Transport anomalies in a simplified model for a heavy electron quantum critical point

We discuss the transport anomalies associated with the development of heavy electrons out of a neutral spin fluid using the large-N treatment of the Kondo-Heisenberg lattice model. At the phase transition in this model the spin excitations suddenly acquire charge. The Higgs process by which this takes place causes the constraint gauge field to loosely ``lock'' together with the external, electromagnetic gauge field. From this perspective, the heavy fermion phase is a Meissner phase in which the field representing the difference between the electromagnetic and constraint gauge field, is excluded from the material. We show that at the transition into the heavy fermion phase, both the linear and the Hall conductivity jump together. However, the Drude weight of the heavy electron fluid does not jump at the quantum critical point, but instead grows linearly with the distance from the quantum critical point, forming a kind of ``gossamer'' Fermi-liquid.Comment: 15 pages, 3 figures. Small change in references in v

Investigations into the Sarcomeric Protein and Ca2+-Regulation Abnormalities Underlying Hypertrophic Cardiomyopathy in Cats (Felix catus).

Hypertrophic cardiomyopathy (HCM) is the most common single gene inherited cardiomyopathy. In cats (Felix catus) HCM is even more prevalent and affects 16% of the outbred population and up to 26% in pedigree breeds such as Maine Coon and Ragdoll. Homozygous MYBPC3 mutations have been identified in these breeds but the mutations in other cats are unknown. At the clinical and physiological level feline HCM is closely analogous to human HCM but little is known about the primary causative mechanism. Most identified HCM causing mutations are in the genes coding for proteins of the sarcomere. We therefore investigated contractile and regulatory proteins in left ventricular tissue from 25 cats, 18 diagnosed with HCM, including a Ragdoll cat with a homozygous MYBPC3 R820W, and 7 non-HCM cats in comparison with human HCM (from septal myectomy) and donor heart tissue. Myofibrillar protein expression was normal except that we observed 20–44% MyBP-C haploinsufficiency in 5 of the HCM cats. Troponin extracted from 8 HCM and 5 non-HCM cat hearts was incorporated into thin filaments and studied by in vitro motility assay. All HCM cat hearts had a higher (2.06 ± 0.13 fold) Ca2+-sensitivity than non-HCM cats and, in all the HCM cats, Ca2+-sensitivity was not modulated by troponin I phosphorylation. We were able to restore modulation of Ca2+-sensitivity by replacing troponin T with wild-type protein or by adding 100 μM Epigallocatechin 3-gallate (EGCG). These fundamental regulatory characteristics closely mimic those seen in human HCM indicating a common molecular mechanism that is independent of the causative mutation. Thus, the HCM cat is a potentially useful large animal model

Fly-by-light flight control system technology development plan

The results of a four-month, phased effort to develop a Fly-by-Light Technology Development Plan are documented. The technical shortfalls for each phase were identified and a development plan to bridge the technical gap was developed. The production configuration was defined for a 757-type airplane, but it is suggested that the demonstration flight be conducted on the NASA Transport Systems Research Vehicle. The modifications required and verification and validation issues are delineated in this report. A detailed schedule for the phased introduction of fly-by-light system components has been generated. It is concluded that a fiber-optics program would contribute significantly toward developing the required state of readiness that will make a fly-by-light control system not only cost effective but reliable without mitigating the weight and high-energy radio frequency related benefits

Staggered Flux Phase in a Model of Strongly Correlated Electrons

We present numerical evidence for the existence of a staggered flux (SF) phase in the half-filled two-leg t-U-V-J ladder, with true long-range order in the counter-circulating currents. The density-matrix renormalization-group (DMRG) / finite-size scaling approach, generalized to describe complex-valued Hamiltonians and wavefunctions, is employed. The SF phase exhibits robust currents at intermediate values of the interaction strength.Comment: Version to appear in Phys. Rev. Let

Exact Equal Time Statistics of Orszag-McLaughlin Dynamics By The Hopf Characteristic Functional Approach

By employing Hopf's functional method, we find the exact characteristic functional for a simple nonlinear dynamical system introduced by Orszag. Steady-state equal-time statistics thus obtained are compared to direct numerical simulation. The solution is both non-trivial and strongly non-Gaussian.Comment: 6 pages and 2 figure

Understanding the health-care experiences of people with sickle cell disorder transitioning from paediatric to adult services: This Sickle Cell Life, a longitudinal qualitative study

Background Transitions from paediatric to adult health-care services cause problems worldwide, particularly for young people with long-term conditions. Sickle cell disorder brings particular challenges needing urgent action. Objectives Understand health-care transitions of young people with sickle cell disorder and how these interact with broader transitions to adulthood to improve services and support. Methods We used a longitudinal design in two English cities. Data collection included 80 qualitative interviews with young people (aged 13–21 years) with sickle cell disorder. We conducted 27 one-off interviews and 53 repeat interviews (i.e. interviews conducted two or three times over 18 months) with 48 participants (30 females and 18 males). We additionally interviewed 10 sickle cell disease specialist health-care providers. We used an inductive approach to analysis and co-produced the study with patients and carers. Results Key challenges relate to young people’s voices being ignored. Participants reported that their knowledge of sickle cell disorder and their own needs are disregarded in hospital settings, in school and by peers. Outside specialist services, health-care staff refuse to recognise patient expertise, reducing patients’ say in decisions about their own care, particularly during unplanned care in accident and emergency departments and on general hospital wards. Participants told us that in transitioning to adult care they came to realise that sickle cell disorder is poorly understood by non-specialist health-care providers. As a result, participants said that they lack trust in staff’s ability to treat them correctly and that they try to avoid hospital. Participants reported that they try to manage painful episodes at home, knowing that this is risky. Participants described engaging in social silencing (i.e. reluctance to talk about and disclose their condition for fear that others will not listen or will not understand) outside hospital; for instance, they would avoid mentioning cell sickle disorder to explain fatigue. Their self-management tactics include internalising their illness experiences, for instance by concealing pain to protect others from worrying. Participants find that working to stay healthy is difficult to reconcile with developing identities to meet adult life goals. Participants have to engage in relentless self-disciplining when trying to achieve educational goals, yet working hard is incompatible with being a ‘good adult patient’ because it can be risky for health. Participants reported that they struggle to reconcile these conflicting demands. Limitations Our findings are derived from interviews with a group of young people in England and reflect what they told us (influenced by how they perceived us). We do not claim to represent all young people with sickle cell disorder. Conclusions Our findings reveal poor care for young people with sickle cell disorder outside specialist services. To improve this, it is vital to engage with young people as experts in their own condition, recognise the legitimacy of their voices and train non-specialist hospital staff in sickle cell disorder care. Young people must be supported both in and outside health-care settings to develop identities that can help them to achieve life goals. Future work Future work should include research into the understanding and perceptions of sickle cell disease among non-specialist health-care staff to inform future training. Whole-school interventions should be developed and evaluated to increase sickle cell disorder awareness. Funding This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 44. See the NIHR Journals Library website for further project information

Polarisation Observations of H2_{2}O JK−1K1=532−441J_{K_{-1}K_{1}} = 5_{32} - 4_{41} 620.701 GHz Maser Emission with Herschel/HIFI in Orion KL

Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition $J_{K_{-1}K_{1}}=5_{32}-4_{41}$ at 620.701 GHz can only be observed from above Earth's strongly absorbing atmosphere; its emission has recently been detected from space. Aims. We sought to further characterize the star-forming environment of Orion KL by investigating the linear polarisation of a source emitting a narrow 620.701 GHz maser feature with the heterodyne spectrometer HIFI on board the Herschel Space Observatory. Methods. High-resolution spectral datasets were collected over a thirteen month period beginning in 2011 March, to establish not only the linear polarisation but also the temporal variability of the source. Results. Within a $3\sigma$ uncertainty, no polarisation was detected to an upper limit of approximately 2%. These results are compared with coeval linear polarisation measurements of the 22.235 GHz $J_{K_{-1}K_{1}}=6_{16}-5_{23}$ maser line from the Effelsberg 100-m radio telescope, typically a much stronger maser transition. Although strongly polarised emission is observed for one component of the 22.235 GHz maser at 7.2 km s$^{-1}$, a weaker component at the same velocity as the 620.701 GHz maser at 11.7 km s$^{-1}$ is much less polarised.Comment: Accepted for publication in A&