A particle-based micromechanics approach to simulate structural changes of plant cells during drying

This paper is concerned with applying a particle-based approach to simulate the micro-level cellular structural changes of plant cells during drying. The objective of the investigation was to relate the micro-level structural properties such as cell area, diameter and perimeter to the change of moisture content of the cell. Model assumes a simplified cell which consists of two basic components, cell wall and cell fluid. The cell fluid is assumed to be a Newtonian fluid with higher viscosity compared to water and cell wall is assumed to be a visco-elastic solid boundary located around the cell fluid. Cell fluid is modelled with Smoothed Particle Hydrodynamics (SPH) technique and for the cell wall; a Discrete Element Method (DEM) is used. The developed model is two-dimensional, but accounts for three-dimensional physical properties of real plant cells. Drying phenomena is simulated as fluid mass reductions and the model is used to predict the above mentioned structural properties as a function of cell fluid mass. Model predictions are found to be in fairly good agreement with experimental data in literature and the particle-based approach is demonstrated to be suitable for numerical studies of drying related structural deformations. Also a sensitivity analysis is included to demonstrate the influence of key model parameters to model predictions.

Standardisation of plant and machinery valuation practices in Malaysia

Plant and machinery valuation is important to every company.s annual financial reporting. It is reported under the non-current assets section, and the valuers are generally employed to provide the up to date valuation of the non-current assets valuation such as property, plant and equipment that can make up to 80% of the total assets of a company. The valuation of plant and machinery is also important for other purposes such as securing loan facilities, sales, takeover, insurance and auction. The application of 2005 International Financial Reporting Standard (IFRS) has a subsequent impact on the financial sector, as a whole. The accountants have to choose between the Historical Cost approach and Market Value approach in determining the value of the client.s assets. In Malaysia, the implementation of IFRS has a domino effect on the financial system, especially for plant and machinery valuation for financial reporting. The comparison data for plant and machinery valuation is limited unlike land and building valuation. The question of Malaysian valuer.s ability to comply with the IFRS standard keeps rising every day, not just to the accountants, but also other related parties such as financial institutions, government agencies and the clients. This is happening because of different interpretations of premise of value for plant and machinery, as well as methods been used and differences in standards of reporting among the valuers conducting plant and machinery valuation. The root of the problem lies in the lack of practical guidelines governing plant and machinery valuation practices and different schools of thought among the valuers. Some follow the United Kingdom.s RICS guidelines, whilst some valuers are more comfortable with the United State.s USPAP rules, especially on the premise of value. This research is to investigate the international best practices of plant and machinery valuation and to establish the common valuation concept, awareness and application of valuation methodology and valuation process for plant and machinery valuation in Malaysia. This research uses a combination of the qualitative and quantitative research approach. In the qualitative approach, the content analyses were conducted from the international practices and current Malaysian implementation of plant and machinery valuation. A survey (quantitative approach) via questionnaire was implemented among the registered and probationary valuers in Malaysia to investigate their understanding and opinion relating to plant and machinery valuation based on the current practices. The significance of this research is the identification of international plant and machinery practices and the understanding of current practices of plant and machinery valuation in Malaysia. It is found that issues embedding plant and machinery valuation practices are limited numbers of resources available either from scholars or practitioner. This is supported by the general finding from the research survey that indicates that there are immediate needs for practical notes or guidelines to be developed and implemented to support the Malaysian valuers practising plant and machinery valuation. This move will lead to a better understanding of plant and machinery valuation, reducing discrepancies in valuation of plant and machinery and increased accuracy among practising valuers.

PCV13 Perceptions of health during pregnancy increase the risk of cardiovascular disease

OBJECTIVES: To examine the prospective association between perception of health during pregnancy and cardiovascular risk factor of mothers 21 years after the index pregnancy. METHODS: Data used were from the Mater University Study of Pregnancy (MUSP), a community- based prospective birth ohort study begun in Brisbane, Australia, in 1983. Logistic regression analyses were conducted. RESULTS: Data were available for 3692 women. Women who perceived themselves as not having a straight forward pregnancy had twice the odds (adjusted OR 2.0, 95% CI 1.1-3.8) of being diagnosed with heart disease 21 years after the indexpregnancyascomparedtowomenwith a straight forward pregnancy. Apart from that, women who had complications (other than serious pregnancy complications) during the pregnancy were also at30%increased odds (adjustedOR 1.3, 95% CI 1.0-1.6) of having hypertension 21 years later. CONCLUSIONS: As a whole, our study suggests that pregnant women who perceived that they had complications and did not have a straight forward pregnancy are likely to experience poorer cardiovascular outcomes 21 years after the pregnancy.

Phenotypical characterisation of the isolated Norfolk Island population focusing on epidemiological indicators of cardiovascular disease

Objectives Only 193 people from Pitcairn Island, all descended from 9 ‘Bounty’ mutineers and 12 Tahitian women, moved to the uninhabited Norfolk Island in 1856. Our objective was to assess the population of Norfolk Island, several thousand km off the eastern coast of Australia, as a genetic isolate of potential use for cardiovascular disease (CVD) gene mapping. Methods A total of 602 participants, approximately two thirds of the island’s present adult population, were characterized for a panel of CVD risk factors. Statistical power and heritability were calculated. Results Norfolk Islander’s possess an increased prevalence of hypertension, obesity and multiple CVD risk factors when compared to outbred Caucasian populations. 64% of the study participants were descendents of the island’s original founder population. Triglycerides, cholesterol, and blood pressures all had heritabilities above 0.2. Conclusions The Norfolk land population is a potentially useful genetic isolate for gene mapping studies aimed at identifying CVD risk factor quantitative trait loci (QTL).

Fluorescence detection of plant extracts that affect neuronal voltage-gated Ca2+ channels

Structurally novel compounds able to block voltage-gated Ca2+ channels (VGCCs) are currently being sought for the development of new drugs directed at neurological disorders. Fluorescence techniques have recently been developed to facilitate the analysis of VGCC blockers in a multi-well format. By utilising the small cell lung carcinoma cell line, NCI-H146, we were able to detect changes in intracellular Ca2+ concentration ([Ca2+]i) using a fluorescence microplate reader. NCI-H146 cells have characteristics resembling those of neuronal cells and express multiple VGCC subtypes, including those of the L-, N- and P-type. We found that K+-depolarisation of fluo-3 loaded NCI-H146 cells causes a rapid and transient increase in fluorescence, which was readily detected in a 96-well plate. Extracts of Australian plants, including those used traditionally as headache or pain treatments, were tested in this study to identify those affecting Ca2+ influx following membrane depolarisation of NCI-H146 cells. We found that E. bignoniiflora, A. symphyocarpa and E. vespertilio caused dose-dependent inhibition of K+-depolarised Ca2+ influx, with IC50 values calculated to be 234, 548 and 209 μg/ml, respectively. This data suggests an effect of these extracts on the function of VGCCs in these cells. Furthermore, we found similar effects using a fluorescence laser imaging plate reader (FLIPR) that allows simultaneous measurement of real-time fluorescence in a multi-well plate. Our results indicate that the dichloromethane extract of E. bignoniiflora and the methanolic extract of E. vespertilio show considerable promise as antagonists of neuronal VGCCs. Further analysis is required to characterise the function of the bioactive constituents in these extracts and determine their selectivity on VGCC subtypes.

Current practice in nutrition assessment for the management of Parkinson’s disease in Australia and Canada

AIM: To document and compare current practice in nutrition assessment of Parkinson’s disease by dietitians in Australia and Canada in order to identify priority areas for review and development of practice guidelines and direct future research. METHODS: An online survey was distributed to DAA members and PEN subscribers through their email newsletters. The survey captured current practice in the phases of the Nutrition Care Plan. The results of the assessment phase are presented here. RESULTS: Eighty-four dietitians responded. Differences in practice existed in the choice of nutrition screening and assessment tools, including appropriate BMI ranges. Nutrition impact symptoms were commonly assessed, but information about Parkinson’s disease medication interactions were not consistently assessed. CONCLUSIONS: he variation in practice related to the use of screening and assessment methods may result in the identification of different goals for subsequent interventions. Even more practice variation was evident for those items more specific to Parkinson’s disease and may be due to the lack of evidence to guide practice. Further research is required to support decisions for nutrition assessment of Parkinson’s disease.

“A politics of what” : A praxiography of renal disease in Indigenous renal patients

The morbidity and mortality rates of renal disease in Indigenous Australians are significantly higher than those of non-Indigenous Australians, and are increasing. The dominant discourses of renal disease currently predicate this as essentially a client problem, rather than (for example) a health care system problem. These discourses are indicative of the dominant “white” paradigm of health care, which fosters an expectation of assimilation by the marginalised “other.” In this paper, we draw upon a sociological methodology (the actor network approach) and a qualitative method (discourse analysis) to tease out these issues in Indigenous renal disease. Based on empirical data, we explore on the one hand the requirements of the discourses, technologies and practices that have been developed for a particular type of renal patient and health system in Australia. On the other, we examine the cultural and practical specificities entailed in the performance of these technologies and practices in the Indigenous Australian context. The meeting of the praxiographic orientation of the actor network approach—which has been called “the politics of what” (Mol 2002)—and the sociocultural concerns of discourse analysis does provide a useful guide as to “what to do” when confronted with issues in health care that currently seems unfathomable. Our praxiographic analysis of the discourse enabled us to understand the difficulties involved in translating renal health care networks across cultural contexts in Australia and to understand the dynamic and contested nature of these networks. The actor network approach has its limitations, however, particularly in the articulation of possible strategies to align two disparate systems in a way that would ensure better health care for Indigenous renal patients. In this paper we will discuss some of the problems we encountered in drawing on this methodology in our attempt to unearth practical solutions to the conundrums our data presented.

The relationship between angiogenesis and the immune response in carcinogenesis and the progression of malignant disease

Recent studies have demonstrated that angiogenesis and suppressed cell- mediated immunity (CMI) play a central role in the pathogenesis of malignant disease facilitating tumour growth, invasion and metastasis. In the majority of tumours, the malignant process is preceded by a pathological condition or exposure to an irritant which itself is associated with the induction of angiogenesis and/or suppressed CMI. These include: cigarette smoking, chronic bronchitis and lung cancer; chronic oesophagitis and oesophageal cancer; chronic viral infections such as human papilloma virus and ano-genital cancers, chronic hepatitis B and C and hepatocellular carcinoma, and Epstein- Barr virus (EBV) and lymphomas; chronic inflammatory conditions such as Crohn's disease and ulcerative colitis and colorectal cancer; asbestos exposure and mesothelioma and excessive sunlight exposure/sunburn and malignant melanoma. Chronic exposure to growth factors (insulin-like growth factor-I in acromegaly), mutations in tumour suppressor genes (TP53 in Li Fraumeni syndrome) and long-term exposure to immunosuppressive agents (cyclosporin A) may also give rise to similar environments and are associated with the development of a range of solid tumours. The increased blood supply would facilitate the development and proliferation of an abnormal clone or clones of cells arising as the result of: (a) an inherited genetic abnormality; and/or (b) acquired somatic mutations, the latter due to local production and/or enhanced delivery of carcinogens and mutagenic growth factors. With progressive detrimental mutations and growth-induced tumour hypoxia, the transformed cell, to a lesser or greater extent, may amplify the angiogenic process and CMI suppression, thereby facilitating further tumour growth and metastasis. There is accumulating evidence that long-term treatment with cyclo-oxygenase inhibitors (aspirin and indomethacin), cytokines such as interferon-α, anti-oestrogens (tamoxifen and raloxifene) and captopril significantly reduces the incidence of solid tumours such as breast and colorectal cancer. These agents are anti-angiogenic and, in the case of aspirin, indomethacin and interferon-α have proven immunomodulatory effects. Collectively these observations indicate that angiogenesis and suppressed CMI play a central role in the development and progression of malignant disease. (C) 2000 Elsevier Science Ltd.

Description of plant tRNA-derived RNA fragments (tRFs) associated with argonaute and identification of their putative targets

tRNA-derived RNA fragments (tRFs) are 19mer small RNAs that associate with Argonaute (AGO) proteins in humans. However, in plants, it is unknown if tRFs bind with AGO proteins. Here, using public deep sequencing libraries of immunoprecipitated Argonaute proteins (AGO-IP) and bioinformatics approaches, we identified the Arabidopsis thaliana AGO-IP tRFs. Moreover, using three degradome deep sequencing libraries, we identified four putative tRF targets. The expression pattern of tRFs, based on deep sequencing data, was also analyzed under abiotic and biotic stresses. The results obtained here represent a useful starting point for future studies on tRFs in plants. © 2013 Loss-Morais et al.; licensee BioMed Central Ltd.

The roles of plant dsRNA-binding proteins in RNAi-like pathways

Dicers are associated with double-stranded RNA-binding proteins (dsRBPs) in animals. In the plant, Arabidopsis, there are four dicer-like (DCL) proteins and five potential dsRBPs. These DCLs act redundantly and hierarchically. However, we show there is little or no redundancy or hierarchy amongst the DRBs in their DCL interactions. DCL1 operates exclusively with DRB1 to produce micro (mi)RNAs, DCL4 operates exclusively with DRB4 to produce trans-acting (ta) siRNAs and 21nt siRNAs from viral RNA. DCL2 and DCL3 produce viral siRNAs without requiring assistance from any dsRBP. DRB2, DRB3 and DRB5 appear unnecessary for mi-, tasi-, viral si-, or heterochromatinising siRNA production but act redundantly in a developmental pathway. © 2008 Federation of European Biochemical Societies.

Effect of cell wall properties of plant tissue on porosity and shrinkage of dried apple

In this study cell wall properties; moisture distribution, stiffness, thickness and cell dimension have been taken into consideration. Cell wall stiffness dependent on complex combination of plant cell microstructures, composition and water holding capacity of the cell. In this work, some preliminary steps taken by investing cell wall properties of apple in order to predict change of porosity and shrinkage during drying. Two different types of apple cell wall characteristic were investigated to correlate with porosity and shrinkage after convective drying. A scanning electron microscope (SEM), 2N Intron, a pyncometer and image J software were used in order to measure and analyze cell characteristics, water dynamics, porosity and shrinkage. Cell stiffness of red delicious apple was found higher than granny smith apples. A significant relationship has found between cell wall characteristics and both heat and mass transfer. Consequently, evolution of porosity and shrinkage noticeably influenced during convective drying by the nature of cell wall. This study has brought better understanding of porosity and shrinkage of dried food stuff in microscopic (cell) level and would provide better insight to attain energy effective drying process and quality food stuff.

The mouse model of Chlamydia genital tract infection: a review of infection, disease, immunity and vaccine development

Chlamydia trachomatis is the most common sexually transmitted bacterial infection worldwide. The impact of this pathogen on human reproduction has intensified research efforts to better understand chlamydial infection and pathogenesis. Whilst there are animal models available that mimic the many aspects of human chlamydial infection, the mouse is regarded as the most practical and widely used of the models. Studies in mice have greatly contributed to our understanding of the host-pathogen interaction and provided an excellent medium for evaluating vaccines. Here we explore the advantages and disadvantages of all animal models of chlamydial genital tract infection, with a focus on the murine model and what we have learnt from it so far.

A sonographer's guide to the assessment of heart disease

The book is mostly designed for students of echocardiography, teachers of echocardiography and cardiac sonographers working in routine clinical practice, but will also be very useful to echocardiologists and cardiac registrars. The goal of the text is to provide a comprehensive review of transthoracic echocardiography in the assessment of various cardiac pathologies. Refresher notes on cardiac anatomy and the relevant cardiac physiology and pathophysiology are included to expand the cardiac sonographer’s knowledge in this area and further their understanding of various diseases, disease processes and associated findings.

Simulation of plant cell shrinkage during drying : A SPH–DEM approach

Plant based dried food products are popular commodities in global market where much research is focused to improve the products and processing techniques. In this regard, numerical modelling is highly applicable and in this work, a coupled meshfree particle-based two-dimensional (2-D) model was developed to simulate micro-scale deformations of plant cells during drying. Smoothed Particle Hydrodynamics (SPH) was used to model the viscous cell protoplasm (cell fluid) by approximating it to an incompressible Newtonian fluid. The visco-elastic characteristic of the cell wall was approximated to a Neo-Hookean solid material augmented with a viscous term and modelled with a Discrete Element Method (DEM). Compared to a previous work [H. C. P. Karunasena, W. Senadeera, Y. T. Gu and R. J. Brown, Appl. Math. Model., 2014], this study proposes three model improvements: linearly decreasing positive cell turgor pressure during drying, cell wall contraction forces and cell wall drying. The improvements made the model more comparable with experimental findings on dried cell morphology and geometric properties such as cell area, diameter, perimeter, roundness, elongation and compactness. This single cell model could be used as a building block for advanced tissue models which are highly applicable for product and process optimizations in Food Engineering.