Self-aligned charge read-out for InAs nanowire quantum dots

A highly sensitive charge detector is realized for a quantum dot in an InAs nanowire. We have developed a self-aligned etching process to fabricate in a single step a quantum point contact in a two-dimensional electron gas and a quantum dot in an InAs nanowire. The quantum dot is strongly coupled to the underlying point contact which is used as a charge detector. The addition of one electron to the quantum dot leads to a change of the conductance of the charge detector by typically 20%. The charge sensitivity of the detector is used to measure Coulomb diamonds as well as charging events outside the dot. Charge stability diagrams measured by transport through the quantum dot and charge detection merge perfectly.Comment: 11 pages, 3 figure

Developing transferable management skills through Action Learning

There has been increasing criticism of the relevance of the Master of Business Administration (MBA) in developing skills and competencies. Action learning, devised to address problem-solving in the workplace, offers a potential response to such criticism. This paper offers an insight into one university’s attempt to integrate action learning into the curriculum. Sixty-five part-time students were questioned at two points in their final year about their action learning experience and the enhancement of relevant skills and competencies. Results showed a mixed picture. Strong confirmation of the importance of selected skills and competencies contrasted with weaker agreement about the extent to which these were developed by action learning. There was, nonetheless, a firm belief in the positive impact on the learning process. The paper concludes that action learning is not a panacea but has an important role in a repertoire of educational approaches to develop relevant skills and competencies

New quantum phases in a one-dimensional Josephson array

We examine the phase diagram of an ordered one-dimensional Josephson array of small grains. The average grain charge in such a system can be tuned by means of gate voltage. At small grain-to-grain conductance, this system is strongly correlated because of the charge discreteness constraint (Coulomb blockade). At the gate voltages in the vicinity of the charge degeneracy points, we find new phases equivalent to a commensurate charge density wave and to a repulsive Luttinger liquid. The existence of these phases can be probed through a special dependence of the Josephson current on the gate voltage.Comment: 4 pages, including 1 eps figur

Exhaled Nitric Oxide is Not a Biomarker for Pulmonary Tuberculosis.

To reduce transmission of tuberculosis (TB) in resource-limited countries where TB remains a major cause of mortality, novel diagnostic tools are urgently needed. We evaluated the fractional concentration of exhaled nitric oxide (FeNO) as an easily measured, noninvasive potential biomarker for diagnosis and monitoring of treatment response in participants with pulmonary TB including multidrug resistant-TB in Lima, Peru. In a longitudinal study however, we found no differences in baseline median FeNO levels between 38 TB participants and 93 age-matched controls (13 parts per billion [ppb] [interquartile range (IQR) = 8-26] versus 15 ppb [IQR = 12-24]), and there was no change over 60 days of treatment (15 ppb [IQR = 10-19] at day 60). Taking this and previous evidence together, we conclude FeNO is not of value in either the diagnosis of pulmonary TB or as a marker of treatment response

When does the action start and finish? Making the case for an ethnographic action research in educational research

This paper explores how ethnographic and action research methodologies can be justifiably combined to create a new methodological approach in educational research. It draws on existing examples in both educational research and development studies that have discussed the use of ethnography and action research in specific projects. Interpretations of ethnography and action research are developed that aim to minimise the epistemological differences between them. The paper also contextualises an ‘ethnographic action research’ approach with reference to an example of the author’s research into participation in three ‘reception’ (first year of schooling) classes in the United Kingdom. It is argued that research into the theme of participation in early years education, using participative methods, was particularly suitable for this new methodological approach

Energy band structure and intrinsic coherent properties in two weakly linked Bose Einstein Condensates

The energy band structure and energy splitting due to quantum tunneling in two weakly linked Bose-Einstein condensates were calculated by using the instanton method. The intrinsic coherent properties of Bose Josephson junction were investigated in terms of energy splitting. For $E_{C}/E_{J}\ll 1$, the energy splitting is small and the system is globally phase coherent. In the opposite limit, $E_{C}/E_{J}\gg 1$, the energy splitting is large and the system becomes a phase dissipation. Our reslults suggest that one should investigate the coherence phenomna of BJJ in proper condition such as $E_{C}/E_{J}\sim 1$.Comment: to appear in Phys. Rev. A, 2 figure

Clay minerals in delta deposits and organic preservation potential on Mars

Clay-rich sedimentary deposits are often sites of organic matter preservation and have therefore been sought in Mars exploration. However, regional deposits of hydrous minerals, including phyllosilicates and sulphates are not typically associated with valley networks and layered sediments that provide geomorphic evidence of surface water transport on early Mars. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) has recently identified phyllosilicates within three lake basins with fans or deltas that indicate sustained sediment deposition: Eberswalde crater Holden crater and Jezero crater. Here we use high-resolution data from the Mars Reconnaissance Orbiter (MRO) to identify clay-rich fluvial–lacustrine sediments within Jezero crater, which has a diameter of 45 km. The crater is an open lake basin on Mars with sedimentary deposits of hydrous minerals sourced from a smectite-rich catchment in the Nili Fossae region. We find that the two deltas and the lowest observed stratigraphic layer within the crater host iron–magnesium smectite clay. Jezero crater holds sediments that record multiple episodes of aqueous activity on early Mars. We suggest that this depositional setting and the smectite mineralogy make these deltaic deposits well suited for the sequestration and preservation of organic material

Double Field Theory Formulation of Heterotic Strings

We extend the recently constructed double field theory formulation of the low-energy theory of the closed bosonic string to the heterotic string. The action can be written in terms of a generalized metric that is a covariant tensor under O(D,D+n), where n denotes the number of gauge vectors, and n additional coordinates are introduced together with a covariant constraint that locally removes these new coordinates. For the abelian subsector, the action takes the same structural form as for the bosonic string, but based on the enlarged generalized metric, thereby featuring a global O(D,D+n) symmetry. After turning on non-abelian gauge couplings, this global symmetry is broken, but the action can still be written in a fully O(D,D+n) covariant fashion, in analogy to similar constructions in gauged supergravities.Comment: 28 pages, v2: minor changes, version published in JHE

Ceramics studio to podiatry clinic: The impact of multi-media resources in the teaching of practical skills across diverse disciplines

This paper draws on the experiences of students from two vastly different disciplines to both explore the theoretical background supporting the use of multimedia resources to teach practical skills and provide a qualitative evaluation of student perceptions and experiences of using bespoke resources. Within ceramics and podiatry, practical skills are traditionally taught via an apprenticeship model within small groups. We explore the practical and pedagogic benefits of developing bespoke multimedia resources to teach practical skills, identifying common themes from these disparate discipline areas. Student focus groups revealed that, practically, the opportunity for repeated viewing at convenient times promoted less reliance on lecturers and better preparation prior to practical demonstrations. Pedagogically, time for reflection and sense making underpinned an increase in confidence which in turn led to increased creativity. The student voice was also used to identify recommendations and challenges driving future change