FATIGUE ALTERS THE BIOMECHANICS OF TURNS WHILE RUNNING

This study identified the effects of fatigue on lower limb kinematics while running with repeated 180°-turns. An increased stiffness of the pivoting limb was observed in terms of a reduction of hip and knee flexion angles, and an increase of hip abduction and internal rotation. We concluded that muscle fatigue can trigger a sequence of adaptations that were previously found to expose the athlete to an increasing risk of ligament injury. These results expand the base of evidence for the development of field-based prevention programs

Role of dental training and distance of the observer on the perception of apically shifted gingival margin with increased vertical tooth size in the esthetic zone

Objectives: To evaluate the influence of the gingival contour on the smile esthetics. The influence of size, symmetry, teeth involved in apically shifted gingival margins, and the distance and clinical training of the observer were investigated. Materials and Methods: Two groups were identified: 33 first‐year dental students (inexperienced) and 40 last‐year students (trained). Each observer expressed four evaluations on four different images assigning a score from 0 to 10. Using a picture of an “ideal” female smile, 10 variants were virtually created by shifting (2 and 4 mm) the gingival contour apically at different sites of the upper incisors and canines. A total of 292 evaluations were collected. Results: Considering a score >6 for a “pleasant smile,” only one 4mm single alteration at the canine gingival contour obtained an insufficient score. “Observa- tional distance” and “clinical training” did not influence the final score, while size and symmetry of alterations displayed a significant role. Conclusions: The dental training of the observer and a close interpersonal distance seemed to be irrelevant in the esthetic perception of gingival margin alterations

DECELERATION COUNTS: ESTIMATING THE ENERGY COST OF SHUlTLE RUNNING FROM MECHANICAL WORK

To estimate the energetic requirements of 5-m shuttle running based on kinematic data, we devised a modified version of existing models for the estimation of the energy cost of gait. In our approach, negative/eccentric work during deceleration phases was added to positive/concentric work in propulsive phases. Ten subjects performed two 5-rnin trials at 50% and 75% of their maximal aerobic speed. The metabolic cost estimated from 30 kinematics was compared to that measured by a portable metabolimeter. The estimation error was 1.2 J/kg/s (7.3%): results encourage to apply this method for the estimation of the workload in sports involving frequent turns and changes of direction

A KINEMATICALLY BASED ALGORITHM TO ESTIMATE THE ENERGY COST OF VARIABLE-SPEED SHUTTLE RUNNING

Changes of direction (CoDs) have a high metabolic and mechanical impact in field and court team sports, but the estimation of the associated workload is still inaccurate. The aim of this study is to establish a kinematic-based algorithm to determine the energy cost of running at variable speed with frequent 180° CoDs. Kinematic and metabolic data were simultaneously collected during 5-minutes 5+5 m shuttle run tests. Mechanical work computation was split into positive (eccentric) and negative (concentric) contributions. When compared to the actual energy cost, the estimation algorithm returned an error of 5%. This model constitutes the theoretical basis to extend the model from the laboratory to the field, obtaining an accurate measure of the workload of training and matches

Erratum to: The Role of Sleeve Gastrectomy in Reducing Cardiovascular Risk

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Extreme stability in de novo-designed repeat arrays is determined by unusually stable short-range interactions

Designed helical repeats (DHRs) are modular helix–loop–helix–loop protein structures that are tandemly repeated to form a superhelical array. Structures combining tandem DHRs demonstrate a wide range of molecular geometries, many of which are not observed in nature. Understanding cooperativity of DHR proteins provides insight into the molecular origins of Rosetta-based protein design hyperstability and facilitates comparison of energy distributions in artificial and naturally occurring protein folds. Here, we use a nearest-neighbor Ising model to quantify the intrinsic and interfacial free energies of four different DHRs. We measure the folding free energies of constructs with varying numbers of internal and terminal capping repeats for four different DHR folds, using guanidine-HCl and glycerol as destabilizing and solubilizing cosolvents. One-dimensional Ising analysis of these series reveals that, although interrepeat coupling energies are within the range seen for naturally occurring repeat proteins, the individual repeats of DHR proteins are intrinsically stable. This favorable intrinsic stability, which has not been observed for naturally occurring repeat proteins, adds to stabilizing interfaces, resulting in extraordinarily high stability. Stable repeats also impart a downhill shape to the energy landscape for DHR folding. These intrinsic stability differences suggest that part of the success of Rosetta-based design results from capturing favorable local interactions

Study of ordered hadron chains with the ATLAS detector

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