Pancreatic cancer has the worst prognosis among all cancers. Cancer screening of body fluids may improve the survival time prognosis of patients, who are often diagnosed too late at an incurable ...stage. Several studies report the dysregulation of lipid metabolism in tumor cells, suggesting that changes in the blood lipidome may accompany tumor growth. Here we show that the comprehensive mass spectrometric determination of a wide range of serum lipids reveals statistically significant differences between pancreatic cancer patients and healthy controls, as visualized by multivariate data analysis. Three phases of biomarker discovery research (discovery, qualification, and verification) are applied for 830 samples in total, which shows the dysregulation of some very long chain sphingomyelins, ceramides, and (lyso)phosphatidylcholines. The sensitivity and specificity to diagnose pancreatic cancer are over 90%, which outperforms CA 19-9, especially at an early stage, and is comparable to established diagnostic imaging methods. Furthermore, selected lipid species indicate a potential as prognostic biomarkers.
The SCS-CN method is a globally known procedure used primarily for direct-runoff estimates. It also is integrated in many modelling applications. However, the method was developed in specific ...geographical conditions, often making its universal applicability problematic. This study aims to determine appropriate values of initial abstraction coefficients λ and curve numbers (CNs), based on measured data in five experimental catchments in the Czech Republic, well representing the physiographic conditions in Central Europe, to improve direct-runoff estimates. Captured rainfall-runoff events were split into calibration and validation datasets. The calibration dataset was analysed by applying three approaches: (1) Modifying λ, both discrete and interpolated, using the tabulated CN values; (2) event analysis based on accumulated rainfall depth at the moment runoff starts to form; and (3) model fitting, an iterative procedure, to search for a pair of λ, S (CN, respectively). To assess individual rainfall characteristics’ possible influence, a principal component analysis and cluster analysis were conducted. The results indicate that the CN method in its traditional arrangement is not very applicable in the five experimental catchments and demands corresponding modifications to determine λ and CN (or S, respectively). Both λ and CN should be viewed as flexible, catchment-dependent (regional) parameters, rather than fixed values. The acquired findings show the need for a systematic yet site-specific revision of the traditional CN method, which may help to improve the accuracy of CN-based rainfall-runoff modelling.
The water retention capacity of a territory is mainly defined by the land conditions, type of soil cover and manner of land management. The manifestations of the climate change reflect the need for ...better water capture from precipitation in agricultural catchment areas. The effect of the soil cover on the water retention capacity was studied in two localities with different soil types (chernozem and cambisol). The results have shown significant effects of permanent grass covers on increasing the water retention capacity. The mean retention capacity measured at permanent grass covers was 1.7-fold higher than at arable land. The soil type did not play a significant role. To some extent, the retention capacity is also influenced by the used agro-technology. After stubble-tillage, the water from precipitation was better infiltrated by arable land than by permanent grass cover. However, during a major part of the vegetation period, arable land is at the rest, and the short-term increase of its retention capacity has no impact on the overall outcome.
Land consolidations represent a unique tool for managing problems of the rural space. They help to settle land property rights and meet the current requirements associated with protection and ...formation of a stable, permanently sustainable rural landscape. In the Czech Republic, complex land consolidations have been completed in 1,965 cadastral areas of the total number 13,100, and in 2,134 more they are in the preparation phase (up to 1st September 2015). It means that about 60 % of cadastral areas in CR still await land consolidation. Our study aimed to localize priority localities (cadastral areas and regions) for preferential implementation of land consolidation. We selected three thematic factors to determine the risk of their occurrence in particular localities and, consequently, the need to initiate the land consolidation. Our analysis is based on the assumption that cadastral areas where land consolidations have been completed or are under way have already dealt with the above-mentioned risk factors or will do so soon. Such areas have therefore not been included into our study. The key selected thematic factors relevant for preferential implementation of land consolidation include: the risk of water and wind erosion in arable land, water management, and water retention in the landscape. For each of these three factors we processed a map of preferential localities (based on the degree of risk/suitability) for initiation of land consolidation. At the same time, a simple multi-criteria analysis of the extent of the Czech Republic's erosion (water and wind) has been prepared. The result of this analysis is the ranking of regions according to the degree of risk of erosion. The most vulnerable regions of the Czech Republic's Jihomoravský (South Moravian Region), Středočeský (Central Bohemia) and Pardubice.
A careful analysis of rainfall-runoff events and patterns of sediment and pollution load to water bodies is crucial for the proper management of agricultural land. This study simultaneously employed ...the WaTEM/SEDEM long-term erosion model and the HEC-HMS episodic hydrological and erosion model to describe the runoff and sediment load evoked by extreme rainfall events in a small agricultural catchment in Czechia, using the long-term monitoring discharge and water quality episodic data. WaTEM/SEDEM helped to delineate the runoff and sediment critical source areas, subsequently incorporated into HEC-HMS. The acquired results showed that the spatial distribution of land use is a fundamental factor in the protection of watercourses from diffuse pollution sources and the transport and delivery of sediment profoundly depends on the status of crop cover on arable land near a watercourse. Integrating both models, it was shown that the tabulated Curve Number (CN) values as well as the average C-factor values had to be lowered for the majority of the modelled events to match the monitored data. A noticeable role of catchment runoff response most probably played tile drainage, which appeared to profoundly modify the episodic runoff pattern. This study showed a promising approach for the simulation of different rainfall-runoff responses of small agricultural catchments and could be applied for the delineation of areas where soil conservation measures or protective management is of high priority. The results further revealed the obvious need to revise the CN values for tile-drained catchments.
The agricultural land fund in the Czech Republic is strongly degraded by water erosion. The main reasons for this situation are changes in the landscape caused by large-area agricultural production ...in the second half of the 20th century. In the model locality Starovice – Hustopeče (223.5 ha) (South Moravia Region), we analysed changes in the landscape structure and land use for the period 1825 – 2018. In 1825, the mean size of a land block was 0.4 ha. In 1968, the studied locality consisted of just one land block of a size of 223.5 ha. This period marks the beginning of massive water erosion. In 2003, the locality was proposed for land consolidation. Its goal was to reduce erosion and risk of floods. To date, a number of protective measures have been applied in the locality. The risk of water erosion was assessed for the landscape state in 1968 and 2018 in GIS using the USLE method. The effect of the adopted measures was strongly manifested in reduction of the erosion risk (by 44 %). Transport of sediment out of the locality was assessed for 1968 and 2018 by the WATEM-SEDEM model. The protective measures resulted in a decrease of sediment transport out of the locality by 111 t/year (40% reduction). The economic balance of the soil loss showed a positive impact of the applied protective measures. Based on the mean price of arable land in the Czech Republic and costs of the soil relocation within the locality, the application of protective measures brought an economy of at least € 5,000 per year. This sum does not include losses caused by a potential decrease of agricultural crop yields due to the soil degradation, reduction of ecosystem services, and other factors in the past years. The real benefits of application of the protective measures aimed at reducing erosion and increasing water retention in the landscape are significantly higher.
The paper deals with the analysis of a river’s regime of a small watercourse and the evaluation of its changes after the construction of a small water reservoir. The aim of the work was to analyse 12 ...years of flow rate measurements at two profiles of a small watercourse, between which a small water reservoir was built, in the middle of the period of the measurements. The analysis uses traditional characteristics (average flow rate, discharge volume), as well as modern indices from applied hydrology (Richards-Baker flashiness index, hydrogram pulse analysis), which study the variability of the flow rate in hourly and daily intervals. The evaluation showed that at the average flow rate, the effect of the water reservoir was the smoothening of the peak flow rates and prolonging the duration of the discharge waves. At higher flow rates, the water reservoir causes a delay in the culmination and in terms of discharge balance causes a decreased discharge volume, in particular during the vegetation period.
Since the 19th century, the irrigation industry on the territory of the Czech Republic has undergone considerable technological development and an increase in irrigated areas. Irrigation has become ...an important part of the Czech landscape. Large complex irrigation systems of tens to hundreds of km2 have been built. Towards the end of the 20th century, there was a significant decline due to the change of political regime, abolition of agricultural companies, etc. Irrigation systems and buildings were often destroyed, devastated, left without maintenance. There have also been several changes in the administrative management of the irrigation sector. The consequence was that there was no single database of irrigation systems. At present, a database of these irrigation systems is being compiled by the Research Institute for Soil and Water Conservation using geographical information systems (GIS). In connection with climate change, the threat of drought, and irregular distribution of precipitation during the growing season, and the issue of irrigation are back on trend. In this study the current state of irrigation systems in the Czech Republic was presented. In the Czech Republic, a total of 175115 ha of irrigation area has been recorded so far (of this area, about 41% is currently in functional). Selected historic irrigation structures were documented by unmanned aerial vehicles (UAV).
This study searched for associations between the extent of hydromelioration systems and the land use (in the past and at present), degree of nature conservation, and infiltration of water through ...soil profile in the Protected Landscape Area (PLA) Železné hory. According to the available evidence, 34.6% of arable land and 32.1% of permanent grasslands in this area are drained by the drainage systems. Analysis of the original design documentations of drainage structures indicate, that the extent of drained areas can actually be even higher. The hydromelioration systems were built namely in the second half of the 20th century. The drainage also affected alluvial meadows, wetlands, and ecologically valuable stations. After establishment of PLA Železné hory in 1991, the protected area was divided into four zones according to their significance and protection regime. This study has revealed the presence of areas drained by systematic drainage systems (101 ha of grasslands) even in the zones of highest landscape protection degree (1st and 2nd protection zones). The inadequately executed drainage systems should be eliminated and the character of the land should be brought closer to its natural conditions. On the model part of the PLA we also performed a study of historical changes in the landscape in three time horizons (1839, 1950, 2014) to show differences in land use before building of drainage, at the time of building, and at present.
The aim of this study was to identify the tile drainage systems within the year (from spring to autumn) using the ground penetrating radar (GPR) geophysical method. The measurements were performed in ...the experimental locality Dehtáře in the Bohemo-Moravian Highland (Czech Republic) in the years 2016 and 2017. The profiles located in the drained area were repeatedly measured together with the drainage discharges, soil moisture and groundwater level. The best visibility of tile drains was observed during snowmelt (in March and April) when the drainage discharges usually reach their maximum. In other months, the visibility of the drains was variable, but mostly worse. For a reliable detection of individual drains, the measurements above the drainage must be performed in several profiles. Under the conditions of the Czech Republic, the best results were obtained by a 500 MHz frequency antenna.
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