Spectral Analysis for Matrix Hamiltonian Operators

In this work, we study the spectral properties of matrix Hamiltonians generated by linearizing the nonlinear Schr\"odinger equation about soliton solutions. By a numerically assisted proof, we show that there are no embedded eigenvalues for the three dimensional cubic equation. Though we focus on a proof of the 3d cubic problem, this work presents a new algorithm for verifying certain spectral properties needed to study soliton stability. Source code for verification of our comptuations, and for further experimentation, are available at http://www.math.toronto.edu/simpson/files/spec_prop_code.tgz.Comment: 57 pages, 22 figures, typos fixe

Childhood abuse and deprivation are associated with distinct sex-dependent differences in brain morphology

Childhood adversity (CA) has been associated with long-term structural brain alterations and an increased risk for psychiatric disorders. Evidence is emerging that subtypes of CA, varying in the dimensions of threat and deprivation, lead to distinct neural and behavioral outcomes. However, these specific associations have yet to be established without potential confounders such as psychopathology. Moreover, differences in neural development and psychopathology necessitate the exploration of sexual dimorphism. Young healthy adult subjects were selected based on history of CA from a large database to assess gray matter (GM) differences associated with specific subtypes of adversity. We compared voxel-based morphometry data of subjects reporting specific childhood exposure to abuse (n = 127) or deprivation (n = 126) and a similar sized group of controls (n = 129) without reported CA. Subjects were matched on age, gender, and educational level. Differences between CA subtypes were found in the fusiform gyrus and middle occipital gyms, where subjects with a history of deprivation showed reduced GM compared with subjects with a history of abuse. An interaction between sex and CA subtype was found. Women showed less GM in the visual posterior precuneal region after both subtypes of CA than controls. Men had less GM in the postcentral gyms after childhood deprivation compared with abuse. Our results suggest that even in a healthy population, CA subtypes are related to specific alterations in brain structure, which are modulated by sex. These findings may help understand neurodevelopmental consequences related to C

The Decadal Climate Prediction Project (DCPP) contribution to CMIP6

The Decadal Climate Prediction Project (DCPP) is a coordinated multi-model investigation into decadal climate prediction, predictability, and variability. The DCPP makes use of past experience in simulating and predicting decadal variability and forced climate change gained from the fifth Coupled Model Intercomparison Project (CMIP5) and elsewhere. It builds on recent improvements in models, in the reanalysis of climate data, in methods of initialization and ensemble generation, and in data treatment and analysis to propose an extended comprehensive decadal prediction investigation as a contribution to CMIP6 (Eyring et al., 2016) and to the WCRP Grand Challenge on Near Term Climate Prediction (Kushnir et al., 2016). The DCPP consists of three components. Component A comprises the production and analysis of an extensive archive of retrospective forecasts to be used to assess and understand historical decadal prediction skill, as a basis for improvements in all aspects of end-to-end decadal prediction, and as a basis for forecasting on annual to decadal timescales. Component B undertakes ongoing production, analysis and dissemination of experimental quasi-real-time multi-model forecasts as a basis for potential operational forecast production. Component C involves the organization and coordination of case studies of particular climate shifts and variations, both natural and naturally forced (e.g. the "hiatus", volcanoes), including the study of the mechanisms that determine these behaviours. Groups are invited to participate in as many or as few of the components of the DCPP, each of which are separately prioritized, as are of interest to them.The Decadal Climate Prediction Project addresses a range of scientific issues involving the ability of the climate system to be predicted on annual to decadal timescales, the skill that is currently and potentially available, the mechanisms involved in long timescale variability, and the production of forecasts of benefit to both science and society

Large variation in use of patient-reported outcome measures: A survey of 188 foot and ankle surgeons

Background: There is an increasing interest in the use of patient reported outcome measures (PROMs). However, there is a large variety of PROMs and a lack of consensus regarding preference for their use. Aim of this study is to determine how often PROMS are used for foot and ankle disorders, for what purpose PROMs are used, and what the preferences of the foot and ankle surgeons are, when choosing a PROM to use.Methods: Members of the Ankleplatform Study Group-Science of Variation Collaborative were invited to participate in this survey by email. The online survey consisted of six questions on the use and preferences regarding foot and ankle PROMs.Results: 188 participants completed the questionnaire. Of the respondents 17% reported not to use PROMs, 72% stated to use PROMS for research, 39% routinely for patient care and 34% for registration or quality assessment. The respondents were familiar with 30 different outcome measures, of which 20 were PROMs. One of the excluded outcome measures, the AOFAS Hindfoot scale was most commonly reported as preferred outcome measure. FAOS and MOXFQ were the preferred PROMs, reported by 9.7% of the surgeons. Subsequently followed by the FFI (4.3%), the FAAM (3.7%) and the VAS-FA (3.7%).Conclusions: A large majority of the foot and ankle surgeons uses PROMs. The AOFAS hindfoot scale is mentioned as the most preferred outcome measure, while in fact this is not a PROM. Of the twenty different PROMs mentioned in this study, most reported were the FAOS and MOXFQ both supported by only 9.7% of the surgeons. For proper comparison between patients in clinical practice and research, consensus is needed on which easy-to-use PROM with adequate clinimetric properties should be used. Therefore more evidence in the field of clinimetrics of foot and ankle outcome measures is needed. (C) 2017 Published by Elsevier Ltd on behalf of European Foot and Ankle Society

The Composition of the Modernist Book: Ulysses, A Draft of XXX Cantos and The Making of Americans.

This is a study of the composition of three Modernist first editions: Ulysses (1922), The Making of Americans (1925) and A Draft of XXX Cantos (1930). The bibliographical and figurative commitments made to being in print by Ulysses, A Draft of XXX Cantos and The Making of Americans set a coherent program for reading Modernist texts in their perfected form: in print. The editorial reception of the Modernist book has proceeded, however, with reference to the editorial and bibliographical principles established by the New Bibliographers. In deferring to the authors and manuscripts of Modernist books as the highest source of textual authority, the vital significance of being in print to literary Modernism is obscured. The figure of the ideal Book concentrates the central aesthetic, intellectual and bibliographic problem posed the Modernist book: the making of literature. The rhyme with The Making of Americans is appropriate: this book intensifies and consolidates the propositions made about objective and autonomous composition made more hesitantly by Ulysses and A Draft of XXX Cantos. These three books display a gradual refusal to equate inscription and intention; their composition effaces all traces of a sovereign creative subjectivity. The vision of the book guides Modernist composition, and requires a critical distinction be drawn between manuscripts and printed letters. Modernism must be read in print. The vestigial nostalgia for Romantic modes of textual production and creation in Ulysses is repeated on the placards and proof-pages for the book. Printed drafts are revised and reformed by the pen of the author. The finality asserted by the printed letter is only reluctantly ceded on the publication of Ulysses. The composition of A Draft of XXX Cantos represents a further transition away from the script economy of Romanticism. The interplay between authorial typescripts, early publications and the first edition of A Draft of XXX Cantos assert an intermediate order of Modernist textuality which takes the printed page as its foundation. The Making of Americans relies on the absolute objectivity and anonymity of its composition for the effect of its narrative. Objectivity is the intellectual and aesthetic strategy which produces literature rather than the personality and memory of the author. The impersonality of the apparently automatically written manuscripts and scarcely revised typescripts for The Making of Americans severs the visible links between the writing author and her page. In their unwillingness to corroborate the modes of textual generation described by the New Bibliographers, these three books thematise their own composition as the exemplary Modernist and modern mode of textual generation. The Modernist book attenuates or denies a Romantic connection between the creative hand of the author and the surface image of the page: the mechanisms of print deliberately detach the author from the literary text. The distance of the author from the scene of textual reproduction is measured by the printed book. The composition of this analytical object is not a fallacy but an actuality, commemorated in the archive, enacted by the book. Modernism is the literature of the imprimatur rather than of authorial inscription and accordingly it is towards the first editions of Modernist texts that the attentions of editors and textual scholars must be directed