3,966 research outputs found
Concepts and action : where does the embodiment debate leave us?
The behavioural evidence of sensorimotor activity during conceptual processing, along with that from neurological research, ignited the debate around the extent to which concept representations are embodied or amodal. Such evidence continues to fuel the debate but it is open to interpretation as being consistent with a variety of the theoretical positions and so it is possible that further, similar evidence may not lead to its resolution. In this paper we propose that independent value accrues from following this line of research through the enhanced understanding of the factors that influence agents’ conceptual processing of action and how this interacts with the agent’s goals in real environments. This approach is in line with broad principles of embodied cognition and is worthy of pursuit regardless of what the results may (or may not) tell us about conceptual representation
Clinical consequences of asbestos-related diffuse pleural thickening: A review
Asbestos-related diffuse pleural thickening (DPT), or extensive fibrosis of the visceral pleura secondary to asbestos exposure, is increasingly common due to the large number of workers previously exposed to asbestos. It may coexist with asbestos related pleural plaques but has a distinctly different pathology. The pathogenesis of this condition as distinct from pleural plaques is gradually becoming understood. Generation of reactive oxygen and nitrogen species, profibrotic cytokines and growth factors in response to asbestos is likely to play a role in the formation of a fibrinous intrapleural matrix. Benign asbestos related pleural effusions commonly antedate the development of diffuse pleural thickening. Environmental as well as occupational exposure to asbestos may also result in pleural fibrosis, particularly in geographic areas with naturally occurring asbestiform soil minerals. Pleural disorders may also occur after household exposure. High resolution computed tomography (CT) is more sensitive and specific than chest radiography for the diagnosis of diffuse pleural thickening, and several classification systems for asbestos-related disorders have been devised. Magnetic resonance imaging and fluorodeoxyglucose positron emission tomography (PET) scanning may be useful in distinguishing between DPT and malignant mesothelioma. DPT may be associated with symptoms such as dyspnoea and chest pain. It causes a restrictive defect on lung function and may rarely result in respiratory failure and death. Treatment is primarily supportive
Student conceptions about energy transformations: progression from general chemistry to biochemistry
Students commencing studies in biochemistry must transfer and build on concepts they learned in chemistry and biology classes. It is well established, however, that students have difficulties in transferring critical concepts from general chemistry courses; one key concept is “energy.” Most previous work on students’ conception of energy has focused on their understanding of energy in the context of physics (including the idea of “work”) and/or their understanding of energy in classical physical and inorganic chemistry contexts (particularly Gibbs Free Energy changes, the second law of thermodynamics, and equilibrium under standard conditions within a closed system). For biochemistry, students must go beyond those basic thermodynamics concepts of work, standard energy changes, and closed systems, and instead they must consider what energy flow, use, and transformation mean in living, open, and dynamic systems. In this study we explored students’ concepts about free energy and flow in biological chemical reactions and metabolic pathways by surveys and in-depth interviews. We worked with students in general chemistry classes and biochemistry courses in both an Australian and a US tertiary institution. We address three primary questions (i) What are the most common alternative conceptions held by students when they explain energy-related phenomena in biochemistry?, (ii) What information do students transfer from introductory chemistry and biology when they are asked to consider energy in a biological reaction or reaction pathway?, and (iii) How do students at varying levels of competence articulate their understandings of energy in pathways and biological reactions? The answers to these questions are used to build a preliminary learning progression for understanding “energy” in biochemistry. We also propose crucial elements of content knowledge that instructors could apply to help students better grasp this threshold concept in biochemistry
Ethnicity and the Writing of Medieval Scottish history
Historians have long tended to define medieval Scottish society in terms of interactions between ethnic groups. This approach was developed over the course of the long nineteenth century, a formative period for the study of medieval Scotland. At that time, many scholars based their analysis upon scientific principles, long since debunked, which held that medieval 'peoples' could only be understood in terms of 'full ethnic packages'. This approach was combined with a positivist historical narrative that defined Germanic Anglo-Saxons and Normans as the harbingers of advances of Civilisation. While the prejudices of that era have largely faded away, the modern discipline still relies all too often on a dualistic ethnic framework. This is particularly evident in a structure of periodisation that draws a clear line between the 'Celtic' eleventh century and the 'Norman' twelfth. Furthermore, dualistic oppositions based on ethnicity continue, particularly in discussions of the law, kingship, lordship and religion
Dental Hygienists\u27 Knowledge of HIV, Attitudes Towards People with HIV and Willingness to Conduct Rapid HIV Testing
This study was aimed to determine the dental hygienists\u27 knowledge of HIV, attitudes towards people living with HIV and willingness to conduct rapid HIV testing
Accuracy of prospective two-dimensional/Doppler echocardiography in the assessment of reparative surgery
Between January 1987 and January 1989, all 129 patients (aged 11 days to 25 years, median 39 months) undergoing both an echocardiographic examination and cardiac catheterization after reparative surgery were prospectively included in a study to assess the accuracy of combined two-dimensional and Doppler color flow imaging. The patient diagnoses were transposition of the great arteries (n = 20), tetralogy of Fallot (n = 38), coarctation of the aorta (n = 24), complete atrioventricular (AV) canal (n = 15), atrial septal defect (n = 8), ventricular septal defects (n = 3), pulmonary stenosis (n = 4), aortic stenosis (n = 8) and subaortic stenosis (n = 9).In arterial tract stenosis, there was high correlation between Doppler estimates and catheterization-derived measurements of residual right ventricular outflow tract obstruction in patients after the arterial switch operation for transposition of the great arteries (r = 0.95) as well as in patients after corrective repair of tetralogy of Fallot (r = 0.84).In semilunar/AV valve regurgitation, graded as none, mild, moderate or severe, echocardiographic estimates correlated exactly with angiographic grading in 84% and differed by one angiographic grade in the other 16%.In residual left to right shunting, no hemodynamically significant shunt was missed by echocardiography. For residual shunts at the ventricular level (n = 32), addition of Doppler color flow imaging improved the sensitivity (from 63% to 94%) and the negative predictive value (from 88% to 98%).In elevated right ventricular pressure, Doppler-derived right ventricular-right atrial pressure estimates in 24 patients correlated well with catheterization measurements (r = 0.93).Combined two-dimensional and Doppler color flow echocardiography was highly accurate in the prospective evaluation of these four types of postoperative residua
Effect of the sphingosine kinase 1 selective inhibitor, PF-543 on arterial and cardiac remodeling in a hypoxic model of pulmonary arterial hypertension
Recent studies have demonstrated that the expression of sphingosine kinase 1, the enzyme that catalyses formation of the bioactive lipid, sphingosine 1-phosphate, is increased in lungs from patients with pulmonary arterial hypertension. In addition, Sk1-/- mice are protected from hypoxic-induced pulmonary arterial hypertension. Therefore, we assessed the effect of the sphingosine kinase 1 selective inhibitor, PF-543 and a sphingosine kinase 1/ceramide synthase inhibitor, RB-005 on pulmonary and cardiac remodeling in a mouse hypoxic model of pulmonary arterial hypertension. Administration of the potent sphingosine kinase 1 inhibitor, PF-543 in a mouse hypoxic model of pulmonary hypertension had no effect on vascular remodeling but reduced right ventricular hypertrophy. The latter was associated with a significant reduction in cardiomyocyte death. The protection involves a reduction in the expression of p53 (that promotes cardiomyocyte death) and an increase in the expression of anti-oxidant nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). In contrast, RB-005 lacked effects on right ventricular hypertrophy, suggesting that SK1 inhibition might be nullified by concurrent inhibition of ceramide synthase. Therefore, our findings with PF-543 suggest an important role for SK1 in the development of hypertrophy in PAH
Geodetic Strain Analysis Tool
A geodetic software analysis tool enables the user to analyze 2D crustal strain from geodetic ground motion, and create models of crustal deformation using a graphical interface. Users can use any geodetic measurements of ground motion and derive the 2D crustal strain interactively. This software also provides a forward-modeling tool that calculates a geodetic velocity and strain field for a given fault model, and lets the user compare the modeled strain field with the strain field obtained from the user s data. Users may change parameters on-the-fly and obtain a real-time recalculation of the resulting strain field. Four data products are computed: maximum shear, dilatation, shear angle, and principal components. The current view and data dependencies are processed first. The remaining data products and views are then computed in a round-robin fashion to anticipate view changes. When an analysis or display parameter is changed, the affected data products and views are invalidated and progressively re-displayed as available. This software is designed to facilitate the derivation of the strain fields from the GPS and strain meter data that sample it to facilitate the understanding of the strengths and weaknesses of the strain field derivation from continuous GPS (CGPS) and other geodetic data from a variety of tectonic settings, to converge on the "best practices" strain derivation strategy for the Solid Earth Science ESDR System (SESES) project given the CGPS station distribution in the western U.S., and to provide SESES users with a scientific and educational tool to explore the strain field on their own with user-defined parameters
Oral Rapid HIV Testing in the Dental Setting: Experiences from Three Dental Hygiene Clinics
Background: Oral rapid HIV testing (ORHT) is implemented in the dental setting to make individuals aware of their possibly undiagnosed HIV infection. The testing process and characteristics of clients willing to receive ORHT has yet, however, to be systematically collected. Case description: Three dental hygiene clinics located in academic institutions implemented ORHT from March 2016 to April 2017. Results: 231 persons received ORHT; all had non-reactive results. Most had seen a primary care provider in the past year (n = 130), had had a previous ORHT (n = 111), and described themselves as extremely likely or likely to accept a chairside screening in the future (n = 169). The main reason cited for accepting ORHT was that it was free (n = 138). Conclusion: In order to ensure everyone living with HIV is aware of their infection, HIV testing should be expanded into non-traditional settings. The dental setting may help achieve this important public health milestone
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