306 research outputs found
Les livres blancs en matiĂšre de politique Ă©trangĂšre ĂpistĂ©mologie et perspectives analytiques
Avant dâaborder lâĂ©tude des livres blancs en matiĂšre de politique Ă©trangĂšre, deux questions se posent : comment les gouvernements traduisent-ils leurs intentions dâaction internationale et comment engagent-ils le dialogue avec lâensemble diversifiĂ© des acteurs interpellĂ©s par le processus de formulation de ces politiques ? Nous y rĂ©pondons Ă partir de trois dimensions : la nature et la culture des livres blancs, les connaissances que nous avons du phĂ©nomĂšne et lâimportance du rĂŽle dĂ©volu aux acteurs engagĂ©s dans le processus de formulation de ces Ă©noncĂ©s de politique. Nous pouvons en conclure que, si les livres blancs constituent une forme particuliĂšre dâĂ©nonciation de politique souvent utilisĂ©e par les gouvernements pour se dĂ©marquer, la pĂ©rennitĂ© des paramĂštres qui y sont Ă©voquĂ©s est toutefois tributaire du contexte international et de la politique intĂ©rieure. Leur utilitĂ© est donc limitĂ©e dans le temps, quoique importante pour donner les grandes orientations de lâaction gouvernementale internationale.Foreign policy white papers are not well known. This paper aims at filling this gap by answering two basic questions: how do governments translate their international policy intents and how do they engage the dialogue with the diversified groups of actors interested in the foreign policymaking process ? The answer to these questions is found in the analysis of three key white papers related dimensions: white papersâ nature and culture, the knowledge we have of the phenomenon, and the importance of the role these actors play in the policymaking process. We can conclude that, if white papers are indeed a non-usual form of policy statement, their shelf life is directly dependent on exogenous factors such as the international context, and endogenous factors such as domestic politics. This first cut might make us consider that, as foreign policy management tools, white papers bear a usefulness limited in time, but they are important keynotes for international governmental action
Expérimentation d'une nouvelle méthode culturale sur billons (BED) pour produire des pommes de terres de semences destinées à l'exportation
Affiche prĂ©sentĂ©e dans le cadre du Colloque de l'ARC, «Des racines et des ailes pour la recherche collĂ©giale», dans le cadre du 85e CongrĂšs de lâAcfas, UniversitĂ© McGill, MontrĂ©al, les 8 et 9 mai 2017.Pour le marchĂ© de lâexportation, la taille de la semence de pomme de terre est un important critĂšre de qualitĂ© : un tubercule entier mesurant entre 38 et 55 mm est recherchĂ©. Lâobjectif du projet Ă©tait dâĂ©valuer lâimpact de la taille et de la densitĂ© de plantation sur la taille des tubercules produits. Deux variĂ©tĂ©s, Chieftain et Harmony, ont Ă©tĂ© expĂ©rimentĂ©es avec deux distances entre les rangs, trois distances sur le rang et deux grosseurs de plantons. La production en plateforme a Ă©tĂ© comparĂ©e Ă la production traditionnelle en rang unique. Pour la variĂ©tĂ© Harmony, la production de tubercules de 38 Ă 55 mm a Ă©tĂ© significativement supĂ©rieure avec une distance entre les rangs de 40 cm, une distance sur le rang de 20 cm et un planton de 100 g. Le systĂšme en plateforme a gĂ©nĂ©rĂ© un rendement total supĂ©rieur et a produit davantage de tubercules de la taille recherchĂ©e. Pour la variĂ©tĂ© Chieftain, la production de tubercules de 38 Ă 55 mm a Ă©tĂ© considĂ©rablement plus Ă©levĂ©e avec une distance entre les rangs de 40 cm, des distances sur le rang de 20 et 25 cm et un planton de 100 g. Le projet a dĂ©montrĂ© que le systĂšme en plateforme est plus performant pour la production de semences de la taille recherchĂ©e pour lâexportation, que la densitĂ© de plantation, tant entre les rangs que sur le rang, a un impact sur la taille des tubercules produits, et enfin, que les variĂ©tĂ©s rĂ©pondent diffĂ©remment aux traitements de densitĂ© de plantation
BMP-2 functions independently of SHH signaling and triggers cell condensation and apoptosis in regenerating axolotl limbs
<p>Abstract</p> <p>Background</p> <p>Axolotls have the unique ability, among vertebrates, to perfectly regenerate complex body parts, such as limbs, after amputation. In addition, axolotls pattern developing and regenerating autopods from the anterior to posterior axis instead of posterior to anterior like all tetrapods studied to date. Sonic hedgehog is important in establishing this anterior-posterior axis of limbs in all tetrapods including axolotls. Interestingly, its expression is conserved (to the posterior side of limb buds and blastemas) in axolotl limbs as in other tetrapods. It has been suggested that <it>BMP-2 </it>may be the secondary mediator of sonic hedgehog, although there is mounting evidence to the contrary in mice. Since <it>BMP-2 </it>expression is on the anterior portion of developing and regenerating limbs prior to digit patterning, opposite to the expression of sonic hedgehog, we examined whether <it>BMP-2 </it>expression was dependent on sonic hedgehog signaling and whether it affects patterning of the autopod during regeneration.</p> <p>Results</p> <p>The expression of <it>BMP-2 </it>and <it>SOX-9 </it>in developing and regenerating axolotl limbs corresponded to the first digits forming in the anterior portion of the autopods. The inhibition of sonic hedgehog signaling with cyclopamine caused hypomorphic limbs (during development and regeneration) but did not affect the expression of <it>BMP-2 </it>and <it>SOX-9</it>. Overexpression of <it>BMP-2 </it>in regenerating limbs caused a loss of digits. Overexpression of <it>Noggin </it>(<it>BMP </it>inhibitor) in regenerating limbs also resulted in a loss of digits. Histological analysis indicated that the loss due to <it>BMP-2 </it>overexpression was the result of increased cell condensation and apoptosis while the loss caused by <it>Noggin </it>was due to a decrease in cell division.</p> <p>Conclusion</p> <p>The expression of <it>BMP-2 </it>and its target <it>SOX-9 </it>was independent of sonic hedgehog signaling in developing and regenerating limbs. Their expression correlated with chondrogenesis and the appearance of skeletal elements has described in other tetrapods. Overexpression of <it>BMP-2 </it>did not cause the formation of extra digits, which is consistent with the hypothesis that it is not the secondary signal of sonic hedgehog. However, it did cause the formation of hypomorphic limbs as a result of increased cellular condensation and apoptosis. Taken together, these results suggest that <it>BMP-2 </it>does not have a direct role in patterning regenerating limbs but may be important to trigger condensation prior to ossification and to mediate apoptosis.</p
alpha,omega-Bis(trialkoxysilyl) difunctionalized polycyclooctenes from ruthenium-catalyzed chain-transfer ring-opening metathesis polymerization
International audienceThe ring-opening metathesis polymerization/cross-metathesis (ROMP/CM) of cyclooctene (COE) using bis(trialkoxysilyl)alkenes as chain-transfer agents (CTAs) and Ru catalysts to afford difunctionalized polyolefins is reported. The formation of alpha,omega-bis(trialkoxysilyl) telechelic polycycloolefins (DF) with controlled molar mass values takes place quite selectively (>90 wt%), along with minor amounts of cyclic non-functionalized polymers (CNF), as evidenced by NMR, MALDI-ToF MS, SEC analyses and fractionation experiments. The nature of the CTA and catalyst influenced much the efficiency and selectivity of the reaction. (MeO)(3)SiCH2CH=CHCH2Si(OMe)(3) (2) and (MeO)(3)Si(CH2)(3)NHC(O)OCH2CH=CHCH2OC(O)NH (CH2)(3)Si(OMe)(3) (5) proved to be the most efficient CTAs in terms of reactivity, catalyst productivity and selectivity towards DF. Diurethane CTA 5 is easily prepared, and can also be conveniently generated in situ during the ROMP/CM. Grubbs' 2nd-generation catalyst (G2) and Hoveyda-Grubbs's catalyst (HG2) afforded the best compromise in terms of selectivity and productivity, with turnover numbers of up to 95 000 mol(COE) mol(Ru)(-1) and 5000 mol(CTA) mol(Ru)(-1)
α,Ï-Di(glycerol carbonate) telechelic polyesters and polyolefins as precursors to polyhydroxyurethanes: an isocyanate-free approach
International audienceα,Ï-Di(glycerol carbonate) telechelic poly(propylene glycol) (PPG), poly(ethylene glycol) (PEG), poly(ester ether) (PEE), and poly(butadiene) (PBD) have been synthesized through chemical modification of the corresponding α,Ï-dihydroxy telechelic polymers (PPG-OH2, PEG-OH2, PEE-OH2 and PBD-OH2, respectively). Tosylation of the polymer diols with 4-tosylmethyl-1,3-dioxolan-2-one (GC-OTs) afforded, in high yields, the desired PPG, PEG, PEE and PBD end-capped at both termini with a five-membered ring cyclic glycerol carbonate (4-hydroxymethyl-1,3-dioxolan-2-one, GC). The GC-functionalization of the polymers at both chain-ends has been confirmed by NMR (1H, 13C, 1D and 2D) and FTIR spectroscopies. Using PPG-GC2 to demonstrate the concept, the corresponding polyhydroxyurethanes (PHUs/non-isocyanate polyurethanes (NIPUs)) have been subsequently prepared following a non-isocyanate method upon ring-opening catalyst-free polyaddition of the PPG-GC2 with JEFFAMINEs (Mn = 230-2000 g molâ1). The effect of various additives introduced during the polyaddition reaction has been studied at different temperatures. In particular, addition of LiBr (5 mol%) to the reaction medium was found to slightly promote the cyclocarbonate/amine reaction. The polymerization process was supported by FTIR and SEC analyses
Ring-opening metathesis polymerization of cyclooctene derivatives with chain transfer agents derived from glycerol carbonate
International audienceThe synthesis of a variety of mono- and di-(glycerol carbonate) telechelic polyolefins has been achieved upon ruthenium-catalyzed ring-opening metathesis polymerization (ROMP) of cyclooctene (COE) derivatives in the presence of a vinyl or acryloyl derivative of glycerol carbonate (GC) acting as a chain-transfer agent (CTA). Reaction monitoring based on SEC and 1H NMR analyses suggested that the ROMP proceeds through the formation of first the α-GC,Ï-vinyl-poly(cyclooctene) (PCOE) intermediate, which eventually evolves over time into the α,Ï-di(GC)-PCOE. The nature of the solvent was shown to have a significant impact on both the reaction rates and the eventual selectivity for the mono-/di-telechelic PCOE. ROMP of 3-alkyl (methyl, ethyl, n-hexyl)-substituted COEs (3-R-COEs) afforded only the α-GC,Ï-vinyl-poly(3-R-COE)s, as a result of the steric hindrance around the active intermediate, while a 5-ethyl substituted COE (5-Et-COE) enabled access to the corresponding α,Ï-di(GC)-poly(5-Et-COE). The ROMP of 5,6-epoxy-, 5-hydroxy- and 5-oxo-functionalized COEs in the presence of acryloyl-GC as the CTA has also been achieved, affording from the first two monomers polymers with GC end-groups at both extremities, while a 60 : 40 mixture of mono- and di-GC terminated P(5-O[double bond, length as m-dash]COE) was observed in the latter case
Responsiveness and clinical utility of the geriatric self-efficacy index for urinary incontinence
OBJECTIVES: To report on the responsiveness testing and clinical utility of the 12-item Geriatric Self-Efficacy Index for Urinary Incontinence (GSE-UI).
DESIGN: Prospective cohort study.
SETTING: Six urinary incontinence (UI) outpatient clinics in Quebec, Canada.
PARTICIPANTS: Community-dwelling incontinent adults aged 65 and older.
MEASUREMENTS: The abridged 12-item GSE-UI, measuring older adults' level of confidence for preventing urine loss, was administered to all new consecutive incontinent patients 1 week before their initial clinic visit, at baseline, and 3 months posttreatment. At follow-up, a positive rating of improvement in UI was ascertained from patients and their physicians using the Patient's and Clinician's Global Impression of Improvement scales, respectively. Responsiveness of the GSE-UI was calculated using Guyatt's change index. Its clinical utility was determined using receiver operating curves.
RESULTS: Eighty-nine of 228 eligible patients (39.0%) participated (mean age 72.6+5.8, range 65â90). At 3-month follow-up, 22.5% of patients were very much better, and 41.6% were a little or much better. Guyatt's change index was 2.6 for patients who changed by a clinically meaningful amount and 1.5 for patients having experienced any level of improvement. An improvement of 14 points on the 12-item GSE-UI had a sensitivity of 75.1% and a specificity of 78.2% for detecting clinically meaningful changes in UI status. Mean GSE-UI scores varied according to improvement status (P<.001) and correlated with changes in quality-of-life scores (r=0.7, P<.001) and reductions in UI episodes (r=0.4, P=.004).
CONCLUSION: The GSE-UI is responsive and clinically useful
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