Forecast comparisons of four models of U.S. interest rates

In this paper we compare the out of sample forecasts from four alternative interest rate models based on expanding information sets. The random walk model is the most restrictive. The univariate time series model allows for a richer dynamic pattern and more conditioning information on own rates. The multivariate time series model permits a flexible dynamic pattern with own- and cross-series information. Finally, the forecasts from the MPS econometric model depend on the full model structure and information set. In theory, more information is preferred to less. In practice, complicated misspecified models can perform much worse than simple (also probably misspecified) models. For forecasts evaluated over the volatile 1970s the multivariate time series model forecasts are considerably better than those from simpler models which use less conditioning information, as well as forecasts from the MPS model which uses substantially more conditioning information but also imposes ‘structural’ economic restrictions.     

Inter-specific avoidance of egg-associated semiochemicals in four tortricids

Oviposition of four tortricid pests of vineyards (the European grapevine moth and the grape berry moth) and fruit orchards (the codling moth and the oriental fruit moth) is deterred by a blend of straight chain fatty acids and esters of fatty acids that have been identified in the eggs of one of them: the European grapevine moth (EGVM)Lobesia botrana. This is the first evidence of inter-specific recognition of an egg-like signal in moths. We demonstrate that oviposition site selection is influenced by population density, avoidance of deterrent being most important when females are isolated. Inter-specific egg recognition might be an important phenomenon, especially in species competing for a common food resource. We propose the term oviposition regulating synomone for molecules and blends that affect the inter-specific spacing of eggs.     

Antifeedant nature of the quinone primin and its quinol miconidin fromMiconia spp

Summary The quinone primin (1) and its quinol miconidin (2) which occur naturally in Miconia spp. (Melastomataceae), were synthesized and then tested as potential antifeedants against 6 insect species. Antifeedant activity was found in all cases, ranging from primin (1) being most active againstPieris brassicae, to miconidin (2) being only slightly effective againstHeliothis armigera.     

Enhanced production of aggregation pheromones in four stored-product coleopterans feeding on methoprene-treated oats

Summary Production of aggregation pheromones by maleOryzaephilus surinamensis, O. mercator, Cryptolestes ferrugineus, andTribolium castaneum was enhanced by feeding on methoprene-treated oats, implicating juvenile hormone in control of pheromone production. Methoprene application to control insects in stored food products may cause enhanced pheromone production by these insects, thus drawing additional beetles into the treated product.Acknowledgments. We thank Dr. G. B. Staal of Zoëcon Corp. for a generous gift of methoprene. Particular thanks are due to J. Dodic for technical assistance. Research funded by the Natural Sciences and Engineering Research Council of Canada and the Science Council of British Columbia.     

Alternariol,a dibenzopyrone mycotoxin ofAlternaria spp., is a new photosensitizing and DNA cross-linking agent

Summary The mycotoxin alternariol (3,4,5-trihydroxy-6-methyldibenzo [a] pyrone) but not alternariol monomethyl ether (3,4-dihydroxy-5-methoxy-6-methyldibenzo [a] pyrone) is phototoxic toEscherichia coli in the presence of near UV light (320–400 nm). The phototoxicity bioassays with a DNA repair-deficient mutant ofE. coli suggested that DNA may be the molecular target for photo-induced toxicity of alternariol. Interactions between alternariol and double-stranded, supercoiled DNA suggest that alternariol interacts with DNA by intercalation. No DNA breakage was detected in this system; however, alternariol forms a complex and cross-links double-stranded DNA in near UV light. These results suggest that alternariol is a new phototoxic, DNA-intercalating agent and is a DNA cross-linking mycotoxin in near UV light.Acknowledgment. Dr Albert Stoessl (Agriculture Canada, London, Ontario, Canada) generously provided a mixture of alternariol and alternariol monomethyl ether, and made many helpful suggestions. Dr Ashwood-Smith (University of Victoria, Victoria, British Columbia, Canada) kindly supplied the microorganisms through Dr G.H.N. Towers (University of British Columbia, Vancouver). We gratefully acknowledge the gifts. It is a pleasure to acknowledge the able assistance of Mr S. Tallevi.     

Accumulation of indole glucosinolates inPsylliodes chrysocephala L.-infested,or-damaged tissues of oilseed rape (Brassica napus L.)

Summary Infestation of oilseed rape (Brassica napus L.) by the cabbage stem flea beetle (Psylliodes chrysocephala L.) leads to an overall reduction in the levels of aliphatic (alkenyl- and hydroxyalkenyl-) glucosinolates in the damaged tissue (lamina, petiole, stem) and a massive accumulation of indole glucosinolates. Whilst artificial damage (puncturing), with and without associated bacterial infection with an isolate fromP. chrysocephala, led to such accumulation, this was less than that observed in the insect-infected situation.     

Development of DNA probes for cytotoxin and enterotoxin genes in enteric bacteria

Summary DNA probes to identify the genes encoding toxins in enteric bacteria have been developed. Use of these probes reduces the number of animals required for toxicity testing, as suspect bacteria can be directly tested for the presence of toxin. We have augmented the gene probes available by developing probes against theEscherichia coli enterotoxin LTII and shiga toxin fromShigella dysenteriae 1.The LTII gene fromE. coli 357900 was identified and characterised and a suitable internal probe was obtained. The LTII gene was found not to be common among enterobacteriae from various geographical locations. Isolates predominately of animal origin from Nigeria and Thailand hybridized with the probe.The shiga toxin gene was isolated fromS. dysenteriae 1 by a combination of in vivo and in vitro methods. An internal probe was identified and used against different serogroups ofShigella andE. coli isolated. The probe was found to hybridize withS. dysenteriae 1 isolates and also someS. flexneri andS. sonnei strains. Representatives were tested for toxin production and found to produce toxin at low levels.     

Partial sequence of the gene for a serine protease from a halophilic archaeumhaloferax mediterranei R4, and nucleotide sequences of 16S rRNA encoding genes from several halophilic archaea

A part of the gene coding for a halophilic serine protease from a halophilic archaeumHaloferax mediterranei R4 was amplified by PCR and its 672 nucleotide sequence was determined. Tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172P1. Nucleotide sequences of 16S rRNA encoding genes from 9 halophilic archaea were determined. Alignment of 19 sequences known so far showed that there are more than 20 positions carrying bases or deletions specific for each halobacterial genus:Halobacterium, Haloarcula, Haloferax, andHalococcus.     

Cytogenetic studies of Hynobiidae (Urodela). IX. Karyological characteristics ofHynobius abei Sato by means of R-and C-banding

Summary Chromosomal characteristics of the salamander speciesHynobius abei, from Ohimya (Kyoto) were revealed by the techniques of R-and C-banding. The karyotype ofH. abei was characterized by the shortness of an R-negative (C-positive) band in the terminal region of the long arm of chromosome 2 and a band encompassing the whole short arm of chromosome 10. These two bands inH. abei were the shortest among those of the variousHynobius species that have been examined. Otherwise no differences could be detected betweenH. abei and seven other pond-type species ofHynobius (2n=56) in terms of the banding patterns of 18 specifically identifiable pairs of their chromosomes.     

Structure and stereochemistry of brianolide,a new antiinflammatory diterpenoid from the Okinawan gorgonianBriareum sp.

Summary Brianolide (1), a new antiinflammatory diterpenoid of the briarein class, possessing a substituent at C-12 (R), has been isolated from the Okinawan gorgonianBriareum sp. Its structure has been established from spectral data in conjunction with a single crystal X-ray analysis.     

A novel antagonist of serotonergic receptors,hymenidin, isolated from the Okinawan marine spongeHymeniacidon sp.

Summary A novel bromine-containing pyrrole compound, hymenidin, has been isolated from the Okinawan marine spongeHymeniacidon sp. as a potent antagonist of serotonergic receptors and its structure elucidated using spectral data.     

2,3-Dihydrolinderazulene,a new bioactive azulene pigment from the gorgonianAcalycigorgia sp.

Summary A new azulene pigment, 2,3-dihydrolinderazulene, has been isolated along with guaiazulene and linderazulene as bioactive metabolites from the gorgonianAcalycigorgia sp.     

Luffariellolide,an anti-inflammatory sesterterpene from the marine spongeLuffariella sp.

Summary Luffariellolide (2) is a sesterterpene from the Palauan spongeLuffariella sp. that has useful anti-inflammatory properties. In contrast with the irreversible action of manoalide (1) on phospholipase A₂, luffariellolide (2) is a slightly less potent but partially reversible PLA₂ inhibitor.30 December 1986Acknowledgment We thank Edward Luedtke, Elise Clason and Ellen Snideman for performing some of the assays reported above. The sponge was identified by Dr. Klaus Rützler, Smithsonian Institution, Washington, D.C. The research was supported by grants from Allergan Pharmaceuticals and the California Sea Grant College Program (Projects R/MP-30 and R/MP-31).