Raw data and R code for plotting

Data and R code to produce figure 2, which gives (a) Percent righting (N=26 birds, number of drops as indicated) and (b) righting mode (N=26 birds, number of successful rightings as indicated), and (c) vertical force production (N=5 birds, except for N=1 at 14 dph; data represent mean ± 1 s.d.) versus age in Chukar Partridge. Righting via roll, as accomplished by asymmetric wing and leg movements, is used prior to 14 dph. Around 9 dph, birds switch to righting via pitch using symmetric wing motions, and vertical force production increases concomitantly

Vascular Cell Adhesion Molecule-Targeted MS2 Viral Capsids for the Detection of Early-Stage Atherosclerotic Plaques

Atherosclerosis is a cardiovascular disease characterized by the formation of lipid-rich plaques within the walls of large arteries. Over time, a portion of these lesions can detach and lead to serious complications, such as strokes or heart attacks. Currently, there is no clinically effective way to detect the presence of atherosclerosis in patients until it has reached a relatively advanced stage. Furthermore, increasing evidence suggests that the pathobiological behavior of plaques is determined mainly by their composition, and not their size, which is the parameter usually monitored with current imaging techniques. In this work, we report protein-based agents that target the vascular cell adhesion molecule (VCAM1), a protein that plays a crucial role in atherosclerosis progression. <i>In vivo</i> experiments with murine atherosclerosis models indicated that the targeted protein nanoparticles were successful in detecting plaques of various sizes in the descending aorta and the aortic arch. This finding encourages the further development of these nanoscale agents for applications in the imaging, diagnosis, and treatment of cardiovascular diseases

Aerodynamic characteristics of feathered dinosaur shapes measured using physical models: a comparative study of maneuvering

<p>Cite as:  Cam, Chun, Huynh, Mehrabani, Tse, and Evangelista 2011.  Journal of Vertebrate Paleontology 31(Supplement 2):129-130. </p> <p> </p> <p>Society of Vertebrate Paleontology Annual Meeting 2011, Las Vegas NV. </p> <p> </p> <p>Related manuscript submitted and in review. </p

Dataset for Evangelista et al (2014), Aerodynamic characteristics of a feathered dinosaur measured using physical models: effects of form on static stability and control effectiveness, accepted to PLoS

<p>Dataset for Evangelista et al (2014) PLoS ONE 9(1):e85203 - the DOI for the main paper is 10.1371/journal.pone.0085203; a preprint has been deposited at bioRxiv at the URL listed below. The data are also hosted on Bitbucket; for the latest bleeding-edge repository copy:</p> <p>hg clone ssh://[email protected]/devangel77b/microraptor-data</p

<i>Microraptor gui</i> from [2], a dromaeosaur from the Cretaceous Jiufotang Formation of Liaoning, China; physical models, and sign conventions.

<p>A, Holotype specimen IVPP V13352, scale bar 5 cm. Notable features include semilunate carpal bones, a boomerang-shaped furcula, a shield-shaped sternum without a keel, uncinate processes on the ribs, unfused digits, an intermediate angle of the scapulocoracoid, and a long tail of roughly snout-vent length. In addition, there are impressions of feathers on the forelimbs, hindlimbs, and tail. B-J, Physical models of <i>M. gui</i>, scale model wingspan 20 cm, snout-vent-length 8 cm. Reconstruction postures, B-I, used for constructing physical models: B, sprawled, after <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Xu1" target="_blank">[2]</a>; C, tent, after <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Davis1" target="_blank">[34]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Xu6" target="_blank">[58]</a>; D, legs-down, after <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Davis1" target="_blank">[34]</a>; E, biplane, after <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Chatterjee1" target="_blank">[32]</a>. F-I additional manipulations: F, asymmetric leg posture with 9090 leg mismatch ( <i>arabesque</i> ); G, example asymmetric leg posture with 45 dihedral on one leg ( <i>dégagé</i> ), H, sprawled without leg or tail feathers; I, tent without leg or tail feathers. J, test setup; K, sign conventions, rotation angles, and definitions for model testing, after <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-McCay1" target="_blank">[10]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-McCay3" target="_blank">[30]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-McCormick1" target="_blank">[31]</a>.</p

Aerodynamic Characteristics of a Feathered Dinosaur Measured Using Physical Models. Effects of Form on Static Stability and Control Effectiveness

<div><p>We report the effects of posture and morphology on the static aerodynamic stability and control effectiveness of physical models based on the feathered dinosaur, <i>Microraptor gui</i>, from the Cretaceous of China. Postures had similar lift and drag coefficients and were broadly similar when simplified metrics of gliding were considered, but they exhibited different stability characteristics depending on the position of the legs and the presence of feathers on the legs and the tail. Both stability and the function of appendages in generating maneuvering forces and torques changed as the glide angle or angle of attack were changed. These are significant because they represent an aerial environment that may have shifted during the evolution of directed aerial descent and other aerial behaviors. Certain movements were particularly effective (symmetric movements of the wings and tail in pitch, asymmetric wing movements, some tail movements). Other appendages altered their function from creating yaws at high angle of attack to rolls at low angle of attack, or reversed their function entirely. While <i>M. gui</i> lived after <i>Archaeopteryx</i> and likely represents a side experiment with feathered morphology, the general patterns of stability and control effectiveness suggested from the manipulations of forelimb, hindlimb and tail morphology here may help understand the evolution of flight control aerodynamics in vertebrates. Though these results rest on a single specimen, as further fossils with different morphologies are tested, the findings here could be applied in a phylogenetic context to reveal biomechanical constraints on extinct flyers arising from the need to maneuver.</p></div

Presence or absence of leg and tail feathers can substantially alter longitudinal plane aerodynamics.

<p>Sprawled and tent postures with and without feathers, all coefficients shown versus angle of attack, solid squares with leg and tail feathers, open squares without leg or tail feathers. A, Lift coefficient. Stall occurs at higher angle of attack when leg feathers are present. B, Drag coefficient. Leg feathers increase drag at high angle of attack, improving parachuting performance. C, Lift coefficient versus drag coefficient. D, Lift to drag ratio. Lift to drag ratio is improved slightly without the additional drag and less-efficient lift generation of hind wings. E, Pitching moment coefficient. Without leg feathers, stability is not achieved in either posture. F, Pitching stability coefficient.</p

Asymmetric tail movement (lateral bending) effect on yaw, tent posture.

<p>Baseline tent position (solid square), tail 10 left (open square), tail 20 left (open triangle), tail 30 left (open diamond). The tail is effective at creating yawing moments but at low angles of attack it is shadowed by the body and larger movements are needed (yellow versus red lines).</p

Asymmetric wing tucking control effectiveness for tent posture; both wings out (solid square), no right wing (open square) and no wings (open diamond).

<p>Tucking one wing produces large roll moments but at the expense of one quarter of the lift. Large yaw moments are not generated except at higher angles of attack where the leg and tail positions become more important. Rolling moments generated in the two-wing symmetric position illustrates the senstivity of symmetry, model positioning, and sting placement; in addition, yawing moments at extreme angle of attack further illustrate sensitivity to position which could be exploited as a control mechanism during high angle of attack flight.</p

Asymmetric wing pronation (e.g. left and right wings pitched in opposite directions) control effectiveness for tent posture for wing pronation angles of –30 (large down triangle), –15 (down triangle), 0 (square), +15 (up triangle) and +30 (large up triangle).

<p>At low angles of attack, asymmetric wing pronation generates large rolling moments. At high angles of attack, there is a shift in function and asymmetric wing pronation tends to generate yawing moments instead of rolling moments. Function at high angle of attack is similar to what is observed in human skydivers <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Cardona1" target="_blank">[37]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085203#pone.0085203-Evangelista1" target="_blank">[38]</a>. Organisms may have navigated this transition from high angle of attack to low.</p