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Copyright of Canadian Journal of Program Evaluation is the property of University of Toronto Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Over time, herbal plants and their various components have been major sources of therapeutic medicine for man. A comparative study was carried out to determine the phytochemical components and antibacterial activities of the different crude extracts of Euphorbia heterophylla and Vitellaria paradoxa roots on four enteric bacteria; Salmonella typhi, Shigella flexneri, Escherichia coli and Proteus vulgaris. Methodology: Root samples of E. heterophylla and V. paradoxa were collected, washed, air dried and processed to fine powder in the microbiology laboratory of Federal University of Technology, Minna, Nigeria. Crude extract of the root samples was done by the cold maceration technique using four solvents (chloroform, methanol, petroleum ether and water). Phytochemical analysis of the extracts was done using previously described technique, and in vitro antibacterial activities of different concentrations of the extracts (50-200 mg/ml) and a standard antibiotic (ciprofloxacin) were tested on four enteric bacteria (S. typhi, S. flexneri, E. coli, P. vulgaris) by the agar diffusion test. In vivo antibacterial activities of the two plants were also tested by daily oral administration of 2000 mg/kg bodyweight (for 7 days) of each extract on inbred mice infected through intraperitoneal inoculation of an infective dose of each of the four enteric bacteria. Data were computed as mean ± standard error and analysed by the Statistical Analysis System (SAS) version 9.4. Associations between variables were determined using analysis of variance (ANOVA), with p < 0.05 considered as significant value. Results: Phytochemical analysis of the crude extracts of both plants revealed the presence of cardiac glycosides, saponins, alkaloids, flavonoids, and tannins but V. paradoxa contain more carbohydrates and starch, and less phlobatannins, compared to E. heterophylla. In vitro assay showed dose-dependent antibacterial activity of the methanol, aqueous and chloroform (but not petroleum ether) extracts of the two plant roots. The in vitro antibacterial activities of the different extracts of V. paradoxica extracts were significantly higher (higher mean diameters of inhibition zones) than those of E. heterophylla (p<0.05), and methanol extracts gave the highest antibacterial effects. However, the root extract of E. heterophylla gave a higher antibacterial activity with the in vivo assay on inbred mice than V. paradoxa, and methanol extracts of the two plant extracts gave the highest in vivo activity, followed by aqueous extract and least activity was obtained with the chloroform extract. Conclusion: Crude extracts of E. heterophylla and V. paradoxa roots produce antibacterial activity against enteric Gram-negative bacteria pathogens involved in diarrhoea illnesses. Further researches should be directed towards isolation and characterization of the active compounds in the crude extracts. [ABSTRACT FROM AUTHOR]

Les réseaux socionumériques ouvrent des espaces de discussion permettant à des individus et à des groupes sociaux d’exprimer leur position sur des points historiques peu abordés par les médias de presse et donc peu visibles dans le débat public. Ils rendent possible la médiatisation et le débat autour de problèmes sociaux qui n’émergent pas de manière forte dans les médias traditionnels. On peut donc légitimement se demander dans quelle mesure ces réseaux sont susceptibles de jouer un rôle dans la médiatisation de l’histoire coloniale et des responsabilités des États dans le système esclavagiste et colonial et dans la circulation des représentations à propos de l’histoire coloniale. Nous aborderons cette question à travers l’analyse d’extraits de la série Racines publiés sur YouTube et des commentaires générés par leur publication. Notre étude met en évidence des choix éditoriaux centrés sur une rhétorique de la domination et la problématique identitaire, qui favorise l’expression des affects et la contestation, et génère des discours polyphoniques sur la situation postcoloniale.

Copyright of Comprendre: Revista Catalana de Filosofía is the property of Herder Editorial S.L. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revue d'Histoire des Mathématiques is the property of Societe Mathematique de France and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Arts Management is the property of International Journal of Arts Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Longleaf pine ( Pinus palustris Mill.) restoration in the southeastern United States offers opportunities for carbon (C) sequestration. Ecosystem C stocks are not well understood in longleaf pine forests, which are typically of low density and maintained by prescribed fire. The objectives of this research were to develop allometric equations for above- and below-ground biomass and quantify ecosystem C stocks in five longleaf pine forests ranging in age from 5 to 87 years and in basal area from 0.4 to 22.6 m2·ha−1. Live aboveground C (woody plant + ground cover) and live root C (longleaf pine below stump + plot level coarse roots + plot level fine roots) ranged from 1.4 and 2.9 Mg C·ha−1, respectively, in the 5-year-old stand to 78.4 and 19.2 Mg C·ha−1, respectively, in the 87-year-old stand. Total ecosystem C (live plant + dead organic matter + mineral soil) values were 71.6, 110.1, 124.6, 141.4, and 185.4 Mg C·ha−1 in the 5-, 12-, 21-, 64-, and 87-year-old stands, respectively, and dominated by tree C and soil C. In the 5-year-old stand, ground cover C and residual taproot C were significant C stocks. This unique, in-depth assessment of above- and below-ground C across a series of longleaf pine stands will improve estimates of C in longleaf pine ecosystems and contribute to development of general biomass models that account for variation in climate, site, and management history in an important but understudied ecosystem. [ABSTRACT FROM AUTHOR]

The article presents the results of a study on the effect of level of fertilization on the competition between Lotus tenuis and Cynodon dactylon both in above and underground soil. The results show that greater fertilizer use efficiency was shown by Cynodon dactylon than Lotus tenuis. The ability of Cynodon dactylon to interact with soil and compete for nutrients and water is more efficient than Lotus tenuis because of its low root hydraulic resistance and high specific root length.

Abstract In this article, I argue that the commemoration of slavery should be seen as a process of emplacement. It refers to a specific politics of belonging in the Netherlands that is focused on autochthony and that carries strong notions of place. I discuss two strategies of emplacement that both engage in these politics of belonging. One is the search for roots in Africa, through which black Dutch negotiate their place in Netherlands as citizens. The other engages in the transformation of the Dutch memoryscape through formal commemorations and monuments. I understand both strategies as processes generating local subjects in Appadurai's sense, emphasizing that locality as a relationship of body and place is a fundamental ingredient in processes of political subjectification. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Forest Science (EDP Sciences) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Xylem conduits increase in size from the apex downwards. While conduit tapering in the stem has often been reported to converge towards a common pattern among all plants, information on conduit tapering in small plants and roots is extremely scarce. We selected 10 small trees (height < 3 m) of Pinus cembra L. and Larix decidua Miller along an altitudinal gradient and measured diameter and conduit dimensions along stems and roots in the last annual ring. Sections of 10 µm were cut from wooden disks taken at different heights in the stem and in the roots and then stained with safranine. Slides were observed under a microscope, the lumen areas of conduits were measured and mean hydraulic diameters (Dh) calculated. Dh increased from stem tip (Dh at 1 cm from the apex averaged 10.75 µm; s = 2.33) to base (Dh from 20.70 to 30.54 µm), following a power trajectory (i.e., Dh = a·Lb, with L being the distance from the tip). Such degrees of conduit tapering may have a considerable effect in minimizing the hydraulic constraints. Despite trees at the treeline being older and smaller than in the subalpine forest (age: 28–70 years at the treeline; 18–39 years in the subalpine forest), conduit tapering did not differ significantly between sites, suggesting that tree height is the main factor controlling the basipetal increase in conduit lumens. In the roots, the increase in conduit dimensions continued towards their tips, even more steeply than in the stem. The widest conduits were measured around the root tips (around 40 µm). Conduit tapering resulted as a stable structural feature in small plants as well as in tall trees. [ABSTRACT FROM AUTHOR]

Copyright of Cahiers d'Études Africaines is the property of Editions EHESS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Annals of Forest Science (EDP Sciences) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Eleven day-old grass pea plants (Lathyrus sativus L.) were grown hydroponically for 96 h in the presence of 0.5 mM lead nitrate (Pb(NO3)2). The survival rate was 100%. The mean lead content (measured by ICP-OES) in root tissues was 153 mg Pb g−1 dry matter. Over three quarters of the lead was not labile. Compared with control plants, lead-exposed plants showed a six-fold, two-fold and three and a half-fold reduction in their root calcium, zinc and copper contents, respectively. Together, these results suggested that Lathyrus sativus L. was tolerant to a deficiency in essential nutrients and able to store large amounts of lead in its root tissues. Therefore, it could be used for the development of new rhizofiltration systems. To cite this article: J. Brunet et al., C. R. Biologies 331 (2008). [Copyright &y& Elsevier]

Genera in the tribe Pyroleae (subfamily Monotropoideae, family Ericaceae) occur as understory plants in northern temperate zones where some form major components of ecosystems. Most have been poorly studied in terms of their association with symbiotic fungi. In this study, colonization patterns of mycorrhizal roots of five members of the Pyroleae (Pyrola asarifolia Michx., Pyrola chlorantha Sw., Orthilia secunda (L.) House, Chimaphila umbellata (L.) W. Bart., Moneses uniflora (L.) Gray) were explored. Root samples were processed for light, fluorescence, and laser scanning confocal, scanning electron, and transmission electron microscopy, as well as for immunocytochemistry. Roots of all species had enlarged epidermal cells containing hyphal complexes, Hartig nets confined to the epidermis, and mantles. Epidermal cells were penetrated by hyphae originating from the Hartig net at more than one site either along the inner tangential wall or radial walls. The outer tangential wall of epidermal cells of all species, except M. uniflora, was thicker than radial and inner tangential walls and consisted of two layers, the outer containing nonesterified pectins that were labeled with JIM 5 antibodies. Radial walls and inner tangential walls did not label, but cortical cell walls did. Intracellular hyphal complexes developed initially around centrally positioned, enlarged epidermal cell nuclei and, through branching, occupied most of the cell volume. Senescence and degradation of the complexes followed. The fungal species in these symbiotic associations may be important functionally in nutrient exchange, as well as in contributing to broader linkages with other hosts in these plant communities. [ABSTRACT FROM AUTHOR]

Abstract: In the present investigation, methanolic extracts from shoots and roots of Tunisian Nigella sativa were assayed for their antioxidant and antimutagenic activities. The phenolic composition of the methanolic extracts was determined by RP–HPLC. The predominant phenolic compound was vanillic acid with a mean concentration of 143.21 and 89.94 mg per 100 g dry weight of shoots and roots, respectively. Shoots and roots showed comparable and strong superoxide scavenger activity; however, shoots exhibited higher DPPH radical scavenging, reducing and chelating activities than roots. Mutagenic and antimutagenic activities were determined by using the Ames test. Shoots and roots demonstrated important antimutagenic effects. Roots exhibited stronger activity than shoots with an inhibition percentage of 71.32%. To cite this article: S. Bourgou et al., C. R. Biologies 331 (2008). [Copyright &y& Elsevier]

The article traces the historical development of the 'Raizal' ethnic community on the island of San Andrés in the Colombian Caribbean. It explains how this Anglophone, Protestant community has survived the attempts, by first Spain and then Colombia, to incorporate them into the Hispanic and Catholic world. It investigates the bases for Raizal culture and identity, explaining the strategies adopted at different times, and evaluating their success, or failure. It focuses particularly on the opportunities afforded by the Colombian Constitution of 1991 to the Raizal community, but how these have not been developed to the extent, or speed, that was hoped. It concludes by placing the Raizal struggle in the wider context of developments in the Southwest Caribbean, arguing for a regional rather than national approach to the general crisis faced by the ethnic communities of the region, and to the opportunities that are opening up. [ABSTRACT FROM AUTHOR]

Location of the critical shear plane (CSP) plays a major role in determining landslide-initiation thresholds. Depth to the CSP increases as the soil shear strength increases. Tree roots provide a significant strength contribution to soil shear strength. Our objective is to understand how vegetation can be used to increase landslide-initiation thresholds by changing the location of the CSP. This will enable us to select and compare combinations of plant species and densities to suit any given situation to increase landslide-initiation thresholds and improve slope stability. The CSP location is estimated incorporating available root cross-sectional area – root depth data in the stability analysis in terms of energy. The energy approach has been developed to take into account the contribution of the roots to soil strength. Generalization of the original energy approach is required to enable its use outside our study areas. Once depth to the CSP is found, the time for the wetting front to reach it is found using a soil-water infiltration model. The composite model described may be used as a simple tool to choose the most appropriate plant density to maximize the stability of a given hillslope. A worked example of the model demonstrates how the approximate thresholds for different hillslopes with known plant densities under different climatic conditions are estimated.Key words: slope stability, safety factor, roots, energy, threshold.La localisation du plan de cisaillement critique (PCC) joue un rôle majeur pour la détermination du seuil d'initiation d'un glissement. La profondeur du PCC augmente avec l'augmentation de la résistance au cisaillement du sol. Les racines des arbres fournissent une contribution significative à la résistance au cisaillement du sol. Notre objectif est de comprendre comment la végétation peut être utilisée pour accroître le seuil d'initiation d'un glissement en changeant la localisation du PCC. Ceci nous permettra de sélectionner et comparer des combinaisons d'espèces et de densités de plantes convenant à n'importe quelle situation donnée de façon à augmenter le seuil d'initiation de glissement et à améliorer la stabilité de la pente. La localisation du PCC est estimée en incorporant les données disponibles de sections en travers de surface-profondeur de racines dans l'analyse de stabilité en termes d'énergie. L'approche de l'énergie a été développée pour tenir compte de la contribution des racines à la résistance du sol. La généralisation de l'approche originale de l'énergie est requise pour permettre son utilisation en dehors de notre champ d'étude. Une fois la profondeur du PCC trouvée, le temps requis pour que le front de saturation atteigne le PCC est déterminé au moyen d'un modèle d'infiltration sol-eau. Le modèle composite décrit peut être utilisé comme un outil simple pour choisir la densité de plante appropriée pour maximiser la stabilité d'une pente de talus donnée. Un exemple solutionné du modèle démontre comment on estime le seuil approximatif pour différentes pentes de talus avec des densités de plantes connues dans des conditions climatiques différentes.Mots clés : stabilité des pentes, coefficient de sécurité, racines, énergie, seuil.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Tracheary elements of the xylem are responsible for the longitudinal (axial) transport of water and ions that have moved radially across the root. These vessel members and (or) tracheids mature some distance behind the root tip, and it is generally believed that this distance is directly related to root growth rate. To test this idea, the distances behind the root tip at which tracheary elements of pouch-grown Pinus banksiana Lamb. and Eucalyptus grandis W. Hill ex Maiden mature were examined. From each species, three root tip types (white, brown, and ectomycorrhizal short lateral) were assessed. Unlike previous studies of this topic, two methods of testing tracheary element maturity were employed concurrently. The first was anatomical and involved visualizing the deposition of lignin in the walls of the tracheids or vessel members. The second was functional and consisted of determining the capability of the tracheary elements to conduct a fluorescent, tracer dye. The distance behind the root tip at which the conductive xylem cells mature varied from 0.16 to 1.6 mm and was highly dependent on species and root type. No significant correlation was found between growth rate and proximity of tracheary element maturation to the tip for white roots. The presence of lignin in the tracheary element wall was not a reliable indicator of the cell's functional maturity.Key words: conductivity, development, roots, tracheary elements, xylem.Les éléments de trachée du xylème sont responsables du transport longitudinal (axial) de l'eau et des ions qui se sont déplacés radialement à travers la racine. Ces éléments de vaisseau et (ou) trachéïdes complètent leur développement à une certaine distance derrière l'apex racinaire, et on croit généralement que cette distance est directement reliée au taux de croissance racinaire. Pour vérifier cette idée, les auteurs ont examiné, chez le Pinus banksiana Lamb. et l'Eucalyptus grandis W. Hill ex Maiden, les distances derrière les apex à lesquelles les éléments de trachée mûrissent. Pour chaque espèce, ils ont examiné trois types de racine (blanche, brune et racines courtes latérales ectomycorhiziennes). Contrairement aux études antécédentes sur ce sujet, les auteurs ont utilisé simultanément deux méthodes pour vérifier la maturité des éléments de trachée. La première méthode est anatomique et implique la visualisation de la déposition de la lignine dans les parois des trachéïdes ou des éléments de vaisseau, alors que la seconde est fonctionnelle et consiste à déterminer la capacité des éléments de trachée à conduire un traceur fluorescent. La distance derrière l'apex racinaire à laquelle les cellules conductrices du xylème mûrissent varie de 0,16 à 1,6 mm et dépend fortement de l'espèce et du type de racine. Chez les racines blanches, on observe aucune corrélation entre le taux de croissance, et la proximité de l'apex racinaire de la maturation des éléments de trachée. La présence de lignine dans les éléments de trachée ne constitue pas un indicateur fiable de la maturité fonctionnelle des cellules.Mots clés : conductivité, développement, racines, éléments de trachée, xylème.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Anatomia Clinica is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

L'imagerie par résonance magnétique (I.R.M.) du système nerveux périphérique a considérablement progressé ces dernières années. De nouvelles séquences I.R.M. sont en effet disponibles permettant : – de mieux visualiser les trajets nerveux ; – de détecter de manière beaucoup plus sensible des anomalies de signal ou les prises de contraste pathologiques. Le terme de neurographie par I.R.M. est ainsi utilisé pour désigner l'ensemble des séquences I.R.M. utilisés pour l'exploration des nerfs périphériques. Parmi ces séquences, la séquence de diffusion a un rôle particulier dans la mesure où elle permet de visualiser de manière sélective les structures nerveuses mais également de définir des paramètres quantitatifs d'évaluation (comme le coefficient apparent de diffusion ou encore la fraction d'anisotropie). Les progrès en termes de résolution spatiale permettent d'analyser en routine l'organisation fasciculaire des nerfs fémoraux et sciatiques. Lors de cette présentation, nous reviendrons sur l'analyse des images puis nous illustrerons l'apport de ces nouvelles techniques I.R.M. au travers de cas cliniques. [ABSTRACT FROM AUTHOR]