M KCl), processes of chemical nitrification and denitrification of applied nitrites were registered in the pseudogley soils.Istraživanja su obavljena na dva tipa zemljišta Zapadne Srbije (pseudoglej i smeđe šumsko zemljište). Oba ispitivana zemljišta karakteriše niska pH vrednost. Kod svih uzoraka smeđeg šumskog zemljišta utvrđene su toksične količine mobilnog Al za biljke i za mikroorganizme, a kod pseudoglejnog zemljišta toksične količine Al su utvrđene samo za neke uzorke. Na proces nitrifikacije, koji je praćen u odabranim uzorcima pseudogleja, direktno su delovali niska pH vrednost (kiselost) i visok sadržaj mobilnog aluminijuma. Dodavanjem NaNO2 utvrđeno je odvijanje procesa hemijske nitrifikacije i denitrfikacije u pseudoglejnom zemljištu pri pH manjem od 4,0 u 1M KCl

Copper(II) and lead(II) complexation by humic acid and humic-like ligands

The stability of metal–humate complexes is an important factor determining and predicting speciation, mobility and bioavailability of heavy metals in the environment. A comparative investigation of the complexation of Cu(II) and Pb(II) with humic acid and humic-like ligands, such as benzoic and salicylic acid, was performed. The analysis was realized at pH 4.0, a temperature of 25 °C and at an ionic strength of 0.01 mol dm-3 (NaCl) using the Schubert ion-exchange method and its modified form. The stability constants were calculated from the experimental data by the Schubert method for complexes with benzoic and humic acid. A modified Schubert method was used for the determination of the stability constants of the complexes with salicylic acid. It was found that Cu(II) and Pb(II) form mononuclear complexes with benzoic and humic acid while with salicylic acid both metals form polynuclear complexes. The results indicate that Pb(II) has a higher binding ability than Cu(II) to all the investigated ligands. The Cu(II)–salicylate and Pb(II)–salicylate complexes showed noticeable higher stability constants compared with their complexes with humic acid, while the stabilities of the complexes with benzoic acid differed less. Salicylic and benzoic acids as humic-like ligands can be used for setting the range of stability constants of humic complexes with Cu(II) and Pb(II)