8,525 research outputs found

    DROUGHT AND CLIMATE CHANGE: IMPLICATIONS FOR THE WEST

    Get PDF
    Environmental Economics and Policy,

    Effects of Climate Change on Water Resources

    Get PDF
    Environmental Economics and Policy, Resource /Energy Economics and Policy, Q25, Q54,

    The persistence of drought impacts across growing seasons: a dynamic stochastic analysis

    Get PDF
    Agricultural producers throughout much of the United States experienced one of the most severe droughts in the last 100 years during the years 1999-2006. The prolonged nature of this drought highlights a need to better understand the impacts and management of drought across growing seasons, rather than just within a growing season. Producers express specific concern about the tendency of drought impacts to persist even after drought itself has subsided. The persistence of drought impacts has received limited attention in the economics literature. The objectives of this study are two-fold: 1) to determine whether inter-year dynamics, in the form of agronomic constraints and financial flows, can cause persistence of a drought's impact in years subsequent to the drought, and 2) to determine whether the impact of one year of drought can alter the impact of a subsequent year of drought. A multi-year, dynamic and stochastic decision model is developed in a discrete stochastic programming framework and solved to address the objectives. The structure and parameters of the farm-level model are based on irrigated row crop farms in eastern Oregon, USA. Analysis of the model's solution reveals the following results: 1) the impact of a drought can persist long after the drought subsides, and 2) the impact of one year of drought can alter the impact of a subsequent year of drought. Potential implications for the administration of drought-related assistance are discussed briefly.Drought, preparedness, response, uncertainty, dynamics, discrete stochastic programming, agriculture, irrigation, eastern Oregon, row crops, crop rotation, Crop Production/Industries, Risk and Uncertainty,

    Variation in size of living articulated brachiopods with latitude and depth

    Get PDF
    Geographical variations in animal characters are one of the main subjects for study in macroecology. Variation with latitude has received special interest. Articulated brachiopods are possibly the commonest macrofossil with large variations in size of taxa through the fossil record. Here, we investigate trends in size of the 3 main orders of articulated brachiopod with latitude and depth. Data were insufficient to identify patterns in Thecideida (a micromorph taxon only recorded from low latitudes). Rhynchonellida had no clear trends in size with latitude or depth. Terebratulida exhibited hemispheric differences in size relations, with increasing length of species towards the pole in the south and no significant trend in the north. Tropical species were small (<20 mm length between 10°N and 10°S), and the largest species were found between 30° and 60° latitude in both hemispheres. There were no articulated brachiopods recorded from the high arctic, and support for a continuous trend in size with latitude was small or absent. In Terebratulida, there was a significant decrease in species length with depth of 1.7 mm per 100 m depth increase. These trends could be explained by competition for space and reduced availability of habitat with progressive depth beyond the continental shelf

    PERISHABLE REFRIGERATED PRODUCTS AND HOME PRACTICES SURVEY

    Get PDF
    The "Perishable Refrigerated Products and Home Practices Survey" was a two-part survey developed to better understand consumers' perceptions and their current level of understanding regarding the proper handling and storage of perishable refrigerated foods. Past studies (e.g. Anonymous, 1997a; Anonymous, 1999a) have demonstrated a lack of consumer knowledge in such areas involving food safety practices. In recent years, there have been a number of large food recalls (i.e. Anonymous, 1997b; Anonymous, 1999b; CDC, 1999) due to the presence or possible presence of foodborne pathogens. Part of this study analyzed consumers' knowledge and attitudes towards the recalled products. A large number of foodborne outbreaks also occur in the household. After examining participant responses concerning food handling practices, (i.e. improper temperature control and lack of food rotation habits), the practices of many of the participants were not suitable to prevent possible foodborne contamination. Open dates and time-temperature integrators (TTI's), especially when used together, can assist consumers in purchasing fresh foods (Taoukis and Labuza, 1989a, b). However, numerous past studies have indicated consumer confusion regarding the meaning of open dates; and the results of this study confirm that the confusion continues. This may be due in part to the fact that there is no federally mandated, uniform open dating legislation in this country. TTI's are a fairly new device on the U.S. marketplace. While participants in this study were optimistic about the potential benefits of TTI's, 76% of consumers were unfamiliar with the device.Food Consumption/Nutrition/Food Safety,

    Frequency-dependent polarizabilities of alkali atoms from ultraviolet through infrared spectral regions

    Full text link
    We present results of first-principles calculations of the frequency-dependent polarizabilities of all alkali atoms for light in the wavelength range 300-1600 nm, with particular attention to wavelengths of common infrared lasers. We parameterize our results so that they can be extended accurately to arbitrary wavelengths above 800 nm. This work is motivated by recent experiments involving simultaneous optical trapping of two different alkali species. Our data can be used to predict the oscillation frequencies of optically-trapped atoms, and particularly the ratios of frequencies of different species held in the same trap. We identify wavelengths at which two different alkali atoms have the same oscillation frequency.Comment: 6 pages, 2 figure

    Observations of extragalactic masers in bright IRAS sources

    Get PDF
    We report the first results of an ongoing survey at 22 GHz with the 100-m Effelsberg telescope to search for water maser emission in bright IRAS sources. We have detected water vapor emission in IC 342. The maser, associated with a star forming region ~10-15 arcsec west of the nucleus, consists of a single 0.5 km/s wide feature and reaches an isotropic luminosity of 0.01 L(sun) (D = 1.8 Mpc). Our detection raises the detection rate among northern galaxies with IRAS point source fluxes S(100micron) > 50 Jy to 16%.Comment: 6 pages, 3 figures. Proceeding of the conference "SRT: the impact of large antennas on Radio Astronomy and Space Science", Cagliari, Italy, 7-10 Nov. 2001, Eds. Porceddu et al. Needs srt_style.st
    • …
    corecore