13 research outputs found

    On Second-best Policing Effort against the Illegal Disposal of Recyclable Waste

    Get PDF
    In this paper, we construct a partial equilibrium model of a product that can be manufactured by using a recycled material as well as a virgin natural resource. In particular, we consider the possibility that a household may resort to the illicit disposal of its waste, such as midnight dumping, instead of discarding it properly. Our focus is on conducting a comparative static analysis on the second-best level of the governmentfs policing effort to counter illegal disposal. More specifically, we examine how the government should adjust the effort level in response to changes in the environmental damage cost of illegal disposal and exported waste.illegal waste disposal, recycling, second-best policy

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Role of mutagenic 8-nitroguanine in estrogen-dependent radiation-induced mammary tumorigenesis of rats

    No full text
    Radiation of female rats during lactation results in a higher incidence of mammary tumors. Inano and Onoda have reported that nitric oxide (NO) participates in the formation of estrogen-dependent mammary adenocarcinomas following radiation. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are considered to play important roles in carcinogenesis through oxidative and nitrative DNA damage. Kawanishi and colleagues have demonstrated the formation of 8-nitroguanine as a potential biomarker to evaluate the risk of inflammation-related carcinogenesis in humans and animals. 8-Nitroguanine is a nitrative DNA lesion caused by RNS, which can lead to mutation via generating apurinic site in DNA. In this study, we examined 8-nitroguanine formation in mammary tumorigenesis induced by radiation with steroid analogue in rats. Wistar-MS rats were exposed to whole-body irradiation with gamma-rays (1.5 Gy) at day 21 of lactation, and then implanted with a pellet of diethylstilbestrol (DES, a tumor promoter) in the interscapular area at one month after irradiation. After 1 year for the development of mammary tumors, mammary tissues were obtained, fixed with formalin, embedded in paraffin, and followed by immunohistochemical analyses. Wistar-MS rats were primed by implantation with 17beta-estradiol (E2) pellet. After 2 weeks of priming the mammary glands were isolated, diced into 5-mm cubes and cultured with an appropriate medium for 24h. The cultured mammary glands were then irradiated with X-rays (0, 5, 10, 20 Gy), incubated for additional 20h, fixed with formalin, and analyzed as described above. In the current study the formation of 8-nitroguanine was clearly obserbed in fibroadenomas and adenocarcinomas developed in rats treated with gamma-rays and DES. This suggests that nitrative DNA damage was induced and accumulated in rat mammary glands by radiation and DES. The formation of 8-nitroguanine were also detected in mammary glands irradiated in the culture after isolation from E2-treated rats. Interestingly, the immunoreactivity to 8-nitroguanine appeared to increase in dose-dependent manner of X-rays. In conclusion, iNOS-derived NO may play a role in the formation of estrogen-dependent mammary adenocarcinomas via 8-nitroguanine formation following radiation.14th International Congress of Radiation Researc