Are power laws that estimate fractal dimension a good descriptor of soil structure and its link to soil biological properties?

The study of interrelationships between soil structure and its functional properties is complicated by the fact that the quantitative description of soil structure is challenging. Soil scientists have tackled this challenge by taking advantage of approaches such as fractal geometry, which describes soil architectural complexity through a scaling exponent (D) relating mass and numbers of particles/aggregates to particle/aggregate size. Typically, soil biologists use empirical indices such as mean weight diameters (MWD) and percent of water stable aggregates (WSA), or the entire size distribution, and they have successfully related these indices to key soil features such as C and N dynamics and biological promoters of soil structure. Here, we focused on D, WSA and MWD and we tested whether: D estimated by the exponent of the power law of number-size distributions is a good and consistent correlate of MWD and WSA; D carries information that differs from MWD and WSA; the fraction of variation in D that is uncorrelated with MWD and WSA is related to soil chemical and biological properties that are thought to establish interdependence with soil structure (e.g., organic C, N, arbuscular mycorrhizal fungi). We analysed observational data from a broad scale field study and results from a greenhouse experiment where arbuscular mycorrhizal fungi (AMF) and collembola altered soil structure. We were able to develop empirical models that account for a highly significant and large portion of the correlation observed between WSA and MWD but we did not uncover the mechanisms that underlie this correlation. We conclude that most of the covariance between D and soil biotic (AMF, plant roots) and abiotic (C. N) properties can be accounted for by WSA and MWD. This result implies that the ecological effects of the fragmentation properties described by D and generally discussed under the framework of fractal models can be interpreted under the intuitive perspective of simpler indices and we suggest that the biotic components mostly impacted the largest size fractions, which dominate MWD, WSA and the scaling exponent ruling number-size distributions. (C) 2010 Elsevier Ltd. All rights reserved.

Preparation of highly stable oligo (ethylene glycol) derivatives-functionalized gold nanoparticles and their application in LSPR-Based detection of PSA/ACT complex

A sandwich immunoassay for PSA/ACT complex detection based on gold nanoparticle aggregation using two probes was developed. The functionalized colloidal gold nanoparticles (AuNPs) showed highly stable not only in the presence of high ionic strength but also in a wide pH range. The functionalized AuNPs were tagged with PSA/ACT complex monoclonal antibody and goat PSA polyclonal antibody and served as the probes to induce aggregation of the colloidal particles. As a result, PSA/ACT complex was detected at concentrations as low as 1 ng/ml. This is the first time that a new aggregation sandwich-immunoassay technique using two gold probes has been used, and the results are generally applicable to other LSPR-based immunoassays.

Psychic Distance, its Business Impact and Modes of Coping: A Study of British and Indian Partner SMEs

This paper reports one of the first investigations to analyze inter-partner perceptions of psychic distance between two countries. Its empirical focus is British and Indian SMEs engaged in business with each other. It examines different dimensions of psychic distance, their impact and modes of coping with them. Potential firm-level and individual influences are also taken into account. The paper aims to transcend some of the conceptual and methodological limitations of previous research on the subject and to identify the theoretical and practical implications that arise. A ‘mirror’ approach is applied, accessing both partners’ perceptions. These are assessed through a ‘mixed’ method combining quantitative measurement with qualitative interpretations. Psychic distance dimensions are found to vary in their impact on doing business with the other country, and there is also variation according to the firm’s sector. There is considerable asymmetry in British and Indian partners’ perceptions of psychic distance but the degree of difference between their psychic distance evaluations lacks predictive power. Culturally embedded psychic distance dimensions tend to have less impact and to be easier to cope with than institutionally embedded dimensions. Four categories of coping are identified. The principal theoretical implication of this study is that a contingency perspective needs to be adopted in the field of ‘distance’ research, taking account of factors such as a firm’s sector, and that this will require a more complex analytical framework that hitherto.

Group 6 carbene complexes derived from lithiated azoles and the crystal structure of a molybdenum thiazolinylidene complex

Fischer-type (alkoxy)azolyl carbene complexes and Ofele-Lappert-type azolylinylidene complexes were synthesised by reaction of 1-phenylpyrazol-3 -yllithium, 4-methylthiazol-2-yllithium, benzothiazol-2-yllithium, 1-methylimidazol-2-yllithium with M(CO)(5)L (L = CO, THF or Cl-; M = Cr, Mo or W) and subsequent alkylation with CF3SO3CH3. The alkylation of Fischer-type carbene complexes containing an azolyl as the organic substituent proceeded via ring opening of tetrahydrofuran. When the alkylation is carried out in THF, the carbocation CH3O(CH2)(4)(+) acts as an electrophile. Protonation rather than alkylation of coordinated imidazolyl furnished cyclic imine complexes. Changing the donor atom of a coordinated thiazole from N to C by deprotonation and alkylation afforded a carbene complex. (C) 1999 Elsevier Science S.A. All rights reserved.

Preparing to prescribe: How do clerkship students learn in the midst of complexity?

Prescribing tasks, which involve pharmacological knowledge, clinical decision-making and practical skill, take place within unpredictable social environments and involve interactions within and between endlessly changing health care teams. Despite this, curriculum designers commonly assume them to be simple to learn and perform. This research used mixed methods to explore how undergraduate medical students learn to prescribe in the 'real world'. It was informed by cognitive psychology, sociocultural theory, and systems thinking. We found that learning to prescribe occurs as a dynamic series of socially negotiated interactions within and between individuals, communities and environments. As well as a thematic analysis, we developed a framework of three conceptual spaces in which learning opportunities for prescribing occur. This illustrates a complex systems view of prescribing education and defines three major system components: the "social space", where the environmental conditions influence or bring about a learning experience; the "process space", describing what happens during the learning experience; and the intra-personal "cognitive space", where the learner may develop aspects of prescribing expertise. This conceptualisation broadens the scope of inquiry of prescribing education research by highlighting the complex interplay between individual and social dimensions of learning. This perspective is also likely to be relevant to students' learning of other clinical competencies.

Ethical reasoning through simulation: a phenomenological analysis of student experience

Background
Medical students transitioning into professional practice feel underprepared to deal with the emotional complexities of real-life ethical situations. Simulation-based learning (SBL) may provide a safe environment for students to probe the boundaries of ethical encounters. Published studies of ethics simulation have not generated sufficiently deep accounts of student experience to inform pedagogy. The aim of this study was to understand students’ lived experiences as they engaged with the emotional challenges of managing clinical ethical dilemmas within a SBL environment.

Methods
This qualitative study was underpinned by an interpretivist epistemology. Eight senior medical students participated in an interprofessional ward-based SBL activity incorporating a series of ethically challenging encounters. Each student wore digital video glasses to capture point-of-view (PoV) film footage. Students were interviewed immediately after the simulation and the PoV footage played back to them. Interviews were transcribed verbatim. An interpretative phenomenological approach, using an established template analysis approach, was used to iteratively analyse the data.

Results
Four main themes emerged from the analysis: (1) ‘Authentic on all levels?’, (2)‘Letting the emotions flow’, (3) ‘Ethical alarm bells’ and (4) ‘Voices of children and ghosts’. Students recognised many explicit ethical dilemmas during the SBL activity but had difficulty navigating more subtle ethical and professional boundaries. In emotionally complex situations, instances of moral compromise were observed (such as telling an untruth). Some participants felt unable to raise concerns or challenge unethical behaviour within the scenarios due to prior negative undergraduate experiences.

Conclusions
This study provided deep insights into medical students’ immersive and embodied experiences of ethical reasoning during an authentic SBL activity. By layering on the human dimensions of ethical decision-making, students can understand their personal responses to emotion, complexity and interprofessional working. This could assist them in framing and observing appropriate ethical and professional boundaries and help smooth the transition into clinical practice.