584 research outputs found

    Field Work Reflections: Journeys in Knowing and Not-Knowing

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    In this paper, I retrace my interest in narrative forms of inquiry. I begin by revisiting a series of research projects that I conducted early in my career, describing some of my own dissatisfactions with the methods I used at the time. I move on to a detailed reexamination of my first piece of narrative research, completed during my PhD. In that project I used a narrative pointed psychosocial method in an attempt to develop new knowledge in the field of drugs, ‘race’ and ethnicity. In the final section, I consider what I have learned from this approach in terms of knowing and not-knowing and how I have used this experience to explore different approaches to narrative inquiry. I finish by drawing out some lessons I have learned from these different studies, which I hope might be of relevance to other social work researchers

    Anointed or appointed? Father–daughter succession within the family business

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    With the focus on events and outcomes shaping most of the existing family business research on intra-family succession, the subtleties of the incumbent-successor relationship and the dynamic nature of succession as a process of becoming is somewhat neglected. In particular, we have limited understanding of how successor identities are constructed as legitimate between incumbent and successor during father-daughter succession. This article addresses this gap in understanding by exploring how the daughter successor engages in identity work with the father incumbent during the process of succession and the role of father-daughter gendered relations in shaping her successor identity. Using a two-stage research design strategy, we draw upon empirical evidence derived from 14 individual and joint semi-structured interviews to present a narrative analysis of five father-daughter dyads. In so doing, we unveil how the daughter’s successor identity was co-constructed as legitimate and how father-daughter gendered relations influenced this process. Although daughters rely on certain father-daughter relations (preparation, endorsement and osmotic credibility) for legitimacy, they also need to develop independently from their father in order to heighten their own visibility and establish credibility

    Caracol, Belize, and Changing Perceptions of Ancient Maya Society

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    Predictive Virtual Patient Modelling of Mechanical Ventilation: Impact of Recruitment Function

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    Mechanical ventilation is a life-support therapy for intensive care patients suffering from respiratory failure. To reduce the current rate of ventilator-induced lung injury requires ventilator settings that are patient-, time-, and disease-specific. A common lung protective strategy is to optimise the level of positive end-expiratory pressure (PEEP) through a recruitment manoeuvre to prevent alveolar collapse at the end of expiration and to improve gas exchange through recruitment of additional alveoli. However, this process can subject parts of the lung to excessively high pressures or volumes. This research significantly extends and more robustly validates a previously developed pulmonary mechanics model to predict lung mechanics throughout recruitment manoeuvres. In particular, the process of recruitment is more thoroughly investigated and the impact of the inclusion of expiratory data when estimating peak inspiratory pressure is assessed. Data from the McREM trial and CURE pilot trial were used to test model predictive capability and assumptions. For PEEP changes of up to and including 14 cmH2O, the parabolic model was shown to improve peak inspiratory pressure prediction resulting in less than 10% absolute error in the CURE cohort and 16% in the McREM cohort. The parabolic model also better captured expiratory mechanics than the exponential model for both cohorts

    Physiological modeling, tight glycemic control, and the ICU clinician: what are models and how can they affect practice?

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    Critically ill patients are highly variable in their response to care and treatment. This variability and the search for improved outcomes have led to a significant increase in the use of protocolized care to reduce variability in care. However, protocolized care does not address the variability of outcome due to inter- and intra-patient variability, both in physiological state, and the response to disease and treatment. This lack of patient-specificity defines the opportunity for patient-specific approaches to diagnosis, care, and patient management, which are complementary to, and fit within, protocolized approaches

    Genesis and development of an interfluvial peatland in the central Congo Basin since the Late Pleistocene

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    The central Congo Basin contains the largest known peatland complex in the tropics. Here we present a detailed multi-proxy record from a peat core, CEN-17.4, from the centre of a 45 km wide interfluvial peatland (Ekolongouma), the first record of its kind from the central Congo peatlands. We use pollen, charcoal, sedimentological and geochemical data to reconstruct the site's history from the late Pleistocene to the present day. Peat began accumulating at the centre of the peatland ∼19,600 cal BP (∼17,500–20,400 cal BP, 95% confidence interval), and between ∼9500 (9430–9535 cal BP) and 10,500 (10,310–10,660 cal BP) cal BP towards the margins. Pollen data from the peatland centre show that an initial grass- and sedge-dominated vegetation, which burned frequently, was replaced by a Manilkara-type dominated flooded forest at ∼12,640 cal BP, replaced in turn by a more mixed swamp forest at ∼9670 cal BP. Mixed swamp forest vegetation has persisted to the present day, with variations in composition and canopy openness likely caused at least in part by changes in palaeo-precipitation. Stable isotope data (δDn-C29-v&icecorr) indicate a large reduction in precipitation beginning ∼5000 and peaking ∼2000 cal BP, associated with the near-complete mineralization of several metres of previously accumulated peat and with a transition to a drier, more heliophilic swamp forest assemblage, likely with a more open canopy. Although the peatland and associated vegetation recovered from this perturbation, the strong response to this climatic event underlines the ecosystem's sensitivity to changes in precipitation. We find no conclusive evidence for anthropogenic activity in our record; charcoal is abundant only in the Pleistocene part of the record and may reflect natural rather than anthropogenic fires. We conclude that autogenic succession and variation in the amount and seasonality of precipitation have been the most important drivers of ecological change in this peatland since the late Pleistocene

    Design and implementation of GRIP: a computerized glucose control system at a surgical intensive care unit

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    BACKGROUND: Tight glucose control by intensive insulin therapy has become a key part of critical care and is an important field of study in acute coronary care. A balance has to be found between frequency of measurements and the risk of hypoglycemia. Current nurse-driven protocols are paper-based and, therefore, rely on simple rules. For safety and efficiency a computer decision support system that employs complex logic may be superior to paper protocols. METHODS: We designed and implemented GRIP, a stand-alone Java computer program. Our implementation of GRIP will be released as free software. Blood glucose values measured by a point-of-care analyzer were automatically retrieved from the central laboratory database. Additional clinical information was asked from the nurse and the program subsequently advised a new insulin pump rate and glucose sampling interval. RESULTS: Implementation of the computer program was uneventful and successful. GRIP treated 179 patients for a total of 957 patient-days. Severe hypoglycemia (< 2.2 mmol/L) only occurred once due to human error. With a median (IQR) of 4.9 (4.2 – 6.2) glucose measurements per day the median percentage of time in which glucose fell in the target range was 78%. Nurses rated the program as easy to work with and as an improvement over the preceding paper protocol. They reported no increase in time spent on glucose control. CONCLUSION: A computer driven protocol is a safe and effective means of glucose control at a surgical ICU. Future improvements in the recommendation algorithm may further improve safety and efficiency

    Design principles for riboswitch function

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    Scientific and technological advances that enable the tuning of integrated regulatory components to match network and system requirements are critical to reliably control the function of biological systems. RNA provides a promising building block for the construction of tunable regulatory components based on its rich regulatory capacity and our current understanding of the sequence–function relationship. One prominent example of RNA-based regulatory components is riboswitches, genetic elements that mediate ligand control of gene expression through diverse regulatory mechanisms. While characterization of natural and synthetic riboswitches has revealed that riboswitch function can be modulated through sequence alteration, no quantitative frameworks exist to investigate or guide riboswitch tuning. Here, we combined mathematical modeling and experimental approaches to investigate the relationship between riboswitch function and performance. Model results demonstrated that the competition between reversible and irreversible rate constants dictates performance for different regulatory mechanisms. We also found that practical system restrictions, such as an upper limit on ligand concentration, can significantly alter the requirements for riboswitch performance, necessitating alternative tuning strategies. Previous experimental data for natural and synthetic riboswitches as well as experiments conducted in this work support model predictions. From our results, we developed a set of general design principles for synthetic riboswitches. Our results also provide a foundation from which to investigate how natural riboswitches are tuned to meet systems-level regulatory demands

    Mining multi-item drug adverse effect associations in spontaneous reporting systems

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    <p>Abstract</p> <p>Background</p> <p>Multi-item adverse drug event (ADE) associations are associations relating multiple drugs to possibly multiple adverse events. The current standard in pharmacovigilance is bivariate association analysis, where each single drug-adverse effect combination is studied separately. The importance and difficulty in the detection of multi-item ADE associations was noted in several prominent pharmacovigilance studies. In this paper we examine the application of a well established data mining method known as association rule mining, which we tailored to the above problem, and demonstrate its value. The method was applied to the FDAs spontaneous adverse event reporting system (AERS) with minimal restrictions and expectations on its output, an experiment that has not been previously done on the scale and generality proposed in this work.</p> <p>Results</p> <p>Based on a set of 162,744 reports of suspected ADEs reported to AERS and published in the year 2008, our method identified 1167 multi-item ADE associations. A taxonomy that characterizes the associations was developed based on a representative sample. A significant number (67% of the total) of potential multi-item ADE associations identified were characterized and clinically validated by a domain expert as previously recognized ADE associations. Several potentially novel ADEs were also identified. A smaller proportion (4%) of associations were characterized and validated as known drug-drug interactions.</p> <p>Conclusions</p> <p>Our findings demonstrate that multi-item ADEs are present and can be extracted from the FDA’s adverse effect reporting system using our methodology, suggesting that our method is a valid approach for the initial identification of multi-item ADEs. The study also revealed several limitations and challenges that can be attributed to both the method and quality of data.</p

    Subtidal macrozoobenthos communities from northern Chile during and post El Niño 1997–1998

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    Despite a large amount of climatic and oceanographic information dealing with the recurring climate phenomenon El Niño (EN) and its well known impact on diversity of marine benthic communities, most published data are rather descriptive and consequently our understanding of the underlying mechanisms and processes that drive community structure during EN are still very scarce. In this study, we address two questions on the effects of EN on macrozoobenthic communities: (1) how does EN affect species diversity of the communities in northern Chile? and (2) is EN a phenomenon that restarts community assembling processes by affecting species interactions in northern Chile? To answer these questions, we compared species diversity and co-occurrence patterns of soft-bottoms macrozoobenthos communities from the continental shelf off northern Chile during (March 1998) and after (September 1998) the strong EN event 1997–1998. The methods used varied from species diversity and species co-occurrence analyses to multivariate ordination methods. Our results indicate that EN positively affects diversity of macrozoobenthos communities in the study area, increasing the species richness and diversity and decreasing the species dominance. EN represents a strong disturbance that affects species interactions that rule the species assembling processes in shallow-water, sea-bottom environments
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