227 research outputs found

    Generalized autoregressive conditional correlation

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    This paper develops a generalized autoregressive conditional correlation (GARCC) model when the standardized residuals follow a random coefficient vector autoregressive process. As a multivariate generalization of the Tsay (1987, Journal of the American Statistical Association 82, 590-604) random coefficient autoregressive (RCA) model, the GARCC model provides a motivation for the conditional correlations to be time varying. GARCC is also more general than the Engle (2002, Journal of Business & Economic Statistics 20, 339-350) dynamic conditional correlation (DCC) and the Tse and Tsui (2002, Journal of Business & Economic Statistics 20, 351-362) varying conditional correlation (VCC) models and does not impose unduly restrictive conditions on the parameters of the DCC model. The structural properties of the GARCC model, specifically, the analytical forms of the regularity conditions, are derived, and the asymptotic theory is established. The Baba, Engle, Kraft, and Kroner (BEKK) model of Engle and Kroner (1995, Econometric Theory 11, 122-150) is demonstrated to be a special case of a multivariate RCA process. A likelihood ratio test is proposed for several special cases of GARCC. The empirical usefulness of GARCC and the practicality of the likelihood ratio test are demonstrated for the daily returns of the Standard and Poor's 500, Nikkei, and Hang Seng indexes

    Ovicidal activity of Pithecellobium dulce (Family: Fabaceae) leaf and seed extracts against fi lariasis vector mosquito Culex quinquefasciatus (Diptera: Culicidae)

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    Mosquito-borne diseases with an economic impact create a loss in commercial and labor outputs, particularly incountries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence ofresistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontroltechniques in the future. In view of recently increased interest in developing plant origin insecticides as analternative to chemical insecticide, in the present study ovicidal efficacy of different solvent leaf and seed extractof Pithecellobium dulce against filariasis vector C. quinquefasciatus. The ovicidal efficacy of the crude leaf extractsof P. dulce with five different solvents, such as benzene, hexane, ethyl acetate, methanol, and chloroform, wastested against C. quinquefasciatus. Ovicidal activity was determined against C. quinquefasciatus mosquito tovarious concentrations ranging from 100 to 600 mg/L under the laboratory conditions. Among five solvent testedthe maximum efficacy was observed in the leaf and seed methanol crude extract was found to be most effectivefor ovicidal activity against vector mosquito. The extract of methanol exerted 100% mortality at 500-600 mg/Lagainst C. quinquefasciatus. From the result, it can be concluded the crude extract of P. dulce was a potentialcandidate to develop newer and safer ovicides against C. quinquefasciatus

    Chemical composition of the essential oil of Ocimum tenuiflorum L. (Krishna Tulsi) from North West Karnataka, India

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    The chemical composition of the essential oil of flowering aerial parts of Ocimum tenuiflorum L. growing in the North West Karnataka, India, was investigated. The hydro-distilled essential oil was analyzed by gas chromatography equipped with flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Results demonstrated that the oil was found to be rich in phenyl derivative compounds (83.8%). The major compound was identified as methyl eugenol (82.9%) among twenty-six compounds, comprising 98.9% of the total oil

    Use of postmenopausal hormone therapy and risk of Alzheimer's disease in Finland : nationwide case-control study

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    OBJECTIVES To compare the use of hormone therapy between Finnish postmenopausal women with and without a diagnosis for Alzheimer's disease. DESIGN Nationwide case-control study. SETTING Finnish national population and drug register, between 1999 and 2013. PARTICIPANTS All postmenopausal women (n= 84 739) in Finland who, between 1999 and 2013, received a diagnosis of Alzheimer's disease from a neurologist or geriatrician, and who were identified from a national drug register. Control women without a diagnosis (n= 84 739), matched by age and hospital district, were traced from the Finnish national population register. INTERVENTIONS Data on hormone therapy use were obtained from the Finnish national drug reimbursement register. MAIN OUTCOME MEASURES Odds ratios and 95% confidence intervals for Alzheimer's disease, calculated with conditional logistic regression analysis. RESULTS In 83 688 (98.8%) women, a diagnosis for Alzheimer's disease was made at the age of 60 years or older, and 47 239 (55.7%) women had been over 80 years of age at diagnosis. Use of systemic hormone therapy was associated with a 9-17% increased risk of Alzheimer's disease. The risk of the disease did not differ significantly between users of estradiol only (odds ratio 1.09, 95% confidence interval 1.05 to 1.14) and those of oestrogen-progestogen (1.17, 1.13 to 1.21). The risk increases in users of oestrogen-progestogen therapy were not related to different progestogens (noreth isterone acetate, medroxyprogesterone acetate, or other progestogens); but in women younger than 60 at hormone therapy initiation, these risk increases were associated with hormone therapy exposure over 10 years. Furthermore, the age at initiation of systemic hormone therapy was not a decisive determinant for the increase in risk of Alzheimer's disease. The exclusive use of vaginal estradiol did not affect the risk of the disease (0.99, 0.96 to 1.01). CONCLUSIONS Long term use of systemic hormone therapy might be accompanied with an overall increased risk of Alzheimer's disease, which is not related to the type of progestogen or the age at initiation of systemic hormone therapy. By contrast, use of vaginal estradiol shows no such risk. Even though the absolute risk increase for Alzheimer's disease is small, our data should be implemented into information for present and future users of hormone therapy.Peer reviewe

    Avoiding Treatment Interruptions: What Role Do Australian Community Pharmacists Play?

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    OBJECTIVE: To explore the reported practice of Australian community pharmacists when dealing with medication supply requests in absence of a valid prescription. METHODS: Self-administered questionnaire was posted to 1490 randomly selected community pharmacies across all Australian states and territories. This sample was estimated to be a 20% of all Australian community pharmacies. RESULTS: Three hundred eighty five pharmacists participated in the study (response rate achieved was 27.9% (there were 111 undelivered questionnaires). Respondents indicated that they were more likely to provide medications to regular customers without a valid prescription compared to non-regular customers (p<0.0001). However, supply was also influenced by the type of prescription and the medication requested. In the case of type of prescription (Standard, Authority or Private) this relates to the complexity/probability of obtaining a valid prescription from the prescriber at a later date (i.e. supply with an anticipated prescription). Decisions to supply and/or not supply related to medication type were more complex. For some cases, including medication with potential for abuse, the practice and/or the method of supply varied significantly according to age and gender of the pharmacist, and pharmacy location (p<0.05). CONCLUSIONS: Although being a regular customer does not guarantee a supply, results of this study reinforce the importance for patients having a regular pharmacy, where pharmacists were more likely to continue medication supply in cases of patients presenting without a valid prescription. We would suggest, more flexible legislation should be implemented to allow pharmacists to continue supplying of medication when obtaining a prescription is not practical

    Is the pharmacy profession innovative enough?: meeting the needs of Australian residents with chronic conditions and their carers using the nominal group technique

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    Background Community pharmacies are ideally located as a source of support for people with chronic conditions. Yet, we have limited insight into what innovative pharmacy services would support this consumer group to manage their condition/s. The aim of this study was to identify what innovations people with chronic conditions and their carers want from their ideal community pharmacy, and compare with what pharmacists and pharmacy support staff think consumers want. Methods We elicited ideas using the nominal group technique. Participants included people with chronic conditions, unpaid carers, pharmacists and pharmacy support staff, in four regions of Australia. Themes were identified via thematic analysis using the constant comparison method. Results Fifteen consumer/carer, four pharmacist and two pharmacy support staff groups were conducted. Two overarching themes were identified: extended scope of practice for the pharmacist and new or improved pharmacy services. The most innovative role for Australian pharmacists was medication continuance, within a limited time-frame. Consumers and carers wanted improved access to pharmacists, but this did not necessarily align with a faster or automated dispensing service. Other ideas included streamlined access to prescriptions via medication reminders, electronic prescriptions and a chronic illness card. Conclusions This study provides further support for extending the pharmacist’s role in medication continuance, particularly as it represents the consumer’s voice. How this is done, or the methods used, needs to optimise patient safety. A range of innovative strategies were proposed and Australian community pharmacies should advocate for and implement innovative approaches to improve access and ensure continuity of care

    Functional profiling of long intergenic non-coding RNAs in fission yeast

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    Eukaryotic genomes express numerous long intergenic non-coding RNAs (lincRNAs) that do not overlap any coding genes. Some lincRNAs function in various aspects of gene regulation, but it is not clear in general to what extent lincRNAs contribute to the information flow from genotype to phenotype. To explore this question, we systematically analysed cellular roles of lincRNAs in Schizosaccharomyces pombe. Using seamless CRISPR/Cas9-based genome editing, we deleted 141 lincRNA genes to broadly phenotype these mutants, together with 238 diverse coding-gene mutants for functional context. We applied high-throughput colony-based assays to determine mutant growth and viability in benign conditions and in response to 145 different nutrient, drug, and stress conditions. These analyses uncovered phenotypes for 47.5% of the lincRNAs and 96% of the protein-coding genes. For 110 lincRNA mutants, we also performed high-throughput microscopy and flow cytometry assays, linking 37% of these lincRNAs with cell-size and/or cell-cycle control. With all assays combined, we detected phenotypes for 84 (59.6%) of all lincRNA deletion mutants tested. For complementary functional inference, we analysed colony growth of strains ectopically overexpressing 113 lincRNA genes under 47 different conditions. Of these overexpression strains, 102 (90.3%) showed altered growth under certain conditions. Clustering analyses provided further functional clues and relationships for some of the lincRNAs. These rich phenomics datasets associate lincRNA mutants with hundreds of phenotypes, indicating that most of the lincRNAs analysed exert cellular functions in specific environmental or physiological contexts. This study provides groundwork to further dissect the roles of these lincRNAs in the relevant conditions
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