Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples

Development and evaluation of instructional strategy based on the triplet model of inorganic chemistry content representation in high school education

Glavni cilj ove disertacije bio je da se ispita u kojoj meri će nastavni pristup zasnovan na interkorelaciji makroskopskog, submikroskopskog i simboličkog nivoa  reprezentacije znanja uticati na performanse učenika u oblasti neorganskih reakcija, a takođe i kakav će biti njen uticaj na samoprocenu uloženog mentalnog napora.  Ukupan uzorak ovog istraživanja sačinjavalo je 313 učenika iz dve gimnazije, a  istraživanje je sprovedeno u toku školske 2012/13. školske godine. Kao merni instrument za merenje performansi korišćen je dvoslojni test znanja sa zadacima  višestrukog izbora, a svaki zadatakje praćen sedmostepenom skalom Likertovog tipa za samoprocenu uloženog mentalnog napora.  Dobijeni rezultati pokazuju da primenjena instrukciona strategija, koja se oslanja na primenu višestrukih nivoa reprezentacije znanja vodi povećanju učeničkih performansi, a istovremeno i smanjenju kognitivnog opterećenja. Rezultati dobijeni za procenu instrukcione efikasnosti sugerišu da primenjeni model predstavlja efikasan nastavni model. Dalje istraživanja performansi pokazala su da  primenjena instrukciona strategija ima  podjednako pozitivan uticaj kako na performanse, tako i na procenjeni mentalni napor ispitanika oba pola. Ispitivana strategija takođe se pokazala efikasnom u obuci svih ispitivanih grupa učenika (najmanje uspešnih, srednje uspešnih i najuspešnijih).  Pored toga  rezultati  su ukazali i na postojanje velikog broja miskoncepcija u K grupi ispitanika, dok su u E grupi, koja je učestvovala u eksperimentalnoj nastavi, veliki broj  miskoncepcija bio eliminisan. Na kraju, rezultati analize kognitivne kompleksnosti ukazali su na postojanje značajnih korelacija između svih ispitivanih parova varijabli (performanse-kognitivna kompleksnost; performanse-mentalni napor i mentalni napor-kognitivna kompleksnost).The central goal of this disserta-tion  was to examine the extent to which a teaching approach fo-cused on the interaction  among macroscopic, submicroscopic and  symbolic levels of chemistry representations could affect high school students’ performance in the field of inorganic reactions, as well as to examine how the appli-ed  instruction influences stu-dents’ assessment of invested mental effort. The total sample of this research included 313 high school stu-dents. The survey was conducted in the 2012-2013 school year. As a measuring instrument for stu-dent  performance a  two-tier mu-ltiple-choice test  of knowledge was used.  Each task in the test was followed by a seven point Likert-type scale for evaluation of invested mental effort.  Obtained results indicate that a teaching strategy relying on the interplay between three levels of knowledge representation leads to an increase in students’ performance and also contributes to the reduction of cognitive load. The obtained results for calcula-ted mental efficiency suggest that the applied instructional model represents an effective teaching model. Further performance te-sting have shown that applied instructional strategy have simi-lar positive impact in terms of both performance and mental effort on the subjects of both genders. This strategy has also  proved to be effective in training all examined groups of students (low achievers,  middle achievers and high achievers). In addition, results indicated the existence of a large number of misconceptions in the K group, while in the group E, that was subjected to experi-mental teaching, a great deal of misconceptions was eliminated. Last but not least, the results of cognitive complexity analysis indicated the existence of signifi-cant correlations between all the examined pairs of variables (pe-rformance-cognitive complexity; performance-mental effort; me-ntal effort-cognitive complexity)

Development and evaluation of instructional strategy based on the triplet model of inorganic chemistry content representation in high school education

Glavni cilj ove disertacije bio je da se ispita u kojoj meri će nastavni pristup zasnovan na interkorelaciji makroskopskog, submikroskopskog i simboličkog nivoa  reprezentacije znanja uticati na performanse učenika u oblasti neorganskih reakcija, a takođe i kakav će biti njen uticaj na samoprocenu uloženog mentalnog napora.  Ukupan uzorak ovog istraživanja sačinjavalo je 313 učenika iz dve gimnazije, a  istraživanje je sprovedeno u toku školske 2012/13. školske godine. Kao merni instrument za merenje performansi korišćen je dvoslojni test znanja sa zadacima  višestrukog izbora, a svaki zadatakje praćen sedmostepenom skalom Likertovog tipa za samoprocenu uloženog mentalnog napora.  Dobijeni rezultati pokazuju da primenjena instrukciona strategija, koja se oslanja na primenu višestrukih nivoa reprezentacije znanja vodi povećanju učeničkih performansi, a istovremeno i smanjenju kognitivnog opterećenja. Rezultati dobijeni za procenu instrukcione efikasnosti sugerišu da primenjeni model predstavlja efikasan nastavni model. Dalje istraživanja performansi pokazala su da  primenjena instrukciona strategija ima  podjednako pozitivan uticaj kako na performanse, tako i na procenjeni mentalni napor ispitanika oba pola. Ispitivana strategija takođe se pokazala efikasnom u obuci svih ispitivanih grupa učenika (najmanje uspešnih, srednje uspešnih i najuspešnijih).  Pored toga  rezultati  su ukazali i na postojanje velikog broja miskoncepcija u K grupi ispitanika, dok su u E grupi, koja je učestvovala u eksperimentalnoj nastavi, veliki broj  miskoncepcija bio eliminisan. Na kraju, rezultati analize kognitivne kompleksnosti ukazali su na postojanje značajnih korelacija između svih ispitivanih parova varijabli (performanse-kognitivna kompleksnost; performanse-mentalni napor i mentalni napor-kognitivna kompleksnost).The central goal of this disserta-tion  was to examine the extent to which a teaching approach fo-cused on the interaction  among macroscopic, submicroscopic and  symbolic levels of chemistry representations could affect high school students’ performance in the field of inorganic reactions, as well as to examine how the appli-ed  instruction influences stu-dents’ assessment of invested mental effort. The total sample of this research included 313 high school stu-dents. The survey was conducted in the 2012-2013 school year. As a measuring instrument for stu-dent  performance a  two-tier mu-ltiple-choice test  of knowledge was used.  Each task in the test was followed by a seven point Likert-type scale for evaluation of invested mental effort.  Obtained results indicate that a teaching strategy relying on the interplay between three levels of knowledge representation leads to an increase in students’ performance and also contributes to the reduction of cognitive load. The obtained results for calcula-ted mental efficiency suggest that the applied instructional model represents an effective teaching model. Further performance te-sting have shown that applied instructional strategy have simi-lar positive impact in terms of both performance and mental effort on the subjects of both genders. This strategy has also  proved to be effective in training all examined groups of students (low achievers,  middle achievers and high achievers). In addition, results indicated the existence of a large number of misconceptions in the K group, while in the group E, that was subjected to experi-mental teaching, a great deal of misconceptions was eliminated. Last but not least, the results of cognitive complexity analysis indicated the existence of signifi-cant correlations between all the examined pairs of variables (pe-rformance-cognitive complexity; performance-mental effort; me-ntal effort-cognitive complexity)

Etiological aspect of left-handedness in adolescents

Introduction. Lateralization of brain functions such as language and manual dominance (hand preferences and fine motor control) are most likely under genetic control. However, this does not preclude the effect of various environmental factors on functional brain lateralization. A strong association of non-right-handedness (left- and mixed-handedness) with various neurodevelopmental conditions (e.g. schizophrenia, autism, Rett syndrome) implies that in some cases, non-right-handedness may be acquired rather than inherited (i.e., pathologically determined). Objective. The aim of the study was: (a) re-investigation of several known risk factors for left-handedness (age of mother and/or father, twin pregnancies, and birth order), and (b) examination of hitherto uninvestigated factors (type of birth, Apgar score, maternal smoking during pregnancy). Methods. Putative, causative environmental agents for this shift in manual distributions are explored in a sample of 1031 high school students (404 males and 627 females) from Belgrade. Both pre-existing (age of parents, twin pregnancy, and birth order) and new (Apgar score, maternal smoking, type of birth) putative agents are examined. Results. We found that maternal smoking and low Apgar score (2-6) can significantly increase risk for left-handedness (p=0.046 and p=0.042, respectively). The remaining factors showed no significant association with left-handedness in adolescents. Conclusion. Our study clearly demonstrates that left-handedness may be related to maternal smoking during pregnancy and a low Apgar score on birth

Examining systems thinking through the application of systemic approach in the secondary school chemistry teaching

This study was conducted during the second semester of 2012/2013 school year, with the aim to investigate two possible applications of systemic synthesis questions, SSynQs: as instructional and assessment tools observing the construct of systems thinking in organic chemistry. In order to achieve this aim, the secondary school students were divided into two groups, one experimental (E: systemic classroom training) and one control (C: traditional classroom training). The final testing was conducting after instruction on three teaching themes: “Alcohols, phenols, ethers”, “Carbonyl compounds” and “Carboxylic acids and their derivatives”. The instrument for assessing students’ systems thinking skills contained isomorphic and analogical SSynQs, while the results focused on E and C group students’ percentage distribution through the four levels of systems thinking construct, as well as differences in their performances. Namely, the results obtained from both isomorphic and analogical SSynQs indicated that male and female students subjected to systemic classroom training developed systems thinking skills in more effective way than students from control group. Perceiving analogical SSynQs and gender as independent variable, the statistically significant difference appeared in E group within the most complex IV level of systems thinking, for the benefit of females. However, contrary to our previous research, E group male students were as much successful as female students in III level, and this finding led us to the conclusion that male students might benefit from longer lasting instruction with SSynQs

Evaluacija utjecaja razine konteksta na učenička postignuća i samopercipirana kognitivna opterećenja u problemskim zadatcima iz kemije

This study was conducted with the aim to examine the effect of context on perceived cognitive load and students’ achievements in problem-solving tasks. It included 161 eighth-grade students. The tasks in the test, which was used as a measuring instrument for assessing knowledge, were designed at three levels of complexity: without context, with moderate and with rich context. Each task was followed by a 7-point Likert-type scale, as a measure of perceived cognitive load. The analysis of obtained results showed that the highest average achievement was reached in the group of tasks without context, followed by the group of tasks with moderate context, while the group of context-rich tasks was characterized by the lowest achievement. Furthermore, the results have shown that there is a statistically significant difference between achievement in tasks without context and tasks with moderate context, as well as between achievement in tasks without context and context-rich tasks, while there was no statistically significant difference between achievement in tasks with moderate and context-rich tasks. Similar results were obtained for the perceived cognitive load, thus indicating that context-rich tasks abound in information and therefore impose high cognitive demands on learners. These findings may represent a significant contribution to the still under-researched area of context-based assessment thus paving way for further research in this area, such as investigating the influence of prior knowledge or motivation on solving context-rich tasks.Ova je studija provedena s ciljem ispitivanja utjecaja konteksta na samopercipirana kognitivna opterećenja i učenička postignuća u problemskim zadatcima. Njome je obuhvaćen 161 učenik osmog razreda osnovne škole. Test je korišten kao mjerilo za procjenu znanja. Zadatci na testu bili su dizajnirani u tri razine kompleksnosti – bez konteksta, s umjerenim i bogatim kontekstom. U okviru svakog zadatka nalazila se ljestvica Likertova tipa sa sedam stupnjeva za mjerenje samopercipiranog kognitivnog opterećenja. Analiza dobivenih rezultata pokazala je da je najviše prosječno postignuće ostvareno u skupini zadataka bez konteksta, zatim u skupini zadataka s umjerenim kontekstom, a najniže je prosječno postignuće ostvareno u skupini zadataka s bogatim kontekstom. Nadalje, rezultati su pokazali da postoji statistički značajna razlika u postignućima u zadatcima bez konteksta i zadatcima s umjerenim kontekstom, kao i između postignuća u zadatcima bez konteksta i zadatcima s bogatim kontekstom, a da razlika u postignućima u zadatcima s umjerenim i zadatcima s bogatim kontekstom nije statistički značajna. Slični rezultati dobiveni su za samopercipirana kognitivna opterećenja, što upućuje na to da zadatci bogati kontekstom obiluju informacijama i stoga učenicima nameću visoke kognitivne zahtjeve. Ti pokazatelji mogu predstavljati važan doprinos do sada nedovoljno istraženom području kontekstualiziranih zadataka, otvarajući put za daljnja istraživanja u tom području, kao što su ispitivanja utjecaja predznanja ili motivacije na rješavanje zadataka bogatih kontekstom

Kognitivno opterećenje na različitim razinama kemijskih prikaza

The purpose of this study was to examine students\u27 achievements and cognitive loads at different levels of chemistry representations. The research was carried out among students majoring in chemistry teaching. A test was used as a measuring instrument for knowledge evaluation. Each task contained three subtasks, in macroscopic, sub-microscopic and symbolic domain. Each subtask in the test was followed by a seven point Likert scale (ranging from \u27extremely easy\u27 to \u27extremely difficult\u27) for the evaluation of cognitive load. A parallel analysis of the obtained results has shown that students\u27 evaluations of cognitive load are in accordance with the accomplishments achieved on the test. Students have estimated that the greatest cognitive load corresponds to sub-microscopic level, which resulted in the lowest achievements. The results have also shown that there are no major differences in the average students\u27 achievements in macroscopic and symbolic level, which are also in line with the evaluated cognitive load. Hence, it can be concluded that the students are able to review the cognitive processes and to evaluate the difficulty of the task.Svrha ovog istraživanja bila je ispitati postignuća studenata i kognitivno opterećenje na različitim razinama kemijskih prikaza. Istraživanje je provedeno među studentima koji će u budućnosti biti nastavnici kemije. Mjerni instrument koji se koristio za vrednovanje znanja bio je test. Svaki zadatak sastojao se od tri podzadatka, u makroskopskoj, submikroskopskoj i simboličkoj domeni. Svaki podzadatak sadržavao je Likertovu skalu od sedam stupnjeva, koja je omogućavala ispitanicima da ocijene tvrdnje ovisno o tome smatraju li da su one „iznimno lagane“, pa sve do onih za koje smatraju da su „iznimno teške“. Paralelna analiza dobivenih rezultata pokazala je da je način na koji su studenti vrednovali kognitivno opterećenje bila u skladu s njhovim postignućima na testu. Studenti su smatrali da je najveće kognitivno opterećenje ono vezano uz submikroskopsku razinu, što je rezultiralo njihovim najslabijim postignućima. Rezultati su također pokazali da ne postoje značajne razlike u prosječnim postignućima studenata na makroskopskoj i simboličkoj razini, što je također u skladu s vrednovanim kognitivnim opterećenjem. Stoga se može zaključiti da su studenti sposobni proučiti kognitivne procese i procijeniti težinu zadatka

Ispitivanje mogućnosti zaštite i revitalizacije livnice 'Pantelić' u Zemunu

Through the teaching process, students of architecture have the opportunity to examine the problem of preserving the industrial heritage of Belgrade, its historical and urban context, the creation, development, cultural, urban and architectural values, as well as examining possibilities and comparing different approaches to its presentation and modern use. The goal was to devise sustainable solutions which will preserve the cultural and historical values, authenticity and integrity of the Pantelic Foundry complex on the one hand and, on the other hand, provide for its revitalization and quality integration into the immediate urban environment, which, despite the care and neglect preserved certain elements of a recognizable historical setting. Through their proposals, the students of Foundry 'Pantelić' have fulfilled numerous contemporary cultural, educational and artistic contents that are related to its character and significance, and provide it with an active life in the future. Through this study, a contribution was given to the research of the development of industrial architecture of Belgrade, but also the design of the possibility of revitalization and sustainable development.Kroz nastavni proces, studentima arhitekture pruža se mogućnost sagledavanja problema očuvanja industrijskog nasleđa Beograda, njegovog istorijskog i urbanog konteksta, nastanka, razvoja, kulturnih, urbanističkih i arhitektonskih vrednosti, kao i ispitivanja mogućnosti i komparacije različitih pristupa njegovoj prezentaciji i savremenom korišćenju. Zadatak je bio da se osmisle održiva rešenja koja će sa jedne strane očuvati kulturno-istorijske vrednosti, autentičnost i integritet kompleksa livnice 'Pantelić', a sa druge strane obezbediti njenu revitalizaciju i kvalitetnu integraciju u neposredno urbano okruženje, koje je i pored nebrige i zapuštenosti očuvalo pojedine elemente prepoznatljivog istorijskog ambijenta. Putem svojih predloge studenti su kompleks livnice ispunili brojnim savremenim kulturnim, edukativnim i umetničkim sadržajima koji su povezani sa njenim karakterom i značajem, a obezbeđuju joj i aktivan život u budućnosti. Ovom studijom dat je prilog istraživanju razvoja industrijske arhitekture Beograda, ali je podstaknuto i osmišljavanje mogućnosti revitalizacije i održivog razvoja

Primjena sistemičkog pristupa u početnoj nastavi kemije:usvajanje pojma mola

Many studies carried out on the mole concept emphasize that students show significant difficulties in learning this concept. The aim of our research was to analyze those difficulties that students, who have their first contact with chemistry in school, encounter, and also to examine the usefulness of systemics as a graphical way of knowledge representation. The sample of the study included seventh grade students from a primary school in Novi Sad, Serbia. Based on the results of the pre-test, students were divided into three main groups: "excellent", "good" and "acceptable", which all consisted of two subgroups: experimental and control. Students in the experimental subgroup were learning by applying systemics, while the students in the control subgroup were taught by traditional method. The final results show that systemics is convenient in overcoming the difficulties in the case of "excellent" and "acceptable" groups of students, while the same cannot be concluded for the students characterized as "good". Systemics has not proved to be adequate for them. The following question remains a topic for the future research: Is there any way that the group of students characterized as “good” still benefits from learning with systemics? In addition, new research on a larger number of students should be conducted, in order to statistically confirm these results, or to discuss new ones.Mnoga istraživanja koja su se bavila pojmom mola naglašavaju činjenicu da učenici imaju znatne poteškoće u usvajanju toga pojma. Cilj našeg istraživanja bio je analizirati upravo one poteškoće s kojima se učenici susreću kada prvi put počinju učiti kemiju kao školski predmet, kao i ispitati korisnost sistemika kao grafičkog načina prikazivanja znanja. Uzorak u istraživanju obuhvatio je učenike sedmog razreda jedne osnovne škole u Novom Sadu, u Srbiji. Na temelju provedenog testa predznanja učenici su bili podijeljeni u tri glavne skupine: „odličnu“, „dobru“ i „prihvatljivu“, a svaka od njih sastojala se od dvije podskupine: eksperimentalne i kontrolne. Učenici u eksperimentalnoj podskupini učili su primjenom sistemika u nastavi, a učenike u kontrolnoj podskupini podučavalo se primjenom tradicionalnih metoda. Završni rezultati pokazuju da je sistemički pristup pogodan za prevladavanje poteškoća u slučaju „odlične“ i „prihvatljive“ skupine učenika, ali se isto ne može zaključiti za učenike koji pripadaju „dobroj“ skupini. Sistemici se nisu pokazali prikladnim za njih. Sljedeće pitanje može biti temom budućih istraživanja: Postoji li ikakav način da skupina učenika koji su opisani kao „dobri“ može imati koristi od učenja po sistemičkom pristupu? K tomu, trebalo bi provesti novo istraživanje na većem uzorku učenika, da bi se navedeni rezultati statistički potvrdili ili da bi se raspravilo o novim rezultatima

Identification of Misconceptions through Multiple Choice Tasks at Municipal Chemistry Competition Test

In this paper, the level of conceptual understanding of chemical contents among seventh grade students who participated in the municipal Chemistry competition in Novi Sad, Serbia, in 2013 have been examined. Tests for the municipal chemistry competition were used as a measuring instrument, wherein only multiple choice tasks were considered and analyzed. Determination of the level of conceptual understanding of the tested chemical contents was based on the calculation of the frequency of choosing the correct answers. Thereby, identification of areas of satisfactory conceptual understanding, areas of roughly adequate performance, areas of inadequate performance, and areas of quite inadequate performance have been conducted. On the other hand, the analysis of misconceptions was based on the analysis of distractors. The results showed that satisfactory level of conceptual understanding and roughly adequate performance characterize majority of contents, which was expected since only the best students who took part in the contest were surveyed. However, this analysis identified a large number of misunderstandings, as well. In most of the cases, these misconceptions were related to the inability to distinguish elements, compounds, homogeneous and heterogeneous mixtures. Besides, it is shown that students are not familiar with crystal structure of the diamond, and with metric prefixes. The obtained results indicate insufficient visualization of the submicroscopic level in school textbooks, the imprecise use of chemical language by teachers and imprecise use of language in chemistry textbooks