Patterns of release of the secondary conidia of Claviceps africana, the sorghum ergot pathogen in Australia

Trials were conducted in southern Queensland, Australia between March and May 2003, 2004 and 2005 to study patterns of hourly and daily release of the secondary conidia of Claviceps africana and their relationships with weather parameters. Conidia were trapped for at least one hour on most (> 90%) days in 2003 and 2004, but only on 55% of days in 2005. Both the highest daily concentration of conidia, and the highest number of hours per day when conidia were trapped, were recorded 1-3 days after rainfall events. Although the pattern of conidial release was different every day, the highest hourly conidial concentrations occurred between 10.00 hours and 17.00 hours on 73% of all days in the three trials. Hours when conidia were trapped were characterized by higher median values of temperature, windspeed and vapour pressure deficit, lower relative humidity, and leaf wetness values of 0%, than hours when no conidia were recorded. The results indicate that fungicides need to be applied to the highly ergot-susceptible male sterile (A-) lines of sorghum in hybrid seed production blocks and breeders' nurseries as soon as possible after rainfall events to minimize ergot severity.

Microprocessor-controlled automatic focusing of a lens

Maximum intensity contrast has been used as a measure of lens defocus. A photodiode array under the control of 8085 microprocessor is used to measure the maximum intensity contrast and to position the lens for best focus. The lens is moved by a stepper motor under processor control at a speed of 350 to 500 steps/s. At this speed, focusing time was found to be between 5 and 8 s. Under coherent illuminating conditions, an accuracy of ± 50 μm has been achieved.

Seed persistence in the field may be predicted by laboratory-controlled aging

Weed management is complicated by the presence of soil seed banks. The complexity of soil-seed interactions means that seed persistence in the field is often difficult to measure, let alone predict. Field trials, although accurate in their context, are time-consuming and expensive to conduct for individual species. Some ex situ techniques for estimating seed life expectancy have been proposed, but these fail to simulate the environmental complexity of the field. Also, it has been questioned whether techniques such as the controlled aging test (CAT) are useful indicators of field persistence. This study aimed to test the validity of the standard CAT (seed aging at 45 C and 60% relative humidity) in use at the Royal Botanic Gardens, Kew, U.K., for predicting field seed-persistence. Comparison of seed persistence and CAT data for 27 northwest European species suggested a significant positive correlation of 0.31. Subsequently, 13 species of emerging and common weeds of Queensland were assessed for their seed longevity using the CAT. The seed longevity data of these species in the CAT were linked with field seed-persistence data according to three broad seed-persistence categories: <1 yr, 1 to 3 yr, and >3 yr. We discuss the scope for using the CAT as a tool for rapid assignment of species to these categories. There is a need for further studies that compare predictions of seed persistence based on the CAT with seed persistence in the field for a larger range of species and environments.

Exercise and psychosocial interventions in breast cancer survivors: Preliminary results of a randomized controlled trial

Physical and psychological decline is common in the post-treatment breast cancer population, yet the efficacy of concurrent interventions to meet both physical- psychosocial needs in this population has not been extensively examined. PURPOSE: This study explores the effects of a combined exercise and psychosocial intervention model on selected physiological-psychological parameters in post-treated breast cancer. METHODS: Forty-one breast cancer survivors were randomly assigned to one of four groups for an 8-week intervention: exercise only [EX, n=13] (aerobic and resistance training), psychosocial therapy only [PS, n=11] (biofeedback), combined EX and PS [EX+PS, n=11], or to control conditions [CO, n=6]. Mean delta score (post-intervention - baseline) were calculated for each of the following: body weight, % body fat (skin folds), predicted VO2max (Modified Bruce Protocol), overall dynamic muscular endurance [OME] (RMCRI protocol), static balance (Single leg stance test), dynamic balance (360° turn and 4-square step test), fatigue (Revised Piper Scale), and quality of life (FACT-B). A one-way ANOVA was used to analyze the preliminary results of this on-going randomized trial. RESULTS: Overall, there were significant differences in the delta scores for predicted VO2max, OME, and dynamic balance among the 4 groups (p<0.05). The EX+PS group showed a significant improvement in VO2max compared with the PS group (4.2 ± 3.8 vs. -0.9 ± 4.2 mL/kg/min; p<0.05). Both the EX+PS and EX groups showed significant improvements in OME compared with the PS and CO groups (44.5 ± 23.5 and 43.4 ± 22.1 vs. -3.9 ± 15.2 and 2.7 ± 13.7 repetitions; p<0.05). All 3 intervention groups showed significant improvements in dynamic balance compared with the CO group (-0.8 ± 0.6, -0.6 ± 0.8, and -0.6 ±1.0 vs. 0.6 ± 0.6 seconds; p<0.05). Overall, changes in fatigue tended towards significance among the 4 groups (p = 0.08), with decreased fatigue in the intervention groups and increased fatigue in the CO group. CONCLUSIONS: Our preliminary findings suggest that EX and PS seem to produce greater positive changes in the outcome measures than CO. However, at this point no definite conclusions can be made on the additive effects of combining the EX and PS interventions.

Prospective decrease in progesterone concentrations in female lightweight rowers during the competition season compared with the off-season: A controlled study examining weight loss and intensive exercise

The purpose of this study was to monitor ovarian hormone function response to intense exercise and body weight changes in female athletes. Ovarian hormone function was evaluated in 12 female lightweight rowers and 10 age-height-weight matched sedentary controls. Ovarian hormone function was assessed during consecutive competition season and off season, by measurement of peak and average alternative day overnight urinary oestrone glucuronide (E1G) and pregnanediol glucuronide (PdG) excretion. Competition season was associated with a 5.8 kg (9.3%) body weight loss in the lightweight rowers. Significantly lower competition season peak and average urinary excretion of PdG were found in the lightweight rowers compared with the controls. Lower competition season peak and average urinary excretion of E1G were also found in the lightweight rowers compared with the controls, but the difference did not reach significance. The number of rowing training hours was a significant determinant of peak PdG excretion in the rowers (R2 = 0.40; p<0.02). The seasonal suppression of PdG excretion was associated with degree of weight loss (R2 = 0.46; p<0.01). The competition related decrease in E1G and PdG excretion for the lightweight rowers was predominantly restored during the off season when exercise intensity and duration were decreased and body weight increased. These results showed a significant (p<0.05) reduction in progesterone metabolite excretion and a non-significant decrease in oestrone metabolite excretion associated with intensive competition season training loads and body weight reduction in female lightweight rowers.

Time-dependent instantaneous mortality rates from multiple tagging experiments with exact times of release and recovery

Instantaneous natural mortality rates and a nonparametric hunting mortality function are estimated from a multiple-year tagging experiment with arbitrary, time-dependent fishing or hunting mortality. Our theory allows animals to be tagged over a range of times in each year, and to take time to mix into the population. Animals are recovered by hunting or fishing, and death events from natural causes occur but are not observed. We combine a long-standing approach based on yearly totals, described by Brownie et al. (1985, Statistical Inference from Band Recovery Data: A Handbook, Second edition, United States Fish and Wildlife Service, Washington, Resource Publication, 156), with an exact-time-of-recovery approach originated by Hearn, Sandland and Hampton (1987, Journal du Conseil International pour l'Exploration de la Mer, 43, 107-117), who modeled times at liberty without regard to time of tagging. Our model allows for exact times of release and recovery, incomplete reporting of recoveries, and potential tag shedding. We apply our methods to data on the heavily exploited southern bluefin tuna (Thunnus maccoyii).

Evaluation of the most effective measures of infectivity of a precocious line of Eimeria acervulina in poultry

Coccidiosis is an economically important parasitic disease of chickens that, in Australia, is caused by seven species of the genus Eimeria.1 The disease has traditionally been controlled by prophylactic drugs, but vaccination with attenuated lines of the parasites2–4 is rapidly gaining acceptance world wide. Live Eimeria vaccines are produced in batches which are not frozen and have a limited shelf life. The per cent infectivity of vaccine seed stocks and the vaccines produced from them must therefore be accurately monitored using standardised dose dependant assays to ensure that shelf life, quality control and vaccine release specifications are met. Infectivity for the chicken host cannot readily be determined by microscopic observation of oocysts or sporocyst hatching.5 Dose dependent parameters such as body weight gain, feed conversion ratio, visual lesion scores, mortality, oocysts production, clinical symptoms and microscopic lesion counts could be used as measures of infectivity.6–11 These parameters show significant dose dependant effects with field strains, but lines of vaccine parasites that have been selected for precocious development with associated reduced virulence and reproductive capability may not have the same effect.3,4 The aim of this trial was to determine which parameters provide the most effective measures of infective dose in birds inoculated with a precocious vaccine strain.

Effects of hooking damage and hook type on post-release survival of sand flathead (Platycephalus bassensis)

This study examined post-release survival in sand flathead (Platycephalus bassensis) and whether there were survival benefits from the use of circle hooks over conventional hook patterns. Anatomical hooking location was the major factor contributing to mortality, with an almost 100% survival rate for fish hooked in the lip, mouth or eye (shallow-hooked) compared with around 64% for fish hooked in the throat or gut (deep-hooked). Mortality in deep-hooked fish was generally associated with injuries to vital organs (gills, heart, liver) and survival was significantly lower if bleeding was associated with injury (54% compared with 85% for non-bleeders). Circle hooks resulted in significantly lower deep-hooking rates (1%) compared with conventional hook types (4-9%) and, based on catch rates, were at least as effective as conventional hook patterns. Estimated survival rates for line-caught sand flathead were high, over 99% for circle hooks and between 94 and 97% for conventional hooks. These findings support the efficacy of management strategies based on size and bag limits and the practice of catch-and-release fishing for sand flathead, as well as a potential conservation benefit from the use of circle hooks.

Systematic analysis of changes in cannabis use among participants in control conditions of randomised controlled trials

Introduction Cannabis remains the most used illegal substance across the globe, and negative outcomes and disorders are common. A spotlight therefore falls on reductions in cannabis use in people with cannabis use disorder. Current estimates of unassisted cessation or reduction in cannabis use rely on community surveys, and few studies focus on individuals with disorder. A key interest of services and researchers is to estimate effect size of reductions in consumption among treatment seekers who do not obtain treatment. Effects within waiting list or information-only control conditions of randomised controlled trials offer an opportunity to study this question. Method This paper examines the extent of reductions in days of cannabis use in the control groups of randomised controlled trials on treatment of cannabis use disorders. A systematic literature search was performed to identify trials that reported days of cannabis use in the previous 30 (or equivalent). Results Since all but one of the eight identified studies had delayed treatment controls, results could only be summarised across 2–4 months. Average weighted days of use in the previous 30 days fell from 24.5 to 19.9, and a meta-analysis using a random effects model showed an average reduction of 0.442 SD. However, every study had at least one significant methodological issue. Conclusions While further high-quality data is needed to confirm the observed effects, these results provide a baseline from which researchers and practitioners can estimate the extent of change required to detect effects of cannabis treatments in services or treatment trials.

Preparation and in vitro release of drug-loaded microparticles for oral delivery using wholegrain sorghum kafirin protein

Kafirin microparticles have been proposed as an oral nutraceutical and drug delivery system. This study investigates microparticles formed with kafirin extracted from white and raw versus cooked red sorghum grains as an oral delivery system. Targeted delivery to the colon would be beneficial for medication such as prednisolone, which is used in the management of inflammatory bowel disease. Therefore, prednisolone was loaded into microparticles of kafirin from the different sources using phase separation. Differences were observed in the protein content, in vitro protein digestibility, and protein electrophoretic profile of the various sources of sorghum grains, kafirin extracts, and kafirin microparticles. For all of the formulations, the majority of the loaded prednisolone was not released in in vitro conditions simulating the upper gastrointestinal tract, indicating that most of the encapsulated drug could reach the target area of the lower gastrointestinal tract. This suggests that these kafirin microparticles may have potential as a colon-targeted nutraceutical and drug delivery system.

Biocontrol of Chromolaena odorata in Papua New Guinea

The status of biocontrol of Chromolaena odorata, a weed of significant agricultural importance in Papua New Guinea, is assessed. Chromolaena is confirmed present in 391 sites in 12 of the 20 provinces of PNG. A collaborative project on the biocontrol of chromolaena involving the PNG National Agricultural Research Institute and the Queensland Department of Primary Industries and Fisheries began in1998, with funding from ACIAR. Three agents, the moth Pareuchaetes pseudoinsulata, which has established only in Morobe Province, the stem-galling fly Cecidochares connexa, which has established in all 12 provinces and the leaf mining fly Calycomyza eupatorivora, which is currently being monitored for establishment, have been introduced. Cecidochares connexa has been the most effective of the agents so far and it has spread more than 100 km in five years from some release sites. Preliminary field data have shown that the numbers of galls per plant have increased, coupled with a decrease in plant height and percent plant cover. In parts of New Ireland and Sandaun provinces, C. connexa has controlled chromolaena, resulting in the regeneration of natural vegetation. In addition, some food gardens have been re-established where chromolaena had once taken over. Consequently, food production has increased and income generated from selling agricultural produce has increased two fold. There is also less time spent in clearing chromolaena from food gardens and plantations. The effectiveness of C. connexa has brought relief to many communities, which are helping in the distribution of the gall fly to other areas affected by chromolaena.

Factors influencing the release and establishment of weed biological control agents

Mike Day and colleagues recently published their paper 'Factors influencing the release and establishment of weed biocontrol agents' in Proceedings of the 16th Australian Weeds Conference. The CRC for Australian Weed Management facilitated an investigation into the factors influencing the release and establishment of weed biological control agents on a wide variety of Australian weeds. The investigation improved the understanding of post-release ecology of biocontrol agents and generated recommendations for best practice. Factors affecting successful establishment on the weed include host plant characteristics, size of releases, dispersal power of the agent, predation and parasitism, and climate. A best practice guide was produced by the CRC to assist practitioners in designing robust release strategies to increase rates of establishment.

Test of the enemy release hypothesis: the native magpie moth prefers a native fireweed (Senecio pinnatifolius) to its introduced congener (S. madagascariensis).

The enemy release hypothesis predicts that native herbivores will either prefer or cause more damage to native than introduced plant species. We tested this using preference and performance experiments in the laboratory and surveys of leaf damage caused by the magpie moth Nyctemera amica on a co-occuring native and introduced species of fireweed (Senecio) in eastern Australia. In the laboratory, ovipositing females and feeding larvae preferred the native S. pinnatifolius over the introduced S. madagascariensis. Larvae performed equally well on foliage of S. pinnatifolius and S. madagascariensis: pupal weights did not differ between insects reared on the two species, but growth rates were significantly faster on S. pinnatifolius. In the field, foliage damage was significantly greater on native S. pinnatifolius than introduced S. madagascariensis. These results support the enemy release hypothesis, and suggest that the failure of native consumers to switch to introduced species contributes to their invasive success. Both plant species experienced reduced, rather than increased, levels of herbivory when growing in mixed populations, as opposed to pure stands in the field; thus, there was no evidence that apparent competition occurred.

Row spacing and planting density effects on the growth and yield of sugarcane. 2. Strategies for the adoption of controlled traffic.

Controlled traffic (matching wheel and row spacing) is being promoted as a means to manage soil compaction in the Australian sugar industry. However, machinery limitations dictate that wider row spacings than the standard 1.5-m single row will need to be adopted to incorporate controlled traffic and many growers are reluctant to widen row spacing for fear of yield penalties. To address these concerns, contrasting row configuration and planting density combinations were investigated for their effect on cane and sugar yield in large-scale experiments in the Gordonvale, Tully, Ingham, Mackay, and Bingera (near Bundaberg) sugarcane-growing regions of Queensland, Australia. The results showed that sugarcane possesses a capacity to compensate for different row configurations and planting densities through variation in stalk number and individual stalk weight. Row configurations ranging from 1.5-m single rows (the current industry standard) to 1.8-m dual rows (50 cm between duals), 2.1-m dual (80 cm between duals) and triple ( 65 cm between triples) rows, and 2.3-m triple rows (65 cm between triples) produced similar yields. Four rows (50 cm apart) on a 2.1-m configuration (quad rows) produced lower yields largely due to crop lodging, while a 1.8-m single row configuration produced lower yields in the plant crop, probably due to inadequate resource availability (water stress/limited radiation interception). The results suggest that controlled traffic can be adopted in the Australian sugar industry by changing from a 1.5-m single row to 1.8-m dual row configuration without yield penalty. Further, the similar yields obtained with wider row configurations (2 m or greater with multiple rows) in these experiments emphasise the physiological and environmental plasticity that exists in sugarcane. Controlled traffic can be implemented with these wider row configurations (>2 m), although it will be necessary to carry out expensive modifications to the current harvester and haul-out equipment. There were indications from this research that not all cultivars were suited to configurations involving multiple rows. The results suggest that consideration be given to assessing clones with different growth habits under a range of row configurations to find the most suitable plant types for controlled traffic cropping systems.

Soil type does not affect seed ageing when soil water potential and temperature are controlled

To investigate the effects of soil type on seed persistence in a manner that controlled for location and climate variables, three weed species—Gomphocarpus physocarpus (swan plant), Avena sterilis ssp. ludoviciana (wild oat) and Ligustrum lucidum (broadleaf privet)—were buried for 21 months in three contrasting soils at a single location. Soil type had a significant effect on seed persistence and seedling vigour, but soil water content and temperature varied between soils due to differences in physical and chemical properties. Warmer, wetter conditions favoured shorter persistence. A laboratory-based test was developed to accelerate the rate of seed ageing within soils, using controlled superoptimal temperature and moisture conditions (the soil-specific accelerated ageing test, SSAAT). The SSAAT demonstrated that soil type per se did not influence seed longevity. Moreover, the order in which seeds aged was the same whether aged in the field or SSAAT, with L. lucidum being shortest-lived and A. sterilis being longest-lived of the three species.