Muddying the unexplored post-industrial waters: Biodiversity and conservation potential of freshwater habitats in fly ash sedimentation lagoons

Deposits of fly ash and other coal combustion wastes are common remnants of the energy industry. Despite their environmental risks from heavy metals and trace elements, they have been revealed as refuges for threatened terrestrial biodiversity. Surprisingly, freshwater biodiversity of fly ash sedimentation lagoons remains unknown despite such lack of knowledge strongly limits the efficient restoration of fly ash deposits. We bring the first comprehensive survey of freshwater biodiversity, including nekton, benthos, zooplankton, phytoplankton, and macrophytes, in fly ash lagoons across industrial regions of the Czech Republic. To assess their conservation potential, we compared their biodiversity with abandoned post-mining ponds, the known strongholds of endangered aquatic species in the region with a shortage of natural ponds. Of 28 recorded threatened species, 15 occurred in the studied fly ash lagoons, some of which were less abundant or even absent in the post-mining ponds. These are often species of nutrient-poor, fishless waters with rich vegetation, although some are specialised extremophiles. Species richness and conservation value of most groups in the fly ash lagoons did not significantly differ from the post-mining ponds, except for species richness of benthos, zooplankton, and macrophytes, which were slightly lower in the fly ash lagoons. Although the concentrations of some heavy metals (mainly Se, V, and As) were significantly higher in the fly ash lagoons, they did not significantly affect species richness or conservation value of the local communities. The differences in species composition therefore does not seem to be caused by water chemistry. Altogether, we have shown that fly ash lagoons are refuges for threatened aquatic species, and we thus suggest maintaining water bodies during site restoration after the cessation of fly ash deposition. Based on our analyses of environmental variables, we discuss suitable restoration practices that efficiently combine biodiversity protection and environmental risk reduction.

Benefits of repeated CT scan in patients with neurosurgical-neurological problems in intensive care retrospective analysis

INTRODUCTION

CT examination of the brain is an integral part of neurointensive care. The examination, however, represents a risk for patients and has side effects. Indications for the procedure should therefore be carefully considered. The aim of the study was to analyze the indications for brain CT and the influence of its result on further treatment.

METHOD

A retrospective analysis of CT examinations of the brain performed during 2010 in 263 patients admitted to neurointensive care. The study assessed whether the indication for a CT scan was due to a change in the patient's neurological status or routine, and also whether pharmacological sedation was used. Implications of the CT scan results for the course of treatment were evaluated.

RESULTS

763 CT examinations of brain were performed in the study group. 81% of the patients were under pharmacological sedation at the time of the exam indication, 19% had no sedation and could be clinically evaluated. In both groups, 80% of examinations were indicated on a routine basis. More than half of all CT examination results were evaluated as no change or improvement. Two thirds of them had no impact on the course of further treatment. Results of CT scans indicated due to a change in neurological status led to a change of therapy more often than in routine indications (24.8 vs. 14.2%). The difference was even greater in patients indicated for surgery (19 vs. 8.4%).

CONCLUSION

CT scans of the brain are and will continue to be a fundamental part of neurointensive care but cannot replace clinical examination, which is influenced by pharmacological sedation. Results of brain CT scans have led to a change in the course of therapy more frequently when indicated due to a change in neurological status. Rational indication of sedation can contribute to rational indication for brain imaging. Key words: neurointesive care - sedation - CT of the brain.

[Toxic shock syndrome]

The authors present an up-to-date review of toxic shock syndrome (TSS) - a life-threatening condition where toxins of the Gram-positive bacteria Staphyloccocus aureus and Streptococcus pyogenes play a key role in the pathogenesis. The authors provide insight into the epidemiology and pathogenesis of the disease and point out the relevant patient history data and clinical signs and symptoms that may indicate progression of TSS. Last but not least, the state of the art diagnostic and therapeutic approaches to early and full blown TSS are summarized. Case reports are presented to illustrate two different etiological forms of this relatively rare nosological entity.