Visual Ecology and Perception of Coloration Patterns by Domestic Chicks

This article suggests how we might understand the way potential predators see coloration patterns used in aposematism and visual mimicry. We start by briefly reviewing work on evolutionary function of eyes and neural mechanisms of vision. Often mechanisms used for achromatic vision are accurately modeled as adaptations for detection and recognition of the generality of optical stimuli, rather than specific stimuli such as biological signals. Colour vision is less well understood, but for photoreceptor spectral sensitivities of birds and hymenopterans there is no evidence for adaptations to species-specific stimuli, such as those of food or mates. Turning to experimental work, we investigate how achromatic and chromatic stimuli are used for object recognition by foraging domestic chicks (Gallus gallus). Chicks use chromatic and achromatic signals in different ways: discrimination of large targets uses (chromatic) colour differences, and chicks remember chromatic signals accurately. However, detection of small targets, and discrimination of visual textures requires achromatic contrast. The different roles of chromatic and achromatic information probably reflect their utility for object recognition in nature. Achromatic (intensity) variation exceeds chromatic variation, and hence is more informative about change in reflectance – for example, object borders, while chromatic signals yield more information about surface reflectance (object colour) under variable illumination. This revised version was published online in July 2006 with corrections to the Cover Date.     

Optimization of a chemical attractant for Epicometis (Tropinota) hirta Poda

In field trapping tests in Hungary cinnamyl alcohol (3-phenyl-2-propen-l-ol) and transanethole [(1-methoxy-4-(1-propenyl)benzene)] attracted significantly more adult Epicometis (Tropinota) hirta (Coleoptera, Scarabaeidae, Cetoniinae) when presented together in the same bait compared to the single compounds Best attraction was recorded by a 1:1 mixture. Addition of other common floral scent compounds, ie. 3-methyl eugenol, 4-methoxy-cinnamaldehyde, anisylacetone, beta-ionone, cinnamyl acetate, cinnamic aldehyde, eugenol, indole, 2-phenylethanol or phenylacetaldehyde did not influence catches. The binary cinnamyl alcohol/trans-anethole bait described in this study is recommended for use in traps of E. hirta for agricultural purposes.     

Al(III)-binding ability of an octapeptide and its phosphorylated derivative

A synthetic octapeptide, H-GlyGluGlyGluGlySerGlyGly-OH, and its phosphorylated Ser derivative were synthetized and their solution speciation and binding modes in their complexes with Al(III) were measured. One goal of the work was find a lead compound for the design of a selective peptide-based Al(III) chelator. pH-potentiometry was used to characterize the stoichiometry and the stability of the species formed in the interactions of the metal ion and the peptides, while multinuclear NMR was applied to characterize the binding sites of the metal ion in the complexes. CD spectroscopy revealed a difference in the conformational behaviour of the phosphorylated peptide as compared with its non-phosphorylated parent derivative. The Al(III) is presumed to enhance aggregation through the -PO3H(-)-Al(3+)-PO3(2-)-Al(3+)- intermolecular bindings between the peptide chains. The results of molecular dynamics calculations supported the experimentally obtained secondary structures and the binding position of Al(III).     

Challenges in oncologic plastic surgery of the breast

Breast screening programs along with advances in diagnostic methods and oncologic treatment have resulted in full recovery for a decisive number of patients diagnosed with early-stage breast cancer. The results of the ultra-radical-, followed by the breast conserving era pose new opportunities and challenges for the oncologic breast surgeon. The focus of oncoplastic surgery is not only on the tumor, but also on the female patient, allowing for individualized immediate breast reconstruction with acceptable esthetic result following radical tumor exstirpation. Modern procedures differ both in concept and technique from that of traditional breast surgery. This paper provides a comprehensive and detailed overview of reconstructive and oncoplastic breast surgery.     

A simple model for the cooperative stabilisation of actin filaments by phalloidin and jasplakinolide

The stabilisation of magnesium actin filaments by phalloidin and jasplakinolide was studied using the method of differential scanning calorimetry. The results showed that actin could adapt three conformations in the presence of drugs. One conformation was adapted in direct interaction with the drug, while another conformation was identical to that observed in the absence of drugs. A third conformation was induced through allosteric inter-protomer interactions. The effect of both drugs propagated cooperatively along the actin filaments. The number of the cooperative units determined by using a quantitative model was larger for jasplakinolide (15 actin protomers) than for phalloidin (7 protomers).     

Involvement of Neurotransmitters in the Action of the Nociceptin/Orphanin FQ Peptide-Receptor System on Passive Avoidance Learning in Rats

The nociceptin/orphanin FQ peptide (NOP) receptor and its endogenous ligand plays role in several physiologic functions of the central nervous system, including pain, locomotion, anxiety and depression, reward and drug addiction, learning and memory. Previous studies demonstrated that the NOP-receptor system induces impairment in memory and learning. However, we have little evidence about the underlying neuromodulation. The aim of the present study was to investigate the involvement of distinct neurotransmitters in the action of the selective NOP receptor agonist orphan G protein-coupled receptor (GPCR) SP9155 P550 on memory consolidation in a passive avoidance learning test in rats. Accordingly, rats were pretreated with a nonselective muscarinic acetylcholine receptor antagonist, atropine, a γ-aminobutyric acid subunit A (GABA-A) receptor antagonist, bicuculline, a D2, D3, D4 dopamine receptor antagonist, haloperidol, a nonselective opioid receptor antagonist, naloxone, a non-specific nitric oxide synthase inhibitor, nitro-l-arginine, a nonselective α-adrenergic receptor antagonist, phenoxybenzamine and a β-adrenergic receptor antagonist, propranolol. Atropine, bicuculline, naloxone and phenoxybenzamine reversed the orphan GPCR SP9155 P550-induced memory impairment, whereas propranolol, haloperidol and nitro-l-arginine were ineffective. Our results suggest that the NOP system-induced impairment of memory consolidation is mediated through muscarinic cholinergic, GABA-A-ergic, opioid and α-adrenergic receptors, whereas β-adrenergic, D2, D3, D4-dopaminergic and nitrergic mechanisms are not be implicated.     

Nicotinic acid adenine dinucleotide phosphate (NAADP) and Ca2+ mobilization

Many physiological processes are controlled by a great diversity of Ca2+ signals that depend on Ca2+ entry into the cell and/or Ca2+ release from internal Ca2+ stores. Ca2+ mobilization from intracellular stores is gated by a family of messengers including inositol-1,4,5-trisphosphate (InsP3), cyclic ADP-ribose (cADPR), and nicotinic acid adenine dinucleotide phosphate (NAADP). There is increasing evidence for a novel intracellular Ca2+ release channel that may be targeted by NAADP and that displays properties distinctly different from the well-characterized InsP3 and ryanodine receptors. These channels appear to localize on a wider range of intracellular organelles, including the acidic Ca2+ stores. Activation of the NAADP-sensitive Ca2+ channels evokes complex changes in cytoplasmic Ca2+ levels by means of channel chatter with other intracellular Ca2+ channels. The recent demonstration of changes in intracellular NAADP levels in response to physiologically relevant extracellular stimuli highlights the significance of NAADP as an important regulator of intracellular Ca2+ signaling.     

Maximum-scoring segment sets

We examine the problem of finding maximum-scoring sets of disjoint segments in a sequence of scores. The problem arises in DNA and protein segmentation and in postprocessing of sequence alignments. Our key result states a simple recursive relationship between maximum-scoring segment sets. The statement leads to fast algorithms for finding such segment sets. We apply our methods to the identification of noncoding RNA genes in thermophiles