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  1. Nutrient availability, the microbiome and intestinal transport during pregnancy [Download]

    Title: Nutrient availability, the microbiome and intestinal transport during pregnancy
    Creator: Astbury, S.
    Description: Adequate adaptation of the gastrointestinal (GI) tract is important during pregnancy to ensure that the increased metabolic demands by the developing fetus are met. These include changes in surface area mediated by villus hypertrophy and enhanced functional capacity of individual nutrient receptors including those transporting glucose, fructose, leucine, and calcium. These processes are regulated either by the enhanced nutrient demand or are facilitated by changes in the secretion of pregnancy hormones. Our review also covers recent research into the microbiome, and how pregnancy could lead to microbial adaptations, which are beneficial to the mother, yet are also similar to those seen in the metabolic syndrome. The potential role of diet in modulating the microbiome during pregnancy, as well as the potential for the intestinal microbiota to induce pregnancy complications are examined. Gaps in the current literature are highlighted including those where only historical evidence is available, and we suggest areas that should be a priority for further research. In summary, although a significant degree of adaptation has been described, there are both well-established processes, and more recent discoveries such as changes within the maternal microbiome that pose new questions as to how the GI tract effectively adapts to pregnancy, especially in conjunction with maternal obesity.
    Subjects: gastrointestinal adaptation, nutrition, maternal health, 54 nutrient transport, pregnancy, microbiome
    Date Created: 2015
  2. Optimal zoning of forested land considering contribution of exotic plantations [Download]

    Title: Optimal zoning of forested land considering contribution of exotic plantations
    Creator: Anderson, Jay A.
    Description: Previous studies suggest that management intensity zoning systems, such as the triad approach, could allow Canada’s forest industry to maintain or increase timber harvest levels while simultaneously reducing its environmental impact. In most such studies, the zones are exogenously specified. In this study, we use a linear programming model to endogenously allocate forest land to management intensity zones given several alternative policy scenario formulations. We examine how alternative policy scenarios affect the net present value of the optimal forest management plan, timber output, and the spatial allocation of land to management intensity zones. We conclude that policies which facilitate optimal zoning could enable land use specialization to increase both profits and ecological protection. Such zoning, however, can only happen if provincial governments in Canada revise their forest policies with respect to allocation of forest tenures and establishment of exotic plantations on public forest land.
    Subjects: hybrid poplar, forest management, timber supply, zoning, triad
    Date Created: 2012
  3. Sustained Yield Forestry in Sweden and Russia: How Does it Correspond to Sustainable Forest Management Policy? [Download]

    Title: Sustained Yield Forestry in Sweden and Russia: How Does it Correspond to Sustainable Forest Management Policy?
    Creator: Marine Elbakidze
    Description: This paper analyzes how sustained yield (SY) forestry is defined and implemented in Sweden and Russia, two countries with different forest-industrial regimes. We first compare definitions of SY forestry in national legislation and policies. Then we study forest management planning in two large forest management units with respect to: delivered forest products and values, how the harvest level of timber is defined, where the harvest takes place, and what treatments are used to sustain desired forest products and values. In Sweden SY forestry is maximum yield based on high-input forest management, and in Russia it is forestry based on natural regeneration with minimum investments in silviculture. We conclude that how SY forestry contributes to SFM depends on the context. Finally, we discuss the consequences of SY forestry as performed in Sweden and Russia related to its ability to support diverse forest functions, as envisioned in sustainable forest management policy.
    Subjects: Silviculture, Sustainable harvest level, Annual allowable cut
    Date Created: 2013