Identity and pathogenicity of Fusarium spp. Isolated from wheat fields in Queensland and northern New South Wales

To establish the identity of Fusarium species associated with head blight (FHB) and crown rot (CR) of wheat, samples were collected from wheat paddocks with different cropping history in southern Queensland and northern New South Wales during 2001. CR was more widespread but FHB was only evident in northern NSW and often occurred with CR in the same paddock. Twenty different Fusarium spp. were identified from monoconidial isolates originating from different plant parts by using morphology and species-specific PCR assays. Fusarium pseudograminearum constituted 48% of all isolates and was more frequently obtained from the crown, whereas Fusarium graminearum made up 28% of all isolates and came mostly from the head. All 17 Fusarium species tested caused FHB and all 10 tested caused CR in plant infection assays, with significant (P < 0.001) difference in aggressiveness among species and among isolates within species for both diseases. Overall, isolates from stubble and crown were more aggressive for CR, whereas isolates from the flag leaf node were more aggressive for FHB. Isolates that were highly aggressive in causing CR were those originating from paddocks with wheat following wheat, whereas those from fields with wheat following maize or sorghum were highly aggressive for FHB. Although 20% of isolates caused severe to highly severe FHB and CR, there was no significant (P < 0.32) correlation between aggressiveness for FHB and CR. Given the ability of F. graminearum to colonise crowns in the field and to cause severe CR in bioassays, it is unclear why this pathogen is not more widely distributed in Australia.

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.

Clonal strains of Pseudomonas aeruginosa in paediatric and adult cystic fibrosis units

Despite recent reports of clonal strains of Pseudomonas aeruginosa in cystic fibrosis (CF) units, the need for routine microbiological surveillance remains contentious. Sputum was collected prospectively from productive patients attending the regional paediatric and adult CF units in Brisbane, Australia. All P. aeruginosa isolates were typed using pulsed-field gel electrophoresis. Spirometry, anthropometrics, hospitalisations and antibiotic sensitivity data were recorded. The first 100 sputum samples (first 50 patients at each clinic) harboured 163 isolates of P. aeruginosa. A total of 39 patients shared a common strain (pulsotype 2), 20 patients shared a strain with at least one other patient and 41 patients harboured unique strains. Eight patients shared a strain identical to a previously reported Australian transmissible strain (pulsotype 1). Compared with the unique strain group, patients harbouring pulsotype 2 were younger and had poorer lung function. Treatment requirements were similar in these two groups, as were the rates of multiresistance. In conclusion, 59% of patients harboured a clonal strain, supporting the need for routine microbiological surveillance. In contrast to previously described clonal strains, the dominant pulsotype was indistinguishable from nonclonal strains with respect to both colonial morphology and multiresistance. The clinical significance of clonal strains remains uncertain and requires longitudinal study.

Modelling predicts positive and negative interactions between three Australian tropical tree species in monoculture and binary mixture

Computer modelling promises to. be an important tool for analysing and predicting interactions between trees within mixed species forest plantations. This study explored the use of an individual-based mechanistic model as a predictive tool for designing mixed species plantations of Australian tropical trees. The 'spatially explicit individually based-forest simulator' (SeXI-FS) modelling system was used to describe the spatial interaction of individual tree crowns within a binary mixed-species experiment. The three-dimensional model was developed and verified with field data from three forest tree species grown in tropical Australia. The model predicted the interactions within monocultures and binary mixtures of Flindersia brayleyana, Eucalyptus pellita and Elaeocarpus grandis, accounting for an average of 42% of the growth variation exhibited by species in different treatments. The model requires only structural dimensions and shade tolerance as species parameters. By modelling interactions in existing tree mixtures, the model predicted both increases and reductions in the growth of mixtures (up to +/- 50% of stem volume at 7 years) compared to monocultures. This modelling approach may be useful for designing mixed tree plantations. (c) 2006 Published by Elsevier B.V.

Reflexive optokinetic nystagmus in younger and older observers under photopic and mesopic viewing conditions

PURPOSE. To investigate the effect of age on optokinetic nystagmus (OKN) in response to stimuli designed to preferentially stimulate the M-pathway. METHOD. OKN was recorded in 10 younger (32.3 +/- 5.98 years) and 10 older (65.6 +/- 6.53) subjects with normal vision. Vertical gratings of 0.43 or 1.08 cpd drifting at 5 degrees/s or 20 degrees/s and presented at either 8% or 80% contrast were displayed on a large screen as full-field stimulation, central stimulation within a central Gaussian-blurred window of 15 diameter, or peripheral stimulation outside this window. All conditions apart from the high-contrast condition were presented in a random order at two light levels, mesopic (1.8 cdm(-2)) and photopic (71.5 cdm(-2)). RESULTS. Partial-field data indicated that central stimulation, mesopic light levels, and lower temporal frequency each significantly increased slow-phase velocity (SPV). Although there was no overall difference between groups for partial-field stimulation, full-field stimulation, or low-contrast stimulation, a change in illumination revealed a significant interaction with age: there was a larger decrease in SPV going from photopic to mesopic conditions for the older group than the younger group, especially for higher temporal frequency stimulation. CONCLUSIONS. OKN becomes reflexive in conditions conducive to M-pathway stimulation, and this rOKN response is significantly diminished in older healthy adults than in younger healthy adults, indicative of decreased M-pathway sensitivity.

Transmitting focussed B1 field and SENSE reconstruction using an 8-element transceive torso phased array coil

In this work, a new design concept in chest imaging for MRI application is presented. A focused, 8-element transceive torso phased array coil is designed to investigate transmitting focused B1 field deep within the torso to enhance signal intensity and use in conjunction with SENSE reconstruction technique. Hybrid FDTD/MOM method is used to accurately predict the RF behavior inside the human torso. The simulation results reported herein demonstrate the feasibility of the design concept which shows that B1 field focusing with SENSE reconstruction is achievable, and the 8-element transceive torso phased array coil has the advantage to be used in transmit and receive mode for optimum and fast chest imaging.

A comparative study of career management practices in Britain and India

This paper examines the developments in the field of career management in a cross-national comparative context. It investigates a wide range of career practices via two large-scale surveys in 108 Indian and 194 British organisations. The influence of a number of organisational characteristics on career practices is analysed. The study has identified a number of similarities as well as differences in the career management systems of firms operating in both India and Britain. Theoretical and managerial implications for the fields of careers and international HRM are discussed.

A comparative study of HR practices in Britain and India

This paper traces the major developments in the field of human resource management briefly and then highlights the need for more cross-national HRM studies. The results from two parallel surveys of matched Indian and British organizations are presented. The main aim of the surveys was to examine a wide range of HRM policies and practices in a cross-national comparative context. The surveys were run in six industries in the manufacturing sector. The study controlled for a number of variables such as size of the organization, product, industry sector and personnel participation. Influence of a number of contingent variables (such as age, size, nature and life-cycle stage of the organization, presence of unions and human resource strategies) on HRM policies and practices is analysed. The study finds significant differences in recruitment, compensation, training and development and employee communication practices between India and Britain.

Evaluation of research in efficiency and productivity:a survey and analysis of the first 30 years of scholarly literature in DEA

Since the original Data Envelopment Analysis (DEA) study by Charnes et al. [Measuring the efficiency of decision-making units. European Journal of Operational Research 1978;2(6):429–44], there has been rapid and continuous growth in the field. As a result, a considerable amount of published research has appeared, with a significant portion focused on DEA applications of efficiency and productivity in both public and private sector activities. While several bibliographic collections have been reported, a comprehensive listing and analysis of DEA research covering its first 30 years of history is not available. This paper thus presents an extensive, if not nearly complete, listing of DEA research covering theoretical developments as well as “real-world” applications from inception to the year 2007. A listing of the most utilized/relevant journals, a keyword analysis, and selected statistics are presented.

Knowledge management: a review of the field and of OR's contribution

This paper examines the field of knowledge management (KM) and identifies the role of operational research (OR) in key milestones and in KM's future. With the presence of the OR Society journal Knowledge Management Research and Practice and with the INFORMS journal Organization Science, OR may be assumed to have an explicit and a leading role in KM. Unfortunately, the origins and the evidence of recent research efforts do not fully support this assumption. We argue that while OR has been inside many of the milestones there is no explicit recognition of its role and while OR research on KM has considerably increased in the last 5 years, it still forms a rather modest explicit contribution to KM research. Nevertheless, the depth of OR's experience in decision-making models and decision support systems, soft systems with hard systems and in risk management suggests that OR is uniquely placed to lead future KM developments. We suggest that a limiting aspect of whether OR will be seen to have a significant profile will be the extent to which developments are recognized as being informed by OR.