The two-sample problem for Poisson processes: adaptive tests with a non-asymptotic wild bootstrap approach

Considering two independent Poisson processes, we address the question of testing equality of their respective intensities. We first propose single tests whose test statistics are U-statistics based on general kernel functions. The corresponding critical values are constructed from a non-asymptotic wild bootstrap approach, leading to level \alpha tests. Various choices for the kernel functions are possible, including projection, approximation or reproducing kernels. In this last case, we obtain a parametric rate of testing for a weak metric defined in the RKHS associated with the considered reproducing kernel. Then we introduce, in the other cases, an aggregation procedure, which allows us to import ideas coming from model selection, thresholding and/or approximation kernels adaptive estimation. The resulting multiple tests are proved to be of level \alpha, and to satisfy non-asymptotic oracle type conditions for the classical L2-norm. From these conditions, we deduce that they are adaptive in the minimax sense over a large variety of classes of alternatives based on classical and weak Besov bodies in the univariate case, but also Sobolev and anisotropic Nikol'skii-Besov balls in the multivariate case

Whispers2mom: a Young Adult Prenatal Text Messaging Intervention

WHISPERS2MOM: A YOUNG ADULT PRENATAL TEXT MESSAGING INTERVENTION by Christine P. Laurent The University of Wisconsin-Milwaukee, 2018 Under the Supervision of Dr. Jennifer Doering Purpose: To evaluate the feasibility of Whispers2Mom, a prenatal text messaging educational intervention designed for young adults, 18 to 26 years old. The findings of this study may inform nursing strategies to improve breastfeeding intention and rates in the emerging adult population. Background: Childbearing young adults are among the least likely populations to breastfeed, yet their infants stand to benefit greatly from breastfeeding. Current methods of prenatal education have failed to increase rates of breastfeeding intention or initiation. Methods: The feasibility of the Whispers2Mom prenatal text messaging program was evaluated through exploration of adherence and acceptability using a mixed methods design. Prior to data collection, daily text messages were delivered for one month. Texts addressed breastfeeding practices, barriers to breastfeeding, strategies for overcoming barriers, and these texts augmented usual prenatal care practices. A convenience sample was recruited. Data were collected using surveys and semi-structured interviews with 14 participants. Interviews were analyzed using thematic analysis. Results: The original intent was to recruit adolescents for this study, but due to many challenges with recruitment, the final sample was comprised only of young adults. Participants were on average 24 (SD= 2.4) years old, high school graduates, and married or partnered. Participants were adherent in using the Whispers2Mom prenatal text message program. Participants indicated that they found the Whispers2Mom prenatal text message program to be acceptable. Generally, the texts were helpful, informative, and provided good information. Several of the interview responses indicated increasing feelings of attachment to baby. Conclusions: Findings suggest the Whispers2Mom intervention, as measured by self-report of acceptability and adherence was feasible. The prenatal text messaging intervention Whispers2Mom, when used as an educational tool, may be an appropriate adjunct to usual care practices. Given the positive preliminary results in this study and the fact that technology is a common and important part of the young adult’s life, text messaging may be an efficacious addition to interventions that already exist for health promotion and disease prevention during the prenatal period in emerging adults

Development of a new QSPR based tool to predict explosibility properties of chemical substances within the framework of REACH and GHS

International audienceThe new European régulation of Chemicals named REACH (for "Registration, Evaluation and Authorization of Chemicals") turned out in the practical registration phase in December 2008. It requires the new assessment of hazard properties for up to 140000 substances. In this context, the development of alternative prédictive methods for assessing hazardous properties of chemical substances is promoted in REACH and in the related new European classification System of substances CLP (Classification, Labelling and Packaging of chemical substances and mixtures

Development of a QSPR model for predicting thermal stabilities of nitroaromatic compounds taking into account their decomposition mechanisms

International audienceThe molecular structures of 77 nitroaromatic compounds have been correlated to their thermal stabilities by combining the quantitative structure-property relationship (QSPR) method with density functional theory (DFT). More than 300 descriptors (constitutional, topological, geometrical and quantum chemical) have been calculated, and multilinear regressions have been performed to find accurate quantitative relationships with experimental heats of decomposition (deltaH). In particular, this work demonstrates the importance of accounting for chemical mechanisms during the selection of an adequate experimental data set. A reliable QSPR model that presents a strong correlation with experimental data for both the training and the validation molecular sets (R 2 = 0.90 and 0.84, respectively) was developed for non-ortho-substituted nitroaromatic compounds. Moreover, its applicability domain was determined, and the model's predictivity reached 0.86 within this applicability domain. To our knowledge, this work has produced the first QSPR model, developed according to the OECD principles of regulatory acceptability, for predicting the thermal stabilities of energetic compounds

On the prediction of thermal stability of nitroaromatic compounds using quantum chemical calculations

International audienceThis work presents a new approach to predict thermal stability of nitroaromatic compounds based on quantum chemical calculations and on quantitative structure-property relationship (QSPR) methods. The data set consists of 22 nitroaromatic compounds of known decomposition enthalpy (taken as a macroscopic property related to explosibility) obtained from differential scanning calorimetry. Geometric, electronic and energetic descriptors have been selected and computed using density functional theory (DFT) calculation to describe the 22 molecules. First approach consisted in looking at their linear correlations with the experimental decomposition enthalpy. Molecular weight, electrophilicity index, electron affinity and oxygen balance appeared as the most correlated descriptors (respectively R2 = 0.76, 0.75, 0.71 and 0.64). Then multilinear regression was computed with these descriptors. The obtained model is a six-parameter equation containing descriptors all issued from quantum chemical calculations. The prediction is satisfactory with a correlation coefficient R2 of 0.91 and a predictivity coefficient R2(cv) of 0.84 using a cross validation method

Wood particle filled polyvinyl chloride composites and their foams

Extruded composite compositions of PVC and wood particles containing chitosan or chitin as a coupling agent are described. The composite compositions have improved physical and mechanical properties.https://digitalcommons.mtu.edu/patents/1029/thumbnail.jp

Une recherche partenariale appuyant l'évolution de la réglementation : Un cas délicat de dimensionnement d'évent pour le stockage de peroxydes organiques

National audienceLes dangers présentés par les peroxydes organiques sont très variés, et dans tous les cas, le risque d'emballement thermique, avec explosion pneumatique du contenant est à considérer. Dans le cas étudié, le danger de déflagration ou d'explosion pneumatique éliminé au niveau du stockage mère par l'emploi d'un emballage plastique de 35 litres peu résistant, réapparaît au cœur même de l'unité de polymérisation utilisant le peroxyde, car le concepteur a prévu un stockage tampon en cuve inox d'environ 1 m3 . La préparation de ditertiobutylperoxyde (DTBP) peut donner lieu à une explosion en phase gazeuse même sous azote, induisant éventuellement une déflagration de la phase liquide. Plus classiquement, on doit tenir compte du scénario d'emballement thermique du stockage menant à l'éclatement de la cuve, suite à un incendie extérieur ou à un auto-échauffement. Nous avons réalisé des essais à l'échelle de 0,8 - 10 et 20 litres, en modifiant des méthodes normalisées ou recommandées internationalement ; une évolution de ces méthodes sera proposée dans le futur. Nous avons pu ainsi étudier le couplage entre 'explosion en phase gazeuse et l'emballement thermique de la phase liquide pour le DTBP, et proposer au vu des résultats des recommandations pour réduire dès la conception de l'installation l'apparition de ce phénomène, tout en limitant la violence de l'emballement thermique s'il apparaît. La présente étude a aussi permis de contribuer à mieux comprendre comment établir le projet d'arrêté pour les cas très différents du stockage et de l'usage des peroxydes, dans le contexte de la révision de la nomenclature et les arrêtés relatifs au stockage et à l'utilisation des peroxydes organiques, au titre des Installations Classées pour la Protection de l'Environnement (ICPE)

Modeling Iron and Light Controls on the Summer \u3ci\u3ePhaeocystis antarctica\u3c/i\u3e Bloom in the Amundsen Sea Polynya

Of all the Antarctic coastal polynyas, the Amundsen Sea Polynya is the most productive per unit area. Observations from the 2010-2011 Amundsen Sea Polynya International Research Expedition (ASPIRE) revealed that both light and iron can limit the growth of phytoplankton (Phaeocystis antarctica), but how these controls manifest over the bloom season is poorly understood, especially with respect to their climate sensitivity. Using a 1-D biogeochemical model, we examine the influence of light and iron limitation on the phytoplankton bloom and vertical carbon flux at 12 stations representing different bloom stages within the polynya. Model parameters are determined by Bayesian optimization and assimilation of ASPIRE observations. The model-data fit is most sensitive to phytoplankton physiological parameters, which among all model parameters are best constrained by the optimization. We find that the 1-D model captures the basic elements of the bloom observed during ASPIRE, despite some discrepancies between modeled and observed dissolved iron distributions. With this model, we explore the way iron availability, in combination with light availability, controlled the rise, peak, and decline of the bloom at the 12 stations. Modeled light limitation by self-shading is very strong, but iron is drawn down as the bloom rises, becoming limiting in combination with light as the bloom declines. These model results mechanistically confirm the importance of climate-sensitive controls like stratification and meltwater on phytoplankton bloom development and carbon export in this region