The 2-Hilbert Space of a Prequantum Bundle Gerbe

We construct a prequantum 2-Hilbert space for any line bundle gerbe whose Dixmier-Douady class is torsion. Analogously to usual prequantisation, this 2-Hilbert space has the category of sections of the line bundle gerbe as its underlying 2-vector space. These sections are obtained as certain morphism categories in Waldorf's version of the 2-category of line bundle gerbes. We show that these morphism categories carry a monoidal structure under which they are semisimple and abelian. We introduce a dual functor on the sections, which yields a closed structure on the morphisms between bundle gerbes and turns the category of sections into a 2-Hilbert space. We discuss how these 2-Hilbert spaces fit various expectations from higher prequantisation. We then extend the transgression functor to the full 2-category of bundle gerbes and demonstrate its compatibility with the additional structures introduced. We discuss various aspects of Kostant-Souriau prequantisation in this setting, including its dimensional reduction to ordinary prequantisation.Comment: 97 pages; v2: minor changes; Final version to be published in Reviews in Mathematical Physic

Portable sandblaster cleans small areas

Portable sandblasting unit rapidly and effectively cleans localized areas on a metal surface. The unit incorporates a bellows enclosure, masking plate, sand container, and used sand accummulator connected to a vacuum system. The bellows is equipped with an inspection window and light for observation of the sanding operation

Distilling Non-Locality

Two parts of an entangled quantum state can have a correlation in their joint behavior under measurements that is unexplainable by shared classical information. Such correlations are called non-local and have proven to be an interesting resource for information processing. Since non-local correlations are more useful if they are stronger, it is natural to ask whether weak non-locality can be amplified. We give an affirmative answer by presenting the first protocol for distilling non-locality in the framework of generalized non-signaling theories. Our protocol works for both quantum and non-quantum correlations. This shows that in many contexts, the extent to which a single instance of a correlation can violate a CHSH inequality is not a good measure for the usefulness of non-locality. A more meaningful measure follows from our results.Comment: Revised abstract, introduction and conclusion. Accepted by PR

The Half-lives of 132^{132}La and 135^{135}La

The half-lives of $^{135}$La and $^{132}$La were determined via gamma spectroscopy and high-precision ionization chamber measurements. The results are 18.930(6) h for $^{135}$La and 4.59(4) h for $^{132}$La compared to the previously compiled values of 19.5(2) h and 4.8(2) h, respectively. The new results represent an improvement in the precision and accuracy of both values. These lanthanum isotopes comprise a medically interesting system with positron emitter $^{132}$La and Auger electron emitter $^{135}$La forming a matched pair for internal diagnostics and therapeutics. The precise half-lives are necessary for proper evaluation of their value in medicine and for a more representative tabulation of nuclear data.Comment: 11 pages, 3 figure

Overburdening of peer review: A multi-stakeholder perspective on causes and effects

Peer review of manuscripts is labour-intensive and time-consuming. Individual reviewers might feel themselves overburdened with the amount of reviewing they are requested to do. Aiming to explore how stakeholder groups perceive reviewing burden and what they believe to be the causes of a potential overburdening of reviewers, we conducted focus groups with early-, mid-, and senior career scholars, editors, and publishers. By means of a thematic analysis, we aimed to identify the causes of overburdening of reviewers. First, we show that, across disciplines and roles, stakeholders believed that the reviewing burden is distributed unequally across members of the academic community, resulting in the overburdening of small groups of reviewers. Second, stakeholders believed this to be caused by (i) an increase in manuscript submissions; (ii) inefficient manuscript handling; (iii) lack of institutionalization of peer review; (iv) lack of reviewing instructions and (v) inadequate reviewer recruiting strategies. These themes were assumed to relate to an inadequate incentive structure in academia that favours publications over peer review. In order to alleviate reviewing burden, a holistic approach is required that addresses both the increased demand for and the insufficient supply of reviewing resources

Unresolved Crisis in Medical Education

A crisis exists in medical education. Changes in methodology have diverted attention from synthesis to mass accumulation of factual data. The response to this crisis has been largely focused on a shell game involving new pathways and curriculum changes without addressing the critical issue of what constitutes education. The ultimate problem in medical education is a crisis of leadership. Until education is given a priority status and the obligations to teach on the part of medical educators and to learn on the part of students are translated into a creative policy by those who can lead, the wheels of learning will continue to spin without significant progress

Trends in odor intensity for human and electronic noses: Relative roles of odorant vapor pressure vs. molecularly specific odorant binding

Response data were collected for a carbon black-polymer composite electronic nose array during exposure to homologous series of alkanes and alcohols. The mean response intensity of the electronic nose detectors and the response intensity of the most strongly driven set of electronic nose detectors were essentially constant for members of a chemically homologous odorant series when the concentration of each odorant in the gas phase was maintained at a constant fraction of the odorant’s vapor pressure. A similar trend is observed in human odor detection threshold values for these same homologous series of odorants. Because the thermodynamic activity of an odorant at equilibrium in a sorbent phase is equal to the partial pressure of the odorant in the gas phase divided by the vapor pressure of the odorant and because the activity coefficients are similar within these homologous series of odorants for sorption of the vapors into specific polymer films, the data imply that the trends in detector response can be understood based on the thermodynamic tendency to establish a relatively constant concentration of sorbed odorant into each of the polymeric films of the electronic nose at a constant fraction of the odorant’s vapor pressure. Similarly, the data are consistent with the hypothesis that the odor detection thresholds observed in human psychophysical experiments for the odorants studied herein are driven predominantly by the similarity in odorant concentrations sorbed into the olfactory epithelium at a constant fraction of the odorant’s vapor pressure

An Investigation of the Concentration Dependence and Response to Analyte Mixtures of Carbon Black/Insulating Organic Polymer Composite Vapor Detectors

The responses relative to an air background of carbon black/polymer composite vapor detectors have been determined as a function of the concentration of a homologous series of alcohols (n-C_nH_(2n+1)OH, 1 ≤ n ≤ 8), a homologous series of alkanes (n-C_nH_(2n+2), 5 ≤ n ≤ 10 and n = 12, 14), and a set of diverse solvent vapors. In all cases, the steady-state relative differential resistance responses, ΔR/R_b, of the carbon black/polymer composite vapor detectors were well-described by a linear relationship with respect to the analyte partial pressure, at least over the tested concentration range (P/P° = 0.005−0.03, where P° is the vapor pressure of the analyte). When two vapors in air were simultaneously presented to the detectors, the ΔR/R_b response, relative to an air background, was the sum of the ΔR/R_b values obtained when each analyte was exposed separately to the carbon black/polymer composite detectors under study. Similarly, when an analyte was exposed to the detectors on top of a background level of another analyte, the ΔR/R_b values of the array of detectors were very close to those obtained when the test analyte was exposed to the detectors only in the presence of background air. The initial training requirements from the array response output data of such detectors are minimized because the ΔR/R_b response pattern produced by the analyte of concern can be associated uniquely with that odor, under the conditions explored in this work