Detection of banana bunchy top virus in virus-infected plants using polymerase chain reaction

Polymerase chain reaction (PCR) was developed for the detection of Banana bunchy top virus (BBTV) at maximum after 210 min and at minimum after 90 min using Pc-1 and Pc-2, respectively. PCR detection of BBTV in crude sap indicated that the freezing of banana tissue in liquid nitrogen (LN2) before extraction was more effective than using sand as the extraction technique. BBTV was also detected using PCR assay in 69 healthy and diseased plants using Na-PO4 buffer containing 1 % SDS. PCR detection of BBTV in nucleic acid extracts using seven different extraction buffers to adapt the use of PCR in routine detection in the field was studied. Results proved that BBTV was detected with high sensitivity in nucleic acid extracts more than in infectious sap. The results also suggested the common aetiology for the BBTV by the PCR reactions of BBTV in nucleic acid extracts from Australia, Burundi, Egypt, France, Gabon, Philippines and Taiwan. Results also proved a positive relation between the Egyptian-BBTV isolate and abaca bunchy top isolate from the Philippines, but there no relation was found with the Cucumber mosaic cucumovirus (CMV) isolates from Egypt and Philippines and Banana bract mosaic virus (BBMV) were found.

Link discovery for Chinese/English cross-language web information retrieval

Nowadays people heavily rely on the Internet for information and knowledge. Wikipedia is an online multilingual encyclopaedia that contains a very large number of detailed articles covering most written languages. It is often considered to be a treasury of human knowledge. It includes extensive hypertext links between documents of the same language for easy navigation. However, the pages in different languages are rarely cross-linked except for direct equivalent pages on the same subject in different languages. This could pose serious difficulties to users seeking information or knowledge from different lingual sources, or where there is no equivalent page in one language or another. In this thesis, a new information retrieval task—cross-lingual link discovery (CLLD) is proposed to tackle the problem of the lack of cross-lingual anchored links in a knowledge base such as Wikipedia. In contrast to traditional information retrieval tasks, cross language link discovery algorithms actively recommend a set of meaningful anchors in a source document and establish links to documents in an alternative language. In other words, cross-lingual link discovery is a way of automatically finding hypertext links between documents in different languages, which is particularly helpful for knowledge discovery in different language domains. This study is specifically focused on Chinese / English link discovery (C/ELD). Chinese / English link discovery is a special case of cross-lingual link discovery task. It involves tasks including natural language processing (NLP), cross-lingual information retrieval (CLIR) and cross-lingual link discovery. To justify the effectiveness of CLLD, a standard evaluation framework is also proposed. The evaluation framework includes topics, document collections, a gold standard dataset, evaluation metrics, and toolkits for run pooling, link assessment and system evaluation. With the evaluation framework, performance of CLLD approaches and systems can be quantified. This thesis contributes to the research on natural language processing and cross-lingual information retrieval in CLLD: 1) a new simple, but effective Chinese segmentation method, n-gram mutual information, is presented for determining the boundaries of Chinese text; 2) a voting mechanism of name entity translation is demonstrated for achieving a high precision of English / Chinese machine translation; 3) a link mining approach that mines the existing link structure for anchor probabilities achieves encouraging results in suggesting cross-lingual Chinese / English links in Wikipedia. This approach was examined in the experiments for better, automatic generation of cross-lingual links that were carried out as part of the study. The overall major contribution of this thesis is the provision of a standard evaluation framework for cross-lingual link discovery research. It is important in CLLD evaluation to have this framework which helps in benchmarking the performance of various CLLD systems and in identifying good CLLD realisation approaches. The evaluation methods and the evaluation framework described in this thesis have been utilised to quantify the system performance in the NTCIR-9 Crosslink task which is the first information retrieval track of this kind.

A preconditioned Lanczos method for space-fractional reaction-diffusion equations on two-dimensional unstructured meshes

We consider a two-dimensional space-fractional reaction diffusion equation with a fractional Laplacian operator and homogeneous Neumann boundary conditions. The finite volume method is used with the matrix transfer technique of Ilić et al. (2006) to discretise in space, yielding a system of equations that requires the action of a matrix function to solve at each timestep. Rather than form this matrix function explicitly, we use Krylov subspace techniques to approximate the action of this matrix function. Specifically, we apply the Lanczos method, after a suitable transformation of the problem to recover symmetry. To improve the convergence of this method, we utilise a preconditioner that deflates the smallest eigenvalues from the spectrum. We demonstrate the efficiency of our approach for a fractional Fisher’s equation on the unit disk.

A picture is worth a thousand words : a cross-curricular approach to learning about visuals in STEM

Visuals are a central feature of STEM in all levels of education and many areas of employment. The wide variety of visuals that students are expected to master in STEM prevents an approach that aims to teach students about every type of visual that they may encounter. This paper proposes a pedagogy that can be applied across year levels and learning areas, allowing a school-wide, cross-curricular, approach to teaching about visual, that enhances learning in STEM and all other learning areas. Visuals are classified into six categories based on their properties, unlike traditional methods that classify visuals according to purpose. As visuals in the same category share common properties, students are able to transfer their knowledge from the familiar to unfamiliar in each category. The paper details the classification and proposes some strategies that can be can be incorporated into existing methods of teaching students about visuals in all learning areas. The approach may also assist students to see the connections between the different learning areas within and outside STEM.

Health status of Thai migrants in Brisbane : findings from a cross-sectional investigation

Australia is a multi-ethnic, multi-cultural country with a long history of migration. In 2006, 22% of the population was born overseas. Thai migrants accounted for 0.2% of the population at this time, with a nearly 40% increase from around 19,000 in 1996 to 30,555 in 2006.1 Despite this, little is known about the health of this migrant group. We investigated the health status and health service utilisation of a Thai community through a cross-sectional postal survey conducted from May to September 2010. Participants were members of a Brisbane Thai temple, aged 18 years and older, who self identified as being Thai. Current health status was assessed using the SF-36v22 and self-report of diagnosed medical conditions. Use of health services was assessed using questions adapted from the Welsh Health Survey.3 Socio-demographic variables included gender, age, language spoken at home, year of arrival in Australia and type of health care insurance.

A cross-sectional analysis of patterns of obesity in a cohort of working nurses and midwives in Australia, New Zealand, and the United Kingdom

Objective The aim of this study was to examine the prevalence of overweight and obesity and the association with demographic, reproductive work variables in a representative cohort of working nurses and midwives. Design A cross sectional study of self reported survey data. Settings Australia, New Zealand and the United Kingdom. Methods Measurement outcomes included BMI categories, demographic (age, gender, marital status, ethnicity), reproductive (parity, number of births, mother's age at first birth, birth type and menopausal status) and workforce (registration council, employment type and principal specialty) variables. Participants 4996 respondents to the Nurses and Midwives e-Cohort study who were currently registered and working in nursing or midwifery in Australia (n=3144), New Zealand (n=778) or the United Kingdom (n=1074). Results Amongst the sample 61.87% were outside the healthy weight range and across all three jurisdictions the prevalence of obesity in nurses and midwives exceeded rates in the source populations by 1.73% up to 3.74%. Being overweight or obese was significantly associated with increasing age (35–44 yrs aOR 1.71, 95% CI 1.41–2.08; 45–55 yrs aOR 1.90, 95%CI 1.56–2.31; 55–64 aOR 2.22, 95% CI 1.71–2.88), and male gender (aOR 1.46, 95% CI 1.15–1.87). Primiparous nurses and midwives were more likely to be overweight or obese (aOR 1.37, 95% CI 1.06–1.76) as were those who had reached menopause (aOR 1.37, 95% CI 1.11–1.69). Nurses and midwives in part-time or casual employment had significantly reduced risk of being overweight or obese, (aOR 0.81, 95% CI 0.70–0.94 and aOR 0.75, 95% CI 0.59–0.96 respectively), whilst working in aged carried increased risk (aOR 1.37, 95% CI 1.04–1.80). Conclusion Nurses and midwives in this study have higher prevalence of obesity and overweight than the general population and those who are older, male, or female primiparous and menopausal have significantly higher risk of overweight or obesity as do those working fulltime, or in aged care. The consequences of overweight and obesity in this occupational group may impact on their workforce participation, their management of overweight and obese patients in their care as well as influencing their individual health behaviours and risks of occupational injury and chronic disease.

Learning environments – Laboratories at the cross roads

Laboratories and technical hands on learning have always been a part of Engineering and Science based university courses. They provide the interface where theory meets practice and students may develop professional skills through interacting with real objects in an environment that models appropriate standards and systems. Laboratories in many countries are facing challenges to their sustainable operation and effectiveness. In some countries such as Australia, significantly reduced funding and staff reduction is eroding a once strong base of technical infrastructure. Other countries such as Thailand are seeking to develop their laboratory infrastructure and are in need of staff skill development, management and staff structure in technical areas. In this paper the authors will address the need for technical development with reference to work undertaken in Thailand and Australia. The authors identify the roads which their respective university sectors are on and point out problems and opportunities. It is hoped that the cross roads where we meet will result in better directions for both.

Factors associated with suboptimal adherence to antiretroviral therapy in Viet Nam: A cross-sectional study using audio computer-assisted self-interview (ACASI)

Background: Optimal adherence to antiretroviral therapy (ART) is necessary for people living with HIV/AIDS (PLHIV). There have been relatively few systematic analyses of factors that promote or inhibit adherence to antiretroviral therapy among PLHIV in Asia. This study assessed ART adherence and examined factors associated with suboptimal adherence in northern Viet Nam. Methods: Data from 615 PLHIV on ART in two urban and three rural outpatient clinics were collected by medical record extraction and from patient interviews using audio computer-assisted self-interview (ACASI). Results: The prevalence of suboptimal adherence was estimated to be 24.9% via a visual analogue scale (VAS) of past-month dose-missing and 29.1% using a modified Adult AIDS Clinical Trial Group scale for on-time dose-taking in the past 4 days. Factors significantly associated with the more conservative VAS score were: depression (p < 0.001), side-effect experiences (p < 0.001), heavy alcohol use (p = 0.001), chance health locus of control (p = 0.003), low perceived quality of information from care providers (p = 0.04) and low social connectedness (p = 0.03). Illicit drug use alone was not significantly associated with suboptimal adherence, but interacted with heavy alcohol use to reduce adherence (p < 0.001). Conclusions: This is the largest survey of ART adherence yet reported from Asia and the first in a developing country to use the ACASI method in this context. The evidence strongly indicates that ART services in Viet Nam should include screening and treatment for depression, linkage with alcohol and/or drug dependence treatment, and counselling to address the belief that chance or luck determines health outcomes.

The implications of cross-regional differences for the design of In-vehicle Information Systems : a comparison of Australian and Chinese drivers

The increasing global distribution of automobiles necessitates that the design of In-vehicle Information Systems (IVIS) is appropriate for the regions to which they are being exported. Differences between regions such as culture, environment and traffic context can influence the needs, usability and acceptance of IVIS. This paper describes two studies aimed at identifying regional differences in IVIS design needs and preferences across drivers from Australia and China to determine the impact of any differences on IVIS design. Using a questionnaire and interaction clinics, the influence of cultural values and driving patterns on drivers' preferences for, and comprehension of, surface- and interaction-level aspects of IVIS interfaces was explored. Similarities and differences were found between the two regional groups in terms of preferences for IVIS input control types and labels and in the comprehension of IVIS functions. Specifically, Chinese drivers preferred symbols and Chinese characters over English words and were less successful (compared to Australians) at comprehending English abbreviations, particularly for complex IVIS functions. Implications in terms of the current trend to introduce Western-styled interfaces into other regions with little or no adaptation are discussed.

Cross-calbration of push-broom 2D LIDARs and cameras in natural scenes

This paper addresses the problem of automatically estimating the relative pose between a push-broom LIDAR and a camera without the need for artificial calibration targets or other human intervention. Further we do not require the sensors to have an overlapping field of view, it is enough that they observe the same scene but at different times from a moving platform. Matching between sensor modalities is achieved without feature extraction. We present results from field trials which suggest that this new approach achieves an extrinsic calibration accuracy of millimeters in translation and deci-degrees in rotation.

Cross-layer design and optimization for wireless networked control systems

Wireless networked control systems (WNCSs) have been widely used in the areas of manufacturing and industrial processing over the last few years. They provide real-time control with a unique characteristic: periodic traffic. These systems have a time-critical requirement. Due to current wireless mechanisms, the WNCS performance suffers from long time-varying delays, packet dropout, and inefficient channel utilization. Current wirelessly networked applications like WNCSs are designed upon the layered architecture basis. The features of this layered architecture constrain the performance of these demanding applications. Numerous efforts have attempted to use cross-layer design (CLD) approaches to improve the performance of various networked applications. However, the existing research rarely considers large-scale networks and congestion network conditions in WNCSs. In addition, there is a lack of discussions on how to apply CLD approaches in WNCSs. This thesis proposes a cross-layer design methodology to address the issues of periodic traffic timeliness, as well as to promote the efficiency of channel utilization in WNCSs. The design of the proposed CLD is highlighted by the measurement of the underlying network condition, the classification of the network state, and the adjustment of sampling period between sensors and controllers. This period adjustment is able to maintain the minimally allowable sampling period, and also maximize the control performance. Extensive simulations are conducted using the network simulator NS-2 to evaluate the performance of the proposed CLD. The comparative studies involve two aspects of communications, with and without using the proposed CLD, respectively. The results show that the proposed CLD is capable of fulfilling the timeliness requirement under congested network conditions, and is also able to improve the channel utilization efficiency and the proportion of effective data in WNCSs.

Addition of diazomethane to armchair single-walled carbon nanotubes and their reaction sequences : A computational study

The sidewall additions of diazomethane to (n, n), n = 3–10 armchair single-walled carbon nanotubes (SWCNTs) on two different orientations of C–C bonds have been studied using the ONIOM(B3LYP/6-31G(d):PM3) approach. The binding energies of SWCNTs complexes with CH2N2, CH2 and their transition-state structures were computed at the B3LYP/6-31G(d) level. The effects of diameters of armchair SWCNTs on their binding energies were studied. Relative reactivities of all the SWCNTs and their complexes based on their frontier orbital energies gaps are reported.

Physico-chemical/biological properties of tripolyphosphate cross-linked chitosan based

In this study, chitosan-PEO blend, prepared in a 15 M acetic acid, was electrospun into nanofibers (~ 78 nm diameter) with bead free morphology. While investigating physico-chemical parameters of blend solutions, effect of yield stress on chitosan based nanofiber fabrication was clearly evidenced. Architectural stability of nanofiber mat in aqueous medium was achieved by ionotropic cross-linking of chitosan by tripolyphosphate (TPP) ions. The TPP cross-linked nanofiber mat showed swelling up to ~ 300 % in 1h and ~ 40 % degradation during 30 d study period. 3T3 fibroblast cells showed good attachment, proliferation and viability on TPP treated chitosan based nanofiber mats. The results indicate non-toxic nature of TPP cross-linked chitosan based nanofibers and their potential to be explored as a tissue engineering matrix.