32 research outputs found

    Patterns of year-to-year variation in haemoglobin and glucose concentrations in the blood of nestling Pied Flycatchers Ficedula hypoleuca

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    Physiological tools can be used to identify the sources and consequences of stressors on animals. Understanding the influences of variation in habitat quality and anthropogenic disturbance on organism condition and health may improve future management and conservation. We present results concerning variation in haemoglobin and glucose concentrations in the blood of about 14-day-old nestling Pied FlycatchersFicedula hypoleuca in central Poland over a 4-year period, 2011–2014, in a deciduous forest. The most important findings of the study are: (1) the concentration of haemoglobin and glucose of the nestlings from the same brood tended to be consistently similar, with much variation occurring among broods; (2) repeatability of haemoglobin concentration was higher than repeatability of glucose concentration; (3) mean levels of haemoglobin and glucose varied among years; (4) haemoglobin and glucose concentrations were negatively correlated; and (5) there was a positive relationship between haemoglobin levels and breeding success.All procedures were approved by the Local Ethical Committee and the State Office for Environment Protection. We thank A. Jaksa, D. Man´kowska, M. Janiszewska and J. Białek for their help and consent in conducting research in the areas under their administration. The study was founded by a grant from the Polish Ministry of Science and Higher Education No. N N304 045136 and University of Ło´dz´ (No. 506/829). We are obliged to P. Procter for linguistic consultation. We thank both reviewers for their valuable and constructive comments

    Circulating serum miR-362-3p and miR-6721-5p as potential biomarkers for classification patients with adult-type diffuse glioma

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    According to the fifth edition of the WHO Classification of Tumours of the Central Nervous System (CNS) published in 2021, grade 4 gliomas classification includes IDH-mutant astrocytomas and wild-type IDH glioblastomas. Unfortunately, despite precision oncology development, the prognosis for patients with grade 4 glioma remains poor, indicating an urgent need for better diagnostic and therapeutic strategies. Circulating miRNAs besides being important regulators of cancer development could serve as promising diagnostic biomarkers for patients with grade 4 glioma. Here, we propose a two-miRNA miR-362-3p and miR-6721-5p screening signature for serum for non-invasive classification of identified glioma cases into the highest-grade 4 and lower-grade gliomas. A total of 102 samples were included in this study, comprising 78 grade 4 glioma cases and 24 grade 2–3 glioma subjects. Using the NanoString platform, seven miRNAs were identified as differentially expressed (DE), which was subsequently confirmed via RT-qPCR analysis. Next, numerous combinations of DE miRNAs were employed to develop classification models. The dual panel of miR-362-3p and miR-6721-5p displayed the highest diagnostic value to differentiate grade 4 patients and lower grade cases with an AUC of 0.867. Additionally, this signature also had a high AUC = 0.854 in the verification cohorts by RT-qPCR and an AUC = 0.842 using external data from the GEO public database. The functional annotation analyses of predicted DE miRNA target genes showed their primary involvement in the STAT3 and HIF-1 signalling pathways and the signalling pathway of pluripotency of stem cells and glioblastoma-related pathways. For additional exploration of miRNA expression patterns correlated with glioma, we performed the Weighted Gene-Co Expression Network Analysis (WGCNA). We showed that the modules most associated with glioma grade contained as many as six DE miRNAs. In conclusion, this study presents the first evidence of serum miRNA expression profiling in adult-type diffuse glioma using a classification based on the WHO 2021 guidelines. We expect that the discovered dual miR-362-3p and miR-6721-5p signatures have the potential to be utilised for grading gliomas in clinical applications

    Avian Feathers as Bioindicators of the Exposure to Heavy Metal Contamination of Food

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    The aim of this study was to determine the possibility of using feathers of blue tit nestlings to assess the level of endogenous accumulation of lead. For this purpose we conducted an experiment with lead application to randomly chosen nestlings from eight randomly drawn broods. Five days after the exposure, feathers of lead-treated nestlings had significantly higher lead concentrations than control nestlings. This result suggests that feathers can be used as reliable non-destructive bioindicators to assess the level of heavy metals originating from contaminated food, which is of great significance for comparative studies on ecological consequences of pollution

    Republic of Korea during Park Chung-hee regime (1961-1979)

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    Praca zatytułowana „Republika Korei za Park Chung-hee (1961-1979)” przedstawia sytuację Korei Południowej w czasie rządów Park Chung-hee. Był on generałem wojskowym, który przejął władzę w wyniku zamachu stanu przeprowadzonego w 1961 roku. Utrzymał on władzę do swojej śmierci w 1979 roku. W tym okresie nastąpił znaczny rozwój gospodarki koreańskiej, zawdzięczany głównie decyzjom państwowym. Był to również czas walki opozycji z systemem, który nie respektował praw obywatelskich i wartości demokratycznych.Praca składa się z trzech rozdziałów. Rozdział pierwszy zatytułowany „Zarys historyczny” zawiera krótki opis historii Republiki Korei, biografię Park Chung-hee oraz przedstawia działania Parka, mające na celu utrzymanie władzy. Rozdział drugi „Sytuacja wewnętrzna Republiki Korei w latach 1961-1979” opisuje politykę społeczną danego okresu, działalność obywatelską w odniesieniu do władzy oraz politykę gospodarczą. Rozdział trzeci „Wybrane kierunki polityki zagranicznej Republiki Korei w latach 1961-1979” przedstawia i podsumowuje relacje Republiki Korei z państwami, które miały w danym okresie największe znaczenie tj. z Koreańską Republiką Ludowo-Demokratyczną, Stanami Zjednoczonymi Ameryki, Japonią oraz Związkiem Socjalistycznych Republik Radzieckich.This bachelor thesis, titled 'Republic of Korea during Park Chung-hee regime (1961-1979)' presents the situation of the Republic of Korea during Park Chung-hee regime. Park was a military general that took power as a head of a junta installed in 1961. He stayed in power until his death in 1979. During his regime South Korean economy achieved significant growth, mainly attributed to government’s decisions. It was also a time of a struggle between the opposition and the system which didn’t respect civil rights nor democratic values.The thesis contains three chapters. First, 'Historical outline' contains short description of South Korean history, biography of Park Chung-hee and portrays Park’s choices in order to keep the power. Second chapter 'The internal situation of the Republic of Korea over the period 1961-1979' describes social politics, civil movements and economic policy of said period. Third chapter 'Selected directions of foreign policy of the Republic of Korea over the period 1961-1979' outlines and summarizes relations with most significant countries for the Republic of Korea: Democratic People's Republic of Korea, United States of America, Japan and Union of Soviet Socialist Republics

    Nest Box Bacterial Loads Are Affected by Cavity Use by Secondary Hole Nesters

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    Among the environmental factors that affect bird nesting in nest boxes, the influence of microbial communities is relatively poorly understood. In this study, nest boxes used for breeding by secondary cavity nesters were sampled before the start of the breeding season to assess the bacterial loads of the nest box in relation to their previous year status. Different parts of the wooden nest box offer variable conditions for the development of bacteria. During the breeding season, the nest box entrance hole is wiped out by birds, delivering bacteria to their bodies, but during winter, it is exposed to unfavourable external conditions. The interior of the nest box, in turn, is also wiped by birds, but the conditions during winter are more stable there. Therefore, samples from the entrance hole and the interior of the nest box were taken at two different study sites: an urban parkland and a natural forest. We predicted that both the occupancy of the nest boxes during the previous breeding season by birds and the nesting sites would influence the bacterial load of the nest box. To verify this prediction, two categories of nest boxes were sampled at both study sites: nest boxes occupied by any of the two tit species (Great Tit or Blue Tit) in the previous season for breeding and nest boxes that had remained empty that year. The interior bacterial load of the nest box was higher in the nest boxes occupied in the previous breeding season, but only in the forest area. Furthermore, the bacterial load of both the entrance hole of the nest box and the interior was significantly higher in the forest study area in both occupied and unoccupied nest boxes. Our results show that the bacterial load of the nest box is positively related to the presence of nests in the previous breeding season and can vary between different sites

    Microsatellite Instability Assay as a Potential Approach to Evaluate Genotoxicity: Lead Exposure in a Nestling Passerine Bird at the Stage of Intensive Erythropoiesis

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    Although many avian studies have investigated the toxic effects of lead on important biochemical and physiological processes, organ and system function, and behavior, studies evaluating the specific genotoxic effects of exposure to lead are scarce. Nowadays, rapid technological advances can provide new molecular techniques in this regard. In this study, as a novel approach in bird studies, we used a panel of ten microsatellite loci to investigate the microsatellite instability (MSI) in response to experimental lead intoxication in a common hole-nesting species, the great tit Parus major. For this purpose, an experiment based on an intentional single supplementation of a lead (II) acetate trihydrate compound was conducted, with the use of two different doses, applied to randomly chosen great tit nestlings from randomly selected broods, being at the stage of intensive erythropoiesis. Although this preliminary study did not find any MSI in the seven microsatellite markers retained for the final comparison, it contributes to the examination of this molecular technique in field conditions as being potentially applicable in ecotoxicological bird studies. We believe that certain issues should be considered in finding an explanation for our result. First, the single doses of lead used in this study may have been too weak to induce genetic instability. Second, the panel of microsatellite markers studied may have been unsusceptible to lead genotoxicity in general. Third, the relatively short time interval (5 days) between the experimental procedure (lead exposure) and the sampling of post-exposure material (blood) for genetic analyses could have limited the effect of lead genotoxicity. Further analyzes are needed to verify these findings and to evaluate the scope of application of the MSI analysis in wild bird population studies

    Spatial and temporal variation in heterophil-to-lymphocyte ratios of nestling passerine birds: comparison of blue tits and great tits.

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    Environmental factors affecting trophic conditions act as stressors on nestling altricial birds. Access of parental birds to a sufficient supply of food in a limited period of the nestling stage differ in time and space, depending on nesting habitat, prey density and weather conditions. Heterophil-to-lymphocyte ratio (H/L) is considered as a reliable indicator of prolonged stress reaction in birds. In this study we examine if variation in H/L shows consistent spatio-temporal patterns in nestlings of two parids, blue tit Cyanistes caeruleus and great tit Parus major. We found that blue tit nestlings had on average higher H/L than great tit nestlings, which corresponds with the ecological sensitivity of these species. In both species H/L was higher in a poor parkland habitat than in a high quality forest habitat. In nestling blue tits, higher H/L values occurred in years characterized by more extreme weather conditions and worse caterpillar availability. Such consistent patterns of variation in the H/L ratio of nestling blue tits and great tits suggest that, when age-dependent effects are controlled, the ratio can be used as an indicator of physiological stress that is generated by food-related stressors differing in space and time. In particular, elevated H/L ratios are indicative of human-induced changes in the structure of breeding habitats

    Inter-annual and inter-habitat variation in breeding performance of Blue Tits (Cyanistes caeruleus) in central Poland

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    Studies at various locations in Europe show that nest-box populations of tits in urban areas lay earlier and produce fewer eggs than do birds in rural areas. Long-term data on laying date and clutch size were studied for Blue Tit (Cyanistes caeruleus) populations in two, structurally and floristically contrasting sites (an urban parkland and a rich decidu-ous forest, located only 10 km apart) in central Poland. The peak abundance of caterpillars, the optimal food of breeding tits, was also studied at both breeding areas. We focused on four environmental factors; year, site, insect availability and ambient temperature. Birds initiated breeding earlier in the urban area compared to the forest area and the laying date was highly correlated with air temperature during the period between 15 March and 15 April. At both study areas there was a similar negative temporal trend – birds started breeding earlier with later years. The number of eggs laid per breeding pair tended to be lower in the parkland than in the forest and it is likely that this is due to the habitat-specific pattern of food abundance and patchy environment in the parkland. This study provides new data on the reproductive biology of a model species and also fills up some knowledge gaps concerning inter-habitat and macro-geographic patterns
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