EJPAU, 2011, Volume 14, Issue 3

Demographic and economic development affects the natural environment in various ways. One of the elements of that influence is undoubtedly the development of town and rural settlement. The objective of the work was to analyze the changes in spatial building structure of two rural districts: Choroszcz (directly neighbouring the city of Białystok) and Narew. Structure changes in years 1931, 1953 and 1998 were compared. In the study, GIS methodology and spatial statistics were applied. Analyses showed a strong influence of development of the suburban zone on the development of rural areas directly neighbouring the city. That influence is visible both in the spatial aspect and in the building structure.

The taxonomic status of cod from the Baltic Sea has not yet been fully recognized. The aim of this study was to determine the suitability of regular SDS-PAGE electrophoresis to differentiate between two cod sub-species from the Baltic Sea. The examined fishing grounds were the Barents Sea (the region of Bear Isle), the Strait of Sund and Puck Bay (Baltic Sea). In muscle extracts from individuals from the Barents Sea and the Strait of Sund, SDS-PAGE analyses showed protein profile consisting of 25 proteins compare to 16 proteins from cod from the Baltic Sea. Fourteen of them were common for both groups. The results obtained in this study show that cod from the Strait of Sund show a high similarity (and are in fact identical) to cod from the Barents Sea. SDS-PAGE protein profiles of proteins from the Baltic Sea cod are different from cod from the Barents Sea and the Strait of Sund. Therefore it may be a strong premise for the statement that G. morhua callarias is a local Baltic subspecies.

Laccases, enzymes involved in lignin degradation are produced by various organisms, specially fungi. The addition of inducers to the culture medium of microorganisms can enhance laccase production and facilitate its purification and utilization. Eighteen media were prepared using full L18 (2¹ x 3⁷) factorial design to maximize the production of laccase by Pleurotus ostreatus. When wheat bran was used as solid substrate, maximum laccase activity was recorded in medium no. 7, while wheat bran extract was added highest enzyme activity was in medium no. 15. Generally, solid wheat bran substrate induced high laccase activity while, bran extract induced higher protein content in culture filtrates and dry biomass of P.ostreatus in all media. The biochemical parameters (protein and sugars) and growth parameters (mycelial growth rate and dry biomass) varied significantly with media composition and nature of wheat bran added as substrate (solid or extract). Maximum of extracellular laccase activity was observed in medium no.7 together with high amount of protein, reducing (DRS) and non-reducing sugars (NRS). Promising degradability action of P.ostreatus especially in presence of solid bran substrate was observed in this medium.

Drought is one of the most important environmental stresses in agriculture. It significantly reduces both the quality and yield of agricultural crops. Under conditions in Poland, spring barley is more sensitive to drought than winter barley. In plants, the expression of dehydrins increases the ability to absorb and hold water in the cell. One can try to obtain plants with increased resistance to drought, among other things, through the selection of genotypes with increased accumulation of dehydrins.
The aim of our study was to examine differences in the expression levels of SRG6 and HVA1 genes in Polish breeding lines of spring barley. In this experiment measurements of the accumulation levels of HVA1 and SRG6 transcripts by means of real-time PCR were performed in twenty seven barley genotypes. Estimations of mRNA abundance were made before drought and on the 15th day of the experiment at a relative maximum water capacity of 32%. The results of our experiments showed that drought stress caused a significant increase in the expression of HVA1 and SRG6 genes in all genotypes. The 27 studied breeding strains of spring barley from Polish breeding companies were characterized by high variation in the expression of both genes.

Physical attributes of two common Iranian varieties of safflower seed (namely Golshid and Afshan), such as geometric properties (size, geometric mean diameter and sphericity), gravimetric properties (thousand seed mass, bulk density, true density and porosity) frictional properties (emptying angle of repose and coefficient of static friction on four structural surfaces) and terminal velocity were determined as a function of size (large, medium, small) and moisture content in the range of 4 to 20% (d.b.). The results showed that the mean values of all geometric properties increased linearly with increasing moisture content. Among the varieties, Afshan had the highest values of geometric properties, in all moisture contents and size studied. At studied moisture contents and size categories, thousand grain mass, true density and porosity increase linearly, but the bulk density of safflower seeds linearly decrease as moisture content increase from 4 to 20 %. Among the applied surfaces, rubber (0.5–0.69) showed the highest value of friction coefficient safflower seed followed by plywood (0.45–0.63), galvanized iron (0.41–0.54) and aluminium (0.36–0.47). The obtained values of emptying angle of repose increase linearly with an increase in moisture content and size categories. The terminal velocity of Golshid variety varied from 6.1 to 6.7, 5.8 to 6.3 and 5.3 to 5.9 m/s for large, medium and small sizes, respectively. The range of terminal velocity for Afshan variety obtained 6.4–7.2, 6.3–6.9 and 6–6.6 m/s, respectively.

The subject of this paper are thin plates with a characteristic two-component structure: periodic in one direction and functionally variable in the second. This provides a gradient microstructure of the material properties of plates in the macro scale. The work is analyzed self-vibrations of this type of composites.

Modeling was made using three independent methods. The results obtained are summarized and compared in terms of accuracy and effort calculations. For comparison and evaluation of modeling methods were selected as follows:

• tolerant approximation technique proposed and described in the monograph [5], which was applied to this kind of plates for mechanical problems in [2][3][4] and for heat conduction problems in [1],
• finite element method, implemented with commercial computer program,
• heuristic method, which consisted of a simple, consistent with engineering intuition, averaged mechanical properties of the plate in one direction and bringing the problem to the problem of vibration of one-dimensional beams with variable cross-section.

The general results are illustrated by the analysis of a specific problem with different kind of boundary conditions plate band.

The profitability of pig production considerably depends on the number of born alive and fostered piglets. Therefore, it could be of interest to estimate the reproductive potential of sows. The progress regarding the number of piglets born for German Landrace, Large White and Pietrain in Germany during 1970–2006 is still moderate (GL: 10,4–11,0; LW: 11,0–11,0; PI: 10,2–10,0). Comparing actual international data, variations between 11.3 to 14.2 piglets born alive are observed. The reproductive performance of sows is mainly determined by (i) the number of ovulated follicles and fertilized oocytes, (ii) the percentage of surviving embryos and fetuses, and (iii) the morphological and functional performance of the uterus to support fetal development until birth. Therefore, the question whether the ovary and/or uterus are limiting factors will be discussed. Although only less than 0.1% of oocytes present in the ovary are ovulated during the sows' lifetime, the pool of ovarian follicles is not the limiting one. Selection for ovulation rate increases the number of ovulating follicles, but not of piglets born alive. Limited uterine capacity and function seems to exert greater influence. Although a relationship exists between uterine dimension and the number of fetuses/piglets, uterine length alone is not a prerequisite of higher uterine capacity. Placental efficiency and the degree of placental blood supply appear to be essentially for litter size. At present, the (realistic) presumed potential of fecundity is 16.0 piglets born alive, 2.4 litters/year, <10% losses and 34.0 piglets per sow/year (compared to current data of 12.2, 2.33, 14.8 and 24.2, respectively).

Fermented milk beverages produced from goat's milk are characterized by loose, soft consistency, which may be improved by the selection of appropriate starter cultures. Taking into account that the starters used in cow's milk technology are not always suitable for goat's milk, the aim of this study was to analyze to what extent two commercially-available yoghurt cultures, with traditional composition, enable obtaining a product with desirable quality properties from goat's milk. Two batches of yoghurt were produced during the experiment. Super jogurt starter of the Canadian Institute Rosell Inc. was used to obtain the first batch (J-A) and Yoghurtferment from Lactoferm (Belgium) for the second batch. The analyzed beverages were subjected to organoleptic, physicochemical and rheological evaluations after 1, 3, 7, 14 and 21 days of refrigerated storage (5 ±1°C). The study demonstrated that fermented milk beverages from goat's milk that was produced with both classic yoghurt cultures had desirable qualitative characteristics.
   The experimental yoghurts did not differ in the organoleptic properties during storage.
   The statistically significant differences were noted in the titratable acidity and pH, and not in the viscosity. The produced beverages were characterized by a low content of acetaldehyde, in turn the highest hardness was noted for the J-A beverage produced with the Super jogurt starter.