Low Mass Neutron Stars and the Equation of State of Dense Matter

Neutron-star radii provide useful information on the equation of state of neutron rich matter. Particularly interesting is the density dependence of the equation of state (EOS). For example, the softening of the EOS at high density, where the pressure rises slower than anticipated, could signal a transition to an exotic phase. However, extracting the density dependence of the EOS requires measuring the radii of neutron stars for a broad range of masses. A ``normal'' 1.4 solar mass neutron star has a central density of a few times nuclear-matter saturation density. In contrast, low mass (of the order of 0.5 solar masses) neutron stars have central densities near nuclear-matter saturation density so its radius provides information on the EOS at low density. Unfortunately, low-mass stars are rare because they may be hard to form. Instead, a precision measurement of nuclear radii on atomic nuclei may contain similar information. Indeed, we find a strong correlation between the neutron radius of 208Pb and the radius of a 0.5 solar-mass neutron star. Thus, the radius of such a neutron star can be inferred from a measurement of the the neutron radius of 208Pb. Comparing this value to the measured radius of a 1.4 solar-mass neutron star should provide the strongest constraint to date on the density dependence of the equation of state.Comment: 9 pages and 5 eps. figures (included

Generationally-Linked Archaeology

The research involved the efforts of a wet archaeological site specialist (Dale Croes) and a Master Basketmaker and Elder from the Suquamish Tribe (Ed Carriere), who joined together to replicate and scientifically analyze the 2,000-year-old basketry collection from the Biderbost wet site, Snoqualmie Tribal Territory, housed at the University of Washington (UW) Burke Museum Archaeology Program (Figure 1). Working on this analysis and replication project over the past four years, we concluded that it was not enough to call this a case of Experimental Archaeology; we describe our work as a new approach termed Generationally-Linked Archaeology, an approach that chronologically connects from both directions, linking contemporary cultural specialists with ancient and ancestral basketmakers through the science of archaeology. We present our approach here after publicly presenting our efforts to both indigenous and scientific archaeological audiences, including Native peoples at the Northwest Native American Basketweavers Association, Indigenous Ainu of northern Japan, and at a National Maori Weavers conference in New Zealand, and to archaeological scientists at two annual SAA conferences, the Wetland Archaeological Research Project (WARP) 30th Anniversary Conference in Bradford, England, and a Wetland Archaeology Conference in central France

Surface decoration of catanionic vesicles with superparamagnetic iron oxide nanoparticles: a model system for triggered release under moderate temperature conditions

International audienceWe report the design of new catanionic vesicles decorated with iron oxide nanoparticles, which could be used as a model system to illustrate controlled delivery of small solutes under mild hyperthermia. Efficient release of fluorescent dye rhodamine 6G was observed when samples were exposed to an oscillating magnetic field. Our system provides direct evidence for reversible permeability upon magnetic stimulation

Nonuniform Neutron-Rich Matter and Coherent Neutrino Scattering

Nonuniform neutron-rich matter present in both core-collapse supernovae and neutron-star crusts is described in terms of a semiclassical model that reproduces nuclear-matter properties and includes long-range Coulomb interactions. The neutron-neutron correlation function and the corresponding static structure factor are calculated from molecular dynamics simulations involving 40,000 to 100,000 nucleons. The static structure factor describes coherent neutrino scattering which is expected to dominate the neutrino opacity. At low momentum transfers the static structure factor is found to be small because of ion screening. In contrast, at intermediate momentum transfers the static structure factor displays a large peak due to coherent scattering from all the neutrons in a cluster. This peak moves to higher momentum transfers and decreases in amplitude as the density increases. A large static structure factor at zero momentum transfer, indicative of large density fluctuations during a first-order phase transition, may increase the neutrino opacity. However, no evidence of such an increase has been found. Therefore, it is unlikely that the system undergoes a simple first-order phase transition. It is found that corrections to the commonly used single heavy nucleus approximation first appear at a density of the order of $10^{13}$ g/cm$^3$ and increase rapidly with increasing density. Thus, neutrino opacities are overestimated in the single heavy nucleus approximation relative to the complete molecular dynamics simulations.Comment: 17 pages, 23 included ps figure

Remote multiparametric monitoring and management of heart failure patients through cardiac implantable electronic devices

In this review we focus on heart failure (HF) which, as known, is associated with a substantial risk of hospitalizations and adverse cardiovascular outcomes, including death. In recent years, systems to monitor cardiac function and patient parameters have been developed with the aim to detect subclinical pathophysiological changes that precede worsening HF. Several patient-specific parameters can be remotely monitored through cardiac implantable electronic devices (CIED) and can be combined in multiparametric scores predicting patients’ risk of worsening HF with good sensitivity and moderate specificity. Early patient management at the time of pre-clinical alerts remotely transmitted by CIEDs to physicians might prevent hospitalizations. However, it is not clear yet which is the best diagnostic pathway for HF patients after a CIED alert, which kind of medications should be changed or escalated, and in which case in-hospital visits or in-hospital admissions are required. Finally, the specific role of healthcare professionals involved in HF patient management under remote monitoring is still matter of definition. We analyzed recent data on multiparametric monitoring of patients with HF through CIEDs. We provided practical insights on how to timely manage CIED alarms with the aim to prevent worsening HF. We also discussed the role of biomarkers and thoracic echo in this context, and potential organizational models including multidisciplinary teams for remote care of HF patients with CIEDs

Acción del análogo tumoral de PTH (PTHrP) en la regulación de factores asociados al fenotipo invasivo y a la angiogénesis en células de cáncer de colon humano

El péptido relacionado con la hormona paratiroidea (PTHrP) está implicado en varios cánceres humanos, entre los que se encuentra el cáncer colorrectal (CCR). Esta patología implica varios procesos, como mayor supervivencia celular, proliferación, migración, invasión, transición epitelio-mesenquimática (TEM) y angiogénesis. Previamente encontramos que PTHrP induce la proliferación, supervivencia y migración de células Caco-2 y HCT116, dos líneas celulares de tumores de colon humano. La invasión celular durante la progresión del cáncer se ha asociado a la pérdida de características epiteliales, la remodelación de la matriz extracelular, y el desarrollo de vascularización, por lo que abordar estos procesos es de relevancia para entender el rol de PTHrP en la enfermedad y constituye el objetivo de este trabajo. Se observó que el tratamiento con PTHrP 10-8 M en estas células aumenta los niveles de ARNm de la metaloproteinasa de la matriz 7 (MMP-7) y la expresión proteica de la proteína ácida y rica en cisteína SPARC, dos proteínas que participan en la reestructuración del estroma y que están fuertemente implicadas en la invasión tumoral. Además el tratamiento con PTHrP disminuyó los niveles proteicos de citoqueratina-18 (CK-18) un marcador epitelial asociado con TEM mediante Western blot e Inmunocitoquímica. Los niveles del factor de crecimiento endotelial vascular (VEGF), del factor inducible por hipoxia 1α (HIF-1α) y de la metaloproteinasa de la matriz 9 (MMP-9) por RT-qPCR mostraron que PTHrP aumenta la transcripción de estos factores implicados en la angiogénesis tumoral. Estos resultados sugieren un nuevo rol de PTHrP en la regulación de fenómenos asociados a un fenotipo más agresivo de células derivadas de cáncer colorrectalFil: Carriere, P.. Universidad Nacional del Sur.Fil: Riquelme, A.N.. Universidad Nacional del Sur.Fil: Novoa Díaz, M.B.. Universidad Nacional del Sur.Fil: Calvo, N. . Universidad Nacional del Sur.Fil: Gentili, C.. Universidad Nacional del Sur

Rheological characterization of jet-cooked Lesquerella fendleri seed gum and cornstarch solutions

Abstract Lesquerella is a potential new seed crop that contains hydroxy fatty acid triglycerides and approximately 15% seed coat gums. The polysaccharide gum of the Lesquerella fendleri seed was isolated and jet-cooked with cornstarch in a series of laboratory experiments to investigate the viscoelastic properties of gum-modified starch solutions. The Lesquerella gum was combined with cornstarch at 1, 5, and 10% levels to produce a jet-cooked and drum dried material with potential application as a thickening or suspension agent. Flow curves were determined for 1% solutions of jet-cooked starch and gum combinations. All materials investigated were biodegradable and exhibited positive thixotropic behavior

Modelling stochastic bivariate mortality

Stochastic mortality, i.e. modelling death arrival via a jump process with stochastic intensity, is gaining increasing reputation as a way to represent mortality risk. This paper represents a first attempt to model the mortality risk of couples of individuals, according to the stochastic intensity approach. On the theoretical side, we extend to couples the Cox processes set up, i.e. the idea that mortality is driven by a jump process whose intensity is itself a stochastic process, proper of a particular generation within each gender. Dependence between the survival times of the members of a couple is captured by an Archimedean copula. On the calibration side, we fit the joint survival function by calibrating separately the (analytical) copula and the (analytical) margins. First, we select the best fit copula according to the methodology of Wang and Wells (2000) for censored data. Then, we provide a sample-based calibration for the intensity, using a time-homogeneous, non mean-reverting, affine process: this gives the analytical marginal survival functions. Coupling the best fit copula with the calibrated margins we obtain, on a sample generation, a joint survival function which incorporates the stochastic nature of mortality improvements and is far from representing independency.On the contrary, since the best fit copula turns out to be a Nelsen one, dependency is increasing with age and long-term dependence exists

Structure and Magnetism of well-defined cobalt nanoparticles embedded in a niobium matrix

Our recent studies on Co-clusters embedded in various matrices reveal that the co-deposition technique (simultaneous deposition of two beams : one for the pre-formed clusters and one for the matrix atoms) is a powerful tool to prepare magnetic nanostructures with any couple of materials even though they are miscible. We study, both sharply related, structure and magnetism of the Co/Nb system. Because such a heterogeneous system needs to be described at different scales, we used microscopic and macroscopic techniques but also local selective absorption ones. We conclude that our clusters are 3 nm diameter f.c.c truncated octahedrons with a pure cobalt core and a solid solution between Co and Nb located at the interface which could be responsible for the magnetically inactive monolayers we found. The use of a very diluted Co/Nb film, further lithographed, would allow us to achieve a pattern of microsquid devices in view to study the magnetic dynamics of a single-Co cluster.Comment: 7 TeX pages, 9 Postscript figures, detailed heading adde