Complete field-induced spectral response of the spin-1/2 triangular-lattice antiferromagnet CsYbSe2

Fifty years after Anderson's resonating valence-bond proposal, the spin-1/2 triangular-lattice Heisenberg antiferromagnet (TLHAF) remains the ultimate platform to explore highly entangled quantum spin states in proximity to magnetic order. Yb-based delafossites are ideal candidate TLHAF materials, which allow experimental access to the full range of applied in-plane magnetic fields. We perform a systematic neutron scattering study of CsYbSe2, first proving the Heisenberg character of the interactions and quantifying the second-neighbor coupling. We then measure the complex evolution of the excitation spectrum, finding extensive continuum features near the 120°-ordered state, throughout the 1/3-magnetization plateau and beyond this up to saturation. We perform cylinder matrix-product-state (MPS) calculations to obtain an unbiased numerical benchmark for the TLHAF and spectacular agreement with the experimental spectra. The measured and calculated longitudinal spectral functions reflect the role of multi-magnon bound and scattering states. These results provide valuable insight into unconventional field-induced spin excitations in frustrated quantum materials.

488 TULA for Bladder Tumours in a University Teaching Hospital: Outcomes Over a 2-Year Period

Aim

TULA (Transurethral laser ablation) of bladder tumours is a relatively non-invasive procedure that is carried out on a day-case basis under local anaesthesia, providing an attractive option for treating recurrent non-muscle invasive bladder cancer (NMIBC). However, data describing efficacy rates are limited.

Method

We carried out a retrospective audit of all TULA procedures carried out for bladder lesions between January 2018 and December 2019. Patients were identified using clinical coding and data collected using electronic case note data. Analysis was performed using Microsoft Excel.

Results

48 patients were identified, 75% were male and the average age was 77. Performance status (PS) was formally documented in 6 patients, with a median of 2.5. A total of 77 TULA procedures were identified. 7 patients had TULA as primary treatment, all but one of these patients had significant co-morbidities.

Biopsies were taken in 83% of procedures. Recurrence rate at 3 months was 29% (n=14). 18% (n=8) of patients went on to have repeat TULA and the remainder went on to have TURBT or biopsy and cystodiathermy. Of those patients with recurrence, 18% had disease progression. 1 patient required catheterisation and irrigation overnight, all other patients were discharged the same day. No patients required re-admission.

Conclusions

TULA is a safe, well tolerated procedure to treat low-grade, recurrent bladder tumours. It can also be used as a palliative procedure for high-grade lesions in patients with multiple co-morbidities. Future work includes collection of objective data on tolerance in the form of VAS pain scoring.

Magic Gap Ratio for Optimally Robust Fermionic Condensation and Its Implications for High-T_{c} Superconductivity

Bardeen-Schrieffer-Cooper (BCS) and Bose-Einstein condensation (BEC) occur at opposite limits of a continuum of pairing interaction strength between fermions. A crossover between these limits is readily observed in a cold atomic Fermi gas. Whether it occurs in other systems such as the high temperature superconducting cuprates has remained an open question. We uncover here unambiguous evidence for a BCS-BEC crossover in the cuprates by identifying a universal magic gap ratio 2Δ/k_{B}T_{c}≈6.5 (where Δ is the pairing gap and T_{c} is the transition temperature) at which paired fermion condensates become optimally robust. At this gap ratio, corresponding to the unitary point in a cold atomic Fermi gas, the measured condensate fraction N_{0} and the height of the jump δγ(T_{c}) in the coefficient γ of the fermionic specific heat at T_{c} are strongly peaked. In the cuprates, δγ(T_{c}) is peaked at this gap ratio when Δ corresponds to the antinodal spectroscopic gap, thus reinforcing its interpretation as the pairing gap. We find the peak in δγ(T_{c}) also to coincide with a normal state maximum in γ, which is indicative of a pairing fluctuation pseudogap above T_{c}.

AB1209 MECHANISTIC FACTORS CONTRIBUTING TO PAIN AND FATIGUE IN FIBROMYALGIA AND ME/CFS: AUTONOMIC AND INFLAMMATORY INSIGHTS FROM AN EXPERIMENTAL MEDICINE STUDY

Background

Fibromyalgia and ME/CFS are multifaceted conditions with overlapping symptoms(1); the pathoaetiological mechanisms are complex and debated(2), however there is a strong association with features of hereditary disorders of connective tissue (hypermobility) and autonomic and inflammatory abnormalities (1,2).

Objectives

To determine potential autonomic and inflammatory mechanisms of pain and fatigue in fibromyalgia and ME/CFS

Methods

After excluding participants with WCC higher than 10 (suggesting acute infection) baseline markers of inflammation (CRP and ESR) were available for 60 patients with confirmed diagnoses of Fibromyalgia and/ or ME/CFS and 23 matched controls. Participants then underwent full research diagnostic evaluation including a hypermobility assessment(1) and autonomic challenge (60 degree head up tilt, ISRCTN78820481). Subjective pain and fatigue were assessed before and after challenge (VAS). Linear regression models were used to explore predictors, with adjustment for confounders as appropriate. Mediation analyses (looking for mechanistic effects) were conducted according to the method of Hayes (3) and mediation considered significant if bootstrapped confidence intervals of the estimated indirect effect did not cross zero. In these mediation analyses predictor variable was group membership (patient or control), outcome variable was change in 1)pain and 2)fatigue induced by challenge and mediatiors 1)no of connective tissue features in hypermobility diagnostic criteria endorsed by participant; 2)baseline inflammatory markers.

Results

ESR and CRP were significantly higher in patients rather than controls, even after correcting for BMI, age and sex (B=5.15, t=2.05, p=0.044; B=1.77, t=2.15, p=0.044 respectively). Adjusted ESR and CRP correlated with both subjective fatigue (B=0.44, t=2.09, p=0.04; B=1.63, t=2.60, p=0.011) and pain severity (B=0.13, t=2.51, p=0.014; B=0.45, t=3.01, p=0.004) at baseline. Autonomic challenge amplified pain (B=14.20, t=2.87, p=0.005) and fatigue (B=31.48, t=5.95, p=<0.001) in patients to a significantly greater degree than controls, controlling for baseline levels. Baseline ESR and CRP also predicted challenge-induced increase in fatigue (B=0.78, t=370, p=<0.001; B=1.91, t=3.36, p=<0.001) and ESR challenge-induced increases in pain (B=0.46, t=2.35, p=0.021).

Mediation analysis demonstrated that number of connective tissue features expressed in hypermobility criteria mediated the degree to which subjective pain was increased by the autonomic challenge (Bootstraped 95% CI of indirect effect do not cross zero, 0.1572 – 6.8171). ESR mediated the degree to which subjective fatigue was increased by the autonomic challenge (Bootstraped 95% CI of indirect effect do not cross zero,0.7541 – 7.3888).

Conclusion

To our knowledge this is the first study to directly explore autonomic and inflammatory mechanisms of pain and fatigue in a combined population of Fibromyalgia and ME/CFS. This study this adds to the evidence-base of baseline inflammatory abnormalities in fibromyalgia and ME/CFS. It highlights their potential role in predicting symptom severity and their potential mechanistic role in autonomic induced pain and fatigue, suggesting future treatment strategies.

References

[1]Eccles JA, Thompson B, Themelis K, Amato ML, Stocks R, Pound A, et al. Beyond bones: The relevance of variants of connective tissue (hypermobility) to fibromyalgia, ME/CFS and controversies surrounding diagnostic classification: an observational study. Clin Med (Lond). 2021;21(1):53-8.

[2]Eccles JA, Davies KA. The challenges of chronic pain and fatigue. Clin Med (Lond). 2021;21(1):19-27.

[3]Hayes AF. Partial, conditional, and moderated moderated mediation: Quantification, inference, and interpretation. Commun Monogr. 2018;85(1):4-40.

Disclosure of Interests

Jessica Eccles: None declared, Charlotte Thompson: None declared, Beth Thompson: None declared, Marisa Amato: None declared, Kristy Themelis: None declared, Hugo Critchley: None declared, Neil Harrison Grant/research support from: speakers bureau, Kevin Davies: None declared

The role of interoception in the mechanism of pain and fatigue in fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Introduction

Pain, fatigue and anxiety are common features of fibromyalgia and ME/CFS and significantly impact quality of life. Aetiology is poorly defined but dysfunctional inflammatory, autonomic and interoceptive (sensing of internal bodily signals) processes are implicated.

Objectives

To investigate how altered interoception relates to baseline expression of pain, fatigue and anxiety symptoms in fibromyalgia and ME/CFS and in response to an inflammatory challenge.

Methods

Sixty-five patients with fibromyalgia and/or ME/CFS diagnosis and 26 matched controls underwent baseline assessment: pressure-pain thresholds and self-report questionnaires assessing pain, fatigue and anxiety severity. Participants received injections of typhoid (inflammatory challenge) or saline (placebo) in a randomised, double-blind, crossover design, before completing heartbeat tracking tasks. Three interoception dimensions were examined: subjective sensibility, objective accuracy and metacognitive awareness. Interoceptive trait prediction error was calculated as discrepancy between accuracy and sensibility.

Results

Patients with fibromyalgia and ME/CFS had significantly higher interoceptive sensibility and trait prediction error, despite no differences in interoceptive accuracy. Interoceptive sensibility and trait prediction error correlated with all self-report pain, fatigue and anxiety measures, and with lower pain thresholds. Anxiety mediated the positive-predictive relationships between pain (Visual Analogue Scale and Widespread Pain Index), fatigue impact and interoceptive sensibility. After inflammatory challenge, metacognitive awareness correlated with baseline self-reported symptom measures and lower pain thresholds.

Conclusions

This is the first study investigating interoceptive dimensions in patients with fibromyalgia and ME/CFS, which were found to be dysregulated and differentially influenced by inflammatory mechanisms. Interoceptive processes may represent a new potential target for diagnostic and therapeutic investigation in these poorly understood conditions.

Disclosure

No significant relationships.

Extraction of Beam-Spin Asymmetries from the Hard Exclusive π^{+} Channel off Protons in a Wide Range of Kinematics

We have measured beam-spin asymmetries to extract the sinϕ moment A_{LU}^{sinϕ} from the hard exclusive e[over →]p→e^{'}nπ^{+} reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center of mass. The A_{LU}^{sinϕ} moment has been measured up to 6.6  GeV^{2} in -t, covering the kinematic regimes of generalized parton distributions (GPD) and baryon-to-meson transition distribution amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found A_{LU}^{sinϕ} to be negative, while a sign change was observed near 90° in the center of mass. The unique results presented in this Letter will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.

AB0949 AUTONOMIC AND INFLAMMATORY MECHANISMS OF PAIN AND FATIGUE IN FIBROMYALGIA AND ME/CFS: AN INTERVENTIONAL STUDY

Background:

Fibromyalgia and ME/CFS are complex disorders with overlapping symptoms; the pathoaetiology and clinical distinction are debated, however inflammatory and autonomic abnormalities are observed.

Objectives:

To investigate the role of inflammatory and autonomic nervous system responses in mechanisms of pain and fatigue in fibromyalgia and ME/CFS

Methods:

63 patient participants with clinical diagnoses of fibromyalgia and/or ME/CFS were recruited into a multi-stage interventional study (ISRCTN78820481) alongside 24 healthy controls. All underwent research diagnostic criteria evaluation. The majority underwent autonomic challenge (60 degree head up tilt) and/or inflammatory challenge (placebo-controlled typhoid vaccination) with baseline characterisation of symptoms, inflammatory markers and pre-post measures of pain and fatigue.

Results:

Of the 63 patients, 32% of patients had received a clinical diagnosis of Fibromyalgia; 38% ME/CFS and 30% dual diagnoses. Following research evaluation 89% met ACR diagnostic criteria for fibromyalgia; 94% Canadian Criteria for ME/CFS; 97% Fukada Criteria for ME/CFS

There was a significantly higher ESR in patients compared to controls (p= 0.036). There was a trend towards higher CRP in patients compared to controls (p= 0.076).

ESR correlated with baseline pain score (r=0.309, p=0.011), fatigue severity (r=0.262, p=0.032), fatigue impact (r=0.382, p=0.014) change in fatigue score induced by tilt (r=0.319, p=0.011) and change in pain score induced by placebo-controlled inflammation (r=-0.279, p=0.043). Similarly CRP level correlated with baseline pain score (r=0.340, p=0.005), fatigue impact (r=0.439, p=0.004), change in fatigue (r=-0.277, p=0.045) and pain score (r=-0.394, p=0.014) induced by placebo-controlled inflammation and change in pressure pain theshold induced by tilt (r=0.286, p=0.027).

Baseline IL6 was higher in patients than controls (p = 0.002), correlating with baseline pain score (r = 0.345, p = 0.002) and change in pain score induced by tilt (r=0.281, p=0.21). Change in IL6 induced by inflammatory challenge correlated with inflammation induced fatigue score (r = 0.378, p = 0.01).

Conclusion:

Inflammatory and autonomic mechanisms contribute to pain and fatigue in this frequently overlooked patient group, highlighting possibilities for targeted treatments. Such data will be enriched going forward by neuroimaging and transcriptomic insights.

References:

n/a

Acknowledgments:

This work was supported by Versus Arthritis, Action for Me, Fibroduck Foundation and NIHR

Disclosure of Interests:

Jessica Eccles: None declared, Marisa Amato: None declared, Charlotte Thompson: None declared, Kristy Themelis: None declared, Hugo Critchley: None declared, Neil Harrison Grant/research support from: Yes, Speakers bureau: Yes, Kevin Davies: None declared

Determination of Lead in Wine by Graphite Furnace Atomic Absorption Spectrophotometry: Interlaboratory Study

An interlaboratory study of a graphite furnace atomic absorption spectrophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to minimize matrix effects between standards and samples. Six wine test materials were prepared and sent to participants as 12 blind duplicate or split level samples. There was good agreement between results obtained from participants and target values (24–279 μg/L) obtained with an inductively coupled plasma-mass spectrometry method. The precision of the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard deviations ranged from 3 to 17%. Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for official purposes.

Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering off a proton bound in ^{4}He. The data used here were accumulated using a 6 GeV longitudinally polarized electron beam incident on a pressurized ^{4}He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle (ϕ) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The Q^{2}, x_{B}, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20% to 40%, indicating possible medium modification of its partonic structure.

Phase stabilization by electronic entropy in plutonium

Plutonium metal undergoes an anomalously large 25% collapse in volume from its largest volume δ phase (δ-Pu) to its low temperature α phase, yet the underlying thermodynamic mechanism has largely remained a mystery. Here we use magnetostriction measurements to isolate a previously hidden yet substantial electronic contribution to the entropy of δ-Pu, which we show to be crucial for the stabilization of this phase. The entropy originates from two competing instabilities of the 5f-electron shell, which we show to drive the volume of Pu in opposing directions, depending on the temperature and volume. Using calorimetry measurements, we establish a robust thermodynamic connection between the two excitation energies, the atomic volume, and the previously reported excess entropy of δ-Pu at elevated temperatures.

Plutonium has strong electronic correlations, which makes it difficult to establish microscopic understanding of the complicated structural phase diagram. Here the authors identify an electronic contribution to the entropy that stabilises the δ-Pu phase.

Direct Observation of Proton-Neutron Short-Range Correlation Dominance in Heavy Nuclei

We measured the triple coincidence A(e,e^{'}np) and A(e,e^{'}pp) reactions on carbon, aluminum, iron, and lead targets at Q^{2}>1.5  (GeV/c)^{2}, x_{B}>1.1 and missing momentum >400  MeV/c. This was the first direct measurement of both proton-proton (pp) and neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all measured nuclei, the average proton-proton (pp) to neutron-proton (np) reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for single-charge exchange effects decreased the SRC pairs ratio to ∼3%, which is lower than previous results. Comparisons to theoretical generalized contact formalism (GCF) cross-section calculations show good agreement using both phenomenological and chiral nucleon-nucleon potentials, favoring a lower pp to np pair ratio. The ability of the GCF calculation to describe the experimental data using either phenomenological or chiral potentials suggests possible reduction of scale and scheme dependence in cross-section ratios. Our results also support the high-resolution description of high-momentum states being predominantly due to nucleons in SRC pairs.

First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N^{*} Resonance Region

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Center of Mass Motion of Short-Range Correlated Nucleon Pairs studied via the A(e,e^{'}pp) Reaction

Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170  MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states.

Highly Asymmetric Nodal Semimetal in Bulk SmB_{6}

We show that novel low temperature properties of bulk SmB_{6}, including the sudden growth of the de Haas-van Alphen (dHvA) amplitude (and heat capacity) at millikelvin temperatures and a previously unreported linear-in-temperature bulk electrical conductivity at liquid helium temperatures, signal the presence of a highly asymmetric nodal semimetal. We show that a highly asymmetric nodal semimetal is also a predicted property of the Kondo lattice model (with dispersionless f-electron levels) in the presence of Sm vacancies or other defects. We show it can result from a topological transformation of the type recently considered by Shen and Fu and eliminates the necessity of a neutral Fermi surface for explaining bulk dHvA oscillations in SmB_{6}.

Alimentary microbes of winter-form Drosophila suzukii

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a damaging pest of fruit. Reproductively diapausing adults overwinter in woodlands and remain active on warmer winter days. It is unknown if this adult phase of the lifecycle feeds during the winter period, and what the food source may be. This study characterized the flora in the digestive tract of D. suzukii using a metagenomics approach. Live D. suzukii were trapped in four woodlands in the south of England and their guts dissected for DNA extraction and amplicon-based metagenomics sequencing (internal transcribed spacer and 16S rRNA). Analysis at genus and family taxonomic levels showed high levels of diversity with no differences in digestive tract bacterial or fungal biota between woodland sites of winter-form D. suzukii. Female D. suzukii at one site appeared to have higher bacterial diversity in the alimentary canal than males, but there was a site, sex interaction. Many of the biota were associated with cold, wet climatic conditions and decomposition. This study provides the first evidence that winter-form D. suzukii may be opportunistic feeders during the winter period and are probably exploiting food sources associated with moisture on decomposing vegetation during this time. A core gut microbiome has been identified for winter-form D. suzukii.

Measurement of the Q^{2} Dependence of the Deuteron Spin Structure Function g_{1} and its Moments at Low Q^{2} with CLAS

We measured the g_{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02  GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

First Exclusive Measurement of Deeply Virtual Compton Scattering off ^{4}He: Toward the 3D Tomography of Nuclei

We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment uses the 6 GeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident on a pressurized ^{4}He gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron is detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber is used to detect the recoiling ^{4}He nuclei. We measure beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we are able to extract, in a model-independent way, the real and imaginary parts of the only ^{4}He Compton form factor, H_{A}. This first measurement of coherent deeply virtual Compton scattering on the ^{4}He nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.

Beam-Target Helicity Asymmetry for γ[over →]n[over →]→π^{-}p in the N^{*} Resonance Region

We report the first beam-target double-polarization asymmetries in the γ+n(p)→π^{-}+p(p) reaction spanning the nucleon resonance region from invariant mass W=1500 to 2300 MeV. Circularly polarized photons and longitudinally polarized deuterons in solid hydrogen deuteride (HD) have been used with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the E polarization observable for an effective neutron target. These results have been incorporated into new partial wave analyses and have led to significant revisions for several γnN^{*} resonance photocouplings.

Magnetic field tuning of an excitonic insulator between the weak and strong coupling regimes in quantum limit graphite

The excitonic insulator phase has long been predicted to form in proximity to a band gap opening in the underlying band structure. The character of the pairing is conjectured to crossover from weak (BCS-like) to strong coupling (BEC-like) as the underlying band structure is tuned from the metallic to the insulating side of the gap opening. Here we report the high-magnetic field phase diagram of graphite to exhibit just such a crossover. By way of comprehensive angle-resolved magnetoresistance measurements, we demonstrate that the underlying band gap opening occurs inside the magnetic field-induced phase, paving the way for a systematic study of the BCS-BEC-like crossover by means of conventional condensed matter probes.

Joint Hypermobility Syndrome and Anxiety Disorder: Structural Brain Correlates

Introduction

Joint hypermobility syndrome/Ehlers Danlos III (JHS/EDS III) is a common, connective tissue condition. This group is over-represented in panic/anxiety disorders and exhibits autonomic abnormalities and heightened interoceptive sensibility. Previous neuroimaging in healthy volunteers with hypermobility has observed differences in key emotional brain regions, notably amygdala and insula.

Aims and objective To explore, in a clinical population, the structural brain correlates underpinning the association between JHS/EDS III and anxiety.

Method

Seventy participants were divided into four experimental groups: (2 × 2 factor design: presence/absence of hypermobility; presence/absence of anxiety). Hypermobility was assessed using Brighton Criteria. All participants underwent brief tests of autonomic function and interoception. Structural images were obtained using a 1.5 T MRI scanner. Results are reported at whole brain uncorrected significance threshold of P < 0.001.

Results

Comparison of grey matter volume revealed increased insular volume in anxious patients with JHS/EDS-III compared to anxious patients without (Fig. 1A, B), correlating with initial peak heart rate on standing. Additionally, amygdala volume correlated with hypermobility score in anxious patients, but not in non-anxious individuals (Fig. 1C, D). Amygdala volume correlated with interoceptive accuracy.

Conclusions

This data implicates amygdala and insula as likely neural substrates mediating clinical relationships between hypermobility syndrome and anxiety, demonstrating the relevance of autonomic and interoceptive influences on this relationship. Further work hopes to explore functional and structural connectivity between these regions in JHS/EDS-III.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Predictors for and coverage of influenza vaccination among HIV-positive patients: a cross-sectional survey

OBJECTIVES

Influenza vaccination is recommended for HIV-infected patients, but limited data about vaccination rates are available. The aim of this study was to evaluate the coverage of and predictors for influenza vaccination among HIV-positive patients.

METHODS

All HIV-positive patients who visited the HIV out-patient department of the University Hospital of Vienna, Austria, between June and August 2015 were asked to participate in this survey by completing a questionnaire.

RESULTS

A total of 455 HIV-positive patients completed a questionnaire, with 359 male and 96 female participants with a mean age of 46 years. The influenza vaccination rate for the previous season (2014/2015) was 11.9% [n = 54/455; 95% confidence interval (CI) 9.2-15.2%]. Older age was significantly associated with a positive influenza vaccination status. Obtaining information through a medical consultation or receiving a direct recommendation for vaccination by a physician had a significant impact on vaccination behaviour. The probability of being vaccinated against influenza was about 13 times higher among patients who received a recommendation for vaccination by their family physician or by their HIV specialist (P < 0.001). Important reasons for declining vaccination were fear of side effects (39%), not considering influenza as a severe disease (36%) and reasons related to HIV: 17% were worried that the vaccine could worsen the course of HIV infection and 16% believed vaccination would fail because of their compromised immune system.

CONCLUSIONS

A low influenza vaccination rate of 11.9% was detected in this HIV-positive cohort. The most effective impact for a positive vaccination status was direct recommendation of the influenza vaccine by the attending physician.

Pulsed field magnetization in rare-earth kagome systems

The rare-earth kagome systems R 3Ga5SiO14 (R  =  Nd or Pr) exhibit cooperative paramagnetism at low temperatures. Evidence for correlated spin clusters in these weakly frustrated systems has previously been obtained from neutron scattering and from ESR and NMR results. The present pulsed field (0-60 T, 25 ms) magnetization measurements made on single crystals of Nd3Ga5SiO14 (NGS) and Pr3Ga5SiO14 (PGS) at temperatures down to 450 mK have revealed striking differences in the magnetic responses of the two materials. For NGS the magnetization shows a low field plateau, saturation in high transient fields, and significant hysteresis while the PGS magnetization does not saturate in transient fields up to 60 T and shows no hysteresis or plateaus. Nd(3+) is a Kramers ion while Pr(3+) is a non-Kramers ion and the crystal field effects are quite different in the two systems. For the conditions used in the experiments the magnetization behavior is not in agreement with Heisenberg model predictions for kagome systems in which easy-axis anisotropy is much larger than the exchange coupling. The extremely slow spin dynamics found below 4 K in NGS is, however, consistent with the model for Kramers ions and provides a basis for explaining the pulsed field magnetization features.

Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions

Unpolarized and beam-polarized fourfold cross sections (d^{4}σ/dQ^{2}dx_{B}dtdϕ) for the ep→e^{'}p^{'}γ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 (Q^{2},x_{B},t) bins over the widest phase space ever explored in the valence-quark region. Several models of generalized parton distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD H, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton form factors, these results support the model predictions of a larger nucleon size at lower quark-momentum fraction x_{B}.

Healthcare professional requirements for the care of adult diabetes patients managed with insulin pumps in Australia

BACKGROUND

Healthcare professional (HCP) time supporting insulin pump therapy (IPT) has not been documented, yet it is important in planning and allocating resources for effective care.

AIM

This study aims to determine HCP time spent in IPT patient care to inform resource planning for optimal IPT delivery.

METHODS

Twenty-four Australian adult IPT-experienced institutions (14 government funded, seven private, three both) collected data between April 2012 and January 2013 prospectively, including: patient demographics, HCP classification, purpose of HCP-patient interaction, interaction mode and HCP time with the patient. A subset of patients was tracked from pre-pump education until stable on IPT.

RESULTS

Data on 2577 HCP-adult patient interactions (62% face-to-face, 29% remote, 9% administrative) were collected over 12.2 ± 6.4 weeks for 895 patients; age 35.4 ± 14.2 years; 67% female; 99% type 1 diabetes, representing 25% of all IPT patients of the institutions. Time (hours) spent on IPT interactions per centre per week were: nurses 5.4 ± 2.8, dietitians 0.4 ± 0.2 and doctors 1.0 ± 0.5. IPT starts accounted for 48% of IPT interaction time. The percentage of available diabetes clinic time spent on outpatient IPT interactions was 20.4%, 4.6% and 2.7% for nurses, dietitians and doctors respectively. Fifteen patients tracked from pre-pump to stabilisation over 11.8 ± 4.5 weeks, required a median (range) of 9.2 (3.0-20.9), 2.4 (0.5-6.0) and 1.8 (0.5-5.4) hours per patient from nurses, dietitians and doctors respectively.

CONCLUSIONS

IPT patient care represents a substantial investment in HCP time, particularly for nurses. Funding models for IPT care need urgent review to ensure this now mainstream therapy integrates well into healthcare resources.

Successive Magnetic-Field-Induced Transitions and Colossal Magnetoelectric Effect in Ni_{3}TeO_{6}

We report the discovery of a metamagnetic phase transition in a polar antiferromagnet Ni_{3}TeO_{6} that occurs at 52 T. The new phase transition accompanies a colossal magnetoelectric effect, with a magnetic-field-induced polarization change of 0.3 μC/cm^{2}, a value that is 4 times larger than for the spin-flop transition at 9 T in the same material, and also comparable to the largest magnetically induced polarization changes observed to date. Via density-functional calculations we construct a full microscopic model that describes the data. We model the spin structures in all fields and clarify the physics behind the 52 T transition. The high-field transition involves a competition between multiple different exchange interactions which drives the polarization change through the exchange-striction mechanism. The resultant spin structure is rather counterintuitive and complex, thus providing new insights on design principles for materials with strong magnetoelectric coupling.

Prevalence and risk factor assessment of Tropheryma whipplei in a rural community in Gabon: a community-based cross-sectional study

Tropheryma whipplei is the causative agent of Whipple's disease and has been detected in stools of asymptomatic carriers. Colonization has been associated with precarious hygienic conditions. There is a lack of knowledge about the epidemiology and transmission characteristics on a population level, so the aim of this study was to determine the overall and age-specific prevalence of T. whipplei and to identify risk factors for colonization. This molecular epidemiological survey was designed as a cross-sectional study in a rural community in Central African Gabon and inhabitants of the entire community were invited to participate. Overall prevalence assessed by real-time PCR and sequencing was 19.6% (95% CI 16-23.2%, n=91) in 465 stool samples provided by the study participants. Younger age groups showed a significantly higher prevalence of T. whipplei colonization ranging from 40.0% (95% CI 27.8-52.2) among the 0-4 year olds to 36.4% (95% CI 26.1-46.6) among children aged 5-10 years. Prevalence decreased in older age groups (p<0.001) from 12.6% (95% CI 5.8-19.4%; 11-20 years) to 9.7% (95% CI 5.7-13.6) among those older than 20. Risk factor analysis revealed young age, male sex, and number of people sharing a bed as factors associated with an increased risk for T. whipplei carriage. These results demonstrate that T. whipplei carriage is highly prevalent in this part of Africa. The high prevalence in early life and the analysis of risk factors suggest that transmission may peak during childhood facilitated through close person-to-person contacts.

Heavy fermions. Unconventional Fermi surface in an insulating state

Insulators occur in more than one guise; a recent finding was a class of topological insulators, which host a conducting surface juxtaposed with an insulating bulk. Here, we report the observation of an unusual insulating state with an electrically insulating bulk that simultaneously yields bulk quantum oscillations with characteristics of an unconventional Fermi liquid. We present quantum oscillation measurements of magnetic torque in high-purity single crystals of the Kondo insulator SmB6, which reveal quantum oscillation frequencies characteristic of a large three-dimensional conduction electron Fermi surface similar to the metallic rare earth hexaborides such as PrB6 and LaB6. The quantum oscillation amplitude strongly increases at low temperatures, appearing strikingly at variance with conventional metallic behavior.

Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates

The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whose primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport, and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y.

Towards a resolution of the proton form factor problem: new electron and positron scattering data

There is a significant discrepancy between the values of the proton electric form factor, G(E)(p), extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of G(E)(p) from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ϵ) and momentum transfer (Q(2)) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ϵ at Q(2)=1.45  GeV(2). This measurement is consistent with the size of the form factor discrepancy at Q(2)≈1.75  GeV(2) and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2-3  GeV(2).

Longitudinal target-spin asymmetries for deeply virtual compton scattering

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.

Mapping QTL associated with Verticillium dahliae resistance in the cultivated strawberry (Fragaria × ananassa)

A biparental cross of octoploid strawberry segregating for resistance to Verticillium dahliae, the causative agent of Verticillium wilt, was screened under field conditions for three seasons. Average wilt scores were significantly associated with multiple QTL, which were mostly significant across all years. Markers significantly associated with the traits were used to screen material with known wilt resistance and susceptibility phenotypes. A clear and statistically significant relationship was observed between resistant, tolerant and susceptible material and the total number of markers present in the different resistance classes. In field situations resistance QTL appear to behave in an additive manner. These markers are abundant in the cultivated strawberry germplasm indicating that, despite the large number of markers, clear genetic gain is possible through marker-assisted breeding.

Normal-state nodal electronic structure in underdoped high-Tc copper oxides

An outstanding problem in the field of high-transition-temperature (high-Tc) superconductivity is the identification of the normal state out of which superconductivity emerges in the mysterious underdoped regime. The normal state uncomplicated by thermal fluctuations can be studied using applied magnetic fields that are sufficiently strong to suppress long-range superconductivity at low temperatures. Proposals in which the normal ground state is characterized by small Fermi surface pockets that exist in the absence of symmetry breaking have been superseded by models based on the existence of a superlattice that breaks the translational symmetry of the underlying lattice. Recently, a charge superlattice model that positions a small electron-like Fermi pocket in the vicinity of the nodes (where the superconducting gap is minimum) has been proposed as a replacement for the prevalent superlattice models that position the Fermi pocket in the vicinity of the pseudogap at the antinodes (where the superconducting gap is maximum). Although some ingredients of symmetry breaking have been recently revealed by crystallographic studies, their relevance to the electronic structure remains unresolved. Here we report angle-resolved quantum oscillation measurements in the underdoped copper oxide YBa2Cu3O6 + x. These measurements reveal a normal ground state comprising electron-like Fermi surface pockets located in the vicinity of the nodes, and also point to an underlying superlattice structure of low frequency and long wavelength with features in common with the charge order identified recently by complementary spectroscopic techniques.

Hard two-body photodisintegration of 3He

We have measured cross sections for the γ(3)He → pd reaction at photon energies of 0.4-1.4 GeV and a center-of-mass angle of 90°. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.

High-magnetic-field lattice length changes in URu2Si2

We report high-magnetic-field (up to 45 T) ĉ-axis thermal-expansion and magnetostriction experiments on URu(2)Si(2) single crystals. The sample length change ΔL(c)(T(HO))/L(c) associated with the transition to the "hidden order" phase becomes increasingly discontinuous as the magnetic field is raised above 25 T. The reentrant ordered phase III is clearly observed in both the thermal expansion ΔL(c)(T)/L(c) and magnetostriction ΔL(c)(B)/L(c) above 36 T, in good agreement with previous results. The sample length is also discontinuous at the boundaries of this phase, mainly at the upper boundary. A change in the sign of the coefficient of thermal expansion α(c)=1/L(c)(∂ΔL(c)/∂T) is observed at the metamagnetic transition (B(M) ~ 38 T), which is likely related to the existence of a quantum critical end point.