1,300 research outputs found
An Empirical and Theoretical Comparison of the Socio-ecological Behaviors of Captive Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Western Lowland Gorillas (Gorilla gorilla): Social Tolerance and Behavioral Responses to Changes in Food Quality and Distribution
Chimpanzees and gorillas are sympatric in most of their range in Central Africa, however, bonobos do not overlap with either of the other two species. This difference has been hypothesized to be the main factor leading to the socio-ecological traits of each species. Access to, and competition for, terrestrial herbaceous vegetation (THV) in each of the three species in thought to be linked to the social relationships and female-female bonds of each species. This study sought to provide a direct comparison of the social relationships of each of the three African Great Apes in captivity in order to elucidate similarities and differences in terms of their social tolerance. We hypothesized that bonobos and gorillas would both me more tolerant of conspecifics in close proximity across multiple behavioral contexts than chimpanzees. Our results did not support this hypothesis, in fact gorillas were the least tolerant of the three species whereas bonobos were the most tolerant. Theoretical modeling was also used to investigate the impact of changing environmental conditions on the behaviors of the three African Great Apes. Here, we hypothesized that high quality, clumped food would select for aggressive behaviors (characteristic of chimpanzees) and low quality, dispersed food would select for affiliative behaviors. Our results indicate that in these kinds of environmental conditions, these types of behaviors did emerge as stable. Moreover, environmental conditions mirroring those reported for gorillas and bonobos suggested the emergence of stable strategies that parallel social characteristics documented for those two species (such as gregariousness within groups)
A poststructural approach to organisational identity construction in the UK magazine publishing industry, 2004-13
This thesis adopts a poststructural approach to the study of organisational identity (OI) arguing that, by destabilising the status of both object and subject, poststructuralism places identity at the centre of organisational life, where a poststructural identity is fragmented, dynamic, decentred, relational and contested. However, the essential indeterminacy of poststructural meaning puts pressure on organisational actors to present identity as coherent, stable and agreed-upon in an attempt to fix meanings, avoid uncertainty, and secure legitimacy. The thesis proposes that poststructuralism helps to provide a convincing account of the tension between the centripetal efforts of organisational actors and the centrifugal empirical evidence found in organisational texts and discourses. The thesis further proposes a categorisation of the organisational identity literature into ācentripetalā and ācentrifugalā approaches to OI, where centripetal approaches present OI in terms of agreed-upon and largely stable attributes of an organisation, and centrifugal approaches consider OI to be fragmented, dynamic and contested. It assesses the theoretical validity of a poststructural approach to the study of OI, explores the feasibility of a robust and valid poststructural methodology, and considers whether a poststructural approach can provide additional explanatory power over existing approaches. The thesis incorporates intertextual analysis, discourse analysis, multimodality, and argumentation as methodological approaches to the study of identity. The thesis is based on an empirical study of three firms operating in the UK magazine publishing industry in the period 2004-13. As its principal data source, the study uses a set of corporate annual reports for the three firms, supplemented by contemporary industry blogs, industry reports, press articles, and interviews with industry figures
'Map and zap' - electrode catheter techniques for treatment of supraventricular tachycardias
No Abstrac
Polarizing intestinal epithelial cells electrically through Ror2
Ā© 2014. Published by The Company of Biologists Ltd.Peer reviewedPublisher PD
Investigation of Isospin Symmetry Breaking in the f7/2 Region, Studied through One-nucleon Knockout and Lifetime Measurements
In this thesis, the results of two experiments are presented. The first experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU), USA, while the second experiment was performed at the Gesellschaft fĆ¼r SchwerIonenforschung (GSI) facility near Darmstadt, Germany.
For the experiment performed at MSU, Ī³-ray spectroscopy has been performed for both the mirror Tz=Ā±3/2 pair 53Ni and 53Mn, produced via mirrored one-nucleon knockout, and the Tz=-1 nuclide 52Co, produced via one-neutron knockout. Several new transitions have been identified in both 53Ni and 52Co, from which new level schemes have been constructed. The presence of a high-spin isomeric state (JĻ=19/2-) in the 53Co beam facilitated the study of high-spin states up to and including the 11+ band termination state in 52Co, where this work also represents the first use of this new technique (isomer knockout) to study high-spin states in exotic nuclei. Relative cross sections for knockout have been analysed and compared with reaction model calculations, where a high level of agreement is observed, especially for states in 52Co. Mirror Energy Differences (MED) between Isobaric Analogue States (IAS) have been measured, compared to large scale shell-model calculations and interpreted in terms of INC effects for both the Tz=Ā±1, A=52 and Tz=Ā±3/2, A=53 mirror pairs. The analysis presented here demonstrates the importance of including a full set of J-dependent INC terms to explain the experimental observations. Finally, lifetimes for the long-lived JĻ=5/2- analogue states in both 53Mn and 53Ni have been extracted through lineshape analysis, giving half-lives of T1/2=120(14)ps and T1/2=198(12)ps, respectively.
In the experiment performed at GSI, Coulex and lifetime measurements (using a novel ''stretched gold target'' technique) were performed for the analogue 2+(T=1)->0+(T=1) transition across the A=46, T=1 isobaric triplet 46Cr(Tz=-1), 46V(Tz=0) and 46Ti(Tz=+1). Preliminary Coulex cross sections have been obtained and a ''proof-of-principle'' test has been performed for the new lifetime method
Normal left ventricular function does not protect against propafenone-induced incessant ventricular tachycardia
Propafenone is a class Ic anti-arrhythmic agent with mild B-blocking properties which has recently become available in South Africa. We have used the drug in 3 patients with sustained m.onomorphic ventricular tachycardia not due to ischaemic heart disease. All had norm.al left ventricular function; 1 had Wegener's granulom.atosis and 2 had arrhythmogenic right ventricular dysplasia. In the latter 2, propafenone provoked incessant monomorphic ventricular tachycardia which persisted for m.ore than 24 hours despite repeated efforts at term.ination. The morphology was similar to the patients' spontaneous ventricular tachycardia, but the rate was slower and the QRS complexes broader, consistent with propafenone's marked ability to slow intraventricular conduction. It is postulated that incessant tachycardia results from. perpetuation of re-entry due to marked conduction slowing produced by the drug. Previous reports have suggested that this is most likely to occur in patients with poor left ventricular function, but our experience indicates that those with normal left ventricular function are also at risk, particularly if the substrate for reentry is present. Propafenone, like all other powerful antiarrhythmic agents, may provoke life-threatening arrhythmias and should be used with great caution after due consideration of the indications, even in patients with norm.al left ventricular function
A poststructural approach to organisational identity construction in the UK magazine publishing industry, 2004-13
This thesis adopts a poststructural approach to the study of organisational identity (OI) arguing that, by destabilising the status of both object and subject, poststructuralism places identity at the centre of organisational life, where a poststructural identity is fragmented, dynamic, decentred, relational and contested. However, the essential indeterminacy of poststructural meaning puts pressure on organisational actors to present identity as coherent, stable and agreed-upon in an attempt to fix meanings, avoid uncertainty, and secure legitimacy. The thesis proposes that poststructuralism helps to provide a convincing account of the tension between the centripetal efforts of organisational actors and the centrifugal empirical evidence found in organisational texts and discourses. The thesis further proposes a categorisation of the organisational identity literature into ācentripetalā and ācentrifugalā approaches to OI, where centripetal approaches present OI in terms of agreed-upon and largely stable attributes of an organisation, and centrifugal approaches consider OI to be fragmented, dynamic and contested. It assesses the theoretical validity of a poststructural approach to the study of OI, explores the feasibility of a robust and valid poststructural methodology, and considers whether a poststructural approach can provide additional explanatory power over existing approaches. The thesis incorporates intertextual analysis, discourse analysis, multimodality, and argumentation as methodological approaches to the study of identity. The thesis is based on an empirical study of three firms operating in the UK magazine publishing industry in the period 2004-13. As its principal data source, the study uses a set of corporate annual reports for the three firms, supplemented by contemporary industry blogs, industry reports, press articles, and interviews with industry figures
Surgical cure of the Wolff-Parkinson-White syndrome a comparison of two techniques
Curative arrhythmia surgery for patients with symptomatic Wolff-Parkinson-White syndrome (WPW) was first performed in South Africa in November 1987. Pre-operatively all patients were symptomatic despite medical therapy, and 32% were assessed as being at risk for sudden death. The first 9 patients (November 1987 to December 1989) underwent either epicardial or localised endocardial surgical dissections, and a cure was obtained in 66%. Aberrant atrioventricular conduction recurred in 2 patients, 30 atrioventricular heart block occurred in 2 patients, and there was 1 postoperative death in a patient who had undergone simultaneous coronary artery bypass grafting. In contrast, a standardised endocardial technique was used in the subsequent 10 patients. Surgical cure was obtained in all 10 patients (P < 0,01). However, 1 patient required reoperation 24 hours after the first procedure because of early postoperative recurrence due to initial incorrect pathway localisation. This was successful. There were no deaths, and no patient developed atrioventricular heart block. In view of the excellent surgical results, arrhythmia surgery should be considered in select WPW patients who either have refractory symptoms or are at risk for sudden death. Furthermore, this reliable surgical technique provides an essential back-up should alternative interventionalprocedures such as percutaneous radiofrequency ablation fail
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