Direct measurement of the transmission matrix of a mesoscopic conductor

We have developed an experimental approach which permits evaluation of the entire transmission matrix of a mesoscopic conductor. Results are presented from two new investigations enabled by this technique: (a) We study ballistic multiprobe conductors in the limit of weak probe coupling, and (b) we image modal features in the distribution function of electrons emerging from a quantum point contact

Imaging dielectric relaxation in nanostructured polymers by frequency modulation electrostatic force microscopy

We have developed a method for imaging the temperature-frequency dependence of the dynamics of nanostructured polymer films with spatial resolution. This method provides images with dielectric compositional contrast well decoupled from topography. Using frequency-modulation electrostatic-force-microscopy, we probe the local frequency-dependent (0.1–100 Hz) dielectric response through measurement of the amplitude and phase of the force gradient in response to an oscillating applied electric field. When the phase is imaged at fixed frequency, it reveals the spatial variation in dielectric losses, i.e., the spatial variation in molecular/dipolar dynamics, with 40 nm lateral resolution. This is demonstrated by using as a model system; a phase separated polystyrene/polyvinyl-acetate (PVAc) blend. We show that nanoscale dynamic domains of PVAc are clearly identifiable in phase images as those which light-up in a band of temperature, reflecting the variations in the molecular/dipolar dynamics approaching the glass transition temperature of PVAc

Experimental measurement of scattering coefficients in mesoscopic conductors

We describe a general experimental approach yielding the entire transmission matrix of a multiprobe mesoscopic conductor. Results are presented for several new investigations with ballistic semiconductor nanostructures enabled by this technique. We measure the transmission coefficients for an open cross junction employing a sample design which is an almost literal realization of the Landauer-Büttiker model and verify that these transmission coefficients are consistent with Hall and bend resistance anomalies obtained by resistance measurements at low magnetic fields. Other investigations utilize a pinched cross junction in which two of the probes are separated from the channel by quantum point contacts. This series arrangement of point contacts allows a sensitive momentum spectroscopy of the emitted distribution. Even in the case of a single propagating mode, through the constrictions we observe modal features in the outgoing distribution. This indicates that the potential is spatially nonadiabatic even though conductance quantization is observed. This pinched geometry also allows the first fully characterized realization of weakly coupled probes

Artificial Intelligence in Health Professions Regulation: An Exploratory Qualitative Study of Nurse Regulators in Three Jurisdictions

Background: Artificial intelligence (AI) refers to a broad group of technologies that are increasingly commonplace in everyday life; however, they have had only limited application in regulatory practice. Purpose: The present study explored nursing regulators’ perceptions of the role and value of AI in regulation and potential barriers and facilitators to the uptake and implementation of AI. Methods: Three facilitated focus group sessions with 28 representatives of regulators from Australia, the United Kingdom, and the United States were conducted. Content analysis of verbatim transcripts was completed. Results: Key themes that emerged included (a) interest in how AI could enhance sustainability and improve cost-effectiveness of certain regulatory processes and (b) concerns regarding how the term “artificial intelligence” itself could be problematic. Specific barriers to the uptake of AI in regulation included concerns regarding codification of system bias, negative public perception, and lack of clarity around accountability for decision-making. Facilitators to implementation included enhancing the consistency of processes and improving the decision-making and utility in supporting trend analyses and audit functions. Conclusion: Additional work in exploring how best to incorporate evolving AI technologies in regulatory practice—and what they should be named—is required, but these findings suggest that promising outcomes may lie ahead.Funding for this research was provided in part through an unrestricted grant from the National Council of State Boards of Nursing (NCSBN) of the United States of America

Health, human rights and mobilization of resources for health

BACKGROUND: There has been an increased interest in the role of a human rights framework to mobilize resources for health. DISCUSSION: This paper argues that the human rights framework does provide us with an appropriate understanding of what values should guide a nation's health policy, and a potentially powerful means of moving the health agenda forward. It also, however, argues that appeals to human rights may not necessarily be effective at mobilizing resources for specific health problems one might want to do something about. Specifically, it is not possible to argue that a particular allocation of scarce health care resources should be changed to a different allocation, benefiting other groups. Lack of access to health care services by some people only shows that something has to be done, but not what should be done. SUMMARY: The somewhat weak claim identified above together with the obligation to realize progressively a right to health can be used to mobilize resources for health

Efficient degradation of tannic acid by black Aspergillus species

A set of aspergillus strains from culture collections and wild-type black aspergilli isolated on non-selective media were used to validate the use of media with 20 % tannic acid for exclusive and complete selection of the black aspergilli. The 20% tannic acid medium proved useful for both quantitative and qualitative selection of all different black aspergilli, including all recognized species: A. carbonarius, A. japonicus, A. aculeatus, A foetidus, A. heteromorphus, A. niger, A. tubingensis and A. brasiliensis haplotypes. Even higher concentrations of tannic acid can be utilized by the black aspergilli suggesting a very efficient tannic acid-degrading system. Colour mutants show that the characteristic ability to grow on high tannic acid concentrations is not causally linked to the other typical feature of these aspergilli, i.e. the formation of brown-black pigments. Sequence analysis of the A. niger genome using the A. orvzae tannase gene yielded eleven tannase-like genes, far more than in related species. Therefore, a unique ecological niche in the degradation of tannic acid and connected nitrogen release seems to be reserved for these black-spored cosmopolitans

Standardized ADOS Scores: Measuring Severity of Autism Spectrum Disorders in a Dutch Sample

The validity of the calibrated severity scores on the ADOS as reported by Gotham et al. (J Autism Dev Disord 39: 693–705, 2009), was investigated in an independent sample of 1248 Dutch children with 1455 ADOS administrations (modules 1, 2 and 3). The greater comparability between ADOS administrations at different times, ages and in different modules, as reached by Gotham et al. with the calibrated severity measures, seems to be corroborated by the current study for module 1 and to a lesser extent for module 3. For module 2, the calibrated severity scores need to be further investigated within a sample that resembles Gotham’s sample in age and level of verbal functioning

North-South dialogues: reflecting on working transnationally with young men, masculinities and gender justice

Dialoguing across national borders and specifically global North-South centres and margins has increasingly been viewed as a way to enhance critical and feminist studies and engagement with men and masculinities. This article draws on narratives generated by a group of researchers in South Africa and Finland who have been engaged in a transnational research project that included a strong focus on young men, masculinities and gender and sexual justice. The piece provides an account of the nuanced and complex experiences and dynamics involved in transnational research collaboration, particularly within the framework on historical and continued inequalities between the global North and South. While obvious benefits are raised, this experience also foregrounds a range of challenges and constraints involved in transnational research collaboration within this field and possibly many others. Key learnings gleaned from this analysis of reported experiences and thoughts include the importance of careful, considered and critical reflexivity at all moments and at all levels, both in interpersonal and intergroup relations, as well as in public representation of collaborative work