57 resultados para Utilization
em University of Queensland eSpace - Australia
Resumo:
Protein, amino acids and ammonium were the main forms of soluble soil nitrogen in the soil solution of a subtropical heathland (wallum). After fire, soil ammonium and nitrate increased 90- and 60-fold, respectively. Despite this increase in nitrate availability after fire, wallum species exhibited uniformly low nitrate reductase activities and low leaf and xylem nitrate, During waterlogging soil amino acids increased, particularly gamma-aminobutyric acid (GABA) which accounted for over 50% of amino nitrogen. Non-mycorrhizal wallum species were significantly (P < 0.05) N-15-enriched (0.3-4.3 parts per thousand) compared to species with mycorrhizal associations (ericoid-type, ecto-, va-mycorrhizal) which were strongly depleted in N-15 (-6.3 to -1.8 parts per thousand). Lignotubers and roots had delta(15)N signatures similar to that of the leaves of respective species. The exceptions were fine roots of ecto-, ecto/va-, and ericoid type mycorrhizal species which were enriched in N-15 (0.1-2 4 parts per thousand). The delta(15)N signatures of delta(15)N(total soil N) and delta(15)N(soil NH4+) were in the range 3.7-4.5 parts per thousand, whereas delta(15)N(soil NO3-) was significantly (P < 0.05) more enriched in N-15 (9.2-9.8 parts per thousand). It is proposed that there is discrimination against N-15 during transfer of nitrogen from fungal to plant partner. Roots of selected species incorporated nitrogen sources in the order of preference: ammonium > glycine > nitrate. The exception were proteoid roots of Hakea (Proteaceae) which incorporated equal amounts of glycine and ammonium.
Resumo:
Recent progress in the production, purification, and experimental and theoretical investigations of carbon nanotubes for hydrogen storage are reviewed. From the industrial point of view, the chemical vapor deposition process has shown advantages over laser ablation and electric-arc-discharge methods. The ultimate goal in nanotube synthesis should be to gain control over geometrical aspects of nanotubes, such as location and orientation, and the atomic structure of nanotubes, including helicity and diameter. There is currently no effective and simple purification procedure that fulfills all requirements for processing carbon nanotubes. Purification is still the bottleneck for technical applications, especially where large amounts of material are required. Although the alkali-metal-doped carbon nanotubes showed high H-2 Weight uptake, further investigations indicated that some of this uptake was due to water rather than hydrogen. This discovery indicates a potential source of error in evaluation of the storage capacity of doped carbon nanotubes. Nevertheless, currently available single-wall nanotubes yield a hydrogen uptake value near 4 wt% under moderate pressure and room temperature. A further 50% increase is needed to meet U.S. Department of Energy targets for commercial exploitation. Meeting this target will require combining experimental and theoretical efforts to achieve a full understanding of the adsorption process, so that the uptake can be rationally optimized to commercially attractive levels. Large-scale production and purification of carbon nanotubes and remarkable improvement of H-2 storage capacity in carbon nanotubes represent significant technological and theoretical challenges in the years to come.
Resumo:
The present study investigated research use and attitudes toward research among pediatric health professionals. All nurses and allied health professionals in a pediatric teaching hospital were surveyed using previously tested and published measures. Over half of the participants had some formal education in research but, for some participants, that education was many years ago. Most participants reported poor or very poor understanding of research design. Two variables were independently associated with a positive attitude towards research: (i) better understanding of how to conduct a literature search; and (ii) higher level of education. Five variables were independently associated with research use: better understanding of research design; having presented at a conference in the past two years; sense of calling to the profession; better understanding of how to conduct a literature search; and attending rounds. A small proportion of variance in both research use and a positive attitude towards research was explained by the independent predicator variables. Further research is required to identify characteristics of the workplace environment that support research use.
Resumo:
Since the 1980s, numerous studies conducted in the United States have attempted to estimate the prevalence of supplement use among the population (e.g., the National Health and Nutrition Survey and the National Health Interview Surveys). Despite these efforts, the true extent of supplement use is unclear. The literature pertaining to the prevalence of supplement use refers to a confusing array of ambiguous terms. Forming accurate conclusions about supplement use is confounded by differences in terminology and methodology between studies. Direct comparisons between studies are therefore inherently problematic. The emphasis in future investigations should be on standardizing the study design; recording data on daily, weekly, or even monthly use in order to establish the safety and efficacy of supplement use; and adopting a consistent, uniform definition of the term supplement.
Resumo:
Objective: Inpatient length of stay (LOS) is an important measure of hospital activity, health care resource consumption, and patient acuity. This research work aims at developing an incremental expectation maximization (EM) based learning approach on mixture of experts (ME) system for on-line prediction of LOS. The use of a batchmode learning process in most existing artificial neural networks to predict LOS is unrealistic, as the data become available over time and their pattern change dynamically. In contrast, an on-line process is capable of providing an output whenever a new datum becomes available. This on-the-spot information is therefore more useful and practical for making decisions, especially when one deals with a tremendous amount of data. Methods and material: The proposed approach is illustrated using a real example of gastroenteritis LOS data. The data set was extracted from a retrospective cohort study on all infants born in 1995-1997 and their subsequent admissions for gastroenteritis. The total number of admissions in this data set was n = 692. Linked hospitalization records of the cohort were retrieved retrospectively to derive the outcome measure, patient demographics, and associated co-morbidities information. A comparative study of the incremental learning and the batch-mode learning algorithms is considered. The performances of the learning algorithms are compared based on the mean absolute difference (MAD) between the predictions and the actual LOS, and the proportion of predictions with MAD < 1 day (Prop(MAD < 1)). The significance of the comparison is assessed through a regression analysis. Results: The incremental learning algorithm provides better on-line prediction of LOS when the system has gained sufficient training from more examples (MAD = 1.77 days and Prop(MAD < 1) = 54.3%), compared to that using the batch-mode learning. The regression analysis indicates a significant decrease of MAD (p-value = 0.063) and a significant (p-value = 0.044) increase of Prop(MAD
Resumo:
Objectives The aims of the study were to describe the prevalence and associations of mental health disorder (MHD) among a cohort of HIV-infected patients attending the Victorian HIV/AIDS Service between 1984 and 2000, and to examine whether antiretroviral therapy use or mortality was influenced by MHD (defined as a record of service provision by psychiatric services on the Victorian Psychiatric Case Register). It was hypothesized that HIV-positive individuals with MHD would have poorer treatment outcomes, reduced responses to highly active antiretroviral therapy (HAART) and increased mortality compared with those without MHD. Methods This is a retrospective cohort of 2981 individuals (73% of the Victorian population diagnosed with HIV infection) captured on an HIV database which was electronically matched with the public Victorian Psychiatric Case Register (VPCR) (accounting for 95% of public system psychiatry service provision). The prevalence, dates and recorded specifics of mental health disorders at the time of the electronic match on 1 June 2000 are described. The association with recorded MHD, gender, age, AIDS illness, HIV exposure category, duration and type of antiviral therapy, treatment era (prior to 1986, post-1987 and pre-HAART, and post-HAART) on hospitalization and mortality at 1 September 2001 was assessed. Results Five hundred and twenty-five individuals (17.6% of the Victorian HIV-positive population) were recorded with MHD, most frequently coded as attributable to substance dependence/abuse or affective disorder. MHD was diagnosed prior to HIV in 33% and, of those diagnosed after HIV, 93.8% were recorded more than 1 year after the HIV diagnosis. Schizophrenia was recorded in 6% of the population with MHD. Hospitalizations for both psychiatric and nonpsychiatric illness were more frequent in those with MHD (relative risk 5.4; 95% confidence interval 3.7, 8.2). The total number of antiretrovirals used (median 6.4 agents vs 5.5 agents) was greater in those with MHD. When adjusted for antiretroviral treatment era, HIV exposure category, CD4 cell count and antiretroviral therapy, survival was not affected by MHD. Conclusions MHD is frequent in this population with HIV infection and is associated with increased healthcare utilization but not with reduced survival.
Resumo:
Objectives: This study aimed to identify rates and correlates of psychotropic drug utilization in children and adolescents in inpatient and outpatient settings. Methods: A retrospective chart review examined 122 inpatient and 126 outpatient charts from a metropolitan child and youth mental health service in Brisbane, Australia. Results: Inpatients received more psychotropic medication than outpatients (71% vs. 25%; p < 0.01). Patients receiving medication were older, had longer hospital admissions, and more complex presentations, including history of abuse or suicide attempts and more diagnoses (all p < 0.01). Selective serotonin reuptake inhibitors (SSRIs) were the most frequently used drug class (44% inpatients; 14% outpatients), primarily indicated for mood disorders (31%). SSRIs and newer antidepressants (ADs) were used more frequently in patients with a high suicide risk (p < 0.01). Atypical antipsychotics (APs) were also used (inpatients 23%; outpatients 3%), primarily for behavioral disturbances. Half of those receiving medication (51%) received polypharmacy (> 1 concurrent drug), with up to four drugs used at one time. Rates of polypharmacy were highest among patients receiving antipsychotics. Conclusions: Use of psychotropic medication is frequent in this population. Future research should initially focus on inpatients and intensive treatment settings and examine both safety and efficacy of interventions for depression in young people, atypical antipsychotics for behavioral disturbances, and polypharmacy.
Resumo:
Current evidence supports parenteral infusion of proton pump inhibitors (PPI) after endoscopic treatment of bleeding peptic ulcers and such treatment seems reasonable where there is active bleeding or visible vessel on endoscopy. Parenteral boluses of PPI can be used in patients nil by mouth who cannot tolerate oral therapy. We sought to examine the appropriateness of parenteral PPI use. Drug utilisation evaluation was performed on 94 patients admitted to a 500 bed metropolitan hospital. 39 patients received continuous parenteral infusion of omeprazole (8 mg/ h) over a mean of 60 ± 29 h. 55 patients had parenteral boluses (40 mg bd) of omeprazole over a mean of 5 ± 4 days. Indications for PPI infusion (n = 39) were: major haemorrhage requiring transfusion (23), minor haemorrhage (8), dyspepsia (4) and others (4). 31 of the 39 patients on PPI infusion had upper gastrointestinal (GI) endoscopy. PPI infusion was commenced prior to endoscopy in 26 (84%) patients. 13 patients (33%) had active bleeding or visible non bleeding vessels at endoscopy. Only 11 patients (28%) had endoscopically treated peptic ulcers. Indications for parenteral PPI boluses (n = 55) included patients nil by mouth unable to take maintenance PPI orally (21), minor haemorrhage (8), peptic ulcer prophylaxis in seriously unwell (6), major haemorrhage (4), dyspepsia (2), postoprative period following peptic ulcer surgery (2) and others (12). Endoscopy was performed in 10 patients (18%) with only 1 endoscopically treated peptic ulcer. Our data suggest significant inappropriate use of parenteral PPI, which may be used for minor GI bleeding and dyspepsia and are typically commenced prior to endoscopy. These findings can explain the costly hospital expenditure on PPI.
Resumo:
Though technology holds significant promise for enhanced teaching and learning it is unlikely to meet this promise without a principled approach to course design. There is burgeoning discourse about the use of technological tools and models in higher education, but much of the discussion is fixed upon distance learning or technology based courses. This paper will develop and propose a balanced model for effective teaching and learning for “on campus” higher education, with particular emphasis on the opportunities for revitalisation available through the judicious utilisation of new technologies. It will explore the opportunities available for the creation of more authentic learning environments through the principled design. Finally it will demonstrate with a case study how these have come together enabling the creation of an effective and authentic learning environment for one pre-service teacher education course at the University of Queensland.