• Title/Summary/Keyword: Agriculture and Forestry

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The Carbon Sequestration Potential of Forestry Sector: Bangladesh Context

  • Sohel, Md. Shawkat Islam;Rana, Md. Parvez;Alam, Mahbubul;Akhter, Sayma;Alamgir, Mohammed
    • Journal of Forest and Environmental Science
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    • v.25 no.3
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    • pp.157-165
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    • 2009

  • Forests potentially contribute to global climate change through their influence on the global carbon (C) cycle. The Kyoto Protocol provides for the involvement of developing countries in an atmospheric greenhouse gas reduction regime under its Clean Development Mechanism (CDM). Carbon credits are gained from reforestation and afforestation activities in developing countries. Bangladesh, a densely populated tropical country in South Asia, has a huge degraded forestland, which can be reforested by CDM projects. To realize the potential of the forestry sector in developing countries like Bangladesh for full-scale emission mitigation, the carbon sequestration potential should be integrated with the carbon trading system under the CDM of the Kyoto Protocol. This paper discusses the prospects of carbon trading in Bangladesh, in relation to the CDM, in the context of global warming.

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The Cryoprotective Effect on Frozen-thawed Boar Semen of Egg Yolk Low Density Lipoproteins

  • Hu, Jian-hong;Li, Qing-Wang;Li, Gang;Chen, Xiao-Yu;Hai-Yang, Hai-Yang;Zhang, Shu-Shan;Wang, Li-Qiang
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.4
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    • pp.486-494
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    • 2006

  • In order to protect the spermatozoa against cold shock, hen egg yolk is widely used as a cryoprotective agent in semen freezing extenders for domestic animals. The protective action of yolk is largely presumed to be due to low density lipoproteins (LDL). The effects of LDL on sperm quality of bull and northern pike (Esox lucius) after freezing-thawing have been reported, but no study has been made to evaluate the effect of LDL on boar sperm motility and other characteristics. The experiment was carried out to investigate the effect of LDL on the freezing of boar sperm in 0.25 ml straws. The aim was to evaluate the quality of boar spermatozoa cryopreserved in the presence of LDL. Motility of semen cryopreserved in LDL was analyzed and compared to semen cryopreserved with Tris-citric acid-glucose (TCG) and Tris-citric acid-fructose (TCF), two basic freezing extenders containing egg yolk. Similarly, acrosome and plasma membrane integrity were also evaluated and compared to semen cryopreserved with TCG and TCF. Analysis of sperm quality after freeze-thaw showed that the motility, acrosome and plasma membrane integrity were improved with LDL in the extender, as compared to the TCG and TCF. The highest post-thaw integrity of acrosome and plasma membrane and motility were obtained with 9% LDL (w/v). Consequently, the optimum LDL concentration in the extender was 9%. It is also suggested that the concentration of LDL addition is important for the effect on boar sperm protection during freezing and thawing. The percentage of motile spermatozoa was significantly higher after freezing in 9% LDL than in TCG and TCF 54.4% versus 30.4% and 30.1% (p<0.05), respectively. The integrity of acrosome and plasma membrane were also significantly higher at 70.3% and 50.5% respectively with semen frozen in 9% LDL extender compared to TCG at 37.8% and 30.3% and TCF at 36.4% and 29.9%, respectively (p<0.05),. In conclusion, we propose that extender containing LDL extracted from hen egg yolk could be used as a cryoprotective media with a better efficiency than TCG and TCF. LDL improved boar semen quality, allowing better spermatozoa motility, acrosome and plasma membrane integrity after the freeze-thaw process. Furthermore, we found out that the extender with 9% LDL concentration significantly enhanced motility, acrosome and plasma membrane integrity of boar sperm after freezing and thawing.

  • https://doi.org/10.5713/ajas.2006.486 인용 PDF KSCI