Illicit drug use between an annual key holiday and a control period: Wastewater analysis in a semi-rural, an urban and a vacation area

Introduction and Aims: Holiday periods are potentially a time for increased substance use as social events and private parties are more common. Data on community illicit drug consumption during holiday periods are limited. Besides existing methods for determining drug use, such as population surveys, one emerging method is to measure illicit drugs and/or their metabolites in wastewater samples. This study examined the change in consumption of cannabis, methamphetamine, cocaine and 3,4- methylenedioxymethamphetamine in three different types of areas (an inland semi-rural area, a coastal urban area and a vacation island) with respect to holiday times. Design and Methods: Samples were collected at the inlet of the major wastewater treatment plant in each area during a key annual holiday (i.e. the summer holiday including Christmas and New Year) and control period. Illicit drug residues in the daily composited samples were measured by liquid chromatography coupled with tandem mass spectrometry. Results: Drug use varied substantially among the three areas within each monitoring period as well as between the holiday and control period within each area. Use consistently increased and peaked over New Year particularly for cocaine and 3,4-methylenedioxymethamphetamine whereas cannabis and methamphetamine were relatively less subjected to holiday times in all the areas. Discussion and Conclusions: Wastewater sampling and analysis provides higher spatio-temporal resolution than national surveys and supplements drug epidemiology studies originating primary in metropolitan locations. Such data is essential for policy makers to plan potential intervention strategies associated with these illicit substances in regional areas and other settings besides urban areas in the future.

The long drive home: Control beliefs and commuting intentions of mine workers

Purpose: It is relatively common for many mine workers in Australia to drive an average of 250 kilometers to and from work following long shifts and shift blocks. Despite the long distances travelled following long shifts of 12- to 14-hours, there is evidence to suggest that these workers are not engaging in a break following their shift prior to driving home. This naturally raises issues of fatigue and sleepiness when driving. There is limited research in respect to commuting behaviours of mine workers and little is known about the factors that influence these workers to leave site immediately following their shift. Using the theory of planned behaviour, this paper examines individual control beliefs that encourage or prevent workers from leaving the site immediately following their shift block. Method: Data was collected using a cross-sectional survey. The survey instrument was developed following a series of in-depth interviews with workers from a Queensland coal mine (n=37). The quantitative written survey sample (n=461) was drawn from the same coal mine and consisted of workers from all levels of the organisation. Results: The results examine workers intentions to leave the work site and drive home immediately following a shift block. The results show differences in control beliefs between workers finishing night shifts compared with those finishing day shifts. Implications: An understanding of these control beliefs may potentially inform more targeted intervention strategies in the attempt to encourage a safer approach to driving home following shift blocks.

Model Predictive Static Programming: A Computationally Efficient Technique For Suboptimal Control Design

Combining the philosophies of nonlinear model predictive control and approximate dynamic programming, a new suboptimal control design technique is presented in this paper, named as model predictive static programming (MPSP), which is applicable for finite-horizon nonlinear problems with terminal constraints. This technique is computationally efficient, and hence, can possibly be implemented online. The effectiveness of the proposed method is demonstrated by designing an ascent phase guidance scheme for a ballistic missile propelled by solid motors. A comparison study with a conventional gradient method shows that the MPSP solution is quite close to the optimal solution.

An accurate rating aggregation method for generating item reputation

Many websites presently provide the facility for users to rate items quality based on user opinion. These ratings are used later to produce item reputation scores. The majority of websites apply the mean method to aggregate user ratings. This method is very simple and is not considered as an accurate aggregator. Many methods have been proposed to make aggregators produce more accurate reputation scores. In the majority of proposed methods the authors use extra information about the rating providers or about the context (e.g. time) in which the rating was given. However, this information is not available all the time. In such cases these methods produce reputation scores using the mean method or other alternative simple methods. In this paper, we propose a novel reputation model that generates more accurate item reputation scores based on collected ratings only. Our proposed model embeds statistical data, previously disregarded, of a given rating dataset in order to enhance the accuracy of the generated reputation scores. In more detail, we use the Beta distribution to produce weights for ratings and aggregate ratings using the weighted mean method. Experiments show that the proposed model exhibits performance superior to that of current state-of-the-art models.

Active Adaptive Gyrostabiliser Control System

A gyrostabiliser control system and method for stabilising marine vessel motion based on precession information only. The control system employs an Automatic Gain Control (AGC) precession controller (60). This system operates with a gain factor that is always being gradually minimized so as to let the gyro flywheel (12) develop as much precession as possible - the higher the precession, the higher the roll stabilising moment. This continuous gain change provides adaptation to changes in sea state and sailing conditions. The system effectively predicts the likelihood of maximum precession being reached. Should this event be detected, then the gain is rapidly increased so as to provide a breaking precession torque. Once the event has passed, the system again attempts to gradually decrease the gain.

Ship Seakeeping Operability, Motion Control, and Autonomy - A Bayesian Perspective

Ship seakeeping operability refers to the quantification of motion performance in waves relative to mission requirements. This is used to make decisions about preferred vessel designs, but it can also be used as comprehensive assessment of the benefits of ship-motion-control systems. Traditionally, operability computation aggregates statistics of motion computed over over the envelope of likely environmental conditions in order to determine a coefficient in the range from 0 to 1 called operability. When used for assessment of motion-control systems, the increase of operability is taken as the key performance indicator. The operability coefficient is often given the interpretation of the percentage of time operable. This paper considers an alternative probabilistic approach to this traditional computation of operability. It characterises operability not as a number to which a frequency interpretation is attached, but as a hypothesis that a vessel will attain the desired performance in one mission considering the envelope of likely operational conditions. This enables the use of Bayesian theory to compute the probability of that this hypothesis is true conditional on data from simulations. Thus, the metric considered is the probability of operability. This formulation not only adheres to recent developments in reliability and risk analysis, but also allows incorporating into the analysis more accurate descriptions of ship-motion-control systems since the analysis is not limited to linear ship responses in the frequency domain. The paper also discusses an extension of the approach to the case of assessment of increased levels of autonomy for unmanned marine craft.

Germination and hardseededness in desmanthus

The mechanisms and control of hardseededness in the 3 Australian cultivars of the genus Desmanthus were investigated in a series of experiments in which the effects of various seedsoftening treatments, particularly boiling water, were measured. Desmanthus seed is predominantly hard, only defective seeds being normally otherwise. As it has only very brief, early embryo dormancy, hardseededness is the only serious barrier to germination. Seed is most readily softened through rupture of the palisade at the lens (strophiole). The lens is of a typically mimosaceous type which is readily ruptured by immersion in boiling water or less readily by application of pressure to adjacent parts of the testa. Ruptures may consist only of separation of the palisade from underlying tissue, which alone does not confer permeability; mostly they also result in fractures to the palisade that then render seeds irreversibly permeable. The palisade becomes reflective as it separates, which allows the event to be witnessed at the moment of separation if suitable pressure is applied to the testa of an individual seed while it is viewed under magnification. Brief (4–10 seconds) immersion of highquality seed in boiling water consistently softened a high proportion of seeds without causing serious damage. Extending the duration of immersion led to a progressive increase in the proportion of seed deaths. Neither previous boiling water treatment nor scarification damage to the testa materially affected results of treatment, but immature and small seeds behaved differently, being more vulnerable to damage than mature seed, and less likely to undergo lens rupture. Adaptation of boiling water treatment to farm-scale seed handling was simple and reliable. Commercial treatment of seed by an alternative method suitable for greater bulks and consisting of passage through a rice-whitener was checked and found to be successful through a combination of gentle scarification and lens rupture, both attributable to the numerous minor impacts of the process. Percentage emergence of seedlings from soil in the greenhouse closely followed percentage laboratory germination, except when inferior seed grades were included in the comparison, when emergence was poor. Very little seed softened in soil. Already-permeable seed either germinated rapidly or died, while buried hard seed mostly remained hard and viable even more than a year after sowing.

A Current Source Inverter Fed Induction Motor Drive with Power Factor Angle Control Using Microprocessor

This paper describes a method of adjusting the stator power factor angle for the control of an induction motor fed from a current source inverter (CSI) based on the concept of space vectors (or park vectors). It is shown that under steady state, if the torque angle is kept constant over the entire operating range, it has the advantage of keeping the slip frequency constant. This can be utilized to dispose of the speed feedback and simplify the control scheme for the drive, such that the stator voltage integral zero crossings alone can be used as a feedback for deciding the triggering instants of the CSI thyristors under stable operation of the system. A closed-loop control strategy is developed for the drive based on this principle, using a microprocessor-based control system and is implemented on a laboratory prototype CSI fed induction motor drive.

Using simulation techniques to investigate methods to determine resistance of helminths to anthelmintic treatment

The widespread and increasing resistance of internal parasites to anthelmintic control is a serious problem for the Australian sheep and wool industry. As part of control programmes, laboratories use the Faecal Egg Count Reduction Test (FECRT) to determine resistance to anthelmintics. It is important to have confidence in the measure of resistance, not only for the producer planning a drenching programme but also for companies investigating the efficacy of their products. The determination of resistance and corresponding confidence limits as given in anthelmintic efficacy guidelines of the Standing Committee on Agriculture (SCA) is based on a number of assumptions. This study evaluated the appropriateness of these assumptions for typical data and compared the effectiveness of the standard FECRT procedure with the effectiveness of alternative procedures. Several sets of historical experimental data from sheep and goats were analysed to determine that a negative binomial distribution was a more appropriate distribution to describe pre-treatment helminth egg counts in faeces than a normal distribution. Simulated egg counts for control animals were generated stochastically from negative binomial distributions and those for treated animals from negative binomial and binomial distributions. Three methods for determining resistance when percent reduction is based on arithmetic means were applied. The first was that advocated in the SCA guidelines, the second similar to the first but basing the variance estimates on negative binomial distributions, and the third using Wadley’s method with the distribution of the response variate assumed negative binomial and a logit link transformation. These were also compared with a fourth method recommended by the International Co-operation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal Products (VICH) programme, in which percent reduction is based on the geometric means. A wide selection of parameters was investigated and for each set 1000 simulations run. Percent reduction and confidence limits were then calculated for the methods, together with the number of times in each set of 1000 simulations the theoretical percent reduction fell within the estimated confidence limits and the number of times resistance would have been said to occur. These simulations provide the basis for setting conditions under which the methods could be recommended. The authors show that given the distribution of helminth egg counts found in Queensland flocks, the method based on arithmetic not geometric means should be used and suggest that resistance be redefined as occurring when the upper level of percent reduction is less than 95%. At least ten animals per group are required in most circumstances, though even 20 may be insufficient where effectiveness of the product is close to the cut off point for defining resistance.

Evaluating legume species as alternative trap crops to chickpea for management of Helicoverpa spp. (Lepidoptera: Noctuidae) in central Queensland cotton cropping systems

Mounting levels of insecticide resistance within Australian Helicoverpa spp. populations have resulted in the adoption of non-chemical IPM control practices such as trap cropping with chickpea, Cicer arietinum (L.). However, a new leaf blight disease affecting chickpea in Australia has the potential to limit its use as a trap crop. Therefore this paper evaluates the potential of a variety of winter-active legume crops for use as an alternative spring trap crop to chickpea as part of an effort to improve the area-wide management strategy for Helicoverpa spp. in central Queensland’s cotton production region. The densities of Helicoverpa eggs and larvae were compared over three seasons on replicated plantings of chickpea, Cicer arietinum (L.), field pea Pisum sativum (L), vetch, Vicia sativa (L.) and faba bean, Vicia faba (L.). Of these treatments, field pea was found to harbour the highest densities of eggs. A partial life table study of the fate of eggs oviposited on field pea and chickpea suggested that large proportions of the eggs laid on field pea suffered mortality due to dislodgment from the plants after oviposition. Plantings of field pea as a replacement trap crop for chickpea under commercial conditions confirmed the high level of attractiveness of this crop to ovipositing moths. The use of field pea as a trap crop as part of an areawide management programme for Helicoverpa spp. is discussed.

Alternative fungicides for controlling husk spot caused by Pseudocercospora macadamiae in macadamia

Husk spot, caused by Pseudocercospora macadamiae is a major fungal disease of macadamia in Australia. Chemicals to control the disease are limited and frequent failure to control the disease is a major concern to growers. The overall goal of this research was to improve the chemical control strategy of P. macadamiae through the provision of fungicides with different modes of action to carbendazim, which is the current industry standard. Husk spot incidence, premature fruit abscission, kernel quality and yield were evaluated following application of different fungicide products in replicated field experiments at three different sites. Results showed significant differences in disease incidence and premature fruit abscission between fungicide treatments, field sites and years. Generally, disease incidence and premature fruit abscission on trees treated with fungicide were significantly (P < 0.05) lower than the untreated control. Pyraclostrobin conferred significantly better protection than trifloxystrobin, reducing disease severity by 70% compared with a 50% reduction by trifloxystrobin. The pyraclostrobin treatment had a similar efficacy to the current industry standard (70% reduction cf. 73% reduction by tank-mixed carbendazim and copper). Higher amounts of immature kernels occurred in the untreated control, followed by difenoconazole and trifloxystrobin. Diseased fruit accounted for 78% of premature fruit abscission, which indicates that husk spot enhances fruit abscission in macadamia. Our results suggest that pyraclostrobin provided similar efficacy to the industry standard and could, therefore, play a key role in the management of husk spot.

Floating row covers and pyriproxyfen help control silverleaf whitefly Bemisia tabaci (Gennadius) Biotype B (Homoptera: Aleyrodidae) in zucchini

In zucchini, the use of row covers until flowering and the insect growth regulator (IGR) pyriproxyfen are effective methods of reducing the number of insects, especially silverleaf whitefly (Bemisia tabaci (Gennadius) Biotype B), on plants. We compared floating row covers (FRCs) up until flowering with silverleaf whitefly (SLW) introduced (FRC + SLW), or not introduced (FRC-only), or with introduction of SLW in open plots (SLW-only), or with introduction of SLW in open plots with IGR (SLW + IGR). FRC increased temperature and humidity compared with the uncovered treatments. Average fruit weight was less (P < 0.01) for the FRC + SLW treatment compared with the other treatments and the percentage of marketable fruit was less for the FRC + SLW than for the other three treatments. This result indicates that the use of either row covers or IGR controls whiteflies, reduces fruit damage and increases the size, weight, and quality of fruit, and may also control other sap-sucking insects. However, if SLW are already present on plants, the use of FRC may reduce predation and favour build up of SLW. Thus, FRC and IGR, if used judiciously, may provide an effective alternative to broad-spectrum pesticides in small-scale cucurbit production.

An evaluation of the apxIVA based PCR-REA method for differentiation of Actinobacillus pleuropneumoniae

A restriction analysis of PCR (PCR-REA) amplified apxIVA gene has been suggested as an alternative method for serotyping of Actinobacillus pleuropneumoniae by Jaglic et al. [Jaglic, Z., Svastova, P., Rychlik, I., Nedbalcova, K., Kucerova, Z., Pavlik, I., Bartos, M., 2004. Differentiation of Actinobacillus pleuropneumoniae by PCR-REA based on sequence variability of the apxIVA gene and by ribotyping. Vet. Microbiol. 103, 63-69]. The current study investigated whether this alternative method could distinguish between the reference strains of serovars 13-15 and the value of the method when applied to 47 field isolates representing serovars 1-3, 5, 7-9, 12 and 15 as well as non-typable isolates. The reference strains of serovars 13 and 14 had the same sized product after the apxIVA PCR, while the product for serovar 15 was of different size compared to all the other serovar reference strains. The CfoI digest profiles of the reference serovars 13 and 14 strains were different from each other and from all other serovars. The HpaII digest profiles of these two serovars were very similar to each other, but both were distinctively different from the other serovar profiles. The CfoI digest profile of serovar 15 strain was very similar to the serovars 3 and 12 strains except for two faint extra bands for serovar 15. The HpaII digest profiles of serovars 12 and 15 reference strains were identical. The PCR-REA method correctly recognized the serovar of 21 of 43 field isolates. It was concluded that the method was a useful additional tool to support, but could not replace, conventional serotyping.

Influence of food supplementation on the fitness of two biological control agents: a predatory nabid bug and a bollworm pupal parasitoid

Many arthropod predators and parasitoids exhibit either stage-specific or lifetime omnivory, in that they include extra-floral nectar, floral nectar, honeydew or pollen in their immature and/or adult diet. Access to these plant-derived foods can enhance pest suppression by increasing both the individual fitness and local density of natural enemies. Commercial products such as Amino-Feed®, Envirofeast®, and Pred-Feed® can be applied to crops to act as artificial-plant-derived foods. In laboratory and glasshouse experiments we examined the influence of carbohydrate and protein rich Amino-Feed UV® or Amino-Feed, respectively, on the fitness of a predatory nabid bug Nabis kinbergii Reuter (Hemiptera: Nabidae) and bollworm pupal parasitoid Ichneumon promissorius (Erichson) (Hymenoptera: Ichneumonidae). Under the chosen conditions, the provision of either wet or dry residues of Amino-Feed UV had no discernable effect on immediate or longer-term survival and immature development times of N. kinbergii. In contrast, the provision of honey, Amino-Feed plus extrafloral nectar, and extrafloral nectar alone had a marked effect on the longevity of I. promissorius, indicating that they were limited by at least carbohydrates as an energy source, but probably not protein. Compared with a water only diet, the provision of Amino-Feed plus extrafloral nectar increased the longevity of males and females of I. promissorius by 3.0- and 2.4-fold, respectively. Not only did female parasitoids live longer when provided food, but the total number of eggs laid and timing of deposition was affected by diet under the chosen conditions. Notably, females in the water and honey treatments deposited greater numbers of eggs earlier in the trial, but this trend was unable to be sustained over their lifetime. Egg numbers in these treatments subsequently fell below the levels achieved by females in the Amino-Feed plus extrafloral nectar and cotton extrafloral nectar only treatments. Furthermore, there were times when the inclusion of the Amino-Feed was beneficial compared with cotton extrafloral nectar only. Artificial food supplements and plant-derived foods are worthy of further investigation because they have potential to improve the ecosystem service of biological pest control in targeted agroecosystems by providing natural enemies with an alternative source of nutrition, particularly during periods of prey/host scarcity.