469 research outputs found
Major Merging: The Way to Make a Massive, Passive Galaxy
We analyze the projected axial ratio distribution, p(b/a), of galaxies that
were spectroscopically selected from the Sloan Digital Sky Survey (DR6) to have
low star-formation rates. For these quiescent galaxies we find a rather abrupt
change in p(b/a) at a stellar mass of ~10^{11} M_sol: at higher masses there
are hardly any galaxies with b/a<0.6, implying that essentially none of them
have disk-like intrinsic shapes and must be spheroidal. This transition mass is
~3-4 times higher than the threshold mass above which quiescent galaxies
dominate in number over star-forming galaxies, which suggests these mass scales
are unrelated. At masses lower than ~10^{11} M_sol, quiescent galaxies show a
large range in axial ratios, implying a mix of bulge- and disk-dominated
galaxies. Our result strongly suggests that major merging is the most
important, and perhaps only relevant, evolutionary channel to produce massive
(>10^{11} M_sol), quiescent galaxies, as it inevitably results in spheroids.Comment: Minor changes to match published version in ApJ Letter
Interactive handwriting recognition with limited user effort
The final publication is available at Springer via http://dx.doi.org/10.1007/s10032-013-0204-5[EN] Transcription of handwritten text in (old) documents is an important, time-consuming task for digital libraries. Although post-editing automatic recognition of handwritten text is feasible, it is not clearly better than simply ignoring it and transcribing the document from scratch. A more effective approach is to follow an interactive approach in which both the system is guided by the user, and the user is assisted by the system to complete the transcription task as efficiently as possible. Nevertheless, in some applications,
the user effort available to transcribe documents is limited and fully supervision of the system output is not realistic. To circumvent these problems, we propose a novel interactive approach which efficiently employs user effort to transcribe a document by improving three different aspects. Firstly, the system employs a limited amount of effort to solely supervise recognised words that are likely to be incorrect. Thus, user effort is efficiently focused on the supervision of words for which the system is not confident enough. Secondly, it refines the initial transcription provided to the user by recomputing it constrained to user supervisions. In this way, incorrect words in unsupervised parts can be automatically amended without user supervision. Finally, it improves the underlying system models by retraining the system from partially supervised transcriptions. In order to prove these statements, empirical results are presented on two real databases showing that the proposed approach can notably reduce user effort in the transcription of handwritten text in (old) documents.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No 287755 (transLectures). Also supported by the Spanish Government (MICINN, MITyC, "Plan E", under Grants MIPRCV "Consolider Ingenio 2010", MITTRAL (TIN2009-14633-C03-01), erudito.com (TSI-020110-2009-439), iTrans2 (TIN2009-14511), and FPU (AP2007-02867), and the Generalitat Valenciana (Grants Prometeo/2009/014 and GV/2010/067).Serrano Martinez Santos, N.; Giménez Pastor, A.; Civera Saiz, J.; Sanchis Navarro, JA.; Juan Císcar, A. (2014). Interactive handwriting recognition with limited user effort. International Journal on Document Analysis and Recognition. 17(1):47-59. https://doi.org/10.1007/s10032-013-0204-5S4759171Agua, M., Serrano, N., Civera, J., Juan, A.: Character-based handwritten text recognition of multilingual documents. In: Proceedings of Advances in Speech and Language Technologies for Iberian Languages (IBERSPEECH 2012), Madrid (Spain), pp. 187–196 (2012)Ahn, L.V., Maurer, B., Mcmillen, C., Abraham, D., Blum, M.: reCAPTCHA: human-based character recognition via web security measures. Science 321, 1465–1468 (2008)Barrachina, S., Bender, O., Casacuberta, F., Civera, J., Cubel, E., Khadivi, S., Lagarda, A.L., Ney, H., Tomás, J., Vidal, E.: Statistical approaches to computer-assisted translation. Comput. Linguist. 35(1), 3–28 (2009)Bertolami, R., Bunke, H.: Hidden markov model-based ensemble methods for offline handwritten text line recognition. Pattern Recognit. 41, 3452–3460 (2008)Bunke, H., Bengio, S., Vinciarelli, A.: Offline recognition of unconstrained handwritten texts using HMMs and statistical language models. IEEE Trans. Pattern Anal. Mach. Intell. 26(6), 709–720 (2004)Dreuw, P., Jonas, S., Ney, H.: White-space models for offline Arabic handwriting recognition. In: Proceedings of the 19th International Conference on, Pattern Recognition, pp. 1–4 (2008)Efron, B., Tibshirani, R.J.: An introduction to bootstrap. Chapman and Hall/CRC, London (1994)Fischer, A., Wuthrich, M., Liwicki, M., Frinken, V., Bunke, H., Viehhauser, G., Stolz, M.: Automatic transcription of handwritten medieval documents. In: Proceedings of the 15th International Conference on Virtual Systems and Multimedia, pp. 137–142 (2009)Frinken, V., Bunke, H.: Evaluating retraining rules for semi-supervised learning in neural network based cursive word recognition. In: Proceedings of the 10th International Conference on Document Analysis and Recognition, Barcelona (Spain), pp. 31–35 (2009)Graves, A., Liwicki, M., Fernandez, S., Bertolami, R., Bunke, H., Schmidhuber, J.: A novel connectionist system for unconstrained handwriting recognition. IEEE Trans. Pattern Anal. Mach. Intell. 31(5), 855–868 (2009)Hakkani-Tür, D., Riccardi, G., Tur, G.: An active approach to spoken language processing. ACM Trans. Speech Lang. Process. 3, 1–31 (2006)Kristjannson, T., Culotta, A., Viola, P., McCallum, A.: Interactive information extraction with constrained conditional random fields. In: Proceedings of the 19th Natural Conference on Artificial Intelligence, San Jose, CA (USA), pp. 412–418 (2004)Laurence Likforman-Sulem, A.Z., Taconet, B.: Text line segmentation of historical documents: a survey. Int. J. Doc. Anal. Recognit. 9, 123–138 (2007)Le Bourgeois, F., Emptoz, H.: Debora: digital access to books of the renaissance. Int. J. Doc. Anal. Recognit. 9, 193–221 (2007)Levenshtein, V.I.: Binary codes capable of correcting deletions, insertions, and reversals. Sov. Phys. Dokl. 10(8), 707–710 (1966)Neal, R.M., Hinton, G.E.: Learning in graphical models. In: A View of the EM Algorithm That Justifies Incremental, Sparse, and Other Variants, Chap. MIT Press, Cambridge, MA, USA, pp. 355–368 (1999)Pérez, D., Tarazón, L., Serrano, N., Ramos-Terrades, O., Juan, A.: The GERMANA database. In: Proceedings of the 10th International Conference on Document Analysis and Recognition, Barcelona (Spain), pp. 301–305 (2009)Plötz, T., Fink, G.A.: Markov models for offline handwriting recognition: a survey. Int. J. Doc. Anal. Recognit. 12(4), 269–298 (2009)Quiniou, S., Cheriet, M., Anquetil, E.: Error handling approach using characterization and correction steps for handwritten document analysis. Int. J. Doc. Anal. Recognit. 15(2), 125–141 (2012)Rodríguez, L., García-Varea, I., Vidal, E.: Multi-modal computer assisted speech transcription. In: International Conference on Multimodal Interfaces and the Workshop on Machine Learning for Multimodal Interaction, ACM, New York, NY, USA, pp. 30:1–30:7 (2010)Serrano, N., Pérez, D., Sanchis, A., Juan, A.: Adaptation from partially supervised handwritten text transcriptions. In: Proceedings of the 11th International Conference on Multimodal Interfaces and the 6th Workshop on Machine Learning for Multimodal Interaction, Cambridge, MA (USA), pp. 289–292 (2009)Serrano, N., Castro, F., Juan, A.: The RODRIGO database. In: Proceedings of the 7th International Conference on Language Resources and Evaluation, Valleta (Malta), pp. 2709–2712 (2010)Serrano, N., Giménez, A., Sanchis, A., Juan, A.: Active learning strategies for handwritten text transcription. In: Proceedings of the 12th International Conference on Multimodal Interfaces and the 7th Workshop on Machine Learning for Multimodal, Interaction, Beijing (China) (2010)Serrano, N., Sanchis, A., Juan, A.: Balancing error and supervision effort in interactive-predictive handwriting recognition. In: Proceedings of the 15th International Conference on Intelligent User Interfaces, Hong Kong (China), pp. 373–376 (2010)Serrano, N., Tarazón, L., Pérez, D., Ramos-Terrades, O., Juan, A.: The GIDOC prototype. In: Proceedings of the 10th International Workshop on Pattern Recognition in Information Systems, Funchal (Portugal), pp. 82–89 (2010)Settles, B.: Active Learning Literature Survey. Computer Sciences Technical Report 1648, University of Wisconsin-Madison (2009)Tarazón, L., Pérez, D., Serrano, N., Alabau, V., Ramos-Terrades, O., Sanchis, A., Juan, A.: Confidence measures for error correction in interactive transcription of handwritten text. In: Proceedings of the 15th International Conference on Image Analysis, Processing, Vietri sul Mare (Italy) (2009)Toselli, A., Juan, A., Keysers, D., González, J., Salvador, I., Ney, H., Vidal, E., Casacuberta, F.: Integrated handwriting recognition and interpretation using finite-state models. Int. J. Pattern Recognit. Artif. Intell. 18(4), 519–539 (2004)Toselli, A., Romero, V., Rodríguez, L., Vidal, E.: Computer assisted transcription of handwritten text. In: Proceedings of the 9th International Conference on Document Analysis and Recognition, Curitiba (Brazil), pp. 944–948 (2007)Valor, J., Pérez, A., Civera, J., Juan, A.: Integrating a state-of-the-art ASR system into the opencast Matterhorn platform. In: Proceedings of the Advances in Speech and Language Technologies for Iberian Languages (IBERSPEECH 2012), Madrid (Spain), pp. 237–246 (2012)Wessel, F., Ney, H.: Unsupervised training of acoustic models for large vocabulary continuous speech recognition. 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Understanding consumer demand for new transport technologies and services, and implications for the future of mobility
The transport sector is witnessing unprecedented levels of disruption.
Privately owned cars that operate on internal combustion engines have been the
dominant modes of passenger transport for much of the last century. However,
recent advances in transport technologies and services, such as the development
of autonomous vehicles, the emergence of shared mobility services, and the
commercialization of alternative fuel vehicle technologies, promise to
revolutionise how humans travel. The implications are profound: some have
predicted the end of private car dependent Western societies, others have
portended greater suburbanization than has ever been observed before. If
transport systems are to fulfil current and future needs of different
subpopulations, and satisfy short and long-term societal objectives, it is
imperative that we comprehend the many factors that shape individual behaviour.
This chapter introduces the technologies and services most likely to disrupt
prevailing practices in the transport sector. We review past studies that have
examined current and future demand for these new technologies and services, and
their likely short and long-term impacts on extant mobility patterns. We
conclude with a summary of what these new technologies and services might mean
for the future of mobility.Comment: 15 pages, 0 figures, book chapte
Making a move in exercise referral: co-development of a physical activity referral scheme
Background. Translational research is required to ensure Exercise Referral Schemes (ERSs) are evidence-based and reflect local needs. This paper reports process data from the co-development phase of an ERS, providing an insight into a) factors that must be considered when translating evidence to practice in an ERS setting, and b) challenges and facilitators of conducting participatory research involving multiple stakeholders. Methods. An ERS was iteratively co-developed by a multidisciplinary stakeholder group (commissioners, managers, practitioners, patients, and academics) via five participatory meetings and an online survey. Audio data (e.g. group discussions) and visual data (e.g. whiteboard notes) were recorded and analysed using NVivo-10 electronic software. Results. Factors to consider when translating evidence to practice in an ERS setting included 1. Current ERS culture; 2. Skills, safety and accountability; and 3. Resources and capacity. The co-development process was facilitated by needs-analysis, open questions, multidisciplinary debate, and reflective practice. Challenges included contrasting views, irregular attendance, and (mis)perceptions of evaluation. Conclusion. The multidisciplinary co-development process highlighted cultural and pragmatic issues related to exercise referral provision, resulting in an evidence-based intervention framework designed to be implemented within existing infrastructures. Further work is required to establish the feasibility and effectiveness of the co-developed intervention in practice
The stellar evolution of Luminous Red Galaxies, and its dependence on colour, redshift, luminosity and modelling
We present a series of colour evolution models for Luminous Red Galaxies
(LRGs) in the 7th spectroscopic data release of the Sloan Digital Sky Survey
(SDSS), computed using the full-spectrum fitting code VESPA on high
signal-to-noise stacked spectra. The colour-evolution models are computed as a
function of colour, luminosity and redshift, and we do not a-priori assume that
LRGs constitute a uniform population of galaxies in terms of stellar evolution.
By computing star-formation histories from the fossil record, the measured
stellar evolution of the galaxies is decoupled from the survey's selection
function, which also evolves with redshift. We present these evolutionary
models computed using three different sets of Stellar Population Synthesis
(SPS) codes. We show that the traditional fiducial model of purely passive
stellar evolution of LRGs is broadly correct, but it is not sufficient to
explain the full spectral signature. We also find that higher-order corrections
to this model are dependent on the SPS used, particularly when calculating the
amount of recent star formation. The amount of young stars can be
non-negligible in some cases, and has important implications for the
interpretation of the number density of LRGs within the selection box as a
function of redshift. Dust extinction, however, is more robust to the SPS
modelling: extinction increases with decreasing luminosity, increasing
redshift, and increasing r-i colour. We are making the colour evolution tracks
publicly available at http://www.icg.port.ac.uk/~tojeiror/lrg_evolution/.Comment: 29 pages, 34 figures, re-submitted to MNRAS after addressing the
referee's repor
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Fitting the integrated Spectral Energy Distributions of Galaxies
Fitting the spectral energy distributions (SEDs) of galaxies is an almost
universally used technique that has matured significantly in the last decade.
Model predictions and fitting procedures have improved significantly over this
time, attempting to keep up with the vastly increased volume and quality of
available data. We review here the field of SED fitting, describing the
modelling of ultraviolet to infrared galaxy SEDs, the creation of
multiwavelength data sets, and the methods used to fit model SEDs to observed
galaxy data sets. We touch upon the achievements and challenges in the major
ingredients of SED fitting, with a special emphasis on describing the interplay
between the quality of the available data, the quality of the available models,
and the best fitting technique to use in order to obtain a realistic
measurement as well as realistic uncertainties. We conclude that SED fitting
can be used effectively to derive a range of physical properties of galaxies,
such as redshift, stellar masses, star formation rates, dust masses, and
metallicities, with care taken not to over-interpret the available data. Yet
there still exist many issues such as estimating the age of the oldest stars in
a galaxy, finer details ofdust properties and dust-star geometry, and the
influences of poorly understood, luminous stellar types and phases. The
challenge for the coming years will be to improve both the models and the
observational data sets to resolve these uncertainties. The present review will
be made available on an interactive, moderated web page (sedfitting.org), where
the community can access and change the text. The intention is to expand the
text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics &
Space Scienc
Pericoronary and periaortic adipose tissue density are associated with inflammatory disease activity in Takayasu arteritis and atherosclerosis.
AimsTo examine pericoronary adipose tissue (PCAT) and periaortic adipose tissue (PAAT) density on coronary computed tomography angiography for assessing arterial inflammation in Takayasu arteritis (TAK) and atherosclerosis.Methods and resultsPCAT and PAAT density was measured in coronary (n = 1016) and aortic (n = 108) segments from 108 subjects [TAK + coronary artery disease (CAD), n = 36; TAK, n = 18; atherosclerotic CAD, n = 32; matched controls, n = 22]. Median PCAT and PAAT densities varied between groups (mPCAT: P P = 0.0002). PCAT density was 7.01 ± standard error of the mean (SEM) 1.78 Hounsfield Unit (HU) higher in coronary segments from TAK + CAD patients than stable CAD patients (P = 0.0002), and 8.20 ± SEM 2.04 HU higher in TAK patients without CAD than controls (P = 0.0001). mPCAT density was correlated with Indian Takayasu Clinical Activity Score (r = 0.43, P = 0.001) and C-reactive protein (r = 0.41, P P = 0.002). mPCAT density above -74 HU had 100% sensitivity and 95% specificity for differentiating active TAK from controls [area under the curve = 0.99 (95% confidence interval 0.97-1)]. The association of PCAT density and coronary arterial inflammation measured by 68Ga-DOTATATE positron emission tomography (PET) equated to an increase of 2.44 ± SEM 0.77 HU in PCAT density for each unit increase in 68Ga-DOTATATE maximum tissue-to-blood ratio (P = 0.002). These findings remained in multivariable sensitivity analyses adjusted for potential confounders.ConclusionsPCAT and PAAT density are higher in TAK than atherosclerotic CAD or controls and are associated with clinical, biochemical, and PET markers of inflammation. Owing to excellent diagnostic accuracy, PCAT density could be useful as a clinical adjunct for assessing disease activity in TAK
Feasibility of brief psychological distress screening by a community-based telephone helpline for cancer patients and carers
Background Up to one-third of people affected by cancer experience ongoing psychological distress and would benefit from screening followed by an appropriate level of psychological intervention. This rarely occurs in routine clinical practice due to barriers such as lack of time and experience. This study investigated the feasibility of community-based telephone helpline operators screening callers affected by cancer for their level of distress using a brief screening tool (Distress Thermometer), and triaging to the appropriate level of care using a tiered model. Methods Consecutive cancer patients and carers who contacted the helpline from September-December 2006 (n = 341) were invited to participate. Routine screening and triage was conducted by helpline operators at this time. Additional socio-demographic and psychosocial adjustment data were collected by telephone interview by research staff following the initial call. Results The Distress Thermometer had good overall accuracy in detecting general psychosocial morbidity (Hospital Anxiety and Depression Scale cut-off score ≥ 15) for cancer patients (AUC = 0.73) and carers (AUC = 0.70). We found 73% of participants met the Distress Thermometer cut-off for distress caseness according to the Hospital Anxiety and Depression Scale (a score ≥ 4), and optimal sensitivity (83%, 77%) and specificity (51%, 48%) were obtained with cut-offs of ≥ 4 and ≥ 6 in the patient and carer groups respectively. Distress was significantly associated with the Hospital Anxiety and Depression Scale scores (total, as well as anxiety and depression subscales) and level of care in cancer patients, as well as with the Hospital Anxiety and Depression Scale anxiety subscale for carers. There was a trend for more highly distressed callers to be triaged to more intensive care, with patients with distress scores ≥ 4 more likely to receive extended or specialist care. Conclusions Our data suggest that it was feasible for community-based cancer helpline operators to screen callers for distress using a brief screening tool, the Distress Thermometer, and to triage callers to an appropriate level of care using a tiered model. The Distress Thermometer is a rapid and non-invasive alternative to longer psychometric instruments, and may provide part of the solution in ensuring distressed patients and carers affected by cancer are identified and supported appropriately
Translational pharmacology of an inhaled small molecule αvβ6 integrin inhibitor for idiopathic pulmonary fibrosis
The αvβ6 integrin plays a key role in the activation of transforming growth factor-β (TGFβ), a pro-fibrotic mediator that is pivotal to the development of idiopathic pulmonary fibrosis (IPF). We identified a selective small molecule αvβ6 RGD-mimetic, GSK3008348, and profiled it in a range of disease relevant pre-clinical systems. To understand the relationship between target engagement and inhibition of fibrosis, we measured pharmacodynamic and diseaserelated end points. Here we report, GSK3008348 binds to αvβ6 with high affinity in human IPF lung and reduces downstream pro-fibrotic TGFβ signaling to normal levels. In human lung epithelial cells, GSK3008348 induces rapid internalization and lysosomal degradation of the αvβ6 integrin. In the murine bleomycin-induced lung fibrosis model, GSK3008348 engages αvβ6, induces prolonged inhibition of TGFβ signaling and reduces lung collagen deposition and serum C3M, a marker of IPF disease progression. These studies highlight the potential of inhaled GSK3008348 as an anti-fibrotic therapy
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