1,475 research outputs found

    Causes of decline of common scoter (Melanitta nigra) in north Scotland: evidence from palaeolimnology

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    The common scoter (Melanitta nigra) is a UK priority species that has experienced severe declines in breeding numbers over the last 30 years. The Flow Country in north Scotland is an internationally important wetland, where the decline of iconic species, such as the common scoter, is particularly concerning. This thesis takes a unique approach to investigating the causes of waterbird decline by combining detailed contemporary ecological data with geospatial modelling and palaeolimnological reconstructions. Detailed surveys were undertaken to characterise the current physical, chemical and biological conditions within 18 Flow Country lochs. These data were used for exploratory analyses and as explanatory variables in a general linear model that examined the predictors of common scoter loch value (SLV). Statistically significant predictors of SLV proved to be dissolved organic carbon, water depth and sediment type. The landscape scale features associated with common scoter distribution in the Flow Country were explored using a species distribution modelling (Maxent) approach. Influential landscape features were found to be proportion of surrounding forestry close to a loch, the soil moisture and bedrock geology. Two theories for common scoter decline were developed using these contemporary data sources; (i) the competitive balance between brown trout and common scoter has altered in recent decades, resulting in less food, (ii) the physico-chemistry of lochs has been altered by afforestation adversely affecting physical loch structure and/or invertebrate food supply. Theories for decline were explored using two palaeolimnological approaches. Multi-proxy top-bottom analysis of cores from 18 lochs demonstrated that these are dynamic environments which have undergone substantial change over the last 150-200 years. Multi-proxy analysis of high temporal resolution cores from four lochs indicated that the study sites have gradually become more productive over the last 150 years, with a distinct shift towards more meso-oligotrophic conditions since the 1980s. These data strongly support the theory that forestry has affected the lochs of the Flow Country, probably due to drainage and fertiliser application resulting in the lochs becoming less oligotrophic. The associated shifts in community composition could have resulted in the lochs being less profitable or suitable for common scoter who typically breed at low nutrient, oligotrophic site

    Combined palaeolimnological and ecological approach provides added value for understanding the character and drivers of recent environmental change in Flow Country lakes

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    The Flow Country peatlands receive national and international recognition and protection as a highly valued habitat, and also provide a number of important ecosystem services. While there has been much research on the terrestrial peatland habitat of the Flow Country, the area’s many hundreds of natural water bodies have been largely unstudied. The first part of this study therefore focuses on establishing the contemporary conditions at 18 Flow Country lakes, examining between-lake heterogeneity in terms of physical structure, water chemistry and biological communities. Temporal change in these lakes is then considered by combining contemporary ecological and palaeolimnological approaches. We examine how the diatom and chironomid communities of Flow Country lakes have changed since a time prior to the mid-nineteenth century. Results show that the lake communities today are different to those present pre-1850, containing more taxa tolerant of increased acidity and nutrient availability. General linear modelling (GLM) analysis demonstrated a statistically significant association between the extent of change in diatom communities and both dissolved organic carbon (DOC) and nitrate. Community shifts, though considerable, are shown to be complex and idiosyncratic and no shift between trophic states is indicated. The extent and type of coarse-scale community change we observed points to widespread bottom-up drivers such as land management, afforestation and/or atmospheric deposition rather than more localised management practices such as fish stocking. The benefits of combining approaches is discussed and palaeolimnological methods by which land management, afforestation and atmospheric deposition could be further disentangled are identified

    A qualitative exploration of the effect of visual field loss on daily life in home-dwelling stroke survivors

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    Objective: To explore the effect of visual field loss on the daily life of community-dwelling stroke survivors. Design: A qualitative interview study. Participants: Adult stroke survivors with visual field loss of at least six months’ duration. Methods: Semi-structured interviews were conducted with a non-purposive sample of 12 stroke survivors in their own homes. These were recorded, transcribed verbatim and analyzed with the framework method, using an inductive approach. Results: Two key analytical themes emerged. ‘Perception, experience and knowledge’ describes participant’s conflicted experience of having knowledge of their impaired vision but lacking perception of that visual field loss and operating under the assumption that they were viewing an intact visual scene when engaged in activities. Inability to recognize and deal with visual difficulties, and experiencing the consequences, contributed to their fear and loss of self-confidence. ‘Avoidance and adaptation’ were two typologies of participant response to visual field loss. Initially, all participants consciously avoided activities. Some later adapted to vision loss using self-directed head and eye scanning techniques. Conclusions: Visual field loss has a marked impact on stroke survivors. Stroke survivors lack perception of their visual loss in everyday life, resulting in fear and loss of confidence. Activity avoidance is a common response, but in some, it is replaced by self-initiated adaptive techniques

    Employing with conviction: The experiences of employers who actively recruit criminalised people

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    Atherton, P., & Buck, G. Employing with conviction: The experiences of employers who actively recruit criminalised people. Probation Journal, 68(2), pp. 186-205. Copyright © [2021] (Copyright Holder). Reprinted by permission of SAGE Publications.In England and Wales, criminal reoffending costs £18 billion annually. Securing employment can support desistance from crime, but only 17% of ex-prisoners are employed a year after release. Understanding the motivations of employers who do recruit criminalised people therefore represents an important area of inquiry. This article draws upon qualitative interviews with twelve business leaders in England who proactively employ criminalised people. Findings reveal that inclusive recruitment can be (indirectly) encouraged by planning policies aimed to improve social and environmental well-being and that employers often work creatively to meet employees’ additional needs, resulting in commercial benefits and (re)settlement opportunities

    Selection at a single locus leads to widespread expansion of toxoplasma gondii lineages that are virulent in mice

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    The determinants of virulence are rarely defined for eukaryotic parasites such as T. gondii, a widespread parasite of mammals that also infects humans, sometimes with serious consequences. Recent laboratory studies have established that variation in a single secreted protein, a serine/threonine kinase known as ROPO18, controls whether or not mice survive infection. Here, we establish the extent and nature of variation in ROP18among a collection of parasite strains from geographically diverse regions. Compared to other genes, ROP18 showed extremely high levels of diversification and changes in expression level, which correlated with severity of infection in mice. Comparison with an out-group demonstrated that changes in the upstream region that regulates expression of ROP18 led to an historical increase in the expression and exposed the protein to diversifying selective pressure. Surprisingly, only three atypically distinct protein variants exist despite marked genetic divergence elsewhere in the genome. These three forms of ROP18 are likely adaptations for different niches in nature, and they confer markedly different virulence to mice. The widespread distribution of a single mouse-virulent allele among geographically and genetically disparate parasites may have consequences for transmission and disease in other hosts, including humans

    Observations of professional-patient relationships: A mixed-methods study exploring whether familiarity is a condition for nurses' provision of psychosocial support

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    Background: There is a popular belief that the professional–patient relationship is a prerequisite in the provision of psychosocial support. Studies suggest that professionals must know, or be familiar with, a patient in order to effectively provide psychosocial support. Aim: To examine the association between familiarity and the provision of psychosocial care by professionals. Design: A mixed-methods study involving participant observation, interviews and organisational and documentary analysis was conducted over 8 months in an inpatient hospice setting. Participants: In total, 38 nurses (registered and auxiliary) and 47 patients were included in a maximum variation sampling strategy. Data were analysed using both qualitative and quantitative techniques. Results: The data disconfirm the belief that familiarity is either a necessary or sufficient condition for the provision of psychosocial support. Nurses familiar with patients did not necessarily respond to patients’ psychosocial needs, and nurses with no prior contact with the patient immediately dealt with psychosocial needs. Conclusion: Psychosocial support can be provided on a patient’s first contact with a clinician and does not rely on building a professional–patient relationship. This suggests that high-quality psychosocial care can be provided in the short time frame available to palliative care clinicians

    Exploring earned value management in the Spanish construction industry as a pathway to competitive advantage

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    [EN] As a well established discipline and profession, project management has its distinctive tools and techniques. One of them that has been considered the embodiment of the core principles of project management is the Earned Value Management (EVM). In managing construction projects, the EVM has been considered as a suitable tool and hence, has been implemented in various construction industry but absent in some others. Taking into account the dynamic environment where construction companies have to operate, particularly in turbulence environments as the direct result of recent global economic downturn, this paper explores the potential implementation of EVM in one of the construction industry, the Spanish construction industry. The outcomes confirm the needs for and feasibility of implementing EVM as a structured approach in the industry to reposition the Spanish construction industry with the long term view to increase its project management maturity level as a pathway to gaining competitive advantage.Universitat Politecnica de Valencia [grant number 19701344]Sutrisna, M.; Pellicer, E.; Torres-Machí, C.; Picornell, M. (2018). Exploring earned value management in the Spanish construction industry as a pathway to competitive advantage. International Journal of Construction Management. 20(1):1-12. https://doi.org/10.1080/15623599.2018.1459155S112201Anbari, F. T. (2004). Earned value project management method and extensions. IEEE Engineering Management Review, 32(3), 97-97. doi:10.1109/emr.2004.25113Aram, J. D., & Walochik, K. (1996). Improvisation and the Spanish Manager. International Studies of Management & Organization, 26(4), 73-89. doi:10.1080/00208825.1996.11656695Brandon, D. M. (1998). Implementing Earned Value Easily and Effectively. Project Management Journal, 29(2), 11-18. doi:10.1177/875697289802900204Brown, A., & Adams, J. (2000). Measuring the effect of project management on construction outputs: a new approach. International Journal of Project Management, 18(5), 327-335. doi:10.1016/s0263-7863(99)00026-5Bryde, D. J. (2003). Modelling project management performance. International Journal of Quality & Reliability Management, 20(2), 229-254. doi:10.1108/02656710310456635Chen, H. L., Chen, W. T., & Lin, Y. L. (2016). Earned value project management: Improving the predictive power of planned value. International Journal of Project Management, 34(1), 22-29. doi:10.1016/j.ijproman.2015.09.008De la Cruz, M. P., del Caño, A., & de la Cruz, E. (2006). Downside Risks in Construction Projects Developed by the Civil Service: The Case of Spain. Journal of Construction Engineering and Management, 132(8), 844-852. doi:10.1061/(asce)0733-9364(2006)132:8(844)Din, S., Abd-Hamid, Z., & Bryde, D. J. (2011). ISO 9000 certification and construction project performance: The Malaysian experience. International Journal of Project Management, 29(8), 1044-1056. doi:10.1016/j.ijproman.2010.11.001Eldin, N. N. (1989). Measurement of Work Progress: Quantitative Technique. Journal of Construction Engineering and Management, 115(3), 462-474. doi:10.1061/(asce)0733-9364(1989)115:3(462)Gidado, K. I. (1996). Project complexity: The focal point of construction production planning. Construction Management and Economics, 14(3), 213-225. doi:10.1080/014461996373476Hastak, M., Halpin, D. W., & Vanegas, J. (1996). COMPASS—New Paradigm for Project Cost Control Strategy and Planning. Journal of Construction Engineering and Management, 122(3), 254-264. doi:10.1061/(asce)0733-9364(1996)122:3(254)D. Holt, G., & S. Goulding, J. (2014). Conceptualisation of ambiguous-mixed-methods within building and construction research. Journal of Engineering, Design and Technology, 12(2), 244-262. doi:10.1108/jedt-02-2013-0020Ibbs, C. W., & Kwak, Y. H. (2000). Assessing Project Management Maturity. Project Management Journal, 31(1), 32-43. doi:10.1177/875697280003100106Jugdev, K., & Thomas, J. (2002). 2002 Student Paper Award Winner: Project Management Maturity Models: The Silver Bullets of Competitive Advantage? Project Management Journal, 33(4), 4-14. doi:10.1177/875697280203300402Kim, E., Wells, W. G., & Duffey, M. R. (2003). A model for effective implementation of Earned Value Management methodology. International Journal of Project Management, 21(5), 375-382. doi:10.1016/s0263-7863(02)00049-2Kim, T., Kim, Y.-W., & Cho, H. (2016). Customer Earned Value: Performance Indicator from Flow and Value Generation View. 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Construction Management and Economics, 24(12), 1225-1229. doi:10.1080/01446190600999097Onwuegbuzie, A. J., & Leech, N. L. (2005). Taking the «Q» Out of Research: Teaching Research Methodology Courses Without the Divide Between Quantitative and Qualitative Paradigms. Quality & Quantity, 39(3), 267-295. doi:10.1007/s11135-004-1670-0Oviedo-Haito, R. J., Jiménez, J., Cardoso, F. F., & Pellicer, E. (2014). Survival Factors for Subcontractors in Economic Downturns. Journal of Construction Engineering and Management, 140(3), 04013056. doi:10.1061/(asce)co.1943-7862.0000811Pellicer, E., Sanz, M. A., Esmaeili, B., & Molenaar, K. R. (2016). Exploration of Team Integration in Spanish Multifamily Residential Building Construction. Journal of Management in Engineering, 32(5), 05016012. doi:10.1061/(asce)me.1943-5479.0000438Potts, K., & Ankrah, N. (2008). Construction Cost Management. doi:10.4324/9780203933015Vanhoucke, M. (2012). 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    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse
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