572 research outputs found
Clustering files of chemical structures using the Szekely-Rizzo generalization of Ward's method
Ward's method is extensively used for clustering chemical structures represented by 2D fingerprints. This paper compares Ward clusterings of 14 datasets (containing between 278 and 4332 molecules) with those obtained using the SzekelyâRizzo clustering method, a generalization of Ward's method. The clusters resulting from these two methods were evaluated by the extent to which the various classifications were able to group active molecules together, using a novel criterion of clustering effectiveness. Analysis of a total of 1400 classifications (Ward and SzĂ©kelyâRizzo clustering methods, 14 different datasets, 5 different fingerprints and 10 different distance coefficients) demonstrated the general superiority of the SzĂ©kelyâRizzo method. The distance coefficient first described by Soergel performed extremely well in these experiments, and this was also the case when it was used in simulated virtual screening experiments
Evaluation du Respect des Bonnes Pratiques de Sondage Vesical a Demeure Chez Lâadulte par les Soignants : Utilisation de « Vignettes Cliniques »
Le sondage urinaire ou vĂ©sical est une technique utilisĂ©e depuis lâantiquitĂ© qui repose sur lâutilisation de dispositifs mĂ©dicaux invasifs pour le patient. Cet acte de soin doit se faire de façon sĂ©curisĂ©e et sâappuyer sur des rĂ©fĂ©rentiels. Les objectifs ont Ă©tĂ© lâĂ©valuation durespect des recommandations du protocole institutionnel sur la pose dâune sonde urinaire Ă demeure chez l'adulte, le respect de lâhygiĂšne et de lâasepsie et lâĂ©valuation des conduites Ă tenir lors dâune fuite urinaire sur sonde. Dans le cadre dâune dĂ©marche dâĂ©valuation des pratiques professionnelles, une enquĂȘte prospective basĂ©e sur le concept des « vignettes cliniques » a Ă©tĂ© menĂ©e, avec des mises en situations des soignants du CHU Charles Nicolle, Bois-Guillaume et Oissel en 2011. LâenquĂȘte rĂ©vĂšle un suivi des recommandations sur certains points comme le respect de lâasepsie et du systĂšme clos. Des divergences ont Ă©tĂ© mises en Ă©vidence concernant notamment lâusage de la bandelette urinaire chez le patient sondĂ©, le choix du type de sonde et les couples de produits Ă utiliser pour la dĂ©tersion et lâantisepsie. Des axes dâamĂ©liorations sont proposĂ©s comme la sensibilisation des Ă©quipes soignantes mais Ă©galement mĂ©dicales par le biais notammentdâune plaquette simple et illustrĂ©e de support dâinformation sur les bonnes pratiques de sondage vĂ©sical Ă demeure chez lâadulte et des kits « prĂȘts Ă lâemploi » de produits pour la dĂ©tersion et lâantisepsie.Since antiquity, the urinary or bladder catheter is a technique that relies on the use of invasive medical devices for the patient. This care act must be done in a secure manner and rely on standards. First, the evaluation of the respect of the recommendations of the institutional protocol on hanging an indwelling urinary catheter in adult, the respect of the hygiene and finally, the asepsis and the evaluation of the behaviors to be maintained during a urinary leak on probe were the objectives. As part of an evaluation of professional practices, a prospective survey based on the concept of "clinical vignettes" was conducted, with situations from nurses from CHU Charles Nicolle, BoisGuillaume and Oissel in 2011. The survey reveals a follow-up of the recommendations like the respect of the asepsis and the closed system. Discrepancies have been identified about the use of the urine strip in the patient being probed, the choice of the type of probe and the pairs of products to be used for the debridement and antisepsis. Different areas for improvement are proposed, first of all, raising the awareness of health care teams, but also medical ones, in particular through a simple plaque illustrated with information support on good practice of adult bladder catheterization and then use the packaging âready to useâ for debridement and antisepsis
Plausibility functions and exact frequentist inference
In the frequentist program, inferential methods with exact control on error
rates are a primary focus. The standard approach, however, is to rely on
asymptotic approximations, which may not be suitable. This paper presents a
general framework for the construction of exact frequentist procedures based on
plausibility functions. It is shown that the plausibility function-based tests
and confidence regions have the desired frequentist properties in finite
samples---no large-sample justification needed. An extension of the proposed
method is also given for problems involving nuisance parameters. Examples
demonstrate that the plausibility function-based method is both exact and
efficient in a wide variety of problems.Comment: 21 pages, 5 figures, 3 table
Naturalness and theoretical constraints on the Higgs boson mass
Arbitrary regularization dependent parameters in Quantum Field Theory are
usually fixed on symmetry or phenomenology grounds. We verify that the
quadratically divergent behavior responsible for the lack of naturalness in the
Standard Model (SM) is intrinsically arbitrary and regularization dependent.
While quadratic divergences are welcome for instance in effective models of low
energy QCD, they pose a problem in the SM treated as an effective theory in the
Higgs sector. Being the very existence of quadratic divergences a matter of
debate, a plausible scenario is to search for a symmetry requirement that could
fix the arbitrary coefficient of the leading quadratic behavior to the Higgs
boson mass to zero. We show that this is possible employing consistency of
scale symmetry breaking by quantum corrections. Besides eliminating a
fine-tuning problem and restoring validity of perturbation theory, this
requirement allows to construct bounds for the Higgs boson mass in terms of
(where is the renormalized Higgs mass and
is the 1-loop Higgs mass correction). Whereas
(perturbative regime) in this scenario allows the Higgs boson mass around the
current accepted value, the inclusion of the quadratic divergence demands
arbitrarily large to reach that experimental value.Comment: 6 pages, 4 figure
Halogen species record Antarctic sea ice extent over glacialâinterglacial periods
Abstract. Sea ice is an integral part of the earth's climate system because it affects planetary albedo, sea-surface salinity, and the atmosphereâocean exchange of reactive gases and aerosols. Bromine and iodine chemistry is active at polar sea ice margins with the occurrence of bromine explosions and the biological production of organoiodine from sea ice algae. Satellite measurements demonstrate that concentrations of bromine oxide (BrO) and iodine oxide (IO) decrease over sea ice toward the Antarctic interior. Here we present speciation measurements of bromine and iodine in the TALDICE (TALos Dome Ice CorE) ice core (159°11' E, 72°49' S; 2315 m a.s.l.) spanning the last 215 ky. The Talos Dome ice core is located 250 km inland and is sensitive to marine air masses intruding onto the Antarctic Plateau. Talos Dome bromide (Brâ) is positively correlated with temperature and negatively correlated with sodium (Na). Based on the Brâ/Na seawater ratio, bromide is depleted in the ice during glacial periods and enriched during interglacial periods. Total iodine, consisting of iodide (Iâ) and iodate (IO3â), peaks during glacials with lower values during interglacial periods. Although IO3â is considered the most stable iodine species in the atmosphere it was only observed in the TALDICE record during glacial maxima. Sea ice dynamics are arguably the primary driver of halogen fluxes over glacialâinterglacial timescales, by altering the distance between the sea ice edge and the Antarctic plateau and by altering the surface area of sea ice available to algal colonization. Based on our results we propose the use of both halogens for examining Antarctic variability of past sea ice extent
Bayesian Exponential Random Graph Models with Nodal Random Effects
We extend the well-known and widely used Exponential Random Graph Model
(ERGM) by including nodal random effects to compensate for heterogeneity in the
nodes of a network. The Bayesian framework for ERGMs proposed by Caimo and
Friel (2011) yields the basis of our modelling algorithm. A central question in
network models is the question of model selection and following the Bayesian
paradigm we focus on estimating Bayes factors. To do so we develop an
approximate but feasible calculation of the Bayes factor which allows one to
pursue model selection. Two data examples and a small simulation study
illustrate our mixed model approach and the corresponding model selection.Comment: 23 pages, 9 figures, 3 table
The Making of a Mobile Caliphate State in the African Sahel
The goal of this chapter is to thoroughly understand the context of the dominant jihadist narratives and the nature of their appeal in the Sahelian region. All these jihadist ideologies are based on a peculiar Salafi Radicalism that aimed to transform the state and society by methods of preaching and violence. Therefore, studying and analyzing the principles of the Salafist discourse as a political project helps us to understand its points of strengths and weaknesses. In addition, we can be better look at the future trends and prospects of violent jihadist groups in the African Sahel. The roots of this Islamic discourse as a political project may be attributed to what Lunay and Suarez call the âIslamic domain.â The rise of violent radical Islamism represents drive from the internal political and socioeconomic dynamics evolving in each Sahelian state. However, the struggle and rivalry of jihadist ideologies after the military defeat of Daesh in Mosul is important at a time when thousands of fighters who have survived the civil wars in Iraq, Syria, and Libya are looking for new jihadist fields
Symmetry preserving regularization with a cutoff
A Lorentz and gauge symmetry preserving regularization method is proposed in
4 dimension based on momentum cutoff. We use the conditions of gauge invariance
or freedom of shift of the loop-momentum to define the evaluation of the terms
carrying Lorentz indices, e.g. proportional to k_{\mu}k_{\nu}. The remaining
scalar integrals are calculated with a four dimensional momentum cutoff. The
finite terms (independent of the cutoff) are unambiguous and agree with the
result of dimensional regularization.Comment: 12 pages, 1 figure, v2 references adde
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