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

Mapping the Local Spatial Charge in Defective Diamond by Means of N- v Sensors - A Self-Diagnostic Concept

Electrically active defects have a significant impact on the performance of electronic devices based on wide-band-gap materials. This issue is ubiquitous in diamond science and technology, since the presence of charge traps in the active regions of different classes of diamond-based devices (detectors, power diodes, transistors) can significantly affect their performance, due to the formation of space charge, memory effects, and the degradation of the electronic response associated with radiation-induced damage. Among the most common defects in diamond, the nitrogen-vacancy (N-V) center possesses unique spin properties that enable high-sensitivity field sensing at the nanoscale. Here, we demonstrate that N-V ensembles can be successfully exploited to perform direct local mapping of the internal electric-field distribution of a graphite-diamond-graphite junction exhibiting electrical properties dominated by trap- and space-charge-related conduction mechanisms. By means of optically detected magnetic resonance measurements, we performed both point-by-point readout and spatial mapping of the electric field in the active region at different bias voltages. In this novel “self-diagnostic” approach, defect complexes represent not only the source of detrimental space-charge effects but also a unique tool for their direct investigation, by providing an insight on the conduction mechanisms that could not be inferred in previous studies on the basis of conventional electrical and optical characterization techniques

A robust, scanning quantum system for nanoscale sensing and imaging

Controllable atomic-scale quantum systems hold great potential as sensitive tools for nanoscale imaging and metrology. Possible applications range from nanoscale electric and magnetic field sensing to single photon microscopy, quantum information processing, and bioimaging. At the heart of such schemes is the ability to scan and accurately position a robust sensor within a few nanometers of a sample of interest, while preserving the sensor's quantum coherence and readout fidelity. These combined requirements remain a challenge for all existing approaches that rely on direct grafting of individual solid state quantum systems or single molecules onto scanning-probe tips. Here, we demonstrate the fabrication and room temperature operation of a robust and isolated atomic-scale quantum sensor for scanning probe microscopy. Specifically, we employ a high-purity, single-crystalline diamond nanopillar probe containing a single Nitrogen-Vacancy (NV) color center. We illustrate the versatility and performance of our scanning NV sensor by conducting quantitative nanoscale magnetic field imaging and near-field single-photon fluorescence quenching microscopy. In both cases, we obtain imaging resolution in the range of 20 nm and sensitivity unprecedented in scanning quantum probe microscopy

Clinical observations of minimal gastrostomy through minilaparotomy in palliative patients

Gastrostomy is used to feed palliative patients with dysphagia. Currently, the preference is given to percutaneous puncture methods of gastrostomy, which do not require general anesthesia. Percutaneous puncture techniques are possible only if the patency of the upper parts of the digestive tract still exists for the «pull method» and can require additional X-ray irradiation in case of the «push method». These operations require expensive disposable kits, which affects the prevalence and availability of the technique. Therefore, the use of an alternative minimally invasive gastrostomy through minilaparotomy is justified. Minimal-invasive pressure gastrostomy is known for a long time, and in combination with small access, it can be successfully used to provide nutrition for palliative patients with dysphagia. Most patients with dysphagia have a thin anterior abdominal wall, which allows using minimal access. It is important to choose the right place of the incision so that access is in the area of the formation of the fistula. To obtain additional diagnostic information one can use a radiography of the abdominal cavity, which shows the gas bubble of the stomach, and other high-tech methods: ultrasound, spiral computed tomography, etc. At the same time such patients do not require general anesthesia, it is possible to perform the operation under a local anesthesia. The article provides a detailed description of the technique of minimal invasive laparotomy gastrostomy and two clinical observations of palliative patients who underwent this operation

Effective modelling of the Seebeck coefficient of Fe2VAl

Previous first-principles calculations have failed to reproduce many of the key thermoelectric features of Fe2VAl, e.g. the maximum values of the Seebeck coefficientSand its asymmetry with respect to the chemical potential. Also, previous theoretical predictions suggested that the pseudo band gap of Fe2VAl switches from indirect to direct upon doping. In this work, we report first-principles calculations that correctly reproduce the experimentally measured thermoelectric properties of Fe2VAl. This is achieved by adding a larger HubbardUterm to V atoms than to Fe atoms and including a scissors operator afterwards. As a result, bulk Fe2VAl is modelled as a gapless semiconductor with maximumSvalues of 76 and -158 μV/K forp- andn-type, respectively, which agree well with the experimental measurements