Olympic Genes on the Podium?

Despite some advances, it remains largely unknown how the millions of variations in the human genome influence athletic performance (especially in endurance events), and no single genetic test can really predict sports talent. However, there is experimental evidence from animal research that selecting for even a simple characteristic such as running ability can produce comparatively large and rapid changes in performance. That such selection has not been specifically documented in humans is more evidence of the limits of physiology-archeology than of the unlikelihood of selection for physical abilities. Here, the authors argue that top Olympians are likely genetically gifted individuals who in addition have numerous contributors to the “complex trait” of being an athletic champion that may not necessarily depend on defined genetic variations.

The Influence of Thermal Bridges on the Energy Need for Heating after Renewal: A Case Study

The contribution deals with the influence of additional heat loss caused by thermal bridges of a building on the energy need for heating. Calculations and comparisons were carried out for a simple characteristic family house built in the sixties in the last century. The family house was evaluated in original state and in four variants of a renewal.

Geological and historical evidence of irregular recurrent earthquakes in Japan

Great ( M ∼8) earthquakes repeatedly occur along the subduction zones around Japan and cause fault slip of a few to several metres releasing strains accumulated from decades to centuries of plate motions. Assuming a simple ‘characteristic earthquake’ model that similar earthquakes repeat at regular intervals, probabilities of future earthquake occurrence have been calculated by a government committee. However, recent studies on past earthquakes including geological traces from giant ( M ∼9) earthquakes indicate a variety of size and recurrence interval of interplate earthquakes. Along the Kuril Trench off Hokkaido, limited historical records indicate that average recurrence interval of great earthquakes is approximately 100 years, but the tsunami deposits show that giant earthquakes occurred at a much longer interval of approximately 400 years. Along the Japan Trench off northern Honshu, recurrence of giant earthquakes similar to the 2011 Tohoku earthquake with an interval of approximately 600 years is inferred from historical records and tsunami deposits. Along the Sagami Trough near Tokyo, two types of Kanto earthquakes with recurrence interval of a few hundred years and a few thousand years had been recognized, but studies show that the recent three Kanto earthquakes had different source extents. Along the Nankai Trough off western Japan, recurrence of great earthquakes with an interval of approximately 100 years has been identified from historical literature, but tsunami deposits indicate that the sizes of the recurrent earthquakes are variable. Such variability makes it difficult to apply a simple ‘characteristic earthquake’ model for the long-term forecast, and several attempts such as use of geological data for the evaluation of future earthquake probabilities or the estimation of maximum earthquake size in each subduction zone are being conducted by government committees.

Study and Inheritance of Daur Male Traditional Costume

Daur is the typical northern minority in China; its male traditional costume has a generous appearance and clear line, which reflects a heroic and simple characteristic. There are many factors that influence formation of Daur male traditional costume culture: natural and geographical environment, social and economic conditions, production method and life style, religious belief, cultural exchange, etc. These factors are reflected in costume directly or indirectly to form the unique style of Daur male costume. These characteristics should be inherited and innovated, and become the ethnic symbol of modern Daur male costume.

The Elastic Limits of Colon Tissues for Different Radii of a Tool Tip End Using a Simple Modeling

Mechanical properties of colon tissues are very important to prevent trauma and perforation during colonoscopy procedure. Most of forces are generated by the shaft of a colonoscope and a distal tip. A shaft of a colonoscope causes mechanical trauma at various locations. A distal tip of a colonoscope can cause not only for mechanical trauma but also serious perforation. In this study, elastic limits of forces were predicted for different sizes of a simplified shape of a tool tip end with a simple characteristic modeling. Published data on the various parts of a colon were used for the reference and a simple way of modeling was applied to estimate the quantity of forces with assumptions. Stress on Descending colon was used and a true stress-strain curve was generated. Descending colon has a wide range of a force limit for two different directions (longitudinal and lateral). A simple characteristic modeling was applied for a spherical shape of tool tip. Even though different parts of a colon and directions will generate diverse results, the model should be insensitive within a limited length and boundary conditions of a colon. The different radii of a tool tip end represent various tool ends from dull to sharp needle-type tool ends in several grades. The results show the elastic limit of force for different radii of tool tip end. The range of tool tip radius is between 0.1 and 10 mm. For the smallest radius of a tool tip, a colon wall will be perforated for a small force (less than 0.05N) and big forces were needed to damage the colon tissue when a tool tip diameter is more than 20 mm with the assumption that the boundary condition of a tool tip test should match up with the simple modeling statement. As the radius of a tool tip end is larger, the contact area between the interface area between a tool tip and a colon wall is wide enough to sustain applied forces. The structure of a human colon was briefly reviewed and determined the elastic limits of forces for different radii of tool ends.

Exact Evaluation of Natural Frequency and Damping Ratio from a Frequency Response Curve

Several experimental modal analysis techniques fit resonance peaks to the response curves of a single degree of freedom system in order to identify the natural frequencies and modal damping ratios. The present study identifies a fundamental property of frequency response curves that allows the natural frequency to be identified from a simple characteristic of the curve, independently of the damping ratio. After the natural frequency has been determined, the damping ratio can be computed directly. The fundamental property holds for all values of damping, which eliminates the need to approximate either the natural frequency or damping ratio.