Additional signalling compounds are required to orchestrate plant development

Plants are necessarily complex systems that require monitoring of multiple environmental signals and, in response to those signals, coordination of differentiation and development of an extensive array of cell types at multiple locations. This coordination must rely on integration of long-distance signals that provide a means of communication among different plant parts. We propose that the relatively well-characterized classical phytohormones must act with several other long-distance signals to achieve this level of organization with dynamic yet measured responses. This is supported by observations that classical phytohormones: (i) operate in complex yet experimentally unresolved networks involving cross-talk and feedback, (ii) are generally multifunctional and nonspecific and hence must rely on other long-distance cues or pre-set conditions to achieve specificity and (iii) are likely to mask roles of other long-distance signals in several experimental contexts. We present evidence for involvement of novel long-distance signals in three developmental processes-branching, flowering and nodulation, and discuss the possible identities of novel signalling molecules.

Electronic commerce investments, the resource-based view of the firm, and firm market value

Firms have embraced electronic commerce as a means of doing business, either because they see it as a way to improve efficiency, grow market share, expand into new markets, or because they view it as essential for survival. Recent research in the United States provides some evidence that the market does value investments in electronic commerce. Following research that suggests that, in certain circumstances, the market values noninnovative investments as well as innovative investments in new products, we partition electronic commerce investment project announcements into innovative and noninnovative to determine whether there are excess returns associated with these types of announcements. Apart from our overall results being consistent with the United States findings that the market values investments in electronic commerce projects, we also find that noninnovative investments are perceived as more valuable to the firm than innovative investments. On average, the market expects innovative investments to earn a return commensurate with their risk. We conclude that innovative electronic commerce projects are most likely seen by the capital market as easily replicable, and consequently have little, if any, competitive advantage period. On the other hand, we conclude from the noninnovative investment results that these types of investments are seen as being compatible with a firm's assets-in-place, in particular, its information technology capabilities, a view consistent with the resource-based view of the firm.

The epidemiology of dysphagia: Describing the problem - are we too late?

The assessment and management of dysphagia is a rapidly growing part of speech pathology clinical practice for both adult and paediatric populations, yet there is limited information available regarding the epidemiology of dysphagia. Very few studies have defined the characteristics of the disorder, its incidence/prevalence in various populations, the natural history of the disorder or the relative risks, comorbidities and outcomes associated with dysphagia. The current paper will identify some fundamental questions that as yet remain unanswered and highlight areas of future research that are required in order for us to have a better understanding of dysphagia and inform assessment and management. In conclusion, the authors propose an epidemiological framework and highlight information needs in the field of dysphagia. This framework urges future dysphagia research to be informed and underpinned by sound epidemiological principles.

Financial and economic performance of long-rotation hardwood plantation investments in Queensland, Australia

In Queensland, Australia, there is presently a high level of interest in long-rotation hardwood plantation investments for sawlog production, despite the consensus in Australian literature that such investments are not financially viable. Continuing genetics, silviculture and processing research, and increasing awareness about the ecosystem services generated by plantations, are anticipated to make future plantings profitable and socio-economically desirable in many parts of Queensland. Financial and economic models of hardwood plantations in Queensland are developed to test this hypothesis. The economic model accounts for carbon sequestration, salinity amelioration and other ecosystem service values of hardwood plantations. A carbon model estimates the value of carbon sequestered, while salinity and other ecosystem service values are estimated by the benefit transfer method. Where high growth rates (20-25 m(3) ha(-1) year(-1)) are achievable, long-rotation hardwood plantations are profitable in Queensland Hardwood Regions 1, 3 and 7 when rural land values are less than $2300/ha. Under optimistic assumptions, hardwood plantations growing at a rate of 15 in 3 ha-1 year 1 are financially viable in Hardwood Regions 2, 4 and 8, provided land values are less than $1600/ha. The major implication of the economic analysis is that long-rotation hardwood plantation forestry is socio-economically justified in most Hardwood Regions, even though financial returns from timber production may be negative. (c) 2003 Elsevier B.V. All rights reserved.

Realtime telemedicine for paediatric otolaryngology pre-admission screening

We conducted a feasibility study to examine whether a paediatric patient at a regional hospital could be assessed by an ear, nose and throat (ENT) specialist via videoconference, therefore saving at least one journey to the tertiary hospital for a pre-admission appointment. A video-otoscope was used with standard videoconference equipment, and realtime images were transmitted at a bandwidth of 384 kbit/s. In all, 13 telepaediatric ENT clinics were conducted between November 2003 and April 2005, and 98 consultations were facilitated for 64 patients. The main reasons for referral were recurrent tonsillitis (25%) and obstructive sleep apnoea (23%). Of the 64 patients examined by telemedicine, 42 (66%) were recommended for surgery and placed on the surgical waiting list. About 12 patients (19%) required travel to the tertiary centre for further investigations and tests not available locally, while four patients (6%) were reviewed via videoconference during a scheduled clinic. Six patients (9%) required no further follow-up after their initial telepaedliatric consultation. Videoconferencing is an effective method of assessing ENT conditions of paediatric patients and for pre-screening potential surgical admissions to a tertiary hospital. Careful consideration of a number of economic and logistical factors needs to be made before large investments are made to expand the service.