1,689 research outputs found
Deep Lesion Graphs in the Wild: Relationship Learning and Organization of Significant Radiology Image Findings in a Diverse Large-scale Lesion Database
Radiologists in their daily work routinely find and annotate significant
abnormalities on a large number of radiology images. Such abnormalities, or
lesions, have collected over years and stored in hospitals' picture archiving
and communication systems. However, they are basically unsorted and lack
semantic annotations like type and location. In this paper, we aim to organize
and explore them by learning a deep feature representation for each lesion. A
large-scale and comprehensive dataset, DeepLesion, is introduced for this task.
DeepLesion contains bounding boxes and size measurements of over 32K lesions.
To model their similarity relationship, we leverage multiple supervision
information including types, self-supervised location coordinates and sizes.
They require little manual annotation effort but describe useful attributes of
the lesions. Then, a triplet network is utilized to learn lesion embeddings
with a sequential sampling strategy to depict their hierarchical similarity
structure. Experiments show promising qualitative and quantitative results on
lesion retrieval, clustering, and classification. The learned embeddings can be
further employed to build a lesion graph for various clinically useful
applications. We propose algorithms for intra-patient lesion matching and
missing annotation mining. Experimental results validate their effectiveness.Comment: Accepted by CVPR2018. DeepLesion url adde
Participation and satisfaction after spinal cord injury: results of a vocational and leisure outcome study
Study design: Survey. Objectives: Insight in (1) the changes in participation in vocational and leisure activities and (2) satisfaction with the current participation level of people with spinal cord injuries (SCIs) after reintegration in society. Design: Descriptive analysis of data from a questionnaire. Setting: Rehabilitation centre with special department for patients with SCIs, Groningen, The Netherlands. Subjects: A total of 57 patients with traumatic SCI living in the community, who were admitted to the rehabilitation centre two to 12 years before the current assessment. Main outcome measures: Changes in participation in activities; current life satisfaction; support and unmet needs. Results: Participation expressed in terms of hours spent on vocational and leisure activities changed to a great extent after the SCI. This was mainly determined by a large reduction of hours spent on paid work. While 60% of the respondents successfully reintegrated in work, many changes took place in the type and extent of the job. Loss of work was partially compensated with domestic and leisure activities. Sports activities were reduced substantially. The change in participation level and compensation for the lost working hours was not significantly associated with the level of SCI-specific health problems and disabilities. As was found in other studies, most respondents were satisfied with their lives. Determinants of a negative life satisfaction several years following SCI were not easily indicated. Reduced quality of life was particularly related to an unsatisfactory work and leisure situation. Conclusions: Most people with SCI in this study group were able to resume work and were satisfied with their work and leisure situation
Supernovae from rotating stars
The present paper discusses the main physical effects produced by stellar
rotation on presupernovae, as well as observations which confirm these effects
and their consequences for presupernova models. Rotation critically influences
the mass of the exploding cores, the mass and chemical composition of the
envelopes and the types of supernovae, as well as the properties of the
remnants and the chemical yields. In the formation of gamma-ray bursts,
rotation and the properties of rotating stars appear as the key factor. In
binaries, the interaction between axial rotation and tidal effects often leads
to interesting and unexpected results. Rotation plays a key role in shaping the
evolution and nucleosynthesis in massive stars with very low metallicities
(metallicity below about the Small Magellanic Cloud metallicity down to
Population III stars). At solar and higher metallicities, the effects of
rotation compete with those of stellar winds. In close binaries, the
synchronisation process can lock the star at a high rotation rate despite
strong mass loss and thus both effects, rotation and stellar winds, have a
strong impact. In conclusion, rotation is a key physical ingredient of the
stellar models and of presupernova stages, and the evolution both of single
stars and close binaries. Moreover, important effects are expected along the
whole cosmic history.Comment: 36 pages, 15 figures, published in Handbook of Supernovae, A.W.
Alsabti and P. Murdin (eds), Springe
The impact of emotional well-being on long-term recovery and survival in physical illness: a meta-analysis
This meta-analysis synthesized studies on emotional well-being as predictor of the prognosis of physical illness, while in addition evaluating the impact of putative moderators, namely constructs of well-being, health-related outcome, year of publication, follow-up time and methodological quality of the included studies. The search in reference lists and electronic databases (Medline and PsycInfo) identified 17 eligible studies examining the impact of general well-being, positive affect and life satisfaction on recovery and survival in physically ill patients. Meta-analytically combining these studies revealed a Likelihood Ratio of 1.14, indicating a small but significant effect. Higher levels of emotional well-being are beneficial for recovery and survival in physically ill patients. The findings show that emotional well-being predicts long-term prognosis of physical illness. This suggests that enhancement of emotional well-being may improve the prognosis of physical illness, which should be investigated by future research
Testing new physics with the electron g-2
We argue that the anomalous magnetic moment of the electron (a_e) can be used
to probe new physics. We show that the present bound on new-physics
contributions to a_e is 8*10^-13, but the sensitivity can be improved by about
an order of magnitude with new measurements of a_e and more refined
determinations of alpha in atomic-physics experiments. Tests on new-physics
effects in a_e can play a crucial role in the interpretation of the observed
discrepancy in the anomalous magnetic moment of the muon (a_mu). In a large
class of models, new contributions to magnetic moments scale with the square of
lepton masses and thus the anomaly in a_mu suggests a new-physics effect in a_e
of (0.7 +- 0.2)*10^-13. We also present examples of new-physics theories in
which this scaling is violated and larger effects in a_e are expected. In such
models the value of a_e is correlated with specific predictions for processes
with violation of lepton number or lepton universality, and with the electric
dipole moment of the electron.Comment: 34 pages, 7 figures. Minor changes and references adde
Massive stars as thermonuclear reactors and their explosions following core collapse
Nuclear reactions transform atomic nuclei inside stars. This is the process
of stellar nucleosynthesis. The basic concepts of determining nuclear reaction
rates inside stars are reviewed. How stars manage to burn their fuel so slowly
most of the time are also considered. Stellar thermonuclear reactions involving
protons in hydrostatic burning are discussed first. Then I discuss triple alpha
reactions in the helium burning stage. Carbon and oxygen survive in red giant
stars because of the nuclear structure of oxygen and neon. Further nuclear
burning of carbon, neon, oxygen and silicon in quiescent conditions are
discussed next. In the subsequent core-collapse phase, neutronization due to
electron capture from the top of the Fermi sea in a degenerate core takes
place. The expected signal of neutrinos from a nearby supernova is calculated.
The supernova often explodes inside a dense circumstellar medium, which is
established due to the progenitor star losing its outermost envelope in a
stellar wind or mass transfer in a binary system. The nature of the
circumstellar medium and the ejecta of the supernova and their dynamics are
revealed by observations in the optical, IR, radio, and X-ray bands, and I
discuss some of these observations and their interpretations.Comment: To be published in " Principles and Perspectives in Cosmochemistry"
Lecture Notes on Kodai School on Synthesis of Elements in Stars; ed. by Aruna
Goswami & Eswar Reddy, Springer Verlag, 2009. Contains 21 figure
Assessment of electrophoresis and electroosmosis in construction materials: effect of enhancing electrolytes and heavy metals contamination
Electrokinetic effects are those that take place by application of an electric field to porous materials, with the zeta potential as the key parameter. Specifically, in the case of contaminated construction materials, the generation of an electroosmotic flux, with the corresponding dragging due to water transport, is a crucial mechanism to succeed in the treatment of decontamination. Therefore, it is of great interest trying to optimize the treatment by the addition of specific electrolytes enhancing the electrokinetic phenomena. Most of the data of zeta potential found in literature for construction materials are based in micro-electrophoresis measurements, which are quite far of the real conditions of application of the remediation treatments. In this paper, electrophoretic and electroosmotic experiments, with monolithic and powdered material respectively, have been carried out for mortar, brick and granite clean and contaminated with Cs, Sr, Co, Cd, Cu and Pb. The electrolytes tested have been distilled water (DW), Na2–EDTA, oxalic acid, acetic acid and citric acid. The zeta potential values have been determined through the two different techniques and the results compared and critically analysed
Type Ia Supernovae as Stellar Endpoints and Cosmological Tools
Empirically, Type Ia supernovae are the most useful, precise, and mature
tools for determining astronomical distances. Acting as calibrated candles they
revealed the presence of dark energy and are being used to measure its
properties. However, the nature of the SN Ia explosion, and the progenitors
involved, have remained elusive, even after seven decades of research. But now
new large surveys are bringing about a paradigm shift --- we can finally
compare samples of hundreds of supernovae to isolate critical variables. As a
result of this, and advances in modeling, breakthroughs in understanding all
aspects of SNe Ia are finally starting to happen.Comment: Invited review for Nature Communications. Final published version.
Shortened, update
Decision Support System for the Response to Infectious Disease Emergencies Based on WebGIS and Mobile Services in China
Background: For years, emerging infectious diseases have appeared worldwide and threatened the health of people. The emergence and spread of an infectious-disease outbreak are usually unforeseen, and have the features of suddenness and uncertainty. Timely understanding of basic information in the field, and the collection and analysis of epidemiological information, is helpful in making rapid decisions and responding to an infectious-disease emergency. Therefore, it is necessary to have an unobstructed channel and convenient tool for the collection and analysis of epidemiologic information in the field. Methodology/Principal Findings: Baseline information for each county in mainland China was collected and a database was established by geo-coding information on a digital map of county boundaries throughout the country. Google Maps was used to display geographic information and to conduct calculations related to maps, and the 3G wireless network was used to transmit information collected in the field to the server. This study established a decision support system for the response to infectious-disease emergencies based on WebGIS and mobile services (DSSRIDE). The DSSRIDE provides functions including data collection, communication and analyses in real time, epidemiological detection, the provision of customized epidemiological questionnaires and guides for handling infectious disease emergencies, and the querying of professional knowledge in the field. These functions of the DSSRIDE could be helpful for epidemiological investigations in the field and the handling of infectious-disease emergencies. Conclusions/Significance: The DSSRIDE provides a geographic information platform based on the Google Maps application programming interface to display information of infectious disease emergencies, and transfers information between workers in the field and decision makers through wireless transmission based on personal computers, mobile phones and personal digital assistants. After a 2-year practice and application in infectious disease emergencies, the DSSRIDE is becoming a useful platform and is a useful tool for investigations in the field carried out by response sections and individuals. The system is suitable for use in developing countries and low-income districts
Affective evolutionary music composition with MetaCompose
This paper describes the MetaCompose music generator, a compositional, extensible framework for affective music composition. In this context ‘affective’ refers to the music generator’s ability to express emotional information. The main purpose of MetaCompose is to create music in real-time that can express different mood-states, which we achieve through a unique combination of a graph traversal-based chord sequence generator, a search-based melody generator, a pattern-based accompaniment generator, and a theory for mood expression. Melody generation uses a novel evolutionary technique combining FI-2POP with multi-objective optimization. This allows us to explore a Pareto front of diverse solutions that are creatively equivalent under the terms of a multi-criteria objective function. Two quantitative user studies were performed to evaluate the system: one focusing on the music generation technique, and the other that explores valence expression, via the introduction of dissonances. The results of these studies demonstrate (i) that each part of the generation system improves the perceived quality of the music produced, and (ii) how valence expression via dissonance produces the perceived affective state. This system, which can reliably generate affect-expressive music, can subsequently be integrated in any kind of interactive application (e.g., games) to create an adaptive and dynamic soundtrack
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