The hypothesis of a Hierarchy of the Sciences with physical sciences at the top, social sciences at the bottom, and biological sciences in-between is nearly 200 years old. This order is intuitive and reflected in many features of academic life, but whether it reflects the "hardness" of scientific research--i.e., the extent to which research questions and results are determined by data and theor...

in 2001, the problems and hazards of hiv/aids have been debated by heads of state and government in who conference. they reported the hiv/aids status in their countries and explained their related activities. like other countries, iranian scientific mission described hiv/aids status in our country. finally, a resolution was issued and requested the members to observe the following points: 1. co...

INTRODUCTION Nearly a century ago, Charles-Edward Amory Winslow, defined public health as “the science and art of preventing disease, prolonging life, and promoting health and efficiency through organized community effort” (1). From health policy reforms to scientific advances with many technological innovations, a range of forces are converging to cause a seismic shift in how public health is ...

Environmental health information resources lack exposure data required to translate molecular insights, elucidate environmental contributions to diseases, and assess human health and ecological risks. We report development of an Exposure Ontology, ExO, designed to address this information gap by facilitating centralization and integration of exposure data. Major concepts were defined and the on...

Embryos, fetuses, and neonates form perfectly functional tissues and organs every day. Despite fevered efforts over the past 30 years, there has been very modest progress toward achieving the bewitching goal of organ replacement with embryonic or iPSCs. What is the basis of this humbling status quo? Surely one reason is our enduring ignorance of mechanisms governing development in any organ or ...