Geometrical frustration versus Kitaev interactions in BaCo2(AsO4)2.

Recently, Co-based honeycomb magnets have been proposed as promising candidate materials to host the Kitaev spin liquid (KSL) state. One of the front-runners is BaCo2(AsO4)2 (BCAO), where it was suggested that the exchange processes between Co2+ ions via the surrounding edge-sharing oxygen octahedra could give rise to bond-dependent Kitaev interactions. In this work, we present and analyze a comprehensive inelastic neutron scattering (INS) study of BCAO with fields in the honeycomb plane. Combining the constraints from the magnon excitations in the high-field polarized state and the inelastic spin structure factor measured in zero magnetic field, we examine two leading theoretical models: the Kitaev-type [Formula: see text] model and the XXZ[Formula: see text]model. We show that the existing experimental data can be consistently accounted for by the XXZ[Formula: see text]model but not by the [Formula: see text] model, and we discuss the implications of these results for the realization of a spin liquid phase in BCAO and more generally for the realization of the Kitaev model in cobaltates.

Romosozumab in patients who experienced an on-study fracture: post hoc analyses of the FRAME and ARCH phase 3 trials.

Post hoc analysis of FRAME and ARCH revealed that on-study nonvertebral and vertebral fractures by Month 12 were less common in women initially treated with romosozumab versus placebo or alendronate. Recurrent fracture risk was also lower in romosozumab­treated patients, and there were no fracture­related complications. Results support continuing romosozumab treatment post­fracture. PURPOSE: Post hoc analysis evaluating efficacy and safety of romosozumab, administered in the immediate post­fracture period, in the FRAME and ARCH phase 3 trials. METHODS: In FRAME (NCT01575834) and ARCH (NCT01631214), postmenopausal women with osteoporosis were randomized 1:1 to romosozumab 210 mg monthly or comparator (FRAME, placebo; ARCH, alendronate 70 mg weekly) for 12 months, followed by antiresorptive therapy (FRAME, denosumab; ARCH, alendronate). In patients who experienced on-study nonvertebral or new/worsening vertebral fracture by Month 12, we report the following: fracture and treatment­emergent adverse event (TEAE) incidence through 36 months, bone mineral density changes (BMD), and romosozumab timing. Due to the sample sizes employed, meaningful statistical comparisons between treatments were not possible. RESULTS: Incidence of on-study nonvertebral and vertebral fractures by Month 12 was numerically lower in romosozumab- versus comparator-treated patients (FRAME, 1.6% and 0.5% versus 2.1% and 1.6%; ARCH, 3.4% and 3.3% versus 4.6% and 4.9%, respectively). In those who experienced on-study nonvertebral fracture by Month 12, recurrent nonvertebral and subsequent vertebral fracture incidences were numerically lower in patients initially treated with romosozumab versus comparator (FRAME, 3.6% [2/56] and 1.8% [1/56] versus 9.2% [7/76] and 3.9% [3/76]; ARCH, 10.0% [7/70] and 5.7% [4/70] versus 12.6% [12/95] and 8.4% [8/95], respectively). Among those with on-study vertebral fracture by Month 12, recurrent vertebral and subsequent nonvertebral fracture incidences were numerically lower with romosozumab versus comparator (FRAME, 0.0% [0/17] and 0.0% [0/17] versus 11.9% [7/59] and 8.5% [5/59]; ARCH, 9.0% [6/67] and 7.5% [5/67] versus 15.0% [15/100] and 16.0% [16/100], respectively). In patients with fracture by Month 12, no fracture­related complications were reported in romosozumab-treated patients. BMD gains were numerically greater with romosozumab than comparators. CONCLUSION: Data suggest support for the efficacy and safety of continuing romosozumab treatment following fracture. TRIAL REGISTRATIONS: NCT01575834; NCT01631214.

Veterinary Services'use of the Global Burden of Animal Diseases to prioritise interventions, monitor impact and develop critical competencies.

Attracting and sustaining investment in Veterinary Services and animal health programmes from national government budgets, development aid and grants, and philanthropic donors requires economic rationale using relevant, reliable and validated analytical approaches. The complex interwoven relationships between animal health, livestock husbandry systems, national food security, global health security and environmental sustainability emphasise the importance of improving data governance and stewardship and applying economic analysis to understand animal disease burdens. These efforts should enable prioritised investment of limited resources and effective monitoring of the impact of programmes over time. Data governance and stewardship capacities are fundamental to development, implementation and performance monitoring of evidence-based policies in animal health. There are challenges in data availability for national and subnational livestock populations in different sectors, for disease incidence and prevalence, and for animal health expenditure in support of optimised allocation of scarce resources, be they finance, land, labour, or management attention and policy focus. Animal health data systems governance and stewardship and economic analysis are core skills for Veterinary Services in developing and applying evidence-based policy, but capability probably varies among World Organisation for Animal Health (WOAH) Members. The WOAH Performance of Veterinary Services programme has several critical competencies that are relevant to economics of animal health and to data governance and stewardship, but these have not yet been targeted for coordinated capacity development. Implementation of publicâ€"private partnership approaches for animal health programmes creates increasing expectations of robust data and methods for prioritisation, options analysis, and assessing impacts and costs. Experience and examples from national systems in New Zealand, Australia, Ethiopia and Indonesia illustrate current challenges associated with prioritisation of animal health programmes using economic analysis. The Global Burden of Animal Diseases programme intends to support WOAH Members and partners to develop capacities for and standardise approaches to economic analysis and prioritisation in animal health programmes.

Les investissements dans les Services vétérinaires et dans les programmes de santé animale à partir des budgets publics nationaux, des aides et subventions au développement et des fonds alloués par des donateurs philanthropiques peuvent être encouragés et pérennisés au moyen d'une argumentation économique solide fondée sur des méthodes analytiques pertinentes, fiables et validées. La complexité et l'imbrication des relations entre la santé animale, les systèmes d'élevage, la sécurité de l'approvisionnement alimentaire à l'échelle nationale, la sécurité sanitaire mondiale et la durabilité environnementale imposent d'améliorer la gouvernance et la gestion des données et de recourir à des analyses économiques pour mieux comprendre l'impact des maladies animales. Ces efforts devraient permettre de définir les investissements prioritaires dans un contexte de ressources limitées et d'assurer un suivi efficace de l'impact des programmes dans le temps. L'existence de capacités de gouvernance et de gestion des données est donc une condition essentielle pour concevoir et mettre en oeuvre des politiques de santé animale fondées sur des données factuelles et pour suivre leurs performances. Les données disponibles sur les populations d'animaux d'élevage des différentes filières aux niveaux national ou infranational, sur l'incidence et la prévalence des maladies ou sur les dépenses de santé animale sont parfois insuffisantes pour étayer une utilisation optimale de ressources limitées, qu'il s'agisse de moyens financiers, des terres, de la main-d'oeuvre, voire des efforts de gestion ou de la volonté politique. La gouvernance et la gestion des systèmes de données de santé animale et la conduite d'analyses économiques sont des compétences cruciales des Services vétérinaires, que ceux-ci mobilisent pour concevoir et mettre en oeuvre des politiques fondées sur des données factuelles ; il est néanmoins peu probable que ces capacités soient d'un niveau homogène parmi tous les Membres de l'Organisation mondiale de la santé animale (OMSA). Le Processus d'évaluation de la Performance des Services vétérinaires mis en place par l'OMSA définit un certain nombre de compétences critiques dans le domaine de l'économie de la santé animale et de la gouvernance et gestion des données, mais ces compétences n'ont pas encore été intégrées dans un effort coordonné de renforcement des capacités. Les stratégies consistant à confier la mise en oeuvre de programmes de santé animale à des partenariats public-privé suscitent des besoins accrus en données et en méthodes robustes pour l'établissement des priorités, l'analyse des options et l'évaluation des impacts et des coûts. Les auteurs mentionnent les expériences et exemples de systèmes nationaux en Nouvelle-Zélande, en Australie, en Ethiopie et en Indonésie pour illustrer les enjeux actuels liés à l'utilisation des analyses économiques pour définir les priorités des programmes de santé animale. Le programme " Impact mondial des maladies animales " vise à aider les Membres et les partenaires de l'OMSA à renforcer leurs capacités dans le domaine de l'analyse économique et de la définition des priorités des programmes de santé animale et à normaliser leurs approches en la matière.

Para atraer y mantener las inversiones en los Servicios Veterinarios y los programas de sanidad animal procedentes de los presupuestos de los gobiernos nacionales, la ayuda para el desarrollo y las subvenciones, así como de donantes filántropos, se requiere un razonamiento económico en el que se utilicen enfoques analíticos pertinentes, fiables y validados. Las complejas relaciones entre la sanidad animal, los sistemas de ganadería, la seguridad alimentaria nacional, la seguridad sanitaria mundial y la sostenibilidad ambiental ponen de relieve la importancia de mejorar la gobernanza y la gestión de datos y de aplicar el análisis económico para comprender el impacto de las enfermedades animales. Estos esfuerzos deberían permitir establecer prioridades para la inversión de los limitados recursos y realizar un seguimiento eficaz de las repercusiones de los programas a lo largo del tiempo. Las capacidades de gobernanza y gestión de datos son fundamentales para el desarrollo y la implementación de políticas de sanidad animal con una base empírica y para el seguimiento de sus resultados. Existen dificultades en cuanto a la disponibilidad de datos sobre las cabañas ganaderas nacionales y subnacionales de los distintos sectores, la incidencia y prevalencia de las enfermedades y el gasto en sanidad animal que plantean problemas a la hora de optimizar la asignación de unos recursos que son escasos, ya sean los recursos financieros, las tierras, la mano de obra o la atención a la gestión y la orientación de las políticas. La gobernanza y la gestión de los sistemas de datos zoosanitarios y el análisis económico son competencias esenciales para que los Servicios Veterinarios elaboren y apliquen políticas con base empírica, pero es probable que la capacidad varíe entre los Miembros de la Organización Mundial de Sanidad Animal (OMSA). El Proceso de Prestaciones de los Servicios Veterinarios de la OMSA abarca varias competencias esenciales que son relevantes para la economía de la sanidad animal y para la gobernanza y la gestión de datos, pero que aún no han sido objeto de actividades coordinadas de desarrollo de capacidades. La aplicación de enfoques de asociación público-privada para los programas de sanidad animal aumenta aún más las expectativas de datos y métodos sólidos para el establecimiento de prioridades, el análisis de opciones y la evaluación de las repercusiones y los costos. La experiencia y los ejemplos de los sistemas nacionales de Nueva Zelanda, Australia, Etiopía e Indonesia ilustran los retos actuales asociados al establecimiento de prioridades en los programas de sanidad animal mediante el análisis económico. El programa sobre el impacto global de las enfermedades animales pretende ayudar a los Miembros y socios de la OMSA a desarrollar capacidades y armonizar enfoques para el análisis económico y el establecimiento de prioridades en los programas de sanidad animal.

The effect of shear-dependent flocculation on the multimodality of effective particle size distributions in a gravel-bed river during high flows.

Purpose: Multimodal effective particle size distributions (EPSDs) develop as flocculation and particle breakage occur dynamically in a fluid shear and such distributions have been previously reported in coastal and estuarine waters to understand flocculation processes. Here, we use time varying multimodal EPSDs and hydraulic parameters (discharge and bed shear stress) to assess freshwater flocculation in a gravel-bed river in southern Alberta, Canada. Methods: Instantaneous discharge, volume concentration (VC), and EPSD of suspended solids were measured during three high discharge events at four study sites in a 10 km reach of the Crowsnest River. The EPSD and VC of suspended solids (< 500 µm) were measured in the centroid of flow with a LISST-200x. Bed shear stress for measured discharge was obtained using a flow model, MOBED. Results: Multimodal EPSDs consisted of primary particles, flocculi, microflocs, and macroflocs. Shear dependent flocculation was consistently observed for all sites and events, due to low and high shear stress flocculation, particle breakage, and mobilization of tributary sub-catchment derived particles. Higher shear stress limited flocculation to smaller floc sizes, while lower bed shear stress conditions created higher volumes of macroflocs. Conclusion: Flocculation and particle breakage processes based on relationships between particle size and hydraulic properties presented herein have implications for advancing fine sediment transport models by a variable cohesion factor as a function of floc size class.

Dirac Magnons, Nodal Lines, and Nodal Plane in Elemental Gadolinium.

We investigate the magnetic excitations of elemental gadolinium (Gd) using inelastic neutron scattering, showing that Gd is a Dirac magnon material with nodal lines at K and nodal planes at half integer ℓ. We find an anisotropic intensity winding around the K-point Dirac magnon cone, which is interpreted to indicate Berry phase physics. Using linear spin wave theory calculations, we show the nodal lines have nontrivial Berry phases, and topological surface modes. We also discuss the origin of the nodal plane in terms of a screw-axis symmetry, and introduce a topological invariant characterizing its presence and effect on the scattering intensity. Together, these results indicate a highly nontrivial topology, which is generic to hexagonal close packed ferromagnets. We discuss potential implications for other such systems.

Diagnosis and Management of Osteoporosis During COVID-19: Systematic Review and Practical Guidance.

It is acknowledged that the COVID-19 pandemic has caused profound disruption to the delivery of healthcare services globally. This has affected the management of many long-term conditions including osteoporosis as resources are diverted to cover urgent care. Osteoporosis is a public health concern worldwide and treatment is required for the prevention of further bone loss, deterioration of skeletal micro-architecture, and fragility fractures. This review provides information on how the COVID-19 pandemic has impacted the diagnosis and management of osteoporosis. We also provide clinical recommendations on the adaptation of care pathways based on experience from five referral centres to ensure that patients with osteoporosis are still treated and to reduce the risk of fractures both for the individual patient and on a societal basis. We address the use of the FRAX tool for risk stratification and initiation of osteoporosis treatment and discuss the potential adaptations to treatment pathways in view of limitations on the availability of DXA. We focus on the issues surrounding initiation and maintenance of treatment for patients on parenteral therapies such as zoledronate, denosumab, teriparatide, and romosozumab during the pandemic. The design of these innovative care pathways for the management of patients with osteoporosis may also provide a platform for future improvement to osteoporosis services when routine clinical care resumes.

Global Burden of Animal Diseases: a novel approach to understanding and managing disease in livestock and aquaculture.

Investments in animal health and Veterinary Services can have a measurable impact on the health of people and the environment. These investments require a baseline metric that describes the burden of animal health and welfare in order to justify and prioritise resource allocation and from which to measure the impact of interventions. This paper is part of a process of scientific enquiry in which problems are identified and solutions sought in an inclusive way. It poses the broad question: what should a system to measure the animal disease burden on society look like and what value would it add? Moreover, it aims to do this in such a way as to be accessible by a wide audience, who are encouraged to engage in this debate. Given that farmed animals, including those raised by poor smallholders, are an economic entity, this system should be based on economic principles. These poor farmers are negatively impacted by disparities in animal health technology, which can be addressed through a mixture of supply-led and demand-driven interventions, reinforcing the relevance of targeted financial support from government and non-governmental organisations. The Global Burden of Animal Diseases (GBADs) Programme will glean existing data to measure animal health losses within carefully characterised production systems. Consistent and transparent attribution of animal health losses will enable meaningful comparisons of the animal disease burden to be made between diseases, production systems and countries, and will show how it is apportioned by people's socio-economic status and gender. The GBADs Programme will produce a cloud-based knowledge engine and data portal, through which users will access burden metrics and associated visualisations, support for decisionmaking in the form of future animal health scenarios, and the outputs of wider economic modelling. The vision of GBADs, strengthening the food system for the benefit of society and the environment, is an example of One Health thinking in action.

Les investissements réalisés en santé animale et dans les Services vétérinaires ont un impact mesurable sur la santé des personnes et de l'environnement. Le système de mesure appliqué à ces investissements doit reposer sur un référentiel de base décrivant l'impact de la santé et du bien-être animal de manière à justifier et classer par priorités les ressources allouées et à mesurer les effets des interventions. Les auteurs présentent une étude conduite dans le cadre d'une enquête scientifique destinée à identifier les problèmes et à rechercher des solutions de manière inclusive. L'étude pose la question de savoir à quoi devrait ressembler un système conçu pour mesurer l'impact sur la société des maladies animales, et quelle serait sa valeur ajoutée. En outre, l'étude est conduite de manière à être accessible à une large audience afin d'encourager cette dernière à participer aux discussions. Étant donné que les animaux d'élevage constituent une entité économique, y compris les animaux appartenant à des éleveurs pauvres, le système de mesure doit reposer sur des principes économiques. Les exploitants pratiquant une agriculture de subsistance subissent les effets négatifs des disparités entre les différentes technologies applicables à la santé animale, disparités auxquelles il est possible de remédier par le biais d'interventions associant des mesures dictées par l'offre et par la demande et en renforçant l'efficacité du soutien financier ciblé apporté par les organisations gouvernementales et non gouvernementales. Le Programme « L'impact mondial des maladies animales ¼ (GBADs) aura pour tâche de glaner les données existantes afin de mesurer les pertes associées à la santé animale au sein de systèmes de production qui auront été soigneusement caractérisés au préalable. Grâce à l'élucidation cohérente et transparente des pertes imputables à chaque problème de santé animale, des comparaisons pertinentes pourront être effectuées concernant l'impact des maladies animales par maladies, par systèmes de production et par pays, et la répartition de cet impact dans les populations concernées suivant le statut socio-économique et le genre des intéressés sera mieux comprise. Le Programme GBADs entend créer un moteur de recherche et un portail de données qui seront disponibles sur le Cloud et donneront aux utilisateurs l'accès à des outils de mesure de l'impact des maladies et à d'autres informations présentées sous forme graphique, ainsi qu'à des outils d'aide à la décision sous forme de scénarios prospectifs sur la santé animale et aux résultats d'études plus larges de modélisation économique. La vision du GBADs, renforcer le système de production de denrées alimentaires au profit de la société et de l'environnement, est un exemple de mise en oeuvre du concept Une seule santé.

Las inversiones en sanidad animal y en los Servicios Veterinarios pueden tener un efecto mensurable en la salud de las personas y el medio ambiente. Para efectuar estas inversiones se precisan parámetros que describan y cuantifiquen la situación de partida y el impacto de los problemas de sanidad y bienestar animales, a fin de poder, a partir de ahí, justificar y jerarquizar la asignación de recursos y medir los efectos de las intervenciones. Este artículo, inscrito en un proceso de indagación científica encaminado a detectar problemas y buscar soluciones de forma incluyente, plantea la cuestión general de cómo debería ser y qué valor añadido aportaría un sistema destinado a medir el impacto que imponen a la sociedad las enfermedades animales. Los autores, además, tratan de exponer la cuestión de manera que sea accesible a un público amplio, al que se alienta a participar en este debate. Dado que los animales de granja (incluidos los de pequeñas explotaciones) constituyen una entidad económica, tal sistema debería estar basado en principios económicos. Los productores que trabajan en régimen de subsistencia se ven negativamente afectados por las disparidades existentes en materia de tecnología zoosanitaria, disparidad que cabe corregir con una combinación de intervenciones marcadas por la oferta y otras marcadas por la demanda, dirigiendo así más selectivamente el apoyo económico de entidades gubernamentales y organizaciones no gubernamentales. El programa GBADs (El impacto global de las enfermedades animales) servirá para compilar datos ya existentes con el fin de medir las pérdidas zoosanitarias dentro de sistemas productivos cuidadosamente caracterizados. La atribución coherente y transparente de estas pérdidas zoosanitarias permitirá efectuar comparaciones significativas del impacto que representan las enfermedades animales en el caso de diferentes dolencias, sistemas productivos o países y pondrá de relieve cómo se distribuye este impacto en función del género y la condición socioeconómica de las personas. Por medio del programa GBADs se creará un motor de conocimiento y portal de datos ubicado en la nube que permita al usuario acceder a mediciones del impacto de enfermedades y representaciones gráficas conexas, a herramientas de apoyo a la adopción de decisiones, en forma de hipotéticas situaciones zoosanitarias futuras, y a los resultados de modelizaciones económicas más generales. La aspiración del programa GBADs ­ reforzar el sistema alimentario en beneficio de la sociedad y el medio ambiente ­ constituye un ejemplo de aplicación en la práctica del pensamiento en clave de Una sola salud.

Octupolar versus Néel Order in Cubic 5d

We report time-of-flight neutron spectroscopy and neutron and x-ray diffraction studies of the 5d^{2} double perovskite magnets, Ba_{2}MOsO_{6} (M=Zn,Mg,Ca). These materials host antiferromagnetically coupled 5d^{2} Os^{6+} ions decorating a face-centered cubic (fcc) lattice and are found to remain cubic down to the lowest temperatures. They all exhibit thermodynamic anomalies consistent with a single phase transition at a temperature T^{*}, and a gapped magnetic excitation spectrum with spectral weight concentrated at wave vectors typical of type-I antiferromagnetic orders. However, while muon spin resonance experiments show clear evidence for time-reversal symmetry breaking below T^{*}, we observe no corresponding magnetic Bragg scattering signal. These results are shown to be consistent with ferro-octupolar symmetry breaking below T^{*}, and are discussed in the context of other 5d double perovskite magnets and theories of exotic orders driven by multipolar interactions.

Quantum Spin Ice Dynamics in the Dipole-Octupole Pyrochlore Magnet Ce_{2}Zr_{2}O_{7}.

Neutron scattering measurements on the pyrochlore magnet Ce_{2}Zr_{2}O_{7} reveal an unusual crystal field splitting of its lowest J=5/2 multiplet, such that its ground-state doublet is composed of m_{J}=±3/2, giving these doublets a dipole-octupole (DO) character with local Ising anisotropy. Its magnetic susceptibility shows weak antiferromagnetic correlations with θ_{CW}=-0.4(2) K, leading to a naive expectation of an all-in, all-out ordered state at low temperatures. Instead, our low-energy inelastic neutron scattering measurements show a dynamic quantum spin ice state, with suppressed scattering near |Q|=0, and no long-range order at low temperatures. This is consistent with recent theory predicting symmetry-enriched U(1) quantum spin liquids for such DO doublets decorating the pyrochlore lattice. Finally, we show that disorder, especially oxidation of powder samples, is important in Ce_{2}Zr_{2}O_{7} and could play an important role in the low-temperature behavior of this material.

Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet.

Quantum spin liquids (QSLs) are topological states of matter exhibiting remarkable properties such as the capacity to protect quantum information from decoherence. Whereas their featureless ground states have precluded their straightforward experimental identification, excited states are more revealing and particularly interesting owing to the emergence of fundamentally new excitations such as Majorana fermions. Ideal probes of these excitations are inelastic neutron scattering experiments. These we report here for a ruthenium-based material, α-RuCl3, continuing a major search (so far concentrated on iridium materials) for realizations of the celebrated Kitaev honeycomb topological QSL. Our measurements confirm the requisite strong spin-orbit coupling and low-temperature magnetic order matching predictions proximate to the QSL. We find stacking faults, inherent to the highly two-dimensional nature of the material, resolve an outstanding puzzle. Crucially, dynamical response measurements above interlayer energy scales are naturally accounted for in terms of deconfinement physics expected for QSLs. Comparing these with recent dynamical calculations involving gauge flux excitations and Majorana fermions of the pure Kitaev model, we propose the excitation spectrum of α-RuCl3 as a prime candidate for fractionalized Kitaev physics.

Destabilization of Magnetic Order in a Dilute Kitaev Spin Liquid Candidate.

The insulating honeycomb magnet α-RuCl_{3} exhibits fractionalized excitations that signal its proximity to a Kitaev quantum spin liquid state; however, at T=0, fragile long-range magnetic order arises from non-Kitaev terms in the Hamiltonian. Spin vacancies in the form of Ir^{3+} substituted for Ru are found to destabilize this long-range order. Neutron diffraction and bulk characterization of Ru_{1-x}Ir_{x}Cl_{3} show that the magnetic ordering temperature is suppressed with increasing x, and evidence of zizag magnetic order is absent for x>0.3. Inelastic neutron scattering demonstrates that the signature of fractionalized excitations is maintained over the full range of x investigated. The depleted lattice without magnetic order thus hosts a spin-liquid-like ground state that may indicate the relevance of Kitaev physics in the magnetically dilute limit of RuCl_{3}.

Effective One-Dimensional Coupling in the Highly Frustrated Square-Lattice Itinerant Magnet CaCo_{2-y}As_{2}.

Inelastic neutron scattering measurements on the itinerant antiferromagnet CaCo_{2-y}As_{2} at a temperature of 8 K reveal two orthogonal planes of scattering perpendicular to the Co square lattice in reciprocal space, demonstrating the presence of effective one-dimensional spin interactions. These results are shown to arise from near-perfect bond frustration within the J_{1}-J_{2} Heisenberg model on a square lattice with ferromagnetic J_{1} and hence indicate that the extensive previous experimental and theoretical study of the J_{1}-J_{2} Heisenberg model on local-moment square spin lattices should be expanded to include itinerant spin systems.

Thermally Driven Electronic Topological Transition in FeTi.

Ab initio molecular dynamics, supported by inelastic neutron scattering and nuclear resonant inelastic x-ray scattering, showed an anomalous thermal softening of the M_{5}^{-} phonon mode in B2-ordered FeTi that could not be explained by phonon-phonon interactions or electron-phonon interactions calculated at low temperatures. A computational investigation showed that the Fermi surface undergoes a novel thermally driven electronic topological transition, in which new features of the Fermi surface arise at elevated temperatures. The thermally induced electronic topological transition causes an increased electronic screening for the atom displacements in the M_{5}^{-} phonon mode and an adiabatic electron-phonon interaction with an unusual temperature dependence.

Interpretation of tympanic membrane findings varies according to level of experience.

The authors administered a written survey consisting of colour images of 28 tympanic membranes (TM) to four groups of examiners: 86 medical students, 68 paediatric residents, 62 paediatricians and seven expert otoscopists. For each image, examiners were asked to indicate whether redness or bulging of the TM was present and to assign a diagnosis. The odds of diagnosing acute otitis media (AOM) was examined according to perceived redness or bulging of the TM. Medical students and paediatricians attributed approximately equal importance to isolated redness and isolated bulging of the TM. In contrast, experts placed significantly greater importance on isolated bulging of the TM compared with isolated redness of the TM. The authors suggest that training curricula emphasize the strong association between a bulging TM and a diagnosis of AOM, while de-emphasizing the association between TM redness and AOM.

Les auteurs ont demandé à quatre groupes d'examinateurs de remplir un sondage écrit composé d'images couleur de 28 tympans. Ces groupes se composaient de 86 étudiants en médecine, 68 résidents en pédiatrie, 62 pédiatres et sept spécialistes de l'otoscopie. Pour chaque image, ils étaient invités à indiquer s'ils observaient une rougeur ou un bombement du tympan et à poser un diagnostic. Les auteurs ont examiné la possibilité de diagnostiquer une otite moyenne aiguë (OMA) selon la rougeur ou le bombement perçu du tympan. Les étudiants en médecine et les pédiatres attribuaient environ autant d'importance à une douleur isolée qu'à un bombement isolé. En revanche, les spécialistes accordaient beaucoup plus d'importance à un bombement isolé du tympan qu'à une rougeur du tympan. Les auteurs proposent que, dans le cursus d'enseignement, les professeurs soulignent l'association importante entre le bombement du tympan et un diagnostic d'OMA, mais atténuent l'association entre la rougeur du tympan et l'OMA.

Association study of genes related to bone formation and resorption and the extent of radiographic change in ankylosing spondylitis.

OBJECTIVE: To identify genetic associations with severity of radiographic damage in ankylosing spondylitis (AS). METHOD: We studied 1537 AS cases of European descent; all fulfilled the modified New York Criteria. Radiographic severity was assessed from digitised lateral radiographs of the cervical and lumbar spine using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). A two-phase genotyping design was used. In phase 1, 498 single nucleotide polymorphisms (SNPs) were genotyped in 688 cases; these were selected to capture >90% of the common haplotypic variation in the exons, exon-intron boundaries, and 5 kb flanking DNA in the 5' and 3' UTR of 74 genes involved in anabolic or catabolic bone pathways. In phase 2, 15 SNPs exhibiting p<0.05 were genotyped in a further cohort of 830 AS cases; results were analysed both separately and in combination with the discovery phase data. Association was tested by contingency tables after separating the samples into 'mild' and 'severe' groups, defined as the bottom and top 40% by mSASSS, adjusted for gender and disease duration. RESULTS: Experiment-wise association was observed with the SNP rs8092336 (combined OR 0.32, p=1.2×10(-5)), which lies within RANK (receptor activator of NFκB), a gene involved in osteoclastogenesis, and in the interaction between T cells and dendritic cells. Association was also found with the SNP rs1236913 in PTGS1 (prostaglandin-endoperoxide synthase 1, cyclooxygenase 1), giving an OR of 0.53 (p=2.6×10(-3)). There was no observed association between radiographic severity and HLA-B*27. CONCLUSIONS: These findings support roles for bone resorption and prostaglandins pathways in the osteoproliferative changes in AS.

Block Magnetic Excitations in the Orbitally Selective Mott Insulator BaFe_{2}Se_{3}.

Iron pnictides and selenides display a variety of unusual magnetic phases originating from the interplay between electronic, orbital, and lattice degrees of freedom. Using powder inelastic neutron scattering on the two-leg ladder BaFe_{2}Se_{3}, we fully characterize the static and dynamic spin correlations associated with the Fe_{4} block state, an exotic magnetic ground state observed in this low-dimensional magnet and in Rb_{0.89}Fe_{1.58}Se_{2}. All the magnetic excitations of the Fe_{4} block state predicted by an effective Heisenberg model with localized spins are observed below 300 meV and quantitatively reproduced. However, the data only account for 16(3)µ_{B}^{2} per Fe^{2+}, approximatively 2/3 of the total spectral weight expected for localized S=2 moments. Our results highlight how orbital degrees of freedom in iron-based magnets can conspire to stabilize an exotic magnetic state.

Interaction driven subgap spin exciton in the Kondo insulator SmB6.

Using inelastic neutron scattering, we map a 14 meV coherent resonant mode in the topological Kondo insulator SmB6 and describe its relation to the low energy insulating band structure. The resonant intensity is confined to the X and R high symmetry points, repeating outside the first Brillouin zone and dispersing less than 2 meV, with a 5d-like magnetic form factor. We present a slave-boson treatment of the Anderson Hamiltonian with a third neighbor dominated hybridized band structure. This approach produces a spin exciton below the charge gap with features that are consistent with the observed neutron scattering. We find that maxima in the wave vector dependence of the inelastic neutron scattering indicate band inversion.

Acknowledging and allocating responsibility for clinical inertia in the management of Type 2 diabetes in primary care: a qualitative study.

AIMS: Failure to intensify treatment in patients with Type 2 diabetes with suboptimal blood glucose control has been termed clinical inertia and has been shown to contribute to poorer patient outcomes. We aimed to identify and explore perceptions about clinical inertia from the perspective of primary healthcare providers. METHODS: A qualitative study was conducted in Leicestershire and Northamptonshire, UK. Purposive sampling was based on healthcare providers working in primary care settings with 'higher' and 'lower' target achievement based on routine data. Twenty semi-structured interviews were conducted, face-to-face or by telephone. Thematic analysis was informed by the constant comparative approach. RESULTS: An important broad theme that emerged during the analysis was related to attribution and explanation of responsibility for clinical inertia. This included general willingness to accept a degree of responsibility for clinical inertia. In some cases, however, participants had inaccurate perceptions about levels of target achievement in their primary care centres, as indicated by routine data. Participants sought to lessen their own sense of accountability by highlighting patient-level barriers such as comorbidities and human fallibility, and also system-level barriers, particularly time constraints. Perceptions about ways of addressing the problem of clinical inertia were not seen as straightforward, further emphasizing a complex and cumulative pattern of barriers. CONCLUSIONS: In order to understand and address the problem of clinical inertia, provider, patient- and system-level barriers should be considered together rather than as separate issues. Acknowledgement of responsibility should be regarded positively as a motivator for change.

Concerns and perceptions about necessity in relation to insulin therapy in an ethnically diverse UK population with Type 2 diabetes: a qualitative study focusing mainly on people of South Asian origin.

AIM: To explore attitudes towards insulin acceptance an ethnically diverse population of people with Type 2 diabetes. METHODS: We conducted semi-structured interviews using a topic guide based on a literature review and findings from our previous study, which explored the perspectives of healthcare professionals about insulin initiation and management. Analysis of data involved undertaking an abductive reasoning approach in response to emerging themes. RESULTS: Participants discussed not only their concerns about insulin therapy, but also their views and beliefs about the necessity of insulin. Their attitudes to insulin treatment could be mapped into four main typologies. These fitted with an attitudinal scale based on the Necessity-Concerns Framework described in the medication adherence literature, comprising four attitudes: accepting, sceptical, ambivalent and indifferent. Decisions about accepting insulin involved balancing concerns (such as needle size) against the perceived necessity of insulin (generally, inadequacy of oral medication). The South Asian and white participants had similar concerns, but these were sometimes greater in South Asian participants, because of the influence of negative views and experiences of other insulin users. CONCLUSIONS: When discussing insulin with people with Type 2 diabetes, healthcare providers need to ensure that they explore and contribute to patients' understanding and interpretation of the necessity of insulin as well as discussing their concerns. Furthermore, they should be aware of how an individual's social context can influence his/her perceptions about the necessity of insulin as well as their concerns, and that this influence may be greater in some South Asian populations.