The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

Lipid vesicles trigger α-synuclein aggregation by stimulating primary nucleation.

α-Synuclein (α-syn) is a 140-residue intrinsically disordered protein that is involved in neuronal and synaptic vesicle plasticity, but its aggregation to form amyloid fibrils is the hallmark of Parkinson's disease (PD). The interaction between α-syn and lipid surfaces is believed to be a key feature for mediation of its normal function, but under other circumstances it is able to modulate amyloid fibril formation. Using a combination of experimental and theoretical approaches, we identify the mechanism through which facile aggregation of α-syn is induced under conditions where it binds a lipid bilayer, and we show that the rate of primary nucleation can be enhanced by three orders of magnitude or more under such conditions. These results reveal the key role that membrane interactions can have in triggering conversion of α-syn from its soluble state to the aggregated state that is associated with neurodegeneration and to its associated disease states.This work was supported by the UK BBSRC and the Wellcome Trust (CMD, TPJK, MV), the Frances and Augustus Newman Foundation (TPJK), Magdalene College, Cambridge (AKB) , St John’s College, Cambridge (TCTM), the Cambridge Home and EU Scholarship Scheme (GM), Elan Pharmaceuticals (CMD, TPJK, MV, CG) and the Leverhulme Trust (AKB).This is the accepted manuscript. The final version is available from NPG at http://www.nature.com/nchembio/journal/v11/n3/abs/nchembio.1750.htm

Unexpected development of autoimmunity in BAFF-R-mutant MRL-lpr mice

BAFF-R is the predominant receptor that mediates B-cell activating factor (BAFF)-dependent B-cell signalling and plays a critical role in late-stage B-cell maturation and survival. BAFF has been implicated in the development of autoimmunity and systemic lupus erythematosus (SLE). To define the role of BAFF-R in autoimmunity and SLE, we crossed A/WySnJ mice with MRL-lpr mice and generated BAFF-R-mutant MRL-lpr mice. The BAFF-R mutation markedly impaired the development of immature, mature and marginal zone B cells in the spleens of MRL-lpr mice. Unexpectedly, the BAFF-R mutation in MRL-lpr mice did not result in decreased autoantibody production, hypergammaglobulinaemia or immune complex-mediated glomerulonephritis. Rather, the ability of BAFF-R-mutant lpr splenic B cells to produce immunoglobulins in vitro was not decreased, although germinal centre formation, antibody response and B-cell proliferation were impaired. Further studies found increased numbers of B cells in the bone marrow of BAFF-R-mutant MRL-lpr mice compared to the BAFF-R-intact lupus mice. ELISPOT analysis revealed that BAFF-R-mutant MRL-lpr mice had more antibody-secreting cells in their bone marrow than the control mice. Thus, these findings could explain the development of autoimmunity and hypergammaglobulinaemia observed in BAFF-R-mutant MRL-lpr mice

A enfermagem no processo da acreditação hospitalar em um serviço de urgência e emergência La enfermería en el proceso de la acreditación hospitalaria en un servicio de urgencia y emergencia Nursing role during accreditation process of an emergency service

OBJETIVO: construir ações de enfermagem para reestruturar o Pronto Socorro de um hospital universitário de acordo com os padrões da Acreditação Hospitalar em urgência e emergência segundo o Ministério da Saúde. MÉTODOS: realizou-se uma prática investigativa com um grupo de oito enfermeiros do setor mediante um processo crítico-reflexivo e interventivo acerca da organização do trabalho da enfermagem. RESULTADOS: os itens destacados para reestruturação foram quatro: Equipe treinada para atendimento em urgência e emergência, registro das ações assistenciais aos pacientes em observação, equipamentos, medicamentos e materiais compatíveis com a estrutura do serviço e acompanhantes ou responsáveis informados sobre o estado geral do paciente assistido. CONCLUSÃO: o estudo possibilitou reflexões em busca da qualidade no cuidado de enfermagem, instrumentalizando a equipe na busca da Acreditação Hospitalar, com vistas à melhoria da qualidade da assistência.<br>OBJETIVO: construir acciones de enfermería para reestructurar el servicio de Emergencia de un hospital universitario de acuerdo a los patrones de la Acreditación Hospitalaria en urgencia y emergencia según el Ministerio de Salud. MÉTODOS: se realizó una práctica investigativa con un grupo de ocho enfermeros del sector mediante un proceso crítico-reflexivo y de intervención acerca de la organización del trabajo de la enfermería. RESULTADOS: los items destacados para la reestructuración fueron cuatro: Equipo entrenado para la atención en urgencia y emergencia, registro de las acciones asistenciales de los pacientes en observación, equipos, medicamentos y materiales compatibles con la estructura del servicio y que los acompañantes o responsables son informados sobre el estado general del paciente asistido. CONCLUSIÓN: el estudio permitió reflexiones en búsqueda de la calidad en el cuidado de enfermería, instrumentando al equipo en la búsqueda de la Acreditación Hospitalaria, con vistas a la mejoría de la calidad de la asistencia.<br>OBJECTIVE: to determine nursing role during the accreditation process of the emergency room of a university hospital to meet the criteria of the Brazilian Ministry of Health. METHODS: a critical-reflexive process was used to obtain the opinion of eight nurses regarding their role in setting up the structure of the nursing service. RESULTS: the main items related to the structure of the nursing service were: (1) well trained emergency team; (2) appropriate documentation of care; (3) maintaining necessary equipment, medications, and supplies accessible; and, (4) keeping family members or responsible party well informed regarding the patient's progress. CONCLUSION: this study may lead to further reflections on ways to reach quality care and meet requirements for accreditation

Gas distribution in a two-compartment model ventilated in high-frequency percussive and pressure-controlled modes

Purpose To demonstrate in a two-compartment heterogeneous mechanical model of the lung how different loads applied to one compartment, while the other is kept constant, would modify gas distribution between the two pathways under high-frequency percussive ventilation (HFPV). Additionally, these results were compared with those generated in the same model by pressure-controlled ventilation (PCV). Methods Analysis was based on a Siemens lung simulator, representing a fixed branch of the system with an elastance equal to 45 cmH2O/L and a resistance of 20 cmH2O/L/s, and a single-compartment lung simulator, representing a variable pathway of the model, presenting three elastic loads varying between 35 and 85 cmH2O/L and three resistive loads varying between 5 and 50 cmH2O/L/s. Each simulator represented one compartment of the model connected to a central airway that was ventilated with either a volumetric diffusive respirator (VDR-4; Percussionaire Corporation, Sandpoint, ID, USA) or a Siemens Servo 900c ventilator. Flow and pressures were measured in each branch of the model under nine conditions representing the combinations of three elastic and three resistive loads (variable branch) while the loads in the other pathway were kept constant. Results HFPV was able to avoid hyperinflation and reduce tidal volume in a bicompartmental heterogeneous lung model. Under HFPV, gas distribution between the two compartments was not constrained by their time constants. PCV yielded gas distribution as determined by the time constant of each compartment. Conclusions HFPV accommodated volume distribution without overinflating compartments with low time constants, thus possibly presenting a potential protective behavior in mechanically heterogeneous lungs