In this paper we present explicit formulas for the eccentric connectivity index of three classes of chain hexagonal cacti. Further, it is shown that the extremal chain hexagonal cacti with respect to the eccentric connectivity index belong to one of the considered types. Some open problems and possible directions of further research are mentioned in the concluding section.

Acta Informatica Medica journal has been accepted for archiving in PubMed Central from 2011 onward. The journal started in 1993 as the official journal of the Society for Medical Informatics of Bosnia and Herzegovina. During the last 3 years, Acta Informatica Medica has een included in almost all prestigious online databases, including PubMed, Scopus and EMBASE. The 20th volume of the journal is fully international, with papers from 18 countries.

Introduction The answer to the question of what a database is and what is its relevance to the scientific research is not easy. We may not be wrong if we say that it is, basically, a kind of information resource, often incomparably richer than it is, for example, a single book or magazine. Discussion and conclusion As a form of storing and retrieval of the knowledge, appeared in the information age, which we’ve just participated and witnesses. In it, thanks to the technical possibilities of information networks, it can be searched for a number of more or less relevant information, and that scientific and profound content. Databases are divided into: bibliographic databases, citation databases and databases containing full-text. In the paper are shortly presented most important on-line databases with their web site links. Thanks to those online databases scientific knowledge is spreading much more easy and useful.

Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegboard Test. Data were analyzed with one-way ANOVA, followed by planned com­parisons between the age groups. We also performed a regression analysis to assess the influence of age and motor coordination on visual-motor integration. The results showed that age has a great effect on the development of fine motor skills. Furthermore, the results indicated that there are possible sensitive periods at preschool age in which the development of fine motor skills is accelerated. Early intervention specialists should make a thorough evaluations of fine motor skills in preschool children and make motor (re)habilitation programs for children at risk of fine motor delays.

Eutrophication, a major problem in many fresh and brackish waters, is largely caused by nonpoint-source pollution by P from agricultural soils. This lysimeter study examined the influence of P content, physical properties, and sorption characteristics in topsoil and subsoil on P leaching measured during 21 mo in 1-m-long, undisturbed soil columns of two clay and two sandy soils. Total P losses during the period varied between 0.65 and 7.40 kg ha. Dissolved reactive P was the dominant form in leachate from the sandy soils and one clay soil, varying from 48 to 76%. Particulate P dominated in leachate from the other clay soil, where low pH (5.2) in the subsoil decreased aggregate stability and thereby probably increased the dispersion of clay particles. Phosphorus leaching was small from soils with high P sorption index (PSI) and low P saturation (<10% of PSI) in the subsoil, even though extractable P (Olsen P) in the topsoil was high, and large from a soil with low sorption capacity and high P saturation (>35% of PSI) in the profile. High sorption capacity in the subsoil was more important for P leaching in sandy soils than in clay soils with macropore flow, where the effect of high sorption capacity was reduced due to less interaction between percolating water and the soil matrix. The results suggest that P leaching is greatly affected by subsoil properties and that topsoil studies, which dominate current research, are insufficient for assessing P leaching in many soils.

The purpose of the research was to see whether work of special educators and rehabilitators in the regular school has a positive influence on peer relationship among students with delayed cognitive development. The accent was on friendship quality, social competence and antisocial behavior. The research comprised 150 students with slow cognitive development, 52 of who have support of special educators and rehabilitators in regular education, while the remaining 98 students are without support. Friendship quality was evaluated applying Friendship Quality Questionnaire.  School Social Behavior Scale was used in order to evaluate social competence and antisocial behavior. Differences among the groups were examined by t-test from SPSS 14 Windows software package. T he results have shown that students with slow cognitive development having support from special educators and rehabilitators evaluate their friendship more qualitative. Students with delayed cognitive development attending schools without special educators and rehabilitators engaged demonstrate better level of the social competence. As far as antisocial behavior concerns, no differences were found. The results obtained indicate need for redefining the role of special educators and rehabilitators in regular primary education.