Spider fauna of soybean crops in south-east Queensland and their potential as predators of Helicoverpa spp. (Lepidoptera: Noctuidae)

Spiders are among the most abundant predators recorded in grain crops in Australia. They are voracious predators, and combined with their high abundance, may play an important role in the reduction of pest populations. The significance of spider assemblages as biological control agents of key pests such as Helicoverpa spp. in Australian agroecosystems is largely unknown. A thorough inventory was made of the spider fauna inhabiting unsprayed soybean fields at Gatton, south-east Queensland. One-hundred-and-two morphospecies from 28 families were collected using vacuum sampling and pitfall traps across two summer seasons (2000-01, 2001-02). No-choice feeding tests in the laboratory, using eggs and larvae of Helicoverpa armigera (Hubner) as prey, were used to ascertain the predatory potential of each spider group. The field-collected spider assemblage ate on average 2.4 (+/-0.7 standard error) to 5.0 (+/-0.8) eggs per 24 h per spider (10-25% of those available), depending on level of starvation. Clubionidae were the only spiders to readily consume eggs in the laboratory (mean of 18.4 +/- 1.5 eggs per starved spider and 8.2 +/- 3.9 per non-starved spider after 24 h). Starved spiders consumed 9.4 (+/- 0.1) first-instar larvae per 24 h per spider (90% of those available). This information was combined with field observations and literature from Australian and overseas studies to assess the potential of spider groups as predators of Helicoverpa spp. Lycosidae, Clubionidae, Oxyopidae, Salticidae and Thomisidae have the capacity to contribute to control of Helicoverpa spp.

Spider ballooning in soybean and non-crop areas of southeast Queensland

Ballooning is a form of aerial movement practiced by most miniature and some adult spiders. Very few studies have investigated the composition and rate of spider ballooning in Australian agroecosystems. Water traps were used to compare ballooning rates in irrigated soybean crops and nearby non-crop areas in southeast Queensland over two summer seasons. The highest ballooning rate (14.8 spiders/m(2) per day) was recorded in a soybean field, non-crop areas (7.0 spiders/m(2) per day) and a dry land mungbean field (6.8 spiders/m(2) per day) having similar rates. Spider ballooning in soybean increased throughout the season and showed three peaks and intervening troughs. A similar pattern in ballooning peaks was observed in non-crop areas however the numbers were lower. Peaks in ballooning activity where synchronised across habitat types and some spider groups. Composition of the ballooning fauna was different from that of the ground-dwelling fauna, some families being present in both. Ballooning is an important behaviour in terms of population dynamics for a number of spider groups in soybean and the implications for pest control are discussed. (C) 2004 Elsevier BN. All rights reserved.

Resistance of three different populations of mulberry silkworm (Bombyx mori L.) to Bacillus thuringiensis

The relative resistance levels of three different populations of mulberry silkworm, Bombyx mori L. to Bacillus thuringiensis (Bt) has been studied. All three populations (two Australian and one Indonesian) were observed for similar characteristics including 3rd instar larval mortality at 24, 48, 72 and 96 h after treatment (HAT), LD50 ratio and probit mortality. Among the Australian two populations, the QuBill (yellow coloured, oval shaped cocoon) population showed higher larval mortality to Bt toxicity compared to the QuBite (white coloured, oval shaped cocoon) population. When all the populations were compared, the Insab (Indonesian population with white Coloured, peanut shaped cocoon) showed lower larval mortality and highest LD50 ratio up to 48 HAT. The Insab population also showed a 24 It longer incubation/latent period prior to the start Of Mortality.

Change in physiotherapy management of children with cystic fibrosis in a large urban hospital

A retrospective audit was conducted in 1998 and 2000 to review the physiotherapy management of hospitalized children with cystic fibrosis (CF) at the Brisbane Royal Children's Hospital (RCH). The objective was to detect and explore possible changes in patient management in this time period and investigate whether these changes reflected changes in the current theory of CF management. All children over two years of age with CF admitted during 1998 and 2000 with pulmonary manifestation and who satisfied set criteria were included (n = 249). Relative frequency of each of six treatment modalities used were examined on two occasions, revealing some degree of change in practice reflecting the changes in current theory. There was a significant decrease in the frequency of usage of postural drainage with head-down tilt (p < 0.001), and autogenic drainage (p < 0.001) between 1998 and 2000. Modified postural drainage without head-down tilt (p < 0.001), and positive expiratory pressure devices (p < 0.001) were used more frequently in 2000 (p < 0.001). No significant changes were identified in the use of Flutter VRP1 (p = 0.145) and exercise (p = 0.763). No significant differences were found in population demographics or occurrence of concomitant factors that may influence patient management.

Computational methods for the detection of facial palsy

We are developing a telemedicine application which offers automated diagnosis of facial (Bell's) palsy through a Web service. We used a test data set of 43 images of facial palsy patients and 44 normal people to develop the automatic recognition algorithm. Three different image pre-processing methods were used. Machine learning techniques (support vector machine, SVM) were used to examine the difference between the two halves of the face. If there was a sufficient difference, then the SVM recognized facial palsy. Otherwise, if the halves were roughly symmetrical, the SVM classified the image as normal. It was found that the facial palsy images had a greater Hamming Distance than the normal images, indicating greater asymmetry. The median distance in the normal group was 331 (interquartile range 277-435) and the median distance in the facial palsy group was 509 (interquartile range 334-703). This difference was significant (P

Electromechanical resonators as measuring transducers

With the increasing use of digital computers for data acquisition and digital process control, frequency domain transducers have become very attractive due to their virtual digital output. Essentially they are electrically maintained oscillators where the sensor is the controlling resonator.They are designed to make the frequency a function of the physical parameter being measured. Because of their high quality factor, mechanical resonators give very good frequency stability and are widely used as sensors. For this work symmetrical mechanical resonators such as the tuning fork were considered, to be the most promising. These are dynamically clamped and can be designed to have extensive regions where no vibrations occur.This enables the resonators to be robustly mounted in a way convenient for various applications. Designs for the measurement of fluid density and tension have been produced. The principle of the design of the resonator for fluid density measurement is a thin gap (trapping a lamina of fluid) between its two members which vibrate in antiphase.An analysis of the inter­ action between this resonator and the fluid lamina has carried out.In gases narrow gaps are needed for a good sensitivity and the use of the material fused quartz, because of its low density and very low temperature coefficient, is ideally suitable. In liquids an adequate sensitivity is achieved even with a wide lamina gap. Practical designs of such transducers have been evolved. The accuracy for liquid measurements is better than 1%. For gases it was found that, in air, a change of atmospheric pressure of 0.3% could be detected. In constructing a tension transducer using such a mechanical sensor as a wire or a beam, major difficulties are encountered in making an efficient clamping arrangement for the sensor. The use of dynamically clamped beams has been found to overcome the problem and this is the basis of the transducer investigated.

Vibrational methods applied to NDT testing and fluid density measurement

A system for the NDI' testing of the integrity of conposite materials and of adhesive bonds has been developed to meet industrial requirements. The vibration techniques used were found to be applicable to the development of fluid measuring transducers. The vibrational spectra of thin rectangular bars were used for the NDT work. A machined cut in a bar had a significant effect on the spectrum but a genuine crack gave an unambiguous response at high amplitudes. This was the generation of fretting crack noise at frequencies far above that of the drive. A specially designed vibrational decrement meter which, in effect, measures mechanical energy loss enabled a numerical classification of material adhesion to be obtained. This was used to study bars which had been flame or plasma sprayed with a variety of materials. It has become a useful tool in optimising coating methods. A direct industrial application was to classify piston rings of high performance I.C. engines. Each consists of a cast iron ring with a channel into which molybdenum, a good bearing surface, is sprayed. The NDT classification agreed quite well with the destructive test normally used. The techniques and equipment used for the NOT work were applied to the development of the tuning fork transducers investigated by Hassan into commercial density and viscosity devices. Using narrowly spaced, large area tines a thin lamina of fluid is trapped between them. It stores a large fraction of the vibrational energy which, acting as an inertia load reduces the frequency. Magnetostrictive and piezoelectric effects together or in combination enable the fork to be operated through a flange. This allows it to be used in pipeline or 'dipstick' applications. Using a different tine geometry the viscosity loading can be predoninant. This as well as the signal decrement of the density transducer makes a practical viscometer.