The evolution of the eutrophication of the Palić Lake (Serbia)

Eutrophication is a world-wide environmental issue. The Palic Lake is a shallow lake typical for the Pannonian plain. The Lake itself was in a very bad condition during the late sixties of the last century; polluted and hypertrophic. Due to inadequate water quality, it was dried out in 1971 and re-established in 1977 and since then its trophicity has been worsening. The lake has recreational purposes but it is also a collector for treated municipal waste waters coming from the lagoons for active sludge water treatment. The sewage discharges from rapidly developing towns in the watershed and the growing use of fertilizers in agriculture increased the nutrient load to the Lake in the last decades. A steady increase of phosphorus loading is the most important factor of the lake  eutrophication. The result of the accelerated eutrophication is the enormous amount of sediment at the bottom of the Palic Lake. Therefore, in the lake that covers an area of 565 ha and volume of 10 million m3, there was 1.900.160 m3 of sediment. The sediment thickness varied from 0.3 to 1.2 m. In summer 2010, the recreational part of the lake (sector IV) was 1.311.356 m3 of sediment, characterized with concentrations of total phosphorus (TP) of 2885 mg/kg, 4300 mg/kg total nitrogen (TN) and 39000 mg/kg total organic carbon TOC. The sediment of the Palic Lake was not loaded with high concentrations of heavy metals. Everything mentioned supports the fact that the restoration of this aquatic system is necessary and applied measures have to be grounded on the principles of ecoremediation technologies.Key words: Eutrophication, Palic Lake, sediment, total N, total P

Mangan-superoksid-dismutaza (MnSOD) katalizuje NO-zavisno nitrovanje ostatka tirozina

The peroxynitrite-induced nitration of manganese superoxide dismutase (MnSOD) tyrosine residue, which causes enzyme inactivation, is well established, This led to suggestions that MnSOD nitration and inactivation in vivo, detected in various diseases associated with oxidative stress and overproduction of nitric monoxide (NO), conditions which favor peroxynitrite formation, is also caused by peroxynitrite. However, our previous ill vitro study demonstrated that exposure of MnSOD to NO led to NO conversion into nitrosonium (NO+) and nitroxyl (NO-) species, which caused enzyme modifications and inactivation. Here it is reported that MnSOD is tyrosine nitrated upon exposure to NO, as well as that MnSOD nitration contributes to inactivation of the enzyme. Collectively, these observations provide a compelling argument supporting the generation of nitrating species in MnSOD exposed to NO and shed a new light on MnSOD tyrosine nitration and inactivation ill vivo. This may represent a novel mechanism by which MnSOD protects cell from deleterious effects associated with overproduction of NO. However, extensive MnSOD modification and inactivation associated with prolonged exposure to NO will amplify the toxic effects caused by increased cell superoxide and NO levels.Dobro je poznato da peroksinitrit izaziva nitrovanje ostataka tirozina u mangan-superoksid- dismutazi (MnSOD) što dovodi do inaktivacije enzima. Pokazano je da nitrovanje i inaktivacija MnSOD-a nastaje u raznim bolestima za koje je karakteristič an oksidativni stres i povećana produkcija azot-monoksida (NO). Pošto se pri ovim uslovima očekuje nastajanje peroksinitrita predloženo je da peroksinitrit izaziva nitrovanje i inaktivaciju MnSOD in vivo. U našem prethodnom radu pokazali smo da MnSOD katalizuje transformaciju NO u nitrozonijum (NO+) i nitroksil (NO–) reaktivne vrste, te identifikovali neke od modifikacija molekula enzima koje pri tome nastaju izazivajući njegovu inaktivaciju. U ovom radu je pokazano da pri izlaganju MnSOD azot-monoksidu dolazi i do nitrovanja ostatka tirozina u molekulu enzima, što doprinosi njegovoj inaktivaciji. Ovi rezultati ukazuju da pri interakciji MnSOD sa NO dolazi do nastajanja nitrujućih vrsta, što baca novo svetlo na proces nitrovanja ostataka tirozina i inaktivaciju MnSOD in vivo. Ovo može da predstavlja novi mehanizam kojim MnSOD štiti ćeliju odštetnih efekata izazvanih hiperprodukcijom azot-monoksida. Međutim ekstenzivne modifikacije i inaktivacija MnSOD do kojih dolazi pri produženom izlaganju enzima NO, uvećaće toksične efekte izazvane povećanim koncentracijama superoksida i NO u ćeliji

Aspergillus Piperis A/5 from Plum-Distilling Waste Compost Produces a Complex of Antifungal Metabolites Active Against the Phytopathogen Pythium Aphanidermatum

Adding compost to soil can result in plant disease suppression through the mechanisms of antagonistic action of compost microflora against plant pathogens. The aim of the study was to select effective antagonists of Pythium aphanidermatum from compost, to assess the effect of its extracellular metabolites on the plant pathogen, and to characterize antifungal metabolites. The fungal isolate selected by a confrontation test was identified as Aspergillus piperis A/5 on the basis of morphological features and the internal transcribed spacer (ITS) region, beta-tubulin and calmodulin partial sequences. Liquid chromatography-mass spectroscopy (LC-MS) analysis showed that gluconic and citric acid were the most abundant in the organic culture extract. However, the main antifungal activity was contained in the aqueous phase remaining after the organic solvent extraction. The presence of considerable amounts of proteins in both the crude culture extract as well as the aqueous phase remaining after solvent extraction was confirmed by SDS-PAGE. Isolated Aspergillus piperis A/ 5 exhibits strong antifungal activity against the phytopathogen Pythium aphanidermatum. It secretes a complex mixture of metabolites consisting of small molecules, including gluconic acid, citric acid and itaconic acid derivatives, but the most potent antifungal activity was associated with proteins resistant to heat and organic solvents. Our findings about the activity and characterization of antagonistic strain metabolites contribute to the understanding of the mechanism of interaction of antifungal metabolites as well as fungal-fungal interaction. The obtained results provide a basis for further application development in agriculture and food processing

A Science4Peace initiative: Alleviating the consequences of sanctions in international scientific cooperation

The armed invasion of Ukraine by the Russian Federation has adversely affected the relations between Russia and Western countries. Among other aspects, it has put scientific cooperation and collaboration into question and changed the scientific landscape significantly. Cooperation between some Western institutions and their Russian and Belarusian partners were put on hold after February 24, 2022. The CERN Council decided at its meeting in December 2023 to terminate cooperation agreements with Russia and Belarus that date back a decade. CERN is an international institution with UN observer status, and has so far played a role in international cooperation which was independent of national political strategies. We argue that the Science4Peace idea still has a great value and scientific collaboration between scientists must continue, since fundamental science is by its nature an international discipline. A ban of scientists participating in international cooperation and collaboration is against the traditions, requirements and understanding of science. We call for measures to reactivate the peaceful cooperation of individual scientists on fundamental research in order to stimulate international cooperation for a more peaceful world in the future. Specifically, we plead for finding ways to continue this cooperation through international organizations, such as CERN and JINR

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum