Showing papers by "Manchester Metropolitan University published in 2010"

Historical (1850–2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application

Abstract: We present and discuss a new dataset of gridded emissions covering the historical period (1850–2000) in decadal increments at a horizontal resolution of 0.5° in latitude and longitude. The primary purpose of this inventory is to provide consistent gridded emissions of reactive gases and aerosols for use in chemistry model simulations needed by climate models for the Climate Model Intercomparison Program #5 (CMIP5) in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Our best estimate for the year 2000 inventory represents a combination of existing regional and global inventories to capture the best information available at this point; 40 regions and 12 sectors are used to combine the various sources. The historical reconstruction of each emitted compound, for each region and sector, is then forced to agree with our 2000 estimate, ensuring continuity between past and 2000 emissions. Simulations from two chemistry-climate models is used to test the ability of the emission dataset described here to capture long-term changes in atmospheric ozone, carbon monoxide and aerosol distributions. The simulated long-term change in the Northern mid-latitudes surface and mid-troposphere ozone is not quite as rapid as observed. However, stations outside this latitude band show much better agreement in both present-day and long-term trend. The model simulations indicate that the concentration of carbon monoxide is underestimated at the Mace Head station; however, the long-term trend over the limited observational period seems to be reasonably well captured. The simulated sulfate and black carbon deposition over Greenland is in very good agreement with the ice-core observations spanning the simulation period. Finally, aerosol optical depth and additional aerosol diagnostics are shown to be in good agreement with previously published estimates and observations.

The Impact of Conservation on the Status of the World’s Vertebrates

Abstract: Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.

Vibration as an exercise modality: how it may work, and what its potential might be.

Abstract: Whilst exposure to vibration is traditionally regarded as perilous, recent research has focussed on potential benefits. Here, the physical principles of forced oscillations are discussed in relation to vibration as an exercise modality. Acute physiological responses to isolated tendon and muscle vibration and to whole body vibration exercise are reviewed, as well as the training effects upon the musculature, bone mineral density and posture. Possible applications in sports and medicine are discussed. Evidence suggests that acute vibration exercise seems to elicit a specific warm-up effect, and that vibration training seems to improve muscle power, although the potential benefits over traditional forms of resistive exercise are still unclear. Vibration training also seems to improve balance in sub-populations prone to fall, such as frail elderly people. Moreover, literature suggests that vibration is beneficial to reduce chronic lower back pain and other types of pain. Other future indications are perceivable.

Entrepreneurial competencies: a literature review and development agenda

Abstract: Purpose – Entrepreneurial competencies are seen as important to business growth and success. The purpose of this paper is therefore to undertake a literature review of research on entrepreneurial competence in order to: provide an integrated account of contributions relating to entrepreneurial competencies by different authors working in different countries and different industry sectors and at different points in time; and, develop an agenda for future research, and practice in relation to entrepreneurial competencies.Design/methodology/approach – The article starts with a review of the development of the concept of competence, with particular reference to its use in the context of management competencies. It then draws together views on the notion of entrepreneurial competence before exploring and summarising research on the link between entrepreneurial competencies and business performance and growth. A core section then compares the models of entrepreneurial competencies cited in the literature, and o...

Sarcopenia: characteristics, mechanisms and functional significance

Abstract: Sarcopenia reflects a progressive withdrawal of anabolism and an increased catabolism, along with a reduced muscle regeneration capacity. Muscle force and power decline more than muscle dimensions: older muscle is intrinsically weak. Sarcopenic obesity (SO) among the elderly corroborates to the loss of muscle mass increasing the risk of metabolic syndrome development. Recent studies on the musculoskeletal adaptations with ageing and key papers on the mechanisms of muscle wasting, its functional repercussions and on SO are included. Neuropathic, hormonal, immunological, nutritional and physical activity factors contribute to sarcopenia. Selective fast fibre atrophy, loss of motor units and an increase in hybrid fibres are typical findings of ageing. Satellite cell number decreases reducing muscle regeneration capacity. SO promotes further muscle wasting and increases risk of metabolic syndrome development. The proportion of fast to slow fibres seems maintained in old age. In elderly humans, nuclear domain is maintained constant. Basal protein synthesis and breakdown show little changes in old age. Instead, blunting of the anabolic response to feeding and exercise and of the antiproteolytic effect of insulin is observed. Further understanding of the mechanisms of sarcopenia requires disentangling of the effects of ageing alone from those of disuse and disease. The causes of the greater anabolic resistance to feeding and exercise of elderly women need elucidating. The enhancement of muscle regeneration via satellite cell activation via the MAPK/notch molecular pathways seems particularly promising.

Fluoride toothpastes of different concentrations for preventing dental caries in children and adolescents

Abstract: Background Caries (dental decay) is a disease of the hard tissues of the teeth caused by an imbalance, over time, in the interactions between cariogenic bacteria in dental plaque and fermentable carbohydrates (mainly sugars). The use of fluoride toothpaste is the primary intervention for the prevention of caries. Objectives To determine the relative effectiveness of fluoride toothpastes of different concentrations in preventing dental caries in children and adolescents, and to examine the potentially modifying effects of baseline caries level and supervised toothbrushing. Search methods A search was undertaken on Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and several other databases. Reference lists of articles were also searched. Date of the most recent searches: 8 June 2009. Selection criteria Randomised controlled trials and cluster-randomised controlled trials comparing fluoride toothpaste with placebo or fluoride toothpaste of a different concentration in children up to 16 years of age with a follow-up period of at least 1 year. The primary outcome was caries increment in the permanent or deciduous dentition as measured by the change in decayed, (missing), filled tooth surfaces (D(M)FS/d(m)fs) from baseline. Data collection and analysis Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were resolved by discussion and consensus or by a third party. The primary effect measure was the prevented fraction (PF), the caries increment of the control group minus the caries increment of the treatment group, expressed as a proportion of the caries increment in the control group. Where it was appropriate to pool data, network meta-analysis, network meta-regression or meta-analysis models were used. Potential sources of heterogeneity were specified a priori and examined through random-effects meta-regression analysis where appropriate. Main results 75 studies were included, of which 71 studies comprising 79 trials contributed data to the network meta-analysis, network meta-regression or meta-analysis. For the 66 studies (74 trials) that contributed to the network meta-analysis of D(M)FS in the mixed or permanent dentition, the caries preventive effect of fluoride toothpaste increased significantly with higher fluoride concentrations (D(M)FS PF compared to placebo was 23% (95% credible interval (CrI) 19% to 27%) for 1000/1055/1100/1250 parts per million (ppm) concentrations rising to 36% (95% CrI 27% to 44%) for toothpastes with a concentration of 2400/2500/2800 ppm), but concentrations of 440/500/550 ppm and below showed no statistically significant effect when compared to placebo. There is some evidence of a dose response relationship in that the PF increased as the fluoride concentration increased from the baseline although this was not always statistically significant. The effect of fluoride toothpaste also increased with baseline level of D(M)FS and supervised brushing, though this did not reach statistical significance. Six studies assessed the effects of fluoride concentrations on the deciduous dentition with equivocal results dependent upon the fluoride concentrations compared and the outcome measure. Compliance with treatment regimen and unwanted effects was assessed in only a minority of studies. When reported, no differential compliance was observed and unwanted effects such as soft tissue damage and tooth staining were minimal. Authors' conclusions This review confirms the benefits of using fluoride toothpaste in preventing caries in children and adolescents when compared to placebo, but only significantly for fluoride concentrations of 1000 ppm and above. The relative caries preventive effects of fluoride toothpastes of different concentrations increase with higher fluoride concentration. The decision of what fluoride levels to use for children under 6 years should be balanced with the risk of fluorosis.

Graphene electrochemistry: an overview of potential applications

Abstract: Graphene, a 2D nanomaterial that possesses spectacular physical, chemical and thermal properties, has caused immense excitement amongst scientists since its freestanding form was isolated in 2004. With research into graphene rife, it promises enhancements and vast applicability within many industrial aspects. Furthermore, graphene possesses a vast array of unique and highly desirable electrochemical properties, and it is this application that offers the most enthralling and spectacular journey. We present a review of the current literature concerning the electrochemical applications and advancements of graphene, starting with its use as a sensor substrate through to applications in energy production and storage, depicting the truly remarkable journey of a material that has just come of age.

Young people's use of online social networking sites – a uses and gratifications perspective

Abstract: Purpose – The purpose of this paper is to explore why young people use and participate in social networking sites (SNSs) with specific reference to Bebo.Design/methodology/approach – A qualitative approach is employed in this paper with a view to exploring the uses and gratifications (U and G) that girls aged 12‐14 years, both seek and obtain from the Bebo SNS. The research is conducted in a school setting in Ireland.Findings – The findings indicate that the participants are actively using Bebo for their own personal motives and gratifications in terms of presenting and managing a certain identity and persona in a social context. Furthermore, the relatively impersonal nature of the online environment is seen to especially facilitate the young participants in negotiating the practicalities and difficulties that can arise offline, in terms of forging identities and managing relationships.Originality/value – U and G theory has attracted criticism in terms of a perceived limitation that it only serves to offe...

Depression and anxiety in chronic heart failure and chronic obstructive pulmonary disease: prevalence, relevance, clinical implications and management principles

Abstract: Objective To review evidence regarding the prevalence, causation, clinical implications, aspects of healthcare utilisation and management of depression and anxiety in chronic heart failure and chronic obstructive pulmonary disease. Design A critical review of the literature (1994–2009). Findings The prevalence of depression and anxiety is high in both chronic obstructive pulmonary disease (8–80% depression; 6–74% anxiety) and chronic heart failure (10–60% depression; 11–45% anxiety). However, methodological weaknesses and the use of a wide range of diagnostic tools make it difficult to reach a consensus on rates of prevalence. Co-morbid depression and anxiety are associated with increased mortality and healthcare utilisation and impact upon functional disability and quality of life. Despite these negative consequences, the identification and management of co-morbid depression and anxiety in these two diseases is inadequate. There is some evidence for the positive role of pulmonary/cardiac rehabilitation and psychotherapy in the management of co-morbid depression and anxiety, however, this is insufficient to guide recommendations. Conclusions The high prevalence and associated increase in morbidity and mortality justifies future research regarding the management of anxiety and depression in both chronic heart failure and chronic obstructive pulmonary disease. Current evidence suggests that multi-faceted interventions such as pulmonary and cardiac rehabilitation may offer the best hope for improving outcomes for depression and anxiety. Copyright © 2009 John Wiley & Sons, Ltd.

Changes in species richness and composition in European acidic grasslands over the past 70 years: the contribution of cumulative atmospheric nitrogen deposition

Abstract: Our study investigates the negative impact of nitrogen (N) deposition on species richness in acidic grasslands, based on a temporal comparison of vegetation data spanning a period of almost 70 years. We compiled a large data base of plots assigned to the Violion caninae grassland type, composed of managed, but unfertilized semi-natural grasslands on nutrient-poor, acidic soils. In total 1114 plots, mainly from Great Britain, the Netherlands and Germany, were compiled, dating back to 1939. Environmental site information included geographical and soil (mean Ellenberg values) variables as well as estimates of cumulative N and sulphur (S) deposition since 1939. Statistical analyses were carried out separately for the data subsets from the three regions. In all regions, the vegetation differentiation was mainly related to soil acidity and nutrient availability, as well as to the year of sampling and the cumulative amounts of N and S deposition. Plot-species richness of vascular plants and bryophytes (analysed for Great Britain only) decreased with time and analyses suggest these are affected by various factors, notably soil pH, but also latitude and cumulative N deposition. The latter explained more of the variation in species number than the year of sampling and cumulative S deposition, which supports the interpretation that the decline in species richness is mainly caused by increasing N availability and less by altered management and soil acidification. For Great Britain and Germany, cumulative N deposition showed a strong negative relationship with several biodiversity measures, especially the proportion of dicots, whereas it was positively related to the proportion of grass species. In general, our results give temporal evidence for the negative effect of N deposition on species richness in semi-natural vegetation.

Effect of ultrasonic processing on food enzymes of industrial importance

Abstract: In the last decade power ultrasound has emerged as an alternative processing option to conventional thermal approaches for pasteurisation and sterilisation of food products. While sonication alone may not be adequate for inactivation of various spoilage and harmful enzymes present in food, ultrasound in combination with mild heat treatment and/or pressure has shown potential for both enzyme and pathogen inactivation. Numerous studies have investigated ultrasound for inactivating enzymes such as pectinmethylesterase, polyphenoloxidases and peroxidases responsible for deterioration of fruit & vegetable juice and various enzymes pertinent to milk quality. The efficacy of ultrasound for the inactivation of enzymes in food is outlined in this review along with a description of the inactivation mechanism to elucidate the effect of ultrasound on important enzymes in fruit juices and dairy products.

Environmental correlates of tree biomass, basal area, wood specific gravity and stem density gradients in Borneo's tropical forests

Abstract: Aim Tropical forests have been recognized as important global carbon sinks and sources. However, many uncertainties about the spatial distribution of live tree above-ground biomass (AGB) remain, mostly due to limited availability of AGB field data. Recent studies in the Amazon have already shown the importance of large sample size for accurate AGB gradient analysis. Here we use a large stem density,basal area,community wood density and AGB dataset to study and explain their spatial patterns in an Asian tropical forest.

The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?

Abstract: An inverse relationship exists between striated muscle fiber size and its oxidative capacity. This relationship implies that muscle fibers, which are triggered to simultaneously increase their mass/strength (hypertrophy) and fatigue resistance (oxidative capacity), increase these properties (strength or fatigue resistance) to a lesser extent compared to fibers increasing either of these alone. Muscle fiber size and oxidative capacity are determined by the balance between myofibrillar protein synthesis, mitochondrial biosynthesis and degradation. New experimental data and an inventory of critical stimuli and state of activation of the signaling pathways involved in regulating contractile and metabolic protein turnover reveal: (1) higher capacity for protein synthesis in high compared to low oxidative fibers; (2) competition between signaling pathways for synthesis of myofibrillar proteins and proteins associated with oxidative metabolism; i.e., increased mitochondrial biogenesis via AMP-activated protein kinase attenuates the rate of protein synthesis; (3) relatively higher expression levels of E3-ligases and proteasome-mediated protein degradation in high oxidative fibers. These observations could explain the fiber type-fiber size paradox that despite the high capacity for protein synthesis in high oxidative fibers, these fibers remain relatively small. However, it remains challenging to understand the mechanisms by which contractile activity, mechanical loading, cellular energy status and cellular oxygen tension affect regulation of fiber size. Therefore, one needs to know the relative contribution of the signaling pathways to protein turnover in high and low oxidative fibers. The outcome and ideas presented are relevant to optimizing treatment and training in the fields of sports, cardiology, oncology, pulmonology and rehabilitation medicine.

Flying into the Future: Aviation Emissions Scenarios to 2050

Abstract: This study describes the methodology and results for calculating future global aviation emissions of carbon dioxide and oxides of nitrogen from air traffic under four of the IPCC/SRES (Intergovernmental Panel on Climate Change/Special Report on Emissions Scenarios) marker scenarios: A1B, A2, B1, and B2. In addition, a mitigation scenario has been calculated for the B1 scenario, requiring rapid and significant technology development and transition. A global model of aircraft movements and emissions (FAST) was used to calculate fuel use and emissions to 2050 with a further outlook to 2100. The aviation emission scenarios presented are designed to interpret the SRES and have been developed to aid in the quantification of the climate change impacts of aviation. Demand projections are made for each scenario, determined by SRES economic growth factors and the SRES storylines. Technology trends are examined in detail and developed for each scenario providing plausible projections for fuel efficiency and emissions control technology appropriate to the individual SRES storylines. The technology trends that are applied are calculated from bottom-up inventory calculations and industry technology trends and targets. Future emissions of carbon dioxide are projected to grow between 2000 and 2050 by a factor in the range of 2.0 and 3.6 depending on the scenario. Emissions of oxides of nitrogen associated with aviation over the same period are projected to grow by between a factor of 1.2 and 2.7.

The offence of theory

Abstract: Theory frequently offends. The paper argues that this is its strength: the value of theory lies in its power to get in the way. Theory is needed to block the reproduction of banality, and thereby, hopefully, open new possibilities for thinking and doing. However, I also note that theory has become somewhat disengaged from its objects, diminishing its power of productive interference. I argue for ‘exemplary’ practices, in which theory proliferates from examples. Caught in the minutiae of the example, yet also open to unexpected connections, theory might develop more productive ways of offending. Or to put it differently, of producing wonder.

Anticipating fatness: childhood, affect and the pre‐emptive ‘war on obesity’

Abstract: This paper draws together recent geographical work on fatness, pre-emptive biopolitics, affect and childhood in order to question the spatiotemporalities of obesity policy in the UK. Through analysis of key policy documents and associated media coverage, the paper questions the dystopian production of the future nation in obesity policy; the role of affect in making futures felt as realities which can be acted on in the present; and the role of childhood and children's bodies within such policy. It argues that children are central to the production and pre-emption of obese futures because of the affective potential of childhood and the paradoxical position of children's bodies both as children in the present and adults of the future. The paper concludes by arguing that obesogenic environment theories are fundamentally problematic and that recognition of the temporalities as well as the spatialities of obesity is necessary for a balanced critical geography.

The role of systemic inflammation in age-related muscle weakness and wasting

Abstract: Ageing is associated with a slow, but progressive muscle weakness, which is largely attributable to muscle wasting. A diminished function of satellite cells at old age may hamper preservation and repair from (contraction)-induced injury and contribute to the age-related muscle wasting. Satellite cell function may be affected by circulating factors, as muscle regeneration in old mice sharing the circulation of young mice is not impaired. Chronic low-grade systemic inflammation in old organisms may be that environmental factor. Indeed, the inflammatory cytokine tumor necrosis factor-alpha (TNFalpha) negatively affects the muscle regenerating capacity. TNFalpha destabilizes MyoD, a muscle-specific transcription factor involved in satellite cell proliferation and differentiation, and induces apoptosis of satellite cells, particularly at old age. Here it is proposed that some of these effects are mediated by TNFalpha-induced expression of inhibitors of differentiation proteins. Yet, the increase in TNFalpha during the normal inflammatory response helps, rather than impairs, the repair process. This apparent contradiction may be resolved by the fact that the effects of TNFalpha are concentration and time dependent. Thus, the negative effect of systemic inflammation on muscle strength at old age may only become apparent when it exceeds a certain threshold and persists for a prolonged period.

In vivo measurements of muscle specific tension in adults and children

Abstract: To better understand the effects of pubertal maturation on the contractile properties of skeletal muscle in vivo, the present study investigated whether there are any differences in the specific tension of the quadriceps muscle in 20 adults and 20 prepubertal children of both sexes. Specific tension was calculated as the ratio between the quadriceps tendon force and the sum of the physiological cross-sectional area (PCSA) multiplied by the cosine of the angle of pennation of each head within the quadriceps muscle. The maximal quadriceps tendon force was calculated from the knee extension maximal voluntary contraction (MVC) by accounting for EMG-based estimates of antagonist co-activation, incomplete quadriceps activation using the interpolation twitch technique and magnetic resonance imaging (MRI)-based measurements of the patellar tendon moment arm. The PCSA was calculated as the muscle volume, measured from MRI scans, divided by optimal fascicle length, measured from ultrasound images during MVC at the estimated angle of peak quadriceps muscle force. It was found that the quadriceps tendon force and PCSA of men (11.4 kN, 214 cm2) were significantly greater than those of the women (8.7 kN, 152 cm2; P 0.05) between groups: men, 55 ± 11 N cm−2; women, 57.3 ± 13 N cm−2; boys, 54 ± 14 N cm−2; and girls, 59.8 ± 15 N cm−2. These findings indicate that the increased muscle strength with maturation is not due to an increase in the specific tension of muscle; instead, it can be attributed to increases in muscle size, moment arm length and voluntary activation level.

The long‐term benefits of cardiac rehabilitation on depression, anxiety, physical activity and quality of life

Abstract: Aims. To investigate the long-term benefits of a six-week comprehensive cardiac rehabilitation programme on physical activity, psychological well-being and quality of life in patients with coronary heart disease. Background. Cardiac rehabilitation (CR) in short term improves exercise capacity and quality of life in patients with cardiac disease. However, the long-term benefits of CR are inconclusive. Design. A prospective CR programme with repeated measures follow-up over 12 months. Methods. A six-week outpatient cardiac rehabilitation programme was conducted including 147 patients with coronary heart disease. Patients completed the physical activity energy expenditure (seven-day recall activity), MacNew Heart Disease Health-Related Quality of Life (MacNew) and Hospital Anxiety and Depression scale (HADs) at baseline, six weeks, six and 12 months. Results. One hundred and five (71%) patients (76 male) mean age of 61·8 (SD 9·7) completed the four-measurement points. Analysis of variance revealed that total energy expenditure (F (2, 231) = 131, p < 0·001), HADs (F (2, 237) = 19·3, p < 0·001), depression score (F (2, 235) = 21·06, p < 0·001), anxiety score (F (2,237) = 17·02, p < 0·001) and MacNew (F (2, 197) = 77·02, p < 0·001) were all statistically significant over time. Bonferroni pairwise follow-up confirmed significant positive differences (p < 0·05) between baseline values and all subsequent measures over time. Depression was independently explained in 22% of the variance in quality of life at 6 or 12 months. The energy expenditure was significantly higher for men compared to women (F (1, 103) = 31, p < 0·001). Conclusion. A six-week cardiac rehabilitation programme is beneficial in improving quality of life, physical activity status, anxiety and depression. These benefits were maintained at 12 months. Elevated levels of depression were associated with impaired quality of life. Relevance to clinical practice. All relevant health care staff should be aware of the benefits of CR and routinely refer and encourage patients with cardiac disease to attend a cardiac rehabilitation programme. Depression and anxiety intervention strategies should be incorporated in cardiac rehabilitation programmes.

Comparison of the tribological and antimicrobial properties of CrN/Ag, ZrN/Ag, TiN/Ag, and TiN/Cu nanocomposite coatings

Abstract: Nanocomposite coatings including CrN/Ag, ZrN/Ag, TiN/Ag and TiN/Cu with varying silver or copper contents were produced by co-deposition in a dual pulsed magnetron sputtering system. The compositions and structures of the coatings were characterised using energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), and the physical and tribological properties were assessed by means of nanoindentation and thrust washer wear testing. Although increasing silver or copper content provided a reduction in the coefficient of friction, this was accompanied by reductions in hardness for all the coatings and wear resistance for some of the coatings. Zones of inhibition were used to determine the extent of silver ion release from the coating surfaces, and a NBT (nitro-blue tetrazolium) redox dye was used to determine the antimicrobial effectiveness of the coatings following incubation. The microorganisms tested were Pseudomonas aeruginosa and Staphylococcus aureus. For the NBT assays, significant reductions in the number of viable cells were observed with increasing Ag or Cu content, compared to the ‘pure’ nitride surfaces. Whilst no zones of inhibition were observed for S. aureus, on any of the surfaces, the diameter of the ‘kill’ zones generally increased with increasing silver content for P. aeruginosa.

Fast fashion in the retail store environment

Abstract: Purpose – The paper aims to establish how fast fashion is translated and communicated in the retail store environment.Design/methodology/approach – An interpretive paradigm and inductive methodology made use of participant observation and key informant interviews.Findings – Whilst efficiencies in the supply chain have facilitated fast fashion's success, centralised control structures have meant that these efficiencies and flexibilities have not been translated into the retail store environment. Marketing communications activity is evident in relation to aspects of fast fashion, for example, through the use of “hero pieces” as identified in this research, however, availability and retail presence must support the fast fashion proposition.Research limitations/implications – The paper has a UK focus where fast fashion is well established, therefore generalisations relating to other fashion markets may not be appropriate.Practical implications – Retailers may have interest in the findings to gain competitive ...