Stochastic background of gravitational waves emitted by magnetars

Two classes of high energy sources in our galaxy are believed to host magnetars, neutron stars whose emission results from the dissipation of their magnetic field. The extremely high magnetic field of magnetars distorts their shape, and causes the emission of a conspicuous gravitational waves signal if rotation is fast and takes place around a different axis than the symmetry axis of the magnetic distortion. Based on a numerical model of the cosmic star formation history, we derive the cosmological background of gravitational waves produced by magnetars, when they are very young and fast spinning. We adopt different models for the configuration and strength of the internal magnetic field (which determines the distortion) as well as different values of the external dipole field strength (which governs the spin evolution of magnetars over a wide range of parameters). We find that the expected gravitational wave background differs considerably from one model to another. The strongest signals are generated for magnetars with very intense toroidal internal fields ($\sim 10^{16}$ G range) and external dipole fields of $\sim 10^{14}$, as envisaged in models aimed at explaining the properties of the Dec 2004 giant flare from SGR 1806-20. Such signals should be easily detectable with third generation ground based interferometers such as the Einstein Telescope.Comment: 9 pages, 5 figures, accepted for publication in MNRA

Workplace change and institutional experimentation: a case study of service-sector work in Europe

This article examines institutional experimentation by linking the dynamics of capital accumulation, the adoption of new digital technologies within the labour process, and institutional settings. Our inductive qualitative case study within the service (logistics) sector in Europe sheds light on the processes through which local stakeholders engage in workplace change through institutional experimentation. It also illustrates how and under which conditions unions can act as political agents of transformation to influence work and employment

Fluctuación estacional de hongos anemófilos en Santiago Norte - Chile

Por el método de cultivo de esporas viables, se monitoreó la concentración fúngica y variabilidad genética presente en la atmosfera de Santiago entre 1991 y 1992. Durante 52 semanas se recolectaron 1.040 muestras en 10 lugares mediante la impactación de 20 litros de aire en la superficie de un medio de cultivo, utilizando un equipo colector portátil RCS.La atmósfera se presentó homogénea cualitativa y cuantitativamente, con una concentraciónmedia de 1.945  ufc/m3. El contenidofúngico aumentó en forma significativa en verano y presentó correlación positiva con la temperatura y luz solar y negativa con humedad relativa y presión barométrica.Se identificaron 39 taxa: 86,7% correspondió a hongos filamentosos y 13,2% a levaduras. Los géneros predominantes en orden decreciente fueron Cladosporium, Ulocladium, Alternaria, Penicilium, Aspergilllus, Aureobasidium, Botrytis y Epicoccum, los que en conjunto representaron el 75,6 del total de las colonias. Cladosporium, Ulocladium y Epicoccum aumentan su concentración en verano y se correlacionan en forma positiva con la temperatura y luz solar; Botrytis y Penicillium aumentan en invierno y otoño y Aspergillus solo en otoño.

Performance Portable Solid Mechanics via Matrix-Free pp-Multigrid

Finite element analysis of solid mechanics is a foundational tool of modern engineering, with low-order finite element methods and assembled sparse matrices representing the industry standard for implicit analysis. We use performance models and numerical experiments to demonstrate that high-order methods greatly reduce the costs to reach engineering tolerances while enabling effective use of GPUs. We demonstrate the reliability, efficiency, and scalability of matrix-free $p$-multigrid methods with algebraic multigrid coarse solvers through large deformation hyperelastic simulations of multiscale structures. We investigate accuracy, cost, and execution time on multi-node CPU and GPU systems for moderate to large models using AMD MI250X (OLCF Crusher), NVIDIA A100 (NERSC Perlmutter), and V100 (LLNL Lassen and OLCF Summit), resulting in order of magnitude efficiency improvements over a broad range of model properties and scales. We discuss efficient matrix-free representation of Jacobians and demonstrate how automatic differentiation enables rapid development of nonlinear material models without impacting debuggability and workflows targeting GPUs

Aportes de la experiencia transdisciplinaria a la política pública en infancia-adolescencia

El presente trabajo tiene como propósito dar cuenta de la contribución de la extensión universitaria a las políticas públicas en niñez y adolescencia. Forma parte del Proyecto de Extensión “Respuestas Transdisciplinarias a problemáticas actuales de infancia y adolescencia”  implementado desde Marzo de 2012 y actualmente en ejecución, por  la cátedra de Psicología Social de la Facultad de Psicología de la UNLP. Los destinatarios del mismo son trabajadores y miembros de la comunidad de Ensenada (Provincia de Buenos Aires) que abordan problemáticas complejas en niñez y adolescencia. Nuestra propuesta está basada en consideración de las siguientes dificultades: niños y jóvenes que expresan altos niveles de conflictividad en el ámbito escolar, incremento de distintos tipos de violencia (física, psíquica, familiar, intra e intergrupal, institucional), aumento en el consumo de tóxicos, trayectorias vitales que pivotean entre lo delictivo y el trabajo informal. Partimos del relevamiento y exploración de dicho entramado. Para ello diseñamos y desarrollamos estrategias de acción interdisciplinarias (psicología, medicina, psicoanálisis, trabajo social, abogacía), interprofesionales (psicólogo/a, trabajador/a social, médico, educador/a), intersectoriales (salud, educación, justicia, trabajo), e interinstitucionales (escuela, centro de salud, organizaciones comunitarias, servicios sociales). Son objetivos del presente proyecto: (1) Aportar un modelo de diagnostico e intervención – replicable en situaciones análogas- al tratamiento de las problemáticas, las dificultades y obstáculos comunitarios para dar respuesta social a las actuales problemáticas complejas que presenta la infancia y la adolescencia; (2) Ofrecer estrategias posibles y facilitar tácticas que apuesten al intercambio grupal, a la discusión y búsqueda de alternativas compartidas; (3) Promover la identificación y la caracterización de aquellas manifestaciones sintomáticas. De las entrevistas realizadas a equipos docentes, profesionales de la salud, representantes de colegios de profesionales  destacamos la presencia de diferentes posiciones subjetivas. A partir de nuestra  escucha, delimitamos  que oscilan entre la queja, la naturalización, la resignación y la mirada política. Resultados que permiten la constitución y puesta en funcionamiento de grupos de discusión, para luego realizar talleres temáticos con la finalidad de construir y fortalecer los lazos sociales entre los actores comunales. En cuanto a los resultados parciales, observamos que se logró propiciar la contención y escucha de los trabajadores; y se generó una mayor participación y compromiso dentro de los espacios propuestos.

Simulating Compressible and Nearly-Incompressible Linear Elasticity Using an Efficient Parallel Scalable Matrix-Free High-Order Finite Element Method

  We examine a residual and matrix-free Jacobian formulation of compressible and nearly incompressible (v → 0.5) displacement-only linear isotropic elasticity with high-order hexahedral finite elements. A matrix-free p-multigrid method is combined with algebraic multigrid on the assembled sparse coarse grid matrix to provide an effective preconditioner. The software is verified with the method of manufactured solutions. We explore convergence to a predetermined L2 error of 10-4, 10-5 and 10-6 for the compressible case and 10-4, 10-5 for the nearly-incompressible cases, as the Poisson's ratio approaches 0.5, based upon grid resolution and polynomial order. We compare our results against results obtained from C3D20H mixed/hybrid element available in the commercial finite element software ABAQUS that is quadratic in displacement and linear in pressure. We determine, for the same problem size, that our matrix-free approach for displacement-only implementation is faster and more efficient for quadratic elements compared to the C3D20H element from ABAQUS that is specially designed to handle nearly-incompressible and incompressible elasticity problems. However, as we approach the near incompressibility limit, the number of Conjugate Gradient iterations required to achieve the desired solution increases significantly. &nbsp

Multicenter observational study on factors and outcomes associated with various methicillin-resistant Staphylococcus aureus types in children with cystic fibrosis

Rationale: Methicillin-resistant Staphylococcus aureus (MRSA) prevalence continues to increase in patients with cystic fibrosis (CF) in the United States, reaching 26.5% in 2012. Approximately 30% of strains are SCCmec (staphylococcal cassette chromosome mec) IV type, frequently USA300, which in the general population have different genotypic and phenotypic features than SCCmec II type. Objectives: We hypothesized that risk factors for acquisition and outcomes in patients with CF differed for "health care-associated" (SCCmec II) versus "community-associated" (SCCmec IV)MRSAstrains. Methods: To determine the role of SCCmec type and Panton-Valentine leukocidin (PVL), MRSA isolates from patients not more than 18 years old at seven CF centers were typed and the association of potential risk factors and subsequent clinical course was assessed, using data provided by the CF Patient Registry. Measurements and Main Results: Participants with chronic MRSA (295) had typeable isolates and clinical data; 205 (69.5%) had SCCmec II PVL(-), 39 (13.2%) had SCCmec IV PVL(-), and 51 (17.3%) had SCCmec IVPVL(1) strains.SCCmec IV, comparedwith SCCmec II, increased during the study period, 1996-2010 (P = 0.03). SCCmec II was associated with Pseudomonas aeruginosa-positive cultures and three or more clinic visits in the 6 months preceding the first positive MRSA culture (adjusted odds ratio, 2.05; 95% confidence interval, 1.13-3.74; P = 0.019). Lung function and anthropometrics remained unchanged in the 6 months after initial MRSA detection compared with the 6 months prior. Although CF care increased for participants in both groups in the 6 months after MRSA detection, inhaled antibiotics were prescribed more frequently in those with SCCmec II strains and increased hospitalizations occurred in those with SCCmec IV PVL(-) strains compared with those with PVL(1) strains (adjusted difference, 34.10%; 95% confidence interval, 7.58-60.61; P = 0.012). Participants in both groups had an increase in CF care in the 2 years after MRSA detection compared with the 2 years prior. Conclusions: Increased exposure to CF clinics and P. aeruginosa may constitute risk factors for acquisition of SCCmec II MRSA strains. Clinical interventions increased 6 months and 2 years after initial MRSA detection regardless of SCCmec type

CD200R1 Supports HSV-1 Viral Replication and Licenses Pro-Inflammatory Signaling Functions of TLR2

The CD200R1:CD200 axis is traditionally considered to limit tissue inflammation by down-regulating pro-inflammatory signaling in myeloid cells bearing the receptor. We generated CD200R1−/− mice and employed them to explore both the role of CD200R1 in regulating macrophage signaling via TLR2 as well as the host response to an in vivo, TLR2-dependent model, herpes simplex virus 1 (HSV-1) infection. CD200R1−/− peritoneal macrophages demonstrated a 70–75% decrease in the generation of IL-6 and CCL5 (Rantes) in response to the TLR2 agonist Pam2CSK4 and to HSV-1. CD200R1−/− macrophages could neither up-regulate the expression of TLR2, nor assemble a functional inflammasome in response to HSV-1. CD200R1−/− mice were protected from HSV-1 infection and exhibited dysfunctional TLR2 signaling. Finally, both CD200R1−/− mice and CD200R1−/− fibroblasts and macrophages showed a markedly reduced ability to support HSV-1 replication. In summary, our data demonstrate an unanticipated and novel requirement for CD200R1 in “licensing” pro-inflammatory functions of TLR2 and in limiting viral replication that are supported by ex vivo and in vivo evidence

CD200R1 Supports HSV-1 Viral Replication and Licenses Pro-Inflammatory Signaling Functions of TLR2

The CD200R1:CD200 axis is traditionally considered to limit tissue inflammation by down-regulating pro-inflammatory signaling in myeloid cells bearing the receptor. We generated CD200R1−/− mice and employed them to explore both the role of CD200R1 in regulating macrophage signaling via TLR2 as well as the host response to an in vivo, TLR2-dependent model, herpes simplex virus 1 (HSV-1) infection. CD200R1−/− peritoneal macrophages demonstrated a 70–75% decrease in the generation of IL-6 and CCL5 (Rantes) in response to the TLR2 agonist Pam2CSK4 and to HSV-1. CD200R1−/− macrophages could neither up-regulate the expression of TLR2, nor assemble a functional inflammasome in response to HSV-1. CD200R1−/− mice were protected from HSV-1 infection and exhibited dysfunctional TLR2 signaling. Finally, both CD200R1−/− mice and CD200R1−/− fibroblasts and macrophages showed a markedly reduced ability to support HSV-1 replication. In summary, our data demonstrate an unanticipated and novel requirement for CD200R1 in “licensing” pro-inflammatory functions of TLR2 and in limiting viral replication that are supported by ex vivo and in vivo evidence

Epidemiology and molecular phylogeny of Babesia sp. in Little Penguins Eudyptula minor in Australia

Blood parasites are potential threats to the health of penguins and to their conservation and management. Little penguins Eudyptula minor are native to Australia and New Zealand, and are susceptible to piroplasmids (Babesia), hemosporidians (Haemoproteus, Leucocytozoon, Plasmodium) and kinetoplastids (Trypanosoma). We studied a total of 263 wild little penguins at 20 sites along the Australian southeastern coast, in addition to 16 captive-bred little penguins. Babesia sp. was identified in seven wild little penguins, with positive individuals recorded in New South Wales, Victoria and Tasmania. True prevalence was estimated between 3.4% and 4.5%. Only round forms of the parasite were observed, and gene sequencing confirmed the identity of the parasite and demonstrated it is closely related to Babesia poelea from boobies (Sula spp.) and B. uriae from murres (Uria aalge). None of the Babesia-positive penguins presented signs of disease, confirming earlier suggestions that chronic infections by these parasites are not substantially problematic to otherwise healthy little penguins. We searched also for kinetoplastids, and despite targeted sampling of little penguins near the location where Trypanosoma eudyptulae was originally reported, this parasite was not detected