Clinician educators' conceptions of assessment in medical education.

In pursuing assessment excellence, clinician-educators who design and implement assessment are pivotal. The influence of their assessment practice in university-run licensure exams on student learning has direct implications for future patient care. While teaching practice has been shown to parallel conceptions of teaching, we know too little about conceptions of assessment in medical education to know if this is the case for assessment practice and conceptions of assessment. To explore clinician-educators' conceptions of assessment, a phenomenographic study was undertaken. Phenomenography explores conceptions, the qualitatively different ways of understanding a phenomenon. Data analysis identifies a range of hierarchically inclusive categories of understanding, from simple to more complex, and the dimensions that distinguish each category or conception. Thirty-one clerkship convenors in three diverse Southern settings were interviewed in three cycles of iterative data collection and analysis. Four conceptions of assessment were identified: passive operator, awakening enquirer, active owner and scholarly assessor. Six dimensions were elucidated to describe and distinguish each conception: purpose of assessment; temporal perspective; role and responsibility; accountability; reflexivity and emotional valence. Additionally, three characteristics that appeared to track the progressive nature of the conceptions were identified: professional identity, assessment literacy and self-efficacy. These conceptions encompass and extend previously described conceptions across different educational levels, disciplines and contexts, suggesting applicability to other settings. There is some evidence of a relationship between conceptions and practice, suggesting, together with the hierarchical nature of these conceptions, that targeting conceptions during faculty development may be an effective approach to enhance assessment practice.

Protein engineering and preclinical development of a GM-CSF receptor antibody for the treatment of rheumatoid arthritis.

BACKGROUND AND PURPOSE: For antibody therapies against receptor targets, in vivo outcomes can be difficult to predict because of target-mediated clearance or antigen 'sink' effects. The purpose of this work was to engineer an antibody to the GM-CSF receptor α (GM-CSFRα) with pharmacological properties optimized for chronic, s.c. treatment of rheumatoid arthritis (RA) patients. EXPERIMENTAL APPROACH: We used an in silico model of receptor occupancy to guide the target affinity and a combinatorial phage display approach for affinity maturation. Mechanism of action and internalization assays were performed on the optimized antibody in vitro before refining the modelling predictions of the eventual dosing in man. Finally, in vivo pharmacology studies in cynomolgus monkeys were carried out to inform the predictions and support future clinical development. KEY RESULTS: Antibody potency was improved 8600-fold, and the target affinity was reached. The refined model predicted pharmacodynamic effects at doses as low as 1 mg kg(-1) and a study in cynomolgus monkeys confirmed in vivo efficacy at 1 mg kg(-1) dosing. CONCLUSIONS AND IMPLICATIONS: This rational approach to antibody drug discovery enabled the isolation of a potent molecule compatible with chronic, s.c. self-administration by RA patients. We believe this general approach enables the development of optimal biopharmaceuticals.

EcoCELLs: tools for mesocosm scale measurements of gas exchange.

We describe the use of a unique plant growth facility, which has as its centerpiece four 'EcoCELLs', or 5x7 m mesocosms designed as open-flow, mass-balance systems for the measurement of carbon, water and trace gas fluxes. This system is unique in that it was conceived specifically to bridge the gap between measurement scales during long-term experiments examining the function and development of model ecosystems. There are several advantages to using EcoCELLs, including (i) the same theory of operation as leaf level gas exchange systems, but with continuous operation at a much larger scale; (ii) the ability to independently evaluate canopy-level and ecosystem models; (iii) simultaneous manipulation of environmental factors and measurement of system-level responses, and (iv) maximum access to, and manipulation of, a large rooting volume. In addition to discussing the theory, construction and relative merits of EcoCELLs, we describe the calibration and use of the EcoCELLs during a 'proof of concept' experiment. This experiment involved growing soybeans under two ambient CO2 concentrations (approximately 360 and 710 micromoles mol-1). During this experiment, we asked 'How accurate is the simplest model that can be used to scale from leaf-level to canopy-level responses?' in order to illustrate the utility of the EcoCELLs in validating canopy-scale models.

Compton scattering from the deuteron and extracted neutron polarizabilities.

Differential cross sections for Compton scattering from the deuteron were measured at MAX-Lab for incident photon energies of 55 and 66 MeV at nominal laboratory angles of 45 degrees, 125 degrees, and 135 degrees. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and the difference of the isospin-averaged nucleon polarizabilities, alpha(N)+beta(N)=17.4+/-3.7 and alpha(N)-beta(N)=6.4+/-2.4 (in units of 10(-4) fm(3)), have been determined. By combining the latter with the global-averaged value for alpha(p)-beta(p) and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of alpha(n)=8.8+/-2.4(total)+/-3.0(model) and beta(n)=6.5-/+2.4(total)-/+3.0(model), respectively.