919 resultados para ANTIOXIDANT ENZYME-ACTIVITIES
Resumo:
Knowledge is a commodity. It is a by-product of learning that involves the creation, sharing, processing and possible use of information in the mind of an individual. Knowledge management (KM) is, therefore, concerned with the effective implementation of such activities within the organisation. It is simply the process of leveraging organisational knowledge to deliver a long-term competitive advantage. This paper presents the results of an empirical research investigation into the interaction between different KM activities within the context of construction contracting organisations. The different KM activities include: responsiveness to the knowledge of business environment, knowledge acquisition, knowledge dissemination, and knowledge application. A questionnaire survey was administered to investigate the opinions of construction professionals regarding the intensity of activities currently implemented by their organisations to facilitate knowledge capturing, sharing and application. A total of 149 responses were then used to statistically examine the inter-relationships between the different KM activities as practised by contracting organisations in Hong Kong. The paper presents and discusses the survey findings and proposes recommendations for improving the effectiveness of current KM practices.
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Interest in the relationship between inflammation and oxidative stress has increased dramatically in recent years, not only within the clinical setting but also in the fields of exercise biochemistry and immunology. Inflammation and oxidative stress share a common role in the etiology of a variety of chronic diseases. During exercise, inflammation and oxidative stress are linked via muscle metabolism and muscle damage. Because oxidative stress and inflammation have traditionally been associated with fatigue and impaired recovery from exercise, research has focused on nutritional strategies aimed at reducing these effects. In this review, we have evaluated the findings of studies involving antioxidant supplementation on alterations in markers of inflammation (e.g., cytokines, C-reactive protein and cortisol). This review focuses predominantly on the role of reactive oxygen and nitrogen species generated from muscle metabolism and muscle damage during exercise and on the modulatory effects of antioxidant supplements. Furthermore, we have analyzed the influence of factors such as the dose, timing, supplementation period and bioavailability of antioxidant nutrients.
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Neutrophils produce free radicals known as reactive oxygen species (ROS), which assist in the clearance of damaged host tissue. Tissue damage may occur during exercise due to muscle damage, thermal stress and ischaemia/reperfusion. When produced in excess, neutrophil-derived ROS may overwhelm the body's endogenous antioxidant defence mechanisms, and this can lead to oxidative stress. There is increasing evidence for links between oxidative stress and a variety of pathological disorders such as cardiovascular diseases, cancer, chronic inflammatory diseases and post-ischaemic organ injury. A small number of studies have investigated whether there is a link between neutrophil activation and oxidative stress during exercise. In this review, we have summarised the findings of these studies. Exercise promotes the release of neutrophils into the circulation, and some evidence suggests that neutrophils mobilised after exercise have an enhanced capacity to generate some forms of ROS when stimulated in vitro. Neutrophil activation during exercise may challenge endogenous antioxidant defence mechanisms, but does not appear to increase lipid markers of oxidative stress to any significant degree, at least in the circulation. Antioxidant supplements such as N-acetylcysteine are effective at attenuating increases in the capacity of neutrophils to generate ROS when stimulated in vitro, whereas vitamin E reduces tissue infiltration of neutrophils during exercise. Free radicals generated during intense exercise may lead to DNA damage in leukocytes, but it is unknown if this damage is the result of neutrophil activation. Exercise enhances the expression of inducible haem (heme)-oxygenase (HO-1) in neutrophils after exercise, however, it is uncertain whether oxidative stress is the stimulus for this response.
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An upper primary multiliteracies project based on the children’s book “Pearl Barley and Charlie Parsley” by Aaron Blabey. The main theme explored is same and different.
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The addition of game design elements to non-game contexts has become known as gamification. Previous research has suggested that framing tedious and non-motivating tasks as game-like can make them enjoyable and motivating (e.g., de Oliveira, et al., 2010; Fujiki, et al., 2007; Chiu, et al., 2009). Smartphone applications lend themselves to being gamified as the underlying mobile technology has the ability to sense user activities and their surrounding environment. These sensed activities can be used to implement and enforce game-like rules based around many physical activities (e.g., exercise, travel, or eating). If researchers wish to investigate this area, they first need an existing gamified application to study. However if an appropriate application does not exist then the researcher may need to create their own gamified prototype to study. Unfortunately, there is little previous research that details or explains the design and integration of game elements to non-game mobile applications. This chapter explores this gap and shares a framework that was used to add videogame-like achievements to an orientation mobile application developed for new university students. The framework proved useful and initial results are discussed from two studies. However, further development of the framework is needed, including further consideration of what makes an effective gamified experience.
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An accurate evaluation of the airborne particle dose-response relationship requires detailed measurements of the actual particle concentration levels that people are exposed to, in every microenvironment in which they reside. The aim of this work was to perform an exposure assessment of children in relation to two different aerosol species: ultrafine particles (UFPs) and black carbon (BC). To this purpose, personal exposure measurements, in terms of UFP and BC concentrations, were performed on 103 children aged 8-11 years (10.1 ± 1.1 years) using hand-held particle counters and aethalometers. Simultaneously, a time-activity diary and a portable GPS were used to determine the children’s daily time-activity pattern and estimate their inhaled dose of UFPs and BC. The median concentration to which the study population was exposed was found to be comparable to the high levels typically detected in urban traffic microenvironments, in terms of both particle number (2.2×104 part. cm-3) and BC (3.8 μg m-3) concentrations. Daily inhaled doses were also found to be relatively high and were equal to 3.35×1011 part. day-1 and 3.92×101 μg day-1 for UFPs and BC, respectively. Cooking and using transportation were recognized as the main activities contributing to overall daily exposure, when normalized according to their corresponding time contribution for UFPs and BC, respectively. Therefore, UFPs and BC could represent tracers of children exposure to particulate pollution from indoor cooking activities and transportation microenvironments, respectively.
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Nha Trang Bay (NTB) is located on the Central Vietnam coast, western South China Sea. Recent coastal development of Nha Trang City has raised public concern over an increasing level of pollution within the bay and degradation of nearby coral reefs. In this study, multiple proxies (e.g., trace metals, rare earth elements (REEs), and Y/Ho) recorded in a massive Porites lutea coral colony were used to reconstruct changes in seawater conditions in the NTB from 1995 to 2009. A 14-year record of REEs and other trace metals revealed that the concentrations of terrestrial trace metals have increased dramatically in response to an increase in coastal development projects such as road, port, and resort constructions, port and river dredging, and dumping activities since 2000. The effects of such developmental processes are also evident in changes in REE patterns and Y/Ho ratios through time, suggesting that both parameters are critical proxies for marine pollution.
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This thesis examines the use of network governance in US airport transportation planning activities involving taxicab services for airport patrons. The research provides US airports with new insights whereby they can successfully engage with both transportation regulatory agencies and taxicab service providers in developing mutually agreeable policies that foster the development of supply-side taxicab service improvements. A mix of quantitative and qualitative research methods is used to unearth how US airports interact with these actors, and to identify attitudes held by airport staff in their engagements involving airport taxicab planning matters. The research may ultimately lead to the achievement of sustainable increases in the air passenger ground transportation modal share at US airports, resulting in both desirable long-term operational and environmental benefits for airport management, those involved with the provision of airport taxicab services, and the traveling public.
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The learner licence, within a graduated driver licensing system, provides new drivers with the opportunity to learn to drive under the supervision of a more experienced driver. The Queensland graduated driver licensing system requires learner drivers to record a minimum of 100 logbook hours of supervised practice with the support of parents appearing critical to ensure that this is achieved. This paper examines differences between mothers and fathers who supervise learner drivers. Mothers and fathers from Queensland who had recently supervised their child while they learnt to drive completed an internet survey about their experiences. It appears that one strategy that parents use to provide practice hours is for the child to drive themselves or their parents to or from activities that they would have attended anyway in addition to undertaking special trips in the car for the purposes of practising. The results suggest that mothers, when compared with fathers, consider driving at all stages of licensure riskier and that mothers provided more hours of supervision than fathers. However, despite this, there are limited differences between how frequently mothers and fathers provide different driving experiences such as deliberately practising in suburban areas or with passengers in the car. This research fills a gap in the literature by providing important information about the way in which parents supervise their children while they are driving on a learner licence as well as identifying some of the differences and similarities between mothers and fathers.
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Saccharification of sugarcane bagasse pretreated at the pilot-scale with different processes (in combination with steam-explosion) was evaluated. Maximum glucan conversion with Celluclast 1.5 L (15–25 FPU/g glucan) was in the following order: glycerol/HCl > HCl > H2SO4 > NaOH, with the glycerol system achieving ∼100% conversion. Surprisingly, the NaOH substrate achieved optimum saccharification with only 8 FPU/g glucan. Glucan conversions (3.6–6%) obtained with mixtures of endo-1,4-β-glucanase (EG) and β-glucosidase (βG) for the NaOH substrate were 2–6 times that of acid substrates. However, glucan conversions (15–60%) obtained with mixtures of cellobiohydrolase (CBH I) and βG on acidified glycerol substrate were 10–30% higher than those obtained for NaOH and acid substrates. The susceptibility of the substrates to enzymatic saccharification was explained by their physical and chemical attributes. Acidified glycerol pretreatment offers the opportunity to simplify the complexity of enzyme mixtures required for saccharification of lignocellulosics.
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Migraine, with and without aura (MA and MO), is a prevalent and complex neurovascular disorder that is likely to be influenced by multiple genes some of which may be capable of causing vascular changes leading to disease onset. This study was conducted to determine whether the ACE I/D gene variant is involved in migraine risk and whether this variant might act in combination with the previously implicated MTHFR C677T genetic variant in 270 migraine cases and 270 matched controls. Statistical analysis of the ACE I/D variant indicated no significant difference in allele or genotype frequencies (P > 0.05). However, grouping of genotypes showed a modest, yet significant, over-representation of the DD/ID genotype in the migraine group (88%) compared to controls (81%) (OR of 1.64, 95% CI: 1.00–2.69, P = 0.048). Multivariate analysis, including genotype data for the MTHFR C677T, provided evidence that the MTHFR (TT) and ACE (ID/DD) genotypes act in combination to increase migraine susceptibility (OR = 2.18, 95% CI: 1.15–4.16, P = 0.018). This effect was greatest for the MA subtype where the genotype combination corresponded to an OR of 2.89 (95% CI:1.47–5.72, P = 0.002). In Caucasians, the ACE D allele confers a weak independent risk to migraine susceptibility and also appears to act in combination with the C677T variant in the MTHFR gene to confer a stronger influence on the disease.
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Background Type 2 diabetes is a leading cause of morbidity and mortality in midlife and older Australian women with known modifiable risk factors for type 2 diabetes including smoking, nutrition, physical activity and obesity. In Australia little research has been done to investigate the perceived barriers to healthy lifestyle activities in midlife and older women with type 2 diabetes. Aims The primary aim of this study was to explore the level and type of perceived barriers to health promotion activities. The secondary aim was to explore the relationship of perceived barriers to smoking behaviour, fruit and vegetable intake, physical activity, and body mass index. Methods The study was a cross sectional survey of women, aged over 45 with type 2 diabetes, recruited from four metropolitan community health clinics (n = 41). Data were collected from self-report questionnaires and analysed using quantitative methods. Results Women in the study had average total barriers scores similar to those reported in the literature for women with a range of physical disabilities and illnesses. The leading barriers for this group of women were: lack of interest, concern about safety, too tired, lack of money and feeling what they do does not help. There was no association between total barriers scores and body mass index, physical activity, fruit and vegetable intake or socio-demographic variables. Conclusion This study contributes to understanding the perceptions of midlife and older women with type 2 diabetes about the level and type of barriers to healthy lifestyle activities that they experience. The participants reported a high level perceived barriers with a range of personal, social and environmental issues identified and described. This study suggests that health promotion education and interventions for risk factor reduction in women with type 2 diabetes may be enhanced by explicitly addressing perceived barriers to healthy lifestyle activities.
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A polymorphism of the angiotensin I converting enzyme (ACE) gene has recently been reported and analysis of this polymorphism has indicated that it is associated with several cardiovascular diseases. However, the results are still controversial and such association has not yet been established conclusively. To determine whether the ACE gene may be responsible for essential hypertension in a Japanese population, we also compared the distribution of genotypes and the allele frequency of this polymorphism in our findings of a Japanese population with these features in other countries. Eighty-seven hypertensive patients with a family history of essential hypertension and 95 normotensive patients whose parents had no such history were enrolled in the study. Polymorphism of the ACE gene was determined by using the polymerase chain reaction. Homozygotes for this polymorphism had either a 490-bp band (II) or a 190-bp band (DD) and heterozygotes had both bands (ID). In hypertensive subjects, the numbers and frequency of the ACE genotypes were: II, 44 (0.51); ID, 26 (0.30); DD, 17 (0.19). In normotensive subjects these were: II, 35 (0.37); ID, 43 (0.45); DD, 17 (0.18). There were no significant differences between the two groups in derived allele frequencies (chi 2 = 1.41). The difference between the overall allelic frequency in Japan and that reported in several other countries was significant. We did not find any association between ACE gene polymorphism and essential hypertension in Japan. However, there were significant differences in derived allele frequencies between our findings in a Japanese population and those reported from Europe and Australia.
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A new bioluminescent creatine kinase (CK) assay using purified luciferase was used to analyse CK activity in serum samples dried on filter paper. Enzyme activity was preserved for over 1 wk on paper stored at room temperature. At 60°C, CK activity in liquid serum samples was rapidly inactivated, but the activity of enzyme stored on paper was preserved for at least 2 days.