161 research outputs found

    Reduction of Post-Harvest Losses: A Gateway to Improving Livelihood of Smallholder Farmers and Ensuring Food Security in Nigeria

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    Nigerian smallholder farmers suffer huge losses on annual basis in terms of monetary value as a result of postharvest losses due to factors such as inadequate storage/processing facilities, poor transportation system, lack of power supply and unorganized marketing network. With the largest population on the African continent and a spiraling increase, a corresponding increase in food supply is inevitable. The food security situation in Nigeria is already challenged by a growing pressure on land and water resources due to population increase, farmers-herders clashes and terrorism which has adversely disrupted farming activities particularly in the northeastern part of the country. With all these challenges, high loss of farm produce due to post-harvest loss is indeed another great threat to the attainment of food security in Nigeria. This paper focused primarily on postharvest losses which are like a recurring decimal in Nigeria’s agricultural sector, it discussed the driving factors, highlights its impacts and suggest some viable solutions and measures that can be adopted to tackle the problem with a view of increasing farmer’s income and ensuring food security in Nigeria. Keywords: Post-harvest loss, Smallholder farmers, Livelihood, Food security and Nigeria. DOI: 10.7176/JBAH/11-22-04 Publication date: November 30th 202

    Mitigation of Multiple Environmental Footprints for China’s Pig Production Using Different Land Use Strategies

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    Pig production contributes considerably to land use and greenhouse gas (GHG) and reactive nitrogen (Nr) emissions. Land use strategies were widely proposed, but the spillover effects on biological flow are rarely explored. Here, we simultaneously assessed the carbon (C), nitrogen (N), and cropland footprints of China's pig production at the provincial scale in 2017. The environmental impacts of land use strategies were further evaluated. Results show that one kg live-weight pig production generated an average of 1.9 kg CO2-equiv and 59 g Nr emissions, occupying 3.5 m2 cropland, with large regional variations. A large reduction in GHG (58-64%) and Nr (12-14%) losses and occupied cropland (10-11%) could be achieved simultaneously if combined strategies of intensive crop production, improved feed-protein utilization efficiency, and feeding co-products were implemented. However, adopting a single strategy may have environmental side-effects. Reallocating cropland that pigs used for feed to plant food alternatives would enhance human-edible energy (3-20 times) and protein delivery (1-5 times) and reduce C and N footprints, except for rice and vegetables. Reallocating cropland to beef and milk production would decrease energy and protein supply. Therefore, a proper combination of land use strategies is essential to alleviate land use changes and nutrient emissions without sacrificing food supply

    Ammonia mitigation campaign with smallholder farmers improves air quality while ensuring high cereal production

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    Reducing cropland ammonia (NH3) emissions while improving air quality and food supply is a challenge, particularly in China with millions of smallholder farmers. We tested the effectiveness of a tailored nitrogen (N) management strategy applied to wheat-maize cropping systems in “Demonstration Squares” across Quzhou county in North China Plain. The N management techniques included optimal N rates, deep fertilizer placement and application of urease inhibitors, implemented through cooperation between government, researchers, businesses and smallholders. Compared with conventional local smallholder practice, our NH3 mitigation campaign reduced NH3 volatilization from wheat and maize by 49% and 39%, and increased N use efficiency by 28% and 40% and farmers’ profitability by 25% and 19%, respectively, with no detriment to crop yields. County-wide atmospheric NH3 and PM2.5 concentrations decreased by 40% and 8%, respectively. County-wide net benefits were estimated at $7.0 million. Our “Demonstration Square” approach demonstrates that cropland NH3 mitigation and improved air quality and farm profitability can be achieved simultaneously by coordinated actions at county level

    A Multi-Center Study to Evaluate the Performance of Phage Amplified Biologically Assay for Detecting TB in Sputum in the Pulmonary TB Patients

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    Objective: To evaluate the performance of phage amplified biologically assay (PhaB) for detecting tuberculosis (TB) in sputum in the pulmonary tuberculosis (PTB) patients. Methods: Shanghai Tuberculosis Key Laboratory of Shanghai Pulmonary Hospital participated in the project in collaboration with the laboratories of six hospitals and a total of 1660 eligible participants (1351 PTB patients and 309 non-TB patients) were included in the study. The sputum samples from the participants were detected by smear microscopy, PhaB, and Löwenstein-Jensen (L-J) culture method, respectively. Results: The overall sensitivity of PhaB were higher than that of L-J culture and smear microscopy (p,0.05). The sensitivity of PhaB for detecting smear-negative specimens was obviously higher than that of L-J culture (p,0.05). Compared with L-J culture, the overall sensitivity, specificity, PPV, NPV, ACC and Kappa value of PhaB were 98.4 (95 % Cl: 96.9–99.3), 71.6 (95% Cl: 68.4–74.6), 67.7, 98.7, 81.7 % and 0.643, respectively. The detection median time of PhaB only needed 48 hours, which was significantly less than that (31 days) of L-J culture method. Conclusion: PhaB method is a rapid and sensitive method for detecting TB in sputum in PTB patients; especially for th

    Progress on improving Agricultural Nitrogen use efficiency: UK-China viortual joint centers on Nitrogen Agronomy

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    Two virtual joint centers for nitrogen agronomy were established between the UK and China to facilitate collaborative research aimed at improving nitrogen use efficiency (NUE) in agricultural production systems and reducing losses of reactive N to the environment. Major focus areas were improving fertilizer NUE, use of livestock manures, soil health, and policy development and knowledge exchange. Improvements to fertilizer NUE included attention to application rate in the context of yield potential and economic considerations and the potential of improved practices including enhanced efficiency fertilizers, plastic film mulching and cropping design. Improved utilization of livestock manures requires knowledge of the available nutrient content, appropriate manure processing technologies and integrated nutrient management practices. Soil carbon, acidification and biodiversity were considered as important aspects of soil health. Both centers identified a range of potential actions that could be taken to improve N management, and the research conducted has highlighted the importance of developing a systemslevel approach to assessing improvement in the overall efficiency of N management and avoiding unintended secondary effects from individual interventions. Within this context, the management of fertilizer emissions and livestock manure at the farm and regional scales appear to be particularly important targets for mitigation

    Trends in secondary inorganic aerosol pollution in China and its responses to emission controls of precursors in wintertime

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    The Chinese government recently proposed ammonia (NH3) emissions reductions (but without a specific national target) as a strategic option to mitigate PM2.5 pollution. We combined a meta-analysis of nationwide measurements and air quality modelling to identify efficiency gains by striking a balance between controlling NH3 and acid gas (SO2 and NOx) emissions. We found that PM2.5 concentrations decreased from 2000 to 2019, but annual mean PM2.5 concentrations still exceeded 35 µg m−3 at 74 % of 1498 monitoring sites in 2015–2019. Secondary inorganic aerosols (SIA) were the dominant contributor to ambient PM2.5 concentrations. While sulfate concentrations significantly decreased over the time period, no significant change was observed for nitrate and ammonium concentrations. Model simulations indicate that the effectiveness of a 50 % NH3 emission reduction for controlling SIA concentrations decreased from 2010 to 2017 in four megacity clusters of eastern China, simulated for the month of January under fixed meteorological conditions (2010). Although the effectiveness further declined in 2020 for simulations including the natural experiment of substantial reductions in acid gas emissions during the CoVID-19 pandemic, the resulting reductions in SIA concentrations were on average 20.8 % lower than that in 2017. In addition, the reduction of SIA concentrations in 2017 was greater for 50 % acid gas reductions than for the 50 % NH3 emissions reduction. Our findings indicate that persistent secondary inorganic aerosol pollution in China is limited by acid gases emissions, while an additional control on NH3 emissions would become more important as reductions of SO2 and NOx emissions progress

    Trends in secondary inorganic aerosol pollution in China and its responses to emission controls of precursors in wintertime

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    The Chinese government recently proposed ammonia (NH3) emission reductions (but without a specific national target) as a strategic option to mitigate fine particulate matter (PM2.5) pollution. We combined a meta-analysis of nationwide measurements and air quality modeling to identify efficiency gains by striking a balance between controlling NH3 and acid gas (SO2 and NOx) emissions. We found that PM2.5 concentrations decreased from 2000 to 2019, but annual mean PM2.5 concentrations still exceeded 35 µg m−3 at 74 % of 1498 monitoring sites during 2015–2019. The concentration of PM2.5 and its components were significantly higher (16 %–195 %) on hazy days than on non-hazy days. Compared with mean values of other components, this difference was more significant for the secondary inorganic ions SO, NO, and NH (average increase 98 %). While sulfate concentrations significantly decreased over this period, no significant change was observed for nitrate and ammonium concentrations. Model simulations indicate that the effectiveness of a 50 % NH3 emission reduction for controlling secondary inorganic aerosol (SIA) concentrations decreased from 2010 to 2017 in four megacity clusters of eastern China, simulated for the month of January under fixed meteorological conditions (2010). Although the effectiveness further declined in 2020 for simulations including the natural experiment of substantial reductions in acid gas emissions during the COVID-19 pandemic, the resulting reductions in SIA concentrations were on average 20.8 % lower than those in 2017. In addition, the reduction in SIA concentrations in 2017 was greater for 50 % acid gas reductions than for the 50 % NH3 emission reductions. Our findings indicate that persistent secondary inorganic aerosol pollution in China is limited by emissions of acid gases, while an additional control of NH3 emissions would become more important as reductions of SO2 and NOx emissions progress

    Association of mutation patterns in gyrA/B genes and ofloxacin resistance levels in Mycobacterium tuberculosis isolates from East China in 2009

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    <p>Abstract</p> <p>Background</p> <p>This study aimed to analyze the association of mutation patterns in <it>gyrA </it>and <it>gyrB </it>genes and the ofloxacin resistance levels in clinical <it>Mycobacterium tuberculosis </it>isolates sampled in 2009 from East China.</p> <p>Methods</p> <p>The quinolone resistance-determining region of <it>gyrA/B </it>were sequenced in 192 <it>M. tuberculosis </it>clinical isolates and the minimal inhibitory concentrations (MICs) of 95 ofloxacin-resistant <it>M. tuberculosis </it>isolates were determined by using microplate nitrate reductase assays.</p> <p>Results</p> <p>Mutations in <it>gyrA </it>(codons 90, 91 and 94) and in <it>gyrB </it>(G551R, D500N, T539N, R485C/L) were observed in 89.5% (85/95) and 11.6% (11/95) of ofloxacin-resistant strains, respectively. The <it>gyrB </it>mutations G551R and G549D were observed in 4.1% (4/97) of ofloxacin-susceptible strains and no mutation was found in <it>gyrA </it>in ofloxacin-susceptible strains. The MICs of all ofloxacin-resistant strains showed no significant difference among strains with mutations at codons 90, 91 or 94 in <it>gyrA </it>(F = 1.268, <it>p </it>= 0.287). No differences were detected among strains with different amino acid mutations in the quinolone resistance-determining region of <it>gyrA </it>(F = 1.877, <it>p </it>= 0.123). The difference in MICs between ofloxacin-resistant strains with mutations in <it>gyrA </it>only and ofloxacin-resistant strains with mutations in both <it>gyrA </it>and <it>gyrB </it>genes was not statistically significant (F = 0.549, <it>p </it>= 0.461).</p> <p>Conclusions</p> <p>Although <it>gyrA/B </it>mutations can lead to ofloxacin resistance in <it>M. tuberculosis</it>, there were no associations of different mutation patterns in <it>gyrA/B </it>and the level of ofloxacin resistance in <it>M. tuberculosis </it>isolates from East China in 2009.</p

    Evaluation of a Novel Biphasic Culture Medium for Recovery of Mycobacteria: A Multi-Center Study

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    on L-J slants. Automated liquid culture systems are expensive. A low-cost culturing medium capable of rapidly indicating the presence of mycobacteria is needed. The aim of this study was to develop and evaluate a novel biphasic culture medium for the recovery of mycobacteria from clinical sputum specimens from suspected pulmonary tuberculosis patients.<0.001).
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