1,038 research outputs found

    The Conservation Movement in New Zealand

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    Over the past 150 years of European settlement of New Zealand, the basis of economic growth has been the exploitation of her natural resources. The object of this study is to examine the character, motives, and exploitation of the natural resources, and the growth of attitudes to conservation. Because of the scope that such a study could cover, it is necessary to restrict it to the more outstanding characteristics of the movement for conservation in New Zealand. In the first chapter the conservation movement, particularly that of the United States, will be discussed. This will be followed in Chapter II by an examination of the resource elements of New Zealand in terms of their nature and degree of exhaustibility. In Chapter III, conservation policies and attitudes towards various resources will be identified, from the early years of European settlement to the end of World War II. The changing attitudes to the utilisation of resources, will be examined to determine their relative importance in deciding how various resources will be utilised. Contemporary attitudes to the utilisation of utilisation of resources, and to the conservation of those resources will be examined in Chapter IV. In the final chapter an attempt will be made to - 6 - identify a "conservation movement" in New Zealand in terms of the development of attitudes to resource use over the 150 years of European settlement. This study is made with the aim of highlighting developments in conservation thought at a time when the implications of' "conservation" are assuming increasing importance for New Zealand

    Military Settlement in the Middle Waikato Basin

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    Military settlement formed a brief but distinctive phase in the European occupation of the Middle Waikato Basin. Prior to the 1863 - 1864 Waikato War, few Europeans, other than a small number of missionaries and traders, were settled in the region. The setting of the Middle Waikato Basin was largely unmodified by Man, except along the major rivers where a dense Maori population was settled. During the 1850's, the encroachment of European settlers upon Maori tribal lands in many North Island regions, including the Waikato, led to an increase in tension between the two populations and open conflict. This conflict slowed down the progress of colonization in the North Island. To enable colonization to continue in those regions disturbed by Maori unrest, a scheme of military settlement was devised. The aim of this scheme was the formation of compact, self-sufficient defensive settlements to act as a deterrent to Maori unrest. These settlements would also provide an assurance to settlers of security for their life and property. Military settlement in the Middle Waikato Basin consisted of two phases. In the first phase, the nodal points of the military settlements, the townships, were established and occupied by the military settlers. In the second phase, farm districts were surveyed around the nodal points and the military settlers moved out from the townships to occupy and develop the land they were allocated. A number of factors, relating to deficiencies in the scheme of military settlement and to the particular problems of settlement in the region, contributed to the failure of the military settlers to successfully establish farms on the land they were allocated. The scheme of military settlement largely failed as a method of colonization in the Middle Waikato Basin. However, the pattern of human occupation, established in the initial phase of military settlement, remained when the need for defensive settlements had gone, and forms the basis of the present pattern of settlement

    Budgets for Major Crop Enterprises in South Dakota

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    Budgets in this publication reflect average yields and production costs for individual areas of the state. Yields are based on ASCS 1976 projected yields for wheat, corn, barley and sorghum. Yields for other crops are based on estimates by Extension agronomists and Farm Management Specialists. The budgets are intended to serve as planning guides for farmers, ranchers, teachers, extension personnel and other individuals or groups who may have use for such information. No single budget can reflect the private situation of all individual producers. There are differences in rate of fertilizer use, weed and pest control practices and machine operations performed. These are just a few of the variables involved. Price of prqduct as well as price of inputs is perhaps the single most important variable affecting return above cost for forward planning purposes. Therefore, provision is made for revision of the budgets according to need. Budgets in this publication may be revised or updated in several ways: 1. By use of a computer terminal. 2. By manual calculations under the column headed your estimate on each budget page. Individuals may find this to be the quickest and easiest way to revise a single budget. 3. By changing prices stored in the data bank price file and calling for a computer revision of all budgets under a new set of prices. It should be noted that each enterprise has budget data presented on the front and back side of a single page. The front side contains a summary of the costs and returns as well as resource requirements. The back side of each budget page contains basic data on file in the computer data bank from which calculations are made to determine the costs and returns as presented on the front side of the page

    Heavy Metal, Organochlorine Pesticide and Polychlorinated Biphenyl Contamination in Arctic Ground Squirrels (Spermophilus Parryi) in Northern Alaska

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    Heavy metal and organochlorine (OC) concentrations including organochlorine pesticides and polychlorinated biphenyl congeners (PCBs), were determined in arctic ground squirrels (Spermophilus parryi) from three sites in the Brooks Range of northern Alaska in 1991-93. Heavy metals were present in most squirrel livers collected, with concentrations of trace elements (As, Cd, Hg, Ni, and Pb) averaging below 1 micro g/g wet weight. Hexachlorobenzene (HCB), p,p'-DDE, gamma hexachlorocyclohexane (gamma-HCH), trans-nonachlor, and PCBs 138, 153, and 170 were the most frequently detected OCs in fat and liver. Average concentrations of individual OC analytes were below 20 ng/g wet weight in liver and below 15 ng/g wet weight in fat. Rank correlations indicate that concentrations of heavy metals and of OCs accumulate in concert with one another (As, Cd, Cu, and Zn; PCBs 138, 170, and 180). Although heavy metal and OC concentrations are low relative to other areas and other arctic species, the occurrence of these compounds illustrates the global pervasiveness of persistent organic compounds and the potential for bioaccumulation in the terrestrial arctic food web.De 1991 à 1993, on a mesuré les concentrations en métaux lourds et en organochlorés, y compris des pesticides organochlorés et des congénères du diphényle polychloré (PCB), chez le spermophile arctique (Spermophilus parryi) à trois endroits situés dans la chaîne de Brooks de l'Alaska septentrional. On a trouvé des métaux lourds dans la plupart des foies de spermophiles prélevés, avec des concentrations en éléments traces (As, Cd, Hg, Ni et Pb) inférieures en moyenne à 1 µg/g de poids frais. L'hexachlorobenzène (HCB), le p,p'-DDE, l'hexachlorocyclohexane gamma (HCH-gamma), le trans-nonachlore et les PCB 138, 153 et 170 étaient les organochlorés les plus fréquemment détectés dans le tissu adipeux et le foie. Les concentrations moyennes des organochlorés analysés individuellement étaient inférieures à 20 ng/g de poids frais pour le foie et à 15 ng/g de poids frais pour le tissu adipeux. Les corrélations de rang révèlent que les concentrations en métaux lourds augmentent de concert avec celles en organochlorés (As, Cd, Cu et Zn; PCB 138, 170 et 180). Bien que les concentrations en métaux lourds et en organochlorés soient faibles par rapport à celles d'autres régions et à celles d'autres espèces arctiques, la présence de ces composés illustre l'omniprésence planétaire de composés organiques persistants et le potentiel pour une accumulation biologique dans le réseau trophique terrestre de l'Arctique

    Quantum Fields in a Big Crunch/Big Bang Spacetime

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    We consider quantum field theory on a spacetime representing the Big Crunch/Big Bang transition postulated in the ekpyrotic or cyclic cosmologies. We show via several independent methods that an essentially unique matching rule holds connecting the incoming state, in which a single extra dimension shrinks to zero, to the outgoing state in which it re-expands at the same rate. For free fields in our construction there is no particle production from the incoming adiabatic vacuum. When interactions are included the total particle production for fixed external momentum is finite at tree level. We discuss a formal correspondence between our construction and quantum field theory on de Sitter spacetime.Comment: 30 pages, RevTex file, five postscript figure file

    Long-distance dispersal of pigeons and doves generated new ecological opportunities for host-switching and adaptive radiation by their parasites.

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    Adaptive radiation is an important mechanism of organismal diversification and can be triggered by new ecological opportunities. Although poorly studied in this regard, parasites are an ideal group in which to study adaptive radiations because of their close associations with host species. Both experimental and comparative studies suggest that the ectoparasitic wing lice of pigeons and doves have adaptively radiated, leading to differences in body size and overall coloration. Here, we show that long-distance dispersal by dove hosts was central to parasite diversification because it provided new ecological opportunities for parasites to speciate after host-switching. We further show that among extant parasite lineages host-switching decreased over time, with cospeciation becoming the more dominant mode of parasite speciation. Taken together, our results suggest that host dispersal, followed by host-switching, provided novel ecological opportunities that facilitated adaptive radiation by parasites

    Non-Gaussianity from Inflation

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    Correlated adiabatic and isocurvature perturbation modes are produced during inflation through an oscillation mechanism when extra scalar degrees of freedom other than the inflaton field are present. We show that this correlation generically leads to sizeable non-Gaussian features both in the adiabatic and isocurvature perturbations. The non-Gaussianity is first generated by large non-linearities in some scalar sector and then efficiently transferred to the inflaton sector by the oscillation process. We compute the cosmic microwave background angular bispectrum, providing a characteristic feature of such inflationary non-Gaussianity,which might be detected by upcoming satellite experiments.Comment: Revised version accepted for publication in Phys. Rev. D. 19 pages, LaTeX fil

    Graviton production from extra dimensions

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    Graviton production due to collapsing extra dimensions is studied. The momenta lying in the extra dimensions are taken into account. A DD-dimensional background is matched to an effectively four-dimensional standard radiation dominated universe. Using observational constraints on the present gravitational wave spectrum, a bound on the maximal temperature at the beginning of the radiation era is derived. This expression depends on the number of extra dimensions, as well as on the DD-dimensional Planck mass. Furthermore, it is found that the extra dimensions have to be large.Comment: LaTeX file, 14 pages, 4 figure
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