A very important segment, which occurs as a result of welding, is the occurrence of residual stresses in welded structures. The effects of residual stresses can be beneficial or harmful to the structure, depending on their size, sign, and stress distribution in relation to the stresses caused by the external load itself. Therefore, the examination of residual stresses is very important because they significantly affect the formation and growth of cracks, the appearance of brittle fractures, material fatigue, etc. The paper presents the test procedure for measuring residual stresses by the method of "hole drilling" and the possibility of practical application of knowledge about residual stresses in order to improve the quality of machine parts and the structure itself.

The main objective of the research is to analyze the possibility of introducing the agro-ecological concept through appropriate agro-ecological measures in agricultural policy of Bosnia and Hercegovina. For this purpose, theoretical and empirical studies have been conducted. Theoretical research included analysis of the strategic and regulatory framework in the European Union and Bosnia and Hercegovina and analysis of the development of the concept of agro ecology. Empirical research has included surveying holders of agricultural holdings of subjects according to the Eco Stack project methodology. The survey results confirm that farmers are generally not familiar with the concept of agro ecology, but do apply some of the agro-environmental measures. On the basis of the research results, steps have been proposed to introduce a new model of support for the application of the agro-environmental concept and measures in the framework of agricultural policy of Bosnia and Hercegovina.

—Longitudinal research is fundamentally important for understanding sustainable behavior change related to human health. This is particularly true for chronic illnesses, such as dementia and mental illness, where treatment is often measured in months and years over the long-term. For research on human-robot interaction (HRI) geared towards addressing such health-related issues, this presents a challenge in that many HRI studies (particularly in lab settings) are performed in a matter of minutes or at most hours. Given that reality, this suggests a need for innovative approaches to longitudinal research in HRI for such health-focused scenarios. Here, we argue that such methodological approaches to longitudinal HRI research should be grounded in existing models of behavior change (e.g. transtheoretical model) and leveraged via novel technology-enabled real-time sampling strategies for user activities outside of lab settings (e.g. ecological momentary assessment, EMA), all geared toward supporting data-driven methods for connecting robot behavior and human behavior over the long-term in in-the-wild settings.

Magnetic nanoparticles (MNPs) are widely used to facilitate magnetic particle imaging (MPI) which has the potential to become the leading diagnostic instrument for biomedical imaging. This comparative study assesses the effects of changing iron content and excitation frequency on point-spread function (PSF) representing the effect of magnetization reversal. PSF is quantified by features of interest for MPI: i.e. gradient amplitude and full-width-at-half-maximum (FWHM). A superparamagnetic quantifier (SPaQ) is used to assess differential magnetic susceptibility of two commercially available MNPs: Synomag ® -D50 and Synomag ® -D70. For both MNPs, the signal output depends on increase in drive field frequency and amount of iron oxide, which might be hampering the sensitivity of MPI systems that perform on higher frequencies. Nevertheless, there is a clear potential of Synomag ® -D for a stable MPI resolution, especially in case of 70 nm version, that is independent of either drive field frequency or amount of iron oxide.

The European Union permitted 6 antimicrobial agents that can be used in laying hens. These are colistin, tyrosine, neomycin, oxytetracycline, chlortetracycline, and erythromycin. Antimicrobial drugs are used today primarily for the prevention and treatment of diseases in poultry and often (not in the EU) to stimulate growth. Because these drugs are often used irrationally, there are good chances that their residues will be found not only in poultry meat but also in the eggs within a certain period after the termination of treatment. In addition to the administration of authorised VMPs, the residues in eggs can be the result of erroneously applied medicated food, the contamination of the food with some antimicrobial drug in the mixing unit, as well as ?extra-label? use of drugs in poultry. The antimicrobial agents are distributed in the body and deposited in the eggs, mainly in the yolk where they persist longer than in the albumen. Drugs that are poorly absorbed from the gastrointestinal tract (aminoglycosides, aminocyclitols, polymyxins) cannot be detected in the eggs, while the residues of some antimicrobial drugs can be detected for up to two months (chloramphenicol) after the last treatment. The rational use of drugs in veterinary medicine has manifold significance. When using drugs only when they are really necessary (indicated), in the right dose and route of administration, the potential damage can be reduced and efficiency increased, while the risk of microorganism resistance development would be significantly decreased. All of this becomes more important when these drugs are used in food animals.

Allelopathy determines the dynamics of germination, development and growth of plant species in the environment. Therefore, in this study, the allelopathic effect of an aqueous extract isolated from walnut (Juglans regia L.) leaves (concentrated extract, 1:2, 1:4 and 1:8) on the germination percentage, mean germination value and germination rate of wheat (Triticum aestivum L.) and peas was monitored (Pisum sativum L.). Both tested species were sensitive to juglone, but the percentage of germination was significantly lower in wheat (by 80%) compared to peas, so it can be said that this species is more sensitive. The length of roots and shoots of both tested species decreased in proportion to the increase in the concentration of the extract. Monitoring of this biological phenomenon could help to understand the changes in the environment caused by allelochemicals.

In this study, changes in Class III peroxidase (POX) and polyphenol oxidase (PPO) activity in Phragmites australis (Cav.) Trin. Ex Steud. Utricularia vulgaris L. and Salvinia natans (L.) from the Bardača wetland during one vegetation season (June-October) were monitored. The highest activities of soluble and ionic cell wall bound peroxidases (solPOX and ionPOX, respectively) were measured for Phragmites communis (leaf > root > rhizome), followed by Utricularia vulgaris (whole plant), then Salvinia natans (whole plant). The results showed that during the vegetation period (August-September) the activity of solPOX, ionPOX and PPO in Phragmites communis increased, but the activity decreased drastically in October. For Salvinia natans and Utricularia vulgaris, a different seasonal distribution was obtained in the PPO activity, i.e. with a maximum activity during July and a minimum one during September. Different seasonal trends in enzyme activities are probably the result of abiotic stress caused by changing physic-chemical environmental conditions and different adaptive capacities of the studied species to habitat conditions. Correlations between physicochemical environmental parameters and enzyme activities indicate the possibility of using POX and PPO activities as an important bioindicatos of environmental status.

Introduction. Hepatitis A virus is the most common cause of acute viral hepatitis, and in people over 25 years of age the disease may have different degrees of severity. Even though hepatitis A virus infection was long believed to be transmitted strictly by fecal-oral route, now this virus is classified among sexually transmitted diseases. Homosexual population, especially those positive for human immunodeficiency virus, is at the greatest risk of hepatitis A virus infection. Case 1. A twenty-six-year-old male homosexual was admitted with clinical and laboratory findings of acute hepatitis. The patient tested positive for enzyme-linked immunosorbent assay immunoglobulin M antibodies to hepatitis A virus and human immunodeficiency virus antibodies, and later on human immunodeficiency virus infection was confirmed by polymerase chain reaction test. After the discharge, the antiretroviral therapy was initiated. Case 2. A twenty-seven-year-old male homosexual was transferred to our clinic from the Regional Hospital, where he was hospitalized due to acute hepatitis A virus infection, after a positive serological test for anti-human immunodeficiency virus antibodies. Human immunodeficiency virus infection was confirmed by polymerase chain reaction test, and upon discharge, antiretroviral therapy was initiated. Conclusion. In order to take the most effective preventive measures, it is very important to identify individuals and groups at high risk of coinfection with human immunodeficiency virus and hepatitis A virus. Timely vaccination against hepatitis A virus among people living with human immunodeficiency virus is recommended and therefore it is necessary to design effective strategies for education of groups at risk.

The suitable characteristics of fly ash from thermal power plants make it a proper adsorbent for removing various pollutants from water and aqueous solutions. Valorization and utilization of fly ash can reduce the use of conventional adsorbents. The paper presents an overview of the possibility of using raw and modified fly ash to remove fluorides from water and aqueous solutions, as well as the influence of different process parameters (sorbent dose, contact time, pH value, temperature, etc.) on the value of adsorption capacity and adsorption efficiency of used sorbent. Fly ash can be used as an effective sorbent for the removal of fluoride, both in raw and modified form, with given optimal process parameters. Raw fly ash shows better adsorption properties when performing the experiment in a column, with a higher dose of sorbent and longer contact time, in an acidic environment (pH = 2-3), compared to batch experiments. Various authors have modified fly ash by treatment with certain chemical agents (HCl, Ca (OH)2…) or by synthesis of zeolite based on fly ash. Modification of fly ash improves its adsorption properties, so in slightly acidic conditions (pH = 6), for a relatively short contact time (10-30 min), in batch conditions, significant adsorption efficiency (~ 90%) can be achieved.