The work is based on data on monthly air temperatures, monthly sums of atmospheric precipitation and early potato yields in 2000-2013 obtained from seven COBORU (Research Centre for Cultivar Testing) stations situated in east-central Poland. Hydrothermal conditions during the growing season (April-July) of early potato were described by means of the Sielianinow's coefficient. The relationships between potato yields and the Sielianinow's hydrothermal coefficient of the growing season were examined using multiple regression equations generated by means of the step-wise regression procedure followed by polynomial regression procedure. The average Sielianinow's coefficient values ranged from 1.43 in April to 1.66 in May during the early potato growing season in east-central Poland. The applied statistical methods revealed that the hydrothermal factors impacted on early potato yields, particularly in the second stage of potato growth and development.

Abstract:The work is an attempt to assess piped water quality in four counties located in east central Poland. Piped water was analysed for three successive years in each county. Water samples were tested for the following physical and chemical parameters: turbidity, colour, conductivity, taste, odour, pH, nitrates (III), nitrates (V), iron and manganese. They were compared with the current standard values. Preliminary data analysis included an analysis of maximum and minimum values of physical and chemical parameters, and it revealed that turbidity, colour, iron and manganese contents exceeded the permissible standards in all the counties. Percentages of parameters exceedances and mean values of the exceedances were used to rank the counties in terms of water quality. The ranking was obtained by means of multidimensional comparative analysis. It was demonstrated that best quality water was supplied by Węgrów County water supply system which was followed by Mińsk Mazowiecki County. The third rank was assigned to Łosice County and the poorest quality water was found to be supplied by Siedlce County water supply system.

This paper presents the results of research aimed at finding the possible ways of disposing of ceramic waste material, focusing mainly on the possibility of using it as aggregates in concretes exposed to an aggressive chemical environment (municipal sewage). The research part presents the preparation method and investigation of waste ceramic aggregates (red, glazed and sanitary ceramic aggregates). A suitable ratio of coarse to fine aggregates was selected, and their density, absorptivity and crushing strength were examined. All examined aggregates were also subjected to SEM analysis. Red ceramic aggregate is characterized by a greater degree of crushing compared to glazed and sanitary ceramic aggregate, by 205.7% and 439.4%, respectively. Another part of the research was to compare the properties of concrete with traditional aggregate (gravel, basalt) and with ceramic waste aggregate. The tested parameters included consistency, apparent density, absorptivity, flexural and compressive strengths of concretes. The study proved that the absorptivity of recycled composites is higher than that of traditional composites by 20.8–24.7%. The concrete based on sanitary ceramic waste has the highest strength parameters. Its compressive strength is higher by 10.5% and flexural strength by 5.9% compared with the basalt aggregate concrete. The compressive strength of sanitary ceramics concrete is higher by 42% and by 59% compared with concrete based on glazed ceramic and red ceramic aggregate, respectively. The last part of the research was to examine the resistance of concrete to aggressive environment. The scope of the work included the preparation of the research environment in the form of solutions with an increased concentration of aggressive agents (hydronium, sulfate, magnesium, ammonium ions). Among the concretes with ceramic aggregate, the highest decrease in the compressive strength was demonstrated by the concrete based on red ceramics (128.2%), while the smallest was demonstrated by the concrete based on sanitary ceramics (aggregate from sanitary ceramics (15.4%). The mass loss at different time intervals and compressive strength loss of samples stored in solutions were tested. The smallest weight loss caused by aggressive environment attack was recorded in the concrete based on ceramic sanitary and glazed aggregate (20.2% and 34.5%, respectively, after 120 days of aggressive environment).

Background: The impact of light on the content of undesirable substances is particularly important in the case of potatoes available in store where the tubers are exposed to continuous light access. Both washed and unwashed potatoes are available, hence the hypothesis that the amount of harmful substances stored in tubers depends not only on the time of their exposure to light, but also on whether they were washed or not. Methods: In order to verify the hypothesis, laboratory tests were carried out on the tubers of five potato varieties originating from a univariate field experiment. The aim of the study was to analyse the change in the content of total glycoalkaloids (TGA) and nitrates (V) in tubers of five potato varieties depending on the time of light exposition (0, 7, 14 days) and pretreatment of tubers. Results: It has been demonstrated that the content of glycoalkaloids and nitrates in potato tubers depended significantly on the variety, time of exposure to light and pretreatment. Most glycoalkaloids were accumulated in the tubers of the Lord (89.67 mg·kg−1) and Irga (89.05 mg·kg−1) varieties. The time of light exposure significantly influenced the increase in glycoalkaloids and nitrates in the studied potato tubers. The increase in TGA after 14 days ranged from 20.67 mg∙kg−1 for variety Vinieta to 54.67 mg∙kg−1 for variety Irga. The increase in nitrates ranged from 11.67 mg∙kg−1 for variety Bellarosa to 27.50 mg∙kg−1 for variety Irga. Exposure time affected the content of glycoalkaloids in a parabolic manner and the content of nitrates in a linear manner.

Parameters of sexual activity were determined in 49 young boars used for artificial insemination, four times at three-month intervals. The parameters included the time from entering the arena until mounting the phantom; the time from mounting the phantom until achieving erection; the time from achieving full erection until the start of ejaculation; duration of ejaculation; and the number of times the boar mounted the phantom. Characteristics of the ejaculates were also assessed. The libido parameter associated with the greatest efficacy of artificial insemination was the effectiveness of artificial insemination service, the time from entering the arena until the start of ejaculation. The significance of this trait for predicting ejaculation performance was analysed. The libido characteristics were classified into three categories: boars with a short reaction time to the phantom, boars with an intermediate reaction time, and boars with a long reaction time. For these groups, the characteristics of ejaculates collected at the start of the period during which ejaculates were collected and after three, six and nine months were determined. The sexual experience of boars was not associated with the expression of sexual behaviour because young boars during their first three months of ejaculate collections required less time to initiate ejaculation. The ejaculates with the greatest utility were obtained after six months of service. These ejaculates had the largest volume (255.22 mL), and the most insemination doses could be prepared from these ejaculates. On average, more than 23 insemination doses were prepared from ejaculates collected after six months of semen collections, which is about four doses more than from ejaculates collected at the start of artificial insemination service (p < 0.01).The time from entering the arena to beginning ejaculation can be used to predict a boar’s future libido. A relationship was shown between the level of libido and ejaculate characteristics. The ejaculates of the boars which needed the longest time to begin ejaculation at the start of semen collections had the greatest sperm concentration and number. In group 3, the boars’ejaculates contained about 6–9 × 109 more sperm than the ejaculates of boars from group 1. After six months of the experimental period, the difference was nearly 15 × 109 sperm (p < 0.05), and after nine months, it exceeded 22 × 109 sperm (p < 0.01).

Air temperature is one of major factors in a subjective assessment of human thermal comfort and discomfort. The work draws on a series of measurements of the average daily air temperatures, relative air humidity and wind speed for 2000-2016 recorded at the Siedlce Meteorological Station. The station is part of the state observation and measurement network of the hydrological and meteorological service of The Institute of Meteorology and Water Management -National Research Institute (IMGW-PIB). The effective temperature was calculated according to the formula recommended by Missenard and the thermal sensation was determined based on a scale suggested by Baranowska. The number of days with individual thermal sensations in individual months of the long-term period was calculated, and months were put into groups of similar sensations by means of principal component analysis (PCA) and cluster analysis. In the last years (2015, 2014, 2012 and 2011) in the months representing the cold season of the year, there were more days which were very cold and cold, whereas the number of days with the thermal comfort was much lower. The long-term period was split into three groups, based on the thermal comfort in the warm season of the year. The years which formed one group included 2011, 2013, 2015 and 2016 when there were no very cold days, the least cold days and the most very hot days.

This study shows an association between the frequency of the nan1 gene (encoding neuraminidase) among 62 clinical Pseudomonas aeruginosa isolates and adhesion of these bacteria to human buccal epithelial cells. The 52 strains in which the gene was present (83.9%) were characterized by a higher adhesiveness (the mean number of adhering bacteria was 23.51 per cell) than strains in which the gene was not detected (16.23 per cell) and the difference was significant (P = 0.009, Mann-Whitney U test). Thus we found that the nan1 gene may play a role in the binding of clinical P. aeruginosa strains to buccal cells.

Moreover, principal component analysis was conducted to indicate elements that exerted the greatest influence on the agroclimate. Also, cluster analysis was carried out to select stations with similar agroclimate. Ward method was used for clustering and the Euclidean distance was applied. Principal component analysis revealed that the agroclimate of east-central Poland was predominantly affected by climatic water balance, number of days of active plant growth, length of the farming period, and the average air temperature during the growing season (Apr-Sept). Based on the analysis, the region of east-central Poland was divided into two groups (areas) with different agroclimatic conditions. The first area comprized the following stations: Szepietowo and Białowieża located in the North Podlasian Lowland and Biała Podlaska situated in the northern part of the South Podlasian Lowland. This area was characterized by shorter farming periods and a lower average air temperature during the growing season. The other group included the remaining stations located in the western part of both the Lowlands which was warmer and where greater water deficits were recorded.K e y w o r d s: agroclimate, variation, growing season, principal component analysis, east-central Poland INTRODUCTION