23,129 research outputs found

    Assessing performance of artificial neural networks and re-sampling techniques for healthcare datasets.

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    Re-sampling methods to solve class imbalance problems have shown to improve classification accuracy by mitigating the bias introduced by differences in class size. However, it is possible that a model which uses a specific re-sampling technique prior to Artificial neural networks (ANN) training may not be suitable for aid in classifying varied datasets from the healthcare industry. Five healthcare-related datasets were used across three re-sampling conditions: under-sampling, over-sampling and combi-sampling. Within each condition, different algorithmic approaches were applied to the dataset and the results were statistically analysed for a significant difference in ANN performance. The combi-sampling condition showed that four out of the five datasets did not show significant consistency for the optimal re-sampling technique between the f1-score and Area Under the Receiver Operating Characteristic Curve performance evaluation methods. Contrarily, the over-sampling and under-sampling condition showed all five datasets put forward the same optimal algorithmic approach across performance evaluation methods. Furthermore, the optimal combi-sampling technique (under-, over-sampling and convergence point), were found to be consistent across evaluation measures in only two of the five datasets. This study exemplifies how discrete ANN performances on datasets from the same industry can occur in two ways: how the same re-sampling technique can generate varying ANN performance on different datasets, and how different re-sampling techniques can generate varying ANN performance on the same dataset

    What is the importance of sperm subpopulations?

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    .The study of sperm subpopulations spans three decades. The origin, meaning, and practical significance, however, are less clear. Current technology for assessing sperm morphology (CASA-Morph) and motility (CASA-Mot) has enabled the accurate evaluation of these features, and there are many options for data classification. Subpopulations could occur as a result of the stage of development of each spermatozoon in the subpopulation. Spermatogenesis might contribute to the production of these subpopulations. Insights from evolutionary biology and recent molecular research are indicative of the diversity among male gametes that could occur from unequal sharing of transcripts and other elements through cytoplasmic bridges between spermatids. Sperm cohorts exiting the gonads would contain different RNA and protein contents, affecting the spermatozoon physiology and associations with the surrounding environmental milieu. Subsequently, these differences could affect how spermatozoa interact with the environmental milieu (maturation, mixing with seminal plasma, and interacting with the environmental milieu, or female genital tract and female gamete). The emergence of sperm subpopulations as an outcome of evolution, related to the reproductive strategies of the species, genital tract structures, and copulatory and fertilization processes. This kind of approach in determining the importance of sperm subpopulations in fertilization capacity should have a practical impact for conducting reproductive technologies, inspiring and enabling new ways for the more efficient use of spermatozoa in the medical, animal breeding, and conservation fields. This manuscript is a contribution to the Special Issue in memory of Dr. Duane GarnerS

    Strung pieces: on the aesthetics of television fiction series

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    As layered and long works, television fiction series have aesthetic properties that are built over time, bit by bit. This thesis develops a group of concepts that enable the study of these properties, It argues that a series is made of strung pieces, a system of related elements. The text begins by considering this sequential form within the fields of film and television. This opening chapter defines the object and methodology of research, arguing for a non-essentialist distinction between cinema and television and against the adequacy of textual and contextual analyses as approaches to the aesthetics of these shows. It proposes instead that these programmes should be described as televisual works that can be scrutinised through aesthetic analysis. The next chapters propose a sequence of interrelated concepts. The second chapter contends that series are composed of building blocks that can be either units into which series are divided or motifs that unify series and are dispersed across their pans. These blocks are patterned according to four kinds of relations or principles of composition. Repetition and variation are treated in tandem in the third chapter because of their close connection, given that variation emerges from established repetition. Exception and progression are also discussed together in the fourth chapter since they both require a long view of these serial works. The former, in order to be recognised as a deviation from the patterns of repetition and variation. The latter, In order to be understood in Its many dimensions as the series advances. Each of these concepts is further detailed with additional distinctions between types of units, motifs, repetitions, variations, and exceptions, using illustrative examples from numerous shows. In contrast, the section on progression uses a single series as case study, Carnivàle (2003-05), because this is the overarching principle that encompasses all the others. The conclusion considers the findings of the research and suggests avenues for their application

    Studies of strategic performance management for classical organizations theory & practice

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    Nowadays, the activities of "Performance Management" have spread very broadly in actually every part of business and management. There are numerous practitioners and researchers from very different disciplines, who are involved in exploring the different contents of performance management. In this thesis, some relevant historic developments in performance management are first reviewed. This includes various theories and frameworks of performance management. Then several management science techniques are developed for assessing performance management, including new methods in Data Envelopment Analysis (DEA) and Soft System Methodology (SSM). A theoretical framework for performance management and its practical procedures (five phases) are developed for "classic" organizations using soft system thinking, and the relationship with the existing theories are explored. Eventually these results are applied in three case studies to verify our theoretical development. One of the main contributions of this work is to point out, and to systematically explore the basic idea that the effective forms and structures of performance management for an organization are likely to depend greatly on the organizational configuration, in order to coordinate well with other management activities in the organization, which has seemingly been neglected in the existing literature of performance management research in the sense that there exists little known research that associated particular forms of performance management with the explicit assumptions of organizational configuration. By applying SSM, this thesis logically derives some main functional blocks of performance management in 'classic' organizations and clarifies the relationships between performance management and other management activities. Furthermore, it develops some new tools and procedures, which can hierarchically decompose organizational strategies and produce a practical model of specific implementation steps for "classic" organizations. Our approach integrates popular types of performance management models. Last but not least, this thesis presents findings from three major cases, which are quite different organizations in terms of management styles, ownership, and operating environment, to illustrate the fliexbility of the developed theoretical framework

    Power in the health service : The effects of reorganisation on professions and bureaucracies

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    The National Health Service (NHS) has been analysed predominantly in terms dictated by a systems/functional model of organisational behaviour. Decision-making processes which did not comply with this model were regarded as pathological or dysfunctional. This study takes a different stance and looks at District Health Authorities (DHAs) to see if the NHS can be better understood by accepting Lukes' conception of a "third dimension of power". The study is not focussed around conflicts of interest because the third dimension of power involves situations in which "real" interests may remain unknown. Power may prevent conflicts becoming apparent and interests becoming realised. Because, however, Lukes had suggested that interests may become realised during periods of change, the study focusses on the restructuring which began with reorganisation of the NHS in 1982. The parts played by medical professionals, administrative staff, nursing staff, and lay-members on DHAs are examined and demonstrate the extent to which their activities were influenced by one another and by their external political environment, notably the Conservative government. The mechanisms of power used during the period 1982-1985 when new management structures were established and then replaced by a further reorganisation of management are examined. This shows the extent to which these new management changes became accepted as legitimate and how the legitimation process began with the 1982 reorganisation. Lukes' third dimension of power is confirmed as too restrictive a conception and that power is more subtle than even he had proposed. Nor is it always repressive or manipulative

    Patterns of subspecies diversity in the giraffe, Giraffa camelopardalis (L. 1758): comparison of systematic methods and their implications for conservation policy

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    This thesis examines the subspecific taxonomic status of the giraffe and considers the role of formal taxonomy in the formulation of conservation policy. Where species show consistent. geographically structured phenotypic variation such geographic patterns may indicate selective forces (or other population-level effects) acting. upon local populations. These consistent geographic patterns may be recognised formally as subspecies and may be of interest in single or multi-species biodiversity or biogeography studies for delimiting areas of conservation priority. Subspecies may also be used in the formulation of management policies and legislation. Subspecies are, by definition, allopatric. This thesis explicitly uses methodology of systematic biology and phylogenetic reconstruction to investigate patterns of variation between geographic groups. The taxonomic status of the giraffe is apposite for review. The species provides three independent data sets that may be analysed quantitatively for geographic structure; pelage patterns, morphology and genetics. Museum specimens. grouped according to geographic origin, were favoured for study as more than one type of data was often available for an individual. Population aggregation analysis of forty pelage pattern characters maintained six separate subspecies, while agglomerating some neighbouring populations into a subspecies. A 'traditional' morphometric approach, using multivariate statistical analysis of adult skull measurements, was complemented by a geometric morphometric approach; landmarkrestricted eigenshape analysis. Four morphologically distinct groups were recognised by both morphological analyses. Phylogenetic analysis of mitochondrial DNA control region sequences indicates five major cIades. Nested cIade analysis identifies population fragmentation, range expansion and genetic isolation by distance as contributing to the genetic structure of the giraffe. The results of the analyses show remarkable congruence. These results are discussed in terms of the formulation of conservation policy and the differing requirements of'blological and legal classification systems. The value of a formal taxonomic framework to the recognition, and subsequent conservation, of biodiversity is emphasised

    Making Sense of Ayahuasca Non-Sense: A critical study of UK groups consuming a psychoactive plant mixture and their struggle to find religious meaning

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    How we make sense of ourselves, and the cosmos is an ongoing concern, guided by the people we meet, environments we exist within, and plants we consume. Having spent over a year observing forty-nine participants within three UK-based ayahuasca churches, it is clear that the psychoactive 'brew' ayahuasca creates intense changes to how individuals think about themselves and the world they live in. At the heart of the ayahuasca experience are non-sensical hallucinations and visions, which often exist outside of perceptual understanding, leaving individuals feeling lost in an unknowable universe. As we will come to see, making sense of non-sensical ayahuasca experiences requires individuals to negotiate multiple 'common-sense' views of reality. Taking a view that mind is something that happens within life, this ethnographic study uses participant observation, interviews, conversations, personal diaries, and my experiences as an ayahuasca tourist to detail how making sense of reality is also an act of making oneself. In so doing, I argue that ayahuasca hallucinations and visions function as a source of ongoing mental innovation, facilitating preferred views of reality throughout these psychoactive churches. Critically, we will see how frequent ayahuasca consumption engenders in-depth beliefs in the supernatural, and in particular, devotion to the goddess Ayahuasca, who functions as the unchallengeable road to knowing oneself and reality. Acting as an otherworldly guide, the immaterial goddess Ayahuasca plays a key part in how individuals convert non-sensical experiences into sense, while providing practical advice for how to achieve salvation. Problematically though, positioning the universe and oneself as predominantly supernatural tends to erode beliefs in the physical world, leaving these churches with incoherent views of reality, and at the periphery of everyday social life. As such, church doctrines seem increasingly unable to cope with life outside of their groups, and thus, tactically stigmatise competing views of reality as sinful and individuals espousing such heresies as under the control of malevolent demonic beings. Not surprisingly, this binary belief in a good and evil cosmos is a powerful regulatory force dictating what reality is within these churches, and who church members can claim to be

    The application of Evidence-Based Medicine methodologies in sports science: problems and solutions

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    This thesis analyses the use of 'Evidence-Based' methodologies of evidence assessment and intervention and policy design from medicine, and their use in sport and exercise science. It argues that problems exist with the application of Evidence-Based methodologies in sports science, meaning that the quality of evidence used to inform decision-making is lower than is often assumed. This thesis also offers realistic solutions to these problems, broadly arguing for the importance of taking evidence from mechanistic studies seriously, in addition to evidence from RCTs

    Constructing Cassandra: The social construction of strategic surprise at the Central Intelligence Agency 1947-2001

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    This dissertation takes a post-positivist approach to strategic surprise, and examines the identity and internal culture of the US Central Intelligence Agency (CIA) through the lens of social constructivism. It identifies numerous social mechanisms that created and maintained four key, persistent attributes of the CIA’s identity and culture between 1947 and 2001. These features are: 1) homogeneity of personnel; 2) scientism and the reification of a narrow form of ‘reason’; 3) an overwhelming preference for ‘secrets’ over openly-available information; and, 4) a relentless drive for consensus. It then documents the influence of these elements of the CIA’s identity and culture in each phase of the intelligence cycle (Tasking, Collection, Analysis, Production and Dissemination), prior to four strategic surprises: the Cuban Missile Crisis, the Iranian Islamic Revolution of 1979, the collapse of the USSR, and al-Qa’ida’s terrorist attacks on September 11th, 2001. It concludes that these key aspects of the CIA’s identity and culture created the antecedent conditions that allowed these four strategic surprises to occur, and thus prevented the CIA from fulfilling its mandate to ‘prevent another Pearl Harbor’. This conclusion is supported by contrasting the majority views at the CIA prior to these events with the views of ‘Cassandras’ (i.e. individuals inside or outside the Agency who anticipated the approximate course of events based on reasoned threat assessments that differed sharply from the Agency’s, but who were ignored or sidelined). In so doing, this work shifts the burden of proof for explaining strategic surprises back to the characteristics and actions of intelligence producers like the CIA, and away from errors by intelligence consumers like politicians and policymakers. This conclusion also allows this work to posit that understanding strategic surprise as a social construction is logically prior to previously proposed, entirely positivist, attempts to explain or to prevent it
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