924 resultados para plant functional traits


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Migraine is a common neurological disorder with a significant genetic component. Although a number of linkage and association studies have been undertaken, the number and identity of all migraine susceptibility genes has yet to be defined. The existence of dopaminergic hypersensitivity in migraine has been recognised on a pharmacological basis and some studies have reported genetic association between migraine and dopamine-related gene variants. Our laboratory has previously reported association of migraine with a promoter STR marker in the dopamine beta hydroxylase (DBH) gene. In the present study, we analysed two additional DBH markers in two independent migraine case–control cohorts. These two markers are putative functional SNPs, one within the promoter (−1021C→T) and another SNP (+1603C→T) in exon 11 of the DBH gene. The results showed a significant association for allelic and genotypic frequency distribution between the DBH marker in the promoter and migraine in the first (P = 0.004 and P = 0.012, respectively) and the second (P = 0.013 and P = 0.031, respectively) tested cohorts. There was no association observed between either genotype and/or allelic frequencies for the DBH marker located in exon 11 and migraine (P ≥ 0.05). The promoter DBH marker, reported associated with migraine in this study, has been shown to affect up to 52% of plasma DBH activity. Varying DBH activity levels have been postulated to be involved in migraine process with an increase of dopamine, resulting from a lower DBH activity shown positively correlated with migraine severity. It is plausible that the functional promoter variant of DBH may play a role in the migraine disorder.

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OBJECTIVE(S): An individual's risk of developing cardiovascular disease (CVD) is influenced by genetic factors. This study focussed on mapping genetic loci for CVD-risk traits in a unique population isolate derived from Norfolk Island. METHODS: This investigation focussed on 377 individuals descended from the population founders. Principal component analysis was used to extract orthogonal components from 11 cardiovascular risk traits. Multipoint variance component methods were used to assess genome-wide linkage using SOLAR to the derived factors. A total of 285 of the 377 related individuals were informative for linkage analysis. RESULTS: A total of 4 principal components accounting for 83% of the total variance were derived. Principal component 1 was loaded with body size indicators; principal component 2 with body size, cholesterol and triglyceride levels; principal component 3 with the blood pressures; and principal component 4 with LDL-cholesterol and total cholesterol levels. Suggestive evidence of linkage for principal component 2 (h(2) = 0.35) was observed on chromosome 5q35 (LOD = 1.85; p = 0.0008). While peak regions on chromosome 10p11.2 (LOD = 1.27; p = 0.005) and 12q13 (LOD = 1.63; p = 0.003) were observed to segregate with principal components 1 (h(2) = 0.33) and 4 (h(2) = 0.42), respectively. CONCLUSION(S): This study investigated a number of CVD risk traits in a unique isolated population. Findings support the clustering of CVD risk traits and provide interesting evidence of a region on chromosome 5q35 segregating with weight, waist circumference, HDL-c and total triglyceride levels.

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Invasive species provide excellent study systems to evaluate the ecological and evolutionary processes that contribute to the colonization of novel environments. While the ecological processes that contribute to the successful establishment of invasive plants have been studied in detail, investigation of the evolutionary processes involved in successful invasions has only recently received attention. In particular, studies investigating the genomic and gene expression differences between native and introduced populations of invasive species are just beginning and are required if we are to understand how plants become invasive. In the current issue of Molecular Ecology, Hodgins et al. () tackle this unresolved question, by examining gene expression differences between native and introduced populations of annual ragweed, Ambrosia artemisiifolia. The study identifies a number of potential candidate genes based on gene expression differences that may be responsible for the success of annual ragweed in its introduced range. Furthermore, genes involved in stress response are over-represented in the differentially expressed gene set. Future experiments could use functional studies to test whether changes in gene expression at these candidate genes do in fact underlie changes in growth characteristics and reproductive output observed in this and other invasive species.

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To understand the underlying genetic architecture of cardiovascular disease (CVD) risk traits, we undertook a genome-wide linkage scan to identify CVD quantitative trait loci (QTLs) in 377 individuals from the Norfolk Island population. The central aim of this research focused on the utilization of a genetically and geographically isolated population of individuals from Norfolk Island for the purposes of variance component linkage analysis to identify QTLs involved in CVD risk traits. Substantial evidence supports the involvement of traits such as systolic and diastolic blood pressures, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, body mass index and triglycerides as important risk factors for CVD pathogenesis. In addition to the environmental inXuences of poor diet, reduced physical activity, increasing age, cigarette smoking and alcohol consumption, many studies have illustrated a strong involvement of genetic components in the CVD phenotype through family and twin studies. We undertook a genome scan using 400 markers spaced approximately 10 cM in 600 individuals from Norfolk Island. Genotype data was analyzed using the variance components methods of SOLAR. Our results gave a peak LOD score of 2.01 localizing to chromosome 1p36 for systolic blood pressure and replicated previously implicated loci for other CVD relevant QTLs.

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Migraine is a common, genetically influenced neurovascular disorder. The dopamine transporter gene is a candidate for migraine association studies. This study tested a functionally linked variable number tandem repeat (VNTR) in intron 8 of the dopamine transporter gene (DATInt8) in 550 migraine cases (401 with aura, 149 without aura) and 550 non-migraine controls. Chi-squared analysis of the DATInt8 revealed that the allele and genotype frequency distributions for migraine cases (including subtype analysis) and controls were not different (P > 0.1). These findings offer no evidence for an association of the DATInt8 with migraine with and without aura and therefore do not implicate the dopamine transporter gene as a modifier of migraine risk.

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Objective. To investigate the reliability and validity of five squat-based loading tests that are clinically appropriate for jumper's knee. The loading tests were step up, double leg squat, double leg squat on a 25-degree decline (decline squat), single leg decline squat, and decline hop. Design. Cross-sectional controlled cohort. Subjects without knee pain comprised controls, those with extensor tendon pain comprised the jumper's knee group. Setting. Institutional athlete study group in Australia Participants. Fifty-six elite adolescent basketball players participated in this study, thirteen comprised the jumper's knee group, fifteen athletes formed a control group. Intervention. Each subject performed each loading test for baseline and reliability data on the first testing day. Subjects then performed three days of intensive (6 h daily) basketball training, after which each loading test was reexamined. Main outcome measures. Eleven point interval scale for pain. Results. The tests that best detected a change in pain due to intensive workload were the single leg decline squat and single leg decline hop. This study found that decline tests have better discriminative ability than the standard squat to detect change in jumper's knee pain due to intensive training. The typical error for these tests ranged from 0.3 to 0.5, however, caution should be exercised in the interpretation of these reliability figures due to relatively low scores. Conclusions. The single leg decline squat is recommended in the physical assessment of adolescent jumper's knee. The decline squat was selected as the best clinical test over the decline hop because it was easier to standardise performance.

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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.

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A high performance liquid chromatographic method for the simultaneous determination of five organochlorine pesticides (aldrin, p,p’-DDT, dieldrin, endrin, and heptachlor) was developed. The method was used to determine the levels of these pesticides in medicinal plant samples. Analysis was carried out using a Merck LiChrospher 100 RP C18 (5 μm) column with a gradient solvent system of acetonitrile-water and PDA UV detection (224 nm). Quantification was carried out by the external standard method. The limit of detection for the utilized method was below the local legal limits (ANZFA) for similar plant materials for all 5 pesticides excepting endrin. Medicinal plant extracts were further analyzed by conventional GC-ECD and GC-NPD means using SPE and GPC cleanup as required.

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This study compared virulence and antibiotic resistance traits in clinical and environmental E. faecalis and E. faecium isolates. E. faecalis isolates harboured a broader spectrum of virulence determinants compared to E. faecium isolates. The virulence traits Cyl-A, Cyl-B, Cyl-M, gel-E and esp were tested and environmental isolates predominantly harboured gel-E (80% of E. faecalis and 31.9% of E. faecium) whereas esp was more prevalent in clinical isolates (67.79% of E. faecalis and 70.37 % of E. faecium). E. faecalis and E. faecium isolated from water had different antibiotic resistance patterns compared to those isolated from clinical samples. Linozolid resistance was not observed in any isolates tested and vancomycin resistance was observed only in clinical isolates. Resistance to other antibiotics (tetracycline, gentamicin, ciprofloxacin and ampicillin) was detected in both clinical and water isolates. Clinical isolates were more resistant to all the antibiotics tested compared to water isolates. Multi-drug resistance was more prevalent in clinical isolates (71.18% of E. faecalis and 70.3 % of E. faecium) compared to water isolates (only 5.66 % E. faecium). tet L and tet M genes were predominantly identified in tetracycline-resistant isolates. All water and clinical isolates resistant to ciprofloxacin and ampicillin contained mutations in the gyrA, parC and pbp5 genes. A significant correlation was found between the presence of virulence determinants and antibiotic resistance in all the isolates tested in this study (p<0.05). The presence of antibiotic resistant enterococci, together with associated virulence traits, in surface recreational water could be a public health risk.

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Objective To assess the effectiveness of an activity programme in improving function, quality of life, and falls in older people in residential care. Design Cluster randomised controlled trial with one year follow-up. Setting 41low level dependency residential carehomes in New Zealand. Participants 682 people aged 65 years or over. Interventions 330 residents were offered a goal setting and individualised activities of daily living activity programme by a gerontology nurse, reinforced by usual healthcare assistants; 352 residents received social visits. Main outcome measures Function (late life function and disability instruments, elderly mobility scale, FICSIT-4

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Nanorod forms of metal oxides is recognised as one of the most remarkable morphologies. Their structure and functionality have driven important advancements in a vast range of electronic devices and applications. In this work, we postulate a novel concept to explain how numerous localised surface states can be engineered into the bandgap of niobium oxide nanorods using tungsten. We discuss their contributions as local state surface charges for the modulation of a Schottky barrier height, relative dielectric constant and their respective conduction mechanisms. Their effect on the hydrogen gas molecule interactions mechanisms are also examined herein. We synthesised niobium tungsten oxide (Nb17W2O25) nanorods via a hydrothermal growth method and evaluated the Schottky barrier height, ideality factor, dielectric constant and trap energy level from the measured I-V vs temperature characteristics in the presence of air and hydrogen to show the validity of our postulations.

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Susceptibility to complex traits, by definition, involves aetiological polymorphisms at multiple genetic loci combined with variable contributions by environmental factors. However, the approaches taken to identifying genetic loci implicated in susceptibility to complex traits frequently overlooks the compounding contribution of multiple loci in favour of highlighting a single gene solely responsible for predisposition. It is only in a small minority of cases that this has resulted in clear disease heritability associated with polymorphisms in a single gene. More often, this approach has led to an accumulation of single-gene associations with minor contributions to disease susceptibility. As the genomic era advances and genome-wide screens become higher in resolution and throughput, the need for simultaneous consideration of multiple loci is becoming more important. With special reference to non-Hodgkin’s lymphoma (NHL), this chapter will overview the current progress made in elucidating genetic polymorphisms associated with disease susceptibility. We also present novel data from a high-resolution single nucleotide polymorphism (SNP) microarray screen for susceptibility loci that are involved in NHL. Using an ‘informed approach’, the findings are highlighted within the context of cellular pathways, and provide insight and new ideas for methods of analysis for genome-wide screens for susceptibility.

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This paper explores how a world-wide operating software solutions provider implemented environmentally sustainable business practices in response to emerging environmental concerns. Through an interpretive case study, we develop a theoretical framework that identifies four important functional affordances originating in information systems, which are required in environmental sustainability transformations as they create an actionable context in which (1) organizations can engage in a sensemaking process related to understanding emerging environmental requirements, and (2) individuals can implement environmentally sustainable work practices. Through our work, we provide several contributions, including a better understanding of IS-enabled organizational change and the types of functional affordances of information systems that are required in sustainability transformations. We describe implications relating to (1) how information systems can contribute to the creation of environmentally sustainable organizations, (2) the design of information systems to create required functional affordances, (3) the management of sustainability transformations, and (4) the further development of the concept of functional affordances in IS research.

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The candidate gene approach has been a pioneer in the field of genetic epidemiology, identifying risk alleles and their association with clinical traits. With the advent of rapidly changing technology, there has been an explosion of in silico tools available to researchers, giving them fast, efficient resources and reliable strategies important to find casual gene variants for candidate or genome wide association studies (GWAS). In this review, following a description of candidate gene prioritisation, we summarise the approaches to single nucleotide polymorphism (SNP) prioritisation and discuss the tools available to assess functional relevance of the risk variant with consideration to its genomic location. The strategy and the tools discussed are applicable to any study investigating genetic risk factors associated with a particular disease. Some of the tools are also applicable for the functional validation of variants relevant to the era of GWAS and next generation sequencing (NGS).

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In vivo small molecules as necessary intermediates are involved in numerous critical metabolic pathways and biological processes associated with many essential biological functions and events. There is growing evidence that MS-based metabolomics is emerging as a powerful tool to facilitate the discovery of functional small molecules that can better our understanding of development, infection, nutrition, disease, toxicity, drug therapeutics, gene modifications and host-pathogen interaction from metabolic perspectives. However, further progress must still be made in MS-based metabolomics because of the shortcomings in the current technologies and knowledge. This technique-driven review aims to explore the discovery of in vivo functional small molecules facilitated by MS-based metabolomics and to highlight the analytic capabilities and promising applications of this discovery strategy. Moreover, the biological significance of the discovery of in vivo functional small molecules with different biological contexts is also interrogated at a metabolic perspective.