We present ground-based and Swift photometric and spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at the centre of PGC 043234 (d ... 90 Mpc) by the All-Sky ...Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity of ... and a total integrated energy of ... erg radiated over the ~6 months of observations presented. The UV/optical emission of the source is well fitted by a blackbody with roughly constant temperature of T ... 35,000 K, while the luminosity declines by roughly a factor of 16 over this time. The optical/UV luminosity decline is broadly consistent with an exponential decline, ..., with t0 ... 60 d. ASASSN-14li also exhibits soft X-ray emission comparable in luminosity to the optical and UV emission but declining at a slower rate, and the X-ray emission now dominates. Spectra of the source show broad Balmer and helium lines in emission as well as strong blue continuum emission at all epochs. We use the discoveries of ASASSN-14li and ASASSN-14ae to estimate the TDE rate implied by ASAS-SN, finding an average rate of ... per galaxy with a 90 per cent confidence interval of ... per galaxy. ASAS-SN found roughly 1 TDE for every 70 Type Ia supernovae in 2014, a rate that is much higher than that of other surveys. (ProQuest: ... denotes formulae/symbols omitted.)
SMAP (Soil Moisture Active and Passive) radiometer observations at ~40 km resolution are routinely assimilated into the NASA Catchment Land Surface Model to generate the 9-km SMAP Level-4 Soil ...Moisture product. This study demonstrates that adding high-resolution radar observations from Sentinel-1 to the SMAP assimilation can increase the spatio-temporal accuracy of soil moisture estimates. Radar observations were assimilated either separately from or simultaneously with radiometer observations. Assimilation impact was assessed by comparing 3-hourly, 9-km surface and root-zone soil moisture simulations with
measurements from 9-km SMAP core validation sites and sparse networks, from May 2015 to December 2016. The Sentinel-1 assimilation consistently improved surface soil moisture, whereas root-zone impacts were mostly neutral. Relatively larger improvements were obtained from SMAP assimilation. The joint assimilation of SMAP and Sentinel-1 observations performed best, demonstrating the complementary value of radar and radiometer observations.
Light, MeV-scale dark matter (DM) is an exciting DM candidate that is undetectable by current experiments. A germanium (Ge) detector utilizing internal charge amplification for the charge carriers ...created by the ionization of impurities is a promising new technology with experimental sensitivity for detecting MeV-scale DM. We analyze the physics mechanisms of the signal formation, charge creation, charge internal amplification, and the projected sensitivity for directly detecting MeV-scale DM particles. We present a design for a novel Ge detector at helium temperature (
∼
4 K) enabling ionization of impurities from DM impacts. With large localized E-fields, the ionized excitations can be accelerated to kinetic energies larger than the Ge bandgap at which point they can create additional electron–hole pairs, producing intrinsic amplification to achieve an ultra-low energy threshold of
∼
0.1 eV for detecting low-mass DM particles in the MeV scale. Correspondingly, such a Ge detector with 1 kg-year exposure will have high sensitivity to a DM-nucleon cross section of
∼
5
×
10
-
45
cm
2
at a DM mass of
∼
10 MeV/c
2
and a DM-electron cross section of
∼
5
×
10
-
46
cm
2
at a DM mass of
∼
1 MeV/c
2
.
Many important industrial processes, such as additive manufacturing, involve rapid mass, flow and heat transport between gas, liquid and solid phases. Various associated challenges, such as the large ...density ratio between gas and condensed phases, make accurate, robust thermal multi-phase flow simulations of these processes very difficult. In order to address some of the associated challenges, a computational framework for thermal multi-phase flows is developed based on the finite element method (FEM). A unified model for thermal multi-phase flows similar to the models widely used in the manufacturing community is adopted. The combination of the level-set method and residual-based variational multi-scale formulation (RBVMS) is used to solve the governing equations of thermal multi-phase flows. Phase transitions between solid and liquid phases, i.e., melting and solidification, are considered. Interfacial forces, including surface tension and Marangoni stress, are taken into account and handled by a density-scaled continuum surface force model. A robust fully coupled solution strategy is adopted to handle various numerical difficulties associated with thermal multi-phase flow simulations, and implemented by means of a matrix-free technique using Flexible GMRES. The mathematical formulation and its algorithmic implementation are described in detail. Four numerical test cases are presented to demonstrate the capability of the proposed formulation. The first case is a benchmark example of solidification of aluminum in a graphite mold, the second case is a thermo-capillary droplet migration problem, the third case is a spot laser melting problem, and the fourth case is the melting of metal with an interior gas bubble. The computational results are compared with analytical, experimental and simulation data from other researchers, with good agreement in cases where such data is available.
• Background and aims Much recent study of plant trichomes has focused on various aspects of glandular secreting trichomes (GSTs) and differentiation of simple trichomes. This Botanical Briefing will ...highlight: ‐ research on various aspects of, and manipulation of glandular secreting trichomes; ‐ molecular aspects of the differentiation and development of simple trichomes of arabidopsis and cotton; ‐ how methods for manipulation of model systems used in the above work can be applied to expand our understanding of less studied surface structures of plants. • Scope The Briefing will cover: ‐ established and suggested roles of simple and glandular secreting trichomes; ‐ recent results regarding solute and ion movement in trichomes; ‐ methods for isolating trichomes; ‐ recent studies of trichome differentiation and development; ‐ attempts to modify metabolism in secreting trichomes; ‐ efforts to exploit trichomes for commercial and agronomic purposes.
Robustness is the invariance of phenotypes in the face of perturbation. The robustness of phenotypes appears at various levels of biological organization, including gene expression, protein folding, ...metabolic flux, physiological homeostasis, development, and even organismal fitness. The mechanisms underlying robustness are diverse, ranging from thermodynamic stability at the RNA and protein level to behavior at the organismal level. Phenotypes can be robust either against heritable perturbations (e.g., mutations) or nonheritable perturbations (e.g., the weather). Here we primarily focus on the first kind of robustness—genetic robustness—and survey three growing avenues of research: (1) measuring genetic robustness in nature and in the laboratory; (2) understanding the evolution of genetic robustness; and (3) exploring the implications of genetic robustness for future evolution.
A set of modified embedded-atom method (MEAM) potentials for the interactions between Al, Si, Mg, Cu, and Fe was developed from a combination of each element's MEAM potential in order to study metal ...alloying. Previously published MEAM parameters of single elements have been improved for better agreement to the generalized stacking fault energy (GSFE) curves when compared with ab initio generated GSFE curves. The MEAM parameters for element pairs were constructed based on the structural and elastic properties of element pairs in the NaCl reference structure garnered from ab initio calculations, with adjustment to reproduce the ab initio heat of formation of the most stable binary compounds. The new MEAM potentials were validated by comparing the formation energies of defects, equilibrium volumes, elastic moduli, and heat of formation for several binary compounds with ab initio simulations and experiments. Single elements in their ground-state crystal structure were subjected to heating to test the potentials at elevated temperatures. An Al potential was modified to avoid formation of an unphysical solid structure at high temperatures. The thermal expansion coefficient of a compound with the composition of AA 6061 alloy was evaluated and compared with experimental values. MEAM potential tests performed in this work, utilizing the universal atomistic simulation environment (ASE), are distributed to facilitate reproducibility of the results.
•An Isogeometric multi-phase flow formulation with surface tension using RBVMS and level-set method is proposed.•Superior accuracy IGA in mean curvature computation is demonstrated.•Comparison of IGA ...and FEM on level-set convection, mean curvature calculation and bubble rising dynamics is shown.•Merging processes of two bubbles under a free-surface is presented to show the capabilities of the proposed formulation.
A novel multi-phase flow formulation using a level-set-based interface-capturing approach is proposed, focusing on addressing numerical challenges associated with the modeling of surface tension. The surface tension is handled through the continuum surface force model. The residual-based variational multiscale (RBVMS) formulation is employed to solve the coupled Navier–Stokes and level-set convection equations. The RBVMS formulation is discretized using either standard low-order finite elements, or Isogeometric Analysis (IGA) based on Non-Uniform Rational B-Splines (NURBS), which are higher-order accurate and smooth. The proposed method is applied to the simulation of 3D bubbles moving in viscous liquids with large density and viscosity ratios representative of common two-phase flow systems. The accuracy of the proposed method is assessed by comparing the results with analytical solutions, experimental data, and computational results, reported in the literature. In all cases IGA showed superior performance to standard finite elements; this superiority is attributed to the higher-order accuracy of IGA and its ability to directly and accurately compute, using smooth NURBS functions, the curvature term, which is a key ingredient the surface tension formulation. For single-bubble rising problems, the proposed approach produced accurate predictions of the terminal bubble shape, velocity and Reynolds number. The advanced nature of the new multi-phase flow formulation is demonstrated with a simulation of merging of two bubbles in the presence of a deforming free-surface.
Electronic health information systems, including electronic medical records (EMRs), have the potential to improve access to information and quality of care, among other things. Success factors and ...challenges for novel EMR implementations in low-resource settings have increasingly been studied, although less is known about maturing systems and sustainability. One systematic review identified seven categories of implementation success factors: ethical, financial, functionality, organizational, political, technical and training. This case study applies this framework to iSanté, Haiti’s national EMR in use in more than 100 sites and housing records for more than 750 000 patients. The author group, consisting of representatives of different agencies within the Haitian Ministry of Health (MSPP), funding partner the Centers for Disease Control and Prevention (CDC) Haiti, and implementing partner the International Training and Education Center for Health (I-TECH), identify successes and lessons learned according to the seven identified categories, and propose an additional cross-cutting category, sustainability. Factors important for long-term implementation success of complex information systems are balancing investments in hardware and software infrastructure upkeep, user capacity and data quality control; designing and building a system within the context of the greater eHealth ecosystem with a plan for interoperability and data exchange; establishing system governance and strong leadership to support local system ownership and planning for system financing to ensure sustainability. Lessons learned from 10 years of implementation of the iSanté EMR system are relevant to sustainability of a full range of increasingly interrelated information systems (e. g. for laboratory, supply chain, pharmacy and human resources) in the health sector in low-resource settings.
Les systèmes électroniques d’information sanitaire, notamment les dossiers médicaux électroniques (DME), ont le potentiel d’améliorer l’accès à l’information et la qualité des soins, entre autres choses. Les facteurs de succès et les défis pour de nouvelles implémentations de DME dans les milieux à faibles ressources font l’objet de nombreuses études, bien que l’on connaisse à peine les systèmes de maturation et de durabilité. Une revue systématique a identifié sept catégories de facteurs de réussite de la mise en œuvre: facteurs éthiques, financiers, fonctionnels, organisationnels, politiques, techniques et formatifs. La présente étude de cas applique ce cadre à l’iSanté, les DME nationaux d’Haïti en usage dans plus de 100 sites de conservation de dossiers pour plus de 750 000 patients. Le groupe d’auteurs, composé de représentants de différents services au sein du Ministère haïtien de la Santé (MSPP), avec comme partenaire financier le Centre de lutte et de prévention des maladies (CDC) d’Haïti et comme partenaire d’exécution le Centre international de formation et d’éducation pour la santé (I-TECH), mentionne les réussites et les leçons apprises en fonction des sept catégories identifiées, et propose une catégorie transversale supplémentaire, à savoir, la durabilité. Les facteurs importants pour la mise en œuvre à long terme des systèmes d’information complexes sont l’équilibre entre les investissements pour la maintenance des infrastructures matérielles et logicielles, la capacité de l’utilisateur et le contrôle de la qualité des données; la conception et la mise en place d’un système dans le contexte d’un plus grand écosystème de cybersanté avec un plan d’interopérabilité et d’échange de données; la mise en place d’une gouvernance et d’un leadership fort en vue de soutenir l’appropriation du système local et de planifier son financement afin d’en assurer la durabilité. Les leçons tirées de 10 années de mise en œuvre du système DME iSanté sont pertinentes pour la durabilité d’une gamme complète de systèmes d’information de plus en plus interdépendants (à savoir, les laboratoires, la chaîne d’approvisionnement, la pharmacie et les ressources humaines), dans le secteur de la santé des milieux à faibles ressources.
电子病历 （EMRs） 等电子健康信息系统除其他作用外, 还有 助于提高信息和优质医疗服务的可及性。有越来越多的研究 关注在资源匮乏地区从零开始建立EMR的因素和挑战, 但对 于系统完善和可持续性的了解较少。有一项系统综述发现了 7类实施成功因素：伦理、经济、功能性、组织、政治、技术 和培训。本个案研究应用这一框架分析海地国家EMR系统 iSanté, 该系统用于100多家机构, 存有75万余名患者的病历。 本文作者来自海地卫生部各部门、疾病预防控制中心和国际 卫生培训与教育中心, 根据以上7种类别发现成功之处和可借 鉴经验, 此外增加了一类因素, ”可持续性”。影响复杂信息 系统成功长期实施的重要因素包括：平衡硬件和软件基础设 施维护、使用者能力和数据质量控制方面的投入；在电子健 康大背景下设计和建立系统, 规划中考虑到互操作性和数据交 换；建立系统管理和强有力的领导, 从而支持地方系统所有 权, 规划对系统的资金支持以确保可持续性。 iSanté EMR系 统实施十年的经验有助于指导在资源匮乏地区卫生部门建立 一整套日益相关的可持续信息系统（如实验室、供应链、药 房和人力资源）。
Los sistemas electrónicos de información de la salud, incluyendo los registros médicos electrónicos (RMEs), tienen el potencial de mejorar el acceso a la información y a la calidad de la atención, entre otras cosas. Los factores de éxito y los desafíos para nuevas implementaciones de los RMEs en entornos de bajos recursos se han estudiado cada vez más, aunque se sabe menos acerca de los sistemas de maduración y sostenibilidad. Una revisión sistemática identificó siete categorías de factores de éxito de implementación: ético, financiero, funcional, organizacional, político, técnico y entrenamiento. Este estudio de caso aplica este marco a iSanté, el RME nacional de Haití en uso en más de 100 sitios y registros de vivienda para más de 750,000 pacientes. El grupo autor, formado por representantes de diferentes agencias del Ministerio de Salud Haitiano (‘MSPP’), el socio financiador de los Centros para el Control y la Prevención de Enfermedades (‘CDC’) en Haití y el socio implementador del Centro Internacional de Entrenamiento y Educación para la Salud (‘ITECH’), identifica los éxitos y las lecciones aprendidas de acuerdo con las siete categorías identificadas, y propone una categoría transversal adicional, la sostenibilidad. Los factores importantes para el éxito de la implementación a largo plazo de los sistemas de información complejos son equilibrar las inversiones en el mantenimiento de la infraestructura de ‘hardware’ y ‘software’, la capacidad del usuario y el control de calidad de los datos; diseñar y construir un sistema dentro del contexto del ecosistema mayor de eSalud con un plan de interoperabilidad e intercambio de datos; establecer la gobernanza del sistema y un liderazgo fuerte para apoyar la propiedad del sistema local y la planeación de la financiación del sistema para garantizar la sostenibilidad. Las lecciones aprendidas en 10 años de implementación del sistema del RME de iSanté son relevantes para la sostenibilidad de una gama completa de sistemas de información cada vez más interrelacionados (por ejemplo, laboratorio, cadena de suministro, farmacia y recursos humanos) en el sector de la salud en entornos de bajos recursos.
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