1,401 research outputs found
When Narrative Fails: Context and Physical Evidence as Means of Understanding the Northwest Boundary Survey Photographs of 1857–1862
The photographs of the Northwest Boundary Survey, taken chiefly in 1860–1861, present many of the problems commonly encountered in the study of nineteenth-century photography. These views documenting the international border between modern British Columbia and the American Pacific Northwest provide a useful case study in the close reading of physical attributes of photographs. They afford an opportunity to compare imagery and evidence across known sets, and to draw conclusions from sequencing, variant captioning, and other physical evidence. These details will help archivists and other collection managers make good decisions about depth of cataloging, digital imaging choices, and interfaces for online presentation of sets of nineteenth-century photographs
Effects of Supplemental Lysine and methionine in Finishing Swine Diets
Considerable research has been conducted in the last few years to evaluate protein and amino acid levels in the various growth phases of porcine animals. Most of this research has been limited to the baby and growing phase of the pig, whereas little research has been conducted with the finishing phase of the pig. Lysine and methionine, essential amino acids in the diet of monogastric animals, have been studied extensively in animal nutrition. The following experiments were designed to gain some insight into the effects of supplementing two crystalline amino acids, lysine and methionine, to a corn-soybean meal-tankage diet for finishing pigs on subsequent growth, feed conversion, carcass composition, nitrogen balance, liver ether extract and free plasma amino acid concentrations of the experimental animals involved
Imaging Pulsed Laser Deposition oxide growth by in-situ Atomic Force Microscopy
To visualize the topography of thin oxide films during growth, thereby
enabling to study its growth behavior quasi real-time, we have designed and
integrated an atomic force microscope (AFM) in a pulsed laser deposition (PLD)
vacuum setup. The AFM scanner and PLD target are integrated in a single support
frame, combined with a fast sample transfer method, such that in-situ
microscopy can be utilized after subsequent deposition pulses. The in-situ
microscope can be operated from room temperature (RT) up to 700C and at
(process) pressures ranging from the vacuum base pressure of 10 mbar up
to 1 mbar, typical PLD conditions for the growth of oxide films. The
performance of this instrument is demonstrated by resolving unit cell height
surface steps and surface topography under typical oxide PLD growth conditions.Comment: 8 pages, 8 figure
Geographical Equity Effects Of The Homeowner Tax Subsidy
The purpose of this study is to provide exploratory evidence concerning the degree to which geographical cost of living differentials interact with homeownership tax incentives in affecting tax system equity. Incorporating both federal and state homeowner tax subsidies calculated using the 1991 Ernst & Young Tax Model File; the authors provide evidence concerning both horizontal and vertical equity in the system. Descriptive statistics and regression results provide findings which indicate positive and direct relationships between the homeowner tax subsidy and 1) taxpayer disposable income (increased regressivity in the tax system) and 2) taxpayer state of residence median housing values (decreased horizontal inequities between similarly situated homeowners in different states). These findings indicate that elimination of the homeowner tax subsidy accompanied by a direct subsidy would increase equity within the system. Furthermore, the findings suggest that the President’s Advisory Panel on Federal Tax Reform (2005) recommendation for a home credit, with a limit based on average cost of housing within a taxpayer’s area, will result in a more equitable distribution of the homeowner tax subsidy
Evaluation of the Impact of Music Program Participation on Students’ Musical and Academic Success, and School Engagement in the Metropolitan Nashville Public Schools: A Comprehensive Test of Pathways and Contextual Factors
Report for Metropolitan Nashville Public SchoolsThe purpose of this project was to examine the effect of participating in music on student school engagement and academic achievement in a Metropolitan Nashville Public School district. Student records for the class of 2012 (N = 6,006) in a major urban school district were collected and examined for student personal characteristics, music participation, their indicated level of school engagement, and their academic achievements. These variables were examined using Structural Equation Modeling techniques. Results indicated that the quantity of Music Participation had an important effect on both the level of School Engagement and Academic Achievement. Conclusions indicate that more music involvement was advantageous to the school system’s overall performance, and that steps being taken to engage a wider cross-section of students might well have a significant impact on the students’ academic lives.This research was funded by the MMU and MNPS
An updated review of the toxicology and ecotoxicology of sodium fluoroacetate (1080) in relation to its use as a pest control tool in New Zealand
Sodium fluoroacetate (1080) is a vertebrate pesticide, originally developed in the 1940s and principally
used for the control of unwanted introduced animals in New Zealand and Australia. Fluoroacetate is also a
toxic component of poisonous plants found in Australia, Africa, South America, and India. In relation to its use
as a pesticide, recent research has focused on further elucidation of its potential sub-lethal effects, on animal
welfare issues, on understanding and reducing its risk to non-target species, on its ecotoxicology, and fate in the
environment following use in baits. 1080 acts by interfering with cellular energy production through inhibition
of the tricarboxylic acid cycle and lethal doses can kill animal pests within 6–48 h of eating baits. Exposure
to sub-lethal doses has been shown to have harmful effects on the heart and testes in animal studies, and strict
safety precautions are enforced to protect contractors and workers in the pest control industry. Considerable
care must be taken when using 1080 for the control of animal pests. Primary poisoning of non-target birds and
secondary poisoning of dogs must be minimised to ensure that benefits in terms of conservation outcomes and
pest and disease control significantly outweigh the risks associated with its use. Despite over 60 years of research
and practical experience, the use of 1080 is still embroiled in controversy, while research efforts continue to
improve its target specificity when it is used as a conservation tool or for Tb vector control
Toxicology and ecotoxicology of para-aminopropiophenone (PAPP) – a new predator control tool for stoats and feral cats in New Zealand
Para-aminopropiophenone (PAPP) paste was approved as a stoat control agent in New Zealand by the Environmental Protection Authority in August 2011 and for feral cat control in November 2011. PAPP was originally researched in Europe and the USA as treatment for cyanide and radiation poisoning. Over the last 10 years, our research has focused on several factors, including determining its toxicity to predators, field effectiveness for controlling stoats and feral cats, animal welfare profile, toxicology, ecotoxicology, and understanding and reducing non-target risks. PAPP has been developed specifically for the control of stoats and feral cats because of the special sensitivity displayed by these species. Its toxicity is mediated by the induction of methaemoglobinaemia (the ferric state of haemoglobin). Normally, methaemoglobin levels in the blood are below 1%. Levels of methaemoglobin in the blood above 70% are usually fatal, creating a lethal deficit of oxygen in cardiac muscle and the brain. In stoats and feral cats, death after a lethal dose usually occurs within
2 h after eating bait, with clinical signs first appearing in 10 to 20 min for stoats and at around 35 min for cats. Animals become lethargic and sleepy before they die, hence PAPP is relatively humane. A simple antidote exists, namely methylene blue. Further, birds display a lack of toxicity to PAPP when compared with other vertebrate pesticides. A paste containing 40% PAPP has been developed for use in meat baits in New Zealand. A toxic dose for stoats and feral cats is achieved when pea-sized amounts of paste are delivered in 10–20 g meat baits. When meat baits containing PAPP are applied in bait stations in field settings, stoat and feral cat numbers can be rapidly reduced. However, there has been limited practical experience with PAPP to date, especially when compared with alternative tools such as traps or sodium monofluoroacetate (1080) baits. Additional practical experience should enable the effective use of PAPP as a tool to help protect native species from introduced predators. In the future, PAPP will be developed in long-life bait and in a resetting toxin delivery system
Segment-scale variations in seafloor volcanic and tectonic processes from multibeam sonar imaging, Mid-Atlantic Ridge Rainbow region (35°45′–36°35′N)
Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 17 (2016): 3560–3579, doi:10.1002/2016GC006433.Along-axis variations in melt supply and thermal structure can lead to significant variations in the mode of crustal accretion at mid-ocean ridges. We examine variations in seafloor volcanic and tectonic processes on the scale of individual ridge segments in a region of the slow spreading Mid-Atlantic Ridge (35°45′–36°35′N) centered on the Rainbow nontransform discontinuity (NTD). We use multibeam sonar backscatter amplitude data, taking advantage of multifold and multidirectional coverage from the MARINER geophysical study to create a gridded compilation of seafloor reflectivity, and interpret the sonar image within the context of other data to examine seafloor properties and identify volcanic flow fields and tectonic features. Along the spreading segments, differences in volcanic productivity, faulting, eruption style, and frequency correlate with inferred magma supply. Regions of low magma supply are associated with more widely spaced faults, and larger volcanic flow fields that are more easily identified in the backscatter image. Identified flow fields with the highest backscatter occur near the ends of ridge segments. Their relatively smooth topography contrasts with the more hummocky, cone-dominated terrain that dominates most of the neovolcanic zone. Patches of seafloor with high, moderately high, and low backscatter intensity across the Rainbow massif are spatially correlated with observations of basalt, gabbro and serpentinized peridotite, and sediment, respectively. Large detachment faults have repeatedly formed along the inside corners of the Rainbow NTD, producing a series of oceanic core complexes along the wake of the NTD. A new detachment fault is currently forming in the ridge segment just north of the now inactive Rainbow massif.National Science Foundation Grant Numbers: OCE-0961151, OCE-09616802017-03-0
Three-dimensional seismic structure of the Mid-Atlantic Ridge : an investigation of tectonic, magmatic, and hydrothermal processes in the Rainbow Area
Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 122 (2017): 9580–9602, doi:10.1002/2017JB015051.To test models of tectonic, magmatic, and hydrothermal processes along slow-spreading mid-ocean ridges, we analyzed seismic refraction data from the Mid-Atlantic Ridge INtegrated Experiments at Rainbow (MARINER) seismic and geophysical mapping experiment. Centered at the Rainbow area of the Mid-Atlantic Ridge (36°14'N), this study examines a section of ridge with volcanically active segments and a relatively amagmatic ridge offset that hosts the ultramafic Rainbow massif and its high-temperature hydrothermal vent field. Tomographic images of the crust and upper mantle show segment-scale variations in crustal structure, thickness, and the crust-mantle transition, which forms a vertical gradient rather than a sharp boundary. There is little definitive evidence for large regions of sustained high temperatures and melt in the lower crust or upper mantle along the ridge axes, suggesting that melts rising from the mantle intrude as small intermittent magma bodies at crustal and subcrustal levels. The images reveal large rotated crustal blocks, which extend to mantle depths in some places, corresponding to off-axis normal fault locations. Low velocities cap the Rainbow massif, suggesting an extensive near-surface alteration zone due to low-temperature fluid-rock reactions. Within the interior of the massif, seismic images suggest a mixture of peridotite and gabbroic intrusions, with little serpentinization. Here diffuse microearthquake activity indicates a brittle deformation regime supporting a broad network of cracks. Beneath the Rainbow hydrothermal vent field, fluid circulation is largely driven by the heat of small cooling melt bodies intruded into the base of the massif and channeled by the crack network and shallow faults.NSF Grant Numbers: OCE-0961151, OCE-09616802018-06-2
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