Robust Lasso-Zero for sparse corruption and model selection with missing covariates

We propose Robust Lasso-Zero, an extension of the Lasso-Zero methodology [Descloux and Sardy, 2018], initially introduced for sparse linear models, to the sparse corruptions problem. We give theoretical guarantees on the sign recovery of the parameters for a slightly simplified version of the estimator, called Thresholded Justice Pursuit. The use of Robust Lasso-Zero is showcased for variable selection with missing values in the covariates. In addition to not requiring the specification of a model for the covariates, nor estimating their covariance matrix or the noise variance, the method has the great advantage of handling missing not-at random values without specifying a parametric model. Numerical experiments and a medical application underline the relevance of Robust Lasso-Zero in such a context with few available competitors. The method is easy to use and implemented in the R library lass0

Validity, reliability and responsiveness of the EORTC QLQ-C30 and the EORTC QLQ-LC13 in Australians with early stage non-small cell lung cancer, CHERE Working Paper 2007/13

Aim: To assess the validity, reliability and responsiveness of two questionnaires, the QLQ-C30 and LC-13, as measures of health-related quality of life (HRQOL) in an Australian sample of people with early stage non-small cell lung cancer. Background: These two questionnaires are complementary components of the European Organisation for Research and Treatment of Cancer?s (EORTC?s) modular approach to measuring HRQOL: the QLQ-C30 is the core questionnaire, containing 30 items relevant to all cancers; the QLQ-LC13 contains 13 items specific to lung cancer. Methods: These two complementary questionnaires were assessed with data obtained from 183 participants of a randomised control trial investigating the use of Positron Emission Tomography in the management of stage I or II non-small cell lung cancer. A cohort of 173 participants, were treated by surgery and then followed for two years. Participants completed HRQOL questionnaires before the PET scan, before and after surgery, one month after surgery, and then four monthly for two years. Construct validity was tested with confirmatory factor analysis and correlation analysis was used to test for convergent/divergent validity. Discriminant validity was tested by assessing the sensitivity of the scales to the effects of moving from early to late stage disease, asymptomatic to mildly symptomatic, and to the effects of age, gender and number of comorbitities. Mean differences (standardized response means (SRM)) and effect sizes were estimated for: patients with Stage 1/11 and metastatic disease; ECOG score 0 and ECOG score 1; older and younger patients; men and women; patients with no comorbidities and those with 1 or more comorbidities. Reliability was assessed in terms of internal consistency and test-retest reliability. Responsiveness to the effects of major thoracic surgery, adjuvant radiotherapy, and disease recurrence was assessed by estimating mean differences (standardized response meansSRM?s and effect sizes for patients who underwent surgery, radiotherapy and whose disease recurred, respectively. Results: The factor structure reported previously was replicated in this sample, confirming the questionnaires? construct validity. Most scales demonstrated good to excellent internal consistency (Cronbach?s alpha range: 0.86 ? 0.94); the exceptions were the cognitive function (0.68) and nausea/vomiting scales (0.67). Test-retest reliability was generally good (intraclass correlation (ICC) range: 0.70 ? 0.81); the exceptions were the pain and nausea/vomiting scales (ICC 0.56 and 0.42). Most scales were sensitive to the large effect of moving from early to later stage disease with (SRM range: 21.3 ? 54.0; effect size range:1.14 ? 1.97 (except for emotional functioning: 13.7; 0.60)). The scales were also sensitive to small effects, detecting small to moderate differences for age (large for social functioning) and comorbidities, and small differences for moving from asymptomatic to mildly symptomatic disease, and for age. Responsiveness was also confirmed with most scales responsive to the large expected effects of surgery and disease progression ( SRM range: 21.6 ? 41.4; effect size range: 0.94 ? 1.89 (emotional functioning: 5.5; 0.19)). Conclusions: The QLQ-C30 and QLQ-LC13, when used together, provide a valid, reliable and responsive measure of HRQOL in Australians with early stage non-small cell lung cancer.Questionnaires, validity, reliability, responsiveness, QOL, lung cancer

Forma y función de los juegos fónicos en el habla juvenil de Puebla (México)

[À l'origine dans / Was originally part of : Thèses et mémoires - FAS - Département de littératures et de langues modernes]Dans le parler des jeunes du Mexique, on retrouve, entre autres formes de vitalité linguistique, un usage fréquent de jeux phoniques qui transforment ou substituent des lexèmes et syntagmes sans qu'il y ait altération significative du signifié. Ce phénomène linguistique utilise trois procédés phoniques: la suffixation parasitaire, la substitution lexicale basée sur la similitude phonique et l'enchaînement en écho. Le présent mémoire contribue à remplir un vide dans la littérature scientifique et faire connaître ce phénomène peu étudié en explorant les aspects formels linguistiques et les fonctions sociales. Nous cherchons à établir les relations qui existent entre la structure linguistique et les fonctions linguistiques et sociales inhérentes à l'usage de jeux phoniques. L'étude empirique menée dans la ville de Puebla (Mexique) a permis la collecte d'un corpus de plus de deux cents jeux phoniques et la réalisation d'entrevues sociolinguistiques avec dix-huit jeunes de Puebla usagers des expressions étudiées. Nous proposons une classification du corpus de jeux phoniques basée sur la structure formelle afin d'apprécier que le phénomène réponde à des patrons fixes de construction. Suite à une analyse thématique des entrevues que nous appuyons d'exemples de jeux phoniques, nous verrons que l'usage de jeux phoniques joue principalement une fonction poétique, ludique ainsi qu'une fonction de cohésion sociale et une fonction identitaire. La présente étude confirme que le caractère non normatif et cryptique intrinsèque aux jeux de mots sert à renforcer ces fonctions sociales, à la manière d'un parler argotique.In the youth speech of Mexico a frequent use of phonic wordplays that transform or substitute lexemes and phrases without significant alteration of the signifier are found among linguistic vitality signs. This linguistic phenomenon uses three phonic techniques: parasitic suffixation, lexical substitution based on phonic similarity and echo chaining. This report contributes by filling a void in the scientific literature and to expose this overlooked phenomenon by exploring its formal linguistic aspects and social functions. The aim of this study is to establish the relationship between linguistic structure and linguistic and social functions inherent to phonic wordplay use. The empiric study conducted in Puebla (Mexico) allowed the collection of a corpus of more than two hundred phonic wordplays and the realization of sociolinguistic interviews with eighteen Puebla youth, who employ the studied expressions. This work proposes a classification of the corpus based on their formal structure in order to highlight that the phenomenon conforms to fixed patterns of construction. After a thematic analysis of the interviews, with an emphasis on phonic wordplay examples, we observe that the use of phonic wordplays mainly accomplishes poetic and ludic, as well as social cohesion and identity functions. This study confirms that the non-normative and cryptic characteristics intrinsic to phonic wordplays help to reinforce the aforementioned social functions as an argotic speech.En el habla de los jóvenes de México encontramos, entre otras muestras de vitalidad lingüística, un uso frecuente de juegos fónicos que transforman o sustituyen lexemas y sintagmas sin que haya alteración significativa del significado. Este fenómeno lingüístico utiliza tres recursos fónicos: la sufijación parasitaria, la sustitución léxica por similitud fónica y el encadenamiento en eco. La presente memoria contribuye a llenar un vacío en la literatura científica y dar a conocer este fenómeno poco estudiado, explorando los aspectos formales lingüísticos y las funciones sociales. Buscamos establecer las relaciones que existen entre la estructura lingüística y las funciones lingüísticas y sociales inherentes al uso de los juegos fónicos. El estudio empírico que se llevó a cabo en la ciudad de Puebla (México) permitió la recolección de un corpus de más de doscientos juegos fónicos y la realización de entrevistas sociolingüísticas con dieciocho jóvenes poblanos usuarios de las expresiones estudiadas. Proponemos una clasificación del corpus de juegos fónicos basada en la estructura formal para apreciar que el fenómeno responde a patrones fijos de construcción. Tras un análisis temático de las entrevistas, que apoyamos con ejemplos de juegos fónicos, veremos que el uso de juegos fónicos cumple principalmente una función poética, lúdica, así como una función de cohesión social y una función identitaria. El presente estudio confirma que el carácter no normativo y críptico intrínseco a los juegos fónicos sirve para reforzar estas funciones sociales, a modo de habla argótica

A Qualitative Study of Leadership Tools and Traits that Foster Effective Relationships in Rural School Communities

The purpose of this qualitative study was to identify leadership qualities and practices that nurture relationships in school settings. The central question framing this study was: What leadership tools and traits foster effective relationships in rural school communities? I conducted semi-structured interviews in a small Northwestern school district. Non-classroom leaders and classroom leaders, who will be referred to using pseudonyms, were recruited from the elementary, middle, and high schools based on recommendations from the district’s superintendent. Prior to conducting interviews, participants were provided with a framework based on Kouzes and Posner’s (2017) exemplary leadership practices and asked to choose five artifacts to share regarding their relevance to the framework. Interview questions were purposefully designed to gain insight to the participants’ lived experiences regarding leadership behaviors which impact relationships. Using the process of coding, I analyzed the data and developed a detailed description of each participant’s responses. From these descriptions, I identified key themes for understanding the nexus of leadership and relationships. Themes included visionary, providing opportunities, reflective practices, and relationships. The findings of this study confirmed the significant influence that school leaders have on school culture and climate when relationships are prioritized. Findings correlated with the five exemplary leadership practices identified by Kouzes and Posner (2017)

Les aspects juridiques des stratégies de propriété occulte et de vote vide réalisées par l’entremise des instruments dérivés

L’auteure traite des stratagèmes de propriété occulte et de vote vide orchestrés par l’entremise des instruments dérivés. Dans un premier temps, cette recherche expose les diverses perturbations occasionnées par ces stratagèmes sur le système d’alerte et de notification ainsi que sur le droit corporatif canadien. Pour illustrer ces propos, une revue de la jurisprudence est détaillée. De plus, de nombreuses solutions législatives sont proposées afin de pallier aux utilisations potentiellement abusives des instruments dérivés. La solution la mieux adaptée au contexte des marchés financiers canadiens est finalement sélectionnée.The research paper herein deals with hidden morphable ownership schemes and empty voting strategies orchestrated through derivatives. Initially, the author exposes the various disturbances caused by these schemes on early warning systems and follows up with repercussions that reverberate through to the Canadian corporate laws framework. Detailed case reviews are also presented to highlight the practical implications of these aforementioned schemes. Legislative solutions to mitigate the potential misuse of derivatives are proposed and ultimately the preferred solution tailored to Canadian financial markets is selected

Medical Care and Procompetitive Reform

It is not the purpose of this Article to reject all features of procompetitive proposals. Competitive health plans, multiple health plan choice, provider and consumer cost consciousness, and antitrust activity all may have some place in a larger strategy to rationalize the medical care system. Each of the proposals has some advantages in terms of increasing consumer choice and altering the balance of power between existing actors. As an approach to universal medical care system reform, however, competition alone is inadequate. In fact, one could argue that the most technically feasible way to both rationalize the medical care system and reduce total societal expenditures on health would be to nationalize a public budget for health care and to pass the total costs of medical care through the political budgetary process. Total societal costs might actually be reduced by increasing the program costs to government, as long as public authority is, as in Canada, adequately increased. The centralization of regulatory and allocative decisions could well result in a more suitably restrained form of American medicine. That, however, is a discussion about the alter-natives to procompetitive proposals, rather than the problems of procompetitive proposals, and is therefore beyond the scope of this Article

Men at work? Debating shifting gender divisions of care

In response to four commentaries on our paper ‘Regendering care in the aftermath of recession?’, we extend our discussion of the ongoing knowledge gap that prevails around shifting patterns of male work/care. Recognizing the spatial limits of extant theories of male primary caregiving, we discuss first the need to attend to the variegated landscapes of male caregiving across the globe. Likewise, the theoretical stakes of expanding the focus of ‘mainstream’ analysis to take account of the situated experiences and knowledges of men and women in countries of the global South. We then consider the subjects of our research inquiry (the ‘who’ of contemporary fathering) and how different definitions of male primary caregivers may reveal or conceal patterns and shifts in male caregiving practices. Lastly we consider questions of scale and research methodology. Although our paper employs a national-level analysis, we fully endorse the use of alternative scalar lenses and underline the need to analyse male care within the context of multiscalar and interacting sites of normative change: from nation state, to community, to home, to the body. </jats:p

Missing Data Imputation using Optimal Transport

Missing data is a crucial issue when applying machine learning algorithms to real-world datasets. Starting from the simple assumption that two batches extracted randomly from the same dataset should share the same distribution, we leverage optimal transport distances to quantify that criterion and turn it into a loss function to impute missing data values. We propose practical methods to minimize these losses using end-to-end learning, that can exploit or not parametric assumptions on the underlying distributions of values. We evaluate our methods on datasets from the UCI repository, in MCAR, MAR and MNAR settings. These experiments show that OT-based methods match or out-perform state-of-the-art imputation methods, even for high percentages of missing values

Processus d’évaluation des compétences en formation à distance dans une approche collaborative en enseignement supérieur

Comprend des références bibliographiquesCette recherche présente des résultats d’une recherche-action-formation visant à améliorer un processus d’évaluation des compétences en formation à distance dans une approche collaborative en enseignement supérieur. Recueillis principalement au moyen d’analyse de documentations produites, d’entrevues semi-structurées et d’artefacts conçus lors d’une formation auprès de concepteurs, de producteurs et de tuteurs engagés dans une genèse instrumentale, les résultats exposent un modèle de processus d’évaluation des compétences en formation à distance qui émergent de plusieurs processus impliquant la collaboration entre les groupes d’acteurs