984 resultados para summative evaluation


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Silverleaf whitefly (SLW), Bemisia tabaci biotype B, is a major horticultural pest that costs Queensland vegetable growers millions of dollars in lost production and control measures each year. In the Bowen and Burdekin districts of North Queensland, the major cultivated SLW host crops are tomatoes, melons, green beans, pumpkins, eggplants, and cucumbers, which cover a total production area of approximately 6500 ha. Eretmocerus hayati, an effective SLW parasitoid, was imported into Australia by CSIRO in 2002 and released from quarantine in 2004. In 2006, DAFF established a mass-rearing unit for E. hayati at Bowen Research Station to provide E. hayati for release on vegetable farms within its SLW integrated pest management research program. A total of 1.3 million E. hayati were released over three seasons on 34 vegetable farms in the Bowen and Burdekin districts (October 2006 to December 2008). Post-release samplings were conducted across the release area over this time period with parasitism levels recorded in tomatoes, melons, beans, eggplants, pumpkins, and various SLW weed hosts. Sample data show that E. hayati established at most release sites as well as some non-release sites, indicating natural spread. Overall results from these three years of evaluation clearly demonstrated that E hayati releases played a significant role in SLW control. In most crops sampled, E hayati exerted between 30 and 80% parasitism. Even in regularly sprayed crops, such as tomato and eggplant, E. hayati was able to achieve an overall average parasitism of 45%.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Queensland fruit flies Bactrocera tryoni and B. neohumeralis are considered major quarantine pests of tomato, a major crop in the horticultural production district around Bowen, North Queensland, Australia. Preharvest and/or postharvest treatments are required to meet the market access requirements of both domestic and international trading partners. The suspension from use of dimethoate and fenthion, the two insecticides used for fruit fly control, has resulted in the loss of both pre and postharvest uses in fresh tomato. Research undertaken quantitatively at Bowen evaluated the effectiveness of pre-harvest production systems without specific fruit fly controls and postharvest mitigation measures in reducing the risk of fruit fly infestation in tomato. A district-wide trapping using cue-lure baited traps was undertaken to determine fruit fly seasonal patterns in relation to the cropping seasons. A total of 17,626 field-harvested and 11,755 pack-house tomatoes were sampled from ten farms over three cropping seasons (2006-2009). The fruit were incubated and examined for fruit fly infestation. No fruit fly infested fruit were recorded over the three seasons in either the field or the pack-house samples. Statistical analyses showed that upper infestation levels were extremely low (between 0.025 and 0.062%) at the 95% confidence level. The trap catches showed a seasonal pattern in fruit fly activity, with low numbers during the autumn and winter months, rising slightly in spring and peaking in summer. This seasonal pattern was similar over the four seasons. The main two species of fruit fly caught were B. tryoni and B. neohumeralis. Based on the results, it is clear that the risk of fruit fly infestation is extremely low under the current production systems in the Bowen region.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Among different methods, the transmission-line or the impedance tube method has been most popular for the experimental evaluation of the acoustical impedance of any termination. The current state of method involves extrapolation of the measured data to the reflecting surface or exact locations of the pressure maxima, both of which are known to be rather tricky. The present paper discusses a method which makes use of the positions of the pressure minima and the values of the standing-wave ratio at these points. Lippert's concept of enveloping curves has been extended. The use of Smith or Beranek charts, with their inherent inaccuracy, has been altogether avoided. The existing formulas for the impedance have been corrected. Incidentally, certain other errors in the current literature have also been brought to light.Subject Classification: 85.20.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper deals with an exact analysis of standing waves in an impedance tube with mean flow. A method is offered for the experimental evaluation of the various wave parameters. Navier–Stokes equations have been solved for evaluating the volume velocity taking into account mean flow, viscosity, etc. The engine exhaust system has been characterized as an acoustic source with an acoustic pressure and internal impedance. A method is suggested for the evaluation of these hypothetical parameters using the exhaust pipe as an impedance tube.Subject Classification: [43]85.20; [43]20.40.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In a very recent study [1] the Renormalisation Group (RNG) turbulence model was used to obtain flow predictions in a strongly swirling quarl burner, and was found to perform well in predicting certain features that are not well captured using less sophisticated models of turbulence. The implication is that the RNG approach should provide an economical and reliable tool for the prediction of swirling flows in combustor and furnace geometries commonly encountered in technological applications. To test this hypothesis the present work considers flow in a model furnace for which experimental data is available [2]. The essential features of the flow which differentiate it from the previous study [1] are that the annular air jet entry is relatively narrow and the base wall of the cylindrical furnace is at 90 degrees to the inlet pipe. For swirl numbers of order 1 the resulting flow is highly complex with significant inner and outer recirculation regions. The RNG and standard k-epsilon models are used to model the flow for both swirling and non-swirling entry jets and the results compared with experimental data [2]. Near wall viscous effects are accounted for in both models via the standard wall function formulation [3]. For the RNG model, additional computations with grid placement extending well inside the near wall viscous-affected sublayer are performed in order to assess the low Reynolds number capabilities of the model.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper deals with a method for the evaluation of exhaust muffers with mean flow. A new set of variables, convective pressure and convective mass velocity, have been defined to replace the acoustic variables. An expression for attenuation (insertion loss) of a muffler has been proposed in terms of convective terminal impedances and a velocity ratio, on the lines of the one existing for acoustic filters. In order to evaluate the velocity ratio in terms of convective variables, transfer matrices for various muffler elements have been derived from the basic relations of energy, mass and momentum. Finally, the velocity ratiocum-transfer matrix method is illustrated for a typical straight-through muffler.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The early and accurate assessment of burns is essential to inform patient treatment regimens; however, this first critical step in clinical practice remains a challenge for specialist burns clinicians worldwide. In this regard, protein biomarkers are a potential adjunct diagnostic tool to assist experienced clinical judgement. Free circulating haemoglobin has previously shown some promise as an indicator of burn depth in a murine animal model. Using blister fluid collected from paediatric burn patients, haemoglobin abundance was measured using semi-quantitative Western blot and immunoassays. Although a trend was observed in which haemoglobin abundance increased with burn wound severity, several patient samples deviated significantly from this trend. Further, it was found that haemoglobin concentration decreased significantly when whole cells, cell debris and fibrinous matrix was removed from the blister fluid by centrifugation; although the relationship to depth was still present. Statistical analyses showed that haemoglobin abundance in the fluid was more strongly related to the time between injury and sample collection and the time taken for spontaneous re-epithelialisation. We hypothesise that prolonged exposure to the blister fluid microenvironment may result in an increased haemoglobin abundance due to erythrocyte lysis, and delayed wound healing

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Clarification performance and flocculant dosage is strongly linked to the mud solids loading in the feed entering the clarifier. The recycle of filtrate can represent an extra ~10-15% mud solids loading on the clarifier, thereby reducing its effective capacity. Filtrate recycling may cause significant increase in turbidity, complexed calcium ion formation, phosphate, proteins and polysaccharides in mixed juice that impact on evaporator scale formation and molasses exhaustion. The paper details the results obtained from laboratory, pilot scale and factory trials of filtrate clarification using both sedimentation and flotation methods. Clarified filtrate could be produced of similar quality to ESJ. Filtrate clarification was able to significantly remove insoluble solids, turbidity, phosphate, and polysaccharides content with slight reductions in minerals content of the filtrate. On the basis of improved filtrate quality, the clarified filtrate could be directed to ESJ, instead of the normal practice of directing the mud filtrate to mixed juice. The potential impacts of implementing filtrate clarification are discussed in respect to improved performance and throughput of the clarification station.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The transmission-line or the impedance-tube method for the measurement of the acoustic impedance of any termination involves a search for various minima and maxima of pressure. For this purpose, arrangement has to be made for the microphone to travel along the length of the impedance tube, and this complicates the design of the tube considerably. The present paper discusses a method which consists in evaluating the tube attenuation factor at any convenient frequency by making use of measured SPL's at two (or more) fixed locations with a rigid termination, calculating the tube attenuation factor and wave number at the required frequency of interest with or without mean flow (as applicable), and finally evaluating the impedance of the given termination by measuring and using SPL's at three (or more) fixed locations. Thus, the required impedance tube is considerably smaller in length, simpler in design, easier to manufacture, cheaper in cost and more convenient to use. The design of the tube is also discussed. Incidentally, it is also possible to evaluate the impedance at any low frequency without having to use a larger impedance tube.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

During the last 10-15 years interest in mouse behavioural analysis has evolved considerably. The driving force is development in molecular biological techniques that allow manipulation of the mouse genome by changing the expression of genes. Therefore, with some limitations it is possible to study how genes participate in regulation of physiological functions and to create models explaining genetic contribution to various pathological conditions. The first aim of our study was to establish a framework for behavioural phenotyping of genetically modified mice. We established comprehensive battery of tests for the initial screening of mutant mice. These included tests for exploratory and locomotor activity, emotional behaviour, sensory functions, and cognitive performance. Our interest was in the behavioural patterns of common background strains used for genetic manipulations in mice. Additionally we studied the behavioural effect of sex differences, test history, and individual housing. Our findings highlight the importance of careful consideration of genetic background for analysis of mutant mice. It was evident that some backgrounds may mask or modify the behavioural phenotype of mutants and thereby lead to false positive or negative findings. Moreover, there is no universal strain that is equally suitable for all tests, and using different backgrounds allows one to address possible phenotype modifying factors. We discovered that previous experience affected performance in several tasks. The most sensitive traits were the exploratory and emotional behaviour, as well as motor and nociceptive functions. Therefore, it may be essential to repeat some of the tests in naïve animals for assuring the phenotype. Social isolation for a long time period had strong effects on exploratory behaviour, but also on learning and memory. All experiments revealed significant interactions between strain and environmental factors (test history or housing condition) indicating genotype-dependent effects of environmental manipulations. Several mutant line analyses utilize this information. For example, we studied mice overexpressing as well as those lacking extracellular matrix protein heparin-binding growth-associated molecule (HB-GAM), and mice lacking N-syndecan (a receptor for HB-GAM). All mutant mice appeared to be fertile and healthy, without any apparent neurological or sensory defects. The lack of HB-GAM and N-syndecan, however, significantly reduced the learning capacity of the mice. On the other hand, overexpression of HB-GAM resulted in facilitated learning. Moreover, HB-GAM knockout mice displayed higher anxiety-like behaviour, whereas anxiety was reduced in HB-GAM overexpressing mice. Changes in hippocampal plasticity accompanied the behavioural phenotypes. We conclude that HB-GAM and N-syndecan are involved in the modulation of synaptic plasticity in hippocampus and play a role in regulation of anxiety- and learning-related behaviour.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Oil palm empty fruit bunch (EFB) is a readily available, lignocellulosic biomass that has potential to be utilized as a carbon substrate for microbial oil production. In order to evaluate the production of microbial oil from EFB, a technical study was performed through the cultivation of oleaginous micro-organisms (Rhodotorula mucilaginosa, Aspergillus oryzae, and Mucor plumbeus) on EFB hydrolyzates. EFB hydrolyzates were prepared through dilute acid pre-treatment of the biomass, where the liquid fraction of pre-treatment was detoxified and used as an EFB liquid hydrolyzate (EFBLH). The solid residue was enzymatically hydrolyzed prior to be used as an EFB enzymatic hydrolyzate (EFBEH). The highest oil concentrations were obtained from M. plumbeus (1.9 g/L of oil on EFBLH and 4.7 g/L of oil on EFBEH). In order to evaluate the feasibility of large-scale microbial oil production, a techno-economic study was performed based on the oil yields of M. plumbeus per hectare of plantation, followed by the estimation of the feedstock cost for oil production. Other oil palm biomasses (frond and trunk) were also included in this study, as it could potentially improve the economics of large-scale microbial oil production. Microbial oil from oil palm biomasses was estimated to potentially increase oil production in the palm oil industry up to 25%, at a cheaper feedstock cost. The outcome of this study demonstrates the potential integration of microbial oil production from oil palm biomasses with existing palm oil industry (biodiesel, food and oleochemicals production), that could potentially enhance sustainability and profitability of microbial oil production.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A number of analogues of diaryl dihydropyrazole-3-carboxamides have been synthesized. Their activities were evaluated for appetite suppression and body weight reduction in animal models. Depending on the chemical modification of the selected dihydropyrazole scaffold, the lead compoundsthe bisulfate salt of (±)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid morpholin-4-ylamide 26 and the bisulfate salt of (−)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid morpholin-4-ylamide 30showed significant body weight reduction in vivo, which is attributed to their CB1 antagonistic activity and exhibited a favorable pharmacokinetic profile. The molecular modeling studies also showed interactions of two isomers of (±)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid morpholin-4-ylamide 9 with CB1 receptor in the homology model similar to those of N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxamide (rimonabant) 1 and 4S-(−)-3-(4-chlorophenyl)-N-methyl-N‘-[(4-chlorophenyl)-sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamidine (SLV-319) 2.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Sport Development Project (SDP) was a comprehensive youth strategy for sport in the Northern Territory aimed at diversion from ‘at-risk’ behaviours, improvement of life choices and outcomes, and strengthening youth service infrastructure through engagement in positive (sport) activities. There were five Remote Service Delivery sites that were involved in the trial of this ‘best practice’ model for delivering sport-focused diversion activities. These include: Gapuwiyak, Wadeye, Yuendumu, Gunbalunya and Nguiu.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The present work deals with the anticancer effect of benzimidazole derivatives associated with the pyridine framework. By varying the functional group at N-terminal of the benzimidazole by different L-amino acids, several 2-(4-(2,2,2-trifluoroethoxy)-3-methylpyridin-2-ylthio)-1H-benzo[d]imid azole derivatives 9(a-j) were synthesized. Their chemical structures were confirmed by H-1 NMR, IR and mass spectroscopic techniques. The synthesized compounds were examined for their antiproliferative effects against human leukemia cell lines, K562 and CEM. The preliminary results showed most of the derivatives had moderate antitumor activity. Compound 9j containing cysteine residue exhibited good inhibition compared to other amino acid resides. In addition DNA fragmentation results suggest that 9j is more cytotoxic and able to induce apoptosis.