India has supported the ideal of health for all since it become an independent nation more than 60 years ago. The Bhore Committee report1 in 1946 recommended a national health system for delivery of comprehensive preventive and curative allopathic services through a rural-focused multilevel public system, financed by the government, through which all citizens would receive care irrespective of their ability to pay. However, a newly independent India faced monumental challenges in 1947. The country had been divided by a bloody partition, poverty was widespread, the economy was weak, and the administrators were new. The population's health was grim. Memories of the Bengal famine of 1943, which killed 2-3 million people, were still fresh, health services were concentrated in urban areas, and health indicators were universally poor with a life expectancy at birth of 37 years. Much progress has been recorded since then. Life expectancy is greater than 60 years, and the India of 2011 is a thriving democracy with a diversified production base, a large scientific community, and an impressive information technology sector.During the same period, however, India's record in expanding social opportunities has been uneven. The health and nutritional status of children and women remains poor, and India is routinely ranked among countries performing weakly on overall health performance.2,3 But there is good reason for hope. The country has withstood the recent global financial crisis and quickly returned to rapid economic growth. There is a refreshing openness to participation by civil society and to the power of ideas to improve performance and governance. We are enthused by India's recent commitments to invigorate the public healthcare system to address health disparities. Furthermore, we are encouraged by a vibrant economic climate that has propelled the nation into the ranks of middle-income countries, vikram.patel@lshtm.ac.uk. We declare that we have no conflicts of interest.
Two-dimensional (2D) topological surface states in a three-dimensional topological insulator (TI) should produce uniform 2D surface current distribution. However, our transport current imaging studies on Bi2Se3 thin film reveal non-uniform current sheet flow at 15 K with strong edge current flow. This is consistent with other imaging studies on thin films of Bi2Se3. In contrast to strong edge current flow in thin films, in single crystal of Bi2Se3 at 15 K our current imaging studies show the presence of 3.6 nm thick uniform 2D sheet current flow. Above 70 K, this uniform 2D sheet current sheet begins to disintegrate into a spatially non-uniform flow. The flow becomes patchy with regions having high and low current density. The area fraction of the patches with high current density rapidly decreases at temperatures above 70 K, with a temperature dependence of the form $$1/\left| {T - 70} \right|^{0.35}$$
1
/
T
-
70
0.35
. The temperature scale of 70 K coincides with the onset of bulk conductivity in the crystal due to electron doping by selenium vacancy clusters in Bi2Se3. Thus our results show a temperature dependent competition between surface and bulk conductivity produces a temperature dependent variation in uniformity of current flow in the topological insulator.
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