20 research outputs found
Impacts des activités d'extraction de gravier au Sud du Bénin et leur perception par la population locale
Impacts of gravel extraction activities in Southern Benin: Residents' perception. Gravel extraction activities in Southern Benin are carried out without formal license from the state authorities. The majority of sites are rented from landowners and located near other forms of land use including human settlements. This study aims at assessing the perception by the residents of these gravel extraction operations. The results show the social services and damages of this industry. An ordinal logit regression revealed significant influences of the respondents' ethnic group, occupation, education level, marital status and age on the perception of road infrastructure, dust pollution, loss of agricultural land and school drop-out. Therefore, it is important that the local authorities undertake mitigation actions in particular in order to prevent road dust occurrence and to restore abandoned sites so that these sites are again available for agriculture
Impacts des activités d'extraction de gravier au Sud du Bénin et leurs perceptions des populations locales
Forest fragmentation: causes, ecological impacts and implications for landscape management
Forest fragmentation: causes, ecological impacts and implications for landscape management
In order to enable the development of appropriate landscape management
plans, the causes and impacts of fragmentation should be fully
understood. A new definition, incorporating the key aspects cited in
landscape ecological literature since the 1980s, is proposed in order to
shed light on the matter of fragmentation. By means of two case studies
in the Democratic Republic of the Congo (Oriental Province) and
in North Benin, the key role of anthropogenic activities in landscape
fragmentation is evidenced; the spatial dispersion of forest vegetation is
linked to population density and land use change. The potential impact
of fragmentation on biodiversity is shown by an analysis of forest diversity
in Ivory Coast (Tanda region), and by a study of edge effects on two
rodent species in the Democratic Republic of the Congo (Kisangani).
The chapter is concluded by an study on how planned corridors, assuming
a spatial regrouping of existing teak plantations, could contribute to
the conservation and management of remaining natural forest patches in
the Atlantic Department in Benin
Effet de lisière sur la productivité du teck (Tectona grandis L.f.): étude de cas des teckeraies privées du Sud-Bénin
info:eu-repo/semantics/publishe
Caractéristiques structurelles et écologiques des phytocénoses de sous-bois des plantations privées de teck du département de l’Atlantique (Sud-Bénin, Afrique de l’Ouest)
Structural and ecological characteristics of private Teak plantations in the Atlantic Department, South Benin, were studied according to the synusial approach of phytosociology in order to contribute to the sustainable management of the plantations. The study of dendrometric characteristics of Teak plantations was done by establishing two temporal plots, each of 1 are. In each plot, the stem girth of the trees and the total height of three mean trees were measured. A total of 99 vegetal synusias has been described, then combined into 18 phytocoenoses. Ecological characteristics are also studied.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Structural characteristics and forest sites identification in Pahou forest reserve, South-Benin
info:eu-repo/semantics/publishe
Anhydrous Monoalkylguanidines in Aprotic and Nonpolar Solvents: Models for Deprotonated Arginine Side Chains in Membrane Environments
In
this study, the synthesis of crystalline dodecylguanidine free
base and its spectroscopic characterization in nonpolar environments
are described. IR as well as <sup>1</sup>H and <sup>15</sup>N NMR
spectra of the free base dissolved in aprotic solvents are substantially
different from the previously reported spectra of arginine, or other
monoalkylguanidinium compounds, at high hydroxide concentrations.
The current results provide improved modeling for the spectroscopic
signals that would be expected from a deprotonated arginine in a nonpolar
environment. On the basis of our spectra of the authentic dodecylguanidine
free base, addition of large amounts of aqueous hydroxide to arginine
or other monoalklyguanidinium salts does not deprotonate them. Instead,
hydroxide addition leads to the formation of a guanidinium hydroxide
complex, with a dissociation constant near ∼500 mM that accounts
for the established arginine p<i>K</i> value of ∼13.7.
We also report a method for synthesizing a compound containing both
phenol and free-base guanidine groups, linked by a dodecyl chain that
should be generalizable to other hydrocarbon linkers. Such alkyl-guanidine
and phenolyl-alkyl-guanidine compounds can serve as small-molecule
models for the conserved arginine–tyrosine groupings that have
been observed in crystallographic structures of both microbial rhodopsins
and G-protein-coupled receptors
War Memories and the Refugees’ Representation in Marie-Thérèse Toyi’s Weep not, Refugee
Tree plantation will not compensate natural woody vegetation cover loss in the Atlantic Department of southern Benin
info:eu-repo/semantics/publishe