Genomic instability in human osteoblast cells after exposure to depleted uranium: delayed lethality and micronuclei formation

It is known that radiation can induce a transmissible persistent destabilization of the genome. We have established an in vitro cellular model using HOS cells to investigate whether genomic instability plays a role in depleted uranium (DU)-induced effects. Transmissible genomic instability, manifested in the progeny of cells exposed to ionizing radiation, has been characterized by de novo chromosomal aberrations, gene mutations, and an enhanced death rate. Cell lethality and micronuclei formation were measured at various times after exposure to DU, Ni, or gamma radiation. Following a prompt, concentration-dependent acute response for both endpoints, there was de novo genomic instability in progeny cells. Delayed reproductive death was observed for many generations (36 days, 30 population doublings) following exposure to DU, Ni, or gamma radiation. While DU stimulated delayed production of micronuclei up to 36 days after exposure, levels in cells exposed to gamma-radiation or Ni returned to normal after 12 days. There was also a persistent increase in micronuclei in all clones isolated from cells that had been exposed to nontoxic concentrations of DU. While clones isolated from gamma-irradiated cells (at doses equitoxic to metal exposure) generally demonstrated an increase in micronuclei, most clonal progeny of Ni-exposed cells did not. These studies demonstrate that DU exposure in vitro results in genomic instability manifested as delayed reproductive death and micronuclei formation.     

Impact assessment of waste management options in Singapore

This paper describes the application of life cycle assessment for evaluating various waste management options in Singapore, a small-island city state. The impact assessment method by SimaPro is carried out for comparing the potential environmental impacts of waste treatment options including landfilling, incineration, recycling, and composting. The inventory data include gases and leachate from landfills, air emissions and energy recovery from incinerators, energy (and emission) savings from recycling, composting gases, and transport pollution. The impact assessment results for climate change, acidification, and ecotoxicity show that the incineration of materials imposes considerable harm to both human health and the environment, especially for the burning of plastics, paper/cardboard, and ferrous metals. The results also show that, although some amount of energy can be derived from the incineration of wastes, these benefits are outweighed by the air pollution (heavy metals and dioxins/furans) that incinerators produce. For Singapore, landfill gases and leachate generate minimal environmental damage because of the nation's policy to landfill only 10% of the total disposed wastes. Land transportation and separation of waste materials also pose minimal environmental damage. However, sea transportation to the landfill could contribute significantly to acidification because of the emissions of sulfur oxides and nitrogen oxides from barges. The composting of horticultural wastes hardly imposes any environmental damage. Out of all the waste strategies, the recycling of wastes offers the best solution for environmental protection and improved human health for the nation. Significant emission savings can be realized through recycling.     

Effects of petroleum contamination on soil microbial numbers, metabolic activity and urease activity

The influence of petroleum contamination on soil microbial activities was investigated in 13 soil samples from sites around an injection water well (Iw-1, 2, 3, 4) (total petroleum hydrocarbons (TPH): 7.5-78 mg kg⁻¹), an oil production well (Op-1, 2, 3, 4, 5) (TPH: 149-1110 mg kg⁻¹), and an oil spill accident well (Os-1, 2, 3, 4) (TPH: 4500-34 600 mg kg⁻¹). The growth rate constant (μ) of glucose stimulated organisms, determined by microcalorimetry, was higher in Iw soil samples than in Op and Os samples. Total cultivable bacteria and fungi and urease activity also decreased with increasing concentration of TPH. Total heat produced demonstrated that TPH at concentrations less than about 1 g kg⁻¹ soil stimulated anaerobic respiration. A positive correlation between TPH and soil organic matter (OM) and stimulation of fungi-bacteria-urease at low TPH doses suggested that TPH is bound to soil OM and slowly metabolized in Iw soils during OM consumption. These methods can be used to evaluate the potential of polluted soils to carry out self-bioremediation by metabolizing TPH.     

Impact caps: why population,affluence and technology strategies should be abandoned

This paper classifies strategies to reduce environmental impact according to the terms of the I = PAT formula. Policies limiting resource depletion and pollution (Impact) – by heavily taxing resources or rationing them on a country basis – are thus called ‘direct’ or ‘left-side’ strategies. Other policies to achieve the environmental goal of lowering Impact strive to limit Population and Affluence, or to use Technology to lower the ratio of resource inputs to goods-and-services outputs. Next it is shown that lowering any of these ‘right-side’ factors causes or at least enables the other two to rise or ‘rebound’. This has two consequences: 1) Since I = PAT does not express these interdependencies on the right side, it is more accurately written I = f(P,A,T); and 2) Success in lowering any of the right-side factors does not necessarily lower Impact. Rationing or Pigouvian taxation of resources or pollution, on the other hand, necessarily lower impact and are therefore preferable to population, consumption and technological environmental strategies. Finally, lifestyle and technology changes towards more sufficiency and efficiency would follow the caps as consumers and producers work to retain the greatest amount of welfare within the limits given.     

Remediation of fly ash landfills through plantation

In India, a significant area of land is occupied by preexisting coal‐fired thermal power plants (TPPs) for the storage of fly ash slurry in ash ponds. However, the area available for storage of fly ash at these TPPs is limited. In addition, this type of fly ash disposal poses a problem due to restricted land availability and potential contamination issues. A viable alternative is the reclamation of fly ash ponds by plantation. A study at the Ramagundam Super Thermal Power Station (RSTPS) in Andhra Pradesh, India, on reclamation of a portion of an ash‐filled, low‐lying area has been performed. This article describes the characteristics of the RSTPS pond ash, ash leachates, and improvements in the fertility status of the reclaimed area over a three‐year period. Furthermore, morphometric observations of different planted species indicate that these types of ash‐filled, low‐lying areas can be suitably reclaimed and the nutrient‐rich leachate from ash‐filled areas potentially can be used for irrigation purposes. © 2008 Wiley Periodicals, Inc.     

Mediated Modeling in Water Resource Dialogues Connecting Multiple Scales

We observe a paradigm shift toward collaborative, multi‐level (from local to global) water management and suggestions for scale‐related design principles in the literature. Decision‐support tools are needed that can help achieve scale design principles. Mediated modeling (MM) refers to model building with people, rather than for people. This tool belongs to a family of participatory, systems oriented tools. This article explores their suitability for addressing challenges and principles that arise at multiple‐scales. MM can promote the understanding of cross‐level and cross‐scale links, creating salient, credible, and legitimate knowledge and encouraging boundary functions. Prerequisites for successful MM processes include an openness and willingness to collaborative learning. As new “meso‐level” institutions emerge to address complex challenges in water management collaboratively, tools like MM may play an important role in structuring dialogues, developing adaptive management capacity and advance an ecosystem services approach.     

Total Factor Productivity Change in the New England Groundfish Fishery: 1964–1993

We develop estimates of total factor productivity (TFP) change in the New England groundfish fishery from 1964 to 1993, using a procedure similar to Squires' (1992, Rand J. Econom.23(2), 221–236) method, which extends standard TFP measurement by including the effect of fluctuations in stock abundance. The results indicate that TFP increased on average by 4.4% per year from 1964 to 1993. A higher average rate of increase occurred between 1964 and 1982, possibly due to new technologies (e.g., fishfinders). TFP declined at 0.33% annually from 1983 to 1993 due to stringent output and effort control measures.     

低碳高能,骑车出行没烦恼

<正>下午5点,一场大雨不期而至。史蒂夫站在窗前,心里不免有些失望,因为不能骑车回家了。史蒂夫是个不折不扣的骑行达人。在北京住了10年,换了4辆自行车。他的上一辆自行车报废之前,里程记录仪上留下的数字是3年18844公里,相当于绕二环576圈。10年间,从家门口的胡同开始,史蒂夫骑车转遍了鼓楼、故宫、工体、国贸和香山……从十三陵到南海子,从门头沟到通州,最后他甚至把车骑到了天津。可以这么说,只要是骑车能到达的地方,史蒂夫绝不选