Bayesian forecasts following a major level change in exponential smoothing

Exponential smoothing techniques enjoy a wide range of applications to problems in signal detection, inventory and production control, financial planning, and many other areas of business and engineering. One of the most useful models used to explain the theoretical structure of the process is a changing levels model, in which the underlying level of the stochastic process is assumed to undergo random changes in each time period. The observation is modelled as a noisy disturbance of this level. Occasionally a major intervention or level change occurs that is much larger than the typical period-to-period fluctuation in the random level. Using a Bayesian approach it is the purpose of this paper to show how the distribution of the major level change can be detected, estimated and then incorporated in forecasts. Updating equations are obtained for the posterior mean and variance of the major level change as well as the new level.     

The complete DNA sequence of yeast chromosome III.

The entire DNA sequence of chromosome III of the yeast Saccharomyces cerevisiae has been determined. This is the first complete sequence analysis of an entire chromosome from any organism. The 315-kilobase sequence reveals 182 open reading frames for proteins longer than 100 amino acids, of which 37 correspond to known genes and 29 more show some similarity to sequences in databases. Of 55 new open reading frames analysed by gene disruption, three are essential genes; of 42 non-essential genes that were tested, 14 show some discernible effect on phenotype and the remaining 28 have no overt function.     

In vitro metabolism of progesterone by the adrenals of spontaneously hypertensive rats

Zusammenfassung Der Einbau des¹⁴C-Progesterons in Corticosteroide bei Nebennierensegmenten von Wistar-Ratten mit spontaner Hypertonie unterscheidet sich in nichts vom Einbau bei Nebennieren der Kontrollratten, was im Gegensatz zu Befunden mit regenerierten Nebennieren steht. Eine kausale Beziehung zwischen Nebennierenrindenfunktion und spontanem Hochdruck scheint ausgeschlossen zu sein.

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Dr. M. K.Birmingham is a Medical Research Associate of the Medical Research Council of Canada. This work was supported by grants from the Medical Research Council of Canada and the 33rd Degree Scottish Rite Committee for Research in Dementia Praecox. The authors thank Dr. R. A.Cleghorn for his interest in this project.     

The genomic and epidemiological dynamics of human influenza A virus

The evolutionary interaction between influenza A virus and the human immune system, manifest as 'antigenic drift' of the viral haemagglutinin, is one of the best described patterns in molecular evolution. However, little is known about the genome-scale evolutionary dynamics of this pathogen. Similarly, how genomic processes relate to global influenza epidemiology, in which the A/H3N2 and A/H1N1 subtypes co-circulate, is poorly understood. Here through an analysis of 1,302 complete viral genomes sampled from temperate populations in both hemispheres, we show that the genomic evolution of influenza A virus is characterized by a complex interplay between frequent reassortment and periodic selective sweeps. The A/H3N2 and A/H1N1 subtypes exhibit different evolutionary dynamics, with diverse lineages circulating in A/H1N1, indicative of weaker antigenic drift. These results suggest a sink-source model of viral ecology in which new lineages are seeded from a persistent influenza reservoir, which we hypothesize to be located in the tropics, to sink populations in temperate regions.     

Sequencing of Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae

The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation.     

Forecasting donors and donations

The authors propose and evaluate a statistical model to make forecasts of donors, gifts and cumulative private donations to an educational fund. Within-season forecasts and confidence intervals are based on binomial counts of donors and a compound Poisson distribution for cumulative donations. Forecasts for the 1984-1985 fiscal year are based on data obtained in the previous two years. The effects of different promotional campaigns are studied.