The flight capacity of Cydia pornonella L. (Lepidoptera: Tortricidae) was measured in the laboratory by using computer-linked flight mills. Codling moths showed a large variation in flight capacity between individuals. We defined arbitrarily a longest single flight (LSF) of more than 5 km as an index for long-flyers. About 16.7% of virgin and 10.0% of mated males and 20.0% of virgin and 7.4% of mated females undertook such flights. Based on the LSF and the total distance flown (TDF),we concluded that males and females have little or no difference in flight capacity and that both the withinand between-habitat flights are similar in number and magnitude for both sexes. In the field, females are therefore potentially able to undertake flights of up to 1 1 km, as reported for males by other authors. This ability was highest at ages of 2-7 days after emergence, i.e. the frrst third of their lifetime, for virgin and mated male moths and for virgin female moths. Mated females showed peak flight capacity between 1 and 3 days after eclosion, which corresponded with the major egg-laying period. Few long flights were undertaken before oviposition. These findings do not agree with the oogenesis flight syndrome described by other authors, and this theory is believed not to apply to C.pomoneflu. Our laboratory results are discussed in relation to field experiments in general and hypotheses are developed about the significance of long-flyers for this species.
One strategy for improving the antitumor selectivity and toxicity profile of antitumor agents is to design drug carrier systems employing suitable carrier proteins. Thus, thiolated human serum transferrin was conjugated with four maleimide derivatives of doxorubicin that differed in the stability of the chemical link between drug and spacer. Of the maleimide derivatives, 3-maleimidobenzoic or 4-maleimidophenylacetic acid was bound to the 3'-amino position of doxorubicin through a benzoyl or phenylacetyl amide bond, and 3-maleimidobenzoic acid hydrazide or 4-maleimidophenylacetic acid hydrazide was bound to the 13-keto position through a benzoyl hydrazone or phenylacetyl hydrazone bond. The acid-sensitive transferrin conjugates prepared with the carboxylic hydrazone doxorubicin derivatives exhibited an inhibitory efficacy in the MDA-MB-468 breast cancer cell line and U937 leukemia cell line comparable to that of the free drug (employing the BrdU (5-bromo-2'-deoxyuridine) incorporation assay and tritiated thymidine incorporation assay, respectively, IC50 approximately 0.1-1 mM), whereas conjugates with the amide derivatives showed no activity. Furthermore, antiproliferative activity of the most active transferrin conjugate (i.e. the conjugate containing a benzoyl hydrazone link) was demonstrated in the LXFL 529 lung carcinoma cell line employing a sulforhodamine B assay. In contrast to in vitro studies in tumor cells, cell culture experiments performed with human endothelial cells (HUVEC) showed that the acid-sensitive transferrin conjugates of doxorubicin were significantly less active than free doxorubicin (IC50 values approximately 10-40 higher by the BrdU incorporation assay), indicating selectivity of the doxorubicin-transferrin conjugates for tumor cells. Fluorescence microscopy studies in the MDA-MB-468 breast cancer cell showed that free doxorubicin accumulates in the cell nucleus, whereas doxorubicin of the transferrin conjugates is found localized primarily in the cytoplasm. The differences in the intracellular distribution between transferrin-doxorubicin conjugates and doxorubicin were confirmed by laser scanning confocal microscopy in LXFL 529 cells after a 24 h incubation that revealed an uptake and mode of action other than intercalation with DNA. The relationship between stability, cellular uptake, and cytotoxicity of the conjugates is discussed.
This article argues that a theory of media selectivity needs a theory of attention, because attention to a media stimulus is the starting point of each process of reception. Attention sequences towards media stimuli – pages of newspapers and online-newspapers – were analyzed using eye-tracking patterns from three different perspectives. First, attention patterns were compared under varying task conditions. Second, different types of media were tested. Third, attention sequences towards different forms of news with different design patterns were compared. Attention was seen as a prerequisite for reception: Its selective functions for these processes are especially important. Reception itself was examined within an action-theoretical framework and therefore described as a form of interaction between recipient and the media. Eye-tracking data were used as indicators of attention. Starting with a hypothesis on the impact of different media such as printed newspapers and online newspapers on the agenda-setting process of their audience, the study examined how the type of media and the form of news influences attention and selectivity. Our findings showed that visual cues such as salient photos or graphics and information hierarchies signalled by design and layout guide attention processes, not as an automatic process driven from the bottom up, but as stimuli for an active, intention-driven selection process. The results indicate that the form of news affects these patterns of interactive attention more than the medium itself.
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