2,227 research outputs found
Gladiators at Pompeii: Roman Spectacle in a Small Town
https://egrove.olemiss.edu/classics_lectures/1025/thumbnail.jp
Impacts of Irrigation Development on Anadromous Fish in the Yakima River Basin, Washington
Prior to Euroamerican development, the Yakima River Basin was a major producer of salmon. Total runs of approximately 800,000 have declined to 3,000-5,000, or less than 1% of original run size. Three species are extinct in the basin, including summer chinook, coho, and sockeye.
Irrigation development, including the construction of unscreened diversions, the blockage of spawning and rearing habitat by reservoir dams, and the dewatering of spawning and rearing habitat, began in the mid-1800\u27s and today totals approximately 500,000 acres. Historical records provide a wealth of information documenting irrigation development and its consequences on anadromous fish populations
Synthetic Aperture Sillouette Imaging for Space Domain Awareness
A gap exists in imaging capabilities necessary for Space Domain Awareness, at Geostationary Equatorial Orbit (GEO) distances and beyond. Synthetic Aperture Silhouette Imaging (SASI), which resolves a space object\u27s silhouette with measurements of the diffraction pattern cast by the object\u27s occultation of a distant star, provides a new method that may be used to characterize these satellites. This research analyzes the reconstruction of satellite silhouettes using data from a scaled benchtop experiment to evaluate the distance and resolution limitations of SASI at distances equal to and beyond GEO. Diffraction patterns of two satellite silhouette targets are captured at various scaled distances and fed to Matab code which utilizes an iterative phase retrieval algorithm to estimate the original silhouettes. Resolutions of 36 centimeters at GEO altitude and 1.54 meters at twice GEO altitude were obtained, and identified measurement improvements show potential for even greater resolution. These results demonstrate the value of SASI as a tool which can provide valuable information of a satellite of interest and fill in the SDA imaging capability gap
Corporate tax avoidance: is tax transparency the solution?
This is the final published version. Also available from Taylor & Francis via the DOI in this record.Corporate tax avoidance has been a matter of considerable public attention, particularly since the 2008 global financial crisis. The nature of calls for tax reform and increased regulation, advocated most prominently by tax activists and NGOs, has revolved around transparency as a possible corrective to unacceptable tax avoidance, although there is no consensus as to what the term tax avoidance encompasses and when it becomes unacceptable. We examine two responses to calls for increased transparency about the tax affairs of multinational entities: firstly, country by country reporting that provides information to tax authorities, and secondly the UK requirement for publication of tax strategies, whereby large companies put information into the public domain. We find considerable misunderstanding about the benefits of transparency in this setting. By failing to consider the limits of transparency initiatives there is a risk of dysfunctional consequences, for example additional costs in providing and processing additional information, the prospect of increased disputes as new information generates new misinterpretations and uncertainty in determining the final tax position. There is a risk that greater disclosure will not effectively address concerns about unacceptable corporate tax avoidance.Economic and Social Research Council (ESRC
Studies on the impact of road freight transport and alternative modes in Australia: a literature study
The freight sector in Australia has been growing at an ever-increasing rate due to domestic and international demand for goods, commodities, and resources. Increased volume of traffic comes with increased greenhouse gas. Greenhouse gas impacts climate change and air pollution, increasing the risk of public health and safety. The European Union used Marco Polo to shift transit freight from road to sea, rail, and inland waterways to reduce the number of trucks on the road to lessen congestion, less pollution, and more reliable and efficient transport of goods. Fuel Tax Credit was similarly introduced in Australia to address some of these issues. It is now time to analyse the impact of these schemes. This paper is a systematic literature review using the Mixed Method Appraisal Tool and Critical Appraisal Skills Programme. Findings include using alternative modes of transport for long distances reduces carbon dioxide and the likelihood of using renewable fuels like electric and hydrogen fuel for trucks. However, research was limited on renewable fuels
UVC rediation therapy for leukemia
Leukocytes from leukemia patients have been found to be readily killed by ultra-violet light-C (UVC) radiation. Cells from healthy donors were minimally affected by doses of UVC 10 times higher than those which caused dramatic drops in the metabolism of diseased cells and eventual death. Irradiated cells from leukemia patients and from healthy individuals demonstrated a number of single strand DNA breaks and alkali-labile sites compared to unirradiated control cells. The extent of DNA damage to both healthy and diseased cells is dose dependent. However, the diseased cells demonstrated more extensive DNA fragmentation and an inability to undergo self-repair. The heightened sensitivity to UVC radiation of diseased leukocytes from leukemia patients is used to provide an excorporeal treatment of diseased leukocytes followed by the re-introduction of the treated leukocytes to the patient
UVC radiation therapy for chronic lymphocytic leukemia
Lymphocytes from chronic lymphocytic leukemia (CLL) patients have been found to be readily killed by ultra-violet light-C (UVC) radiation. Cells from healthy donors were minimally affected by doses of UVC 10 times higher than those which caused dramatic drops in the metabolism of CLL cells and eventual death. Irradiated cells from CLL patients and from healthy individuals all demonstrated a number of single strand DNA breaks and alkali-labile sites compared to unirradiated control cells. The extent of DNA damage to both healthy and CLL cells is dose dependent. However, the CLL cells demonstrated more extensive DNA fragmentation and an inability to undergo self-repair. The heightened sensitivity to UVC radiation of lymphocytes from CLL patients is used to provide an excorporeal treatment of CLL lymphocytes followed by the re-introduction of the treated lymphocytes to the patient
MODISTools - downloading and processing MODIS remotely sensed data in R
Remotely sensed data – available at medium to high resolution across global spatial and temporal scales – are a valuable resource for ecologists. In particular, products from NASA's MODerate-resolution Imaging Spectroradiometer (MODIS), providing twice-daily global coverage, have been widely used for ecological applications. We present MODISTools, an R package designed to improve the accessing, downloading, and processing of remotely sensed MODIS data. MODISTools automates the process of data downloading and processing from any number of locations, time periods, and MODIS products. This automation reduces the risk of human error, and the researcher effort required compared to manual per-location downloads. The package will be particularly useful for ecological studies that include multiple sites, such as meta-analyses, observation networks, and globally distributed experiments. We give examples of the simple, reproducible workflow that MODISTools provides and of the checks that are carried out in the process. The end product is in a format that is amenable to statistical modeling. We analyzed the relationship between species richness across multiple higher taxa observed at 526 sites in temperate forests and vegetation indices, measures of aboveground net primary productivity. We downloaded MODIS derived vegetation index time series for each location where the species richness had been sampled, and summarized the data into three measures: maximum time-series value, temporal mean, and temporal variability. On average, species richness covaried positively with our vegetation index measures. Different higher taxa show different positive relationships with vegetation indices. Models had high R2 values, suggesting higher taxon identity and a gradient of vegetation index together explain most of the variation in species richness in our data. MODISTools can be used on Windows, Mac, and Linux platforms, and is available from CRAN and GitHub (https://github.com/seantuck12/MODISTools)
A kinetic study of cation transport in erythrocytes from uremic patients
A kinetic study of cation transport from uremic patients. We previously described in red blood cells (RBCs) from uremic patients on dialysis a reduction in sodium (Na) efflux through the Na, potassium (K) cotransport system (Na,K CoT) while Na efflux through the Na,K pump was normal. We then examined Na efflux in fresh cells and in cells loaded to obtain one level of intracellular sodium (Nai) concentration at about 25 mmol/liter cell. In the present study we used similar cation flux methodology to examine the kinetics of cation efflux through the Na,K pump and Na,K CoT in uremic patients on dialysis. RBCs were Na-loaded to attain five different levels of Nat concentration over a range of 5 to 50 mmol/liter cells using the ionophore nystatin. At each level of Na-loading, the Nai achieved was similar in RBCs from controls and patients. Ouabain–sensitive Na efflux through the Na,K pump showed no difference in rate between normals and dialysis patients. When the kinetic parameters of this transport pathway were considered, the apparent affinity (K0.5) for sodium was not significantly different between controls and patients (18.4 ± 2.3 vs. 20.0 ± 2.6 mmol/liter cell) and the maximal velocity of efflux (Vmax) was also not different between controls and patients (9.6 ± 0.7 vs. 8.5 ± 1.2 mmol/liter cell/hr). Comparison of Nai-activated Na versus K efflux rates through the Na,K CoT in normal subjects demonstrated similar saturation kinetics, (K0.5 15.8 ± 3.3 vs. 12.2 ± 2.8 mmol/liter cell, Vmax0.81 ± 0.1 vs. 0.78 ± 0.1 mmol/liter cell/hr) consistent with the known stoichiometric ratio of 1 Na:l K:2 C1 described for this mechanism. In dialysis patients Nai-activated, Na,K CoT-mediated Na efflux was markedly reduced. Analysis of the kinetic parameters of Na1-activated Na efflux showed that the reduced RBC Na,K CoT is due to reduction in Vmax and not to a change in K0.5 Maximum furosemide–sensitive K efflux rate was also reduced in dialysis patients. However, instead of exhibiting the anticipated saturation kinetics observed for Na, the K efflux rates were high at low levels of Nai and remained unchanged with increasing Nai concentrations. Ouabain- and furosemide-resistant Na and K effluxes were not significantly different between normals and dialysis patients. We conclude that Na efflux through RBC Na,K pump is intact over a wide range of Nai concentrations in dialysis patients. On the other hand, the furosemide–sensitive co-efflux of Na and K, which in normal RBCs displayed a typical 1 Na to 1 K transport characteristic, was quantitatively and qualitatively altered in dialysis patients. The maximum efflux rate of both Na and K was reduced and in addition, the usual stoichiometric ratio for Na and K exit through this furosemide–sensitive pathway was no longer observed
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