259 research outputs found
Checklist of spiders in Sungai Dusun Wildlife Reserve, Selangor, Malaysia
Sungai Dusun Wildlife Reserve, Selangor was established since 1964. It comprises an area of 4,330 hectares. It is considered one of the important biodiversity hotspots and also the first reserved area to protect Sumatran Rhinos. A study of the biodiversity of spider was carried out during the Biodiversity Inventory Program at Sungai Dusun Wildlife Reserve, Selangor from 26th to 31st October 2009. Samples were collected at selected area. Throughout the program a total of 89 spiders were collected. Among them, spiders from the family Agelenidae, Araneidae, Lycosidae, Oxyopidae, Pisauridae, Salticidae, Sparassidae and Tetragnathidae were recorded. Members of Lycosidae and Araneidae were easily spotted in this area
An electron microscopic method for localization of ribosomal proteins during transcription of ribosomal DNA: a method for studying protein assembly.
Checklist of spiders in Tasek Bera Ramsar Site, Pahang, Malaysia
Established since 1995, Tasek Bera is a wetland of international importance. It comprises an area of 31,120 hectares. It is the largest natural freshwater lake in Malaysia. The natural freshwater lake is rich in local flora and fauna. A study of the biodiversity of spider was carried out during the Biodiversity Inventory Program at Tasek Bera Ramsar Site, Pahang from 20th to 26th May 2009.
Throughout the program a total of 216 spiders were collected. Among them, 13 families of spider, namely the Agelenidae, Araneidae, Lycosidae, Nephilidae, Oxyopidae, Pholcidae, Pisauridae, Psechridae, Salticidae, Sparassidae, Tetragnathidae, Theridiidae, and Thomisidae were recorded. Most spiders found on web built between branches are the members of Araneidae, Nephilidae, Psechridae, Tetragnathidae, and Theridiidae while others were either foraging on trees (Oxyopidae, Pholcidae, Pisauridae, and Salticidae) or on the ground (Agelenidae, Lycosidae, and Sparassidae). A high variety of spider species were recorded
Prey preference of four species of forest spiders to Spodoptera litura and Plutella xylostella
The prey preference of Heteropoda garciai, Olios mahabangkawitus, Ctenus floweri, and Pardosa apostoli was examined on Spodoptera litura and Plutella xylostella in laboratory. These spiders showed a clear preference for P. xylostella compared to S. litura. However, there was no significant difference observed between the second and third instars larvae of P. xylostella. Similarly, the size of prey was not an important factor in the prey selection by H. garciai, O. mahabangkawitus in this study. P. apostoli showed higher preference on smaller sized S. litura larvae
Contingent Valuation Method: Valuing Cultural Heritage
Cultural heritage is not easy to be valued in a market because it is a very unique product which gives a
community (ies), nation(s) an identity and a sense of belonging. Debate on the valuation of cultural
heritage surrounds despite growing attention by economists and policy makers. The attention on the
estimation of economic values for cultural goods and services has been great by economics throughout
the past two decades (Choi, et al., 2009; Kaminski, McLoughlin, & Sodagar, 2007; Navrud & Ready,
2002, Noonan, 2003; Venkatachalam, 2004). The two stated preference methods which are commonly
used in valuing non-use goods; i.e. contingent valuation method and choice modelling. Each of these two
valuation method has its own strengths and weaknesses and may even complement each other
depending on the parameters of the study. However, according to Kaminski et al., 2007; Noonan, 2003,
the usage of choice modelling to estimate cultural values has been limited due to the growing usage of
contingent valuation. Therefore, this paper will discuss contingent valuation method in valuing amenities
and aim to contribute the knowledge on contingent valuation method for nonmarket goods. (Abstract by author
Functional redundancy of necrotrophic effectors – consequences for exploitation for breeding
Necrotrophic diseases of wheat cause major losses in most wheat growing areas of world. Tan spot (caused by Pyrenophora tritici-repentis) and septoria nodorum blotch (SNB; Parastagonospora nodorum) have been shown to reduce yields by 10–20% across entire agri-ecological zones despite the application of fungicides and a heavy focus over the last 30 years on resistance breeding. Efforts by breeders to improve the resistance of cultivars has been compromised by the universal finding that resistance was quantitative and governed by multiple quantitative trait loci (QTL). Most QTL had a limited effect that was hard to measure precisely and varied significantly from site to site and season to season. The discovery of necrotrophic effectors has given breeding for disease resistance new methods and tools. In the case of tan spot in West Australia, a single effector, PtrToxA and its recogniser gene Tsn1, has a dominating impact in disease resistance. The delivery of ToxA to breeders has had a major impact on cultivar choice and breeding strategies. For P. nodorum, three effectors – SnToxA, SnTox1, and SnTox3 – have been well characterized. Unlike tan spot, no one effector has a dominating role. Genetic analysis of various mapping populations and pathogen isolates has shown that different effectors have varying impact and that epistatic interactions also occur. As a result of these factors the deployment of these effectors for SNB resistance breeding is more complex. We have deleted the three effectors in a strain of P. nodorum and measured effector activity and disease potential of the triple knockout mutant. The culture filtrate causes necrosis in several cultivars and the strain causes disease, albeit the overall levels are less than in the wild type. Modeling of the field disease resistance scores of cultivars from their reactions to the microbially expressed effectors SnToxA, SnTox1, and SnTox3 is significantly improved by including the response to the triple knockout mutant culture filtrate. This indicates that one or more further effectors are secreted into the culture filtrate. We conclude that the in vitro-secreted necrotrophic effectors explain a very large part of the disease response of wheat germplasm and that this method of resistance breeding promises to further reduce the impact of these globally significant diseases
Checklist of spiders in Fraser's Hill Wildlife Reserve, Selangor, Malaysia
A study of the biodiversity of spider was carried out during Biodiversity Inventory Program at Fraser's Hill Wildlife Reserve, Selangor from 26th July to 2nd August 2009. Samples were collected along selected trails and in the area around the base camp. A total of 249 spiders were collected and 13 families of spiders, namely the Family of Agelenidae, Araneidae, Clubionidae, Lycosidae, Oxyopidae, Pholcidae, Pisauridae, Psechridae, Salticidae, Sparassidae, Tetragnathidae, Theraphosidae, and Theridiidae, were
recorded. These spiders were found foraging on trees and the ground. Besides the diverse fauna and flora, Fraser's Hill Wildlife Reserve, Selangor is also a famous host to hairy tropical spiders called tarantulas. Throughout this inventory program, two tarantulas were recorded
The genome of the Tiger Milk mushroom, Lignosus rhinocerotis, provides insights into the genetic basis of its medicinal properties
BACKGROUND The sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden or Tiger milk mushroom (Polyporales, Basidiomycota) is a valuable folk medicine for indigenous peoples in Southeast Asia. Despite the increasing interest in this ethnobotanical mushroom, very little is known about the molecular and genetic basis of its medicinal and nutraceutical properties. RESULTS The de novo assembled 34.3 Mb L. rhinocerotis genome encodes 10,742 putative genes with 84.30% of them having detectable sequence similarities to others available in public databases. Phylogenetic analysis revealed a close evolutionary relationship of L. rhinocerotis to Ganoderma lucidum, Dichomitus squalens, and Trametes versicolor in the core polyporoid clade. The L. rhinocerotis genome encodes a repertoire of enzymes engaged in carbohydrate and glycoconjugate metabolism, along with cytochrome P450s, putative bioactive proteins (lectins and fungal immunomodulatory proteins) and laccases. Other genes annotated include those encoding key enzymes for secondary metabolite biosynthesis, including those from polyketide, nonribosomal peptide, and triterpenoid pathways. Among them, the L. rhinocerotis genome is particularly enriched with sesquiterpenoid biosynthesis genes. CONCLUSIONS The genome content of L. rhinocerotis provides insights into the genetic basis of its reported medicinal properties as well as serving as a platform to further characterize putative bioactive proteins and secondary metabolite pathway enzymes and as a reference for comparative genomics of polyporoid fungi.This research is supported by High Impact Research Grant UM.C/625/1/HIR/
MoE/E20040-20001 from the University of Malaya/Ministry of Education,
Malaysia. H-YYY is supported by the postgraduate research grant (PPP) PV024/
2012A from University of Malaya, Malaysia. Y-HC is a recipient of Australian Research
Council Discovery Early Career Researcher Award (ARC DECRA)
The genome of the Tiger Milk mushroom, Lignosus rhinocerotis, provides insights into the genetic basis of its medicinal properties
BACKGROUND: The sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden or Tiger milk mushroom (Polyporales, Basidiomycota) is a valuable folk medicine for indigenous peoples in Southeast Asia. Despite the increasing interest in this ethnobotanical mushroom, very little is known about the molecular and genetic basis of its medicinal and nutraceutical properties. RESULTS: The de novo assembled 34.3 Mb L. rhinocerotis genome encodes 10,742 putative genes with 84.30% of them having detectable sequence similarities to others available in public databases. Phylogenetic analysis revealed a close evolutionary relationship of L. rhinocerotis to Ganoderma lucidum, Dichomitus squalens, and Trametes versicolor in the core polyporoid clade. The L. rhinocerotis genome encodes a repertoire of enzymes engaged in carbohydrate and glycoconjugate metabolism, along with cytochrome P450s, putative bioactive proteins (lectins and fungal immunomodulatory proteins) and laccases. Other genes annotated include those encoding key enzymes for secondary metabolite biosynthesis, including those from polyketide, nonribosomal peptide, and triterpenoid pathways. Among them, the L. rhinocerotis genome is particularly enriched with sesquiterpenoid biosynthesis genes. CONCLUSIONS: The genome content of L. rhinocerotis provides insights into the genetic basis of its reported medicinal properties as well as serving as a platform to further characterize putative bioactive proteins and secondary metabolite pathway enzymes and as a reference for comparative genomics of polyporoid fungi. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-635) contains supplementary material, which is available to authorized users
Targeted Molecular Iron Oxide Contrast Agents for Imaging Atherosclerotic Plaque
Overview: Cardiovascular disease remains a leading cause of death worldwide, with vulnerable plaque rupture the underlying cause of many heart attacks and strokes. Much research is focused on identifying an imaging biomarker to differentiate stable and vulnerable plaque. Magnetic Resonance Imaging (MRI) is a non-ionising and non-invasive imaging modality with excellent soft tissue contrast. However, MRI has relatively low sensitivity (micromolar) for contrast agent detection compared to nuclear imaging techniques. There is also an increasing emphasis on developing MRI probes that are not based on gadolinium chelates because of increasing concerns over associated systemic toxicity and deposits1. To address the sensitivity and safety concerns of gadolinium this project focused on the development of a high relaxivity probe based on superparamagnetic iron oxide nanoparticles for the imaging of atherosclerotic plaque with MRI. With development, this may facilitate differentiating stable and vulnerable plaque in vivo.
Aim: To develop a range of MRI contrast agents based on superparamagnetic iron oxide nanoparticles (SPIONs), and test them in a murine model of advanced atherosclerosis.
Methods: Nanoparticles of four core sizes were synthesised by thermal decomposition and coated with poly(maleicanhydride-alt-1-octadecene) (PMAO), poly(ethyleneimine) (PEI) or alendronate, then characterised for core size, hydrodynamic size, surface potential and relaxivity. On the basis of these results, one candidate was selected for further studies. In vivo studies using 10 nm PMAO-coated SPIONs were performed in ApoE-/- mice fed a western diet and instrumented with a perivascular cuff on the left carotid artery. Control ApoE-/- mice were fed a normal chow diet and were not instrumented. Mice were scanned on a 3T MR scanner (Philips Achieva) with the novel SPION contrast agent, and an elastin-targeted gadolinium agent that was shown previously to enable visualisation of plaque burden. Histological analysis was undertaken to confirm imaging findings through staining for macrophages, CX3CL1, elastin, tropoelastin, and iron.
Results: The lead SPION agent consisted of a 10 nm iron oxide core with poly(maleicanhydride-alt-1-octadecene), (-36.21 mV, r2 18.806 mmol-1/s-1). The irregular faceting of the iron oxide core resulted in high relaxivity and the PMAO provided a foundation for further functionalisation on surface -COOH groups. The properties of the contrast agent, including the negative surface charge and hydrodynamic size, were designed to maximise circulation time and evade rapid clearance through the renal system or phagocytosis. In vitro testing showed that the SPION agent was non-toxic.
In vivo results show that the novel contrast agent accumulates in similar vascular regions to a gadolinium-based contrast agent (Gd-ESMA) targeted to elastin, which accumulates in plaque. There was a significant difference in SPION signal between the instrumented and the contralateral non-instrumented vessels in diseased mice (p = 0.0411, student’s t-test), and between the instrumented diseased vessel and control vessels (p = 0.0043, 0.0022, student’s t-test). There was no significant difference between the uptake of either contrast agent between stable and vulnerable plaques (p = 0.3225, student’s t-test). Histological verification was used to identify plaques, and Berlin Blue staining confirmed the presence of nanoparticle deposits within vulnerable plaques and co-localisation with macrophages.
Conclusion: This work presents a new MRI contrast agent for atherosclerosis which uses an under-explored surface ligand, demonstrating promising properties for in vivo behaviour, is still in circulation 24 hours post-injection with limited liver uptake, and shows good accumulation in a murine plaque model
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