Background Selection 20 Years on

THE WILHELMINE E . KEY 2012 INVITATIONAL LECTURE Background Selection 20 Years on

The mutation process continually produces new deleterious variants at sites throughout the genome, which are then mostly eliminated by selection. This causes a reduction in variability at linked neutral or nearly neutral sites, as well as distortions of the genealogies of samples of alleles from a population. In regions of the genome where recombination is frequent, the effects of selection aga...

1 20. Cosmic background radiation 20. COSMIC BACKGROUND RADIATION

The observed cosmic microwave background (CMB) radiation provides strong evidence for the hot big bang. The success of pri-mordial nucleosynthesis calculations (see Sec. 16, " Big-bang nucle-osynthesis ") requires a cosmic background radiation (CBR) characterized by a temperature kT ∼ 1 MeV at a redshift of z ≃ 10 9. In their pioneering work, Gamow, Alpher, and Herman [1] realized this and pred...

Reye's syndrome: 20 years on.

Helicobacter pylori: 20 years on.

Helicobacters are a new genus of bacteria, inhabiting the interface between mucosa and lumen of the gut. Microaerophilic, spiral, flagellated and urease positive, they possess features necessary for colonisation of the juxtamucosal mucus environment. Helicobacter pylori is the major pathogenic species. Once attached to the gastric epithelial cells, it incites an immune response characterised hi...

Nanoimprint lithography 20 years on.

To celebrate the 20th anniversary of nanoimprint lithography (NIL) we present a perspective of how the technique and its prospects have evolved over the past two decades. We describe how it overcame certain fabrication challenges at the time it was first reported and look at some of the obstacles that hindered uptake in industry initially, as well as likely sectors for future successful commerc...