Is it time for a metagenomic basis of therapeutics?

The trillions of microbes associated with the human body are a key part of a comprehensive view of pharmacology. A mechanistic understanding of how the gut microbiota directly and indirectly affects drug metabolism is beginning to emerge.     

Agricultural performance in Tanzania under structural adjustment programs: Is it really so positive?

The performances in the food and cashcrop sectors and the availability and consumption ofagricultural inputs in Tanzania during structuraladjustment programs (1986–1996) are compared withperiods prior to this IMF/World Bank backed reform.The positive developments in the first five years ofreform appear to be not sustainable. Presentlyproductivity levels per rural capita for importantfood and cash crops are declining. There are nofurther improvements in the availability andconsumption of agricultural inputs. The removal ofsubsidies on agricultural inputs from 1991 onwards iscrucial in explaining the decline in maize production,the main food crop in Tanzania. Some assumptionsbehind the reform measures are proving to be wrong.Modifications are thus needed to improve theagricultural sector of Tanzania in a sustainable way.Structural adjustment programs usually go too far inreducing the role of the government. However,government involvement might be necessary to ensure ahigher consumption of agricultural inputs and thus abetter performance of the agricultural sector inTanzania. A higher productivity in the agriculturalsector is needed in Tanzania to avoid food securityproblems in the future.     

Is nanotechnology dangerous?

As co-founder and chief scientist of Sun Microsystems, Bill Joy can match technophile credentials with anybody on the planet. So when he argued that research into nanotechnology and other fields should be stopped before it wipes out humanity, humanity took notice. But most researchers think he's overstating the case.     

Is El Nino changing?

Recent advances in observational and theoretical studies of El Nino have shed light on controversies concerning the possible effect of global warming on this phenomenon over the past few decades and in the future. El Nino is now understood to be one phase of a natural mode of oscillation-La Nina is the complementary phase-that results from unstable interactions between the tropical Pacific Ocean and the atmosphere. Random disturbances maintain this neutrally stable mode, whose properties depend on the background (time-averaged) climate state. Apparent changes in the properties of El Nino could reflect the importance of random disturbances, but they could also be a consequence of decadal variations of the background state. The possibility that global warming is affecting those variations cannot be excluded.     

Is the sun shrinking?

Observations of 23 transits of Mercury in front of the sun between 1736 and 1973 show no indication of any significant change in the diameter of the sun. Regression analysis yields a decrease of the angular diameter, as viewed from the earth, of under 0.3 arc second per century (> 90 percent confidence limit). This limit is incompatible with the 2 arc seconds per century decrease obtained by Eddy for the equatorial diameter from direct observations made at the Greenwich Observatory and at the U.S. Naval Observatory.