915 resultados para utilization


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An aging electricity distribution system and reduced availability of naturally durable tropical hardwoods in Australia will combine in the next decade to produce a major shortage of poles. One approach to mitigating this shortage is to utilize lower durability species and improve the penetration of preservatives into the refractory heartwood by introducing additional pretreatment processes. A potential method for improving preservative penetration in the critical ground-line zone is through-boring. This process, in which holes are drilled through the pole perpendicular to the grain in the ground-line zone, is widely used in the western United States for treatment of Douglas-fir and may be Suitable for many Australian wood species. The potential for improving heartwood penetration in eucalypts with alkaline-copper-quaternary (ACQ) compound was assessed on heartwood specimens from four species (Eucalyptus cloeziana F.Muell., E. grandis W.Hill ex Maiden, E. obliqua L'Her. and E. pellita F.Muell.) and Lophostemon confertus (R.Br.) Peter G.Wilson & J.T.Wateril). Longitudinal ACQ penetration was extremely shallow in L. confertus and only slightly better in E. cloeziana. Longitudinal penetration was good in both E. obliqua and E. pellita, although there was some variation in treatment results with length of pressure period. The results suggest that through-boring might be a reasonable approach for achieving heartwood penetration in some Eucalyptus species, although further studies are required to assess additional treatment schedules and to determine the effects of the process oil flexural properties of the poles.

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Anatomically precontoured plates are commonly used to treat periarticular fractures. A well-fitting plate can be used as a tool for anatomical reduction of the fractured bone. Recent studies highlighted that some plates fit poorly for many patients due to considerable shape variations between bones of the same anatomical site. While it is impossible to design one shape that fits all, it is also burdensome for the manufacturers and hospitals to produce, store and manage multiple plate shapes without the certainty of utilization by a patient population. In this study, we investigated the number of shapes required for maximum fit within a given dataset, and if they could be obtained by manually deforming the original plate. A distal medial tibial plate was automatically positioned on 45 individual tibiae, and the optimal deformation was determined iteratively using finite element analysis simulation. Within the studied dataset, we found that: (i) 89% fit could be achieved with four shapes, (ii) 100% fit was impossible through mechanical deformation, and (iii) the deformations required to obtain the four plate shapes were safe for the stainless steel plate for further clinical use. The proposed framework is easily transferable to other orthopaedic plates.

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Exotic and invasive woody vines are major environmental weeds of riparian areas, rainforest communities and remnant natural vegetation in coastal eastern Australia, where they smother standing vegetation, including large trees, and cause canopy collapse. We investigated, through glasshouse resource manipulative experiments, the ecophysiological traits that might facilitate faster growth, better resource acquisition and/or utilization and thus dominance of four exotic and invasive vines of South East Queensland, Australia, compared with their native counterparts. Relative growth rate was not significantly different between the two groups but water use efficiency (WUE) was higher in the native species while the converse was observed for light use efficiency (quantum efficiency, AQE) and maximum photosynthesis on a mass basis (Amax mass). The invasive species, as a group, also exhibited higher respiration load, higher light compensation point and higher specific leaf area. There were stronger correlations of leaf traits and greater structural (but not physiological) plasticity in invasive species than in their native counterparts. The scaling coefficients of resource use efficiencies (WUE, AQE and respiration efficiency) as well as those of fitness (biomass accumulated) versus many of the performance traits examined did not differ between the two species-origin groups, but there were indications of significant shifts in elevation (intercept values) and shifts along common slopes in many of these relationships – signalling differences in carbon economy (revenue returned per unit energy invested) and/or resource usage. Using ordination and based on 14 ecophysiological attributes, a fair level of separation between the two groups was achieved (51.5% explanatory power), with AQE, light compensation point, respiration load, WUE, specific leaf area and leaf area ratio, in decreasing order, being the main drivers. This study suggests similarity in trait plasticity, especially for physiological traits, but there appear to be fundamental differences in carbon economy and resource conservation between native and invasive vine species.

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A 2 × 2 factorial combination of thinned or unthinned, and pruned or unpruned 11-year-old Eucalyptus dunnii (DWG) and 12-year-old Corymbia citriodora subsp. variegata (CCV) was destructively sampled to provide 60 trees in total per species. Two 1.4 m long billets were cut from each tree and were rotary veneered in a spindleless lathe down to a 45 mm diameter core to expose knots which were classified as either alive, partially occluded or fully occluded. Non-destructive evaluation of a wider range of thinning treatments available in these trials was undertaken with Pilodyn and Fakopp tools. Disc samples were also taken for basic density and modulus of elasticity. Differences between treatments for all wood property assessments were generally small and not significantly different.Thinning and pruning had little effect on the stem diameter growth required to achieve occlusion, therefore occlusion would be more rapid after thinning due to more rapid stem diameter growth. The difference between the treatments of greatest management interest, thinned and pruned (T&P) and unthinned and unpruned (UT&UP) were small. The production of higher value clear wood produced after all knots had occluded, measured as the average stem diameter growth over occlusion of the three outermost knots, was approximately 2 centimetres diameter. Two of the treatments can be ruled out as viable management alternatives: (i) the effect of thinning without pruning (T&UP) is clear, leading to a large inner core of stem wood containing knots (large knotty core diameter) and (ii) pruning without thinning (UT&P) results in a small knotty core diameter, however the tree and therefore log diameters are also small.

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A mature Caribbean pine (Pinus caribaea var. hondurensis) silviculture experiment provided initial square spacing treatments of 1.8 m2, 2.4 m2, 3.0 m2 and 3.6 m2 (equal to 3088, 1737, 1111 and 772 stems/ha) that were thinned at age 10 years to 600, 400 and 200 stems/ha, retaining an unthinned control for each initial spacing. The trial was destructively sampled at age of 28 years and discs taken along 8 various stem heights were analysed for variation in basic density and SilviScan wood properties. In addition, the logs from ten stocking × thinning treatments were processed in a sawing study. Results indicate thinning effects were generally more pronounced than initial spacing effects. Fast growing trees produced wood with significantly higher average wood densities and higher average stiffness values. Detailed SilviScan densitometry results obtained radially and at various stem heights enabled construction of tree maps for wood properties, providing insights into the variation in juvenile to mature wood proportion across the initial and post-thinning stocking treatments studied. Dried dressed recovery was strongly related to tree size, and log value decreased consistently from butt to top logs across all treatments. The estimated value per hectare was highest in unthinned plots due to values being multiplied by high stem numbers per hectare. However, a complete economic analysis considering all cost structures is required to investigate the optimal silviculture to maximise economic returns to growers and processors. Improved understanding of the relationship between initial spacing, post-thinning stocking and wood and end-product quality should help to customize future forest management strategies required to produce better quality wood and wood products.

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The objective of this study was to gain an understanding for drying sawn timber produced from fast-grown, well-managed Queensland hardwood plantations using accelerated drying methods. Due to limited resources, this was a preliminary study and further work will be required to optimize schedules for industrial implementation. Three conventional kiln trials, including two for 38-mm-thick, 19-year-old plantation Gympie messmate (Eucalyptus cloeziana F. Muell.) and one for 25mm thick, 15-year-old plantation red mahogany (Eucalyptus pellita F. Muell.), and two vacuum kiln drying trials, one each for 38- and 25mm thick Gympie messmate, were conducted. Measurements of final cross-sectional moisture content, moisture content gradient, residual drying stress, and internal and surface checking were used to quantify dried quality. Drying schedules were chosen based on either existing published schedules or, in the case of the vacuum drying trials, existing schedules for species with similar wood density and dying degrade properties, or manipulated schedules based on the results of trials conducted during this study. The findings indicate that both species can be dried using conventional drying techniques with acceptable grade quality in approximately 75 percent of the drying time that industry is currently achieving when drying native forest timber of the same species. The vacuum drying time was 60 percent less than conventional drying for 38-mm-thick, 19-year-old Gympie messmate, although drying quality needs improving. The findings have shown that through careful schedule manipulation and adjustment, the grade quality can be optimized to suit the desired expectation. Additional research is required to further optimize the schedules to ensure acceptable grade qualities can be reliably achieved across all drying criteria and exploit opportunities to reduce drying times further.

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Displacement of the fungus Fusarium pseudograminearum from stubble by antagonists is a potential means of biocontrol of crown rot in cereals. The role of carbon and nitrogen nutrition in interactions between the pathogen and the antagonists Fusarium equiseti, Fusarium nygamai, Trichoderma harzianum and the non-antagonistic straw fungus Alternaria infectoria was investigated. Sole carbon source utilization patterns on Biolog plates were similar among the three Fusarium species, suggesting a possible role for competition. However, carbon niche overlap was unlikely to be important in antagonism by T. harzianum. Straw medium supplemented with sugars generally reduced the inhibitory effect of antagonists on growth of F. pseudograminearum in dual culture, indicating that availability of simple carbon sources does not limit antagonism. Adding nitrogen as urea, nitrate or ammonium to straw medium had little effect on antagonism by F. equiseti and F. nygamai, but ammonium addition removed the inhibitory effect of T. harzianum on growth of F. pseudograminearum. Displacement of F. pseudograminearum from straw by all fungi in a Petri dish assay was greater when urea or nitrate was used as a nitrogen source than with ammonium. All forms of nitrogen significantly increased displacement of F. pseudograminearum from straw under simulated field conditions when straws were either inoculated with T. harzianum or exposed to resident soil microbes. However, in 2 out of 3 experiments urea and nitrate were more effective than ammonium. The results suggest that availability of nitrogen, but not carbon, is limiting the activities of antagonists of F. pseudograminearum in straw, and the way nitrogen is applied can influence the rate of displacement and mortality of the pathogen in host residues.

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Malnutrition is a significant clinical and public health problem. The prevalence of malnutrition was determined in a sample of older people living in 2 residential aged care facilities in Australia. The Subjective Global Assessment tool was used to determine the prevalence of malnutrition in 57 residents. The majority of residents were well nourished (67), 26 moderately malnourished, and 7 severely malnourished. Prevalence of malnutrition was higher for those receiving high-level care (42), but this was not statistically significant (P =.437). No relationship was found between malnutrition status and age (P =.529) or sex (P =.839).

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Sample medications represented 4 (3.8 million Australian dollars) of the Australian general practice promotional budget of pharmaceutical companies in the second quarter of 2005. In the United States, general practitioners have been shown to use sample medication in up to 20 of encounters both for commencing and for full treatment. Given the USA does not have a universal subsidy for medications like Australia, sample use may be higher than Australian GPs operating with the Pharmaceutical Benefits Scheme. Australian GPs perceive benefits for samples as a trial run: to test patient tolerability, enhance patient satisfaction, and for those who cannot afford multiple trials of drugs. Acceptance of samples by GPs is associated with preference for and rapid prescription of new drugs and positive attitudes toward pharmaceutical representatives. Concerns with sample medications include prescribing medication that is not the GP's preferred choice owing to the limited range of samples available. Other concerns include dispensing expired medication and wastage of medications.

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The aim of the present study was to determine relationships between insurance status and utilization of oral health care and its characteristics and to identify factors related to insured patients’ selection of dental clinic or dentist. The study was based on cross-sectional data obtained through phone interviews. The target population included adults in the city of Tehran. Using a two-stage stratified random technique, 3,200 seven-digit numbers resembling real phone numbers were drawn; when calling, 1,669 numbers were unavailable (busy, no answer, fax, line blocked). Of the 1,531 subjects who answered the phone call, 224 were outside the target age (under 18), and 221 refused to respond, leaving 1,086 subjects in the final sample. The interviews were carried out using a structured questionnaire and covered characteristics of dental visits, the respondent’s reason for selecting a particular dentist or clinic and demographic and socio-economic background (gender, age, level of education, income, and insurance status). Data analysis included the Chi-square test, ANOVA, and logistic regression and the corresponding odds ratios (OR). Of all the 1,086 respondents, 57% were women, 62% were under age 35, 46% had a medium and 34% a high level of education, 13% were under the poverty line, and 70% had insurance coverage; 64% with the public, and 6% with a commercial insurance. Having insurance coverage was more likely for women (OR=1.5), for those in the oldest age group (OR=2.0), and for those with a high level of education (OR=2.5). Of those with dental insurance, 54% reported having had a dental visit within the past 12 months ; more often by those with commercial insurance in comparison with public (65% vs. 53% p<0.001). Check-up as the reason for the most recent visit occurred most frequently among those with commercial insurance (28%) compared with those having public insurance (16%) or being non-insured (13%) (p<0.001). Having had two or more dental visits within the past 12 months was most common among insured respondents, when compared with the non-insured (31% vs. 22% p=0.01). The non-insured respondents reported tooth extractions almost twice as frequently as did the insured ones (p<0.001). Of the 726 insured subjects, 60% selected fully out-of-pocket-paid services (FOP), and 53% were unaware of their insurance benefits. Of those who selected FOP, good interpersonal aspects (OR=4.6), being unaware of dental insurance benefits (OR=4.6), and good technical aspects (OR=2.3) as a reason had greater odds of selecting FOP. The present study revealed that dental insurance was positively related to demand for oral health care as well as to utilization of services, but to the latter with a minor extent. Among insured respondents, despite their opportunity to use fully or highly subsidized oral health care services, good interpersonal relationship and high quality of services were the most important factors when an insured patient selected a dentist or a clinic. The present findings indicate a clear need to modify dental insurance systems in Iran to facilitate optimal use of oral health care services to maximize the oral health of the population. A special emphasis in the insurance schemes should be focused on preventive care.

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Candida yeast species are widespread opportunistic microbes, which are usually innocent opportunists unless the systemic or local defense system of the host becomes compromised. When they adhere on a fertile substrate such as moist and warm, protein-rich human mucosal membrane or biomaterial surface, they become activated and start to grow pseudo and real hyphae. Their growth is intricately guided by their ability to detect surface defects (providing secure hiding , thigmotropism) and nutrients (source of energy, chemotropism). The hypothesis of this work was that body mobilizes both non-specific and specific host defense against invading candidal cells and that these interactions involve resident epithelial cells, rapidly responding non-specific protector neutrophils and mast cells as well as the antigen presenting and responding den-dritic cell lymphocyte plasma cell system. It is supposed that Candida albicans, as a result of dar-winistic pressure, has developed or is utilizing strategies to evade these host defense reactions by e.g. adhering to biomaterial surfaces and biofilms. The aim of the study was to assess the host defense by taking such key molecules of the anti-candidal defense into focus, which are also more or less characteristic for the main cellular players in candida-host cell interactions. As a model for candidal-host interaction, sections of chronic hyperplastic candidosis were used and compared with sections of non-infected leukoplakia and healthy tissue. In this thesis work, neutrophil-derived anti-candidal α-defensin was found in the epithelium, not only diffusely all over in the epithelium, but as a strong α-defensin-rich superficial front probably able to slow down or prevent penetration of candida into the epithelium. Neutrophil represents the main host defence cell in the epithelium, to which it can rapidly transmigrate from the circulation and where it forms organized multicellular units known as microabscesses (study I). Neutrophil chemotactic inter-leukin-8 (IL-8) and its receptor (IL-8R) were studied and were surprisingly also found in the candidal cells, probably helping the candida to keep away from IL-8- and neutrophil-rich danger zones (study IV). Both leukocytes and resident epithelial cells contained TLR2, TLR4 and TLR6 receptors able to recognize candidal structures via utilization of receptors similar to the Toll of the banana fly. It seems that candida can avoid host defence via stimulation of the candida permissive TLR2 instead of the can-dida injurious TLR4 (study V). TLR also provides the danger signal to the immune system without which it will not be activated to specifically respond against candidal antigens. Indeed, diseased sites contained receptor activator of nuclear factor kappa B ligand (RANKL; II study), which is important for the antigen capturing, processing and presenting dendritic cells and for the T lymphocyte activation (study III). Chronic hyperplastic candidosis provides a disease model that is very useful to study local and sys-temic host factors, which under normal circumstances restrain C. albicans to a harmless commensal state, but failure of which in e.g. HIV infection, cancer and aging may lead to chronic infection.

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Nanocrystalline Ce1-xRuxO2-delta (x = 0.05 and 0.10) of 8-10 nm sizes have been synthesized by hydrothermal method using melamine as complexing agent. Compounds have been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray analysis (EDX) and their structures have been refined by the Rietveld method.The compounds crystallize in fluorite structure and the composition is Ce1-xRuxO2-x/2 where Ru is in +4 state and Ce is in mixed-valence (+3, +4) state. Substitution of Ru4+ ion in CeO2 activated the lattice oxygen. Ce1-xRuxO2-x/2 reversibly releases 0.22[O] and 0.42[O] for x = 0.05 and 0.10, respectively, which is higher than the maximumpossible OSC of 0.22 [O] observed for Ce0.50Zr0.50O2. Utilization of Higher OSC of Ce1-xRuxO2-delta (x = 0.05 and 0.10) is also reflected in terms of low-temperature CO oxidation with these catalysts, both in the presence and absence of feed oxygen. The Ru4+ ion acts as an active center for reducing molecules (CO, hydrocarbon ``HC'') and oxide ion vacancy acts as an active center for O-2 and NO, leading to low-temperature NO conversion to N-2. Thus due to Ru4+ ion, Ce1-xRuxO2-delta is not just a high oxygen storage material but also shows high activity toward CO, hydrocarbon ``HC'' oxidation, and NO reduction by CO at low temperature with high N-2 selectivity for three-way catalysis.

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Gelatin-g-poly(methyl acrylate) and gelatin-g-poly(acrylonitrile) copolymers were prepared in an aqueous medium using K2S2O8 initiator. A plausible mechanism has been put forward for the observed grafting behavior of monomers. Gelatin-g-PAN showed a greater resistance to mixed bacterial inolucum compared to gelatin-g-PMA samples. The rate of degradation decreased with the increase in grafting efficiency. A parallel set of experiments carried out by employing the samples as the only source of both carbon and nitrogen showed a marginal but definite increase in the utilization of the polymer. The nitrogen analysis also showed the utilization of the polymer. Scanning electron micographs of the polymer films do show extensive pitting after microbiological testing.

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To improve the yield of marketable high value sawn and/or veneer timber from young plantation grown eucalypts: through the greater understanding and management of growth stresses; grain angle; juvenile wood; and other important wood properties.

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The number of genetic factors associated with common human traits and disease is increasing rapidly, and the general public is utilizing affordable, direct-to-consumer genetic tests. The results of these tests are often in the public domain. A combination of factors has increased the potential for the indirect estimation of an individual's risk for a particular trait. Here we explain the basic principals underlying risk estimation which allowed us to test the ability to make an indirect risk estimation from genetic data by imputing Dr. James Watson's redacted apolipoprotein E gene (APOE) information. The principles underlying risk prediction from genetic data have been well known and applied for many decades, however, the recent increase in genomic knowledge, and advances in mathematical and statistical techniques and computational power, make it relatively easy to make an accurate but indirect estimation of risk. There is a current hazard for indirect risk estimation that is relevant not only to the subject but also to individuals related to the subject; this risk will likely increase as more detailed genomic data and better computational tools become available.