Macroarray for studying chloroplast gene expression profiles associated with the initial development of wheat

Item does not contain fulltextOBJECTIVES: Feedback should facilitate learning, but within medical education it often fails to deliver on its promise. To better understand why feedback is challenging, we explored the unique perspectives of doctors who had also trained extensively in sport or music, aiming to: (i) distinguish the elements of the response to feedback that are determined by the individual learner from those determined by the learning culture, and (ii) understand how these elements interact in order to make recommendations for improving feedback in medical education. METHODS: Using a constructivist grounded theory approach, we conducted semi-structured interviews with 27 doctors or medical students who had high-level training and competitive or performance experience in sport (n = 15) or music (n = 12). Data were analysed iteratively using constant comparison. Key themes were identified and their relationships critically examined to derive a conceptual understanding of feedback and its impact. RESULTS: We identified three essential sources of influence on the meaning that feedback assumed: the individual learner; the characteristics of the feedback, and the learning culture. Individual learner traits, such as motivation and orientation toward feedback, appeared stable across learning contexts. Similarly, certain feedback characteristics, including specificity, credibility and actionability, were valued in sport, music and medicine alike. Learning culture influenced feedback in three ways: (i) by defining expectations for teachers and teacher-learner relationships; (ii) by establishing norms for and expectations of feedback, and (iii) by directing teachers' and learners' attention toward certain dimensions of performance. Learning culture therefore neither creates motivated learners nor defines 'good feedback'; rather, it creates the conditions and opportunities that allow good feedback to occur and learners to respond. CONCLUSIONS: An adequate understanding of feedback requires an integrated approach incorporating both the individual and the learning culture. Our research offers a clear direction for medicine's learning culture: normalise feedback; promote trusting teacher-learner relationships; define clear performance goals, and ensure that the goals of learners and teachers align

Sensing remote nuclear spins

Sensing single nuclear spins is a central challenge in magnetic resonance based imaging techniques. Although different methods and especially diamond defect based sensing and imaging techniques in principle have shown sufficient sensitivity, signals from single nuclear spins are usually too weak to be distinguished from background noise. Here, we present the detection and identification of remote single C-13 nuclear spins embedded in nuclear spin baths surrounding a single electron spins of a nitrogen-vacancy centre in diamond. With dynamical decoupling control of the centre electron spin, the weak magnetic field ~10 nT from a single nuclear spin located ~3 nm from the centre with hyperfine coupling as weak as ~500 Hz is amplified and detected. The quantum nature of the coupling is confirmed and precise position and the vector components of the nuclear field are determined. Given the distance over which nuclear magnetic fields can be detected the technique marks a firm step towards imaging, detecting and controlling nuclear spin species external to the diamond sensor

Operation and performance of the 4H-SiC junctionless FinFET

Abstract: This work presents a comprehensive study on the behaviour and operation of a vertical 1.2 kV 4H-SiC junctionless power FinFET. The increased bulk conduction in the channel of this topology may bring reductions in the channel resistance compared to trench MOSFETs, whose performance is limited by the high interface state density. For this purpose, finite element (FE) simulations are used to examine the operation of this device. It is hence demonstrated that the junctionless FinFET can attain a high average channel drift mobility well above 100 cm2/(Vs), leaving the resistance to be determined by the drift and substrate regions. This allows the FinFET to turn on and reach its steady state current using a much (> 3x) smaller gate overdrive than standard designs. On the other hand, however, the overly high field in the gate oxide, the lack of an efficient mechanism for hole extraction, and the low threshold voltage can cause significant reliability issues. Furthermore, it is shown that the high input capacitance of the FinFET can limit its switching speed to slower levels than in standard trench MOSFETs, which raises the need for further development of the original design proposed for vertical GaN devices. In this context, it is demonstrated that the addition of a p-shield below the trenches can alleviate the off-state reliability issues and increase the speed, while still maintaining a competitive R on ∼ 2mΩ cm2 even without the use of n-JFET enhancement doping