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Methodological narrative\institutional dualism was developed as an epistemological strategy to facilitate an approach to the study of political discourse that incorporates figures of disorder into the construction of order. The symmetrization of various theories of narration and argumentation and related analytical research approaches enables an examination of how discursive world-making engages syncretically narrative and argumentative repertoires of rhetoric and hermeneutics to ensure interconnected discursive and organizational interventions. Actors strive to occupy a strategically important position in discourse-worlds as the prelude to their occupation of influential power positions in organizational fields. Such a two-fold – textual and pragma-dialectical – interventionism can be uncovered by a ‘perspective interplay’ between complementary research strategies, one based on a narrative\routine duality (focused on communicability by studying the textualized sequencing of speech acts), the other on a duality of the pragmatic use of plot\argument (focused on the pragmatic implications of speech acts by studying the political claim-making accompanying strategic maneuvering). Our efforts at theory-building are illustrated by an empirical probe into a moment in a Czech election campaign (a three-day media dialogical network) in which the metaphor of dinosaurs was deployed as a powerful trope by candidates, opponents and journalists in credibility and consistency tests with respect to qualification for political office.

Maritime engagement in the Gulf of Aden is a puzzling case for anyone interested in the political and institutional problems underlying European Union–North Atlantic Treaty Organization (EU–NATO) cooperation. Although the EU’s operation NAVFOR ‘Atalanta’ and NATO’s ‘Ocean Shield’ operate in the same theatre and with similar mandates, there is no formal link between them. No joint planning has been envisaged, and no official task-sharing takes place. As this article aims to show, cooperation and coordination between EU and NATO forces at the operational and tactical levels have nevertheless worked surprisingly well. Two faces of EU–NATO cooperation become apparent: the political level is dominated by a permanent deadlock, while on the ground and at sea staff have developed a modus operandi that allows them to deliver fairly successfully in complementing yet detached operations. Based on 60 interviews with EU and NATO officials (2010–2013), this article illustrates how the operational and tactical levels have developed ways of coordinating efforts informally despite the lack of a formal framework. It aims to show to what extent and how they succeed at bypassing organizational boundaries and at overcoming political limitations. Although these practices are becoming increasingly institutionalized, it remains to be seen whether this will translate into formal changes.

Four 28 mm diameter alumina-alumina hip prostheses were tested in the MkII Durham hip simulator for 5 × 106 cycles using 25 per cent bovine serum as lubricant. Wear of the heads and cups was measured gravimetrically. The mean and standard deviation of the wear rate for the alumina cups was 0.097 ± 0.039 mm3/106 cycles. The femoral heads produced such low wear that it could not be measured by weighing but could be detected by increased surface roughness measurements. Such low wear rates represent about one-five-hundredth of the wear of ultra-high molecular weight polyethylene (UHMWPE) against ceramic in a similar test and supports work which indicates that fluid film lubrication exists in these joints.

It has been found that a remarkable reduction in the wear of metal-on-metal hip joints can be achieved by simply increasing the diameter of the joint. A tribological evaluation of metal-on-metal joints of 16, 22,225, 28 and 36 mm diameter was conducted in 25 per cent bovine serum using a hip joint simulator. The joints were subject to dynamic motion and loading cycles simulating walking for both lubrication and wear studies. For each size of joint in the lubrication study, an electrical resistivity technique was used to detect the extent of surface separation through a complete walking cycle. Wear of each size of joint was measured gravimetrically in wear tests of at least 2 × 106cycles duration.Joints of 16 and 22.225mm diameter showed no surface separation in the lubrication study. This suggested that wear would be proportional to the sliding distance and hence joint size in this boundary lubrication regime. A 28 mm diameter joint showed only limited evidence of surface separation suggesting that these joints were operating in a mixed lubrication regime. A 36 mm diameter joint showed surface separation for considerable parts of each walking cycle and hence evidence of the formation of a protective lubricating film.Wear testing of 16 and 22.225mm diameter metal-on-metal joints gave mean wear rates of 4.85 and 6.30mm3/106cycles respectively. The ratio of these wear rates, 0.77, is approximately the same as the joint diameters ratio, 16/22.225 or 0.72, as expected from simple wear theory for dry or boundary lubrication conditions. No bedding-in was observed with these smaller diameter joints. For the 28 mm diameter joint, from 0 to 2 × 106cycles, the mean wear rate was 1.62 mm3/106cycles as the joints bedded-in. Following bedding-in, from 2.0 × 106to 4.7 × 106cycles, the wear rate was 0.54mm3/106cycles. As reported previously by Goldsmith in 2000 [1], the mean steady state wear rate of the 36 mm diameter joints was lower than those of all the other diameters at 0.07 mm3/106cycles. For a range of joints of various diameters, subjected to identical test conditions, mean wear rates differed by almost two orders of magnitude. This study has demonstrated that the application of sound tribological principles to prosthetic design can reduce the wear of metal-on-metal joints, using currently available materials, to a negligible level.

A study of surface contact and separation of 36mm diameter metal-on-metal joints was undertaken in 25 per cent bovine serum using a hip simulator. A range of diametral clearances from 130 to 170 μm was tested and each joint was subjected to two different dynamic motion and loading walking cycles. One simulation used physiological motion and loading cycles as described by Paul [I], while the other used simplified motion cycles, as described by Barbour et al. [2], and simplified loading. An electrical resistivity technique was used to detect the extent of surface separation throughout a complete walking cycle. The proportion of surface separation per cycle was generally greater in the simplified than in the physiological walking cycle. The latter cycle thus appears to present a more severe condition than the simplified cycle as far as joint lubrication is concerned. No surface separation was observed, for either cycle, with the largest diametral clearance of 170 μm. All of the remaining joints, with smaller diametral clearances, showed surface separation for at least a portion of each walking cycle. The proportion of surface separation per simulated walking cycle generally increased as the diametral clearance decreased.

A five-station hip joint wear simulator was designed and built which featured simplified motion and loading. An elliptical wear path was produced using approximately sinusoidal motion in the flexion/extension and internal/external rotation axes and the dynamic loading approximated to a square wave. Five 28 mm diameter zirconia femoral heads articulated against ultra-high molecular weight polyethylene acetabular cups in 25 per cent bovine serum for 5 × 106 cycles. Gravimetric wear measurement was used with moisture absorption compensation using a dynamically loaded soak control. With motion of physiological magnitude, the mean acetabular cup wear rate was 52.2 mm3/106 cycles which is comparable with a number of clinical studies.

To evaluate the functioning of the Durham hip joint wear simulator, the wear rates of ultra high molecular weight polyethylene (UHMWPE) and polytetrafluoroethylene (PTFE) acetabular cups articulating against 22 mm diameter cobalt-chromium-molybdenum (CoCrMo) femoral heads were studied. A wear test was conducted in a lubricant of distilled water at 37°C for a duration of 4.8 million cycles. The average penetration rate for the CoCrMo femoral heads against UHMWPE acetabular cups was 0.03mm/106cycles, while penetration rate for PTFE cups was some twenty times greater. These results are of a similar order of magnitude to other simulator studies in distilled water and are in a similar ratio to clinical data.

Our Book Review Editor, Simon E. Smith, here shares with us a report on an interesting missiological gathering held this last fall which promises to have important consequences on Catholic mission for the next several decades.