Science & Mathematics

À plusieurs reprises au cours de sa vie, le naturaliste nîmois Jean-François Séguier (1703-1784) a tenu des journaux de plantation. Écritures sans qualité, ils accompagnent la gestion matérielle et intellectuelle des centaines de graines que Séguier collecte, reçoit et fait pousser chaque année dans ses jardins. Dans une perspective d'archéologie des jardins, ils permettent d'appréhender la matérialité et l'organisation de ces espaces botaniques domestiques, à l'échelle du jardin tout entier ou de ses parties. Les journaux s'inscrivent aussi dans une chaîne d'écritures qui couturent ensemble les semences et leur nom, les mots et les choses. En cela, ils font du jardin, à l'instar d'autres formes de collections, une projection visible et affective des réseaux invisibles de leur propriétaire.

O presente artigo traz uma análise sobre a trajetória intelectual da escritora cearense Rachel de Queiroz (1910-2003) a partir da memória construída por ela mesma e por terceiros, sobretudo no que se refere ao período entre 1930 e 1964. Pretende, com isso, problematizar a complexidade, as ambiguidades e paradoxos da ação política de uma das mais importantes intelectuais brasileiras do século XX.

Dans le but de comprendre comment le directeur met en oeuvre une politique associative dont il n’a plus la maîtrise, nous organisons la monographie du DITEP en trois temps. Dans une première partie, nous étudions les jeux de pouvoir internes au DITEP. Cette lecture, inspirée de Crozier et Friedberg, nous permet de comprendre que l’adhésion du directeur est à géométrie variable. Elle dépend de ses intérêts et de sa stratégie. Dans une seconde partie, nous nous focalisons sur le rôle de médiation du directeur en tant qu’intermédiaire entre des mondes différents. Pris entre la DG et le terrain, cet acteur produit du consensus entre les diverses parties, nommées « cités » par Boltanski et Thévenot. Enfin, dans une troisième et dernière partie, nous comprenons que certains pouvoirs spécifiques du directeur d’établissement échappent à tout contrôle des DG. L’analyse de Lipsky, croisée avec celle de Friedberg nous apporte les outils nécessaires pour analyser cette particularité du médico-social. Le métier de directeur d’établissement semble donc avoir été transformé, mais à la marge. En tant qu’acteur local incontournable, il reste acteur de son territoire.

In the present study, nanoliposomes composed of rapeseed lecithin were used for the encapsulation of anthocyanin compounds (AC). The nanoliposomes were prepared using hydration and ultrasound combined method, and the effect of AC concentration (4.5, 6.75, 9% w/w) on the characteristics of nanoliposomes including particle size, polydispersity index (PDI), zeta potential, and the encapsulation efficiency (EE) of nanoliposomes with and without AC were studied. The results suggested the fabricated nanoliposomes had a size range of 141–196 nm, negative zeta potential and narrow particle size distribution. Further, the samples containing 9% extract had the maximum EE (43%). The results showed elevation of AC concentration resulted in increased particle size, PDI, EE, and surface charge of nanoparticles. The presence of AC extract led to diminished membrane fluidity through the hydrophobic interactions with the hydrocarbon chain of fatty acids. TEM images suggested that the nanoliposomes were nearly spherical and the AC caused their improved sphericity. Further, in vitro biocompatibility tests for human mesenchymal (MSC) and fibroblast (FBL) cells indicated nanoparticles were not toxic. Specifically, the best formulations with the maximum compatibility and bioavailability for MSC and FBL cells were AC-loaded nanoliposomes with concentrations of 0.5 mL/mg and 10.3 mL/µg and, respectively.

A new and inexpensive system allowing rapid and synchronized changes of solutions around a membrane patch or a cell under voltage-clamp conditions is described. Four plastic capillary tubings (OD 640 gin; ID 430 ~tm) were glued together horizontally and attached to a coil of a commercially available loudspeaker. Servo-control of the position of the coil allowed the mouth of any of the capillaries to be positioned near the pipette tip within 6 ms. A high flow speed of the test solution was crucial to achieve rapid solution exchange. At a flow speed of 5 cm/s, complete exchange of the external environment of a frog ventricular cell was achieved within 20-30 ms. The time course of solution change was found to be 3-5 times faster at the tip of an open patch pipette. To preserve the physical integrity of the cell, the cell was usually perfused by a control capillary at a slow velocity (0.2-0.4 cm/s) and test solutions flowing out of adjacent capillaries at high velocity (4-5 cm/s) were applied to the cell only for short periods. Determination of the three-dimensional contamination profile around the mouth of the control capillary allowed the optimal conditions for the use of the system to be established and possible sources of contamination to be avoided between adjacent capillaries with unmatched flow speeds. Successive and multiple changes in external solutions could be easily synchronized with voltage-clamp depolarizations to examine the time course of the effect of drugs on voltageoperated ion channels. An example of this application is given with rapid applications of the dihydropyridine agonist (-)BayK 8644 to the L-type Ca 2+ channel current in frog ventricular myocytes.

Ce mémoire a pour objectif d’apporter un regard sur la construction d’une politique publique face à un problème extrêmement complexe et bien singulier. Une chose est certaine, la maladie d'Alzheimer n’est pas encore bien comprise aujourd’hui. Cette compréhension limitée est d’ailleurs à l’origine de nombreuses interrogations concernant les modes de prise en charge de la maladie, leur qualité et leur évaluation. Elle pose également de nombreuses questions éthiques, notamment sur le thème de la volonté des malades en situation de désorientation ou encore le débat opposant sécurité et liberté. Elle pose enfin la question de l’adéquation de l’offre de soins et des équipements au regard de certaines innovations en matière d’accompagnement. Les connaissances limitées des mécanismes du cerveau nous cantonnent en outre à une position d’attente d’éventuels progrès techniques ou médicaux. Une position qui semble déstabiliser un système sanitaire et social habitué à soigner et pour qui il est difficile de proposer une solution adaptée à la particularité de cette affection. D’où l’idée du "casse-tête" de la politique Alzheimer qui ne sait effectivement pas sur quel pied danser. Dès lors, il convient de se demander, dans l’intérêt des malades, quelles sont les conséquences de l’inter "dépendance" des politiques vieillesse et Alzheimer sur les réponses institutionnelles déployées et à venir ?

Two experiments studied the relative effects on body mass and testicular growth of stimulatory photoperiods applied simultaneously to two photosensitive species, the house sparrow (Passer domesticus) and brahminy myna (Sturnus pagodarum). Experiment 1 on the house sparrow consisted of two parts. In experiment 1A, beginning on 24 March 2002, short day pretreated sparrows were exposed for 12 weeks to 13L: 11D (13 h light: 11 h darkness), 20L: 4D and NDL (control). Experiment 1B was similar to 1A except that it used sparrows that were not treated with short days. This experiment was repeated at three different times in the year. Beginning on 29 December 2002 (for 24 weeks), 26 March 2003 (for 12 weeks) and 16 August 2003 (for 8 weeks), sparrows captured from the wild and acclimated to captive condition for 1 week were exposed to 13L: 11D and 20L: 4D. Each time, a group was maintained in NDL and served as the control. Experiment 2 was performed on myna and used an identical protocol. Beginning on 24 March 2002, myna that were captured from the wild and acclimated to captivity conditions were exposed for 16 weeks to 13L: 11D and 20L: 4D; a group was maintained in NDL and served as the control. There was photostimulation and subsequent regression of the testes on all day lengths except in the August group of experiment 1B. The effect on body mass was variable. Interestingly, however, the response to 20L:4D was relatively smaller as compared to 13L:11D. Taken together, these results confirm that the two species use photoperiods in control of their reproductive cycle, and tend to indicate that exposure to unnatural long photoperiods may in fact be unfavorable and could compromise gonadal growth and development.

Using original survey data from France we study the importance of technical efficiency as a potential determinant of farm conversion to organic farming in the dairy sector. We run a two-stage analysis. In the first stage we calculate technical efficiency of farms when they were conventional (including organic farms before they convert) as well as technical efficiency change indices, using Data Envelopment Analysis and correcting for sample bias with Simar and Wilson’s bootstrapping procedure. In the second stage, we estimate a Probit model to explain the decision of farmers to convert to organic farming. The model is estimated on a sample of 209 farmers. We find that farmers who switched to organic farming were more technically efficient (before conversion) than farmers who remained conventional, but they had experienced a slowdown in technical efficiency (also before conversion).

The authors investigated the association between vision impairment and physical activity among older adults from low- and middle-income countries. Visual acuity was measured using the tumbling ElogMAR chart, and vision impairment was defined as visual acuity worse than 6/18 (0.48 logMAR) in the better seeing eye. Physical activity was assessed by the Global Physical Activity Questionnaire. Multivariable logistic regression and meta-analysis were conducted to assess associations. The sample included 34,129 individuals aged 50–114 years (mean [SD] age 62.4 [16.0] years; 47.9% male). After adjustment for confounders, near vision impairment was not significantly associated with low physical activity, but far vision impairment showed a significant association (odds ratio = 1.32; 95% confidence interval [1.17, 1.49], I2 = 0.0%). Far vision impairment was dose-dependently associated with low physical activity (e.g., severe [<6/10] vs. no [≥6/12] far vision impairment; odds ratio = 1.80; 95% confidence interval [1.03, 3.15]). Interventions to address low levels of physical activity in the visually impaired in low- and middle-income countries should target those with far vision impairment.

Les Bisu, regroupés avec les Mpi, les Phou Noy, les Pyen et les Côông dans la famille Bisoïde, appartiennent à la division Lolo de la famille des langues tibéto-birmanes. Ils représentent, au nord de la Thaïlande, une population d'environ 500 individus répartis en 4 villages, dans un rayon de 80 km au sud de Chiang Raï. Fortement intégrés, les Bisu, que les Thaï considèrent comme des Lua (Lawa), ont abandonné la quasi-totalité de leurs traditions, adoptant le mode de vie des Yuan, les Thaï du nord. Le seul indice de leur identité à avoir, jusque-là, survécu est leur langue, déjà bien métissée d'emprunts au Thaï et dont l'extinction est prévisible à court terme. "Une monographie du Bisu" présente, en 2 tomes, la description du peuple Bisu et de sa langue. Le tome 1 comprend quatre parties distinctes : - une présentation ethnographique du peuple Bisu - une étude phonologique de la langue - l'analyse de la grammaire - Six textes retranscrivant les traditions Bisu. Le tome 2 est un dictionnaire de 1600 mots.

17 Pseudostratified epithelia (PSE) are a common type of columnar epithelia found in a wealth of 18 embryonic and adult tissues such as ectodermal placodes, the trachea, the ureter, the gut and 19 the neuroepithelium. PSE are characterized by the choreographed displacement of cells' 20 nuclei along the apicobasal axis according to phases of their cell cycle. Such movements, 21 called interkinetic movements (INM) have been proposed to influence tissue expansion and 22 shape and suggested as culprit in several congenital diseases such as CAKUT and esophageal 23 atresia. INM rely on cytoskeleton dynamics just as adhesion, contractility and mitosis do. 24 Therefore, longer term impairment of INM without affecting proliferation and adhesion is 25 currently technically unachievable. Here we bypassed this hurdle by generating a 2D agent-26 based model of a proliferating PSE and compared its output to the growth of the chick 27 neuroepithelium to assess the interplay between INM and these other important cell 28 processes during growth of a PSE. We found that INM directly generates apical expansion and

We present a methodology and a tool for analyzing the activity of an operator interacting with a complex technical device. The goal is of refining cognitive models of the operator by relating them to patterns of behavior in real situations. The activity is observed to be modeled as a trace having a graph structure. The trace is transformed according to a "use model" in order to become meaningful in the context of modeling theories. Our "Trace Based System" thus gathers both a representation of the activity and of the analyst's expertise for facilitating the discovery of knowledge in the field of cognitive psychology. The approach is illustrated by its application for car driver cognitive modeling.

This article aims to investigate musico-literary intermediality in William H. Gass's works by examining both "A Fugue", a passage from The Tunnel (1995) and his novella The Pedersen Kid (1961). The paper focuses on Gass's conception and use of language, musicality and musicalization. One of the questions raised is to what extent texts that do not necessarily present a direct link to music can be given a musical reading. By analyzing Gass's novella the article demonstrates that the intermedial context conveys semiotic meanings that may allow a better understanding of the contents relating to initiation and rites of passage that the story draws upon, thus providing a new reading of Gass's text. On a more general level, the article reflects upon the textual effects produced by musico-literary intermediality and their impact on time structures in fiction.

L'essor des access panels en ligne a bouleversé en profondeur le paysage des études de marché. Souvent présentés par leurs propriétaires comme des outils très performants, ils suscitent toutefois d'importantes interrogations scientifiques, particulièrement en ce qui concerne la représentativité des échantillons qui en sont issus et, partant, la validité des informations obtenues. Dans cet article, sont analysées toutes les sources de biais susceptibles d'affecter la représentativité des échantillons extraits d'access panels en ligne, ainsi que les moyens de les prévenir ou d'y remédier. Le but est notamment de permettre aux utilisateurs de tels dispositifs de disposer d'éléments les aidant à en apprécier la qualité.