982 resultados para 332.224
Resumo:
Data warehouse projects, today, are in an ambivalent situation. On the one hand, data warehouses are critical for a company’s success and various methodological and technological tools are sophisticatedly developed to implement them. On the other hand, a significant amount of data warehouse projects fails due to non-technical reasons such as insufficient management support or in-corporative employees. But management support and user participation can be increased dramatically with specification methods that are understandable to these user groups. This paper aims at overcoming possible non-technical failure reasons by introducing a user-adequate specification approach within the field of management information systems.
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This paper explores the important role the media play in informing young people about masturbation. A pilot study of focus groups with twenty-two young Australians, aged between 14-16 explored what they know about sex and sexuality, and where they have found that knowledge. This paper reports on their knowledge about masturbation. Although researchers agree that masturbation can be a positive part of healthy sexual development, most young people reported that they received very little positive information about it from their parents or in formal sex education in school. These young people’s discussions around this topic were largely ambivalent, but also highly complex due to the varying levels and types of information that they receive. In this context the media play a vital role in providing information about masturbation through books and magazines for young women, and television comedies for young men.
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In many applications of active noise control (ANC), an online secondary path modelling method using a white noise as a training signal is required to ensure convergence of the system. The modelling accuracy and the convergence rate increase when a white noise with larger variance is used, however larger the variance increases the residual noise, which decreases performance of the system. The proposed algorithm uses the advantages of the white noise with larger variance to model the secondary path, but the injection is stopped at the optimum point to increase performance of the system. In this approach, instead of continuous injection of the white noise, a sudden change in secondary path during the operation makes the algorithm to reactivate injection of the white noise to adjust the secondary path estimation. Comparative simulation results shown in this paper indicate effectiveness of the proposed method.
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Current design rules for determining the member strength of cold-formed steel columns are based on the effective length of the member and a single column capacity curve for both pin-ended and fixed-ended columns. This research has reviewed the use of AS/NZS 4600 design rules for their accuracy in determining the member compression capacities of slender cold-formed steel columns using detailed numerical studies. It has shown that AS/NZS 4600 design rules accurately predicted the capacities of pinned and fixed ended columns undergoing flexural buckling. However, for fixed ended columns undergoing flexural-torsional buckling, it was found that current AS/NZS 4600 design rules did not include the beneficial effect of warping fixity. Therefore AS/NZS 4600 design rules were found to be excessively conservative and hence uneconomical in predicting the failure loads obtained from tests and finite element analyses of fixed-ended lipped channel columns. Based on this finding, suitable recommendations have been made to modify the current AS/NZS 4600 design rules to more accurately reflect the results obtained from the numerical and experimental studies conducted in this research. This paper presents the details of this research on cold-formed steel columns and the results.
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In response to current developments In the tertiary education sector, the Queensland University of Technology Library has mounted an Intensive course - Advanced Information Retrieval Skills - for higher degree students. In determining need for such a course, a survey of postgraduate students and their supervisors was conducted. Results of this survey are discussed and details of the four credit point subjects are outlined.
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Familial hemiplegic migraine is a severe, rare subtype of migraine. Gene mutations on chromosome 19 have been identified in the calcium channel, voltage-dependent, P/Q type, alpha-1A subunit gene (chromosome 19p13) for familial hemiplegic migraine. Recently a gene mutation (Serine-218-Leucine) for a dramatic syndrome associated with familial hemiplegic migraine, commonly named “migraine coma”, has implicated exon 5 of this gene. The occurrence of trivial head trauma, in such familial hemiplegic migraine patients, may also be complicated by severe, sometimes even fatal, cerebral edema and coma occurring after a lucid interval. Sporadic hemiplegic migraine shares a similar spectrum of clinical presentation and genetic heterogeneity. The case report presented in this article implicates the involvement of the Serine-218-Leucine mutation in the extremely rare disorder of minor head trauma–induced migraine coma. We conclude that the Serine-218-Leucine mutation in the calcium channel, voltage-dependent, P/Q type, alpha-1A subunit gene is involved in sporadic hemiplegic migraine, delayed cerebral edema and coma after minor head trauma.
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Migraine is a painful and debilitating disorder with a significant genetic component. Steroid hormones, in particular estrogen, have long been considered to play a role in migraine, as variations in hormone levels are associated with migraine onset in many sufferers of the disorder. Steroid hormones mediate their activity via hormone receptors, which have a wide tissue distribution. Estrogen receptors have been localized to the brain in regions considered to be involved in migraine pathogenesis. Hence it is possible that genetic variation in the estrogen receptor gene may play a role in migraine susceptibility. This study thus examined the estrogen receptor 1 (ESRα) gene for a potential role in migraine pathogenesis and susceptibility. A population-based cohort of 224 migraine sufferers and 224 matched controls were genotyped for the G594A polymorphism located in exon 8 of the ESR1 gene. Statistical analysis indicated a significant difference between migraineurs and non-migraineurs in both the allele frequencies (P=0.003) and genotype distributions (P=0.008) in this sample. An independent follow-up study was then undertaken using this marker in an additional population-based cohort of 260 migraine sufferers and 260 matched controls. This resulted in a significant association between the two groups with regard to allele frequencies (P=8×10−6) and genotype distributions (P=4×10−5). Our findings support the hypothesis that genetic variation in hormone receptors, in particular the ESR1 gene, may play a role in migraine.
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MC1R gene variants have previously been associated with red hair and fair skin color, moreover skin ultraviolet sensitivity and a strong association with melanoma has been demonstrated for three variant alleles that are active in influencing pigmentation: Arg151Cys, Arg160Trp, and Asp294His. This study has confirmed these pigmentary associations with MC1R genotype in a collection of 220 individuals drawn from the Nambour community in Queensland, Australia, 111 of whom were at high risk and 109 at low risk of basal cell carcinoma and squamous cell carcinoma. Comparative allele frequencies for nine MC1R variants that have been reported in the Caucasian population were determined for these two groups, and an association between prevalence of basal cell carcinoma, squamous cell carcinoma, solar keratosis and the same three active MC1R variant alleles was demonstrated [odds ratio = 3.15 95% CI (1.7, 5.82)]. Three other commonly occurring variant alleles: Val60Leu, Val92Met, and Arg163Gln were identified as having a minimal impact on pigmentation phenotype as well as basal cell carcinoma and squamous cell carcinoma risk. A significant heterozygote effect was demonstrated where individuals carrying a single MC1R variant allele were more likely to have fair and sun sensitive skin as well as carriage of a solar lesion when compared with those individuals with a consensus MC1R genotype. After adjusting for the effects of pigmentation on the association between MC1R variant alleles and basal cell carcinoma and squamous cell carcinoma risk, the association persisted, confirming that presence of at least one variant allele remains informative in terms of predicting risk for developing a solar-induced skin lesion beyond that information wained through observation of pigmentation phenotype.
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A high performance liquid chromatographic method for the simultaneous determination of five organochlorine pesticides (aldrin, p,p’-DDT, dieldrin, endrin, and heptachlor) was developed. The method was used to determine the levels of these pesticides in medicinal plant samples. Analysis was carried out using a Merck LiChrospher 100 RP C18 (5 μm) column with a gradient solvent system of acetonitrile-water and PDA UV detection (224 nm). Quantification was carried out by the external standard method. The limit of detection for the utilized method was below the local legal limits (ANZFA) for similar plant materials for all 5 pesticides excepting endrin. Medicinal plant extracts were further analyzed by conventional GC-ECD and GC-NPD means using SPE and GPC cleanup as required.
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Objectives This randomised, controlled trial compared the effectiveness of 0.12% chlorhexidine (CHX) gel and 304% fluoride toothpaste to prevent early childhood caries (ECC) in a birth cohort by 24 months. Methods The participants were randomised to receive either (i) twice daily toothbrushing with toothpaste and once daily 0.12% CHX gel (n = 110) or (ii) twice daily toothbrushing with toothpaste only (study controls) (n = 89). The primary outcome measured was caries incidence and the secondary outcome was percentage of children with mutans streptococci (MS). All mothers were contacted by telephone at 6, 12, and 18 months. At 24 months, all children were examined at a community dental clinic. Results At 24 months, the caries prevalence was 5% (3/61) in the CHX and 7% (4/58) in the controls (P = 0.7). There were no differences in percentages of MS-positive children between the CHX and control groups (54%vs 53%). Only 20% applied the CHX gel once daily and 80% less than once daily. Conclusions Toothbrushing using 304% fluoride toothpaste with or without the application of chlorhexidine gel (0.12%) reduces ECC from 23% found in the general community to 5–7%. The lack of effect with chlorhexidine is likely to be due to low compliance.
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The genetic basis of primary hypertension is not known. Renin is important in blood pressure and volume control and a HindIII restriction fragment length polymorphism (RFLP) is present within the human renin gene locus. To examine whether there is a relationship between this RFLP and primary hypertension, DNA and renin analyses were performed on leukocytes and plasma from hypertensive and normotensive individuals. In hypertensives the frequencies of alleles for the HindIII RFLP were found to be 0.55 and 0.45, compared with 0.60 and 0.40 in the total population of 231 subjects examined, a difference that was not statistically significant. There also appeared to be no significant difference in renin activity in plasma for hypertensive patients of each genotype, nor in their pre- or post-treatment blood pressures. We thus conclude that, within the limits of the present study, the suspected genetic abnormalities associated with primary hypertension in man do not appear to be related to a HindIII RFLP in the renin gene.
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Purpose This article reports on a research project that explored social media best practice in the public library sector. Design/methodology/approach The primary research approach for the project was case study. Two organisations participated in case studies that involved interviews, document analysis, and social media observation. Findings The two case study organisations use social media effectively to facilitate participatory networks, however, there have been challenges surrounding its implementation in both organisations. Challenges include negotiating requirements of governing bodies and broader organisational environments, and managing staff reluctance around the implementations. As social media use continues to grow and libraries continue to take up new platforms, social media must be considered to be another service point of the virtual branch, and indeed, for the library service as a whole. This acceptance of social media as being core business is critical to the successful implementation of social media based activities. Practical implications The article provides an empirically grounded discussion of best practice and the conditions that support it. The findings are relevant for information organisations across all sectors and could inform the development of policy and practice in other organisations. This paper contributes to the broader dialogue around best practice in participatory service delivery and social media use in library and information organisations.
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The life course of Australian researchers includes regular funding applications, which incur large personal and time costs. We previously estimated that Australian researchers spent 550 years preparing 3,727 proposals for the 2012 NHMRC Project Grant funding round, at an estimated annual salary cost of AU$66 million. Despite the worldwide importance of funding rounds, there is little evidence on what researchers think of the application process. We conducted a web-based survey of Australian researchers (May–July 2013) asking about their experience with NHMRC Project Grants. Almost all researchers (n=224 at 31 May) supported changes to the application (96%) and peer-review (88%) processes; 73% supported the introduction of shorter initial Expressions of Interest; and half (50%) provided extensive comments on the NHMRC processes. Researchers agreed preparing their proposals always took top priority over other work (97%) and personal (87%) commitments. More than half (57%) provided extensive comments on the ongoing personal impact of concurrent grant-writing and holiday seasons on family, children and other relationships. Researchers with experience on Grant Review Panels (34%) or as External Reviewers (78%) reported many sections of the proposals were rarely or never read, which suggests these sections could be cut with no impact on the quality of peer review. Our findings provide evidence on the experience of Australian researchers as applicants. The process of preparing, submitting and reviewing proposals could be streamlined to minimise the burden on applicants and peer reviewers, giving Australian researchers more time to work on actual research and be with their families.