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81.
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Media, and particularly TV media, have a great impact on the general public. In recent years, spatial patterns of information and the relevance of intangible geographies have become increasingly important. Gatekeeping plays a critical role in the selection of information that is transformed into media. Therefore, gatekeeping, through national media, also co-forms the generation of mental maps. In this paper, correspondence analysis (a statistical method) combined with cloud lines (a new visual analytics technique) is used to analyze how individual major regional events in one of the post-communist countries, the Czech Republic, penetrate into the media on a national scale. Although national news should minimize distortions about regions, this assumption has not been verified by our research. Impressions presented by the media of selected regions that were markedly influenced by one or several events in those regions demonstrate that gatekeepers, especially news reporters, functioned as a filter by selecting only a few specific, and in many cases, unusual events for dissemination.  相似文献   
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The combined effect of ocean acidification and warming is expected to have significant effects on several traits of marine organisms. The gastropod Concholepas concholepas is a rocky shore keystone predator characteristic of the south-eastern Pacific coast of South America and an important natural resource exploited by small-scale artisanal fishermen along the coast of Chile and Peru. In this study, we used small juveniles of C. concholepas collected from the rocky intertidal habitats of southern Chile (39°S) to evaluate under laboratory conditions the potential consequences of projected near-future levels of ocean acidification and warming for important early ontogenetic traits. The individuals were exposed long-term (5.8 months) to contrasting pCO2 (ca. 500 and 1400 μatm) and temperature (15 and 19°C) levels. After this period we compared body growth traits, dislodgement resistance, predator-escape response, self-righting and metabolic rates. With respect to these traits there was no evidence of a synergistic interaction between pCO2 and temperature. Shell growth was negatively affected by high pCO2 levels only at 15°C. High pCO2 levels also had a negative effect on the predator-escape response. Conversely, dislodgement resistance and self-righting were positively affected by high pCO2 levels at both temperatures. High tenacity and fast self-righting would reduce predation risk in nature and might compensate for the negative effects of high pCO2 levels on other important defensive traits such as shell size and escape behaviour. We conclude that climate change might produce in C. concholepas positive and negative effects in physiology and behaviour. In fact, some of the behavioural responses might be a consequence of physiological effects, such as changes in chemosensory capacity (e.g. predator-escape response) or secretion of adhesive mucous (e.g. dislodgement resistance). Moreover, we conclude that positive behavioural responses may assist in the adaptation to negative physiological impacts, and that this may also be the case for other benthic organisms.  相似文献   
84.
For the first time ever, the International Union for Conservation of Nature Red List Index for habitat types was calculated for an entire country, Finland. The RLIs were based on species threat assessments from 2000 and 2010 and included habitat definitions for all 10,131 species of 12 organism groups. The RLIs were bootstrapped to track statistically significant changes. The RLI changes of species grouped by habitats were negative for all habitat types except for forests and rural biotopes which showed a stable trend. Trends of beetles and true bugs were positive in rural and forest habitats. Other 16 observed trends of species group and habitat combinations were negative. Several trends observed were in accordance with studies focusing on particular taxa and habitats, and drivers for their change. This study demonstrates the usefulness of the RLI as a tool for observing habitat change based on species threat assessment data.  相似文献   
85.
The removal of polycyclic aromatic hydrocarbons by membrane bioreactor (MBR) under aerobic conditions had been studied using naphthalene (NAP) and phenanthrene (PHE) as model compounds. Three MBRs with submerged ultra-filtration hollow fiber membranes were operated applying different operational conditions during 6.5 months. Complete NAP and PHE removal was obtained applying loads of 7 gNAP kgTSS?1 day?1 and 0.5 gPHE kgTSS?1 day?1, while the organic loading rate was adjusted to 0.26 kgCOD kgTSS?1 day?1, with the biomass concentration being 6000 mgTSS L?1, the hydraulic retention time (HRT) 8 h and the solids retention time (SRT) 30 days. Load increases, as well as HRT and SRT reductions, affected the NAP and PHE removals. Biodegradation was found to be the major NAP and PHE removal mechanism. There was no NAP accumulation in the biomass. Low PHE quantities remain sorbed in the biomass and the contribution of the sorption in the removal of this compound was estimated to be less than 0.01 %. The volatilization does not contribute to the PHE removal in MBRs, but the contribution of NAP volatilization can reach up to 0.6 % when HRT of 8 h is applied.  相似文献   
86.
This research tested the utility of two classes of skin secretion compounds to the phylogeny of the Bufo crucifer group. Skin secretions from specimens of nine populations of B. crucifer group were obtained and submitted to qualitative analysis. We observed a clear difference in the composition of the skin secretion molecules obtained from the species of Bufo studied. Fifty-nine molecules, 16 indolealkylamines and 43 proteins, were used as characters, and 39 of these were parsimonious informative. The tree topology of the skin secretion combined data showed areas of congruence and conflict when compared to an mtDNA phylogeny of the B. crucifer group. We used the Templeton test to evaluate the heterogeneity between the skin secretion and mtDNA data. Although not recommended, we performed a combined analysis with the two partitions. The skin secretion characters from the species of Bufo studied have phylogenetic signal. These data are indicative, at least as a preliminary study, of the phylogenetic relationships among the B. crucifer group taxa.  相似文献   
87.
Cytokinesis must be initiated only after chromosomes have been segregated in anaphase and must be terminated once cleavage is completed. We show that the fission yeast protein Etd1 plays a central role in both of these processes. Etd1 activates the guanosine triphosphatase (GTPase) Spg1 to trigger signaling through the septum initiation network (SIN) pathway and onset of cytokinesis. Spg1 is activated in late anaphase when spindle elongation brings spindle pole body (SPB)–localized Spg1 into proximity with its activator Etd1 at cell tips, ensuring that cytokinesis is only initiated when the spindle is fully elongated. Spg1 is active at just one of the two SPBs during cytokinesis. When the actomyosin ring finishes constriction, the SIN triggers disappearance of Etd1 from the half of the cell with active Spg1, which then triggers Spg1 inactivation. Asymmetric activation of Spg1 is crucial for timely inactivation of the SIN. Together, these results suggest a mechanism whereby cell asymmetry is used to monitor cytoplasmic partitioning to turn off cytokinesis signaling.  相似文献   
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Ten Swiss albino ICR SPF female mice 110 days old (weight about 30 g) were exposed for 48 hours to a solution of plutonium-238 nitrate (spec. act. 5 MBq/1 m1, pH 2.7) injected in amounts of 0.01 ml into the popliteal area of the right femur, each thus receiving about 500 kBq per 30 g body weight. Of the injected activity, 50% was retained in the right femur, 2% in the left femur and approximately 2-3% in the excrements collected separately from each animal during the whole exposure period. Ultrastructurally, electron micrographs revealed a variety of changes, including hypertrophy and destruction of endosteal cell organelles (primary damage), deformation and hypertrophy of osteocytes (secondary damage) and the irregularities in the osteocyte self-burial process leading to an abnormal formation of bone tissue structure (tertiary damage). Qualitatively, these changes in the irradiated bone ultrastructure were analogous to those occurring with age. This was confirmed by comparing two groups of control mice 110 and 330 days old. Assessed quantitatively, changes due to irradiation were more pronounced than those associated with aging.  相似文献   
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