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The equation of the surface waves in deep water, given here by (1), is extended to (2+1) dimensions, which is a novel equation.. It is shown that the surface waves equation is self- free source. So, it has a class of infinite solutions. Here many types of self-similar and semi-self similar solutions are obtained. The self-similar waves show various geometric structures. Among them, wave crest in the form of coupled lumps and soliton wave moving along the characteristic curve in the plane. It is entrained by troughs with cavities. The semi-self similar waves exhibit multi lumps or periodic waves with troughs and multi-periodic waves. The study of bifurcation shows that the trajectories are open, so that the traveling wave solutions are unstable. The time-dependent steepness-function is defined here and it is found that it attains a maximum value and then it decreases with time. The results found are interesting in ocean engineering and sciences. The extended unified method is used, here, to find the exact solutions, which was proposed recently.

Self-presentation is an omnipresent form of behaviour that involves building a self-image in front of other people. This form of behaviour aims at structuring the impression of a person. Self-presentation explains numerous social relations and situations, but it also depends on numerous factors, primarily personality factors, as well as a number of situational factors. The main goal of this research is to examine the relationship between broad personality dimensions, operationalized by the Big Five + 2 personality model (Neuroticism, Extraversion, Aggression, Conscientiousness, Openness, Positive Valence and Negative Valence) and self-presentation. The possibility of predicting self-presentation in total, as well as some of its individual tactics, based on broad personality dimensions, is also examined. The survey uses the Big Five + 2 Personality Questionnaire and the Self-Presentation Tactics Scale. The sample included 526 respondents, average age 21.6 years (SD=2.88). Of all the examined personality dimensions, Neuroticism and Negative Self-Image have the strongest correlations with overall self-presentation. The Conscientiousness dimension records the highest number of negative correlations, while the Openness dimension records the lowest number of statistically significant correlations with the overall self-presentation and individual self-presentation tactics. As for the prediction of self-presentation, all dimensions of personality, except Openness, are important predictors, but their constellation is different in relation to the content of self-presentation tactics. The obtained findings make it possible to predict the direction of the presentation of self-image. Namely, knowing the personality traits, we can assume which self-presentation tactics will be used, especially in a situation when people are motivated to do so.

Despite the fact that soil organic matter (SOM) concentration is much lower compared to mineral portion, its importance is very valuable for soil fertility, agriculture, ecosystems and global environmental change. Soil organic carbon (SOC) is a key component of SOM. The amount of SOC varies greatly in surface layer of soil, but the vertical distribu­tion of SOC is also very important. The purpose of the study was to investigate vertical distribution of SOC in soil profiles of the most common soil types in Vojvodina (Arenosols, Chernozems, Fluvisols, Vertisols, Solonetz) and in different land uses (arable land, meadow and forest). Soil samples were collected from 0-30, 30-60 and 60-100 cm depth. Dichromate wet oxidation method proposed by Tyurin’s was performed to determine SOC concentration. Except arenosols, obtained results showed the decrease of SOC concentration with depth in all observed soil types and land uses. Vertisols had the highest SOC concentration in both surface (0-30 cm) and subsurface (30-60 cm) layers compared to the other soil types, while arenosols had the highest SOC concentration in the deepest layer (60-100 cm). Higher con­centrations of SOC in surface layers were measured in forests and meadows in relation to arable land, while in the lower layers these differences were not detected. Differences in SOC concentration in observed soil types and land uses were more pronounced in surface than in deeper layers. Soil organic carbon concentrations in deeper layers were substantially different only between soil types.

Introduction. The purposes of this study were to determine the presence of daily variations in hematological parameters of the black rat snake (Pantherophis obsoletus) and to compare them with the reference interval values of its subspecies, yellow rat snake (Pantherophis obsoleta quadrivittata). Materials and Methods. Blood from four black rat snakes was collected in the morning and in the evening, and after each collection, blood smears, packed cell volume (PCV), red blood cell count (RBC) and hemoglobin concentration (HGB) were determined, while erythrocyte indices of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were calculated and differential leukocyte counts were evaluated. Results and Conclusions. There were no statistically significant differences in any of the blood parameters in the morning and in the evening. Most of the complete blood count values in the black rat snakes were lower, but still within the reference range of those found in the literature for the yellow rat snake. The results of hematological parameters of the black rat snake could be beneficial for further research of physiological and pathological variations in complete blood count of these snakes, for diagnosing health conditions and for detecting various diseases.