966 resultados para Lysine content analyses


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Glutamine synthetase (GS) is a key enzyme in nitrogen (N) assimilation, particularly during seed development. Three cytosolic GS isoforms (HvGS1) were identified in barley (Hordeum vulgare L. cv Golden Promise). Quantitation of gene expression, localization and response to N supply revealed that each gene plays a non-redundant role in different tissues and during development. Localization of HvGS1_1 in vascular cells of different tissues, combined with its abundance in the stem and its response to changes in N supply, indicate that it is important in N transport and remobilization. HvGS1_1 is located on chromosome 6H at 72.54 cM, close to the marker HVM074 which is associated with a major quantitative trait locus (QTL) for grain protein content (GPC). HvGS1_1 may be a potential candidate gene to manipulate barley GPC. HvGS1_2 mRNA was localized to the leaf mesophyll cells, in the cortex and pericycle of roots, and was the dominant HvGS1 isoform in these tissues. HvGS1_2 expression increased in leaves with an increasing supply of N, suggesting its role in the primary assimilation of N. HvGS1_3 was specifically and predominantly localized in the grain, being highly expressed throughout grain development. HvGS1_3 expression increased specifically in the roots of plants grown on high NH+4, suggesting that it has a primary role in grain N assimilation and also in the protection against ammonium toxicity in roots. The expression of HvGS1 genes is directly correlated with protein and enzymatic activity, indicating that transcriptional regulation is of prime importance in the control of GS activity in barley.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this pilot study water was extracted from samples of two Holocene stalagmites from Socotra Island, Yemen, and one Eemian stalagmite from southern continental Yemen. The amount of water extracted per unit mass of stalagmite rock, termed "water yield" hereafter, serves as a measure of its total water content. Based on direct correlation plots of water yields and δ18Ocalcite and on regime shift analyses, we demonstrate that for the studied stalagmites the water yield records vary systematically with the corresponding oxygen isotopic compositions of the calcite (δ18Ocalcite). Within each stalagmite lower δ18Ocalcite values are accompanied by lower water yields and vice versa. The δ18Ocalcite records of the studied stalagmites have previously been interpreted to predominantly reflect the amount of rainfall in the area; thus, water yields can be linked to drip water supply. Higher, and therefore more continuous drip water supply caused by higher rainfall rates, supports homogeneous deposition of calcite with low porosity and therefore a small fraction of water-filled inclusions, resulting in low water yields of the respective samples. A reduction of drip water supply fosters irregular growth of calcite with higher porosity, leading to an increase of the fraction of water-filled inclusions and thus higher water yields. The results are consistent with the literature on stalagmite growth and supported by optical inspection of thin sections of our samples. We propose that for a stalagmite from a dry tropical or subtropical area, its water yield record represents a novel paleo-climate proxy recording changes in drip water supply, which can in turn be interpreted in terms of associated rainfall rates.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. However, there is still considerable uncertainty over whether the use of organic production standards affects milk quality. Here we report results of meta-analyses based on 170 published studies comparing the nutrient content of organic and conventional bovine milk. There were no significant differences in total SFA and MUFA concentrations between organic and conventional milk. However, concentrations of total PUFA and n-3 PUFA were significantly higher in organic milk, by an estimated 7 (95 % CI −1, 15) % and 56 (95 % CI 38, 74) %, respectively. Concentrations of α-linolenic acid (ALA), very long-chain n-3 fatty acids (EPA+DPA+DHA) and conjugated linoleic acid were also significantly higher in organic milk, by an 69 (95 % CI 53, 84) %, 57 (95 % CI 27, 87) % and 41 (95 % CI 14, 68) %, respectively. As there were no significant differences in total n-6 PUFA and linoleic acid (LA) concentrations, the n-6:n-3 and LA:ALA ratios were lower in organic milk, by an estimated 71 (95 % CI −122, −20) % and 93 (95 % CI −116, −70) %. It is concluded that organic bovine milk has a more desirable fatty acid composition than conventional milk. Meta-analyses also showed that organic milk has significantly higher α-tocopherol and Fe, but lower I and Se concentrations. Redundancy analysis of data from a large cross-European milk quality survey indicates that the higher grazing/conserved forage intakes in organic systems were the main reason for milk composition differences.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Nowadays the composting process has shown itself to be an alternative in the treatment of municipal solid wastes by composting plants. However, although more than 50% of the waste generated by the Brazilian population is composed of matter susceptible to organic composting, this process is, still today, insufficiently developed in Brazil, due to low compost quality and lack of investments in the sector. The objective of this work was to use physical analyses to evaluate the quality of the compost produced at 14 operative composting plants in the Sao Paulo State in Brazil. For this purpose, size distribution and total inert content tests were done. The results were analyzed by grouping the plants according to their productive processes: plants with a rotating drum, plants with shredders or mills, and plants without treatment after the sorting conveyor belt. Compost quality was analyzed considering the limits imposed by the Brazilian Legislation and the European standards for inert contents. The size distribution tests showed the influence of the machinery after the sorting conveyer on the granule sizes as well as the inert content, which contributes to the presence of materials that reduce the quality of the final product. (C) 2007 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

To date, limited numbers of dental calculus samples have been analyzed by researchers in diverse parts of the world. The combined analyses of these have provided some general guidelines for the analysis of calculus that is non-destructive to archaeological teeth. There is still a need for a quantitative study of large numbers of calculus samples to establish protocols, assess the level of contamination, evaluate the quantity of microfossils in dental calculus, and to compare analysis results with the literature concerning the biology of calculus formation. We analyzed dental calculus from 53 teeth from four Brazilian sambaquis. Sambaquis are the shell-mounds that were established prehistorically along the Brazilian coast. The analysis of sambaqui dental calculi shows that there are relatively high concentrations of microfossils (phytoliths and starch), mineral fragments, and charcoal in dental calculus. Mineral fragments and charcoal are possibly contaminants. The largest dental calculi have the lowest concentrations of microfossils. Biologically, this is explained by individual variation in calculus formation between people. Importantly, starch is ubiquitous in dental calculus. The starch and phytoliths show that certainly Dioscorea (yam) and Araucaria angustifolia (Parana pine) were eaten by sambaqui people. Araceae (arum family), Ipomoea batatas (sweet potato) and Zea mays (maize) were probably in their diet. (C) 2009 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Anomalous and natural concentrations of Cr(6+), occasionally exceeding the permitted limit for human consumption (0.05 mg/L), have been detected in groundwater in the northwestern region of the state of Sao Paulo. As part of a water-rock interaction investigation, this article describes the chemical and mineralogical characterization of rock samples taken from boreholes in the municipality of Urania, with the objective of identifying Cr-bearing minerals and determining how chromium is associated with these minerals. Rock sample analysis were performed using X-ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy, electron microprobe and sequential extraction techniques. Chemical analyses indicated that the quartzose sandstones show a geochemical anomaly of chromium, with an average content of 221 ppm, which is higher than the reported chromium content of generic sandstones (35 ppm). Diopside was identified as the primary Cr-bearing mineral potentially subject to weathering processes, with a chromium content of up to 1.2% as Cr(2)O(3). Many of the diopside grains showed dissolution features, confirming the occurrence of weathering. Sequential extraction experiments indicated that 99.3% of the chromium in samples is tightly bonded to minerals, whereas 0.24% is weakly bonded via adsorption. Assuming hypothetically that all adsorbed chromium is released via desorption, the theoretical Cr concentration in water would be one order of magnitude higher than the concentrations of Cr(6+) detected in groundwater. (C) 2010 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: To test the hypothesis that many foods with reduced-fat (RF) claims are relatively energy-dense and that high-fat (HF) vegetable-based dishes are relatively energy-dilute.

Design: Nutrient data were collected from available foods in Melbourne supermarkets that had an RF claim and a full-fat (FF) equivalent. Nutrient analyses were also conducted on recipes for HF vegetable-based dishes that had more than 30% energy from fat but less than 10% from saturated fat. The dietary intake data (beverages removed) from the 1995 National Nutrition Survey were used for the reference relationships between energy density (ED) and percentage energy as fat and carbohydrate and percentage of water by weight.

Statistics: Linear regression modelled relationships of macronutrients and ED. Paired t-tests compared observed and predicted reductions in the ED of RF foods compared with FF equivalents.

Results: Both FF and RF foods were more energy-dense than the Australian diet and the HF vegetable-based dishes were less energy-dense. The Australian diet showed significant relationships with ED, which were positive for percentage energy as fat and negative for percentage energy as carbohydrate. There were no such relationships for the products with RF claims or for the HF vegetable-based dishes.

Conclusion: While, overall, a reduced-fat diet is relatively energy-dilute and is likely to protect against weight gain, there appear to be two important exceptions. A high intake of products with RF claims could lead to a relatively energy-dense diet and thus promote weight gain. Alternatively, a high intake of vegetable-based foods, even with substantial added fat, could reduce ED and protect against weight gain.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The development of critical skills in social work students and practitioners has been a major focus of social work education and training in recent years. Critical incident analysis has developed as a tool to aid critical reflection in practice, in health and social work. This paper provides an overview of the use of the tool in these fields. It then reports on a demonstration project which sought to examine how critical incident analysis might be used as a form of assessment and as a supervisory tool by social work students and practice teachers. An evaluation of the project is provided. Completion of critical incident analyses using the framework was found to provide a structured approach to critical reflection. It assisted the integration of theory and practice and the examination of value issues. Students and practice teachers identify its use in supervision and its potential as an assessment tool. The paper concludes with a discussion on the potential uses of critical incident analyses, with particular attention given to its use to develop anti-oppressive practice.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The recently completed Australian Screen Producer Survey provides the most current and detailed picture of the culture, motivations and aspirations of a highly influential sector of the content production industries. Drawing upon the results of the survey, this article reflects on the historical and theoretical difficulties entailed in defining the producer as a professional category, before outlining some of the survey’s key findings. In particular, it examines producers’ demographic and sectoral profile, analyses their attitudes towards the relative importance of education and experience, and explores their underlying motivations. Amongst other findings, the survey reveals a tendency towards idealism among Australian producers that would appear to be at odds with the financial realities of the business. It therefore offers a variety of stakeholders (including government and educational institutions, as well as producers themselves) with the opportunity to reflect upon the future shape and direction of the Australian media industry.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Best practice in obesity prevention has generally been defined in terms of ‘what’ needs to be done while neglecting ‘how’. A multifaceted definition of best practice, which combines available evidence on what actions to take, with an established process for interpreting this information in a specific community context, provides a more appropriate basis for defining the principles of best practice in community-based obesity prevention. Based on analysis of a range of literature, a preliminary set of principles was drafted and progressively revised through further analyses of published literature and a series of consultations. The framework for best practice principles comprises: community engagement, programme design and planning, evaluation, implementation and sustainability, and governance. Specific principles were formulated within this framework. While many principles were generic, distinctive features of obesity prevention were also covered. The engagement of end-users influenced the design of the formatting of the outputs, which represent three levels of knowledge transfer: detailed evidence summaries, guiding questions for programme planners and a briefer set of questions for simpler communication purposes. The best practice principles provide a valuable mechanism for the translation of existing evidence and experience into the decision-making processes for planning, implementing and evaluating the complex community-based interventions needed for successful obesity prevention.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The Saccharomyces cerevisiae WD-40 repeat protein Swd2p associates with two functionally distinct multiprotein complexes: the cleavage and polyadenylation factor (CPF) that is involved in pre-mRNA and snoRNA 3′ end formation and the SET1 complex (SET1C) that methylates histone 3 lysine 4. Based on bioinformatic analysis we predict a seven-bladed β-propeller structure for Swd2p proteins. Northern, transcriptional run-on and in vitro 3′ end cleavage analyses suggest that temperature sensitive swd2 strains were defective in 3′ end formation of specific mRNAs and snoRNAs. Protein–protein interaction studies support a role for Swd2p in the assembly of 3′ end formation complexes. Furthermore, histone 3 lysine 4 di-and tri-methylation were adversely affected and telomeres were shortened in swd2 mutants. Underaccumulation of the Set1p methyltransferase accounts for the observed loss of SET1C activity and suggests a requirement for Swd2p for the stability or assembly of this complex. We also provide evidence that the roles of Swd2p as component of CPF and SET1C are functionally independent. Taken together, our results establish a dual requirement for Swd2p in 3′ end formation and histone tail modification.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background The quality of support provided to people with disability who show challenging behaviour could be influenced by the quality of the behaviour support plans (BSPs) on which staff rely for direction. This study investigated the content validity of the Behaviour Support Plan Quality Evaluation tool (BSP-QEII), originally developed to guide the development of BSPs for children in school settings, and evaluated its application for use in accommodation and day-support services for adults with intellectual disability.

Method A three-round Delphi study involving a purposive sample of experienced behaviour support practitioners (n = 30) was conducted over an 8-week period. The analyses included deductive content analysis and descriptive statistics.

Results The 12 quality domains of the BSP-QEII were affirmed as valid for application in adult accommodation and day-support service settings. Two additional quality domains were suggested, relating to the provision of detailed background on the client and the need for plans to reflect contemporary service philosophy. Furthermore, the results suggest that some issues previously identified in the literature as being important for inclusion in BSPs might not currently be a priority for practitioners. These included: the importance of specifying replacement or alternative behaviours to be taught, descriptions of teaching strategies to be used, reinforcers, and the specification of objective goals against which to evaluate the success of the intervention programme.

Conclusions The BSP-QEII provides a potentially useful framework to guide and evaluate the development of BSPs in services for adults with intellectual disability. Further research is warranted to investigate why practitioners are potentially giving greater attention to some areas of intervention practice than others, even where research has demonstrated these others areas of practice could be important to achieving quality outcomes.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This editorial captures the essence of each of the papers in this journal and synthesises the findings to highlight the complexity of developing practices that enable students to develop mathematical understandings. Papers described and discussed come from sources internal and external to Australasia. They include new perspectives on analysis of classroom practices, analyses of mathematical registers and mathematical language in classroom activity, action research of a teacher developing new pedagogical understandings, and various analyses associated with teacher education (pre-service teacher programs, interactions between pre-service teachers and their mentors, and how limited content knowledge can affect teacher interpretation of classroom activity. The editorial captures many of the complexities highlighted in the papers and points to the enormity of the expertise required to optimise the teaching of mathematics..

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Environmental context Soils contaminated with metals can pose both environmental and human health risks. This study showed that a common crop vegetable grown in the presence of cadmium and zinc readily accumulated these metals, and thus could be a source of toxicity when eaten. The work highlights potential health risks from consuming crops grown on contaminated soils. Abstract Ingestion of plants grown in heavy metal contaminated soils can cause toxicity because of metal accumulation. We compared Cd and Zn levels in Brassica rapa, a widely grown crop vegetable, with that of the hyperaccumulator Solanum nigrum L. Solanum nigrum contained 4 times more Zn and 12 times more Cd than B. rapa, relative to dry mass. In S. nigrum Cd and Zn preferentially accumulated in the roots whereas in B. rapa Cd and Zn were concentrated more in the shoots than in the roots. The different distribution of Cd and Zn in B. rapa and S. nigrum suggests the presence of distinct metal uptake mechanisms. We correlated plant metal content with the expression of a conserved putative natural resistance-associated macrophage protein (NRAMP) metal transporter in both plants. Treatment of both plants with either Cd or Zn increased expression of the NRAMP, with expression levels being higher in the roots than in the shoots. These findings provide insights into the molecular mechanisms of heavy metal processing by S. nigrum L. and the crop vegetable B. rapa that could assist in application of these plants for phytoremediation. These investigations also highlight potential health risks associated with the consumption of crops grown on contaminated soils.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose – The purpose of this study is to explore Australian public and stakeholders views towards the regulation of the Internet and its content. The federal government called for submissions addressing their proposal, and this paper analyses these submissions for themes and provides clarity as to the Australian public and stakeholders key concerns in regards to the proposed policy. Design/methodology/approach – The paper uses a qualitative approach to analyse the public consultations to the Australian Federal Government. These documents are coded and analysed to determine negative and positive viewpoints. Findings – The research has shown, based upon the analysis of the consultation, that there was no public support for any of the measures put forward, that the Australian Federal Government in its response has not recognised this public feedback and instead has only utilised some of the qualitative feedback obtained through the public consultation process to try to justify its case to proceed with its proposals. Research limitations/implications – The study is focussed on Australia. Practical implications – The paper analyses a proposed national approach to filtering the content of the Internet and discussed the public reaction to such an approach. Social implications – The paper looks at how different parts of Australian society view Internet filtering in a positive or negative manner. Originality/value – The only study that directly looks at the viewpoint of the Australian public.