Variation of phloem turgor pressure in Hevea brasiliensis: An implication for latex yield and tapping system optimization

Phloem turgor pressure (PTP) is the initial driving force for latex flow after a rubber tree is tapped and therefore plays an important role in rubber tree latex production. Variation in PTP with rubber tree clone, age, yield potential and commonly used Ethrel (an ethylene releaser) stimulation have, however, not been comprehensively studied to date. The aim of this study was to investigate these relations and examine whether PTP can be used as an index for rubber tree clone assessment and tapping system optimization. The results showed that: (1) the daily change of PTP in the foliation season suggests that a high PTP can ensure a high latex yield and tapping could be moved forward to midnight or earlier in the night; (2) the decrease of PTP from the basal to distal stem indicates the benefit of a controlled upward tapping system; (3) the logarithmic increase in PTP with rubber tree planting age and age-based mean girth suggests that the preferred age for the commencement of rubber tree tapping is eight years; (4) the change of PTP with regenerated bark age suggests that the regenerated bark could be exploited again after the second year; (5) PTP is positively related to the yield potential of rubber tree clones; (6) although Ethrel stimulation could not significantly increase the initial PTP of a rubber tree, it delays the recovery of PTP after tapping. Therefore, PTP is an indicator of rubber tree latex yield and can be used for tapping system optimization. © 2014 Elsevier B.V.

Distribution of carbon nanotubes in fresh ordinary Portland cement pastes: understanding from a two-phase perspective

Significant research advances have been made in the field of carbon nanotube (CNT) reinforced ordinary Portland cement (OPC) paste composites in recent years. However, the distribution of CNTs in fresh OPC paste is yet to be fully researched and quantified, thereby creating a technical barrier to CNT utilization in concrete construction. In this study, fresh OPC paste was treated as a two-phase material containing solid particles (cement grains) and liquid solutions (pore solutions). A centrifugation-based technique was proposed to separate these two phases and the presence of CNTs in each phase was quantified. UV-Vis spectrometry showed that the degree of dispersion can achieve above 90 wt% using polycarboxylate superplasticizer. The results suggested an upper limit of 0.26 wt% for CNT addition into water before mixing with OPC, and the dispersion was found to be stable for at least 4 hours. Based on scanning electron imaging, the adsorption phenomenon of CNTs on OPC grains with size less than 4 μm was discovered. Energy-dispersive X-ray spectroscopy indicated these adsorptive particles have lower Ca to Si ratio. It was observed that about 0.5 mg of CNTs per gram of OPC grains was adsorbed in solid OPC grains in typical fresh OPC pastes. On the basis of these results, a conceptual model was proposed for the distribution of CNTs in fresh OPC paste where about 33 wt% of the CNTs stay in pore solution and 65 wt% of CNTs are adsorbed on OPC grains.

An agent-based hybrid intelligent system for financial investment planning

Many complex problems including financial investment planning require hybrid intelligent systems that integrate many intelligent techniques including expert systems, fuzzy logic, neural networks, and genetic algorithms. However, hybrid intelligent systems are difficult to develop due to complicated interactions and technique incompatibilities. This paper describes a hybrid intelligent system for financial investment planning that was built from agent points of view. This system currently consists of 13 different agents. The experimental results show that all agents in the system can work cooperatively to provide reasonable investment advice. The system is very flexible and robust. The success of the system indicates that agent technologies can significantly facilitate the construction of hybrid intelligent systems.

An agent-based hybrid intelligent system for foreign exchange trading

The foreign exchange (FX) market has many features including (1) Each trader’s payoff depends not only on his own behavior, but also on other traders’ decisions; (2) The number of traders is too large to make them all know the other dealers’ methods of decision making; and (3) The FX market has many levels. The FX market is complex because of these features. A diversity of techniques are required to deal with such complex problems. That is hybrid solutions are crucial for the FX market. On the other hand, research into the FX market has revealed that it demonstrates some characteristics of multi-agent systems such as autonomy, interaction, and emergence. To this end, an agent-based hybrid intelligent system was developed for FX trading, which is based on our proposed agent-based hybrid framework. This paper is to discuss the analysis, design, and implementation such a system. Some experimental results and comparisons with related works are also provided. The interest of this paper does not reside in improving the predictive capabilities of different FX models, but rather in how to integrate different models into one system under the unifying agent framework. The success of this system indicates that agent perspectives are very appropriate to model complex problems such as the FX trading.

Session initiation protocol (SIP) based event notification system architecture for telemedicine applications

Mobility service for hospital technicians involved in telemedicine applications is one of the key issues in providing more flexible and efficient in-house or remote health care services. Today, the Internet based communication has widened the opportunity of event monitoring systems in the medical field. The session initiation protocol (SIP) can work on a variety of devices and can be used to create a medical event notification system. Its adoption as the protocol of choice for third generation wireless networks allows for a robust and scalable environment. One of the advantages of SIP is that it supports personal mobility through the separation of user addressing and device addressing. In this paper, the authors propose a possible solution framework for telemedicine alert notification system based SIP-specific event notification.

Latex-based nanocomposites

Nanoparticles have been widely used as filler in polymer because of their unique reinforcing effect. There are many compounding methods for nanocomposites. The recent development on latex nanocomposites, a group of special nanocomposites, is reviewed in this chapter. They include carbon black/latex nanocomposite, silica/latex nanocomposite, layered silicate/latex nanocomposite, ZnO/latex nanocomposite, carbon nanotubellatex nanocomposite, lignin/latex nanocomposite, starch/latex nanocomposite, nano-fiber/latex nanocomposite, and Chitin whiskers/latex nanocomposite. Advanced compounding techniques and the latest advance on these latex nanocomposites are described. The nanoreinforcing theories of latex nanocomposites are also studied.

Prevalence and cost of musculoskeletal disorders: a population-based, public hospital system healthcare consumption approach.

Objective: To use a population-level, public-hospital approach to compare the prevalence and cost of musculoskeletal diseases (MSD) with other clinical specialties.

Methods: A healthcare utilization survey of 4 million individual records over 4 years, from all major public hospitals in the state of Victoria (estimated population 4.8 million residents in 2000/01) from 1997/98 to 2000/01. Main outcome measures were inpatient episodes of care, bed-days, and outpatient clinic encounters. MSD was defined as the combination of orthopedics and rheumatology.

Results: After obstetrics, MSD was the most frequent outpatient service, with orthopedics accounting for 9.9% of all visits in 2000/01. The proportion of MSD outpatient encounters (on average 11.6% of the total) was constant over the study period. Among 26 medical specialties, MSD had the sixth highest number of inpatient episodes (6.2% in 2000/01), following renal dialysis (14.6%), general surgery (8.2%), obstetrics (7.6%), gastroenterology (7.1%), and general medicine (6.7%). MSD was the fifth highest consumer of bed-days, occupying on average 7.7% of all beds per annum in the period 1997/98 to 2000/01, behind psychiatry (10.1%), respiratory medicine (8.5%), rehabilitation (8.3%), and general medicine (7.8%). MSD was the third most-costly discipline in 2000/01, with total costs of over A dollars 169 million (9.7% of total inpatient costs that year), behind respiratory medicine (11.6%) and general surgery (11.5%).

Conclusion: Compared to other diseases, MSD consumes a substantial proportion of healthcare resources in Victorian public hospitals. These data have important implications for allocation of healthcare resources, clinical care pathways, and prevention strategies.

A principles-based Anglo governance system is not a science but an art

Anglo governance systems rely of a number of controls to align shareholder and boards of director’s interests. In general they are referred to as market control, regulatory control, and political and cultural control. Agency theory proposes that these control mechanisms are necessary as human nature is such that directors and managers act in a self-interested and boundedly rational manner in decision-making that can result in sub optimality. Notwithstanding that each country within the Anglo system accepts such controls are necessary they have their own foci and priorities, being a product of their own system’s characteristics. This paper through interviewing a number of Australian business executives adds to the academic literature by providing evidence from the field of the important characteristics of the Australian governance system, the drivers of change and the effectiveness of the principles-based approach. It argues that debate needs to move beyond the principles versus rules approach to look at how firms can be provided with more guidance in operationalising some of the principles that appear to be key to governance effectiveness. It concludes that there is a need for a holistic model of governance that is broader than that focusing on the control/legalistic approach; that top management is important in setting and driving the in-firm governance agenda; that the public needs to be informed and educated about governance and its importance; and that disclosure still requires an improvement in quality.

MVGL analyser for multi-classifier based spam filtering system

In the last decade, the rapid growth of the Internet and email, there has been a dramatic growth in spam. Spam is commonly defined as unsolicited email messages and protecting email from the infiltration of spam is an important research issue. Classifications algorithms have been successfully used to filter spam, but with a certain amount of false positive trade-offs, which is unacceptable to users sometimes. This paper presents an approach to overcome the burden of GL (grey list) analyzer as further refinements to our multi-classifier based classification model (Islam, M. and W. Zhou 2007). In this approach, we introduce a ldquomajority voting grey list (MVGL)rdquo analyzing technique which will analyze the generated GL emails by using the majority voting (MV) algorithm. We have presented two different variations of the MV system, one is simple MV (SMV) and other is the ranked MV (RMV). Our empirical evidence proofs the improvements of this approach compared to the existing GL analyzer of multi-classifier based spam filtering process.

Context-based e-health system access control mechanism

E-Health systems logically demand a sufficiently fine-grained authorization policy for access control. The access to medical information should not be just role-based but should also include the contextual condition of the role to access data. In this paper, we present a mechanism to extend the standard role-based access control to incorporate contextual information for making access control decisions in e-health application. We present an architecture consisting of authorisation and context infrastructure that work cooperatively to grant access rights based on context-aware authorization policies and context information.

Experiences gained from building a services-based distributed operating system

The goal of this paper is to present the experiences gained over 15 years of research into the design and development of a services-based distributed operating system. The lessons learnt over this period, we hope, will be of value to researchers involved in the design and development of operating systems that wish to harness the collective resources of ever-expanding distributed systems.