737 resultados para SHIFT WORK
Resumo:
In June 2011 a large phytoplankton bloom resulted in a catastrophic mortality event that affected a large coastal embayment in the Solomon Islands. This consisted of an area in excess of 20 km2 of reef and soft sandy habitats in Marovo Lagoon, the largest double barrier lagoon in the world. This embayment is home to over 1200 people leading largely subsistence lifestyles depending on the impacted reefs for majority of their protein needs. A toxic diatom (Psuedo-nitzchia spp.) and toxic dinoflagellate (Pyrodinium bahamense var. compressum) reached concentrations of millions of cells per litre. The senescent phytoplankton bloom led to complete de-oxygenation of the water column that reportedly caused substantial mortality of marine animal life in the immediate area within a rapid timeframe (24 h). Groups affected included holothurians, crabs and reef and pelagic fish species. Dolphins, reptiles and birds were also found dead within the area, indicating algal toxin accumulation in the food chain. Deep reefs and sediments, whilst initially unaffected, have now been blanketed in large cyanobacterial mats which have negatively impacted live coral cover especially within the deep reef zone (> 6 m depth). Reef recovery within the deep zone has been extremely slow and may indicate an alternative state for the system.
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PURPOSE To investigate changes in the characteristics of the corneal optics, total optics, anterior biometrics and axial length of the eye during a near task, in downward gaze, over 10 min. METHODS Ten emmetropes (mean - 0.14 ± 0.24 DS) and 10 myopes (mean - 2.26 ± 1.42 DS) aged from 18 to 30 years were recruited. To measure ocular biometrics and corneal topography in downward gaze, an optical biometer (Lenstar LS900) and a rotating Scheimpflug camera (Pentacam HR) were inclined on a custom built, height and tilt adjustable table. The total optics of the eye were measured in downward gaze with binocular fixation using a modified Shack-Hartmann wavefront sensor. Initially, subjects performed a distance viewing task at primary gaze for 10 min to provide a "wash-out" period for prior visual tasks. A distance task (watching video at 6 m) in downward gaze (25°) and a near task (watching video on a portable LCD screen with 2.5 D accommodation demand) in primary gaze and 25°downward gaze were then carried out, each for 10 min in a randomized order. During measurements, in dichoptic view, a Maltese cross was fixated with the right (untested) eye and the instrument’s fixation target was fixated with the subject’s tested left eye. Immediately after (0 min), 5 and 10 min from the commencement of each trial, measurements of ocular parameters were acquired in downward gaze. RESULTS Axial length exhibited a significant increase with downward gaze and accommodation over time (p<0.05). The greatest axial elongation was observed in downward gaze with 2.5 D accommodation after 10 min (mean change from baseline 23±3 µm). Downward gaze also caused greater changes in anterior chamber depth (ACD) and lens thickness (LT) with accommodation (ACD mean change -163±12µm at 10 min; LT mean change 173±17 µm at 10 min) compared to primary gaze with accommodation (ACD mean change -138±12µm at 10 min; LT mean change 131±15 µm at 10 min). Both corneal power and total ocular power changed by a small but significant amount with downward gaze (p<0.05), resulting in a myopic shift (~0.10 D) in the spherical power of the eye compared with primary gaze. CONCLUSION The axial length, anterior biometrics and ocular refraction change significantly with accommodation in downward gaze as a function of time. These findings provide new insights into the optical and bio-mechanical changes of the eye during typical near tasks.
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Australian labour law, at least from the mid-twentieth century, was dominated by the employment paradigm: the assumption that labour law’s scope was the regulation of employment relationships –full-time and part-time, and continuing, fixed term or casual – with a single (usually corporate) entity employer. But no sooner had the employment paradigm established and consolidated its shape, it began to fall apart. Since the 1980s there has been a significant growth of patterns of work that fall outside this paradigm, driven by organisational restructuring and management techniques such as labour hire, sub-contracting and franchising. Beyond Employment analyses the way in which Australian labour law is being reframed in this shift away from the pre-eminence of the employment paradigm. Its principal concern is with the legal construction and regulation of various forms of contracting, including labour hire arrangements, complex contractual chains and modern forms like franchising, and of casual employment. It outlines the current array of work relationships in Australia, and describes and analyses the way in which those outside continuous and fixed term employment are regulated. The book seeks to answer the central question: How does law (legal rules and principles) construct these work relationships, and how does it regulate these relationships? The book identifies the way in which current law draws the lines between the various work relationships through the use of contract and property ownership, and describes, analyses and synthesises the legal rules that govern these different forms of work relationships. The legal rules that govern work relationships are explored through the traditional lens of labour law’s protective function, principally in four themes: control of property, and the distribution of risks and rewards; maintenance of income security; access to collective voice mechanisms, focusing on collective bargaining; and health, safety and welfare. The book critically evaluates the gaps in the coverage and content of these rules and principles, and the implications of these gaps for workers. It also reflects upon the power relationships that underpin the work arrangements that are the focus of the book and that are enhanced through the laws of contract and property. Finally, it frames an agenda to address the gaps and identified weaknesses insofar as they affect the economic wellbeing, democratic voice, and health and safety of workers.
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Understandings of male sex workers (MSWs) shift with technological, conceptual, and social changes. Research has historically constructed MSWs as psychologically unstable, desperate, or destitute victims and their clients as socially deviant perverts. These perceptions, however, are no longer supported by contemporary research and changing societal perceptions of the sex industry, challenging how we understand and describe “escorts.” The changing understandings of sexuality and the increasing power of the Internet are both important forces behind recent changes in the structure and organization of MSWs. The growth in the visibility and reach of escorts has created opportunities to form an occupational account of MSWs that better accounts for the dynamic and diverse nature of the MSW experience in the early 21st century. Recent changes in the structure and organization of male sex work have provided visibility to the increasingly diverse geographical distribution of MSW, the commodification of race and racialized desire, new populations of heterosexual men and women as clients, and the successful dissemination of safer sexual messages to MSWs through online channels. This article provides a broad overview of the literature on MSWs, concentrating its focus on studies that have emerged over the past 20 years and identifying areas for future research.
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The mean shift tracker has achieved great success in visual object tracking due to its efficiency being nonparametric. However, it is still difficult for the tracker to handle scale changes of the object. In this paper, we associate a scale adaptive approach with the mean shift tracker. Firstly, the target in the current frame is located by the mean shift tracker. Then, a feature point matching procedure is employed to get the matched pairs of the feature point between target regions in the current frame and the previous frame. We employ FAST-9 corner detector and HOG descriptor for the feature matching. Finally, with the acquired matched pairs of the feature point, the affine transformation between target regions in the two frames is solved to obtain the current scale of the target. Experimental results show that the proposed tracker gives satisfying results when the scale of the target changes, with a good performance of efficiency.
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Photographic documentation of sculpture produces significant consequences for the way in which sculptural space is conceived. When viewed as discrete mediums the interaction of the photograph and its sculptural subject is always framed by notions of loss. However, when taken as a composite system, the sculpture-photograph proposes a new ontology of space. In place of the fixity of medium, we can observe a topology at play: a theory drawn from mathematics in which space is understood not as a static field but in terms of properties of connectedness, movement and differentiation. Refracted through the photographic medium, sculpture becomes not a field of fixed points in space, but rather as a fluid set of relations - a continuous sequence of multiple ‘surfaces’, a network of shifting views. This paper will develop a topological account of studio practice through an examination of the work of the contemporary Belgian sculptor Didier Vermeiren (b. 1951). Since the 1980s, Vermeiren has made extensive use of photography in his sculptural practice. By analysing a series of iterations of his work Cariatide à la Pierre (1997-1998), this paper proposes that Vermeiren’s use of photography reveals patterns of connection that expand and complicate the language of sculpture, while also emphasising the broader topology of the artist’s practice as a network of ‘backward glances’ to previous works from the artist’s oeuvre and the art-historical canon. In this context, photography is not simply a method of documentation, but rather a means of revealing the intrinsic condition of sculpture as medium shaped by dynamic patterns of connection and change. In Vermeiren’s work the sculpture-photograph, has a composite identity that exceeds straightforward categories of medium. In their place, we can observe a practice based upon the complex interactions of objects whose ontology is always underpinned by a certain contingency. It is in this fundamental mobility, that the topology of Vermeiren’s practice can be said to rest.
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Purpose The aim of this study was to explore how first-line nurse managers constructed the meaning of resilience and its relationship to work-life balance for nurses in Korea. Methods Participants were 20 first-line nurse managers working in six university hospitals. Data were collected through in-depth interviews from December 2011 to August 2012, and analyzed using Strauss and Corbin's grounded theory method. Results Analysis revealed that participants perceived work-life balance and resilience to be shaped by dynamic, reflective processes. The features consisting resilience included "positive thinking", "flexibility", "assuming responsibility", and "separating work and life". This perception of resilience has the potential to facilitate a shift in focus from negative to positive experiences, from rigidity to flexibility, from task-centered to person-centered thinking, and from the organization to life. Conclusions Recognizing the importance of work-life balance in producing and sustaining resilience in first-line nurse managers could increase retention in the Korean nursing workforce.
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In this work we discuss the development of a mathematical model to predict the shift in gas composition observed over time from a producing CSG (coal seam gas) well, and investigate the effect that physical properties of the coal seam have on gas production. A detailed (local) one-dimensional, two-scale mathematical model of a coal seam has been developed. The model describes the competitive adsorption and desorption of three gas species (CH4, CO2 and N2) within a microscopic, porous coal matrix structure. The (diffusive) flux of these gases between the coal matrices (microscale) and a cleat network (macroscale) is accounted for in the model. The cleat network is modelled as a one-dimensional, volume averaged, porous domain that extends radially from a central well. Diffusive and advective transport of the gases occurs within the cleat network, which also contains liquid water that can be advectively transported. The water and gas phases are assumed to be immiscible. The driving force for the advection in the gas and liquid phases is taken to be a pressure gradient with capillarity also accounted for. In addition, the relative permeabilities of the water and gas phases are considered as functions of the degree of water saturation.
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This paper explores the changing employment expectations that frame the early professional work experiences of young planners in Australia. In particular, it considers the rising popularity of pre-graduation professional work experience as a precursor to formal entry into the workforce as a practising planner. This shift is being driven in part by employer expectations that graduates will already have ‘real world’ and relevant work experience. However, an equally significant driver appears to be a growing desire for early career and graduate planners to find ways to distinguish themselves from their peers in an increasingly tight labour market. Using data from an ongoing research project into the formative work experiences of young people this paper describes the three main types of pre-graduation professional work experience undertaken by young planners. It highlights the potential challenges and benefits of pre-graduation work experience from a legal, social and ethical perspective as well as from the perspective of young planners themselves. The paper concludes by reflecting on the role of the planning profession – employers, peak bodies and planning educators – in managing the tensions between producing ‘work ready’ graduates and safeguarding the employment conditions of early career planning professionals.
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Objective: We aimed to assess the impact of task demands and individual characteristics on threat detection in baggage screeners. Background: Airport security staff work under time constraints to ensure optimal threat detection. Understanding the impact of individual characteristics and task demands on performance is vital to ensure accurate threat detection. Method: We examined threat detection in baggage screeners as a function of event rate (i.e., number of bags per minute) and time on task across 4 months. We measured performance in terms of the accuracy of detection of Fictitious Threat Items (FTIs) randomly superimposed on X-ray images of real passenger bags. Results: Analyses of the percentage of correct FTI identifications (hits) show that longer shifts with high baggage throughput result in worse threat detection. Importantly, these significant performance decrements emerge within the first 10 min of these busy screening shifts only. Conclusion: Longer shift lengths, especially when combined with high baggage throughput, increase the likelihood that threats go undetected. Application: Shorter shift rotations, although perhaps difficult to implement during busy screening periods, would ensure more consistently high vigilance in baggage screeners and, therefore, optimal threat detection and passenger safety.