Effects of clumping on temperature I: externally heated clouds

We present a study of radiative transfer in dusty, clumpy star-forming regions. A series of self-consistent, 3-D, continuum radiative transfer models are constructed for a grid of models parameterized by central luminosity, filling factor, clump radius, and face-averaged optical depth. The temperature distribution within the clouds is studied as a function of this parameterization. Among our results, we find that: (a) the effective optical depth is smaller in clumpy regions than in equivalent homogeneous regions; (b) penetration of radiation is drive by the fraction of open sky (FOS) -- which measures the fraction of solid angle which is devoid of clumps; (c) FOS increases as clump radius increases and filling factor decreases; (d) for FOS > 0.6-0.8 the sky is sufficiently open that the temperature is relatively insensitive to FOS; (e) the physical process by which radiation penetrates is streaming between clumps; (f) filling factor dominates the temperature distribution for large optical depths, and at small clump radii for small optical depths; (g) at lower optical depths, the temperature distribution is most sensitive to filling factors of 1-10 per cent, in accordance with many observations; (h) direct shadowing can be important approximately one clump radius behind a clump.Comment: 12 pages, 17 figures, accepted by MNRA

The Kelvin-Helmholtz instability in weakly ionised plasmas: Ambipolar dominated and Hall dominated flows

The Kelvin-Helmholtz instability is well known to be capable of converting well-ordered flows into more disordered, even turbulent, flows. As such it could represent a path by which the energy in, for example, bowshocks from stellar jets could be converted into turbulent energy thereby driving molecular cloud turbulence. We present the results of a suite of fully multifluid magnetohydrodynamic simulations of this instability using the HYDRA code. We investigate the behaviour of the instability in a Hall dominated and an ambipolar diffusion dominated plasma as might be expected in certain regions of accretion disks and molecular clouds respectively. We find that, while the linear growth rates of the instability are unaffected by multifluid effects, the non-linear behaviour is remarkably different with ambipolar diffusion removing large quantities of magnetic energy while the Hall effect, if strong enough, introduces a dynamo effect which leads to continuing strong growth of the magnetic field well into the non-linear regime and a lack of true saturation of the instability.Comment: 12 pages, 20 figures. Accepted for publication in MNRA

The Kelvin-Helmholtz instability in weakly ionised plasmas II: multifluid effects in molecular clouds

We present a study of the Kelvin-Helmholtz instability in a weakly ionised, multifluid MHD plasma with parameters matching those of a typical molecular cloud. The instability is capable of transforming well-ordered flows into disordered flows. As a result, it may be able to convert the energy found in, for example, bowshocks from stellar jets into the turbulent energy found in molecular clouds. As these clouds are weakly ionised, the ideal magnetohydrodynamic approximation does not apply at scales of around a tenth of a parsec or less. This paper extends the work of Jones & Downes (2011) on the evolution of the Kelvin-Helmholtz instability in the presence of multifluid magnetohydrodynamic effects. These effects of ambipolar diffusion and the Hall effect are here studied together under physical parameters applicable to molecular clouds. We restrict our attention to the case of a single shear layer with a transonic, but super-Alfvenic, velocity jump and the computational domain is chosen to match the wavelength of the linearly fastest growing mode of the instability. We find that while the introduction of multifluid effects does not affect the linear growth rates of the instability, the non-linear behaviour undergoes considerable change. The magnetic field is decoupled from the bulk flow as a result of the ambipolar diffusion, which leads to a significant difference in the evolution of the field. The Hall effect would be expected to lead to a noticeable re-orientation of the magnetic field lines perpendicular to the plane. However, the results reveal that the combination with ambipolar diffusion leads to a surprisingly effective suppression of this effect.Comment: 13 pages, 13 figures, accepted for publication in MNRA

Khresmoi – multilingual semantic search of medical text and images

The Khresmoi project is developing a multilingual multimodal search and access system for medical and health information and documents. This scientific demonstration presents the current state of the Khresmoi integrated system, which includes components for text and image annotation, semantic search, search by image similarity and machine translation. The flexibility in adapting the system to varying requirements for different types of medical information search is demonstrated through two instantiations of the system, one aimed at medical professionals in general and the second aimed at radiologists. The key innovations of the Khresmoi system are the integration of multiple software components in a flexible scalable medical search system, the use of annotation cycles including manual correction to improve semantic search, and the possibility to do large scale visual similarity search on 2D and 3D (CT, MR) medical images

Structural characterization of the Magallanes-Fagnano transform fault, Tierra del Fuego, South America

Structural analyses in the area of Fagnano and Deseado lakes show different deformational events that took place in the southernmost South America. The compressional structures represent at least two deformational episodes associated with the Upper Cretaceous Andean Orogeny. A series of NE-vergent thrust faults, product of this compression, show that these faults have accommodated some sinistral motion during Upper Cretaceous times. The NE orientation of reverse faults in the Monte Hope area may indicate the later rotation of these faults by the left-lateral strike-slip motion of the Magallanes-Fagnano fault. The secondary faults of the Deseado and Magallanes-Fagnano fault zones fit quiet well with the Riedel shear model, and some of the normal faults cut the Quaternary sediments, indicating a recent activity. These faults may be the evidence of a significant extensional component of the transcurrent system

LifeSnaps, a 4-month multi-modal dataset capturing unobtrusive snapshots of our lives in the wild

Ubiquitous self-tracking technologies have penetrated various aspects of our lives, from physical and mental health monitoring to fitness and entertainment. Yet, limited data exist on the association between in the wild large-scale physical activity patterns, sleep, stress, and overall health, and behavioral and psychological patterns due to challenges in collecting and releasing such datasets, including waning user engagement or privacy considerations. In this paper, we present the LifeSnaps dataset, a multi-modal, longitudinal, and geographically-distributed dataset containing a plethora of anthropological data, collected unobtrusively for the total course of more than 4 months by n = 71 participants. LifeSnaps contains more than 35 different data types from second to daily granularity, totaling more than 71 M rows of data. The participants contributed their data through validated surveys, ecological momentary assessments, and a Fitbit Sense smartwatch and consented to make these data available to empower future research. We envision that releasing this large-scale dataset of multi-modal real-world data will open novel research opportunities and potential applications in multiple disciplines

Overview of the CLEF eHealth Evaluation Lab 2019

In this paper, we provide an overview of the seventh annual edition of the CLEF eHealth evaluation lab. CLEF eHealth 2019 continues our evaluation resource building efforts around the easing and support of patients, their next-of-kins, clinical staff, and health scientists in understanding, accessing, and authoring electronic health information in a multilingual setting. This year’s lab advertised three tasks: Task 1 on indexing non-technical summaries of German animal experiments with International Classification of Diseases, Version 10 codes; Task 2 on technology assisted reviews in empirical medicine building on 2017 and 2018 tasks in English; and Task 3 on consumer health search in mono- and multilingual settings that builds on the 2013–18 Information Retrieval tasks. In total nine teams took part in these tasks (six in Task 1 and three in Task 2). Herein, we describe the resources created for these tasks and evaluation methodology adopted. We also provide a brief summary of participants of this year’s challenges and results obtained. As in previous years, the organizers have made data and tools associated with the lab tasks available for future research and development