The effect of fluoride on the calcium level in serum was analyzed in the laboratory rat Rattus norvegicus. The control group consisted of 10, and the experimental group of 15 animals. In the experimental group, fluoride at a concentration of 3 mg/100 g body weight of rats was intramuscularly injected into the musculus gluteus maximus. The concentration of calcium was measured by the CPC method. The average serum calcium concentration was 2.46 mmol/l, with female rats having higher values of serum calcium than male rats. Fluoride caused the reduction of calcium concentration in serum (p<0.05); the reduction was significantly expressed in female rats (p<0.000).

This paper attempts to answer the usually neglected ethical questions of the interaction between tourism workers and participants in tourism movements and users of tourism services in general. Contact with numerous people in the work place, dynamic work with customers, continuous phone calls and stress due to constant responsibility, are just some of the conditions which tourism workers encounter on the daily basis and which sometimes make them ask themselves: Am I really able to do this job? Will their behaviour with each customer be ethical? Will they be able to hide from the customers their stress, nervousness and mental fatigue? Have all the employees in travel agencies attended the training courses in communication with customers, or does everything depend on their own decisions and home upbringing? Is it worth taking risk and putting agency`s reputation at stake? Which moral dilemmas do the tour guides encounter on the journeys? These are just some of the questions which will be put in the spotlight in this paper. The aim of this paper is to indicate the necessity to establish the codes of conduct for all professionals who are in direct contact with tourists.

The paper describes a procedure for identification of single machine infinite bus system. Mathematical model of synchronous generator is identified using data obtained from monitoring system. To determine the model parameters of the synchronous generator, a procedure based on Kalman filter was applied. The identified model of the synchronous generator can be used for parameter setting of the voltage controller and optimal parameter tuning of power system stabilizers.

In this article the neurotoxic disorders appearing in patients poisoned with organophosphorus pesticides (OPs) are reviewed. OPs cause four important neurotoxic effects in humans: the cholinergic syndrome, the intermediate syndrome, organophosphate-induced delayed polyneuropathy and chronic organophosphateinduced neuropsychiatric disorder. Compared to the cholinergic syndrome, that causes millions of cases of poisoning with fatality of more than 15% each year, other disorders involve much smaller number of patients. This article is focused on neurotoxic disorders appearing after acute and chronic exposure to OPs with emphasis on clinical presentation, molecular mechanisms and possibilities of medical treatment.

Abstract Today's business environment challenges company managers in ways different than those in the past. All sectors, including profit and non-profit, as well as non-governmental are caught in the dynamic and fast changes, which require prompt responses from the management. One of the oldest, but still most difficult tasks that every manager has to face is employee motivation. This is notably true when speaking of successful employee performance. If one takes into consideration the fact that motivation cannot be observed solely as a series of actions that managers undertake in order to delegate tasks, one realizes that managers must be creative in shaping a plethora of stimuli which can generate personal and internal commitment, as well as increase employee enthusiasm in reaching company's goals. It is precisely for this reason that the goal of this research is to identify different motivational techniques and skills that managers of companies in Bosnia and Herzegovina employ. In order to establish the relationship between the motivational techniques applied by the management and good and/or bad practices resulting from these methods, this research primarily focuses on managers of various organizations. The principal aim of this analysis is to determine the level of management competences in the process of employee motivation. The research will examine the issue of motivation from the point of view of managers in Bosnia and Herzegovina. More precisely, this work will show the level of their competence which help them in their relations with the employees. The scientific hypothesis examines the ways in which management competences influence work commitment and employee loyalty.