Aza-β-amino acid containing peptidomimetics as cAMP-dependent protein kinase substrates

Peptidomimetic analogs of the peptide RRASVA, known as the “minimal substrate” of the catalytic subunit of the cAMP-dependent protein kinase (PKA), were synthesized by consecutive replacement of natural amino acids by their aza-β³ analogs. The peptidomimetics were tested as PKA substrates and the kinetic parameters of the phosphorylation reaction were determined. It was found that the interaction of these peptidomimetics with the enzyme active center was sensitive to the location of the backbone modification, while the maximal rate of the reaction was practically not affected by the structure of substrates. The pattern of molecular recognition of peptidomimetics was in agreement with the results of structure modeling and also with the results of computational docking study of peptide and peptidomimetic substrates with the active center of PKA. It was concluded that the specificity determining factors which govern substrate recognition by the enzyme should be grouped along the phosphorylatable substrate, and such clustering might open new perspectives for pharmacophore design of peptides and peptide-like ligands.     

Social dominance in female bighorn sheep

A group of six individually identified bighorn ewes (Ovis canadensis canadensis) in the Denver Zoo, Denver, Colorado, was studied to determine the existence of a dominance hierarchy. Using success in displacement interactions as an index to rank, a very linear, age-related hierarchy was found.     

Copulatory Courtship in Drosophila birchii and D. serrata,Species Recognition and Sexual Selection

Two endemic Australian Drosophila species, D. birchii and D. serrata, have a copulatory courtship, i.e., the males court the female mainly during copulation. In the present study we found the males of both species to mount their prospective mating partners selectively, exhibiting both sex and species recognition. The males began to sing after mounting the female, and they often exhibited also postcopulatory displays typical to copulatory courtship. D. birchii and D. serrata females discriminated against males which did not sing during mounting/copulation, which suggests that the females utilize cryptic female choice. Our findings raise the question of how widespread a phenomenon cryptic female choice is in Drosophila species.     

Regeneration of a Gentiana pneumonanthe population in an oligotrophic wet meadow

Abstract. The aim of this study was to evaluate the critical phases of the life cycle of Gentiana pneumonanthe, the marsh gentian, a threatened species of the Bohemian flora. The effect of various conditions on germination and seedling establishment and the possible effect of competition on the performance of the species were tested. Seeds were sown in plots which were subjected to four treatments in a randomized complete blocks experiment: unmanaged meadow, mown meadow, burned meadow, and meadow with cut sod. The significantly highest recruitment was found in plots with cut sod, the lowest in the unmanaged control plots. Seedling survival also differed among the treatments. In the following year surviving individuals were only found in plots with cut sod. The influence of neighbouring vegetation on target gentian individuals was evaluated by removing the surrounding vegetation and comparing the performance of these individuals with controls. The initial height of each individual was measured and used as a covariable. No significant effect of neighbouring vegetation on performance was detected. Thus, the establishment phase appears to be critical for population persistence and is also more influenced by the management regime than other stages of the life cycle.     

Male aggression,limited female choice and the ontogeny of mating behaviour in the flesh fly Sarcophaga crassipalpis

Previous work has shown that male flesh flies (Sarcophaga crassipalpis Macquart) exhibit an ontogeny of behaviour from eclosion through sexual maturity that includes extensive changes in the expression of aggressive, non‐aggressive interactive and non‐interactive behaviours. To determine how the presence of a female flesh fly influences the manifestation of these behaviours, male flesh flies of different ages post‐eclosion are paired with same‐age females and their behaviours are monitored in a simple arena during a 50‐min observation period. All flies are socially isolated until pairing. Although the levels of expression of aggressive and non‐aggressive interactive behaviours are depressed relative to previous findings in male‐opponent pairs, the ontogeny of aggression still occurs as indicated by a significant increase, with age, in the agonistic behaviour ‘hold’. Similar to male‐opponent pairs and individual males, the performance by males of the non‐interactive behaviours ‘walking’ and ‘standing’ diminishes, whereas ‘upside‐down’ increases with age. By contrast, ‘grooming’ shows a significant age‐related decline. No courtship behaviours are observed in the males, although the aggressive behaviour ‘hold’ is a significant transition to mating. Females show no obvious courtship or rejection behaviours, although the significant increase in ‘upside‐down’ with age could possibly be a behavioural gateway to mating. The results of this study indicate that extensive age‐related changes encompassing the entire behavioural repertoire are intrinsic to male flesh flies and persist under a variety of different social contexts.     

Inverse investigation of non-Fourier heat conduction in tissue

This paper attempts to describe the heat conduction in tissue using the dual-phase-lag mode. Evaluating the thermo-physical parameters is one of the ways to certify the thermal behavior. As a result, the paper simultaneously and inversely estimates the values of τ_q, τ_T and α for bologna based on the dual-phase-lag mode with the measurement data in the literature. The inconsistence in theory discovered in the literatures is eliminated. The calculated results of temperature variation with the estimated values of τ_q, τ_T and α at the measurement location are very close to the experimental data and address the rationality of the present results.     

Response of female melon fly, Bactrocera cucurbitae, to host-associated visual and olfactory stimuli

In a series of studies conducted in Hawaii under seminatural conditions, we quantified the response of sexually mature, host‐seeking female melon flies, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), to different types of visual and chemical host‐associated stimuli with the main aim of developing a monitoring device for females. Experiments were conducted using Tangletrap‐coated fruit mimics of either spherical (8 cm diameter) or cylindrical (4.3 cm diameter; 15 cm length) shapes coated with different artificial color pigments both at the ground level and at the tree‐canopy level so as to take into account the foraging behavior of adult melon flies. Females were particularly attracted to objects of spherical shape colored either yellow, white, or orange; these three pigments offered the highest reflectance values. Cucumber (Cucumis sativus L.) (Cucurbitaceae) odor was more attractive to females than odors of three other cultivated host fruit [zucchini, Cucurbita pepo L. var. medullosa Alef. (Cucurbitaceae); papaya, Carica papaya L. (Caricaceae); or tomato Solanum lycopersicum L. (Solanaceae)] or of ivy gourd [Coccinia grandis (L.) Voigt (Cucurbitaceae)], one of the major wild hosts of melon fly in Hawaii. A combination of both visual and olfactory stimuli was needed to elicit high levels of response compared to each stimulus offered alone. We discuss our results in relation to the potential implementation of improved female monitoring and/or attract‐and‐kill strategies for melon flies in Hawaii.     

Female-specific color is a signal of quality in the striped plateau lizard (Sceloporus virgatus)

Recent theoretical and empirical studies confirm that male matechoice and/or female–female mate competition can be expressedin the absence of sex-role reversal. Such reproductive patternsmay select for the evolution of female traits that indicatefemale phenotypic or genotypic quality among non–role-reversedspecies. Although attention to the evolution and function offemale ornaments is increasing, additional focus is needed onfemale-specific ornaments (those not expressed in conspecificmales) and on nonavian systems in order to gain a broad understandingof how selection acts directly on ornamentation of female animals.In the striped plateau lizard, Sceloporus virgatus, only femalesdevelop orange throat patches during the reproductive season.The color peaks in expression near the time of ovulation andappears to stimulate male courtship. Here, I examine whetherthis female-specific ornament can be used by males to reliablyassess female phenotypic quality. Using multivariate regressionanalyses, I show that the area of the orange color patch predictsbody condition and mite load, the chroma (i.e., saturation)of the color patch predicts body size, and both patch area andchroma reliably predict average egg mass. Thus, female reproductivecolor may function as a condition-dependent signal, indicatingphenotypic quality to potential mates.