Presently high-speed tracks are built on a large scale. Although ballasted tracks are still popular, more and more slab tracks are constructed. They have some significant advantages such as low maintenance, high availability, low structure height, and low weight. The main emphasis of this paper is on the application of non-ballasted concepts for high-speed operation. Special attention is given ...

The aim of this study is to investigate the effects of corporate governance mechanisms in preventing the bankruptcy of companies listed in Tehran Stock Exchange. For this purpose, corporate governance mechanisms, including institutional ownership, non-executive members of the board, CEO dual responsibility and free float stock are determined as independent variables and Bankruptcy based on the ...

The aim of this study is to investigate the effects of corporate governance mechanisms in preventing the bankruptcy of companies listed in Tehran Stock Exchange. For this purpose, corporate governance mechanisms, including institutional ownership, non-executive members of the board, CEO dual responsibility and free float stock are determined as independent variables and Bankruptcy based on the ...

Triassic vertebrate tracks are known from the beginning of the 19th century and have a worldwide distribution. Several Triassic track ichnoassemblages and ichnotaxa have a restricted stratigraphic range and are useful in biochronology and biostratigraphy. The record of Triassic tracks in the Iberian Peninsula has gone almost unnoticed although more than 25 localities have been described since 1...

California’s primary hydrologic system, the San Francisco Estuary and its upstream watershed, is vulnerable to the regional hydrologic consequences of projected global climate change. Previous work has shown that a projected warming would result in a reduction of snowpack storage leading to higher winter and lower spring-summer streamflows and increased spring-summer salinities in the estuary. ...

• The Roma Teaching Assistant is a remedial education program with the assistant and treated students belonging to same minority. In medium-term, it has modest but positive effects on educational attainments. choose longer secondary tracks needed enter higher education. There are spillovers for Non-Roma students. teaching reference point community can act as role model. A poor-performing studen...

BACKGROUND telomere length has been used to represent biological ageing and is found to be associated with various physiological, psychological and social factors. OBJECTIVE to explore the effects of income and marriage on leucocyte telomere length in a representative sample of older adults. DESIGN AND SUBJECTS cross-sectional analysis among 298 adults, aged 65-74, randomly selected from th...

The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development...