The Town Lake Report, Volumes I and II

This report makes brief references to sediment and other trends seen in Waller Creek.EXECUTIVE SUMMARY: Town Lake’s importance as a natural resource is growing in tandem with Austin’s rapid population. The lake is a source of drinking water for the City, and its greenbelt and open waters are widely used for recreation and as a focal-point for public events. In 1992, under the Clean Lakes program, a comprehensive report entitled the “Town Lake Study” (COA 1992a; COA 1992b; COA 1992c) was prepared. It examined the condition of the lake (Volume I), water quality control alternatives (Volume II) and a feasibility study (Volume III). This report updates the diagnostic study, Volume I (COA 1992a), including the current status of water quality with data analyzed through the year 2000. It also includes a summary of measures taken to reduce pollution from urban runoff since 1990.Waller Creek Working Grou

Meaning theory and the problem of the acquisition of a first language.

The thesis begins by making two distinctions which are\ud central to its methodology. The first is that between valid\ud and invalid criticism, the second between philosophy of\ud language and meaning theory. These distinctions combine to\ud produce the methodology which informs the thesis, namely\ud that a theory of meaning can be validly criticised in terms\ud of its account, implicit or explicit, of first language\ud acquisition and, conversely, an account of first language\ud acquisition can be validly criticised in terms of its\ud theory, implicit or explicit, of meaning. The thesis\ud continues by testing the appropriateness of the methodology\ud against the classical empiricist and rationalist accounts of\ud meaning expressed in terms of Ideas, arguing that the\ud majority of criticisms of these accounts misfire as they do\ud not operate within the framework of the positions they\ud purport to criticise. Such invalid criticism is replaced\ud with that argued for here, the conclusion being that the\ud classical accounts of meaning are to be rejected on the\ud grounds that they make use of a phenomenon, language, whose\ud acquisition they cannot, within the terms of their own\ud position, explain. Modern, post-Fregean, empiricist and\ud rationalist positions, those of Quine and Chomsky\ud respectively, are then subjected to similar treatment. Both\ud of these positions have explicit accounts of first language acquisition and so the conclusion to this section of the\ud thesis reverses that reached when discussing the classical\ud positions, in that the explanations of first language\ud acquisition given by modern empiricists and rationalists are\ud based on meaning theories which, for a variety of reasons,\ud do not justify their explanations of the phenomenon of first\ud language acquisition.\ud In an attempt to move towards a more positive position two\ud alternative accounts of meaning theory, the formal and the\ud descriptive, are then examined. The formal account,\ud Davidson's, is defended against those critics who produce\ud attacks centering upon its meaning theory as being, in the\ud sense described above, invalid. However, as it is then\ud shown not to be able to account for first language\ud acquisition, it is eventually rejected. The descriptivist\ud account is identified by tracing the development of\ud Wittgenstein's philosophy to support a particular\ud interpretation of his later account of meaning as being a\ud descriptive one and a defence is offered to a number of\ud criticisms of that position. A poorly worked out\ud experiential account of first language acquisition is then\ud identified, and this is developed further by introducing the\ud area of non-linguistics, where meaning can be given without\ud words. The thesis concludes by suggesting that this area's\ud account of first language acquisition, although having a\ud number of difficulties with its implied meaning theory, can be combined with the later work of Wittgenstein to produce\ud what is at least a descriptively adequate account of both\ud meaning and first language acquisition. Moreover, it points\ud to an area of enquiry where philosophical techniques can be\ud utilised to great effect so as to add new dimensions t

Effects of Accelerated Carbonation Curing on CO2 Sequestration and on the Compressive Strength of Concrete Masonry Units

The global consumption of Portland cement has risen to over 4 billion tonnes per annum. Its manufacture is energy and carbon intensive and approximately 900 kg of CO2 is emitted into the atmosphere for each tonne of Portland cement produced. The International Energy Agency (IEA) roadmap sets out a goal to reduce emissions due to cement production to 18 % below 2006 levels by 2050. Concrete has the potential to re-absorb CO2 by the process of carbonation, where it reacts with CaO in the concrete to form calcium carbonate. Accelerated carbonation curing (ACC) is a technique for curing fresh concrete that can sequester CO2. ACC of concrete masonry units (CMU’s) can reduce the embodied carbon footprint and play a major role in sustainability by reducing global CO2. ACC also offers potential improvements in the mechanical and durability properties of concrete. Experimental work was carried out which involved the ACC of CMU’s at a CO2 concentration of 50% over various time intervals and exposure conditions. It was calculated that the maximum possible CO2 uptake potential of the cement was approximately 49.5%. A CO2 uptake of 23% per mass of cement was achieved after 7 days of ACC along with compressive strength increases of 15.4% and 28% for ACC samples at 7 and 28 days respectively. The study found that the greatest compressive strength increase occurred between 4 and 24 hours. After 24 hours the ACC process showed a similar proportional rate of strength gain over time when compared to the control. The study shows that ACC is different from weathering carbonation as it accelerates the hydration reaction of the unhydrated cement phases C3S and C2S producing rapid strength gains. Weathering carbonation occurs in concrete after the hydration process has been predominately completed and results in the decalcification of C-S-H and the formation of silica gel which is detrimental to the cement paste

Impacts of oil palm expansion on avian biodiversity in a Neotropical natural savanna

The consequences of converting tropical rainforest to oil palm are well-documented, but the impacts of oil palm conversion on natural savanna landscapes remain little-known. Natural savannas in South America have been identified as fertile grounds for future oil palm expansion, partly due to perceived low biodiversity impacts relative to forest systems. We quantify the impacts of oil palm conversion for bird communities inhabiting natural savannas in the Colombian Llanos. Bird species richness and abundance were significantly reduced at sampling points in oil palm relative to adjacent natural savannas, with marked concomitant shifts in community composition. Aquatic, forest and grassland specialists all showed significantly lower abundances in oil palm habitat relative to savanna, as did migratory species and carnivorous/insectivorous dietary guilds. In both habitats, point-level species richness and total bird abundance increased with proximity to remnant forest patches. Within savanna, total bird abundance also decreased with proximity to adjacent oil palm, though species richness was not significantly affected. Within oil palm, point-level abundance increased with proximity to savanna, suggesting that communities in both habitats may be impacted by reciprocal edge or spill-over effects. Point-level abundance in oil palm also increased significantly with the presence of an invasive vine ‘kudzu’, a species introduced in some plantations as a soil protection measure, although species richness was not affected. Our work underlines the need for careful monitoring of further large-scale agro-industrial conversion in the Llanos. In particular, we suggest greater efforts to direct oil palm expansion towards already degraded lands (e.g. improved grassland areas currently used for intensive cattle grazing) to ensure remaining natural savannas are spared

The Purple Heart: Background and Issues for Congress

Report that explores the history of the Purple Heart and changes in eligibility over time as well as several current issues facing Congress

Near-Infrared Photoluminescence and Electrochemiluminescence from an Exceptionally Simple Boron Difluoride Formazanate Dye

Electrochemiluminescence involves the generation of light via electrochemical reactions and has recently shown utility for single-cell imaging. To further develop this novel imaging platform, it is necessary to produce readily available dyes that photoluminesce and electrochemiluminesce in the near-infrared region to limit absorption by biological tissue. To address this need, we prepared a boron difluoride formazanate dye that exhibits near-infrared photoluminescence and electrochemiluminescence in two straightforward synthetic steps. Examination of its solid-state structure suggests that the N-aryl substituents have significant quinoidal character, which narrows the S1-S0 energy gap and leads to near-infrared absorption and photoluminescence. Electrochemical properties were probed using cyclic voltammetry and revealed four electrochemically reversible waves. Electrochemiluminescence properties were examined in the presence of tri-n-propylamine, leading to maximum intensity at 910 nm, at least 85 nm (1132 cm‒1) red-shifted compared to all other organic dyes. This work sets the stage for the development of future generations of dyes for emerging applications, including single-cell imaging, that require near-infrared photoluminescence and electrochemiluminescence

A Glossary of Selected Telecommunications Terms

The following glossary provides short definitions and descriptions of selected telecommunications terminology, agencies, and organizations, as well as a listing of key laws and Federal Communications Commission regulations and decisions

Tropical secondary forest regeneration conserves high levels of avian phylogenetic diversity

Secondary forests are promoted as having pivotal roles in reversing the tropical extinction crisis. While secondary forests recover carbon and species over time, a key question is whether phylogenetic diversity—the total evolutionary history across all species within a community—also recovers. Conserving phylogenetic diversity protects unique phenotypic and ecological traits, and benefits ecosystem functioning and stability. We examined the extent to which avian phylogenetic diversity recovers in secondary forests in the Colombian Chocó-Andes. sesPD, a measure of phylogenetic richness corrected for species richness, recovered to old-growth forest levels after ~ 30 years, while sesMPD, a measure of the phylogenetic distance between individuals in a community, recovered to old-growth levels even within young secondary forest. Mean evolutionary distinctiveness also recovered rapidly in secondary forest communities. Our results suggest that secondary forests can play a vital role in conserving distinct evolutionary lineages and high levels of evolutionary history. Focusing conservation and carbon-based payments for ecosystem services on secondary forest recovery and their subsequent protection thus represent a good use of scarce conservation resources

The Monstrous ‘White Theory Boy’: Symbolic Capital, Pedagogy and the Politics of Knowledge

This article presents a critical uncovering of the continued dominance of whiteness and maleness in processes and practices of knowledge formation. Tracking the figure of the ‘white theory boy’ or ‘dead white man’ across experiential accounts of theory, scholarship on canonicity, and pedagogical strategies, the article demonstrates his enduring authority in theoretical knowledge making and dissemination. Where this article moves somewhere different is its suggestion that a space of sympathy be extended to this hegemonic figure. Though the dominance of the ‘white theory boy’ undoubtedly perpetuates inequalities throughout social theoretic thought, it is necessary to locate a new method of tackling such ingrained problems. Though extending sympathy to the ‘white theory boy’ is perhaps initially counter-intuitive, my suggestion is that he does not hold the sort of monolithic power we might first assume. Bringing an intersectional analysis of gender, class, ‘race’ and ethnicity to bear on this figure, creates a space in which a more critical and fine-grained account of the relationship between power, knowledge, and social status can be uncovered. It is through extending this space of sympathy and mutual cooperation to ‘white theory boys’ that the practical and conceptual machinations of their power are further revealed. From here a more thorough dismantling of this power becomes possible