4 resultados para area of soil elevation

em Bucknell University Digital Commons - Pensilvania - USA


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The European Union’s (EU) area of Freedom, Security and Justice (AFSJ) portfolio comprises policy areas such as immigration and asylum, and police and judicial cooperation. Steps were taken to bring this field into the mandate of the EU first by the Maastricht Treaty, followed by changes implemented by the Amsterdam and Lisbon Treaties, the last one ‘normalizing’ the EU’s erstwhile Third Pillar. As the emergent EU regime continues to consolidate in this field, NGOs of various kinds continue to seek to influence policy-making and implementation, with varying success. This article seeks to establish the context in which NGOs carry out their work and argues that the EU-NGO interface is impacted both by the institutional realities of the European Union and the capacities of EU-oriented NGOs to seize and expand opportunities for access and input into the policy cycle. Using EU instruments representing three different policy bundles in AFSJ (immigration, asylum and judicial cooperation in criminal matters), the article seeks to map out NGO strategies in engaging and oftentimes resisting European Union policy instruments.

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Maternal effects are a mother¿s non-genetic contributions to development that alter phenotypic traits in offspring. Maternal effects can take the form of prenatal allocation of resources, such as the deposition of androgens into egg yolks. For example, elevated yolk testosterone increases male sexual behaviors such as copulation solicitation and courtship displays in some avian species, in addition to aggressive behaviors like pecks and intimidating postures towards same-sex competitors. However, the mechanism connecting in ovo testosterone exposure with changes in sexual and aggressive behaviors has yet to be elucidated. While testosterone released by the gonads is important in the activation of sexual behaviors, it must undergo conversion to estrogen by the enzyme aromatase in the pre-optic area (POA) of the avian brain for full expression of sexual activity. POA aromatase is also necessary for the activation of aggressive behaviors in male birds. This experiment tested the hypothesis that elevated yolk testosterone leads to changes in POA aromatase activity and levels of gonadal testosterone, as these two endocrine parameters may mediate the effect of yolk testosterone on the frequency of sexual and aggressive behaviors. The effect of elevated yolk testosterone on gonadal testosterone levels and aromatase activity in the POA of 3-day-old domestic chickens Gallus gallus domesticus was investigated. Unincubated eggs were injected with either 10 ng testosterone in 50 ¿L sesame oil (¿T chicks¿) or 50 ¿L sesame oil (¿C chicks¿). At 3 days post-hatch, gonadal testosterone content was measured after steroid extraction using an EIA, and aromatase activity in the POA was quantified by measuring the production of tritiated water from [1ß-3H]-androstenedione. I predicted that gonadal testosterone levels and brain aromatase activity would be higher in T chicks, however found no difference between treatments. Though juvenile T production peaks at 3 days post-hatch, it is possible that the reproductive systems, including the testes and POA, are not fully developed at this time.

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This study examined the chemical compatibility of several model soil-bentonite(SB) backfills with an inorganic salt solution (CaCl2). First, bentonite-water slurry was created using a natural sodium-bentonite, as well as two modified bentonites –multiswellable bentonite (MSB) and a “salt-resistant” bentonite (SW101). Once slurries that met typical construction specifications had been created using the various bentonites,the model SB backfills were prepared for each type of bentonite. These backfills werealso designed to meet conventional construction and design requirements. The SB backfills were then subjected to permeation with tap water and/or CaCl2 solutions of various concentrations in order to evaluate the compatibility of the SB backfills with inorganic chemicals. The results indicate that SB backfill experiences only minor compatibility issues (i.e., no large differences between the hydraulic conductivity of the SB backfill to tap water and CaCl2) compared to many other types of clay barriers. In addition, SB backfills show no major change in final hydraulic conductivity to CaCl2 when permeated with tap water before CaCl2 versus being permeated with CaCl2 directly. These results may be due to the ability of the bentonite in the SB backfills to undergo osmotic swelling before permeation begins, and the inability of the CaCl2 solutions to undo the osmotic swelling. Similar results were obtained for all three clays tested, and while MSB did show less compatibility issues than the natural bentonite and SW101, it appears that the differences in performance may generally be negligible. Overall, thisstudy makes a significant addition to the understanding of SB cutoff wall compatibility.

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This study investigated the effect of cyclic wetting and drying on the backfill used in soil-bentonite (SB) cutoff walls. For this purpose, model SB vertical cutoff wall backfills were prepared comprising of a fine grained mortar sand and 2% bentonite (by total weight) and 4% bentonite (by total weight). Results of the study indicate that the volume change is influenced by the bentonite content, that is, the increase in volume change increased with increasing bentonite content.