260 research outputs found

    An alternative characterization of MAR in shared parameter models for incomplete longitudinal data and its utili

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    Dropout is a common complication in longitudinal studies, especially since the distinction between missing not at random (MNAR) and missing at random (MAR) dropout is intractable. Consequently, one starts with an analysis that is valid under MAR and then performs a sensitivity analysis by considering MNAR departures from it. To this end, specific classes of joint models, such as pattern-mixture models (PMMs) and selection models (SeMs), have been proposed. On the contrary, shared-parameter models (SPMs) have received less attention, possibly because they do not embody a characterization of MAR. A few approaches to achieve MAR in SPMs exist, but are difficult to implement in existing software. In this article, we focus on SPMs for incomplete longitudinal and time-to-dropout data and propose an alternative characterization of MAR by exploiting the conditional independence assumption, under which outcome and missingness are independent given a set of random effects. By doing so, the censoring distribution can be utilized to cover a wide range of assumptions for the missing data mechanism on the subject-specific level. This approach offers substantial advantages over its counterparts and can be easily implemented in existing software. More specifically, it offers flexibility over the assumption for the missing data generating mechanism that governs dropout by allowing subject-specific perturbations of the censoring distribution, whereas in PMMs and SeMs dropout is considered MNAR strictly

    On the screening of the potential between adjoint sources in QCD3QCD_3

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    We calculate the potential between adjoint sources in SU(2)SU(2) pure gauge theory in three dimensions. We investigate whether the potential saturates at large separations due to the creation of a pair of gluelumps, colour-singlet states formed when glue binds to an adjoint source.Comment: 3 pages, uuencoded Z-compressed postscript file, contribution to Lattice '9

    A Paradigm Shift: Detecting Human Rights Violations Through Web Images

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    The growing presence of devices carrying digital cameras, such as mobile phones and tablets, combined with ever improving internet networks have enabled ordinary citizens, victims of human rights abuse, and participants in armed conflicts, protests, and disaster situations to capture and share via social media networks images and videos of specific events. This paper discusses the potential of images in human rights context including the opportunities and challenges they present. This study demonstrates that real-world images have the capacity to contribute complementary data to operational human rights monitoring efforts when combined with novel computer vision approaches. The analysis is concluded by arguing that if images are to be used effectively to detect and identify human rights violations by rights advocates, greater attention to gathering task-specific visual concepts from large-scale web images is required

    Variational Principles on Geometric Rough Paths and the L\'{e}vy Area Correction

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    In this paper, we describe two effects of the L\'evy area correction on the invariant measure of stochastic rigid body dynamics on geometric rough paths. From the viewpoint of dynamics, the L\'evy area correction introduces an additional deterministic torque into the rigid body motion equation on geometric rough paths. When the dynamics is driven by coloured noise, and for rigid body dynamics with double-bracket dissipation, theoretical and numerical results show that this additional deterministic torque shifts the centre of the probability distribution function by shifting the Hamiltonian function in the exponent of the Gibbsian invariant measure.Comment: 39 pages, 9 figures, 3rd version, comments welcom

    Les rapports entre l'Église et l'État au sein des Églises orthodoxes "établies localement"

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    This paper applies the Church's understanding of the dual nature -in one person- of Christ, human and divine, to the issue of the strained between the Church and the State, within the Creation and the History. This question is approached and analysed through two theological, ecclesiological and canonical categories, alterity (otherness) and communion , which are based on the antinomical conciliar formula of a (comm)union "without confusion and without division". With the help of the systematic and canonical theology of the Fourth Ecumenical Council of Chalcedon (451), it has investigated the Christological question , according to the author, of the relationships between the Church and the State on a global level, in the name of the a double and symmetrical divergence: occurs: on the one hand, the autonomisation of otherness leading to the minorisation of communion, in other words, division and separation between Church and State arising from turning otherness into absolute autonomy (without any communion and relationship); and on the other hand, the alienation of communion causing confusion, and leading to the absorption of otherness , in other words, absorption of the weak locally established Church by the powerful State leading to "confusion" (in the Chalcedonian sense) - without any alterity. In the first case, priority is given to being "without confusion" at the detriment of being "without division" (communion), whereas in the second, we observe the predominance of "without division" and the total abolition of "without confusion" (otherness-autonomy). The author enshrines in Church, Body of Christ, its very nature a combination of alterity (otherness) and communion. He argues that these characteristics are undermined by the twin distortions of State infliction and untamed separation, which are marred the relations between these two entities, the Church and the State. For fifteen centuries now, this conception of relationships between the Church and the State has placed a burden at an ecumenical level. More precisely, the ecclesiological vision of the Council of Chalcedon was the simultaneous coexistence of otherness and communion between State and Church as a clearly paradoxical or antinomial feature of the christological mode of coexistence of the two natures of Christ: the human nature and the divine one. It naturally emerges that the coexistence of Church and State in a given state territory is realised through the acceptance of their ontological and institutional otherness and the preservation of communi(cati)on and relationship among them. Special reference is made to the case of the Political Dimension of the Church Eschatology

    GET-AID: Visual Recognition of Human Rights Abuses via Global Emotional Traits

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    In the era of social media and big data, the use of visual evidence to document conflict and human rights abuse has become an important element for human rights organizations and advocates. In this paper, we address the task of detecting two types of human rights abuses in challenging, everyday photos: (1) child labour, and (2) displaced populations. We propose a novel model that is driven by a human-centric approach. Our hypothesis is that the emotional state of a person -- how positive or pleasant an emotion is, and the control level of the situation by the person -- are powerful cues for perceiving potential human rights violations. To exploit these cues, our model learns to predict global emotional traits over a given image based on the joint analysis of every detected person and the whole scene. By integrating these predictions with a data-driven convolutional neural network (CNN) classifier, our system efficiently infers potential human rights abuses in a clean, end-to-end system we call GET-AID (from Global Emotional Traits for Abuse IDentification). Extensive experiments are performed to verify our method on the recently introduced subset of Human Rights Archive (HRA) dataset (2 violation categories with the same number of positive and negative samples), where we show quantitatively compelling results. Compared with previous works and the sole use of a CNN classifier, this paper improves the coverage up to 23.73% for child labour and 57.21% for displaced populations. Our dataset, codes and trained models are available online at https://github.com/GKalliatakis/GET-AID

    The Complex Evolutionary History of Aminoacyl-tRNA Synthetases

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    Aminoacyl-tRNA synthetases (AARSs) are a superfamily of enzymes responsible for the faithful translation of the genetic code and have lately become a prominent target for synthetic biologists. Our large-scale analysis of \u3e2500 prokaryotic genomes reveals the complex evolutionary history of these enzymes and their paralogs, in which horizontal gene transfer played an important role. These results show that a widespread belief in the evolutionary stability of this superfamily is misconceived. Although AlaRS, GlyRS, LeuRS, IleRS, ValRS are the most stable members of the family, GluRS, LysRS and CysRS often have paralogs, whereas AsnRS, GlnRS, PylRS and SepRS are often absent from many genomes. In the course of this analysis, highly conserved protein motifs and domains within each of the AARS loci were identified and used to build a web-based computational tool for the genome-wide detection of AARS coding sequences. This is based on hidden Markov models (HMMs) and is available together with a cognate database that may be used for specific analyses. The bioinformatics tools that we have developed may also help to identify new antibiotic agents and targets using these essential enzymes. These tools also may help to identify organisms with alternative pathways that are involved in maintaining the fidelity of the genetic code

    The Remarkable Evolutionary Plasticity of Coronaviruses by Mutation and Recombination: Insights for the COVID-19 Pandemic and the Future Evolutionary Paths of SARS-CoV-2.

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    Coronaviruses (CoVs) constitute a large and diverse subfamily of positive-sense single-stranded RNA viruses. They are found in many mammals and birds and have great importance for the health of humans and farm animals. The current SARS-CoV-2 pandemic, as well as many previous epidemics in humans that were of zoonotic origin, highlights the importance of studying the evolution of the entire CoV subfamily in order to understand how novel strains emerge and which molecular processes affect their adaptation, transmissibility, host/tissue tropism, and patho non-homologous genicity. In this review, we focus on studies over the last two years that reveal the impact of point mutations, insertions/deletions, and intratypic/intertypic homologous and non-homologous recombination events on the evolution of CoVs. We discuss whether the next generations of CoV vaccines should be directed against other CoV proteins in addition to or instead of spike. Based on the observed patterns of molecular evolution for the entire subfamily, we discuss five scenarios for the future evolutionary path of SARS-CoV-2 and the COVID-19 pandemic. Finally, within this evolutionary context, we discuss the recently emerged Omicron (B.1.1.529) VoC
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