Parenting Style, Involvement of Parents in School Activities and Adolescents’ Academic Achievement

AbstractThis paper deals with problems of correlations between a parenting style, involvement of parents in school activities and academic achievements of adolescents. The theoretical concepts of Baumrind (1991) and Epstein (2002) were used as theoretical framework. The research was conducted with the aim to determine a correlation between a parenting style, involvement of parents in school activities and success of adolescents in schools. There were 400 parents and 200 adolescents who were examined. A PSDQ questionnaire of parenting styles and dimensions was used (Parenting Styles & Dimensions Questionnaire, Robinson, Mandleco, Olsen, & Hart, 2001) for examining parenting styles. A scale was designed according to the Epstein concept for examining the involvement of parents. The results of the research showed that an authoritative parenting style was characteristic for mothers, which was correlated with a higher involvement in school activities and a greater success of adolescents. An authoritarian parenting style is dominant for fathers and it is correlated with a lack of time necessary for involvement in school activities. The given results indicate a problem concerning involvement of fathers in school activities of children and the indifference of school to establish a partner relationship with parents. School should offer relevant information about effects of various parenting styles on achievements of students within collaborating between school and a family and establishing a partnership between school and a family

Socio-demographic inequalities in satisfaction with primary health care and utilization of chosen doctors’ services: a cross-sectional study

Aim: The aim of the study was to examine socio-demographic inequalities in user satisfaction with PHC and utilization of chosen doctors’ services. Methods: This cross-sectional study was conducted in 2016 among 232 respondents who participated in PHC user satisfaction survey in PHC center Valjevo, Serbia. Inclusion criteria were an age of at least 20 years, sufficient skills of Serbian language to fill in questionnaires and consent to participation. Two hundreds and six patients completed an anonymous questionnaire about the user satisfaction with PHC. Results: The chosen doctor was seven times more often visited by the elderly (OR=7.03) and almost three times more often by the middle-aged (OR=2.66) compared to the youngest category of respondents. Those with low education and poor financial status of the household visited a doctor four (OR=4.14) and almost nine times (OR=8.66) more often, respectively, compared to those with high education and good socioeconomic status. A statistically significant higher level of PHC satisfaction was recorded in the rural population (p<0.001) and among respondents with poor socioeconomic status of the household (p=0.014). Conclusion: The chosen doctor was more frequently visited by respondents with low education and those with poor socioeconomic status of the household, while a higher degree of satisfaction with PHC was recorded in the rural population as well as in those with poor socioeconomic status of the household.   Conflicts of interest: None declared. &nbsp

Synthesis of bile acid amines via microwave irradiation

Herein, we present microwave-assisted reductive amination of oxo derivative of deoxycholic acid with morpholine in the presence of sodium-cyanoborohydride. These chemical transformation produces a majority of the 3β-amino isomer 5 as a new compound after five minutes of irradiation. In addition, formylated bile acid have been proved as excellent starting material for the synthesis of bile acid`s N-morpholino amine. Microwave-assisted reactions of formylation in the absence of catalyst, selective deformylation, as well as further oxidation with N-bromosuccinimide gained 3-oxo derivatives of deoxycholic acid acid in high yield. Compared to the conventional protocol a remarkable reduction in overall processing time from hours to a few minutes was achieved

Socio-demographic inequalities in satisfaction with primary health care and utilization of chosen doctors’ services: a cross-sectional study

Aim: The aim of the study was to examine socio-demographic inequalities in user satisfaction with PHC and utilization of chosen doctors’ services. Methods: This cross-sectional study was conducted in 2016 among 232 respondents who participated in PHC user satisfaction survey in PHC center Valjevo, Serbia. Inclusion criteria were an age of at least 20 years, sufficient skills of Serbian language to fill in questionnaires and consent to participation. Two hundreds and six patients completed an anonymous questionnaire about the user satisfaction with PHC. Results: The chosen doctor was seven times more often visited by the elderly (OR=7.03) and almost three times more often by the middle-aged (OR=2.66) compared to the youngest category of respondents. Those with low education and poor financial status of the household visited a doctor four (OR=4.14) and almost nine times (OR=8.66) more often, respectively, compared to those with high education and good socioeconomic status. A statistically significant higher level of PHC satisfaction was recorded in the rural population (p<0.001) and among respondents with poor socioeconomic status of the household (p=0.014). Conclusion: The chosen doctor was more frequently visited by respondents with low education and those with poor socioeconomic status of the household, while a higher degree of satisfaction with PHC was recorded in the rural population as well as in those with poor socioeconomic status of the household. &nbsp

Counterpropagating surface solitons in two-dimensional photorefractive lattices

We study interaction of counterpropagating beams in truncated two-dimensional photonic lattices induced optically in photorefractive crystals, and demonstrate the existence of counterpropagating surface solitons localized in the lattice corners and at the edges. We display intriguing dynamical properties of such composite optical beams and reveal that the lattice surface provides a strong stabilization effect on the beam propagation. We also observe dynamical instabilities for stronger coupling and longer propagation distances in the form of beam splitting. No such instabilities exist in the single beam surface propagation

Značaj i upotreba žita u ishrani riba

Proizvodnja hrane za ribe, poslednjih godina beleži najbrži rast u industrijskoj proizvodnji hrane za životinje (Jovanović i sar. 2006). Ukoliko sektor akvakulture nastavi sa dosadašnjim prosečnim rastom od 8-10% godišnje do 2025. godine, i proizvodnja hrane moraće da prati taj rast (Tacon,2010). Danas se u hranu za ribe uglavnom uključuju riblje brašno i riblje ulje zbog visoke nutritivne vrednosti. Zbog ograničenosti prirodnih resursa. nameće se potreba za značajnijim uključivanjem biljnih hraniva, pre svega žita u ishrani riba. Žita prvenstveno predstavljaju izvor energije i služe za prihranu riba, međutim, njihovom preradom mogu se dobiti koncentati proteina koji se mogu koristiti kao delimična zamena za proteine animalnog porekla. Žita kao energetska hraniva čine osnovni deo obroka u poluintenzivnom sistemu gajenja riba. Proteinski deo potreba obezbeđuje im fauna dna i zooplankton. U našoj zemlji kukuruz je najvažnije žito koja se koristi u ishrani životinja. Visok sadržaj skroba, srazmerno velika zastupljenost ulja i malo celuloze, čini kukuruz izrazito energetskim hranivom (Đorđević i Dinić, 2007). Kukuruz karakteriše nizak sadržaj proteina sa nepovoljnim aminokiselinskim sastavom. Protein kukuruza pretežno čini zein koji ima nisku nutritivnu vrednost, pre svega usled deficita lizina i triptofana. Proteini ječma su niske biološke vrednosti, ali nešto bolji u odnosu na proteine kukuruza (Perović, Janković et al.,2009). Siromašni su u lizinu i metioninu, mada su selekcijom dobijene sorte sa većim sadržajem lizina. U poređenju sa kukuruzom, po hranljivoj vrednosti, pšenica sadrži više proteina, a manje masti. Sadržaj proteina kod različitih sorata pšenice varira od 10-14% (Protić, Janković,1998). Proteini pšenice su siromašni lizinom, zatim metioninom, treoninom, leucinom i izoleucinom (Janković et al.,2008). Količina lizina, koji je prva limitirajuća aminokiselina, iznosi 0,3-0,37%. Tritikale je hibrid pšenice i raži, koji se zbog relativno visoke nutritivne vrednosti sve više se koristi u ishrani svih kategorija životinja, pa i riba. Tritikale sadrži 11-20% sirovih proteina. Sadržaj aminokiselina je sličan sadržaju aminokiselina pšenice. Najsavremeniju tehnološku operaciju u procesu proizvodnje hrane za ribe predstavlja proces ekstrudiranja. Ekstruzionim kuvanjem na principu «visoka temperatura-kratko vreme» postižu se veca svarljivosti skroba, veća nutritivna vrednost, plutanje ili sporo tonjenje sto omogucava vece učesće žita u hrani za ribe. (Jovanović et al.2006).. Žita kao komponente u kompletnim smešama za ribe u intenzivnom uzgoju imaju izuzetno veliki značaj, posebno u ishrani šarana koji značajan deo energetskih potreba može zadovoljiti iz skroba. Proteinska hraniva, uz dodatak sintetičkih aminokiselina dobijena preradom žita, poput kukuruznog, pšeničnog glutena, kao i proteina pirinča, u značajnoj meri mogu zameniti, riblje brašno kao najkvalitetnije hranivo u ishrani riba. Selekcijom i genetskim modofikacijama treba stvarati žita sa povoljnim nutritivnim svojstvima potrebnim za hranu za ribe

Microwave-assisted synthesis of n-doped carbon quantum dots for the photocatalytic removal of methylene blue from wastewater

Wastewater treatment is an emerging problem in the industrialized world. The development of new semiconducting materials with the potential to be used in photocatalysis is the focus of the scientific community. Here, we present the synthesis of N-doped carbon quantum dots (NCQDs) using microwave radiation. N-CQDs were synthesized by irradiation of glucose solution in the presence of ammonia hydroxide as a nitrogen doping agent at low temperature (100 °C), low applied microwave power (100 and 200 W), and for a short period of time (60 s). The possible application of N-CQDs as a catalyst for photocatalytic degradation of Methylene Blue (MB) dye under blue light, green light, red light, and daylight was investigated. The highest values of MB degradation were observed for the samples exposed to red light with a maximum of 58.8 % for N-CQDs sample prepared at the reactor power of 200 W exposed to red light for 2 h

Uticaj ulja uljane repice u ribljoj hrani na kvalitet mesa šarana

Meso šarana, najzastupljenije ribe na ribnjacima u Republici Srbiji, predstavlja značajan nutritivni izvor n-3 visoko nezasićenih masnih kisleina (HUFA), pre svega eikozapentaenske (EPA) i dokozaheksaenske (DHA) kiseline, koje imaju važnu ulogu u bitnim fiziološkim procesima u organizmu i očuvanju zdravlja ljudi. Sadržaj masti i masnokiselinski sastav šarana su pod uticajem pola, godišnjeg doba, reproduktivnog statusa, uslova životne sredine, načina gajenja a posebno načina ishrane. Dobra tehnologija proizvodnje na ribnjaku je od nesumnjivog značaja za odgovarajuću strukturu planktonskih i bentosnih organizama, što igra veliku ulogu u dobijanju mesa šarana što boljeg hemijskog sastava. Riblje ulje je dugo predstavljalo glavni izvor masti u hrani za ribe, ali je zbog sve veće potrošnje, pa samim tim smanjene raspoloživosti i drastičnog povećanja cene istog došlo do povećanja upotrebe ulja biljnog porekla kao potpune ili delimične zamene za riblje ulje u hrani za ribe. Zamena ribljeg ulja sa biljnim uljima može imati i negativnih efekata na ribe iz uzgoja pošto je riblje ulje dobar izvor n-3 HUFA, što nije slučaj kada su u pitanju ulja biljnog porekla koja sadrže visok procenat 18C n-3 masnih kiselina, ali su siromašna ili potpuno lišena n-3 HUFA. Prema dosadašnjim istraživanima šaran ima veće potrebe za n-6, nego za n-3 masnim kisleinama za optimalan rast i razvoj. Uljana repica ima višestruku namenu: za ishranu ljudi, životinja i kao industrijska biljka. Odnos n-6/n-3 u ulju uljane repice je 2:1, što je pogodno sa aspekta zdravlja ljudi; bogato je oleinskom kisleinom i polinezasićenom masnim kiselinama (PUFA), pogotovo sa linolnom i linoleinskom kiselinom, ali ne poseduje n-3 HUFA. Često se upotrebljava u komercijalnim smešama za ishranu riba, bez negativnog uticaja na proizvodne parametre, ali može imati negativan uticaj na masnokiselinski sastav mesa šarana. Međutim, najveći broj istraživanja o zameni ribljeg ulja uljem uljane repice je izveden na salmonidnim vrtsama riba, pa su poželjna dalja ispitivanja o uticaju ovog ulja na kvalitet mesa i imunološki status šarana. Može se reći da meso šarana uglavnom poseduje povoljan masnokisleinski sastav i svrstati se u zdravu hranu za ljude. Gajenje šarana sa korišćenjem gotovih krmnih smeša bi trebalo da postane praksa na ribnjacima u Srbiji, kako bi se povećala proizvodnja po jedinici površine, dobio šaran što boljeg kvaliteta i postigla dugoročna ekonomska održivost. Takođe, potrebno je vršiti promociju šarana kao nacionalog zdravog proizvoda poželjnog u svakodnevnoj ishrani ljudi. Istraživanja o daljem unapređenju kvaliteta mesa šarana, kao i o načinu ishrane koji će zadovoljiti potrebe ove vrste, ali i ciljeve što ekonomičnije proizvodnje su neophodna u cilju dobijanja što jeftinijeg šarana, koji će zadovoljiti sve potrebe potrošača

Ulja biljnog porekla u ishrani ciprinidnih vrsta riba

Meso ciprinidnih vrsta riba predstavlja značajan izvor proteina, masti, vitamina i minerala u ishrani ljudi. Masti ovih ribljih vrsta su bogate nezasićenim masnim kiselinama (USFA), kako mononezasićenom (MUFA), tako i polinezasićenim (PUFA) masnim kiselinama. Navedene grupe masnih kiselina imaju mnogobrojne povoljne efekte na održavanje fizioloških procesa u organizmu, pa samim tim i na očuvanje zdravlja ljudi. Hemijski sastav mesa ciprinidnih vrsta riba, kao i masnokisleinski sastav istog su pod uticajem brojnih faktora, među kojima je ishrana jedan od najznačajnijih. Glavni izvor masti u hrani za ribe je dugo bilo riblje ulje, ali je zbog drastičnog povećanja proizvodnje ribe iz akvakulture, njegova dalja upotreba u istoj meri postala neodrživa. U zavisnosti od vrste ribe, kao izvor masti se sve više koriste ulja biljnog porekla, kao delimična ili potpuna zamena za riblje ulje u kompletnoj hrani za ribe. Ovaj alternativni izvor masti može imati i negativnih efekata na ribe iz akvakulture, pre svega jer su ulja biljnog porekla siromašna ili su potpuno bez n-3 visoko nezasićenih masnih kiselina (n-3 HUFA), dok je riblje ulje poznato kao jako dobar izvor pomenutih masnih kiselina. Ovaj problem je slabije izražen kod ciprinidnih vrsta riba, koje su omnivori ili herbivori i prema rezultatima dosadašnjih istraživanja imaju veće potrebe za n-6 nego za n-3 masnim kiselinama za optimalan rast i održavanje bitnih fizioloških funkcija. Biljna ulja koje se najčešće koriste u ishrani riba su sojino, laneno, ulje uljane repice, suncokretovo, palmino i druga ulja. Upotrebljavaju se u komercijalnim smešama za ishranu ciprinidnih vrsta riba, bez negativnog uticaja na proizvodne parametre, ali mogu nepovoljno uticati na masnokiselinski sastav mesa ovako hranjenih riba. Međutim, najveći broj istraživanja o zameni ribljeg ulja uljima biljnog porekla je izveden na salmonidnim vrstama riba, pa su poželjna dalja ispitivanja o uticaju različitih vrsta ulja biljnog porekla na hemijski i masnokiselinski sastav mesa, kao i na zdravstveno stanje ciprinida. Meso cipirinidnih vrsta je uglavnom pogodnog hemijskog i masnokiselinskog sastava i predstavlja važnu komponentu u zdravoj ishrani ljudi. Sve navedeno ukazuje na neophodnost istraživanja o daljem unapređenju kvaliteta mesa ciprinidnih vrsta riba upotrebom kompletnih smeša, kako bi se zadovoljile nutritivne potrebe ovih vrsta, povećala proizvodnja po jedinici površine, dobila riba kao finalni proizvod što boljeg kvaliteta i postigla dugoročna ekonomska održivost i zadovoljile potrebe potrošača. Pored toga, potrebno je kontinuirano vršiti promociju ribe gajene na ribnjacima Srbije kao nacionalog zdravog proizvoda poželjnog u svakodnevnoj ishrani ljudi