308 research outputs found

    Urbanization of irrigated land and water transfers

    Get PDF
    Presented at Urbanization of irrigated land and water transfers: a USCID water management conference on May 28-31, 2008 in Scottsdale, Arizona.An ever increasing challenge for rural irrigation districts in the agriculturally rich San Joaquin Valley of California is adjusting to urbanization while maintaining an effective and efficient irrigation water delivery system. The Oakdale Irrigation District (OID) is currently facing this challenge and has developed a Subdivision/Parcel Map Development Policy that attempts to bring balance to that concern. This paper will present OID's Subdivision Policy and discuss the reasoning behind the conditions and requirements within the policy. It is the intent of this paper to provide other irrigation districts, facing similar urbanization pressures, a foundation for development of similar policies in the hopes of preserving and protecting the water delivery systems so vital to our agricultural communities

    USCID fourth international conference

    Get PDF
    Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.In response to a range of internal and external drivers and the need to protect the district's pre-1914 water rights, Oakdale Irrigation District (OID) developed a long-term Water Resources Plan (WRP). The 100-year-old irrigation district provides irrigation and domestic water service to over 55,000 acres in California's San Joaquin Valley. The study effort created a strategic roadmap for the implementation of a $170 million capital program focused on protecting OID's water rights while meeting the changing needs of its constituency and serving the region. The second phase included programmatic environmental documentation, which is being followed by design and construction of facility improvements. This multi-disciplined effort included detailed land use modeling, water balance modeling, on-farm surveys, a comprehensive infrastructure assessment, and the development of a phased infrastructure plan to rehabilitate and modernize an out-of-date system. The approach also integrated water right evaluations, groundwater studies, development and evaluation of program alternatives, financial analyses, environmental compliance, and public outreach. Key benefits resulting from WRP implementation include protecting the district's water rights, increasing reliability during droughts, and modernizing a century-old system to meet the needs of its current and future customer base. Implementation includes a balanced effort of water transfers and expansion of service into OID's sphere of influence while keeping water rates affordable. OID's infrastructure will be rebuilt, modernized, and expanded, and customer service and water use efficiency will be enhanced

    Morph-specific investment in testes mass in a trimorphic beetle, Proagoderus watanabei

    Get PDF
    When competition between males for mates is intense, it is common to find that some males will adopt alternative tactics for acquiring fertilizations, often involving the use of ‘sneak’ tactics whereby males avoid precopulatory contests. These alternative tactics are sometimes associated with discrete differences in male morphology, with sneak males investing less in weaponry but more in traits such as testes which may give an advantage in sperm competition. In some cases, it appears that males develop into more than two morphs, with a number of examples of tri- and even tetramorphic arthropod species being described. Here, we analyse the scaling relations of the dung beetle species Proagoderus watanabei, which expresses two distinct weapon traits: paired head horns and a pronotal horn. We find that males of this species are trimorphic, with alpha males expressing long head horns and a pronotal horn, beta males with long head horns but no pronotal horn and gamma males with short head horns only. We also find that alpha males invest relatively less in testes than do beta or gamma males, indicating that beta and gamma males in this species probably experience higher risks of sperm competition than do alphas

    Enhanced Spontaneous Emission Into The Mode Of A Cavity QED System

    Get PDF
    We study the light generated by spontaneous emission into a mode of a cavity QED system under weak excitation of the orthogonally polarized mode. Operating in the intermediate regime of cavity QED with comparable coherent and decoherent coupling constants, we find an enhancement of the emission into the undriven cavity mode by more than a factor of 18.5 over that expected by the solid angle subtended by the mode. A model that incorporates three atomic levels and two polarization modes quantitatively explains the observations.Comment: 9 pages, 2 figures, to appear in May 2007 Optics Letter

    Foundation and empire : a critique of Hardt and Negri

    Get PDF
    In this article, Thompson complements recent critiques of Hardt and Negri's Empire (see Finn Bowring in Capital and Class, no. 83) using the tools of labour process theory to critique the political economy of Empire, and to note its unfortunate similarities to conventional theories of the knowledge economy

    Ownership-dependent mating tactics of minor males of the beetle Librodor japonicus (Nitidulidae) with intra-sexual dimorphism of mandibles

    Get PDF
    Intra-sexual dimorphism is found in the weapons of many male beetles. Different behavioral tactics to access females between major and minor males, which adopt fighting and alternative tactics, respectively, are thought to maintain the male dimorphism. In these species major males have enlarged weapons that they use in fights with rival males. Minor males also have small weapons in some of these species, and it is unclear why these males possess weapons. We examined the hypothesis that minor males might adopt a fighting tactic when their status was relatively high in comparison with that of other males (e.g., ownership of a territory). We observed the behavioral tactics of major and minor males of the beetle Librodor japonicus, whose males have a dimorphism of their mandibles. Major males fought for resources, whereas minor males adopted two status-dependent tactics, fighting and sneaking, to access females, depending on their ownership of a sap site. We suggest that ownership status-dependent mating tactics in minor males may maintain the intra-sexual dimorphism in this beetle.</p

    Till death (or an intruder) do us part: intrasexual-competition in a monogamous Primate

    Get PDF
    Polygynous animals are often highly dimorphic, and show large sex-differences in the degree of intra-sexual competition and aggression, which is associated with biased operational sex ratios (OSR). For socially monogamous, sexually monomorphic species, this relationship is less clear. Among mammals, pair-living has sometimes been assumed to imply equal OSR and low frequency, low intensity intra-sexual competition; even when high rates of intra-sexual competition and selection, in both sexes, have been theoretically predicted and described for various taxa. Owl monkeys are one of a few socially monogamous primates. Using long-term demographic and morphological data from 18 groups, we show that male and female owl monkeys experience intense intra-sexual competition and aggression from solitary floaters. Pair-mates are regularly replaced by intruding floaters (27 female and 23 male replacements in 149 group-years), with negative effects on the reproductive success of both partners. Individuals with only one partner during their life produced 25% more offspring per decade of tenure than those with two or more partners. The termination of the pair-bond is initiated by the floater, and sometimes has fatal consequences for the expelled adult. The existence of floaters and the sporadic, but intense aggression between them and residents suggest that it can be misleading to assume an equal OSR in socially monogamous species based solely on group composition. Instead, we suggest that sexual selection models must assume not equal, but flexible, context-specific, OSR in monogamous species.Wenner-Gren Foundation, L.S.B. Leakey Foundation, the National Geographic Society, National Science Foundation (BCS- 0621020), the University of Pennsylvania Research Foundation and the Zoological Society of San Diego, German Science Foundation (HU 1746-2/1
    corecore