241 research outputs found

    Possible Sources of Bias in Primary Care Electronic Health Record Data Use and Reuse

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    Background - Enormous amounts of data are recorded routinely in health care as part of the care process, primarily for managing individual patient care. There are significant opportunities to use this data for other purposes, many of which would contribute to establishing a learning health system. This is particularly true for data recorded in primary care settings, as in many countries, these are the first place patients turn to for most health problems. Objective - In this paper, we discuss whether data that is recorded routinely as part of the health care process in primary care is actually fit to use for these other purposes, how the original purpose may affect the extent to which the data is fit for another purpose and the mechanisms behind these effects. In doing so, we want to identify possible sources of bias that are relevant for the (re-)use of this type of data. Methods –This discussion paper is based on the authors’ experience as users of electronic health records data, as a general practitioner, health informatics experts, and health services researchers. It is a product of the discussions they had during the TRANSFoRm project, which was funded by the EU and sought to develop, pilot and evaluate a core information architecture for the Learning Health System (LHS) in Europe, based on primary care electronic health records. Results – We first describe the different stages in the processing of EHR data, as well as the different purposes for which this data is used. Given the different data processing steps and purposes, we then discuss the possible mechanisms for each individual data processing step, that can generate biased outcomes. We identified thirteen possible sources of bias. Four of them are related to the organization of a health care system, some are of a more technical nature. Conclusions - There are a substantial number of possible sources of bias, and very little is known about the size and direction of their impact. However, any (re-)user of data that was recorded as part of the health care process (such as researchers and clinicians) should be aware of the associated data collection process and environmental influences that can affect the quality of the data. Our stepwise, actor and purpose oriented approach may help to identify these possible sources of bias. Unless data quality issues are better understood and unless adequate controls are embedded throughout the data lifecycle, data-driven healthcare will not live up to its expectations. We need a data quality research agenda to devise the appropriate instruments needed to assess the magnitude of each of the possible sources of bias, and then start measuring their impact. The possible sources of bias described in this paper serve as a starting point for this research agenda

    Association between Loin Ultimate pH and Plasma Indicators of Pre-Slaughter Stressors in Australian Lamb

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    The purpose of this study was to test if associations exist between plasma indicators of acute and chronic stress and lamb ultimate pH. Blood was collected at exsanguination from 2,877 lambs from the Meat and Livestock Australia Genetic Research flock with a suite of indicators analyzed. Ultimate pH was measured in the loin (M. longissimus lumborum) at 24 h post-slaughter. There was a positive association (

    Effects of different ageing methods on colour, yield, oxidation and sensory qualities of Australian beef loins consumed in Australia and Japan

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    This study investigated the effect of three ageing methods (dry, wet and stepwise wet-then-dry) and ageing time on pH, colour, yield, lipid and protein oxidation and eating quality of beef loins using Meat Standards Australia (MSA) sensory protocol with 900 and 540 consumers in Australia and Japan, respectively. Australian beef loins (Longissimus thoracis et lumborum) at four days post mortem were subjected to wet ageing (boneless; for 7, 21, 35 or 56 days), dry ageing (bone-in; for 35 or 56 days) or a wet-then-dry ageing method (bone-in; 21 days wet ageing followed by 35 days dry ageing). The pH was higher in dry aged than wet aged beef loins (P < .001). Instrumental measurement of surface colour of trimmed dry and wet aged steaks showed significant differences in a*, b* and hue angle. Weight loss was higher in dry aged primals (P < .001), however, total water content was similar among the two ageing methods (P = .934). Retail yield did not differ between 35 and 56 days dry aged primals. Lipid (TBARS) and protein (total carbonyl content) oxidation between the dry and wet aged samples differed depending on the ageing time. When comparing the wet-then-dry and 56 days dry aged samples, only pH and retail yield differed. Australian and Japanese consumers rated dry aged steaks significantly higher (P < .001) than the wet aged counterparts for tenderness, juiciness, flavour, overall liking and weighted palatability scores. The wet-then-dry steaks were also rated higher than the 56 days wet aged steaks for flavour, overall liking and palatability within the Japanese sensory panels. The Japanese consumers also consistently rated all MSA sensory attributes lower (P < .001) than the Australian consumers. The results from this study show dry ageing provides a value adding opportunity for the meat industry in both domestic and export markets

    The contribution of the Unresolved Extragalactic Radio Sources to the Brightness Temperature of the sky

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    The contribution of the Unresolved Extragalactic Radio Sources to the diffuse brightness of the sky was evaluated using the source number - flux measurements available in literature. We first optimized the fitting function of the data based on number counts distribution. We then computed the brightness temperature at various frequencies from 151 MHz to 8440 MHz and derived its spectral dependence. As expected the frequency dependence can be described by a power law with a spectral index γ≃−2.7\gamma \simeq -2.7, in agreement with the flux emitted by the {\it steep spectrum} sources. The contribution of {\it flat spectrum} sources becomes relevant at frequencies above several GHz. Using the data available in literature we improved our knowledge of the brightness of the unresolved extragalactic radio sources. The results obtained have general validity and they can be used to disentangle the various contributions of the sky brightness and to evaluate the CMB temperature.Comment: Accepted for publication in the Astrophysical Journa

    Radio Frequency Spectra of 388 Bright 74 MHz Sources

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    As a service to the community, we have compiled radio frequency spectra from the literature for all sources within the VLA Low Frequency Sky Survey (VLSS) that are brighter than 15 Jy at 74 MHz. Over 160 references were used to maximize the amount of spectral data used in the compilation of the spectra, while also taking care to determine the corrections needed to put the flux densities from all reference on the same absolute flux density scale. With the new VLSS data, we are able to vastly improve upon previous efforts to compile spectra of bright radio sources to frequencies below 100 MHz because (1) the VLSS flux densities are more reliable than those from some previous low frequency surveys and (2) the VLSS covers a much larger area of the sky (declination >-30 deg.) than many other low frequency surveys (e.g., the 8C survey). In this paper, we discuss how the spectra were constructed and how parameters quantifying the shapes of the spectra were derived. Both the spectra and the shape parameters are made available here to assist in the calibration of observations made with current and future low frequency radio facilities.Comment: Accepted to ApJ

    Slower Decline in C-Reactive Protein after an Inflammatory Insult Is Associated with Longer Survival in Older Hospitalised Patients

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    Background Enhancing biological resilience may offer a novel way to prevent and ameliorate disease in older patients. We investigated whether changes in C-reactive protein (CRP), as a dynamic marker of the acute inflammatory response to diverse stressors, may provide a way to operationalize the concept of resilience in older adults. We tested this hypothesis by examining whether such changes could predict prognosis by identifying which individuals are at greater risk of 6-month mortality. Methods Analysis of prospective, routinely collected datasets containing data on hospitalization, clinical chemistry and rehabilitation outcomes for rehabilitation inpatients between 1999 and 2011. Maximum CRP response during acute illness and CRP recovery indices (time and slope of CRP decay to half maximum, and t

    A zoo-led study of the great ape bushmeat commodity chain in Cameroon

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    Current levels of bushmeat hunting in west and central Africa are largely unsustainable, and will lead to the loss of an important natural resource and cause the extinction of threatened species. Worryingly, great apes are hunted for their meat despite being protected across their range. In this paper, we highlight the main actors involved in the trafficking of great ape meat around the Dja Biosphere Reserve (DBR) in Cameroon, and describe the commodity chain associated with the trade. In total, 78 hunters, porters, traders and consumers were interviewed. Hunters, all men, were primarily driven by profit, encouraged by middlemen, though some hunt for their own consumption. However, we identify that great ape hunting is undertaken by specialised hunters along a relatively short supply chain. Gorilla and chimpanzee meat is sold to restaurants and wealthy buyers via few intermediaries. The price of great ape meat varied at different stages of the chain. Middlemen obtained the greatest financial gain, whereas wholesale traders profited least. Movement of ape meat to markets was predominantly by public transport and facilitated by drivers who can pass through checkpoints unnoticed. Based on our study we recommend potential interventions, including support of law enforcement, investments in conservation and development initiatives, and monitoring and research

    The philosopher of ambiguity: exploring stories of spirituality of people with aphasia through the lens of Merleau-Ponty

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    Spirituality as a concept has only recently begun to be considered in speech and language therapy research and practice, and phenomenology as a research methodology is also not widely used in SLT research. Yet, concepts propounded by the phenomenologist Maurice Merleau-Ponty arguably offer a useful theoretical framework from which to view certain aspects of SLT including the concept of spirituality and how this is expressed by people with a communication difficulty. In this project, eight people with aphasia were interviewed about their spirituality. The interviews were transcribed, themes identified and stories created. These stories were viewed using one of the concepts propounded by Merleau-Ponty, namely ambiguity

    Catalog of Radio Galaxies with z>0.3. I:Construction of the Sample

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    The procedure of the construction of a sample of distant (z>0.3z>0.3) radio galaxies using NED, SDSS, and CATS databases for further application in statistical tests is described. The sample is assumed to be cleaned from objects with quasar properties. Primary statistical analysis of the list is performed and the regression dependence of the spectral index on redshift is found.Comment: 9 pages, 6 figures, 2 table

    Predicting the Effect of Surface Texture on the Qualitative Form of Prehension

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    Reach-to-grasp movements change quantitatively in a lawful (i.e. predictable) manner with changes in object properties. We explored whether altering object texture would produce qualitative changes in the form of the precontact movement patterns. Twelve participants reached to lift objects from a tabletop. Nine objects were produced, each with one of three grip surface textures (high-friction, medium-friction and low-friction) and one of three widths (50 mm, 70 mm and 90 mm). Each object was placed at three distances (100 mm, 300 mm and 500 mm), representing a total of 27 trial conditions. We observed two distinct movement patterns across all trials—participants either: (i) brought their arm to a stop, secured the object and lifted it from the tabletop; or (ii) grasped the object ‘on-the-fly’, so it was secured in the hand while the arm was moving. A majority of grasps were on-the-fly when the texture was high-friction and none when the object was low-friction, with medium-friction producing an intermediate proportion. Previous research has shown that the probability of on-the-fly behaviour is a function of grasp surface accuracy constraints. A finger friction rig was used to calculate the coefficients of friction for the objects and these calculations showed that the area available for a stable grasp (the ‘functional grasp surface size’) increased with surface friction coefficient. Thus, knowledge of functional grasp surface size is required to predict the probability of observing a given qualitative form of grasping in human prehensile behaviour
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