113 research outputs found
A hydroponics based high throughput screening system for Phytophthora root rot resistance in chickpea (Cicer arietinum L.)
Published online: 26 July 2019Background: Phytophthora root rot (PRR) caused by P. medicaginis is a major soil borne disease in chickpea growing regions of Australia. Sources of resistance have been identified in both cultivated and wild Cicer species. However, the molecular basis underlying PRR resistance is not known. Current phenotyping methods rely on mycelium slurry or oospore inoculum. Sensitive and reliable methods are desirable to study variation for PRR resistance in chickpea and allow for a controlled inoculation process to better capture early defence responses following PRR infection. Results: In this study, a procedure for P. medicaginis zoospore production was standardized and used as the inoculum to develop a hydroponics based in planta infection method to screen chickpea genotypes with established levels of PRR resistance. The efficiency of the system was both qualitatively validated based on observation of characteristic PRR symptom development, and quantitatively validated based on the amount of pathogen DNA in roots. This system was scaled up to screen two biparental mapping populations previously developed for PRR studies. For each of the screenings, plant survival time was measured after inoculation and used to derive Kaplan–Meier estimates of plant survival (KME-survival). KME-survival and canker length were then selected as phenotypic traits associated with PRR resistance. Genetic analysis of these traits was conducted which identified quantitative trait loci (QTL). Additionally, these hydroponic traits and a set of previously published plant survival traits obtained from multiple PRR field experiments were combined in a model-based correlation analysis. The results suggest that the underlying genetic basis for plant survival during PRR infection within hydroponics and field disease environments is linked. The QTL QRBprrkms03 and QRBprrck03 on chromosome 4 identified for the traits KME-survival and canker length, respectively, correspond to the same region reported for PRR resistance in a field disease experiment. Conclusion: A hydroponics based screening system will facilitate reliable and rapid screening in both small- and large-scale experiments to study PRR disease in chickpea. It can be applied in chickpea breeding programs to screen for PRR resistance and classify the virulence of new and existing P. medicaginis isolates.Amritha Amalraj, Julian Taylor and Tim Sutto
Effect of chrysin endothelial vasodilation on L-NAME induced hypertensive rats
572-577Hypertension is the major risk factor for cardiovascular diseases and stroke and it is one of leading causes of disability and mortality worldwide. The present study was aimed to investigate the antihypertensive and vasodilation properties of chrysin, a naturally occurring flavone, in hypertensive rats. Hypertension was induced using Nω-nitro-l arginine methyl ester (L-NAME; 40 mg/kg BWT/day for 4 weeks) in adult rats and chrysin (25 mg/kg BWT/day) or vehicle was administered for 4 weeks. A siginificant increase of blood pressure and serum fibrinogen along with a significant reduction of bilirubin level were observed in hypertensive rats and these changes were significantly attenuated upon administration of crysin. Further, L-NAME induced increase of tissue levels of mRNAs of β-MHC and TGF-β (in heart) as well as eNOS (in aorta, heart, kidney) were significantly reduced in chrysin treated rats. These results suggest that chrysin has a potential to attenuate impairment of organs (heart and renal) and endothelial function caused by L-NAME induced hypertension
Effect of chrysin endothelial vasodilation on L-NAME induced hypertensive rats
Hypertension is the major risk factor for cardiovascular diseases and stroke and it is one of leading causes of disability and mortality worldwide. The present study was aimed to investigate the antihypertensive and vasodilation properties of chrysin, a naturally occurring flavone, in hypertensive rats. Hypertension was induced using Nω-nitro-l arginine methyl ester (L-NAME; 40 mg/kg BWT/day for 4 weeks) in adult rats and chrysin (25 mg/kg BWT/day) or vehicle was administered for 4 weeks. A siginificant increase of blood pressure and serum fibrinogen along with a significant reduction of bilirubin level were observed in hypertensive rats and these changes were significantly attenuated upon administration of crysin. Further, L-NAME induced increase of tissue levels of mRNAs of β-MHC and TGF-β (in heart) as well as eNOS (in aorta, heart, kidney) were significantly reduced in chrysin treated rats. These results suggest that chrysin has a potential to attenuate impairment of organs (heart and renal) and endothelial function caused by L-NAME induced hypertension
Maternal over-the-counter analgesics use during pregnancy and adverse perinatal outcomes : Cohort study of 151,141 singleton pregnancies
Funding: This work is supported by the Biotechnology and Biological Sciences Research council (BBSRC) funding the lead author under the EASTBIO doctoral training programme and to PAF, the EU Horizon 2020 project FREIA (Grant Number 825100). RTM is supported by MRC Centre for Reproductive Health Grant MR/N022556/1. The funders had no role in study design, data collection, data analysis, decision to publish, or manuscript preparation.Peer reviewedPublisher PD
Waste-derived activated carbons for control of nitrogen oxides
Activated carbons were produced from waste and investigated for their efficiency for the removal of mono-nitrogen oxides (NOx) in simulated flue gases at a low temperature. The wastes used were waste biomass (date seeds), processed municipal solid waste in the form of refuse-derived fuel and waste tyres. The morphology, porous texture and surface chemistry of the prepared activated carbons were evaluated by scanning electron microscopy, energy-dispersive X-ray spectrometry, nitrogen adsorption and Boehm titration, and were compared with several commercial activated carbons. The carbons were then investigated in terms of their use in adsorbing NOx at a low temperature. The waste-derived activated carbons had NOx adsorption efficiencies at 50°C which were between 50 and 70% of those achieved for the commercial activated carbons. Increasing the adsorption temperature from 25 to 100°C significantly reduced nitrogen oxide (NO) adsorption. It was also shown that the NO adsorption efficiency depends on the porous structure, particularly the presence of micropores in the activated carbon, but to a lesser extent on the surface area of the carbons and acid–base surface groups on the carbon surface
A Systematic Review of Mosquito Coils and Passive Emanators: Defining Recommendations for Spatial Repellency Testing Methodologies.
Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control
In vitro inhibitory activities of selected Australian medicinal plant extracts against protein glycation, angiotensin converting enzyme (ACE) and digestive enzymes linked to type II diabetes
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background
There is a need to develop potential new therapies for the management of diabetes and hypertension. Australian medicinal plants collected from the Kuuku I’yu (Northern Kaanju) homelands, Cape York Peninsula, Queensland, Australia were investigated to determine their therapeutic potential. Extracts were tested for inhibition of protein glycation and key enzymes relevant to the management of hyperglycaemia and hypertension. The inhibitory activities were further correlated with the antioxidant activities.
Methods
Extracts of five selected plant species were investigated: Petalostigma pubescens, Petalostigma banksii, Memecylon pauciflorum, Millettia pinnata and Grewia mesomischa. Enzyme inhibitory activity of the plant extracts was assessed against α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). Antiglycation activity was determined using glucose-induced protein glycation models and formation of protein-bound fluorescent advanced glycation endproducts (AGEs). Antioxidant activity was determined by measuring the scavenging effect of plant extracts against 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and using the ferric reducing anti-oxidant potential assay (FRAP). Total phenolic and flavonoid contents were also determined.
Results
Extracts of the leaves of Petalostigma banksii and P. pubescens showed the strongest inhibition of α-amylase with IC50 values of 166.50 ± 5.50 μg/mL and 160.20 ± 27.92 μg/mL, respectively. The P. pubescens leaf extract was also the strongest inhibitor of α-glucosidase with an IC50 of 167.83 ± 23.82 μg/mL. Testing for the antiglycation potential of the extracts, measured as inhibition of formation of protein-bound fluorescent AGEs, showed that P. banksii root and fruit extracts had IC50 values of 34.49 ± 4.31 μg/mL and 47.72 ± 1.65 μg/mL, respectively, which were significantly lower (p < 0.05) than other extracts. The inhibitory effect on α-amylase, α-glucosidase and the antiglycation potential of the extracts did not correlate with the total phenolic, total flavonoid, FRAP or DPPH. For ACE inhibition, IC50 values ranged between 266.27 ± 6.91 to 695.17 ± 15.38 μg/mL.
Conclusions
The tested Australian medicinal plant extracts inhibit glucose-induced fluorescent AGEs, α-amylase, α-glucosidase and ACE with extracts of Petalostigma species showing the most promising activity. These medicinal plants could potentially be further developed as therapeutic agents in the treatment of hyperglycaemia and hypertension
The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis
<p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p
Unravelling structural ambiguities in lithium- and manganese-rich transition metal oxides
Although Li- and Mn-rich transition metal oxides have been extensively studied as high-capacity cathode materials for Li-ion batteries, the crystal structure of these materials in their pristine state is not yet fully understood. Here we apply complementary electron microscopy and spectroscopy techniques at multi-length scale on well-formed Li1.2(Ni0.13Mn0.54Co0.13)O2 crystals with two different morphologies as well as two commercially available materials with similar compositions, and unambiguously describe the structural make-up of these samples. Systematically observing the entire primary particles along multiple zone axes reveals that they are consistently made up of a single phase, save for rare localized defects and a thin surface layer on certain crystallographic facets. More specifically, we show the bulk of the oxides can be described as an aperiodic crystal consisting of randomly stacked domains that correspond to three variants of monoclinic structure, while the surface is composed of a Co- and/or Ni-rich spinel with antisite defects
- …