An example of game theory is the classic Prisoner’s Dilemma. Suppose you and a friend are arrested for robbery. You are put in separate cells. The police lack sufficient evidence to convict either of you, so they try to get one of you to testify against each other. The police tell you that if you testify against your friend, you will be released, provided your friend does not testify against yo...

Classification was a key practice of the natural history sciences in the early 19th century, but leading taxonomists disagreed over basic matters, such as how many species the British flora contained. In this arena, the impact of Charles Darwin's ideas was surprisingly limited. For taxonomists like Darwin's friend, Joseph Dalton Hooker, the priority was to establish a reputation as a philosophi...

A surface plasmon resonance imaging-based Ni(2+)-iminodiacetic acid-coated gold chip system was developed to enable specific detection of a hexahistidine-tagged recombinant protein in crude extracts or in column chromatography fractions. This system is especially advantageous for high-throughput analysis of multiple proteins.

Fluorescent probes are essential for the exploration of protein function, detection of molecular interactions, and conformational changes. The nitrilotriacetic acid derivatives of different chromophores were successfully used for site-selective noncovalent fluorescence labeling of histidine-tagged proteins. All of them, however, suffer from the same drawback--loss of the fluorescence upon bindi...

Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, S...

Machado de Assis's own writings about his epilepsy are here given. They come from his correspondence with his friend Mario de Alencar during the last 8 months of Machado de Assis's life. These are the only places where Machado de Assis dealt clearly with his epilepsy during his entire life.

Once upon a time, in a backyard not very far from you, lived a dog named Rex with long fluffy and shiny hair. Rex really loved to play outside, especially with his best friend and owner Jack, a nine-year-old boy. On a perfect spring day, when it was not too cold or too hot, Jack and Rex went for a walk in a green park close by, and when they returned home Jack noticed that his loyal friend was ...