Light-driven tipping points in polar ecosystems.

Some ecosystems can undergo abrupt transformation in response to relatively small environmental change. Identifying imminent 'tipping points' is crucial for biodiversity conservation, particularly in the face of climate change. Here, we describe a tipping point mechanism likely to induce widespread regime shifts in polar ecosystems.

In situ lubricant degradation in Antarctic marine sediments. 1. Short-term changes.

A large-scale, in situ experiment was set up near the Bailey Peninsula area (Casey Station, East Antarctica) to monitor the natural attenuation of synthetic lubricants in marine sediments over five years. Here, we report the short-term changes after 5 and 56 weeks. The lubricants tested were an unused and used Mobil lubricant (0W/40; Exxon Mobil, Irving, TX, USA) and a biodegradable alternative (0W/20; Fuchs Lubricants, Harvey, IL, USA).

Howard Florey, Alexander Fleming and the fairy tale of penicillin.

The public myth of the discovery of penicillin is an archetypal "quest story" of the type common to every human culture. But the real story of the discovery, testing and refinement of penicillin is a complex tale of accident, serendipity, oversight, conflict, the pressure of war, idiosyncratic personalities and even--the invention of history.

Ceftazidime and cefotaxime--the clinician's choice.

A review of two third-generation cephalosporins, ceftazidime and cefotaxime, is presented. Ceftazidime, often used as a single agent, has shown greater activity than cefotaxime against Pseudomonas aeruginosa and other Pseudomonas species, Enterobacteriaceae, Acinetobacter sp, and Enterobacter sp. It has been effective as monotherapy in the treatment of peritonitis, gynecologic infections, chronic bronchitis, and infections in patients with leukemia and granulocytopenia, as has cefotaxime when in combination with an aminoglycoside.