‘On-track’ and ‘off-track’ shoulder lesions

‘On-track’ and ‘off-track’ shoulder lesions

Shoulder stability depends on the position of the arm as well as activities of the muscles around the shoulder. The capsulo-ligamentous structures are the main stabilisers with the arm at the end-range of movement, whereas negative intra-articular pressure and concavity-compression effect are the main stabilisers with the arm in the mid-range of movement.There are two types of glenoid bone loss...

Radiation track and DNA damage

Off Track: Problems with “On Track” Inferences in Empirical and Predictive Standard Setting

Off Track: Problems with “On Track” Inferences in Empirical and Predictive Standard Setting Andrew Ho, Harvard Graduate School of Education October 24, 2012 Abstract Predictive statements about future student performance can guide the selection of a performance standard. These predictive statements often take the following form: “A student with a current score X has a P% chance of exceeding a f...

Investigation of the Influences of Track Superstructure Parameters on Ballasted Railway Track Design

The main design criteria of ballasted railway tracks include rail deflections, rail bending stresses, rail wheel contact stresses, sleeper bending moments and ballast sleeper contact pressures. Numerous criteria have been defined for the design of ballasted railway tracks owing to the various mechanical properties of track components and their complex interaction. Therefore, railway track desig...

Remarks on Modern Track Geometry Maintenance

A short survey on modern track maintenance methods is given, concentrating on the developments in recent years. The ongoing refinement of the machinery should be shown as the influence of IT-solutions. On top the economic view to the track infrastructure is briefly demonstrated. Further developments in track hardware solutions must respect the obtained high level of track work mechanization. H...