Straightforward synthesis of 1-alkyl-2-(trifluoromethyl)aziridines starting from 1,1,1-trifluoroacetone

An efficient and straightforward approach towards the synthesis of 1-alkyl-2-(trifluoromethyl)aziridines starting from 1,1,1-trifluoroacetone via imination, alpha-chlorination, hydride reduction and ring closure was developed. In addition, novel primary beta-iodo amines were obtained by regioselective ring opening of these 2-(trifluoromethyl)aziridines using alkyl iodides, and their synthetic potential was demonstrated by converting them into novel alpha-CF(3)-beta-phenylethylamines upon treatment with lithium diphenylcuprate

Synthesis of new simplified hemiasterlin derivatives with α,β-unsaturated carbonyl moiety.

International audienceIn this Letter, we report a convenient and efficient method for the synthesis of new simplified derivatives of hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groups as Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumor cell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB and Hep-G2 cancer cell lines comparable to paclitaxel and ellipticine

Synthesis of new bioisosteric hemiasterlin analogues with extremely high cytotoxicity

International audienceIn this article, we report a convenient and efficient method for the synthesis of new simplified derivativesof hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groupsas Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumorcell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB andHep-G2 cancer cell lines comparable to paclitaxel and ellipticine

Environmental isues of mining activities in Tay Nguyen

Intensive mining activities, specially illegal, negatively affect environment in Tay Nguyen. Mining of gold and tin placers, sand and pebble disturbed the landscape, changed river bed caussing river bank erosion. Exploited wastes from mine, for example, kaolin mine in Loc Chau (Lam Dong province) destroyed and retrograded tea land. There observed evidences of acid mine drainage and pollution of heavy metal including Cu, Pb, Hg, et.c in surface water, stream sediments and soils from some gold mines such as Dak Ripen (Kon Tum), Krong A (Dak Lak) and Tra Nang (Lam Dong). Main causes of mining environmental problems are failure of management, so the first and most important measure of mitigation is to improve the management of mining activities.ReferencesBorisenko A.S., Trần Trọng Hòa, V.I. Vasilev, N.K. Morsev, Vũ Văn Vấn, Ngô Thị Phượng, Hoàng Hữu Thành, Trần Tuấn Anh, Phạm Thị Dung, 2008: Phát hiện lần đầu tiên khoáng vật Jonassonite - AuBi5S4 ở Việt Nam. Tạp chí Các Khoa học về Trái Đất, T.30, (3), tr.193-198. Damigos D., 2006: An overview of environmental valuation methods for the mining industry. Journal of Cleaner Production, Volume 14, Issues 3-4, P. 234-247 Dixon-Hardy, D.W. Engels, J.M., 2007: Guidelines and Recommendations for the Safe Operation of Tailings Management Facilities. - Environmental Engineering Science, 24 (5), 14-26. Doolittle, J.J., Frisbee, N.M. and Hossner, L.R., 1992: Evaluation of acid-base accounting techniques used in surface-mine reclamation, Proc. 1992 Meeting of the American Society of Surface Mining and Reclamation, 14-18 June, Duluth, MN, p68-76. Trần Trọng Hòa, Ngô Thi Phượng, Borisenko A.S., Izokh A.E., Vũ Văn Vấn, Bùi Ấn Niên, Trần Tuấn Anh, Phạm Thị Dung, 2005: Đặc điểm địa hóa-đồng vị của quặng hóa vàng Mesozoi sớm và Mesozoi muộn trong mối liên quan với hoạt động magma rìa Đông Nam địa khối Đông Dương. Tạp chí Địa chất, Loạt A, số 295, tr.15-24. Nguyễn Kim Hoàng, Nguyễn Văn Mài, 2010: Đặc điểm khoáng hóa và triển vọng vàng gốc Trà Năng, tỉnh Lâm Đồng. Đại học Quốc gia Tp. HCM. Nilsson J-A, Randhem J., 2008: Environmental Impacts and Health Aspects in the Mining Industry. Department of Energy and Environment. Division of Environmental Systems Analysis. Chambers University of Technology. Göteborg, Sweden, 2008. publications.lib.chalmers.se/records/fulltext/85984.pdf‎ Plumlee, G.S. and Nash, J.T., 1995: Geoenvironmental models of mineral deposits--fundamentals and applications. U.S. Geol. Survey Open-File Report 95-831, p.1-18. Lê Văn Thành, 2004: Khai thác khoáng sản và tác động đến môi trường. Địa chất, N.281 Vũ Văn Vấn, Trần Trọng Hòa, A.S. Borisenko, Ngô Thị Phượng, Trần Tuấn Anh, Trần Hồng Lam, Đặng Trung Thuận, Phạm Thị Dung, 2007: Quặng hóa vàng Tà Năng, đới cấu trúc Đà Lạt: Điều kiện hình thành và bối cảnh địa động lực. Tạp chí Các Khoa học về Trái Đất, T.29, (2), tr.154-160. Báo cáo hiện trạng môi trường tỉnh Lâm Đồng giai đoạn 2006 - 2010: Sở Tài nguyên và Môi trường Lâm Đồng. http://www.lamdong.gov.vn/vi-VN/a/sotnmt/du-lieu-so/moi-truong/Pages/baocaohientrang2006-2010.aspx. Guidebook for Evaluating Mining Project EIAs, 2010: www.elaw.org/files/mining-eia-guidebook/Chapter1.pdf Global Acid Rock Drainage Guide (http://www.gardguide.com/index.php/Main_Page) UNEP, 1997: Industry and environment, mining and sustainable development. http://www.uneptie.org/vol20no4.htmO; 1997.

Radio Detection of the Sun

The radio emission of the Sun has been measured using a radio interferometer including two Yagi antennas operated at 610 MHz. We report the observation of interferences and comment on the results

Assessing decentralised policy implementation in Vietnam : The case of land recovery and resettlement in the Vung Ang Economic Zone

From 2006 plans were implemented to create a deep-sea water port linked to an Economic Zone in the coastal Province of Ha Tinh, located in north central Vietnam. The multi-purpose Zone entitled ‘Vung Ang’, was to attract foreign investors, while the port would provide a link to nearby Laos and Thailand. The project obviously had large implications for the administrations at various levels of governance from Hanoi to the coastal communes and villages, but even more serious impacts on the people living in the affected areas. A large area of about 23,000 hectares was to be cleared, affecting the people of 9 communes, in some of which all inhabitants had to leave their houses and homesteads, to be relocated to completely new settlements about 10 miles inland. These tightly knit communities were not too happy with the prospect to leave their homes and land, the burial places of their ancestors, and the long term comforts of community support networks. While initial decision making process started at the highest levels of Vietnam Governance, the implementation of port and industrial park construction and the related relocation policy was delegated to Ha Tinh province, which is consistent with current decentralisation policies in Vietnam. Actual implementation was carried out by the affected District and Commune level officials – with support from the Communist Party led Mass Organisations – who were in charge of the planning and implementation of the relocation process. This entailed a complex and sensitive series of steps to inform affected households, prepare relocation areas and allocate compensation and alternative housing. This paper describes the implementation dynamics of relocation by depicting and assessing the roles of all stakeholders involved, including the impacts - for better or for worse – of the relocated households. It brings out the way local authorities dealt with affected people, including efforts linked to the ideal of grass-roots democracy. Key areas of contestation are uncovered, such as inadequate infrastructure and low compensation rates. The paper has a second objective to assess the degree to which decentralisation in Vietnam has been actually implemented, and how this affects policy making processes such as the Vung Ang port/industrial zone project. The paper concludes that the relocation policy was implemented in a fairly efficient and harmonious way – with a very intensive engagement of the entire provincial administrative machinery, but that it is too early to assess the livelihood opportunities of the relocated households

Bringing social and cultural considerations into environmental management for vulnerable coastal communities: Responses to environmental change in Xuan Thuy National Park, Nam Dinh Province, Vietnam

This paper elaborates the importance of considering social and cultural factors within management responses to environmental change in coastal areas. The case study taken is Xuan Thuy National Park in Nam Dinh Province, Vietnam. This is a marginalised coastal area where rising sea levels, increasing storm surges and saltwater intrusion place pressure on coastal ecosystems, yet where communities continue to rely on these same ecosystems for agriculture- and aquaculture-related livelihoods. We interview stakeholders in Xuan Thuy National Park, connecting these with a narrative review of existing research into social and environmental change in the park to understand research gaps and challenges for vulnerable coastal areas like the Nam Dinh coast. Based on our findings, we suggest that whilst the effects of a changing environment on physical health and economic activity are increasingly well understood, effects on wellbeing and social relations can be even more immediate and profound in daily living. In turn, we argue environmental management has a crucial role to play not only for ecosystem-based adaptation, but also in sustaining wellbeing and allowing culturally meaningful practices to continue – especially in coastal regions where changes can be even more intense and immediate. However, we caution that whilst techno-scientific solutions grounded in environmental management do have significant potential in reducing impacts of extreme events and slower-onset environmental changes, they must not divert attention away from structural issues that can make some people or areas more vulnerable in the first instance

Logging intensity drives variability in carbon stocks in lowland forests in Vietnam

Forest degradation in the tropics is generating large carbon (C) emissions. In tropical Asia, logging is the main driver of forest degradation. For effective implementation of REDD+ projects in logged forests in Southeast Asia, the impacts of logging on forest C stocks need to be assessed. Here, we assess C stocks in logged lowland forests in central Vietnam and explore correlations between logging intensity, soil, topography and living aboveground carbon (AGC) stocks. We present an approach to estimate historical logging intensities for the prevalent situation when complete records on logging history are unavailable. Landsat analysis and participatory mapping were used to quantify the density of historical disturbances, used as a proxy of logging intensities in the area. Carbon in AGC, dead wood, belowground carbon (BGC) and soil (SOC) was measured in twenty-four 0.25 ha plots that vary in logging intensity, and data on recent logging, soil properties, elevation and slope were also collected. Heavily logged forests stored only half the amount of AGC of stems ≥10 cm dbh as lightly logged forests, mainly due to a reduction in the number of large (≥60 cm dbh) trees. Carbon in AGC of small trees (5–10 cm dbh), dead wood and BGC comprised only small fractions of total C stocks, while SOC in the topsoil of 0–30 cm depth stored ~50% of total C stocks. Combining logging intensities with soil and topographic data showed that logging intensity was the main factor explaining the variability in AGC. Our research shows large reductions in AGC in medium and heavily logged forests. It highlights the critical importance of conserving big trees to maintain high forest C stocks and accounting for SOC in total C stock estimates