1,311 research outputs found

    Self-Healing Concrete in Commercial Construction

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    Crack formation is common among concrete used for all different types of construction. While cracking is inevitable in concrete, it can create instabilities that can compromise an entire building’s structural integrity. New advancements are being made in the biological and engineering fields that are providing a solution to this problem. Certain bacteria and chemicals when mixed provide a reaction that creates limestone material to re-heal cracks in concrete. Using these materials to create this reaction, while incorporating the reactants necessary in concrete mixtures for building, it is possible to eliminate maintenance costs and improve building strength over time. Currently, these materials have not been mass produced for the construction market because they are still in the trial phases in many European experiments. It is my intention to discover which methods and materials have proven most effective and cost efficient. This paper will also provide insight as to why self-healing concrete has not yet seen many practical uses in the U.S. and the applications it may have in the future

    Powering Accra: Projecting Electricity Demand for Ghana‘s Capital City

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    The purpose of this research was to create an agent-based urban simulation based on land use at the plot level for projecting the disaggregated electricity demand of the Greater Accra Metropolitan Area (GAMA). A simulation system comprised of location choice, regression, and simple models were used to project household, employment and land development decisions. Households, persons, and jobs tables were synthetically generated from GLSS5 (Ghana Living Standards Survey 2005) data using Stata, built in a MySQL database and incorporated for use in the Open Platform for Urban Simulation (OPUS). Electricity demand was projected for each of the simulation years based on a regression model. Numerous geospatial datasets were projected and edited in ArcGIS which describe the physical composition of Accra in its totality, including buildings, roads and electricity infrastructure. Household mobility was estimated from a modified Cox Regression of residential mobility in Accra (Bertrand et al.) and applied to the GLSS5 for use in the location choice model, while employment coefficients and parameters describing land value were derived from literature (Buckley et al.). The model has been applied for projecting the electricity demand of the Korle Bu district in terms of high, medium and low economic and population growth rates for the time period 2006 until 2025, based on monthly electricity consumption per meter. An additional phase of this research envisions including all 12 GAMA districts (using data which has been obtained); infrastructure models to project demand for transportation, water & sewer, and solid waste facilities; as well as comparing weak and strong sustainability scenarios with the business-as-usual development path for cost-benefit analysis of proposed public policies

    Finite Simple Graphs and Their Associated Graph Lattices

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    In his 2005 dissertation, Antoine Vella explored combinatorical aspects of finite graphs utilizing a topological space whose open sets are intimately tied to the structure of the graph. In this paper, we go a step further and examine some aspects of the open set lattices induced by these topological spaces. In particular, we will characterize all lattices that constitute the opens for finite simple graphs endowed with this topology, explore the structure of these lattices, and show that these lattices contain information necessary to reconstruct the graph and its complement in several ways

    Adverse drug reaction and toxicity caused by commonly used antimicrobials in canine practice

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    An adverse drug reaction (ADR) is a serious concern for practicing veterinarians and other health professionals, and refers to an unintended, undesired and unexpected response to a drug that negatively affects the patient's health. It may be iatrogenic or genetically induced, and may result in death of the affected animal. The ADRs are often complicated and unexpected due to myriad clinical symptoms and multiple mechanisms of drug-host interaction. Toxicity due to commonly used drugs is not uncommon when they are used injudiciously or for a prolonged period. Licosamides, exclusively prescribed against anaerobic pyoderma, often ends with diarrhoea and vomiting in canines. Treatment with Penicillin and β-lactam antibiotics induces onset of pemphigious vulgare, drug allergy or hypersensitivity. Chloroamphenicol and aminoglycosides causes Gray's baby syndrome and ototoxicity in puppies, respectively. Aminoglycosides are very often associated with nephrotoxicity, ototoxicity and neuromuscular blockage. Injudicious use of fluroquinones induces the onset of arthropathy in pups at the weight bearing joints. The most effective therapeutic measure in managing ADR is to treat the causative mediators, followed by supportive and symptomatic treatment. So, in this prospective review, we attempt to bring forth the commonly occurring adverse drug reactions, their classification, underlying mechanism, epidemiology, treatment and management as gleaned from the literature available till date and the different clinical cases observed by the authors

    High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health

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    BACKGROUND: Recent declines in honey bees for crop pollination threaten fruit, nut, vegetable and seed production in the United States. A broad survey of pesticide residues was conducted on samples from migratory and other beekeepers across 23 states, one Canadian province and several agricultural cropping systems during the 2007-08 growing seasons. METHODOLOGY/PRINCIPAL FINDINGS: We have used LC/MS-MS and GC/MS to analyze bees and hive matrices for pesticide residues utilizing a modified QuEChERS method. We have found 121 different pesticides and metabolites within 887 wax, pollen, bee and associated hive samples. Almost 60% of the 259 wax and 350 pollen samples contained at least one systemic pesticide, and over 47% had both in-hive acaricides fluvalinate and coumaphos, and chlorothalonil, a widely-used fungicide. In bee pollen were found chlorothalonil at levels up to 99 ppm and the insecticides aldicarb, carbaryl, chlorpyrifos and imidacloprid, fungicides boscalid, captan and myclobutanil, and herbicide pendimethalin at 1 ppm levels. Almost all comb and foundation wax samples (98%) were contaminated with up to 204 and 94 ppm, respectively, of fluvalinate and coumaphos, and lower amounts of amitraz degradates and chlorothalonil, with an average of 6 pesticide detections per sample and a high of 39. There were fewer pesticides found in adults and brood except for those linked with bee kills by permethrin (20 ppm) and fipronil (3.1 ppm). CONCLUSIONS/SIGNIFICANCE: The 98 pesticides and metabolites detected in mixtures up to 214 ppm in bee pollen alone represents a remarkably high level for toxicants in the brood and adult food of this primary pollinator. This represents over half of the maximum individual pesticide incidences ever reported for apiaries. While exposure to many of these neurotoxicants elicits acute and sublethal reductions in honey bee fitness, the effects of these materials in combinations and their direct association with CCD or declining bee health remains to be determined

    Genome-wide association study of proneness to anger

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    BACKGROUND: Community samples suggest that approximately 1 in 20 children and adults exhibit clinically significant anger, hostility, and aggression. Individuals with dysregulated emotional control have a greater lifetime burden of psychiatric morbidity, severe impairment in role functioning, and premature mortality due to cardiovascular disease. METHODS: With publically available data secured from dbGaP, we conducted a genome-wide association study of proneness to anger using the Spielberger State-Trait Anger Scale in the Atherosclerosis Risk in Communities (ARIC) study (n = 8,747). RESULTS: Subjects were, on average, 54 (range 45-64) years old at baseline enrollment, 47% (n = 4,117) were male, and all were of European descent by self-report. The mean Angry Temperament and Angry Reaction scores were 5.8 +/- 1.8 and 7.6 +/- 2.2. We observed a nominally significant finding (p = 2.9E-08, lambda = 1.027 - corrected pgc = 2.2E-07, lambda = 1.0015) on chromosome 6q21 in the gene coding for the non-receptor protein-tyrosine kinase, Fyn. CONCLUSIONS: Fyn interacts with NDMA receptors and inositol-1,4,5-trisphosphate (IP3)-gated channels to regulate calcium influx and intracellular release in the post-synaptic density. These results suggest that signaling pathways regulating intracellular calcium homeostasis, which are relevant to memory, learning, and neuronal survival, may in part underlie the expression of Angry Temperament
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