880 resultados para Peripheral Aberrations


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Background: Falls are a major health and injury problem for people with Parkinson disease (PD). Despite the severe consequences of falls, a major unresolved issue is the identification of factors that predict the risk of falls in individual patients with PD. The primary aim of this study was to prospectively determine an optimal combination of functional and disease-specific tests to predict falls in individuals with PD. ----- ----- Methods: A total of 101 people with early-stage PD undertook a battery of neurologic and functional tests in their optimally medicated state. The tests included Tinetti, Berg, Timed Up and Go, Functional Reach, and the Physiological Profile Assessment of Falls Risk; the latter assessment includes physiologic tests of visual function, proprioception, strength, cutaneous sensitivity, reaction time, and postural sway. Falls were recorded prospectively over 6 months. ----- ----- Results: Forty-eight percent of participants reported a fall and 24% more than 1 fall. In the multivariate model, a combination of the Unified Parkinson's Disease Rating Scale (UPDRS) total score, total freezing of gait score, occurrence of symptomatic postural orthostasis, Tinetti total score, and extent of postural sway in the anterior-posterior direction produced the best sensitivity (78%) and specificity (84%) for predicting falls. From the UPDRS items, only the rapid alternating task category was an independent predictor of falls. Reduced peripheral sensation and knee extension strength in fallers contributed to increased postural instability. ----- ----- Conclusions: Falls are a significant problem in optimally medicated early-stage PD. A combination of both disease-specific and balance- and mobility-related measures can accurately predict falls in individuals with PD.

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Historically, 'Creativity' has had a complex set of meanings. Not long ago, 'Creativity' had a kind of marginal or peripheral status, being seen as the province of a gifted few; in many cases it was associated almost exclusively with the arts and with artists. But these traditional attitudes to creativity are changing. Mainstream businesses are employing people with creative skills as diverse as writing, directing, graphic design and event management. So what we’re beginning to see is an innovation framework and creative content adding value not just to SMEs, but to traditional industries such as manufacturing and mining, and to wider service industries. And this is why Education is such an important element, particularly with a focus on innovation, and on creative people and the contributions they make across different parts of the economy.

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From 19 authoritative lists with 164 entries of ‘endangered’ Australian mammal species, 39 species have been reported as extinct. When examined in the light of field conditions, the 18 of these species thought to be from Queensland consist of (a) species described from fragmentary museum material collected in the earliest days of exploration, (b) populations inferred to exist in Queensland by extrapolation from distribution records in neighbouring States or countries, (c) inhabitants of remote and harsh locations where search effort is extraordinarily difficult (especially in circumstances of drought or flooding). and/or (d) individuals that are clearly transitory or peripheral in distribution. ‘Rediscovery’ of such scarce species - a not infrequent occurrence - is nowadays attracting increasing attention. Management in respect of any scarce wildlife in Queensland presently derives from such official lists. The analyses here indicate that this method of prioritizing action needs review. This is especially so because action then tends to be centred on species chosen out of the lists for populist reasons and that mostly addresses Crown lands. There is reason to believe that the preferred management may lie private lands where casual observation has provided for rediscovery and where management is most desirable and practicable.

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Chlamydia trachomatis is an obligate intracellular bacterial pathogen that infects the genital and ocular mucosa of humans, causing infections that can lead to pelvic inflammatory disease, infertility, and blinding trachoma. C. pneumoniae is a respiratory pathogen that is the cause of 12–15% of community-acquired pneumonia. Both chlamydial species were believed to be restricted to the epithelia of the genital, ocular, and respiratory mucosa; however, increasing evidence suggests that both these pathogens can be isolated from peripheral blood of both healthy individuals and patients with inflammatory conditions such as coronary artery disease and asthma. Chlamydia can also be isolated from brain tissues of patients with degenerative neurological disorders such as Alzheimer’s disease and multiple sclerosis, and also from certain lymphomas. An increasing number of in vitro studies suggest that some chlamydial species can infect immune cells, at least at low levels. These infections may alter immune cell function in a way that promotes chlamydial persistence in the host and contributes to the progression of several chronic inflammatory diseases. In this paper, we review the evidence for the growth of Chlamydia in immune cells, particularly monocytes/macrophages and dendritic cells, and describe how infection may affect the function of these cells.

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β-Adrenoceptor blocking agents (β-blockers) that at low concentrations antagonize cardiostimulant effects of catecholamines, but at high concentrations also cause cardiostimulation, have been appearing since the late 1960s. These cardiostimulant β-blockers, coined non-conventional partial agonists, antagonize the effects of catecholamines through a high-affinity site (β1HAR), but cause cardiostimulation mainly through a low-affinity site (β1LAR) of the myocardial β1-adrenoceptor. The experimental non-conventional partial agonist (−)-CGP12177 increases cardiac L-type Ca2+ current density and Ca2+ transients, shortens action potential duration but augments action potential plateau, increases heart rate and force, as well as causes arrhythmic Ca2+ transients and arrhythmic cardiocyte contractions. Other β-blockers, which do not cause cardiostimulation, consistently have lower affinity for β1LAR than β1HAR. These sites were verified and the cardiac pharmacology of non-conventional partial agonists confirmed on recombinant β1-adrenoceptors and on β1-adrenoceptors overexpressed into the heart. A targeted mutation of Asp138 to Glu138 virtually abolished the pharmacology of β1HAR but left intact the pharmacology of β1LAR. Non-conventional partial agonists may be beneficial for the treatment of peripheral autonomic neuropathy but probably due to their arrhythmic propensities, may be harmful for the treatment of chronic heart failure.

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Azobenzenes (1,2-diaryldiazenes) are very important organic pigments, and they have a unique place in the field of photoresponsive conjugated molecules due to their (usually) reversible E/Z photoisomerisation. The current intense interest in molecular analogues of mechanical components and information storage and processing elements has stimulated research into conjugated molecules whose shape and/or optical properties can be switched electro- or photochemically. Among the classes of conjugated pigments being explored in these contexts are the porphyrinoids, which offer advantages of intense light absorption, a variety of accessible oxidation states, and synthetic control of properties through peripheral or central substitution. Extension of porphyrinoid conjugation can be achieved by linking the peripheral carbons either by three direct bonds (as in the “porphyrin tapes” of Osuka et al.) or through potentially conjugating bridges such as alkenes or, even better, alkynes.

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After bone fracture, various cellular activities lead to the formation of different tissue types, which form the basis for the process of secondary bone healing. Although these tissues have been quantified by histology, their material properties are not well understood. Thus, the aim of this study is to correlate the spatial and temporal variations in the mineral content and the nanoindentation modulus of the callus formed via intramembranous ossification over the course of bone healing. Midshaft tibial samples from a sheep osteotomy model at time points of 2, 3, 6 and 9 weeks were employed. PMMA embedded blocks were used for quantitative back scattered electron imaging and nanoindentation of the newly formed periosteal callus near the cortex. The resulting indentation modulus maps show the heterogeneity in the modulus in the selected regions of the callus. The indentation modulus of the embedded callus is about 6 GPa at the early stage. At later stages of mineralization, the average indentation modulus reaches 14 GPa. There is a slight decrease in average indentation modulus in regions distant to the cortex, probably due to remodelling of the peripheral callus. The spatial and temporal distribution of mineral content in the callus tissue also illustrates the ongoing remodelling process observed from histological analysis. Most interestingly the average indentation modulus, even at 9 weeks, remains as low as 13 GPa, which is roughly 60% of that for cortical sheep bone. The decreased indentation modulus in the callus compared to cortex is due to the lower average mineral content and may be perhaps also due to the properties of the organic matrix which might be different from normal bone.

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Obestatin is a 23 amino acid, ghrelin gene-derived peptide hormone produced in the stomach and a range of other tissues throughout the body. While it was initially reported that obestatin opposed the actions of ghrelin with regards to appetite and food intake, it is now clear that obestatin is not an endogenous ghrelin antagonist of ghrelin, but it is a multi-functional peptide hormone in its own right. In this review we will discuss the controversies associated with the discovery of obestatin and explore emerging central and peripheral roles of obestatin, roles in adipogenesis, pancreatic homeostasis and cancer.

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It is known that the depth of focus (DOF) of the human eye can be affected by the higher order aberrations. We estimated the optimal combinations of primary and secondary Zernike spherical aberration to expand the DOF and evaluated their efficiency in real eyes using an adaptive optics system. The ratio between increased DOF and loss of visual acuity was used as the performance indicator. The results indicate that primary or secondary spherical aberration alone shows similar effectiveness in extending the DOF. However, combinations of primary and secondary spherical aberration with different signs provide better efficiency for expanding the DOF. This finding suggests that the optimal combinations of primary and secondary spherical aberration may be useful in the design of optical presbyopic corrections. © 2011 Elsevier Ltd. All rights reserved.

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Introduction The ability to screen blood of early stage operable breast cancer patients for circulating tumour cells is of potential importance for identifying patients at risk of developing distant relapse. We present the results of a study of the efficacy of the immunobead RT-PCR method in identifying patients with circulating tumour cells. Results Immunomagnetic enrichment of circulating tumour cells followed by RT-PCR (immunobead RT-PCR) with a panel of five epithelial specific markers (ELF3, EPHB4, EGFR, MGB1 and TACSTD1) was used to screen for circulating tumour cells in the peripheral blood of 56 breast cancer patients. Twenty patients were positive for two or more RT-PCR markers, including seven patients who were node negative by conventional techniques. Significant increases in the frequency of marker positivity was seen in lymph node positive patients, in patients with high grade tumours and in patients with lymphovascular invasion. A strong trend towards improved disease free survival was seen for marker negative patients although it did not reach significance (p = 0.08). Conclusion Multi-marker immunobead RT-PCR analysis of peripheral blood is a robust assay that is capable of detecting circulating tumour cells in early stage breast cancer patients.

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An inverse association exists between some bacterial infections and the prevalence of asthma. We investigated whether Streptococcus pneumoniae infection protects against asthma using mouse models of ovalbumin (OVA)-induced allergic airway disease (AAD). Mice were intratracheally infected or treated with killed S. pneumoniae before, during or after OVA sensitisation and subsequent challenge. The effects of S. pneumoniae on AAD were assessed. Infection or treatment with killed S. pneumoniae suppressed hallmark features of AAD, including antigen-specific T-helper cell (Th) type 2 cytokine and antibody responses, peripheral and pulmonary eosinophil accumulation, goblet cell hyperplasia, and airway hyperresponsiveness. The effect of infection on the development of specific features of AAD depended on the timing of infection relative to allergic sensitisation and challenge. Infection induced significant increases in regulatory T-cell (Treg) numbers in lymph nodes, which correlated with the degree of suppression of AAD. Tregs reduced T-cell proliferation and Th2 cytokine release. The suppressive effects of infection were reversed by anti-CD25 treatment. Respiratory infection or treatment with S. pneumoniae attenuates allergic immune responses and suppresses AAD. These effects may be mediated by S. pneumoniae-induced Tregs. This identifies the potential for the development of therapeutic agents for asthma from S. pneumoniae.

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Background Techniques for detecting circulating tumor cells in the peripheral blood of patients with head and neck cancers may identify individuals likely to benefit from early systemic treatment. Methods Reconstruction experiments were used to optimise immunomagnetic enrichment and RT-PCR detection of circulating tumor cells using four markers (ELF3, CK19, EGFR and EphB4). This method was then tested in a pilot study using samples from 16 patients with advanced head and neck carcinomas. Results Seven patients were positive for circulating tumour cells both prior to and after surgery, 4 patients were positive prior to but not after surgery, 3 patients were positive after but not prior to surgery and 2 patients were negative. Two patients tested positive for circulating cells but there was no other evidence of tumor spread. Given this patient cohort had mostly advanced disease, as expected the detection of circulating tumour cells was not associated with significant differences in overall or disease free survival. Conclusion For the first time, we show that almost all patients with advanced head and neck cancers have circulating cells at the time of surgery. The clinical application of techniques for detection of spreading disease, such as the immunomagnetic enrichment RT-PCR analysis used in this study, should be explored further.

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Issues of equity and inequity have always been part of employment relations and are a fundamental part of the industrial landscape. For example, in most countries in the nineteenth century and a large part of the twentieth century women and members of ethnic groups (often a minority in the workforce) were barred from certain occupations, industries or work locations, and received less pay than the dominant male ethnic group for the same work. In recent decades attention has been focused on issues of equity between groups, predominantly women and different ethnic groups in the workforce. This has been embodied in industrial legislation, for example in equal pay for women and men, and frequently in specific equity legislation. In this way a whole new area of law and associated workplace practice has developed in many countries. Historically, employment relations and industrial relations research has not examined employment issues disaggregated by gender or ethnic group. Born out of concern with conflict and regulation at the workplace, studies tended to concentrate on white, male, unionized workers in manufacturing and heavy industry (Ackers, 2002, p. 4). The influential systems model crafted by Dunlop (1958) gave rise to The discipline’s preoccupation with the ‘problem of order’ [which] ensures the invisibility of women, not only because women have generally been less successful in mobilizing around their own needs and discontents, but more profoundly because this approach identifies the employment relationship as the ultimate source of power and conflict at work (Forrest, 1993, p. 410). While ‘the system approach does not deliberately exclude gender . . . by reproducing a very narrow research approach and understanding of issues of relevance for the research, gender is in general excluded or looked on as something of peripheral interest’ (Hansen, 2002, p. 198). However, long-lived patterns of gender segregation in occupations and industries, together with discriminatory access to work and social views about women and ethnic groups in the paid workforce, mean that the employment experience of women and ethnic groups is frequently quite different to that of men in the dominant ethnic group. Since the 1980s, research into women and employment has figured in the employment relations literature, but it is often relegated to a separate category in specific articles or book chapters, with women implicitly or explicitly seen as the atypical or exceptional worker (Hansen, 2002; Wajcman, 2000). The same conclusion can be reached for other groups with different labour force patterns and employment outcomes. This chapter proposes that awareness of equity issues is central to employment relations. Like industrial relations legislation and approaches, each country will have a unique set of equity policies and legislation, reflecting their history and culture. Yet while most books on employment and industrial relations deal with issues of equity in a separate chapter (most commonly on equity for women or more recently on ‘diversity’), the reality in the workplace is that all types of legislation and policies which impact on the wages and working conditions interact, and their impact cannot be disentangled one from another. When discussing equity in workplaces in the twenty-first century we are now faced with a plethora of different terms in English. Terms used include discrimination, equity, equal opportunity, affirmative action and diversity with all its variants (workplace diversity, managing diversity, and so on). There is a lack of agreed definitions, particularly when the terms are used outside of a legislative context. This ‘shifting linguistic terrain’ (Kennedy-Dubourdieu, 2006b, p. 3) varies from country to country and changes over time even within the one country. There is frequently a division made between equity and its related concepts and the range of expressions using the term ‘diversity’ (Wilson and Iles, 1999; Thomas and Ely, 1996). These present dilemmas for practitioners and researchers due to the amount and range of ideas prevalent – and the breadth of issues that are covered when we say ‘equity and diversity in employment’. To add to these dilemmas, the literature on equity and diversity has become bifurcated: the literature on workplace diversity/management diversity appears largely in the business literature while that on equity in employment appears frequently in legal and industrial relations journals. Workplaces of the twenty-first century differ from those of the nineteenth and twentieth century not only in the way they deal with individual and group differences but also in the way they interpret what are fair and equitable outcomes for different individuals and groups. These variations are the result of a range of social conditions, legislation and workplace constraints that have influenced the development of employment equity and the management of diversity. Attempts to achieve employment equity have primarily been dealt with through legislative means, and in the last fifty years this legislation has included elements of anti-discrimination, affirmative action, and equal employment opportunity in virtually all OECD countries (Mor Barak, 2005, pp. 17–52). Established on human rights and social justice principles, this legislation is based on the premise that systemic discrimination has and/or continues to exist in the labour force and particular groups of citizens have less advantageous employment outcomes. It is based on group identity, and employment equity programmes in general apply across all workplaces and are mandatory. The more recent notions of diversity in the workplace are based on ideas coming principally from the USA in the 1980s which have spread widely in the Western world since the 1990s. Broadly speaking, diversity ideas focus on individual differences either on their own or in concert with the idea of group differences. The diversity literature is based on a business case: that is diversity is profitable in a variety of ways for business, and generally lacks a social justice or human rights justification (Burgess et al., 2009, pp. 81–2). Managing diversity is represented at the organizational level as a voluntary and local programme. This chapter discusses some major models and theories for equity and diversity. It begins by charting the history of ideas about equity in employment and then briefly discusses what is meant by equality and equity. The chapter then analyses the major debates about the ways in which equity can be achieved. The more recent ideas about diversity are then discussed, including the history of these ideas and the principles which guide this concept. The following section discusses both major frameworks of equity and diversity. The chapter then raises some ways in which insights from the equity and diversity literature can inform employment relations. Finally, the future of equity and diversity ideas is discussed.

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This is a deliberately contentious paper about the future of the socio-political sphere in the West based on what we know about its past. I argue that the predominant public discourse in Western countries is best characterised as one of selective forgetfulness; a semi-blissful, amnesiacal state of collective dementia that manifests itself in symbolic idealism: informationalism. Informationalism is merely the latest form of idealism. It is a lot like religion insofar as it causally relates abstract concepts with reality and, consequently, becomes confused between the two. Historically, this has proven to be a dangerous state of affairs, especially when elites becomes confused between ideas about how a society should work, and the way it actually does work. Central to the idealism of the information age, at least in intellectual spheres, is the so called "problem of the subject". I argue that the "problem of the subject" is a largely synthetic, destabilising, and ultimately fruitless theoretical abstraction which turns on a synthetically derived, generalised intradiscursive space; existentialist nihilism; and the theoretical baubles of ontological metaphysics. These philosophical aberrations are, in turn, historically concomitant with especially destructive political and social configurations. This paper sketches a theoretical framework for identity formation which rejects the problem of the subject, and proposes potential resources, sources, and strategies with which to engage the idealism that underpins this obfuscating problematic in an age of turbulent social uncertainty. Quite simply, I turn to history as the source of human identity. While informationalism, like religion, is mostly focused on utopian futures, I assert that history, not the future, holds the solutions for substantive problematics concerning individual and social identities. I argue here that history, language, thought, and identity are indissolubly entangled and so should be understood as such: they are the fundamental parts of 'identities in action'. From this perspective, the ‘problem of the subject’ becomes less a substantive intellectual problematic and more a theoretical red herring.

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Purpose: To compare self-reported driving difficulty by persons with hemianopic or quadrantanopic field loss with that reported by age-matched drivers with normal visual fields; and to examine how their self- reported driving difficulty compares to ratings of driving performance provided by a certified driving rehabilitation specialist(CDRS). Method: Participants were 17 persons with hemianopic field loss, 7 with quadrantanopic loss, and 24 age-matched controls with normal visual fields, all of whom had current drivers’ licenses. Information was collected via questionnaire regarding driving difficulties experienced in 21 typical driving situations grouped into 3 categories(involvement of peripheral vision, low visibility conditions, and independent mobility). On-road driving performance was evaluated by a CDRS using a standard assessment scale. Results: Drivers with hemianopic and quadrantanopic field loss expressed significantly more difficulty with driving maneuvers involving peripheral vision and independent mobility, compared to those with normal visual fields. Drivers with hemianopia and quadrantanopia who were rated as unsafe to drive based upon an on-road assessment by the CDRS were no more likely to report driving difficulty than those rated as safe. Conclusion: This study highlights aspects of driving that hemianopic or quadrantanopic persons find particularly problematic, thus suggesting areas that could be focused on driving rehabilitation. Some drivers with hemianopia or quadrantanopia may inappropriately view themselves as good drivers when in fact their driving performance is unsafe as judged by a driving professional.