Simulation Study of the Emittance Measurements in Magnetized Electron Beam

Electron cooling of the ion beam is key to obtaining the required high luminosity of proposed electron-ion colliders. For the Jefferson Lab Electron Ion Collider, the expected luminosity of 10³⁴ 〖 cm〗⁻² s⁻¹ will be achieved through so-called ’magnetized electron cooling’, where the cooling process occurs inside a solenoid field, which will be part of the collider ring and facilitated using a circulator ring and Energy Recovery Linac (ERL). As an initial step, we generated magnetized electron beam using a new compact DC high voltage photogun biased at -300 kV employing an alkali-antimonide photocathode. This contribution presents the characterization of the magnetized electron beam (emittance variations with the magnetic field strength for different laser spot sizes) and a comparison to GPT simulations

300 kV DC High Voltage Photogun With Inverted Insulator Geometry and CsK₂sb Photocathode

A compact DC high voltage photogun with inverted-insulator geometry was designed, built and operated reliably at 300 kV bias voltage using alkali-antimonide photocathodes. This presentation describes key electrostatic design features of the photogun with accompanying emittance measurements obtained across the entire photocathode surface that speak to field non-uniformity within the cathode/anode gap. A summary of initial photocathode lifetime measurements at beam currents up to 4.5 mA is also presented

Quantum information processing using quasiclassical electromagnetic interactions between qubits and electrical resonators

Electrical resonators are widely used in quantum information processing, by engineering an electromagnetic interaction with qubits based on real or virtual exchange of microwave photons. This interaction relies on strong coupling between the qubits' transition dipole moments and the vacuum fluctuations of the resonator in the same manner as cavity quantum electrodynamics (QED), and has consequently come to be called 'circuit QED' (cQED). Great strides in the control of quantum information have already been made experimentally using this idea. However, the central role played by photon exchange induced by quantum fluctuations in cQED does result in some characteristic limitations. In this paper, we discuss an alternative method for coupling qubits electromagnetically via a resonator, in which no photons are exchanged, and where the resonator need not have strong quantum fluctuations. Instead, the interaction can be viewed in terms of classical, effective 'forces' exerted by the qubits on the resonator, and the resulting resonator dynamics used to produce qubit entanglement are purely classical in nature. We show how this type of interaction is similar to that encountered in the manipulation of atomic ion qubits, and we exploit this analogy to construct two-qubit entangling operations that are largely insensitive to thermal or other noise in the resonator, and to its quality factor. These operations are also extensible to larger numbers of qubits, allowing interactions to be selectively generated among any desired subset of those coupled to a single resonator. Our proposal is potentially applicable to a variety of physical qubit modalities, including superconducting and semiconducting solid-state qubits, trapped molecular ions, and possibly even electron spins in solids.United States. Dept. of Defense. Assistant Secretary of Defense for Research & Engineering (United States. Air Force Contract FA8721-05-C-0002

Radioactive 26Al and massive stars in the Galaxy

Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a 'snapshot' view of ongoing nucleosynthesis in the Galaxy. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane of the Galaxy. This led to the conclusion1 that massive stars throughout the Galaxy dominate the production of 26Al. On the other hand, meteoritic data show locally-produced 26Al, perhaps from spallation reactions in the protosolar disk. Furthermore, prominent gamma-ray emission from the Cygnus region suggests that a substantial fraction of Galactic 26Al could originate in localized star-forming regions. Here we report high spectral resolution measurements of 26Al emission at 1808.65 keV, which demonstrate that the 26Al source regions corotate with the Galaxy, supporting its Galaxy-wide origin. We determine a present-day equilibrium mass of 2.8 (+/-0.8) M_sol of 26Al. We use this to estimate that the frequency of core collapse (i.e. type Ib/c and type II) supernovae to be 1.9(+/- 1.1) events per century.Comment: accepted for publication in Nature, 24 pages including Online Supplements, 11 figures, 1 tabl

Cost-effectiveness of Outpatient Parenteral Antibiotic Therapy: A Simulation Modelling Approach

Objectives: In the UK, patients who require intravenous antimicrobial (IVA) treatment may receive this in the community through outpatient parenteral antimicrobial therapy (OPAT) services. Services include: IVA administration at a hospital outpatient clinic (HO); IVA administration at home by a general nurse (GN) or a specialist nurse (SN); or patient self-administered (SA) IVA administration following training. There is uncertainty regarding which OPAT services represent value for money; this study aimed to estimate their cost-effectiveness. Methods: A cost-effectiveness decision-analytic model was developed using a simulation technique utilizing data from hospital records and a systematic review of the literature. The model estimates cost per QALY gained from the National Health Service (NHS) perspective for short- and long-term treatment of infections and service combinations across these. Results: In short-term treatments, HO was estimated as the most effective (0.7239 QALYs), but at the highest cost (£973). SN was the least costly (£710), producing 0.7228 QALYs. The combination between SN and HO was estimated to produce 0.7235 QALYs at a cost of £841. For long-term treatments, SN was the most effective (0.677 QALYs), costing £2379, while SA was the least costly at £1883, producing 0.666 QALYs. A combination of SA and SN was estimated to produce 0.672 QALYs at a cost of £2128. Conclusions: SN and SA are cost-effective for short- and long-term treatment of infections, while combining services may represent the second-best alternative for OPAT in the UK

On electrostatic and Casimir force measurements between conducting surfaces in a sphere-plane configuration

We report on measurements of forces acting between two conducting surfaces in a spherical-plane configuration in the 35 nm-1 micrometer separation range. The measurements are obtained by performing electrostatic calibrations followed by a residual analysis after subtracting the electrostatic-dependent component. We find in all runs optimal fitting of the calibrations for exponents smaller than the one predicted by electrostatics for an ideal sphere-plane geometry. We also find that the external bias potential necessary to minimize the electrostatic contribution depends on the sphere-plane distance. In spite of these anomalies, by implementing a parametrixation-dependent subtraction of the electrostatic contribution we have found evidence for short-distance attractive forces of magnitude comparable to the expected Casimir-Lifshitz force. We finally discuss the relevance of our findings in the more general context of Casimir-Lifshitz force measurements, with particular regard to the critical issues of the electrical and geometrical characterization of the involved surfaces.Comment: 22 pages, 15 figure

Cost-effectiveness of Outpatient Parenteral Antibiotic Therapy: A Simulation Modelling Approach

Objectives: In the UK, patients who require intravenous antimicrobial (IVA) treatment may receive this in the community through outpatient parenteral antimicrobial therapy (OPAT) services. Services include: IVA administration at a hospital outpatient clinic (HO); IVA administration at home by a general nurse (GN) or a specialist nurse (SN); or patient self-administered (SA) IVA administration following training. There is uncertainty regarding which OPAT services represent value for money; this study aimed to estimate their cost-effectiveness. Methods: A cost-effectiveness decision-analytic model was developed using a simulation technique utilizing data from hospital records and a systematic review of the literature. The model estimates cost per QALY gained from the National Health Service (NHS) perspective for short- and long-term treatment of infections and service combinations across these. Results: In short-term treatments, HO was estimated as the most effective (0.7239 QALYs), but at the highest cost (£973). SN was the least costly (£710), producing 0.7228 QALYs. The combination between SN and HO was estimated to produce 0.7235 QALYs at a cost of £841. For long-term treatments, SN was the most effective (0.677 QALYs), costing £2379, while SA was the least costly at £1883, producing 0.666 QALYs. A combination of SA and SN was estimated to produce 0.672 QALYs at a cost of £2128. Conclusions: SN and SA are cost-effective for short- and long-term treatment of infections, while combining services may represent the second-best alternative for OPAT in the UK

Performance of the inFLUenza Patient-Reported Outcome (FLU-PRO) diary in patients with influenza-like illness (ILI)

BACKGROUND: The inFLUenza Patient Reported Outcome (FLU-PRO) measure is a daily diary assessing signs/symptoms of influenza across six body systems: Nose, Throat, Eyes, Chest/Respiratory, Gastrointestinal, Body/Systemic, developed and tested in adults with influenza. OBJECTIVES: This study tested the reliability, validity, and responsiveness of FLU-PRO scores in adults with influenza-like illness (ILI). METHODS: Data from the prospective, observational study used to develop and test the FLU-PRO in influenza virus positive patients were analyzed. Adults (≥18 years) presenting with influenza symptoms in outpatient settings in the US, UK, Mexico, and South America were enrolled, tested for influenza virus, and asked to complete the 37-item draft FLU-PRO daily for up to 14-days. Analyses were performed on data from patients testing negative. Reliability of the final, 32-item FLU-PRO was estimated using Cronbach's alpha (α; Day 1) and intraclass correlation coefficients (ICC; 2-day reproducibility). Convergent and known-groups validity were assessed using patient global assessments of influenza severity (PGA). Patient report of return to usual health was used to assess responsiveness (Day 1-7). RESULTS: The analytical sample included 220 ILI patients (mean age = 39.3, 64.1% female, 88.6% white). Sixty-one (28%) were hospitalized at some point in their illness. Internal consistency reliability (α) of FLU-PRO Total score was 0.90 and ranged from 0.72-0.86 for domain scores. Reproducibility (Day 1-2) was 0.64 for Total, ranging from 0.46-0.78 for domain scores. Day 1 FLU-PRO scores correlated (≥0.30) with the PGA (except Gastrointestinal) and were significantly different across PGA severity groups (Total: F = 81.7, p<0.001; subscales: F = 6.9-62.2; p<0.01). Mean score improvements Day 1-7 were significantly greater in patients reporting return to usual health compared with those who did not (p<0.05, Total and subscales, except Gastrointestinal and Eyes). CONCLUSIONS: Results suggest FLU-PRO scores are reliable, valid, and responsive in adults with influenza-like illness

Educación ciudadana, democracia y participación

En este texto se han reunido los contenidos de las sesiones plenarias de la Conferencia Internacional sobre Educación Ciudadana, Democracia y Participación, que contó con el apoyo adicional de la UNESCO y de la Agencia de Información de los Estados Unidos, USIS. Cada sección corresponde a una de las mesas en que fueron presentadas las ponencias. La primera parte lleva por título "Ciudadanía, democracia y educación: situación, perspectivas y áreas de intervención". En ella, Juan Carlos Tedesco, director de la Oficina Internacional de la Educación de la UNESCO en Ginebra, analiza los retos que debe en frentar la educación ciudadana en el mundo cambiante de hoy. Esta ponencia tuvo tres comentaristas: Jorge Santistevan de Noriega, Defensor del Pueblo; Cynthia Sanborn, de la Universidad del Pacífico; y Ricardo Morales, de Foro Educativo. Esta primera mesa tenía como objetivo principal sentar las bases teóricas para la discusión de los temas que siguieron, muchos de ellos vinculados a aspectos más específicos de la educación ciudadana. La segunda parte del libro, "Diseño, implementación y evaluación de proyectos de educación ciudadana", contiene dos ponencias. En la primera, Marcia Bernbaum, experta internacional en evaluación de proyectos, da algunas pautas para la elaboración de evaluaciones en educación ciudadana. La segunda presentación, que corresponde a Christopher Sabatini, funcionario del National Endowment for Democracy de los Estados Unidos, describe los métodos y resultados de la evaluación de una serie de programas internacionales de educación ciudadana auspiciados por la USAID en República Dominicana. El énfasis en la evaluación se explica por ser ésta un área que requiere fortalecerse significativamente, si ha de mejorar y perdurar el impacto de las iniciativas de educación ciudadana en curso en nuestro país. Esta sesión no tuvo comentaristas, sino que fue seguida por una discusión abierta con el público. La tercera y cuarta sesiones estuvieron dedicadas a analizar el rol de la educación ciudadana en las escuelas, ámbito en el cual el desprestigio de la tradicional Educación Cívica está dando paso al dise ño y la experimentación de alternativas muy diversas para la formación en valores y comportamientos sociales, y en el cual también se desarrollaron varios de los proyectos auspiciados por DEMPAR. El tema general fue "Escuela y educación en democracia". En la primera mesa participó Erwin Epstein, profesor de la Universidad estatal de Ohio y editor de la revista Comparative Education Review, quien reflexionó sobre las paradojas de la educación pública obligatoria como camino a una sociedad plural y democrática y sobre los efectos que ella puede tener en sociedades en transición. Comentaron e hicieron sus propias reflexiones sobre escuela, educación y valores, Marita Palacios de Tarea y Constantino Carvallo del Colegio Los Reyes Rojos. En la segunda mesa participó Francisco Cajiao, de la Fundación de Estudios Sociales, quien enfocó su presentación en el rol de las escuelas, y principalmente el de los maestros, en la educación ciudadana. Fueron sus comentaristas León Trahtemberg, director del Colegio León Pinelo, y Rolando Andrade, Director Nacional de Formación y Capacitación Docente del Ministerio de Educación. La quinta sesión se llamó "Educación ciudadana para la formación de líderes democráticos". El presentador principal fue Francisco Estévez, de la Fundación IDEAS de Chile. Lo acompañaron Rolando Ames, del Instituto Diálogo y Propuestas, y Luis Bustamante, de la Universidad Peruana de Ciencias Aplicadas. Estévez centró inicialmente su exposición en el impacto que la globalización y la globalidad cultural tendrían sobre la estructura de valores de sociedades en que la trayectoria de la democracia ha sido diferente a la de los países donde ésta se originó históricamente. Procedió luego a la descripción comparada de cómo se forma actualmente para el liderazgo social y político en los Estados Unidos y en los países de América Latina. La siguiente mesa se denominó "La influencia de los medios en la formación de ciudadanía". Reunió a Germán Rey, de la Fundación Social de Colombia; a Rosa María Alfaro, de Calandria; y a Federico Salazar, de América Televisión. El análisis y los comentarios se centraron en el potencial y los límites de los medios en la formación de una opinión pública y en la movilización de una ciudadanía activa y democrática, en estos tiempos postmodernos en los que están vigentes —y compiten— tantos y tan diversos lenguajes y mensajes. Finalmente, para tratar el rol de uno de los más importantes actores en la formación de ciudadanos y en el fortalecimiento de la democracia, la mesa "Rol del Estado en el desarrollo de la educación ciudadana" reunió a tres congresistas de la república: Carlos Ferrero (Nueva Mayoría-Cambio 90), Henry Pease (Unión por el Perú) y Lourdes Flores (Partido Popular Cristiano), representativos de las principales fuerzas políticas del país actualmente en el Parlamento peruano. Esta sesión fue moderada por el periodista Raúl Vargas