Kazimierz Wielki University in Bydgoszcz

About: Kazimierz Wielki University in Bydgoszcz is a education organization based out in Bydgoszcz, Poland. It is known for research contribution in the topics: Population & Luminescence. The organization has 1109 authors who have published 2923 publications receiving 19548 citations. The organization is also known as: Casimir the Great University & Uniwersytet Kazimierza Wielkiego w Bydgoszczy.

Contact angle and surface free energy of electron-beam irradiated polymer composites

Abstract: The effects of the electron radiation dose and of compatibilizers on the contact angle and surface free energy (SFE) of the composites made of low-density polyethylene (PE-LD), high-density polyethylene (PE-HD), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) were studied. Use of the high-energy electron radiation with doses up to 300 kGy and of compatibilizers was done to reach better mechanical and adhesion properties of the composites studied and, at the same time, to investigate the possibility of applying of this technique in the processes of polymeric materials recycling. The compatibilizers were the styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride (SEBS-g-MA), added at the amounts of 5, 10 or 15 wt. %, and trimethylol propane trimethylacrylate (TMPTA), added at the amounts of 1,2 or 3 wt. %. The effects, discussed in the present article, are: enhancement of wettability and increase in SFE of the composites studied. It was found that the contact angle steadily decreased and SFE of the composites increased with the rising dose of the electron radiation and that TMPTA intensified these tendencies.

The occurrence of molds in patients with chronic sinusitis

Abstract: Chronic rhinosinusitis (CRS) is a common inflammatory condition of nasal and paranasal sinus mucosa. Although pathogenic bacteria were postulated as main etiological factor responsible for most cases of CRS, the involvement of molds was recently proved in some cases. The aim of the study was to conduct mycological analysis of material obtained from patients operated on due to chronic sinusitis. The study included 107 patients, 45 women and 62 men. During the surgery, a fragment of mucosa from the region of the ethmoid bulla was obtained as microbiological characteristics of this material closely resemble those of sinus mucosa. In addition, maxillary sinus lavage was obtained. The control group comprised patients without chronic sinusitis. The dithiothreitol solution method was used for the lavage examination. The tissue material (mucosal fragment from the region of the ethmoid bulla) was incubated in 2 % liquid Sabouraud medium for 24 h. The material was inoculated onto culture media. The presence of molds was detected in 67 % of examined samples. Overall, 41 species belonging to 12 genera were isolated. The most frequently detected genera included Penicillium spp. (46 %) and Aspergillus spp. (16 %). In addition, Cladosporium spp. (11 %), Fusarium spp. (7 %), Acremonium spp. (4 %), Eurotium spp. (4 %), Alternaria spp. (2 %), Chaetomium spp. (1 %), Geotrichum spp. (1 %), Verticillium spp. (1 %), Rhizopus spp. (1 %), and some unidentified colonies (5 %) were isolated. Penicillium crustosum, Penicillium citrinum, Aspergillus niger, Cladosporium cladosporioides, and Fusarium verticillioides were the most prevalent species.

A new fuzzy approach to ordinary differential equations

Abstract: In real-life problems, both parameters and data used in mathematical modeling are often vague or uncertain. In fields like system biology, diagnosis, image analysis, fault detection and many others, fuzzy differential equations and stochastic differential equations are an alternative to classical, or in the present context crisp, differential equations. The aim of the paper is to propose a new formulation of fuzzy ordinary differential equations for which the Hukuhara derivative is not needed. After a short review of recent results in the theory of ordered fuzzy numbers, an exemplary application to a dynamical system in mechanics is presented. Departing from the classical framework of dynamics, equations describing the fuzzy representation of the state are introduced and solved numerically for chosen fuzzy parameters and initial data.

Gene flow and reproductive success in ash ( Fraxinus excelsior L.) in the face of ash dieback: restoration and conservation

Abstract: Ash dieback decreases individual reproductive success of ash trees leaving healthy ash overrepresented as seed and pollen parents for next-generation seedlings. Substantial gene flow over hundreds of meters combined with superior fertility of healthy trees creates optimism for the species’ future in European forests. Hymenoscyphus fraxineus is causing high mortality in European ash (Fraxinus excelsior L.). Due to inheritable resistance to the pathogen, natural selection is likely to act in favour of improved resistance in ash forests following natural regeneration. Still, the frequency of healthy trees is low, and the effect of natural selection will depend on survival, reproductive success and the dispersal capacity of healthy trees under natural conditions. We aim to test whether healthy trees contribute more to the next generation and to infer their potential for dispersing progenies across the forested landscape. Using parentage modelling, we estimate mating parameters and dispersal distances of seeds and pollen and compare realised reproductive success of healthy trees to that of unhealthy ones. Healthy trees are overrepresented as the parents of randomly sampled seeds and seedlings in the forest, although that is more pronounced on the female side. We observe long dispersal events and estimate the mean seed and pollen dispersal distances as 67 m and 347 m, respectively. Variation in reproductive success results in selection in favour of lowered susceptibility to ash dieback. The large dispersal capacity decreases the risk of genetic bottlenecks and inbreeding and allows resistant trees to disperse their genes into the neighbourhoods of substantial sizes.

Fungal diversity and mycotoxin distribution in echinoderm aquaculture

Abstract: Aquaculture has been a growing sector of food production worldwide in the last decades, and now starts to include new, unconventional species from the Phylum Echinodermata, such as sea urchin (Paracentrotus lividus) and sea cucumber (Holothuria tubulosa). However, little is known in this context with regard to food safety aspects arising from toxigenic fungi. In this study, samples of feed (n = 7) and water (n = 8) or water filters (n = 4) from experimental aquaculture systems, producing sea urchin and sea cucumber, were analyzed by culture-based microbiological methods to assess fungal associations. Additionally, a search using molecular techniques for toxigenic sections within the genus Aspergillus in these materials was done. Finally, samples were analyzed for 37 mycotoxins by LC-MS/MS. In feed samples, Fusarium verticillioides and F. culmorum were detected. In water and water filter samples, Aureobasidium spp., Penicillium spp., and Cladosporium spp. were found. No genes of species from toxigenic Aspergillus sections were detected. Some feed samples were contaminated by multiple mycotoxins, namely deoxynivalenol (DON), zearalenone (ZEN), fumonisins (FBs), T-2 toxin, ochratoxin A (OTA), and mycophenolic acid (MPA). This is the first one study dealing with toxigenic fungi and mycotoxins in echinoderm-producting aquaculture. Although no clear evidence for adverse effects on the production systems could be found, the confirmed environmental association of mycotoxins and echinoderms requires further consideration. Studies on the consequences of introducing cereal-based fungi and their mycotoxins via feeds into aquaculture systems for echinoderm production seem to be advisable, to assess possible adverse effects on production and to clarify the potential impact on public health.