The diversification of Heliconius butterflies: what have we learned in 150 years?

Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here, we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. Whereas no single group of organisms can be sufficient for understanding life's diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.

Effects of tooth-whitening gels on enamel and dentin ultrastructure--a confocal laser scanning microscopy pilot study.

Confocal laser scanning microscopy (CLSM) in reflection mode provides a useful means for nondestructive microscopic examination of the ultrastructural characteristics of hard tissues, including enamel and dentin. In this study, CLSM was used to examine the effects of in vitro bleaching on enamel and dentin. The crowns of extracted human third molars were sectioned below the occlusal fissure, revealing subsurface dentin and the outer surface ring of enamel. Specimens were polished with 1,200-grit alumina followed by fine polish lapidary film, and cut into four equal sections per tooth, allowing each tooth to serve as internal control. Sections were mounted in acrylate for handling and were bleached for 0, 15, and 30 hours in 0.25 g of commercial Opalescence whitening gel (10% carbamide peroxide), the 5.3% hydrogen peroxide gel used in Crest Whitestrips, or 5% HClO4 solution. Blank glycerin served as a control treatment. In vitro whitening was confirmed by colorimeter readings of delta b and delta L with a PR 650 spectrophotometer/colorimeter. Treated teeth were examined with CLSM comparing enamel surface, dentoenamel junction (DEJ), and dentin at approximately 5 microns subsurface to the polished surfaces under an oil immersion objective. A single sample from each treatment (30-hour whitening) was also examined by environmental variable pressure scanning electron microscopy (VP-SEM). Internal comparison of glycerin (no whitening) controls (0-, 15-, and 30-hour exposures) revealed reproducible ultrastructure, facilitating treatment comparisons. Whitened teeth revealed no significant micromorphological changes associated with the whitening process in subsurface enamel, DEJ, and dentin areas. The direct treatment of cross sections permitted simple access of all areas to whitening gel, thereby eliminating the possibility of diffusion limitation of the gel in producing artifacts. VP-SEM observations similarly showed no significant changes in the surfaces after treatment.

[Theopek in the treatment of patients with obstructive diseases of the respiratory organs]. / Teopék v lechenii bol'nykh obstruktivnymi zabolevaniiami organov dykhaniia.

Data are reported on the high clinical and broncholytic efficacy of a new native preparation of theophylline of prolonged action--theopek. The drug is well tolerated by the patients, reduces the necessity in broncholytics and glucocorticosteroids and is recommended for basis therapy of patients with obstructive diseases of the respiratory organs.