Abstract: Aqueous mixtures of glycerol and 2-hydroxypropyl-β-cyclodextrin (CD), two non-toxic eco-friendly substances, were used as a means of extracting antioxidant polyphenols from oak acorn (Quercur robur) husks. The process was optimized by implementing a central composite (Box-Behnken) experimental design and response surface methodology, taking into consideration the critical parameters (independent variables) of glycerol concentration (Cgl), CD concentration (CCD) and temperature (T). The assessment of the extraction model was based on three responses: the total polyphenol yield (YTP), the antiradical activity (AAR) and the reducing power (PR). The model illustrated that YTP depended significantly on Cgl and CCD, but not on T, whereas both antioxidant properties considered (AAR and PR) were temperature-dependent. The maximum predicted YTP was 122.19 mg GAE per g dry husk weight, while the extract obtained under optimized conditions displayed strong antioxidant activity.
Abstract: Smallholders in Asia and Africa require low-cost seed drills for minimal soil disturbance while establishing various crops. A seed drill that can be drawn by the widely-available two-wheel tractor (2WT) is an attractive option for mechanization of no-till in small-sized fields. The Versatile Strip Seed Drill (VSSD) was designed with the capacity to make up to 40 mm wide and 60 mm deep strips in untilled land along with seed and basal fertilizer application in a single-pass operation, while powered by the 8.95 to 11.93 kW 2WT. An important innovation of the VSSD was to fit the seed box with both fluted roller-type seed meters for delivery of sufficient small-size seeds to achieve adequate plant density per unit row length; and vertical disk-type seed meters for precision and spaced row planting of larger seeds. Both incessant seed dropping by fluted roller seed meters and spaced planting by vertical disk type seed meters provided optimum plant populations that were generally higher than in conventional, full-tillage plots with the same rate of hand broadcasted seed and fertilizers. Time required for crop establishment by VSSD ranged from 0.13 to 0.18 ha·h−1. When the VSSD was attached to the 2WT for crop establishment, the diesel fuel consumption varied from 4.4 to 6.1 L·ha−1, which was lower than for most 2WT-based planters previously used in Bangladesh. In on-farm multi-locations trials, wheat crops established with the VSSD had statistically similar grain yield compared to conventional tillage; however, significantly higher grain yield was obtained from mustard and lentil, by 14% and 19%, respectively. The VSSD is a unique, minimum-soil-disturbance multi-crop planter, and can be a platform on which to build conservation agriculture systems for small farms in Asia and Africa.
Abstract: Using a logistic regression model, this paper examines key factors that influence individual support for communal conservancies in Namibia. It tests the hypothesis that if individuals are compensated for their wildlife related losses, they are more likely to support community based wildlife management projects. Data for this study were collected from 472 members of five conservancies in the Caprivi Region of Namibia. Respondents were selected through convenience sampling. The key findings are that receiving meat, activity during the Annual General Meeting (AGM), and being a member of a specific conservancy are the key predictors of satisfaction with the conservancy among the respondents. On the other hand, cash and jobs have no significant impact on individual attitudes toward communal conservancies. Based on these findings, the paper argues that the focus on incentives omits broader factors that motivate individuals to participate in community-based conservation.
Abstract: The present review summarizes the literature on the effects of oil spill on the U.S. Gulf of Mexico coastal vegetation including freshwater-, brackish-, and salt-marshes. When in contact with plant tissues, oil may have adverse impacts via physical and chemical effects. Oil may also become detrimental to plants by covering soil surfaces, leading to root oxygen stress and/or penetrate into the soil where it becomes in contact with the roots. The affected vegetation may survive the impact by producing new leaves, however, an episode of oil spill may impose severe stress. Oil spills may lead to partial or complete plant death but in many situations plants recover by regenerating new shoots. Plant sensitivity to oil varies among species; plants from salt marshes appear to be more sensitive than freshwater species. In addition, sensitivity appears to be dependent on the oil characteristics and the quantity of oil being spilled, repeated oiling events, season of spill, greenhouse vs. field conditions, and plant age are among the many factors that interact simultaneously. Many aspects of coastal plant responses to oiling remain in need of additional research, including the possibility that differences in oil sensitivity may interact with changes in the environment, and contribution to additional wetland losses through coastal erosion. Environmental stressors such as drought and salinity may also interact with oil, leading to the observed changes in plant species community composition following an oil spill.
Abstract: In sub-Saharan Africa, hydro-meteorological related disasters, such as floods, account for the majority of the total number of natural disasters. Over the past century, floods have affected 38 million people, claimed several lives and caused substantial economic losses in the region. The goal of this paper is to examine how personality disposition, social network, and socio-demographic factors mitigate the complex relationship between stressful life experiences of floods and ocean surges and the adoption of coping strategies among coastal communities in Nigeria and Tanzania. Generalized linear models (GLM) were fitted to cross-sectional survey data on 1003 and 1253 individuals in three contiguous coastal areas in Nigeria and Tanzania, respectively. Marked differences in the type of coping strategies were observed across the two countries. In Tanzania, the zero-order relationships between adoption of coping strategies and age, employment and income disappeared at the multivariate level. Only experience of floods in the past year and social network resources were significant predictors of participants’ adoption of coping strategies, unlike in Nigeria, where a plethora of factors such as experience of ocean surges in the past one year, personality disposition, age, education, experience of flood in the past one year, ethnicity, income, housing quality and employment status were still statistically significant at the multivariate level. Our findings suggest that influence of previous experience on adoption of coping strategies is spatially ubiquitous. Consequently, context-specific policies aimed at encouraging the adoption of flood-related coping strategies in vulnerable locations should be designed based on local needs and orientation.