319 research outputs found

    A midden excavation - Royal Tasmanian Botanical Gardens, Hobart.

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    Radiocarbon analysis of charcoal taken from the base of a midden located within the Royal Tasmanian Botanical Gardens, Hobart, indicates that first occupancy of this site occurred some 5 000 years ago. The mussel Mytilus edulis planulatus provided the bulk of the shellfish diet which may have been supplemented with a number of small species including the gastropods Bembicium auratum and Austrocochlea constricta zebra. A feature of this site is the relatively rich supply of petrologically diverse stone artefacts. This is at variance with the general pattern for middens previously excavated in the Derwent River estuary. Also present are small, round, hard pebbles, a feature not previously reported from similar sites on the Derwent River. Scanning electron microscopic analysis of charcoal indicates that the she oak Casuarina stricta provided some of the wood fuel for fires at this site

    Effects of focal frontal lesions on response inhibition

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    This study examined the performance of 38 normal subjects and 43 patients with focal lesions of the frontal lobes on a simple go-nogo task where the probability of the nogo stimulus was either 75% or 25%. Patients with lesions to the superior medial parts of the frontal lobes, in particular to the left superior portion of Brodmann area 6 (which includes the supplementary motor areas and the premotor areas for the right hand) had an increased number of false alarms (incorrect responses to the nogo stimulus). These results indicate that area 6 is specifically involved in the inhibition of response. Patients with lesions to the right anterior cingulate (areas 24 and 32) were slower and more variable in their reaction time. These findings could be explained by an inability to sustain stimulus-response contingencies. Lesions to the right ventrolateral prefrontal cortex (Brodmann areas 44, 45, 47) also increased the variability of response, perhaps by disrupting monitoring performance

    Prevalence of Dietary Supplement Use in Healthy Pre-School Chinese Children in Australia and China

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    There is a growing use of dietary supplements in many countries including China. This study aimed to document the prevalence of dietary supplements use and characteristics of Chinese pre-school children using dietary supplements in Australia and China. A survey was carried out in Perth, Western Australia of 237 mothers with children under five years old and 2079 in Chengdu and Wuhan, China. A total of 22.6% and 32.4% of the Chinese children were taking dietary supplements in Australia and China, respectively. In China, the most commonly used dietary supplements were calcium (58.5%) and zinc (40.4%), while in Australia, the most frequently used types were multi-vitamins/minerals (46.2%) and fish oil (42.3%). In Australia, “not working”, “never breastfeed”, “higher education level of the mother” and “older age of the child” were associated with dietary supplement use in children. In China, being unwell and “having higher household income” were significantly related to dietary supplement usage. Because of the unknown effects of many supplements on growth and development and the potential for adverse drug interactions, parents should exercise caution when giving their infants or young children dietary supplements. Wherever possible it is preferable to achieve nutrient intakes from a varied diet rather than from supplements

    Observations of the Askaryan Effect in Ice

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    We report on the first observations of the Askaryan effect in ice: coherent impulsive radio Cherenkov radiation from the charge asymmetry in an electromagnetic (EM) shower. Such radiation has been observed in silica sand and rock salt, but this is the first direct observation from an EM shower in ice. These measurements are important since the majority of experiments to date that rely on the effect for ultra-high energy neutrino detection are being performed using ice as the target medium. As part of the complete validation process for the Antarctic Impulsive Transient Antenna (ANITA) experiment, we performed an experiment at the Stanford Linear Accelerator Center (SLAC) in June 2006 using a 7.5 metric ton ice target, yielding results fully consistent with theoretical expectations

    New Limits on the Ultra-high Energy Cosmic Neutrino Flux from the ANITA Experiment

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    We report initial results of the first flight of the Antarctic Impulsive Transient Antenna (ANITA-1) 2006-2007 Long Duration Balloon flight, which searched for evidence of a diffuse flux of cosmic neutrinos above energies of 3 EeV. ANITA-1 flew for 35 days looking for radio impulses due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. We report here on our initial analysis, which was performed as a blind search of the data. No neutrino candidates are seen, with no detected physics background. We set model-independent limits based on this result. Upper limits derived from our analysis rule out the highest cosmogenic neutrino models. In a background horizontal-polarization channel, we also detect six events consistent with radio impulses from ultra-high energy extensive air showers.Comment: 4 pages, 2 table

    The gene-specific codon counting database: a genome-based catalog of one-, two-, three-, four- and five-codon combinations present in Saccharomyces cerevisiae genes

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    A codon consists of three nucleotides and functions during translation to dictate the insertion of a specific amino acid in a growing peptide or, in the case of stop codons, to specify the completion of protein synthesis. There are 64 possible single codons and there are 4096 double, 262 144 triple, 16 777 216 quadruple and 1 073 741 824 quintuple codon combinations available for use by specific genes and genomes. In order to evaluate the use of specific single, double, triple, quadruple and quintuple codon combinations in genes and gene networks, we have developed a codon counting tool and employed it to analyze 5780 Saccharomyces cerevisiae genes. We have also developed visualization approaches, including codon painting, combination and bar graphs, and have used them to identify distinct codon usage patterns in specific genes and groups of genes. Using our developed Gene-Specific Codon Counting Database, we have identified extreme codon runs in specific genes. We have also demonstrated that specific codon combinations or usage patterns are over-represented in genes whose corresponding proteins belong to ribosome or translation-associated biological processes. Our resulting database provides a mineable list of multi-codon data and can be used to identify unique sequence runs and codon usage patterns in individual and functionally linked groups of genes

    Condom and Oral Contraceptive Use and Risk of Cervical Intraepithelial Neoplasia in Australian Women

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    Objective: To assess the association between condom use and oral contraceptive consumption and the risk of cervical intraepithelial neoplasia (CIN).Methods: A cross-sectional study was conducted in Perth clinics. A total of 348 women responded to the structured questionnaire. Information sought included demographic and lifestyle characteristics such as the use of condom for contraception, consumption of oral contraceptive, and duration of oral contraceptive usage. Crude and adjusted odds ratio (OR) and associated 95% confidence interval (CI) were calculated using unconditional logistic regression models and reported as estimates of the relative risk. Results: The prevalence of CIN was found to be 15.8%. The duration of oral contraceptive consumption among women with abnormal Papanicolaou (Pap) smear result indicating CIN was significantly shorter than those without abnormal Pap smear result (mean±SD, 5.6±5.2 years vs. 8.2±7.6 years; p=0.002). Comparing to =3 years usage, prolonged consumption of oral contraceptive for =10 years reduced the risk of CIN (p=0.012). However, use of condom for contraception might not be associated with a reduced risk of CIN after accounting for the effects of confounding factors (adjusted OR, 0.52; 95% CI, 0.05 to 5.11; p=0.577).Conclusion: Use of oral contraceptives, but not condoms, for contraception appeared to be inversely associated with CIN. Prolonged use of oral contraceptive demonstrated its benefits of reducing the risk of CIN

    Which women stop smoking during pregnancy and the effect on breastfeeding duration

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    BACKGROUND: Cigarette smoking during pregnancy increases the risk of adverse pregnancy outcomes and women who quit smoking at this time are able to reduce the risk of low birth weight, preterm labour, spontaneous abortion and perinatal death. This study investigates the socio-demographic characteristics of pregnant women who stop smoking during pregnancy and the association between stopping smoking and breastfeeding duration. METHODS: A 12 month longitudinal study was conducted in two public maternity hospitals in Perth, Australia between mid-September 2002 and mid-July 2003. While in hospital, participating mothers completed a self-administered baseline questionnaire. Follow up telephone interviews were conducted at 4, 10, 16, 22, 32, 40 and 52 weeks. RESULTS: A total of 587 (55%) mothers participated in the study. Two hundred and twenty six (39%) mothers reported smoking prior to pregnancy and 77 (34%) of these stopped smoking during pregnancy. Women who were pregnant for the first time were twice as likely (OR = 2.05; 95% CI 1.047 – 4.03; p < 0.05) to quit smoking as multiparous women. Women who smoked more than 10 cigarettes per day were significantly less likely to quit smoking during pregnancy (OR = 0.36; 95% CI 0.18 – 0.69; p < 0.05). Women who consumed alcohol before pregnancy were three times more likely to quit smoking (OR = 2.58; 95% CI 1.00 – 6.66; p < 0.05). Quitting smoking during pregnancy was significantly associated with breastfeeding for longer than six months (OR = 3.70; 95% CI 1.55 – 8.83; p < 0.05). CONCLUSION: Pregnancy is a time when many women are motivated to quit smoking and providing targeted smoking cessation interventions at this time, which take into account factors predictive of quitting smoking, are more likely to be successful

    Cervical HPV infection and neoplasia in a large population-based prospective study: the Manchester cohort

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    Cytology and histology records and cervical samples for HPV assay were obtained from a prospective cohort of 49 655 women attending clinics for routine cervical cytology in or near Manchester between 1988 and 1993. The women were followed up for cytological abnormality and neoplasia through the cytology laboratory's records. HPV at entry was assayed in an age- and period-stratified random sample of 7278 women and in prevalent and incident CIN3 cases. The prevalence of newly diagnosed CIN3 increased with time since last normal smear, indicating that most cases persist for several years. CIN3 prevalence did not increase further for screening intervals exceeding 5 years, however, suggesting that CIN3 eventually regresses cytologically. CIN2 prevalence increased less steeply with screening interval, while the prevalence of lesser abnormality was almost independent of screening interval. The prevalence of oncogenic HPV at entry declined from 19% among women aged under 25 to less than 3% at age 40 or above. Oncogenic HPV infection was strongly predictive of subsequent CIN3 (OR 17.2, 95% CI 10.4-28.4), but only weakly related to CIN2 (OR 2.3, 95% CI 0.5-10.7) and lesser abnormality (OR 1.4, 95% CI 0.8-2.5). At current incidence rates, the lifetime risk of developing CIN3 will be 9% in this population. The cumulative risk of CIN3 diagnosis among cytologically normal women with oncogenic HPV detected at entry was 28% (CI 18-43%) after 14 years. Persistence of oncogenic HPV may be more sensitive and specific than cytology for early detection of CIN3 and invasive cancer
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