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There are only a few studies of land cover-land use changes which provide an integrated assessment of the biophysical and
societal causes and consequences of environmental degradation in Ethiopia. Our objectives were to determine the status of
the environmental degradation, analyse and evaluate the relationships among vegetation, geomorphological and socio-economic
factors contributing to environmental degradation, and propose opportunities for rehabilitation of these natural resources.
Field and other environmental data in northern Ethiopia and those acquired by remote sensing techniques were used to accomplish
these objectives. These were integrated with socio-economic data obtained from official sources using a Geographic Information
System (GIS).Spatial information such as the percent of land cover-land use types and geomorphological categories, and the
percent of each land cover-land use type in the geomorphological categories were calculated using Geographic Information System
(GIS). The three most dominant features of the geomorphological categories (93.0%) are scarps and denuded rock slopes, erosion
surfaces and badlands, while the three most dominant features in the land cover-land use types (71.3%) are croplands, open
woodlands and bushlands. Badlands account for 38.7% of the geomorphological units and 41.8% of the croplands currently occur
on badlands. Simple and partial correlation analyses were applied to explore the extent of the interaction between the anthropogenic
and the natural system. The anthropogenic system is influenced by elevation, which is positively correlated with human population
and livestock densities and area of croplands. The natural system finds its place only on steep slopes as shown by the positive
correlation between woodland,slope, high potential erosion, scarps and denudational rock slopes. The study indicates that
agriculture in the study area is in a critical environmental situation. A change of paradigm in land-use and development is
needed to encourage participation of the landowners and users in the efforts to conserve the vegetation and the soil. This
study provides sound options that could be used to rehabilitate the vegetation directly and to alleviate the current pressure
on the land and improve human welfare indirectly. Matching the human and livestock densities with the carrying capacity of
the land through recruitment of the surplus labour force for a modern economy, resettlement,off-farm employment and intensification
of agriculture are t he long and short-term actions that may contribute to the rehabilitation of the degraded areas.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Marco Vuerich Elisa Petrussa Antonio Filippi Stéphanie Cluzet Josep Valls Fonayet Angela Sepulcri Barbara Piani Paolo Ermacora Enrico Braidot 《Pest management science》2023,79(7):2503-2516
BACKGROUND
In recent years, biofungicides have drawn increasing interest in vineyards for a more sustainable integrated and copper-limited pest management. Among alternatives, botanicals could represent valuable tools, being rich sources of biologically active compounds. Conversely to the well-known antioxidant and biological properties in relation to health benefits, investigation on bioactivity of hot pungent Capsicum sp. products against fungal phytopathogens in vineyards is still scarce. Therefore, the present study aimed at exploring the biologically active compounds profile of a chili pepper (Capsicum chinense Jacq.) pod extract and its antimicrobial properties against some of the major fungal and Oomycetes pathogens of grapevine, including Botrytis cinerea Pers., Guignardia bidwellii (Ellis) Viala & Ravaz and Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni.RESULTS
The ethyl acetate-extracted oleoresin from the most pungent varieties was rich in capsaicinoids and polyphenols (371.09 and 268.5 μg mg−1 dry weight, respectively). Capsaicin and dihydrocapsaicin, hydroxycinnamic and hydroxybenzoic acids and quercetin derivatives were the most abundant, while carotenoids represented only a minor fraction. The oleoresin was efficient to inhibit all three pathogenic fungi and ED50 values were determined, evidencing that G. bidwellii was the more sensitive (0.233 ± 0.034 mg mL−1).CONCLUSION
The results suggested a potentiality of chili pepper extract for the control of some important grapevine pathogens, their possible application being helpful for the recommended limitation in extensive use of copper in vineyard. The complex mixture of high amounts of capsaicinoids, associated to specific phenolic acids and other minor bioactive components might contribute to the observed antimicrobial action of chili pepper extract. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献3.
Francesco Mancini Sara Nannarone Sandra Buratta Giuseppina Ferrara Anna Maria Stabile Matteo Vuerich Isabella Santinelli Alessandra Pistilli Elisabetta Chiaradia 《Veterinary anaesthesia and analgesia》2017,44(2):295-308
Objective
To assess the effects of xylazine and dexmedetomidine on equine chondrocytes, in vitro.Study design
Prospective, experimental study.Study material
Equine articular chondrocytes from five male horses.Methods
Chondrocytes were isolated from healthy equine articular cartilage of the metacarpo/metatarsophalangeal joints. Cell viability was assessed using the WST-8 assay by exposing chondrocytes to xylazine (0.5, 1, 2, 4, 8, 16.6, 25, 50 mg mL?1) or dexmedetomidine (0.001, 0.005, 0.01, 0.05, 0.175, 0.25 mg mL?1) for 15, 30 and 60 minutes. Based on the results of these tests, cells were treated with xylazine (1, 4, 25 mg mL?1) or dexmedetomidine (0.05, 0.175, 0.25 mg mL?1) for 15 minutes to further evaluate: cell viability by neutral red uptake; cell membrane integrity by lactate dehydrogenase release and by fluorescence microscopy with Hoechst 33342 and propidium iodide (PI), and apoptosis by flow cytometry using double staining with annexin V-fluorescein isothiocyanate/PI and by cell morphology.Results
Both drugs reduced cell viability in a dose-dependent manner. Specifically, all xylazine concentrations, except 0.5 mg mL?1 and 1 mg mL?1, significantly reduced cell viability, whereas the effects of dexmedetomidine were evident only at 0.175 mg mL?1 and 0.25 mg mL?1. The highest concentrations of xylazine (25 mg mL?1) and dexmedetomidine (0.25 mg mL?1) caused loss of membrane integrity. Cell morphology and flow cytometry analyses demonstrated signs of late apoptosis in xylazine-treated cells, and signs of late apoptosis and necrosis in dexmedetomidine-treated cells.Conclusions and clinical relevance
This study offers new insights into the potential chondrotoxicity induced by dexmedetomidine and xylazine. Therefore, the intra-articular administration of α2-agonists should be conducted with care, especially for doses of ≥ 4 mg mL?1 of xylazine and 0.175 mg mL?1 and 0.25 mg mL?1 of dexmedetomidine. 相似文献
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