Multicanonical Parallel Tempering

We present a novel implementation of the parallel tempering Monte Carlo method in a multicanonical ensemble. Multicanonical weights are derived by a self-consistent iterative process using a Boltzmann inversion of global energy histograms. This procedure gives rise to a much broader overlap of thermodynamic-property histograms; fewer replicas are necessary in parallel tempering simulations, and the acceptance of trial swap moves can be made arbitrarily high. We demonstrate the usefulness of the method in the context of a grand-multicanonical ensemble, where we use multicanonical simulations in energy space with the addition of an unmodified chemical potential term in particle-number space. Several possible implementations are discussed, and the best choice is presented in the context of the liquid-gas phase transition of the Lennard-Jones fluid. A substantial decrease in the necessary number of replicas can be achieved through the proposed method, thereby providing a higher efficiency and the possibility of parallelization.Comment: 8 pages, 3 figure, accepted by J Chem Phy

Inter-organisational communication networks in healthcare: centralised versus decentralised approaches

Background: To afford efficient and high quality care, healthcare providers increasingly need to exchange patient data. The existence of a communication network amongst care providers will help them to exchange patient data more efficiently. Information and communication technology (ICT) has much potential to facilitate the development of such a communication network. Moreover, in order to offer integrated care interoperability of healthcare organizations based upon the exchanged data is of crucial importance. However, complications around such a development are beyond technical impediments. Objectives: To determine the challenges and complexities involved in building an Inter-organisational Communication network (IOCN) in healthcare and the appropriations in the strategies. Case study: Interviews, literature review, and document analysis were conducted to analyse the developments that have taken place toward building a countrywide electronic patient record and its challenges in The Netherlands. Due to the interrelated nature of technical and non-technical problems, a socio-technical approach was used to analyse the data and define the challenges. Results: Organisational and cultural changes are necessary before technical solutions can be applied. There are organisational, financial, political, and ethicolegal challenges that have to be addressed appropriately. Two different approaches, one ‘‘centralised’’ and the other ‘‘decentralised’’ have been used by Dutch healthcare providers to adopt the necessary changes and cope with these challenges. Conclusion: The best solutions in building an IOCN have to be drawn from both the centralised and the decentralised approaches. Local communication initiatives have to be supervised and supported centrally and incentives at the organisations’ interest level have to be created to encourage the stakeholder organisations to adopt the necessary changes

Nineteenth-Century Mathematics in the Mirror of Its Literature: A Quantitative Approach

AbstractThe point of departure of this paper is the idea that the development of mathematics is reflected in its publications. Hence, the existence of a nearly complete database renders possible general statistical accounts of the development of mathematical activities. To this end, the authors utilize the mathematical index of theCatalogue of Scientific Papersof the Royal Society of London dealing with the mathematical journal literature of the 19th century. The relation between the journal and book literature of that century is discussed, with the result that the size of the journal literature is presumably a valid indicator of the intensity of mathematical activities in particular areas. On the basis of thisCatalogue,graphs of the publication activity of all of 19th-century mathematics and of 34 of its most important subareas are displayed; both the number of active contributors in each area and its share of 19th-century mathematics publications are exhibited. Furthermore, the share of mathematics of the total scientific journal literature of the 19th-century is estimated. Frequency distributions of publication activity and the specialization of 19th-century mathematicians conform to patterns well known in modern scientometrics.In dieser Arbeit wird davon ausgegangen, daß sich die Entwicklung der Mathematik in ihren Publikationen widerspiegelt. Eine annähernd vollständige bibliographische Datengrundlage gestattet daher globale statistische Beschreibungen der Entwicklung mathematischer Aktivitäten. Die Autoren werteten zu diesem Zweck den mathematischen Index desCatalogue of Scientific Papersder Royal Society of London aus, der die mathematische Zeitschriftenliteratur des 19. Jahrhunderts berücksichtigt. Sie diskutieren das Verhältnis von Zeitschriften- zu Buchliteratur in diesem Jahrhundert mit dem Ergebnis, daß der Umfang der Zeitschriftenliteratur vermutlich als Indikator der Intensität mathematischer Aktivitäten auf einzelnen Gebieten gelten kann. Auf der Grundlage des Catalogue werden zur gesamten Mathematik sowie zu 34 der wichtigsten Teilgebiete Verlaufskurven der Publikationsaktivitäten gezeigt, zum einen als Publikationsanteile am Gesamtgebiet, zum anderen als absolute Zahl der auf einem Teilgebiet überhaupt aktiven Mathematiker. Ferner wird der Anteil der Mathematik an der gesamten naturwissenschaftlichen Zeitschriftenliteratur des 19. Jahrhunderts geschätzt. Häufigkeitsverteilungen der Publikationsaktivität und der Spezialisierung der mathematischen Autoren des 19. Jahrhunderts ergaben in der zeitgenössischen Szientometrie bekannte Verteilungsmuster.Utgångspunkten för denna artikel är föreställningen, att matematikens utveckling återspeglas i dess publikationer. Existensen av en så gott som fullständig databas möjliggör därför allmänna statistiska beskrivningar av utvecklingen av matematiska aktiviteter. För detta ändamål utnyttjade författarna det matematiska indexet till denCatalogue of Scientific Papers,som utgivits av Royal Society of London och som behandler 1800-talets matematiska tidskriftslitteratur. Förhållandet mellan det åhundradets tidskrifts- och boklitteratur diskuteras med resultatet, att tidskriftslitteraturens omfång förmodligen gör, att den kan gälla som indikator på itensiteten hos matematiska aktiviteter på ensklida områden. Utgående från dennaCataloguevisas kurvor på 34 av dess viktigaste delområden; i det senare fallet anges dels varje delområdes andel i publikationer av hela mathematiken, dels antalet aktiva matematiker på området. Vidare uppskattas matematikens andel av hela den naturvetenskapliga tidskriftslitteraturen under 1800-talet. Frekvensfördelningar av publikationsaktiviteten och specialiseringen hos 1800-talets matematiker följer mönster, som är bekanta i den moderna scientometrin

Continuous Flow Synthesis of Azoxybenzenes by Reductive Dimerization of Nitrosobenzenes with Gel‐Bound Catalysts

In the search for a new synthetic pathway for azoxybenzenes with different substitution patterns, an approach using a microfluidic reactor with gel-bound proline organocatalysts under continuous flow is presented. Herein the formation of differently substituted azoxybezenes by reductive dimerization of nitrosobenzenes within minutes at mild conditions in good to almost quantitative yields is described. The conversion within the microfluidic reactor is analyzed and used for optimizing and validating different parameters. The effects of the different functionalities on conversion, yield, and reaction times are analyzed in detail by NMR. The applicability of this reductive dimerization is demonstrated for a wide range of differently substituted nitrosobenzenes. The effects of these different functionalities on the structure of the obtained azoxyarenes are analyzed in detail by NMR and single-crystal X-ray diffraction. Based on these results, the turnover number and the turnover frequency were determined

Strongly correlating liquids and their isomorphs

This paper summarizes the properties of strongly correlating liquids, i.e., liquids with strong correlations between virial and potential energy equilibrium fluctuations at constant volume. We proceed to focus on the experimental predictions for strongly correlating glass-forming liquids. These predictions include i) density scaling, ii) isochronal superposition, iii) that there is a single function from which all frequency-dependent viscoelastic response functions may be calculated, iv) that strongly correlating liquids are approximately single-parameter liquids with close to unity Prigogine-Defay ratio, and v) that the fictive temperature initially decreases for an isobaric temperature up jump. The "isomorph filter", which allows one to test for universality of theories for the non-Arrhenius temperature dependence of the relaxation time, is also briefly discussed

Telemedicine in interdisciplinary work practices: On an IT system that met the criteria for success set out by its sponsors, yet failed to become part of every-day clinical routines

Background. Information systems can play a key role in care innovations including task redesign and shared care. Many demonstration projects have presented evidence of clinical and cost effectiveness and high levels of patient satisfaction. Yet these same projects often fail to become part of everyday clinical routines. The aim of the paper is to gain insight into a common paradox that a technology can meet the criteria for success set out at the start of the project yet fail to become part of everyday clinical routines. Methods. We evaluated a telecare service set up to reduce the workload of ophthalmologists. In this project, optometrists in 10 optical shops made digital images to detect patients with glaucoma which were furth

Evidence for differential effects of reduced and oxidised nitrogen deposition on vegetation independent of nitrogen load

Nitrogen (N) deposition impacts natural and semi-natural ecosystems globally. The responses of vegetation to N deposition may, however, differ strongly between habitats and may be mediated by the form of N. Although much attention has been focused on the impact of total N deposition, the effects of reduced and oxidised N, independent of the total N deposition, have received less attention. In this paper, we present new analyses of national monitoring data in the UK to provide an extensive evaluation of whether there are differences in the effects of reduced and oxidised N deposition across eight habitat types (acid, calcareous and mesotrophic grasslands, upland and lowland heaths, bogs and mires, base-rich mires, woodlands). We analysed data from 6860 plots in the British Countryside Survey 2007 for effects of total N deposition and N form on species richness, Ellenberg N values and grass:forb ratio. Our results provide clear evidence that that N deposition affects species richness in all habitats except base-rich mires, after factoring out correlated explanatory variables (climate and sulphur deposition). In addition, the form of N in deposition appears important for the biodiversity of grasslands and woodlands but not mires and heaths. Ellenberg N increased more in relation to NHx deposition than NOy deposition in all but one habitat type. Relationships between species richness and N form were habitat-specific: acid and mesotrophic grasslands appear more sensitive to NHx deposition while calcareous grasslands and woodlands appeared more responsive to NOy deposition. These relationships are likely driven by the preferences of the component plant species for oxidised or reduced forms of N, rather than by soil acidification

Modeling genetic imprinting effects of DNA sequences with multilocus polymorphism data

Single nucleotide polymorphisms (SNPs) represent the most widespread type of DNA sequence variation in the human genome and they have recently emerged as valuable genetic markers for revealing the genetic architecture of complex traits in terms of nucleotide combination and sequence. Here, we extend an algorithmic model for the haplotype analysis of SNPs to estimate the effects of genetic imprinting expressed at the DNA sequence level. The model provides a general procedure for identifying the number and types of optimal DNA sequence variants that are expressed differently due to their parental origin. The model is used to analyze a genetic data set collected from a pain genetics project. We find that DNA haplotype GAC from three SNPs, OPRKG36T (with two alleles G and T), OPRKA843G (with alleles A and G), and OPRKC846T (with alleles C and T), at the kappa-opioid receptor, triggers a significant effect on pain sensitivity, but with expression significantly depending on the parent from which it is inherited (p = 0.008). With a tremendous advance in SNP identification and automated screening, the model founded on haplotype discovery and statistical inference may provide a useful tool for genetic analysis of any quantitative trait with complex inheritance

KAI407, a potent non-8-aminoquinoline compound that kills Plasmodium cynomolgi early dormant liver stage parasites in vitro.

Preventing relapses of Plasmodium vivax malaria through a radical cure depends on use of the 8-aminoquinoline primaquine, which is associated with safety and compliance issues. For future malaria eradication strategies, new, safer radical curative compounds that efficiently kill dormant liver stages (hypnozoites) will be essential. A new compound with potential radical cure activity was identified using a low-throughput assay of in vitro-cultured hypnozoite forms of Plasmodium cynomolgi (an excellent and accessible model for Plasmodium vivax). In this assay, primary rhesus hepatocytes are infected with P. cynomolgi sporozoites, and exoerythrocytic development is monitored in the presence of compounds. Liver stage cultures are fixed after 6 days and stained with anti-Hsp70 antibodies, and the relative proportions of small (hypnozoite) and large (schizont) forms relative to the untreated controls are determined. This assay was used to screen a series of 18 known antimalarials and 14 new non-8-aminoquinolines (preselected for blood and/or liver stage activity) in three-point 10-fold dilutions (0.1, 1, and 10 μM final concentrations). A novel compound, designated KAI407 showed an activity profile similar to that of primaquine (PQ), efficiently killing the earliest stages of the parasites that become either primary hepatic schizonts or hypnozoites (50% inhibitory concentration [IC50] for hypnozoites, KAI407, 0.69 μM, and PQ, 0.84 μM; for developing liver stages, KAI407, 0.64 μM, and PQ, 0.37 μM). When given as causal prophylaxis, a single oral dose of 100 mg/kg of body weight prevented blood stage parasitemia in mice. From these results, we conclude that KAI407 may represent a new compound class for P. vivax malaria prophylaxis and potentially a radical cure