37 research outputs found
Unfolding the assessment process in a whole class mathematics setting
Aktivnosti ocenjivanja na času predstavljaju važan aspekt prakse u učionici. U isto vreme, debata o prednostima i značaju formativnog ocenjivanja spram sumativnog i dalje se nastavlja. Ocenjivanje se ne odvija izvan okvira svakodnevne prakse u učionici, pa se, samim tim, na ocenjivanje gleda kao veoma kompleksan proces. U ovom radu želimo da istražimo način na koji se ocenjivanje stavlja u službu učenja učenika i da li se informacije koje nastavnik kroz ocenjivanje prikuplja koriste (ili ne) kako bi se svakodnevna praksa nastavnika u nastavi matematike prilagodila raznovrsnim potrebama učenika. Za potrebe ovog rada autori su pratili nastavnu praksu iskusnog nastavnika matematike u jednoj gimnaziji u Beogradu. Prakse ocenjivanja nastavnika posmatrane su u periodu od tri nedelje. Analiza pokazuje da nastavnik poseduje kompleksnu predstavu o tome kako ocenjivanje u učionici treba da izgleda, ali je percepcija toga u velikoj meri odvojena od nastave, što je u skladu s prethodnim nalazima. Međutim, elementi formativnog ocenjivanja se pojavljuju, pa doprinose tome da se ocenjivanje nađe u službi učenja. Uprkos tome, kada se pobliže posmatra način na koji nastavnik prati napredak učenika, evidentiran je ograničen skup praksi. Uočen je i nesklad između percepcija učenika i nastavnika u vezi s procesom ocenjivanja i primenjenim praksama. Takođe, nastavnik se suočava s teškoćama kada treba da verbalizuje neke od aspekata sopstvene prakse, naročito ako se oni vezuju za formativne karakteristike procene postgnuća učenika. PR Projekat Ministarstva nauke Republike Srbije, br. 179034 i br. 179018. .Assessment activities in the class are an important aspect of classroom practice, while there is much debate with respect to the formative vs. summative assessment routines and the outcomes that each of them provides for students' learning. As classroom assessment does not occur in seclusion of other aspects of classroom life, the process is seen as rather complex. In this study we wished to explore how assessment serves the function of supporting students' learning and whether this evidence is used to adapt teacher's practices in meeting different learning needs in the mathematics classroom. The authors observed assessment practices of an experienced math teacher in a grammar school in Belgrade. Teacher's assessment practices were observed during a three week period. The analysis has shown the teacher to hold a somewhat complex perception of assessment, yet the perception is largely detached from teaching, which is in line with the previously reported results. However, the elements of formative assessment do emerge, thus contributing to the assessment being in service of learning. In spite of this, a narrow set of practices are visible when observing how the teacher keeps track of students' progress. A mismatch is visible between students' and teacher's perceptions of the assessment as a whole and some of the practices exercised in the process. The teacher struggled to verbalize some aspects of own assessment practices, especially those related to more formative aspects
Mathematics related anxiety: Mathematics bogeyman or not?
Podaci PISA testiranja iz 2003. godine ukazuju na visok nivo matematičke anksioznosti učenika u Srbiji. Više od polovine naših učenika brine da će imati teškoće na časovima matematike i da će dobiti loše ocene. Ciljevi ovog istraživanja jesu: ispitivanje veza između matematičke anksioznosti i postignuća na skali matematičke pismenosti; utvrđivanje mogućih prediktora matematičke anksioznosti i identifikovanje grupa učenika koje se razlikuju u njihovom odnosu prema matematici. Matematička anksioznost je u statistički značajnoj negativnoj korelaciji i sa školskim postignućem i sa postignućem na skali matematičke pismenosti. Sociodemografski faktori, motivacioni i kognitivni aspekti učenja matematike, doživljaj školske klime i klime na času objašnjavaju 40% varijanse matematičke anksioznosti. Na osnovu odnosa prema matematici učenici se mogu svrstati u tri grupe; dimenzije koje ih razdvajaju jesu nezainteresovanost -zainteresovanost i prisustvo - odsustvo anksioznosti. Grupa koja pokazuje anksioznost ima najlošije postignuće. Primenom kvalitativne analize ispitivani su stavovi učenika i nastavnika o specifičnim problemima u vezi sa nastavom i savlađivanjem gradiva iz matematike.Data of the PISA 2003 survey indicate high levels of mathematics anxiety of students in Serbia. More than half of our students worry whether they will have difficulties in mathematics class or whether they will earn poor marks. Aims of this study therefore are: examining relationship between math anxiety and achievement at mathematics literacy scale; establishing possible predictors of math anxiety and identification of students' groups in relations to their relationship towards mathematics as a subject. Mathematics anxiety is statistically negatively correlated with school achievement and achievement at mathematics literacy scale. Socio-demographic factors, motivational and cognitive aspects related to learning mathematics, perception of school and classroom climate explain 40% variance of mathematics anxiety. Based on students' relationship towards mathematics they cam be divided into three groups; while dimensions that apart them are uninterested-interested in mathematics and presence-absence of anxiety. The group displaying anxiety scores lowest among the three. Applying qualitative analysis students' and teachers' attitudes on specific issues related to teaching and learning mathematics was examined
Korelacija stepena konverzije i količine oslobođenih supstanci iz dentalnih kompozitnih cemenata
This study examined the possible correlation between the degree of conversion (DC) and the amount of substances eluted from three commercial cured resin-based cements. The DC of the various resin-based cements was measured by Raman spectroscopy, while the quantity of unreacted monomers released from the cement matrix (triethylene glycol dimethacrylate, TEGDMA, urethane dimethacrylate, UDMA, 2-hydroxyethyl methacrylate, HEMA and bisphenol A) was determined by high pressure liquid chromatography (HPLC). The obtained results, after multiple statistical evaluation (one way ANOVA, LSD post hoc test), showed no significant differences in the DC values between the resin cements. On the contrary, the results of the HPLC analysis depicted statistically significant differences between the three materials with respect to the amount of leached monomers. In addition, no correlation between the DC and the amount of eluted substances from the tested cured composite cements was found.Rad istražuje moguću korelaciju stepena konverzije (DC) i količine oslobođenih monomernih supstanci iz tri komercijalna preparata kompozitnih dentalnih cemenata. Stepen konverzije kompozitnih cemenata određen je metodom Raman spektroskopije, dok je količina neizreagovalih i oslobođenih monomera iz cementnog matriksa detektovana pomoću HPLC metode. Rezultati dobijeni nakon višestruke statističke evaluacije (one way ANOVA, LSD past hoc test) ne pokazuju značajne razlike u stepenu konverzije različitih preparata kompozitnih cemenata. Nasuprot tome, rezultati HPLC analize beleže značajne razlike u količini i vrsti monomernih supstanci otpuštenih iz kompozitnih cemenata. Takođe, statistička analiza u okviru ove studije nije pokazala korelaciju stepena konverzije ispitivanih kompozitnih dentalnih cemenata i količine oslobođenih supstanci iz ovih materijala
Supplementary data for article: Tomašević, A.; Mijin, D.; Radišić, M.; Prlainović, N.; Cvijetić, I.; Kovačević, D. V.; Marinković, A. Photolysis of Insecticide Methomyl in Various Solvents: An Experimental and Theoretical Study. Journal of Photochemistry and Photobiology A: Chemistry 2020, 391. https://doi.org/10.1016/j.jphotochem.2020.112366
Supplementary material for: [https://doi.org/10.1016/j.jphotochem.2020.112366]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3832
Fatty acid composition of Baranjski kulen from two diverse production systems
Received: 2018-05-07 | Accepted: 2018-05-14 | Available online: 2018-11-26https://doi.org/10.15414/afz.2018.21.04.152-154The aim of the present study was to compare the fatty acid composition of dry fermented sausage made from Crna slavonska pig and modern hybrids reared in diverse production systems. The study was performed on Baranjski kulen, a traditional PGI (Protected Geographical Indication) labelled sausage. Baranjski kulen produced from pigs included in the study differed in their fatty acid profile, with kulen made from Crna slavonska pigs having a higher content of MUFA, lower content of PUFA and a more favourable PUFA/SFA ratio. The results of the present study demonstrate that meat originating from breeds raised in specific production system affects the fatty acid composition as one of the major determinants of nutritional product quality. Keywords: autochthonous breed, fatty acids, nutritional quality, pigsReferencesAgostoni, C., Moreno, L., Shamir, R. (2015) Palmitic Acid and Health: Introduction. Critical Reviews in Food Science and Nutrition, 12, 141-142. DOI: https://dx.doi.org/10.1080/10408398.2015.1017435Djurkin Kušec, I., Buha, I., Margeta, V., Gvozdanović, K., Radišić, Ž, Komlenić, M., Kušec, G. (2017) Carcass Composition and Meat Quality of Crna slavonska Pigs from Two Different Housing Conditions. Agriculturae Conspectus Scientificus, 82 (3), 221-225.Karolyi, D., Salajpal, K., Kiš, G., Đikić, M., Jurić, I. (2007) Influence of finishing diet on fatty acid profile of longissimus muscle of Black Slavonian pigs. Poljoprivreda, 13 (1), 176-179.Kasprzyk A., Tyra M., Babicz M. (2015) Fatty acid profile of pork from a local and a commercial breed. Archives Animal Breeding, 58, 379–385. DOI: https://dx.doi.org/10.5194/aab-58-379-2015Komlenić, M., Margeta, V., Djurkin Kušec, I., Gvozdanović, K., Margeta, P., Kušec, G. (2018) Carcass composition and meat quality of pigs from different pork chains in the production of Baranjski kulen (PGI). Archivos de Zootecnia, 209-212.Medić, H., Djurkin Kušec, I., Pleadin, J., Kozačinski, L., Njari, B., Hengl, B., Kušec, G. (2018) The impact of frozen storage duration on physical, chemical and microbiological properties of pork, Meat Science, 140, 119-127. DOI: https://dx.doi.org/10.1016/j.meatsci.2018.03.006Morse, N (2015). Are some health benefits of palmitoleic acid supplementation due to its effects on 5′ adenosine monophosphate-activated protein kinase (AMPK)? Lipid technology, 27 (12), 278-281. DOI: https://dx.doi.org/10.1002/lite.201500061Nevrkla, P., Kapelanski, W., Václavková, E., Hadaš, Z., Cebulska A., Horký, P. (2017) Meat quality and fatty acid profile of pork and backfat from an indigenous breed and a commercial hybrid of pigs. Annals of Animal Science, 17 (4), 1215-1227. DOI: https://dx.doi.org/10.1515/aoas-2017-0014Parunović, N., Radović, Č., Savić, R. (2017): Sensory properties and fatty acids profiles of fermented dry sausages made of pork meat from various breeds. IOP Conference Series: Earth and Environmental Sciences
Supplementary data for article: Božić, A. R.; Filipović, N. R.; Verbić, T.; Milčić, M. K.; Todorović, T.; Cvijetić, I.; Klisurić, O.; Radišić, M.; Marinković, A. A Detailed Experimental and Computational Study of Monocarbohydrazones. Arabian Journal of Chemistry 2020. https://doi.org/10.1016/j.arabjc.2017.08.010
Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S1878535217301661?via%3Dihub]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/318
Development and application of liquid chromatography-tandem mass spectroskopy method for pesticide analysis in fruits and fruit juices
Predmet ovog rada je razvoj i primena nove, brze i osetljive multirezidualne analitičke
metode za određivanje tragova pesticida različitih hemijskih grupa u voćnim sokovima i
voću. Za analizu su odabrani pesticidi koji spadaju u najčešće korišćene u našoj zemlji.
Rad obuhvata razvoj metode disperzije matrice na čvrstoj fazi, za efikasnu ekstrakciju i
predkoncentrisanje veoma različitih analita. Metoda obuhvata istovremeno razaranje,
usitnjavanje i homogenizaciju čvstih i polučvstih uzoraka, kao i ekstrakciju i
prečišćavanje analita. Kao sorbent korišćena je dijatomejska zemlja a dihlormetan je
korišćen za eluiranje analita. Takođe, urađena je optimizacija hromatografskog
razdvajanja i uspostavljen je protokol za potvrdu prisustva analita pomoću masenog
detektora sa jonskim trapom. Kvantifikacija analita je urađena posmatranjem
najintenzivnijeg fragmenta. Razvijena metoda za određivanje pesticida u voćnim
sokovima obuhvata dvanaest pesticida i uspešno je validirana na uzorcima soka od
jabuke, narandže, breskve i maline. Metoda je proširena sa još pet pesticida i uspešno
validirana na uzorcima voća, jabuke, kajsije, narandže i jagode. Kao parametri
validacije određivani su: prinos, linearnost, granica detekcija i granica kvantifikacije za
sve ispitivane pesticide u svim ispitivanim matricama. Vrednosti dobijene za prinose u
većini slučajeva su bile u opsegu od 70 do 120% uz relativnu standardnu devijaciju
uglavnom ispod 20%. Dostignute su veoma niske granice detekcije i kvantifikacije.
Razvijena metoda je primenjena na realne uzorke komercijalno dostupnih sokova i voća
dostupnih na beogradskom tržištuThis study presents the development and application of a new, rapid and sensitive
analytical method for determination of pesticide residues in fruit juices and fruits.
Pesticides, chosen for the analysis, belong to different chemical classes and are among
the most frequently used in our country. The study includes the development of the
matrix solid-phase dispersion sample preparation method for extracting and preconcentrating
different analytes. This sample preparation technique involves
simultaneous disruption, fragmentation and homogenization of solid and semi-solid
samples as well as extraction and clean-up of the analytes. Diathomeus earth was used
as a dispersant, while dichloromethane was used as an eluting solvent. Also,
optimization of the chromatographic separation was done and the protocol for reliable
confirmation of pesticide residues with ion trap mass detector was established. The
quantification of the analytes was carried out using the most sensitive transition.
Developed method for pesticide analysis in fruit juices includes twelve pesticides and
was successfully validated in apple, orange, peach and raspberry fruit juices. The
method was expanded with five more pesticides and it was successfully validated for
fruit samples, apple, apricot, orange and strawberry. The method was validated for
accuracy, linearity, reproducibility, and sensitivity. Mean values for recoveries were in
the range of 70–120 % for all tested matrices. Repeatability of the method, expressed as
the relative standard deviation, was in general, lower than 20 %. Low limits of detection
and quantification were readily achieved with this method for all tested pesticides. The
applicability of the method to routine analysis was tested in real fruit and fruit juices
samples with good performance
Influence of Physical Therapy Procedures on Postoperative Recovery after Cesarean Section
Cilj: Prikazati koji su najučestaliji uzroci koji dovode do carskog reza. Ispitati utjecaj bavljenja tjelesnom aktivnošću prije i za vrijeme trudnoće na poslijeoperativni oporavak. Ispitati utjecaj provedene fizikalne terapije na smanjenje boli prilikom ustajanja, hodanja i sjedenja.
Metode: Istraživanje za završni rad provedeno je anketom koja sadržava 23 pitanja. Anketu je u cijelosti ispunilo 52 ispitanice. Kriterij za rješavanje ankete je rodilja s carskim rezom. U svrhu prevencije komplikacije carskog reza postoperativno su provođene vježbe disanja, cirkulacijske vježbe, pravilno pozicioniranje u krevetu i edukacija o okretanju i ustajanju te vježbe za mišiće zdjeličnog dna i abdominalne muskulature. Cilj provedenih vježbi je prevencija i ublažavanje respiratornih i cirkulacijskih poremećaja.
Rezultati: Puerpere koje su vježbale prije i za vrijeme trudnoće imaju smanjene komplikacije carskog reza i fizikalna terapija je pozitivno utjecala na smanjenje bolnosti pri okretanju, ustajanju i hodanju. Puerpere koje su prvi put ustale s fizioterapeutom u jedinici Intenzivne njege imaju smanjenu razinu boli poslije fizioterapeutskog tretmana.
Zaključak: Fizikalna terapija pozitivno utječe na poslijeoperativni oporavak kod perpera s carskim rezom. Od 44 rodilje 31 se osjećaju bolje poslije provedene fizikalne terapije te im je smanjena bolnost prilikom ustajanja hodanja i sjedenja. Smanjenje problema s mokrenjem poslije provedeni vježbi od 8 ima 7 rodilja.Goal of this paper is: To determine affectivnes of physical theraphy on recovery of women, puerpuera who had C – section. To show most common cause who lead to perfom C – section. To question impact that phyical exercise has on puerpueras recovery based on activity before and after surgery. To question all effects that physical theraphy had on reducing pain, and reliefd walking and sitting process.
Methods: Research for final paper has been survey conducted, havin 23 question that needed to be answered. Survey has been answered by 52 women. Kriterion for survey resolution was that a women had to be pacient with C – section. ( The purpose was prevention of C- section complications, postoperative exercise including breathing exercises, circulation exercises, proper bed positioning and education how to properly move and turn while in bed, so as exercise for abdominal and pelvic muscles. The purpose of those exercises was prevention and reduction of respiratory and cirulation disorders).
Results: Results of survey that has been made showed that most of the puerpure who had been exercising with therapist before, and during the pregnancy had less complications after C- section and therapy had positive effect on their rotation in bed, had reduced pain level and they had less trouble of getting up and walking. Puerpere who got up with therapist for the first time, in the Intensive care unit had reduced pain after operation.
Conclusion: From my research, it was obvious that effects of phyisical theraphy performed with women who had C – section are noumerous. It affects easier, quicker and less painfull recovery at puerpuera. Statisticly, 31 from 44 pacients felt much better and stronger after physical theraphy, mostly they showd signs of reduced pain while walking. Also, it is significant to mention that 7 from 8 pacients had less urinary problem after the treatment with theraphis
Development and application of liquid chromatography-tandem mass spectroskopy method for pesticide analysis in fruits and fruit juices
Predmet ovog rada je razvoj i primena nove, brze i osetljive multirezidualne analitičke
metode za određivanje tragova pesticida različitih hemijskih grupa u voćnim sokovima i
voću. Za analizu su odabrani pesticidi koji spadaju u najčešće korišćene u našoj zemlji.
Rad obuhvata razvoj metode disperzije matrice na čvrstoj fazi, za efikasnu ekstrakciju i
predkoncentrisanje veoma različitih analita. Metoda obuhvata istovremeno razaranje,
usitnjavanje i homogenizaciju čvstih i polučvstih uzoraka, kao i ekstrakciju i
prečišćavanje analita. Kao sorbent korišćena je dijatomejska zemlja a dihlormetan je
korišćen za eluiranje analita. Takođe, urađena je optimizacija hromatografskog
razdvajanja i uspostavljen je protokol za potvrdu prisustva analita pomoću masenog
detektora sa jonskim trapom. Kvantifikacija analita je urađena posmatranjem
najintenzivnijeg fragmenta. Razvijena metoda za određivanje pesticida u voćnim
sokovima obuhvata dvanaest pesticida i uspešno je validirana na uzorcima soka od
jabuke, narandže, breskve i maline. Metoda je proširena sa još pet pesticida i uspešno
validirana na uzorcima voća, jabuke, kajsije, narandže i jagode. Kao parametri
validacije određivani su: prinos, linearnost, granica detekcija i granica kvantifikacije za
sve ispitivane pesticide u svim ispitivanim matricama. Vrednosti dobijene za prinose u
većini slučajeva su bile u opsegu od 70 do 120% uz relativnu standardnu devijaciju
uglavnom ispod 20%. Dostignute su veoma niske granice detekcije i kvantifikacije.
Razvijena metoda je primenjena na realne uzorke komercijalno dostupnih sokova i voća
dostupnih na beogradskom tržištuThis study presents the development and application of a new, rapid and sensitive
analytical method for determination of pesticide residues in fruit juices and fruits.
Pesticides, chosen for the analysis, belong to different chemical classes and are among
the most frequently used in our country. The study includes the development of the
matrix solid-phase dispersion sample preparation method for extracting and preconcentrating
different analytes. This sample preparation technique involves
simultaneous disruption, fragmentation and homogenization of solid and semi-solid
samples as well as extraction and clean-up of the analytes. Diathomeus earth was used
as a dispersant, while dichloromethane was used as an eluting solvent. Also,
optimization of the chromatographic separation was done and the protocol for reliable
confirmation of pesticide residues with ion trap mass detector was established. The
quantification of the analytes was carried out using the most sensitive transition.
Developed method for pesticide analysis in fruit juices includes twelve pesticides and
was successfully validated in apple, orange, peach and raspberry fruit juices. The
method was expanded with five more pesticides and it was successfully validated for
fruit samples, apple, apricot, orange and strawberry. The method was validated for
accuracy, linearity, reproducibility, and sensitivity. Mean values for recoveries were in
the range of 70–120 % for all tested matrices. Repeatability of the method, expressed as
the relative standard deviation, was in general, lower than 20 %. Low limits of detection
and quantification were readily achieved with this method for all tested pesticides. The
applicability of the method to routine analysis was tested in real fruit and fruit juices
samples with good performance
Influence of Physical Therapy Procedures on Postoperative Recovery after Cesarean Section
Cilj: Prikazati koji su najučestaliji uzroci koji dovode do carskog reza. Ispitati utjecaj bavljenja tjelesnom aktivnošću prije i za vrijeme trudnoće na poslijeoperativni oporavak. Ispitati utjecaj provedene fizikalne terapije na smanjenje boli prilikom ustajanja, hodanja i sjedenja.
Metode: Istraživanje za završni rad provedeno je anketom koja sadržava 23 pitanja. Anketu je u cijelosti ispunilo 52 ispitanice. Kriterij za rješavanje ankete je rodilja s carskim rezom. U svrhu prevencije komplikacije carskog reza postoperativno su provođene vježbe disanja, cirkulacijske vježbe, pravilno pozicioniranje u krevetu i edukacija o okretanju i ustajanju te vježbe za mišiće zdjeličnog dna i abdominalne muskulature. Cilj provedenih vježbi je prevencija i ublažavanje respiratornih i cirkulacijskih poremećaja.
Rezultati: Puerpere koje su vježbale prije i za vrijeme trudnoće imaju smanjene komplikacije carskog reza i fizikalna terapija je pozitivno utjecala na smanjenje bolnosti pri okretanju, ustajanju i hodanju. Puerpere koje su prvi put ustale s fizioterapeutom u jedinici Intenzivne njege imaju smanjenu razinu boli poslije fizioterapeutskog tretmana.
Zaključak: Fizikalna terapija pozitivno utječe na poslijeoperativni oporavak kod perpera s carskim rezom. Od 44 rodilje 31 se osjećaju bolje poslije provedene fizikalne terapije te im je smanjena bolnost prilikom ustajanja hodanja i sjedenja. Smanjenje problema s mokrenjem poslije provedeni vježbi od 8 ima 7 rodilja.Goal of this paper is: To determine affectivnes of physical theraphy on recovery of women, puerpuera who had C – section. To show most common cause who lead to perfom C – section. To question impact that phyical exercise has on puerpueras recovery based on activity before and after surgery. To question all effects that physical theraphy had on reducing pain, and reliefd walking and sitting process.
Methods: Research for final paper has been survey conducted, havin 23 question that needed to be answered. Survey has been answered by 52 women. Kriterion for survey resolution was that a women had to be pacient with C – section. ( The purpose was prevention of C- section complications, postoperative exercise including breathing exercises, circulation exercises, proper bed positioning and education how to properly move and turn while in bed, so as exercise for abdominal and pelvic muscles. The purpose of those exercises was prevention and reduction of respiratory and cirulation disorders).
Results: Results of survey that has been made showed that most of the puerpure who had been exercising with therapist before, and during the pregnancy had less complications after C- section and therapy had positive effect on their rotation in bed, had reduced pain level and they had less trouble of getting up and walking. Puerpere who got up with therapist for the first time, in the Intensive care unit had reduced pain after operation.
Conclusion: From my research, it was obvious that effects of phyisical theraphy performed with women who had C – section are noumerous. It affects easier, quicker and less painfull recovery at puerpuera. Statisticly, 31 from 44 pacients felt much better and stronger after physical theraphy, mostly they showd signs of reduced pain while walking. Also, it is significant to mention that 7 from 8 pacients had less urinary problem after the treatment with theraphis