Kinematics and Economy of Novel Barefoot Running

The purpose of the study was to compare key physiological, anthropometric, and kinematic attributes between barefoot and shod runners while also comparing these variables to the running economy of their respective conditions. We hypothesize that when running in the acute barefoot condition participants will exhibit significant biomechanical, physiological, and kinematic differences compared to the shod condition that may be correlated with a superior or inferior running economy. Male (4) and female (5) test subjects (19.2±0.83 years, 171.06±6.89 cm, 71.09±14.52 kg) participated in two separate testing sessions. The first session involved collecting the weight, height, sitting height, ankle and hip widths, hamstring flexibility, and body fat percentage preceding a maximal oxygen consumption test. The second session required subjects to run at a variety of submaximal velocities while they were recorded with high speed video. Kinematic variables were measured using Dartfish Video Analysis Software. Results showed that VO2 was greater when shod than barefoot at 2.68 m/s, but shod running required less oxygen at 3.58 m/s. There was no difference at 3.13 m/s. Body composition was the only physiological variable that correlated with economy. Knee angle decreased and stride frequency increased when switching from shod to barefoot running. These findings suggest that as habitually shod runners begin barefoot running they adapt to increased ground reaction forces by incorporating greater knee flexion and a faster stride frequency. These changes may cause a decrease in economy at slower speeds and an improvement in economy at greater velocities

The bivalve Anopaea (Inoceramidae) from the Upper Jurassic-lowermost Cretaceous of Mexico

In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian–lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic–earliest Cretaceous, between Mexico and the Antarctic Realm

First Flavor-Tagged Determination of Bounds on Mixing-Induced CP Violation in Bs -> J/psi phi Decays

This Letter describes the first determination of bounds on the CP-violation parameter 2*beta_s using Bs decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2,000 Bs -> J/psi phi decays reconstructed in a 1.35 fb-1 data sample collected with the CDF II detector using p-bar p collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2*beta_s and the decay-width difference Delta-Gamma. Assuming the standard model predictions of 2*beta_s and Delta-Gamma, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations. Dedicated to the memory of our dear friend and colleague, Michael P. Schmidt.Comment: 7 pages, 2 figures, submitted to PR

Paleobiology of the Latest Tithonian (Late Jurassic) Ammonite Salinites grossicostatum Inferred from Internal and External Shell Parameters.

Based on material from the uppermost Tithonian La Caja Formation at Puerto Piñones, northeastern Mexico, the complete ontogenetic development (protoconch to adult) of the ammonite Salinites grossicostatum is outlined by a detailed morphometrical shell analysis. The embryonic stage, consisting of a small ellipsoid protoconch and ammonitella, ends at about 0.6 mm. Four major morphological changes are differentiated throughout ontogeny based on internal features such as reduced septal spacing and siphuncle position. Sexual dimorphism is reflected by shell size, siphuncular diameter, differences in the morphology of the apophysis, and by two distinct general trends in septal spacing. In addition, macroconchs are characterized by septal crowding at different stages, followed by the return to normal septum distances. Our analysis indicates a change in the mode of life after the neanic stage. A change in habitat preference is inferred for adult individuals. While microconchs persisted at Puerto Piñones, large mature macroconchs temporarily migrated to other areas, possibly for egg deposition. Salinites grossicostatum is endemic to the ancient Gulf of Mexico and is there restricted to outer continental shelf environments

Ratio between septal angle versus septal number for four mature specimens and one juvenile (CPC-1231).

<p>Specific correlative septal “events” are marked by dashed lines. D = diameter at the last septum.</p

Early ontogenetic internal shell development and measurements of <i>Salinites grossicostatum</i> based on four median sections.

<p>(a) CPC-1217, with sketch to the right (a₂) to illustrate internal shell structures; (b) CPC-1214; measurements are provided in mm.</p

A Novel Approach to Efficient Monte-Carlo Localization

Abstract. Recently, efficient self-localization methods have been developed, among which probabilistic Monte-Carlo localization (MCL) is one of the most popular. However, standard MCL algorithms need at least 100 samples to compute an acceptable position estimation. This paper presents a novel approach to MCL that uses an adaptive number of samples that drops down to a single sample if the pose estimation is sufficiently accurate. Experiments show that the method remains in this efficient single sample tracking mode for more than 90 % of the cycles.

The Attempto Tübingen Robot Soccer Team

Abstract. This paper describes the Attempto Tübingen Robot Soccer Team 2004. The robot platform, its sensors and actuators, and the software system running on the onboard computer are presented. The main part of the paper concentrates on our current scientific work on modelling and tracking a dynamic environment. Information about dynamic objects moving around in the environment can be useful especially in RoboCup to predict the motion of the ball, to avoid collisions, or to consider objects which cannot be detected over a short period of time. In our robot soccer team we recently implemented an efficient object and landmark detection algorithm based on images of our omnidirectional vision system. To track the detected objects, we use a tracking approach which on the one hand combines the specific advantages of Kalman- and particle filters and on the other hand uses an interacting multiple model filtering approach to model object dynamics as accurately as possible. In addition to the general tracking techniques we present our real-time approach to detect and track uncoloured objects, such as a standard soccer ball.

Measurements of the siphuncle in five specimens.

<p>The upper plot illustrates the ratio between siphuncular diameter [DS] versus shell diameter [D]; the lower plot figures the siphuncular diameter versus apertural height at the plane of coiling [ah]. To the right, high-resolution scans illustrate the siphuncle; (a) longitudinal median section of CPC-1228; (b) transversal section through the plane of coiling in CPC-1214. Black arrows indicate position of the siphuncle; scale bars = 2.5 mm.</p