Cet article propose une analyse critique de la grille multicritères proposée par Stosic & Fagard (2019) et destinée à guider la catégorisation des prépositions complexes du français en permettant de ...positionner les séquences candidates à cette sous-classe suivant un continuum entre les PrepComp les plus typiques (à l’instar de, à l’égard de, en ce qui concerne, …) et les agencements libres. L’objectif, après avoir discuté et amendé certains des critères syntaxiques, sémantiques, fréquentiels et statistiques présentés par les auteurs, est de formuler une grille alternative dont on montre que le pouvoir discriminant est plus élevé.
The core of our proposal is the determination of a “matrix of economic–financial knowledge”, which states fuzzy relations between symptoms and causes. In this case, the symptoms of a firm can be ...represented by the diverse ratios, which are in the end the indicators the analysts look at to make their predictions and suggestions. On the other hand, the diseases of the firm will be the causes to be determined, which generate anomalies at the firm. The ability to create such a matrix of economic–financial knowledge implies that given the level of intensity of the chosen symptoms we can determine the extent to which the main problems or diseases affecting a firm's cost-effectiveness and efficiency are present at the firm, in order to act upon them. With the utilization of the same one, can be complemented the activity of the analyst of the business.
In this interview, originally published in the Czech journal Contradictions, John Bellamy Foster discusses the history of environmental thought among socialists from Marx to the present day, with a ...view to the need to mobilize in order to protect humanity's only home.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Arterial hypertension in adults is often associated with an increased arterial stiffness, which correlates with the ambulatory arterial stiffness index (AASI) as derived from ambulatory blood ...pressure (BP) measurements. The purpose of this study was to demonstrate whether children with diagnosed hypertension have an increased AASI as in hypertensive adults. AASI was calculated from 185 ambulatory BP measurements of 114 hypertensive and 71 normotensive, healthy children. Hypertensive children had higher AASI values compared with their normotensive healthy counterparts (0.370 +/- 0.120 versus 0.204 +/- 0.199, p < 0.0001). Children with longer duration of hypertension or a history of primary or secondary aortic coarctation displayed even more elevated AASI values. A receiver operator curve derived cut-off of AASI set at 0.301 distinguished (p < 0.0001) hypertensive from normotensive children with an odds ratio of 8.2, a sensitivity of 81%, and a specificity of 65%. Moreover, AASI correlated with pulse and systolic BP. In conclusion, AASI is elevated in hypertensive children and correlates with the duration and the origin of hypertension in childhood.
Isosorbide isomerisation is a known reaction that can proceed over Ru and Ni-based heterogeneous catalysts. As a rule, an exogenous H 2 pressure (40–100 bar) is required, even though H 2 does not ...participate stoichiometrically in the reaction. By marrying experiments with DFT computations, we ascribe the role of H 2 in isosorbide isomerisation to a coverage effect on the catalyst surface. We demonstrate the possibility of conducting the reaction at a low H 2 pressure either in the presence of an inert gas to increase H 2 solubility in an underlying solvent or using 2-propanol as a hydrogen donor. This might benefit the economy and safety of a potential industrial process.
Abstract
Ophiolites and high-pressure/low-temperature (HP–LT) terranes are important sites for the study of geochemical cycling in ancient oceanic lithosphere. We have analysed Li abundances and ...isotope composition in a series of ultrabasic and basic rocks from the Variscan Limousin ophiolite, as well as in basic and pelitic rocks from the Ile de Groix HP–LT terrane. Both bulk and in situ analyses are employed to evaluate Li mobility and isotope fractionation in the oceanic lithosphere during fluid–rock interactions related to seafloor and sub-seafloor hydrothermal alteration, subduction and exhumation processes. In the Limousin ophiolite, early stages of high-temperature (high-T) hydrothermal alteration of oceanic ultrabasic rocks produced serpentine with low Li abundances (0·9–4·6 ppm) and low δ7Li (–8·9‰). The δ7Li increase from –2·2 to +4·2‰ in the following generations of serpentine during late-stage hydrothermal alteration results from changes in the fluid composition and temperature conditions. Therefore, even if dehydrating subducted serpentinites generate high amounts of fluids during subduction, abyssal serpentinites do not constitute an important source of Li for Li-rich metabasic rocks. In the associated amphibolites, hornblende displays typical Li contents (3·1–8·2 ppm) and isotopic compositions (+3·5 to +12·5‰) similar to hydrothermally altered sheeted dykes and gabbros. In contrast, the low Li abundances and extremely high δ7Li values recorded by omphacite and pargasitic amphibole in the ultrahigh-pressure (UHP) zoisite-eclogite from the Limousin probably reflect interaction with a heavy-Li sediment-derived fluid. The HP–LT metabasites of the Ile de Groix record different Li behaviour, with high Li abundances and low δ7Li. They contain Li abundances significantly higher than fresh mid-ocean ridge basalts (MORB) (16–124 ppm), indicating a metasomatic overprint by fluids derived from the neighbouring Li-rich mica-schist (15–52 ppm) in addition to seawater during the early stages of subduction. Lithium is mainly hosted by (1) glaucophane and omphacite in blueschists and eclogites, (2) chlorite and albite in retrograde greenschists, and (3) phengite and chlorite in mica-schists. The metabasites have δ7Li values of –4·8 to +3·2‰ that are generally lower than those of fresh and altered MORB. The intercalated mica-schists display δ7Li values ranging from –1·7 to +0·2‰ that are typical of subducted sediments. The δ7Li decrease from blueschists to eclogites from +1·8 to –4·8‰, as well as the rimward δ7Li decrease in glaucophane from MORB-like δ7Li values to negative values in blueschists (core: –2·4 to +8·8‰; rims: –7·1 to +2·2‰), reveals that significant fluid-induced Li isotope fractionation occurred at the transition from the lawsonite-blueschist facies to the epidote-blueschist facies, and may be triggered by prograde lawsonite breakdown. In eclogites, the low δ7Li measured in whole-rocks (–4·8 to –2·5‰), omphacite (–22·4 to +3·3‰) and glaucophane (–6·9 to +1·4‰) indicates that Li isotope kinetic fractionation had stronger effects under eclogite-facies conditions. The δ7Li increase toward positive values in the most retrogressed greenschist samples suggests Li mineral–fluid isotopic exchange during rehydration reactions and interaction with a Li-heavy fluid that is probably derived from the dehydrating metabasites. Thus, lithium isotope fractionation in the HP–LT rocks of the Ile de Groix highlights migration of heavy-Li fluids along the oceanic crust–mantle interface in the subduction zone.
The Front Cover shows how combining theoretical and experimental investigations allows predicting the feasibility and the selectivity of Diels–Alder reactions involving furfural as a bio‐based diene, ...opening a straightforward route to renewable aromatics. More information can be found in the Full Paper by I. van Scodeller et al.
The direct amination of biomass-derived isohexides with NH3 over a Ru/C catalyst was systematically investigated to understand the role of H2 and NH3 in the production of isohexide diamines vs ...aminoalcohols, i.e., the transformation of one or both OH-groups in isohexides into NH2 groups. Only aminoalcohols with an exo-OH group were generated starting from isosorbide, which contains both an exo-OH and an endo-OH group, while a moderate yield of diamines was obtained from isomannide with two endo-OH groups due to the higher reactivity of the latter. The main byproducts were identified, including a variety of N- and O-containing cyclic compounds, such as 2,5-dimethylpyrrolidine, that arise from a decomposition path driven by hydrolysis/hydrodeoxygenation of a tricyclic amine intermediate. By combining density functional theory calculations with microkinetics, NH3 was found to adsorb strongly on the catalyst surface and generate adsorbed NH2 and NH species with variable coverage depending on the temperature and the nominal H2/NH3 ratio. Isomerization of isohexides was greatly suppressed by adsorbed NH3. Meanwhile, adsorbed NH3 discouraged the formation of byproducts driven by competing side reactions promoted by H2. The H2/NH3 ratio, which conditions the distribution of NH2 and NH species on the Ru surface, influences drastically the catalytic performance.
Gonadal differentiation is the first step of mammalian sex determination. The expression of the Y chromosomal testis determining factor Sry leads to up-regulation of the transcription factor Sox9 ...which promotes testis differentiation. Previous studies showed that Sox9 deficiency induces expression of ovarian markers in XY mutant fetal gonads before they die. To better understand the genome-wide transcriptional profile underlying this process we compared samples from XY Sf1:CreTg/+; Sox9flox/flox mutant gonads in which Sox9 is ablated in Sertoli-precursor cells during early stages of gonad development to XX Sox9flox/flox ovaries and XY Sox9flox/flox testes at E13.5. We found a complex mRNA signature that indicates wide-spread transcriptional de-regulation and revealed for XY mutants at E13.5 an intermediate transcript profile between male and female gonads. However, XY Sf1:CreTg/+; Sox9flox/flox mutant gonads develop as ovaries containing XY developing follicles at P0 but less frequently so than in XX control ovaries. Furthermore, we studied the extent to which developing XY mutant ovaries are able to mediate adult fertility and observed that XY oocytes from XY mutant ovaries are competent for fertilization; however, two thirds of them fail to develop beyond two-cell stage embryos. Taken together, we found that XY Sf1:CreTg/+; Sox9flox/flox females are capable of producing viable offspring albeit at a reduced level.
► Sox9 is a key gene required for male development. ► A viable mouse model of Sox9 loss-of-function exhibits male-to-female sex reversal. ► XY follicles develop but their number is reduced. ► XY oocytes fail to pass two-cell stage with mitotic cells which do not separate. ► Although Sox9 is expressed in ovaries, Sox9 is dispensable for fertility in females.
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