139 research outputs found

    Review on the Role of Underutilized Crops in Achieving Food Security in Ghana: Implications for Policy

    Get PDF
    Food security globally is constrained by several factors including the heavy reliance on very few key staple crops. In Africa over dependence on a few major crops remain a major challenge due to its potential impact and contribution to food security. This review explores the potential contribution of underutilized crops to the attainment of food security. The paper also explores the relevance of a specific policy provision that promotes the use of underutilized crops. In Ghana the challenge of food insecurity still remains a major concern, particularly in the three northern regions. The 2009 Comprehensive Food Security & Vulnerability Analysis (CFSVA) report revealed that food insecurity in Ghana is a challenge particularly in the areas most prone to adverse weather conditions, such as floods and droughts, which are also the poorest regions of the country. In Ghana, as in many African countries considerable attention has not been given to the impact of underutilized crops and plant species on food security. This is evidenced by the 2013 Accra Statement for a food secure Africa report, which identified most countries in Africa, including Ghana, as pursuing agricultural and food policies based on a limited number of crops or staples such as maize and rice. The review showed that Ghana currently lacks a comprehensive policy, on the use of underutilized crops. A specific policy that will ensure the promotion and use of underutilized crops in Ghana, is suggested

    Ethnobotanical study of the use of natural dye plant species in the southern forest-savanna transition zone of Ghana

    Get PDF
    Ethnobotanical studies were carried out in the United Nations University People’s Land-Use and Environmental Change (UNU/PLEC) demonstration sites of Gyamfiase-Adenya, Sekesua-Osonson and Amanase-Whanabenya with detailed floral inventory undertaken in the Gyamfiase-Adenya demonstration site. Ethnobotanical knowledge gathered from focus group discussions indicated that a number of plant species were used traditionally as food colours and dyes for clothing. These included Alchornea cordifolia, Carica papaya, Citrus sinensis, Combretum mucronatum, Lecaniodiscus cupanioides, Mangifera indica, Lonchocarpus cyanescense and Morinda lucida. The use of these species for food colouring was widespread among females than among males. Food colouring was also found to be a common household practice although it was not commercialised. Floral inventory in the Gyamfiase-Adenya site indicated that Albizia zygia, Bombax buonopozense, Ceiba pentandra, Cola gigantea, Morinda lucida, Rauvolfia vomitoria and Terminalia ivorensis are left as standard trees in-situ on farms in traditional agro-forestry. Out of seven species screened initially as sources of materials for food colouring and dyes for clothing, Morinda lucida and Combretum mucronatum were predominant in the area. Whilst Combretum mucronatum was readily available in the fallows, Morinda lucida was found in each of the different land-use types (farms with annual crops, fallows and tree crop farms). Local communities with the support of district assemblies should be encouraged to maintain and pursue other effective and sustainable methods in the harvesting of these plants

    Impact of Urban Effluents on the Macroinvertebrates of a Creek in Accra, Ghana

    Get PDF
    The impact of effluents on the macroinvertebrate communities of an urban creek in Accra was studied. Five study stations were selected along the reaches of the creek. Water and benthic samples were collected and analyzed between September 2005 and February 2006. The study showed that the effluent discharges caused a significant increase in BOD, COD and NH3 at the stations that received the effluents. The high levels of total and faecal coliforms at the midstream sections of the creek (626.0 x 104 cfu/100 ml and 75.30 x 104 cfu/100 ml, respectively) indicated increased pollution levels compared to the reference stations (446.0 x 103 cfu/100 ml and 133.0 x 103 cfu/100 ml). The Nima Creek showed characteristics of a disturbed urban creek. A total of 19 macroinvertebrate taxa, comprising a total of 11,613 individuals, were collected. Estimated Shannon-Weiner Diversity Index (H´) was low at the midstream section of the creek, H’= 1.14, where the effluents were concentrated than at the upstream H’=1.44 or downstream H’= 1.38 sections of the creek. Chironomini and Physa were the most abundant taxa within the creek, dominated by the genus Chironomus, which is known to be tolerant to pollution, which confirmed the polluted state of the creek. Rigorous and regular assessment and monitoring of effluents from waste treatment plants and other sources that discharge into the creek, with the aim of complying with the Environmental Protection Agency (EPA) guidelines are some of the mitigative measures suggested to protect life in the creek

    Changing Agricultural Practices and Indigenous Food Crops in the Upper Afram Basin of Ghana

    Get PDF
    The Forest Savanna Transition zone within which the Upper Afram basin lies, account for a wide variety of food crops and plant species. This study examined the effects of changing ag­ricultural practices on cultivation and availability of indigenous food crops within the basin. Qualitative data obtained from 240 farmers through individual interviews and Focus group dis­cussions were analyzed thematically. The study revealed that even though the farmers employed the traditional mixed cropping system, the widespread use of agro-chemicals in the study area was limiting the practice of intercropping. This accounts for the current dominance of mono cropping system in the study area. These changes have affected the cultivation of a wide variety of indigenous foods within the basin. The uncontrolled use of agro-chemicals constituted one of the major agronomic constraints affecting the cultivation of these crops. Adequate technical support services to effectively control agrochemical abuse among the local farmers will, there­fore, be required. Increased sensitization on the need for local farmers to refocus and maintain some of the traditional agricultural practices that ensured the cultivation of a wide variety of indigenous food crop varieties (NUCS) in their farms is also suggested

    Inclusive V0V^0 Production Cross Sections from 920 GeV Fixed Target Proton-Nucleus Collisions

    Full text link
    Inclusive differential cross sections dσpA/dxFd\sigma_{pA}/dx_F and dσpA/dpt2d\sigma_{pA}/dp_t^2 for the production of \kzeros, \lambdazero, and \antilambda particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to s=41.6\sqrt {s} = 41.6 GeV in the proton-nucleon system. The ratios of differential cross sections \rklpa and \rllpa are measured to be 6.2±0.56.2\pm 0.5 and 0.66±0.070.66\pm 0.07, respectively, for \xf 0.06\approx-0.06. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions dσpA/dpt2d\sigma_{pA}/dp_t^2 also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections σpA\sigma_{pA} on the atomic mass AA of the target material is discussed, and the deduced cross sections per nucleon σpN\sigma_{pN} are compared with results obtained at other energies.Comment: 17 pages, 7 figures, 5 table

    Design and Synthesis of Potent in Vitro and in Vivo Anticancer Agents Based on 1-(3′,4′,5′-Trimethoxyphenyl)-2-Aryl-1H-Imidazole

    Get PDF
    A novel series of tubulin polymerization inhibitors, based on the 1-(3',4',5'-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold and designed as cis-restricted combretastatin A-4 analogues, was synthesized with the goal of evaluating the effects of various patterns of substitution on the phenyl at the 2-position of the imidazole ring on biological activity. A chloro and ethoxy group at the meta- and para-positions, respectively, produced the most active compound in the series (4o), with IC50 values of 0.4-3.8 nM against a panel of seven cancer cell lines. Except in HL-60 cells, 4o had greater antiproliferative than CA-4, indicating that the 3'-chloro-4'-ethoxyphenyl moiety was a good surrogate for the CA-4 B-ring. Experiments carried out in a mouse syngenic model demonstrated high antitumor activity of 4o, which significantly reduced the tumor mass at a dose thirty times lower than that required for CA-4P, which was used as a reference compound. Altogether, our findings suggest that 4o is a promising anticancer drug candidate that warrants further preclinical evaluation

    CycADS: an annotation database system to ease the development and update of BioCyc databases.

    Get PDF
    International audienceIn recent years, genomes from an increasing number of organisms have been sequenced, but their annotation remains a time-consuming process. The BioCyc databases offer a framework for the integrated analysis of metabolic networks. The Pathway tool software suite allows the automated construction of a database starting from an annotated genome, but it requires prior integration of all annotations into a specific summary file or into a GenBank file. To allow the easy creation and update of a BioCyc database starting from the multiple genome annotation resources available over time, we have developed an ad hoc data management system that we called Cyc Annotation Database System (CycADS). CycADS is centred on a specific database model and on a set of Java programs to import, filter and export relevant information. Data from GenBank and other annotation sources (including for example: KAAS, PRIAM, Blast2GO and PhylomeDB) are collected into a database to be subsequently filtered and extracted to generate a complete annotation file. This file is then used to build an enriched BioCyc database using the PathoLogic program of Pathway Tools. The CycADS pipeline for annotation management was used to build the AcypiCyc database for the pea aphid (Acyrthosiphon pisum) whose genome was recently sequenced. The AcypiCyc database webpage includes also, for comparative analyses, two other metabolic reconstruction BioCyc databases generated using CycADS: TricaCyc for Tribolium castaneum and DromeCyc for Drosophila melanogaster. Linked to its flexible design, CycADS offers a powerful software tool for the generation and regular updating of enriched BioCyc databases. The CycADS system is particularly suited for metabolic gene annotation and network reconstruction in newly sequenced genomes. Because of the uniform annotation used for metabolic network reconstruction, CycADS is particularly useful for comparative analysis of the metabolism of different organisms. Database URL: http://www.cycadsys.org

    The associations between serum brain-derived neurotrophic factor, potential confounders, and cognitive decline: A longitudinal study

    Get PDF
    Brain-derived neurotrophic factor (BDNF) plays a role in the maintenance and function of neurons. Although persons with Alzheimer's disease have lower cortical levels of BDNF, evidence regarding the association between circulating BDNF and cognitive function is conflicting. We sought to determine the correlates of BDNF level and whether BDNF level was prospectively associated with cognitive decline in healthy older adults. We measured serum BDNF near baseline in 912 individuals. Cognitive status was assessed repeatedly with the modified Mini-Mental Status Examination and the Digit Symbol Substitution test over the next 10 years. We evaluated the association between BDNF and cognitive decline with longitudinal models. We also assessed the association between BDNF level and demographics, comorbidities and health behaviors. We found an association between serum BDNF and several characteristics that are also associated with dementia (race and depression), suggesting that future studies should control for these potential confounders. We did not find evidence of a longitudinal association between serum BDNF and subsequent cognitive test trajectories in older adults, although we did identify a potential trend toward a cross-sectional association. Our results suggest that serum BDNF may have limited utility as a biomarker of prospective cognitive decline

    Synthesis and Biological Evaluation of 2-Methyl-4,5-Disubstituted Oxazoles as a Novel Class of Highly Potent Antitubulin Agents

    Get PDF
    Antimitotic agents that interfere with microtubule formation are one of the major classes of cytotoxic drugs for cancer treatment. Multiple 2-methyl-4-(3′,4′,5′-trimethoxyphenyl)-5-substituted oxazoles and their related 4-substituted-5-(3′,4′,5′-trimethoxyphenyl) regioisomeric derivatives designed as cis-constrained combretastatin A-4 (CA-4) analogues were synthesized and evaluated for their antiproliferative activity in vitro against a panel of cancer cell lines and, for selected highly active compounds, interaction with tubulin, cell cycle effects and in vivo potency. Both these series of compounds were characterized by the presence of a common 3′,4′,5′-trimethoxyphenyl ring at either the C-4 or C-5 position of the 2-methyloxazole ring. Compounds 4g and 4i, bearing a m-fluoro-p-methoxyphenyl or p-ethoxyphenyl moiety at the 5-position of 2-methyloxazole nucleus, respectively, exhibited the greatest antiproliferative activity, with IC50 values of 0.35-4.6 nM (4g) and 0.5–20.2 nM (4i), which are similar to those obtained with CA-4. These compounds bound to the colchicine site of tubulin and inhibited tubulin polymerization at submicromolar concentrations. Furthermore, 4i strongly induced apoptosis that follows the mitochondrial pathway. In vivo, 4i in a mouse syngeneic model demonstrated high antitumor activity which significantly reduced the tumor mass at doses ten times lower than that required for CA-4P, suggesting that 4i warrants further evaluation as a potential anticancer drug

    Manipulating the Hype: contemporary art's response to media cliches

    Get PDF
    Manipulating the Hype addresses art’s reaction to the barrage of signs produced by the media. The paper researches contemporary art’s response to clichéd media stereotypes and elucidates artists’ multifaceted perspective on overtly obvious yet widely embraced paradigms marketed by the media. Contemporary art’s strategic reconfiguration of media stereotypes is a valuable introspection upon the superficiality and impracticability of advertising and entertainment industry constructs. By reconsidering the mediated image, art has the ability to inspire reevaluation of cultural values. The thesis additionally attempts to ascertain the reinterpretation of media stereotypes as a common thread linking principal art movements and historically significant artworks from around the world since 1960. How does contemporary art respond to the extensive cultural influence of the media? Is a reaction to mass media a thematic commonality linking contemporary artists in the age of globalization? Manipulating the Hype is a dual outcome investigation comprised of written thesis and studio practice. The written thesis combines experience from a lengthy professional practice with historical and theoretical research. The visual thesis consists of twelve photographic works taken at on the Big Island of Hawaii. The images juxtapose artificial icons of power from popular culture with the natural force of the active lava flow. The process of research discloses how the advertising and entertainment industries capitalize upon innate human desires through the manipulative proliferation of archetypal imagery. Furthermore, the thesis establishes the widespread retort to media clichés as a palpable commonality in studio practices worldwide. The findings in the research make evident that although contemporary art does not have sufficient influence to reform the media, it can heighten public awareness of media tactics
    corecore