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The aim of this study was to investigate the effects of subchronic exposure to atrazine on fish growth and the development of histopathological changes in selected organs (gill, kidney, liver) in Danio rerio. Juvenile growth tests were performed on D. rerio according to OECD method No. 215. For 28 days, fish at an initial age of 30 days were exposed to the environmental atrazine concentration commonly detected in Czech rivers (0.3 μg/L) and a range of sublethal concentrations of atrazine (3.0, 30.0 and 90.0 μg/L). The results showed decreasing growth rates and morphological changes in the liver (dystrophic lesions of hepatocytes) at 90.0 μg/L of atrazine. The environmental concentration of atrazine in Czech rivers did not have any effect on fish growth and development of histopathological changes in D. rerio. The value of NOEC was 30.0 μg/L and the value of LOEC was 90.0 μg/L.

Question We connected tree‐census and dendrochronological research data (74.2 ha) in order to answer the following questions: How do we apply an individual‐based approach, which allows us to abandon the traditional patch model, in the research of disturbance history through spatial scales? What is the disturbance history of the natural forest? How do we understand the influence of the Kyrill storm, which affected the reserve on 18 January 2007? How does the disturbance history in dendrochronological records correspond to real disturbances? Location Žofínský Prales (48 °40′ N, 14 °42′ E, 735–830 m a.s.l., granite, Czech Republic) Methods Repeated tree‐censuses (>20 000 trees) were carried out in 1975, 1997 and 2008. These surveys served as the basis of dendrochronological research, during which 3 020 trees were sampled. A boundary line (BL) approach and geostatistical techniques were used to detect disturbance intensity and its spatial pattern. Results The mean disturbance rate was 11.0% canopy loss per decade (maximum 33.7%) in the core zone. Bordering forests were directly affected by humans after 1800. A maximum of nine disturbance events were recorded per tree, but there were also 3% of non‐suppressed trees without records of disturbance events. The Kyrill storm represented a singular event in the forest history from the point of view of its exceptional spatial pattern (ranges up to 320.0 m), but not from the perspective of disturbance intensity. The relationship between disturbance intensity (y) and the range of spatial autocorrelation (x) can be explained by the equation y = 10.6863 + 0.0783*x (R2 = 0.546, P = 0.009). The spatial variability of releases ≥50% of BL corresponds to real disturbance events, while the insertion of weak releases led to the overestimation of range. The frequency of releases was affected by a decrease in air pollution at the beginning of the 1990s. Conclusions Effects of small‐scale disturbances predominate in forest dynamics. Disturbance intensity was often not directly in accordance with the range of spatial autocorrelation. The ecological role of disturbance is therefore biased if disturbance intensity is used as the sole criterion. The results suggest the importance of historical and geographical contingency in ecosystem development.

Clove oil (active substance eugenol) is an anaesthetic used in aquaculture for stress prevention and prevention of mechanical damage during veterinary procedures. The aim of this study was to determine the acute toxicity of clove oil in two aquarium fish species -zebrafish (Danio rerio) and guppy (Poecilia reticulata), which are considered the most commonly used model organisms in toxicity testing. The semi-static method according to OECD no. 203 (Fish, acute toxicity test) was used for testing the toxicity of clove oil for juvenile fish. A series of 5 acute toxicity tests was performed, with 10 fish of both species used for each concentration and for the control. The results obtained (number of dead individuals at particular test concentrations) were subjected to a probit analysis using the EKO-TOX 5.2 program in order to determine 96hLC50 clove oil values. The significance of the difference between 96hLC50 values in D. rerio and P. reticulata was tested using the Mann-Whitney non-parametric test. The 96hLC50 mean value for clove oil was 18.2 ± 5.52 mg·l -1 in juvenile D. rerio and 21.7 ± 0.8 mg·l -1 in P. reticulata. In spite of variability in clove oil composition, acute toxicity values of clove oil for juvenile stages of both fish species were comparable. The results did not show different sensitivities to clove oil in tested fish species. This is the first similar study in these fish species.

Many invasive procedures, including surgery (ear cropping, tail docking, and debarking in the dog), are performed on dogs for purely cosmetic reasons or convenience. These procedures, also known as "cosmetic surgery", fall into a variety of categories from the questionably unethical to the undoubtedly criminal, because they are mostly carried out solely to alter a dog's physical appearance. Although in several European countries these procedures are banned, except when performed by a veterinarian for medical reasons, veterinarians are often requested to perform them for various reasons. Though controversial, canine cosmetic surgery continues to be performed, reaching epidemic proportions. The authors summarize legislation, individual positions and veterinary attitudes regarding cosmetic surgery in Italy and the Czech Republic. Additionally, they explain the ways in which the law is being used in the two countries to prevent these unnecessary procedures, and how current and future anti-cruelty laws can stop unethical use of cosmetic surgery.