Les passions de l'ame: On obsessive and harmonious passion.

Passion is defined as a strong inclination toward an activity that people like, that they find important, and in which they invest time and energy. Two types of passion are proposed: obsessive and harmonious. Obsessive passion (OP) refers to a controlled internalization of an activity in one's identity that creates an internal pressure to engage in the activity that the person likes. Harmonious passion (HP) refers to an autonomous internalization that leads individuals to choose to engage in the activity that they like. HP promotes healthy adaptation whereas OP thwarts it by causing negative affect and rigid persistence. Results from four studies involving more than 900 participants from different populations supported the proposed conceptualization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A dimensional approach to maternal attachment state of mind: Relations to maternal sensitivity and maternal autonomy support.

The aim of this study was to examine the developmental significance of the newly developed dimensional approach to attachment state of mind by investigating its capacity to predict individual differences in the quality of two caregiving behaviors—maternal sensitivity and maternal autonomy support—that are linked to numerous important child outcomes. Seventy-one upper-middle-class, predominantly French-speaking and Caucasian dyads participated in 3 home visits (34 girls). The Adult Attachment Interview (AAI) was administered when the infants were 8 months old, maternal sensitivity was assessed when they were 12 months old, and maternal autonomy support was assessed at 15 months. The results revealed that, above and beyond SES, maternal sensitivity was negatively related to the dismissing dimension of the AAI, whereas maternal autonomy support was negatively linked to the preoccupied/unresolved dimension. In contrast, the traditional AAI categories were not significantly linked to parenting. These results speak to the relevance of using a continuous approach to attachment state of mind when predicting individual differences in specific caregiving behaviors. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Probing Silica Aerogel Structure with Spin-Polarised Helium-3 Gas

We report on systematic low-field NMR measurements on room temperature ³ He gas imbibed into a 98% porous silica aerogel. Laser polarised helium is used to obtain large NMR signals at 0.1 T even for small amounts of gas. We use a multi-echo technique in a controlled magnetic field gradient to characterize spin diffusion. Measurements are carried out for pressures P ranging from 10 mbar to 1 bar (mean free path of free ³ He ranging from 19 to 0.19 m respectively). In a free gas, the damping rate 1/T ₂ of the amplitude of the echoes is checked to be proportional to the known diffusion coefficient (T ₂ P). Damping rates 2–5 times smaller than those in a free gas are measured within the aerogel. This reduction is quite significant at 1 bar, suggesting that ³ He- ³ He and ³ He-silica collisions occur with comparable frequencies at this density. However, a stong dependence of T ₂ on P is still observed at low pressure, revealing a significant reduction of diffusion due to binary atomic collisions even for the lowest gas density. Measurements over such a large range of gas densities indirectely probe collisional effects over a wide range of sizes up to tens of m. In our sample, results are not consistent with a single geometrical mean free path for ³ He-silica collisions.     

L'organisation cognitive du système d'attachement des adolescents et leurs perceptions de l'encadrement dyadique en tutorat.

Examined the relationships between adolescents' attachment, cognitive organization, and their perceptions of control and support in an academic mentoring relationship. 98 students involved in a volunteer mentoring program were interviewed using the Adult Attachment Interview (AAI). Perceptions of security and control in the mentor-student relationship and perceptions of the program effectiveness were also assessed at the end of the program and 4 mo later. Results show that both adolescents' dismissing and preoccupied strategies in the AAI were negatively associated with their interpersonal perceptions of the mentoring experience. Some of these relationships were moderated by the sex of the dyad (same-sex vs opposite-sex). These findings are discussed in light of theoretical postulates of attachment theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contact Sex Signals in Two Sympatric Spider Species, Tegenaria domestica and Tegenaria pagana

Bioassays in two sympatric spider species, Tegenaria domestica and T. pagana, demonstrate that the total female chemical extract, and in particular the polar fraction, are involved in the sexual behavior of males and reproductive isolation mechanisms. In T. domestica female attractiveness was correlated with changes in 18 chemical compounds. In T. pagana little difference was observed between 12 compounds in extracts of attractive and unattractive females. 12- + 10-Methyloctacosane was not detected in attractive females of either species. Reproductive isolation was linked not only to quantitative changes in 18 chemical compounds detected in both species, but also to nine compounds present in one or the other species.     

<Emphasis Type="Italic">Sphagnum</Emphasis> Species Modulate their Phenolic Profiles and Mycorrhizal Colonization of Surrounding <Emphasis Type="Italic">Andromeda polifolia</Emphasis> along Peatland Microhabitats

Sphagnum mosses mediate long-term carbon accumulation in peatlands. Given their functional role as keystone species, it is important to consider their responses to ecological gradients and environmental changes through the production of phenolics. We compared the extent to which Sphagnum phenolic production was dependent on species, microhabitats and season, and how surrounding dwarf shrubs responded to Sphagnum phenolics. We evaluated the phenolic profiles of aqueous extracts of Sphagnum fallax and Sphagnum magellanicum over a 6-month period in two microhabitats (wet lawns versus dry hummocks) in a French peatland. Phenolic profiles of water-soluble extracts were measured by UHPLC-QTOF-MS. Andromeda polifolia mycorrhizal colonization was quantified by assessing the intensity of global root cortex colonization. Phenolic profiles of both Sphagnum mosses were species-, season- and microhabitat- dependant. Sphagnum-derived acids were the phenolics mostly recovered; relative quantities were 2.5-fold higher in S. fallax than in S. magellanicum. Microtopography and vascular plant cover strongly influenced phenolic profiles, especially for minor metabolites present in low abundance. Higher mycorrhizal colonization of A. polifolia was found in lawns as compared to hummocks. Mycorrhizal abundance, in contrast to environmental parameters, was correlated with production of minor phenolics in S. fallax. Our results highlight the close interaction between mycorrhizae such as those colonizing A. polifolia and the release of Sphagnum phenolic metabolites and suggest that Sphagnum-derived acids and minor phenolics play different roles in this interaction. This work provides new insight into the ecological role of Sphagnum phenolics by proposing a strong association with mycorrhizal colonization of shrubs.     

Copper Extraction Kinetics by Beta-Diketone Derivatives (Acylpyrazolones and Acylisoxazolones) in Water/Chloroform Biphasic System

Abstract

Copper(II) extraction and back-extraction rates were determined in a water/chloroform system using a bell-shaped transport cell. Various 1-phenyl-3-methyl-4-acyl-pyrazol-5-ones (with acyl = benzoyl, 2-thenoyl, octadecanoyl, p-tert-butylbenzoyl, 3-phenyl-propanoyl, and iso-nonanoyl) and 3-phenyl-4-acylisoxazol-5-ones (with acyl = benzoyl and p-tert-butylbenzoyl) were considered. The back-extraction rate is shown to be limited by the diffusion of the complex in the organic unstirred layer, whatever the stirring speed and whatever the ligand considered. At low stirring speed, the extraction rate appears to be limited by the diffusion of either a complex or a ligand species in the unstirred layers, depending on the pH. At high stirring speed, the extraction rate is limited by the interfacial complexation. The extraction rate dependence on side-group variation cannot be correlated with hydrophobicity or acidity of the extractants and may be explained by structural differences of the CO vicinal group of the acyl.     

Comparison of two soft chemistry routes for the synthesis of mesoporous carbon/β-SiC nanocomposites

We compare the influence of using either molecular or colloidal precursors on the synthesis of a ceramic material containing SiC and porous carbon. Remarkably, the temperature of synthesis for crystalline SiC is independent of the route chosen. The excess carbon in the initial mixture is the source of the excess porous carbon that binds to the crystalline domains of SiC in the final products. Interestingly, increasing the initial area of surface contact between carbon and silicon in the ceramic precursor results in different porosities in the ‘meso’ range. Simultaneous control of the size and the relative amounts of Si and C in the precursors allows control to be exerted over the nature and texture of the final powders. A simple and general mechanism is herein proposed to explain the evolution of the surface area as a function of the volume fraction of residual carbon in the synthesised ceramic.     

Filtrage dans le plan tempsfréquence. Caractérisation de signaux UBF et du milieu magnétosphérique

The authors are concerned in studying some signals whose energetic frequency-time representation (given for example by a sonagram) exhibits several distinct patterns. A method is proposed in order to isolate each pattern from the others. The principle of the method is a variable frequency demodulation. The resolving power of this processing and its properties are evaluated with synthetic signals. Then this method is applied to Ulf signals of Pc1type. The Pc1are usually first approximated by a gliding tone with numerous echoes. The proposed method enables one to isolate the echoes and to compare them one to another. A characterization of the magnetospheric medium is made from an interspectral analysis between any two isolated echoes. It is then possible to avoid the averaging effects of classical methods. Thus one may follow the evolution of the propagating medium from one wave train to another.