Roles in bullying and academic achievement of students

Vršnjačko nasilje i školski uspeh učenika predstavljaju dva važna pedagoška problema čije proučavanje doprinosi unapređivanju vaspitno-obrazovnog rada savremene škole. Danas preovladava stav da je prilikom proučavanja vršnjačkog nasilja važno razmotriti uloge koje u tom procesu imaju učenici koji nisu direktno uključeni u nasilje u ulogama nasilnika i žrtve, već daju pasivnu ili aktivnu podršku nasilničkom ponašanju kroz zauzimanje različitih poduloga u okviru uloge posmatrača (asistenti nasilniku, podstrekači nasilnika, branioci žrtve i autsajderi). Sagledavanje povezanosti uloga u vršnjačkom nasilju i školskog uspeha učenika, kao i faktora koji mogu uticati na jačinu navedene veze, važno je sa aspekta Školske i Socijalne pedagogije, ali je značajno i za školsku praksu, jer može da ukaže na mogućnosti i načine uspešnog ostvarivanja preventivnog delovanja škole. Rad je imao za cilj da se ispita povezanost između uloge u nasilju (nasilnik, žrtva, asistent, podstrekač, autsajder i branilac) i školskog uspeha učenika, kao i da se razradi predlog preventivnog i interventnog pedagoškog delovanja u tom domenu. Kao osnovne tehnike istraživanja korišćene su tehnika nominacije (sociometrijska tehnika) i skaliranje. Putem primene skaliranja nastojalo se da se utvrdi koju ulogu učenik najčešće ima u situacijama vršnjačkog nasilјa, dok je sociometrijska tehnika primenjena kako bi se utvrdio sociometrijski status učenika. Oslanjajući se na tehniku analize sadržaja, izvršena je i analiza postojećih Programa zaštite učenika od nasilja, kako bi se utvrdilo koje mere i aktivnosti škole nameravaju da realizuju u pravcu predupređivanja vršnjačkog nasilja. Rezultati istraživanja pokazuju da se za većinu učenika mogu utvrditi učesničke uloge u nasilju. Utvrđeno je da postoji povezanost između pojedinih uloga u nasilju i sociometrijskog statusa učenika; između uloge u nasilju i školskog uspeha učenika; između uloge u nasilju i pola učenika; između uloge u nasilju, pola i školskog uspeha učenika; između uloge u nasilju, sociometrijskog statusa i školskog uspeha učenika; između učestalosti nasilja na nivou odeljenja i školskog uspeha učenika i između učestalosti nasilja na nivou škole i školskog uspeha učenika. Analiza postojećih Programa zaštite učenika od nasilja je pokazala da postoje mogućnosti za poboljšanje preventivnog i interventnog delovanja škole u nastojanju da se smanji učestalost vršnjačkog nasilja. Saznanja do kojih se došlo empirijskim istraživanjem poslužila su kao osnov za razradu predloga preventivnih i interventnih mera i aktivnosti koje se mogu primenjivati u školama u cilju smanjenja ispoljavanja vršnjačkog nasilja i, indirektno, prevencije školskog neuspeha učenika.Bullying and academic achievement represent two important pedagogical problems whose examination contributes to the improvement of the educational activities of a modern school. The standpoint which is dominant today implies that the study of bullying needs to incorporate the roles played in that process by students not directly involved in it as bullies or victims, but who provide passive or active support to the bullying behaviour by assuming various subroles within the bystander role (assistants of the bully, reinforcers of the bully, defenders of the victim, and outsiders). Observing the connection between bullying and academic achievement of students, as well as other factors which may affect the intensity of the said connection, is important not only from the perspective of School pedagogy and Social pedagogy, but also significant for school practice, since it can point to the possibilities and manners of a successful preventive action which school can undertake. The thesis aims at studying the link between a role in bullying (bully, victim, assistant, reinforcer, outsider, and defender) and academic achievement of students, as well as developing a proposal for preventive and interventive pedagogical action in this field. The nomination technique (sociometric technique) and scaling were used as basic research techniques. Scaling was applied to determine which role is most often performed by a student in bullying situations, while the sociometric technique was employed to determine the sociometric status of students. Relying upon the technique of content analysis, the existing Programs for the protection of students against bullying were analyzed to determine which measures and activities schools intend to implement so as to prevent bullying. Research results show that the participating roles in bullying situations can be determined for the majority of students. It is concluded that there is a connection between certain roles in bullying and the sociometric status of students; between certain role in bullying and academic achievement of students; between the role in bullying and students’ sex; between certain role in bullying, sex and academic achievement of students; between certain role in bullying, sociometric status and academic achievement of students; between the frequency of bullying at the class level and academic achievement of students, and between the frequency of bullying at the school level and academic achievement of students. The analysis of the existing Programs for the protection of students against bullying showed that there are opportunities for the improvement of the preventive and interventive actions carried out by a school in order to reduce the frequency of bullying. The findings yielded by empirical research served as the basis for the development of proposals for preventive and interventive measures and activities which can be implemented in schools with the aim of reducing the occurrence of bullying and, indirectly, the prevention of school failure of students

Retraction notice to “Growth performance, carcass characteristics, and selected meat quality traits of two strains of Pekin duck reared in intensive vs semi-intensive housing systems” [Animal 15(2) (2022) 100087]

Retraction notice to “Growth performance, carcass characteristics, and selected meat quality traits of two strains of Pekin duck reared in intensive vs semi-intensive housing systems” [Animal 15(2) (2022) 100087

Pouzdanost merenja različitih kontraktilnih funkcija pregibača prstiju šake kod muškaraca različitog uzrasta

The aim of the research is to determine the reliability of testing various contractile functions of a male hand based on motoric and functional dominance and age. The examinee takes a seat with their arm extended or mildly flexed in a mildly abducted position. For the measuring purposes, dynamometric probe with isometric straining conditions fixed to a special construction was used. The 'Isometrics' (ver. 3.1.1) was used and frequency of data selection was realized on the level of 500 Hz. The sample includes 269 male examinees aged from 14.0 to 69.9. The results of descriptive statistics have shown that in relation to the tested sample for the non-dominant hand, values for maximum force (Fmax) range from 462.8 to 529.0 N, for explosive force (RFDmax) the range is from 1621.6 to 1972.8 N/s and for muscular force impulse (ImpF50%max) from 8203.9 to 15552.3 Ns, while Fmax values the dominant hand ranges from 478.1 to 566.2 N, for RFDmax it ranges from 1742.6 to 2119.0 N/s and for ImpF50%max 9516.7 to 16845.1 Ns. The results have shown that it is reliable to measure all three examined contractile hand characteristics where by ICC ranges from 0.938 to 0.977 for Fmax, from 0.903 to 0.971 for RFDmaxand from 0.747 to 0.943 for ImpF50%max. The second try as the better result should be considered the representational value for Fmaxand RFDmaxvariables, regardless of the hand dominance or age group. While for the variable ImpF50%max, in the age groups from 35.0 to 49.9 and from 50.0 to 69.9, the first tested try for both hands should be considered, in 14.0 to 19.9 years group the second try should be taken into consideration, and in 20.0 to 34.9 age range, the better result of the non-dominant hand is the first try, and of the dominant is the second try.Cilj istraživanja je da se utvrdi pouzdanost testiranja različitih kontraktilnih funkcija šake muškaraca, u zavisnosti od motoričko-funkcionalne dominantnosti i uzrasta. Ispitanik zauzima sedeći položaj sa opruženom ili blago fleksiranom rukom, postavljenom u blago abdukcioni položaj. Za potrebe merenja upotrebljena je dinamometrijska sonda, sa izometrijskim uslovima naprezanja, fiksirana za specijalnu konstrukciju. Korišćen je softver 'Isometrics' (ver. 3.1.1), a frekvencija odabira podataka realizovana je na nivou od 500 Hz. Uzorak je obuhvatio 269 ispitanika muškog pola, uzrasta od 14.0 do 69.9 godina. Rezultati deskriptivne statistike su pokazali da se u odnosu na testirani uzorak za nedominantnu ruku vrednosti ispoljene maksimalne jačine (Fmax) nalaze u rasponu od 462.8 do 529.0 N, za eksplozivnu jačinu (RFDmax) u rasponu od 1621.6 do 1972.8 N/s i za impuls mišićne jačine (ImpF50%max) od 8203.9 do 15552.3 Ns, dok su vrednosti Fmax za dominantnu ruku u rasponu od 478.1 do 566.2 N, za RFDmax u rasponu od 1742.6 do 2119.0 N/s i za ImpF50%max od 9516.7 do 16845.1 Ns. Utvrđeno je da se pouzdano mogu meriti sve tri ispitivane kontraktilne karakteristike šake, pri čemu se ICC nalazi u rasponu od 0.938 do 0.977 za Fmax, od 0.903 do 0.971 za RFDmax, i od 0.747 do 0.943 za ImpF50%max.Kao reprezentativnu vrednost za varijable Fmax i RFDmax, bez obzira na dominantnost ruke, ili uzrasnu grupu, treba uzimati drugi pokušaj kao bolji rezultat. Dok za varijablu ImpF50%max, u uzrasnim grupama od 35.0 do 49.9 i od 50.0 do 69.9 godina, uglavnom treba uzimati prvi testirani pokušaj za obe ruke, u grupi od 14.0 do 19.9 godina drugi testirani pokušaj, a u uzrastu od 20.0 do 34.9 godina bolji rezultat nedominantne ruke je prvi, a dominantne drugi pokušaj

Dynamic adsorption characteristics of thin layered activated charcoal materials used in chemical protective overgarments

The efficiency of a thin layered activated charcoal material used in chemical protective overgarments has been evaluated. The study has been conducted with the aim to obtain protective materials with best characteristics considering resistance to benzene effect under dynamic conditions and to create a new filtration protection device. In order to evaluate dynamic adsorption characteristics of thin layered sorption materials, sophisticated dynamic gas chromatography method is used. The curves of benzene penetration are determined for sandwich materials, and sorption layers used in filtrating protective clothing shows that thin layered carbon sorption materials (type MOO) have good protective properties as compared to other similar materials. The findings will help to create conditions for developing a functional model for producing a new protective overgarment in the near future

Spektrohemijsko određivanje olova u vinima

The determination of lead in wines of different origin was performed by means of atomic emission spectroscopy with argon stabilized DC. U-shaped arc and electrothermal atomic absorption spectrometry. The comparison of the results obtained by the direct and standard addition method has indicated the presence of a depressive effect of the complex organic matrix. The effect is avoided successfully by mineralization, as well as by dissolution of the samples. Thus, a relative simple but precise and sensitive method involving the application of a stabilized arc and photoelectric detection with time integration of the emission signals is recommended for the determination of low concentrations of lead in wines. The complex organic matrix was investigated by recording the IR spectra of different wine fractions.Određivanje olova u vinima različitog porekla vršeno je primenom atomske emisione spektroskopije sa argonom stabilisanim lukom U-oblika i atomske apsorpcione spektrofotometrije sa grafitnom kivetom. Poređenje rezultata dobijenih direktnom i metodom standardnog dodatka pokazalo je da postoji znatan depresivni efekat složene organske osnove. Efekat je uspešno izbegnut mineralizacijom ili razblaženjem uzorka. Kombinacijom razblaženja uzorka i primenom stabilizovanog luka i fotoelektrične detekcije sa vremenskom integraciijom emisionih signala razvijena je jednostavna i precizna metoda za određeivanje niskih koncentracija olova u vinima. Kompleksan organski matriks ispitivan je snimanjem IC spektara različitih frakcija vina

Growth performance, carcass characteristics, and selected meat quality traits of two strains of Pekin duck reared in intensive vs semi-intensive housing systems

Selection of optimal hybrid of Pekin duck and housing system could improve yield and quality of duck meat. The aim of this study was to investigate the effects of two rearing systems (intensive vs semi-intensive housing) on growth performance, carcass quality, and selected physical meat quality traits of two commercial strains of Pekin ducks. The study was performed on 240 one-day-old Pekin ducklings of two different strains (120 ducklings of STAR 53 medium hybrid and 120 ducklings of SM3 heavy hybrid) during a 49-day period. Half the birds (120) were reared in a complete confinement system on a floor (intensive system), while the remaining 120 ducks had access to land outside (semi-intensive system). Growth performance of ducks was determined by BW, weight gain, feed intake, and feed conversion ratio (FCR), carcass quality by dressing percentage, percentage of basic cuts in carcasses, and content of various tissues in basic cuts, while meat quality was determined by pH, drip loss, cooking loss, Warner-Bratzler shear force, and color (L*, a*, and b*) values. At the end of the study, SM3 heavy hybrid and STAR 53 hybrid Pekin ducks achieved similar BWs. Higher final BW and lower overall FCR were found in ducks reared in the intensive system than in ducks kept in the semi-intensive system. Higher dressing percentage, weight and percentage of breast, but also a lower percentage of back with pelvis in the carcasses were determined in SM3 hybrid ducks than in STAR 53 hybrid ducks. The strain of duck did not affect meat pH, drip loss, or L* color value. Moreover, housing system affected the physical meat quality of the ducks, since breasts from ducks reared in the semi-intensive system had higher initial meat pH, higher percentage of EZ-drip loss and cooking loss, and higher L*, a*, and b* values than did breasts from intensively-reared ducks. In conclusion, SM3 ducks were more suited for broiler production due to their better carcass quality than STAR 53 ducks. Furthermore, ducks reared in the intensive system had better growth performance results and better physical meat quality traits than did ducks from the semi-intensive system

Supplementary data for the article: Filipović, N. R.; Marković, I.; Mitić, D.; Polović, N.; Milčić, M.; Dulović, M.; Jovanović, M.; Savić, M.; Nikšić, M.; Andelković, K.; et al. A Comparative Study of In Vitro Cytotoxic, Antioxidant, and Antimicrobial Activity of Pt(II), Zn(II), Cu(II), and Co(III) Complexes with N-Heteroaromatic Schiff Base (E)-2-[N’-(1-Pyridin-2-Yl-Ethylidene)Hydrazino]Acetate. Journal of Biochemical and Molecular Toxicology 2014, 28 (3), 99–110. https://doi.org/10.1002/jbt.21541

Supplementary material for: [https://doi.org/10.1002/jbt.21541]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1509

Spektralno ispitivanje soli alkalnih elemenata 12-volframfosforne kiseline

In this paper the latest results of our continuing investigation of heteropoly acids and their salts are reported. Specially attention was paid to the influence of cations on the dynamic equilibrium of protonic species, as well as on the structure of the host lattice itself, i.e., the Keggin anions. The investigations were done by IR and Raman spectroscopy within the range of 1200-40 cm-1.U ovom radu saopšteni su poslednji rezultati naših sistematskih ispitivanja heteropolikiselina i njihovih soli. Posebna pažnja posvećena je uticaju katjona na dinamičku ravnotežu protonskih vrsta, kao i na strukturu kristalne rešetke, odnosno Keginovih anjona. Ispitivanja su vršena metodama infracrvene i ramanske spektroskopije u oblasti 1200-40 cm-1. Dobijeni rezultati su važni za objašnjenje mehanizma provodljivosti, kao i za rešavanje problema praktične primene ovih jedinjenja kao čvrstih elektrolita. PR Projekat Ministarstva nauke Republike Srbije

IR i ramanska ispitivanja strukturnih modifikacija bakarne soli 12-volframfosforne kiseline

In this paper local processes and structural phase transformations of the copper salt of 12-tungstophosphoric acid are investigated. The structural phase transformations were followed through bands, characteristic for the host lattice, in the IR and Raman spectra. The results of these investigations, as well as those of XRPD analysis and impedance measurements as a function of temperature show that some local processes provoke the change in the secondary structure of the Keggin anions.U ovom radu ispitivani su lokalni procesi i strukturne fazne transformacije soli bakra 12-volframfosforne kiseline. Strukturne fazne transformacije praćene su preko traka karakterističnih za kristalnu rešetku u infracrvenim i ramanskim spektrima. Rezultati ovih ispitivanja, kao i oni dobiveni rendgeno-strukturnom analizom i iz impedansnih merenja, odnosno provodljivost u funkciji temperature, pokazuju da je fazna transformacija vezana za promene lokalne strukture, tj. sekundarne strukture Keginovih anjona. PR Projekat Ministarstva nauke Republike Srbije

Zearalenone and ochratoxin A: adsorption by kaolin modified with surfactant

Octadecyldimethylbenzyl ammonium chloride (OA) was used as a surfactant for the preparation of organokaolin. The natural kaolin (from a plant for production of quartz sand in Rgotina, Serbia) was modified with a surfactant in amount equal to 90% of the kaolin cation exchange capacity (CEC). FTIR spectroscopy was used for characterization of the new product. FTIR spectra confirmed the presence of OA ions at the kaolin surface. Adsorption of mycotoxins – zearalenone (ZEN) and ochratoxin A (OCHRA) was studied by organokaolin at different amounts of adsorbent and pHs. Results showed that the presence of organic cations in the kaolin structure increased adsorption of both ZEN and OCHRA. Adsorption of the mycotoxins by organokaolin increased with increasing amounts of adsorbent and, at the lowest amount of solids in suspension, adsorption of ZEN and OCHRA was slightly higher at pH 7 and 9