Tuberculosis (TB) represents a serious public health problem. The latest reports estimate an incidence of 8.7 million cases in 2001 and over 1.4 million deaths per year. The disease is usually be treated with a first-line drugs, isoniazid and rifampin, the two most potent anti-tuberculosis agents. However, the prevalence of multidrug-resistant (MDR) tuberculosis cause by […]
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Lone gene determines wing mimicry in butterflies One gene can determine the wing patterns of female swallowtail butterflies, making them resemble a different, and toxic, butterfly species, according to a study published in Nature. The finding adds to the debate over mimicry and how it helps put off would-be predators. A team of evolutionary biologists […]
It seems to be useful to begin this short article with the following quote: ¨ with courageous simplification, one might assert that the chemistry of the last century was largely the chemistry of covalent bonding, whereas that of the present century is more likely to be the chemistry of noncovalent binding¨. There are different terms […]
It has been a long time since we have learned that “going nano” leads to new properties arising from matter. One of those size-dependent properties that promises huge benefits due to its potential applications is magnetism. Magnetic materials are classified according to their susceptibility to magnetic fields into diamagnetic, paramagnetic and ferromagnetic materials, the first […]
Questions on the digit expansion of mathematical constants, such as , , or have fascinated mathematicians for centuries. However, many of these questions remain elusive to the efforts of researchers. For instance, it is not known for sure if the number 1 appears infinitely often in the decimal expansion of . Among the most remarkable […]
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The beringia standstill hypothesis A review of genetic evidence suggests that the Native American founding population lived in Beringia for thousands of years before migrating south into North America. And sediments taken from the Bering Sea show that at the time, the region also had woody plants for building fires, and grassland steppes where woolly […]
If we were to ask a bunch of science geeks about their favourite animals, I have no doubt that the mantis shrimps would top many rankings. The mantis shrimps (or stomatopods) are an order of marine crustaceans, typically inhabiting the colourful coral reefs in tropical or subtropical seas. They are neither shrimp nor mantis, although […]
Curiosity has been studying the surface of Mars since its landing on August 6, 2012, at Gale Crater. One of its primary goals was to determine Mar’s habitability, present or past, as written in the geology of the red planet. For doing so, and after not a little debate, the landing site was selected to […]
I will end this survey of the main contributions to the economics of scientific knowledge (ESK) by discussing the works which attempt to offer a more or less systematic conception of the process of scientific discovery; in this entry, I will talk about ‘institutionalist’ theories, i.e., those that abstain from using mathematical models. The first […]
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Beluga whales infected with cat parasites Parasites known to infect cats have been discovered in Arctic beluga whales. Toxoplasma gondii can cause people to go blind. Scientists have issued a health advisory for those in the Western Arctic region who eat beluga meat. BBC News Higgs boson bubbles sent shock waves throughout nascent universe Bubbles […]