Managing discomfort and developing participation in non-emergency MRI: Children's coping strategies during their first procedure

INTRODUCTION

Building on existing work, this paper aims to develop a detailed analysis of the practical coping strategies developed by children who had not previously experienced an MRI, regarding a non-emergency examination of the brain.

METHODS

Semi-structured interviews with 22 children, aged between eight and sixteen years, were conducted immediately post-procedure. Emergent data were thematically analysed in line with the core precepts of Grounded Theory, and triangulated against interview data with their parents where pertinent.

RESULTS

The primary concern among interviewees related to how they had coped with the discomfort of an unfamiliar medical procedure; this was recurrently managed through a process herein termed Participation Development. This comprised three phases. The first, preparative participation, describes the children's reported attempts to ready themselves for the examination (with parents) ahead of arriving in hospital. The second, enabling participation, describes how the children (with input from parents and radiographers) endeavoured to understand what was to come, and select viable distraction techniques. Finally, sustaining participation describes the children's reports of actualizing their preparations during the examination itself. Where the overall process of participation development was successful, the children reported a sense of mastery, growth and even joy.

CONCLUSION

While much work in the domain portrays children as relatively 'passive' agents during an MRI procedure, the findings herein point to how they can (with varying degrees of success) actively and constructively work with others. This, it is contended, has direct import for the improvement of support, both prior to and within a procedure itself.

Superinfection and the coevolution of parasite virulence and host recovery

Parasite strategies of host exploitation may be affected by host defence strategies and multiple infections. In particular, within-host competition between multiple parasite strains has been shown to select for higher virulence. However, little is known on how multiple infections could affect the coevolution between host recovery and parasite virulence. Here, we extend a coevolutionary model introduced by van Baalen (Proc. R. Soc. B, 265, 1998, 317) to account for superinfection. When the susceptibility to superinfection is low, we recover van Baalen's results and show that there are two potential evolutionary endpoints: one with avirulent parasites and poorly defended hosts, and another one with high virulence and high recovery. However, when the susceptibility to superinfection is above a threshold, the only possible evolutionary outcome is one with high virulence and high investment into defence. We also show that within-host competition may select for lower host recovery, as a consequence of selection for more virulent strains. We discuss how different parasite and host strategies (superinfection facilitation, competitive exclusion) as well as demographic and environmental parameters, such as host fecundity or various costs of defence, may affect the interplay between multiple infections and host-parasite coevolution. Our model shows the interplay between coevolutionary dynamics and multiple infections may be affected by crucial mechanistic or ecological details.

Differential electron flow around photosystem I by two C(4)-photosynthetic-cell-specific ferredoxins

In the C(4) plant maize (Zea mays L.), two ferredoxin isoproteins, Fd I and Fd II, are expressed specifically in mesophyll and bundle-sheath cells, respectively. cDNAs for these ferredoxins were introduced separately into the cyanobacterium Plectonema boryanum with a disrupted endogenous ferredoxin gene, yielding TM202 and KM2-9 strains expressing Fd I and Fd II. The growth of TM202 was retarded under high light (130 micromol/m(2)/s), whereas KM2-9 grew at a normal rate but exhibited a nitrogen-deficient phenotype. Measurement of photosynthetic O(2) evolution revealed that the reducing power was not efficiently partitioned into nitrogen assimilation in KM2-9. After starvation of the cells in darkness, the P700 oxidation level under far-red illumination increased significantly in TM202. However, it remained low in KM2-9, indicating an active cyclic electron flow. In accordance with this, the cellular ratio of ATP/ADP increased and that of NADPH/NADP(+) decreased in KM2-9 as compared with TM202. These results demonstrated that the two cell type-specific ferredoxins differentially modulate electron flow around photosystem I.

Absolute stereochemistry of gastric antisecretory compound P371A1 and its congener P371A2 from streptomyces species P371

Absolute configurations of the gastric antisecretory compound P371A1 (1) and its congener P371A2 (2) from Streptomyces sp. P371 were determined on the basis of identification of the methyl glycosides 9, 10, and 11 obtained by the acid degradation of 1 and 2, as well as application of the modified Mosher method to the P371A2 C-glycoside MTPA esters 7 and 8 and observation of the excitation chiralities in the P371A2 C-glycoside benzoate derivatives 5 and 6.