Egg Discrimination in an Open Nesting Passerine Under Dim Light Conditions

Many hosts of avian brood parasites such as the common cuckoo (Cuculus canorus) show refined egg discrimination behaviour. Egg recognition in most open‐nesting hosts seems to be based entirely on differences in colour. However, hole‐ and dome‐nesting hosts may rely largely on luminance contrasts. Here, we studied egg rejection behaviour in nightingales (Luscinia megarhynchos), an open‐nesting species that nests in deeply shadowed positions and lays very specific dark olive‐green eggs. Although being theoretically suitable as hosts of the cuckoo, nightingales are very rarely parasitized and no cuckoo egg morph mimicking nightingale eggs is known. Thus, we predicted high rejection rate of foreign eggs, but because of the dim nesting environments, luminance contrasts would be an important cue in egg rejection decisions, similar to cavity‐ or dome‐nesting species. We experimentally parasitized nightingale nests with two groups of model egg types: ‘bright eggs’ and ‘dark eggs’. Within each group, one of the egg types was an effective match while the other type was a poor colour match (whitish vs. pale blue and olive‐green vs. black).We used a discrimination visual model to quantify host‐model egg similarity and compared egg rejection predicted by the model with the observed rejection pattern. Consistent with a scenario of largely luminance‐based egg recognition, blue and white eggs, which had larger achromatic mismatching, were rejected at a higher relative rate than the better achromatic matching black and green eggs. Nightingales showed strong aggression to a cuckoo dummy, suggesting that they were involved in coevolutionary interactions with the cuckoo in the past. However, because of the highly distinct appearance of nightingale eggs relative to the other sympatrically breeding passerines, and the largely luminance‐based egg recognition, this arms race was likely terminated at an early stage.     

DRUGSURV: a resource for repositioning of approved and experimental drugs in oncology based on patient survival information

The use of existing drugs for new therapeutic applications, commonly referred to as drug repositioning, is a way for fast and cost-efficient drug discovery. Drug repositioning in oncology is commonly initiated by in vitro experimental evidence that a drug exhibits anticancer cytotoxicity. Any independent verification that the observed effects in vitro may be valid in a clinical setting, and that the drug could potentially affect patient survival in vivo is of paramount importance. Despite considerable recent efforts in computational drug repositioning, none of the studies have considered patient survival information in modelling the potential of existing/new drugs in the management of cancer. Therefore, we have developed DRUGSURV; this is the first computational tool to estimate the potential effects of a drug using patient survival information derived from clinical cancer expression data sets. DRUGSURV provides statistical evidence that a drug can affect survival outcome in particular clinical conditions to justify further investigation of the drug anticancer potential and to guide clinical trial design. DRUGSURV covers both approved drugs (∼1700) as well as experimental drugs (∼5000) and is freely available at http://www.bioprofiling.de/drugsurv.     

Investigation of low-frequency waves in plasma-filled microwave oscillators

The excitation of microwave oscillations by an electron beam in a hybrid plasma waveguide—a slow-wave structure (a sequence of inductively coupled resonators) with a plasma-filled transport channel—is studied both experimentally and theoretically. It is shown that the governing role in the generation of microwaves and their transmission to a feeder line is played by the spatial and temporal plasma-density variations associated with low-frequency ion plasma oscillations. The microwave pressure gives rise to low-frequency plasma oscillations with a rise time shorter than their period. This nonlinear mechanism for the excitation of low-frequency oscillations has a threshold in terms of the microwave power. The unsteady character of the spatial distribution of the plasma density results in intermittent microwave generation and shortens the duration of microwave pulses.     

Influence of individual psychological features on the EEG spatial organization in nonverbal divergent thinking

Effects of different psychophysiological characteristics on the speed of associative processes during the performance of a nonverbal-divergent (NVD) test (formation of the maximal possible number of visual images on the basis of two simple geometrical figures within 5 min) and on the spatial organization of bioelectric potentials (SOBP) were studied. Changes in the indices of spatial synchronization (SS) and spatial disorder (SD) of bioelectric potentials, which characterize, respectively, simple linear and more intricate nonlinear interrelations, were analyzed. A significant correlation was shown between 8 out of 35 psychophysiological indices analyzed (reflecting the emotional, motivational-behavioral, and cognitive styles; the total working capacity; and the autonomic tone) and the productivity index of the NVD test (fluency). Psychological features such as “stress susceptibility,” “disposition to nonstandard decisions and behavior,” “eccentricity,” “reflectivity,” and high “general and autonomic tone” facilitate activation (an increase in the SS and SD) in the frontotemporal areas of the right hemisphere, which is probably a neurophysiological correlate of success in performance of the test. Moreover, psychological features such as “field independence” and “autonomy” contribute to an increase in the activity of the occipital areas of the left hemisphere. In aggregate, the direction “frontal right-occipital left” areas becomes accentuated in the SOBP (the “creative axis”). According to our concept, this axis is of special importance in search operations and creative processes.     

The inhibitors of Arp2/3 complex and WASP proteins modulate the effect of glutoxim on Na<Superscript>+</Superscript> transport in frog skin

Using voltage-clamp technique, the involvement of WASP proteins and Arp2/3 complex in the effect of immunomodulator drug glutoxim on Na⁺ transport in frog skin was investigated. It was shown for the first time that preincubation of the skin with the N-WASP inhibitor wiskostatin or the Arp2/3 complex inhibitor CK-0944666 significantly decreases the stimulatory effect of glutoxim on Na⁺ transport. The data suggest the involvement of actin filament polymerization and branching in the glutoxim effect on Na⁺ transport in frog skin.     

Amitriptyline Attenuates Ca<Superscript>2+</Superscript> Responses Induced by Glutoxim and Molixan in Macrophages

Using Fura-2AM microfluorimetry, we have shown for the first time that sigma-1 receptor agonist, tricyclic antidepressant amitriptyline, significantly inhibits glutoxim- and molixan-induced Ca²⁺-responses in rat peritoneal macrophages. The results suggest possible involvement of sigma-1 receptors in the signaling cascade induced by glutoxim or molixan and leading to intracellular Ca²⁺ concentration increase in macrophages.     

Recombinant models of lipoproteins. Apolipoprotein A-I/phosphatidylcholine/cholesterol complexes formed in a 2-chloroethanol-water mixture

Apolipoprotein A-I can spontaneously associate with phosphatidylcholine and cholesterol in 2-chloroethanol-water mixture. It was demonstrated, using a spin label technique, that dissolved molecules participate in complex formation. The apolipoprotein A-I/phosphatidylcholine/cholesterol complexes were isolated by gel chromatography. Complexes of three types were prepared and characterized: type A, large heterogeneous aggregates with molecular weight 600 000, sedimentation coefficient 10 S and the following molar composition - protein/phosphatidylcholine/cholesterol, 1:(70-100):(10-12); types B and C, with weight average molecular weights 140 000 and 110 000, average sedimentation coefficients 3.6 S and 1.7 S, respectively. Both types have the same molar composition - protein/phosphatidylcholine/cholesterol, 1:25:8. The dissimilar sedimentation coefficients between complexes B and C may be explained by the difference in the monomer/tetramer ratio (monomer molecular weight 50 000). The spin label sn-1-O-stearoyl-2-O-9'-spiro(4',4'-dimethyloxazolidine-3'-oxyl) heptadecanoylglycero-3-phosphocholine introduced into the complexes A and B showed different thermal properties of these complexes, which may be due to differences in the lipid-protein interactions.     

Epoxygenase Inhibitors Attenuate the Stimulatory Effect of Glutoxim on Na<Superscript>+</Superscript> Transport in Frog Skin

Using voltage-clamp technique, the involvement of epoxygenases in immunomodulatory drug glutoxim regulation of Na⁺ transport in frog skin was investigated. We have shown for the first time that preincubation of the frog skin with epoxygenase inhibitors econazole or proadifen almost completely inhibits the stimulatory effect of glutoxim on Na⁺ transport. The data suggest the involvement of the enzymes and/or products of epoxygenase oxidation pathway of arachidonic acid metabolism in glutoxim effect on Na⁺ transport in frog skin epithelium.     

Trifluoperazine Attenuates Store-Dependent Ca<Superscript>2+</Superscript> Entry in Macrophages

Using Fura-2AM microfluorimetry, we have shown for the first time that preincubation of macrophages with the calsequestrin inhibitor neuroleptic trifluoperazine leads to a significant inhibition of the store-dependent Ca²⁺ entry induced by endoplasmic Ca²⁺-ATPase inhibitors thapsigargin or cyclopiazonic acid in rat peritoneal macrophages. The results suggest calsequestrin involvement in the regulation of the store-dependent Ca²⁺ entry in macrophages.