187 resultados para Mansfield
Resumo:
The effects of reductions in cell wall lignin content, manifested by RNA interference suppression of coumaroyl 3'-hydroxylase, on plant growth, water transport, gas exchange, and photosynthesis were evaluated in hybrid poplar trees (Populus alba 3 grandidentata). The growth characteristics of the reduced lignin trees were significantly impaired, resulting in smaller stems and reduced root biomass when compared to wild-type trees, as well as altered leaf morphology and architecture. The severe inhibition of cell wall lignification produced trees with a collapsed xylem phenotype, resulting in compromised vascular integrity, and displayed reduced hydraulic conductivity and a greater susceptibility to wall failure and cavitation. In the reduced lignin trees, photosynthetic carbon assimilation and stomatal conductance were also greatly reduced, however, shoot xylem pressure potential and carbon isotope discrimination were higher and water-use efficiency was lower, inconsistent with water stress. Reductions in assimilation rate could not be ascribed to increased stomatal limitation. Starch and soluble sugars analysis of leaves revealed that photosynthate was accumulating to high levels, suggesting that the trees with substantially reduced cell wall lignin were not carbon limited and that reductions in sink strength were, instead, limiting photosynthesis.
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In this chapter we introduce and explore the notion of “intentionally enriched awareness”. Intentional enrichment refers to the process of actively engaging users in the awareness process by enabling them to express intentions. We initially look at the phenomenon if sharing intentional information in related collaborative systems. We then explore the concept of intentional enrichment through designing and evaluating the AnyBiff system which allows users to freely create, share and use a variety of biff applications. Biffs are simple representation of pre-defined activities. Users can select biffs to indicate that they are engaged in an activity. We summarise the results of a trial which allowed us to gain insights into the potential of the AnyBiff prototype and the underlying biff concept to implement intentionally enriched awareness. Our findings show that intentional disclosure mechanisms in the form of biffs were successfully used in a variety of contexts. Users actively engaged in the design of a large variety of biffs and explored many different uses of the concept. The study revealed a whole host of issues with regard to intentionally enriched awareness which give valuable insight into the conception and design of future applications in this area.
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Copy number variants (CNVs) account for a major proportion of human genetic polymorphism and have been predicted to have an important role in genetic susceptibility to common disease. To address this we undertook a large, direct genome-wide study of association between CNVs and eight common human diseases. Using a purpose-designed array we typed 19,000 individuals into distinct copy-number classes at 3,432 polymorphic CNVs, including an estimated 50% of all common CNVs larger than 500 base pairs. We identified several biological artefacts that lead to false-positive associations, including systematic CNV differences between DNAs derived from blood and cell lines. Association testing and follow-up replication analyses confirmed three loci where CNVs were associated with diseaseIRGM for Crohns disease, HLA for Crohns disease, rheumatoid arthritis and type 1 diabetes, and TSPAN8 for type 2 diabetesalthough in each case the locus had previously been identified in single nucleotide polymorphism (SNP)-based studies, reflecting our observation that most common CNVs that are well-typed on our array are well tagged by SNPs and so have been indirectly explored through SNP studies. We conclude that common CNVs that can be typed on existing platforms are unlikely to contribute greatly to the genetic basis of common human diseases. © 2010 Macmillan Publishers Limited. All rights reserved.
Resumo:
Elevated blood pressure is a common, heritable cause of cardiovascular disease worldwide. To date, identification of common genetic variants influencing blood pressure has proven challenging. We tested 2.5 million genotyped and imputed SNPs for association with systolic and diastolic blood pressure in 34,433 subjects of European ancestry from the Global BPgen consortium and followed up findings with direct genotyping (N 71,225 European ancestry, N 12,889 Indian Asian ancestry) and in silico comparison (CHARGE consortium, N = 29,136). We identified association between systolic or diastolic blood pressure and common variants in eight regions near the CYP17A1 (P = 7 × 10 24), CYP1A2 (P = 1 × 10 23), FGF5 (P = 1 × 10 21), SH2B3 (P = 3 × 10 18), MTHFR (P = 2 × 10 13), c10orf107 (P = 1 × 10 9), ZNF652 (P = 5 × 10 9) and PLCD3 (P = 1 × 10 8) genes. All variants associated with continuous blood pressure were associated with dichotomous hypertension. These associations between common variants and blood pressure and hypertension offer mechanistic insights into the regulation of blood pressure and may point to novel targets for interventions to prevent cardiovascular disease.
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Ulcerative colitis is a common form of inflammatory bowel disease with a complex etiology. As part of the Wellcome Trust Case Control Consortium 2, we performed a genome-wide association scan for ulcerative colitis in 2,361 cases and 5,417 controls. Loci showing evidence of association at P 1 × 10 5 were followed up by genotyping in an independent set of 2,321 cases and 4,818 controls. We find genome-wide significant evidence of association at three new loci, each containing at least one biologically relevant candidate gene, on chromosomes 20q13 (HNF4A; P = 3.2 × 10 17), 16q22 (CDH1 and CDH3; P = 2.8 × 10 8) and 7q31 (LAMB1; P = 3.0 × 10 8). Of note, CDH1 has recently been associated with susceptibility to colorectal cancer, an established complication of longstanding ulcerative colitis. The new associations suggest that changes in the integrity of the intestinal epithelial barrier may contribute to the pathogenesis of ulcerative colitis. © 2009 Nature America, Inc. All rights reserved.
Resumo:
We have genotyped 14,436 nonsynonymous SNPs (nsSNPs) and 897 major histocompatibility complex (MHC) tag SNPs from 1,000 independent cases of ankylosing spondylitis (AS), autoimmune thyroid disease (AITD), multiple sclerosis (MS) and breast cancer (BC). Comparing these data against a common control dataset derived from 1,500 randomly selected healthy British individuals, we report initial association and independent replication in a North American sample of two new loci related to ankylosing spondylitis, ARTS1 and IL23R, and confirmation of the previously reported association of AITD with TSHR and FCRL3. These findings, enabled in part by increased statistical power resulting from the expansion of the control reference group to include individuals from the other disease groups, highlight notable new possibilities for autoimmune regulation and suggest that IL23R may be a common susceptibility factor for the major 'seronegative' diseases.
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The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1–3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region4, 5, 6, 7, 8, 9, 10, 11. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods—recursive partitioning and regression...
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Bigeyed bugs (Geocoris spp., Hemiptera: Geocoridae) are common predators in Australian agricultural crops yet the development and reproductive biology of Australian geocorids has not been described before. Here we present the effects of diet, temperature and photoperiod on the development and survival of Geocoris lubra Kirkaldy from egg to adult. Nymphal survival of G. lubra reared on live aphids (Aphis gossypii Glover) was very low but improved slightly on a diet of Helicoverpa armigera (Hübner) eggs. Development was faster and nymphal survival improved significantly at 27°C compared with 25°C. Further investigation at 27°C showed photoperiod influenced development time, but not survival of immature G. lubra. Development time was significantly longer at 10L:14D. Fecundity of first generation G. lubra was not affected by photoperiod, although egg viability was greater at 12L:12D.
Resumo:
This paper proposes a framework for building resilience in teacher education. The framework is informed by a focused review of relevant literature to determine factors that may be addressed in teacher education to support teacher resilience and ways in which this may occur. Findings show that personal and contextual resources along with use of particular strategies all contribute to resilience outcomes and that many of these can be developed in teacher education. Using these findings, a comprehensive resilience framework is proposed with five overarching themes - understanding resilience, relationships, wellbeing, motivation and emotions. Implementation possibilities are discussed.
Resumo:
Considerando-se o papel representado pela literatura diante da formação de novas subjetividades, esta pesquisa investigou os discursos acerca do feminino presentes em três romances de autoria feminina do século XIX Razão e sensibilidade, Orgulho e Preconceito e Mansfield Park da romancista Jane Austen, uma das escritoras mais aclamadas da Inglaterra. Utilizando-se os personagens femininos desses romances e como eles se posicionam diante das relações afetivas e sociais, buscou-se estabelecer um paralelo entre a literatura e a história das mulheres. Sendo considerada uma das responsáveis pela consolidação do gênero romanesco inglês, Jane Austen insere em seus romances a questão da feminilidade como histórica e socialmente construída, além de ser ela própria também um exemplo da desconstrução dos papéis femininos, já que escreveu num tempo no qual a vida literária não era um espaço que as mulheres deveriam ocupar. No entanto, muitas vezes, tanto a discussão sobre as representações das mulheres nas suas obras, como a própria representatividade da autora para o campo de atuação das mulheres inglesas são negligenciados devido a uma leitura superficial de seus romances. Assim, este trabalho buscou dialogar com a história das mulheres, enriquecendo este campo de estudo, trazendo novos dados e formas de pensar as relações das mulheres na sociedade, através da literatura, além de objetivar dar mais destaque à romancista dentro deste campo de estudo. Não foi intenção fazer uma análise literária das obras, mas uma análise dos discursos existentes por trás dos papéis femininos nos romances escritos por Jane Austen, enquanto possível espelho da visão social da feminilidade, levando-se em consideração o contexto sócio histórico em que foram escritas
Resumo:
Glycogen storage disease type-Ia (GSD-Ia) patients deficient in glucose-6-phosphatase-α (G6Pase-α or G6PC) manifest impaired glucose homeostasis characterized by fasting hypoglycemia, growth retardation, hepatomegaly, nephromegaly, hyperlipidemia, hyperuricemia, and lactic acidemia. Two efficacious recombinant adeno-associated virus pseudotype 2/8 (rAAV8) vectors expressing human G6Pase-α have been independently developed. One is a single-stranded vector containing a 2864-bp of the G6PC promoter/enhancer (rAAV8-GPE) and the other is a double-stranded vector containing a shorter 382-bp minimal G6PC promoter/enhancer (rAAV8-miGPE). To identify the best construct, a direct comparison of the rAAV8-GPE and the rAAV8-miGPE vectors was initiated to determine the best vector to take forward into clinical trials. We show that the rAAV8-GPE vector directed significantly higher levels of hepatic G6Pase-α expression, achieved greater reduction in hepatic glycogen accumulation, and led to a better toleration of fasting in GSD-Ia mice than the rAAV8-miGPE vector. Our results indicated that additional control elements in the rAAV8-GPE vector outweigh the gains from the double-stranded rAAV8-miGPE transduction efficiency, and that the rAAV8-GPE vector is the current choice for clinical translation in human GSD-Ia.
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Abstract In theory, improvements in healthy life expectancy should generate increases in the average age of retirement, with little effect on savings rates. In many countries, however, retirement incentives in social security programs prevent retirement ages from keeping pace with changes in life expectancy, leading to an increased need for life-cycle savings. Analyzing a cross-country panel of macroeconomic data, we find that increased longevity raises aggregate savings rates in countries with universal pension coverage and retirement incentives, though the effect disappears in countries with pay-as-you-go systems and high replacement rates.
Resumo:
Suppressors of cytokine signaling (SOCS) proteins are a family of proteins that are able to act in a classic negative feedback loop to regulate cytokine signal transduction. The regulation of the immune response by SOCS proteins may contribute to persistent infection or even a fatal outcome. In this study, we have investigated the induction of SOCS 1-3 after peripheral infection with West Nile virus (WNV) or tick-borne encephalitis virus (TBEV) in the murine model. We have shown that the cytokine response after infection of mice with WNV or TBEV induces an upregulation in the brain of mRNA transcripts for SOCS 1 and SOCS 3, but not SOCS 2. We hypothesize that SOCS proteins may play a role in limiting cytokine responses in the brain as a neuroprotective mechanism, which may actually enhance the ability of neuroinvasive viruses such as WNV and TBEV to spread and cause disease.
Resumo:
Objectives: We determined the prevalence and nature of behavioural symptoms at the time of admission to a long-term care home (LTCH) and occurrence of resident-to-resident aggressive behaviour associated with behavioural symptoms within three months following admission. Method: The Cohen-Mansfield Agitation Inventory and Aggressive Behaviour Scale were completed at the time residents were admitted into the LTCH. A chart review, conducted three months after admission into the LTCH, abstracted documented resident-to-resident aggression. Three LTCHs located in Ontario, Canada participated in the study. Results: During a 16-month period, 339 individuals admitted to the LTCHs comprised the study sample. A comparison was made between residents with and without dementia. At admission, residents with dementia had a greater number of behavioural symptoms than those without dementia (mean = 3.79, SD = 3.32 versus mean = 2.56, SD = 2.24, respectively; t(200) = 1.91; p = 0.059). Residents with and without dementia exhibited similar behaviours but differed on the prevalence of these behaviours. The most frequently reported behavioural symptoms for residents in both groups were verbal agitation and non-aggressive physical behaviours. The most frequently recorded aggressive behaviour for all residents was resisting care. In the three months post admission, 79 (23%) residents were involved in a documented incident that involved aggressive behaviour to another resident. Conclusion: A standardized comprehensive assessment for admission to a LTCH is an important strategy that can be used to identify behavioural symptoms and plan appropriate care management.