Large, ball rolling dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are competitively dominant and can strongly influence community succession in dung pads. Ball production by Scarabaeus sacer Linnaeus was recorded in the Kizilirmak Delta on the Black Sea coast of Turkey by using artificial dung pads from 125 g to 2,000 g. Utilisation of pads across the 16-fold range of pad sizes demonstrated behavioural variation that may reduce intraspecies competition. Ball production was highly concentrated, with 66 balls (61%) produced from 8 pads of the 3 largest pad sizes, which may be related to chemical attraction between males and females. Ball size increased with increasing pad size (P < 0.05) but the number of balls produced per 100 g of dung decreased with increasing pad size (P < 0.01). Pad size for maximum ball production and ball size were 1,371 g and 1,260 g, respectively. The highest and lowest percentage of dung used for ball production was 43% of 125 g pads and 13% of 2,000 g pads, respectively. Ball production and time of day were significantly related (P < 0.01); S. sacer was almost exclusively nocturnal, with 59% of all balls produced between 21.00 and 22.00. This optimum period for ball production early in the night may be a compromise between reduced risk of predation and the increased energy costs of ball production as the temperature falls., Gregory T. Sullivan, Sebahat K. Ozman-Sullivan, Jean-Pierre Lumaret, Myron P. Zalucki, Greg Baxter., and Obsahuje bibliografii
RNA interference (RNAi) technology uses dsRNAs to silence specific targeted genes by downregulating their expression. It has become a potent tool for functional and regulatory studies of insect genes and has potential to be applied for insect control. Though it has been challenging to generate effective RNAi in lepidopteran insects, in the current study this technology was applied to develop specific RNAi-based molecular tools that could be used to negatively impact the invasive lepidopteran forest pest, gypsy moth (GM). GM midgut-specific genes were selected for dsRNA design from larval transcriptome profiles. Two methods were used to produce specific dsRNAs, bacterial expression and in vitro synthesis, which were then fed per os to GM larvae. Depletion of uncharacterized gene targets known as locus 365 and locus 28365, or their stacked combination, depleted target transcripts in a sequence specific manner and resulted in 60% reduction in body mass. Treated GM females that were able to moult to the adult stage displayed an approximately two-fold reduction in egg masses. These have potential to be developed as molecular biopesticides for GM., Saikat Kumar B. Ghosh, Dawn E. Gundersen-Rindal., and Obsahuje bibliografii
The expansion of urban areas is one of the most significant anthropogenic impacts on the natural landscape. Due to their sensitivity to stressors in both aquatic and terrestrial habitats, dragonflies and damselflies (the Odonata) may provide insights into the effects of urbanisation on biodiversity. However, while knowledge about the impacts of urbanisation on odonates is growing, there has not been a comprehensive review of this body of literature until now. This is the first systematic literature review conducted to evaluate both the quantity and topics of research conducted on odonates in urban ecosystems. From this research, 79 peer-reviewed papers were identified, the vast majority (89.87%) of which related to studies of changing patterns of biodiversity in urban odonate communities. From the papers regarding biodiversity changes, 31 were performed in an urban-rural gradient and 21 of these reported lower diversity towards built up city cores. Twelve of the cases of biodiversity loss were directly related to the concentrations of pollutants in the water. Other studies found higher concentrations of pollutants in odonates from built-up catchments and suggested that odonates such as Aeshna juncea and Platycnemis pennipes may be candidate indicators for particular contaminants. We conclude by identifying current research needs, which include the need for more studies regarding behavioural ecology and life-history traits in response to urbanisation, and a need to investigate the mechanisms behind diversity trends beyond pollution., Giovanna Villalobos-Jiménez, Alison M. Dunn, Christopher Hassall., and Obsahuje bibliografii
Apple rootstock seedling M.9-T337 was selected to explore the effect of drought stress. The findings indicated that the relative water content of both the leaf and soil gradually decreased with an increase in drought stress. The water-use efficiency of the leaves increased gradually but decreased sharply after 20 d of drought. Changes in the gas-exchange parameters and chlorophyll fluorescence parameters reflected the gradual decrease in the photosynthetic capacity of the plants with drought stress duration. Infrared thermal imaging showed significant temperature differences between the drought-stressed and control plants after 15 d of drought treatment. When irreversible damage occurred under drought stress, the crop water-stress index and relative water content of the leaf and soil were 0.7, 60.5, and 17.8%, respectively. Based on the results, we formulated a drought stress-grade standard. Further, we established that the best time for irrigation is when drought stress reaches grade 3., D. T. Gao, C. Y. Shi, Q. L. Li, Z. F. Wei, L. Liu, J. R. Feng., and Obsahuje bibliografické odkazy
Our previous studies have shown that the combined administration of drugs elevating extracellular adenosine, i.e. dipyridamole (DP) and adenosine monophosphate (AMP), enhances murine hematopoiesis and potentiates the action of granulocyte colony-stimulating factor (G-CSF). In this study, colony-stimulating activity (CSA) of blood serum of mice treated with DP+AMP, G-CSF or all these drugs in combination, i.e. the ability of the sera to stimulate the growth of GM-CFC colonies, was assayed in vitro. Furthermore, the concentration of GM-CSF and IL-6 in the sera was determined. Administration of DP+AMP was found to enhance significantly serum CSA at all time intervals of serum sampling including 24 h after the last injection of the tested drugs. Additive effects of DP+AMP and G-CSF on serum CSA were noted at early intervals after administration of the drugs. Furthermore, IL-6 levels were significantly elevated in the sera of mice which were administered DP+AMP either alone or in combination with G-CSF. Our results show that the effects of DP+AMP are indirect, mediated through the induction of some cytokine(s) and/or growth factor(s) and that extracellular adenosine can act in cooperation with G-CSF. These findings contribute to the further elucidation of the role of adenosine in hematopoiesis., L. Weiterová, M. Hofer, M. Pospíšil, V. Znojil, D. Štreitová., and Obsahuje bibliografii a bibliografické odkazy
This article provides brief information on the history and prominent botanists exploring the surroundings of Prague. it is dedicated to V. Skalický, who intensively studied Prague flora in the second half of the 20th century. Two new sites of C. rivulare and C. heterophyllum in Prague are described. While the occurrence of C. rivulare can be found in numerous and vital populations in the Šárecký potok valley. and Jiří Hadinec.
Twenty years ago, Przewalski’s horse (last spotted in the wild in 1969) returned to Mongolia and China. In the mid-1980’s, number of horses in zoological gardens reached 500 and ideas of their reintroduction started to take shape. After a failure of the first plan, private foundations took up the initiative, helped to build acclimatization stations and arranged the air trans - port. Not only the acclimatization but also a behavioural adaptation of the horses proved to be crucial. Despite the definite success, the wild populations remain small, they are exposed to winters with extreme amounts of snow, and will face a risk of inbreeding in the future. and Evžen Kůs.