The Ostrich Market

Marketing,

Patricia C. Leitch to Mr. Meredith (2 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1464/thumbnail.jp

Missouri River Water Use in North Dakota

Resource /Energy Economics and Policy,

Expanding the North Dakota Input-Output Model to Include Recreation and Tourism

Resource /Energy Economics and Policy,

Economic Impact of Wildlife-Based Tourism in Northern Botswana

Resource /Energy Economics and Policy,

A Study of the SP Geophysical Technique in a Campus Setting

The self potential (SP) method is a simple and inexpensive geophysical surveying technique, which involves measuring electrical potentials on the surface due to charge separations in the subsurface. These charge separations can arise from a number of different physical and electrochemical processes, and hence interpretations tend to be qualitative. Small anomalies are typically neglected as transient, inexplicable, or uninteresting. In contrast, large negative anomalies associated with ore bodies are noted for their constancy. In this study, an area on the campus of Memorial University was repeatedly surveyed in order to determine which natural and anthropogenic features generated SP anomalies, and whether these anomalies were constant or transient. We found anomalies associated with a building, a buried metallic pipe, trees, and subtler ground variations. The locations of anomalies, both large and small, were notably unvarying over a period of days and weeks. The building always generated a significant negative anomaly, but the sign of other anomalies (including that associated with the pipe) and the magnitude of all anomalies varied with time. In a second area dominated by a shallow sewer pipe, SP data allowed modeling of the burial depth and charge distribution of the pipe. Our results show that SP can be a useful and reliable method for shallow ground surveys, but that the time-varying nature of both sign and magnitude of small to moderate anomalies should be taken into account in data collection and interpretation. Résumé La méthode des potentiels spontanés est une technique d’exécution de levés géophysiques simple et peu dispendieuse consistant à mesurer les potentiels électriques à la surface liés aux séparations des charges dans le sous-sol. Ces séparations des charges peuvent découler d’un certain nombre de processus physiques et électrochimiques différents, de sorte que les interprétations données ont tendance à être qualitatives. On néglige généralement les petites anomalies, les considérant comme des anomalies transitoires, inexplicables ou peu intéressantes. En revanche, on note les anomalies négatives poussées qui sont associées aux corps minéralisés en raison de leur constance. Dans le cadre de cette étude, on a réalisé des levés répétés dans un secteur du campus de l’Université Memorial pour déterminer quelles particularités naturelles et artificielles produisaient des anomalies des PS et si ces anomalies étaient constantes ou transitoires. Nous avons découvert des anomalies associées à un bâtiment, à un tuyau en métal enfoui, à des arbres et à des irrégularités du terrain plus subtiles. Fait remarquable, les emplacements des anomalies, tant prononcées que minimes, n’ont pas changé au cours d’une période de plusieurs jours et semaines. Le bâtiment a toujours produit une anomalie négative marquée, mais le signal d’autres anomalies (notamment celle associée au tuyau) et la magnitude de toutes les anomalies ont varié au fil du temps. Dans un second secteur où était surtout présent un tuyau d’égout peu profond, les données des PS ont permis la modélisation de la profondeur d’enfouissement et de la distribution des charges du tuyau. Nos résultats révèlent que la polarisation spontanée peut s’avérer une méthode utile et fiable pour les levés terrestres peu profonds, mais qu’il faudrait tenir compte de la nature variable des signaux et de la magnitude des anomalies minimes à moyennes lors de la collecte et de l’interprétation des données. [Traduit par la redaction

Changes in the gut microbiota of mice orally exposed to methylimidazolium ionic liquids

Ionic liquids are salts used in a variety of industrial processes, and being relatively non-volatile, are proposed as environmentally-friendly replacements for existing volatile liquids. Methylimidazolium ionic liquids resist complete degradation in the environment, likely because the imidazolium moiety does not exist naturally in biological systems. However, there is limited data available regarding their mammalian effects in vivo. This study aimed to examine the effects of exposing mice separately to 2 different methylimidazolium ionic liquids (BMI and M8OI) through their addition to drinking water. Potential effects on key target organs-the liver and kidney-were examined, as well as the gut microbiome. Adult male mice were exposed to drinking water containing ionic liquids at a concentration of 440 mg/L for 18 weeks prior to examination of tissues, serum, urine and the gut microbiome. Histopathology was performed on tissues and clinical chemistry on serum for biomarkers of hepatic and renal injury. Bacterial DNA was isolated from the gut contents and subjected to targeted 16S rRNA sequencing. Mild hepatic and renal effects were limited to glycogen depletion and mild degenerative changes respectively. No hepatic or renal adverse effects were observed. In contrast, ionic liquid exposure altered gut microbial composition but not overall alpha diversity. Proportional abundance of Lachnospiraceae, Clostridia and Coriobacteriaceae spp. were significantly greater in ionic liquid-exposed mice, as were predicted KEGG functional pathways associated with xenobiotic and amino acid metabolism. Exposure to ionic liquids via drinking water therefore resulted in marked changes in the gut microbiome in mice prior to any overt pathological effects in target organs. Ionic liquids may be an emerging risk to health through their potential effects on the gut microbiome, which is implicated in the causes and/or severity of an array of chronic disease in humans

DASI Three-Year Cosmic Microwave Background Polarization Results

We present the analysis of the complete 3-year data set obtained with the Degree Angular Scale Interferometer (DASI) polarization experiment, operating from the Amundsen-Scott South Pole research station. Additional data obtained at the end of the 2002 Austral winter and throughout the 2003 season were added to the data from which the first detection of polarization of the cosmic microwave background radiation was reported. The analysis of the combined data supports, with increased statistical power, all of the conclusions drawn from the initial data set. In particular, the detection of E-mode polarization is increased to 6.3 sigma confidence level, TE cross-polarization is detected at 2.9 sigma, and B-mode polarization is consistent with zero, with an upper limit well below the level of the detected E-mode polarization. The results are in excellent agreement with the predictions of the cosmological model that has emerged from CMB temperature measurements. The analysis also demonstrates that contamination of the data by known sources of foreground emission is insignificant.Comment: 13 pages Latex, 10 figures, submitted to Ap