Nuapapuin A and sigmosceptrellins D and E: New norterpene cyclic peroxides from a southern Australian marine sponge, Sigmosceptrella sp.

A Sigmosceptrella sp. from the Great Australian Eight, Australia, has yielded the new norditerpene cyclic peroxide, nuapapuin A (2a), and the norsesterterpene cyclic peroxide sigmosceptrellin D (3a), characterized as the corresponding methyl esters 2b and 3b. The crude methylated sponge extract also yielded the new norsesterterpene cyclic peroxide sigmosceptrellin E methyl ester (4). Relative stereochemistry about C2, C3, and C6 was assigned by established empirical rules and absolute stereochemistry by the advanced Mosher procedure. A plausible biosynthetic pathway has been proposed that rationalizes key transformations in the biosynthesis of all known norterpene cyclic peroxides and related norterpene ketones, dienes and sigmosceptrins.

Inactive Australian college students' preferred activities, sources of assistance, and motivators

Participation in regular physical activity reduces the risk of cardiovascular disease and all-cause mortality as well as providing numerous health benefits.' The steepest decline in physical activity occurs during adolescence (approximately 15 to 18 years of age) and young adulthood (20 to 25 years).(2) Australian population studies have found that levels of physical inactivity are twice as high for those 20 to 29 years old as they are for those under 20 years old.(3,4) As college students move through this period of changing roles within family and peer groups, they may be expected to have specific preferences and expected outcomes for physical activity participation that are different from those they had previously as high school students.(5) Studies of physical activity determinants suggest that while there are some similarities between males and females, there are differences in preferences for specific types of activity.(6) Calfas et al.(5) found that women reported body image factors (weight loss, dissatisfaction with body) to be more motivating, while young men rated strength (muscle gain, muscle tone) and social aspects (organized competition, meeting people) of physical activity more highly than did young women. We examined preferred physical activities, sources of assistance to be more active, and perceived motivators for activity in a sample of inactive college students. Differences between males and females were examined, and the implications for campus-based physical activity promotion strategies are considered.

Phylogeny of the hard ticks (Ixodidae) inferred from 18S rRNA indicates that the genus Aponomma is paraphyletic

We examined the phylogeny of ticks (Acari:Parasitiformes:Ixodida) and their closest known mite relatives (Acari:Parasitiformes:Mesostigmata and Holothyrida) using 18S rRNA sequences. In our analyses, we included sequences from 36 taxa. Sequences for 13 hard ticks (Family Ixodidae), 5 soft ticks (Family Argasidae), and 2 mesostigmatid mites were obtained from the GenBank database and we generated sequences for 15 hard ticks and 1 holothyrid mite. Ten of these tick species were endemic to Australia. Our analyses indicated that the suborder Holothyrida is more closely related to Ixodida than to Mesostigmata, the group used as outgroup in earlier molecular studies. This finding is consistent with Lehtinen's (1991) hypothesis that the Holothyrida rather than the Mesostigmata is the sister-group to the Ixodida. Within the hard ticks the genus Aponomma and thus the family Amblyomminae were paraphyletic. Taxonomic revision of these taxa is needed. The genus Amblyomma was paraphyletic without the inclusion of typical Aponomma species (Ap. latum and Ap. fimbriatum). There was a basal divergence between endemic Australian and other species in both the Metastriata and the Prostriata divisions of the hard ticks. (C) 1999 Academic Press.

Australian doctors' beliefs and practice regarding Helicobacter pylori

Objective: To determine beliefs and behaviours of Australian doctors regarding Helicobacter pylori. Design: Anonymous reply-paid postal survey mailed in December 1995 and again in March 1996. Subjects: All members on the mailing lists of the Gastroenterological Society of Australia Endoscopy Section (n = 397) and the Australian Society of Infectious Diseases (n = 264; those without medical qualifications were asked not to reply), and 400 general practitioners (GPs) randomly selected from the Royal Australian College of General Practitioners. Main outcome measures: Differences between specialist groups in belief in a causative association between H. pylori and peptic disease and in use of eradication therapy and pre- and post-treatment testing for H. pylori. Results: 92.6% of doctors believed H. pylori causes duodenal ulcer, with GPs significantly less likely to believe than gastroenterologists (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.00-0.81). In duodenal ulcer, 93.4% of doctors believed H. pylori eradication therapy should be given, but fewer (83.4%) claimed to give it always or mostly, with GPs less likely to report giving it than gastroenterologists (OR, 0.06; 95% CI, 0.02-0.19). For non-ulcer dyspepsia, gastrointestinal surgeons were more likely than gastroenterologists to believe in a causative link with H. pylori (OR, 5.6; 95% CI, 3.0-10.7) and in a need for eradication therapy (OR, 3.6; 95% CI, 1.7-7.7). Most doctors (79.3%) believed in confirming the presence of H. pylori before eradication therapy in duodenal ulcer. Only 51.6% believed post-eradication testing necessary (45.5%), yet 79.1% reported performing it. Conclusions: Significant differences exist between specialist groups in beliefs and self-reported behaviours regarding H. pylori.

Identification and characterisation of a cytochrome P450 gene and processed pseudogene from an arachnid: the cattle tick, Boophilus microplus

We isolated and sequenced the first known cytochrome P450 gene and pseudogene from an arachnid, the cattle tick, Boophilus microplus. Bath the gene and pseudogene belong to the family CYP4, but a new subfamily, CYP4W, had to be created for these genes because they are substantially different to other CYP4 genes. The gene, CPP4W1, has greatest homology with CYP4C1 from a cockroach, Blaberus discoidalis. The predicted molecular weight of the protein encoded by CYP4W1 (63 KDa) is greater than that of the other CYP4 genes. The pseudogene, CYP4W1P, is probably a processed pseudogene derived from the functional gene CYP4W1. This is only the third CYP processed pseudogene to be identified. The pseudogene is 98% identical to the functional gene, CYP4W1, therefore we hypothesise that this pseudogene evolved recently from the functional gene. The CYP4 genes from arthropods have diverged from each other more than those of mammals; consequently the phylogeny of the arthropod genes could not be resolved. (C) 1999 Elsevier Science Ltd. All rights reserved.

Molecular characterization of Drosophila C virus isolates

Reverse transcription coupled with polymerase chain reaction and restriction enzyme analysis was used to characterize 12 Drosophila C virus isolates from geographically different regions. A 1.2-kb fragment was amplified from cDNA and profiles from digestion with 20 restriction enzymes were generated. Analysis of the restriction fragment data gave estimates of nucleotide divergence of 0-10% between isolates. The isolates were grouped on the basis of genetic distance estimates derived from the restriction data. For the isolates from which a single genotype could be purified, a geographical pattern in the distribution of viral genotypes was identified. The 4 Moroccan isolates were very closely related to each other, differing in only 1 restriction profile. The 2 Australian isolates were each other's closest relatives, as were the 2 isolates first recovered in France. The PCR-RFLP technique used in this study has provided us with a simple procedure which can be used to characterize DCV isolates. A single enzyme, Tag I, generated 5 distinct and diagnostic restriction fragment patterns, which allowed easy assignment of isolates to one of the five viral genotypes identified in this study. (C) 1999 Academic Press.

Glycine metabolism by plant roots and its occurrence in Australian plant communities

Soluble organic nitrogen, including protein and amino acids, was found to be a ubiquitous form of soil N in diverse Australian environments. Fine roots of species representative of these environments were found to be active in the metabolism of glycine. The ability to incorporate [N-15]glycine was widespread among plant species from subantarctic to tropical communities. In species from subantarctic herbfield, subtropical coral cay, subtropical rainforest and wet heathland, [N-15]glycine incorporation ranged from 26 to 45% of (NH4+)-N-15 incorporation and was 2- to 3-fold greater than (NO3-)-N-15 incorporation. Most semiarid mulga and tropical savanna woodland species incorporated [N-15]glycine and (NO3-)-N-15 in similar amounts, 18-26% of (NH4+)-N-15 incorporation. We conclude that the potential to utilise amino acids as N sources is of widespread occurrence in plant communities and is not restricted to those from low temperature regimes or where N mineralisation is limited. Seedlings of Hakea (Proteaceae) were shown to metabolise glycine, with a rapid transfer of N-15 from glycine to serine and other amino compounds. The ability to take up and metabolise glycine was unaffected by the presence of equimolar concentrations of NO3- and NH4+. Isonicotinic acid hydrazide (INH) did not inhibit the transfer of N-15-label from glycine to serine indicating that serine hydroxymethyltransferase was not active in glycine catabolism. In contrast aminooxyacetate (AOA) strongly inhibited transfer of N-15 from glycine to serine and labelling of other amino compounds, suggesting that glycine is metabolised in roots and cluster roots of Hakea via an aminotransferase.

The novel mitochondrial gene arrangement of the cattle tick, Boophilus microplus: Fivefold tandem repetition of a coding region

We sequenced across all of the gene boundaries in the mitochondrial genome of the cattle tick, Boophilus microplus, to determine the arrangement of its genes. The mtDNA of B. microplus has a coding region, composed of tRNA(Glu) and 60 bp of the 3' end of ND1, that is repeated five times. Boophilus microplus is the first coelomate animal known to have more than two copies of a coding sequence. The mitochondrial genome of B, microplus has other unusual features, including (1) reduced T arms in tRNAs, (2) an AT bias in codon use, (3) two control regions that have evolved in concert, (4) three gene rearrangements, and (5) a stem-loop between tRNA(Gln) and tRNA(Phe). The short T arms and small control regions (CRs) of B. microplus and other ticks suggest strong selection for small genomes. Imprecise termination of replication beyond its origin, which can account for the evolution of tandem repeats of coding regions in other mitochondrial genomes, cannot explain the evolution of the fivefold repeated sequence in the mitochondrial genome of B. microplus. Instead, slipped-strand mispairing or recombination are the most plausible explanations for the evolution of these tandem repeats.

Isolation of a cDNA for an octopamine-like, G-protein coupled receptor from the cattle tick, Boophilus microplus

Octopamine is a biogenic amine neurotransmitter of invertebrates that binds to a G-protein coupled receptor that has seven transmembrane domains. Formamidine pesticides like amitraz are highly specific agonists of the octopamine receptor. Amitraz is used extensively to control the cattle tick, Boophilus microplus, and many other ticks but now there are strains of ticks that are resistant to amitraz. We have isolated a cDNA from the cattle tick, B. miciroplus, that belongs to the biogenic amine family of receptors. The predicted amino acid sequence from this cDNA is most similar to octopamine receptors from insects. The nucleotide sequence of this gene from amitraz-resistant and amitraz-susceptible cattle ticks was identical. Thus, a point mutation/s did not confer resistance to amitraz in the strains we studied. Alternative explanations for resistance to amitraz in B. microplus are discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.

Urban and rural suicide differentials in migrants and the Australian-born, New South Wales, Australia 1985-1994

We estimated risk of suicide in adults in New South Wales (NSW) by sex, country of birth and rural/urban residence, after adjusting for age; we also examined youth suicide (age 15-24 years). The study population was the entire population of NSW, Australia, aged greater than or equal to 15 years during the period 1985-1994. Poisson regression was used to examine the relationship between predictor variables and the risk of suicide, with the focus on migrant status and area of residence. A significantly higher risk of suicide was found in male migrants from Northern Europe and Eastern Europe/former USSR, compared to Australian-born males; a significantly lower suicide risk occurred in males from Southern Europe, the Middle East and Asia. In female migrants, those from UK/Eire, Northern Europe, Eastern Europe/former USSR and New Zealand exhibited a significantly higher risk of suicide compared to Australian-born females. A significantly lower risk of suicide occurred in females from the Middle East. Male migrants overall were at significantly lower risk of suicide than the Australian-born, while female migrants overall had a significantly higher risk of suicide than Australian-born females. Among migrant males overall, the rural-urban suicide risk differential was significantly higher for those living in non-metropolitan areas (RR = 1.9; 95% CI: 1.7-2.1). Suicide risk was significantly higher in non-metropolitan male immigrants from the UK/Eire (RR = 1.4; 95% CI: 1.1-1.7), Southern Europe (RR = 1.7; 95% CI: 1.2-2.4), Northern/Western Europe (1.5; 95% CI: 1.2-1.9), the Middle East (RR = 3.8; 95% CI: 1.9-7.8), New :Zealand (RR = 1.4; 95% CI: 1.0-1.8) and 'other' (RR = 2.6; 95% CI: 1.9-3.5), when compared to their urban counterparts. There was no statistically significant difference in suicide risk between rural and urban Australian-born males. For female suicide, significantly lower risk was found in female immigrants living in non-metropolitan areas who were from Northern/Western Europe (RR = 0.7; 95% CI: 0.4-0.96), as well as the Australian-born (RR = 0.7; 95% CI: 0.6-0.8), when compared to their urban counterparts. The non-metropolitan/metropolitan relative risk for suicide in female migrants overall was not significantly different from one. Among male youth there was a significantly higher suicide risk in non-metropolitan areas, with a relative risk estimate of 1.4 for Australian-born youth (95% CI: 1.2-1.5) and 1.7 for migrant youth (95% CI: 1.2-2.4), when compared with metropolitan counterparts. We conclude that suicide among migrant males living in non-metropolitan areas accounts for most of the excess of male suicide in rural NSW, and the significantly lower risk of suicide for non-metropolitan Australian-born women does not apply to migrant women. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.

Agri-food restructuring: A synthesis of recent Australian research

Globalizing tendencies within capitalism are leading to important alterations in the structure of agricultural production and the ways food companies are involving themselves in processing and marketing. Increasingly, finance capital and transnational agribusiness have sought ways to influence, and in some cases redirect, farming activities in Australia. The penetration of farming structures by corporate capital has been hastened by state deregulation. Rather than providing detailed empirical evidence, this paper presents a broad synthesis of recent Australian research with the aim of informing readers otherwise unaware of events in the Antipodes of the forms and impacts of agri-food change in Australia.

Is the Australian wool futures market efficient as a predictor of spot prices?

Giles and Goss (1980) have suggested that, if a futures market provides a forward pricing function, then it is an efficient market. In this article a simple test for whether the Australian Wool Futures market is efficient is proposed. The test is based on applying cointegration techniques to test the Law of One Price over a three, six, nine, and twelve month spread of futures prices. We found that the futures market is efficient for up to a six-month spread, but no further into the future. Because futures market prices can be used to predict spot prices up to six months in advance, woolgrowers can use the futures price to assess when they market their clip, but not for longer-term production planning decisions. (C) 1999 John Wiley & Sons, Inc.

A case-control study of employment status and mortality in a cohort of Australian youth

Recent studies have demonstrated a link in young populations between unemployment and ill health. The purpose of this study is to correlate mortality with employment status in two cohorts of young Australian males, aged 17-25 years, from 1984 to 1988. Two youth cohorts consisting of an initially unemployed sample (n = 1424 males) and a population sample (n = 4573 males), were surveyed annually throughout the study period. Those lost to follow-up during the survey period were matched with death registries across Australia. Employment status was determined from weekly diaries and death certificates and was designated as: employed or student; unemployed; not in the work force (excluding students). Conditional logistic regression, using age- and cohort- matched cases (deaths) and controls (alive), was used to estimate the odds ratio (OR) of dying with regard to employment status, taking into account potential confounders such as ethnicity, aboriginality, educational attainment, pre-existing health problems, socio-economic status of parents, and other factors. Twenty three male survey respondents were positively matched to death registry records. Compared to those employed or students (referent group), significantly elevated ORs were found to be associated with neither being in the workforce nor a student for all cause, external cause, and external cause mortality other than suicide. Odds ratios were adjusted for age, survey cohort, ethnicity, pre-existing physical and mental health status, education level, and socio-economic status of parent(s). A statistically significant increasing linear trend in odds ratios of male mortality for most cause groups was found across the employment categories, from those employed or student (lowest ORs), through those unemployed; to those not in the workforce (highest ORs). Suicide was higher, but not statistically significantly, in those unemployed or not in the workforce. Suicide also was associated, though not significantly, with the respondent not living with their parents when they were 14 years of age. No association was found between mortality and past unemployment experience, as measured by length of time spent unemployed, or the number of spells of unemployment experienced during the survey. The results of this study underscore the elevated risk to survival in young males as a consequence of being neither employed nor a student. (C) 1999 Elsevier Science Ltd. All rights reserved.