Synthetic solid solutions formed between goethite and diaspore

The substitutional solid solutions of goethite (a-FeOOH) and diaspore (α-AlOOH) have been investigated by X-ray powder diffraction and chemical analysis in order to establish the solubility limits of aluminium in the goethite structure. α-Fe_1-xAI_xOOH samples were obtained by ageing of coprecipitated amorphous (Fe,Al) hydroxides at pH 13 in NaOH and Na[Al(OH)₄] solutions at 25°C (G25 series) and 70°C (G70 series), respectively. Chemical analysis reveals that the aluminium content of Al goethites is consistent with Al concentration in the coprecipitated hydroxides up to about 10 mol% Al. In Al goethites obtained from (Fe,Al) hydroxides with higher Al:Fe ratios, the relative Al content is considerably lower. It was found that pure ferrihydrite stored in the aluminate solution is also transformed into Al goethite. The X-ray diffraction results show a significant divergence of the unitcell parameters from Vegard's law. This points out the limited ranges of the solid solution between goethite and diaspore and suggests the formation of defect, cation-deficient structures.     

Selected Physico-Chemical Properties of Zinc and Lead Ore Tailings and their Biological Stabilisation

The following work focuses on problems and possibilities for revegetation of zinc and lead ore tailings in the Mining and Metallurgic Plant ‘Boleslaw’ in Poland, and on selected physical and chemical properties also regarding the vegetation, which spontaneously appears on the ponds. It was found that main factors impeding the development of vegetation are excessive contents of Zn, Pb, and Cd, as well as eolian erosion and deficiency of macroelements. The results of biological fertilisation tests were discussed in particular with regard to the deficiency of macroelements and the immobilisation of Zn, Pb, and Cd. Pot and field experiments permitted determination of this kind of interaction with doses of mineral fertilization ensuring plant growth. Plants were introduced to the sediment without a layer of insulation. The obtained results, along with some thorough research into the conditions prevailing on the sedimentation ponds, may be used as a basis for the biological stabilisation of this kind of waste material.     

Morphology of the inferior pharyngeal bones of white bream (Blicca bjoerkna) in River Warta

The inferior pharyngeal bones are a characteristic feature of the Cyprinidae. Morphology of inferior pharyngeal bones is important in the diagnosis of carnivorous food, or determining the diet of fishes. Due to the lack of literature data, the aim of the study was to examine the morphology of the inferior pharyngeal bone in detail. 102 Blicca bjoerkna specimens caught in the River Warta (Poland) were analysed. 204 inferior pharyngeal bones were collected. The parameters of the inferior pharyngeal bones correlated with the measured head features and the total fish length. The arches of inferior pharyngeal bones did not have directional asymmetry for the two main parameters (height and width of inferior pharyngeal bone). However, there was a left‐sided directional asymmetry of the ventral part of inferior pharyngeal bone. In the case of the B. bjoerkna from River Warta, large differences in terms of individual parameters of inferior pharyngeal bones were observed. Fluctuation asymmetry was low. Shape of inferior pharyngeal bones was very round. In total, 12 teeth formulas were described. The 35.29% of the fish had formula different than described in the literature 2.5–5.2 and more teeth in the right arches. Following identification, measurements of the structures enable estimation of the lengths and weights of prey to be determined from biometric relationships. Analysis of body morphological features in combination with pharyngeal bone morphology could show a hybrid in the Warta river's population.     

The use of human and bovine commercial media for oocyte maturation and embryo development in the domestic cat (Felis catus)

The aim of this study was to examine the suitability of commercial media designed for humans and cattle for oocyte maturation and embryo culture in the domestic cat. In Exp. I, feline oocytes collected ex vivo were subjected to in vitro maturation in a laboratory‐made culture medium (based on M199) or a commercial medium designed for cattle cells (BO‐IVM^®). In Exp. II, ICSI‐derived feline embryos were cultured for 7 days in a commercial human (Continuous Single Culture^®) or bovine (BO‐EC^®) cell medium. The rates of cleavage, morula and blastocyst formation were evaluated at 24 hr, 6 days and 7 days after ICSI, respectively, and compared between experimental groups. At the end of culture, embryos were assessed for viability and apoptotic changes. In Exp. I, no statistically significant difference in oocyte maturation outcome between laboratory‐made (52.7%) and commercial media (58.9%) was observed. However, the use of a commercial medium prepared for use with bovine cells resulted in a significantly lower variance of the maturation rate. In Exp. II, no statistically significant differences between two commercial media were observed for cleavage (67.5% and 64.5%), morula (39.3% and 47.1%) and blastocyst rates (25.0% and 19.6%), as well as for the percentage of late apoptotic blastomeres. Morulae cultured in medium marketed for humans exhibited significantly more early apoptotic (43.2 ± 31.2% vs. 23.4 ± 23.2%) and necrotic (60.6 ± 47.6% vs. 29.4 ± 22.6%) blastomeres. In conclusion, both commercial media tested are suitable for in vitro oocyte maturation and embryo culture procedures in cats. It is remarkable that a culture medium designed for use in cattle for in vitro maturation of cat oocytes provides more reproducible results.     

Auxin-dependent development and habituation of highbush blueberry (Vaccinium × covilleanum But. et Pl.) ‘Herbert’ in vitro shoot cultures

The influence of IAA (1.0 mg dm⁻³), and IBA (1.16 mg dm⁻³), on the development of highbush blueberry (Vaccinium × covilleanum But. et Pl.) ‘Herbert’ in vitro shoot cultures was examined. Depending on the kind of auxin and 2iP concentration in vitro cultures consisted of various number of axillary (AX) and adventitious (AD) shoots. Three different categories of AD shoots were found: leaf shoots (AD-L), node-adjoin shoots (AD-P), and base-adjoin shoots (AD-M, madshoots). The AX shoots were the least habituated (towards auxins, cytokinins and vitamins) whereas the AD-M shoots (madshoots) the most. In comparison to IAA, IBA caused dying or callusing higher number of initial explants. However, IBA generally suppressed development of AD shoots, especially madshoots whereas slightly weakened multiplication of AX shoots. IBA significantly enhanced elongation of AX shoots also. Axillary shoots obtained on IBA-media had relative long internodes and rigid, well-developed leaves. The adventitious shoots, especially base-adjoin (AD-M) ones, were easily distinguishable as were more thin and fragile, more or less vitrified, and had short internodes and smaller, sometimes unfolded leaves. Development of blueberry in vitro cultures on auxin-free and IAA-supplemented media was similar. AX shoots grown on such media resembled AD shoots. 2iP applied in higher doses along with IAA promoted much proliferation of AD than AX shoots. In contrast, 2iP applied in higher doses together with IBA stimulated significantly only growth of AX shoots whereas in general, development of adventitious shoots was not affected. Micropropagation carried out through routine method based on subculturing of shoot explants or shoot clumps on the medium supplemented with IAA (4 mg dm⁻³) and 2iP (10–15 mg dm⁻³) as well as stimulation of shoot elongation on the blank medium causes in fact the propagation of highbush blueberry through highly habituated adventitious madshoots. Replacement of IAA by IBA facilitates micropropagation of highbush blueberry cv. Herbert through axillary shoots.     

Availability of Microelements as Affected by Soil Reaction and Fertilization in Long-Term Field Experiments

Results presented in this paper come from two long-term fertilization experiments carried out in Skierniewice (since 1923) and _ yczyn (since 1960). The top layer of soil in Skierniewice contains a little more clay and silt (17%) than at _ yczyn (14%), but the climatic conditions are alike - the mean for many years shows the precipitation of 520mm and temperature 7,9°C. Soil samples for the determination of microelements were collected in the years 1999 and 2000 from the control plots (Ca) and from combinations corresponding to 3 fertilization systems: mineral (CaNPK), organic (Ca + FYM) and mixed organic-mineral (CaNPK + FYM). The contents of B, Cu, Zn, Mn were determined in 4 extract solutions: 0,01mol CaCl2, EDTA, 1mol HCl and HF (total contents). The paper presents average results for the last two years. The following amounts of microelements (%) in relation to the total contents in particular extract solutions were obtained: CaCl 2 m Cu 0,4< Zn 2,2< Mn 3,5 < B 5,0; EDTA - B 2,4 < Mn 5,7 < Zn 9,0 < Cu 13,9; HCl - B 7,8 < Cu 37,3 < Zn 37,6< Mn 72,5. The soil contents of readily soluble forms of Mn were significantly higher in non-limed than in limed soil, while the amounts of B, Cu and Zn were higher in limed soils as some amounts of Cu and Zn were present in lime fertilizers. In the system of mineral fertilization, some amounts of boron and zinc were introduced to the soil together with fertilizers, however, they were insufficient in view of nutritional requirements. On the other hand, in the organic-mineral system the amounts of introduced boron were adequate, copper and zinc twice higher and manganese four times higher. The use of mineral fertilization alone for 26 years, leads to soil depletion of zinc and copper and the use of manure alone enriches soil in those components.     

Assessing differences in connectivity based on habitat versus movement models for brown bears in the Carpathians

Context

Connectivity assessments typically rely on resistance surfaces derived from habitat models, assuming that higher-quality habitat facilitates movement. This assumption remains largely untested though, and it is unlikely that the same environmental factors determine both animal movements and habitat selection, potentially biasing connectivity assessments.

Objectives

We evaluated how much connectivity assessments differ when based on resistance surfaces from habitat versus movement models. In addition, we tested how sensitive connectivity assessments are with respect to the parameterization of the movement models.

Methods

We parameterized maximum entropy models to predict habitat suitability, and step selection functions to derive movement models for brown bear (Ursus arctos) in the northeastern Carpathians. We compared spatial patterns and distributions of resistance values derived from those models, and locations and characteristics of potential movement corridors.

Results

Brown bears preferred areas with high forest cover, close to forest edges, high topographic complexity, and with low human pressure in both habitat and movement models. However, resistance surfaces derived from the habitat models based on predictors measured at broad and medium scales tended to underestimate connectivity, as they predicted substantially higher resistance values for most of the study area, including corridors.

Conclusions

Our findings highlighted that connectivity assessments should be based on movement information if available, rather than generic habitat models. However, the parameterization of movement models is important, because the type of movement events considered, and the sampling method of environmental covariates can greatly affect connectivity assessments, and hence the predicted corridors.

     

General combining ability and heterosis regarding the phytochemical properties in strawberry (Fragaria × ananassa) hybrids

Strawberries are a common and important fruit in human diet because of their high content of essential nutrients and beneficial phytochemicals, which have relevant biological activity in human health. In this study, six cultivars and 15 selected F₁ hybrids between S₄ inbred lines and tester (cv. ‘Dukat’) were evaluated in a field trial over a period of two consecutive years. The amounts of total anthocyanin, phenolics and vitamin C in fruits and antiradical activity were analysed. General combining ability (GCA) and mid‐parent heterosis were also determined for those characteristics. Among all the genotypes tested, the inbred lines of ‘Senga Sengana’ 17 showed the highest breeding value based on GCA for all studied traits. Estimated heterosis varied among genotypes tested. The highest heterosis in terms of vitamin C occurred in the offspring of clone 1387 18‐15 × ‘Dukat’, but with regard to phenols and antiradical activity in hybrid ‘Teresa’ 18‐15 with cv. ‘Dukat’. This study revealed that the differentiation in chemical composition of strawberry fruits between genotypes is clearly dependent on individual genotype combinations and demonstrated the presence of heterosis in phytochemical contents in some specific genotypic combinations.     

The fate of nitrogen,phosphorus and potassium in long‐term experiments in Skierniewice

On the basis of long‐term fertilization experiments in Skierniewice, being conducted since 1923 at the Experimental Field of Warsaw Agricultural University, the fate (or balance) of nitrogen for a period of 35 years and that of phosphorus and potassium for 20 years, was studied. The balance includes N, P and K rates applied in mineral fertilizers and farmyard manure (FYM), uptake of these nutrients by the crop plants and the changes in the content of total N and total P and of slow release K in the soil during that time. The nitrogen balance shows a loss of this nutrient of 11—14 kg N ha^—1 y^—1, which corresponds to 15% of the applied ammonium nitrate on fields without FYM but to 23% on fields with FYM, in spite of crop yields being considerably greater on fields treated with FYM. The phosphorus balance indicated that in the 0—70 cm soil layer less than 4% of P from superphosphate was not found. In the treatment not fertilized with potassium for many years, the plants took up 49 kg K ha^—1 y^—1 from slow release forms because the fraction of available K did not change during that period. When calculating the potassium balance only 1.6% of K from potash salt were not found in plots without FYM but 12.3% of the applied KCl were not recovered in treatments with FYM. The comparison of the P‐ and K‐uptake from organic and mineral fertilizer in the two crop rotations indicates a higher P‐ and K‐efficiency from FYM than from inorganic fertilizer.     

Novel Spray Dried Glycerol 2-Phosphate Cross-Linked Chitosan Microparticulate Vaginal Delivery System—Development,Characterization and Cytotoxicity Studies

Chitosan microparticulate delivery systems containing clotrimazole were prepared by a spray drying technique using glycerol 2-phosphate as an ion cross-linker. The impact of a cross-linking ratio on microparticle characteristics was evaluated. Drug-free and drug-loaded unmodified or ion cross-linked chitosan microparticles were examined for the in vitro cytotoxicity in VK2/E6E7 human vaginal epithelial cells. The presence of glycerol 2-phosphate influenced drug loading and encapsulation efficacy in chitosan microparticles. By increasing the cross-linking ratio, the microparticles with lower diameter, moisture content and smoother surface were observed. Mucoadhesive studies displayed that all formulations possessed mucoadhesive properties. The in vitro release profile of clotrimazole was found to alter considerably by changing the glycerol 2-phosphate/chitosan ratio. Results from cytotoxicity studies showed occurrence of apoptotic cells in the presence of chitosan and ion cross-linked chitosan microparticles, followed by a loss of membrane potential suggesting that cell death might go through the mitochondrial apoptotic pathway.