Quantitative investigation of the esthetic impact of lip prominence in relation to the esthetic line

Introduction The purpose of this quantitative investigation was to assess the influence of lip prominence in relation to the esthetic line (E-line) on perceived attractiveness and threshold values of desire for treatment. Methods The lip prominence of an idealized silhouette male white profile image was altered incrementally between −16 mm to 4 mm from the E-line. The images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), laypeople (n = 75), and clinicians (n = 35). Results In terms of perceived attractiveness, lips to E-line distance within the ranges of −12 mm to −16 mm and 0-4 mm in relation to the E-line was associated with a reduction in median attractiveness scores to below 4 in the patient and clinician groups of observers; for the lay group, the corresponding ranges were −14 mm to −16 mm and 2-4 mm. Relative lip prominence appears to be viewed as more attractive than lip retrusion. Clinicians were generally least likely to suggest treatment for varying levels of bilabial position. For a number of the images, there was reasonable agreement among clinicians and laypeople regarding whether treatment is required. For the clinician group, the only categories for desire for treatment were at a lip to E-line distance within the ranges of −14 mm to −16 mm and 2-4 mm. Conclusions It is recommended that the range of normal variability of the prominence of the lips and threshold values of the desire for treatment be considered in planning

The Structure of a Rigorously Conserved RNA Element within the SARS Virus Genome

We have solved the three-dimensional crystal structure of the stem-loop II motif (s2m) RNA element of the SARS virus genome to 2.7-Å resolution. SARS and related coronaviruses and astroviruses all possess a motif at the 3′ end of their RNA genomes, called the s2m, whose pathogenic importance is inferred from its rigorous sequence conservation in an otherwise rapidly mutable RNA genome. We find that this extreme conservation is clearly explained by the requirement to form a highly structured RNA whose unique tertiary structure includes a sharp 90° kink of the helix axis and several novel longer-range tertiary interactions. The tertiary base interactions create a tunnel that runs perpendicular to the main helical axis whose interior is negatively charged and binds two magnesium ions. These unusual features likely form interaction surfaces with conserved host cell components or other reactive sites required for virus function. Based on its conservation in viral pathogen genomes and its absence in the human genome, we suggest that these unusual structural features in the s2m RNA element are attractive targets for the design of anti-viral therapeutic agents. Structural genomics has sought to deduce protein function based on three-dimensional homology. Here we have extended this approach to RNA by proposing potential functions for a rigorously conserved set of RNA tertiary structural interactions that occur within the SARS RNA genome itself. Based on tertiary structural comparisons, we propose the s2m RNA binds one or more proteins possessing an oligomer-binding-like fold, and we suggest a possible mechanism for SARS viral RNA hijacking of host protein synthesis, both based upon observed s2m RNA macromolecular mimicry of a relevant ribosomal RNA fold

The modulation of galactic cosmic-ray electrons in the heliosheath

Voyager 1 has observed strong increases in the intensities of 2-160 MeV electrons since crossing the termination shock of the heliosphere in 2004 December. Before this time these intensities were submerged below the detector background, except for occasional transient events. These increases are large compared to the concurrent increases of positive ions such as H, He, and O. A significant part is probably due to temporal effects as the heliosphere was recovering to solar minimum conditions from 2005 to early 2010. The intensity observed by Voyager 2 since its crossing of the shock in 2007 September is 5-10 times lower than that observed by Voyager 1, which is so low that the electron intensity may still be below the background produced by high-energy protons in the detector. This points to a large north-south asymmetry in the properties of the heliosheath. It is shown that the observations suggest that these electrons are not freshly accelerated on the termination shock, but rather that they are of galactic origin—while they may be re-accelerated by that shock. In this paper, these intensities are modeled with numerical solutions of the cosmic-ray transport equation. It is shown that because they are relativistic, the electrons are much more sensitive to the form of the diffusion coefficient at low rigidities than ions, and that this can explain the asymmetr

Logistic Approximation to the Normal: The KL Rationale

IRT, logistic approximation, Kullback-Leibler information,