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10. Urban Ecology as an Interdisciplinary Field: Differences in the use of "Urban" Between the Social and Natural Sciences.

Author

Marzluff, John M., Shulenberger, Eric, Endlicher, Wilfried, Alberti, Marina, Bradley, Gordon, Ryan, Clare, Simon, Ute, ZumBrunnen, Craig, McIntyre, Nancy E., Knowles-Yánez, K., and Hope, D.

Abstract

Though there is a growing appreciation of the importance of research on urban ecosystems, the question of what constitutes an urban ecosystem remains. Although a human-dominated ecosystem is sometimes considered to be an accurate description of an urban ecosystem, describing an ecosystem as human-dominated does not adequately take into account the history of development, sphere of influence, and potential impacts required in order to understand the true nature of an urban ecosystem. While recognizing that no single definition of "urban" is possible or even necessary, we explore the importance of attaching an interdisciplinary, quantitative, and considered description of an urban ecosystem such that projects and findings are easier to compare, repeat, and build upon. Natural science research about urban ecosystems, particularly in the field of ecology, often includes only a tacit assumption about what urban means. Following the lead of a more developed social science literature on urban issues, we make suggestions towards a consistent, quantitative description of urban that would take into account the dynamic and heterogeneous physical and social characteristics of an urban ecosystem. We provide case studies that illustrate how social and natural scientists might collaborate in research where a more clearly understood definition of "urban" would be desirable. [ABSTRACT FROM AUTHOR]

Published
2008
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13. ANTIOXIDANT ACTIVITY AND DIFFERENTIATION OF ESSENTIAL OILS OF GUAVIDUCA (PIPER CARPUNYA L.) AND SACHA AJO (MANSOA ALLIACEA L.).

Author

ENRÍQUEZ, M., PÉREZ, M., MANOBANDA, P., VILLAFUERTE, F., YÁNEZ, K., RAMOS, M., and MORELL, L.

Subjects
*ANTIOXIDANTS, *ESSENTIAL oils, *BIGNONIACEAE, *POLYPHENOLS, *SULFONIC acids, *AROMATIC plants
Abstract

Essential oils are aromatic substances found in different parts of plants, which can be extracted from leaves, stems, flowers and/or roots. These complex mixtures of hydrocarbons, terpenes, alcohols, carbonyl compounds, aromatic aldehydes and phenols, coming from spices and condiments, are increasingly used in the food and pharmaceutical industry. The present work aim was to differentiate the essential oils levels of Guaviduca (Piper carpunya L.) and Sacha Ajo (Mansoa alliacea L.) species, from the Ecuadorian Amazon region from fresh and dry leaves, by means the polyphenolic activity trough Folin-Ciocalteau, also total antioxidant activity according to FRAP (Ferric ion reducing antioxidant Power) and ABTS (2,2-azinobis (3-ethylbenzthiazolin)-6-sulphonic acid). The essential oils extraction method used in this investigation was steam distillation, using reflux with a Clevenger trap in order to separate them, taking advantage that oils are lighter than water. The yield for each the essential oils was determined quantitatively from the wet weight of each aromatic plant. A Simplex-Lattice design was used to determine the measuring points of antioxidant activity (essential oils proportions). Higher values are observed, in all determinations, in the essential oils obtained from fresh samples of guaviduca leaves and Sacha Ajo. This behavior might be due to the active compounds degradation with antioxidant activity and to the loss of essential oils by the evaporation process during drying. [ABSTRACT FROM AUTHOR]

Published
2018

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