The heavy metal contents and their bioavailability were monitored in soils of Central Spiš region of SR. This area belongs to long term contaminated and hygienically loaded areas. Soil contamination by heavy metals is caused especially by ore mining, processing and treatment. Soil samples from the Central Spiš contained higher proportions of mobile forms which corresponded to the following sequence Pb > Zn > Cu, while for mobilizable forms the sequence of investigated metals was as follows: Cu > Zn > Pb. Soil pH is one of the parameters that affect significantly the share of bioavailable forms of metals. Higher proportions of mobile fractions of metals were detected in samples taken from soils with acidic pH. Statistical processing confirmed a relationship between the percentage share of lead and zinc in the mobile form and the level of pH/KCl, which was significant for Zn: r = -0.53. The relationships for lead and copper were insignificant.

In general, college students have concerns about mastering the Statistics course. Several scientific articles suggest that methodologies in which the student is an active part of the educational process lead to their greater involvement in teaching activities and better results in their overall assessment. A modified form of the Mathematics course inspires this study. The Mathematics course precedes the Statistics course. This study presents students’ results from both affected courses for the last 12 years. The authors obtained the data from the Modular Academic Information System (MAIS). The study describes the Statistics course, which is a combination of the traditional form of teaching and learning with elements of active learning. The product is a redesign of this course. The proposed changes are based on the requirements of some stakeholders. The results are from a survey of course graduates, from the experience of online teaching during the COVID-19 pandemic, and the introduction of active-learning elements. The authors of the article point out the risks and opportunities they found in teaching the Statistics course.

The aim of our study was to evaluate the influence of seasonal ambient temperature on the thyroid gland function in terms of serum total thyroxine (TT4), free thyroxine (fT4), total triiodothyronine (TT3), and canine thyroid stimulating hormone (cTSH) concentrations in healthy dogs of various breeds living outdoors and to compare them with those living indoors in flats and houses. The monitoring was conducted for 5 years and our study included 162 indoor dogs and 148 outdoor dogs of both sexes from 2 to 12 years of age, categorised into 3 groups according to their body weight: large (n = 17), medium (n = 16) and small (n = 17) breeds.Comparison of the seasonal serum TT4 and fT4 concentrations in both the indoor and outdoor dogs confirmed their fluctuation in relation to the ambient temperature in all weight groups with the lowest average of TT4 and fT4 concentrations recorded in summer and the highest ones in winter. In dogs kept outdoors, the fluctuation of hormone values was significant (P < 0.05). Seasonal serum cTSH fluctuation was found to be significant (P < 0.05) only in the medium breeds living outdoors, but their concentrations did not exceed the reference ranges. The 5-year monitoring of serum TT3 in indoor and outdoor dogs of large, medium, and small breeds clearly showed that its concentrations were not influenced by varying ambient temperature. The study provides for the first time evidence that serum TT4 and fT4 concentrations in dogs kept outdoors directly depend on ambient temperature. This correlation was also expressed by mathematical equations. Dog, ambient temperature, thyroxine, thyreotropineThyroid hormones influence numerous physiological and biochemical events in cells, and are essential for healthy growth and development of neurological and skeletal systems. They have catabolic effects on muscle and adipose tissue and regulate cholesterol synthesis and degradation. Thyroid hormones have positive ionotropic and chronotropic effects on the heart (Scott-Moncrieff 2007). Thyroid hormones markedly stimulate Na + K + ATPase activity, which is connected to Na + and K + transport through the plasma membrane (Schaafsma et al. 2002;Slob et al. 2004). This process increases ATP utilisation. As a great part of oxygen consumption in the whole organism maintaining this transport system, the principal effect of the thyroid gland on the basal metabolism is expected to be correlated exactly with this effect. Thyroid hormones increase the metabolic rate and oxygen consumption of most tissues, with the exception of the adult brain, testes, uterus, lymph nodes, spleen and anterior pituitary (Ferguson 1988; Freake and Oppenheimer 1995). They increase the 2,3-diphosphoglycerate production in erythrocytes, which facilitates oxygen release from haemoglobin and they stimulate the generation of heat. This supports the hypothesis that total thyroxine concentrations should vary in relation to ambient temperature and should reflect seasonal variation, too (Freake and Oppenheimer 1995).

Abstract. The aim of the study was to assess the influence of different fertilizer doses on the content of macroelements (nitrogen, phosphorus and potassium) in dry biomass and grain of maize during the 2016 – 2018 period. A field experiment with fertilization of maize was carried out on Alluvial-meadow soil (Fluvisol) in the region of Tsalapitsa village, near Plovdiv. Three variants of mineral fertilization were studied V2 (N15P10K0), V3 (N20P15K0) and V4 (N25P20K0), and a control variant V1 (N0P0K0) – without fertilization. It was established that N% content in maize dry biomass was affected significantly by the variants of fertilization (18% of the variance). Significant differences (P≤0.05) between the control variant and all the variants of fertilization were established. Increasing the fertilizer dose, nitrogen content in dry biomass increased, too. The highest was the average content of nitrogen in maize leaves (0.94%), followed by the cobs (0.71%) and the lowest was the content in the stems (0.58%). Phosphorus and potassium content of dry biomass were affected significantly by the year of the study (10% and 9% of the variance, respectively). At the 7-8th leaf growth stage of maize, the highest nutrients content (N, P, K) in dry biomass were reported. With aging of plants the nutrient content in their biomass decreased. Nitrogen, phosphorus and potassium content in maize grain was significantly affected by the year of the experiment. Mineral fertilization had impact mostly on the nitrogen content of the grain, which was the highest in V3 variant, accepted as optimal – 0.66% on average.

Short-term intensive exercise may be associated with many short-lasting metabolic changes. These changes depend on the duration and intensity of the exercise. The aim of our study was to determine potential changes in C-reactive protein (CRP) and selected haematological and biochemical parameters in clinically healthy German shepherd dogs before short duration high-intensity exercise and 6 hours after the exercise. During the study, the dogs were subjected to the following defensive training: detaining a figurant running away from a dog (2×) and detaining with a counterattack (2×). The running distance was 200 m at a mean speed of 28 km.h-1. The investigation of haematological parameters revealed a significant decrease in the mean values of platelet haematocrit (PCT) 6 hours after the training. Significant differences in the levels determined before and after exercise were observed also for phosphorus (P) and for iron (Fe). At the same time, we observed a significant increase in the mean calcium (Ca) level and a significant decrease in sodium (Na) and chlorides (Cl). The activity of aspartate aminotransferase (AST) significantly increased after exercise. Concentrations of acute phase C-reactive proteins were increased 6 hours after exercise in comparison to those before exercise but the difference was insignificant. Although the concentration of CRP was increased insignificantly after the exercise, when interpreting concentrations of this nonspecific indicator of inflammation, one should keep in mind that intensive exercise may also affect its concentrations.