Northern Poland Research Articles

Outcomes of Bridging Therapy in Liver Transplantation for Hepatocellular Carcinoma

Background: Liver transplantation (LT) is a method for treating hepatocellular carcinoma (HCC) with satisfactory outcomes. One of the novel methods for predicting LT outcomes is the Metroticket 2.0 model. The disease in patients initially within the Milan criteria (MC) may progress while on a transplantation waitlist; thus, various transplantation bridging therapy (BT) methods are proposed for patients to stay within the MC and optimize the LT outcome. Methods: We performed a retrospective analysis of patients who underwent LT for HCC at an oncological and transplantation center in northern Poland. Patients who underwent (n = 10) or did not undergo (n = 11) BT were included. The primary endpoints of the study were mortality among the patients, HCC recurrence, and Metroticket 2.0 scores based on LT qualification results and explant pathology outcomes. The median follow-up length was 44.03 months. Results: Patients who underwent BT had significantly lower Metroticket 2.0 scores and greater AFP concentrations at baseline. At LT, there was no significant difference in Metroticket 2.0 scores or AFP concentrations between the groups. Explant Metroticket 2.0 scores were significantly lower in patients who received BT. A complete pathologic response was achieved in 30.0% of patients who underwent BT. The recurrence-free survival rates were 100% and 90.91% in patients who underwent and did not undergo BT, respectively. Overall survival was 80.0% and 81.81% in patients who underwent and did not undergo BT, respectively. Conclusions: BT should be considered only as a means of remaining within the LT criteria. Routine BT does not appear to be justified for LT patients.

Traceology suggests an unexpected use of antler cheekpieces from the Early Iron Age site at Gzin, Poland

Archaeological data confirm the widespread use of horse tack throughout the North European Bronze Age and the succeeding Hallstatt period in an inventory that included metal cheekpieces, phalerae, rein-knobs and other horse-related accessories. Similar usage has been assumed in the region of northern Poland, which has also furnished evidence for the use of horse gear accessories made of antler. This paper reports the results of traceological, isotopic and experimental research on three antler cheekpieces found at the Early Iron Age stronghold of Gzin in northern Poland and relates them further with archaeological and ethnographic patterns of horse exploitation. The results indicate that the artefacts from Gzin have rare comparanda and are isotopically consistent with the δ18Ow range of the site location, which can both be taken as evidence of their local origin. Moreover, traceological and experimental evidence from this study places the function and use of the analysed objects into a new light, undermining their use for horseback riding and suggesting that they were employed as cheekpiece coverings. Combined with the ethnographic record, ceramic iconography and archaeolinguistics, our findings fuel a discussion of deer valorisation during the Lusatian period in Poland, showing that the cheekpieces from Gzin may have served as elements of deer headgear.

Investigating and Analyzing the Influence of a Solar Power Plant’s Life Cycle on the Depletion of Natural Materials and Mineral Resources

The production process requires massive amounts of minerals, fossil fuels, and energy. The efficient use of energy and natural resources appears to be crucial to the state of affairs. It should be noted that the post-consumer management of solar power plant elements results in a certain amount of power and matter, as well as harmful effects on the natural world. The major goal of this study was to examine the environmental effect of the solar power plant throughout its life cycle, taking into consideration the depletion of natural materials and mineral resources, using the ReCiPe 2016 model. A life cycle study was performed on an actual 2 MW solar power facility located in northern Poland. This study was conducted using the ReCiPe 2016 model and the Life Cycle Assessment (LCA) methodology. The analyzed renewable energy system’s impact was assessed utilizing 22 impact categories, focusing mostly on the depletion of natural resources. A Life Cycle Assessment was conducted for two post-consumer development scenarios (landfill and recycling). This research focuses on the full solar power plant, not just the photovoltaic panels. Recycling, as a kind of post-consumer development, can provide major environmental benefits and minimize negative environmental consequences throughout the solar power plant’s life cycle. The exceedingly harmful effects can be evident in losses related to water and the aquatic environment. The obtained study findings enabled the development of sustainable-friendly recommendations towards the continuous advancement of the life cycle of solar power plants, thereby reducing the use of rare earth minerals.

Macrolithic retouched blades from Kałdus and Stare Marzy: foreign technology and new ideology in the lithic traditions of the TRB communities in the Lower Vistula region

At the turn of the 20th and 21st century, over a dozen macrolithic retouched blades or their fragments were obtained from archaeological sites at Kałdus and Stare Marzy, located in the Lower Vistula region in northern Poland. The context of deposition links the blades to the settlements of the younger Funnel Beaker culture (3650/3500–3300/3100 BC). This article presents and discusses the results of morphological, technological, and raw material investigations of the macrolithic retouched blades or their fragments from Kałdus and Stare Marzy and relates them to the patterns of use and cultural significance of the macrolithic industry in the local TRB communities. The obtained results show that the retouched blades were made of high-quality flint materials sourced from the Polish and Ukrainian Uplands, namely Świeciechów, Volhynian and Jurassic flints. The results, furthermore, indicate that production technology of macrolithic retouched blades is very specific and, what is more important, it is not rooted in the lithic traditions of the region. Archaeological evidence from this study suggests exceptional patterns of use of macrolithic retouched blades in the Lower Vistula region and their perception by local TRB people, which can be traced to the Eneolithic milieu located southeast of the Polish Lowlands.

Mesolithic Ulna “daggers” from Dąbki Site 9 – on the track of their function

So-called “bone daggers” made from ulna bones of Cervidae are commonly found at Late Mesolithic hunter-gatherer sites of the western circum-Baltic area. The main objective of this paper is to showcase the results of the technological and functional analysis conducted on three tools found at the Dąbki 9 site in northern Poland. During the traceological analysis, technological traces facilitated the reconstruction of the chaîne opératoire of the tools’ production process. The use-wear also points to the probable function of the artefacts. The results presented in this work are discussed in the context of other artefacts of a similar type known from various prehistoric contexts.

Prevalence and genotyping of Toxoplasma gondii in questing Ixodes ricinus ticks from forest areas of Northern Poland.

Toxoplasma gondii occurs in a wide range of intermediate hosts, whose blood may be a meal for different tick species. A few studies have examined the role of ticks in the life cycle of T. gondii. This one includes the largest number and all stages of Ixodes ricinus collected from the widest area, covering seven recreational localities within a forest biotope in Northern Poland. This study aimed to determine the prevalence of T. gondii DNA in 2144 collected questing ticks to establish whether they may be involved in T. gondii life cycle. The additional goal was to genotype the detected T. gondii, as knowledge about its genotypes occurring in European ticks is insufficient. A further purpose was to detect coinfection with T. gondii and Borreliaceae in the collected ticks, as all of them have previously been tested for the presence of bacteria DNA. Nested PCR and sequencing of the obtained B1 gene fragment were conducted. T. gondii DNA was detected in 0.9% of all ticks (1.1% of nymphs and 0.7% of larvae). The presence of T. gondii in unfed larvae and nymphs may indicate the possibility of its vertical transmission. The prevalence of T. gondii DNA in ticks collected from individual sites was focal (0-4.3%) and seems to depend on local climatic conditions. Among all examined ticks, 0.3% were coinfected with T. gondii and Borreliella spp., vs. 0.6% of specimens with a single T. gondii infection. The obtained B1 sequences showed the greatest similarity (99.71-100%) to the sequence representing type III.

The Prevalence of Demodex spp. Infestation in Dermatological Patients in Northern Poland.

The presence of Demodex spp. mites on the skin is a common phenomenon in the human population. In most people, it is an asymptomatic infestation, but in some patients, it can contribute to the occurrence of diseases such as demodicosis, rosacea, or blepharitis, as well as non-specific symptoms. In this study, the results of tests assessing the presence of Demodex spp. by direct microscopic examination (DME) in 2508 patients from northern Poland with the suspicion of demodicosis were retrospectively analyzed. A total of 3684 tests were performed. Among them, only 1585 (43.02%) revealed the presence of Demodex spp., while 2099 (56.98%) were negative. It was shown that in the analyzed population of patients with clinical suspicion of demodicosis, the degree of confirmation of the presence of Demodex spp. positively correlated with the patient's age (p = 0.001) and the mite was mainly found on the edges of eyelids and on the facial skin. Additionally, in men, the presence of Demodex was more often confirmed than in women (p = 0.004). In conclusion, the proper diagnosis of demodicosis still constitutes an important clinical problem due to the non-specificity of symptoms and the low confirmation of clinical suspicions of infestation by DME, especially in lower age groups.

Imprint of a dead-ice environment on lidar imagery—Spatial patterns at the last Scandinavian Ice Sheet margin (N Poland)

There is a unique glacial landscape system in the southern Żarnowiec Moraine Plateau of northern Poland. Here the terrain is characterized by a very high concentration of ridges that are often adjacent to pits, which together constitutes a special type of hummocky topography. The morphological diversity of the study-area ridges and pits was determined from high-resolution lidar imagery that was qualitatively and quantitatively processed, then analysed. Fourteen test fields of spatial dimensions 0.5 km × 0.5 km were selected within the moraine plateau for detailed studies. The results show that the ridges and pits constitute a very dense network of approximately circular, diverse-oriented forms of various sizes, most of which are linked to each other in a step-wise fashion. The pits are surrounded by ridges of various heights and widths that separate one pit from another. A characteristic feature of the studied pits is the orientation of their long axis. Form-based morphological analysis revealed that their genesis was associated with a glacial rather than a periglacial environment. It is believed that ridge orientation reflects a spatial pattern related to ice crevasses. A moraine plateau constituted a terrain obstacle that acted as a counterslope to the advancing ice sheet. The studied landforms and landscape resulted from the ice sheet's breaking up into dead-ice blocks of various sizes. The very dense system of perpendicular, parallel, and diagonal crevasses was related to ice sheet advance from a northerly direction, resulting in a flow around the obstacle and differences in ice-mass speed.

Do organizations based in Poland need identity leadership? Polish adaptation of the short and full form of identity leadership inventory

PurposeThe study aimed to test the validity and reliability of the Polish version of the identity leadership inventory (ILI) proposed by Steffens, Haslam, Reicher et al. (2014) and to confirm the relationship between identity leadership and various job-related outcomes (i.e., trust in leaders, job satisfaction, work engagement and turnover intentions) among employees from Poland-based organizations. Identity leadership appears to be a universal construct (van Dick, Ciampa, & Liang, 2018) but no one has studied it in Poland so far.Design/methodology/approachThe sample consisted of 1078 employees collected in two independent subsamples from different organizations located in Northern and Central Poland. We evaluated the ILI’s factorial structure using confirmatory factor analysis.FindingsThe results confirm that the 15-item Polish version of the ILI has a four-dimensional structure with factors representing prototypicality, advancement, entrepreneurship and impresarioship. It showed satisfactory reliability. The identity leadership inventory-short form (four items) also showed a good fit with the data. As expected, the relationships between identity leadership and important work-related outcomes (general level of job satisfaction, work engagement, trust toward the leader and turnover intentions) were also significant.Originality/valueDespite the cultural specifics of Polish organizations, the research results were generally very similar to those in other countries, confirming the universality of the ILI as shown in the Global Identity Leadership Development project (GILD, see van Dick, Ciampa, & Liang, 2018; van Dick et al., 2021).

Analysis of Erythrocyte Parameters in Multiple and Long-Term Blood Donors from Northern Pomerania (Poland)

Background/Aims: Assessment of the levels of vital blood parameters in donors is essential to evaluate their health status, ensure their suitability for donation, preserve the integrity of the circulatory system, and facilitate comprehensive health monitoring. The aim of our study was to analyse the levels of haemoglobin, haematocrit, erythrocyte count, MCV, MCH, and MCHC in 12 groups of first-time donors and experienced donors of both sexes at the John Paul II Regional Blood Donation and Treatment Centre in Słupsk, northern Poland. The donors were divided into three age groups (18-30 years, 31-45 years, and 46-65 years). Methods: Using MANOVA multivariate significance tests, we examined the main effects of donor-related factors (age, sex, donor stage) on morphological blood parameters to evaluate different haematological parameters, such as Hb, Ht, RBC, MCV, MCH, and MCHC, and identified statistically significant relationships between all variables. Results: The multivariate analysis of these three main factors showed that the variation in haemoglobin (Hb) levels accounted for 46% of the explained dependence in this statistical model. In particular, approximately half of the variability in the multivariate statistical analysis was attributed to the role of Hb and haematocrit (Ht). In addition, the β-coefficient values for Hb and Ht were statistically higher in relation to donor sex and donor type (single versus repeat). These β-coefficient values from our data represent the strength and direction of the relationship between the haematological parameters (Hb and Ht) and the specific donor characteristics. A higher β-coefficient indicates a stronger influence of donor sex and donor type on these parameters, suggesting that these factors contribute significantly to the variation in the Hb and Ht levels. Based on our results, the comprehensive analysis of the entire statistical model of metabolic biomarkers revealed the following hierarchy: Hb > Ht > MCHC > MCV > RBC > MCH. The results obtained showed strong statistical relationships, as indicated by the high values of the key statistical indicators in our analysis. The coefficient of determination (R²) showed that the model explained a significant proportion of the variance in the data, while the F-test statistic confirmed the significance of the predictors. Conclusion: These strong statistical dependencies provided a clear justification for selecting this model over others, as it effectively represented the underlying relationships within the data. These statistics help to assess how well the model matches the actual data, thereby helping to reduce the risks associated with blood donation, optimise donor safety, and maintain the quality and efficiency of blood transfusion services.

Lobelia Lakes' Vegetation and Its Photosynthesis Pathways Concerning Water Parameters and the Stable Carbon Isotopic Composition of Plants' Organic Matter.

Most of the aquatic vegetation produces organic substances via the C3 photosynthetic pathway (mosses, isoetids-Lobelia dortmanna L., Luronium natans (L.) Raf., and vascular plants) or Crassulacean acid metabolism (CAM, e.g., Littorella uniflora (L.) Asch. and Isoëtes lacustris L.) or by their ability to use HCO3- via carbon concentration mechanisms (CCMs-some elodeids and charophytes). Differentiating these predominant photosynthetic pathways in aquatic vegetation based on their organic matter (OM) carbon stable isotopes (δ13CORG) is a complex task, in contrast to terrestrial plants. This study investigates the OM deposition, characterized by δ13CORG values in 10 macrophyte species with different photosynthetic pathways (C3, CAM, and CCM) collected from 14 softwater Lobelia lakes in northern Poland. The higher δ13CORG values distinguish the CCM group, indicating their use of 13C-enriched HCO3¯ in photosynthesis. CAM species show slightly higher δ13CORG values than C3, particularly in lower pH lakes. Principal component analysis of isotopic and environmental data did not yield clear distinctions by the groups, but still, they significantly differ in light of analyzed parameters and isotopic signals (PRMANOVA = 5.08, p < 0.01; K-W H = 27.01, p < 0.001). The first two PCA dimensions showed that the water pH and Ca2+ concentration positively influenced δ13C values. The influence of light conditions on δ13CORG values revealed by third PCA components seems to also be important. In summary, northern Polish Lobelia lakes serve as a key differentiation point between vegetation employing CCMs and those relying on C3/CAM photosynthesis without HCO3- utilization, providing insights into transitions in plant communities within these ecosystems.

Comparison of the Energy Efficiency of Fixed and Tracking Home Photovoltaic Systems in Northern Poland

The relevance of the article’s results lies in presenting the actual energy yields of PV panels of various generations and types of installations. The aim of the article is to provide answers about the effective operation of three different photovoltaic systems: a stationary off-grid system operated for several years, a stationary on-grid system, and a system mounted on trackers. A stationary on-grid system was used as the reference system, taking its area and energy yield as the reference point. The assessment was made on the basis of energy and cost efficiency analysis using the comparative method. The obtained results were compared to the results of other PV systems whose parameters were obtained from literature analysis. The analysis showed significant differences in adapting them to different sunlight conditions. The results confirmed the validity of using fixed PV panels (Installation II) in the short term and the advantage of the PV panel tracking system (Installation III) in the long term. The results also confirm that Installation I, despite its eight years of operation time, shows a relatively small decrease in efficiency, which confirms the validity of the long-term operation of the PV installation.

Lake sediments as microplastic sink: The case of three lakes from Northern and Central Poland

Lake sediments as microplastic sink: The case of three lakes from Northern and Central Poland

Thermal modernization of historic church with valuable historic facades

The article describes a case study of a collegiate basilica located in northern Poland and listed in the register of monuments of the Kuyavian-Pomeranian Voivodeship under the identification number 601148. This building dates back to the 14th century and has been rebuilt many times in its history, serving both a sacred and penitentiary function. Currently, the facility is used only for religious purposes. Its owner and user set himself the goal of maintaining the temperature inside at a level of approximately +16C all year round, which required insulation of the external partitions, but this was only possible from the inside due to the historic nature of the façade, which is protected by law. As part of the article, a thermal-humidity analysis of vertical envelopes was carried out regarding the possibility of moisture accumulating in them after thermal modernization and its impact on their technical condition over time. The above-mentioned analysis was carried out with the support of the WUFI 2D program to assess the possibility and amount of moisture accumulation inside the envelopes and on their internal surface, as well as the Physibel Trisco program regarding temperature distribution in the cold season.

Factors controlling methylmercury concentration in soils of Northern Poland

Soil acts as storage for many toxic substances, including mercury and its compounds. However, in addition to its storage function, soil can also be a source of many substances to the aquatic environment. Methylmercury (MeHg) is one of the most toxic form of mercury (Hg) present in the environment. Some studies consider Poland to be one of the major emitters of Hg into both the atmosphere and the Baltic Sea. The purpose of the study was to identify factors affecting the formation and retention of MeHg in the soil as well as it remobilization to the river. Fifteen soil core samples with a length of 200 cm were collected during the fall/winter of 2021–2022. The factors responsible for the inflow and formation of MeHg were precipitation, distance from the riverbank, soil moisture and age of organic matter. MeHg can be transported to topsoil with precipitation. An increase in MeHg concentration was also observed in moist soils located in the vicinity of riverbank. MeHg concentration was lower in soils with degraded organic matter than with fresh organic matter.

Present-day stress stratification in the lower Palaeozoic shale sequence of the Baltic Basin, northern Poland, inferred from borehole data

We performed an analysis of present-day stress profiles for four wells penetrating the Lower Palaeozoic shale sequence of the Baltic Basin (northern Poland). Breakouts, hydraulic fracturing and leak-off tests were used to calibrate stress models based on anisotropic elastic shale properties. Initial stress models, balancing the lengths of the modelled and observed breakouts, indicated a degradation of the mechanical properties reconstructed from the density and dipole acoustic tool logs. Taking this adverse effect into account, final stress models were calculated which showed a stratification of the stress regime consistent with the lithostratigraphic shale units. A clear dominance of the horizontal stress-generating gravity factor over the horizontal tectonic strain was demonstrated. The obtained values of tectonic strain in the shale sequence compared to the previously determined strain in the crystalline basement of the same study area suggest a significant role of viscoelastic relaxation of the shale sequence.

Evaluation of the Effectiveness of Sex Determination in the Great Cormorant (Phalacrocorax carbo) Based on External Measurements.

The possibility of sex identification of birds has substantial importance for studies on different aspects of bird ecology and behaviour. Using discriminant functions is becoming increasingly popular in studies of bird species that are monomorphic in plumage characteristics because they are cheap, hardly invasive and may be applied to data collected in the past. In this paper, we provide a discriminant function to sex great cormorants using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, data on juveniles and adults within a sex was combined. Discriminant equations with the most commonly used linear measurements, wing length and bill length, were provided. If identifying birds with discriminant function values D2 < -1.256 as females and those with D2 > 0.916 as males, 99% of birds will be correctly sexed. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The cross-application of discriminant functions developed for other populations of the great cormorant produces a 5.4% and 7.5% misclassification rate for birds from northern Poland using discriminant equations developed for populations in Greece and the Netherlands, respectively.

Zooplankton functional diversity as a bioindicator of freshwater ecosystem health across land use gradient

Zooplankton are critical indicators of pressures impacting freshwater ecosystems. We analyzed the response of zooplankton communities across different sub-catchment types—headwaters, natural, urban, urban-agricultural, and agricultural—within the Łyna river–lake system in Northern Poland. Using taxonomic groups and functional traits (body size, feeding strategies), we applied Partial Least Squares Regression (PLS-R) to elucidate the relationships between environmental conditions, land use, and zooplankton metacommunity structure. Two-Way Cluster Analysis (TWCA) identified local subsets with characteristic patterns, while Indicator Species Analysis (ISA) determined area-specific taxa. The natural river zone exhibited significant habitat heterogeneity and feeding niches, whereas urban areas created functional homogenization of zooplankton, dominated by small, broad-diet microphages. Agricultural areas promoted diversity among large filter feeders (Crustacea), active suctors (Rotifera), and amoebae (Protozoa). However, intensified agricultural activities, substantially diminished the zooplankton population, biomass, taxonomic richness, and overall ecosystem functionality. The impact of land cover change is more pronounced at small-scale sub-catchments than at the catchment level as a whole. Therefore, assessing these impacts requires detailed spatial and temporal analysis at the sub-catchment level to identify the most affected areas. This study introduces a new sub-catchment-based perspective on ecosystem health assessment and underscores the zooplankton's role as robust indicators of ecological change.

Lake level fluctuations and varve preservation – The sediment record from Lake Suminko (Poland) reflects European paleoclimatic changes

We present a reconstruction of Holocene lake-level fluctuations at Lake Suminko, a eutrophic hardwater lake in northern Poland. The lake contains annually laminated (varved) sediments, forming a unique archive of past hydroclimatic variability. Employing a combination of sedimentological and geochemical methods, we demonstrate that sediment core sections with well-preserved varves and lower Ca/Fe ratios correspond to periods of higher water levels associated with colder and wetter climatic conditions. We identify twelve periods of lake level high stands, consistent with other lake sediment records from western Poland and Europe, as well as with North Atlantic IRD events. Pollen data and geochemical proxies confirm negligible human impact on the lake during most of the Holocene, except for the last 500 years when accelerated soil erosion related to landscape opening and agricultural activities occurred. Therefore, we conclude that Holocene lake-level fluctuations at Lake Suminko are primarily controlled by climatic conditions regulating water availability and groundwater supplies to the lake. Our study also highlights the potential of varve preservation as a useful indicator of lake-level changes.

Are parks as favourable habitats for wild bees as wastelands in watercourse valleys of a large city?

Because of the growing population density and rate of urban development, the question of biodiversity conservation in cities and towns is increasingly important. In general, urban environments provide attractive habitats for a diversity of wild bees, but different types of urban habitats can have different effects on these pollinating insects. In this study, we compared the attractiveness of two different urban habitat types – parks (10 sites) and wastelands (10 sites) located in river and canal valleys in Bydgoszcz (northern Poland) – with respect to abundance, species richness, species composition, and functional trait composition of wild bees. We hypothesized that urban wastelands are more attractive to wild bees than urban parks are. Urban wastelands were characterized by higher abundance and species richness of wild bees compared to urban parks. When habitat type was the only predictor, nonlinearity of wild bee abundance and species richness was significant exclusively for wastelands. Overall, both wild bee abundance and species richness depended on the percentage of total bee food plant coverage, regardless of habitat type. Wild bee community composition also responded significantly to the percentage of total bee food plant coverage. Local and landscape features of the green spaces affected the functional traits of the wild bees recorded there. These findings reveal that formal green spaces, such as managed parks, are not sufficient to conserve wild bee resources in urban environments in river and canal valleys. In contrast, high-quality informal urban green spaces, such as urban wastelands, can promote abundant and rich wild bee communities. Thus it is crucial to strive for appreciation and protection of this persistently overlooked category of urban green spaces.