Selective pressure from parasites is thought to maintain the polymorphism of major histocompatibility complex (MHC) genes. Although a number of studies have shown a relationship between the MHC and parasitic infections, the fitness consequences of such associations are less well documented. In the present paper, we characterised the variation in exon 2 of MHC class II DRB gene in the root vole and examined the effects of that gene on parasite prevalence and winter survival. We identified 18 unique exon 2 sequences, which translated into 10 unique amino acid sequences. Phylogenetic analysis revealed the presence of three distinct clusters, and allele distributions among these individuals suggested that the clusters correspond to three different loci. Although the rate of synonymous substitutions (d S ) exceeded the rate of nonsynonymous substitutions (d N ) across sequences, implying purifying selection, d N was significantly elevated at antigen-binding sites, suggesting that these sites could be under positive selection. Screening for parasites revealed a moderate prevalence of infection with gastrointestinal parasites (24 % infected), but a high infection rate for blood parasites (56 % infected). Infection with the blood parasite Babesia ssp. decreased survival almost twofold (25.7 vs. 13.9 %). Animals possessing the amino acid sequence AA*08 survived better than others (44.9 vs. 22 %), and they were infected with Babesia ssp. less often (13.9 vs 25.7 %). In contrast, individuals carrying allele AA*05 were infected more often (31.7 vs. 15.3 %). Heterozygosity at one of the putative loci was associated with a lower probability of infection with Babesia ssp., but at the other locus, the association was reversed. The unexpected latter result could be at least partly explained by the increased frequency of the susceptible allele AA*05 among heterozygotes. Overall, we demonstrate that infection with Babesia ssp. is a strong predictor of Electronic supplementary material The online version of this article

Limiting junction temperature T j and maintaining its low value is crucial for the lifetime and reliability of semi-conductive light sources. Obtaining the lowest possible temperature of T j is especially important in the case of LED panels, where in a short distance there are many light sources installed, between which there occurs mutual thermal coupling. The article presents results of simulation studies connected with the influence of construction and ambient factors that influence the value of junction temperature of exemplary LED panel sources. The influence of radiator's construction, printed circuit boards, as well as the influence of ambient factors, such as ambient temperature T a and air flow velocity v were subjected to the analysis. Numerical calculations were done in the FloEFD software of the Mentor Graphics company, which is based on computational fluid dynamics (CFD). For construction of the LED thermal panel model the optical efficiency η o and real thermal resistance Rth j-c were determined in a laboratory for the applied light sources.

Semiconductor light sources are currently the fastest growing and most energy efficient group of light sources used in lighting technology. Their lighting parameters, such as luminous flux, correlated color temperature and color rendering index depend on the value of the forward current, as well as the temperature of the junction. LED source manufacturers usually specify, in data sheets, the effect of junction temperature and forward current on the luminous flux for individual light sources. The difficulty, however, is the correct determination of temperature and then lighting parameters, by simulation methods for multi-source lighting systems. Determining the junction temperature which affects lighting parameters is particulary important in the case of LED panels and luminaires, where thermally coupled LED sources shaping the output lighting parameters are in close proximity to each other. Additionally, other factors influencing the temperature distribution of sources, such as the design and geometry of the cooling system, the design of the printed circuit and thermal interface material used, should be considered. The article is a continuation of the publication in this journal where the influence of factors influencing the temperature distribution of the LED panel is presented. The purpose of the research in this article was to confirm the possibility of using CFD (Computational Fluid Dynamics) software, as well as to determine the accuracy of the results obtained in the temperature analysis of the multi-source LED panel, and in determining the output lighting parameters of the LED panel based on it. In this article, based on previously published research, a LED panel model with a cooling system was made, and then the CFD software determined the junction temperature of all light sources. The determined temperature of the LED sources constituted the basis for determining the output lighting parameters of the panel: luminous flux, color temperature and color rendering index. The simulation results were verified by real measurements on the constructed LED panel prototype. The LED panel temperature difference between the simulation results and the real results on the prototype did not exceed 5%. Moreover, the error of lighting parameters between the simulation results obtained and the results on the LED panel prototype in the worst case was 4.36%, which proves the validity and accuracy of simulation studies.

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Industrial facilities such as production and storage halls are a specific environment, which is usually characterized by a large usable area, which is managed in a way that brings together in the given area many functional zones for various purposes. Frequent changes in the management of industrial halls gives a need to change the lighting method. In such a situation, a lighting solution that enables the photometric characteristics of the luminaires to be adapted to variable development of the facility, covering not only the quantitative regulation of the luminous flux, but also the direction of its radiation into the environment, can be a helpful solution. The article presents an innovative concept of a luminaire, which makes it possible to change the light distribution without the need to replace optical elements. Simulation tests were carried out for the developed luminaire in order to check the possibility of obtaining the assumed distribution and shapes of light spots on the working plane. Thanks to the application of this solution in an environment where there is a need for frequent changes in the development of usable space requiring changes in lighting conditions, it is possible to dynamically adjust the characteristics of the installed system to new environmental conditions.

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