The Police of the Czech Republic (Czech: Policie České republiky) is the national law enforcement agency of the Czech Republic. It was established on 15 July 1991 under the jurisdiction of the Ministry of the Interior. The agency is tasked with protecting citizens, property and public order and as of 2015, there were around 40,500 employees. Czech state police cooperates with municipal police departments, which are present in local municipalities.
Under certain conditions, metal surfaces undergo chemical passivation or corrosion. By selecting a suitable electrolyte, oxidation processes can be used to visualize latent fingerprints. Latent fingerprints were deposited on clean metal substrates (copper, brass, and aluminium), and an electrolytic method was evaluated using Britton-Robinson buffer at pH values of 2, 7, and 12, with and without methylene blue. The visualization efficiency was evaluated using a stereomicroscope as a function of deposition time, and the developed latent fingerprints were further characterized by SEM. The best contrast was achieved on brass and copper at neutral pH of Britton-Robinson buffer without methylene blue, while for aluminium, under acidic conditions. Methylene blue was effective only under certain conditions; otherwise, it caused staining or blurring of ridge details. This simple and low-destructive method shows the potential for latent fingerprint visualization on metals and offers scope for further optimization in forensic applications.
Post-mining lakes in the Czech Republic, especially in North Bohemia, represent distinctive opportunities for ecological transformation of degraded landscapes. Such lakes form in closed open-pit mines, where they create new water and wetland habitats. The ecological development of such systems is strongly affected by water quality, which is often impaired by residual contamination from mining and nutrient imbalances. Investigating the water quality is therefore essential for understanding the ecological potential, implementation of restoration strategies, and for evaluation of environmental risks to ensure further safe human and ecological use. This study explores the water quality of four post-mining lakes in the Czech Republic-Medard, Milada, Most, and Barbora. It focuses on biological indicators (microbial and plankton diversity) and water chemistry. The aim was to assess whether the current properties meet environmental standards, potentially supporting their use beyond recreation, such as for agricultural irrigation, drinking, or other practical purposes. Diverse microbial and plankton taxa were detected, with notable seasonal variations indicating continuing environmental succession. Water chemistry was mostly within acceptable limits; however, sulphates and total dissolved solids concentrations exceeded the threshold at Medard and Milada, and hydrocarbon C10-C40 tolerable concentration was surpassed at Most.
This work presents an electrochemical approach to the visualization of fingerprints on brass cartridges with the aim of characterizing how visualization using polyphenazine dyes affects latent fingerprints. After visualization using cyclic voltammetry and chronoamperometry, the individual layers (substrate/fingerprint/polymer film) and their interfaces were characterized profilometrically, spectroscopically by Fourier transform infrared spectroscopy (FT-IR) and via scanning electron microscopy (SEM). The morphology and surface quality observed by SEM revealed the size of the particles formed from both electrochemically deposited polymer films. Profilometry showed the homogeneity and surface roughness of the deposited layers. It was found that poly(toluidine blue) forms a thinner homogeneous layer with better adhesion to the brass substrate than the poly(neutral red) film. Based on the FT-IR spectra, it can be concluded that the polymer films of the dyes were deposited on the surface of the substrates as a result of the observed changes and band intensities belonging to the mono- and polymer forms of neutral red and toluidine blue, respectively. The electrochemical visualization method proved to be effective, gentle, and relatively fast.
Canadian goldenrod (Solidago canadensis) is among the most-studied invasive plants in Europe. This plant overgrows large areas and has negative impact on other plants due to its rapid growth and allelopathy. With its conspicuous yellow inflorescences rich in pollen and nectar, it is attractive for insects and is known to be one of the most important nectar and pollen sources for various insect groups in their native habitat. We studied bees and wasps, beetles, butterflies, and dipterans visiting flowers of S. canadensis in 18 sites around the largest cities in the Czech Republic. In total, 6,862 individuals of 273 species were recorded, with dipterans being the most abundant in number and bees and wasps the richest in species richness. Most of the species in the dataset were common generalists (e.g. the honey bee), but we also recorded 23 species included in the Red List and three specialists on pollen from Asteraceae. About a quarter of all recorded individuals of studied insect groups were pollen collecting bees. The number of species and individuals per site correlated positively with the proportion of goldenrods and with the proportion of flowering goldenrods. Implications for conservation practices. Flowers of Solidago canadensis are visited by a wide range of insects, including specialists on Asteraceae and red-listed species. The proportion of specialists and species of conservation interest was small and S. canadensis is certainly not important for flower visiting insects. In the current landscape full of fields and forest plantations (which represents something like a green desert for insects and other biota), these plants certainly nonetheless supply pollen and nectar. Because S. canadensis has predominantly negative impact, it would be better to eradicate this plant and reintroduce native plant species into the habitats.
