Grain marketing policy changes and spatial efficiency of maize and wheat markets in Ethiopia

"In the context of on-going market reform in developing countries, there is a need for an improvement in the existing methods of spatial market efficiency analysis in order to better inform the debate toward designing and implementing new grain marketing policies, institutions, and infrastructure that facilitate the emergence of a well developed and competitive grain marketing system. The standard parity bounds model (PBM), while it overcomes many weaknesses of the conventional methods of spatial market efficiency analysis, it does not allow for the test of structural changes in spatial market efficiency as a result of policy changes. In this paper, building on the standard PBM, we develop an extended parity bounds model (EPBM). The EPBM is a stochastic gradual switching model with three trade regimes. The EPBM is estimated by maximum likelihood procedure and allows for tracing the time path and structural change in spatial market efficiency conditions due to the policy changes. We applied the EPBM to analyze the effect of grain marketing policy changes on spatial efficiency of maize and wheat markets in Ethiopia. The results show that the effect of policy changes on spatial market efficiency is not significant statistically in many cases; there is high probability of spatial inefficiency in maize and wheat markets before and after the policy changes. The implication of these results is that maize and wheat markets are characterized by periodic gluts and shortages, which can undermine the welfare of producers, grain traders and consumers. It is also observed that the nature of spatial inefficiency for maize and wheat markets is different implying that the two commodities might require different policy responses in order to improve spatial market efficiency. Maize traders made losses most of the time while wheat traders made excess profits most of the time covered by the study." Authors' AbstractStochastic analysis ,structural change ,

Homegardens and Agrobiodiversity Conservation in Sabata Town, Oromia Regional State, Ethiopia

Homegardens are repositories of biocultural assets of communities, the hub of plant-based resources and the microcosms of agrobiodiversity hotspots. The homegardens of Sabata, a peri-urban town located in the tepid-humid mid highland agroecological zone of southwest Shewa of Oromia Regional State (Ethiopia), were investigated using standard methods of ethnobotany with the aim of elucidating their diagnostic features and significance in agrobiodiversity conservation. Semi-structured interviews, observations, discussion with key informants and guided garden tour with plant specimen collection and identification constituted the main study methods. The resulting data were subjected to matrix ranking, descriptive statistical analysis and calculations of diversity and similarity indices. One hundred thirty-five plant species of different use categories and life forms, distributed in 110 genera and 58 families were recorded. Each homegarden had an average of 33 species. Ensete ventricosum, represented by 18 locally identified landrace clones, was the most frequent (91.60%) species. Among 240 randomly sampled households, 78% had attached homegardens. These homegardens provide sizeable returns in terms of plant material for home use and income generation on top of their ecological and aesthetic values. Cupressus lusitanica had the highest relative density (0.02%) among the tree species. An average Shannon-Wiener diversity index of 4.301 indicated the richness of Sabata homegardens in plant agrobiodiversity. These homegardens represent rich compositional, structural and functional diversity playing key roles for on-farm conservation and ensuring environmental well-being while contributing to livelihood support. This rich agrobiodiversity together with the local biocultural knowledge and management skills, backed by household decision-making and information networks of the multiethnic communities are the regulators of the homegarden dynamics. Key desirable actions relevant to Sabata homegardens include enhancement and development programmes that would facilitate climate adaptation efforts and optimize provision of resources with conservation of agrobiodiversity while preserving the local biocultural knowledge

Ethnobotany of Wild and Semi-Wild Edible Plants of Chelia District, West-Central Ethiopia

This study was aimed at carrying out ethnobotanical investigation of wild and semi-wild edible plants (WSWEPs) involving documentation and analysis of the associated indigenous knowledge in Chelia District, West-Central Ethiopia. Semi-structured interviewing, direct matrix ranking, focus group discussions (FGDs), and guided field walks with informants were employed to collect qualitative and quantitative data. A total of 58 WSWEPs species classified into 48 genera and 30 botanical families were documented. The Moraceae with five species (16.66%) and Asteraceae with four species (13.33%) were the most represented families with high number of wild edible plant species. However, Urtica simensis (Urticaceae) (74.3% of informants), Chionanthus mildbraedii (Oleaceae) (68.4% of informants), Carissa spinarum (Apocynaceae) (66.1% of informants) and Ficus sur (Moraceae) (65.3% of informants) were the highly cited wild food plants. Most of the WSWEP species were shrubs represented with 21 species (36.20%) followed by trees and herbs with 18 species each (31.03% each) and liana with one species (1.72%). About 13.33% of the WSWEPs of Chelia District were endemic to Ethiopia. The average number of WSWEPs reported by women was more than that reported by men, and similarly senior members of the community also reported significantly higher numbers of edible species than younger members (P<0.05). The key informants reported significantly higher mean number of edible species of WSWEPs than the general informants (P<0.05). Women (80.1 ±1.6%) and children (76.1 ±2.3%) were the major gatherers followed by men (13.2±2.4%) and all household members (12.9 ±1.3%). The majority of respondents (77.4 ±2.1%) reported that WSWEPs were consumed by all household members followed by women (23.1± 2.2%), elders (15.8 ±2.3%), children (19.4 ±1.6%) and men 8.2±2.1%). Most inhabitants predominantly consumed fruits (40%) and fresh leaves (17.5%) followed by shoots (12.5%). Based on multipurpose criteria, Cordia africana, Vepris dainellii and Chionanthus mildbraedii were the most commonly used multipurpose species. Forests were the major reservoirs contributing 19 species (18%) of WSWEPs followed by woodland and disturbed bushland adding 28 species (17%) and river banks contributing 26 species (16%). Our analysis also showed that agricultural expansion was identified as a major threat to WSWEPs followed by overgrazing and fuelwood collection in the study area. In light of our findings, we recommend further research on the possibility of adapting, growing and intentionally managing some of the commonly consumed WSWEPs as well as on the toxicity and nutritional composition of these plants to ensure safety of consumption and economic benefits

Pattern of functional diversity along the elevation gradient in the dry evergreen Afromontane forest of Hararghe Highland, Southeast Ethiopia

Understanding plant species distribution patterns along environmental gradients is fundamental to managing ecosystems, particularly when habitats are fragmented due to intensive human land use pressure. The variation pattern of functional diversity of plant communities along the elevation gradient in the Dindin dry evergreen Afromontane forest was tested. Fifty four plots of 20 x 20 m (400 m2) were established at 200 m intervals starting 2,300–2,900 m a. s. l. and woody species composition, and environmental variables were recorded. Nine functional diversity indices based on functional distances were employed to esimate functional diversity. The mixed effect model was used to determine the effect of elevation, aspect and slope on functional diversity indices. The results showed that functional diversity in communities varied greatly; functional diversity revealed a decrease with increasing elevation and a‘‘humped’’ pattern, with peak diversity appearing at middle elevation. Functional diversity was significantly correlated with elevation, slope, and aspect. Functional diversity was significantly correlated with species richness and evenness. Environmental filtering was important to the functional diversity pattern; the nine indices were all successful in the analysis of functional diversity in the plant community with different effectiveness, and modified functional attribute diversity, plot-based functional diversity, community based functional diversity, functional richness, and community weight mean of woody density performed better than the other four indices in this study

Dietary values of wild and semi-wild edible plants in Southern Ethiopia

Ethnobotanical studies have shown that many wild plant species are sporadically consumed alongside regular food sources in developing countries. Many plants of wild and semi-wild origin are consumed in the remote parts of southern Ethiopia. Dietetic values of Ethiopia’s non-crop food plants, though important in prevention of malnutrition and contribution to food security, remains shrouded for lack of chemical information. The chemical composition of popularly used wild edibles in Hamar and Konso (Xonso) of southern Ethiopia was examined. The most preferred 15 semi-wild and wild edible plants were selected using a mix of standard ethnobotanical field methods. Edible parts of target plants were collected with local participants, lyophilized and analyzed for proximate composition, amino acids, minerals and anti-nutritional factors. The wild edibles constituted good amounts of nutrients essential in human diet. Green leafy vegetables (GLVs) gave 1.5-5.8% ether extractives and total mineral composition of 12.5%-25.6%; Ca being highest (1100 - 3419 mg %) and exceptionally high for Justicia ladanoides (6177 mg %). Fe, Mg, Mn and Zn ranged from 11.7-23.14, 175-2049, 3.4-9.9 and 1.2-3.3 mg %, respectively. All GLVs contained ≥20% protein, highest in Coccinia grandis (36.3%). The latter species and Trigonella foenum-graecum yielded high lysine level. Anti-nutrients of concern include phenolics (158-1564 mg %) and tannins (448-2254 mg %) in GLVs and phenolics (1997mg %) and tannins (6314 mg %) in Ximenia caffra fruits. Total oxalates in mg % were high in Amaranthus graecizans (14067), Celosia argentea (12706) and Portulaca quadrifida (10162). Bulk consumption of monotype edible plant part in one meal may lead to nutritional and health impairment. However, traditional processing methods lower most of the anti-nutritionals and their respective risks. New food composition tables that integrate indigenous knowledge and nutritional content of the semi-wild and wild edibles are recommended. Wild edibles can be considered to improve livelihood security and reduce malnutrition in tune with the Millennium Development Goals aimed at reducing poverty and hunger

Antimicrobial activity of traditional medicinal plants from Ankober District, North Shewa Zone, Amhara Region, Ethiopia

Context: Traditional medicinal plants have long been used in Ethiopia to treat human and livestock ailments. Despite a well-documented rich tradition of medicinal plant use in the country, their direct antimicrobial effects are still poorly known. Objective: To investigate the antimicrobial activity of 19 medicinal plant species that were selected based on the ethnobotanical information on their traditional use to treat infectious diseases in Ankober District. Methods: About 23 different ethanol extracts of plants obtained by maceration of various parts of 19 medicinal plant species were studied for potential antimicrobial activity using a broth microdilution method against Bacillus cereus, Bacteroides fragilis, Candida albicans, Clostridium perfringens, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Results: Plant extracts from Embelia schimperi Vatke (Myrsinaceae) showed the strongest antibacterial activity with a minimum inhibitory concentration (MIC) value of 64 mu g/ml against B. cereus, L. monocytogenes, and S. pyogenes. Growth inhibitory activities were also observed for extracts of Ocimum lamiifolium Hochst. (Lamiaceae) against S. pyogenes, and those of Rubus steudneri Schweinf. (Rosaceae) against S. epidermidis at an MIC value of 128 mu g/ml. Generally, 74% of ethanol extracts (17 extracts) showed antimicrobial activity against one or more of the microbial strains tested at an MIC value of 512 mu g/ml or below. Discussion and conclusions: Results confirm the antimicrobial role of traditional medicinal plants of Ankober and warrant further investigations on promising medicinal plant species so as to isolate and characterise chemicals responsible for the observed strong antimicrobial activities

PrP is a central player in toxicity mediated by soluble aggregates of neurodegeneration-causing proteins

Neurodegenerative diseases are an enormous public health problem, affecting tens of millions of people worldwide. Nearly all of these diseases are characterized by oligomerization and fibrillization of neuronal proteins, and there is great interest in therapeutic targeting of these aggregates. Here, we show that soluble aggregates of α-synuclein and tau bind to plate-immobilized PrP in vitro and on mouse cortical neurons, and that this binding requires at least one of the same N-terminal sites at which soluble Aβ aggregates bind. Moreover, soluble aggregates of tau, α-synuclein and Aβ cause both functional (impairment of LTP) and structural (neuritic dystrophy) compromise and these deficits are absent when PrP is ablated, knocked-down, or when neurons are pre-treated with anti-PrP blocking antibodies. Using an all-human experimental paradigm involving: (1) isogenic iPSC-derived neurons expressing or lacking PRNP, and (2) aqueous extracts from brains of individuals who died with Alzheimer's disease, dementia with Lewy bodies, and Pick's disease, we demonstrate that Aβ, α-synuclein and tau are toxic to neurons in a manner that requires PrPC. These results indicate that PrP is likely to play an important role in a variety of late-life neurodegenerative diseases and that therapeutic targeting of PrP, rather than individual disease proteins, may have more benefit for conditions which involve the aggregation of more than one protein

Direct observation of active material concentration gradients and crystallinity breakdown in LiFePO4 electrodes during charge/discharge cycling of lithium batteries

The phase changes that occur during discharge of an electrode comprised of LiFePO4, carbon, and PTFE binder have been studied in lithium half cells by using X-ray diffraction measurements in reflection geometry. Differences in the state of charge between the front and the back of LiFePO4 electrodes have been visualized. By modifying the X-ray incident angle the depth of penetration of the X-ray beam into the electrode was altered, allowing for the examination of any concentration gradients that were present within the electrode. At high rates of discharge the electrode side facing the current collector underwent limited lithium insertion while the electrode as a whole underwent greater than 50% of discharge. This behavior is consistent with depletion at high rate of the lithium content of the electrolyte contained in the electrode pores. Increases in the diffraction peak widths indicated a breakdown of crystallinity within the active material during cycling even during the relatively short duration of these experiments, which can also be linked to cycling at high rate