Artistic expression: freedom or curse? Some thoughts on jurisprudence of the european court of human rights from the theoretical perspective of visual and performance arts and rationales behind freedom of political expression

The purpose of this contribution is to evaluate the jurisprudence of the European Court of Human Rights (ECtHR) in freedom of artistic expression cases dealing with visual and performance arts. The reasons for this particular evaluation are salient to the fact that the ECtHR has consistently provided a lesser level of protection to artistic expression than to political expression. The aim of this article is to challenge the approach of the Court to the freedom of artistic expression in relation to visual and performance arts. The critical evaluation is based on two different but complementary grounds: contemporary theory of art critique of the ECtHR’s understanding of art and critique based on the ECtHR’s own political freedom of expression cases. The argument of the authors is that the ECtHR approach to visual and performance arts as an exercise in ethics and aesthetics is contradicted by contemporary art theory and practice which invariably assumes the societal role of art, its potential subversive and transformative function within a society at large, and, ultimately, its lato sensu political value. In addition, visual and performance arts are powerful yet fragile instruments for delivering the debate to society at large. Viewed from this perspective, artistic expression has the same beneficial effect on a democratic society as political expression stricto sensu. Therefore, the rationales underpinning protection of political expression are essentially the same as those of artistic expression, therefore the ECtHR should extend the same level of legal protection to arts and artists to keep valuable social dialogue alive

History of mathematics as a factor

In this paper the authors consider the role of history of mathematics and some historical dataas a factor for encouraging interest and motivation of students to study mathematics. History of mathematics has a lot of questions, examples, and problems which can be adapted to cater for contemporary teaching and to become a direct support for content that needs to be processed, determined and deepened. Well-presented historical examples can have great importance in supporting mathematical and didactical meaning. The starting point in this paper is that “old” tasks preserved on the earliest memorials of mathematics, the anecdotes of great mathematicians and the ways of solving tasks can serve as a special kind of motivation for students’ learning of mathematics because they introduce a special spirit and motive for solving such tasks and problems.Publishe

Validation of analytical method for determination of terbuthylazine and S-metolachlor residues in soil

Terbuthylazine and s-metolachlor are commonly used herbicides, especially after prohibition of some other triazine and chloracetanilide herbicides. However, often used pesticides pose the risk of soil contamination due to their persistence, toxicity and bioaccumulation. The trace determination of herbicide residues, generally in environmental samples, presents a challenging analytical problem. The present work was carried out to analyze terbuthylazine and s-metolachlor residues in soil based on high performance liquid chromatography (HPLC), and QuEChERS extraction method. The method was optimized and validated according to the parameters of precision, accuracy, linearity, limits of detection and limits of quantification. Analysis was carried out using an HPLC-UV diode array detection system (Agilent 1100, USA), with an Agilent Zorbax Eclipse C18 column (50 mm × 4.6 mm, 1.8 μm) and mobile phase consisting of ultrapure water and acetonitrile (55/45, v/v). Mean recoveries obtained from soil samples fortified at three different levels ranged from 81 to 92%. The method detection limits ranged from 0.01 to 0.05 mg kg-1 . Obtained results completely fulfilled the SANCO/825/00 rev. 8.1 16/11/2010 criteria

Sulfonylurea herbicides residues analysis in soil

Prosulfuron, rimsulfuron, thifensulfuron-methyl and tritosulfuron are widely used sulfonylurea herbicides (SUs), applied in low-dose rates. However, these herbicides under specific conditions as low temperature, poor rainfall, microbial activity. high pH of soil, can remain at low concentrations in soil and can affect the growth of sensitive plants. This paper presents the method that we developed for determination of prosulfuron, rimsulfuron, thifensulfuron-methyl and tritosulfuron residues in soil. Determination and quantification were performed by HPLC/DAD using Agilent Zorbax SB-C18 column (3.0 mm*250 mm. 5 um particle size). Mobile phase was acetonitrile/0.1% CH3COOH solution. Analyzed SUs showed linear calibrations from 0.05 to 0.2 mg/ml with correlation coefficient (1°) above 0.990%. The recovery data were obtained by spiking blank soil samples at two concentration levels (2.5-5.0 mg/kg), yielding average recovery between 95.56 and 99.79%. Precision values expressed as relative standard deviation (RSD) were between 0.91-1.11% for all SUs herbicides for the intraday precision. Considering the obtained values of analytical parameters, the proposed method proved to be an efficient and sensitive method for the determination of prosulfuron, rimsulfuron, thifensulfuron-methyl and tritosulfuron in soil samples

Utjecaj sadržaja na razvijanje kritičkog mišljenja učenika u početnoj nastavi matematike

This paper points out the importance of developing critical thinking in the initial teaching of mathematics and highlights some of the problems associated with its realization. In this context, the authors draw attention to the definition of critical thinking and the role of content (tasks) in its development. Starting from the specificity of initial teaching of mathematics and students\u27 age, critical thinking is operationalized through specific skills (formulation of the problem, reformulation of the problem, evaluation, sensitivity to the problems), that become apparent in work with mathematical content. On a sample of 246 students (9.5–10.4 years old), an experimental study (experiment with parallel groups) was organized in order to examine whether, with the selection of appropriate content (tasks), critical thinking in the initial teaching of mathematics can be developed. The results show that, with the appropriate choice of content, students\u27 critical thinking, viewed as a whole, can be developed and that, in that process, we can significantly influence the development of each of its skills (formulation of the problem, reformulation of the problem, evaluation, sensitivity to the problems).U radu se ukazuje na važnost razvijanja kritičkog mišljenja učenika u početnoj nastavi matematike i ističu neki od problema koji prate njegovo ostvarivanje. U tom kontekstu autori skreću pozornost na određenje pojma kritičko mišljenje i ulogu sadržaja (zadataka) u njegovu razvijanju. Polazeći od specifičnosti početne nastave matematike i dobi učenika, kritičko mišljenje operacionaliziraju kroz konkretne sposobnosti (formuliranje problema, reformuliranje problema, evaluacija, osjetljivost za probleme) koje dolaze do izražaja u radu s matematičkim sadržajima. Na uzorku od 246 učenika (dobi od 9,5 do 10,4 godina) organizirali su eksperimentalno istraživanje (eksperiment s paralelnim skupinama) s ciljem da ispitaju može li se izborom odgovarajućih sadržaja (zadataka) razvijati kritičko mišljenje učenika u početnoj nastavi matematike. Rezultati istraživanja pokazuju da se adekvatnim izborom sadržaja kritičko mišljenje učenika, promatrano u cjelini, može razvijati i da se pri tome može značajno utjecati na razvijanje svake od njegovih sposobnosti (formuliranje problema, reformuliranje problema, evaluacija, osjetljivost za probleme)

Primena tečne hromatografije sa DAD detektorom za određivanje ostataka acetamiprida i 6-hlornikotinske kiseline u uzorcima trešanja

A rapid and simple method for simultaneous determination of acetamiprid and its metabolite 6-chloronicotinic acid in sweet cherry samples has been developed. This residue analysis method is based on the reversed phase separation on C18 column with gradient elution. Analytes' determination and quantification were performed by high performance liquid chromatography (HPLC) with diode-array detector and chromatograms were extracted at 230 nm. Extraction efficiency experiments demonstrated the ability of this method to extract neonicotinoids from sweet cherry samples. These insecticides were extracted with a mixture of acetonitril/0.1N ammonium-chloride (8/2, v/v). The average recoveries of acetamiprid and 6-chlornicotinic acid from sweet cherry samples were in the range of 95-101% and 73-83%, respectively, with the associated relative standard deviations (RSDs) lt 5%. Expanded measurement uncertainties for the analyzed compounds were 2.7 and 3.01%. The limit of quantification (LOQ) was 10 μg/kg and 30 μg/kg for acetamiprid and 6-chloronicotinic acid, respectively. Thus, the developed HPLC/DAD method can be considered a useful tool for sensitive and rapid determination of acetamiprid and 6-chloronicotinic acid. Hence, the method may find further application in the analysis of real sweet cherry samples contaminated with these insecticides at a ppb level.U radu je predstavljena jednostavna metoda za određivanje acetamiprida i njegovog metabolita, 6-hlornikotinske kiseline, u uzorcima trešanja. Metoda je bazirana na primeni reverzno-faznog razdvajanja na C18 koloni primenom gradijentnog eluiranja. Određivanje i kvantifikacija analita je vršena tečnom hromatografijom (HPLC) sa DAD detektorom, pri čemu je korišćena talasna dužina od 230 nm. Tačnost metode je ocenjena procenom merne nesigurnosti. Ekstrakcija acetamiprida i 6-hlornikotinske kiseline iz uzoraka trešanja je vršena smešom acetonitril/amonijum-hlorid (0,1N) u odnosu 80:20 (v/v). Sva merenja su vršena u tri ponavljanja, pri čemu su dobijeni prinosi određivanja acetamiprida i 6-hlornikotinske kiseline u rasponima 95-101% i 73-83%, respektivno. Relativne standardne devijacije (RSD) merenja su u svim slučajevima bile ispod 5%. Limiti kvantifikacije za acetamiprid i 6-HNK iznosili su 10 i 30 μg/kg, respektivno. Kombinovana merna nesigurnost rezultata analize acetamiprida i njegovog metabolita procenjena je na 1,35, odnosno 1,50%, a proširena na 2,7 i 3,01%, upotrebom faktora pokrivanja (k=2) koji odgovara nivou poverenja od 95%, za normalnu raspodelu. Nakon validacije i procene merne neizvesnosti dobijeni rezultati pokazuju da se razvijena HPLC/DAD metoda može primeniti za određivanje sadržaja acetamiprida i 6-hlornikotinske kiseline u uzorcima trešanja i relevantnim matriksima kontaminiranim ovim jedinjenjima

Simultaneous determination of mesotrione and nicosulfuron in OD formulations

In this study an isocratic high-performance liquid chromatographic method with diode array detection was developed for simultaneous determination of mesotrione and nicosulfuron active ingredients content in pesticide products formulated as oil dispersion (OD). For the analysis, LC system an Agilent Technologies 1100 was used. Good separation was achieved on a Zorbax SB-C18 column using a mobile phase consisting of 0.1% CH3COOH/acetonitrile (75:25), at a flow rate of 0.9 ml/minute and UV detection at 245 nm. Column temperature was 40 °C, injected volume was 1 µl. Retention times for nicosulfuron and mesotrione were 3.009 min and 4.363 min, respectively. Validation of the method was performed according to IAEA guidelines. The obtained results showed that the linear coefficients were 0.9999 for both analyzed herbicides in the mixture. The repeatability of the method expressed as relative standard deviations (%RSDr) was 0.33% for mesotrione and 0.18% for nicosulfuron. The accuracy of the proposed method was determined from recovery experiments. The obtained results for mesotrione and nicosulfuron were 100.5-102.9% and 99.3-103.9%, respectively, proved to be acceptable. Precision of the method expressed as %RSD was 0.38% for mesotrione and 0.99% for nicosulfuron and are lower than the values calculated by the Horwitz equation

Razgradnja acetamiprida u plodovima trešanja

Degradation of acetamiprid in sweet cherry samples was evaluated at several intervals from the product application until the end of the pre-harvest interval. An orchard of sweet cherries located at Stepanovićevo village near Novi Sad was used in this study. Acetamiprid was applied according to the manufacturer's recommendation for protecting sweet cherries from their most important pests. Sweet cherry fruit samples were collected at eight intervals: immediately after acetamiprid application and 2, 4, 6, 8, 10, 12 and 14 days after application. The extraction of acetamiprid from sweet cherry samples was performed using a QuEChERS-based method. Determination was carried out using an HPLC-UV diode array detection system (Agilent 1100, United States) with an Agilent Zorbax Eclipse C18 column (50 mm × 4.6 mm internal diameter, 1.8 μm particle size). The method was subjected to a thorough validation procedure. The recovery data were obtained by spiking blank sweet cherry samples at three concentration levels (0.1-0.3 mg/ kg), yielding 85.4% average recovery. Precision values expressed as relative standard deviation (RSD) were below 1.61% for the intraday precision. Acetamiprid showed linear calibrations from 0.05 to 2.5 μg/ml with correlation coefficient (R2) of 0.995%. The limit of detection and limit of quantification were found to be 5 μg/kg and 14 μg/kg, respectively. The validated method was applied in the analysis of acetamiprid in sweet cherry samples. During the study period, the concentration of acetamiprid decreased from 0.529 mg/kg to 0.111 mg/kg. The content of acetamiprid in sweet cherry samples at the end of the pre-harvest interval was below the maximum permissible level specified by the Serbian and EU MRLs.U cilju praćenja razgradnje acetamiprida u plodovima trešanja u periodu od primene preparata do isteka karence, izvršen je tretman preparatom na bazi ove aktivne materije u preporučenoj dozi. Ogled je postavljen u zasadu srednje kasne sorte trešnje na lokalitetu Stepanovićevo u okolini Novog Sada. Plodovi su uzorkovani osam puta - odmah nakon primene preparata, 2, 4, 6, 8, 10, 12 i 14 dana. Ekstrakcija acetamiprida iz trešanja izvedena je QuEChERS metodom. Za određivanje acetamiprida korišćena je tečna hromatografija sa DAD detektorom (Agilent 1100, United States) i Agilent Zorbax Eclipse C18 kolonom (unutrašnji prečnik 50 mm x 4.6 mm, veličina čestica 1.8 μm). Kao mobilna faza upotrebljeni su acetonitril i 1.5% rastvor CH3COOH (30/70), sa protokom 1 ml/min, temperaturom kolone 25 oC i injektovanom zapreminom 2,5 μl, dok je kao odgovarajuća talasna dužina usvojena vrednost od 254 nm. Validacija metode je u potpunosti sprovedena u skladu sa zahtevima standarda SANCO/12495/2011 (EU Commission Health and Consumer Protection Directorate- General, 2011). Prosečna vrednost prinosa ekstrakcije acetamiprida iz trešanja proverena na tri nivoa obogaćenja (0.1-0.3 mg/kg) iznosila je 85.4%. Preciznost merenja razmotrena proverom ponovljivosti određivanja acetamiprida izražena je relativnom standardnom devijacijom (RSD) sa vrednošću manjom od 1.61%. U opsegu masenih koncentracija acetamiprida od 0,05 do 2,5 μg/ml postignuta je dobra linearnost odziva detektora sa koeficijentom varijacije od 0,995%. Limit detekcije i kvantifikacije za određivanje acetamiprida u trešnjama prikazanom metodom iznose 5 μg/kg i 14 μg/kg. Tokom ispitivanog perioda koncentracija acetamiprida u trešnjama se smanjivala od 0,592 mg/kg neposredno nakon primene insekticida do 0,111 mg/kg po isteku karence od 14 dana. Analizom je utvrđeno da je sadržaj acetamiprida u uzorcima plodova trešnje nakon isteka perioda karence ispod maksimalno dozvoljene količine za ovu aktivnu materiju propisane Pravilnikom Republike Srbije (0,2 mg/kg) i Evropske Unije (1,5 mg/kg)

Determination of clindamycin in pig plasma after implantation of poly(D,Llactide-co-glycolide)/hydroxyapatite/clindamycin core–shell nanosphere by liquid chromatography-tandem mass spectrometry

Clindamycin was determined in pig plasma by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The multiple reaction monitoring (MRM) mode of precursor-product ion transitions for clindamycin (m/z=421.1/126.1) and the internal standard, caffeine (m/z=192/125) was used. The samples were prepared by two methods: 0.1% formic acid in methanol and 1.5% trichloacetic acid. The recovery for the two preparation methods at 0.05mg/ml (n=6) was found to be for the first 104.3% and for the second method 106.5%, with repeatability RSD 1.1% and RSD 4.34%, respectively. The results of the comparison of the two different preparation methods of samples demonstrated that both methods were satisfactory

The inhibitory activity of Lactic acid bacteria isolated from fresh cow cheese

Bakterije mliječne kiseline sastavni su dio prirodne mikroflore mlijeka, a produktima svog metabolizma mogu utjecati i na sigurnost mliječnih proizvoda. Njihovo antimikrobno djelovanje odvija se preko organskih kiselina, vodikovog peroksida, ugljičnog dioksida ili bakteriocina. Svrha ovog rada bila je utvrditi sastav populacije bakterija mliječne kiseline u svježim sirevima prikupljenim na zagrebačkim tržnicama, te istražiti njihov antimikrobni potencijal. Broj bakterija mliječne kiseline određivan je metodom ISO 1524:1998, biokemijska determinacija pomoću API 50 CHL, a inhibicijsko djelovanje prema Listeria monocytogenes NCTC 10527 agar difuzijskim testom. Broj bakterija mliječne kiseline u svježim sirevima (n=10) kretao se od 5,87 do 8,38 log10 CFU g-1. Biokemijskom determinacijom izolata (n=52) utvrđene su vrste Lactococcus lactis subsp. lactis (61,54 %), Lactobacillus helveticus (23,07 %), Leuconostoc mesenteroides subsp. cremoris (11,54 %) te Leuconostoc mesenteroides subsp. mesenteroides (3,85 %). Inhibicijsko djelovanje prema L. monocytogenes NCTC 10527 zabilježeno je u 18 izolata.Lactic acid bacteria are the constituent part of milk microbial flora that could influence the safety of dairy products due production of organic acids, hydrogen peroxide, carbon dioxide and bacteriocins. Taking this in consideration, the objective of this study was to investigate the composition of lactic acid bacteria population in fresh cow cheeses taken from local markets, as well as their antimicrobial capacity. Lactic acid bacteria counts were determined according to ISO 1524:1998 method, biochemical determination using API 50 CHL system, and inhibitory activity against L. monocytogenes NCTC 10527 by agar well diffusion assay. Lactic acid bacteria count in fresh cow cheeses (n=10) ranged from 5.87 to 8.38 log10 CFU g-1. Among 52 MRS isolates collected, 61.54 % were assigned to the Lactococcus lactis subsp. Lactis species, 23.07 % Lactobacillus helveticus, 11.54 % Leuconostoc mesenteroides subsp. cremoris and 3.85 % Leuconostoc mesenteroides subsp. mesenteroides. Antilisterial activity was found in 18 isolates