The role of judgement in macroeconomic forecasting

This paper examines the rationale for, and influence of, judgemental adjustments in macroeconomic forecasting, using two particular forecasts for the UK economy recently published by the National Institute of Economic and Social Research and the London Business School. It is found that in some cases such adjustments have a major effect on the forecasts and can also explain some of the differences in the two rival forecasts. However the number of adjustments for which this is true is not great. An implication of these findings is that, if these forecasts can be regarded as typical, then macroeconomic forecasters should be urged to give a reasonable account of the role of judgemental adjustments in their forecasts, particularly since the amount of information which would be required is not likely to be excessive.     

Germline mutations and sequence variants of the macrophage scavenger receptor 1 gene are associated with prostate cancer risk

Deletions on human chromosome 8p22-23 in prostate cancer cells and linkage studies in families affected with hereditary prostate cancer (HPC) have implicated this region in the development of prostate cancer. The macrophage scavenger receptor 1 gene (MSR1, also known as SR-A) is located at 8p22 and functions in several processes proposed to be relevant to prostate carcinogenesis. Here we report the results of genetic analyses that indicate that mutations in MSR1 may be associated with risk of prostate cancer. Among families affected with HPC, we identified six rare missense mutations and one nonsense mutation in MSR1. A family-based linkage and association test indicated that these mutations co-segregate with prostate cancer (P = 0.0007). In addition, among men of European descent, MSR1 mutations were detected in 4.4% of individuals affected with non-HPC as compared with 0.8% of unaffected men (P = 0.009). Among African American men, these values were 12.5% and 1.8%, respectively (P = 0.01). These results show that MSR1 may be important in susceptibility to prostate cancer in men of both African American and European descent.     

Characterization of extrasolar terrestrial planets from diurnal photometric variability

The detection of massive planets orbiting nearby stars has become almost routine, but current techniques are as yet unable to detect terrestrial planets with masses comparable to the Earth's. Future space-based observatories to detect Earth-like planets are being planned. Terrestrial planets orbiting in the habitable zones of stars-where planetary surface conditions are compatible with the presence of liquid water-are of enormous interest because they might have global environments similar to Earth's and even harbour life. The light scattered by such a planet will vary in intensity and colour as the planet rotates; the resulting light curve will contain information about the planet's surface and atmospheric properties. Here we report a model that predicts features that should be discernible in the light curve obtained by low-precision photometry. For extrasolar planets similar to Earth, we expect daily flux variations of up to hundreds of per cent, depending sensitively on ice and cloud cover as well as seasonal variations. This suggests that the meteorological variability, composition of the surface (for example, ocean versus land fraction) and rotation period of an Earth-like planet could be derived from photometric observations. Even signatures of Earth-like plant life could be constrained or possibly, with further study, even uniquely determined.     

6 A-resolution X-ray structure of a variable surface glycoprotein from Trypanosoma brucei

The variable surface glycoprotein (VSG) is the predominant component of the surface coat of the African trypanosome. The expression of antigenically distinct VSGs on minor populations during infection allows the parasite to escape the host immune response. Purification of the protein is facilitated by the enzymatic release of a soluble form of VSG (sVSG) which occurs on cell lysis. The soluble form is a dimer with an approximate molecular weight of 120,000-130,000. Partial proteolysis of sVSG reveals a protease-sensitive link between an amino-terminal domain which comprises about two-thirds of the molecule, and a C-terminal domain which contains the membrane attachment site. We have obtained crystals suitable for high-resolution structural analysis from preparations of three sVSG: MITat 1.2, ILTat 1.25 and ILTat 1.22. The crystal structure of the dimer of the MITat 1.2 amino-terminal domain has been solved to 6 A resolution. We report here that the dimer is an unusual 90 A rod-like molecule composed of a helical bundle of at least four 80 A-long alpha-helices.     

Cannabiripsol: A novelCannabis constituent

Summary Cannabiripsol [(–)(6aR, 9S, 10S, 10aR)9,10-dihydroxy-hexahydrocannabinol] (1), a new cannabinoid was isolated from a South African Cannabis variant. The structure was determined by spectral means and by synthesis.Acknowledgments. This work was supported by contract HSM-42-70-103 from the National Institute on Drug Abuse and by the Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677. —Cannabis Herbarium specimens are stored in the Herbarium, Department of Pharmacognosy, School of Pharmacy, University of Mississippi.To whom inquiries should be addressed.     

Expression of a polypeptide containing a dipeptide repeat is confined to the insect stage of Trypanosoma brucei

The protozoan parasite Trypanosoma brucei is transmitted between mammalian hosts by the tsetse fly (Glossina spp.). Trypanosomes ingested by the fly undergo a number of changes in the insect midgut during differentiation to procyclic forms. These include the loss of the variant specific glycoprotein (VSG) coat and the appearance of a common set of procyclic surface antigens. In order to investigate genes other than VSG genes which are expressed only at certain stages of the life cycle, the first cDNA specific to procyclic culture form trypanosomes (equivalent to the stage found in the insect midgut) has been characterized. The encoded polypeptide shows several characteristics of membrane proteins, but its most striking feature is the presence of a repetitive amino-acid sequence in which there are 22 tandem repeats of the dipeptide-Glu-Pro-. Related genes are also found in other trypanosome species and in leishmania. This gene shows many similarities to a number of surface antigen genes described in malaria and, more recently, Trypanosoma cruzi. This is the first example of a repetitive sequence in a parasite protein which is present only in the insect vector, and which therefore cannot be implicated in the mammalian host immune response.